tmpfs - Fix tmpfs_fid, fix NFS exports
[dragonfly.git] / contrib / binutils-2.25 / gold / arm.cc
blob6c472bb469451ce38a3d2e2b1b0b41bc6ce401c7
1 // arm.cc -- arm target support for gold.
3 // Copyright (C) 2009-2014 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"
54 #include "nacl.h"
56 namespace
59 using namespace gold;
61 template<bool big_endian>
62 class Output_data_plt_arm;
64 template<bool big_endian>
65 class Output_data_plt_arm_standard;
67 template<bool big_endian>
68 class Stub_table;
70 template<bool big_endian>
71 class Arm_input_section;
73 class Arm_exidx_cantunwind;
75 class Arm_exidx_merged_section;
77 class Arm_exidx_fixup;
79 template<bool big_endian>
80 class Arm_output_section;
82 class Arm_exidx_input_section;
84 template<bool big_endian>
85 class Arm_relobj;
87 template<bool big_endian>
88 class Arm_relocate_functions;
90 template<bool big_endian>
91 class Arm_output_data_got;
93 template<bool big_endian>
94 class Target_arm;
96 // For convenience.
97 typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address;
99 // Maximum branch offsets for ARM, THUMB and THUMB2.
100 const int32_t ARM_MAX_FWD_BRANCH_OFFSET = ((((1 << 23) - 1) << 2) + 8);
101 const int32_t ARM_MAX_BWD_BRANCH_OFFSET = ((-((1 << 23) << 2)) + 8);
102 const int32_t THM_MAX_FWD_BRANCH_OFFSET = ((1 << 22) -2 + 4);
103 const int32_t THM_MAX_BWD_BRANCH_OFFSET = (-(1 << 22) + 4);
104 const int32_t THM2_MAX_FWD_BRANCH_OFFSET = (((1 << 24) - 2) + 4);
105 const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4);
107 // Thread Control Block size.
108 const size_t ARM_TCB_SIZE = 8;
110 // The arm target class.
112 // This is a very simple port of gold for ARM-EABI. It is intended for
113 // supporting Android only for the time being.
115 // TODOs:
116 // - Implement all static relocation types documented in arm-reloc.def.
117 // - Make PLTs more flexible for different architecture features like
118 // Thumb-2 and BE8.
119 // There are probably a lot more.
121 // Ideally we would like to avoid using global variables but this is used
122 // very in many places and sometimes in loops. If we use a function
123 // returning a static instance of Arm_reloc_property_table, it will be very
124 // slow in an threaded environment since the static instance needs to be
125 // locked. The pointer is below initialized in the
126 // Target::do_select_as_default_target() hook so that we do not spend time
127 // building the table if we are not linking ARM objects.
129 // An alternative is to to process the information in arm-reloc.def in
130 // compilation time and generate a representation of it in PODs only. That
131 // way we can avoid initialization when the linker starts.
133 Arm_reloc_property_table* arm_reloc_property_table = NULL;
135 // Instruction template class. This class is similar to the insn_sequence
136 // struct in bfd/elf32-arm.c.
138 class Insn_template
140 public:
141 // Types of instruction templates.
142 enum Type
144 THUMB16_TYPE = 1,
145 // THUMB16_SPECIAL_TYPE is used by sub-classes of Stub for instruction
146 // templates with class-specific semantics. Currently this is used
147 // only by the Cortex_a8_stub class for handling condition codes in
148 // conditional branches.
149 THUMB16_SPECIAL_TYPE,
150 THUMB32_TYPE,
151 ARM_TYPE,
152 DATA_TYPE
155 // Factory methods to create instruction templates in different formats.
157 static const Insn_template
158 thumb16_insn(uint32_t data)
159 { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); }
161 // A Thumb conditional branch, in which the proper condition is inserted
162 // when we build the stub.
163 static const Insn_template
164 thumb16_bcond_insn(uint32_t data)
165 { return Insn_template(data, THUMB16_SPECIAL_TYPE, elfcpp::R_ARM_NONE, 1); }
167 static const Insn_template
168 thumb32_insn(uint32_t data)
169 { return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); }
171 static const Insn_template
172 thumb32_b_insn(uint32_t data, int reloc_addend)
174 return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24,
175 reloc_addend);
178 static const Insn_template
179 arm_insn(uint32_t data)
180 { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); }
182 static const Insn_template
183 arm_rel_insn(unsigned data, int reloc_addend)
184 { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_JUMP24, reloc_addend); }
186 static const Insn_template
187 data_word(unsigned data, unsigned int r_type, int reloc_addend)
188 { return Insn_template(data, DATA_TYPE, r_type, reloc_addend); }
190 // Accessors. This class is used for read-only objects so no modifiers
191 // are provided.
193 uint32_t
194 data() const
195 { return this->data_; }
197 // Return the instruction sequence type of this.
198 Type
199 type() const
200 { return this->type_; }
202 // Return the ARM relocation type of this.
203 unsigned int
204 r_type() const
205 { return this->r_type_; }
207 int32_t
208 reloc_addend() const
209 { return this->reloc_addend_; }
211 // Return size of instruction template in bytes.
212 size_t
213 size() const;
215 // Return byte-alignment of instruction template.
216 unsigned
217 alignment() const;
219 private:
220 // We make the constructor private to ensure that only the factory
221 // methods are used.
222 inline
223 Insn_template(unsigned data, Type type, unsigned int r_type, int reloc_addend)
224 : data_(data), type_(type), r_type_(r_type), reloc_addend_(reloc_addend)
227 // Instruction specific data. This is used to store information like
228 // some of the instruction bits.
229 uint32_t data_;
230 // Instruction template type.
231 Type type_;
232 // Relocation type if there is a relocation or R_ARM_NONE otherwise.
233 unsigned int r_type_;
234 // Relocation addend.
235 int32_t reloc_addend_;
238 // Macro for generating code to stub types. One entry per long/short
239 // branch stub
241 #define DEF_STUBS \
242 DEF_STUB(long_branch_any_any) \
243 DEF_STUB(long_branch_v4t_arm_thumb) \
244 DEF_STUB(long_branch_thumb_only) \
245 DEF_STUB(long_branch_v4t_thumb_thumb) \
246 DEF_STUB(long_branch_v4t_thumb_arm) \
247 DEF_STUB(short_branch_v4t_thumb_arm) \
248 DEF_STUB(long_branch_any_arm_pic) \
249 DEF_STUB(long_branch_any_thumb_pic) \
250 DEF_STUB(long_branch_v4t_thumb_thumb_pic) \
251 DEF_STUB(long_branch_v4t_arm_thumb_pic) \
252 DEF_STUB(long_branch_v4t_thumb_arm_pic) \
253 DEF_STUB(long_branch_thumb_only_pic) \
254 DEF_STUB(a8_veneer_b_cond) \
255 DEF_STUB(a8_veneer_b) \
256 DEF_STUB(a8_veneer_bl) \
257 DEF_STUB(a8_veneer_blx) \
258 DEF_STUB(v4_veneer_bx)
260 // Stub types.
262 #define DEF_STUB(x) arm_stub_##x,
263 typedef enum
265 arm_stub_none,
266 DEF_STUBS
268 // First reloc stub type.
269 arm_stub_reloc_first = arm_stub_long_branch_any_any,
270 // Last reloc stub type.
271 arm_stub_reloc_last = arm_stub_long_branch_thumb_only_pic,
273 // First Cortex-A8 stub type.
274 arm_stub_cortex_a8_first = arm_stub_a8_veneer_b_cond,
275 // Last Cortex-A8 stub type.
276 arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx,
278 // Last stub type.
279 arm_stub_type_last = arm_stub_v4_veneer_bx
280 } Stub_type;
281 #undef DEF_STUB
283 // Stub template class. Templates are meant to be read-only objects.
284 // A stub template for a stub type contains all read-only attributes
285 // common to all stubs of the same type.
287 class Stub_template
289 public:
290 Stub_template(Stub_type, const Insn_template*, size_t);
292 ~Stub_template()
295 // Return stub type.
296 Stub_type
297 type() const
298 { return this->type_; }
300 // Return an array of instruction templates.
301 const Insn_template*
302 insns() const
303 { return this->insns_; }
305 // Return size of template in number of instructions.
306 size_t
307 insn_count() const
308 { return this->insn_count_; }
310 // Return size of template in bytes.
311 size_t
312 size() const
313 { return this->size_; }
315 // Return alignment of the stub template.
316 unsigned
317 alignment() const
318 { return this->alignment_; }
320 // Return whether entry point is in thumb mode.
321 bool
322 entry_in_thumb_mode() const
323 { return this->entry_in_thumb_mode_; }
325 // Return number of relocations in this template.
326 size_t
327 reloc_count() const
328 { return this->relocs_.size(); }
330 // Return index of the I-th instruction with relocation.
331 size_t
332 reloc_insn_index(size_t i) const
334 gold_assert(i < this->relocs_.size());
335 return this->relocs_[i].first;
338 // Return the offset of the I-th instruction with relocation from the
339 // beginning of the stub.
340 section_size_type
341 reloc_offset(size_t i) const
343 gold_assert(i < this->relocs_.size());
344 return this->relocs_[i].second;
347 private:
348 // This contains information about an instruction template with a relocation
349 // and its offset from start of stub.
350 typedef std::pair<size_t, section_size_type> Reloc;
352 // A Stub_template may not be copied. We want to share templates as much
353 // as possible.
354 Stub_template(const Stub_template&);
355 Stub_template& operator=(const Stub_template&);
357 // Stub type.
358 Stub_type type_;
359 // Points to an array of Insn_templates.
360 const Insn_template* insns_;
361 // Number of Insn_templates in insns_[].
362 size_t insn_count_;
363 // Size of templated instructions in bytes.
364 size_t size_;
365 // Alignment of templated instructions.
366 unsigned alignment_;
367 // Flag to indicate if entry is in thumb mode.
368 bool entry_in_thumb_mode_;
369 // A table of reloc instruction indices and offsets. We can find these by
370 // looking at the instruction templates but we pre-compute and then stash
371 // them here for speed.
372 std::vector<Reloc> relocs_;
376 // A class for code stubs. This is a base class for different type of
377 // stubs used in the ARM target.
380 class Stub
382 private:
383 static const section_offset_type invalid_offset =
384 static_cast<section_offset_type>(-1);
386 public:
387 Stub(const Stub_template* stub_template)
388 : stub_template_(stub_template), offset_(invalid_offset)
391 virtual
392 ~Stub()
395 // Return the stub template.
396 const Stub_template*
397 stub_template() const
398 { return this->stub_template_; }
400 // Return offset of code stub from beginning of its containing stub table.
401 section_offset_type
402 offset() const
404 gold_assert(this->offset_ != invalid_offset);
405 return this->offset_;
408 // Set offset of code stub from beginning of its containing stub table.
409 void
410 set_offset(section_offset_type offset)
411 { this->offset_ = offset; }
413 // Return the relocation target address of the i-th relocation in the
414 // stub. This must be defined in a child class.
415 Arm_address
416 reloc_target(size_t i)
417 { return this->do_reloc_target(i); }
419 // Write a stub at output VIEW. BIG_ENDIAN select how a stub is written.
420 void
421 write(unsigned char* view, section_size_type view_size, bool big_endian)
422 { this->do_write(view, view_size, big_endian); }
424 // Return the instruction for THUMB16_SPECIAL_TYPE instruction template
425 // for the i-th instruction.
426 uint16_t
427 thumb16_special(size_t i)
428 { return this->do_thumb16_special(i); }
430 protected:
431 // This must be defined in the child class.
432 virtual Arm_address
433 do_reloc_target(size_t) = 0;
435 // This may be overridden in the child class.
436 virtual void
437 do_write(unsigned char* view, section_size_type view_size, bool big_endian)
439 if (big_endian)
440 this->do_fixed_endian_write<true>(view, view_size);
441 else
442 this->do_fixed_endian_write<false>(view, view_size);
445 // This must be overridden if a child class uses the THUMB16_SPECIAL_TYPE
446 // instruction template.
447 virtual uint16_t
448 do_thumb16_special(size_t)
449 { gold_unreachable(); }
451 private:
452 // A template to implement do_write.
453 template<bool big_endian>
454 void inline
455 do_fixed_endian_write(unsigned char*, section_size_type);
457 // Its template.
458 const Stub_template* stub_template_;
459 // Offset within the section of containing this stub.
460 section_offset_type offset_;
463 // Reloc stub class. These are stubs we use to fix up relocation because
464 // of limited branch ranges.
466 class Reloc_stub : public Stub
468 public:
469 static const unsigned int invalid_index = static_cast<unsigned int>(-1);
470 // We assume we never jump to this address.
471 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
473 // Return destination address.
474 Arm_address
475 destination_address() const
477 gold_assert(this->destination_address_ != this->invalid_address);
478 return this->destination_address_;
481 // Set destination address.
482 void
483 set_destination_address(Arm_address address)
485 gold_assert(address != this->invalid_address);
486 this->destination_address_ = address;
489 // Reset destination address.
490 void
491 reset_destination_address()
492 { this->destination_address_ = this->invalid_address; }
494 // Determine stub type for a branch of a relocation of R_TYPE going
495 // from BRANCH_ADDRESS to BRANCH_TARGET. If TARGET_IS_THUMB is set,
496 // the branch target is a thumb instruction. TARGET is used for look
497 // up ARM-specific linker settings.
498 static Stub_type
499 stub_type_for_reloc(unsigned int r_type, Arm_address branch_address,
500 Arm_address branch_target, bool target_is_thumb);
502 // Reloc_stub key. A key is logically a triplet of a stub type, a symbol
503 // and an addend. Since we treat global and local symbol differently, we
504 // use a Symbol object for a global symbol and a object-index pair for
505 // a local symbol.
506 class Key
508 public:
509 // If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and
510 // R_SYM. Otherwise, this is a local symbol and RELOBJ must non-NULL
511 // and R_SYM must not be invalid_index.
512 Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj,
513 unsigned int r_sym, int32_t addend)
514 : stub_type_(stub_type), addend_(addend)
516 if (symbol != NULL)
518 this->r_sym_ = Reloc_stub::invalid_index;
519 this->u_.symbol = symbol;
521 else
523 gold_assert(relobj != NULL && r_sym != invalid_index);
524 this->r_sym_ = r_sym;
525 this->u_.relobj = relobj;
529 ~Key()
532 // Accessors: Keys are meant to be read-only object so no modifiers are
533 // provided.
535 // Return stub type.
536 Stub_type
537 stub_type() const
538 { return this->stub_type_; }
540 // Return the local symbol index or invalid_index.
541 unsigned int
542 r_sym() const
543 { return this->r_sym_; }
545 // Return the symbol if there is one.
546 const Symbol*
547 symbol() const
548 { return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; }
550 // Return the relobj if there is one.
551 const Relobj*
552 relobj() const
553 { return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; }
555 // Whether this equals to another key k.
556 bool
557 eq(const Key& k) const
559 return ((this->stub_type_ == k.stub_type_)
560 && (this->r_sym_ == k.r_sym_)
561 && ((this->r_sym_ != Reloc_stub::invalid_index)
562 ? (this->u_.relobj == k.u_.relobj)
563 : (this->u_.symbol == k.u_.symbol))
564 && (this->addend_ == k.addend_));
567 // Return a hash value.
568 size_t
569 hash_value() const
571 return (this->stub_type_
572 ^ this->r_sym_
573 ^ gold::string_hash<char>(
574 (this->r_sym_ != Reloc_stub::invalid_index)
575 ? this->u_.relobj->name().c_str()
576 : this->u_.symbol->name())
577 ^ this->addend_);
580 // Functors for STL associative containers.
581 struct hash
583 size_t
584 operator()(const Key& k) const
585 { return k.hash_value(); }
588 struct equal_to
590 bool
591 operator()(const Key& k1, const Key& k2) const
592 { return k1.eq(k2); }
595 // Name of key. This is mainly for debugging.
596 std::string
597 name() const;
599 private:
600 // Stub type.
601 Stub_type stub_type_;
602 // If this is a local symbol, this is the index in the defining object.
603 // Otherwise, it is invalid_index for a global symbol.
604 unsigned int r_sym_;
605 // If r_sym_ is an invalid index, this points to a global symbol.
606 // Otherwise, it points to a relobj. We used the unsized and target
607 // independent Symbol and Relobj classes instead of Sized_symbol<32> and
608 // Arm_relobj, in order to avoid making the stub class a template
609 // as most of the stub machinery is endianness-neutral. However, it
610 // may require a bit of casting done by users of this class.
611 union
613 const Symbol* symbol;
614 const Relobj* relobj;
615 } u_;
616 // Addend associated with a reloc.
617 int32_t addend_;
620 protected:
621 // Reloc_stubs are created via a stub factory. So these are protected.
622 Reloc_stub(const Stub_template* stub_template)
623 : Stub(stub_template), destination_address_(invalid_address)
626 ~Reloc_stub()
629 friend class Stub_factory;
631 // Return the relocation target address of the i-th relocation in the
632 // stub.
633 Arm_address
634 do_reloc_target(size_t i)
636 // All reloc stub have only one relocation.
637 gold_assert(i == 0);
638 return this->destination_address_;
641 private:
642 // Address of destination.
643 Arm_address destination_address_;
646 // Cortex-A8 stub class. We need a Cortex-A8 stub to redirect any 32-bit
647 // THUMB branch that meets the following conditions:
649 // 1. The branch straddles across a page boundary. i.e. lower 12-bit of
650 // branch address is 0xffe.
651 // 2. The branch target address is in the same page as the first word of the
652 // branch.
653 // 3. The branch follows a 32-bit instruction which is not a branch.
655 // To do the fix up, we need to store the address of the branch instruction
656 // and its target at least. We also need to store the original branch
657 // instruction bits for the condition code in a conditional branch. The
658 // condition code is used in a special instruction template. We also want
659 // to identify input sections needing Cortex-A8 workaround quickly. We store
660 // extra information about object and section index of the code section
661 // containing a branch being fixed up. The information is used to mark
662 // the code section when we finalize the Cortex-A8 stubs.
665 class Cortex_a8_stub : public Stub
667 public:
668 ~Cortex_a8_stub()
671 // Return the object of the code section containing the branch being fixed
672 // up.
673 Relobj*
674 relobj() const
675 { return this->relobj_; }
677 // Return the section index of the code section containing the branch being
678 // fixed up.
679 unsigned int
680 shndx() const
681 { return this->shndx_; }
683 // Return the source address of stub. This is the address of the original
684 // branch instruction. LSB is 1 always set to indicate that it is a THUMB
685 // instruction.
686 Arm_address
687 source_address() const
688 { return this->source_address_; }
690 // Return the destination address of the stub. This is the branch taken
691 // address of the original branch instruction. LSB is 1 if it is a THUMB
692 // instruction address.
693 Arm_address
694 destination_address() const
695 { return this->destination_address_; }
697 // Return the instruction being fixed up.
698 uint32_t
699 original_insn() const
700 { return this->original_insn_; }
702 protected:
703 // Cortex_a8_stubs are created via a stub factory. So these are protected.
704 Cortex_a8_stub(const Stub_template* stub_template, Relobj* relobj,
705 unsigned int shndx, Arm_address source_address,
706 Arm_address destination_address, uint32_t original_insn)
707 : Stub(stub_template), relobj_(relobj), shndx_(shndx),
708 source_address_(source_address | 1U),
709 destination_address_(destination_address),
710 original_insn_(original_insn)
713 friend class Stub_factory;
715 // Return the relocation target address of the i-th relocation in the
716 // stub.
717 Arm_address
718 do_reloc_target(size_t i)
720 if (this->stub_template()->type() == arm_stub_a8_veneer_b_cond)
722 // The conditional branch veneer has two relocations.
723 gold_assert(i < 2);
724 return i == 0 ? this->source_address_ + 4 : this->destination_address_;
726 else
728 // All other Cortex-A8 stubs have only one relocation.
729 gold_assert(i == 0);
730 return this->destination_address_;
734 // Return an instruction for the THUMB16_SPECIAL_TYPE instruction template.
735 uint16_t
736 do_thumb16_special(size_t);
738 private:
739 // Object of the code section containing the branch being fixed up.
740 Relobj* relobj_;
741 // Section index of the code section containing the branch begin fixed up.
742 unsigned int shndx_;
743 // Source address of original branch.
744 Arm_address source_address_;
745 // Destination address of the original branch.
746 Arm_address destination_address_;
747 // Original branch instruction. This is needed for copying the condition
748 // code from a condition branch to its stub.
749 uint32_t original_insn_;
752 // ARMv4 BX Rx branch relocation stub class.
753 class Arm_v4bx_stub : public Stub
755 public:
756 ~Arm_v4bx_stub()
759 // Return the associated register.
760 uint32_t
761 reg() const
762 { return this->reg_; }
764 protected:
765 // Arm V4BX stubs are created via a stub factory. So these are protected.
766 Arm_v4bx_stub(const Stub_template* stub_template, const uint32_t reg)
767 : Stub(stub_template), reg_(reg)
770 friend class Stub_factory;
772 // Return the relocation target address of the i-th relocation in the
773 // stub.
774 Arm_address
775 do_reloc_target(size_t)
776 { gold_unreachable(); }
778 // This may be overridden in the child class.
779 virtual void
780 do_write(unsigned char* view, section_size_type view_size, bool big_endian)
782 if (big_endian)
783 this->do_fixed_endian_v4bx_write<true>(view, view_size);
784 else
785 this->do_fixed_endian_v4bx_write<false>(view, view_size);
788 private:
789 // A template to implement do_write.
790 template<bool big_endian>
791 void inline
792 do_fixed_endian_v4bx_write(unsigned char* view, section_size_type)
794 const Insn_template* insns = this->stub_template()->insns();
795 elfcpp::Swap<32, big_endian>::writeval(view,
796 (insns[0].data()
797 + (this->reg_ << 16)));
798 view += insns[0].size();
799 elfcpp::Swap<32, big_endian>::writeval(view,
800 (insns[1].data() + this->reg_));
801 view += insns[1].size();
802 elfcpp::Swap<32, big_endian>::writeval(view,
803 (insns[2].data() + this->reg_));
806 // A register index (r0-r14), which is associated with the stub.
807 uint32_t reg_;
810 // Stub factory class.
812 class Stub_factory
814 public:
815 // Return the unique instance of this class.
816 static const Stub_factory&
817 get_instance()
819 static Stub_factory singleton;
820 return singleton;
823 // Make a relocation stub.
824 Reloc_stub*
825 make_reloc_stub(Stub_type stub_type) const
827 gold_assert(stub_type >= arm_stub_reloc_first
828 && stub_type <= arm_stub_reloc_last);
829 return new Reloc_stub(this->stub_templates_[stub_type]);
832 // Make a Cortex-A8 stub.
833 Cortex_a8_stub*
834 make_cortex_a8_stub(Stub_type stub_type, Relobj* relobj, unsigned int shndx,
835 Arm_address source, Arm_address destination,
836 uint32_t original_insn) const
838 gold_assert(stub_type >= arm_stub_cortex_a8_first
839 && stub_type <= arm_stub_cortex_a8_last);
840 return new Cortex_a8_stub(this->stub_templates_[stub_type], relobj, shndx,
841 source, destination, original_insn);
844 // Make an ARM V4BX relocation stub.
845 // This method creates a stub from the arm_stub_v4_veneer_bx template only.
846 Arm_v4bx_stub*
847 make_arm_v4bx_stub(uint32_t reg) const
849 gold_assert(reg < 0xf);
850 return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx],
851 reg);
854 private:
855 // Constructor and destructor are protected since we only return a single
856 // instance created in Stub_factory::get_instance().
858 Stub_factory();
860 // A Stub_factory may not be copied since it is a singleton.
861 Stub_factory(const Stub_factory&);
862 Stub_factory& operator=(Stub_factory&);
864 // Stub templates. These are initialized in the constructor.
865 const Stub_template* stub_templates_[arm_stub_type_last+1];
868 // A class to hold stubs for the ARM target.
870 template<bool big_endian>
871 class Stub_table : public Output_data
873 public:
874 Stub_table(Arm_input_section<big_endian>* owner)
875 : Output_data(), owner_(owner), reloc_stubs_(), reloc_stubs_size_(0),
876 reloc_stubs_addralign_(1), cortex_a8_stubs_(), arm_v4bx_stubs_(0xf),
877 prev_data_size_(0), prev_addralign_(1)
880 ~Stub_table()
883 // Owner of this stub table.
884 Arm_input_section<big_endian>*
885 owner() const
886 { return this->owner_; }
888 // Whether this stub table is empty.
889 bool
890 empty() const
892 return (this->reloc_stubs_.empty()
893 && this->cortex_a8_stubs_.empty()
894 && this->arm_v4bx_stubs_.empty());
897 // Return the current data size.
898 off_t
899 current_data_size() const
900 { return this->current_data_size_for_child(); }
902 // Add a STUB using KEY. The caller is responsible for avoiding addition
903 // if a STUB with the same key has already been added.
904 void
905 add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
907 const Stub_template* stub_template = stub->stub_template();
908 gold_assert(stub_template->type() == key.stub_type());
909 this->reloc_stubs_[key] = stub;
911 // Assign stub offset early. We can do this because we never remove
912 // reloc stubs and they are in the beginning of the stub table.
913 uint64_t align = stub_template->alignment();
914 this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, align);
915 stub->set_offset(this->reloc_stubs_size_);
916 this->reloc_stubs_size_ += stub_template->size();
917 this->reloc_stubs_addralign_ =
918 std::max(this->reloc_stubs_addralign_, align);
921 // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
922 // The caller is responsible for avoiding addition if a STUB with the same
923 // address has already been added.
924 void
925 add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
927 std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
928 this->cortex_a8_stubs_.insert(value);
931 // Add an ARM V4BX relocation stub. A register index will be retrieved
932 // from the stub.
933 void
934 add_arm_v4bx_stub(Arm_v4bx_stub* stub)
936 gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
937 this->arm_v4bx_stubs_[stub->reg()] = stub;
940 // Remove all Cortex-A8 stubs.
941 void
942 remove_all_cortex_a8_stubs();
944 // Look up a relocation stub using KEY. Return NULL if there is none.
945 Reloc_stub*
946 find_reloc_stub(const Reloc_stub::Key& key) const
948 typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
949 return (p != this->reloc_stubs_.end()) ? p->second : NULL;
952 // Look up an arm v4bx relocation stub using the register index.
953 // Return NULL if there is none.
954 Arm_v4bx_stub*
955 find_arm_v4bx_stub(const uint32_t reg) const
957 gold_assert(reg < 0xf);
958 return this->arm_v4bx_stubs_[reg];
961 // Relocate stubs in this stub table.
962 void
963 relocate_stubs(const Relocate_info<32, big_endian>*,
964 Target_arm<big_endian>*, Output_section*,
965 unsigned char*, Arm_address, section_size_type);
967 // Update data size and alignment at the end of a relaxation pass. Return
968 // true if either data size or alignment is different from that of the
969 // previous relaxation pass.
970 bool
971 update_data_size_and_addralign();
973 // Finalize stubs. Set the offsets of all stubs and mark input sections
974 // needing the Cortex-A8 workaround.
975 void
976 finalize_stubs();
978 // Apply Cortex-A8 workaround to an address range.
979 void
980 apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
981 unsigned char*, Arm_address,
982 section_size_type);
984 protected:
985 // Write out section contents.
986 void
987 do_write(Output_file*);
989 // Return the required alignment.
990 uint64_t
991 do_addralign() const
992 { return this->prev_addralign_; }
994 // Reset address and file offset.
995 void
996 do_reset_address_and_file_offset()
997 { this->set_current_data_size_for_child(this->prev_data_size_); }
999 // Set final data size.
1000 void
1001 set_final_data_size()
1002 { this->set_data_size(this->current_data_size()); }
1004 private:
1005 // Relocate one stub.
1006 void
1007 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
1008 Target_arm<big_endian>*, Output_section*,
1009 unsigned char*, Arm_address, section_size_type);
1011 // Unordered map of relocation stubs.
1012 typedef
1013 Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1014 Reloc_stub::Key::equal_to>
1015 Reloc_stub_map;
1017 // List of Cortex-A8 stubs ordered by addresses of branches being
1018 // fixed up in output.
1019 typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1020 // List of Arm V4BX relocation stubs ordered by associated registers.
1021 typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1023 // Owner of this stub table.
1024 Arm_input_section<big_endian>* owner_;
1025 // The relocation stubs.
1026 Reloc_stub_map reloc_stubs_;
1027 // Size of reloc stubs.
1028 off_t reloc_stubs_size_;
1029 // Maximum address alignment of reloc stubs.
1030 uint64_t reloc_stubs_addralign_;
1031 // The cortex_a8_stubs.
1032 Cortex_a8_stub_list cortex_a8_stubs_;
1033 // The Arm V4BX relocation stubs.
1034 Arm_v4bx_stub_list arm_v4bx_stubs_;
1035 // data size of this in the previous pass.
1036 off_t prev_data_size_;
1037 // address alignment of this in the previous pass.
1038 uint64_t prev_addralign_;
1041 // Arm_exidx_cantunwind class. This represents an EXIDX_CANTUNWIND entry
1042 // we add to the end of an EXIDX input section that goes into the output.
1044 class Arm_exidx_cantunwind : public Output_section_data
1046 public:
1047 Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1048 : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1051 // Return the object containing the section pointed by this.
1052 Relobj*
1053 relobj() const
1054 { return this->relobj_; }
1056 // Return the section index of the section pointed by this.
1057 unsigned int
1058 shndx() const
1059 { return this->shndx_; }
1061 protected:
1062 void
1063 do_write(Output_file* of)
1065 if (parameters->target().is_big_endian())
1066 this->do_fixed_endian_write<true>(of);
1067 else
1068 this->do_fixed_endian_write<false>(of);
1071 // Write to a map file.
1072 void
1073 do_print_to_mapfile(Mapfile* mapfile) const
1074 { mapfile->print_output_data(this, _("** ARM cantunwind")); }
1076 private:
1077 // Implement do_write for a given endianness.
1078 template<bool big_endian>
1079 void inline
1080 do_fixed_endian_write(Output_file*);
1082 // The object containing the section pointed by this.
1083 Relobj* relobj_;
1084 // The section index of the section pointed by this.
1085 unsigned int shndx_;
1088 // During EXIDX coverage fix-up, we compact an EXIDX section. The
1089 // Offset map is used to map input section offset within the EXIDX section
1090 // to the output offset from the start of this EXIDX section.
1092 typedef std::map<section_offset_type, section_offset_type>
1093 Arm_exidx_section_offset_map;
1095 // Arm_exidx_merged_section class. This represents an EXIDX input section
1096 // with some of its entries merged.
1098 class Arm_exidx_merged_section : public Output_relaxed_input_section
1100 public:
1101 // Constructor for Arm_exidx_merged_section.
1102 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1103 // SECTION_OFFSET_MAP points to a section offset map describing how
1104 // parts of the input section are mapped to output. DELETED_BYTES is
1105 // the number of bytes deleted from the EXIDX input section.
1106 Arm_exidx_merged_section(
1107 const Arm_exidx_input_section& exidx_input_section,
1108 const Arm_exidx_section_offset_map& section_offset_map,
1109 uint32_t deleted_bytes);
1111 // Build output contents.
1112 void
1113 build_contents(const unsigned char*, section_size_type);
1115 // Return the original EXIDX input section.
1116 const Arm_exidx_input_section&
1117 exidx_input_section() const
1118 { return this->exidx_input_section_; }
1120 // Return the section offset map.
1121 const Arm_exidx_section_offset_map&
1122 section_offset_map() const
1123 { return this->section_offset_map_; }
1125 protected:
1126 // Write merged section into file OF.
1127 void
1128 do_write(Output_file* of);
1130 bool
1131 do_output_offset(const Relobj*, unsigned int, section_offset_type,
1132 section_offset_type*) const;
1134 private:
1135 // Original EXIDX input section.
1136 const Arm_exidx_input_section& exidx_input_section_;
1137 // Section offset map.
1138 const Arm_exidx_section_offset_map& section_offset_map_;
1139 // Merged section contents. We need to keep build the merged section
1140 // and save it here to avoid accessing the original EXIDX section when
1141 // we cannot lock the sections' object.
1142 unsigned char* section_contents_;
1145 // A class to wrap an ordinary input section containing executable code.
1147 template<bool big_endian>
1148 class Arm_input_section : public Output_relaxed_input_section
1150 public:
1151 Arm_input_section(Relobj* relobj, unsigned int shndx)
1152 : Output_relaxed_input_section(relobj, shndx, 1),
1153 original_addralign_(1), original_size_(0), stub_table_(NULL),
1154 original_contents_(NULL)
1157 ~Arm_input_section()
1158 { delete[] this->original_contents_; }
1160 // Initialize.
1161 void
1162 init();
1164 // Whether this is a stub table owner.
1165 bool
1166 is_stub_table_owner() const
1167 { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1169 // Return the stub table.
1170 Stub_table<big_endian>*
1171 stub_table() const
1172 { return this->stub_table_; }
1174 // Set the stub_table.
1175 void
1176 set_stub_table(Stub_table<big_endian>* stub_table)
1177 { this->stub_table_ = stub_table; }
1179 // Downcast a base pointer to an Arm_input_section pointer. This is
1180 // not type-safe but we only use Arm_input_section not the base class.
1181 static Arm_input_section<big_endian>*
1182 as_arm_input_section(Output_relaxed_input_section* poris)
1183 { return static_cast<Arm_input_section<big_endian>*>(poris); }
1185 // Return the original size of the section.
1186 uint32_t
1187 original_size() const
1188 { return this->original_size_; }
1190 protected:
1191 // Write data to output file.
1192 void
1193 do_write(Output_file*);
1195 // Return required alignment of this.
1196 uint64_t
1197 do_addralign() const
1199 if (this->is_stub_table_owner())
1200 return std::max(this->stub_table_->addralign(),
1201 static_cast<uint64_t>(this->original_addralign_));
1202 else
1203 return this->original_addralign_;
1206 // Finalize data size.
1207 void
1208 set_final_data_size();
1210 // Reset address and file offset.
1211 void
1212 do_reset_address_and_file_offset();
1214 // Output offset.
1215 bool
1216 do_output_offset(const Relobj* object, unsigned int shndx,
1217 section_offset_type offset,
1218 section_offset_type* poutput) const
1220 if ((object == this->relobj())
1221 && (shndx == this->shndx())
1222 && (offset >= 0)
1223 && (offset <=
1224 convert_types<section_offset_type, uint32_t>(this->original_size_)))
1226 *poutput = offset;
1227 return true;
1229 else
1230 return false;
1233 private:
1234 // Copying is not allowed.
1235 Arm_input_section(const Arm_input_section&);
1236 Arm_input_section& operator=(const Arm_input_section&);
1238 // Address alignment of the original input section.
1239 uint32_t original_addralign_;
1240 // Section size of the original input section.
1241 uint32_t original_size_;
1242 // Stub table.
1243 Stub_table<big_endian>* stub_table_;
1244 // Original section contents. We have to make a copy here since the file
1245 // containing the original section may not be locked when we need to access
1246 // the contents.
1247 unsigned char* original_contents_;
1250 // Arm_exidx_fixup class. This is used to define a number of methods
1251 // and keep states for fixing up EXIDX coverage.
1253 class Arm_exidx_fixup
1255 public:
1256 Arm_exidx_fixup(Output_section* exidx_output_section,
1257 bool merge_exidx_entries = true)
1258 : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1259 last_inlined_entry_(0), last_input_section_(NULL),
1260 section_offset_map_(NULL), first_output_text_section_(NULL),
1261 merge_exidx_entries_(merge_exidx_entries)
1264 ~Arm_exidx_fixup()
1265 { delete this->section_offset_map_; }
1267 // Process an EXIDX section for entry merging. SECTION_CONTENTS points
1268 // to the EXIDX contents and SECTION_SIZE is the size of the contents. Return
1269 // number of bytes to be deleted in output. If parts of the input EXIDX
1270 // section are merged a heap allocated Arm_exidx_section_offset_map is store
1271 // in the located PSECTION_OFFSET_MAP. The caller owns the map and is
1272 // responsible for releasing it.
1273 template<bool big_endian>
1274 uint32_t
1275 process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1276 const unsigned char* section_contents,
1277 section_size_type section_size,
1278 Arm_exidx_section_offset_map** psection_offset_map);
1280 // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1281 // input section, if there is not one already.
1282 void
1283 add_exidx_cantunwind_as_needed();
1285 // Return the output section for the text section which is linked to the
1286 // first exidx input in output.
1287 Output_section*
1288 first_output_text_section() const
1289 { return this->first_output_text_section_; }
1291 private:
1292 // Copying is not allowed.
1293 Arm_exidx_fixup(const Arm_exidx_fixup&);
1294 Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1296 // Type of EXIDX unwind entry.
1297 enum Unwind_type
1299 // No type.
1300 UT_NONE,
1301 // EXIDX_CANTUNWIND.
1302 UT_EXIDX_CANTUNWIND,
1303 // Inlined entry.
1304 UT_INLINED_ENTRY,
1305 // Normal entry.
1306 UT_NORMAL_ENTRY,
1309 // Process an EXIDX entry. We only care about the second word of the
1310 // entry. Return true if the entry can be deleted.
1311 bool
1312 process_exidx_entry(uint32_t second_word);
1314 // Update the current section offset map during EXIDX section fix-up.
1315 // If there is no map, create one. INPUT_OFFSET is the offset of a
1316 // reference point, DELETED_BYTES is the number of deleted by in the
1317 // section so far. If DELETE_ENTRY is true, the reference point and
1318 // all offsets after the previous reference point are discarded.
1319 void
1320 update_offset_map(section_offset_type input_offset,
1321 section_size_type deleted_bytes, bool delete_entry);
1323 // EXIDX output section.
1324 Output_section* exidx_output_section_;
1325 // Unwind type of the last EXIDX entry processed.
1326 Unwind_type last_unwind_type_;
1327 // Last seen inlined EXIDX entry.
1328 uint32_t last_inlined_entry_;
1329 // Last processed EXIDX input section.
1330 const Arm_exidx_input_section* last_input_section_;
1331 // Section offset map created in process_exidx_section.
1332 Arm_exidx_section_offset_map* section_offset_map_;
1333 // Output section for the text section which is linked to the first exidx
1334 // input in output.
1335 Output_section* first_output_text_section_;
1337 bool merge_exidx_entries_;
1340 // Arm output section class. This is defined mainly to add a number of
1341 // stub generation methods.
1343 template<bool big_endian>
1344 class Arm_output_section : public Output_section
1346 public:
1347 typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1349 // We need to force SHF_LINK_ORDER in a SHT_ARM_EXIDX section.
1350 Arm_output_section(const char* name, elfcpp::Elf_Word type,
1351 elfcpp::Elf_Xword flags)
1352 : Output_section(name, type,
1353 (type == elfcpp::SHT_ARM_EXIDX
1354 ? flags | elfcpp::SHF_LINK_ORDER
1355 : flags))
1357 if (type == elfcpp::SHT_ARM_EXIDX)
1358 this->set_always_keeps_input_sections();
1361 ~Arm_output_section()
1364 // Group input sections for stub generation.
1365 void
1366 group_sections(section_size_type, bool, Target_arm<big_endian>*, const Task*);
1368 // Downcast a base pointer to an Arm_output_section pointer. This is
1369 // not type-safe but we only use Arm_output_section not the base class.
1370 static Arm_output_section<big_endian>*
1371 as_arm_output_section(Output_section* os)
1372 { return static_cast<Arm_output_section<big_endian>*>(os); }
1374 // Append all input text sections in this into LIST.
1375 void
1376 append_text_sections_to_list(Text_section_list* list);
1378 // Fix EXIDX coverage of this EXIDX output section. SORTED_TEXT_SECTION
1379 // is a list of text input sections sorted in ascending order of their
1380 // output addresses.
1381 void
1382 fix_exidx_coverage(Layout* layout,
1383 const Text_section_list& sorted_text_section,
1384 Symbol_table* symtab,
1385 bool merge_exidx_entries,
1386 const Task* task);
1388 // Link an EXIDX section into its corresponding text section.
1389 void
1390 set_exidx_section_link();
1392 private:
1393 // For convenience.
1394 typedef Output_section::Input_section Input_section;
1395 typedef Output_section::Input_section_list Input_section_list;
1397 // Create a stub group.
1398 void create_stub_group(Input_section_list::const_iterator,
1399 Input_section_list::const_iterator,
1400 Input_section_list::const_iterator,
1401 Target_arm<big_endian>*,
1402 std::vector<Output_relaxed_input_section*>*,
1403 const Task* task);
1406 // Arm_exidx_input_section class. This represents an EXIDX input section.
1408 class Arm_exidx_input_section
1410 public:
1411 static const section_offset_type invalid_offset =
1412 static_cast<section_offset_type>(-1);
1414 Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1415 unsigned int link, uint32_t size,
1416 uint32_t addralign, uint32_t text_size)
1417 : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1418 addralign_(addralign), text_size_(text_size), has_errors_(false)
1421 ~Arm_exidx_input_section()
1424 // Accessors: This is a read-only class.
1426 // Return the object containing this EXIDX input section.
1427 Relobj*
1428 relobj() const
1429 { return this->relobj_; }
1431 // Return the section index of this EXIDX input section.
1432 unsigned int
1433 shndx() const
1434 { return this->shndx_; }
1436 // Return the section index of linked text section in the same object.
1437 unsigned int
1438 link() const
1439 { return this->link_; }
1441 // Return size of the EXIDX input section.
1442 uint32_t
1443 size() const
1444 { return this->size_; }
1446 // Return address alignment of EXIDX input section.
1447 uint32_t
1448 addralign() const
1449 { return this->addralign_; }
1451 // Return size of the associated text input section.
1452 uint32_t
1453 text_size() const
1454 { return this->text_size_; }
1456 // Whether there are any errors in the EXIDX input section.
1457 bool
1458 has_errors() const
1459 { return this->has_errors_; }
1461 // Set has-errors flag.
1462 void
1463 set_has_errors()
1464 { this->has_errors_ = true; }
1466 private:
1467 // Object containing this.
1468 Relobj* relobj_;
1469 // Section index of this.
1470 unsigned int shndx_;
1471 // text section linked to this in the same object.
1472 unsigned int link_;
1473 // Size of this. For ARM 32-bit is sufficient.
1474 uint32_t size_;
1475 // Address alignment of this. For ARM 32-bit is sufficient.
1476 uint32_t addralign_;
1477 // Size of associated text section.
1478 uint32_t text_size_;
1479 // Whether this has any errors.
1480 bool has_errors_;
1483 // Arm_relobj class.
1485 template<bool big_endian>
1486 class Arm_relobj : public Sized_relobj_file<32, big_endian>
1488 public:
1489 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1491 Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1492 const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1493 : Sized_relobj_file<32, big_endian>(name, input_file, offset, ehdr),
1494 stub_tables_(), local_symbol_is_thumb_function_(),
1495 attributes_section_data_(NULL), mapping_symbols_info_(),
1496 section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1497 output_local_symbol_count_needs_update_(false),
1498 merge_flags_and_attributes_(true)
1501 ~Arm_relobj()
1502 { delete this->attributes_section_data_; }
1504 // Return the stub table of the SHNDX-th section if there is one.
1505 Stub_table<big_endian>*
1506 stub_table(unsigned int shndx) const
1508 gold_assert(shndx < this->stub_tables_.size());
1509 return this->stub_tables_[shndx];
1512 // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1513 void
1514 set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1516 gold_assert(shndx < this->stub_tables_.size());
1517 this->stub_tables_[shndx] = stub_table;
1520 // Whether a local symbol is a THUMB function. R_SYM is the symbol table
1521 // index. This is only valid after do_count_local_symbol is called.
1522 bool
1523 local_symbol_is_thumb_function(unsigned int r_sym) const
1525 gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1526 return this->local_symbol_is_thumb_function_[r_sym];
1529 // Scan all relocation sections for stub generation.
1530 void
1531 scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1532 const Layout*);
1534 // Convert regular input section with index SHNDX to a relaxed section.
1535 void
1536 convert_input_section_to_relaxed_section(unsigned shndx)
1538 // The stubs have relocations and we need to process them after writing
1539 // out the stubs. So relocation now must follow section write.
1540 this->set_section_offset(shndx, -1ULL);
1541 this->set_relocs_must_follow_section_writes();
1544 // Downcast a base pointer to an Arm_relobj pointer. This is
1545 // not type-safe but we only use Arm_relobj not the base class.
1546 static Arm_relobj<big_endian>*
1547 as_arm_relobj(Relobj* relobj)
1548 { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1550 // Processor-specific flags in ELF file header. This is valid only after
1551 // reading symbols.
1552 elfcpp::Elf_Word
1553 processor_specific_flags() const
1554 { return this->processor_specific_flags_; }
1556 // Attribute section data This is the contents of the .ARM.attribute section
1557 // if there is one.
1558 const Attributes_section_data*
1559 attributes_section_data() const
1560 { return this->attributes_section_data_; }
1562 // Mapping symbol location.
1563 typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1565 // Functor for STL container.
1566 struct Mapping_symbol_position_less
1568 bool
1569 operator()(const Mapping_symbol_position& p1,
1570 const Mapping_symbol_position& p2) const
1572 return (p1.first < p2.first
1573 || (p1.first == p2.first && p1.second < p2.second));
1577 // We only care about the first character of a mapping symbol, so
1578 // we only store that instead of the whole symbol name.
1579 typedef std::map<Mapping_symbol_position, char,
1580 Mapping_symbol_position_less> Mapping_symbols_info;
1582 // Whether a section contains any Cortex-A8 workaround.
1583 bool
1584 section_has_cortex_a8_workaround(unsigned int shndx) const
1586 return (this->section_has_cortex_a8_workaround_ != NULL
1587 && (*this->section_has_cortex_a8_workaround_)[shndx]);
1590 // Mark a section that has Cortex-A8 workaround.
1591 void
1592 mark_section_for_cortex_a8_workaround(unsigned int shndx)
1594 if (this->section_has_cortex_a8_workaround_ == NULL)
1595 this->section_has_cortex_a8_workaround_ =
1596 new std::vector<bool>(this->shnum(), false);
1597 (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1600 // Return the EXIDX section of an text section with index SHNDX or NULL
1601 // if the text section has no associated EXIDX section.
1602 const Arm_exidx_input_section*
1603 exidx_input_section_by_link(unsigned int shndx) const
1605 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1606 return ((p != this->exidx_section_map_.end()
1607 && p->second->link() == shndx)
1608 ? p->second
1609 : NULL);
1612 // Return the EXIDX section with index SHNDX or NULL if there is none.
1613 const Arm_exidx_input_section*
1614 exidx_input_section_by_shndx(unsigned shndx) const
1616 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1617 return ((p != this->exidx_section_map_.end()
1618 && p->second->shndx() == shndx)
1619 ? p->second
1620 : NULL);
1623 // Whether output local symbol count needs updating.
1624 bool
1625 output_local_symbol_count_needs_update() const
1626 { return this->output_local_symbol_count_needs_update_; }
1628 // Set output_local_symbol_count_needs_update flag to be true.
1629 void
1630 set_output_local_symbol_count_needs_update()
1631 { this->output_local_symbol_count_needs_update_ = true; }
1633 // Update output local symbol count at the end of relaxation.
1634 void
1635 update_output_local_symbol_count();
1637 // Whether we want to merge processor-specific flags and attributes.
1638 bool
1639 merge_flags_and_attributes() const
1640 { return this->merge_flags_and_attributes_; }
1642 // Export list of EXIDX section indices.
1643 void
1644 get_exidx_shndx_list(std::vector<unsigned int>* list) const
1646 list->clear();
1647 for (Exidx_section_map::const_iterator p = this->exidx_section_map_.begin();
1648 p != this->exidx_section_map_.end();
1649 ++p)
1651 if (p->second->shndx() == p->first)
1652 list->push_back(p->first);
1654 // Sort list to make result independent of implementation of map.
1655 std::sort(list->begin(), list->end());
1658 protected:
1659 // Post constructor setup.
1660 void
1661 do_setup()
1663 // Call parent's setup method.
1664 Sized_relobj_file<32, big_endian>::do_setup();
1666 // Initialize look-up tables.
1667 Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1668 this->stub_tables_.swap(empty_stub_table_list);
1671 // Count the local symbols.
1672 void
1673 do_count_local_symbols(Stringpool_template<char>*,
1674 Stringpool_template<char>*);
1676 void
1677 do_relocate_sections(
1678 const Symbol_table* symtab, const Layout* layout,
1679 const unsigned char* pshdrs, Output_file* of,
1680 typename Sized_relobj_file<32, big_endian>::Views* pivews);
1682 // Read the symbol information.
1683 void
1684 do_read_symbols(Read_symbols_data* sd);
1686 // Process relocs for garbage collection.
1687 void
1688 do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1690 private:
1692 // Whether a section needs to be scanned for relocation stubs.
1693 bool
1694 section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1695 const Relobj::Output_sections&,
1696 const Symbol_table*, const unsigned char*);
1698 // Whether a section is a scannable text section.
1699 bool
1700 section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1701 const Output_section*, const Symbol_table*);
1703 // Whether a section needs to be scanned for the Cortex-A8 erratum.
1704 bool
1705 section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1706 unsigned int, Output_section*,
1707 const Symbol_table*);
1709 // Scan a section for the Cortex-A8 erratum.
1710 void
1711 scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1712 unsigned int, Output_section*,
1713 Target_arm<big_endian>*);
1715 // Find the linked text section of an EXIDX section by looking at the
1716 // first relocation of the EXIDX section. PSHDR points to the section
1717 // headers of a relocation section and PSYMS points to the local symbols.
1718 // PSHNDX points to a location storing the text section index if found.
1719 // Return whether we can find the linked section.
1720 bool
1721 find_linked_text_section(const unsigned char* pshdr,
1722 const unsigned char* psyms, unsigned int* pshndx);
1725 // Make a new Arm_exidx_input_section object for EXIDX section with
1726 // index SHNDX and section header SHDR. TEXT_SHNDX is the section
1727 // index of the linked text section.
1728 void
1729 make_exidx_input_section(unsigned int shndx,
1730 const elfcpp::Shdr<32, big_endian>& shdr,
1731 unsigned int text_shndx,
1732 const elfcpp::Shdr<32, big_endian>& text_shdr);
1734 // Return the output address of either a plain input section or a
1735 // relaxed input section. SHNDX is the section index.
1736 Arm_address
1737 simple_input_section_output_address(unsigned int, Output_section*);
1739 typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1740 typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1741 Exidx_section_map;
1743 // List of stub tables.
1744 Stub_table_list stub_tables_;
1745 // Bit vector to tell if a local symbol is a thumb function or not.
1746 // This is only valid after do_count_local_symbol is called.
1747 std::vector<bool> local_symbol_is_thumb_function_;
1748 // processor-specific flags in ELF file header.
1749 elfcpp::Elf_Word processor_specific_flags_;
1750 // Object attributes if there is an .ARM.attributes section or NULL.
1751 Attributes_section_data* attributes_section_data_;
1752 // Mapping symbols information.
1753 Mapping_symbols_info mapping_symbols_info_;
1754 // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1755 std::vector<bool>* section_has_cortex_a8_workaround_;
1756 // Map a text section to its associated .ARM.exidx section, if there is one.
1757 Exidx_section_map exidx_section_map_;
1758 // Whether output local symbol count needs updating.
1759 bool output_local_symbol_count_needs_update_;
1760 // Whether we merge processor flags and attributes of this object to
1761 // output.
1762 bool merge_flags_and_attributes_;
1765 // Arm_dynobj class.
1767 template<bool big_endian>
1768 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1770 public:
1771 Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1772 const elfcpp::Ehdr<32, big_endian>& ehdr)
1773 : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1774 processor_specific_flags_(0), attributes_section_data_(NULL)
1777 ~Arm_dynobj()
1778 { delete this->attributes_section_data_; }
1780 // Downcast a base pointer to an Arm_relobj pointer. This is
1781 // not type-safe but we only use Arm_relobj not the base class.
1782 static Arm_dynobj<big_endian>*
1783 as_arm_dynobj(Dynobj* dynobj)
1784 { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1786 // Processor-specific flags in ELF file header. This is valid only after
1787 // reading symbols.
1788 elfcpp::Elf_Word
1789 processor_specific_flags() const
1790 { return this->processor_specific_flags_; }
1792 // Attributes section data.
1793 const Attributes_section_data*
1794 attributes_section_data() const
1795 { return this->attributes_section_data_; }
1797 protected:
1798 // Read the symbol information.
1799 void
1800 do_read_symbols(Read_symbols_data* sd);
1802 private:
1803 // processor-specific flags in ELF file header.
1804 elfcpp::Elf_Word processor_specific_flags_;
1805 // Object attributes if there is an .ARM.attributes section or NULL.
1806 Attributes_section_data* attributes_section_data_;
1809 // Functor to read reloc addends during stub generation.
1811 template<int sh_type, bool big_endian>
1812 struct Stub_addend_reader
1814 // Return the addend for a relocation of a particular type. Depending
1815 // on whether this is a REL or RELA relocation, read the addend from a
1816 // view or from a Reloc object.
1817 elfcpp::Elf_types<32>::Elf_Swxword
1818 operator()(
1819 unsigned int /* r_type */,
1820 const unsigned char* /* view */,
1821 const typename Reloc_types<sh_type,
1822 32, big_endian>::Reloc& /* reloc */) const;
1825 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1827 template<bool big_endian>
1828 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1830 elfcpp::Elf_types<32>::Elf_Swxword
1831 operator()(
1832 unsigned int,
1833 const unsigned char*,
1834 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1837 // Specialized Stub_addend_reader for RELA type relocation sections.
1838 // We currently do not handle RELA type relocation sections but it is trivial
1839 // to implement the addend reader. This is provided for completeness and to
1840 // make it easier to add support for RELA relocation sections in the future.
1842 template<bool big_endian>
1843 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1845 elfcpp::Elf_types<32>::Elf_Swxword
1846 operator()(
1847 unsigned int,
1848 const unsigned char*,
1849 const typename Reloc_types<elfcpp::SHT_RELA, 32,
1850 big_endian>::Reloc& reloc) const
1851 { return reloc.get_r_addend(); }
1854 // Cortex_a8_reloc class. We keep record of relocation that may need
1855 // the Cortex-A8 erratum workaround.
1857 class Cortex_a8_reloc
1859 public:
1860 Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1861 Arm_address destination)
1862 : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1865 ~Cortex_a8_reloc()
1868 // Accessors: This is a read-only class.
1870 // Return the relocation stub associated with this relocation if there is
1871 // one.
1872 const Reloc_stub*
1873 reloc_stub() const
1874 { return this->reloc_stub_; }
1876 // Return the relocation type.
1877 unsigned int
1878 r_type() const
1879 { return this->r_type_; }
1881 // Return the destination address of the relocation. LSB stores the THUMB
1882 // bit.
1883 Arm_address
1884 destination() const
1885 { return this->destination_; }
1887 private:
1888 // Associated relocation stub if there is one, or NULL.
1889 const Reloc_stub* reloc_stub_;
1890 // Relocation type.
1891 unsigned int r_type_;
1892 // Destination address of this relocation. LSB is used to distinguish
1893 // ARM/THUMB mode.
1894 Arm_address destination_;
1897 // Arm_output_data_got class. We derive this from Output_data_got to add
1898 // extra methods to handle TLS relocations in a static link.
1900 template<bool big_endian>
1901 class Arm_output_data_got : public Output_data_got<32, big_endian>
1903 public:
1904 Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1905 : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1908 // Add a static entry for the GOT entry at OFFSET. GSYM is a global
1909 // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1910 // applied in a static link.
1911 void
1912 add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1913 { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1915 // Add a static reloc for the GOT entry at OFFSET. RELOBJ is an object
1916 // defining a local symbol with INDEX. R_TYPE is the code of a dynamic
1917 // relocation that needs to be applied in a static link.
1918 void
1919 add_static_reloc(unsigned int got_offset, unsigned int r_type,
1920 Sized_relobj_file<32, big_endian>* relobj,
1921 unsigned int index)
1923 this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1924 index));
1927 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
1928 // The first one is initialized to be 1, which is the module index for
1929 // the main executable and the second one 0. A reloc of the type
1930 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1931 // be applied by gold. GSYM is a global symbol.
1932 void
1933 add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1935 // Same as the above but for a local symbol in OBJECT with INDEX.
1936 void
1937 add_tls_gd32_with_static_reloc(unsigned int got_type,
1938 Sized_relobj_file<32, big_endian>* object,
1939 unsigned int index);
1941 protected:
1942 // Write out the GOT table.
1943 void
1944 do_write(Output_file*);
1946 private:
1947 // This class represent dynamic relocations that need to be applied by
1948 // gold because we are using TLS relocations in a static link.
1949 class Static_reloc
1951 public:
1952 Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1953 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1954 { this->u_.global.symbol = gsym; }
1956 Static_reloc(unsigned int got_offset, unsigned int r_type,
1957 Sized_relobj_file<32, big_endian>* relobj, unsigned int index)
1958 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1960 this->u_.local.relobj = relobj;
1961 this->u_.local.index = index;
1964 // Return the GOT offset.
1965 unsigned int
1966 got_offset() const
1967 { return this->got_offset_; }
1969 // Relocation type.
1970 unsigned int
1971 r_type() const
1972 { return this->r_type_; }
1974 // Whether the symbol is global or not.
1975 bool
1976 symbol_is_global() const
1977 { return this->symbol_is_global_; }
1979 // For a relocation against a global symbol, the global symbol.
1980 Symbol*
1981 symbol() const
1983 gold_assert(this->symbol_is_global_);
1984 return this->u_.global.symbol;
1987 // For a relocation against a local symbol, the defining object.
1988 Sized_relobj_file<32, big_endian>*
1989 relobj() const
1991 gold_assert(!this->symbol_is_global_);
1992 return this->u_.local.relobj;
1995 // For a relocation against a local symbol, the local symbol index.
1996 unsigned int
1997 index() const
1999 gold_assert(!this->symbol_is_global_);
2000 return this->u_.local.index;
2003 private:
2004 // GOT offset of the entry to which this relocation is applied.
2005 unsigned int got_offset_;
2006 // Type of relocation.
2007 unsigned int r_type_;
2008 // Whether this relocation is against a global symbol.
2009 bool symbol_is_global_;
2010 // A global or local symbol.
2011 union
2013 struct
2015 // For a global symbol, the symbol itself.
2016 Symbol* symbol;
2017 } global;
2018 struct
2020 // For a local symbol, the object defining object.
2021 Sized_relobj_file<32, big_endian>* relobj;
2022 // For a local symbol, the symbol index.
2023 unsigned int index;
2024 } local;
2025 } u_;
2028 // Symbol table of the output object.
2029 Symbol_table* symbol_table_;
2030 // Layout of the output object.
2031 Layout* layout_;
2032 // Static relocs to be applied to the GOT.
2033 std::vector<Static_reloc> static_relocs_;
2036 // The ARM target has many relocation types with odd-sizes or noncontiguous
2037 // bits. The default handling of relocatable relocation cannot process these
2038 // relocations. So we have to extend the default code.
2040 template<bool big_endian, int sh_type, typename Classify_reloc>
2041 class Arm_scan_relocatable_relocs :
2042 public Default_scan_relocatable_relocs<sh_type, Classify_reloc>
2044 public:
2045 // Return the strategy to use for a local symbol which is a section
2046 // symbol, given the relocation type.
2047 inline Relocatable_relocs::Reloc_strategy
2048 local_section_strategy(unsigned int r_type, Relobj*)
2050 if (sh_type == elfcpp::SHT_RELA)
2051 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
2052 else
2054 if (r_type == elfcpp::R_ARM_TARGET1
2055 || r_type == elfcpp::R_ARM_TARGET2)
2057 const Target_arm<big_endian>* arm_target =
2058 Target_arm<big_endian>::default_target();
2059 r_type = arm_target->get_real_reloc_type(r_type);
2062 switch(r_type)
2064 // Relocations that write nothing. These exclude R_ARM_TARGET1
2065 // and R_ARM_TARGET2.
2066 case elfcpp::R_ARM_NONE:
2067 case elfcpp::R_ARM_V4BX:
2068 case elfcpp::R_ARM_TLS_GOTDESC:
2069 case elfcpp::R_ARM_TLS_CALL:
2070 case elfcpp::R_ARM_TLS_DESCSEQ:
2071 case elfcpp::R_ARM_THM_TLS_CALL:
2072 case elfcpp::R_ARM_GOTRELAX:
2073 case elfcpp::R_ARM_GNU_VTENTRY:
2074 case elfcpp::R_ARM_GNU_VTINHERIT:
2075 case elfcpp::R_ARM_THM_TLS_DESCSEQ16:
2076 case elfcpp::R_ARM_THM_TLS_DESCSEQ32:
2077 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
2078 // These should have been converted to something else above.
2079 case elfcpp::R_ARM_TARGET1:
2080 case elfcpp::R_ARM_TARGET2:
2081 gold_unreachable();
2082 // Relocations that write full 32 bits and
2083 // have alignment of 1.
2084 case elfcpp::R_ARM_ABS32:
2085 case elfcpp::R_ARM_REL32:
2086 case elfcpp::R_ARM_SBREL32:
2087 case elfcpp::R_ARM_GOTOFF32:
2088 case elfcpp::R_ARM_BASE_PREL:
2089 case elfcpp::R_ARM_GOT_BREL:
2090 case elfcpp::R_ARM_BASE_ABS:
2091 case elfcpp::R_ARM_ABS32_NOI:
2092 case elfcpp::R_ARM_REL32_NOI:
2093 case elfcpp::R_ARM_PLT32_ABS:
2094 case elfcpp::R_ARM_GOT_ABS:
2095 case elfcpp::R_ARM_GOT_PREL:
2096 case elfcpp::R_ARM_TLS_GD32:
2097 case elfcpp::R_ARM_TLS_LDM32:
2098 case elfcpp::R_ARM_TLS_LDO32:
2099 case elfcpp::R_ARM_TLS_IE32:
2100 case elfcpp::R_ARM_TLS_LE32:
2101 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED;
2102 default:
2103 // For all other static relocations, return RELOC_SPECIAL.
2104 return Relocatable_relocs::RELOC_SPECIAL;
2110 template<bool big_endian>
2111 class Target_arm : public Sized_target<32, big_endian>
2113 public:
2114 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2115 Reloc_section;
2117 // When were are relocating a stub, we pass this as the relocation number.
2118 static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2120 Target_arm(const Target::Target_info* info = &arm_info)
2121 : Sized_target<32, big_endian>(info),
2122 got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
2123 copy_relocs_(elfcpp::R_ARM_COPY),
2124 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2125 stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2126 should_force_pic_veneer_(false),
2127 arm_input_section_map_(), attributes_section_data_(NULL),
2128 fix_cortex_a8_(false), cortex_a8_relocs_info_()
2131 // Whether we force PCI branch veneers.
2132 bool
2133 should_force_pic_veneer() const
2134 { return this->should_force_pic_veneer_; }
2136 // Set PIC veneer flag.
2137 void
2138 set_should_force_pic_veneer(bool value)
2139 { this->should_force_pic_veneer_ = value; }
2141 // Whether we use THUMB-2 instructions.
2142 bool
2143 using_thumb2() const
2145 Object_attribute* attr =
2146 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2147 int arch = attr->int_value();
2148 return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2151 // Whether we use THUMB/THUMB-2 instructions only.
2152 bool
2153 using_thumb_only() const
2155 Object_attribute* attr =
2156 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2158 if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2159 || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2160 return true;
2161 if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2162 && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2163 return false;
2164 attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2165 return attr->int_value() == 'M';
2168 // Whether we have an NOP instruction. If not, use mov r0, r0 instead.
2169 bool
2170 may_use_arm_nop() const
2172 Object_attribute* attr =
2173 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2174 int arch = attr->int_value();
2175 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2176 || arch == elfcpp::TAG_CPU_ARCH_V6K
2177 || arch == elfcpp::TAG_CPU_ARCH_V7
2178 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2181 // Whether we have THUMB-2 NOP.W instruction.
2182 bool
2183 may_use_thumb2_nop() const
2185 Object_attribute* attr =
2186 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2187 int arch = attr->int_value();
2188 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2189 || arch == elfcpp::TAG_CPU_ARCH_V7
2190 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2193 // Whether we have v4T interworking instructions available.
2194 bool
2195 may_use_v4t_interworking() const
2197 Object_attribute* attr =
2198 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2199 int arch = attr->int_value();
2200 return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2201 && arch != elfcpp::TAG_CPU_ARCH_V4);
2204 // Whether we have v5T interworking instructions available.
2205 bool
2206 may_use_v5t_interworking() const
2208 Object_attribute* attr =
2209 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2210 int arch = attr->int_value();
2211 if (parameters->options().fix_arm1176())
2212 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2213 || arch == elfcpp::TAG_CPU_ARCH_V7
2214 || arch == elfcpp::TAG_CPU_ARCH_V6_M
2215 || arch == elfcpp::TAG_CPU_ARCH_V6S_M
2216 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2217 else
2218 return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2219 && arch != elfcpp::TAG_CPU_ARCH_V4
2220 && arch != elfcpp::TAG_CPU_ARCH_V4T);
2223 // Process the relocations to determine unreferenced sections for
2224 // garbage collection.
2225 void
2226 gc_process_relocs(Symbol_table* symtab,
2227 Layout* layout,
2228 Sized_relobj_file<32, big_endian>* object,
2229 unsigned int data_shndx,
2230 unsigned int sh_type,
2231 const unsigned char* prelocs,
2232 size_t reloc_count,
2233 Output_section* output_section,
2234 bool needs_special_offset_handling,
2235 size_t local_symbol_count,
2236 const unsigned char* plocal_symbols);
2238 // Scan the relocations to look for symbol adjustments.
2239 void
2240 scan_relocs(Symbol_table* symtab,
2241 Layout* layout,
2242 Sized_relobj_file<32, big_endian>* object,
2243 unsigned int data_shndx,
2244 unsigned int sh_type,
2245 const unsigned char* prelocs,
2246 size_t reloc_count,
2247 Output_section* output_section,
2248 bool needs_special_offset_handling,
2249 size_t local_symbol_count,
2250 const unsigned char* plocal_symbols);
2252 // Finalize the sections.
2253 void
2254 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2256 // Return the value to use for a dynamic symbol which requires special
2257 // treatment.
2258 uint64_t
2259 do_dynsym_value(const Symbol*) const;
2261 // Relocate a section.
2262 void
2263 relocate_section(const Relocate_info<32, big_endian>*,
2264 unsigned int sh_type,
2265 const unsigned char* prelocs,
2266 size_t reloc_count,
2267 Output_section* output_section,
2268 bool needs_special_offset_handling,
2269 unsigned char* view,
2270 Arm_address view_address,
2271 section_size_type view_size,
2272 const Reloc_symbol_changes*);
2274 // Scan the relocs during a relocatable link.
2275 void
2276 scan_relocatable_relocs(Symbol_table* symtab,
2277 Layout* layout,
2278 Sized_relobj_file<32, big_endian>* object,
2279 unsigned int data_shndx,
2280 unsigned int sh_type,
2281 const unsigned char* prelocs,
2282 size_t reloc_count,
2283 Output_section* output_section,
2284 bool needs_special_offset_handling,
2285 size_t local_symbol_count,
2286 const unsigned char* plocal_symbols,
2287 Relocatable_relocs*);
2289 // Emit relocations for a section.
2290 void
2291 relocate_relocs(const Relocate_info<32, big_endian>*,
2292 unsigned int sh_type,
2293 const unsigned char* prelocs,
2294 size_t reloc_count,
2295 Output_section* output_section,
2296 typename elfcpp::Elf_types<32>::Elf_Off
2297 offset_in_output_section,
2298 const Relocatable_relocs*,
2299 unsigned char* view,
2300 Arm_address view_address,
2301 section_size_type view_size,
2302 unsigned char* reloc_view,
2303 section_size_type reloc_view_size);
2305 // Perform target-specific processing in a relocatable link. This is
2306 // only used if we use the relocation strategy RELOC_SPECIAL.
2307 void
2308 relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2309 unsigned int sh_type,
2310 const unsigned char* preloc_in,
2311 size_t relnum,
2312 Output_section* output_section,
2313 typename elfcpp::Elf_types<32>::Elf_Off
2314 offset_in_output_section,
2315 unsigned char* view,
2316 typename elfcpp::Elf_types<32>::Elf_Addr
2317 view_address,
2318 section_size_type view_size,
2319 unsigned char* preloc_out);
2321 // Return whether SYM is defined by the ABI.
2322 bool
2323 do_is_defined_by_abi(const Symbol* sym) const
2324 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2326 // Return whether there is a GOT section.
2327 bool
2328 has_got_section() const
2329 { return this->got_ != NULL; }
2331 // Return the size of the GOT section.
2332 section_size_type
2333 got_size() const
2335 gold_assert(this->got_ != NULL);
2336 return this->got_->data_size();
2339 // Return the number of entries in the GOT.
2340 unsigned int
2341 got_entry_count() const
2343 if (!this->has_got_section())
2344 return 0;
2345 return this->got_size() / 4;
2348 // Return the number of entries in the PLT.
2349 unsigned int
2350 plt_entry_count() const;
2352 // Return the offset of the first non-reserved PLT entry.
2353 unsigned int
2354 first_plt_entry_offset() const;
2356 // Return the size of each PLT entry.
2357 unsigned int
2358 plt_entry_size() const;
2360 // Map platform-specific reloc types
2361 static unsigned int
2362 get_real_reloc_type(unsigned int r_type);
2365 // Methods to support stub-generations.
2368 // Return the stub factory
2369 const Stub_factory&
2370 stub_factory() const
2371 { return this->stub_factory_; }
2373 // Make a new Arm_input_section object.
2374 Arm_input_section<big_endian>*
2375 new_arm_input_section(Relobj*, unsigned int);
2377 // Find the Arm_input_section object corresponding to the SHNDX-th input
2378 // section of RELOBJ.
2379 Arm_input_section<big_endian>*
2380 find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2382 // Make a new Stub_table
2383 Stub_table<big_endian>*
2384 new_stub_table(Arm_input_section<big_endian>*);
2386 // Scan a section for stub generation.
2387 void
2388 scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2389 const unsigned char*, size_t, Output_section*,
2390 bool, const unsigned char*, Arm_address,
2391 section_size_type);
2393 // Relocate a stub.
2394 void
2395 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2396 Output_section*, unsigned char*, Arm_address,
2397 section_size_type);
2399 // Get the default ARM target.
2400 static Target_arm<big_endian>*
2401 default_target()
2403 gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2404 && parameters->target().is_big_endian() == big_endian);
2405 return static_cast<Target_arm<big_endian>*>(
2406 parameters->sized_target<32, big_endian>());
2409 // Whether NAME belongs to a mapping symbol.
2410 static bool
2411 is_mapping_symbol_name(const char* name)
2413 return (name
2414 && name[0] == '$'
2415 && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2416 && (name[2] == '\0' || name[2] == '.'));
2419 // Whether we work around the Cortex-A8 erratum.
2420 bool
2421 fix_cortex_a8() const
2422 { return this->fix_cortex_a8_; }
2424 // Whether we merge exidx entries in debuginfo.
2425 bool
2426 merge_exidx_entries() const
2427 { return parameters->options().merge_exidx_entries(); }
2429 // Whether we fix R_ARM_V4BX relocation.
2430 // 0 - do not fix
2431 // 1 - replace with MOV instruction (armv4 target)
2432 // 2 - make interworking veneer (>= armv4t targets only)
2433 General_options::Fix_v4bx
2434 fix_v4bx() const
2435 { return parameters->options().fix_v4bx(); }
2437 // Scan a span of THUMB code section for Cortex-A8 erratum.
2438 void
2439 scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2440 section_size_type, section_size_type,
2441 const unsigned char*, Arm_address);
2443 // Apply Cortex-A8 workaround to a branch.
2444 void
2445 apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2446 unsigned char*, Arm_address);
2448 protected:
2449 // Make the PLT-generator object.
2450 Output_data_plt_arm<big_endian>*
2451 make_data_plt(Layout* layout, Output_data_space* got_plt)
2452 { return this->do_make_data_plt(layout, got_plt); }
2454 // Make an ELF object.
2455 Object*
2456 do_make_elf_object(const std::string&, Input_file*, off_t,
2457 const elfcpp::Ehdr<32, big_endian>& ehdr);
2459 Object*
2460 do_make_elf_object(const std::string&, Input_file*, off_t,
2461 const elfcpp::Ehdr<32, !big_endian>&)
2462 { gold_unreachable(); }
2464 Object*
2465 do_make_elf_object(const std::string&, Input_file*, off_t,
2466 const elfcpp::Ehdr<64, false>&)
2467 { gold_unreachable(); }
2469 Object*
2470 do_make_elf_object(const std::string&, Input_file*, off_t,
2471 const elfcpp::Ehdr<64, true>&)
2472 { gold_unreachable(); }
2474 // Make an output section.
2475 Output_section*
2476 do_make_output_section(const char* name, elfcpp::Elf_Word type,
2477 elfcpp::Elf_Xword flags)
2478 { return new Arm_output_section<big_endian>(name, type, flags); }
2480 void
2481 do_adjust_elf_header(unsigned char* view, int len);
2483 // We only need to generate stubs, and hence perform relaxation if we are
2484 // not doing relocatable linking.
2485 bool
2486 do_may_relax() const
2487 { return !parameters->options().relocatable(); }
2489 bool
2490 do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
2492 // Determine whether an object attribute tag takes an integer, a
2493 // string or both.
2495 do_attribute_arg_type(int tag) const;
2497 // Reorder tags during output.
2499 do_attributes_order(int num) const;
2501 // This is called when the target is selected as the default.
2502 void
2503 do_select_as_default_target()
2505 // No locking is required since there should only be one default target.
2506 // We cannot have both the big-endian and little-endian ARM targets
2507 // as the default.
2508 gold_assert(arm_reloc_property_table == NULL);
2509 arm_reloc_property_table = new Arm_reloc_property_table();
2512 // Virtual function which is set to return true by a target if
2513 // it can use relocation types to determine if a function's
2514 // pointer is taken.
2515 virtual bool
2516 do_can_check_for_function_pointers() const
2517 { return true; }
2519 // Whether a section called SECTION_NAME may have function pointers to
2520 // sections not eligible for safe ICF folding.
2521 virtual bool
2522 do_section_may_have_icf_unsafe_pointers(const char* section_name) const
2524 return (!is_prefix_of(".ARM.exidx", section_name)
2525 && !is_prefix_of(".ARM.extab", section_name)
2526 && Target::do_section_may_have_icf_unsafe_pointers(section_name));
2529 virtual void
2530 do_define_standard_symbols(Symbol_table*, Layout*);
2532 virtual Output_data_plt_arm<big_endian>*
2533 do_make_data_plt(Layout* layout, Output_data_space* got_plt)
2535 return new Output_data_plt_arm_standard<big_endian>(layout, got_plt);
2538 private:
2539 // The class which scans relocations.
2540 class Scan
2542 public:
2543 Scan()
2544 : issued_non_pic_error_(false)
2547 static inline int
2548 get_reference_flags(unsigned int r_type);
2550 inline void
2551 local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2552 Sized_relobj_file<32, big_endian>* object,
2553 unsigned int data_shndx,
2554 Output_section* output_section,
2555 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2556 const elfcpp::Sym<32, big_endian>& lsym,
2557 bool is_discarded);
2559 inline void
2560 global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2561 Sized_relobj_file<32, big_endian>* object,
2562 unsigned int data_shndx,
2563 Output_section* output_section,
2564 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2565 Symbol* gsym);
2567 inline bool
2568 local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2569 Sized_relobj_file<32, big_endian>* ,
2570 unsigned int ,
2571 Output_section* ,
2572 const elfcpp::Rel<32, big_endian>& ,
2573 unsigned int ,
2574 const elfcpp::Sym<32, big_endian>&);
2576 inline bool
2577 global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2578 Sized_relobj_file<32, big_endian>* ,
2579 unsigned int ,
2580 Output_section* ,
2581 const elfcpp::Rel<32, big_endian>& ,
2582 unsigned int , Symbol*);
2584 private:
2585 static void
2586 unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2587 unsigned int r_type);
2589 static void
2590 unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2591 unsigned int r_type, Symbol*);
2593 void
2594 check_non_pic(Relobj*, unsigned int r_type);
2596 // Almost identical to Symbol::needs_plt_entry except that it also
2597 // handles STT_ARM_TFUNC.
2598 static bool
2599 symbol_needs_plt_entry(const Symbol* sym)
2601 // An undefined symbol from an executable does not need a PLT entry.
2602 if (sym->is_undefined() && !parameters->options().shared())
2603 return false;
2605 return (!parameters->doing_static_link()
2606 && (sym->type() == elfcpp::STT_FUNC
2607 || sym->type() == elfcpp::STT_ARM_TFUNC)
2608 && (sym->is_from_dynobj()
2609 || sym->is_undefined()
2610 || sym->is_preemptible()));
2613 inline bool
2614 possible_function_pointer_reloc(unsigned int r_type);
2616 // Whether we have issued an error about a non-PIC compilation.
2617 bool issued_non_pic_error_;
2620 // The class which implements relocation.
2621 class Relocate
2623 public:
2624 Relocate()
2627 ~Relocate()
2630 // Return whether the static relocation needs to be applied.
2631 inline bool
2632 should_apply_static_reloc(const Sized_symbol<32>* gsym,
2633 unsigned int r_type,
2634 bool is_32bit,
2635 Output_section* output_section);
2637 // Do a relocation. Return false if the caller should not issue
2638 // any warnings about this relocation.
2639 inline bool
2640 relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2641 Output_section*, size_t relnum,
2642 const elfcpp::Rel<32, big_endian>&,
2643 unsigned int r_type, const Sized_symbol<32>*,
2644 const Symbol_value<32>*,
2645 unsigned char*, Arm_address,
2646 section_size_type);
2648 // Return whether we want to pass flag NON_PIC_REF for this
2649 // reloc. This means the relocation type accesses a symbol not via
2650 // GOT or PLT.
2651 static inline bool
2652 reloc_is_non_pic(unsigned int r_type)
2654 switch (r_type)
2656 // These relocation types reference GOT or PLT entries explicitly.
2657 case elfcpp::R_ARM_GOT_BREL:
2658 case elfcpp::R_ARM_GOT_ABS:
2659 case elfcpp::R_ARM_GOT_PREL:
2660 case elfcpp::R_ARM_GOT_BREL12:
2661 case elfcpp::R_ARM_PLT32_ABS:
2662 case elfcpp::R_ARM_TLS_GD32:
2663 case elfcpp::R_ARM_TLS_LDM32:
2664 case elfcpp::R_ARM_TLS_IE32:
2665 case elfcpp::R_ARM_TLS_IE12GP:
2667 // These relocate types may use PLT entries.
2668 case elfcpp::R_ARM_CALL:
2669 case elfcpp::R_ARM_THM_CALL:
2670 case elfcpp::R_ARM_JUMP24:
2671 case elfcpp::R_ARM_THM_JUMP24:
2672 case elfcpp::R_ARM_THM_JUMP19:
2673 case elfcpp::R_ARM_PLT32:
2674 case elfcpp::R_ARM_THM_XPC22:
2675 case elfcpp::R_ARM_PREL31:
2676 case elfcpp::R_ARM_SBREL31:
2677 return false;
2679 default:
2680 return true;
2684 private:
2685 // Do a TLS relocation.
2686 inline typename Arm_relocate_functions<big_endian>::Status
2687 relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2688 size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2689 const Sized_symbol<32>*, const Symbol_value<32>*,
2690 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2691 section_size_type);
2695 // A class which returns the size required for a relocation type,
2696 // used while scanning relocs during a relocatable link.
2697 class Relocatable_size_for_reloc
2699 public:
2700 unsigned int
2701 get_size_for_reloc(unsigned int, Relobj*);
2704 // Adjust TLS relocation type based on the options and whether this
2705 // is a local symbol.
2706 static tls::Tls_optimization
2707 optimize_tls_reloc(bool is_final, int r_type);
2709 // Get the GOT section, creating it if necessary.
2710 Arm_output_data_got<big_endian>*
2711 got_section(Symbol_table*, Layout*);
2713 // Get the GOT PLT section.
2714 Output_data_space*
2715 got_plt_section() const
2717 gold_assert(this->got_plt_ != NULL);
2718 return this->got_plt_;
2721 // Create a PLT entry for a global symbol.
2722 void
2723 make_plt_entry(Symbol_table*, Layout*, Symbol*);
2725 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2726 void
2727 define_tls_base_symbol(Symbol_table*, Layout*);
2729 // Create a GOT entry for the TLS module index.
2730 unsigned int
2731 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2732 Sized_relobj_file<32, big_endian>* object);
2734 // Get the PLT section.
2735 const Output_data_plt_arm<big_endian>*
2736 plt_section() const
2738 gold_assert(this->plt_ != NULL);
2739 return this->plt_;
2742 // Get the dynamic reloc section, creating it if necessary.
2743 Reloc_section*
2744 rel_dyn_section(Layout*);
2746 // Get the section to use for TLS_DESC relocations.
2747 Reloc_section*
2748 rel_tls_desc_section(Layout*) const;
2750 // Return true if the symbol may need a COPY relocation.
2751 // References from an executable object to non-function symbols
2752 // defined in a dynamic object may need a COPY relocation.
2753 bool
2754 may_need_copy_reloc(Symbol* gsym)
2756 return (gsym->type() != elfcpp::STT_ARM_TFUNC
2757 && gsym->may_need_copy_reloc());
2760 // Add a potential copy relocation.
2761 void
2762 copy_reloc(Symbol_table* symtab, Layout* layout,
2763 Sized_relobj_file<32, big_endian>* object,
2764 unsigned int shndx, Output_section* output_section,
2765 Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2767 this->copy_relocs_.copy_reloc(symtab, layout,
2768 symtab->get_sized_symbol<32>(sym),
2769 object, shndx, output_section, reloc,
2770 this->rel_dyn_section(layout));
2773 // Whether two EABI versions are compatible.
2774 static bool
2775 are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2777 // Merge processor-specific flags from input object and those in the ELF
2778 // header of the output.
2779 void
2780 merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2782 // Get the secondary compatible architecture.
2783 static int
2784 get_secondary_compatible_arch(const Attributes_section_data*);
2786 // Set the secondary compatible architecture.
2787 static void
2788 set_secondary_compatible_arch(Attributes_section_data*, int);
2790 static int
2791 tag_cpu_arch_combine(const char*, int, int*, int, int);
2793 // Helper to print AEABI enum tag value.
2794 static std::string
2795 aeabi_enum_name(unsigned int);
2797 // Return string value for TAG_CPU_name.
2798 static std::string
2799 tag_cpu_name_value(unsigned int);
2801 // Query attributes object to see if integer divide instructions may be
2802 // present in an object.
2803 static bool
2804 attributes_accept_div(int arch, int profile,
2805 const Object_attribute* div_attr);
2807 // Query attributes object to see if integer divide instructions are
2808 // forbidden to be in the object. This is not the inverse of
2809 // attributes_accept_div.
2810 static bool
2811 attributes_forbid_div(const Object_attribute* div_attr);
2813 // Merge object attributes from input object and those in the output.
2814 void
2815 merge_object_attributes(const char*, const Attributes_section_data*);
2817 // Helper to get an AEABI object attribute
2818 Object_attribute*
2819 get_aeabi_object_attribute(int tag) const
2821 Attributes_section_data* pasd = this->attributes_section_data_;
2822 gold_assert(pasd != NULL);
2823 Object_attribute* attr =
2824 pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2825 gold_assert(attr != NULL);
2826 return attr;
2830 // Methods to support stub-generations.
2833 // Group input sections for stub generation.
2834 void
2835 group_sections(Layout*, section_size_type, bool, const Task*);
2837 // Scan a relocation for stub generation.
2838 void
2839 scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2840 const Sized_symbol<32>*, unsigned int,
2841 const Symbol_value<32>*,
2842 elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2844 // Scan a relocation section for stub.
2845 template<int sh_type>
2846 void
2847 scan_reloc_section_for_stubs(
2848 const Relocate_info<32, big_endian>* relinfo,
2849 const unsigned char* prelocs,
2850 size_t reloc_count,
2851 Output_section* output_section,
2852 bool needs_special_offset_handling,
2853 const unsigned char* view,
2854 elfcpp::Elf_types<32>::Elf_Addr view_address,
2855 section_size_type);
2857 // Fix .ARM.exidx section coverage.
2858 void
2859 fix_exidx_coverage(Layout*, const Input_objects*,
2860 Arm_output_section<big_endian>*, Symbol_table*,
2861 const Task*);
2863 // Functors for STL set.
2864 struct output_section_address_less_than
2866 bool
2867 operator()(const Output_section* s1, const Output_section* s2) const
2868 { return s1->address() < s2->address(); }
2871 // Information about this specific target which we pass to the
2872 // general Target structure.
2873 static const Target::Target_info arm_info;
2875 // The types of GOT entries needed for this platform.
2876 // These values are exposed to the ABI in an incremental link.
2877 // Do not renumber existing values without changing the version
2878 // number of the .gnu_incremental_inputs section.
2879 enum Got_type
2881 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
2882 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
2883 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
2884 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
2885 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
2888 typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2890 // Map input section to Arm_input_section.
2891 typedef Unordered_map<Section_id,
2892 Arm_input_section<big_endian>*,
2893 Section_id_hash>
2894 Arm_input_section_map;
2896 // Map output addresses to relocs for Cortex-A8 erratum.
2897 typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2898 Cortex_a8_relocs_info;
2900 // The GOT section.
2901 Arm_output_data_got<big_endian>* got_;
2902 // The PLT section.
2903 Output_data_plt_arm<big_endian>* plt_;
2904 // The GOT PLT section.
2905 Output_data_space* got_plt_;
2906 // The dynamic reloc section.
2907 Reloc_section* rel_dyn_;
2908 // Relocs saved to avoid a COPY reloc.
2909 Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2910 // Offset of the GOT entry for the TLS module index.
2911 unsigned int got_mod_index_offset_;
2912 // True if the _TLS_MODULE_BASE_ symbol has been defined.
2913 bool tls_base_symbol_defined_;
2914 // Vector of Stub_tables created.
2915 Stub_table_list stub_tables_;
2916 // Stub factory.
2917 const Stub_factory &stub_factory_;
2918 // Whether we force PIC branch veneers.
2919 bool should_force_pic_veneer_;
2920 // Map for locating Arm_input_sections.
2921 Arm_input_section_map arm_input_section_map_;
2922 // Attributes section data in output.
2923 Attributes_section_data* attributes_section_data_;
2924 // Whether we want to fix code for Cortex-A8 erratum.
2925 bool fix_cortex_a8_;
2926 // Map addresses to relocs for Cortex-A8 erratum.
2927 Cortex_a8_relocs_info cortex_a8_relocs_info_;
2930 template<bool big_endian>
2931 const Target::Target_info Target_arm<big_endian>::arm_info =
2933 32, // size
2934 big_endian, // is_big_endian
2935 elfcpp::EM_ARM, // machine_code
2936 false, // has_make_symbol
2937 false, // has_resolve
2938 false, // has_code_fill
2939 true, // is_default_stack_executable
2940 false, // can_icf_inline_merge_sections
2941 '\0', // wrap_char
2942 "/usr/lib/libc.so.1", // dynamic_linker
2943 0x8000, // default_text_segment_address
2944 0x1000, // abi_pagesize (overridable by -z max-page-size)
2945 0x1000, // common_pagesize (overridable by -z common-page-size)
2946 false, // isolate_execinstr
2947 0, // rosegment_gap
2948 elfcpp::SHN_UNDEF, // small_common_shndx
2949 elfcpp::SHN_UNDEF, // large_common_shndx
2950 0, // small_common_section_flags
2951 0, // large_common_section_flags
2952 ".ARM.attributes", // attributes_section
2953 "aeabi", // attributes_vendor
2954 "_start" // entry_symbol_name
2957 // Arm relocate functions class
2960 template<bool big_endian>
2961 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2963 public:
2964 typedef enum
2966 STATUS_OKAY, // No error during relocation.
2967 STATUS_OVERFLOW, // Relocation overflow.
2968 STATUS_BAD_RELOC // Relocation cannot be applied.
2969 } Status;
2971 private:
2972 typedef Relocate_functions<32, big_endian> Base;
2973 typedef Arm_relocate_functions<big_endian> This;
2975 // Encoding of imm16 argument for movt and movw ARM instructions
2976 // from ARM ARM:
2978 // imm16 := imm4 | imm12
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 // | | |imm4 | |imm12 |
2983 // +-------+---------------+-------+-------+-----------------------+
2985 // Extract the relocation addend from VAL based on the ARM
2986 // instruction encoding described above.
2987 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2988 extract_arm_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) | (val & 0xfff));
2996 // Insert X into VAL based on the ARM instruction encoding described
2997 // above.
2998 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2999 insert_val_arm_movw_movt(
3000 typename elfcpp::Swap<32, big_endian>::Valtype val,
3001 typename elfcpp::Swap<32, big_endian>::Valtype x)
3003 val &= 0xfff0f000;
3004 val |= x & 0x0fff;
3005 val |= (x & 0xf000) << 4;
3006 return val;
3009 // Encoding of imm16 argument for movt and movw Thumb2 instructions
3010 // from ARM ARM:
3012 // imm16 := imm4 | i | imm3 | imm8
3014 // 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
3015 // +---------+-+-----------+-------++-+-----+-------+---------------+
3016 // | |i| |imm4 || |imm3 | |imm8 |
3017 // +---------+-+-----------+-------++-+-----+-------+---------------+
3019 // Extract the relocation addend from VAL based on the Thumb2
3020 // instruction encoding described above.
3021 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3022 extract_thumb_movw_movt_addend(
3023 typename elfcpp::Swap<32, big_endian>::Valtype val)
3025 // According to the Elf ABI for ARM Architecture the immediate
3026 // field is sign-extended to form the addend.
3027 return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
3028 | ((val >> 15) & 0x0800)
3029 | ((val >> 4) & 0x0700)
3030 | (val & 0x00ff));
3033 // Insert X into VAL based on the Thumb2 instruction encoding
3034 // described above.
3035 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3036 insert_val_thumb_movw_movt(
3037 typename elfcpp::Swap<32, big_endian>::Valtype val,
3038 typename elfcpp::Swap<32, big_endian>::Valtype x)
3040 val &= 0xfbf08f00;
3041 val |= (x & 0xf000) << 4;
3042 val |= (x & 0x0800) << 15;
3043 val |= (x & 0x0700) << 4;
3044 val |= (x & 0x00ff);
3045 return val;
3048 // Calculate the smallest constant Kn for the specified residual.
3049 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3050 static uint32_t
3051 calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3053 int32_t msb;
3055 if (residual == 0)
3056 return 0;
3057 // Determine the most significant bit in the residual and
3058 // align the resulting value to a 2-bit boundary.
3059 for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3061 // The desired shift is now (msb - 6), or zero, whichever
3062 // is the greater.
3063 return (((msb - 6) < 0) ? 0 : (msb - 6));
3066 // Calculate the final residual for the specified group index.
3067 // If the passed group index is less than zero, the method will return
3068 // the value of the specified residual without any change.
3069 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3070 static typename elfcpp::Swap<32, big_endian>::Valtype
3071 calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3072 const int group)
3074 for (int n = 0; n <= group; n++)
3076 // Calculate which part of the value to mask.
3077 uint32_t shift = calc_grp_kn(residual);
3078 // Calculate the residual for the next time around.
3079 residual &= ~(residual & (0xff << shift));
3082 return residual;
3085 // Calculate the value of Gn for the specified group index.
3086 // We return it in the form of an encoded constant-and-rotation.
3087 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3088 static typename elfcpp::Swap<32, big_endian>::Valtype
3089 calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3090 const int group)
3092 typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3093 uint32_t shift = 0;
3095 for (int n = 0; n <= group; n++)
3097 // Calculate which part of the value to mask.
3098 shift = calc_grp_kn(residual);
3099 // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3100 gn = residual & (0xff << shift);
3101 // Calculate the residual for the next time around.
3102 residual &= ~gn;
3104 // Return Gn in the form of an encoded constant-and-rotation.
3105 return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3108 public:
3109 // Handle ARM long branches.
3110 static typename This::Status
3111 arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3112 unsigned char*, const Sized_symbol<32>*,
3113 const Arm_relobj<big_endian>*, unsigned int,
3114 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3116 // Handle THUMB long branches.
3117 static typename This::Status
3118 thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3119 unsigned char*, const Sized_symbol<32>*,
3120 const Arm_relobj<big_endian>*, unsigned int,
3121 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3124 // Return the branch offset of a 32-bit THUMB branch.
3125 static inline int32_t
3126 thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3128 // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3129 // involving the J1 and J2 bits.
3130 uint32_t s = (upper_insn & (1U << 10)) >> 10;
3131 uint32_t upper = upper_insn & 0x3ffU;
3132 uint32_t lower = lower_insn & 0x7ffU;
3133 uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3134 uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3135 uint32_t i1 = j1 ^ s ? 0 : 1;
3136 uint32_t i2 = j2 ^ s ? 0 : 1;
3138 return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3139 | (upper << 12) | (lower << 1));
3142 // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3143 // UPPER_INSN is the original upper instruction of the branch. Caller is
3144 // responsible for overflow checking and BLX offset adjustment.
3145 static inline uint16_t
3146 thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3148 uint32_t s = offset < 0 ? 1 : 0;
3149 uint32_t bits = static_cast<uint32_t>(offset);
3150 return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3153 // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3154 // LOWER_INSN is the original lower instruction of the branch. Caller is
3155 // responsible for overflow checking and BLX offset adjustment.
3156 static inline uint16_t
3157 thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3159 uint32_t s = offset < 0 ? 1 : 0;
3160 uint32_t bits = static_cast<uint32_t>(offset);
3161 return ((lower_insn & ~0x2fffU)
3162 | ((((bits >> 23) & 1) ^ !s) << 13)
3163 | ((((bits >> 22) & 1) ^ !s) << 11)
3164 | ((bits >> 1) & 0x7ffU));
3167 // Return the branch offset of a 32-bit THUMB conditional branch.
3168 static inline int32_t
3169 thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3171 uint32_t s = (upper_insn & 0x0400U) >> 10;
3172 uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3173 uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3174 uint32_t lower = (lower_insn & 0x07ffU);
3175 uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3177 return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3180 // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3181 // instruction. UPPER_INSN is the original upper instruction of the branch.
3182 // Caller is responsible for overflow checking.
3183 static inline uint16_t
3184 thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3186 uint32_t s = offset < 0 ? 1 : 0;
3187 uint32_t bits = static_cast<uint32_t>(offset);
3188 return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3191 // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3192 // instruction. LOWER_INSN is the original lower instruction of the branch.
3193 // The caller is responsible for overflow checking.
3194 static inline uint16_t
3195 thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3197 uint32_t bits = static_cast<uint32_t>(offset);
3198 uint32_t j2 = (bits & 0x00080000U) >> 19;
3199 uint32_t j1 = (bits & 0x00040000U) >> 18;
3200 uint32_t lo = (bits & 0x00000ffeU) >> 1;
3202 return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3205 // R_ARM_ABS8: S + A
3206 static inline typename This::Status
3207 abs8(unsigned char* view,
3208 const Sized_relobj_file<32, big_endian>* object,
3209 const Symbol_value<32>* psymval)
3211 typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3212 Valtype* wv = reinterpret_cast<Valtype*>(view);
3213 Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3214 int32_t addend = Bits<8>::sign_extend32(val);
3215 Arm_address x = psymval->value(object, addend);
3216 val = Bits<32>::bit_select32(val, x, 0xffU);
3217 elfcpp::Swap<8, big_endian>::writeval(wv, val);
3219 // R_ARM_ABS8 permits signed or unsigned results.
3220 return (Bits<8>::has_signed_unsigned_overflow32(x)
3221 ? This::STATUS_OVERFLOW
3222 : This::STATUS_OKAY);
3225 // R_ARM_THM_ABS5: S + A
3226 static inline typename This::Status
3227 thm_abs5(unsigned char* view,
3228 const Sized_relobj_file<32, big_endian>* object,
3229 const Symbol_value<32>* psymval)
3231 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3232 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3233 Valtype* wv = reinterpret_cast<Valtype*>(view);
3234 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3235 Reltype addend = (val & 0x7e0U) >> 6;
3236 Reltype x = psymval->value(object, addend);
3237 val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3238 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3239 return (Bits<5>::has_overflow32(x)
3240 ? This::STATUS_OVERFLOW
3241 : This::STATUS_OKAY);
3244 // R_ARM_ABS12: S + A
3245 static inline typename This::Status
3246 abs12(unsigned char* view,
3247 const Sized_relobj_file<32, big_endian>* object,
3248 const Symbol_value<32>* psymval)
3250 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3251 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3252 Valtype* wv = reinterpret_cast<Valtype*>(view);
3253 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3254 Reltype addend = val & 0x0fffU;
3255 Reltype x = psymval->value(object, addend);
3256 val = Bits<32>::bit_select32(val, x, 0x0fffU);
3257 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3258 return (Bits<12>::has_overflow32(x)
3259 ? This::STATUS_OVERFLOW
3260 : This::STATUS_OKAY);
3263 // R_ARM_ABS16: S + A
3264 static inline typename This::Status
3265 abs16(unsigned char* view,
3266 const Sized_relobj_file<32, big_endian>* object,
3267 const Symbol_value<32>* psymval)
3269 typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3270 Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3271 int32_t addend = Bits<16>::sign_extend32(val);
3272 Arm_address x = psymval->value(object, addend);
3273 val = Bits<32>::bit_select32(val, x, 0xffffU);
3274 elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3276 // R_ARM_ABS16 permits signed or unsigned results.
3277 return (Bits<16>::has_signed_unsigned_overflow32(x)
3278 ? This::STATUS_OVERFLOW
3279 : This::STATUS_OKAY);
3282 // R_ARM_ABS32: (S + A) | T
3283 static inline typename This::Status
3284 abs32(unsigned char* view,
3285 const Sized_relobj_file<32, big_endian>* object,
3286 const Symbol_value<32>* psymval,
3287 Arm_address thumb_bit)
3289 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3290 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3291 Valtype x = psymval->value(object, addend) | thumb_bit;
3292 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3293 return This::STATUS_OKAY;
3296 // R_ARM_REL32: (S + A) | T - P
3297 static inline typename This::Status
3298 rel32(unsigned char* view,
3299 const Sized_relobj_file<32, big_endian>* object,
3300 const Symbol_value<32>* psymval,
3301 Arm_address address,
3302 Arm_address thumb_bit)
3304 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3305 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3306 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3307 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3308 return This::STATUS_OKAY;
3311 // R_ARM_THM_JUMP24: (S + A) | T - P
3312 static typename This::Status
3313 thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3314 const Symbol_value<32>* psymval, Arm_address address,
3315 Arm_address thumb_bit);
3317 // R_ARM_THM_JUMP6: S + A – P
3318 static inline typename This::Status
3319 thm_jump6(unsigned char* view,
3320 const Sized_relobj_file<32, big_endian>* object,
3321 const Symbol_value<32>* psymval,
3322 Arm_address address)
3324 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3325 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3326 Valtype* wv = reinterpret_cast<Valtype*>(view);
3327 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3328 // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3329 Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3330 Reltype x = (psymval->value(object, addend) - address);
3331 val = (val & 0xfd07) | ((x & 0x0040) << 3) | ((val & 0x003e) << 2);
3332 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3333 // CZB does only forward jumps.
3334 return ((x > 0x007e)
3335 ? This::STATUS_OVERFLOW
3336 : This::STATUS_OKAY);
3339 // R_ARM_THM_JUMP8: S + A – P
3340 static inline typename This::Status
3341 thm_jump8(unsigned char* view,
3342 const Sized_relobj_file<32, big_endian>* object,
3343 const Symbol_value<32>* psymval,
3344 Arm_address address)
3346 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3347 Valtype* wv = reinterpret_cast<Valtype*>(view);
3348 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3349 int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3350 int32_t x = (psymval->value(object, addend) - address);
3351 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3352 | ((x & 0x01fe) >> 1)));
3353 // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3354 return (Bits<9>::has_overflow32(x)
3355 ? This::STATUS_OVERFLOW
3356 : This::STATUS_OKAY);
3359 // R_ARM_THM_JUMP11: S + A – P
3360 static inline typename This::Status
3361 thm_jump11(unsigned char* view,
3362 const Sized_relobj_file<32, big_endian>* object,
3363 const Symbol_value<32>* psymval,
3364 Arm_address address)
3366 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3367 Valtype* wv = reinterpret_cast<Valtype*>(view);
3368 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3369 int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3370 int32_t x = (psymval->value(object, addend) - address);
3371 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3372 | ((x & 0x0ffe) >> 1)));
3373 // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3374 return (Bits<12>::has_overflow32(x)
3375 ? This::STATUS_OVERFLOW
3376 : This::STATUS_OKAY);
3379 // R_ARM_BASE_PREL: B(S) + A - P
3380 static inline typename This::Status
3381 base_prel(unsigned char* view,
3382 Arm_address origin,
3383 Arm_address address)
3385 Base::rel32(view, origin - address);
3386 return STATUS_OKAY;
3389 // R_ARM_BASE_ABS: B(S) + A
3390 static inline typename This::Status
3391 base_abs(unsigned char* view,
3392 Arm_address origin)
3394 Base::rel32(view, origin);
3395 return STATUS_OKAY;
3398 // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3399 static inline typename This::Status
3400 got_brel(unsigned char* view,
3401 typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3403 Base::rel32(view, got_offset);
3404 return This::STATUS_OKAY;
3407 // R_ARM_GOT_PREL: GOT(S) + A - P
3408 static inline typename This::Status
3409 got_prel(unsigned char* view,
3410 Arm_address got_entry,
3411 Arm_address address)
3413 Base::rel32(view, got_entry - address);
3414 return This::STATUS_OKAY;
3417 // R_ARM_PREL: (S + A) | T - P
3418 static inline typename This::Status
3419 prel31(unsigned char* view,
3420 const Sized_relobj_file<32, big_endian>* object,
3421 const Symbol_value<32>* psymval,
3422 Arm_address address,
3423 Arm_address thumb_bit)
3425 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3426 Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3427 Valtype addend = Bits<31>::sign_extend32(val);
3428 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3429 val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3430 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3431 return (Bits<31>::has_overflow32(x)
3432 ? This::STATUS_OVERFLOW
3433 : This::STATUS_OKAY);
3436 // R_ARM_MOVW_ABS_NC: (S + A) | T (relative address base is )
3437 // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3438 // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3439 // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3440 static inline typename This::Status
3441 movw(unsigned char* view,
3442 const Sized_relobj_file<32, big_endian>* object,
3443 const Symbol_value<32>* psymval,
3444 Arm_address relative_address_base,
3445 Arm_address thumb_bit,
3446 bool check_overflow)
3448 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3449 Valtype* wv = reinterpret_cast<Valtype*>(view);
3450 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3451 Valtype addend = This::extract_arm_movw_movt_addend(val);
3452 Valtype x = ((psymval->value(object, addend) | thumb_bit)
3453 - relative_address_base);
3454 val = This::insert_val_arm_movw_movt(val, x);
3455 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3456 return ((check_overflow && Bits<16>::has_overflow32(x))
3457 ? This::STATUS_OVERFLOW
3458 : This::STATUS_OKAY);
3461 // R_ARM_MOVT_ABS: S + A (relative address base is 0)
3462 // R_ARM_MOVT_PREL: S + A - P
3463 // R_ARM_MOVT_BREL: S + A - B(S)
3464 static inline typename This::Status
3465 movt(unsigned char* view,
3466 const Sized_relobj_file<32, big_endian>* object,
3467 const Symbol_value<32>* psymval,
3468 Arm_address relative_address_base)
3470 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3471 Valtype* wv = reinterpret_cast<Valtype*>(view);
3472 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3473 Valtype addend = This::extract_arm_movw_movt_addend(val);
3474 Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3475 val = This::insert_val_arm_movw_movt(val, x);
3476 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3477 // FIXME: IHI0044D says that we should check for overflow.
3478 return This::STATUS_OKAY;
3481 // R_ARM_THM_MOVW_ABS_NC: S + A | T (relative_address_base is 0)
3482 // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3483 // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3484 // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3485 static inline typename This::Status
3486 thm_movw(unsigned char* view,
3487 const Sized_relobj_file<32, big_endian>* object,
3488 const Symbol_value<32>* psymval,
3489 Arm_address relative_address_base,
3490 Arm_address thumb_bit,
3491 bool check_overflow)
3493 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3494 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3495 Valtype* wv = reinterpret_cast<Valtype*>(view);
3496 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3497 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3498 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3499 Reltype x =
3500 (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3501 val = This::insert_val_thumb_movw_movt(val, x);
3502 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3503 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3504 return ((check_overflow && Bits<16>::has_overflow32(x))
3505 ? This::STATUS_OVERFLOW
3506 : This::STATUS_OKAY);
3509 // R_ARM_THM_MOVT_ABS: S + A (relative address base is 0)
3510 // R_ARM_THM_MOVT_PREL: S + A - P
3511 // R_ARM_THM_MOVT_BREL: S + A - B(S)
3512 static inline typename This::Status
3513 thm_movt(unsigned char* view,
3514 const Sized_relobj_file<32, big_endian>* object,
3515 const Symbol_value<32>* psymval,
3516 Arm_address relative_address_base)
3518 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3519 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3520 Valtype* wv = reinterpret_cast<Valtype*>(view);
3521 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3522 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3523 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3524 Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3525 val = This::insert_val_thumb_movw_movt(val, x);
3526 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3527 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3528 return This::STATUS_OKAY;
3531 // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3532 static inline typename This::Status
3533 thm_alu11(unsigned char* view,
3534 const Sized_relobj_file<32, big_endian>* object,
3535 const Symbol_value<32>* psymval,
3536 Arm_address address,
3537 Arm_address thumb_bit)
3539 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3540 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3541 Valtype* wv = reinterpret_cast<Valtype*>(view);
3542 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3543 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3545 // 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
3546 // -----------------------------------------------------------------------
3547 // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd |imm8
3548 // ADDW 1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd |imm8
3549 // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd |imm8
3550 // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd |imm8
3551 // SUBW 1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd |imm8
3552 // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd |imm8
3554 // Determine a sign for the addend.
3555 const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3556 || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3557 // Thumb2 addend encoding:
3558 // imm12 := i | imm3 | imm8
3559 int32_t addend = (insn & 0xff)
3560 | ((insn & 0x00007000) >> 4)
3561 | ((insn & 0x04000000) >> 15);
3562 // Apply a sign to the added.
3563 addend *= sign;
3565 int32_t x = (psymval->value(object, addend) | thumb_bit)
3566 - (address & 0xfffffffc);
3567 Reltype val = abs(x);
3568 // Mask out the value and a distinct part of the ADD/SUB opcode
3569 // (bits 7:5 of opword).
3570 insn = (insn & 0xfb0f8f00)
3571 | (val & 0xff)
3572 | ((val & 0x700) << 4)
3573 | ((val & 0x800) << 15);
3574 // Set the opcode according to whether the value to go in the
3575 // place is negative.
3576 if (x < 0)
3577 insn |= 0x00a00000;
3579 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3580 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3581 return ((val > 0xfff) ?
3582 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3585 // R_ARM_THM_PC8: S + A - Pa (Thumb)
3586 static inline typename This::Status
3587 thm_pc8(unsigned char* view,
3588 const Sized_relobj_file<32, big_endian>* object,
3589 const Symbol_value<32>* psymval,
3590 Arm_address address)
3592 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3593 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3594 Valtype* wv = reinterpret_cast<Valtype*>(view);
3595 Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3596 Reltype addend = ((insn & 0x00ff) << 2);
3597 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3598 Reltype val = abs(x);
3599 insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3601 elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3602 return ((val > 0x03fc)
3603 ? This::STATUS_OVERFLOW
3604 : This::STATUS_OKAY);
3607 // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3608 static inline typename This::Status
3609 thm_pc12(unsigned char* view,
3610 const Sized_relobj_file<32, big_endian>* object,
3611 const Symbol_value<32>* psymval,
3612 Arm_address address)
3614 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3615 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3616 Valtype* wv = reinterpret_cast<Valtype*>(view);
3617 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3618 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3619 // Determine a sign for the addend (positive if the U bit is 1).
3620 const int sign = (insn & 0x00800000) ? 1 : -1;
3621 int32_t addend = (insn & 0xfff);
3622 // Apply a sign to the added.
3623 addend *= sign;
3625 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3626 Reltype val = abs(x);
3627 // Mask out and apply the value and the U bit.
3628 insn = (insn & 0xff7ff000) | (val & 0xfff);
3629 // Set the U bit according to whether the value to go in the
3630 // place is positive.
3631 if (x >= 0)
3632 insn |= 0x00800000;
3634 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3635 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3636 return ((val > 0xfff) ?
3637 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3640 // R_ARM_V4BX
3641 static inline typename This::Status
3642 v4bx(const Relocate_info<32, big_endian>* relinfo,
3643 unsigned char* view,
3644 const Arm_relobj<big_endian>* object,
3645 const Arm_address address,
3646 const bool is_interworking)
3649 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3650 Valtype* wv = reinterpret_cast<Valtype*>(view);
3651 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3653 // Ensure that we have a BX instruction.
3654 gold_assert((val & 0x0ffffff0) == 0x012fff10);
3655 const uint32_t reg = (val & 0xf);
3656 if (is_interworking && reg != 0xf)
3658 Stub_table<big_endian>* stub_table =
3659 object->stub_table(relinfo->data_shndx);
3660 gold_assert(stub_table != NULL);
3662 Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3663 gold_assert(stub != NULL);
3665 int32_t veneer_address =
3666 stub_table->address() + stub->offset() - 8 - address;
3667 gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3668 && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3669 // Replace with a branch to veneer (B <addr>)
3670 val = (val & 0xf0000000) | 0x0a000000
3671 | ((veneer_address >> 2) & 0x00ffffff);
3673 else
3675 // Preserve Rm (lowest four bits) and the condition code
3676 // (highest four bits). Other bits encode MOV PC,Rm.
3677 val = (val & 0xf000000f) | 0x01a0f000;
3679 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3680 return This::STATUS_OKAY;
3683 // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3684 // R_ARM_ALU_PC_G0: ((S + A) | T) - P
3685 // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3686 // R_ARM_ALU_PC_G1: ((S + A) | T) - P
3687 // R_ARM_ALU_PC_G2: ((S + A) | T) - P
3688 // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3689 // R_ARM_ALU_SB_G0: ((S + A) | T) - B(S)
3690 // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3691 // R_ARM_ALU_SB_G1: ((S + A) | T) - B(S)
3692 // R_ARM_ALU_SB_G2: ((S + A) | T) - B(S)
3693 static inline typename This::Status
3694 arm_grp_alu(unsigned char* view,
3695 const Sized_relobj_file<32, big_endian>* object,
3696 const Symbol_value<32>* psymval,
3697 const int group,
3698 Arm_address address,
3699 Arm_address thumb_bit,
3700 bool check_overflow)
3702 gold_assert(group >= 0 && group < 3);
3703 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3704 Valtype* wv = reinterpret_cast<Valtype*>(view);
3705 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3707 // ALU group relocations are allowed only for the ADD/SUB instructions.
3708 // (0x00800000 - ADD, 0x00400000 - SUB)
3709 const Valtype opcode = insn & 0x01e00000;
3710 if (opcode != 0x00800000 && opcode != 0x00400000)
3711 return This::STATUS_BAD_RELOC;
3713 // Determine a sign for the addend.
3714 const int sign = (opcode == 0x00800000) ? 1 : -1;
3715 // shifter = rotate_imm * 2
3716 const uint32_t shifter = (insn & 0xf00) >> 7;
3717 // Initial addend value.
3718 int32_t addend = insn & 0xff;
3719 // Rotate addend right by shifter.
3720 addend = (addend >> shifter) | (addend << (32 - shifter));
3721 // Apply a sign to the added.
3722 addend *= sign;
3724 int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3725 Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3726 // Check for overflow if required
3727 if (check_overflow
3728 && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3729 return This::STATUS_OVERFLOW;
3731 // Mask out the value and the ADD/SUB part of the opcode; take care
3732 // not to destroy the S bit.
3733 insn &= 0xff1ff000;
3734 // Set the opcode according to whether the value to go in the
3735 // place is negative.
3736 insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3737 // Encode the offset (encoded Gn).
3738 insn |= gn;
3740 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3741 return This::STATUS_OKAY;
3744 // R_ARM_LDR_PC_G0: S + A - P
3745 // R_ARM_LDR_PC_G1: S + A - P
3746 // R_ARM_LDR_PC_G2: S + A - P
3747 // R_ARM_LDR_SB_G0: S + A - B(S)
3748 // R_ARM_LDR_SB_G1: S + A - B(S)
3749 // R_ARM_LDR_SB_G2: S + A - B(S)
3750 static inline typename This::Status
3751 arm_grp_ldr(unsigned char* view,
3752 const Sized_relobj_file<32, big_endian>* object,
3753 const Symbol_value<32>* psymval,
3754 const int group,
3755 Arm_address address)
3757 gold_assert(group >= 0 && group < 3);
3758 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3759 Valtype* wv = reinterpret_cast<Valtype*>(view);
3760 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3762 const int sign = (insn & 0x00800000) ? 1 : -1;
3763 int32_t addend = (insn & 0xfff) * sign;
3764 int32_t x = (psymval->value(object, addend) - address);
3765 // Calculate the relevant G(n-1) value to obtain this stage residual.
3766 Valtype residual =
3767 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3768 if (residual >= 0x1000)
3769 return This::STATUS_OVERFLOW;
3771 // Mask out the value and U bit.
3772 insn &= 0xff7ff000;
3773 // Set the U bit for non-negative values.
3774 if (x >= 0)
3775 insn |= 0x00800000;
3776 insn |= residual;
3778 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3779 return This::STATUS_OKAY;
3782 // R_ARM_LDRS_PC_G0: S + A - P
3783 // R_ARM_LDRS_PC_G1: S + A - P
3784 // R_ARM_LDRS_PC_G2: S + A - P
3785 // R_ARM_LDRS_SB_G0: S + A - B(S)
3786 // R_ARM_LDRS_SB_G1: S + A - B(S)
3787 // R_ARM_LDRS_SB_G2: S + A - B(S)
3788 static inline typename This::Status
3789 arm_grp_ldrs(unsigned char* view,
3790 const Sized_relobj_file<32, big_endian>* object,
3791 const Symbol_value<32>* psymval,
3792 const int group,
3793 Arm_address address)
3795 gold_assert(group >= 0 && group < 3);
3796 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3797 Valtype* wv = reinterpret_cast<Valtype*>(view);
3798 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3800 const int sign = (insn & 0x00800000) ? 1 : -1;
3801 int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3802 int32_t x = (psymval->value(object, addend) - address);
3803 // Calculate the relevant G(n-1) value to obtain this stage residual.
3804 Valtype residual =
3805 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3806 if (residual >= 0x100)
3807 return This::STATUS_OVERFLOW;
3809 // Mask out the value and U bit.
3810 insn &= 0xff7ff0f0;
3811 // Set the U bit for non-negative values.
3812 if (x >= 0)
3813 insn |= 0x00800000;
3814 insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3816 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3817 return This::STATUS_OKAY;
3820 // R_ARM_LDC_PC_G0: S + A - P
3821 // R_ARM_LDC_PC_G1: S + A - P
3822 // R_ARM_LDC_PC_G2: S + A - P
3823 // R_ARM_LDC_SB_G0: S + A - B(S)
3824 // R_ARM_LDC_SB_G1: S + A - B(S)
3825 // R_ARM_LDC_SB_G2: S + A - B(S)
3826 static inline typename This::Status
3827 arm_grp_ldc(unsigned char* view,
3828 const Sized_relobj_file<32, big_endian>* object,
3829 const Symbol_value<32>* psymval,
3830 const int group,
3831 Arm_address address)
3833 gold_assert(group >= 0 && group < 3);
3834 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3835 Valtype* wv = reinterpret_cast<Valtype*>(view);
3836 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3838 const int sign = (insn & 0x00800000) ? 1 : -1;
3839 int32_t addend = ((insn & 0xff) << 2) * sign;
3840 int32_t x = (psymval->value(object, addend) - address);
3841 // Calculate the relevant G(n-1) value to obtain this stage residual.
3842 Valtype residual =
3843 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3844 if ((residual & 0x3) != 0 || residual >= 0x400)
3845 return This::STATUS_OVERFLOW;
3847 // Mask out the value and U bit.
3848 insn &= 0xff7fff00;
3849 // Set the U bit for non-negative values.
3850 if (x >= 0)
3851 insn |= 0x00800000;
3852 insn |= (residual >> 2);
3854 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3855 return This::STATUS_OKAY;
3859 // Relocate ARM long branches. This handles relocation types
3860 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3861 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3862 // undefined and we do not use PLT in this relocation. In such a case,
3863 // the branch is converted into an NOP.
3865 template<bool big_endian>
3866 typename Arm_relocate_functions<big_endian>::Status
3867 Arm_relocate_functions<big_endian>::arm_branch_common(
3868 unsigned int r_type,
3869 const Relocate_info<32, big_endian>* relinfo,
3870 unsigned char* view,
3871 const Sized_symbol<32>* gsym,
3872 const Arm_relobj<big_endian>* object,
3873 unsigned int r_sym,
3874 const Symbol_value<32>* psymval,
3875 Arm_address address,
3876 Arm_address thumb_bit,
3877 bool is_weakly_undefined_without_plt)
3879 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3880 Valtype* wv = reinterpret_cast<Valtype*>(view);
3881 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3883 bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3884 && ((val & 0x0f000000UL) == 0x0a000000UL);
3885 bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3886 bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3887 && ((val & 0x0f000000UL) == 0x0b000000UL);
3888 bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3889 bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3891 // Check that the instruction is valid.
3892 if (r_type == elfcpp::R_ARM_CALL)
3894 if (!insn_is_uncond_bl && !insn_is_blx)
3895 return This::STATUS_BAD_RELOC;
3897 else if (r_type == elfcpp::R_ARM_JUMP24)
3899 if (!insn_is_b && !insn_is_cond_bl)
3900 return This::STATUS_BAD_RELOC;
3902 else if (r_type == elfcpp::R_ARM_PLT32)
3904 if (!insn_is_any_branch)
3905 return This::STATUS_BAD_RELOC;
3907 else if (r_type == elfcpp::R_ARM_XPC25)
3909 // FIXME: AAELF document IH0044C does not say much about it other
3910 // than it being obsolete.
3911 if (!insn_is_any_branch)
3912 return This::STATUS_BAD_RELOC;
3914 else
3915 gold_unreachable();
3917 // A branch to an undefined weak symbol is turned into a jump to
3918 // the next instruction unless a PLT entry will be created.
3919 // Do the same for local undefined symbols.
3920 // The jump to the next instruction is optimized as a NOP depending
3921 // on the architecture.
3922 const Target_arm<big_endian>* arm_target =
3923 Target_arm<big_endian>::default_target();
3924 if (is_weakly_undefined_without_plt)
3926 gold_assert(!parameters->options().relocatable());
3927 Valtype cond = val & 0xf0000000U;
3928 if (arm_target->may_use_arm_nop())
3929 val = cond | 0x0320f000;
3930 else
3931 val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0.
3932 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3933 return This::STATUS_OKAY;
3936 Valtype addend = Bits<26>::sign_extend32(val << 2);
3937 Valtype branch_target = psymval->value(object, addend);
3938 int32_t branch_offset = branch_target - address;
3940 // We need a stub if the branch offset is too large or if we need
3941 // to switch mode.
3942 bool may_use_blx = arm_target->may_use_v5t_interworking();
3943 Reloc_stub* stub = NULL;
3945 if (!parameters->options().relocatable()
3946 && (Bits<26>::has_overflow32(branch_offset)
3947 || ((thumb_bit != 0)
3948 && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3950 Valtype unadjusted_branch_target = psymval->value(object, 0);
3952 Stub_type stub_type =
3953 Reloc_stub::stub_type_for_reloc(r_type, address,
3954 unadjusted_branch_target,
3955 (thumb_bit != 0));
3956 if (stub_type != arm_stub_none)
3958 Stub_table<big_endian>* stub_table =
3959 object->stub_table(relinfo->data_shndx);
3960 gold_assert(stub_table != NULL);
3962 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3963 stub = stub_table->find_reloc_stub(stub_key);
3964 gold_assert(stub != NULL);
3965 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3966 branch_target = stub_table->address() + stub->offset() + addend;
3967 branch_offset = branch_target - address;
3968 gold_assert(!Bits<26>::has_overflow32(branch_offset));
3972 // At this point, if we still need to switch mode, the instruction
3973 // must either be a BLX or a BL that can be converted to a BLX.
3974 if (thumb_bit != 0)
3976 // Turn BL to BLX.
3977 gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3978 val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3981 val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
3982 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3983 return (Bits<26>::has_overflow32(branch_offset)
3984 ? This::STATUS_OVERFLOW
3985 : This::STATUS_OKAY);
3988 // Relocate THUMB long branches. This handles relocation types
3989 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3990 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3991 // undefined and we do not use PLT in this relocation. In such a case,
3992 // the branch is converted into an NOP.
3994 template<bool big_endian>
3995 typename Arm_relocate_functions<big_endian>::Status
3996 Arm_relocate_functions<big_endian>::thumb_branch_common(
3997 unsigned int r_type,
3998 const Relocate_info<32, big_endian>* relinfo,
3999 unsigned char* view,
4000 const Sized_symbol<32>* gsym,
4001 const Arm_relobj<big_endian>* object,
4002 unsigned int r_sym,
4003 const Symbol_value<32>* psymval,
4004 Arm_address address,
4005 Arm_address thumb_bit,
4006 bool is_weakly_undefined_without_plt)
4008 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4009 Valtype* wv = reinterpret_cast<Valtype*>(view);
4010 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4011 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4013 // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4014 // into account.
4015 bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4016 bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4018 // Check that the instruction is valid.
4019 if (r_type == elfcpp::R_ARM_THM_CALL)
4021 if (!is_bl_insn && !is_blx_insn)
4022 return This::STATUS_BAD_RELOC;
4024 else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4026 // This cannot be a BLX.
4027 if (!is_bl_insn)
4028 return This::STATUS_BAD_RELOC;
4030 else if (r_type == elfcpp::R_ARM_THM_XPC22)
4032 // Check for Thumb to Thumb call.
4033 if (!is_blx_insn)
4034 return This::STATUS_BAD_RELOC;
4035 if (thumb_bit != 0)
4037 gold_warning(_("%s: Thumb BLX instruction targets "
4038 "thumb function '%s'."),
4039 object->name().c_str(),
4040 (gsym ? gsym->name() : "(local)"));
4041 // Convert BLX to BL.
4042 lower_insn |= 0x1000U;
4045 else
4046 gold_unreachable();
4048 // A branch to an undefined weak symbol is turned into a jump to
4049 // the next instruction unless a PLT entry will be created.
4050 // The jump to the next instruction is optimized as a NOP.W for
4051 // Thumb-2 enabled architectures.
4052 const Target_arm<big_endian>* arm_target =
4053 Target_arm<big_endian>::default_target();
4054 if (is_weakly_undefined_without_plt)
4056 gold_assert(!parameters->options().relocatable());
4057 if (arm_target->may_use_thumb2_nop())
4059 elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4060 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4062 else
4064 elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4065 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4067 return This::STATUS_OKAY;
4070 int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4071 Arm_address branch_target = psymval->value(object, addend);
4073 // For BLX, bit 1 of target address comes from bit 1 of base address.
4074 bool may_use_blx = arm_target->may_use_v5t_interworking();
4075 if (thumb_bit == 0 && may_use_blx)
4076 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4078 int32_t branch_offset = branch_target - address;
4080 // We need a stub if the branch offset is too large or if we need
4081 // to switch mode.
4082 bool thumb2 = arm_target->using_thumb2();
4083 if (!parameters->options().relocatable()
4084 && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4085 || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4086 || ((thumb_bit == 0)
4087 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4088 || r_type == elfcpp::R_ARM_THM_JUMP24))))
4090 Arm_address unadjusted_branch_target = psymval->value(object, 0);
4092 Stub_type stub_type =
4093 Reloc_stub::stub_type_for_reloc(r_type, address,
4094 unadjusted_branch_target,
4095 (thumb_bit != 0));
4097 if (stub_type != arm_stub_none)
4099 Stub_table<big_endian>* stub_table =
4100 object->stub_table(relinfo->data_shndx);
4101 gold_assert(stub_table != NULL);
4103 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4104 Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4105 gold_assert(stub != NULL);
4106 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4107 branch_target = stub_table->address() + stub->offset() + addend;
4108 if (thumb_bit == 0 && may_use_blx)
4109 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4110 branch_offset = branch_target - address;
4114 // At this point, if we still need to switch mode, the instruction
4115 // must either be a BLX or a BL that can be converted to a BLX.
4116 if (thumb_bit == 0)
4118 gold_assert(may_use_blx
4119 && (r_type == elfcpp::R_ARM_THM_CALL
4120 || r_type == elfcpp::R_ARM_THM_XPC22));
4121 // Make sure this is a BLX.
4122 lower_insn &= ~0x1000U;
4124 else
4126 // Make sure this is a BL.
4127 lower_insn |= 0x1000U;
4130 // For a BLX instruction, make sure that the relocation is rounded up
4131 // to a word boundary. This follows the semantics of the instruction
4132 // which specifies that bit 1 of the target address will come from bit
4133 // 1 of the base address.
4134 if ((lower_insn & 0x5000U) == 0x4000U)
4135 gold_assert((branch_offset & 3) == 0);
4137 // Put BRANCH_OFFSET back into the insn. Assumes two's complement.
4138 // We use the Thumb-2 encoding, which is safe even if dealing with
4139 // a Thumb-1 instruction by virtue of our overflow check above. */
4140 upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4141 lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4143 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4144 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4146 gold_assert(!Bits<25>::has_overflow32(branch_offset));
4148 return ((thumb2
4149 ? Bits<25>::has_overflow32(branch_offset)
4150 : Bits<23>::has_overflow32(branch_offset))
4151 ? This::STATUS_OVERFLOW
4152 : This::STATUS_OKAY);
4155 // Relocate THUMB-2 long conditional branches.
4156 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
4157 // undefined and we do not use PLT in this relocation. In such a case,
4158 // the branch is converted into an NOP.
4160 template<bool big_endian>
4161 typename Arm_relocate_functions<big_endian>::Status
4162 Arm_relocate_functions<big_endian>::thm_jump19(
4163 unsigned char* view,
4164 const Arm_relobj<big_endian>* object,
4165 const Symbol_value<32>* psymval,
4166 Arm_address address,
4167 Arm_address thumb_bit)
4169 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4170 Valtype* wv = reinterpret_cast<Valtype*>(view);
4171 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4172 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4173 int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4175 Arm_address branch_target = psymval->value(object, addend);
4176 int32_t branch_offset = branch_target - address;
4178 // ??? Should handle interworking? GCC might someday try to
4179 // use this for tail calls.
4180 // FIXME: We do support thumb entry to PLT yet.
4181 if (thumb_bit == 0)
4183 gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4184 return This::STATUS_BAD_RELOC;
4187 // Put RELOCATION back into the insn.
4188 upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4189 lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4191 // Put the relocated value back in the object file:
4192 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4193 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4195 return (Bits<21>::has_overflow32(branch_offset)
4196 ? This::STATUS_OVERFLOW
4197 : This::STATUS_OKAY);
4200 // Get the GOT section, creating it if necessary.
4202 template<bool big_endian>
4203 Arm_output_data_got<big_endian>*
4204 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4206 if (this->got_ == NULL)
4208 gold_assert(symtab != NULL && layout != NULL);
4210 // When using -z now, we can treat .got as a relro section.
4211 // Without -z now, it is modified after program startup by lazy
4212 // PLT relocations.
4213 bool is_got_relro = parameters->options().now();
4214 Output_section_order got_order = (is_got_relro
4215 ? ORDER_RELRO_LAST
4216 : ORDER_DATA);
4218 // Unlike some targets (.e.g x86), ARM does not use separate .got and
4219 // .got.plt sections in output. The output .got section contains both
4220 // PLT and non-PLT GOT entries.
4221 this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4223 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4224 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4225 this->got_, got_order, is_got_relro);
4227 // The old GNU linker creates a .got.plt section. We just
4228 // create another set of data in the .got section. Note that we
4229 // always create a PLT if we create a GOT, although the PLT
4230 // might be empty.
4231 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4232 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4233 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4234 this->got_plt_, got_order, is_got_relro);
4236 // The first three entries are reserved.
4237 this->got_plt_->set_current_data_size(3 * 4);
4239 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4240 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4241 Symbol_table::PREDEFINED,
4242 this->got_plt_,
4243 0, 0, elfcpp::STT_OBJECT,
4244 elfcpp::STB_LOCAL,
4245 elfcpp::STV_HIDDEN, 0,
4246 false, false);
4248 return this->got_;
4251 // Get the dynamic reloc section, creating it if necessary.
4253 template<bool big_endian>
4254 typename Target_arm<big_endian>::Reloc_section*
4255 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4257 if (this->rel_dyn_ == NULL)
4259 gold_assert(layout != NULL);
4260 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4261 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4262 elfcpp::SHF_ALLOC, this->rel_dyn_,
4263 ORDER_DYNAMIC_RELOCS, false);
4265 return this->rel_dyn_;
4268 // Insn_template methods.
4270 // Return byte size of an instruction template.
4272 size_t
4273 Insn_template::size() const
4275 switch (this->type())
4277 case THUMB16_TYPE:
4278 case THUMB16_SPECIAL_TYPE:
4279 return 2;
4280 case ARM_TYPE:
4281 case THUMB32_TYPE:
4282 case DATA_TYPE:
4283 return 4;
4284 default:
4285 gold_unreachable();
4289 // Return alignment of an instruction template.
4291 unsigned
4292 Insn_template::alignment() const
4294 switch (this->type())
4296 case THUMB16_TYPE:
4297 case THUMB16_SPECIAL_TYPE:
4298 case THUMB32_TYPE:
4299 return 2;
4300 case ARM_TYPE:
4301 case DATA_TYPE:
4302 return 4;
4303 default:
4304 gold_unreachable();
4308 // Stub_template methods.
4310 Stub_template::Stub_template(
4311 Stub_type type, const Insn_template* insns,
4312 size_t insn_count)
4313 : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4314 entry_in_thumb_mode_(false), relocs_()
4316 off_t offset = 0;
4318 // Compute byte size and alignment of stub template.
4319 for (size_t i = 0; i < insn_count; i++)
4321 unsigned insn_alignment = insns[i].alignment();
4322 size_t insn_size = insns[i].size();
4323 gold_assert((offset & (insn_alignment - 1)) == 0);
4324 this->alignment_ = std::max(this->alignment_, insn_alignment);
4325 switch (insns[i].type())
4327 case Insn_template::THUMB16_TYPE:
4328 case Insn_template::THUMB16_SPECIAL_TYPE:
4329 if (i == 0)
4330 this->entry_in_thumb_mode_ = true;
4331 break;
4333 case Insn_template::THUMB32_TYPE:
4334 if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4335 this->relocs_.push_back(Reloc(i, offset));
4336 if (i == 0)
4337 this->entry_in_thumb_mode_ = true;
4338 break;
4340 case Insn_template::ARM_TYPE:
4341 // Handle cases where the target is encoded within the
4342 // instruction.
4343 if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4344 this->relocs_.push_back(Reloc(i, offset));
4345 break;
4347 case Insn_template::DATA_TYPE:
4348 // Entry point cannot be data.
4349 gold_assert(i != 0);
4350 this->relocs_.push_back(Reloc(i, offset));
4351 break;
4353 default:
4354 gold_unreachable();
4356 offset += insn_size;
4358 this->size_ = offset;
4361 // Stub methods.
4363 // Template to implement do_write for a specific target endianness.
4365 template<bool big_endian>
4366 void inline
4367 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4369 const Stub_template* stub_template = this->stub_template();
4370 const Insn_template* insns = stub_template->insns();
4372 // FIXME: We do not handle BE8 encoding yet.
4373 unsigned char* pov = view;
4374 for (size_t i = 0; i < stub_template->insn_count(); i++)
4376 switch (insns[i].type())
4378 case Insn_template::THUMB16_TYPE:
4379 elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4380 break;
4381 case Insn_template::THUMB16_SPECIAL_TYPE:
4382 elfcpp::Swap<16, big_endian>::writeval(
4383 pov,
4384 this->thumb16_special(i));
4385 break;
4386 case Insn_template::THUMB32_TYPE:
4388 uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4389 uint32_t lo = insns[i].data() & 0xffff;
4390 elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4391 elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4393 break;
4394 case Insn_template::ARM_TYPE:
4395 case Insn_template::DATA_TYPE:
4396 elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4397 break;
4398 default:
4399 gold_unreachable();
4401 pov += insns[i].size();
4403 gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4406 // Reloc_stub::Key methods.
4408 // Dump a Key as a string for debugging.
4410 std::string
4411 Reloc_stub::Key::name() const
4413 if (this->r_sym_ == invalid_index)
4415 // Global symbol key name
4416 // <stub-type>:<symbol name>:<addend>.
4417 const std::string sym_name = this->u_.symbol->name();
4418 // We need to print two hex number and two colons. So just add 100 bytes
4419 // to the symbol name size.
4420 size_t len = sym_name.size() + 100;
4421 char* buffer = new char[len];
4422 int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4423 sym_name.c_str(), this->addend_);
4424 gold_assert(c > 0 && c < static_cast<int>(len));
4425 delete[] buffer;
4426 return std::string(buffer);
4428 else
4430 // local symbol key name
4431 // <stub-type>:<object>:<r_sym>:<addend>.
4432 const size_t len = 200;
4433 char buffer[len];
4434 int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4435 this->u_.relobj, this->r_sym_, this->addend_);
4436 gold_assert(c > 0 && c < static_cast<int>(len));
4437 return std::string(buffer);
4441 // Reloc_stub methods.
4443 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4444 // LOCATION to DESTINATION.
4445 // This code is based on the arm_type_of_stub function in
4446 // bfd/elf32-arm.c. We have changed the interface a little to keep the Stub
4447 // class simple.
4449 Stub_type
4450 Reloc_stub::stub_type_for_reloc(
4451 unsigned int r_type,
4452 Arm_address location,
4453 Arm_address destination,
4454 bool target_is_thumb)
4456 Stub_type stub_type = arm_stub_none;
4458 // This is a bit ugly but we want to avoid using a templated class for
4459 // big and little endianities.
4460 bool may_use_blx;
4461 bool should_force_pic_veneer;
4462 bool thumb2;
4463 bool thumb_only;
4464 if (parameters->target().is_big_endian())
4466 const Target_arm<true>* big_endian_target =
4467 Target_arm<true>::default_target();
4468 may_use_blx = big_endian_target->may_use_v5t_interworking();
4469 should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4470 thumb2 = big_endian_target->using_thumb2();
4471 thumb_only = big_endian_target->using_thumb_only();
4473 else
4475 const Target_arm<false>* little_endian_target =
4476 Target_arm<false>::default_target();
4477 may_use_blx = little_endian_target->may_use_v5t_interworking();
4478 should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4479 thumb2 = little_endian_target->using_thumb2();
4480 thumb_only = little_endian_target->using_thumb_only();
4483 int64_t branch_offset;
4484 bool output_is_position_independent =
4485 parameters->options().output_is_position_independent();
4486 if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4488 // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4489 // base address (instruction address + 4).
4490 if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4491 destination = Bits<32>::bit_select32(destination, location, 0x2);
4492 branch_offset = static_cast<int64_t>(destination) - location;
4494 // Handle cases where:
4495 // - this call goes too far (different Thumb/Thumb2 max
4496 // distance)
4497 // - it's a Thumb->Arm call and blx is not available, or it's a
4498 // Thumb->Arm branch (not bl). A stub is needed in this case.
4499 if ((!thumb2
4500 && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4501 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4502 || (thumb2
4503 && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4504 || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4505 || ((!target_is_thumb)
4506 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4507 || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4509 if (target_is_thumb)
4511 // Thumb to thumb.
4512 if (!thumb_only)
4514 stub_type = (output_is_position_independent
4515 || should_force_pic_veneer)
4516 // PIC stubs.
4517 ? ((may_use_blx
4518 && (r_type == elfcpp::R_ARM_THM_CALL))
4519 // V5T and above. Stub starts with ARM code, so
4520 // we must be able to switch mode before
4521 // reaching it, which is only possible for 'bl'
4522 // (ie R_ARM_THM_CALL relocation).
4523 ? arm_stub_long_branch_any_thumb_pic
4524 // On V4T, use Thumb code only.
4525 : arm_stub_long_branch_v4t_thumb_thumb_pic)
4527 // non-PIC stubs.
4528 : ((may_use_blx
4529 && (r_type == elfcpp::R_ARM_THM_CALL))
4530 ? arm_stub_long_branch_any_any // V5T and above.
4531 : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4533 else
4535 stub_type = (output_is_position_independent
4536 || should_force_pic_veneer)
4537 ? arm_stub_long_branch_thumb_only_pic // PIC stub.
4538 : arm_stub_long_branch_thumb_only; // non-PIC stub.
4541 else
4543 // Thumb to arm.
4545 // FIXME: We should check that the input section is from an
4546 // object that has interwork enabled.
4548 stub_type = (output_is_position_independent
4549 || should_force_pic_veneer)
4550 // PIC stubs.
4551 ? ((may_use_blx
4552 && (r_type == elfcpp::R_ARM_THM_CALL))
4553 ? arm_stub_long_branch_any_arm_pic // V5T and above.
4554 : arm_stub_long_branch_v4t_thumb_arm_pic) // V4T.
4556 // non-PIC stubs.
4557 : ((may_use_blx
4558 && (r_type == elfcpp::R_ARM_THM_CALL))
4559 ? arm_stub_long_branch_any_any // V5T and above.
4560 : arm_stub_long_branch_v4t_thumb_arm); // V4T.
4562 // Handle v4t short branches.
4563 if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4564 && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4565 && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4566 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4570 else if (r_type == elfcpp::R_ARM_CALL
4571 || r_type == elfcpp::R_ARM_JUMP24
4572 || r_type == elfcpp::R_ARM_PLT32)
4574 branch_offset = static_cast<int64_t>(destination) - location;
4575 if (target_is_thumb)
4577 // Arm to thumb.
4579 // FIXME: We should check that the input section is from an
4580 // object that has interwork enabled.
4582 // We have an extra 2-bytes reach because of
4583 // the mode change (bit 24 (H) of BLX encoding).
4584 if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4585 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4586 || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4587 || (r_type == elfcpp::R_ARM_JUMP24)
4588 || (r_type == elfcpp::R_ARM_PLT32))
4590 stub_type = (output_is_position_independent
4591 || should_force_pic_veneer)
4592 // PIC stubs.
4593 ? (may_use_blx
4594 ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4595 : arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub.
4597 // non-PIC stubs.
4598 : (may_use_blx
4599 ? arm_stub_long_branch_any_any // V5T and above.
4600 : arm_stub_long_branch_v4t_arm_thumb); // V4T.
4603 else
4605 // Arm to arm.
4606 if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4607 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4609 stub_type = (output_is_position_independent
4610 || should_force_pic_veneer)
4611 ? arm_stub_long_branch_any_arm_pic // PIC stubs.
4612 : arm_stub_long_branch_any_any; /// non-PIC.
4617 return stub_type;
4620 // Cortex_a8_stub methods.
4622 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4623 // I is the position of the instruction template in the stub template.
4625 uint16_t
4626 Cortex_a8_stub::do_thumb16_special(size_t i)
4628 // The only use of this is to copy condition code from a conditional
4629 // branch being worked around to the corresponding conditional branch in
4630 // to the stub.
4631 gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4632 && i == 0);
4633 uint16_t data = this->stub_template()->insns()[i].data();
4634 gold_assert((data & 0xff00U) == 0xd000U);
4635 data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4636 return data;
4639 // Stub_factory methods.
4641 Stub_factory::Stub_factory()
4643 // The instruction template sequences are declared as static
4644 // objects and initialized first time the constructor runs.
4646 // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4647 // to reach the stub if necessary.
4648 static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4650 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4651 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4652 // dcd R_ARM_ABS32(X)
4655 // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4656 // available.
4657 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4659 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4660 Insn_template::arm_insn(0xe12fff1c), // bx ip
4661 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4662 // dcd R_ARM_ABS32(X)
4665 // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4666 static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4668 Insn_template::thumb16_insn(0xb401), // push {r0}
4669 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4670 Insn_template::thumb16_insn(0x4684), // mov ip, r0
4671 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4672 Insn_template::thumb16_insn(0x4760), // bx ip
4673 Insn_template::thumb16_insn(0xbf00), // nop
4674 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4675 // dcd R_ARM_ABS32(X)
4678 // V4T Thumb -> Thumb long branch stub. Using the stack is not
4679 // allowed.
4680 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4682 Insn_template::thumb16_insn(0x4778), // bx pc
4683 Insn_template::thumb16_insn(0x46c0), // nop
4684 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4685 Insn_template::arm_insn(0xe12fff1c), // bx ip
4686 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4687 // dcd R_ARM_ABS32(X)
4690 // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4691 // available.
4692 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4694 Insn_template::thumb16_insn(0x4778), // bx pc
4695 Insn_template::thumb16_insn(0x46c0), // nop
4696 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4697 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4698 // dcd R_ARM_ABS32(X)
4701 // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4702 // one, when the destination is close enough.
4703 static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4705 Insn_template::thumb16_insn(0x4778), // bx pc
4706 Insn_template::thumb16_insn(0x46c0), // nop
4707 Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8)
4710 // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use
4711 // blx to reach the stub if necessary.
4712 static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4714 Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc]
4715 Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip
4716 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4717 // dcd R_ARM_REL32(X-4)
4720 // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use
4721 // blx to reach the stub if necessary. We can not add into pc;
4722 // it is not guaranteed to mode switch (different in ARMv6 and
4723 // ARMv7).
4724 static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4726 Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4]
4727 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4728 Insn_template::arm_insn(0xe12fff1c), // bx ip
4729 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4730 // dcd R_ARM_REL32(X)
4733 // V4T ARM -> ARM long branch stub, PIC.
4734 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4736 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4737 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4738 Insn_template::arm_insn(0xe12fff1c), // bx ip
4739 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4740 // dcd R_ARM_REL32(X)
4743 // V4T Thumb -> ARM long branch stub, PIC.
4744 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4746 Insn_template::thumb16_insn(0x4778), // bx pc
4747 Insn_template::thumb16_insn(0x46c0), // nop
4748 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4749 Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc
4750 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4751 // dcd R_ARM_REL32(X)
4754 // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4755 // architectures.
4756 static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4758 Insn_template::thumb16_insn(0xb401), // push {r0}
4759 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4760 Insn_template::thumb16_insn(0x46fc), // mov ip, pc
4761 Insn_template::thumb16_insn(0x4484), // add ip, r0
4762 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4763 Insn_template::thumb16_insn(0x4760), // bx ip
4764 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4765 // dcd R_ARM_REL32(X)
4768 // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4769 // allowed.
4770 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4772 Insn_template::thumb16_insn(0x4778), // bx pc
4773 Insn_template::thumb16_insn(0x46c0), // nop
4774 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4775 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4776 Insn_template::arm_insn(0xe12fff1c), // bx ip
4777 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4778 // dcd R_ARM_REL32(X)
4781 // Cortex-A8 erratum-workaround stubs.
4783 // Stub used for conditional branches (which may be beyond +/-1MB away,
4784 // so we can't use a conditional branch to reach this stub).
4786 // original code:
4788 // b<cond> X
4789 // after:
4791 static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4793 Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true
4794 Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after
4795 Insn_template::thumb32_b_insn(0xf000b800, -4) // true:
4796 // b.w X
4799 // Stub used for b.w and bl.w instructions.
4801 static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4803 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4806 static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4808 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4811 // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w
4812 // instruction (which switches to ARM mode) to point to this stub. Jump to
4813 // the real destination using an ARM-mode branch.
4814 static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4816 Insn_template::arm_rel_insn(0xea000000, -8) // b dest
4819 // Stub used to provide an interworking for R_ARM_V4BX relocation
4820 // (bx r[n] instruction).
4821 static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4823 Insn_template::arm_insn(0xe3100001), // tst r<n>, #1
4824 Insn_template::arm_insn(0x01a0f000), // moveq pc, r<n>
4825 Insn_template::arm_insn(0xe12fff10) // bx r<n>
4828 // Fill in the stub template look-up table. Stub templates are constructed
4829 // per instance of Stub_factory for fast look-up without locking
4830 // in a thread-enabled environment.
4832 this->stub_templates_[arm_stub_none] =
4833 new Stub_template(arm_stub_none, NULL, 0);
4835 #define DEF_STUB(x) \
4836 do \
4838 size_t array_size \
4839 = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4840 Stub_type type = arm_stub_##x; \
4841 this->stub_templates_[type] = \
4842 new Stub_template(type, elf32_arm_stub_##x, array_size); \
4844 while (0);
4846 DEF_STUBS
4847 #undef DEF_STUB
4850 // Stub_table methods.
4852 // Remove all Cortex-A8 stub.
4854 template<bool big_endian>
4855 void
4856 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4858 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4859 p != this->cortex_a8_stubs_.end();
4860 ++p)
4861 delete p->second;
4862 this->cortex_a8_stubs_.clear();
4865 // Relocate one stub. This is a helper for Stub_table::relocate_stubs().
4867 template<bool big_endian>
4868 void
4869 Stub_table<big_endian>::relocate_stub(
4870 Stub* stub,
4871 const Relocate_info<32, big_endian>* relinfo,
4872 Target_arm<big_endian>* arm_target,
4873 Output_section* output_section,
4874 unsigned char* view,
4875 Arm_address address,
4876 section_size_type view_size)
4878 const Stub_template* stub_template = stub->stub_template();
4879 if (stub_template->reloc_count() != 0)
4881 // Adjust view to cover the stub only.
4882 section_size_type offset = stub->offset();
4883 section_size_type stub_size = stub_template->size();
4884 gold_assert(offset + stub_size <= view_size);
4886 arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4887 address + offset, stub_size);
4891 // Relocate all stubs in this stub table.
4893 template<bool big_endian>
4894 void
4895 Stub_table<big_endian>::relocate_stubs(
4896 const Relocate_info<32, big_endian>* relinfo,
4897 Target_arm<big_endian>* arm_target,
4898 Output_section* output_section,
4899 unsigned char* view,
4900 Arm_address address,
4901 section_size_type view_size)
4903 // If we are passed a view bigger than the stub table's. we need to
4904 // adjust the view.
4905 gold_assert(address == this->address()
4906 && (view_size
4907 == static_cast<section_size_type>(this->data_size())));
4909 // Relocate all relocation stubs.
4910 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4911 p != this->reloc_stubs_.end();
4912 ++p)
4913 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4914 address, view_size);
4916 // Relocate all Cortex-A8 stubs.
4917 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4918 p != this->cortex_a8_stubs_.end();
4919 ++p)
4920 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4921 address, view_size);
4923 // Relocate all ARM V4BX stubs.
4924 for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4925 p != this->arm_v4bx_stubs_.end();
4926 ++p)
4928 if (*p != NULL)
4929 this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4930 address, view_size);
4934 // Write out the stubs to file.
4936 template<bool big_endian>
4937 void
4938 Stub_table<big_endian>::do_write(Output_file* of)
4940 off_t offset = this->offset();
4941 const section_size_type oview_size =
4942 convert_to_section_size_type(this->data_size());
4943 unsigned char* const oview = of->get_output_view(offset, oview_size);
4945 // Write relocation stubs.
4946 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4947 p != this->reloc_stubs_.end();
4948 ++p)
4950 Reloc_stub* stub = p->second;
4951 Arm_address address = this->address() + stub->offset();
4952 gold_assert(address
4953 == align_address(address,
4954 stub->stub_template()->alignment()));
4955 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4956 big_endian);
4959 // Write Cortex-A8 stubs.
4960 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4961 p != this->cortex_a8_stubs_.end();
4962 ++p)
4964 Cortex_a8_stub* stub = p->second;
4965 Arm_address address = this->address() + stub->offset();
4966 gold_assert(address
4967 == align_address(address,
4968 stub->stub_template()->alignment()));
4969 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4970 big_endian);
4973 // Write ARM V4BX relocation stubs.
4974 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4975 p != this->arm_v4bx_stubs_.end();
4976 ++p)
4978 if (*p == NULL)
4979 continue;
4981 Arm_address address = this->address() + (*p)->offset();
4982 gold_assert(address
4983 == align_address(address,
4984 (*p)->stub_template()->alignment()));
4985 (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4986 big_endian);
4989 of->write_output_view(this->offset(), oview_size, oview);
4992 // Update the data size and address alignment of the stub table at the end
4993 // of a relaxation pass. Return true if either the data size or the
4994 // alignment changed in this relaxation pass.
4996 template<bool big_endian>
4997 bool
4998 Stub_table<big_endian>::update_data_size_and_addralign()
5000 // Go over all stubs in table to compute data size and address alignment.
5001 off_t size = this->reloc_stubs_size_;
5002 unsigned addralign = this->reloc_stubs_addralign_;
5004 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5005 p != this->cortex_a8_stubs_.end();
5006 ++p)
5008 const Stub_template* stub_template = p->second->stub_template();
5009 addralign = std::max(addralign, stub_template->alignment());
5010 size = (align_address(size, stub_template->alignment())
5011 + stub_template->size());
5014 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5015 p != this->arm_v4bx_stubs_.end();
5016 ++p)
5018 if (*p == NULL)
5019 continue;
5021 const Stub_template* stub_template = (*p)->stub_template();
5022 addralign = std::max(addralign, stub_template->alignment());
5023 size = (align_address(size, stub_template->alignment())
5024 + stub_template->size());
5027 // Check if either data size or alignment changed in this pass.
5028 // Update prev_data_size_ and prev_addralign_. These will be used
5029 // as the current data size and address alignment for the next pass.
5030 bool changed = size != this->prev_data_size_;
5031 this->prev_data_size_ = size;
5033 if (addralign != this->prev_addralign_)
5034 changed = true;
5035 this->prev_addralign_ = addralign;
5037 return changed;
5040 // Finalize the stubs. This sets the offsets of the stubs within the stub
5041 // table. It also marks all input sections needing Cortex-A8 workaround.
5043 template<bool big_endian>
5044 void
5045 Stub_table<big_endian>::finalize_stubs()
5047 off_t off = this->reloc_stubs_size_;
5048 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5049 p != this->cortex_a8_stubs_.end();
5050 ++p)
5052 Cortex_a8_stub* stub = p->second;
5053 const Stub_template* stub_template = stub->stub_template();
5054 uint64_t stub_addralign = stub_template->alignment();
5055 off = align_address(off, stub_addralign);
5056 stub->set_offset(off);
5057 off += stub_template->size();
5059 // Mark input section so that we can determine later if a code section
5060 // needs the Cortex-A8 workaround quickly.
5061 Arm_relobj<big_endian>* arm_relobj =
5062 Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5063 arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5066 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5067 p != this->arm_v4bx_stubs_.end();
5068 ++p)
5070 if (*p == NULL)
5071 continue;
5073 const Stub_template* stub_template = (*p)->stub_template();
5074 uint64_t stub_addralign = stub_template->alignment();
5075 off = align_address(off, stub_addralign);
5076 (*p)->set_offset(off);
5077 off += stub_template->size();
5080 gold_assert(off <= this->prev_data_size_);
5083 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5084 // and VIEW_ADDRESS + VIEW_SIZE - 1. VIEW points to the mapped address
5085 // of the address range seen by the linker.
5087 template<bool big_endian>
5088 void
5089 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5090 Target_arm<big_endian>* arm_target,
5091 unsigned char* view,
5092 Arm_address view_address,
5093 section_size_type view_size)
5095 // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5096 for (Cortex_a8_stub_list::const_iterator p =
5097 this->cortex_a8_stubs_.lower_bound(view_address);
5098 ((p != this->cortex_a8_stubs_.end())
5099 && (p->first < (view_address + view_size)));
5100 ++p)
5102 // We do not store the THUMB bit in the LSB of either the branch address
5103 // or the stub offset. There is no need to strip the LSB.
5104 Arm_address branch_address = p->first;
5105 const Cortex_a8_stub* stub = p->second;
5106 Arm_address stub_address = this->address() + stub->offset();
5108 // Offset of the branch instruction relative to this view.
5109 section_size_type offset =
5110 convert_to_section_size_type(branch_address - view_address);
5111 gold_assert((offset + 4) <= view_size);
5113 arm_target->apply_cortex_a8_workaround(stub, stub_address,
5114 view + offset, branch_address);
5118 // Arm_input_section methods.
5120 // Initialize an Arm_input_section.
5122 template<bool big_endian>
5123 void
5124 Arm_input_section<big_endian>::init()
5126 Relobj* relobj = this->relobj();
5127 unsigned int shndx = this->shndx();
5129 // We have to cache original size, alignment and contents to avoid locking
5130 // the original file.
5131 this->original_addralign_ =
5132 convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5134 // This is not efficient but we expect only a small number of relaxed
5135 // input sections for stubs.
5136 section_size_type section_size;
5137 const unsigned char* section_contents =
5138 relobj->section_contents(shndx, &section_size, false);
5139 this->original_size_ =
5140 convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5142 gold_assert(this->original_contents_ == NULL);
5143 this->original_contents_ = new unsigned char[section_size];
5144 memcpy(this->original_contents_, section_contents, section_size);
5146 // We want to make this look like the original input section after
5147 // output sections are finalized.
5148 Output_section* os = relobj->output_section(shndx);
5149 off_t offset = relobj->output_section_offset(shndx);
5150 gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5151 this->set_address(os->address() + offset);
5152 this->set_file_offset(os->offset() + offset);
5154 this->set_current_data_size(this->original_size_);
5155 this->finalize_data_size();
5158 template<bool big_endian>
5159 void
5160 Arm_input_section<big_endian>::do_write(Output_file* of)
5162 // We have to write out the original section content.
5163 gold_assert(this->original_contents_ != NULL);
5164 of->write(this->offset(), this->original_contents_,
5165 this->original_size_);
5167 // If this owns a stub table and it is not empty, write it.
5168 if (this->is_stub_table_owner() && !this->stub_table_->empty())
5169 this->stub_table_->write(of);
5172 // Finalize data size.
5174 template<bool big_endian>
5175 void
5176 Arm_input_section<big_endian>::set_final_data_size()
5178 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5180 if (this->is_stub_table_owner())
5182 this->stub_table_->finalize_data_size();
5183 off = align_address(off, this->stub_table_->addralign());
5184 off += this->stub_table_->data_size();
5186 this->set_data_size(off);
5189 // Reset address and file offset.
5191 template<bool big_endian>
5192 void
5193 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5195 // Size of the original input section contents.
5196 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5198 // If this is a stub table owner, account for the stub table size.
5199 if (this->is_stub_table_owner())
5201 Stub_table<big_endian>* stub_table = this->stub_table_;
5203 // Reset the stub table's address and file offset. The
5204 // current data size for child will be updated after that.
5205 stub_table_->reset_address_and_file_offset();
5206 off = align_address(off, stub_table_->addralign());
5207 off += stub_table->current_data_size();
5210 this->set_current_data_size(off);
5213 // Arm_exidx_cantunwind methods.
5215 // Write this to Output file OF for a fixed endianness.
5217 template<bool big_endian>
5218 void
5219 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5221 off_t offset = this->offset();
5222 const section_size_type oview_size = 8;
5223 unsigned char* const oview = of->get_output_view(offset, oview_size);
5225 Output_section* os = this->relobj_->output_section(this->shndx_);
5226 gold_assert(os != NULL);
5228 Arm_relobj<big_endian>* arm_relobj =
5229 Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5230 Arm_address output_offset =
5231 arm_relobj->get_output_section_offset(this->shndx_);
5232 Arm_address section_start;
5233 section_size_type section_size;
5235 // Find out the end of the text section referred by this.
5236 if (output_offset != Arm_relobj<big_endian>::invalid_address)
5238 section_start = os->address() + output_offset;
5239 const Arm_exidx_input_section* exidx_input_section =
5240 arm_relobj->exidx_input_section_by_link(this->shndx_);
5241 gold_assert(exidx_input_section != NULL);
5242 section_size =
5243 convert_to_section_size_type(exidx_input_section->text_size());
5245 else
5247 // Currently this only happens for a relaxed section.
5248 const Output_relaxed_input_section* poris =
5249 os->find_relaxed_input_section(this->relobj_, this->shndx_);
5250 gold_assert(poris != NULL);
5251 section_start = poris->address();
5252 section_size = convert_to_section_size_type(poris->data_size());
5255 // We always append this to the end of an EXIDX section.
5256 Arm_address output_address = section_start + section_size;
5258 // Write out the entry. The first word either points to the beginning
5259 // or after the end of a text section. The second word is the special
5260 // EXIDX_CANTUNWIND value.
5261 uint32_t prel31_offset = output_address - this->address();
5262 if (Bits<31>::has_overflow32(offset))
5263 gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5264 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5265 prel31_offset & 0x7fffffffU);
5266 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5267 elfcpp::EXIDX_CANTUNWIND);
5269 of->write_output_view(this->offset(), oview_size, oview);
5272 // Arm_exidx_merged_section methods.
5274 // Constructor for Arm_exidx_merged_section.
5275 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5276 // SECTION_OFFSET_MAP points to a section offset map describing how
5277 // parts of the input section are mapped to output. DELETED_BYTES is
5278 // the number of bytes deleted from the EXIDX input section.
5280 Arm_exidx_merged_section::Arm_exidx_merged_section(
5281 const Arm_exidx_input_section& exidx_input_section,
5282 const Arm_exidx_section_offset_map& section_offset_map,
5283 uint32_t deleted_bytes)
5284 : Output_relaxed_input_section(exidx_input_section.relobj(),
5285 exidx_input_section.shndx(),
5286 exidx_input_section.addralign()),
5287 exidx_input_section_(exidx_input_section),
5288 section_offset_map_(section_offset_map)
5290 // If we retain or discard the whole EXIDX input section, we would
5291 // not be here.
5292 gold_assert(deleted_bytes != 0
5293 && deleted_bytes != this->exidx_input_section_.size());
5295 // Fix size here so that we do not need to implement set_final_data_size.
5296 uint32_t size = exidx_input_section.size() - deleted_bytes;
5297 this->set_data_size(size);
5298 this->fix_data_size();
5300 // Allocate buffer for section contents and build contents.
5301 this->section_contents_ = new unsigned char[size];
5304 // Build the contents of a merged EXIDX output section.
5306 void
5307 Arm_exidx_merged_section::build_contents(
5308 const unsigned char* original_contents,
5309 section_size_type original_size)
5311 // Go over spans of input offsets and write only those that are not
5312 // discarded.
5313 section_offset_type in_start = 0;
5314 section_offset_type out_start = 0;
5315 section_offset_type in_max =
5316 convert_types<section_offset_type>(original_size);
5317 section_offset_type out_max =
5318 convert_types<section_offset_type>(this->data_size());
5319 for (Arm_exidx_section_offset_map::const_iterator p =
5320 this->section_offset_map_.begin();
5321 p != this->section_offset_map_.end();
5322 ++p)
5324 section_offset_type in_end = p->first;
5325 gold_assert(in_end >= in_start);
5326 section_offset_type out_end = p->second;
5327 size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5328 if (out_end != -1)
5330 size_t out_chunk_size =
5331 convert_types<size_t>(out_end - out_start + 1);
5333 gold_assert(out_chunk_size == in_chunk_size
5334 && in_end < in_max && out_end < out_max);
5336 memcpy(this->section_contents_ + out_start,
5337 original_contents + in_start,
5338 out_chunk_size);
5339 out_start += out_chunk_size;
5341 in_start += in_chunk_size;
5345 // Given an input OBJECT, an input section index SHNDX within that
5346 // object, and an OFFSET relative to the start of that input
5347 // section, return whether or not the corresponding offset within
5348 // the output section is known. If this function returns true, it
5349 // sets *POUTPUT to the output offset. The value -1 indicates that
5350 // this input offset is being discarded.
5352 bool
5353 Arm_exidx_merged_section::do_output_offset(
5354 const Relobj* relobj,
5355 unsigned int shndx,
5356 section_offset_type offset,
5357 section_offset_type* poutput) const
5359 // We only handle offsets for the original EXIDX input section.
5360 if (relobj != this->exidx_input_section_.relobj()
5361 || shndx != this->exidx_input_section_.shndx())
5362 return false;
5364 section_offset_type section_size =
5365 convert_types<section_offset_type>(this->exidx_input_section_.size());
5366 if (offset < 0 || offset >= section_size)
5367 // Input offset is out of valid range.
5368 *poutput = -1;
5369 else
5371 // We need to look up the section offset map to determine the output
5372 // offset. Find the reference point in map that is first offset
5373 // bigger than or equal to this offset.
5374 Arm_exidx_section_offset_map::const_iterator p =
5375 this->section_offset_map_.lower_bound(offset);
5377 // The section offset maps are build such that this should not happen if
5378 // input offset is in the valid range.
5379 gold_assert(p != this->section_offset_map_.end());
5381 // We need to check if this is dropped.
5382 section_offset_type ref = p->first;
5383 section_offset_type mapped_ref = p->second;
5385 if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5386 // Offset is present in output.
5387 *poutput = mapped_ref + (offset - ref);
5388 else
5389 // Offset is discarded owing to EXIDX entry merging.
5390 *poutput = -1;
5393 return true;
5396 // Write this to output file OF.
5398 void
5399 Arm_exidx_merged_section::do_write(Output_file* of)
5401 off_t offset = this->offset();
5402 const section_size_type oview_size = this->data_size();
5403 unsigned char* const oview = of->get_output_view(offset, oview_size);
5405 Output_section* os = this->relobj()->output_section(this->shndx());
5406 gold_assert(os != NULL);
5408 memcpy(oview, this->section_contents_, oview_size);
5409 of->write_output_view(this->offset(), oview_size, oview);
5412 // Arm_exidx_fixup methods.
5414 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5415 // is not an EXIDX_CANTUNWIND entry already. The new EXIDX_CANTUNWIND entry
5416 // points to the end of the last seen EXIDX section.
5418 void
5419 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5421 if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5422 && this->last_input_section_ != NULL)
5424 Relobj* relobj = this->last_input_section_->relobj();
5425 unsigned int text_shndx = this->last_input_section_->link();
5426 Arm_exidx_cantunwind* cantunwind =
5427 new Arm_exidx_cantunwind(relobj, text_shndx);
5428 this->exidx_output_section_->add_output_section_data(cantunwind);
5429 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5433 // Process an EXIDX section entry in input. Return whether this entry
5434 // can be deleted in the output. SECOND_WORD in the second word of the
5435 // EXIDX entry.
5437 bool
5438 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5440 bool delete_entry;
5441 if (second_word == elfcpp::EXIDX_CANTUNWIND)
5443 // Merge if previous entry is also an EXIDX_CANTUNWIND.
5444 delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5445 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5447 else if ((second_word & 0x80000000) != 0)
5449 // Inlined unwinding data. Merge if equal to previous.
5450 delete_entry = (merge_exidx_entries_
5451 && this->last_unwind_type_ == UT_INLINED_ENTRY
5452 && this->last_inlined_entry_ == second_word);
5453 this->last_unwind_type_ = UT_INLINED_ENTRY;
5454 this->last_inlined_entry_ = second_word;
5456 else
5458 // Normal table entry. In theory we could merge these too,
5459 // but duplicate entries are likely to be much less common.
5460 delete_entry = false;
5461 this->last_unwind_type_ = UT_NORMAL_ENTRY;
5463 return delete_entry;
5466 // Update the current section offset map during EXIDX section fix-up.
5467 // If there is no map, create one. INPUT_OFFSET is the offset of a
5468 // reference point, DELETED_BYTES is the number of deleted by in the
5469 // section so far. If DELETE_ENTRY is true, the reference point and
5470 // all offsets after the previous reference point are discarded.
5472 void
5473 Arm_exidx_fixup::update_offset_map(
5474 section_offset_type input_offset,
5475 section_size_type deleted_bytes,
5476 bool delete_entry)
5478 if (this->section_offset_map_ == NULL)
5479 this->section_offset_map_ = new Arm_exidx_section_offset_map();
5480 section_offset_type output_offset;
5481 if (delete_entry)
5482 output_offset = Arm_exidx_input_section::invalid_offset;
5483 else
5484 output_offset = input_offset - deleted_bytes;
5485 (*this->section_offset_map_)[input_offset] = output_offset;
5488 // Process EXIDX_INPUT_SECTION for EXIDX entry merging. Return the number of
5489 // bytes deleted. SECTION_CONTENTS points to the contents of the EXIDX
5490 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5491 // If some entries are merged, also store a pointer to a newly created
5492 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP. The caller
5493 // owns the map and is responsible for releasing it after use.
5495 template<bool big_endian>
5496 uint32_t
5497 Arm_exidx_fixup::process_exidx_section(
5498 const Arm_exidx_input_section* exidx_input_section,
5499 const unsigned char* section_contents,
5500 section_size_type section_size,
5501 Arm_exidx_section_offset_map** psection_offset_map)
5503 Relobj* relobj = exidx_input_section->relobj();
5504 unsigned shndx = exidx_input_section->shndx();
5506 if ((section_size % 8) != 0)
5508 // Something is wrong with this section. Better not touch it.
5509 gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5510 relobj->name().c_str(), shndx);
5511 this->last_input_section_ = exidx_input_section;
5512 this->last_unwind_type_ = UT_NONE;
5513 return 0;
5516 uint32_t deleted_bytes = 0;
5517 bool prev_delete_entry = false;
5518 gold_assert(this->section_offset_map_ == NULL);
5520 for (section_size_type i = 0; i < section_size; i += 8)
5522 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5523 const Valtype* wv =
5524 reinterpret_cast<const Valtype*>(section_contents + i + 4);
5525 uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5527 bool delete_entry = this->process_exidx_entry(second_word);
5529 // Entry deletion causes changes in output offsets. We use a std::map
5530 // to record these. And entry (x, y) means input offset x
5531 // is mapped to output offset y. If y is invalid_offset, then x is
5532 // dropped in the output. Because of the way std::map::lower_bound
5533 // works, we record the last offset in a region w.r.t to keeping or
5534 // dropping. If there is no entry (x0, y0) for an input offset x0,
5535 // the output offset y0 of it is determined by the output offset y1 of
5536 // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5537 // in the map. If y1 is not -1, then y0 = y1 + x0 - x1. Otherwise, y1
5538 // y0 is also -1.
5539 if (delete_entry != prev_delete_entry && i != 0)
5540 this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5542 // Update total deleted bytes for this entry.
5543 if (delete_entry)
5544 deleted_bytes += 8;
5546 prev_delete_entry = delete_entry;
5549 // If section offset map is not NULL, make an entry for the end of
5550 // section.
5551 if (this->section_offset_map_ != NULL)
5552 update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5554 *psection_offset_map = this->section_offset_map_;
5555 this->section_offset_map_ = NULL;
5556 this->last_input_section_ = exidx_input_section;
5558 // Set the first output text section so that we can link the EXIDX output
5559 // section to it. Ignore any EXIDX input section that is completely merged.
5560 if (this->first_output_text_section_ == NULL
5561 && deleted_bytes != section_size)
5563 unsigned int link = exidx_input_section->link();
5564 Output_section* os = relobj->output_section(link);
5565 gold_assert(os != NULL);
5566 this->first_output_text_section_ = os;
5569 return deleted_bytes;
5572 // Arm_output_section methods.
5574 // Create a stub group for input sections from BEGIN to END. OWNER
5575 // points to the input section to be the owner a new stub table.
5577 template<bool big_endian>
5578 void
5579 Arm_output_section<big_endian>::create_stub_group(
5580 Input_section_list::const_iterator begin,
5581 Input_section_list::const_iterator end,
5582 Input_section_list::const_iterator owner,
5583 Target_arm<big_endian>* target,
5584 std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5585 const Task* task)
5587 // We use a different kind of relaxed section in an EXIDX section.
5588 // The static casting from Output_relaxed_input_section to
5589 // Arm_input_section is invalid in an EXIDX section. We are okay
5590 // because we should not be calling this for an EXIDX section.
5591 gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5593 // Currently we convert ordinary input sections into relaxed sections only
5594 // at this point but we may want to support creating relaxed input section
5595 // very early. So we check here to see if owner is already a relaxed
5596 // section.
5598 Arm_input_section<big_endian>* arm_input_section;
5599 if (owner->is_relaxed_input_section())
5601 arm_input_section =
5602 Arm_input_section<big_endian>::as_arm_input_section(
5603 owner->relaxed_input_section());
5605 else
5607 gold_assert(owner->is_input_section());
5608 // Create a new relaxed input section. We need to lock the original
5609 // file.
5610 Task_lock_obj<Object> tl(task, owner->relobj());
5611 arm_input_section =
5612 target->new_arm_input_section(owner->relobj(), owner->shndx());
5613 new_relaxed_sections->push_back(arm_input_section);
5616 // Create a stub table.
5617 Stub_table<big_endian>* stub_table =
5618 target->new_stub_table(arm_input_section);
5620 arm_input_section->set_stub_table(stub_table);
5622 Input_section_list::const_iterator p = begin;
5623 Input_section_list::const_iterator prev_p;
5625 // Look for input sections or relaxed input sections in [begin ... end].
5628 if (p->is_input_section() || p->is_relaxed_input_section())
5630 // The stub table information for input sections live
5631 // in their objects.
5632 Arm_relobj<big_endian>* arm_relobj =
5633 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5634 arm_relobj->set_stub_table(p->shndx(), stub_table);
5636 prev_p = p++;
5638 while (prev_p != end);
5641 // Group input sections for stub generation. GROUP_SIZE is roughly the limit
5642 // of stub groups. We grow a stub group by adding input section until the
5643 // size is just below GROUP_SIZE. The last input section will be converted
5644 // into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5645 // input section after the stub table, effectively double the group size.
5647 // This is similar to the group_sections() function in elf32-arm.c but is
5648 // implemented differently.
5650 template<bool big_endian>
5651 void
5652 Arm_output_section<big_endian>::group_sections(
5653 section_size_type group_size,
5654 bool stubs_always_after_branch,
5655 Target_arm<big_endian>* target,
5656 const Task* task)
5658 // States for grouping.
5659 typedef enum
5661 // No group is being built.
5662 NO_GROUP,
5663 // A group is being built but the stub table is not found yet.
5664 // We keep group a stub group until the size is just under GROUP_SIZE.
5665 // The last input section in the group will be used as the stub table.
5666 FINDING_STUB_SECTION,
5667 // A group is being built and we have already found a stub table.
5668 // We enter this state to grow a stub group by adding input section
5669 // after the stub table. This effectively doubles the group size.
5670 HAS_STUB_SECTION
5671 } State;
5673 // Any newly created relaxed sections are stored here.
5674 std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5676 State state = NO_GROUP;
5677 section_size_type off = 0;
5678 section_size_type group_begin_offset = 0;
5679 section_size_type group_end_offset = 0;
5680 section_size_type stub_table_end_offset = 0;
5681 Input_section_list::const_iterator group_begin =
5682 this->input_sections().end();
5683 Input_section_list::const_iterator stub_table =
5684 this->input_sections().end();
5685 Input_section_list::const_iterator group_end = this->input_sections().end();
5686 for (Input_section_list::const_iterator p = this->input_sections().begin();
5687 p != this->input_sections().end();
5688 ++p)
5690 section_size_type section_begin_offset =
5691 align_address(off, p->addralign());
5692 section_size_type section_end_offset =
5693 section_begin_offset + p->data_size();
5695 // Check to see if we should group the previously seen sections.
5696 switch (state)
5698 case NO_GROUP:
5699 break;
5701 case FINDING_STUB_SECTION:
5702 // Adding this section makes the group larger than GROUP_SIZE.
5703 if (section_end_offset - group_begin_offset >= group_size)
5705 if (stubs_always_after_branch)
5707 gold_assert(group_end != this->input_sections().end());
5708 this->create_stub_group(group_begin, group_end, group_end,
5709 target, &new_relaxed_sections,
5710 task);
5711 state = NO_GROUP;
5713 else
5715 // But wait, there's more! Input sections up to
5716 // stub_group_size bytes after the stub table can be
5717 // handled by it too.
5718 state = HAS_STUB_SECTION;
5719 stub_table = group_end;
5720 stub_table_end_offset = group_end_offset;
5723 break;
5725 case HAS_STUB_SECTION:
5726 // Adding this section makes the post stub-section group larger
5727 // than GROUP_SIZE.
5728 if (section_end_offset - stub_table_end_offset >= group_size)
5730 gold_assert(group_end != this->input_sections().end());
5731 this->create_stub_group(group_begin, group_end, stub_table,
5732 target, &new_relaxed_sections, task);
5733 state = NO_GROUP;
5735 break;
5737 default:
5738 gold_unreachable();
5741 // If we see an input section and currently there is no group, start
5742 // a new one. Skip any empty sections. We look at the data size
5743 // instead of calling p->relobj()->section_size() to avoid locking.
5744 if ((p->is_input_section() || p->is_relaxed_input_section())
5745 && (p->data_size() != 0))
5747 if (state == NO_GROUP)
5749 state = FINDING_STUB_SECTION;
5750 group_begin = p;
5751 group_begin_offset = section_begin_offset;
5754 // Keep track of the last input section seen.
5755 group_end = p;
5756 group_end_offset = section_end_offset;
5759 off = section_end_offset;
5762 // Create a stub group for any ungrouped sections.
5763 if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5765 gold_assert(group_end != this->input_sections().end());
5766 this->create_stub_group(group_begin, group_end,
5767 (state == FINDING_STUB_SECTION
5768 ? group_end
5769 : stub_table),
5770 target, &new_relaxed_sections, task);
5773 // Convert input section into relaxed input section in a batch.
5774 if (!new_relaxed_sections.empty())
5775 this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5777 // Update the section offsets
5778 for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5780 Arm_relobj<big_endian>* arm_relobj =
5781 Arm_relobj<big_endian>::as_arm_relobj(
5782 new_relaxed_sections[i]->relobj());
5783 unsigned int shndx = new_relaxed_sections[i]->shndx();
5784 // Tell Arm_relobj that this input section is converted.
5785 arm_relobj->convert_input_section_to_relaxed_section(shndx);
5789 // Append non empty text sections in this to LIST in ascending
5790 // order of their position in this.
5792 template<bool big_endian>
5793 void
5794 Arm_output_section<big_endian>::append_text_sections_to_list(
5795 Text_section_list* list)
5797 gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5799 for (Input_section_list::const_iterator p = this->input_sections().begin();
5800 p != this->input_sections().end();
5801 ++p)
5803 // We only care about plain or relaxed input sections. We also
5804 // ignore any merged sections.
5805 if (p->is_input_section() || p->is_relaxed_input_section())
5806 list->push_back(Text_section_list::value_type(p->relobj(),
5807 p->shndx()));
5811 template<bool big_endian>
5812 void
5813 Arm_output_section<big_endian>::fix_exidx_coverage(
5814 Layout* layout,
5815 const Text_section_list& sorted_text_sections,
5816 Symbol_table* symtab,
5817 bool merge_exidx_entries,
5818 const Task* task)
5820 // We should only do this for the EXIDX output section.
5821 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5823 // We don't want the relaxation loop to undo these changes, so we discard
5824 // the current saved states and take another one after the fix-up.
5825 this->discard_states();
5827 // Remove all input sections.
5828 uint64_t address = this->address();
5829 typedef std::list<Output_section::Input_section> Input_section_list;
5830 Input_section_list input_sections;
5831 this->reset_address_and_file_offset();
5832 this->get_input_sections(address, std::string(""), &input_sections);
5834 if (!this->input_sections().empty())
5835 gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5837 // Go through all the known input sections and record them.
5838 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5839 typedef Unordered_map<Section_id, const Output_section::Input_section*,
5840 Section_id_hash> Text_to_exidx_map;
5841 Text_to_exidx_map text_to_exidx_map;
5842 for (Input_section_list::const_iterator p = input_sections.begin();
5843 p != input_sections.end();
5844 ++p)
5846 // This should never happen. At this point, we should only see
5847 // plain EXIDX input sections.
5848 gold_assert(!p->is_relaxed_input_section());
5849 text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5852 Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5854 // Go over the sorted text sections.
5855 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5856 Section_id_set processed_input_sections;
5857 for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5858 p != sorted_text_sections.end();
5859 ++p)
5861 Relobj* relobj = p->first;
5862 unsigned int shndx = p->second;
5864 Arm_relobj<big_endian>* arm_relobj =
5865 Arm_relobj<big_endian>::as_arm_relobj(relobj);
5866 const Arm_exidx_input_section* exidx_input_section =
5867 arm_relobj->exidx_input_section_by_link(shndx);
5869 // If this text section has no EXIDX section or if the EXIDX section
5870 // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5871 // of the last seen EXIDX section.
5872 if (exidx_input_section == NULL || exidx_input_section->has_errors())
5874 exidx_fixup.add_exidx_cantunwind_as_needed();
5875 continue;
5878 Relobj* exidx_relobj = exidx_input_section->relobj();
5879 unsigned int exidx_shndx = exidx_input_section->shndx();
5880 Section_id sid(exidx_relobj, exidx_shndx);
5881 Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5882 if (iter == text_to_exidx_map.end())
5884 // This is odd. We have not seen this EXIDX input section before.
5885 // We cannot do fix-up. If we saw a SECTIONS clause in a script,
5886 // issue a warning instead. We assume the user knows what he
5887 // or she is doing. Otherwise, this is an error.
5888 if (layout->script_options()->saw_sections_clause())
5889 gold_warning(_("unwinding may not work because EXIDX input section"
5890 " %u of %s is not in EXIDX output section"),
5891 exidx_shndx, exidx_relobj->name().c_str());
5892 else
5893 gold_error(_("unwinding may not work because EXIDX input section"
5894 " %u of %s is not in EXIDX output section"),
5895 exidx_shndx, exidx_relobj->name().c_str());
5897 exidx_fixup.add_exidx_cantunwind_as_needed();
5898 continue;
5901 // We need to access the contents of the EXIDX section, lock the
5902 // object here.
5903 Task_lock_obj<Object> tl(task, exidx_relobj);
5904 section_size_type exidx_size;
5905 const unsigned char* exidx_contents =
5906 exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5908 // Fix up coverage and append input section to output data list.
5909 Arm_exidx_section_offset_map* section_offset_map = NULL;
5910 uint32_t deleted_bytes =
5911 exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5912 exidx_contents,
5913 exidx_size,
5914 &section_offset_map);
5916 if (deleted_bytes == exidx_input_section->size())
5918 // The whole EXIDX section got merged. Remove it from output.
5919 gold_assert(section_offset_map == NULL);
5920 exidx_relobj->set_output_section(exidx_shndx, NULL);
5922 // All local symbols defined in this input section will be dropped.
5923 // We need to adjust output local symbol count.
5924 arm_relobj->set_output_local_symbol_count_needs_update();
5926 else if (deleted_bytes > 0)
5928 // Some entries are merged. We need to convert this EXIDX input
5929 // section into a relaxed section.
5930 gold_assert(section_offset_map != NULL);
5932 Arm_exidx_merged_section* merged_section =
5933 new Arm_exidx_merged_section(*exidx_input_section,
5934 *section_offset_map, deleted_bytes);
5935 merged_section->build_contents(exidx_contents, exidx_size);
5937 const std::string secname = exidx_relobj->section_name(exidx_shndx);
5938 this->add_relaxed_input_section(layout, merged_section, secname);
5939 arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5941 // All local symbols defined in discarded portions of this input
5942 // section will be dropped. We need to adjust output local symbol
5943 // count.
5944 arm_relobj->set_output_local_symbol_count_needs_update();
5946 else
5948 // Just add back the EXIDX input section.
5949 gold_assert(section_offset_map == NULL);
5950 const Output_section::Input_section* pis = iter->second;
5951 gold_assert(pis->is_input_section());
5952 this->add_script_input_section(*pis);
5955 processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5958 // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5959 exidx_fixup.add_exidx_cantunwind_as_needed();
5961 // Remove any known EXIDX input sections that are not processed.
5962 for (Input_section_list::const_iterator p = input_sections.begin();
5963 p != input_sections.end();
5964 ++p)
5966 if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5967 == processed_input_sections.end())
5969 // We discard a known EXIDX section because its linked
5970 // text section has been folded by ICF. We also discard an
5971 // EXIDX section with error, the output does not matter in this
5972 // case. We do this to avoid triggering asserts.
5973 Arm_relobj<big_endian>* arm_relobj =
5974 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5975 const Arm_exidx_input_section* exidx_input_section =
5976 arm_relobj->exidx_input_section_by_shndx(p->shndx());
5977 gold_assert(exidx_input_section != NULL);
5978 if (!exidx_input_section->has_errors())
5980 unsigned int text_shndx = exidx_input_section->link();
5981 gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5984 // Remove this from link. We also need to recount the
5985 // local symbols.
5986 p->relobj()->set_output_section(p->shndx(), NULL);
5987 arm_relobj->set_output_local_symbol_count_needs_update();
5991 // Link exidx output section to the first seen output section and
5992 // set correct entry size.
5993 this->set_link_section(exidx_fixup.first_output_text_section());
5994 this->set_entsize(8);
5996 // Make changes permanent.
5997 this->save_states();
5998 this->set_section_offsets_need_adjustment();
6001 // Link EXIDX output sections to text output sections.
6003 template<bool big_endian>
6004 void
6005 Arm_output_section<big_endian>::set_exidx_section_link()
6007 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
6008 if (!this->input_sections().empty())
6010 Input_section_list::const_iterator p = this->input_sections().begin();
6011 Arm_relobj<big_endian>* arm_relobj =
6012 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6013 unsigned exidx_shndx = p->shndx();
6014 const Arm_exidx_input_section* exidx_input_section =
6015 arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6016 gold_assert(exidx_input_section != NULL);
6017 unsigned int text_shndx = exidx_input_section->link();
6018 Output_section* os = arm_relobj->output_section(text_shndx);
6019 this->set_link_section(os);
6023 // Arm_relobj methods.
6025 // Determine if an input section is scannable for stub processing. SHDR is
6026 // the header of the section and SHNDX is the section index. OS is the output
6027 // section for the input section and SYMTAB is the global symbol table used to
6028 // look up ICF information.
6030 template<bool big_endian>
6031 bool
6032 Arm_relobj<big_endian>::section_is_scannable(
6033 const elfcpp::Shdr<32, big_endian>& shdr,
6034 unsigned int shndx,
6035 const Output_section* os,
6036 const Symbol_table* symtab)
6038 // Skip any empty sections, unallocated sections or sections whose
6039 // type are not SHT_PROGBITS.
6040 if (shdr.get_sh_size() == 0
6041 || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6042 || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6043 return false;
6045 // Skip any discarded or ICF'ed sections.
6046 if (os == NULL || symtab->is_section_folded(this, shndx))
6047 return false;
6049 // If this requires special offset handling, check to see if it is
6050 // a relaxed section. If this is not, then it is a merged section that
6051 // we cannot handle.
6052 if (this->is_output_section_offset_invalid(shndx))
6054 const Output_relaxed_input_section* poris =
6055 os->find_relaxed_input_section(this, shndx);
6056 if (poris == NULL)
6057 return false;
6060 return true;
6063 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6064 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6066 template<bool big_endian>
6067 bool
6068 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6069 const elfcpp::Shdr<32, big_endian>& shdr,
6070 const Relobj::Output_sections& out_sections,
6071 const Symbol_table* symtab,
6072 const unsigned char* pshdrs)
6074 unsigned int sh_type = shdr.get_sh_type();
6075 if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6076 return false;
6078 // Ignore empty section.
6079 off_t sh_size = shdr.get_sh_size();
6080 if (sh_size == 0)
6081 return false;
6083 // Ignore reloc section with unexpected symbol table. The
6084 // error will be reported in the final link.
6085 if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6086 return false;
6088 unsigned int reloc_size;
6089 if (sh_type == elfcpp::SHT_REL)
6090 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6091 else
6092 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6094 // Ignore reloc section with unexpected entsize or uneven size.
6095 // The error will be reported in the final link.
6096 if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6097 return false;
6099 // Ignore reloc section with bad info. This error will be
6100 // reported in the final link.
6101 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6102 if (index >= this->shnum())
6103 return false;
6105 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6106 const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6107 return this->section_is_scannable(text_shdr, index,
6108 out_sections[index], symtab);
6111 // Return the output address of either a plain input section or a relaxed
6112 // input section. SHNDX is the section index. We define and use this
6113 // instead of calling Output_section::output_address because that is slow
6114 // for large output.
6116 template<bool big_endian>
6117 Arm_address
6118 Arm_relobj<big_endian>::simple_input_section_output_address(
6119 unsigned int shndx,
6120 Output_section* os)
6122 if (this->is_output_section_offset_invalid(shndx))
6124 const Output_relaxed_input_section* poris =
6125 os->find_relaxed_input_section(this, shndx);
6126 // We do not handle merged sections here.
6127 gold_assert(poris != NULL);
6128 return poris->address();
6130 else
6131 return os->address() + this->get_output_section_offset(shndx);
6134 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6135 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6137 template<bool big_endian>
6138 bool
6139 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6140 const elfcpp::Shdr<32, big_endian>& shdr,
6141 unsigned int shndx,
6142 Output_section* os,
6143 const Symbol_table* symtab)
6145 if (!this->section_is_scannable(shdr, shndx, os, symtab))
6146 return false;
6148 // If the section does not cross any 4K-boundaries, it does not need to
6149 // be scanned.
6150 Arm_address address = this->simple_input_section_output_address(shndx, os);
6151 if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6152 return false;
6154 return true;
6157 // Scan a section for Cortex-A8 workaround.
6159 template<bool big_endian>
6160 void
6161 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6162 const elfcpp::Shdr<32, big_endian>& shdr,
6163 unsigned int shndx,
6164 Output_section* os,
6165 Target_arm<big_endian>* arm_target)
6167 // Look for the first mapping symbol in this section. It should be
6168 // at (shndx, 0).
6169 Mapping_symbol_position section_start(shndx, 0);
6170 typename Mapping_symbols_info::const_iterator p =
6171 this->mapping_symbols_info_.lower_bound(section_start);
6173 // There are no mapping symbols for this section. Treat it as a data-only
6174 // section. Issue a warning if section is marked as containing
6175 // instructions.
6176 if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6178 if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6179 gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6180 "erratum because it has no mapping symbols."),
6181 shndx, this->name().c_str());
6182 return;
6185 Arm_address output_address =
6186 this->simple_input_section_output_address(shndx, os);
6188 // Get the section contents.
6189 section_size_type input_view_size = 0;
6190 const unsigned char* input_view =
6191 this->section_contents(shndx, &input_view_size, false);
6193 // We need to go through the mapping symbols to determine what to
6194 // scan. There are two reasons. First, we should look at THUMB code and
6195 // THUMB code only. Second, we only want to look at the 4K-page boundary
6196 // to speed up the scanning.
6198 while (p != this->mapping_symbols_info_.end()
6199 && p->first.first == shndx)
6201 typename Mapping_symbols_info::const_iterator next =
6202 this->mapping_symbols_info_.upper_bound(p->first);
6204 // Only scan part of a section with THUMB code.
6205 if (p->second == 't')
6207 // Determine the end of this range.
6208 section_size_type span_start =
6209 convert_to_section_size_type(p->first.second);
6210 section_size_type span_end;
6211 if (next != this->mapping_symbols_info_.end()
6212 && next->first.first == shndx)
6213 span_end = convert_to_section_size_type(next->first.second);
6214 else
6215 span_end = convert_to_section_size_type(shdr.get_sh_size());
6217 if (((span_start + output_address) & ~0xfffUL)
6218 != ((span_end + output_address - 1) & ~0xfffUL))
6220 arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6221 span_start, span_end,
6222 input_view,
6223 output_address);
6227 p = next;
6231 // Scan relocations for stub generation.
6233 template<bool big_endian>
6234 void
6235 Arm_relobj<big_endian>::scan_sections_for_stubs(
6236 Target_arm<big_endian>* arm_target,
6237 const Symbol_table* symtab,
6238 const Layout* layout)
6240 unsigned int shnum = this->shnum();
6241 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6243 // Read the section headers.
6244 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6245 shnum * shdr_size,
6246 true, true);
6248 // To speed up processing, we set up hash tables for fast lookup of
6249 // input offsets to output addresses.
6250 this->initialize_input_to_output_maps();
6252 const Relobj::Output_sections& out_sections(this->output_sections());
6254 Relocate_info<32, big_endian> relinfo;
6255 relinfo.symtab = symtab;
6256 relinfo.layout = layout;
6257 relinfo.object = this;
6259 // Do relocation stubs scanning.
6260 const unsigned char* p = pshdrs + shdr_size;
6261 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6263 const elfcpp::Shdr<32, big_endian> shdr(p);
6264 if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6265 pshdrs))
6267 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6268 Arm_address output_offset = this->get_output_section_offset(index);
6269 Arm_address output_address;
6270 if (output_offset != invalid_address)
6271 output_address = out_sections[index]->address() + output_offset;
6272 else
6274 // Currently this only happens for a relaxed section.
6275 const Output_relaxed_input_section* poris =
6276 out_sections[index]->find_relaxed_input_section(this, index);
6277 gold_assert(poris != NULL);
6278 output_address = poris->address();
6281 // Get the relocations.
6282 const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6283 shdr.get_sh_size(),
6284 true, false);
6286 // Get the section contents. This does work for the case in which
6287 // we modify the contents of an input section. We need to pass the
6288 // output view under such circumstances.
6289 section_size_type input_view_size = 0;
6290 const unsigned char* input_view =
6291 this->section_contents(index, &input_view_size, false);
6293 relinfo.reloc_shndx = i;
6294 relinfo.data_shndx = index;
6295 unsigned int sh_type = shdr.get_sh_type();
6296 unsigned int reloc_size;
6297 if (sh_type == elfcpp::SHT_REL)
6298 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6299 else
6300 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6302 Output_section* os = out_sections[index];
6303 arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6304 shdr.get_sh_size() / reloc_size,
6306 output_offset == invalid_address,
6307 input_view, output_address,
6308 input_view_size);
6312 // Do Cortex-A8 erratum stubs scanning. This has to be done for a section
6313 // after its relocation section, if there is one, is processed for
6314 // relocation stubs. Merging this loop with the one above would have been
6315 // complicated since we would have had to make sure that relocation stub
6316 // scanning is done first.
6317 if (arm_target->fix_cortex_a8())
6319 const unsigned char* p = pshdrs + shdr_size;
6320 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6322 const elfcpp::Shdr<32, big_endian> shdr(p);
6323 if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6324 out_sections[i],
6325 symtab))
6326 this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6327 arm_target);
6331 // After we've done the relocations, we release the hash tables,
6332 // since we no longer need them.
6333 this->free_input_to_output_maps();
6336 // Count the local symbols. The ARM backend needs to know if a symbol
6337 // is a THUMB function or not. For global symbols, it is easy because
6338 // the Symbol object keeps the ELF symbol type. For local symbol it is
6339 // harder because we cannot access this information. So we override the
6340 // do_count_local_symbol in parent and scan local symbols to mark
6341 // THUMB functions. This is not the most efficient way but I do not want to
6342 // slow down other ports by calling a per symbol target hook inside
6343 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6345 template<bool big_endian>
6346 void
6347 Arm_relobj<big_endian>::do_count_local_symbols(
6348 Stringpool_template<char>* pool,
6349 Stringpool_template<char>* dynpool)
6351 // We need to fix-up the values of any local symbols whose type are
6352 // STT_ARM_TFUNC.
6354 // Ask parent to count the local symbols.
6355 Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6356 const unsigned int loccount = this->local_symbol_count();
6357 if (loccount == 0)
6358 return;
6360 // Initialize the thumb function bit-vector.
6361 std::vector<bool> empty_vector(loccount, false);
6362 this->local_symbol_is_thumb_function_.swap(empty_vector);
6364 // Read the symbol table section header.
6365 const unsigned int symtab_shndx = this->symtab_shndx();
6366 elfcpp::Shdr<32, big_endian>
6367 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6368 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6370 // Read the local symbols.
6371 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6372 gold_assert(loccount == symtabshdr.get_sh_info());
6373 off_t locsize = loccount * sym_size;
6374 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6375 locsize, true, true);
6377 // For mapping symbol processing, we need to read the symbol names.
6378 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6379 if (strtab_shndx >= this->shnum())
6381 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6382 return;
6385 elfcpp::Shdr<32, big_endian>
6386 strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6387 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6389 this->error(_("symbol table name section has wrong type: %u"),
6390 static_cast<unsigned int>(strtabshdr.get_sh_type()));
6391 return;
6393 const char* pnames =
6394 reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6395 strtabshdr.get_sh_size(),
6396 false, false));
6398 // Loop over the local symbols and mark any local symbols pointing
6399 // to THUMB functions.
6401 // Skip the first dummy symbol.
6402 psyms += sym_size;
6403 typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6404 this->local_values();
6405 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6407 elfcpp::Sym<32, big_endian> sym(psyms);
6408 elfcpp::STT st_type = sym.get_st_type();
6409 Symbol_value<32>& lv((*plocal_values)[i]);
6410 Arm_address input_value = lv.input_value();
6412 // Check to see if this is a mapping symbol.
6413 const char* sym_name = pnames + sym.get_st_name();
6414 if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6416 bool is_ordinary;
6417 unsigned int input_shndx =
6418 this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6419 gold_assert(is_ordinary);
6421 // Strip of LSB in case this is a THUMB symbol.
6422 Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6423 this->mapping_symbols_info_[msp] = sym_name[1];
6426 if (st_type == elfcpp::STT_ARM_TFUNC
6427 || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6429 // This is a THUMB function. Mark this and canonicalize the
6430 // symbol value by setting LSB.
6431 this->local_symbol_is_thumb_function_[i] = true;
6432 if ((input_value & 1) == 0)
6433 lv.set_input_value(input_value | 1);
6438 // Relocate sections.
6439 template<bool big_endian>
6440 void
6441 Arm_relobj<big_endian>::do_relocate_sections(
6442 const Symbol_table* symtab,
6443 const Layout* layout,
6444 const unsigned char* pshdrs,
6445 Output_file* of,
6446 typename Sized_relobj_file<32, big_endian>::Views* pviews)
6448 // Call parent to relocate sections.
6449 Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6450 pshdrs, of, pviews);
6452 // We do not generate stubs if doing a relocatable link.
6453 if (parameters->options().relocatable())
6454 return;
6456 // Relocate stub tables.
6457 unsigned int shnum = this->shnum();
6459 Target_arm<big_endian>* arm_target =
6460 Target_arm<big_endian>::default_target();
6462 Relocate_info<32, big_endian> relinfo;
6463 relinfo.symtab = symtab;
6464 relinfo.layout = layout;
6465 relinfo.object = this;
6467 for (unsigned int i = 1; i < shnum; ++i)
6469 Arm_input_section<big_endian>* arm_input_section =
6470 arm_target->find_arm_input_section(this, i);
6472 if (arm_input_section != NULL
6473 && arm_input_section->is_stub_table_owner()
6474 && !arm_input_section->stub_table()->empty())
6476 // We cannot discard a section if it owns a stub table.
6477 Output_section* os = this->output_section(i);
6478 gold_assert(os != NULL);
6480 relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6481 relinfo.reloc_shdr = NULL;
6482 relinfo.data_shndx = i;
6483 relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6485 gold_assert((*pviews)[i].view != NULL);
6487 // We are passed the output section view. Adjust it to cover the
6488 // stub table only.
6489 Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6490 gold_assert((stub_table->address() >= (*pviews)[i].address)
6491 && ((stub_table->address() + stub_table->data_size())
6492 <= (*pviews)[i].address + (*pviews)[i].view_size));
6494 off_t offset = stub_table->address() - (*pviews)[i].address;
6495 unsigned char* view = (*pviews)[i].view + offset;
6496 Arm_address address = stub_table->address();
6497 section_size_type view_size = stub_table->data_size();
6499 stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6500 view_size);
6503 // Apply Cortex A8 workaround if applicable.
6504 if (this->section_has_cortex_a8_workaround(i))
6506 unsigned char* view = (*pviews)[i].view;
6507 Arm_address view_address = (*pviews)[i].address;
6508 section_size_type view_size = (*pviews)[i].view_size;
6509 Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6511 // Adjust view to cover section.
6512 Output_section* os = this->output_section(i);
6513 gold_assert(os != NULL);
6514 Arm_address section_address =
6515 this->simple_input_section_output_address(i, os);
6516 uint64_t section_size = this->section_size(i);
6518 gold_assert(section_address >= view_address
6519 && ((section_address + section_size)
6520 <= (view_address + view_size)));
6522 unsigned char* section_view = view + (section_address - view_address);
6524 // Apply the Cortex-A8 workaround to the output address range
6525 // corresponding to this input section.
6526 stub_table->apply_cortex_a8_workaround_to_address_range(
6527 arm_target,
6528 section_view,
6529 section_address,
6530 section_size);
6535 // Find the linked text section of an EXIDX section by looking at the first
6536 // relocation. 4.4.1 of the EHABI specifications says that an EXIDX section
6537 // must be linked to its associated code section via the sh_link field of
6538 // its section header. However, some tools are broken and the link is not
6539 // always set. LD just drops such an EXIDX section silently, causing the
6540 // associated code not unwindabled. Here we try a little bit harder to
6541 // discover the linked code section.
6543 // PSHDR points to the section header of a relocation section of an EXIDX
6544 // section. If we can find a linked text section, return true and
6545 // store the text section index in the location PSHNDX. Otherwise
6546 // return false.
6548 template<bool big_endian>
6549 bool
6550 Arm_relobj<big_endian>::find_linked_text_section(
6551 const unsigned char* pshdr,
6552 const unsigned char* psyms,
6553 unsigned int* pshndx)
6555 elfcpp::Shdr<32, big_endian> shdr(pshdr);
6557 // If there is no relocation, we cannot find the linked text section.
6558 size_t reloc_size;
6559 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6560 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6561 else
6562 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6563 size_t reloc_count = shdr.get_sh_size() / reloc_size;
6565 // Get the relocations.
6566 const unsigned char* prelocs =
6567 this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6569 // Find the REL31 relocation for the first word of the first EXIDX entry.
6570 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6572 Arm_address r_offset;
6573 typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6574 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6576 typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6577 r_info = reloc.get_r_info();
6578 r_offset = reloc.get_r_offset();
6580 else
6582 typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6583 r_info = reloc.get_r_info();
6584 r_offset = reloc.get_r_offset();
6587 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6588 if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6589 continue;
6591 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6592 if (r_sym == 0
6593 || r_sym >= this->local_symbol_count()
6594 || r_offset != 0)
6595 continue;
6597 // This is the relocation for the first word of the first EXIDX entry.
6598 // We expect to see a local section symbol.
6599 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6600 elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6601 if (sym.get_st_type() == elfcpp::STT_SECTION)
6603 bool is_ordinary;
6604 *pshndx =
6605 this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6606 gold_assert(is_ordinary);
6607 return true;
6609 else
6610 return false;
6613 return false;
6616 // Make an EXIDX input section object for an EXIDX section whose index is
6617 // SHNDX. SHDR is the section header of the EXIDX section and TEXT_SHNDX
6618 // is the section index of the linked text section.
6620 template<bool big_endian>
6621 void
6622 Arm_relobj<big_endian>::make_exidx_input_section(
6623 unsigned int shndx,
6624 const elfcpp::Shdr<32, big_endian>& shdr,
6625 unsigned int text_shndx,
6626 const elfcpp::Shdr<32, big_endian>& text_shdr)
6628 // Create an Arm_exidx_input_section object for this EXIDX section.
6629 Arm_exidx_input_section* exidx_input_section =
6630 new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6631 shdr.get_sh_addralign(),
6632 text_shdr.get_sh_size());
6634 gold_assert(this->exidx_section_map_[shndx] == NULL);
6635 this->exidx_section_map_[shndx] = exidx_input_section;
6637 if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6639 gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6640 this->section_name(shndx).c_str(), shndx, text_shndx,
6641 this->name().c_str());
6642 exidx_input_section->set_has_errors();
6644 else if (this->exidx_section_map_[text_shndx] != NULL)
6646 unsigned other_exidx_shndx =
6647 this->exidx_section_map_[text_shndx]->shndx();
6648 gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6649 "%s(%u) in %s"),
6650 this->section_name(shndx).c_str(), shndx,
6651 this->section_name(other_exidx_shndx).c_str(),
6652 other_exidx_shndx, this->section_name(text_shndx).c_str(),
6653 text_shndx, this->name().c_str());
6654 exidx_input_section->set_has_errors();
6656 else
6657 this->exidx_section_map_[text_shndx] = exidx_input_section;
6659 // Check section flags of text section.
6660 if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6662 gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6663 " in %s"),
6664 this->section_name(shndx).c_str(), shndx,
6665 this->section_name(text_shndx).c_str(), text_shndx,
6666 this->name().c_str());
6667 exidx_input_section->set_has_errors();
6669 else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6670 // I would like to make this an error but currently ld just ignores
6671 // this.
6672 gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6673 "%s(%u) in %s"),
6674 this->section_name(shndx).c_str(), shndx,
6675 this->section_name(text_shndx).c_str(), text_shndx,
6676 this->name().c_str());
6679 // Read the symbol information.
6681 template<bool big_endian>
6682 void
6683 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6685 // Call parent class to read symbol information.
6686 this->base_read_symbols(sd);
6688 // If this input file is a binary file, it has no processor
6689 // specific flags and attributes section.
6690 Input_file::Format format = this->input_file()->format();
6691 if (format != Input_file::FORMAT_ELF)
6693 gold_assert(format == Input_file::FORMAT_BINARY);
6694 this->merge_flags_and_attributes_ = false;
6695 return;
6698 // Read processor-specific flags in ELF file header.
6699 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6700 elfcpp::Elf_sizes<32>::ehdr_size,
6701 true, false);
6702 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6703 this->processor_specific_flags_ = ehdr.get_e_flags();
6705 // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6706 // sections.
6707 std::vector<unsigned int> deferred_exidx_sections;
6708 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6709 const unsigned char* pshdrs = sd->section_headers->data();
6710 const unsigned char* ps = pshdrs + shdr_size;
6711 bool must_merge_flags_and_attributes = false;
6712 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6714 elfcpp::Shdr<32, big_endian> shdr(ps);
6716 // Sometimes an object has no contents except the section name string
6717 // table and an empty symbol table with the undefined symbol. We
6718 // don't want to merge processor-specific flags from such an object.
6719 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6721 // Symbol table is not empty.
6722 const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6723 elfcpp::Elf_sizes<32>::sym_size;
6724 if (shdr.get_sh_size() > sym_size)
6725 must_merge_flags_and_attributes = true;
6727 else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6728 // If this is neither an empty symbol table nor a string table,
6729 // be conservative.
6730 must_merge_flags_and_attributes = true;
6732 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6734 gold_assert(this->attributes_section_data_ == NULL);
6735 section_offset_type section_offset = shdr.get_sh_offset();
6736 section_size_type section_size =
6737 convert_to_section_size_type(shdr.get_sh_size());
6738 const unsigned char* view =
6739 this->get_view(section_offset, section_size, true, false);
6740 this->attributes_section_data_ =
6741 new Attributes_section_data(view, section_size);
6743 else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6745 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6746 if (text_shndx == elfcpp::SHN_UNDEF)
6747 deferred_exidx_sections.push_back(i);
6748 else
6750 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6751 + text_shndx * shdr_size);
6752 this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6754 // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6755 if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6756 gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6757 this->section_name(i).c_str(), this->name().c_str());
6761 // This is rare.
6762 if (!must_merge_flags_and_attributes)
6764 gold_assert(deferred_exidx_sections.empty());
6765 this->merge_flags_and_attributes_ = false;
6766 return;
6769 // Some tools are broken and they do not set the link of EXIDX sections.
6770 // We look at the first relocation to figure out the linked sections.
6771 if (!deferred_exidx_sections.empty())
6773 // We need to go over the section headers again to find the mapping
6774 // from sections being relocated to their relocation sections. This is
6775 // a bit inefficient as we could do that in the loop above. However,
6776 // we do not expect any deferred EXIDX sections normally. So we do not
6777 // want to slow down the most common path.
6778 typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6779 Reloc_map reloc_map;
6780 ps = pshdrs + shdr_size;
6781 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6783 elfcpp::Shdr<32, big_endian> shdr(ps);
6784 elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6785 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6787 unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6788 if (info_shndx >= this->shnum())
6789 gold_error(_("relocation section %u has invalid info %u"),
6790 i, info_shndx);
6791 Reloc_map::value_type value(info_shndx, i);
6792 std::pair<Reloc_map::iterator, bool> result =
6793 reloc_map.insert(value);
6794 if (!result.second)
6795 gold_error(_("section %u has multiple relocation sections "
6796 "%u and %u"),
6797 info_shndx, i, reloc_map[info_shndx]);
6801 // Read the symbol table section header.
6802 const unsigned int symtab_shndx = this->symtab_shndx();
6803 elfcpp::Shdr<32, big_endian>
6804 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6805 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6807 // Read the local symbols.
6808 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6809 const unsigned int loccount = this->local_symbol_count();
6810 gold_assert(loccount == symtabshdr.get_sh_info());
6811 off_t locsize = loccount * sym_size;
6812 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6813 locsize, true, true);
6815 // Process the deferred EXIDX sections.
6816 for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6818 unsigned int shndx = deferred_exidx_sections[i];
6819 elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6820 unsigned int text_shndx = elfcpp::SHN_UNDEF;
6821 Reloc_map::const_iterator it = reloc_map.find(shndx);
6822 if (it != reloc_map.end())
6823 find_linked_text_section(pshdrs + it->second * shdr_size,
6824 psyms, &text_shndx);
6825 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6826 + text_shndx * shdr_size);
6827 this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6832 // Process relocations for garbage collection. The ARM target uses .ARM.exidx
6833 // sections for unwinding. These sections are referenced implicitly by
6834 // text sections linked in the section headers. If we ignore these implicit
6835 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6836 // will be garbage-collected incorrectly. Hence we override the same function
6837 // in the base class to handle these implicit references.
6839 template<bool big_endian>
6840 void
6841 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6842 Layout* layout,
6843 Read_relocs_data* rd)
6845 // First, call base class method to process relocations in this object.
6846 Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6848 // If --gc-sections is not specified, there is nothing more to do.
6849 // This happens when --icf is used but --gc-sections is not.
6850 if (!parameters->options().gc_sections())
6851 return;
6853 unsigned int shnum = this->shnum();
6854 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6855 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6856 shnum * shdr_size,
6857 true, true);
6859 // Scan section headers for sections of type SHT_ARM_EXIDX. Add references
6860 // to these from the linked text sections.
6861 const unsigned char* ps = pshdrs + shdr_size;
6862 for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6864 elfcpp::Shdr<32, big_endian> shdr(ps);
6865 if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6867 // Found an .ARM.exidx section, add it to the set of reachable
6868 // sections from its linked text section.
6869 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6870 symtab->gc()->add_reference(this, text_shndx, this, i);
6875 // Update output local symbol count. Owing to EXIDX entry merging, some local
6876 // symbols will be removed in output. Adjust output local symbol count
6877 // accordingly. We can only changed the static output local symbol count. It
6878 // is too late to change the dynamic symbols.
6880 template<bool big_endian>
6881 void
6882 Arm_relobj<big_endian>::update_output_local_symbol_count()
6884 // Caller should check that this needs updating. We want caller checking
6885 // because output_local_symbol_count_needs_update() is most likely inlined.
6886 gold_assert(this->output_local_symbol_count_needs_update_);
6888 gold_assert(this->symtab_shndx() != -1U);
6889 if (this->symtab_shndx() == 0)
6891 // This object has no symbols. Weird but legal.
6892 return;
6895 // Read the symbol table section header.
6896 const unsigned int symtab_shndx = this->symtab_shndx();
6897 elfcpp::Shdr<32, big_endian>
6898 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6899 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6901 // Read the local symbols.
6902 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6903 const unsigned int loccount = this->local_symbol_count();
6904 gold_assert(loccount == symtabshdr.get_sh_info());
6905 off_t locsize = loccount * sym_size;
6906 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6907 locsize, true, true);
6909 // Loop over the local symbols.
6911 typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6912 Output_sections;
6913 const Output_sections& out_sections(this->output_sections());
6914 unsigned int shnum = this->shnum();
6915 unsigned int count = 0;
6916 // Skip the first, dummy, symbol.
6917 psyms += sym_size;
6918 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6920 elfcpp::Sym<32, big_endian> sym(psyms);
6922 Symbol_value<32>& lv((*this->local_values())[i]);
6924 // This local symbol was already discarded by do_count_local_symbols.
6925 if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6926 continue;
6928 bool is_ordinary;
6929 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6930 &is_ordinary);
6932 if (shndx < shnum)
6934 Output_section* os = out_sections[shndx];
6936 // This local symbol no longer has an output section. Discard it.
6937 if (os == NULL)
6939 lv.set_no_output_symtab_entry();
6940 continue;
6943 // Currently we only discard parts of EXIDX input sections.
6944 // We explicitly check for a merged EXIDX input section to avoid
6945 // calling Output_section_data::output_offset unless necessary.
6946 if ((this->get_output_section_offset(shndx) == invalid_address)
6947 && (this->exidx_input_section_by_shndx(shndx) != NULL))
6949 section_offset_type output_offset =
6950 os->output_offset(this, shndx, lv.input_value());
6951 if (output_offset == -1)
6953 // This symbol is defined in a part of an EXIDX input section
6954 // that is discarded due to entry merging.
6955 lv.set_no_output_symtab_entry();
6956 continue;
6961 ++count;
6964 this->set_output_local_symbol_count(count);
6965 this->output_local_symbol_count_needs_update_ = false;
6968 // Arm_dynobj methods.
6970 // Read the symbol information.
6972 template<bool big_endian>
6973 void
6974 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6976 // Call parent class to read symbol information.
6977 this->base_read_symbols(sd);
6979 // Read processor-specific flags in ELF file header.
6980 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6981 elfcpp::Elf_sizes<32>::ehdr_size,
6982 true, false);
6983 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6984 this->processor_specific_flags_ = ehdr.get_e_flags();
6986 // Read the attributes section if there is one.
6987 // We read from the end because gas seems to put it near the end of
6988 // the section headers.
6989 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6990 const unsigned char* ps =
6991 sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6992 for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6994 elfcpp::Shdr<32, big_endian> shdr(ps);
6995 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6997 section_offset_type section_offset = shdr.get_sh_offset();
6998 section_size_type section_size =
6999 convert_to_section_size_type(shdr.get_sh_size());
7000 const unsigned char* view =
7001 this->get_view(section_offset, section_size, true, false);
7002 this->attributes_section_data_ =
7003 new Attributes_section_data(view, section_size);
7004 break;
7009 // Stub_addend_reader methods.
7011 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7013 template<bool big_endian>
7014 elfcpp::Elf_types<32>::Elf_Swxword
7015 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7016 unsigned int r_type,
7017 const unsigned char* view,
7018 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7020 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
7022 switch (r_type)
7024 case elfcpp::R_ARM_CALL:
7025 case elfcpp::R_ARM_JUMP24:
7026 case elfcpp::R_ARM_PLT32:
7028 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7029 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7030 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7031 return Bits<26>::sign_extend32(val << 2);
7034 case elfcpp::R_ARM_THM_CALL:
7035 case elfcpp::R_ARM_THM_JUMP24:
7036 case elfcpp::R_ARM_THM_XPC22:
7038 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7039 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7040 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7041 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7042 return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7045 case elfcpp::R_ARM_THM_JUMP19:
7047 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7048 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7049 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7050 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7051 return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7054 default:
7055 gold_unreachable();
7059 // Arm_output_data_got methods.
7061 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
7062 // The first one is initialized to be 1, which is the module index for
7063 // the main executable and the second one 0. A reloc of the type
7064 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7065 // be applied by gold. GSYM is a global symbol.
7067 template<bool big_endian>
7068 void
7069 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7070 unsigned int got_type,
7071 Symbol* gsym)
7073 if (gsym->has_got_offset(got_type))
7074 return;
7076 // We are doing a static link. Just mark it as belong to module 1,
7077 // the executable.
7078 unsigned int got_offset = this->add_constant(1);
7079 gsym->set_got_offset(got_type, got_offset);
7080 got_offset = this->add_constant(0);
7081 this->static_relocs_.push_back(Static_reloc(got_offset,
7082 elfcpp::R_ARM_TLS_DTPOFF32,
7083 gsym));
7086 // Same as the above but for a local symbol.
7088 template<bool big_endian>
7089 void
7090 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7091 unsigned int got_type,
7092 Sized_relobj_file<32, big_endian>* object,
7093 unsigned int index)
7095 if (object->local_has_got_offset(index, got_type))
7096 return;
7098 // We are doing a static link. Just mark it as belong to module 1,
7099 // the executable.
7100 unsigned int got_offset = this->add_constant(1);
7101 object->set_local_got_offset(index, got_type, got_offset);
7102 got_offset = this->add_constant(0);
7103 this->static_relocs_.push_back(Static_reloc(got_offset,
7104 elfcpp::R_ARM_TLS_DTPOFF32,
7105 object, index));
7108 template<bool big_endian>
7109 void
7110 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7112 // Call parent to write out GOT.
7113 Output_data_got<32, big_endian>::do_write(of);
7115 // We are done if there is no fix up.
7116 if (this->static_relocs_.empty())
7117 return;
7119 gold_assert(parameters->doing_static_link());
7121 const off_t offset = this->offset();
7122 const section_size_type oview_size =
7123 convert_to_section_size_type(this->data_size());
7124 unsigned char* const oview = of->get_output_view(offset, oview_size);
7126 Output_segment* tls_segment = this->layout_->tls_segment();
7127 gold_assert(tls_segment != NULL);
7129 // The thread pointer $tp points to the TCB, which is followed by the
7130 // TLS. So we need to adjust $tp relative addressing by this amount.
7131 Arm_address aligned_tcb_size =
7132 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7134 for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7136 Static_reloc& reloc(this->static_relocs_[i]);
7138 Arm_address value;
7139 if (!reloc.symbol_is_global())
7141 Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7142 const Symbol_value<32>* psymval =
7143 reloc.relobj()->local_symbol(reloc.index());
7145 // We are doing static linking. Issue an error and skip this
7146 // relocation if the symbol is undefined or in a discarded_section.
7147 bool is_ordinary;
7148 unsigned int shndx = psymval->input_shndx(&is_ordinary);
7149 if ((shndx == elfcpp::SHN_UNDEF)
7150 || (is_ordinary
7151 && shndx != elfcpp::SHN_UNDEF
7152 && !object->is_section_included(shndx)
7153 && !this->symbol_table_->is_section_folded(object, shndx)))
7155 gold_error(_("undefined or discarded local symbol %u from "
7156 " object %s in GOT"),
7157 reloc.index(), reloc.relobj()->name().c_str());
7158 continue;
7161 value = psymval->value(object, 0);
7163 else
7165 const Symbol* gsym = reloc.symbol();
7166 gold_assert(gsym != NULL);
7167 if (gsym->is_forwarder())
7168 gsym = this->symbol_table_->resolve_forwards(gsym);
7170 // We are doing static linking. Issue an error and skip this
7171 // relocation if the symbol is undefined or in a discarded_section
7172 // unless it is a weakly_undefined symbol.
7173 if ((gsym->is_defined_in_discarded_section()
7174 || gsym->is_undefined())
7175 && !gsym->is_weak_undefined())
7177 gold_error(_("undefined or discarded symbol %s in GOT"),
7178 gsym->name());
7179 continue;
7182 if (!gsym->is_weak_undefined())
7184 const Sized_symbol<32>* sym =
7185 static_cast<const Sized_symbol<32>*>(gsym);
7186 value = sym->value();
7188 else
7189 value = 0;
7192 unsigned got_offset = reloc.got_offset();
7193 gold_assert(got_offset < oview_size);
7195 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7196 Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7197 Valtype x;
7198 switch (reloc.r_type())
7200 case elfcpp::R_ARM_TLS_DTPOFF32:
7201 x = value;
7202 break;
7203 case elfcpp::R_ARM_TLS_TPOFF32:
7204 x = value + aligned_tcb_size;
7205 break;
7206 default:
7207 gold_unreachable();
7209 elfcpp::Swap<32, big_endian>::writeval(wv, x);
7212 of->write_output_view(offset, oview_size, oview);
7215 // A class to handle the PLT data.
7216 // This is an abstract base class that handles most of the linker details
7217 // but does not know the actual contents of PLT entries. The derived
7218 // classes below fill in those details.
7220 template<bool big_endian>
7221 class Output_data_plt_arm : public Output_section_data
7223 public:
7224 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7225 Reloc_section;
7227 Output_data_plt_arm(Layout*, uint64_t addralign, Output_data_space*);
7229 // Add an entry to the PLT.
7230 void
7231 add_entry(Symbol* gsym);
7233 // Return the .rel.plt section data.
7234 const Reloc_section*
7235 rel_plt() const
7236 { return this->rel_; }
7238 // Return the number of PLT entries.
7239 unsigned int
7240 entry_count() const
7241 { return this->count_; }
7243 // Return the offset of the first non-reserved PLT entry.
7244 unsigned int
7245 first_plt_entry_offset() const
7246 { return this->do_first_plt_entry_offset(); }
7248 // Return the size of a PLT entry.
7249 unsigned int
7250 get_plt_entry_size() const
7251 { return this->do_get_plt_entry_size(); }
7253 protected:
7254 // Fill in the first PLT entry.
7255 void
7256 fill_first_plt_entry(unsigned char* pov,
7257 Arm_address got_address,
7258 Arm_address plt_address)
7259 { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
7261 void
7262 fill_plt_entry(unsigned char* pov,
7263 Arm_address got_address,
7264 Arm_address plt_address,
7265 unsigned int got_offset,
7266 unsigned int plt_offset)
7267 { do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); }
7269 virtual unsigned int
7270 do_first_plt_entry_offset() const = 0;
7272 virtual unsigned int
7273 do_get_plt_entry_size() const = 0;
7275 virtual void
7276 do_fill_first_plt_entry(unsigned char* pov,
7277 Arm_address got_address,
7278 Arm_address plt_address) = 0;
7280 virtual void
7281 do_fill_plt_entry(unsigned char* pov,
7282 Arm_address got_address,
7283 Arm_address plt_address,
7284 unsigned int got_offset,
7285 unsigned int plt_offset) = 0;
7287 void
7288 do_adjust_output_section(Output_section* os);
7290 // Write to a map file.
7291 void
7292 do_print_to_mapfile(Mapfile* mapfile) const
7293 { mapfile->print_output_data(this, _("** PLT")); }
7295 private:
7296 // Set the final size.
7297 void
7298 set_final_data_size()
7300 this->set_data_size(this->first_plt_entry_offset()
7301 + this->count_ * this->get_plt_entry_size());
7304 // Write out the PLT data.
7305 void
7306 do_write(Output_file*);
7308 // The reloc section.
7309 Reloc_section* rel_;
7310 // The .got.plt section.
7311 Output_data_space* got_plt_;
7312 // The number of PLT entries.
7313 unsigned int count_;
7316 // Create the PLT section. The ordinary .got section is an argument,
7317 // since we need to refer to the start. We also create our own .got
7318 // section just for PLT entries.
7320 template<bool big_endian>
7321 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7322 uint64_t addralign,
7323 Output_data_space* got_plt)
7324 : Output_section_data(addralign), got_plt_(got_plt), count_(0)
7326 this->rel_ = new Reloc_section(false);
7327 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7328 elfcpp::SHF_ALLOC, this->rel_,
7329 ORDER_DYNAMIC_PLT_RELOCS, false);
7332 template<bool big_endian>
7333 void
7334 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7336 os->set_entsize(0);
7339 // Add an entry to the PLT.
7341 template<bool big_endian>
7342 void
7343 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7345 gold_assert(!gsym->has_plt_offset());
7347 // Note that when setting the PLT offset we skip the initial
7348 // reserved PLT entry.
7349 gsym->set_plt_offset((this->count_) * this->get_plt_entry_size()
7350 + this->first_plt_entry_offset());
7352 ++this->count_;
7354 section_offset_type got_offset = this->got_plt_->current_data_size();
7356 // Every PLT entry needs a GOT entry which points back to the PLT
7357 // entry (this will be changed by the dynamic linker, normally
7358 // lazily when the function is called).
7359 this->got_plt_->set_current_data_size(got_offset + 4);
7361 // Every PLT entry needs a reloc.
7362 gsym->set_needs_dynsym_entry();
7363 this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7364 got_offset);
7366 // Note that we don't need to save the symbol. The contents of the
7367 // PLT are independent of which symbols are used. The symbols only
7368 // appear in the relocations.
7371 template<bool big_endian>
7372 class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
7374 public:
7375 Output_data_plt_arm_standard(Layout* layout, Output_data_space* got_plt)
7376 : Output_data_plt_arm<big_endian>(layout, 4, got_plt)
7379 protected:
7380 // Return the offset of the first non-reserved PLT entry.
7381 virtual unsigned int
7382 do_first_plt_entry_offset() const
7383 { return sizeof(first_plt_entry); }
7385 // Return the size of a PLT entry.
7386 virtual unsigned int
7387 do_get_plt_entry_size() const
7388 { return sizeof(plt_entry); }
7390 virtual void
7391 do_fill_first_plt_entry(unsigned char* pov,
7392 Arm_address got_address,
7393 Arm_address plt_address);
7395 virtual void
7396 do_fill_plt_entry(unsigned char* pov,
7397 Arm_address got_address,
7398 Arm_address plt_address,
7399 unsigned int got_offset,
7400 unsigned int plt_offset);
7402 private:
7403 // Template for the first PLT entry.
7404 static const uint32_t first_plt_entry[5];
7406 // Template for subsequent PLT entries.
7407 static const uint32_t plt_entry[3];
7410 // ARM PLTs.
7411 // FIXME: This is not very flexible. Right now this has only been tested
7412 // on armv5te. If we are to support additional architecture features like
7413 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7415 // The first entry in the PLT.
7416 template<bool big_endian>
7417 const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] =
7419 0xe52de004, // str lr, [sp, #-4]!
7420 0xe59fe004, // ldr lr, [pc, #4]
7421 0xe08fe00e, // add lr, pc, lr
7422 0xe5bef008, // ldr pc, [lr, #8]!
7423 0x00000000, // &GOT[0] - .
7426 template<bool big_endian>
7427 void
7428 Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry(
7429 unsigned char* pov,
7430 Arm_address got_address,
7431 Arm_address plt_address)
7433 // Write first PLT entry. All but the last word are constants.
7434 const size_t num_first_plt_words = (sizeof(first_plt_entry)
7435 / sizeof(plt_entry[0]));
7436 for (size_t i = 0; i < num_first_plt_words - 1; i++)
7437 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7438 // Last word in first PLT entry is &GOT[0] - .
7439 elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7440 got_address - (plt_address + 16));
7443 // Subsequent entries in the PLT.
7445 template<bool big_endian>
7446 const uint32_t Output_data_plt_arm_standard<big_endian>::plt_entry[3] =
7448 0xe28fc600, // add ip, pc, #0xNN00000
7449 0xe28cca00, // add ip, ip, #0xNN000
7450 0xe5bcf000, // ldr pc, [ip, #0xNNN]!
7453 template<bool big_endian>
7454 void
7455 Output_data_plt_arm_standard<big_endian>::do_fill_plt_entry(
7456 unsigned char* pov,
7457 Arm_address got_address,
7458 Arm_address plt_address,
7459 unsigned int got_offset,
7460 unsigned int plt_offset)
7462 int32_t offset = ((got_address + got_offset)
7463 - (plt_address + plt_offset + 8));
7465 gold_assert(offset >= 0 && offset < 0x0fffffff);
7466 uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7467 elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7468 uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7469 elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7470 uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7471 elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7474 // Write out the PLT. This uses the hand-coded instructions above,
7475 // and adjusts them as needed. This is all specified by the arm ELF
7476 // Processor Supplement.
7478 template<bool big_endian>
7479 void
7480 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7482 const off_t offset = this->offset();
7483 const section_size_type oview_size =
7484 convert_to_section_size_type(this->data_size());
7485 unsigned char* const oview = of->get_output_view(offset, oview_size);
7487 const off_t got_file_offset = this->got_plt_->offset();
7488 const section_size_type got_size =
7489 convert_to_section_size_type(this->got_plt_->data_size());
7490 unsigned char* const got_view = of->get_output_view(got_file_offset,
7491 got_size);
7492 unsigned char* pov = oview;
7494 Arm_address plt_address = this->address();
7495 Arm_address got_address = this->got_plt_->address();
7497 // Write first PLT entry.
7498 this->fill_first_plt_entry(pov, got_address, plt_address);
7499 pov += this->first_plt_entry_offset();
7501 unsigned char* got_pov = got_view;
7503 memset(got_pov, 0, 12);
7504 got_pov += 12;
7506 unsigned int plt_offset = this->first_plt_entry_offset();
7507 unsigned int got_offset = 12;
7508 const unsigned int count = this->count_;
7509 for (unsigned int i = 0;
7510 i < count;
7511 ++i,
7512 pov += this->get_plt_entry_size(),
7513 got_pov += 4,
7514 plt_offset += this->get_plt_entry_size(),
7515 got_offset += 4)
7517 // Set and adjust the PLT entry itself.
7518 this->fill_plt_entry(pov, got_address, plt_address,
7519 got_offset, plt_offset);
7521 // Set the entry in the GOT.
7522 elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7525 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7526 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7528 of->write_output_view(offset, oview_size, oview);
7529 of->write_output_view(got_file_offset, got_size, got_view);
7532 // Create a PLT entry for a global symbol.
7534 template<bool big_endian>
7535 void
7536 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7537 Symbol* gsym)
7539 if (gsym->has_plt_offset())
7540 return;
7542 if (this->plt_ == NULL)
7544 // Create the GOT sections first.
7545 this->got_section(symtab, layout);
7547 this->plt_ = this->make_data_plt(layout, this->got_plt_);
7549 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7550 (elfcpp::SHF_ALLOC
7551 | elfcpp::SHF_EXECINSTR),
7552 this->plt_, ORDER_PLT, false);
7554 this->plt_->add_entry(gsym);
7557 // Return the number of entries in the PLT.
7559 template<bool big_endian>
7560 unsigned int
7561 Target_arm<big_endian>::plt_entry_count() const
7563 if (this->plt_ == NULL)
7564 return 0;
7565 return this->plt_->entry_count();
7568 // Return the offset of the first non-reserved PLT entry.
7570 template<bool big_endian>
7571 unsigned int
7572 Target_arm<big_endian>::first_plt_entry_offset() const
7574 return this->plt_->first_plt_entry_offset();
7577 // Return the size of each PLT entry.
7579 template<bool big_endian>
7580 unsigned int
7581 Target_arm<big_endian>::plt_entry_size() const
7583 return this->plt_->get_plt_entry_size();
7586 // Get the section to use for TLS_DESC relocations.
7588 template<bool big_endian>
7589 typename Target_arm<big_endian>::Reloc_section*
7590 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7592 return this->plt_section()->rel_tls_desc(layout);
7595 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7597 template<bool big_endian>
7598 void
7599 Target_arm<big_endian>::define_tls_base_symbol(
7600 Symbol_table* symtab,
7601 Layout* layout)
7603 if (this->tls_base_symbol_defined_)
7604 return;
7606 Output_segment* tls_segment = layout->tls_segment();
7607 if (tls_segment != NULL)
7609 bool is_exec = parameters->options().output_is_executable();
7610 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7611 Symbol_table::PREDEFINED,
7612 tls_segment, 0, 0,
7613 elfcpp::STT_TLS,
7614 elfcpp::STB_LOCAL,
7615 elfcpp::STV_HIDDEN, 0,
7616 (is_exec
7617 ? Symbol::SEGMENT_END
7618 : Symbol::SEGMENT_START),
7619 true);
7621 this->tls_base_symbol_defined_ = true;
7624 // Create a GOT entry for the TLS module index.
7626 template<bool big_endian>
7627 unsigned int
7628 Target_arm<big_endian>::got_mod_index_entry(
7629 Symbol_table* symtab,
7630 Layout* layout,
7631 Sized_relobj_file<32, big_endian>* object)
7633 if (this->got_mod_index_offset_ == -1U)
7635 gold_assert(symtab != NULL && layout != NULL && object != NULL);
7636 Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7637 unsigned int got_offset;
7638 if (!parameters->doing_static_link())
7640 got_offset = got->add_constant(0);
7641 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7642 rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7643 got_offset);
7645 else
7647 // We are doing a static link. Just mark it as belong to module 1,
7648 // the executable.
7649 got_offset = got->add_constant(1);
7652 got->add_constant(0);
7653 this->got_mod_index_offset_ = got_offset;
7655 return this->got_mod_index_offset_;
7658 // Optimize the TLS relocation type based on what we know about the
7659 // symbol. IS_FINAL is true if the final address of this symbol is
7660 // known at link time.
7662 template<bool big_endian>
7663 tls::Tls_optimization
7664 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7666 // FIXME: Currently we do not do any TLS optimization.
7667 return tls::TLSOPT_NONE;
7670 // Get the Reference_flags for a particular relocation.
7672 template<bool big_endian>
7674 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
7676 switch (r_type)
7678 case elfcpp::R_ARM_NONE:
7679 case elfcpp::R_ARM_V4BX:
7680 case elfcpp::R_ARM_GNU_VTENTRY:
7681 case elfcpp::R_ARM_GNU_VTINHERIT:
7682 // No symbol reference.
7683 return 0;
7685 case elfcpp::R_ARM_ABS32:
7686 case elfcpp::R_ARM_ABS16:
7687 case elfcpp::R_ARM_ABS12:
7688 case elfcpp::R_ARM_THM_ABS5:
7689 case elfcpp::R_ARM_ABS8:
7690 case elfcpp::R_ARM_BASE_ABS:
7691 case elfcpp::R_ARM_MOVW_ABS_NC:
7692 case elfcpp::R_ARM_MOVT_ABS:
7693 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7694 case elfcpp::R_ARM_THM_MOVT_ABS:
7695 case elfcpp::R_ARM_ABS32_NOI:
7696 return Symbol::ABSOLUTE_REF;
7698 case elfcpp::R_ARM_REL32:
7699 case elfcpp::R_ARM_LDR_PC_G0:
7700 case elfcpp::R_ARM_SBREL32:
7701 case elfcpp::R_ARM_THM_PC8:
7702 case elfcpp::R_ARM_BASE_PREL:
7703 case elfcpp::R_ARM_MOVW_PREL_NC:
7704 case elfcpp::R_ARM_MOVT_PREL:
7705 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7706 case elfcpp::R_ARM_THM_MOVT_PREL:
7707 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7708 case elfcpp::R_ARM_THM_PC12:
7709 case elfcpp::R_ARM_REL32_NOI:
7710 case elfcpp::R_ARM_ALU_PC_G0_NC:
7711 case elfcpp::R_ARM_ALU_PC_G0:
7712 case elfcpp::R_ARM_ALU_PC_G1_NC:
7713 case elfcpp::R_ARM_ALU_PC_G1:
7714 case elfcpp::R_ARM_ALU_PC_G2:
7715 case elfcpp::R_ARM_LDR_PC_G1:
7716 case elfcpp::R_ARM_LDR_PC_G2:
7717 case elfcpp::R_ARM_LDRS_PC_G0:
7718 case elfcpp::R_ARM_LDRS_PC_G1:
7719 case elfcpp::R_ARM_LDRS_PC_G2:
7720 case elfcpp::R_ARM_LDC_PC_G0:
7721 case elfcpp::R_ARM_LDC_PC_G1:
7722 case elfcpp::R_ARM_LDC_PC_G2:
7723 case elfcpp::R_ARM_ALU_SB_G0_NC:
7724 case elfcpp::R_ARM_ALU_SB_G0:
7725 case elfcpp::R_ARM_ALU_SB_G1_NC:
7726 case elfcpp::R_ARM_ALU_SB_G1:
7727 case elfcpp::R_ARM_ALU_SB_G2:
7728 case elfcpp::R_ARM_LDR_SB_G0:
7729 case elfcpp::R_ARM_LDR_SB_G1:
7730 case elfcpp::R_ARM_LDR_SB_G2:
7731 case elfcpp::R_ARM_LDRS_SB_G0:
7732 case elfcpp::R_ARM_LDRS_SB_G1:
7733 case elfcpp::R_ARM_LDRS_SB_G2:
7734 case elfcpp::R_ARM_LDC_SB_G0:
7735 case elfcpp::R_ARM_LDC_SB_G1:
7736 case elfcpp::R_ARM_LDC_SB_G2:
7737 case elfcpp::R_ARM_MOVW_BREL_NC:
7738 case elfcpp::R_ARM_MOVT_BREL:
7739 case elfcpp::R_ARM_MOVW_BREL:
7740 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7741 case elfcpp::R_ARM_THM_MOVT_BREL:
7742 case elfcpp::R_ARM_THM_MOVW_BREL:
7743 case elfcpp::R_ARM_GOTOFF32:
7744 case elfcpp::R_ARM_GOTOFF12:
7745 case elfcpp::R_ARM_SBREL31:
7746 return Symbol::RELATIVE_REF;
7748 case elfcpp::R_ARM_PLT32:
7749 case elfcpp::R_ARM_CALL:
7750 case elfcpp::R_ARM_JUMP24:
7751 case elfcpp::R_ARM_THM_CALL:
7752 case elfcpp::R_ARM_THM_JUMP24:
7753 case elfcpp::R_ARM_THM_JUMP19:
7754 case elfcpp::R_ARM_THM_JUMP6:
7755 case elfcpp::R_ARM_THM_JUMP11:
7756 case elfcpp::R_ARM_THM_JUMP8:
7757 // R_ARM_PREL31 is not used to relocate call/jump instructions but
7758 // in unwind tables. It may point to functions via PLTs.
7759 // So we treat it like call/jump relocations above.
7760 case elfcpp::R_ARM_PREL31:
7761 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
7763 case elfcpp::R_ARM_GOT_BREL:
7764 case elfcpp::R_ARM_GOT_ABS:
7765 case elfcpp::R_ARM_GOT_PREL:
7766 // Absolute in GOT.
7767 return Symbol::ABSOLUTE_REF;
7769 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7770 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7771 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7772 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7773 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7774 return Symbol::TLS_REF;
7776 case elfcpp::R_ARM_TARGET1:
7777 case elfcpp::R_ARM_TARGET2:
7778 case elfcpp::R_ARM_COPY:
7779 case elfcpp::R_ARM_GLOB_DAT:
7780 case elfcpp::R_ARM_JUMP_SLOT:
7781 case elfcpp::R_ARM_RELATIVE:
7782 case elfcpp::R_ARM_PC24:
7783 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7784 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7785 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7786 default:
7787 // Not expected. We will give an error later.
7788 return 0;
7792 // Report an unsupported relocation against a local symbol.
7794 template<bool big_endian>
7795 void
7796 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7797 Sized_relobj_file<32, big_endian>* object,
7798 unsigned int r_type)
7800 gold_error(_("%s: unsupported reloc %u against local symbol"),
7801 object->name().c_str(), r_type);
7804 // We are about to emit a dynamic relocation of type R_TYPE. If the
7805 // dynamic linker does not support it, issue an error. The GNU linker
7806 // only issues a non-PIC error for an allocated read-only section.
7807 // Here we know the section is allocated, but we don't know that it is
7808 // read-only. But we check for all the relocation types which the
7809 // glibc dynamic linker supports, so it seems appropriate to issue an
7810 // error even if the section is not read-only.
7812 template<bool big_endian>
7813 void
7814 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7815 unsigned int r_type)
7817 switch (r_type)
7819 // These are the relocation types supported by glibc for ARM.
7820 case elfcpp::R_ARM_RELATIVE:
7821 case elfcpp::R_ARM_COPY:
7822 case elfcpp::R_ARM_GLOB_DAT:
7823 case elfcpp::R_ARM_JUMP_SLOT:
7824 case elfcpp::R_ARM_ABS32:
7825 case elfcpp::R_ARM_ABS32_NOI:
7826 case elfcpp::R_ARM_PC24:
7827 // FIXME: The following 3 types are not supported by Android's dynamic
7828 // linker.
7829 case elfcpp::R_ARM_TLS_DTPMOD32:
7830 case elfcpp::R_ARM_TLS_DTPOFF32:
7831 case elfcpp::R_ARM_TLS_TPOFF32:
7832 return;
7834 default:
7836 // This prevents us from issuing more than one error per reloc
7837 // section. But we can still wind up issuing more than one
7838 // error per object file.
7839 if (this->issued_non_pic_error_)
7840 return;
7841 const Arm_reloc_property* reloc_property =
7842 arm_reloc_property_table->get_reloc_property(r_type);
7843 gold_assert(reloc_property != NULL);
7844 object->error(_("requires unsupported dynamic reloc %s; "
7845 "recompile with -fPIC"),
7846 reloc_property->name().c_str());
7847 this->issued_non_pic_error_ = true;
7848 return;
7851 case elfcpp::R_ARM_NONE:
7852 gold_unreachable();
7856 // Scan a relocation for a local symbol.
7857 // FIXME: This only handles a subset of relocation types used by Android
7858 // on ARM v5te devices.
7860 template<bool big_endian>
7861 inline void
7862 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7863 Layout* layout,
7864 Target_arm* target,
7865 Sized_relobj_file<32, big_endian>* object,
7866 unsigned int data_shndx,
7867 Output_section* output_section,
7868 const elfcpp::Rel<32, big_endian>& reloc,
7869 unsigned int r_type,
7870 const elfcpp::Sym<32, big_endian>& lsym,
7871 bool is_discarded)
7873 if (is_discarded)
7874 return;
7876 r_type = get_real_reloc_type(r_type);
7877 switch (r_type)
7879 case elfcpp::R_ARM_NONE:
7880 case elfcpp::R_ARM_V4BX:
7881 case elfcpp::R_ARM_GNU_VTENTRY:
7882 case elfcpp::R_ARM_GNU_VTINHERIT:
7883 break;
7885 case elfcpp::R_ARM_ABS32:
7886 case elfcpp::R_ARM_ABS32_NOI:
7887 // If building a shared library (or a position-independent
7888 // executable), we need to create a dynamic relocation for
7889 // this location. The relocation applied at link time will
7890 // apply the link-time value, so we flag the location with
7891 // an R_ARM_RELATIVE relocation so the dynamic loader can
7892 // relocate it easily.
7893 if (parameters->options().output_is_position_independent())
7895 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7896 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7897 // If we are to add more other reloc types than R_ARM_ABS32,
7898 // we need to add check_non_pic(object, r_type) here.
7899 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7900 output_section, data_shndx,
7901 reloc.get_r_offset());
7903 break;
7905 case elfcpp::R_ARM_ABS16:
7906 case elfcpp::R_ARM_ABS12:
7907 case elfcpp::R_ARM_THM_ABS5:
7908 case elfcpp::R_ARM_ABS8:
7909 case elfcpp::R_ARM_BASE_ABS:
7910 case elfcpp::R_ARM_MOVW_ABS_NC:
7911 case elfcpp::R_ARM_MOVT_ABS:
7912 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7913 case elfcpp::R_ARM_THM_MOVT_ABS:
7914 // If building a shared library (or a position-independent
7915 // executable), we need to create a dynamic relocation for
7916 // this location. Because the addend needs to remain in the
7917 // data section, we need to be careful not to apply this
7918 // relocation statically.
7919 if (parameters->options().output_is_position_independent())
7921 check_non_pic(object, r_type);
7922 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7923 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7924 if (lsym.get_st_type() != elfcpp::STT_SECTION)
7925 rel_dyn->add_local(object, r_sym, r_type, output_section,
7926 data_shndx, reloc.get_r_offset());
7927 else
7929 gold_assert(lsym.get_st_value() == 0);
7930 unsigned int shndx = lsym.get_st_shndx();
7931 bool is_ordinary;
7932 shndx = object->adjust_sym_shndx(r_sym, shndx,
7933 &is_ordinary);
7934 if (!is_ordinary)
7935 object->error(_("section symbol %u has bad shndx %u"),
7936 r_sym, shndx);
7937 else
7938 rel_dyn->add_local_section(object, shndx,
7939 r_type, output_section,
7940 data_shndx, reloc.get_r_offset());
7943 break;
7945 case elfcpp::R_ARM_REL32:
7946 case elfcpp::R_ARM_LDR_PC_G0:
7947 case elfcpp::R_ARM_SBREL32:
7948 case elfcpp::R_ARM_THM_CALL:
7949 case elfcpp::R_ARM_THM_PC8:
7950 case elfcpp::R_ARM_BASE_PREL:
7951 case elfcpp::R_ARM_PLT32:
7952 case elfcpp::R_ARM_CALL:
7953 case elfcpp::R_ARM_JUMP24:
7954 case elfcpp::R_ARM_THM_JUMP24:
7955 case elfcpp::R_ARM_SBREL31:
7956 case elfcpp::R_ARM_PREL31:
7957 case elfcpp::R_ARM_MOVW_PREL_NC:
7958 case elfcpp::R_ARM_MOVT_PREL:
7959 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7960 case elfcpp::R_ARM_THM_MOVT_PREL:
7961 case elfcpp::R_ARM_THM_JUMP19:
7962 case elfcpp::R_ARM_THM_JUMP6:
7963 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7964 case elfcpp::R_ARM_THM_PC12:
7965 case elfcpp::R_ARM_REL32_NOI:
7966 case elfcpp::R_ARM_ALU_PC_G0_NC:
7967 case elfcpp::R_ARM_ALU_PC_G0:
7968 case elfcpp::R_ARM_ALU_PC_G1_NC:
7969 case elfcpp::R_ARM_ALU_PC_G1:
7970 case elfcpp::R_ARM_ALU_PC_G2:
7971 case elfcpp::R_ARM_LDR_PC_G1:
7972 case elfcpp::R_ARM_LDR_PC_G2:
7973 case elfcpp::R_ARM_LDRS_PC_G0:
7974 case elfcpp::R_ARM_LDRS_PC_G1:
7975 case elfcpp::R_ARM_LDRS_PC_G2:
7976 case elfcpp::R_ARM_LDC_PC_G0:
7977 case elfcpp::R_ARM_LDC_PC_G1:
7978 case elfcpp::R_ARM_LDC_PC_G2:
7979 case elfcpp::R_ARM_ALU_SB_G0_NC:
7980 case elfcpp::R_ARM_ALU_SB_G0:
7981 case elfcpp::R_ARM_ALU_SB_G1_NC:
7982 case elfcpp::R_ARM_ALU_SB_G1:
7983 case elfcpp::R_ARM_ALU_SB_G2:
7984 case elfcpp::R_ARM_LDR_SB_G0:
7985 case elfcpp::R_ARM_LDR_SB_G1:
7986 case elfcpp::R_ARM_LDR_SB_G2:
7987 case elfcpp::R_ARM_LDRS_SB_G0:
7988 case elfcpp::R_ARM_LDRS_SB_G1:
7989 case elfcpp::R_ARM_LDRS_SB_G2:
7990 case elfcpp::R_ARM_LDC_SB_G0:
7991 case elfcpp::R_ARM_LDC_SB_G1:
7992 case elfcpp::R_ARM_LDC_SB_G2:
7993 case elfcpp::R_ARM_MOVW_BREL_NC:
7994 case elfcpp::R_ARM_MOVT_BREL:
7995 case elfcpp::R_ARM_MOVW_BREL:
7996 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7997 case elfcpp::R_ARM_THM_MOVT_BREL:
7998 case elfcpp::R_ARM_THM_MOVW_BREL:
7999 case elfcpp::R_ARM_THM_JUMP11:
8000 case elfcpp::R_ARM_THM_JUMP8:
8001 // We don't need to do anything for a relative addressing relocation
8002 // against a local symbol if it does not reference the GOT.
8003 break;
8005 case elfcpp::R_ARM_GOTOFF32:
8006 case elfcpp::R_ARM_GOTOFF12:
8007 // We need a GOT section:
8008 target->got_section(symtab, layout);
8009 break;
8011 case elfcpp::R_ARM_GOT_BREL:
8012 case elfcpp::R_ARM_GOT_PREL:
8014 // The symbol requires a GOT entry.
8015 Arm_output_data_got<big_endian>* got =
8016 target->got_section(symtab, layout);
8017 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8018 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
8020 // If we are generating a shared object, we need to add a
8021 // dynamic RELATIVE relocation for this symbol's GOT entry.
8022 if (parameters->options().output_is_position_independent())
8024 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8025 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8026 rel_dyn->add_local_relative(
8027 object, r_sym, elfcpp::R_ARM_RELATIVE, got,
8028 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
8032 break;
8034 case elfcpp::R_ARM_TARGET1:
8035 case elfcpp::R_ARM_TARGET2:
8036 // This should have been mapped to another type already.
8037 // Fall through.
8038 case elfcpp::R_ARM_COPY:
8039 case elfcpp::R_ARM_GLOB_DAT:
8040 case elfcpp::R_ARM_JUMP_SLOT:
8041 case elfcpp::R_ARM_RELATIVE:
8042 // These are relocations which should only be seen by the
8043 // dynamic linker, and should never be seen here.
8044 gold_error(_("%s: unexpected reloc %u in object file"),
8045 object->name().c_str(), r_type);
8046 break;
8049 // These are initial TLS relocs, which are expected when
8050 // linking.
8051 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8052 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8053 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8054 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8055 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8057 bool output_is_shared = parameters->options().shared();
8058 const tls::Tls_optimization optimized_type
8059 = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
8060 r_type);
8061 switch (r_type)
8063 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8064 if (optimized_type == tls::TLSOPT_NONE)
8066 // Create a pair of GOT entries for the module index and
8067 // dtv-relative offset.
8068 Arm_output_data_got<big_endian>* got
8069 = target->got_section(symtab, layout);
8070 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8071 unsigned int shndx = lsym.get_st_shndx();
8072 bool is_ordinary;
8073 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
8074 if (!is_ordinary)
8076 object->error(_("local symbol %u has bad shndx %u"),
8077 r_sym, shndx);
8078 break;
8081 if (!parameters->doing_static_link())
8082 got->add_local_pair_with_rel(object, r_sym, shndx,
8083 GOT_TYPE_TLS_PAIR,
8084 target->rel_dyn_section(layout),
8085 elfcpp::R_ARM_TLS_DTPMOD32);
8086 else
8087 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
8088 object, r_sym);
8090 else
8091 // FIXME: TLS optimization not supported yet.
8092 gold_unreachable();
8093 break;
8095 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8096 if (optimized_type == tls::TLSOPT_NONE)
8098 // Create a GOT entry for the module index.
8099 target->got_mod_index_entry(symtab, layout, object);
8101 else
8102 // FIXME: TLS optimization not supported yet.
8103 gold_unreachable();
8104 break;
8106 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8107 break;
8109 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8110 layout->set_has_static_tls();
8111 if (optimized_type == tls::TLSOPT_NONE)
8113 // Create a GOT entry for the tp-relative offset.
8114 Arm_output_data_got<big_endian>* got
8115 = target->got_section(symtab, layout);
8116 unsigned int r_sym =
8117 elfcpp::elf_r_sym<32>(reloc.get_r_info());
8118 if (!parameters->doing_static_link())
8119 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
8120 target->rel_dyn_section(layout),
8121 elfcpp::R_ARM_TLS_TPOFF32);
8122 else if (!object->local_has_got_offset(r_sym,
8123 GOT_TYPE_TLS_OFFSET))
8125 got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
8126 unsigned int got_offset =
8127 object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
8128 got->add_static_reloc(got_offset,
8129 elfcpp::R_ARM_TLS_TPOFF32, object,
8130 r_sym);
8133 else
8134 // FIXME: TLS optimization not supported yet.
8135 gold_unreachable();
8136 break;
8138 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8139 layout->set_has_static_tls();
8140 if (output_is_shared)
8142 // We need to create a dynamic relocation.
8143 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8144 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8145 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8146 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8147 output_section, data_shndx,
8148 reloc.get_r_offset());
8150 break;
8152 default:
8153 gold_unreachable();
8156 break;
8158 case elfcpp::R_ARM_PC24:
8159 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8160 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8161 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8162 default:
8163 unsupported_reloc_local(object, r_type);
8164 break;
8168 // Report an unsupported relocation against a global symbol.
8170 template<bool big_endian>
8171 void
8172 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8173 Sized_relobj_file<32, big_endian>* object,
8174 unsigned int r_type,
8175 Symbol* gsym)
8177 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8178 object->name().c_str(), r_type, gsym->demangled_name().c_str());
8181 template<bool big_endian>
8182 inline bool
8183 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8184 unsigned int r_type)
8186 switch (r_type)
8188 case elfcpp::R_ARM_PC24:
8189 case elfcpp::R_ARM_THM_CALL:
8190 case elfcpp::R_ARM_PLT32:
8191 case elfcpp::R_ARM_CALL:
8192 case elfcpp::R_ARM_JUMP24:
8193 case elfcpp::R_ARM_THM_JUMP24:
8194 case elfcpp::R_ARM_SBREL31:
8195 case elfcpp::R_ARM_PREL31:
8196 case elfcpp::R_ARM_THM_JUMP19:
8197 case elfcpp::R_ARM_THM_JUMP6:
8198 case elfcpp::R_ARM_THM_JUMP11:
8199 case elfcpp::R_ARM_THM_JUMP8:
8200 // All the relocations above are branches except SBREL31 and PREL31.
8201 return false;
8203 default:
8204 // Be conservative and assume this is a function pointer.
8205 return true;
8209 template<bool big_endian>
8210 inline bool
8211 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8212 Symbol_table*,
8213 Layout*,
8214 Target_arm<big_endian>* target,
8215 Sized_relobj_file<32, big_endian>*,
8216 unsigned int,
8217 Output_section*,
8218 const elfcpp::Rel<32, big_endian>&,
8219 unsigned int r_type,
8220 const elfcpp::Sym<32, big_endian>&)
8222 r_type = target->get_real_reloc_type(r_type);
8223 return possible_function_pointer_reloc(r_type);
8226 template<bool big_endian>
8227 inline bool
8228 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8229 Symbol_table*,
8230 Layout*,
8231 Target_arm<big_endian>* target,
8232 Sized_relobj_file<32, big_endian>*,
8233 unsigned int,
8234 Output_section*,
8235 const elfcpp::Rel<32, big_endian>&,
8236 unsigned int r_type,
8237 Symbol* gsym)
8239 // GOT is not a function.
8240 if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8241 return false;
8243 r_type = target->get_real_reloc_type(r_type);
8244 return possible_function_pointer_reloc(r_type);
8247 // Scan a relocation for a global symbol.
8249 template<bool big_endian>
8250 inline void
8251 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8252 Layout* layout,
8253 Target_arm* target,
8254 Sized_relobj_file<32, big_endian>* object,
8255 unsigned int data_shndx,
8256 Output_section* output_section,
8257 const elfcpp::Rel<32, big_endian>& reloc,
8258 unsigned int r_type,
8259 Symbol* gsym)
8261 // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8262 // section. We check here to avoid creating a dynamic reloc against
8263 // _GLOBAL_OFFSET_TABLE_.
8264 if (!target->has_got_section()
8265 && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8266 target->got_section(symtab, layout);
8268 r_type = get_real_reloc_type(r_type);
8269 switch (r_type)
8271 case elfcpp::R_ARM_NONE:
8272 case elfcpp::R_ARM_V4BX:
8273 case elfcpp::R_ARM_GNU_VTENTRY:
8274 case elfcpp::R_ARM_GNU_VTINHERIT:
8275 break;
8277 case elfcpp::R_ARM_ABS32:
8278 case elfcpp::R_ARM_ABS16:
8279 case elfcpp::R_ARM_ABS12:
8280 case elfcpp::R_ARM_THM_ABS5:
8281 case elfcpp::R_ARM_ABS8:
8282 case elfcpp::R_ARM_BASE_ABS:
8283 case elfcpp::R_ARM_MOVW_ABS_NC:
8284 case elfcpp::R_ARM_MOVT_ABS:
8285 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8286 case elfcpp::R_ARM_THM_MOVT_ABS:
8287 case elfcpp::R_ARM_ABS32_NOI:
8288 // Absolute addressing relocations.
8290 // Make a PLT entry if necessary.
8291 if (this->symbol_needs_plt_entry(gsym))
8293 target->make_plt_entry(symtab, layout, gsym);
8294 // Since this is not a PC-relative relocation, we may be
8295 // taking the address of a function. In that case we need to
8296 // set the entry in the dynamic symbol table to the address of
8297 // the PLT entry.
8298 if (gsym->is_from_dynobj() && !parameters->options().shared())
8299 gsym->set_needs_dynsym_value();
8301 // Make a dynamic relocation if necessary.
8302 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8304 if (!parameters->options().output_is_position_independent()
8305 && gsym->may_need_copy_reloc())
8307 target->copy_reloc(symtab, layout, object,
8308 data_shndx, output_section, gsym, reloc);
8310 else if ((r_type == elfcpp::R_ARM_ABS32
8311 || r_type == elfcpp::R_ARM_ABS32_NOI)
8312 && gsym->can_use_relative_reloc(false))
8314 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8315 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8316 output_section, object,
8317 data_shndx, reloc.get_r_offset());
8319 else
8321 check_non_pic(object, r_type);
8322 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8323 rel_dyn->add_global(gsym, r_type, output_section, object,
8324 data_shndx, reloc.get_r_offset());
8328 break;
8330 case elfcpp::R_ARM_GOTOFF32:
8331 case elfcpp::R_ARM_GOTOFF12:
8332 // We need a GOT section.
8333 target->got_section(symtab, layout);
8334 break;
8336 case elfcpp::R_ARM_REL32:
8337 case elfcpp::R_ARM_LDR_PC_G0:
8338 case elfcpp::R_ARM_SBREL32:
8339 case elfcpp::R_ARM_THM_PC8:
8340 case elfcpp::R_ARM_BASE_PREL:
8341 case elfcpp::R_ARM_MOVW_PREL_NC:
8342 case elfcpp::R_ARM_MOVT_PREL:
8343 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8344 case elfcpp::R_ARM_THM_MOVT_PREL:
8345 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8346 case elfcpp::R_ARM_THM_PC12:
8347 case elfcpp::R_ARM_REL32_NOI:
8348 case elfcpp::R_ARM_ALU_PC_G0_NC:
8349 case elfcpp::R_ARM_ALU_PC_G0:
8350 case elfcpp::R_ARM_ALU_PC_G1_NC:
8351 case elfcpp::R_ARM_ALU_PC_G1:
8352 case elfcpp::R_ARM_ALU_PC_G2:
8353 case elfcpp::R_ARM_LDR_PC_G1:
8354 case elfcpp::R_ARM_LDR_PC_G2:
8355 case elfcpp::R_ARM_LDRS_PC_G0:
8356 case elfcpp::R_ARM_LDRS_PC_G1:
8357 case elfcpp::R_ARM_LDRS_PC_G2:
8358 case elfcpp::R_ARM_LDC_PC_G0:
8359 case elfcpp::R_ARM_LDC_PC_G1:
8360 case elfcpp::R_ARM_LDC_PC_G2:
8361 case elfcpp::R_ARM_ALU_SB_G0_NC:
8362 case elfcpp::R_ARM_ALU_SB_G0:
8363 case elfcpp::R_ARM_ALU_SB_G1_NC:
8364 case elfcpp::R_ARM_ALU_SB_G1:
8365 case elfcpp::R_ARM_ALU_SB_G2:
8366 case elfcpp::R_ARM_LDR_SB_G0:
8367 case elfcpp::R_ARM_LDR_SB_G1:
8368 case elfcpp::R_ARM_LDR_SB_G2:
8369 case elfcpp::R_ARM_LDRS_SB_G0:
8370 case elfcpp::R_ARM_LDRS_SB_G1:
8371 case elfcpp::R_ARM_LDRS_SB_G2:
8372 case elfcpp::R_ARM_LDC_SB_G0:
8373 case elfcpp::R_ARM_LDC_SB_G1:
8374 case elfcpp::R_ARM_LDC_SB_G2:
8375 case elfcpp::R_ARM_MOVW_BREL_NC:
8376 case elfcpp::R_ARM_MOVT_BREL:
8377 case elfcpp::R_ARM_MOVW_BREL:
8378 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8379 case elfcpp::R_ARM_THM_MOVT_BREL:
8380 case elfcpp::R_ARM_THM_MOVW_BREL:
8381 // Relative addressing relocations.
8383 // Make a dynamic relocation if necessary.
8384 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8386 if (parameters->options().output_is_executable()
8387 && target->may_need_copy_reloc(gsym))
8389 target->copy_reloc(symtab, layout, object,
8390 data_shndx, output_section, gsym, reloc);
8392 else
8394 check_non_pic(object, r_type);
8395 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8396 rel_dyn->add_global(gsym, r_type, output_section, object,
8397 data_shndx, reloc.get_r_offset());
8401 break;
8403 case elfcpp::R_ARM_THM_CALL:
8404 case elfcpp::R_ARM_PLT32:
8405 case elfcpp::R_ARM_CALL:
8406 case elfcpp::R_ARM_JUMP24:
8407 case elfcpp::R_ARM_THM_JUMP24:
8408 case elfcpp::R_ARM_SBREL31:
8409 case elfcpp::R_ARM_PREL31:
8410 case elfcpp::R_ARM_THM_JUMP19:
8411 case elfcpp::R_ARM_THM_JUMP6:
8412 case elfcpp::R_ARM_THM_JUMP11:
8413 case elfcpp::R_ARM_THM_JUMP8:
8414 // All the relocation above are branches except for the PREL31 ones.
8415 // A PREL31 relocation can point to a personality function in a shared
8416 // library. In that case we want to use a PLT because we want to
8417 // call the personality routine and the dynamic linkers we care about
8418 // do not support dynamic PREL31 relocations. An REL31 relocation may
8419 // point to a function whose unwinding behaviour is being described but
8420 // we will not mistakenly generate a PLT for that because we should use
8421 // a local section symbol.
8423 // If the symbol is fully resolved, this is just a relative
8424 // local reloc. Otherwise we need a PLT entry.
8425 if (gsym->final_value_is_known())
8426 break;
8427 // If building a shared library, we can also skip the PLT entry
8428 // if the symbol is defined in the output file and is protected
8429 // or hidden.
8430 if (gsym->is_defined()
8431 && !gsym->is_from_dynobj()
8432 && !gsym->is_preemptible())
8433 break;
8434 target->make_plt_entry(symtab, layout, gsym);
8435 break;
8437 case elfcpp::R_ARM_GOT_BREL:
8438 case elfcpp::R_ARM_GOT_ABS:
8439 case elfcpp::R_ARM_GOT_PREL:
8441 // The symbol requires a GOT entry.
8442 Arm_output_data_got<big_endian>* got =
8443 target->got_section(symtab, layout);
8444 if (gsym->final_value_is_known())
8445 got->add_global(gsym, GOT_TYPE_STANDARD);
8446 else
8448 // If this symbol is not fully resolved, we need to add a
8449 // GOT entry with a dynamic relocation.
8450 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8451 if (gsym->is_from_dynobj()
8452 || gsym->is_undefined()
8453 || gsym->is_preemptible()
8454 || (gsym->visibility() == elfcpp::STV_PROTECTED
8455 && parameters->options().shared()))
8456 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8457 rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8458 else
8460 if (got->add_global(gsym, GOT_TYPE_STANDARD))
8461 rel_dyn->add_global_relative(
8462 gsym, elfcpp::R_ARM_RELATIVE, got,
8463 gsym->got_offset(GOT_TYPE_STANDARD));
8467 break;
8469 case elfcpp::R_ARM_TARGET1:
8470 case elfcpp::R_ARM_TARGET2:
8471 // These should have been mapped to other types already.
8472 // Fall through.
8473 case elfcpp::R_ARM_COPY:
8474 case elfcpp::R_ARM_GLOB_DAT:
8475 case elfcpp::R_ARM_JUMP_SLOT:
8476 case elfcpp::R_ARM_RELATIVE:
8477 // These are relocations which should only be seen by the
8478 // dynamic linker, and should never be seen here.
8479 gold_error(_("%s: unexpected reloc %u in object file"),
8480 object->name().c_str(), r_type);
8481 break;
8483 // These are initial tls relocs, which are expected when
8484 // linking.
8485 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8486 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8487 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8488 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8489 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8491 const bool is_final = gsym->final_value_is_known();
8492 const tls::Tls_optimization optimized_type
8493 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8494 switch (r_type)
8496 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8497 if (optimized_type == tls::TLSOPT_NONE)
8499 // Create a pair of GOT entries for the module index and
8500 // dtv-relative offset.
8501 Arm_output_data_got<big_endian>* got
8502 = target->got_section(symtab, layout);
8503 if (!parameters->doing_static_link())
8504 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8505 target->rel_dyn_section(layout),
8506 elfcpp::R_ARM_TLS_DTPMOD32,
8507 elfcpp::R_ARM_TLS_DTPOFF32);
8508 else
8509 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8511 else
8512 // FIXME: TLS optimization not supported yet.
8513 gold_unreachable();
8514 break;
8516 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8517 if (optimized_type == tls::TLSOPT_NONE)
8519 // Create a GOT entry for the module index.
8520 target->got_mod_index_entry(symtab, layout, object);
8522 else
8523 // FIXME: TLS optimization not supported yet.
8524 gold_unreachable();
8525 break;
8527 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8528 break;
8530 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8531 layout->set_has_static_tls();
8532 if (optimized_type == tls::TLSOPT_NONE)
8534 // Create a GOT entry for the tp-relative offset.
8535 Arm_output_data_got<big_endian>* got
8536 = target->got_section(symtab, layout);
8537 if (!parameters->doing_static_link())
8538 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
8539 target->rel_dyn_section(layout),
8540 elfcpp::R_ARM_TLS_TPOFF32);
8541 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
8543 got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
8544 unsigned int got_offset =
8545 gsym->got_offset(GOT_TYPE_TLS_OFFSET);
8546 got->add_static_reloc(got_offset,
8547 elfcpp::R_ARM_TLS_TPOFF32, gsym);
8550 else
8551 // FIXME: TLS optimization not supported yet.
8552 gold_unreachable();
8553 break;
8555 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8556 layout->set_has_static_tls();
8557 if (parameters->options().shared())
8559 // We need to create a dynamic relocation.
8560 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8561 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
8562 output_section, object,
8563 data_shndx, reloc.get_r_offset());
8565 break;
8567 default:
8568 gold_unreachable();
8571 break;
8573 case elfcpp::R_ARM_PC24:
8574 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8575 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8576 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8577 default:
8578 unsupported_reloc_global(object, r_type, gsym);
8579 break;
8583 // Process relocations for gc.
8585 template<bool big_endian>
8586 void
8587 Target_arm<big_endian>::gc_process_relocs(
8588 Symbol_table* symtab,
8589 Layout* layout,
8590 Sized_relobj_file<32, big_endian>* object,
8591 unsigned int data_shndx,
8592 unsigned int,
8593 const unsigned char* prelocs,
8594 size_t reloc_count,
8595 Output_section* output_section,
8596 bool needs_special_offset_handling,
8597 size_t local_symbol_count,
8598 const unsigned char* plocal_symbols)
8600 typedef Target_arm<big_endian> Arm;
8601 typedef typename Target_arm<big_endian>::Scan Scan;
8603 gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
8604 typename Target_arm::Relocatable_size_for_reloc>(
8605 symtab,
8606 layout,
8607 this,
8608 object,
8609 data_shndx,
8610 prelocs,
8611 reloc_count,
8612 output_section,
8613 needs_special_offset_handling,
8614 local_symbol_count,
8615 plocal_symbols);
8618 // Scan relocations for a section.
8620 template<bool big_endian>
8621 void
8622 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
8623 Layout* layout,
8624 Sized_relobj_file<32, big_endian>* object,
8625 unsigned int data_shndx,
8626 unsigned int sh_type,
8627 const unsigned char* prelocs,
8628 size_t reloc_count,
8629 Output_section* output_section,
8630 bool needs_special_offset_handling,
8631 size_t local_symbol_count,
8632 const unsigned char* plocal_symbols)
8634 typedef typename Target_arm<big_endian>::Scan Scan;
8635 if (sh_type == elfcpp::SHT_RELA)
8637 gold_error(_("%s: unsupported RELA reloc section"),
8638 object->name().c_str());
8639 return;
8642 gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
8643 symtab,
8644 layout,
8645 this,
8646 object,
8647 data_shndx,
8648 prelocs,
8649 reloc_count,
8650 output_section,
8651 needs_special_offset_handling,
8652 local_symbol_count,
8653 plocal_symbols);
8656 // Finalize the sections.
8658 template<bool big_endian>
8659 void
8660 Target_arm<big_endian>::do_finalize_sections(
8661 Layout* layout,
8662 const Input_objects* input_objects,
8663 Symbol_table*)
8665 bool merged_any_attributes = false;
8666 // Merge processor-specific flags.
8667 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
8668 p != input_objects->relobj_end();
8669 ++p)
8671 Arm_relobj<big_endian>* arm_relobj =
8672 Arm_relobj<big_endian>::as_arm_relobj(*p);
8673 if (arm_relobj->merge_flags_and_attributes())
8675 this->merge_processor_specific_flags(
8676 arm_relobj->name(),
8677 arm_relobj->processor_specific_flags());
8678 this->merge_object_attributes(arm_relobj->name().c_str(),
8679 arm_relobj->attributes_section_data());
8680 merged_any_attributes = true;
8684 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8685 p != input_objects->dynobj_end();
8686 ++p)
8688 Arm_dynobj<big_endian>* arm_dynobj =
8689 Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8690 this->merge_processor_specific_flags(
8691 arm_dynobj->name(),
8692 arm_dynobj->processor_specific_flags());
8693 this->merge_object_attributes(arm_dynobj->name().c_str(),
8694 arm_dynobj->attributes_section_data());
8695 merged_any_attributes = true;
8698 // Create an empty uninitialized attribute section if we still don't have it
8699 // at this moment. This happens if there is no attributes sections in all
8700 // inputs.
8701 if (this->attributes_section_data_ == NULL)
8702 this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
8704 const Object_attribute* cpu_arch_attr =
8705 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8706 // Check if we need to use Cortex-A8 workaround.
8707 if (parameters->options().user_set_fix_cortex_a8())
8708 this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8709 else
8711 // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8712 // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8713 // profile.
8714 const Object_attribute* cpu_arch_profile_attr =
8715 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8716 this->fix_cortex_a8_ =
8717 (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8718 && (cpu_arch_profile_attr->int_value() == 'A'
8719 || cpu_arch_profile_attr->int_value() == 0));
8722 // Check if we can use V4BX interworking.
8723 // The V4BX interworking stub contains BX instruction,
8724 // which is not specified for some profiles.
8725 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8726 && !this->may_use_v4t_interworking())
8727 gold_error(_("unable to provide V4BX reloc interworking fix up; "
8728 "the target profile does not support BX instruction"));
8730 // Fill in some more dynamic tags.
8731 const Reloc_section* rel_plt = (this->plt_ == NULL
8732 ? NULL
8733 : this->plt_->rel_plt());
8734 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8735 this->rel_dyn_, true, false);
8737 // Emit any relocs we saved in an attempt to avoid generating COPY
8738 // relocs.
8739 if (this->copy_relocs_.any_saved_relocs())
8740 this->copy_relocs_.emit(this->rel_dyn_section(layout));
8742 // Handle the .ARM.exidx section.
8743 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8745 if (!parameters->options().relocatable())
8747 if (exidx_section != NULL
8748 && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
8750 // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8751 // the .ARM.exidx section.
8752 if (!layout->script_options()->saw_phdrs_clause())
8754 gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
8756 == NULL);
8757 Output_segment* exidx_segment =
8758 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8759 exidx_segment->add_output_section_to_nonload(exidx_section,
8760 elfcpp::PF_R);
8765 // Create an .ARM.attributes section if we have merged any attributes
8766 // from inputs.
8767 if (merged_any_attributes)
8769 Output_attributes_section_data* attributes_section =
8770 new Output_attributes_section_data(*this->attributes_section_data_);
8771 layout->add_output_section_data(".ARM.attributes",
8772 elfcpp::SHT_ARM_ATTRIBUTES, 0,
8773 attributes_section, ORDER_INVALID,
8774 false);
8777 // Fix up links in section EXIDX headers.
8778 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
8779 p != layout->section_list().end();
8780 ++p)
8781 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
8783 Arm_output_section<big_endian>* os =
8784 Arm_output_section<big_endian>::as_arm_output_section(*p);
8785 os->set_exidx_section_link();
8789 // Return whether a direct absolute static relocation needs to be applied.
8790 // In cases where Scan::local() or Scan::global() has created
8791 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8792 // of the relocation is carried in the data, and we must not
8793 // apply the static relocation.
8795 template<bool big_endian>
8796 inline bool
8797 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8798 const Sized_symbol<32>* gsym,
8799 unsigned int r_type,
8800 bool is_32bit,
8801 Output_section* output_section)
8803 // If the output section is not allocated, then we didn't call
8804 // scan_relocs, we didn't create a dynamic reloc, and we must apply
8805 // the reloc here.
8806 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8807 return true;
8809 int ref_flags = Scan::get_reference_flags(r_type);
8811 // For local symbols, we will have created a non-RELATIVE dynamic
8812 // relocation only if (a) the output is position independent,
8813 // (b) the relocation is absolute (not pc- or segment-relative), and
8814 // (c) the relocation is not 32 bits wide.
8815 if (gsym == NULL)
8816 return !(parameters->options().output_is_position_independent()
8817 && (ref_flags & Symbol::ABSOLUTE_REF)
8818 && !is_32bit);
8820 // For global symbols, we use the same helper routines used in the
8821 // scan pass. If we did not create a dynamic relocation, or if we
8822 // created a RELATIVE dynamic relocation, we should apply the static
8823 // relocation.
8824 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8825 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8826 && gsym->can_use_relative_reloc(ref_flags
8827 & Symbol::FUNCTION_CALL);
8828 return !has_dyn || is_rel;
8831 // Perform a relocation.
8833 template<bool big_endian>
8834 inline bool
8835 Target_arm<big_endian>::Relocate::relocate(
8836 const Relocate_info<32, big_endian>* relinfo,
8837 Target_arm* target,
8838 Output_section* output_section,
8839 size_t relnum,
8840 const elfcpp::Rel<32, big_endian>& rel,
8841 unsigned int r_type,
8842 const Sized_symbol<32>* gsym,
8843 const Symbol_value<32>* psymval,
8844 unsigned char* view,
8845 Arm_address address,
8846 section_size_type view_size)
8848 if (view == NULL)
8849 return true;
8851 typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8853 r_type = get_real_reloc_type(r_type);
8854 const Arm_reloc_property* reloc_property =
8855 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8856 if (reloc_property == NULL)
8858 std::string reloc_name =
8859 arm_reloc_property_table->reloc_name_in_error_message(r_type);
8860 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8861 _("cannot relocate %s in object file"),
8862 reloc_name.c_str());
8863 return true;
8866 const Arm_relobj<big_endian>* object =
8867 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8869 // If the final branch target of a relocation is THUMB instruction, this
8870 // is 1. Otherwise it is 0.
8871 Arm_address thumb_bit = 0;
8872 Symbol_value<32> symval;
8873 bool is_weakly_undefined_without_plt = false;
8874 bool have_got_offset = false;
8875 unsigned int got_offset = 0;
8877 // If the relocation uses the GOT entry of a symbol instead of the symbol
8878 // itself, we don't care about whether the symbol is defined or what kind
8879 // of symbol it is.
8880 if (reloc_property->uses_got_entry())
8882 // Get the GOT offset.
8883 // The GOT pointer points to the end of the GOT section.
8884 // We need to subtract the size of the GOT section to get
8885 // the actual offset to use in the relocation.
8886 // TODO: We should move GOT offset computing code in TLS relocations
8887 // to here.
8888 switch (r_type)
8890 case elfcpp::R_ARM_GOT_BREL:
8891 case elfcpp::R_ARM_GOT_PREL:
8892 if (gsym != NULL)
8894 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8895 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8896 - target->got_size());
8898 else
8900 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8901 gold_assert(object->local_has_got_offset(r_sym,
8902 GOT_TYPE_STANDARD));
8903 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8904 - target->got_size());
8906 have_got_offset = true;
8907 break;
8909 default:
8910 break;
8913 else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8915 if (gsym != NULL)
8917 // This is a global symbol. Determine if we use PLT and if the
8918 // final target is THUMB.
8919 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
8921 // This uses a PLT, change the symbol value.
8922 symval.set_output_value(target->plt_section()->address()
8923 + gsym->plt_offset());
8924 psymval = &symval;
8926 else if (gsym->is_weak_undefined())
8928 // This is a weakly undefined symbol and we do not use PLT
8929 // for this relocation. A branch targeting this symbol will
8930 // be converted into an NOP.
8931 is_weakly_undefined_without_plt = true;
8933 else if (gsym->is_undefined() && reloc_property->uses_symbol())
8935 // This relocation uses the symbol value but the symbol is
8936 // undefined. Exit early and have the caller reporting an
8937 // error.
8938 return true;
8940 else
8942 // Set thumb bit if symbol:
8943 // -Has type STT_ARM_TFUNC or
8944 // -Has type STT_FUNC, is defined and with LSB in value set.
8945 thumb_bit =
8946 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8947 || (gsym->type() == elfcpp::STT_FUNC
8948 && !gsym->is_undefined()
8949 && ((psymval->value(object, 0) & 1) != 0)))
8951 : 0);
8954 else
8956 // This is a local symbol. Determine if the final target is THUMB.
8957 // We saved this information when all the local symbols were read.
8958 elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8959 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8960 thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8963 else
8965 // This is a fake relocation synthesized for a stub. It does not have
8966 // a real symbol. We just look at the LSB of the symbol value to
8967 // determine if the target is THUMB or not.
8968 thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8971 // Strip LSB if this points to a THUMB target.
8972 if (thumb_bit != 0
8973 && reloc_property->uses_thumb_bit()
8974 && ((psymval->value(object, 0) & 1) != 0))
8976 Arm_address stripped_value =
8977 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8978 symval.set_output_value(stripped_value);
8979 psymval = &symval;
8982 // To look up relocation stubs, we need to pass the symbol table index of
8983 // a local symbol.
8984 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8986 // Get the addressing origin of the output segment defining the
8987 // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8988 Arm_address sym_origin = 0;
8989 if (reloc_property->uses_symbol_base())
8991 if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8992 // R_ARM_BASE_ABS with the NULL symbol will give the
8993 // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8994 // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8995 sym_origin = target->got_plt_section()->address();
8996 else if (gsym == NULL)
8997 sym_origin = 0;
8998 else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8999 sym_origin = gsym->output_segment()->vaddr();
9000 else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
9001 sym_origin = gsym->output_data()->address();
9003 // TODO: Assumes the segment base to be zero for the global symbols
9004 // till the proper support for the segment-base-relative addressing
9005 // will be implemented. This is consistent with GNU ld.
9008 // For relative addressing relocation, find out the relative address base.
9009 Arm_address relative_address_base = 0;
9010 switch(reloc_property->relative_address_base())
9012 case Arm_reloc_property::RAB_NONE:
9013 // Relocations with relative address bases RAB_TLS and RAB_tp are
9014 // handled by relocate_tls. So we do not need to do anything here.
9015 case Arm_reloc_property::RAB_TLS:
9016 case Arm_reloc_property::RAB_tp:
9017 break;
9018 case Arm_reloc_property::RAB_B_S:
9019 relative_address_base = sym_origin;
9020 break;
9021 case Arm_reloc_property::RAB_GOT_ORG:
9022 relative_address_base = target->got_plt_section()->address();
9023 break;
9024 case Arm_reloc_property::RAB_P:
9025 relative_address_base = address;
9026 break;
9027 case Arm_reloc_property::RAB_Pa:
9028 relative_address_base = address & 0xfffffffcU;
9029 break;
9030 default:
9031 gold_unreachable();
9034 typename Arm_relocate_functions::Status reloc_status =
9035 Arm_relocate_functions::STATUS_OKAY;
9036 bool check_overflow = reloc_property->checks_overflow();
9037 switch (r_type)
9039 case elfcpp::R_ARM_NONE:
9040 break;
9042 case elfcpp::R_ARM_ABS8:
9043 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9044 reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
9045 break;
9047 case elfcpp::R_ARM_ABS12:
9048 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9049 reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
9050 break;
9052 case elfcpp::R_ARM_ABS16:
9053 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9054 reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
9055 break;
9057 case elfcpp::R_ARM_ABS32:
9058 if (should_apply_static_reloc(gsym, r_type, true, output_section))
9059 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9060 thumb_bit);
9061 break;
9063 case elfcpp::R_ARM_ABS32_NOI:
9064 if (should_apply_static_reloc(gsym, r_type, true, output_section))
9065 // No thumb bit for this relocation: (S + A)
9066 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9068 break;
9070 case elfcpp::R_ARM_MOVW_ABS_NC:
9071 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9072 reloc_status = Arm_relocate_functions::movw(view, object, psymval,
9073 0, thumb_bit,
9074 check_overflow);
9075 break;
9077 case elfcpp::R_ARM_MOVT_ABS:
9078 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9079 reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
9080 break;
9082 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9083 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9084 reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
9085 0, thumb_bit, false);
9086 break;
9088 case elfcpp::R_ARM_THM_MOVT_ABS:
9089 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9090 reloc_status = Arm_relocate_functions::thm_movt(view, object,
9091 psymval, 0);
9092 break;
9094 case elfcpp::R_ARM_MOVW_PREL_NC:
9095 case elfcpp::R_ARM_MOVW_BREL_NC:
9096 case elfcpp::R_ARM_MOVW_BREL:
9097 reloc_status =
9098 Arm_relocate_functions::movw(view, object, psymval,
9099 relative_address_base, thumb_bit,
9100 check_overflow);
9101 break;
9103 case elfcpp::R_ARM_MOVT_PREL:
9104 case elfcpp::R_ARM_MOVT_BREL:
9105 reloc_status =
9106 Arm_relocate_functions::movt(view, object, psymval,
9107 relative_address_base);
9108 break;
9110 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9111 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9112 case elfcpp::R_ARM_THM_MOVW_BREL:
9113 reloc_status =
9114 Arm_relocate_functions::thm_movw(view, object, psymval,
9115 relative_address_base,
9116 thumb_bit, check_overflow);
9117 break;
9119 case elfcpp::R_ARM_THM_MOVT_PREL:
9120 case elfcpp::R_ARM_THM_MOVT_BREL:
9121 reloc_status =
9122 Arm_relocate_functions::thm_movt(view, object, psymval,
9123 relative_address_base);
9124 break;
9126 case elfcpp::R_ARM_REL32:
9127 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9128 address, thumb_bit);
9129 break;
9131 case elfcpp::R_ARM_THM_ABS5:
9132 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9133 reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9134 break;
9136 // Thumb long branches.
9137 case elfcpp::R_ARM_THM_CALL:
9138 case elfcpp::R_ARM_THM_XPC22:
9139 case elfcpp::R_ARM_THM_JUMP24:
9140 reloc_status =
9141 Arm_relocate_functions::thumb_branch_common(
9142 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9143 thumb_bit, is_weakly_undefined_without_plt);
9144 break;
9146 case elfcpp::R_ARM_GOTOFF32:
9148 Arm_address got_origin;
9149 got_origin = target->got_plt_section()->address();
9150 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9151 got_origin, thumb_bit);
9153 break;
9155 case elfcpp::R_ARM_BASE_PREL:
9156 gold_assert(gsym != NULL);
9157 reloc_status =
9158 Arm_relocate_functions::base_prel(view, sym_origin, address);
9159 break;
9161 case elfcpp::R_ARM_BASE_ABS:
9162 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9163 reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9164 break;
9166 case elfcpp::R_ARM_GOT_BREL:
9167 gold_assert(have_got_offset);
9168 reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9169 break;
9171 case elfcpp::R_ARM_GOT_PREL:
9172 gold_assert(have_got_offset);
9173 // Get the address origin for GOT PLT, which is allocated right
9174 // after the GOT section, to calculate an absolute address of
9175 // the symbol GOT entry (got_origin + got_offset).
9176 Arm_address got_origin;
9177 got_origin = target->got_plt_section()->address();
9178 reloc_status = Arm_relocate_functions::got_prel(view,
9179 got_origin + got_offset,
9180 address);
9181 break;
9183 case elfcpp::R_ARM_PLT32:
9184 case elfcpp::R_ARM_CALL:
9185 case elfcpp::R_ARM_JUMP24:
9186 case elfcpp::R_ARM_XPC25:
9187 gold_assert(gsym == NULL
9188 || gsym->has_plt_offset()
9189 || gsym->final_value_is_known()
9190 || (gsym->is_defined()
9191 && !gsym->is_from_dynobj()
9192 && !gsym->is_preemptible()));
9193 reloc_status =
9194 Arm_relocate_functions::arm_branch_common(
9195 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9196 thumb_bit, is_weakly_undefined_without_plt);
9197 break;
9199 case elfcpp::R_ARM_THM_JUMP19:
9200 reloc_status =
9201 Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9202 thumb_bit);
9203 break;
9205 case elfcpp::R_ARM_THM_JUMP6:
9206 reloc_status =
9207 Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9208 break;
9210 case elfcpp::R_ARM_THM_JUMP8:
9211 reloc_status =
9212 Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9213 break;
9215 case elfcpp::R_ARM_THM_JUMP11:
9216 reloc_status =
9217 Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9218 break;
9220 case elfcpp::R_ARM_PREL31:
9221 reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9222 address, thumb_bit);
9223 break;
9225 case elfcpp::R_ARM_V4BX:
9226 if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9228 const bool is_v4bx_interworking =
9229 (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9230 reloc_status =
9231 Arm_relocate_functions::v4bx(relinfo, view, object, address,
9232 is_v4bx_interworking);
9234 break;
9236 case elfcpp::R_ARM_THM_PC8:
9237 reloc_status =
9238 Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9239 break;
9241 case elfcpp::R_ARM_THM_PC12:
9242 reloc_status =
9243 Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9244 break;
9246 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9247 reloc_status =
9248 Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9249 thumb_bit);
9250 break;
9252 case elfcpp::R_ARM_ALU_PC_G0_NC:
9253 case elfcpp::R_ARM_ALU_PC_G0:
9254 case elfcpp::R_ARM_ALU_PC_G1_NC:
9255 case elfcpp::R_ARM_ALU_PC_G1:
9256 case elfcpp::R_ARM_ALU_PC_G2:
9257 case elfcpp::R_ARM_ALU_SB_G0_NC:
9258 case elfcpp::R_ARM_ALU_SB_G0:
9259 case elfcpp::R_ARM_ALU_SB_G1_NC:
9260 case elfcpp::R_ARM_ALU_SB_G1:
9261 case elfcpp::R_ARM_ALU_SB_G2:
9262 reloc_status =
9263 Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9264 reloc_property->group_index(),
9265 relative_address_base,
9266 thumb_bit, check_overflow);
9267 break;
9269 case elfcpp::R_ARM_LDR_PC_G0:
9270 case elfcpp::R_ARM_LDR_PC_G1:
9271 case elfcpp::R_ARM_LDR_PC_G2:
9272 case elfcpp::R_ARM_LDR_SB_G0:
9273 case elfcpp::R_ARM_LDR_SB_G1:
9274 case elfcpp::R_ARM_LDR_SB_G2:
9275 reloc_status =
9276 Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9277 reloc_property->group_index(),
9278 relative_address_base);
9279 break;
9281 case elfcpp::R_ARM_LDRS_PC_G0:
9282 case elfcpp::R_ARM_LDRS_PC_G1:
9283 case elfcpp::R_ARM_LDRS_PC_G2:
9284 case elfcpp::R_ARM_LDRS_SB_G0:
9285 case elfcpp::R_ARM_LDRS_SB_G1:
9286 case elfcpp::R_ARM_LDRS_SB_G2:
9287 reloc_status =
9288 Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9289 reloc_property->group_index(),
9290 relative_address_base);
9291 break;
9293 case elfcpp::R_ARM_LDC_PC_G0:
9294 case elfcpp::R_ARM_LDC_PC_G1:
9295 case elfcpp::R_ARM_LDC_PC_G2:
9296 case elfcpp::R_ARM_LDC_SB_G0:
9297 case elfcpp::R_ARM_LDC_SB_G1:
9298 case elfcpp::R_ARM_LDC_SB_G2:
9299 reloc_status =
9300 Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9301 reloc_property->group_index(),
9302 relative_address_base);
9303 break;
9305 // These are initial tls relocs, which are expected when
9306 // linking.
9307 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9308 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9309 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9310 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9311 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9312 reloc_status =
9313 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9314 view, address, view_size);
9315 break;
9317 // The known and unknown unsupported and/or deprecated relocations.
9318 case elfcpp::R_ARM_PC24:
9319 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9320 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9321 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9322 default:
9323 // Just silently leave the method. We should get an appropriate error
9324 // message in the scan methods.
9325 break;
9328 // Report any errors.
9329 switch (reloc_status)
9331 case Arm_relocate_functions::STATUS_OKAY:
9332 break;
9333 case Arm_relocate_functions::STATUS_OVERFLOW:
9334 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9335 _("relocation overflow in %s"),
9336 reloc_property->name().c_str());
9337 break;
9338 case Arm_relocate_functions::STATUS_BAD_RELOC:
9339 gold_error_at_location(
9340 relinfo,
9341 relnum,
9342 rel.get_r_offset(),
9343 _("unexpected opcode while processing relocation %s"),
9344 reloc_property->name().c_str());
9345 break;
9346 default:
9347 gold_unreachable();
9350 return true;
9353 // Perform a TLS relocation.
9355 template<bool big_endian>
9356 inline typename Arm_relocate_functions<big_endian>::Status
9357 Target_arm<big_endian>::Relocate::relocate_tls(
9358 const Relocate_info<32, big_endian>* relinfo,
9359 Target_arm<big_endian>* target,
9360 size_t relnum,
9361 const elfcpp::Rel<32, big_endian>& rel,
9362 unsigned int r_type,
9363 const Sized_symbol<32>* gsym,
9364 const Symbol_value<32>* psymval,
9365 unsigned char* view,
9366 elfcpp::Elf_types<32>::Elf_Addr address,
9367 section_size_type /*view_size*/ )
9369 typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9370 typedef Relocate_functions<32, big_endian> RelocFuncs;
9371 Output_segment* tls_segment = relinfo->layout->tls_segment();
9373 const Sized_relobj_file<32, big_endian>* object = relinfo->object;
9375 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9377 const bool is_final = (gsym == NULL
9378 ? !parameters->options().shared()
9379 : gsym->final_value_is_known());
9380 const tls::Tls_optimization optimized_type
9381 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9382 switch (r_type)
9384 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9386 unsigned int got_type = GOT_TYPE_TLS_PAIR;
9387 unsigned int got_offset;
9388 if (gsym != NULL)
9390 gold_assert(gsym->has_got_offset(got_type));
9391 got_offset = gsym->got_offset(got_type) - target->got_size();
9393 else
9395 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9396 gold_assert(object->local_has_got_offset(r_sym, got_type));
9397 got_offset = (object->local_got_offset(r_sym, got_type)
9398 - target->got_size());
9400 if (optimized_type == tls::TLSOPT_NONE)
9402 Arm_address got_entry =
9403 target->got_plt_section()->address() + got_offset;
9405 // Relocate the field with the PC relative offset of the pair of
9406 // GOT entries.
9407 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9408 return ArmRelocFuncs::STATUS_OKAY;
9411 break;
9413 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9414 if (optimized_type == tls::TLSOPT_NONE)
9416 // Relocate the field with the offset of the GOT entry for
9417 // the module index.
9418 unsigned int got_offset;
9419 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9420 - target->got_size());
9421 Arm_address got_entry =
9422 target->got_plt_section()->address() + got_offset;
9424 // Relocate the field with the PC relative offset of the pair of
9425 // GOT entries.
9426 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9427 return ArmRelocFuncs::STATUS_OKAY;
9429 break;
9431 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9432 RelocFuncs::rel32_unaligned(view, value);
9433 return ArmRelocFuncs::STATUS_OKAY;
9435 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9436 if (optimized_type == tls::TLSOPT_NONE)
9438 // Relocate the field with the offset of the GOT entry for
9439 // the tp-relative offset of the symbol.
9440 unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9441 unsigned int got_offset;
9442 if (gsym != NULL)
9444 gold_assert(gsym->has_got_offset(got_type));
9445 got_offset = gsym->got_offset(got_type);
9447 else
9449 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9450 gold_assert(object->local_has_got_offset(r_sym, got_type));
9451 got_offset = object->local_got_offset(r_sym, got_type);
9454 // All GOT offsets are relative to the end of the GOT.
9455 got_offset -= target->got_size();
9457 Arm_address got_entry =
9458 target->got_plt_section()->address() + got_offset;
9460 // Relocate the field with the PC relative offset of the GOT entry.
9461 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9462 return ArmRelocFuncs::STATUS_OKAY;
9464 break;
9466 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9467 // If we're creating a shared library, a dynamic relocation will
9468 // have been created for this location, so do not apply it now.
9469 if (!parameters->options().shared())
9471 gold_assert(tls_segment != NULL);
9473 // $tp points to the TCB, which is followed by the TLS, so we
9474 // need to add TCB size to the offset.
9475 Arm_address aligned_tcb_size =
9476 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9477 RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size);
9480 return ArmRelocFuncs::STATUS_OKAY;
9482 default:
9483 gold_unreachable();
9486 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9487 _("unsupported reloc %u"),
9488 r_type);
9489 return ArmRelocFuncs::STATUS_BAD_RELOC;
9492 // Relocate section data.
9494 template<bool big_endian>
9495 void
9496 Target_arm<big_endian>::relocate_section(
9497 const Relocate_info<32, big_endian>* relinfo,
9498 unsigned int sh_type,
9499 const unsigned char* prelocs,
9500 size_t reloc_count,
9501 Output_section* output_section,
9502 bool needs_special_offset_handling,
9503 unsigned char* view,
9504 Arm_address address,
9505 section_size_type view_size,
9506 const Reloc_symbol_changes* reloc_symbol_changes)
9508 typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
9509 gold_assert(sh_type == elfcpp::SHT_REL);
9511 // See if we are relocating a relaxed input section. If so, the view
9512 // covers the whole output section and we need to adjust accordingly.
9513 if (needs_special_offset_handling)
9515 const Output_relaxed_input_section* poris =
9516 output_section->find_relaxed_input_section(relinfo->object,
9517 relinfo->data_shndx);
9518 if (poris != NULL)
9520 Arm_address section_address = poris->address();
9521 section_size_type section_size = poris->data_size();
9523 gold_assert((section_address >= address)
9524 && ((section_address + section_size)
9525 <= (address + view_size)));
9527 off_t offset = section_address - address;
9528 view += offset;
9529 address += offset;
9530 view_size = section_size;
9534 gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
9535 Arm_relocate, gold::Default_comdat_behavior>(
9536 relinfo,
9537 this,
9538 prelocs,
9539 reloc_count,
9540 output_section,
9541 needs_special_offset_handling,
9542 view,
9543 address,
9544 view_size,
9545 reloc_symbol_changes);
9548 // Return the size of a relocation while scanning during a relocatable
9549 // link.
9551 template<bool big_endian>
9552 unsigned int
9553 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
9554 unsigned int r_type,
9555 Relobj* object)
9557 r_type = get_real_reloc_type(r_type);
9558 const Arm_reloc_property* arp =
9559 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9560 if (arp != NULL)
9561 return arp->size();
9562 else
9564 std::string reloc_name =
9565 arm_reloc_property_table->reloc_name_in_error_message(r_type);
9566 gold_error(_("%s: unexpected %s in object file"),
9567 object->name().c_str(), reloc_name.c_str());
9568 return 0;
9572 // Scan the relocs during a relocatable link.
9574 template<bool big_endian>
9575 void
9576 Target_arm<big_endian>::scan_relocatable_relocs(
9577 Symbol_table* symtab,
9578 Layout* layout,
9579 Sized_relobj_file<32, big_endian>* object,
9580 unsigned int data_shndx,
9581 unsigned int sh_type,
9582 const unsigned char* prelocs,
9583 size_t reloc_count,
9584 Output_section* output_section,
9585 bool needs_special_offset_handling,
9586 size_t local_symbol_count,
9587 const unsigned char* plocal_symbols,
9588 Relocatable_relocs* rr)
9590 gold_assert(sh_type == elfcpp::SHT_REL);
9592 typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
9593 Relocatable_size_for_reloc> Scan_relocatable_relocs;
9595 gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
9596 Scan_relocatable_relocs>(
9597 symtab,
9598 layout,
9599 object,
9600 data_shndx,
9601 prelocs,
9602 reloc_count,
9603 output_section,
9604 needs_special_offset_handling,
9605 local_symbol_count,
9606 plocal_symbols,
9607 rr);
9610 // Emit relocations for a section.
9612 template<bool big_endian>
9613 void
9614 Target_arm<big_endian>::relocate_relocs(
9615 const Relocate_info<32, big_endian>* relinfo,
9616 unsigned int sh_type,
9617 const unsigned char* prelocs,
9618 size_t reloc_count,
9619 Output_section* output_section,
9620 typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
9621 const Relocatable_relocs* rr,
9622 unsigned char* view,
9623 Arm_address view_address,
9624 section_size_type view_size,
9625 unsigned char* reloc_view,
9626 section_size_type reloc_view_size)
9628 gold_assert(sh_type == elfcpp::SHT_REL);
9630 gold::relocate_relocs<32, big_endian, elfcpp::SHT_REL>(
9631 relinfo,
9632 prelocs,
9633 reloc_count,
9634 output_section,
9635 offset_in_output_section,
9637 view,
9638 view_address,
9639 view_size,
9640 reloc_view,
9641 reloc_view_size);
9644 // Perform target-specific processing in a relocatable link. This is
9645 // only used if we use the relocation strategy RELOC_SPECIAL.
9647 template<bool big_endian>
9648 void
9649 Target_arm<big_endian>::relocate_special_relocatable(
9650 const Relocate_info<32, big_endian>* relinfo,
9651 unsigned int sh_type,
9652 const unsigned char* preloc_in,
9653 size_t relnum,
9654 Output_section* output_section,
9655 typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
9656 unsigned char* view,
9657 elfcpp::Elf_types<32>::Elf_Addr view_address,
9658 section_size_type,
9659 unsigned char* preloc_out)
9661 // We can only handle REL type relocation sections.
9662 gold_assert(sh_type == elfcpp::SHT_REL);
9664 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
9665 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
9666 Reltype_write;
9667 const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
9669 const Arm_relobj<big_endian>* object =
9670 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9671 const unsigned int local_count = object->local_symbol_count();
9673 Reltype reloc(preloc_in);
9674 Reltype_write reloc_write(preloc_out);
9676 elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
9677 const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9678 const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
9680 const Arm_reloc_property* arp =
9681 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9682 gold_assert(arp != NULL);
9684 // Get the new symbol index.
9685 // We only use RELOC_SPECIAL strategy in local relocations.
9686 gold_assert(r_sym < local_count);
9688 // We are adjusting a section symbol. We need to find
9689 // the symbol table index of the section symbol for
9690 // the output section corresponding to input section
9691 // in which this symbol is defined.
9692 bool is_ordinary;
9693 unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
9694 gold_assert(is_ordinary);
9695 Output_section* os = object->output_section(shndx);
9696 gold_assert(os != NULL);
9697 gold_assert(os->needs_symtab_index());
9698 unsigned int new_symndx = os->symtab_index();
9700 // Get the new offset--the location in the output section where
9701 // this relocation should be applied.
9703 Arm_address offset = reloc.get_r_offset();
9704 Arm_address new_offset;
9705 if (offset_in_output_section != invalid_address)
9706 new_offset = offset + offset_in_output_section;
9707 else
9709 section_offset_type sot_offset =
9710 convert_types<section_offset_type, Arm_address>(offset);
9711 section_offset_type new_sot_offset =
9712 output_section->output_offset(object, relinfo->data_shndx,
9713 sot_offset);
9714 gold_assert(new_sot_offset != -1);
9715 new_offset = new_sot_offset;
9718 // In an object file, r_offset is an offset within the section.
9719 // In an executable or dynamic object, generated by
9720 // --emit-relocs, r_offset is an absolute address.
9721 if (!parameters->options().relocatable())
9723 new_offset += view_address;
9724 if (offset_in_output_section != invalid_address)
9725 new_offset -= offset_in_output_section;
9728 reloc_write.put_r_offset(new_offset);
9729 reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
9731 // Handle the reloc addend.
9732 // The relocation uses a section symbol in the input file.
9733 // We are adjusting it to use a section symbol in the output
9734 // file. The input section symbol refers to some address in
9735 // the input section. We need the relocation in the output
9736 // file to refer to that same address. This adjustment to
9737 // the addend is the same calculation we use for a simple
9738 // absolute relocation for the input section symbol.
9740 const Symbol_value<32>* psymval = object->local_symbol(r_sym);
9742 // Handle THUMB bit.
9743 Symbol_value<32> symval;
9744 Arm_address thumb_bit =
9745 object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9746 if (thumb_bit != 0
9747 && arp->uses_thumb_bit()
9748 && ((psymval->value(object, 0) & 1) != 0))
9750 Arm_address stripped_value =
9751 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9752 symval.set_output_value(stripped_value);
9753 psymval = &symval;
9756 unsigned char* paddend = view + offset;
9757 typename Arm_relocate_functions<big_endian>::Status reloc_status =
9758 Arm_relocate_functions<big_endian>::STATUS_OKAY;
9759 switch (r_type)
9761 case elfcpp::R_ARM_ABS8:
9762 reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
9763 psymval);
9764 break;
9766 case elfcpp::R_ARM_ABS12:
9767 reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
9768 psymval);
9769 break;
9771 case elfcpp::R_ARM_ABS16:
9772 reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
9773 psymval);
9774 break;
9776 case elfcpp::R_ARM_THM_ABS5:
9777 reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
9778 object,
9779 psymval);
9780 break;
9782 case elfcpp::R_ARM_MOVW_ABS_NC:
9783 case elfcpp::R_ARM_MOVW_PREL_NC:
9784 case elfcpp::R_ARM_MOVW_BREL_NC:
9785 case elfcpp::R_ARM_MOVW_BREL:
9786 reloc_status = Arm_relocate_functions<big_endian>::movw(
9787 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9788 break;
9790 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9791 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9792 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9793 case elfcpp::R_ARM_THM_MOVW_BREL:
9794 reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
9795 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9796 break;
9798 case elfcpp::R_ARM_THM_CALL:
9799 case elfcpp::R_ARM_THM_XPC22:
9800 case elfcpp::R_ARM_THM_JUMP24:
9801 reloc_status =
9802 Arm_relocate_functions<big_endian>::thumb_branch_common(
9803 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9804 false);
9805 break;
9807 case elfcpp::R_ARM_PLT32:
9808 case elfcpp::R_ARM_CALL:
9809 case elfcpp::R_ARM_JUMP24:
9810 case elfcpp::R_ARM_XPC25:
9811 reloc_status =
9812 Arm_relocate_functions<big_endian>::arm_branch_common(
9813 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9814 false);
9815 break;
9817 case elfcpp::R_ARM_THM_JUMP19:
9818 reloc_status =
9819 Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
9820 psymval, 0, thumb_bit);
9821 break;
9823 case elfcpp::R_ARM_THM_JUMP6:
9824 reloc_status =
9825 Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
9827 break;
9829 case elfcpp::R_ARM_THM_JUMP8:
9830 reloc_status =
9831 Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
9833 break;
9835 case elfcpp::R_ARM_THM_JUMP11:
9836 reloc_status =
9837 Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
9839 break;
9841 case elfcpp::R_ARM_PREL31:
9842 reloc_status =
9843 Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
9844 thumb_bit);
9845 break;
9847 case elfcpp::R_ARM_THM_PC8:
9848 reloc_status =
9849 Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
9851 break;
9853 case elfcpp::R_ARM_THM_PC12:
9854 reloc_status =
9855 Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
9857 break;
9859 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9860 reloc_status =
9861 Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
9862 0, thumb_bit);
9863 break;
9865 // These relocation truncate relocation results so we cannot handle them
9866 // in a relocatable link.
9867 case elfcpp::R_ARM_MOVT_ABS:
9868 case elfcpp::R_ARM_THM_MOVT_ABS:
9869 case elfcpp::R_ARM_MOVT_PREL:
9870 case elfcpp::R_ARM_MOVT_BREL:
9871 case elfcpp::R_ARM_THM_MOVT_PREL:
9872 case elfcpp::R_ARM_THM_MOVT_BREL:
9873 case elfcpp::R_ARM_ALU_PC_G0_NC:
9874 case elfcpp::R_ARM_ALU_PC_G0:
9875 case elfcpp::R_ARM_ALU_PC_G1_NC:
9876 case elfcpp::R_ARM_ALU_PC_G1:
9877 case elfcpp::R_ARM_ALU_PC_G2:
9878 case elfcpp::R_ARM_ALU_SB_G0_NC:
9879 case elfcpp::R_ARM_ALU_SB_G0:
9880 case elfcpp::R_ARM_ALU_SB_G1_NC:
9881 case elfcpp::R_ARM_ALU_SB_G1:
9882 case elfcpp::R_ARM_ALU_SB_G2:
9883 case elfcpp::R_ARM_LDR_PC_G0:
9884 case elfcpp::R_ARM_LDR_PC_G1:
9885 case elfcpp::R_ARM_LDR_PC_G2:
9886 case elfcpp::R_ARM_LDR_SB_G0:
9887 case elfcpp::R_ARM_LDR_SB_G1:
9888 case elfcpp::R_ARM_LDR_SB_G2:
9889 case elfcpp::R_ARM_LDRS_PC_G0:
9890 case elfcpp::R_ARM_LDRS_PC_G1:
9891 case elfcpp::R_ARM_LDRS_PC_G2:
9892 case elfcpp::R_ARM_LDRS_SB_G0:
9893 case elfcpp::R_ARM_LDRS_SB_G1:
9894 case elfcpp::R_ARM_LDRS_SB_G2:
9895 case elfcpp::R_ARM_LDC_PC_G0:
9896 case elfcpp::R_ARM_LDC_PC_G1:
9897 case elfcpp::R_ARM_LDC_PC_G2:
9898 case elfcpp::R_ARM_LDC_SB_G0:
9899 case elfcpp::R_ARM_LDC_SB_G1:
9900 case elfcpp::R_ARM_LDC_SB_G2:
9901 gold_error(_("cannot handle %s in a relocatable link"),
9902 arp->name().c_str());
9903 break;
9905 default:
9906 gold_unreachable();
9909 // Report any errors.
9910 switch (reloc_status)
9912 case Arm_relocate_functions<big_endian>::STATUS_OKAY:
9913 break;
9914 case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
9915 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9916 _("relocation overflow in %s"),
9917 arp->name().c_str());
9918 break;
9919 case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
9920 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9921 _("unexpected opcode while processing relocation %s"),
9922 arp->name().c_str());
9923 break;
9924 default:
9925 gold_unreachable();
9929 // Return the value to use for a dynamic symbol which requires special
9930 // treatment. This is how we support equality comparisons of function
9931 // pointers across shared library boundaries, as described in the
9932 // processor specific ABI supplement.
9934 template<bool big_endian>
9935 uint64_t
9936 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
9938 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
9939 return this->plt_section()->address() + gsym->plt_offset();
9942 // Map platform-specific relocs to real relocs
9944 template<bool big_endian>
9945 unsigned int
9946 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
9948 switch (r_type)
9950 case elfcpp::R_ARM_TARGET1:
9951 // This is either R_ARM_ABS32 or R_ARM_REL32;
9952 return elfcpp::R_ARM_ABS32;
9954 case elfcpp::R_ARM_TARGET2:
9955 // This can be any reloc type but usually is R_ARM_GOT_PREL
9956 return elfcpp::R_ARM_GOT_PREL;
9958 default:
9959 return r_type;
9963 // Whether if two EABI versions V1 and V2 are compatible.
9965 template<bool big_endian>
9966 bool
9967 Target_arm<big_endian>::are_eabi_versions_compatible(
9968 elfcpp::Elf_Word v1,
9969 elfcpp::Elf_Word v2)
9971 // v4 and v5 are the same spec before and after it was released,
9972 // so allow mixing them.
9973 if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
9974 || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
9975 || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9976 return true;
9978 return v1 == v2;
9981 // Combine FLAGS from an input object called NAME and the processor-specific
9982 // flags in the ELF header of the output. Much of this is adapted from the
9983 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9984 // in bfd/elf32-arm.c.
9986 template<bool big_endian>
9987 void
9988 Target_arm<big_endian>::merge_processor_specific_flags(
9989 const std::string& name,
9990 elfcpp::Elf_Word flags)
9992 if (this->are_processor_specific_flags_set())
9994 elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9996 // Nothing to merge if flags equal to those in output.
9997 if (flags == out_flags)
9998 return;
10000 // Complain about various flag mismatches.
10001 elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
10002 elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
10003 if (!this->are_eabi_versions_compatible(version1, version2)
10004 && parameters->options().warn_mismatch())
10005 gold_error(_("Source object %s has EABI version %d but output has "
10006 "EABI version %d."),
10007 name.c_str(),
10008 (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
10009 (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
10011 else
10013 // If the input is the default architecture and had the default
10014 // flags then do not bother setting the flags for the output
10015 // architecture, instead allow future merges to do this. If no
10016 // future merges ever set these flags then they will retain their
10017 // uninitialised values, which surprise surprise, correspond
10018 // to the default values.
10019 if (flags == 0)
10020 return;
10022 // This is the first time, just copy the flags.
10023 // We only copy the EABI version for now.
10024 this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
10028 // Adjust ELF file header.
10029 template<bool big_endian>
10030 void
10031 Target_arm<big_endian>::do_adjust_elf_header(
10032 unsigned char* view,
10033 int len)
10035 gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
10037 elfcpp::Ehdr<32, big_endian> ehdr(view);
10038 elfcpp::Elf_Word flags = this->processor_specific_flags();
10039 unsigned char e_ident[elfcpp::EI_NIDENT];
10040 memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
10042 if (elfcpp::arm_eabi_version(flags)
10043 == elfcpp::EF_ARM_EABI_UNKNOWN)
10044 e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
10045 else
10046 e_ident[elfcpp::EI_OSABI] = 0;
10047 e_ident[elfcpp::EI_ABIVERSION] = 0;
10049 // FIXME: Do EF_ARM_BE8 adjustment.
10051 // If we're working in EABI_VER5, set the hard/soft float ABI flags
10052 // as appropriate.
10053 if (elfcpp::arm_eabi_version(flags) == elfcpp::EF_ARM_EABI_VER5)
10055 elfcpp::Elf_Half type = ehdr.get_e_type();
10056 if (type == elfcpp::ET_EXEC || type == elfcpp::ET_DYN)
10058 Object_attribute* attr = this->get_aeabi_object_attribute(elfcpp::Tag_ABI_VFP_args);
10059 if (attr->int_value())
10060 flags |= elfcpp::EF_ARM_ABI_FLOAT_HARD;
10061 else
10062 flags |= elfcpp::EF_ARM_ABI_FLOAT_SOFT;
10063 this->set_processor_specific_flags(flags);
10066 elfcpp::Ehdr_write<32, big_endian> oehdr(view);
10067 oehdr.put_e_ident(e_ident);
10070 // do_make_elf_object to override the same function in the base class.
10071 // We need to use a target-specific sub-class of
10072 // Sized_relobj_file<32, big_endian> to store ARM specific information.
10073 // Hence we need to have our own ELF object creation.
10075 template<bool big_endian>
10076 Object*
10077 Target_arm<big_endian>::do_make_elf_object(
10078 const std::string& name,
10079 Input_file* input_file,
10080 off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
10082 int et = ehdr.get_e_type();
10083 // ET_EXEC files are valid input for --just-symbols/-R,
10084 // and we treat them as relocatable objects.
10085 if (et == elfcpp::ET_REL
10086 || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
10088 Arm_relobj<big_endian>* obj =
10089 new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
10090 obj->setup();
10091 return obj;
10093 else if (et == elfcpp::ET_DYN)
10095 Sized_dynobj<32, big_endian>* obj =
10096 new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
10097 obj->setup();
10098 return obj;
10100 else
10102 gold_error(_("%s: unsupported ELF file type %d"),
10103 name.c_str(), et);
10104 return NULL;
10108 // Read the architecture from the Tag_also_compatible_with attribute, if any.
10109 // Returns -1 if no architecture could be read.
10110 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
10112 template<bool big_endian>
10114 Target_arm<big_endian>::get_secondary_compatible_arch(
10115 const Attributes_section_data* pasd)
10117 const Object_attribute* known_attributes =
10118 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10120 // Note: the tag and its argument below are uleb128 values, though
10121 // currently-defined values fit in one byte for each.
10122 const std::string& sv =
10123 known_attributes[elfcpp::Tag_also_compatible_with].string_value();
10124 if (sv.size() == 2
10125 && sv.data()[0] == elfcpp::Tag_CPU_arch
10126 && (sv.data()[1] & 128) != 128)
10127 return sv.data()[1];
10129 // This tag is "safely ignorable", so don't complain if it looks funny.
10130 return -1;
10133 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10134 // The tag is removed if ARCH is -1.
10135 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10137 template<bool big_endian>
10138 void
10139 Target_arm<big_endian>::set_secondary_compatible_arch(
10140 Attributes_section_data* pasd,
10141 int arch)
10143 Object_attribute* known_attributes =
10144 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10146 if (arch == -1)
10148 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10149 return;
10152 // Note: the tag and its argument below are uleb128 values, though
10153 // currently-defined values fit in one byte for each.
10154 char sv[3];
10155 sv[0] = elfcpp::Tag_CPU_arch;
10156 gold_assert(arch != 0);
10157 sv[1] = arch;
10158 sv[2] = '\0';
10160 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10163 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10164 // into account.
10165 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10167 template<bool big_endian>
10169 Target_arm<big_endian>::tag_cpu_arch_combine(
10170 const char* name,
10171 int oldtag,
10172 int* secondary_compat_out,
10173 int newtag,
10174 int secondary_compat)
10176 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10177 static const int v6t2[] =
10179 T(V6T2), // PRE_V4.
10180 T(V6T2), // V4.
10181 T(V6T2), // V4T.
10182 T(V6T2), // V5T.
10183 T(V6T2), // V5TE.
10184 T(V6T2), // V5TEJ.
10185 T(V6T2), // V6.
10186 T(V7), // V6KZ.
10187 T(V6T2) // V6T2.
10189 static const int v6k[] =
10191 T(V6K), // PRE_V4.
10192 T(V6K), // V4.
10193 T(V6K), // V4T.
10194 T(V6K), // V5T.
10195 T(V6K), // V5TE.
10196 T(V6K), // V5TEJ.
10197 T(V6K), // V6.
10198 T(V6KZ), // V6KZ.
10199 T(V7), // V6T2.
10200 T(V6K) // V6K.
10202 static const int v7[] =
10204 T(V7), // PRE_V4.
10205 T(V7), // V4.
10206 T(V7), // V4T.
10207 T(V7), // V5T.
10208 T(V7), // V5TE.
10209 T(V7), // V5TEJ.
10210 T(V7), // V6.
10211 T(V7), // V6KZ.
10212 T(V7), // V6T2.
10213 T(V7), // V6K.
10214 T(V7) // V7.
10216 static const int v6_m[] =
10218 -1, // PRE_V4.
10219 -1, // V4.
10220 T(V6K), // V4T.
10221 T(V6K), // V5T.
10222 T(V6K), // V5TE.
10223 T(V6K), // V5TEJ.
10224 T(V6K), // V6.
10225 T(V6KZ), // V6KZ.
10226 T(V7), // V6T2.
10227 T(V6K), // V6K.
10228 T(V7), // V7.
10229 T(V6_M) // V6_M.
10231 static const int v6s_m[] =
10233 -1, // PRE_V4.
10234 -1, // V4.
10235 T(V6K), // V4T.
10236 T(V6K), // V5T.
10237 T(V6K), // V5TE.
10238 T(V6K), // V5TEJ.
10239 T(V6K), // V6.
10240 T(V6KZ), // V6KZ.
10241 T(V7), // V6T2.
10242 T(V6K), // V6K.
10243 T(V7), // V7.
10244 T(V6S_M), // V6_M.
10245 T(V6S_M) // V6S_M.
10247 static const int v7e_m[] =
10249 -1, // PRE_V4.
10250 -1, // V4.
10251 T(V7E_M), // V4T.
10252 T(V7E_M), // V5T.
10253 T(V7E_M), // V5TE.
10254 T(V7E_M), // V5TEJ.
10255 T(V7E_M), // V6.
10256 T(V7E_M), // V6KZ.
10257 T(V7E_M), // V6T2.
10258 T(V7E_M), // V6K.
10259 T(V7E_M), // V7.
10260 T(V7E_M), // V6_M.
10261 T(V7E_M), // V6S_M.
10262 T(V7E_M) // V7E_M.
10264 static const int v4t_plus_v6_m[] =
10266 -1, // PRE_V4.
10267 -1, // V4.
10268 T(V4T), // V4T.
10269 T(V5T), // V5T.
10270 T(V5TE), // V5TE.
10271 T(V5TEJ), // V5TEJ.
10272 T(V6), // V6.
10273 T(V6KZ), // V6KZ.
10274 T(V6T2), // V6T2.
10275 T(V6K), // V6K.
10276 T(V7), // V7.
10277 T(V6_M), // V6_M.
10278 T(V6S_M), // V6S_M.
10279 T(V7E_M), // V7E_M.
10280 T(V4T_PLUS_V6_M) // V4T plus V6_M.
10282 static const int* comb[] =
10284 v6t2,
10285 v6k,
10287 v6_m,
10288 v6s_m,
10289 v7e_m,
10290 // Pseudo-architecture.
10291 v4t_plus_v6_m
10294 // Check we've not got a higher architecture than we know about.
10296 if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10298 gold_error(_("%s: unknown CPU architecture"), name);
10299 return -1;
10302 // Override old tag if we have a Tag_also_compatible_with on the output.
10304 if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10305 || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10306 oldtag = T(V4T_PLUS_V6_M);
10308 // And override the new tag if we have a Tag_also_compatible_with on the
10309 // input.
10311 if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10312 || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10313 newtag = T(V4T_PLUS_V6_M);
10315 // Architectures before V6KZ add features monotonically.
10316 int tagh = std::max(oldtag, newtag);
10317 if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10318 return tagh;
10320 int tagl = std::min(oldtag, newtag);
10321 int result = comb[tagh - T(V6T2)][tagl];
10323 // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10324 // as the canonical version.
10325 if (result == T(V4T_PLUS_V6_M))
10327 result = T(V4T);
10328 *secondary_compat_out = T(V6_M);
10330 else
10331 *secondary_compat_out = -1;
10333 if (result == -1)
10335 gold_error(_("%s: conflicting CPU architectures %d/%d"),
10336 name, oldtag, newtag);
10337 return -1;
10340 return result;
10341 #undef T
10344 // Helper to print AEABI enum tag value.
10346 template<bool big_endian>
10347 std::string
10348 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10350 static const char* aeabi_enum_names[] =
10351 { "", "variable-size", "32-bit", "" };
10352 const size_t aeabi_enum_names_size =
10353 sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10355 if (value < aeabi_enum_names_size)
10356 return std::string(aeabi_enum_names[value]);
10357 else
10359 char buffer[100];
10360 sprintf(buffer, "<unknown value %u>", value);
10361 return std::string(buffer);
10365 // Return the string value to store in TAG_CPU_name.
10367 template<bool big_endian>
10368 std::string
10369 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10371 static const char* name_table[] = {
10372 // These aren't real CPU names, but we can't guess
10373 // that from the architecture version alone.
10374 "Pre v4",
10375 "ARM v4",
10376 "ARM v4T",
10377 "ARM v5T",
10378 "ARM v5TE",
10379 "ARM v5TEJ",
10380 "ARM v6",
10381 "ARM v6KZ",
10382 "ARM v6T2",
10383 "ARM v6K",
10384 "ARM v7",
10385 "ARM v6-M",
10386 "ARM v6S-M",
10387 "ARM v7E-M"
10389 const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10391 if (value < name_table_size)
10392 return std::string(name_table[value]);
10393 else
10395 char buffer[100];
10396 sprintf(buffer, "<unknown CPU value %u>", value);
10397 return std::string(buffer);
10401 // Query attributes object to see if integer divide instructions may be
10402 // present in an object.
10404 template<bool big_endian>
10405 bool
10406 Target_arm<big_endian>::attributes_accept_div(int arch, int profile,
10407 const Object_attribute* div_attr)
10409 switch (div_attr->int_value())
10411 case 0:
10412 // Integer divide allowed if instruction contained in
10413 // archetecture.
10414 if (arch == elfcpp::TAG_CPU_ARCH_V7 && (profile == 'R' || profile == 'M'))
10415 return true;
10416 else if (arch >= elfcpp::TAG_CPU_ARCH_V7E_M)
10417 return true;
10418 else
10419 return false;
10421 case 1:
10422 // Integer divide explicitly prohibited.
10423 return false;
10425 default:
10426 // Unrecognised case - treat as allowing divide everywhere.
10427 case 2:
10428 // Integer divide allowed in ARM state.
10429 return true;
10433 // Query attributes object to see if integer divide instructions are
10434 // forbidden to be in the object. This is not the inverse of
10435 // attributes_accept_div.
10437 template<bool big_endian>
10438 bool
10439 Target_arm<big_endian>::attributes_forbid_div(const Object_attribute* div_attr)
10441 return div_attr->int_value() == 1;
10444 // Merge object attributes from input file called NAME with those of the
10445 // output. The input object attributes are in the object pointed by PASD.
10447 template<bool big_endian>
10448 void
10449 Target_arm<big_endian>::merge_object_attributes(
10450 const char* name,
10451 const Attributes_section_data* pasd)
10453 // Return if there is no attributes section data.
10454 if (pasd == NULL)
10455 return;
10457 // If output has no object attributes, just copy.
10458 const int vendor = Object_attribute::OBJ_ATTR_PROC;
10459 if (this->attributes_section_data_ == NULL)
10461 this->attributes_section_data_ = new Attributes_section_data(*pasd);
10462 Object_attribute* out_attr =
10463 this->attributes_section_data_->known_attributes(vendor);
10465 // We do not output objects with Tag_MPextension_use_legacy - we move
10466 // the attribute's value to Tag_MPextension_use. */
10467 if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10469 if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10470 && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10471 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10473 gold_error(_("%s has both the current and legacy "
10474 "Tag_MPextension_use attributes"),
10475 name);
10478 out_attr[elfcpp::Tag_MPextension_use] =
10479 out_attr[elfcpp::Tag_MPextension_use_legacy];
10480 out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10481 out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10484 return;
10487 const Object_attribute* in_attr = pasd->known_attributes(vendor);
10488 Object_attribute* out_attr =
10489 this->attributes_section_data_->known_attributes(vendor);
10491 // This needs to happen before Tag_ABI_FP_number_model is merged. */
10492 if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10493 != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10495 // Ignore mismatches if the object doesn't use floating point. */
10496 if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
10497 out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10498 in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10499 else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10500 && parameters->options().warn_mismatch())
10501 gold_error(_("%s uses VFP register arguments, output does not"),
10502 name);
10505 for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10507 // Merge this attribute with existing attributes.
10508 switch (i)
10510 case elfcpp::Tag_CPU_raw_name:
10511 case elfcpp::Tag_CPU_name:
10512 // These are merged after Tag_CPU_arch.
10513 break;
10515 case elfcpp::Tag_ABI_optimization_goals:
10516 case elfcpp::Tag_ABI_FP_optimization_goals:
10517 // Use the first value seen.
10518 break;
10520 case elfcpp::Tag_CPU_arch:
10522 unsigned int saved_out_attr = out_attr->int_value();
10523 // Merge Tag_CPU_arch and Tag_also_compatible_with.
10524 int secondary_compat =
10525 this->get_secondary_compatible_arch(pasd);
10526 int secondary_compat_out =
10527 this->get_secondary_compatible_arch(
10528 this->attributes_section_data_);
10529 out_attr[i].set_int_value(
10530 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10531 &secondary_compat_out,
10532 in_attr[i].int_value(),
10533 secondary_compat));
10534 this->set_secondary_compatible_arch(this->attributes_section_data_,
10535 secondary_compat_out);
10537 // Merge Tag_CPU_name and Tag_CPU_raw_name.
10538 if (out_attr[i].int_value() == saved_out_attr)
10539 ; // Leave the names alone.
10540 else if (out_attr[i].int_value() == in_attr[i].int_value())
10542 // The output architecture has been changed to match the
10543 // input architecture. Use the input names.
10544 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10545 in_attr[elfcpp::Tag_CPU_name].string_value());
10546 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10547 in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10549 else
10551 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10552 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10555 // If we still don't have a value for Tag_CPU_name,
10556 // make one up now. Tag_CPU_raw_name remains blank.
10557 if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10559 const std::string cpu_name =
10560 this->tag_cpu_name_value(out_attr[i].int_value());
10561 // FIXME: If we see an unknown CPU, this will be set
10562 // to "<unknown CPU n>", where n is the attribute value.
10563 // This is different from BFD, which leaves the name alone.
10564 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10567 break;
10569 case elfcpp::Tag_ARM_ISA_use:
10570 case elfcpp::Tag_THUMB_ISA_use:
10571 case elfcpp::Tag_WMMX_arch:
10572 case elfcpp::Tag_Advanced_SIMD_arch:
10573 // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10574 case elfcpp::Tag_ABI_FP_rounding:
10575 case elfcpp::Tag_ABI_FP_exceptions:
10576 case elfcpp::Tag_ABI_FP_user_exceptions:
10577 case elfcpp::Tag_ABI_FP_number_model:
10578 case elfcpp::Tag_VFP_HP_extension:
10579 case elfcpp::Tag_CPU_unaligned_access:
10580 case elfcpp::Tag_T2EE_use:
10581 case elfcpp::Tag_Virtualization_use:
10582 case elfcpp::Tag_MPextension_use:
10583 // Use the largest value specified.
10584 if (in_attr[i].int_value() > out_attr[i].int_value())
10585 out_attr[i].set_int_value(in_attr[i].int_value());
10586 break;
10588 case elfcpp::Tag_ABI_align8_preserved:
10589 case elfcpp::Tag_ABI_PCS_RO_data:
10590 // Use the smallest value specified.
10591 if (in_attr[i].int_value() < out_attr[i].int_value())
10592 out_attr[i].set_int_value(in_attr[i].int_value());
10593 break;
10595 case elfcpp::Tag_ABI_align8_needed:
10596 if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10597 && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10598 || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10599 == 0)))
10601 // This error message should be enabled once all non-conforming
10602 // binaries in the toolchain have had the attributes set
10603 // properly.
10604 // gold_error(_("output 8-byte data alignment conflicts with %s"),
10605 // name);
10607 // Fall through.
10608 case elfcpp::Tag_ABI_FP_denormal:
10609 case elfcpp::Tag_ABI_PCS_GOT_use:
10611 // These tags have 0 = don't care, 1 = strong requirement,
10612 // 2 = weak requirement.
10613 static const int order_021[3] = {0, 2, 1};
10615 // Use the "greatest" from the sequence 0, 2, 1, or the largest
10616 // value if greater than 2 (for future-proofing).
10617 if ((in_attr[i].int_value() > 2
10618 && in_attr[i].int_value() > out_attr[i].int_value())
10619 || (in_attr[i].int_value() <= 2
10620 && out_attr[i].int_value() <= 2
10621 && (order_021[in_attr[i].int_value()]
10622 > order_021[out_attr[i].int_value()])))
10623 out_attr[i].set_int_value(in_attr[i].int_value());
10625 break;
10627 case elfcpp::Tag_CPU_arch_profile:
10628 if (out_attr[i].int_value() != in_attr[i].int_value())
10630 // 0 will merge with anything.
10631 // 'A' and 'S' merge to 'A'.
10632 // 'R' and 'S' merge to 'R'.
10633 // 'M' and 'A|R|S' is an error.
10634 if (out_attr[i].int_value() == 0
10635 || (out_attr[i].int_value() == 'S'
10636 && (in_attr[i].int_value() == 'A'
10637 || in_attr[i].int_value() == 'R')))
10638 out_attr[i].set_int_value(in_attr[i].int_value());
10639 else if (in_attr[i].int_value() == 0
10640 || (in_attr[i].int_value() == 'S'
10641 && (out_attr[i].int_value() == 'A'
10642 || out_attr[i].int_value() == 'R')))
10643 ; // Do nothing.
10644 else if (parameters->options().warn_mismatch())
10646 gold_error
10647 (_("conflicting architecture profiles %c/%c"),
10648 in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10649 out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10652 break;
10653 case elfcpp::Tag_VFP_arch:
10655 static const struct
10657 int ver;
10658 int regs;
10659 } vfp_versions[7] =
10661 {0, 0},
10662 {1, 16},
10663 {2, 16},
10664 {3, 32},
10665 {3, 16},
10666 {4, 32},
10667 {4, 16}
10670 // Values greater than 6 aren't defined, so just pick the
10671 // biggest.
10672 if (in_attr[i].int_value() > 6
10673 && in_attr[i].int_value() > out_attr[i].int_value())
10675 *out_attr = *in_attr;
10676 break;
10678 // The output uses the superset of input features
10679 // (ISA version) and registers.
10680 int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10681 vfp_versions[out_attr[i].int_value()].ver);
10682 int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10683 vfp_versions[out_attr[i].int_value()].regs);
10684 // This assumes all possible supersets are also a valid
10685 // options.
10686 int newval;
10687 for (newval = 6; newval > 0; newval--)
10689 if (regs == vfp_versions[newval].regs
10690 && ver == vfp_versions[newval].ver)
10691 break;
10693 out_attr[i].set_int_value(newval);
10695 break;
10696 case elfcpp::Tag_PCS_config:
10697 if (out_attr[i].int_value() == 0)
10698 out_attr[i].set_int_value(in_attr[i].int_value());
10699 else if (in_attr[i].int_value() != 0
10700 && out_attr[i].int_value() != 0
10701 && parameters->options().warn_mismatch())
10703 // It's sometimes ok to mix different configs, so this is only
10704 // a warning.
10705 gold_warning(_("%s: conflicting platform configuration"), name);
10707 break;
10708 case elfcpp::Tag_ABI_PCS_R9_use:
10709 if (in_attr[i].int_value() != out_attr[i].int_value()
10710 && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10711 && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10712 && parameters->options().warn_mismatch())
10714 gold_error(_("%s: conflicting use of R9"), name);
10716 if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10717 out_attr[i].set_int_value(in_attr[i].int_value());
10718 break;
10719 case elfcpp::Tag_ABI_PCS_RW_data:
10720 if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10721 && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10722 != elfcpp::AEABI_R9_SB)
10723 && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10724 != elfcpp::AEABI_R9_unused)
10725 && parameters->options().warn_mismatch())
10727 gold_error(_("%s: SB relative addressing conflicts with use "
10728 "of R9"),
10729 name);
10731 // Use the smallest value specified.
10732 if (in_attr[i].int_value() < out_attr[i].int_value())
10733 out_attr[i].set_int_value(in_attr[i].int_value());
10734 break;
10735 case elfcpp::Tag_ABI_PCS_wchar_t:
10736 if (out_attr[i].int_value()
10737 && in_attr[i].int_value()
10738 && out_attr[i].int_value() != in_attr[i].int_value()
10739 && parameters->options().warn_mismatch()
10740 && parameters->options().wchar_size_warning())
10742 gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10743 "use %u-byte wchar_t; use of wchar_t values "
10744 "across objects may fail"),
10745 name, in_attr[i].int_value(),
10746 out_attr[i].int_value());
10748 else if (in_attr[i].int_value() && !out_attr[i].int_value())
10749 out_attr[i].set_int_value(in_attr[i].int_value());
10750 break;
10751 case elfcpp::Tag_ABI_enum_size:
10752 if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10754 if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10755 || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10757 // The existing object is compatible with anything.
10758 // Use whatever requirements the new object has.
10759 out_attr[i].set_int_value(in_attr[i].int_value());
10761 else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10762 && out_attr[i].int_value() != in_attr[i].int_value()
10763 && parameters->options().warn_mismatch()
10764 && parameters->options().enum_size_warning())
10766 unsigned int in_value = in_attr[i].int_value();
10767 unsigned int out_value = out_attr[i].int_value();
10768 gold_warning(_("%s uses %s enums yet the output is to use "
10769 "%s enums; use of enum values across objects "
10770 "may fail"),
10771 name,
10772 this->aeabi_enum_name(in_value).c_str(),
10773 this->aeabi_enum_name(out_value).c_str());
10776 break;
10777 case elfcpp::Tag_ABI_VFP_args:
10778 // Already done.
10779 break;
10780 case elfcpp::Tag_ABI_WMMX_args:
10781 if (in_attr[i].int_value() != out_attr[i].int_value()
10782 && parameters->options().warn_mismatch())
10784 gold_error(_("%s uses iWMMXt register arguments, output does "
10785 "not"),
10786 name);
10788 break;
10789 case Object_attribute::Tag_compatibility:
10790 // Merged in target-independent code.
10791 break;
10792 case elfcpp::Tag_ABI_HardFP_use:
10793 // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10794 if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10795 || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10796 out_attr[i].set_int_value(3);
10797 else if (in_attr[i].int_value() > out_attr[i].int_value())
10798 out_attr[i].set_int_value(in_attr[i].int_value());
10799 break;
10800 case elfcpp::Tag_ABI_FP_16bit_format:
10801 if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10803 if (in_attr[i].int_value() != out_attr[i].int_value()
10804 && parameters->options().warn_mismatch())
10805 gold_error(_("fp16 format mismatch between %s and output"),
10806 name);
10808 if (in_attr[i].int_value() != 0)
10809 out_attr[i].set_int_value(in_attr[i].int_value());
10810 break;
10812 case elfcpp::Tag_DIV_use:
10814 // A value of zero on input means that the divide
10815 // instruction may be used if available in the base
10816 // architecture as specified via Tag_CPU_arch and
10817 // Tag_CPU_arch_profile. A value of 1 means that the user
10818 // did not want divide instructions. A value of 2
10819 // explicitly means that divide instructions were allowed
10820 // in ARM and Thumb state.
10821 int arch = this->
10822 get_aeabi_object_attribute(elfcpp::Tag_CPU_arch)->
10823 int_value();
10824 int profile = this->
10825 get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile)->
10826 int_value();
10827 if (in_attr[i].int_value() == out_attr[i].int_value())
10829 // Do nothing.
10831 else if (attributes_forbid_div(&in_attr[i])
10832 && !attributes_accept_div(arch, profile, &out_attr[i]))
10833 out_attr[i].set_int_value(1);
10834 else if (attributes_forbid_div(&out_attr[i])
10835 && attributes_accept_div(arch, profile, &in_attr[i]))
10836 out_attr[i].set_int_value(in_attr[i].int_value());
10837 else if (in_attr[i].int_value() == 2)
10838 out_attr[i].set_int_value(in_attr[i].int_value());
10840 break;
10842 case elfcpp::Tag_MPextension_use_legacy:
10843 // We don't output objects with Tag_MPextension_use_legacy - we
10844 // move the value to Tag_MPextension_use.
10845 if (in_attr[i].int_value() != 0
10846 && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10848 if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10849 != in_attr[i].int_value())
10851 gold_error(_("%s has has both the current and legacy "
10852 "Tag_MPextension_use attributes"),
10853 name);
10857 if (in_attr[i].int_value()
10858 > out_attr[elfcpp::Tag_MPextension_use].int_value())
10859 out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10861 break;
10863 case elfcpp::Tag_nodefaults:
10864 // This tag is set if it exists, but the value is unused (and is
10865 // typically zero). We don't actually need to do anything here -
10866 // the merge happens automatically when the type flags are merged
10867 // below.
10868 break;
10869 case elfcpp::Tag_also_compatible_with:
10870 // Already done in Tag_CPU_arch.
10871 break;
10872 case elfcpp::Tag_conformance:
10873 // Keep the attribute if it matches. Throw it away otherwise.
10874 // No attribute means no claim to conform.
10875 if (in_attr[i].string_value() != out_attr[i].string_value())
10876 out_attr[i].set_string_value("");
10877 break;
10879 default:
10881 const char* err_object = NULL;
10883 // The "known_obj_attributes" table does contain some undefined
10884 // attributes. Ensure that there are unused.
10885 if (out_attr[i].int_value() != 0
10886 || out_attr[i].string_value() != "")
10887 err_object = "output";
10888 else if (in_attr[i].int_value() != 0
10889 || in_attr[i].string_value() != "")
10890 err_object = name;
10892 if (err_object != NULL
10893 && parameters->options().warn_mismatch())
10895 // Attribute numbers >=64 (mod 128) can be safely ignored.
10896 if ((i & 127) < 64)
10897 gold_error(_("%s: unknown mandatory EABI object attribute "
10898 "%d"),
10899 err_object, i);
10900 else
10901 gold_warning(_("%s: unknown EABI object attribute %d"),
10902 err_object, i);
10905 // Only pass on attributes that match in both inputs.
10906 if (!in_attr[i].matches(out_attr[i]))
10908 out_attr[i].set_int_value(0);
10909 out_attr[i].set_string_value("");
10914 // If out_attr was copied from in_attr then it won't have a type yet.
10915 if (in_attr[i].type() && !out_attr[i].type())
10916 out_attr[i].set_type(in_attr[i].type());
10919 // Merge Tag_compatibility attributes and any common GNU ones.
10920 this->attributes_section_data_->merge(name, pasd);
10922 // Check for any attributes not known on ARM.
10923 typedef Vendor_object_attributes::Other_attributes Other_attributes;
10924 const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10925 Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10926 Other_attributes* out_other_attributes =
10927 this->attributes_section_data_->other_attributes(vendor);
10928 Other_attributes::iterator out_iter = out_other_attributes->begin();
10930 while (in_iter != in_other_attributes->end()
10931 || out_iter != out_other_attributes->end())
10933 const char* err_object = NULL;
10934 int err_tag = 0;
10936 // The tags for each list are in numerical order.
10937 // If the tags are equal, then merge.
10938 if (out_iter != out_other_attributes->end()
10939 && (in_iter == in_other_attributes->end()
10940 || in_iter->first > out_iter->first))
10942 // This attribute only exists in output. We can't merge, and we
10943 // don't know what the tag means, so delete it.
10944 err_object = "output";
10945 err_tag = out_iter->first;
10946 int saved_tag = out_iter->first;
10947 delete out_iter->second;
10948 out_other_attributes->erase(out_iter);
10949 out_iter = out_other_attributes->upper_bound(saved_tag);
10951 else if (in_iter != in_other_attributes->end()
10952 && (out_iter != out_other_attributes->end()
10953 || in_iter->first < out_iter->first))
10955 // This attribute only exists in input. We can't merge, and we
10956 // don't know what the tag means, so ignore it.
10957 err_object = name;
10958 err_tag = in_iter->first;
10959 ++in_iter;
10961 else // The tags are equal.
10963 // As present, all attributes in the list are unknown, and
10964 // therefore can't be merged meaningfully.
10965 err_object = "output";
10966 err_tag = out_iter->first;
10968 // Only pass on attributes that match in both inputs.
10969 if (!in_iter->second->matches(*(out_iter->second)))
10971 // No match. Delete the attribute.
10972 int saved_tag = out_iter->first;
10973 delete out_iter->second;
10974 out_other_attributes->erase(out_iter);
10975 out_iter = out_other_attributes->upper_bound(saved_tag);
10977 else
10979 // Matched. Keep the attribute and move to the next.
10980 ++out_iter;
10981 ++in_iter;
10985 if (err_object && parameters->options().warn_mismatch())
10987 // Attribute numbers >=64 (mod 128) can be safely ignored. */
10988 if ((err_tag & 127) < 64)
10990 gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10991 err_object, err_tag);
10993 else
10995 gold_warning(_("%s: unknown EABI object attribute %d"),
10996 err_object, err_tag);
11002 // Stub-generation methods for Target_arm.
11004 // Make a new Arm_input_section object.
11006 template<bool big_endian>
11007 Arm_input_section<big_endian>*
11008 Target_arm<big_endian>::new_arm_input_section(
11009 Relobj* relobj,
11010 unsigned int shndx)
11012 Section_id sid(relobj, shndx);
11014 Arm_input_section<big_endian>* arm_input_section =
11015 new Arm_input_section<big_endian>(relobj, shndx);
11016 arm_input_section->init();
11018 // Register new Arm_input_section in map for look-up.
11019 std::pair<typename Arm_input_section_map::iterator, bool> ins =
11020 this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
11022 // Make sure that it we have not created another Arm_input_section
11023 // for this input section already.
11024 gold_assert(ins.second);
11026 return arm_input_section;
11029 // Find the Arm_input_section object corresponding to the SHNDX-th input
11030 // section of RELOBJ.
11032 template<bool big_endian>
11033 Arm_input_section<big_endian>*
11034 Target_arm<big_endian>::find_arm_input_section(
11035 Relobj* relobj,
11036 unsigned int shndx) const
11038 Section_id sid(relobj, shndx);
11039 typename Arm_input_section_map::const_iterator p =
11040 this->arm_input_section_map_.find(sid);
11041 return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
11044 // Make a new stub table.
11046 template<bool big_endian>
11047 Stub_table<big_endian>*
11048 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
11050 Stub_table<big_endian>* stub_table =
11051 new Stub_table<big_endian>(owner);
11052 this->stub_tables_.push_back(stub_table);
11054 stub_table->set_address(owner->address() + owner->data_size());
11055 stub_table->set_file_offset(owner->offset() + owner->data_size());
11056 stub_table->finalize_data_size();
11058 return stub_table;
11061 // Scan a relocation for stub generation.
11063 template<bool big_endian>
11064 void
11065 Target_arm<big_endian>::scan_reloc_for_stub(
11066 const Relocate_info<32, big_endian>* relinfo,
11067 unsigned int r_type,
11068 const Sized_symbol<32>* gsym,
11069 unsigned int r_sym,
11070 const Symbol_value<32>* psymval,
11071 elfcpp::Elf_types<32>::Elf_Swxword addend,
11072 Arm_address address)
11074 const Arm_relobj<big_endian>* arm_relobj =
11075 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11077 bool target_is_thumb;
11078 Symbol_value<32> symval;
11079 if (gsym != NULL)
11081 // This is a global symbol. Determine if we use PLT and if the
11082 // final target is THUMB.
11083 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
11085 // This uses a PLT, change the symbol value.
11086 symval.set_output_value(this->plt_section()->address()
11087 + gsym->plt_offset());
11088 psymval = &symval;
11089 target_is_thumb = false;
11091 else if (gsym->is_undefined())
11092 // There is no need to generate a stub symbol is undefined.
11093 return;
11094 else
11096 target_is_thumb =
11097 ((gsym->type() == elfcpp::STT_ARM_TFUNC)
11098 || (gsym->type() == elfcpp::STT_FUNC
11099 && !gsym->is_undefined()
11100 && ((psymval->value(arm_relobj, 0) & 1) != 0)));
11103 else
11105 // This is a local symbol. Determine if the final target is THUMB.
11106 target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
11109 // Strip LSB if this points to a THUMB target.
11110 const Arm_reloc_property* reloc_property =
11111 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
11112 gold_assert(reloc_property != NULL);
11113 if (target_is_thumb
11114 && reloc_property->uses_thumb_bit()
11115 && ((psymval->value(arm_relobj, 0) & 1) != 0))
11117 Arm_address stripped_value =
11118 psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
11119 symval.set_output_value(stripped_value);
11120 psymval = &symval;
11123 // Get the symbol value.
11124 Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
11126 // Owing to pipelining, the PC relative branches below actually skip
11127 // two instructions when the branch offset is 0.
11128 Arm_address destination;
11129 switch (r_type)
11131 case elfcpp::R_ARM_CALL:
11132 case elfcpp::R_ARM_JUMP24:
11133 case elfcpp::R_ARM_PLT32:
11134 // ARM branches.
11135 destination = value + addend + 8;
11136 break;
11137 case elfcpp::R_ARM_THM_CALL:
11138 case elfcpp::R_ARM_THM_XPC22:
11139 case elfcpp::R_ARM_THM_JUMP24:
11140 case elfcpp::R_ARM_THM_JUMP19:
11141 // THUMB branches.
11142 destination = value + addend + 4;
11143 break;
11144 default:
11145 gold_unreachable();
11148 Reloc_stub* stub = NULL;
11149 Stub_type stub_type =
11150 Reloc_stub::stub_type_for_reloc(r_type, address, destination,
11151 target_is_thumb);
11152 if (stub_type != arm_stub_none)
11154 // Try looking up an existing stub from a stub table.
11155 Stub_table<big_endian>* stub_table =
11156 arm_relobj->stub_table(relinfo->data_shndx);
11157 gold_assert(stub_table != NULL);
11159 // Locate stub by destination.
11160 Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
11162 // Create a stub if there is not one already
11163 stub = stub_table->find_reloc_stub(stub_key);
11164 if (stub == NULL)
11166 // create a new stub and add it to stub table.
11167 stub = this->stub_factory().make_reloc_stub(stub_type);
11168 stub_table->add_reloc_stub(stub, stub_key);
11171 // Record the destination address.
11172 stub->set_destination_address(destination
11173 | (target_is_thumb ? 1 : 0));
11176 // For Cortex-A8, we need to record a relocation at 4K page boundary.
11177 if (this->fix_cortex_a8_
11178 && (r_type == elfcpp::R_ARM_THM_JUMP24
11179 || r_type == elfcpp::R_ARM_THM_JUMP19
11180 || r_type == elfcpp::R_ARM_THM_CALL
11181 || r_type == elfcpp::R_ARM_THM_XPC22)
11182 && (address & 0xfffU) == 0xffeU)
11184 // Found a candidate. Note we haven't checked the destination is
11185 // within 4K here: if we do so (and don't create a record) we can't
11186 // tell that a branch should have been relocated when scanning later.
11187 this->cortex_a8_relocs_info_[address] =
11188 new Cortex_a8_reloc(stub, r_type,
11189 destination | (target_is_thumb ? 1 : 0));
11193 // This function scans a relocation sections for stub generation.
11194 // The template parameter Relocate must be a class type which provides
11195 // a single function, relocate(), which implements the machine
11196 // specific part of a relocation.
11198 // BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type:
11199 // SHT_REL or SHT_RELA.
11201 // PRELOCS points to the relocation data. RELOC_COUNT is the number
11202 // of relocs. OUTPUT_SECTION is the output section.
11203 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11204 // mapped to output offsets.
11206 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11207 // VIEW_SIZE is the size. These refer to the input section, unless
11208 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11209 // the output section.
11211 template<bool big_endian>
11212 template<int sh_type>
11213 void inline
11214 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11215 const Relocate_info<32, big_endian>* relinfo,
11216 const unsigned char* prelocs,
11217 size_t reloc_count,
11218 Output_section* output_section,
11219 bool needs_special_offset_handling,
11220 const unsigned char* view,
11221 elfcpp::Elf_types<32>::Elf_Addr view_address,
11222 section_size_type)
11224 typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11225 const int reloc_size =
11226 Reloc_types<sh_type, 32, big_endian>::reloc_size;
11228 Arm_relobj<big_endian>* arm_object =
11229 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11230 unsigned int local_count = arm_object->local_symbol_count();
11232 gold::Default_comdat_behavior default_comdat_behavior;
11233 Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11235 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11237 Reltype reloc(prelocs);
11239 typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11240 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11241 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11243 r_type = this->get_real_reloc_type(r_type);
11245 // Only a few relocation types need stubs.
11246 if ((r_type != elfcpp::R_ARM_CALL)
11247 && (r_type != elfcpp::R_ARM_JUMP24)
11248 && (r_type != elfcpp::R_ARM_PLT32)
11249 && (r_type != elfcpp::R_ARM_THM_CALL)
11250 && (r_type != elfcpp::R_ARM_THM_XPC22)
11251 && (r_type != elfcpp::R_ARM_THM_JUMP24)
11252 && (r_type != elfcpp::R_ARM_THM_JUMP19)
11253 && (r_type != elfcpp::R_ARM_V4BX))
11254 continue;
11256 section_offset_type offset =
11257 convert_to_section_size_type(reloc.get_r_offset());
11259 if (needs_special_offset_handling)
11261 offset = output_section->output_offset(relinfo->object,
11262 relinfo->data_shndx,
11263 offset);
11264 if (offset == -1)
11265 continue;
11268 // Create a v4bx stub if --fix-v4bx-interworking is used.
11269 if (r_type == elfcpp::R_ARM_V4BX)
11271 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11273 // Get the BX instruction.
11274 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11275 const Valtype* wv =
11276 reinterpret_cast<const Valtype*>(view + offset);
11277 elfcpp::Elf_types<32>::Elf_Swxword insn =
11278 elfcpp::Swap<32, big_endian>::readval(wv);
11279 const uint32_t reg = (insn & 0xf);
11281 if (reg < 0xf)
11283 // Try looking up an existing stub from a stub table.
11284 Stub_table<big_endian>* stub_table =
11285 arm_object->stub_table(relinfo->data_shndx);
11286 gold_assert(stub_table != NULL);
11288 if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11290 // create a new stub and add it to stub table.
11291 Arm_v4bx_stub* stub =
11292 this->stub_factory().make_arm_v4bx_stub(reg);
11293 gold_assert(stub != NULL);
11294 stub_table->add_arm_v4bx_stub(stub);
11298 continue;
11301 // Get the addend.
11302 Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11303 elfcpp::Elf_types<32>::Elf_Swxword addend =
11304 stub_addend_reader(r_type, view + offset, reloc);
11306 const Sized_symbol<32>* sym;
11308 Symbol_value<32> symval;
11309 const Symbol_value<32> *psymval;
11310 bool is_defined_in_discarded_section;
11311 unsigned int shndx;
11312 if (r_sym < local_count)
11314 sym = NULL;
11315 psymval = arm_object->local_symbol(r_sym);
11317 // If the local symbol belongs to a section we are discarding,
11318 // and that section is a debug section, try to find the
11319 // corresponding kept section and map this symbol to its
11320 // counterpart in the kept section. The symbol must not
11321 // correspond to a section we are folding.
11322 bool is_ordinary;
11323 shndx = psymval->input_shndx(&is_ordinary);
11324 is_defined_in_discarded_section =
11325 (is_ordinary
11326 && shndx != elfcpp::SHN_UNDEF
11327 && !arm_object->is_section_included(shndx)
11328 && !relinfo->symtab->is_section_folded(arm_object, shndx));
11330 // We need to compute the would-be final value of this local
11331 // symbol.
11332 if (!is_defined_in_discarded_section)
11334 typedef Sized_relobj_file<32, big_endian> ObjType;
11335 typename ObjType::Compute_final_local_value_status status =
11336 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11337 relinfo->symtab);
11338 if (status == ObjType::CFLV_OK)
11340 // Currently we cannot handle a branch to a target in
11341 // a merged section. If this is the case, issue an error
11342 // and also free the merge symbol value.
11343 if (!symval.has_output_value())
11345 const std::string& section_name =
11346 arm_object->section_name(shndx);
11347 arm_object->error(_("cannot handle branch to local %u "
11348 "in a merged section %s"),
11349 r_sym, section_name.c_str());
11351 psymval = &symval;
11353 else
11355 // We cannot determine the final value.
11356 continue;
11360 else
11362 const Symbol* gsym;
11363 gsym = arm_object->global_symbol(r_sym);
11364 gold_assert(gsym != NULL);
11365 if (gsym->is_forwarder())
11366 gsym = relinfo->symtab->resolve_forwards(gsym);
11368 sym = static_cast<const Sized_symbol<32>*>(gsym);
11369 if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11370 symval.set_output_symtab_index(sym->symtab_index());
11371 else
11372 symval.set_no_output_symtab_entry();
11374 // We need to compute the would-be final value of this global
11375 // symbol.
11376 const Symbol_table* symtab = relinfo->symtab;
11377 const Sized_symbol<32>* sized_symbol =
11378 symtab->get_sized_symbol<32>(gsym);
11379 Symbol_table::Compute_final_value_status status;
11380 Arm_address value =
11381 symtab->compute_final_value<32>(sized_symbol, &status);
11383 // Skip this if the symbol has not output section.
11384 if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11385 continue;
11386 symval.set_output_value(value);
11388 if (gsym->type() == elfcpp::STT_TLS)
11389 symval.set_is_tls_symbol();
11390 else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11391 symval.set_is_ifunc_symbol();
11392 psymval = &symval;
11394 is_defined_in_discarded_section =
11395 (gsym->is_defined_in_discarded_section()
11396 && gsym->is_undefined());
11397 shndx = 0;
11400 Symbol_value<32> symval2;
11401 if (is_defined_in_discarded_section)
11403 if (comdat_behavior == CB_UNDETERMINED)
11405 std::string name = arm_object->section_name(relinfo->data_shndx);
11406 comdat_behavior = default_comdat_behavior.get(name.c_str());
11408 if (comdat_behavior == CB_PRETEND)
11410 // FIXME: This case does not work for global symbols.
11411 // We have no place to store the original section index.
11412 // Fortunately this does not matter for comdat sections,
11413 // only for sections explicitly discarded by a linker
11414 // script.
11415 bool found;
11416 typename elfcpp::Elf_types<32>::Elf_Addr value =
11417 arm_object->map_to_kept_section(shndx, &found);
11418 if (found)
11419 symval2.set_output_value(value + psymval->input_value());
11420 else
11421 symval2.set_output_value(0);
11423 else
11425 if (comdat_behavior == CB_WARNING)
11426 gold_warning_at_location(relinfo, i, offset,
11427 _("relocation refers to discarded "
11428 "section"));
11429 symval2.set_output_value(0);
11431 symval2.set_no_output_symtab_entry();
11432 psymval = &symval2;
11435 // If symbol is a section symbol, we don't know the actual type of
11436 // destination. Give up.
11437 if (psymval->is_section_symbol())
11438 continue;
11440 this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11441 addend, view_address + offset);
11445 // Scan an input section for stub generation.
11447 template<bool big_endian>
11448 void
11449 Target_arm<big_endian>::scan_section_for_stubs(
11450 const Relocate_info<32, big_endian>* relinfo,
11451 unsigned int sh_type,
11452 const unsigned char* prelocs,
11453 size_t reloc_count,
11454 Output_section* output_section,
11455 bool needs_special_offset_handling,
11456 const unsigned char* view,
11457 Arm_address view_address,
11458 section_size_type view_size)
11460 if (sh_type == elfcpp::SHT_REL)
11461 this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11462 relinfo,
11463 prelocs,
11464 reloc_count,
11465 output_section,
11466 needs_special_offset_handling,
11467 view,
11468 view_address,
11469 view_size);
11470 else if (sh_type == elfcpp::SHT_RELA)
11471 // We do not support RELA type relocations yet. This is provided for
11472 // completeness.
11473 this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11474 relinfo,
11475 prelocs,
11476 reloc_count,
11477 output_section,
11478 needs_special_offset_handling,
11479 view,
11480 view_address,
11481 view_size);
11482 else
11483 gold_unreachable();
11486 // Group input sections for stub generation.
11488 // We group input sections in an output section so that the total size,
11489 // including any padding space due to alignment is smaller than GROUP_SIZE
11490 // unless the only input section in group is bigger than GROUP_SIZE already.
11491 // Then an ARM stub table is created to follow the last input section
11492 // in group. For each group an ARM stub table is created an is placed
11493 // after the last group. If STUB_ALWAYS_AFTER_BRANCH is false, we further
11494 // extend the group after the stub table.
11496 template<bool big_endian>
11497 void
11498 Target_arm<big_endian>::group_sections(
11499 Layout* layout,
11500 section_size_type group_size,
11501 bool stubs_always_after_branch,
11502 const Task* task)
11504 // Group input sections and insert stub table
11505 Layout::Section_list section_list;
11506 layout->get_executable_sections(&section_list);
11507 for (Layout::Section_list::const_iterator p = section_list.begin();
11508 p != section_list.end();
11509 ++p)
11511 Arm_output_section<big_endian>* output_section =
11512 Arm_output_section<big_endian>::as_arm_output_section(*p);
11513 output_section->group_sections(group_size, stubs_always_after_branch,
11514 this, task);
11518 // Relaxation hook. This is where we do stub generation.
11520 template<bool big_endian>
11521 bool
11522 Target_arm<big_endian>::do_relax(
11523 int pass,
11524 const Input_objects* input_objects,
11525 Symbol_table* symtab,
11526 Layout* layout,
11527 const Task* task)
11529 // No need to generate stubs if this is a relocatable link.
11530 gold_assert(!parameters->options().relocatable());
11532 // If this is the first pass, we need to group input sections into
11533 // stub groups.
11534 bool done_exidx_fixup = false;
11535 typedef typename Stub_table_list::iterator Stub_table_iterator;
11536 if (pass == 1)
11538 // Determine the stub group size. The group size is the absolute
11539 // value of the parameter --stub-group-size. If --stub-group-size
11540 // is passed a negative value, we restrict stubs to be always after
11541 // the stubbed branches.
11542 int32_t stub_group_size_param =
11543 parameters->options().stub_group_size();
11544 bool stubs_always_after_branch = stub_group_size_param < 0;
11545 section_size_type stub_group_size = abs(stub_group_size_param);
11547 if (stub_group_size == 1)
11549 // Default value.
11550 // Thumb branch range is +-4MB has to be used as the default
11551 // maximum size (a given section can contain both ARM and Thumb
11552 // code, so the worst case has to be taken into account). If we are
11553 // fixing cortex-a8 errata, the branch range has to be even smaller,
11554 // since wide conditional branch has a range of +-1MB only.
11556 // This value is 48K less than that, which allows for 4096
11557 // 12-byte stubs. If we exceed that, then we will fail to link.
11558 // The user will have to relink with an explicit group size
11559 // option.
11560 stub_group_size = 4145152;
11563 // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11564 // page as the first half of a 32-bit branch straddling two 4K pages.
11565 // This is a crude way of enforcing that. In addition, long conditional
11566 // branches of THUMB-2 have a range of +-1M. If we are fixing cortex-A8
11567 // erratum, limit the group size to (1M - 12k) to avoid unreachable
11568 // cortex-A8 stubs from long conditional branches.
11569 if (this->fix_cortex_a8_)
11571 stubs_always_after_branch = true;
11572 const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11573 stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11576 group_sections(layout, stub_group_size, stubs_always_after_branch, task);
11578 // Also fix .ARM.exidx section coverage.
11579 Arm_output_section<big_endian>* exidx_output_section = NULL;
11580 for (Layout::Section_list::const_iterator p =
11581 layout->section_list().begin();
11582 p != layout->section_list().end();
11583 ++p)
11584 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11586 if (exidx_output_section == NULL)
11587 exidx_output_section =
11588 Arm_output_section<big_endian>::as_arm_output_section(*p);
11589 else
11590 // We cannot handle this now.
11591 gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11592 "non-relocatable link"),
11593 exidx_output_section->name(),
11594 (*p)->name());
11597 if (exidx_output_section != NULL)
11599 this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11600 symtab, task);
11601 done_exidx_fixup = true;
11604 else
11606 // If this is not the first pass, addresses and file offsets have
11607 // been reset at this point, set them here.
11608 for (Stub_table_iterator sp = this->stub_tables_.begin();
11609 sp != this->stub_tables_.end();
11610 ++sp)
11612 Arm_input_section<big_endian>* owner = (*sp)->owner();
11613 off_t off = align_address(owner->original_size(),
11614 (*sp)->addralign());
11615 (*sp)->set_address_and_file_offset(owner->address() + off,
11616 owner->offset() + off);
11620 // The Cortex-A8 stubs are sensitive to layout of code sections. At the
11621 // beginning of each relaxation pass, just blow away all the stubs.
11622 // Alternatively, we could selectively remove only the stubs and reloc
11623 // information for code sections that have moved since the last pass.
11624 // That would require more book-keeping.
11625 if (this->fix_cortex_a8_)
11627 // Clear all Cortex-A8 reloc information.
11628 for (typename Cortex_a8_relocs_info::const_iterator p =
11629 this->cortex_a8_relocs_info_.begin();
11630 p != this->cortex_a8_relocs_info_.end();
11631 ++p)
11632 delete p->second;
11633 this->cortex_a8_relocs_info_.clear();
11635 // Remove all Cortex-A8 stubs.
11636 for (Stub_table_iterator sp = this->stub_tables_.begin();
11637 sp != this->stub_tables_.end();
11638 ++sp)
11639 (*sp)->remove_all_cortex_a8_stubs();
11642 // Scan relocs for relocation stubs
11643 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11644 op != input_objects->relobj_end();
11645 ++op)
11647 Arm_relobj<big_endian>* arm_relobj =
11648 Arm_relobj<big_endian>::as_arm_relobj(*op);
11649 // Lock the object so we can read from it. This is only called
11650 // single-threaded from Layout::finalize, so it is OK to lock.
11651 Task_lock_obj<Object> tl(task, arm_relobj);
11652 arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11655 // Check all stub tables to see if any of them have their data sizes
11656 // or addresses alignments changed. These are the only things that
11657 // matter.
11658 bool any_stub_table_changed = false;
11659 Unordered_set<const Output_section*> sections_needing_adjustment;
11660 for (Stub_table_iterator sp = this->stub_tables_.begin();
11661 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11662 ++sp)
11664 if ((*sp)->update_data_size_and_addralign())
11666 // Update data size of stub table owner.
11667 Arm_input_section<big_endian>* owner = (*sp)->owner();
11668 uint64_t address = owner->address();
11669 off_t offset = owner->offset();
11670 owner->reset_address_and_file_offset();
11671 owner->set_address_and_file_offset(address, offset);
11673 sections_needing_adjustment.insert(owner->output_section());
11674 any_stub_table_changed = true;
11678 // Output_section_data::output_section() returns a const pointer but we
11679 // need to update output sections, so we record all output sections needing
11680 // update above and scan the sections here to find out what sections need
11681 // to be updated.
11682 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
11683 p != layout->section_list().end();
11684 ++p)
11686 if (sections_needing_adjustment.find(*p)
11687 != sections_needing_adjustment.end())
11688 (*p)->set_section_offsets_need_adjustment();
11691 // Stop relaxation if no EXIDX fix-up and no stub table change.
11692 bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11694 // Finalize the stubs in the last relaxation pass.
11695 if (!continue_relaxation)
11697 for (Stub_table_iterator sp = this->stub_tables_.begin();
11698 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11699 ++sp)
11700 (*sp)->finalize_stubs();
11702 // Update output local symbol counts of objects if necessary.
11703 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11704 op != input_objects->relobj_end();
11705 ++op)
11707 Arm_relobj<big_endian>* arm_relobj =
11708 Arm_relobj<big_endian>::as_arm_relobj(*op);
11710 // Update output local symbol counts. We need to discard local
11711 // symbols defined in parts of input sections that are discarded by
11712 // relaxation.
11713 if (arm_relobj->output_local_symbol_count_needs_update())
11715 // We need to lock the object's file to update it.
11716 Task_lock_obj<Object> tl(task, arm_relobj);
11717 arm_relobj->update_output_local_symbol_count();
11722 return continue_relaxation;
11725 // Relocate a stub.
11727 template<bool big_endian>
11728 void
11729 Target_arm<big_endian>::relocate_stub(
11730 Stub* stub,
11731 const Relocate_info<32, big_endian>* relinfo,
11732 Output_section* output_section,
11733 unsigned char* view,
11734 Arm_address address,
11735 section_size_type view_size)
11737 Relocate relocate;
11738 const Stub_template* stub_template = stub->stub_template();
11739 for (size_t i = 0; i < stub_template->reloc_count(); i++)
11741 size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11742 const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11744 unsigned int r_type = insn->r_type();
11745 section_size_type reloc_offset = stub_template->reloc_offset(i);
11746 section_size_type reloc_size = insn->size();
11747 gold_assert(reloc_offset + reloc_size <= view_size);
11749 // This is the address of the stub destination.
11750 Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11751 Symbol_value<32> symval;
11752 symval.set_output_value(target);
11754 // Synthesize a fake reloc just in case. We don't have a symbol so
11755 // we use 0.
11756 unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11757 memset(reloc_buffer, 0, sizeof(reloc_buffer));
11758 elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11759 reloc_write.put_r_offset(reloc_offset);
11760 reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11761 elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11763 relocate.relocate(relinfo, this, output_section,
11764 this->fake_relnum_for_stubs, rel, r_type,
11765 NULL, &symval, view + reloc_offset,
11766 address + reloc_offset, reloc_size);
11770 // Determine whether an object attribute tag takes an integer, a
11771 // string or both.
11773 template<bool big_endian>
11775 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11777 if (tag == Object_attribute::Tag_compatibility)
11778 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11779 | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11780 else if (tag == elfcpp::Tag_nodefaults)
11781 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11782 | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11783 else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11784 return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11785 else if (tag < 32)
11786 return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11787 else
11788 return ((tag & 1) != 0
11789 ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11790 : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11793 // Reorder attributes.
11795 // The ABI defines that Tag_conformance should be emitted first, and that
11796 // Tag_nodefaults should be second (if either is defined). This sets those
11797 // two positions, and bumps up the position of all the remaining tags to
11798 // compensate.
11800 template<bool big_endian>
11802 Target_arm<big_endian>::do_attributes_order(int num) const
11804 // Reorder the known object attributes in output. We want to move
11805 // Tag_conformance to position 4 and Tag_conformance to position 5
11806 // and shift everything between 4 .. Tag_conformance - 1 to make room.
11807 if (num == 4)
11808 return elfcpp::Tag_conformance;
11809 if (num == 5)
11810 return elfcpp::Tag_nodefaults;
11811 if ((num - 2) < elfcpp::Tag_nodefaults)
11812 return num - 2;
11813 if ((num - 1) < elfcpp::Tag_conformance)
11814 return num - 1;
11815 return num;
11818 // Scan a span of THUMB code for Cortex-A8 erratum.
11820 template<bool big_endian>
11821 void
11822 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11823 Arm_relobj<big_endian>* arm_relobj,
11824 unsigned int shndx,
11825 section_size_type span_start,
11826 section_size_type span_end,
11827 const unsigned char* view,
11828 Arm_address address)
11830 // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11832 // The opcode is BLX.W, BL.W, B.W, Bcc.W
11833 // The branch target is in the same 4KB region as the
11834 // first half of the branch.
11835 // The instruction before the branch is a 32-bit
11836 // length non-branch instruction.
11837 section_size_type i = span_start;
11838 bool last_was_32bit = false;
11839 bool last_was_branch = false;
11840 while (i < span_end)
11842 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11843 const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11844 uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11845 bool is_blx = false, is_b = false;
11846 bool is_bl = false, is_bcc = false;
11848 bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11849 if (insn_32bit)
11851 // Load the rest of the insn (in manual-friendly order).
11852 insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11854 // Encoding T4: B<c>.W.
11855 is_b = (insn & 0xf800d000U) == 0xf0009000U;
11856 // Encoding T1: BL<c>.W.
11857 is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11858 // Encoding T2: BLX<c>.W.
11859 is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11860 // Encoding T3: B<c>.W (not permitted in IT block).
11861 is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11862 && (insn & 0x07f00000U) != 0x03800000U);
11865 bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11867 // If this instruction is a 32-bit THUMB branch that crosses a 4K
11868 // page boundary and it follows 32-bit non-branch instruction,
11869 // we need to work around.
11870 if (is_32bit_branch
11871 && ((address + i) & 0xfffU) == 0xffeU
11872 && last_was_32bit
11873 && !last_was_branch)
11875 // Check to see if there is a relocation stub for this branch.
11876 bool force_target_arm = false;
11877 bool force_target_thumb = false;
11878 const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11879 Cortex_a8_relocs_info::const_iterator p =
11880 this->cortex_a8_relocs_info_.find(address + i);
11882 if (p != this->cortex_a8_relocs_info_.end())
11884 cortex_a8_reloc = p->second;
11885 bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11887 if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11888 && !target_is_thumb)
11889 force_target_arm = true;
11890 else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11891 && target_is_thumb)
11892 force_target_thumb = true;
11895 off_t offset;
11896 Stub_type stub_type = arm_stub_none;
11898 // Check if we have an offending branch instruction.
11899 uint16_t upper_insn = (insn >> 16) & 0xffffU;
11900 uint16_t lower_insn = insn & 0xffffU;
11901 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
11903 if (cortex_a8_reloc != NULL
11904 && cortex_a8_reloc->reloc_stub() != NULL)
11905 // We've already made a stub for this instruction, e.g.
11906 // it's a long branch or a Thumb->ARM stub. Assume that
11907 // stub will suffice to work around the A8 erratum (see
11908 // setting of always_after_branch above).
11910 else if (is_bcc)
11912 offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11913 lower_insn);
11914 stub_type = arm_stub_a8_veneer_b_cond;
11916 else if (is_b || is_bl || is_blx)
11918 offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11919 lower_insn);
11920 if (is_blx)
11921 offset &= ~3;
11923 stub_type = (is_blx
11924 ? arm_stub_a8_veneer_blx
11925 : (is_bl
11926 ? arm_stub_a8_veneer_bl
11927 : arm_stub_a8_veneer_b));
11930 if (stub_type != arm_stub_none)
11932 Arm_address pc_for_insn = address + i + 4;
11934 // The original instruction is a BL, but the target is
11935 // an ARM instruction. If we were not making a stub,
11936 // the BL would have been converted to a BLX. Use the
11937 // BLX stub instead in that case.
11938 if (this->may_use_v5t_interworking() && force_target_arm
11939 && stub_type == arm_stub_a8_veneer_bl)
11941 stub_type = arm_stub_a8_veneer_blx;
11942 is_blx = true;
11943 is_bl = false;
11945 // Conversely, if the original instruction was
11946 // BLX but the target is Thumb mode, use the BL stub.
11947 else if (force_target_thumb
11948 && stub_type == arm_stub_a8_veneer_blx)
11950 stub_type = arm_stub_a8_veneer_bl;
11951 is_blx = false;
11952 is_bl = true;
11955 if (is_blx)
11956 pc_for_insn &= ~3;
11958 // If we found a relocation, use the proper destination,
11959 // not the offset in the (unrelocated) instruction.
11960 // Note this is always done if we switched the stub type above.
11961 if (cortex_a8_reloc != NULL)
11962 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11964 Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11966 // Add a new stub if destination address in in the same page.
11967 if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11969 Cortex_a8_stub* stub =
11970 this->stub_factory_.make_cortex_a8_stub(stub_type,
11971 arm_relobj, shndx,
11972 address + i,
11973 target, insn);
11974 Stub_table<big_endian>* stub_table =
11975 arm_relobj->stub_table(shndx);
11976 gold_assert(stub_table != NULL);
11977 stub_table->add_cortex_a8_stub(address + i, stub);
11982 i += insn_32bit ? 4 : 2;
11983 last_was_32bit = insn_32bit;
11984 last_was_branch = is_32bit_branch;
11988 // Apply the Cortex-A8 workaround.
11990 template<bool big_endian>
11991 void
11992 Target_arm<big_endian>::apply_cortex_a8_workaround(
11993 const Cortex_a8_stub* stub,
11994 Arm_address stub_address,
11995 unsigned char* insn_view,
11996 Arm_address insn_address)
11998 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11999 Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
12000 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
12001 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
12002 off_t branch_offset = stub_address - (insn_address + 4);
12004 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12005 switch (stub->stub_template()->type())
12007 case arm_stub_a8_veneer_b_cond:
12008 // For a conditional branch, we re-write it to be an unconditional
12009 // branch to the stub. We use the THUMB-2 encoding here.
12010 upper_insn = 0xf000U;
12011 lower_insn = 0xb800U;
12012 // Fall through
12013 case arm_stub_a8_veneer_b:
12014 case arm_stub_a8_veneer_bl:
12015 case arm_stub_a8_veneer_blx:
12016 if ((lower_insn & 0x5000U) == 0x4000U)
12017 // For a BLX instruction, make sure that the relocation is
12018 // rounded up to a word boundary. This follows the semantics of
12019 // the instruction which specifies that bit 1 of the target
12020 // address will come from bit 1 of the base address.
12021 branch_offset = (branch_offset + 2) & ~3;
12023 // Put BRANCH_OFFSET back into the insn.
12024 gold_assert(!Bits<25>::has_overflow32(branch_offset));
12025 upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
12026 lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
12027 break;
12029 default:
12030 gold_unreachable();
12033 // Put the relocated value back in the object file:
12034 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
12035 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
12038 // Target selector for ARM. Note this is never instantiated directly.
12039 // It's only used in Target_selector_arm_nacl, below.
12041 template<bool big_endian>
12042 class Target_selector_arm : public Target_selector
12044 public:
12045 Target_selector_arm()
12046 : Target_selector(elfcpp::EM_ARM, 32, big_endian,
12047 (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
12048 (big_endian ? "armelfb" : "armelf"))
12051 Target*
12052 do_instantiate_target()
12053 { return new Target_arm<big_endian>(); }
12056 // Fix .ARM.exidx section coverage.
12058 template<bool big_endian>
12059 void
12060 Target_arm<big_endian>::fix_exidx_coverage(
12061 Layout* layout,
12062 const Input_objects* input_objects,
12063 Arm_output_section<big_endian>* exidx_section,
12064 Symbol_table* symtab,
12065 const Task* task)
12067 // We need to look at all the input sections in output in ascending
12068 // order of of output address. We do that by building a sorted list
12069 // of output sections by addresses. Then we looks at the output sections
12070 // in order. The input sections in an output section are already sorted
12071 // by addresses within the output section.
12073 typedef std::set<Output_section*, output_section_address_less_than>
12074 Sorted_output_section_list;
12075 Sorted_output_section_list sorted_output_sections;
12077 // Find out all the output sections of input sections pointed by
12078 // EXIDX input sections.
12079 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
12080 p != input_objects->relobj_end();
12081 ++p)
12083 Arm_relobj<big_endian>* arm_relobj =
12084 Arm_relobj<big_endian>::as_arm_relobj(*p);
12085 std::vector<unsigned int> shndx_list;
12086 arm_relobj->get_exidx_shndx_list(&shndx_list);
12087 for (size_t i = 0; i < shndx_list.size(); ++i)
12089 const Arm_exidx_input_section* exidx_input_section =
12090 arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
12091 gold_assert(exidx_input_section != NULL);
12092 if (!exidx_input_section->has_errors())
12094 unsigned int text_shndx = exidx_input_section->link();
12095 Output_section* os = arm_relobj->output_section(text_shndx);
12096 if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
12097 sorted_output_sections.insert(os);
12102 // Go over the output sections in ascending order of output addresses.
12103 typedef typename Arm_output_section<big_endian>::Text_section_list
12104 Text_section_list;
12105 Text_section_list sorted_text_sections;
12106 for (typename Sorted_output_section_list::iterator p =
12107 sorted_output_sections.begin();
12108 p != sorted_output_sections.end();
12109 ++p)
12111 Arm_output_section<big_endian>* arm_output_section =
12112 Arm_output_section<big_endian>::as_arm_output_section(*p);
12113 arm_output_section->append_text_sections_to_list(&sorted_text_sections);
12116 exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
12117 merge_exidx_entries(), task);
12120 template<bool big_endian>
12121 void
12122 Target_arm<big_endian>::do_define_standard_symbols(
12123 Symbol_table* symtab,
12124 Layout* layout)
12126 // Handle the .ARM.exidx section.
12127 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
12129 if (exidx_section != NULL)
12131 // Create __exidx_start and __exidx_end symbols.
12132 symtab->define_in_output_data("__exidx_start",
12133 NULL, // version
12134 Symbol_table::PREDEFINED,
12135 exidx_section,
12136 0, // value
12137 0, // symsize
12138 elfcpp::STT_NOTYPE,
12139 elfcpp::STB_GLOBAL,
12140 elfcpp::STV_HIDDEN,
12141 0, // nonvis
12142 false, // offset_is_from_end
12143 true); // only_if_ref
12145 symtab->define_in_output_data("__exidx_end",
12146 NULL, // version
12147 Symbol_table::PREDEFINED,
12148 exidx_section,
12149 0, // value
12150 0, // symsize
12151 elfcpp::STT_NOTYPE,
12152 elfcpp::STB_GLOBAL,
12153 elfcpp::STV_HIDDEN,
12154 0, // nonvis
12155 true, // offset_is_from_end
12156 true); // only_if_ref
12158 else
12160 // Define __exidx_start and __exidx_end even when .ARM.exidx
12161 // section is missing to match ld's behaviour.
12162 symtab->define_as_constant("__exidx_start", NULL,
12163 Symbol_table::PREDEFINED,
12164 0, 0, elfcpp::STT_OBJECT,
12165 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12166 true, false);
12167 symtab->define_as_constant("__exidx_end", NULL,
12168 Symbol_table::PREDEFINED,
12169 0, 0, elfcpp::STT_OBJECT,
12170 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12171 true, false);
12175 // NaCl variant. It uses different PLT contents.
12177 template<bool big_endian>
12178 class Output_data_plt_arm_nacl;
12180 template<bool big_endian>
12181 class Target_arm_nacl : public Target_arm<big_endian>
12183 public:
12184 Target_arm_nacl()
12185 : Target_arm<big_endian>(&arm_nacl_info)
12188 protected:
12189 virtual Output_data_plt_arm<big_endian>*
12190 do_make_data_plt(Layout* layout, Output_data_space* got_plt)
12191 { return new Output_data_plt_arm_nacl<big_endian>(layout, got_plt); }
12193 private:
12194 static const Target::Target_info arm_nacl_info;
12197 template<bool big_endian>
12198 const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info =
12200 32, // size
12201 big_endian, // is_big_endian
12202 elfcpp::EM_ARM, // machine_code
12203 false, // has_make_symbol
12204 false, // has_resolve
12205 false, // has_code_fill
12206 true, // is_default_stack_executable
12207 false, // can_icf_inline_merge_sections
12208 '\0', // wrap_char
12209 "/lib/ld-nacl-arm.so.1", // dynamic_linker
12210 0x20000, // default_text_segment_address
12211 0x10000, // abi_pagesize (overridable by -z max-page-size)
12212 0x10000, // common_pagesize (overridable by -z common-page-size)
12213 true, // isolate_execinstr
12214 0x10000000, // rosegment_gap
12215 elfcpp::SHN_UNDEF, // small_common_shndx
12216 elfcpp::SHN_UNDEF, // large_common_shndx
12217 0, // small_common_section_flags
12218 0, // large_common_section_flags
12219 ".ARM.attributes", // attributes_section
12220 "aeabi", // attributes_vendor
12221 "_start" // entry_symbol_name
12224 template<bool big_endian>
12225 class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
12227 public:
12228 Output_data_plt_arm_nacl(Layout* layout, Output_data_space* got_plt)
12229 : Output_data_plt_arm<big_endian>(layout, 16, got_plt)
12232 protected:
12233 // Return the offset of the first non-reserved PLT entry.
12234 virtual unsigned int
12235 do_first_plt_entry_offset() const
12236 { return sizeof(first_plt_entry); }
12238 // Return the size of a PLT entry.
12239 virtual unsigned int
12240 do_get_plt_entry_size() const
12241 { return sizeof(plt_entry); }
12243 virtual void
12244 do_fill_first_plt_entry(unsigned char* pov,
12245 Arm_address got_address,
12246 Arm_address plt_address);
12248 virtual void
12249 do_fill_plt_entry(unsigned char* pov,
12250 Arm_address got_address,
12251 Arm_address plt_address,
12252 unsigned int got_offset,
12253 unsigned int plt_offset);
12255 private:
12256 inline uint32_t arm_movw_immediate(uint32_t value)
12258 return (value & 0x00000fff) | ((value & 0x0000f000) << 4);
12261 inline uint32_t arm_movt_immediate(uint32_t value)
12263 return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12);
12266 // Template for the first PLT entry.
12267 static const uint32_t first_plt_entry[16];
12269 // Template for subsequent PLT entries.
12270 static const uint32_t plt_entry[4];
12273 // The first entry in the PLT.
12274 template<bool big_endian>
12275 const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] =
12277 // First bundle:
12278 0xe300c000, // movw ip, #:lower16:&GOT[2]-.+8
12279 0xe340c000, // movt ip, #:upper16:&GOT[2]-.+8
12280 0xe08cc00f, // add ip, ip, pc
12281 0xe52dc008, // str ip, [sp, #-8]!
12282 // Second bundle:
12283 0xe3ccc103, // bic ip, ip, #0xc0000000
12284 0xe59cc000, // ldr ip, [ip]
12285 0xe3ccc13f, // bic ip, ip, #0xc000000f
12286 0xe12fff1c, // bx ip
12287 // Third bundle:
12288 0xe320f000, // nop
12289 0xe320f000, // nop
12290 0xe320f000, // nop
12291 // .Lplt_tail:
12292 0xe50dc004, // str ip, [sp, #-4]
12293 // Fourth bundle:
12294 0xe3ccc103, // bic ip, ip, #0xc0000000
12295 0xe59cc000, // ldr ip, [ip]
12296 0xe3ccc13f, // bic ip, ip, #0xc000000f
12297 0xe12fff1c, // bx ip
12300 template<bool big_endian>
12301 void
12302 Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry(
12303 unsigned char* pov,
12304 Arm_address got_address,
12305 Arm_address plt_address)
12307 // Write first PLT entry. All but first two words are constants.
12308 const size_t num_first_plt_words = (sizeof(first_plt_entry)
12309 / sizeof(first_plt_entry[0]));
12311 int32_t got_displacement = got_address + 8 - (plt_address + 16);
12313 elfcpp::Swap<32, big_endian>::writeval
12314 (pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement));
12315 elfcpp::Swap<32, big_endian>::writeval
12316 (pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement));
12318 for (size_t i = 2; i < num_first_plt_words; ++i)
12319 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
12322 // Subsequent entries in the PLT.
12324 template<bool big_endian>
12325 const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] =
12327 0xe300c000, // movw ip, #:lower16:&GOT[n]-.+8
12328 0xe340c000, // movt ip, #:upper16:&GOT[n]-.+8
12329 0xe08cc00f, // add ip, ip, pc
12330 0xea000000, // b .Lplt_tail
12333 template<bool big_endian>
12334 void
12335 Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry(
12336 unsigned char* pov,
12337 Arm_address got_address,
12338 Arm_address plt_address,
12339 unsigned int got_offset,
12340 unsigned int plt_offset)
12342 // Calculate the displacement between the PLT slot and the
12343 // common tail that's part of the special initial PLT slot.
12344 int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t))
12345 - (plt_address + plt_offset
12346 + sizeof(plt_entry) + sizeof(uint32_t)));
12347 gold_assert((tail_displacement & 3) == 0);
12348 tail_displacement >>= 2;
12350 gold_assert ((tail_displacement & 0xff000000) == 0
12351 || (-tail_displacement & 0xff000000) == 0);
12353 // Calculate the displacement between the PLT slot and the entry
12354 // in the GOT. The offset accounts for the value produced by
12355 // adding to pc in the penultimate instruction of the PLT stub.
12356 const int32_t got_displacement = (got_address + got_offset
12357 - (plt_address + sizeof(plt_entry)));
12359 elfcpp::Swap<32, big_endian>::writeval
12360 (pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement));
12361 elfcpp::Swap<32, big_endian>::writeval
12362 (pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement));
12363 elfcpp::Swap<32, big_endian>::writeval
12364 (pov + 8, plt_entry[2]);
12365 elfcpp::Swap<32, big_endian>::writeval
12366 (pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff));
12369 // Target selectors.
12371 template<bool big_endian>
12372 class Target_selector_arm_nacl
12373 : public Target_selector_nacl<Target_selector_arm<big_endian>,
12374 Target_arm_nacl<big_endian> >
12376 public:
12377 Target_selector_arm_nacl()
12378 : Target_selector_nacl<Target_selector_arm<big_endian>,
12379 Target_arm_nacl<big_endian> >(
12380 "arm",
12381 big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl",
12382 big_endian ? "armelfb_nacl" : "armelf_nacl")
12386 Target_selector_arm_nacl<false> target_selector_arm;
12387 Target_selector_arm_nacl<true> target_selector_armbe;
12389 } // End anonymous namespace.