1 // arm.cc -- arm target support for gold.
3 // Copyright 2009 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
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.
35 #include "parameters.h"
42 #include "copy-relocs.h"
44 #include "target-reloc.h"
45 #include "target-select.h"
55 template<bool big_endian
>
56 class Output_data_plt_arm
;
58 template<bool big_endian
>
61 template<bool big_endian
>
62 class Arm_input_section
;
64 template<bool big_endian
>
65 class Arm_output_section
;
67 template<bool big_endian
>
70 template<bool big_endian
>
74 typedef elfcpp::Elf_types
<32>::Elf_Addr Arm_address
;
76 // Maximum branch offsets for ARM, THUMB and THUMB2.
77 const int32_t ARM_MAX_FWD_BRANCH_OFFSET
= ((((1 << 23) - 1) << 2) + 8);
78 const int32_t ARM_MAX_BWD_BRANCH_OFFSET
= ((-((1 << 23) << 2)) + 8);
79 const int32_t THM_MAX_FWD_BRANCH_OFFSET
= ((1 << 22) -2 + 4);
80 const int32_t THM_MAX_BWD_BRANCH_OFFSET
= (-(1 << 22) + 4);
81 const int32_t THM2_MAX_FWD_BRANCH_OFFSET
= (((1 << 24) - 2) + 4);
82 const int32_t THM2_MAX_BWD_BRANCH_OFFSET
= (-(1 << 24) + 4);
84 // The arm target class.
86 // This is a very simple port of gold for ARM-EABI. It is intended for
87 // supporting Android only for the time being. Only these relocation types
116 // R_ARM_THM_MOVW_ABS_NC
117 // R_ARM_THM_MOVT_ABS
118 // R_ARM_MOVW_PREL_NC
120 // R_ARM_THM_MOVW_PREL_NC
121 // R_ARM_THM_MOVT_PREL
124 // - Generate various branch stubs.
125 // - Support interworking.
126 // - Define section symbols __exidx_start and __exidx_stop.
127 // - Support more relocation types as needed.
128 // - Make PLTs more flexible for different architecture features like
130 // There are probably a lot more.
132 // Instruction template class. This class is similar to the insn_sequence
133 // struct in bfd/elf32-arm.c.
138 // Types of instruction templates.
147 // Factory methods to create instrunction templates in different formats.
149 static const Insn_template
150 thumb16_insn(uint32_t data
)
151 { return Insn_template(data
, THUMB16_TYPE
, elfcpp::R_ARM_NONE
, 0); }
153 // A bit of a hack. A Thumb conditional branch, in which the proper
154 // condition is inserted when we build the stub.
155 static const Insn_template
156 thumb16_bcond_insn(uint32_t data
)
157 { return Insn_template(data
, THUMB16_TYPE
, elfcpp::R_ARM_NONE
, 1); }
159 static const Insn_template
160 thumb32_insn(uint32_t data
)
161 { return Insn_template(data
, THUMB32_TYPE
, elfcpp::R_ARM_NONE
, 0); }
163 static const Insn_template
164 thumb32_b_insn(uint32_t data
, int reloc_addend
)
166 return Insn_template(data
, THUMB32_TYPE
, elfcpp::R_ARM_THM_JUMP24
,
170 static const Insn_template
171 arm_insn(uint32_t data
)
172 { return Insn_template(data
, ARM_TYPE
, elfcpp::R_ARM_NONE
, 0); }
174 static const Insn_template
175 arm_rel_insn(unsigned data
, int reloc_addend
)
176 { return Insn_template(data
, ARM_TYPE
, elfcpp::R_ARM_JUMP24
, reloc_addend
); }
178 static const Insn_template
179 data_word(unsigned data
, unsigned int r_type
, int reloc_addend
)
180 { return Insn_template(data
, DATA_TYPE
, r_type
, reloc_addend
); }
182 // Accessors. This class is used for read-only objects so no modifiers
187 { return this->data_
; }
189 // Return the instruction sequence type of this.
192 { return this->type_
; }
194 // Return the ARM relocation type of this.
197 { return this->r_type_
; }
201 { return this->reloc_addend_
; }
203 // Return size of instrunction template in bytes.
207 // Return byte-alignment of instrunction template.
212 // We make the constructor private to ensure that only the factory
215 Insn_template(unsigned data
, Type type
, unsigned int r_type
, int reloc_addend
)
216 : data_(data
), type_(type
), r_type_(r_type
), reloc_addend_(reloc_addend
)
219 // Instruction specific data. This is used to store information like
220 // some of the instruction bits.
222 // Instruction template type.
224 // Relocation type if there is a relocation or R_ARM_NONE otherwise.
225 unsigned int r_type_
;
226 // Relocation addend.
227 int32_t reloc_addend_
;
230 // Macro for generating code to stub types. One entry per long/short
234 DEF_STUB(long_branch_any_any) \
235 DEF_STUB(long_branch_v4t_arm_thumb) \
236 DEF_STUB(long_branch_thumb_only) \
237 DEF_STUB(long_branch_v4t_thumb_thumb) \
238 DEF_STUB(long_branch_v4t_thumb_arm) \
239 DEF_STUB(short_branch_v4t_thumb_arm) \
240 DEF_STUB(long_branch_any_arm_pic) \
241 DEF_STUB(long_branch_any_thumb_pic) \
242 DEF_STUB(long_branch_v4t_thumb_thumb_pic) \
243 DEF_STUB(long_branch_v4t_arm_thumb_pic) \
244 DEF_STUB(long_branch_v4t_thumb_arm_pic) \
245 DEF_STUB(long_branch_thumb_only_pic) \
246 DEF_STUB(a8_veneer_b_cond) \
247 DEF_STUB(a8_veneer_b) \
248 DEF_STUB(a8_veneer_bl) \
249 DEF_STUB(a8_veneer_blx)
253 #define DEF_STUB(x) arm_stub_##x,
259 // First reloc stub type.
260 arm_stub_reloc_first
= arm_stub_long_branch_any_any
,
261 // Last reloc stub type.
262 arm_stub_reloc_last
= arm_stub_long_branch_thumb_only_pic
,
264 // First Cortex-A8 stub type.
265 arm_stub_cortex_a8_first
= arm_stub_a8_veneer_b_cond
,
266 // Last Cortex-A8 stub type.
267 arm_stub_cortex_a8_last
= arm_stub_a8_veneer_blx
,
270 arm_stub_type_last
= arm_stub_a8_veneer_blx
274 // Stub template class. Templates are meant to be read-only objects.
275 // A stub template for a stub type contains all read-only attributes
276 // common to all stubs of the same type.
281 Stub_template(Stub_type
, const Insn_template
*, size_t);
289 { return this->type_
; }
291 // Return an array of instruction templates.
294 { return this->insns_
; }
296 // Return size of template in number of instructions.
299 { return this->insn_count_
; }
301 // Return size of template in bytes.
304 { return this->size_
; }
306 // Return alignment of the stub template.
309 { return this->alignment_
; }
311 // Return whether entry point is in thumb mode.
313 entry_in_thumb_mode() const
314 { return this->entry_in_thumb_mode_
; }
316 // Return number of relocations in this template.
319 { return this->relocs_
.size(); }
321 // Return index of the I-th instruction with relocation.
323 reloc_insn_index(size_t i
) const
325 gold_assert(i
< this->relocs_
.size());
326 return this->relocs_
[i
].first
;
329 // Return the offset of the I-th instruction with relocation from the
330 // beginning of the stub.
332 reloc_offset(size_t i
) const
334 gold_assert(i
< this->relocs_
.size());
335 return this->relocs_
[i
].second
;
339 // This contains information about an instruction template with a relocation
340 // and its offset from start of stub.
341 typedef std::pair
<size_t, section_size_type
> Reloc
;
343 // A Stub_template may not be copied. We want to share templates as much
345 Stub_template(const Stub_template
&);
346 Stub_template
& operator=(const Stub_template
&);
350 // Points to an array of Insn_templates.
351 const Insn_template
* insns_
;
352 // Number of Insn_templates in insns_[].
354 // Size of templated instructions in bytes.
356 // Alignment of templated instructions.
358 // Flag to indicate if entry is in thumb mode.
359 bool entry_in_thumb_mode_
;
360 // A table of reloc instruction indices and offsets. We can find these by
361 // looking at the instruction templates but we pre-compute and then stash
362 // them here for speed.
363 std::vector
<Reloc
> relocs_
;
367 // A class for code stubs. This is a base class for different type of
368 // stubs used in the ARM target.
374 static const section_offset_type invalid_offset
=
375 static_cast<section_offset_type
>(-1);
378 Stub(const Stub_template
* stub_template
)
379 : stub_template_(stub_template
), offset_(invalid_offset
)
386 // Return the stub template.
388 stub_template() const
389 { return this->stub_template_
; }
391 // Return offset of code stub from beginning of its containing stub table.
395 gold_assert(this->offset_
!= invalid_offset
);
396 return this->offset_
;
399 // Set offset of code stub from beginning of its containing stub table.
401 set_offset(section_offset_type offset
)
402 { this->offset_
= offset
; }
404 // Return the relocation target address of the i-th relocation in the
405 // stub. This must be defined in a child class.
407 reloc_target(size_t i
)
408 { return this->do_reloc_target(i
); }
410 // Write a stub at output VIEW. BIG_ENDIAN select how a stub is written.
412 write(unsigned char* view
, section_size_type view_size
, bool big_endian
)
413 { this->do_write(view
, view_size
, big_endian
); }
416 // This must be defined in the child class.
418 do_reloc_target(size_t) = 0;
420 // This must be defined in the child class.
422 do_write(unsigned char*, section_size_type
, bool) = 0;
426 const Stub_template
* stub_template_
;
427 // Offset within the section of containing this stub.
428 section_offset_type offset_
;
431 // Reloc stub class. These are stubs we use to fix up relocation because
432 // of limited branch ranges.
434 class Reloc_stub
: public Stub
437 static const unsigned int invalid_index
= static_cast<unsigned int>(-1);
438 // We assume we never jump to this address.
439 static const Arm_address invalid_address
= static_cast<Arm_address
>(-1);
441 // Return destination address.
443 destination_address() const
445 gold_assert(this->destination_address_
!= this->invalid_address
);
446 return this->destination_address_
;
449 // Set destination address.
451 set_destination_address(Arm_address address
)
453 gold_assert(address
!= this->invalid_address
);
454 this->destination_address_
= address
;
457 // Reset destination address.
459 reset_destination_address()
460 { this->destination_address_
= this->invalid_address
; }
462 // Determine stub type for a branch of a relocation of R_TYPE going
463 // from BRANCH_ADDRESS to BRANCH_TARGET. If TARGET_IS_THUMB is set,
464 // the branch target is a thumb instruction. TARGET is used for look
465 // up ARM-specific linker settings.
467 stub_type_for_reloc(unsigned int r_type
, Arm_address branch_address
,
468 Arm_address branch_target
, bool target_is_thumb
);
470 // Reloc_stub key. A key is logically a triplet of a stub type, a symbol
471 // and an addend. Since we treat global and local symbol differently, we
472 // use a Symbol object for a global symbol and a object-index pair for
477 // If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and
478 // R_SYM. Otherwise, this is a local symbol and RELOBJ must non-NULL
479 // and R_SYM must not be invalid_index.
480 Key(Stub_type stub_type
, const Symbol
* symbol
, const Relobj
* relobj
,
481 unsigned int r_sym
, int32_t addend
)
482 : stub_type_(stub_type
), addend_(addend
)
486 this->r_sym_
= Reloc_stub::invalid_index
;
487 this->u_
.symbol
= symbol
;
491 gold_assert(relobj
!= NULL
&& r_sym
!= invalid_index
);
492 this->r_sym_
= r_sym
;
493 this->u_
.relobj
= relobj
;
500 // Accessors: Keys are meant to be read-only object so no modifiers are
506 { return this->stub_type_
; }
508 // Return the local symbol index or invalid_index.
511 { return this->r_sym_
; }
513 // Return the symbol if there is one.
516 { return this->r_sym_
== invalid_index
? this->u_
.symbol
: NULL
; }
518 // Return the relobj if there is one.
521 { return this->r_sym_
!= invalid_index
? this->u_
.relobj
: NULL
; }
523 // Whether this equals to another key k.
525 eq(const Key
& k
) const
527 return ((this->stub_type_
== k
.stub_type_
)
528 && (this->r_sym_
== k
.r_sym_
)
529 && ((this->r_sym_
!= Reloc_stub::invalid_index
)
530 ? (this->u_
.relobj
== k
.u_
.relobj
)
531 : (this->u_
.symbol
== k
.u_
.symbol
))
532 && (this->addend_
== k
.addend_
));
535 // Return a hash value.
539 return (this->stub_type_
541 ^ gold::string_hash
<char>(
542 (this->r_sym_
!= Reloc_stub::invalid_index
)
543 ? this->u_
.relobj
->name().c_str()
544 : this->u_
.symbol
->name())
548 // Functors for STL associative containers.
552 operator()(const Key
& k
) const
553 { return k
.hash_value(); }
559 operator()(const Key
& k1
, const Key
& k2
) const
560 { return k1
.eq(k2
); }
563 // Name of key. This is mainly for debugging.
569 Stub_type stub_type_
;
570 // If this is a local symbol, this is the index in the defining object.
571 // Otherwise, it is invalid_index for a global symbol.
573 // If r_sym_ is invalid index. This points to a global symbol.
574 // Otherwise, this points a relobj. We used the unsized and target
575 // independent Symbol and Relobj classes instead of Arm_symbol and
576 // Arm_relobj. This is done to avoid making the stub class a template
577 // as most of the stub machinery is endianity-neutral. However, it
578 // may require a bit of casting done by users of this class.
581 const Symbol
* symbol
;
582 const Relobj
* relobj
;
584 // Addend associated with a reloc.
589 // Reloc_stubs are created via a stub factory. So these are protected.
590 Reloc_stub(const Stub_template
* stub_template
)
591 : Stub(stub_template
), destination_address_(invalid_address
)
597 friend class Stub_factory
;
600 // Return the relocation target address of the i-th relocation in the
603 do_reloc_target(size_t i
)
605 // All reloc stub have only one relocation.
607 return this->destination_address_
;
610 // A template to implement do_write below.
611 template<bool big_endian
>
613 do_fixed_endian_write(unsigned char*, section_size_type
);
617 do_write(unsigned char* view
, section_size_type view_size
, bool big_endian
);
619 // Address of destination.
620 Arm_address destination_address_
;
623 // Stub factory class.
628 // Return the unique instance of this class.
629 static const Stub_factory
&
632 static Stub_factory singleton
;
636 // Make a relocation stub.
638 make_reloc_stub(Stub_type stub_type
) const
640 gold_assert(stub_type
>= arm_stub_reloc_first
641 && stub_type
<= arm_stub_reloc_last
);
642 return new Reloc_stub(this->stub_templates_
[stub_type
]);
646 // Constructor and destructor are protected since we only return a single
647 // instance created in Stub_factory::get_instance().
651 // A Stub_factory may not be copied since it is a singleton.
652 Stub_factory(const Stub_factory
&);
653 Stub_factory
& operator=(Stub_factory
&);
655 // Stub templates. These are initialized in the constructor.
656 const Stub_template
* stub_templates_
[arm_stub_type_last
+1];
659 // A class to hold stubs for the ARM target.
661 template<bool big_endian
>
662 class Stub_table
: public Output_data
665 Stub_table(Arm_input_section
<big_endian
>* owner
)
666 : Output_data(), addralign_(1), owner_(owner
), has_been_changed_(false),
673 // Owner of this stub table.
674 Arm_input_section
<big_endian
>*
676 { return this->owner_
; }
678 // Whether this stub table is empty.
681 { return this->reloc_stubs_
.empty(); }
683 // Whether this has been changed.
685 has_been_changed() const
686 { return this->has_been_changed_
; }
688 // Set the has-been-changed flag.
690 set_has_been_changed(bool value
)
691 { this->has_been_changed_
= value
; }
693 // Return the current data size.
695 current_data_size() const
696 { return this->current_data_size_for_child(); }
698 // Add a STUB with using KEY. Caller is reponsible for avoid adding
699 // if already a STUB with the same key has been added.
701 add_reloc_stub(Reloc_stub
* stub
, const Reloc_stub::Key
& key
);
703 // Look up a relocation stub using KEY. Return NULL if there is none.
705 find_reloc_stub(const Reloc_stub::Key
& key
) const
707 typename
Reloc_stub_map::const_iterator p
= this->reloc_stubs_
.find(key
);
708 return (p
!= this->reloc_stubs_
.end()) ? p
->second
: NULL
;
711 // Relocate stubs in this stub table.
713 relocate_stubs(const Relocate_info
<32, big_endian
>*,
714 Target_arm
<big_endian
>*, Output_section
*,
715 unsigned char*, Arm_address
, section_size_type
);
718 // Write out section contents.
720 do_write(Output_file
*);
722 // Return the required alignment.
725 { return this->addralign_
; }
727 // Finalize data size.
729 set_final_data_size()
730 { this->set_data_size(this->current_data_size_for_child()); }
732 // Reset address and file offset.
734 do_reset_address_and_file_offset();
737 // Unordered map of stubs.
739 Unordered_map
<Reloc_stub::Key
, Reloc_stub
*, Reloc_stub::Key::hash
,
740 Reloc_stub::Key::equal_to
>
745 // Owner of this stub table.
746 Arm_input_section
<big_endian
>* owner_
;
747 // This is set to true during relaxiong if the size of the stub table
749 bool has_been_changed_
;
750 // The relocation stubs.
751 Reloc_stub_map reloc_stubs_
;
754 // A class to wrap an ordinary input section containing executable code.
756 template<bool big_endian
>
757 class Arm_input_section
: public Output_relaxed_input_section
760 Arm_input_section(Relobj
* relobj
, unsigned int shndx
)
761 : Output_relaxed_input_section(relobj
, shndx
, 1),
762 original_addralign_(1), original_size_(0), stub_table_(NULL
)
772 // Whether this is a stub table owner.
774 is_stub_table_owner() const
775 { return this->stub_table_
!= NULL
&& this->stub_table_
->owner() == this; }
777 // Return the stub table.
778 Stub_table
<big_endian
>*
780 { return this->stub_table_
; }
782 // Set the stub_table.
784 set_stub_table(Stub_table
<big_endian
>* stub_table
)
785 { this->stub_table_
= stub_table
; }
787 // Downcast a base pointer to an Arm_input_section pointer. This is
788 // not type-safe but we only use Arm_input_section not the base class.
789 static Arm_input_section
<big_endian
>*
790 as_arm_input_section(Output_relaxed_input_section
* poris
)
791 { return static_cast<Arm_input_section
<big_endian
>*>(poris
); }
794 // Write data to output file.
796 do_write(Output_file
*);
798 // Return required alignment of this.
802 if (this->is_stub_table_owner())
803 return std::max(this->stub_table_
->addralign(),
804 this->original_addralign_
);
806 return this->original_addralign_
;
809 // Finalize data size.
811 set_final_data_size();
813 // Reset address and file offset.
815 do_reset_address_and_file_offset();
819 do_output_offset(const Relobj
* object
, unsigned int shndx
,
820 section_offset_type offset
,
821 section_offset_type
* poutput
) const
823 if ((object
== this->relobj())
824 && (shndx
== this->shndx())
826 && (convert_types
<uint64_t, section_offset_type
>(offset
)
827 <= this->original_size_
))
837 // Copying is not allowed.
838 Arm_input_section(const Arm_input_section
&);
839 Arm_input_section
& operator=(const Arm_input_section
&);
841 // Address alignment of the original input section.
842 uint64_t original_addralign_
;
843 // Section size of the original input section.
844 uint64_t original_size_
;
846 Stub_table
<big_endian
>* stub_table_
;
849 // Arm output section class. This is defined mainly to add a number of
850 // stub generation methods.
852 template<bool big_endian
>
853 class Arm_output_section
: public Output_section
856 Arm_output_section(const char* name
, elfcpp::Elf_Word type
,
857 elfcpp::Elf_Xword flags
)
858 : Output_section(name
, type
, flags
)
861 ~Arm_output_section()
864 // Group input sections for stub generation.
866 group_sections(section_size_type
, bool, Target_arm
<big_endian
>*);
868 // Downcast a base pointer to an Arm_output_section pointer. This is
869 // not type-safe but we only use Arm_output_section not the base class.
870 static Arm_output_section
<big_endian
>*
871 as_arm_output_section(Output_section
* os
)
872 { return static_cast<Arm_output_section
<big_endian
>*>(os
); }
876 typedef Output_section::Input_section Input_section
;
877 typedef Output_section::Input_section_list Input_section_list
;
879 // Create a stub group.
880 void create_stub_group(Input_section_list::const_iterator
,
881 Input_section_list::const_iterator
,
882 Input_section_list::const_iterator
,
883 Target_arm
<big_endian
>*,
884 std::vector
<Output_relaxed_input_section
*>*);
887 // Utilities for manipulating integers of up to 32-bits
891 // Sign extend an n-bit unsigned integer stored in an uint32_t into
892 // an int32_t. NO_BITS must be between 1 to 32.
893 template<int no_bits
>
894 static inline int32_t
895 sign_extend(uint32_t bits
)
897 gold_assert(no_bits
>= 0 && no_bits
<= 32);
899 return static_cast<int32_t>(bits
);
900 uint32_t mask
= (~((uint32_t) 0)) >> (32 - no_bits
);
902 uint32_t top_bit
= 1U << (no_bits
- 1);
903 int32_t as_signed
= static_cast<int32_t>(bits
);
904 return (bits
& top_bit
) ? as_signed
+ (-top_bit
* 2) : as_signed
;
907 // Detects overflow of an NO_BITS integer stored in a uint32_t.
908 template<int no_bits
>
910 has_overflow(uint32_t bits
)
912 gold_assert(no_bits
>= 0 && no_bits
<= 32);
915 int32_t max
= (1 << (no_bits
- 1)) - 1;
916 int32_t min
= -(1 << (no_bits
- 1));
917 int32_t as_signed
= static_cast<int32_t>(bits
);
918 return as_signed
> max
|| as_signed
< min
;
921 // Detects overflow of an NO_BITS integer stored in a uint32_t when it
922 // fits in the given number of bits as either a signed or unsigned value.
923 // For example, has_signed_unsigned_overflow<8> would check
924 // -128 <= bits <= 255
925 template<int no_bits
>
927 has_signed_unsigned_overflow(uint32_t bits
)
929 gold_assert(no_bits
>= 2 && no_bits
<= 32);
932 int32_t max
= static_cast<int32_t>((1U << no_bits
) - 1);
933 int32_t min
= -(1 << (no_bits
- 1));
934 int32_t as_signed
= static_cast<int32_t>(bits
);
935 return as_signed
> max
|| as_signed
< min
;
938 // Select bits from A and B using bits in MASK. For each n in [0..31],
939 // the n-th bit in the result is chosen from the n-th bits of A and B.
940 // A zero selects A and a one selects B.
941 static inline uint32_t
942 bit_select(uint32_t a
, uint32_t b
, uint32_t mask
)
943 { return (a
& ~mask
) | (b
& mask
); }
946 template<bool big_endian
>
947 class Target_arm
: public Sized_target
<32, big_endian
>
950 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, big_endian
>
954 : Sized_target
<32, big_endian
>(&arm_info
),
955 got_(NULL
), plt_(NULL
), got_plt_(NULL
), rel_dyn_(NULL
),
956 copy_relocs_(elfcpp::R_ARM_COPY
), dynbss_(NULL
),
957 may_use_blx_(true), should_force_pic_veneer_(false)
960 // Whether we can use BLX.
963 { return this->may_use_blx_
; }
967 set_may_use_blx(bool value
)
968 { this->may_use_blx_
= value
; }
970 // Whether we force PCI branch veneers.
972 should_force_pic_veneer() const
973 { return this->should_force_pic_veneer_
; }
975 // Set PIC veneer flag.
977 set_should_force_pic_veneer(bool value
)
978 { this->should_force_pic_veneer_
= value
; }
980 // Whether we use THUMB-2 instructions.
984 // FIXME: This should not hard-coded.
988 // Whether we use THUMB/THUMB-2 instructions only.
990 using_thumb_only() const
992 // FIXME: This should not hard-coded.
996 // Process the relocations to determine unreferenced sections for
997 // garbage collection.
999 gc_process_relocs(const General_options
& options
,
1000 Symbol_table
* symtab
,
1002 Sized_relobj
<32, big_endian
>* object
,
1003 unsigned int data_shndx
,
1004 unsigned int sh_type
,
1005 const unsigned char* prelocs
,
1007 Output_section
* output_section
,
1008 bool needs_special_offset_handling
,
1009 size_t local_symbol_count
,
1010 const unsigned char* plocal_symbols
);
1012 // Scan the relocations to look for symbol adjustments.
1014 scan_relocs(const General_options
& options
,
1015 Symbol_table
* symtab
,
1017 Sized_relobj
<32, big_endian
>* object
,
1018 unsigned int data_shndx
,
1019 unsigned int sh_type
,
1020 const unsigned char* prelocs
,
1022 Output_section
* output_section
,
1023 bool needs_special_offset_handling
,
1024 size_t local_symbol_count
,
1025 const unsigned char* plocal_symbols
);
1027 // Finalize the sections.
1029 do_finalize_sections(Layout
*);
1031 // Return the value to use for a dynamic symbol which requires special
1034 do_dynsym_value(const Symbol
*) const;
1036 // Relocate a section.
1038 relocate_section(const Relocate_info
<32, big_endian
>*,
1039 unsigned int sh_type
,
1040 const unsigned char* prelocs
,
1042 Output_section
* output_section
,
1043 bool needs_special_offset_handling
,
1044 unsigned char* view
,
1045 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
1046 section_size_type view_size
,
1047 const Reloc_symbol_changes
*);
1049 // Scan the relocs during a relocatable link.
1051 scan_relocatable_relocs(const General_options
& options
,
1052 Symbol_table
* symtab
,
1054 Sized_relobj
<32, big_endian
>* object
,
1055 unsigned int data_shndx
,
1056 unsigned int sh_type
,
1057 const unsigned char* prelocs
,
1059 Output_section
* output_section
,
1060 bool needs_special_offset_handling
,
1061 size_t local_symbol_count
,
1062 const unsigned char* plocal_symbols
,
1063 Relocatable_relocs
*);
1065 // Relocate a section during a relocatable link.
1067 relocate_for_relocatable(const Relocate_info
<32, big_endian
>*,
1068 unsigned int sh_type
,
1069 const unsigned char* prelocs
,
1071 Output_section
* output_section
,
1072 off_t offset_in_output_section
,
1073 const Relocatable_relocs
*,
1074 unsigned char* view
,
1075 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
1076 section_size_type view_size
,
1077 unsigned char* reloc_view
,
1078 section_size_type reloc_view_size
);
1080 // Return whether SYM is defined by the ABI.
1082 do_is_defined_by_abi(Symbol
* sym
) const
1083 { return strcmp(sym
->name(), "__tls_get_addr") == 0; }
1085 // Return the size of the GOT section.
1089 gold_assert(this->got_
!= NULL
);
1090 return this->got_
->data_size();
1093 // Map platform-specific reloc types
1095 get_real_reloc_type (unsigned int r_type
);
1097 // Get the default ARM target.
1098 static const Target_arm
<big_endian
>&
1101 gold_assert(parameters
->target().machine_code() == elfcpp::EM_ARM
1102 && parameters
->target().is_big_endian() == big_endian
);
1103 return static_cast<const Target_arm
<big_endian
>&>(parameters
->target());
1107 // The class which scans relocations.
1112 : issued_non_pic_error_(false)
1116 local(const General_options
& options
, Symbol_table
* symtab
,
1117 Layout
* layout
, Target_arm
* target
,
1118 Sized_relobj
<32, big_endian
>* object
,
1119 unsigned int data_shndx
,
1120 Output_section
* output_section
,
1121 const elfcpp::Rel
<32, big_endian
>& reloc
, unsigned int r_type
,
1122 const elfcpp::Sym
<32, big_endian
>& lsym
);
1125 global(const General_options
& options
, Symbol_table
* symtab
,
1126 Layout
* layout
, Target_arm
* target
,
1127 Sized_relobj
<32, big_endian
>* object
,
1128 unsigned int data_shndx
,
1129 Output_section
* output_section
,
1130 const elfcpp::Rel
<32, big_endian
>& reloc
, unsigned int r_type
,
1135 unsupported_reloc_local(Sized_relobj
<32, big_endian
>*,
1136 unsigned int r_type
);
1139 unsupported_reloc_global(Sized_relobj
<32, big_endian
>*,
1140 unsigned int r_type
, Symbol
*);
1143 check_non_pic(Relobj
*, unsigned int r_type
);
1145 // Almost identical to Symbol::needs_plt_entry except that it also
1146 // handles STT_ARM_TFUNC.
1148 symbol_needs_plt_entry(const Symbol
* sym
)
1150 // An undefined symbol from an executable does not need a PLT entry.
1151 if (sym
->is_undefined() && !parameters
->options().shared())
1154 return (!parameters
->doing_static_link()
1155 && (sym
->type() == elfcpp::STT_FUNC
1156 || sym
->type() == elfcpp::STT_ARM_TFUNC
)
1157 && (sym
->is_from_dynobj()
1158 || sym
->is_undefined()
1159 || sym
->is_preemptible()));
1162 // Whether we have issued an error about a non-PIC compilation.
1163 bool issued_non_pic_error_
;
1166 // The class which implements relocation.
1176 // Return whether the static relocation needs to be applied.
1178 should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
1181 Output_section
* output_section
);
1183 // Do a relocation. Return false if the caller should not issue
1184 // any warnings about this relocation.
1186 relocate(const Relocate_info
<32, big_endian
>*, Target_arm
*,
1187 Output_section
*, size_t relnum
,
1188 const elfcpp::Rel
<32, big_endian
>&,
1189 unsigned int r_type
, const Sized_symbol
<32>*,
1190 const Symbol_value
<32>*,
1191 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
1194 // Return whether we want to pass flag NON_PIC_REF for this
1197 reloc_is_non_pic (unsigned int r_type
)
1201 case elfcpp::R_ARM_REL32
:
1202 case elfcpp::R_ARM_THM_CALL
:
1203 case elfcpp::R_ARM_CALL
:
1204 case elfcpp::R_ARM_JUMP24
:
1205 case elfcpp::R_ARM_PREL31
:
1206 case elfcpp::R_ARM_THM_ABS5
:
1207 case elfcpp::R_ARM_ABS8
:
1208 case elfcpp::R_ARM_ABS12
:
1209 case elfcpp::R_ARM_ABS16
:
1210 case elfcpp::R_ARM_BASE_ABS
:
1218 // A class which returns the size required for a relocation type,
1219 // used while scanning relocs during a relocatable link.
1220 class Relocatable_size_for_reloc
1224 get_size_for_reloc(unsigned int, Relobj
*);
1227 // Get the GOT section, creating it if necessary.
1228 Output_data_got
<32, big_endian
>*
1229 got_section(Symbol_table
*, Layout
*);
1231 // Get the GOT PLT section.
1233 got_plt_section() const
1235 gold_assert(this->got_plt_
!= NULL
);
1236 return this->got_plt_
;
1239 // Create a PLT entry for a global symbol.
1241 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
1243 // Get the PLT section.
1244 const Output_data_plt_arm
<big_endian
>*
1247 gold_assert(this->plt_
!= NULL
);
1251 // Get the dynamic reloc section, creating it if necessary.
1253 rel_dyn_section(Layout
*);
1255 // Return true if the symbol may need a COPY relocation.
1256 // References from an executable object to non-function symbols
1257 // defined in a dynamic object may need a COPY relocation.
1259 may_need_copy_reloc(Symbol
* gsym
)
1261 return (gsym
->type() != elfcpp::STT_ARM_TFUNC
1262 && gsym
->may_need_copy_reloc());
1265 // Add a potential copy relocation.
1267 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
1268 Sized_relobj
<32, big_endian
>* object
,
1269 unsigned int shndx
, Output_section
* output_section
,
1270 Symbol
* sym
, const elfcpp::Rel
<32, big_endian
>& reloc
)
1272 this->copy_relocs_
.copy_reloc(symtab
, layout
,
1273 symtab
->get_sized_symbol
<32>(sym
),
1274 object
, shndx
, output_section
, reloc
,
1275 this->rel_dyn_section(layout
));
1278 // Information about this specific target which we pass to the
1279 // general Target structure.
1280 static const Target::Target_info arm_info
;
1282 // The types of GOT entries needed for this platform.
1285 GOT_TYPE_STANDARD
= 0 // GOT entry for a regular symbol
1289 Output_data_got
<32, big_endian
>* got_
;
1291 Output_data_plt_arm
<big_endian
>* plt_
;
1292 // The GOT PLT section.
1293 Output_data_space
* got_plt_
;
1294 // The dynamic reloc section.
1295 Reloc_section
* rel_dyn_
;
1296 // Relocs saved to avoid a COPY reloc.
1297 Copy_relocs
<elfcpp::SHT_REL
, 32, big_endian
> copy_relocs_
;
1298 // Space for variables copied with a COPY reloc.
1299 Output_data_space
* dynbss_
;
1300 // Whether we can use BLX.
1302 // Whether we force PIC branch veneers.
1303 bool should_force_pic_veneer_
;
1306 template<bool big_endian
>
1307 const Target::Target_info Target_arm
<big_endian
>::arm_info
=
1310 big_endian
, // is_big_endian
1311 elfcpp::EM_ARM
, // machine_code
1312 false, // has_make_symbol
1313 false, // has_resolve
1314 false, // has_code_fill
1315 true, // is_default_stack_executable
1317 "/usr/lib/libc.so.1", // dynamic_linker
1318 0x8000, // default_text_segment_address
1319 0x1000, // abi_pagesize (overridable by -z max-page-size)
1320 0x1000, // common_pagesize (overridable by -z common-page-size)
1321 elfcpp::SHN_UNDEF
, // small_common_shndx
1322 elfcpp::SHN_UNDEF
, // large_common_shndx
1323 0, // small_common_section_flags
1324 0 // large_common_section_flags
1327 // Arm relocate functions class
1330 template<bool big_endian
>
1331 class Arm_relocate_functions
: public Relocate_functions
<32, big_endian
>
1336 STATUS_OKAY
, // No error during relocation.
1337 STATUS_OVERFLOW
, // Relocation oveflow.
1338 STATUS_BAD_RELOC
// Relocation cannot be applied.
1342 typedef Relocate_functions
<32, big_endian
> Base
;
1343 typedef Arm_relocate_functions
<big_endian
> This
;
1345 // Get an symbol value of *PSYMVAL with an ADDEND. This is a wrapper
1346 // to Symbol_value::value(). If HAS_THUMB_BIT is true, that LSB is used
1347 // to distinguish ARM and THUMB functions and it is treated specially.
1348 static inline Symbol_value
<32>::Value
1349 arm_symbol_value (const Sized_relobj
<32, big_endian
> *object
,
1350 const Symbol_value
<32>* psymval
,
1351 Symbol_value
<32>::Value addend
,
1354 typedef Symbol_value
<32>::Value Valtype
;
1358 Valtype raw
= psymval
->value(object
, 0);
1359 Valtype thumb_bit
= raw
& 1;
1360 return ((raw
& ~((Valtype
) 1)) + addend
) | thumb_bit
;
1363 return psymval
->value(object
, addend
);
1366 // Encoding of imm16 argument for movt and movw ARM instructions
1369 // imm16 := imm4 | imm12
1371 // 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
1372 // +-------+---------------+-------+-------+-----------------------+
1373 // | | |imm4 | |imm12 |
1374 // +-------+---------------+-------+-------+-----------------------+
1376 // Extract the relocation addend from VAL based on the ARM
1377 // instruction encoding described above.
1378 static inline typename
elfcpp::Swap
<32, big_endian
>::Valtype
1379 extract_arm_movw_movt_addend(
1380 typename
elfcpp::Swap
<32, big_endian
>::Valtype val
)
1382 // According to the Elf ABI for ARM Architecture the immediate
1383 // field is sign-extended to form the addend.
1384 return utils::sign_extend
<16>(((val
>> 4) & 0xf000) | (val
& 0xfff));
1387 // Insert X into VAL based on the ARM instruction encoding described
1389 static inline typename
elfcpp::Swap
<32, big_endian
>::Valtype
1390 insert_val_arm_movw_movt(
1391 typename
elfcpp::Swap
<32, big_endian
>::Valtype val
,
1392 typename
elfcpp::Swap
<32, big_endian
>::Valtype x
)
1396 val
|= (x
& 0xf000) << 4;
1400 // Encoding of imm16 argument for movt and movw Thumb2 instructions
1403 // imm16 := imm4 | i | imm3 | imm8
1405 // 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
1406 // +---------+-+-----------+-------++-+-----+-------+---------------+
1407 // | |i| |imm4 || |imm3 | |imm8 |
1408 // +---------+-+-----------+-------++-+-----+-------+---------------+
1410 // Extract the relocation addend from VAL based on the Thumb2
1411 // instruction encoding described above.
1412 static inline typename
elfcpp::Swap
<32, big_endian
>::Valtype
1413 extract_thumb_movw_movt_addend(
1414 typename
elfcpp::Swap
<32, big_endian
>::Valtype val
)
1416 // According to the Elf ABI for ARM Architecture the immediate
1417 // field is sign-extended to form the addend.
1418 return utils::sign_extend
<16>(((val
>> 4) & 0xf000)
1419 | ((val
>> 15) & 0x0800)
1420 | ((val
>> 4) & 0x0700)
1424 // Insert X into VAL based on the Thumb2 instruction encoding
1426 static inline typename
elfcpp::Swap
<32, big_endian
>::Valtype
1427 insert_val_thumb_movw_movt(
1428 typename
elfcpp::Swap
<32, big_endian
>::Valtype val
,
1429 typename
elfcpp::Swap
<32, big_endian
>::Valtype x
)
1432 val
|= (x
& 0xf000) << 4;
1433 val
|= (x
& 0x0800) << 15;
1434 val
|= (x
& 0x0700) << 4;
1435 val
|= (x
& 0x00ff);
1439 // FIXME: This probably only works for Android on ARM v5te. We should
1440 // following GNU ld for the general case.
1441 template<unsigned r_type
>
1442 static inline typename
This::Status
1443 arm_branch_common(unsigned char *view
,
1444 const Sized_relobj
<32, big_endian
>* object
,
1445 const Symbol_value
<32>* psymval
,
1446 elfcpp::Elf_types
<32>::Elf_Addr address
,
1449 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Valtype
;
1450 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1451 Valtype val
= elfcpp::Swap
<32, big_endian
>::readval(wv
);
1453 bool insn_is_b
= (((val
>> 28) & 0xf) <= 0xe)
1454 && ((val
& 0x0f000000UL
) == 0x0a000000UL
);
1455 bool insn_is_uncond_bl
= (val
& 0xff000000UL
) == 0xeb000000UL
;
1456 bool insn_is_cond_bl
= (((val
>> 28) & 0xf) < 0xe)
1457 && ((val
& 0x0f000000UL
) == 0x0b000000UL
);
1458 bool insn_is_blx
= (val
& 0xfe000000UL
) == 0xfa000000UL
;
1459 bool insn_is_any_branch
= (val
& 0x0e000000UL
) == 0x0a000000UL
;
1461 if (r_type
== elfcpp::R_ARM_CALL
)
1463 if (!insn_is_uncond_bl
&& !insn_is_blx
)
1464 return This::STATUS_BAD_RELOC
;
1466 else if (r_type
== elfcpp::R_ARM_JUMP24
)
1468 if (!insn_is_b
&& !insn_is_cond_bl
)
1469 return This::STATUS_BAD_RELOC
;
1471 else if (r_type
== elfcpp::R_ARM_PLT32
)
1473 if (!insn_is_any_branch
)
1474 return This::STATUS_BAD_RELOC
;
1479 Valtype addend
= utils::sign_extend
<26>(val
<< 2);
1480 Valtype x
= (This::arm_symbol_value(object
, psymval
, addend
, has_thumb_bit
)
1483 // If target has thumb bit set, we need to either turn the BL
1484 // into a BLX (for ARMv5 or above) or generate a stub.
1488 if (insn_is_uncond_bl
)
1489 val
= (val
& 0xffffff) | 0xfa000000 | ((x
& 2) << 23);
1491 return This::STATUS_BAD_RELOC
;
1494 gold_assert(!insn_is_blx
);
1496 val
= utils::bit_select(val
, (x
>> 2), 0xffffffUL
);
1497 elfcpp::Swap
<32, big_endian
>::writeval(wv
, val
);
1498 return (utils::has_overflow
<26>(x
)
1499 ? This::STATUS_OVERFLOW
: This::STATUS_OKAY
);
1504 // R_ARM_ABS8: S + A
1505 static inline typename
This::Status
1506 abs8(unsigned char *view
,
1507 const Sized_relobj
<32, big_endian
>* object
,
1508 const Symbol_value
<32>* psymval
)
1510 typedef typename
elfcpp::Swap
<8, big_endian
>::Valtype Valtype
;
1511 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Reltype
;
1512 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1513 Valtype val
= elfcpp::Swap
<8, big_endian
>::readval(wv
);
1514 Reltype addend
= utils::sign_extend
<8>(val
);
1515 Reltype x
= This::arm_symbol_value(object
, psymval
, addend
, false);
1516 val
= utils::bit_select(val
, x
, 0xffU
);
1517 elfcpp::Swap
<8, big_endian
>::writeval(wv
, val
);
1518 return (utils::has_signed_unsigned_overflow
<8>(x
)
1519 ? This::STATUS_OVERFLOW
1520 : This::STATUS_OKAY
);
1523 // R_ARM_THM_ABS5: S + A
1524 static inline typename
This::Status
1525 thm_abs5(unsigned char *view
,
1526 const Sized_relobj
<32, big_endian
>* object
,
1527 const Symbol_value
<32>* psymval
)
1529 typedef typename
elfcpp::Swap
<16, big_endian
>::Valtype Valtype
;
1530 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Reltype
;
1531 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1532 Valtype val
= elfcpp::Swap
<16, big_endian
>::readval(wv
);
1533 Reltype addend
= (val
& 0x7e0U
) >> 6;
1534 Reltype x
= This::arm_symbol_value(object
, psymval
, addend
, false);
1535 val
= utils::bit_select(val
, x
<< 6, 0x7e0U
);
1536 elfcpp::Swap
<16, big_endian
>::writeval(wv
, val
);
1537 return (utils::has_overflow
<5>(x
)
1538 ? This::STATUS_OVERFLOW
1539 : This::STATUS_OKAY
);
1542 // R_ARM_ABS12: S + A
1543 static inline typename
This::Status
1544 abs12(unsigned char *view
,
1545 const Sized_relobj
<32, big_endian
>* object
,
1546 const Symbol_value
<32>* psymval
)
1548 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Valtype
;
1549 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Reltype
;
1550 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1551 Valtype val
= elfcpp::Swap
<32, big_endian
>::readval(wv
);
1552 Reltype addend
= val
& 0x0fffU
;
1553 Reltype x
= This::arm_symbol_value(object
, psymval
, addend
, false);
1554 val
= utils::bit_select(val
, x
, 0x0fffU
);
1555 elfcpp::Swap
<32, big_endian
>::writeval(wv
, val
);
1556 return (utils::has_overflow
<12>(x
)
1557 ? This::STATUS_OVERFLOW
1558 : This::STATUS_OKAY
);
1561 // R_ARM_ABS16: S + A
1562 static inline typename
This::Status
1563 abs16(unsigned char *view
,
1564 const Sized_relobj
<32, big_endian
>* object
,
1565 const Symbol_value
<32>* psymval
)
1567 typedef typename
elfcpp::Swap
<16, big_endian
>::Valtype Valtype
;
1568 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Reltype
;
1569 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1570 Valtype val
= elfcpp::Swap
<16, big_endian
>::readval(wv
);
1571 Reltype addend
= utils::sign_extend
<16>(val
);
1572 Reltype x
= This::arm_symbol_value(object
, psymval
, addend
, false);
1573 val
= utils::bit_select(val
, x
, 0xffffU
);
1574 elfcpp::Swap
<16, big_endian
>::writeval(wv
, val
);
1575 return (utils::has_signed_unsigned_overflow
<16>(x
)
1576 ? This::STATUS_OVERFLOW
1577 : This::STATUS_OKAY
);
1580 // R_ARM_ABS32: (S + A) | T
1581 static inline typename
This::Status
1582 abs32(unsigned char *view
,
1583 const Sized_relobj
<32, big_endian
>* object
,
1584 const Symbol_value
<32>* psymval
,
1587 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Valtype
;
1588 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1589 Valtype addend
= elfcpp::Swap
<32, big_endian
>::readval(wv
);
1590 Valtype x
= This::arm_symbol_value(object
, psymval
, addend
, has_thumb_bit
);
1591 elfcpp::Swap
<32, big_endian
>::writeval(wv
, x
);
1592 return This::STATUS_OKAY
;
1595 // R_ARM_REL32: (S + A) | T - P
1596 static inline typename
This::Status
1597 rel32(unsigned char *view
,
1598 const Sized_relobj
<32, big_endian
>* object
,
1599 const Symbol_value
<32>* psymval
,
1600 elfcpp::Elf_types
<32>::Elf_Addr address
,
1603 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Valtype
;
1604 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1605 Valtype addend
= elfcpp::Swap
<32, big_endian
>::readval(wv
);
1606 Valtype x
= (This::arm_symbol_value(object
, psymval
, addend
, has_thumb_bit
)
1608 elfcpp::Swap
<32, big_endian
>::writeval(wv
, x
);
1609 return This::STATUS_OKAY
;
1612 // R_ARM_THM_CALL: (S + A) | T - P
1613 static inline typename
This::Status
1614 thm_call(unsigned char *view
,
1615 const Sized_relobj
<32, big_endian
>* object
,
1616 const Symbol_value
<32>* psymval
,
1617 elfcpp::Elf_types
<32>::Elf_Addr address
,
1620 // A thumb call consists of two instructions.
1621 typedef typename
elfcpp::Swap
<16, big_endian
>::Valtype Valtype
;
1622 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Reltype
;
1623 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1624 Valtype hi
= elfcpp::Swap
<16, big_endian
>::readval(wv
);
1625 Valtype lo
= elfcpp::Swap
<16, big_endian
>::readval(wv
+ 1);
1626 // Must be a BL instruction. lo == 11111xxxxxxxxxxx.
1627 gold_assert((lo
& 0xf800) == 0xf800);
1628 Reltype addend
= utils::sign_extend
<23>(((hi
& 0x7ff) << 12)
1629 | ((lo
& 0x7ff) << 1));
1630 Reltype x
= (This::arm_symbol_value(object
, psymval
, addend
, has_thumb_bit
)
1633 // If target has no thumb bit set, we need to either turn the BL
1634 // into a BLX (for ARMv5 or above) or generate a stub.
1637 // This only works for ARMv5 and above with interworking enabled.
1640 hi
= utils::bit_select(hi
, (x
>> 12), 0x7ffU
);
1641 lo
= utils::bit_select(lo
, (x
>> 1), 0x7ffU
);
1642 elfcpp::Swap
<16, big_endian
>::writeval(wv
, hi
);
1643 elfcpp::Swap
<16, big_endian
>::writeval(wv
+ 1, lo
);
1644 return (utils::has_overflow
<23>(x
)
1645 ? This::STATUS_OVERFLOW
1646 : This::STATUS_OKAY
);
1649 // R_ARM_BASE_PREL: B(S) + A - P
1650 static inline typename
This::Status
1651 base_prel(unsigned char* view
,
1652 elfcpp::Elf_types
<32>::Elf_Addr origin
,
1653 elfcpp::Elf_types
<32>::Elf_Addr address
)
1655 Base::rel32(view
, origin
- address
);
1659 // R_ARM_BASE_ABS: B(S) + A
1660 static inline typename
This::Status
1661 base_abs(unsigned char* view
,
1662 elfcpp::Elf_types
<32>::Elf_Addr origin
)
1664 Base::rel32(view
, origin
);
1668 // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
1669 static inline typename
This::Status
1670 got_brel(unsigned char* view
,
1671 typename
elfcpp::Swap
<32, big_endian
>::Valtype got_offset
)
1673 Base::rel32(view
, got_offset
);
1674 return This::STATUS_OKAY
;
1677 // R_ARM_GOT_PREL: GOT(S) + A – P
1678 static inline typename
This::Status
1679 got_prel(unsigned char* view
,
1680 typename
elfcpp::Swap
<32, big_endian
>::Valtype got_offset
,
1681 elfcpp::Elf_types
<32>::Elf_Addr address
)
1683 Base::rel32(view
, got_offset
- address
);
1684 return This::STATUS_OKAY
;
1687 // R_ARM_PLT32: (S + A) | T - P
1688 static inline typename
This::Status
1689 plt32(unsigned char *view
,
1690 const Sized_relobj
<32, big_endian
>* object
,
1691 const Symbol_value
<32>* psymval
,
1692 elfcpp::Elf_types
<32>::Elf_Addr address
,
1695 return arm_branch_common
<elfcpp::R_ARM_PLT32
>(view
, object
, psymval
,
1696 address
, has_thumb_bit
);
1699 // R_ARM_CALL: (S + A) | T - P
1700 static inline typename
This::Status
1701 call(unsigned char *view
,
1702 const Sized_relobj
<32, big_endian
>* object
,
1703 const Symbol_value
<32>* psymval
,
1704 elfcpp::Elf_types
<32>::Elf_Addr address
,
1707 return arm_branch_common
<elfcpp::R_ARM_CALL
>(view
, object
, psymval
,
1708 address
, has_thumb_bit
);
1711 // R_ARM_JUMP24: (S + A) | T - P
1712 static inline typename
This::Status
1713 jump24(unsigned char *view
,
1714 const Sized_relobj
<32, big_endian
>* object
,
1715 const Symbol_value
<32>* psymval
,
1716 elfcpp::Elf_types
<32>::Elf_Addr address
,
1719 return arm_branch_common
<elfcpp::R_ARM_JUMP24
>(view
, object
, psymval
,
1720 address
, has_thumb_bit
);
1723 // R_ARM_PREL: (S + A) | T - P
1724 static inline typename
This::Status
1725 prel31(unsigned char *view
,
1726 const Sized_relobj
<32, big_endian
>* object
,
1727 const Symbol_value
<32>* psymval
,
1728 elfcpp::Elf_types
<32>::Elf_Addr address
,
1731 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Valtype
;
1732 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1733 Valtype val
= elfcpp::Swap
<32, big_endian
>::readval(wv
);
1734 Valtype addend
= utils::sign_extend
<31>(val
);
1735 Valtype x
= (This::arm_symbol_value(object
, psymval
, addend
, has_thumb_bit
)
1737 val
= utils::bit_select(val
, x
, 0x7fffffffU
);
1738 elfcpp::Swap
<32, big_endian
>::writeval(wv
, val
);
1739 return (utils::has_overflow
<31>(x
) ?
1740 This::STATUS_OVERFLOW
: This::STATUS_OKAY
);
1743 // R_ARM_MOVW_ABS_NC: (S + A) | T
1744 static inline typename
This::Status
1745 movw_abs_nc(unsigned char *view
,
1746 const Sized_relobj
<32, big_endian
>* object
,
1747 const Symbol_value
<32>* psymval
,
1750 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Valtype
;
1751 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1752 Valtype val
= elfcpp::Swap
<32, big_endian
>::readval(wv
);
1753 Valtype addend
= This::extract_arm_movw_movt_addend(val
);
1754 Valtype x
= This::arm_symbol_value(object
, psymval
, addend
, has_thumb_bit
);
1755 val
= This::insert_val_arm_movw_movt(val
, x
);
1756 elfcpp::Swap
<32, big_endian
>::writeval(wv
, val
);
1757 return This::STATUS_OKAY
;
1760 // R_ARM_MOVT_ABS: S + A
1761 static inline typename
This::Status
1762 movt_abs(unsigned char *view
,
1763 const Sized_relobj
<32, big_endian
>* object
,
1764 const Symbol_value
<32>* psymval
)
1766 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Valtype
;
1767 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1768 Valtype val
= elfcpp::Swap
<32, big_endian
>::readval(wv
);
1769 Valtype addend
= This::extract_arm_movw_movt_addend(val
);
1770 Valtype x
= This::arm_symbol_value(object
, psymval
, addend
, 0) >> 16;
1771 val
= This::insert_val_arm_movw_movt(val
, x
);
1772 elfcpp::Swap
<32, big_endian
>::writeval(wv
, val
);
1773 return This::STATUS_OKAY
;
1776 // R_ARM_THM_MOVW_ABS_NC: S + A | T
1777 static inline typename
This::Status
1778 thm_movw_abs_nc(unsigned char *view
,
1779 const Sized_relobj
<32, big_endian
>* object
,
1780 const Symbol_value
<32>* psymval
,
1783 typedef typename
elfcpp::Swap
<16, big_endian
>::Valtype Valtype
;
1784 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Reltype
;
1785 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1786 Reltype val
= ((elfcpp::Swap
<16, big_endian
>::readval(wv
) << 16)
1787 | elfcpp::Swap
<16, big_endian
>::readval(wv
+ 1));
1788 Reltype addend
= extract_thumb_movw_movt_addend(val
);
1789 Reltype x
= This::arm_symbol_value(object
, psymval
, addend
, has_thumb_bit
);
1790 val
= This::insert_val_thumb_movw_movt(val
, x
);
1791 elfcpp::Swap
<16, big_endian
>::writeval(wv
, val
>> 16);
1792 elfcpp::Swap
<16, big_endian
>::writeval(wv
+ 1, val
& 0xffff);
1793 return This::STATUS_OKAY
;
1796 // R_ARM_THM_MOVT_ABS: S + A
1797 static inline typename
This::Status
1798 thm_movt_abs(unsigned char *view
,
1799 const Sized_relobj
<32, big_endian
>* object
,
1800 const Symbol_value
<32>* psymval
)
1802 typedef typename
elfcpp::Swap
<16, big_endian
>::Valtype Valtype
;
1803 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Reltype
;
1804 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1805 Reltype val
= ((elfcpp::Swap
<16, big_endian
>::readval(wv
) << 16)
1806 | elfcpp::Swap
<16, big_endian
>::readval(wv
+ 1));
1807 Reltype addend
= This::extract_thumb_movw_movt_addend(val
);
1808 Reltype x
= This::arm_symbol_value(object
, psymval
, addend
, 0) >> 16;
1809 val
= This::insert_val_thumb_movw_movt(val
, x
);
1810 elfcpp::Swap
<16, big_endian
>::writeval(wv
, val
>> 16);
1811 elfcpp::Swap
<16, big_endian
>::writeval(wv
+ 1, val
& 0xffff);
1812 return This::STATUS_OKAY
;
1815 // R_ARM_MOVW_PREL_NC: (S + A) | T - P
1816 static inline typename
This::Status
1817 movw_prel_nc(unsigned char *view
,
1818 const Sized_relobj
<32, big_endian
>* object
,
1819 const Symbol_value
<32>* psymval
,
1820 elfcpp::Elf_types
<32>::Elf_Addr address
,
1823 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Valtype
;
1824 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1825 Valtype val
= elfcpp::Swap
<32, big_endian
>::readval(wv
);
1826 Valtype addend
= This::extract_arm_movw_movt_addend(val
);
1827 Valtype x
= (This::arm_symbol_value(object
, psymval
, addend
, has_thumb_bit
)
1829 val
= This::insert_val_arm_movw_movt(val
, x
);
1830 elfcpp::Swap
<32, big_endian
>::writeval(wv
, val
);
1831 return This::STATUS_OKAY
;
1834 // R_ARM_MOVT_PREL: S + A - P
1835 static inline typename
This::Status
1836 movt_prel(unsigned char *view
,
1837 const Sized_relobj
<32, big_endian
>* object
,
1838 const Symbol_value
<32>* psymval
,
1839 elfcpp::Elf_types
<32>::Elf_Addr address
)
1841 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Valtype
;
1842 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1843 Valtype val
= elfcpp::Swap
<32, big_endian
>::readval(wv
);
1844 Valtype addend
= This::extract_arm_movw_movt_addend(val
);
1845 Valtype x
= (This::arm_symbol_value(object
, psymval
, addend
, 0)
1847 val
= This::insert_val_arm_movw_movt(val
, x
);
1848 elfcpp::Swap
<32, big_endian
>::writeval(wv
, val
);
1849 return This::STATUS_OKAY
;
1852 // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
1853 static inline typename
This::Status
1854 thm_movw_prel_nc(unsigned char *view
,
1855 const Sized_relobj
<32, big_endian
>* object
,
1856 const Symbol_value
<32>* psymval
,
1857 elfcpp::Elf_types
<32>::Elf_Addr address
,
1860 typedef typename
elfcpp::Swap
<16, big_endian
>::Valtype Valtype
;
1861 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Reltype
;
1862 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1863 Reltype val
= (elfcpp::Swap
<16, big_endian
>::readval(wv
) << 16)
1864 | elfcpp::Swap
<16, big_endian
>::readval(wv
+ 1);
1865 Reltype addend
= This::extract_thumb_movw_movt_addend(val
);
1866 Reltype x
= (This::arm_symbol_value(object
, psymval
, addend
, has_thumb_bit
)
1868 val
= This::insert_val_thumb_movw_movt(val
, x
);
1869 elfcpp::Swap
<16, big_endian
>::writeval(wv
, val
>> 16);
1870 elfcpp::Swap
<16, big_endian
>::writeval(wv
+ 1, val
& 0xffff);
1871 return This::STATUS_OKAY
;
1874 // R_ARM_THM_MOVT_PREL: S + A - P
1875 static inline typename
This::Status
1876 thm_movt_prel(unsigned char *view
,
1877 const Sized_relobj
<32, big_endian
>* object
,
1878 const Symbol_value
<32>* psymval
,
1879 elfcpp::Elf_types
<32>::Elf_Addr address
)
1881 typedef typename
elfcpp::Swap
<16, big_endian
>::Valtype Valtype
;
1882 typedef typename
elfcpp::Swap
<32, big_endian
>::Valtype Reltype
;
1883 Valtype
* wv
= reinterpret_cast<Valtype
*>(view
);
1884 Reltype val
= (elfcpp::Swap
<16, big_endian
>::readval(wv
) << 16)
1885 | elfcpp::Swap
<16, big_endian
>::readval(wv
+ 1);
1886 Reltype addend
= This::extract_thumb_movw_movt_addend(val
);
1887 Reltype x
= (This::arm_symbol_value(object
, psymval
, addend
, 0)
1889 val
= This::insert_val_thumb_movw_movt(val
, x
);
1890 elfcpp::Swap
<16, big_endian
>::writeval(wv
, val
>> 16);
1891 elfcpp::Swap
<16, big_endian
>::writeval(wv
+ 1, val
& 0xffff);
1892 return This::STATUS_OKAY
;
1896 // Get the GOT section, creating it if necessary.
1898 template<bool big_endian
>
1899 Output_data_got
<32, big_endian
>*
1900 Target_arm
<big_endian
>::got_section(Symbol_table
* symtab
, Layout
* layout
)
1902 if (this->got_
== NULL
)
1904 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
1906 this->got_
= new Output_data_got
<32, big_endian
>();
1909 os
= layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
1911 | elfcpp::SHF_WRITE
),
1915 // The old GNU linker creates a .got.plt section. We just
1916 // create another set of data in the .got section. Note that we
1917 // always create a PLT if we create a GOT, although the PLT
1919 this->got_plt_
= new Output_data_space(4, "** GOT PLT");
1920 os
= layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
1922 | elfcpp::SHF_WRITE
),
1926 // The first three entries are reserved.
1927 this->got_plt_
->set_current_data_size(3 * 4);
1929 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1930 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
1932 0, 0, elfcpp::STT_OBJECT
,
1934 elfcpp::STV_HIDDEN
, 0,
1940 // Get the dynamic reloc section, creating it if necessary.
1942 template<bool big_endian
>
1943 typename Target_arm
<big_endian
>::Reloc_section
*
1944 Target_arm
<big_endian
>::rel_dyn_section(Layout
* layout
)
1946 if (this->rel_dyn_
== NULL
)
1948 gold_assert(layout
!= NULL
);
1949 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
1950 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
1951 elfcpp::SHF_ALLOC
, this->rel_dyn_
);
1953 return this->rel_dyn_
;
1956 // Insn_template methods.
1958 // Return byte size of an instruction template.
1961 Insn_template::size() const
1963 switch (this->type())
1976 // Return alignment of an instruction template.
1979 Insn_template::alignment() const
1981 switch (this->type())
1994 // Stub_template methods.
1996 Stub_template::Stub_template(
1997 Stub_type type
, const Insn_template
* insns
,
1999 : type_(type
), insns_(insns
), insn_count_(insn_count
), alignment_(1),
2000 entry_in_thumb_mode_(false), relocs_()
2004 // Compute byte size and alignment of stub template.
2005 for (size_t i
= 0; i
< insn_count
; i
++)
2007 unsigned insn_alignment
= insns
[i
].alignment();
2008 size_t insn_size
= insns
[i
].size();
2009 gold_assert((offset
& (insn_alignment
- 1)) == 0);
2010 this->alignment_
= std::max(this->alignment_
, insn_alignment
);
2011 switch (insns
[i
].type())
2013 case Insn_template::THUMB16_TYPE
:
2015 this->entry_in_thumb_mode_
= true;
2018 case Insn_template::THUMB32_TYPE
:
2019 if (insns
[i
].r_type() != elfcpp::R_ARM_NONE
)
2020 this->relocs_
.push_back(Reloc(i
, offset
));
2022 this->entry_in_thumb_mode_
= true;
2025 case Insn_template::ARM_TYPE
:
2026 // Handle cases where the target is encoded within the
2028 if (insns
[i
].r_type() == elfcpp::R_ARM_JUMP24
)
2029 this->relocs_
.push_back(Reloc(i
, offset
));
2032 case Insn_template::DATA_TYPE
:
2033 // Entry point cannot be data.
2034 gold_assert(i
!= 0);
2035 this->relocs_
.push_back(Reloc(i
, offset
));
2041 offset
+= insn_size
;
2043 this->size_
= offset
;
2046 // Reloc_stub::Key methods.
2048 // Dump a Key as a string for debugging.
2051 Reloc_stub::Key::name() const
2053 if (this->r_sym_
== invalid_index
)
2055 // Global symbol key name
2056 // <stub-type>:<symbol name>:<addend>.
2057 const std::string sym_name
= this->u_
.symbol
->name();
2058 // We need to print two hex number and two colons. So just add 100 bytes
2059 // to the symbol name size.
2060 size_t len
= sym_name
.size() + 100;
2061 char* buffer
= new char[len
];
2062 int c
= snprintf(buffer
, len
, "%d:%s:%x", this->stub_type_
,
2063 sym_name
.c_str(), this->addend_
);
2064 gold_assert(c
> 0 && c
< static_cast<int>(len
));
2066 return std::string(buffer
);
2070 // local symbol key name
2071 // <stub-type>:<object>:<r_sym>:<addend>.
2072 const size_t len
= 200;
2074 int c
= snprintf(buffer
, len
, "%d:%p:%u:%x", this->stub_type_
,
2075 this->u_
.relobj
, this->r_sym_
, this->addend_
);
2076 gold_assert(c
> 0 && c
< static_cast<int>(len
));
2077 return std::string(buffer
);
2081 // Reloc_stub methods.
2083 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
2084 // LOCATION to DESTINATION.
2085 // This code is based on the arm_type_of_stub function in
2086 // bfd/elf32-arm.c. We have changed the interface a liitle to keep the Stub
2090 Reloc_stub::stub_type_for_reloc(
2091 unsigned int r_type
,
2092 Arm_address location
,
2093 Arm_address destination
,
2094 bool target_is_thumb
)
2096 Stub_type stub_type
= arm_stub_none
;
2098 // This is a bit ugly but we want to avoid using a templated class for
2099 // big and little endianities.
2101 bool should_force_pic_veneer
;
2104 if (parameters
->target().is_big_endian())
2106 const Target_arm
<true>& big_endian_target
=
2107 Target_arm
<true>::default_target();
2108 may_use_blx
= big_endian_target
.may_use_blx();
2109 should_force_pic_veneer
= big_endian_target
.should_force_pic_veneer();
2110 thumb2
= big_endian_target
.using_thumb2();
2111 thumb_only
= big_endian_target
.using_thumb_only();
2115 const Target_arm
<false>& little_endian_target
=
2116 Target_arm
<false>::default_target();
2117 may_use_blx
= little_endian_target
.may_use_blx();
2118 should_force_pic_veneer
= little_endian_target
.should_force_pic_veneer();
2119 thumb2
= little_endian_target
.using_thumb2();
2120 thumb_only
= little_endian_target
.using_thumb_only();
2123 int64_t branch_offset
= (int64_t)destination
- location
;
2125 if (r_type
== elfcpp::R_ARM_THM_CALL
|| r_type
== elfcpp::R_ARM_THM_JUMP24
)
2127 // Handle cases where:
2128 // - this call goes too far (different Thumb/Thumb2 max
2130 // - it's a Thumb->Arm call and blx is not available, or it's a
2131 // Thumb->Arm branch (not bl). A stub is needed in this case.
2133 && (branch_offset
> THM_MAX_FWD_BRANCH_OFFSET
2134 || (branch_offset
< THM_MAX_BWD_BRANCH_OFFSET
)))
2136 && (branch_offset
> THM2_MAX_FWD_BRANCH_OFFSET
2137 || (branch_offset
< THM2_MAX_BWD_BRANCH_OFFSET
)))
2138 || ((!target_is_thumb
)
2139 && (((r_type
== elfcpp::R_ARM_THM_CALL
) && !may_use_blx
)
2140 || (r_type
== elfcpp::R_ARM_THM_JUMP24
))))
2142 if (target_is_thumb
)
2147 stub_type
= (parameters
->options().shared() | should_force_pic_veneer
)
2150 && (r_type
== elfcpp::R_ARM_THM_CALL
))
2151 // V5T and above. Stub starts with ARM code, so
2152 // we must be able to switch mode before
2153 // reaching it, which is only possible for 'bl'
2154 // (ie R_ARM_THM_CALL relocation).
2155 ? arm_stub_long_branch_any_thumb_pic
2156 // On V4T, use Thumb code only.
2157 : arm_stub_long_branch_v4t_thumb_thumb_pic
)
2161 && (r_type
== elfcpp::R_ARM_THM_CALL
))
2162 ? arm_stub_long_branch_any_any
// V5T and above.
2163 : arm_stub_long_branch_v4t_thumb_thumb
); // V4T.
2167 stub_type
= (parameters
->options().shared() | should_force_pic_veneer
)
2168 ? arm_stub_long_branch_thumb_only_pic
// PIC stub.
2169 : arm_stub_long_branch_thumb_only
; // non-PIC stub.
2176 // FIXME: We should check that the input section is from an
2177 // object that has interwork enabled.
2179 stub_type
= (parameters
->options().shared()
2180 || should_force_pic_veneer
)
2183 && (r_type
== elfcpp::R_ARM_THM_CALL
))
2184 ? arm_stub_long_branch_any_arm_pic
// V5T and above.
2185 : arm_stub_long_branch_v4t_thumb_arm_pic
) // V4T.
2189 && (r_type
== elfcpp::R_ARM_THM_CALL
))
2190 ? arm_stub_long_branch_any_any
// V5T and above.
2191 : arm_stub_long_branch_v4t_thumb_arm
); // V4T.
2193 // Handle v4t short branches.
2194 if ((stub_type
== arm_stub_long_branch_v4t_thumb_arm
)
2195 && (branch_offset
<= THM_MAX_FWD_BRANCH_OFFSET
)
2196 && (branch_offset
>= THM_MAX_BWD_BRANCH_OFFSET
))
2197 stub_type
= arm_stub_short_branch_v4t_thumb_arm
;
2201 else if (r_type
== elfcpp::R_ARM_CALL
2202 || r_type
== elfcpp::R_ARM_JUMP24
2203 || r_type
== elfcpp::R_ARM_PLT32
)
2205 if (target_is_thumb
)
2209 // FIXME: We should check that the input section is from an
2210 // object that has interwork enabled.
2212 // We have an extra 2-bytes reach because of
2213 // the mode change (bit 24 (H) of BLX encoding).
2214 if (branch_offset
> (ARM_MAX_FWD_BRANCH_OFFSET
+ 2)
2215 || (branch_offset
< ARM_MAX_BWD_BRANCH_OFFSET
)
2216 || ((r_type
== elfcpp::R_ARM_CALL
) && !may_use_blx
)
2217 || (r_type
== elfcpp::R_ARM_JUMP24
)
2218 || (r_type
== elfcpp::R_ARM_PLT32
))
2220 stub_type
= (parameters
->options().shared()
2221 || should_force_pic_veneer
)
2224 ? arm_stub_long_branch_any_thumb_pic
// V5T and above.
2225 : arm_stub_long_branch_v4t_arm_thumb_pic
) // V4T stub.
2229 ? arm_stub_long_branch_any_any
// V5T and above.
2230 : arm_stub_long_branch_v4t_arm_thumb
); // V4T.
2236 if (branch_offset
> ARM_MAX_FWD_BRANCH_OFFSET
2237 || (branch_offset
< ARM_MAX_BWD_BRANCH_OFFSET
))
2239 stub_type
= (parameters
->options().shared()
2240 || should_force_pic_veneer
)
2241 ? arm_stub_long_branch_any_arm_pic
// PIC stubs.
2242 : arm_stub_long_branch_any_any
; /// non-PIC.
2250 // Template to implement do_write for a specific target endianity.
2252 template<bool big_endian
>
2254 Reloc_stub::do_fixed_endian_write(unsigned char* view
,
2255 section_size_type view_size
)
2257 const Stub_template
* stub_template
= this->stub_template();
2258 const Insn_template
* insns
= stub_template
->insns();
2260 // FIXME: We do not handle BE8 encoding yet.
2261 unsigned char* pov
= view
;
2262 for (size_t i
= 0; i
< stub_template
->insn_count(); i
++)
2264 switch (insns
[i
].type())
2266 case Insn_template::THUMB16_TYPE
:
2267 // Non-zero reloc addends are only used in Cortex-A8 stubs.
2268 gold_assert(insns
[i
].reloc_addend() == 0);
2269 elfcpp::Swap
<16, big_endian
>::writeval(pov
, insns
[i
].data() & 0xffff);
2271 case Insn_template::THUMB32_TYPE
:
2273 uint32_t hi
= (insns
[i
].data() >> 16) & 0xffff;
2274 uint32_t lo
= insns
[i
].data() & 0xffff;
2275 elfcpp::Swap
<16, big_endian
>::writeval(pov
, hi
);
2276 elfcpp::Swap
<16, big_endian
>::writeval(pov
+ 2, lo
);
2279 case Insn_template::ARM_TYPE
:
2280 case Insn_template::DATA_TYPE
:
2281 elfcpp::Swap
<32, big_endian
>::writeval(pov
, insns
[i
].data());
2286 pov
+= insns
[i
].size();
2288 gold_assert(static_cast<section_size_type
>(pov
- view
) == view_size
);
2291 // Write a reloc stub to VIEW with endianity specified by BIG_ENDIAN.
2294 Reloc_stub::do_write(unsigned char* view
, section_size_type view_size
,
2298 this->do_fixed_endian_write
<true>(view
, view_size
);
2300 this->do_fixed_endian_write
<false>(view
, view_size
);
2303 // Stub_factory methods.
2305 Stub_factory::Stub_factory()
2307 // The instruction template sequences are declared as static
2308 // objects and initialized first time the constructor runs.
2310 // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
2311 // to reach the stub if necessary.
2312 static const Insn_template elf32_arm_stub_long_branch_any_any
[] =
2314 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
2315 Insn_template::data_word(0, elfcpp::R_ARM_ABS32
, 0),
2316 // dcd R_ARM_ABS32(X)
2319 // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
2321 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb
[] =
2323 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
2324 Insn_template::arm_insn(0xe12fff1c), // bx ip
2325 Insn_template::data_word(0, elfcpp::R_ARM_ABS32
, 0),
2326 // dcd R_ARM_ABS32(X)
2329 // Thumb -> Thumb long branch stub. Used on M-profile architectures.
2330 static const Insn_template elf32_arm_stub_long_branch_thumb_only
[] =
2332 Insn_template::thumb16_insn(0xb401), // push {r0}
2333 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
2334 Insn_template::thumb16_insn(0x4684), // mov ip, r0
2335 Insn_template::thumb16_insn(0xbc01), // pop {r0}
2336 Insn_template::thumb16_insn(0x4760), // bx ip
2337 Insn_template::thumb16_insn(0xbf00), // nop
2338 Insn_template::data_word(0, elfcpp::R_ARM_ABS32
, 0),
2339 // dcd R_ARM_ABS32(X)
2342 // V4T Thumb -> Thumb long branch stub. Using the stack is not
2344 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb
[] =
2346 Insn_template::thumb16_insn(0x4778), // bx pc
2347 Insn_template::thumb16_insn(0x46c0), // nop
2348 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
2349 Insn_template::arm_insn(0xe12fff1c), // bx ip
2350 Insn_template::data_word(0, elfcpp::R_ARM_ABS32
, 0),
2351 // dcd R_ARM_ABS32(X)
2354 // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
2356 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm
[] =
2358 Insn_template::thumb16_insn(0x4778), // bx pc
2359 Insn_template::thumb16_insn(0x46c0), // nop
2360 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
2361 Insn_template::data_word(0, elfcpp::R_ARM_ABS32
, 0),
2362 // dcd R_ARM_ABS32(X)
2365 // V4T Thumb -> ARM short branch stub. Shorter variant of the above
2366 // one, when the destination is close enough.
2367 static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm
[] =
2369 Insn_template::thumb16_insn(0x4778), // bx pc
2370 Insn_template::thumb16_insn(0x46c0), // nop
2371 Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8)
2374 // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use
2375 // blx to reach the stub if necessary.
2376 static const Insn_template elf32_arm_stub_long_branch_any_arm_pic
[] =
2378 Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc]
2379 Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip
2380 Insn_template::data_word(0, elfcpp::R_ARM_REL32
, -4),
2381 // dcd R_ARM_REL32(X-4)
2384 // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use
2385 // blx to reach the stub if necessary. We can not add into pc;
2386 // it is not guaranteed to mode switch (different in ARMv6 and
2388 static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic
[] =
2390 Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4]
2391 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
2392 Insn_template::arm_insn(0xe12fff1c), // bx ip
2393 Insn_template::data_word(0, elfcpp::R_ARM_REL32
, 0),
2394 // dcd R_ARM_REL32(X)
2397 // V4T ARM -> ARM long branch stub, PIC.
2398 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic
[] =
2400 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
2401 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
2402 Insn_template::arm_insn(0xe12fff1c), // bx ip
2403 Insn_template::data_word(0, elfcpp::R_ARM_REL32
, 0),
2404 // dcd R_ARM_REL32(X)
2407 // V4T Thumb -> ARM long branch stub, PIC.
2408 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic
[] =
2410 Insn_template::thumb16_insn(0x4778), // bx pc
2411 Insn_template::thumb16_insn(0x46c0), // nop
2412 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
2413 Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc
2414 Insn_template::data_word(0, elfcpp::R_ARM_REL32
, -4),
2415 // dcd R_ARM_REL32(X)
2418 // Thumb -> Thumb long branch stub, PIC. Used on M-profile
2420 static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic
[] =
2422 Insn_template::thumb16_insn(0xb401), // push {r0}
2423 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
2424 Insn_template::thumb16_insn(0x46fc), // mov ip, pc
2425 Insn_template::thumb16_insn(0x4484), // add ip, r0
2426 Insn_template::thumb16_insn(0xbc01), // pop {r0}
2427 Insn_template::thumb16_insn(0x4760), // bx ip
2428 Insn_template::data_word(0, elfcpp::R_ARM_REL32
, 4),
2429 // dcd R_ARM_REL32(X)
2432 // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
2434 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic
[] =
2436 Insn_template::thumb16_insn(0x4778), // bx pc
2437 Insn_template::thumb16_insn(0x46c0), // nop
2438 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
2439 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
2440 Insn_template::arm_insn(0xe12fff1c), // bx ip
2441 Insn_template::data_word(0, elfcpp::R_ARM_REL32
, 0),
2442 // dcd R_ARM_REL32(X)
2445 // Cortex-A8 erratum-workaround stubs.
2447 // Stub used for conditional branches (which may be beyond +/-1MB away,
2448 // so we can't use a conditional branch to reach this stub).
2455 static const Insn_template elf32_arm_stub_a8_veneer_b_cond
[] =
2457 Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true
2458 Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after
2459 Insn_template::thumb32_b_insn(0xf000b800, -4) // true:
2463 // Stub used for b.w and bl.w instructions.
2465 static const Insn_template elf32_arm_stub_a8_veneer_b
[] =
2467 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
2470 static const Insn_template elf32_arm_stub_a8_veneer_bl
[] =
2472 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
2475 // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w
2476 // instruction (which switches to ARM mode) to point to this stub. Jump to
2477 // the real destination using an ARM-mode branch.
2478 const Insn_template elf32_arm_stub_a8_veneer_blx
[] =
2480 Insn_template::arm_rel_insn(0xea000000, -8) // b dest
2483 // Fill in the stub template look-up table. Stub templates are constructed
2484 // per instance of Stub_factory for fast look-up without locking
2485 // in a thread-enabled environment.
2487 this->stub_templates_
[arm_stub_none
] =
2488 new Stub_template(arm_stub_none
, NULL
, 0);
2490 #define DEF_STUB(x) \
2494 = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
2495 Stub_type type = arm_stub_##x; \
2496 this->stub_templates_[type] = \
2497 new Stub_template(type, elf32_arm_stub_##x, array_size); \
2505 // Stub_table methods.
2507 // Add a STUB with using KEY. Caller is reponsible for avoid adding
2508 // if already a STUB with the same key has been added.
2510 template<bool big_endian
>
2512 Stub_table
<big_endian
>::add_reloc_stub(
2514 const Reloc_stub::Key
& key
)
2516 const Stub_template
* stub_template
= stub
->stub_template();
2517 gold_assert(stub_template
->type() == key
.stub_type());
2518 this->reloc_stubs_
[key
] = stub
;
2519 if (this->addralign_
< stub_template
->alignment())
2520 this->addralign_
= stub_template
->alignment();
2521 this->has_been_changed_
= true;
2524 template<bool big_endian
>
2526 Stub_table
<big_endian
>::relocate_stubs(
2527 const Relocate_info
<32, big_endian
>* relinfo
,
2528 Target_arm
<big_endian
>* arm_target
,
2529 Output_section
* output_section
,
2530 unsigned char* view
,
2531 Arm_address address
,
2532 section_size_type view_size
)
2534 // If we are passed a view bigger than the stub table's. we need to
2536 gold_assert(address
== this->address()
2538 == static_cast<section_size_type
>(this->data_size())));
2540 for (typename
Reloc_stub_map::const_iterator p
= this->reloc_stubs_
.begin();
2541 p
!= this->reloc_stubs_
.end();
2544 Reloc_stub
* stub
= p
->second
;
2545 const Stub_template
* stub_template
= stub
->stub_template();
2546 if (stub_template
->reloc_count() != 0)
2548 // Adjust view to cover the stub only.
2549 section_size_type offset
= stub
->offset();
2550 section_size_type stub_size
= stub_template
->size();
2551 gold_assert(offset
+ stub_size
<= view_size
);
2553 arm_target
->relocate_stub(stub
, relinfo
, output_section
,
2554 view
+ offset
, address
+ offset
,
2560 // Reset address and file offset.
2562 template<bool big_endian
>
2564 Stub_table
<big_endian
>::do_reset_address_and_file_offset()
2567 uint64_t max_addralign
= 1;
2568 for (typename
Reloc_stub_map::const_iterator p
= this->reloc_stubs_
.begin();
2569 p
!= this->reloc_stubs_
.end();
2572 Reloc_stub
* stub
= p
->second
;
2573 const Stub_template
* stub_template
= stub
->stub_template();
2574 uint64_t stub_addralign
= stub_template
->alignment();
2575 max_addralign
= std::max(max_addralign
, stub_addralign
);
2576 off
= align_address(off
, stub_addralign
);
2577 stub
->set_offset(off
);
2578 stub
->reset_destination_address();
2579 off
+= stub_template
->size();
2582 this->addralign_
= max_addralign
;
2583 this->set_current_data_size_for_child(off
);
2586 // Write out the stubs to file.
2588 template<bool big_endian
>
2590 Stub_table
<big_endian
>::do_write(Output_file
* of
)
2592 off_t offset
= this->offset();
2593 const section_size_type oview_size
=
2594 convert_to_section_size_type(this->data_size());
2595 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
2597 for (typename
Reloc_stub_map::const_iterator p
= this->reloc_stubs_
.begin();
2598 p
!= this->reloc_stubs_
.end();
2601 Reloc_stub
* stub
= p
->second
;
2602 Arm_address address
= this->address() + stub
->offset();
2604 == align_address(address
,
2605 stub
->stub_template()->alignment()));
2606 stub
->write(oview
+ stub
->offset(), stub
->stub_template()->size(),
2609 of
->write_output_view(this->offset(), oview_size
, oview
);
2612 // Arm_input_section methods.
2614 // Initialize an Arm_input_section.
2616 template<bool big_endian
>
2618 Arm_input_section
<big_endian
>::init()
2620 Relobj
* relobj
= this->relobj();
2621 unsigned int shndx
= this->shndx();
2623 // Cache these to speed up size and alignment queries. It is too slow
2624 // to call section_addraglin and section_size every time.
2625 this->original_addralign_
= relobj
->section_addralign(shndx
);
2626 this->original_size_
= relobj
->section_size(shndx
);
2628 // We want to make this look like the original input section after
2629 // output sections are finalized.
2630 Output_section
* os
= relobj
->output_section(shndx
);
2631 off_t offset
= relobj
->output_section_offset(shndx
);
2632 gold_assert(os
!= NULL
&& !relobj
->is_output_section_offset_invalid(shndx
));
2633 this->set_address(os
->address() + offset
);
2634 this->set_file_offset(os
->offset() + offset
);
2636 this->set_current_data_size(this->original_size_
);
2637 this->finalize_data_size();
2640 template<bool big_endian
>
2642 Arm_input_section
<big_endian
>::do_write(Output_file
* of
)
2644 // We have to write out the original section content.
2645 section_size_type section_size
;
2646 const unsigned char* section_contents
=
2647 this->relobj()->section_contents(this->shndx(), §ion_size
, false);
2648 of
->write(this->offset(), section_contents
, section_size
);
2650 // If this owns a stub table and it is not empty, write it.
2651 if (this->is_stub_table_owner() && !this->stub_table_
->empty())
2652 this->stub_table_
->write(of
);
2655 // Finalize data size.
2657 template<bool big_endian
>
2659 Arm_input_section
<big_endian
>::set_final_data_size()
2661 // If this owns a stub table, finalize its data size as well.
2662 if (this->is_stub_table_owner())
2664 uint64_t address
= this->address();
2666 // The stub table comes after the original section contents.
2667 address
+= this->original_size_
;
2668 address
= align_address(address
, this->stub_table_
->addralign());
2669 off_t offset
= this->offset() + (address
- this->address());
2670 this->stub_table_
->set_address_and_file_offset(address
, offset
);
2671 address
+= this->stub_table_
->data_size();
2672 gold_assert(address
== this->address() + this->current_data_size());
2675 this->set_data_size(this->current_data_size());
2678 // Reset address and file offset.
2680 template<bool big_endian
>
2682 Arm_input_section
<big_endian
>::do_reset_address_and_file_offset()
2684 // Size of the original input section contents.
2685 off_t off
= convert_types
<off_t
, uint64_t>(this->original_size_
);
2687 // If this is a stub table owner, account for the stub table size.
2688 if (this->is_stub_table_owner())
2690 Stub_table
<big_endian
>* stub_table
= this->stub_table_
;
2692 // Reset the stub table's address and file offset. The
2693 // current data size for child will be updated after that.
2694 stub_table_
->reset_address_and_file_offset();
2695 off
= align_address(off
, stub_table_
->addralign());
2696 off
+= stub_table
->current_data_size();
2699 this->set_current_data_size(off
);
2702 // Arm_output_section methods.
2704 // Create a stub group for input sections from BEGIN to END. OWNER
2705 // points to the input section to be the owner a new stub table.
2707 template<bool big_endian
>
2709 Arm_output_section
<big_endian
>::create_stub_group(
2710 Input_section_list::const_iterator begin
,
2711 Input_section_list::const_iterator end
,
2712 Input_section_list::const_iterator owner
,
2713 Target_arm
<big_endian
>* target
,
2714 std::vector
<Output_relaxed_input_section
*>* new_relaxed_sections
)
2716 // Currently we convert ordinary input sections into relaxed sections only
2717 // at this point but we may want to support creating relaxed input section
2718 // very early. So we check here to see if owner is already a relaxed
2721 Arm_input_section
<big_endian
>* arm_input_section
;
2722 if (owner
->is_relaxed_input_section())
2725 Arm_input_section
<big_endian
>::as_arm_input_section(
2726 owner
->relaxed_input_section());
2730 gold_assert(owner
->is_input_section());
2731 // Create a new relaxed input section.
2733 target
->new_arm_input_section(owner
->relobj(), owner
->shndx());
2734 new_relaxed_sections
->push_back(arm_input_section
);
2737 // Create a stub table.
2738 Stub_table
<big_endian
>* stub_table
=
2739 target
->new_stub_table(arm_input_section
);
2741 arm_input_section
->set_stub_table(stub_table
);
2743 Input_section_list::const_iterator p
= begin
;
2744 Input_section_list::const_iterator prev_p
;
2746 // Look for input sections or relaxed input sections in [begin ... end].
2749 if (p
->is_input_section() || p
->is_relaxed_input_section())
2751 // The stub table information for input sections live
2752 // in their objects.
2753 Arm_relobj
<big_endian
>* arm_relobj
=
2754 Arm_relobj
<big_endian
>::as_arm_relobj(p
->relobj());
2755 arm_relobj
->set_stub_table(p
->shndx(), stub_table
);
2759 while (prev_p
!= end
);
2762 // Group input sections for stub generation. GROUP_SIZE is roughly the limit
2763 // of stub groups. We grow a stub group by adding input section until the
2764 // size is just below GROUP_SIZE. The last input section will be converted
2765 // into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
2766 // input section after the stub table, effectively double the group size.
2768 // This is similar to the group_sections() function in elf32-arm.c but is
2769 // implemented differently.
2771 template<bool big_endian
>
2773 Arm_output_section
<big_endian
>::group_sections(
2774 section_size_type group_size
,
2775 bool stubs_always_after_branch
,
2776 Target_arm
<big_endian
>* target
)
2778 // We only care about sections containing code.
2779 if ((this->flags() & elfcpp::SHF_EXECINSTR
) == 0)
2782 // States for grouping.
2785 // No group is being built.
2787 // A group is being built but the stub table is not found yet.
2788 // We keep group a stub group until the size is just under GROUP_SIZE.
2789 // The last input section in the group will be used as the stub table.
2790 FINDING_STUB_SECTION
,
2791 // A group is being built and we have already found a stub table.
2792 // We enter this state to grow a stub group by adding input section
2793 // after the stub table. This effectively doubles the group size.
2797 // Any newly created relaxed sections are stored here.
2798 std::vector
<Output_relaxed_input_section
*> new_relaxed_sections
;
2800 State state
= NO_GROUP
;
2801 section_size_type off
= 0;
2802 section_size_type group_begin_offset
= 0;
2803 section_size_type group_end_offset
= 0;
2804 section_size_type stub_table_end_offset
= 0;
2805 Input_section_list::const_iterator group_begin
=
2806 this->input_sections().end();
2807 Input_section_list::const_iterator stub_table
=
2808 this->input_sections().end();
2809 Input_section_list::const_iterator group_end
= this->input_sections().end();
2810 for (Input_section_list::const_iterator p
= this->input_sections().begin();
2811 p
!= this->input_sections().end();
2814 section_size_type section_begin_offset
=
2815 align_address(off
, p
->addralign());
2816 section_size_type section_end_offset
=
2817 section_begin_offset
+ p
->data_size();
2819 // Check to see if we should group the previously seens sections.
2825 case FINDING_STUB_SECTION
:
2826 // Adding this section makes the group larger than GROUP_SIZE.
2827 if (section_end_offset
- group_begin_offset
>= group_size
)
2829 if (stubs_always_after_branch
)
2831 gold_assert(group_end
!= this->input_sections().end());
2832 this->create_stub_group(group_begin
, group_end
, group_end
,
2833 target
, &new_relaxed_sections
);
2838 // But wait, there's more! Input sections up to
2839 // stub_group_size bytes after the stub table can be
2840 // handled by it too.
2841 state
= HAS_STUB_SECTION
;
2842 stub_table
= group_end
;
2843 stub_table_end_offset
= group_end_offset
;
2848 case HAS_STUB_SECTION
:
2849 // Adding this section makes the post stub-section group larger
2851 if (section_end_offset
- stub_table_end_offset
>= group_size
)
2853 gold_assert(group_end
!= this->input_sections().end());
2854 this->create_stub_group(group_begin
, group_end
, stub_table
,
2855 target
, &new_relaxed_sections
);
2864 // If we see an input section and currently there is no group, start
2865 // a new one. Skip any empty sections.
2866 if ((p
->is_input_section() || p
->is_relaxed_input_section())
2867 && (p
->relobj()->section_size(p
->shndx()) != 0))
2869 if (state
== NO_GROUP
)
2871 state
= FINDING_STUB_SECTION
;
2873 group_begin_offset
= section_begin_offset
;
2876 // Keep track of the last input section seen.
2878 group_end_offset
= section_end_offset
;
2881 off
= section_end_offset
;
2884 // Create a stub group for any ungrouped sections.
2885 if (state
== FINDING_STUB_SECTION
|| state
== HAS_STUB_SECTION
)
2887 gold_assert(group_end
!= this->input_sections().end());
2888 this->create_stub_group(group_begin
, group_end
,
2889 (state
== FINDING_STUB_SECTION
2892 target
, &new_relaxed_sections
);
2895 // Convert input section into relaxed input section in a batch.
2896 if (!new_relaxed_sections
.empty())
2897 this->convert_input_sections_to_relaxed_sections(new_relaxed_sections
);
2899 // Update the section offsets
2900 for (size_t i
= 0; i
< new_relaxed_sections
.size(); ++i
)
2902 Arm_relobj
<big_endian
>* arm_relobj
=
2903 Arm_relobj
<big_endian
>::as_arm_relobj(
2904 new_relaxed_sections
[i
]->relobj());
2905 unsigned int shndx
= new_relaxed_sections
[i
]->shndx();
2906 // Tell Arm_relobj that this input section is converted.
2907 arm_relobj
->convert_input_section_to_relaxed_section(shndx
);
2911 // A class to handle the PLT data.
2913 template<bool big_endian
>
2914 class Output_data_plt_arm
: public Output_section_data
2917 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, big_endian
>
2920 Output_data_plt_arm(Layout
*, Output_data_space
*);
2922 // Add an entry to the PLT.
2924 add_entry(Symbol
* gsym
);
2926 // Return the .rel.plt section data.
2927 const Reloc_section
*
2929 { return this->rel_
; }
2933 do_adjust_output_section(Output_section
* os
);
2935 // Write to a map file.
2937 do_print_to_mapfile(Mapfile
* mapfile
) const
2938 { mapfile
->print_output_data(this, _("** PLT")); }
2941 // Template for the first PLT entry.
2942 static const uint32_t first_plt_entry
[5];
2944 // Template for subsequent PLT entries.
2945 static const uint32_t plt_entry
[3];
2947 // Set the final size.
2949 set_final_data_size()
2951 this->set_data_size(sizeof(first_plt_entry
)
2952 + this->count_
* sizeof(plt_entry
));
2955 // Write out the PLT data.
2957 do_write(Output_file
*);
2959 // The reloc section.
2960 Reloc_section
* rel_
;
2961 // The .got.plt section.
2962 Output_data_space
* got_plt_
;
2963 // The number of PLT entries.
2964 unsigned int count_
;
2967 // Create the PLT section. The ordinary .got section is an argument,
2968 // since we need to refer to the start. We also create our own .got
2969 // section just for PLT entries.
2971 template<bool big_endian
>
2972 Output_data_plt_arm
<big_endian
>::Output_data_plt_arm(Layout
* layout
,
2973 Output_data_space
* got_plt
)
2974 : Output_section_data(4), got_plt_(got_plt
), count_(0)
2976 this->rel_
= new Reloc_section(false);
2977 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
2978 elfcpp::SHF_ALLOC
, this->rel_
);
2981 template<bool big_endian
>
2983 Output_data_plt_arm
<big_endian
>::do_adjust_output_section(Output_section
* os
)
2988 // Add an entry to the PLT.
2990 template<bool big_endian
>
2992 Output_data_plt_arm
<big_endian
>::add_entry(Symbol
* gsym
)
2994 gold_assert(!gsym
->has_plt_offset());
2996 // Note that when setting the PLT offset we skip the initial
2997 // reserved PLT entry.
2998 gsym
->set_plt_offset((this->count_
) * sizeof(plt_entry
)
2999 + sizeof(first_plt_entry
));
3003 section_offset_type got_offset
= this->got_plt_
->current_data_size();
3005 // Every PLT entry needs a GOT entry which points back to the PLT
3006 // entry (this will be changed by the dynamic linker, normally
3007 // lazily when the function is called).
3008 this->got_plt_
->set_current_data_size(got_offset
+ 4);
3010 // Every PLT entry needs a reloc.
3011 gsym
->set_needs_dynsym_entry();
3012 this->rel_
->add_global(gsym
, elfcpp::R_ARM_JUMP_SLOT
, this->got_plt_
,
3015 // Note that we don't need to save the symbol. The contents of the
3016 // PLT are independent of which symbols are used. The symbols only
3017 // appear in the relocations.
3021 // FIXME: This is not very flexible. Right now this has only been tested
3022 // on armv5te. If we are to support additional architecture features like
3023 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
3025 // The first entry in the PLT.
3026 template<bool big_endian
>
3027 const uint32_t Output_data_plt_arm
<big_endian
>::first_plt_entry
[5] =
3029 0xe52de004, // str lr, [sp, #-4]!
3030 0xe59fe004, // ldr lr, [pc, #4]
3031 0xe08fe00e, // add lr, pc, lr
3032 0xe5bef008, // ldr pc, [lr, #8]!
3033 0x00000000, // &GOT[0] - .
3036 // Subsequent entries in the PLT.
3038 template<bool big_endian
>
3039 const uint32_t Output_data_plt_arm
<big_endian
>::plt_entry
[3] =
3041 0xe28fc600, // add ip, pc, #0xNN00000
3042 0xe28cca00, // add ip, ip, #0xNN000
3043 0xe5bcf000, // ldr pc, [ip, #0xNNN]!
3046 // Write out the PLT. This uses the hand-coded instructions above,
3047 // and adjusts them as needed. This is all specified by the arm ELF
3048 // Processor Supplement.
3050 template<bool big_endian
>
3052 Output_data_plt_arm
<big_endian
>::do_write(Output_file
* of
)
3054 const off_t offset
= this->offset();
3055 const section_size_type oview_size
=
3056 convert_to_section_size_type(this->data_size());
3057 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
3059 const off_t got_file_offset
= this->got_plt_
->offset();
3060 const section_size_type got_size
=
3061 convert_to_section_size_type(this->got_plt_
->data_size());
3062 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
3064 unsigned char* pov
= oview
;
3066 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
3067 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
3069 // Write first PLT entry. All but the last word are constants.
3070 const size_t num_first_plt_words
= (sizeof(first_plt_entry
)
3071 / sizeof(plt_entry
[0]));
3072 for (size_t i
= 0; i
< num_first_plt_words
- 1; i
++)
3073 elfcpp::Swap
<32, big_endian
>::writeval(pov
+ i
* 4, first_plt_entry
[i
]);
3074 // Last word in first PLT entry is &GOT[0] - .
3075 elfcpp::Swap
<32, big_endian
>::writeval(pov
+ 16,
3076 got_address
- (plt_address
+ 16));
3077 pov
+= sizeof(first_plt_entry
);
3079 unsigned char* got_pov
= got_view
;
3081 memset(got_pov
, 0, 12);
3084 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
3085 unsigned int plt_offset
= sizeof(first_plt_entry
);
3086 unsigned int plt_rel_offset
= 0;
3087 unsigned int got_offset
= 12;
3088 const unsigned int count
= this->count_
;
3089 for (unsigned int i
= 0;
3092 pov
+= sizeof(plt_entry
),
3094 plt_offset
+= sizeof(plt_entry
),
3095 plt_rel_offset
+= rel_size
,
3098 // Set and adjust the PLT entry itself.
3099 int32_t offset
= ((got_address
+ got_offset
)
3100 - (plt_address
+ plt_offset
+ 8));
3102 gold_assert(offset
>= 0 && offset
< 0x0fffffff);
3103 uint32_t plt_insn0
= plt_entry
[0] | ((offset
>> 20) & 0xff);
3104 elfcpp::Swap
<32, big_endian
>::writeval(pov
, plt_insn0
);
3105 uint32_t plt_insn1
= plt_entry
[1] | ((offset
>> 12) & 0xff);
3106 elfcpp::Swap
<32, big_endian
>::writeval(pov
+ 4, plt_insn1
);
3107 uint32_t plt_insn2
= plt_entry
[2] | (offset
& 0xfff);
3108 elfcpp::Swap
<32, big_endian
>::writeval(pov
+ 8, plt_insn2
);
3110 // Set the entry in the GOT.
3111 elfcpp::Swap
<32, big_endian
>::writeval(got_pov
, plt_address
);
3114 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
3115 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
3117 of
->write_output_view(offset
, oview_size
, oview
);
3118 of
->write_output_view(got_file_offset
, got_size
, got_view
);
3121 // Create a PLT entry for a global symbol.
3123 template<bool big_endian
>
3125 Target_arm
<big_endian
>::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
3128 if (gsym
->has_plt_offset())
3131 if (this->plt_
== NULL
)
3133 // Create the GOT sections first.
3134 this->got_section(symtab
, layout
);
3136 this->plt_
= new Output_data_plt_arm
<big_endian
>(layout
, this->got_plt_
);
3137 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
3139 | elfcpp::SHF_EXECINSTR
),
3142 this->plt_
->add_entry(gsym
);
3145 // Report an unsupported relocation against a local symbol.
3147 template<bool big_endian
>
3149 Target_arm
<big_endian
>::Scan::unsupported_reloc_local(
3150 Sized_relobj
<32, big_endian
>* object
,
3151 unsigned int r_type
)
3153 gold_error(_("%s: unsupported reloc %u against local symbol"),
3154 object
->name().c_str(), r_type
);
3157 // We are about to emit a dynamic relocation of type R_TYPE. If the
3158 // dynamic linker does not support it, issue an error. The GNU linker
3159 // only issues a non-PIC error for an allocated read-only section.
3160 // Here we know the section is allocated, but we don't know that it is
3161 // read-only. But we check for all the relocation types which the
3162 // glibc dynamic linker supports, so it seems appropriate to issue an
3163 // error even if the section is not read-only.
3165 template<bool big_endian
>
3167 Target_arm
<big_endian
>::Scan::check_non_pic(Relobj
* object
,
3168 unsigned int r_type
)
3172 // These are the relocation types supported by glibc for ARM.
3173 case elfcpp::R_ARM_RELATIVE
:
3174 case elfcpp::R_ARM_COPY
:
3175 case elfcpp::R_ARM_GLOB_DAT
:
3176 case elfcpp::R_ARM_JUMP_SLOT
:
3177 case elfcpp::R_ARM_ABS32
:
3178 case elfcpp::R_ARM_ABS32_NOI
:
3179 case elfcpp::R_ARM_PC24
:
3180 // FIXME: The following 3 types are not supported by Android's dynamic
3182 case elfcpp::R_ARM_TLS_DTPMOD32
:
3183 case elfcpp::R_ARM_TLS_DTPOFF32
:
3184 case elfcpp::R_ARM_TLS_TPOFF32
:
3188 // This prevents us from issuing more than one error per reloc
3189 // section. But we can still wind up issuing more than one
3190 // error per object file.
3191 if (this->issued_non_pic_error_
)
3193 object
->error(_("requires unsupported dynamic reloc; "
3194 "recompile with -fPIC"));
3195 this->issued_non_pic_error_
= true;
3198 case elfcpp::R_ARM_NONE
:
3203 // Scan a relocation for a local symbol.
3204 // FIXME: This only handles a subset of relocation types used by Android
3205 // on ARM v5te devices.
3207 template<bool big_endian
>
3209 Target_arm
<big_endian
>::Scan::local(const General_options
&,
3210 Symbol_table
* symtab
,
3213 Sized_relobj
<32, big_endian
>* object
,
3214 unsigned int data_shndx
,
3215 Output_section
* output_section
,
3216 const elfcpp::Rel
<32, big_endian
>& reloc
,
3217 unsigned int r_type
,
3218 const elfcpp::Sym
<32, big_endian
>&)
3220 r_type
= get_real_reloc_type(r_type
);
3223 case elfcpp::R_ARM_NONE
:
3226 case elfcpp::R_ARM_ABS32
:
3227 case elfcpp::R_ARM_ABS32_NOI
:
3228 // If building a shared library (or a position-independent
3229 // executable), we need to create a dynamic relocation for
3230 // this location. The relocation applied at link time will
3231 // apply the link-time value, so we flag the location with
3232 // an R_ARM_RELATIVE relocation so the dynamic loader can
3233 // relocate it easily.
3234 if (parameters
->options().output_is_position_independent())
3236 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
3237 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
3238 // If we are to add more other reloc types than R_ARM_ABS32,
3239 // we need to add check_non_pic(object, r_type) here.
3240 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_ARM_RELATIVE
,
3241 output_section
, data_shndx
,
3242 reloc
.get_r_offset());
3246 case elfcpp::R_ARM_REL32
:
3247 case elfcpp::R_ARM_THM_CALL
:
3248 case elfcpp::R_ARM_CALL
:
3249 case elfcpp::R_ARM_PREL31
:
3250 case elfcpp::R_ARM_JUMP24
:
3251 case elfcpp::R_ARM_PLT32
:
3252 case elfcpp::R_ARM_THM_ABS5
:
3253 case elfcpp::R_ARM_ABS8
:
3254 case elfcpp::R_ARM_ABS12
:
3255 case elfcpp::R_ARM_ABS16
:
3256 case elfcpp::R_ARM_BASE_ABS
:
3257 case elfcpp::R_ARM_MOVW_ABS_NC
:
3258 case elfcpp::R_ARM_MOVT_ABS
:
3259 case elfcpp::R_ARM_THM_MOVW_ABS_NC
:
3260 case elfcpp::R_ARM_THM_MOVT_ABS
:
3261 case elfcpp::R_ARM_MOVW_PREL_NC
:
3262 case elfcpp::R_ARM_MOVT_PREL
:
3263 case elfcpp::R_ARM_THM_MOVW_PREL_NC
:
3264 case elfcpp::R_ARM_THM_MOVT_PREL
:
3267 case elfcpp::R_ARM_GOTOFF32
:
3268 // We need a GOT section:
3269 target
->got_section(symtab
, layout
);
3272 case elfcpp::R_ARM_BASE_PREL
:
3273 // FIXME: What about this?
3276 case elfcpp::R_ARM_GOT_BREL
:
3277 case elfcpp::R_ARM_GOT_PREL
:
3279 // The symbol requires a GOT entry.
3280 Output_data_got
<32, big_endian
>* got
=
3281 target
->got_section(symtab
, layout
);
3282 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
3283 if (got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
))
3285 // If we are generating a shared object, we need to add a
3286 // dynamic RELATIVE relocation for this symbol's GOT entry.
3287 if (parameters
->options().output_is_position_independent())
3289 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
3290 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
3291 rel_dyn
->add_local_relative(
3292 object
, r_sym
, elfcpp::R_ARM_RELATIVE
, got
,
3293 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
));
3299 case elfcpp::R_ARM_TARGET1
:
3300 // This should have been mapped to another type already.
3302 case elfcpp::R_ARM_COPY
:
3303 case elfcpp::R_ARM_GLOB_DAT
:
3304 case elfcpp::R_ARM_JUMP_SLOT
:
3305 case elfcpp::R_ARM_RELATIVE
:
3306 // These are relocations which should only be seen by the
3307 // dynamic linker, and should never be seen here.
3308 gold_error(_("%s: unexpected reloc %u in object file"),
3309 object
->name().c_str(), r_type
);
3313 unsupported_reloc_local(object
, r_type
);
3318 // Report an unsupported relocation against a global symbol.
3320 template<bool big_endian
>
3322 Target_arm
<big_endian
>::Scan::unsupported_reloc_global(
3323 Sized_relobj
<32, big_endian
>* object
,
3324 unsigned int r_type
,
3327 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3328 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
3331 // Scan a relocation for a global symbol.
3332 // FIXME: This only handles a subset of relocation types used by Android
3333 // on ARM v5te devices.
3335 template<bool big_endian
>
3337 Target_arm
<big_endian
>::Scan::global(const General_options
&,
3338 Symbol_table
* symtab
,
3341 Sized_relobj
<32, big_endian
>* object
,
3342 unsigned int data_shndx
,
3343 Output_section
* output_section
,
3344 const elfcpp::Rel
<32, big_endian
>& reloc
,
3345 unsigned int r_type
,
3348 r_type
= get_real_reloc_type(r_type
);
3351 case elfcpp::R_ARM_NONE
:
3354 case elfcpp::R_ARM_ABS32
:
3355 case elfcpp::R_ARM_ABS32_NOI
:
3357 // Make a dynamic relocation if necessary.
3358 if (gsym
->needs_dynamic_reloc(Symbol::ABSOLUTE_REF
))
3360 if (target
->may_need_copy_reloc(gsym
))
3362 target
->copy_reloc(symtab
, layout
, object
,
3363 data_shndx
, output_section
, gsym
, reloc
);
3365 else if (gsym
->can_use_relative_reloc(false))
3367 // If we are to add more other reloc types than R_ARM_ABS32,
3368 // we need to add check_non_pic(object, r_type) here.
3369 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
3370 rel_dyn
->add_global_relative(gsym
, elfcpp::R_ARM_RELATIVE
,
3371 output_section
, object
,
3372 data_shndx
, reloc
.get_r_offset());
3376 // If we are to add more other reloc types than R_ARM_ABS32,
3377 // we need to add check_non_pic(object, r_type) here.
3378 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
3379 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
3380 data_shndx
, reloc
.get_r_offset());
3386 case elfcpp::R_ARM_MOVW_ABS_NC
:
3387 case elfcpp::R_ARM_MOVT_ABS
:
3388 case elfcpp::R_ARM_THM_MOVW_ABS_NC
:
3389 case elfcpp::R_ARM_THM_MOVT_ABS
:
3390 case elfcpp::R_ARM_MOVW_PREL_NC
:
3391 case elfcpp::R_ARM_MOVT_PREL
:
3392 case elfcpp::R_ARM_THM_MOVW_PREL_NC
:
3393 case elfcpp::R_ARM_THM_MOVT_PREL
:
3396 case elfcpp::R_ARM_THM_ABS5
:
3397 case elfcpp::R_ARM_ABS8
:
3398 case elfcpp::R_ARM_ABS12
:
3399 case elfcpp::R_ARM_ABS16
:
3400 case elfcpp::R_ARM_BASE_ABS
:
3402 // No dynamic relocs of this kinds.
3403 // Report the error in case of PIC.
3404 int flags
= Symbol::NON_PIC_REF
;
3405 if (gsym
->type() == elfcpp::STT_FUNC
3406 || gsym
->type() == elfcpp::STT_ARM_TFUNC
)
3407 flags
|= Symbol::FUNCTION_CALL
;
3408 if (gsym
->needs_dynamic_reloc(flags
))
3409 check_non_pic(object
, r_type
);
3413 case elfcpp::R_ARM_REL32
:
3414 case elfcpp::R_ARM_PREL31
:
3416 // Make a dynamic relocation if necessary.
3417 int flags
= Symbol::NON_PIC_REF
;
3418 if (gsym
->needs_dynamic_reloc(flags
))
3420 if (target
->may_need_copy_reloc(gsym
))
3422 target
->copy_reloc(symtab
, layout
, object
,
3423 data_shndx
, output_section
, gsym
, reloc
);
3427 check_non_pic(object
, r_type
);
3428 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
3429 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
3430 data_shndx
, reloc
.get_r_offset());
3436 case elfcpp::R_ARM_JUMP24
:
3437 case elfcpp::R_ARM_THM_CALL
:
3438 case elfcpp::R_ARM_CALL
:
3440 if (Target_arm
<big_endian
>::Scan::symbol_needs_plt_entry(gsym
))
3441 target
->make_plt_entry(symtab
, layout
, gsym
);
3442 // Make a dynamic relocation if necessary.
3443 int flags
= Symbol::NON_PIC_REF
;
3444 if (gsym
->type() == elfcpp::STT_FUNC
3445 || gsym
->type() == elfcpp::STT_ARM_TFUNC
)
3446 flags
|= Symbol::FUNCTION_CALL
;
3447 if (gsym
->needs_dynamic_reloc(flags
))
3449 if (target
->may_need_copy_reloc(gsym
))
3451 target
->copy_reloc(symtab
, layout
, object
,
3452 data_shndx
, output_section
, gsym
,
3457 check_non_pic(object
, r_type
);
3458 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
3459 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
3460 data_shndx
, reloc
.get_r_offset());
3466 case elfcpp::R_ARM_PLT32
:
3467 // If the symbol is fully resolved, this is just a relative
3468 // local reloc. Otherwise we need a PLT entry.
3469 if (gsym
->final_value_is_known())
3471 // If building a shared library, we can also skip the PLT entry
3472 // if the symbol is defined in the output file and is protected
3474 if (gsym
->is_defined()
3475 && !gsym
->is_from_dynobj()
3476 && !gsym
->is_preemptible())
3478 target
->make_plt_entry(symtab
, layout
, gsym
);
3481 case elfcpp::R_ARM_GOTOFF32
:
3482 // We need a GOT section.
3483 target
->got_section(symtab
, layout
);
3486 case elfcpp::R_ARM_BASE_PREL
:
3487 // FIXME: What about this?
3490 case elfcpp::R_ARM_GOT_BREL
:
3491 case elfcpp::R_ARM_GOT_PREL
:
3493 // The symbol requires a GOT entry.
3494 Output_data_got
<32, big_endian
>* got
=
3495 target
->got_section(symtab
, layout
);
3496 if (gsym
->final_value_is_known())
3497 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
3500 // If this symbol is not fully resolved, we need to add a
3501 // GOT entry with a dynamic relocation.
3502 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
3503 if (gsym
->is_from_dynobj()
3504 || gsym
->is_undefined()
3505 || gsym
->is_preemptible())
3506 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
3507 rel_dyn
, elfcpp::R_ARM_GLOB_DAT
);
3510 if (got
->add_global(gsym
, GOT_TYPE_STANDARD
))
3511 rel_dyn
->add_global_relative(
3512 gsym
, elfcpp::R_ARM_RELATIVE
, got
,
3513 gsym
->got_offset(GOT_TYPE_STANDARD
));
3519 case elfcpp::R_ARM_TARGET1
:
3520 // This should have been mapped to another type already.
3522 case elfcpp::R_ARM_COPY
:
3523 case elfcpp::R_ARM_GLOB_DAT
:
3524 case elfcpp::R_ARM_JUMP_SLOT
:
3525 case elfcpp::R_ARM_RELATIVE
:
3526 // These are relocations which should only be seen by the
3527 // dynamic linker, and should never be seen here.
3528 gold_error(_("%s: unexpected reloc %u in object file"),
3529 object
->name().c_str(), r_type
);
3533 unsupported_reloc_global(object
, r_type
, gsym
);
3538 // Process relocations for gc.
3540 template<bool big_endian
>
3542 Target_arm
<big_endian
>::gc_process_relocs(const General_options
& options
,
3543 Symbol_table
* symtab
,
3545 Sized_relobj
<32, big_endian
>* object
,
3546 unsigned int data_shndx
,
3548 const unsigned char* prelocs
,
3550 Output_section
* output_section
,
3551 bool needs_special_offset_handling
,
3552 size_t local_symbol_count
,
3553 const unsigned char* plocal_symbols
)
3555 typedef Target_arm
<big_endian
> Arm
;
3556 typedef typename Target_arm
<big_endian
>::Scan Scan
;
3558 gold::gc_process_relocs
<32, big_endian
, Arm
, elfcpp::SHT_REL
, Scan
>(
3568 needs_special_offset_handling
,
3573 // Scan relocations for a section.
3575 template<bool big_endian
>
3577 Target_arm
<big_endian
>::scan_relocs(const General_options
& options
,
3578 Symbol_table
* symtab
,
3580 Sized_relobj
<32, big_endian
>* object
,
3581 unsigned int data_shndx
,
3582 unsigned int sh_type
,
3583 const unsigned char* prelocs
,
3585 Output_section
* output_section
,
3586 bool needs_special_offset_handling
,
3587 size_t local_symbol_count
,
3588 const unsigned char* plocal_symbols
)
3590 typedef typename Target_arm
<big_endian
>::Scan Scan
;
3591 if (sh_type
== elfcpp::SHT_RELA
)
3593 gold_error(_("%s: unsupported RELA reloc section"),
3594 object
->name().c_str());
3598 gold::scan_relocs
<32, big_endian
, Target_arm
, elfcpp::SHT_REL
, Scan
>(
3608 needs_special_offset_handling
,
3613 // Finalize the sections.
3615 template<bool big_endian
>
3617 Target_arm
<big_endian
>::do_finalize_sections(Layout
* layout
)
3619 // Fill in some more dynamic tags.
3620 Output_data_dynamic
* const odyn
= layout
->dynamic_data();
3623 if (this->got_plt_
!= NULL
)
3624 odyn
->add_section_address(elfcpp::DT_PLTGOT
, this->got_plt_
);
3626 if (this->plt_
!= NULL
)
3628 const Output_data
* od
= this->plt_
->rel_plt();
3629 odyn
->add_section_size(elfcpp::DT_PLTRELSZ
, od
);
3630 odyn
->add_section_address(elfcpp::DT_JMPREL
, od
);
3631 odyn
->add_constant(elfcpp::DT_PLTREL
, elfcpp::DT_REL
);
3634 if (this->rel_dyn_
!= NULL
)
3636 const Output_data
* od
= this->rel_dyn_
;
3637 odyn
->add_section_address(elfcpp::DT_REL
, od
);
3638 odyn
->add_section_size(elfcpp::DT_RELSZ
, od
);
3639 odyn
->add_constant(elfcpp::DT_RELENT
,
3640 elfcpp::Elf_sizes
<32>::rel_size
);
3643 if (!parameters
->options().shared())
3645 // The value of the DT_DEBUG tag is filled in by the dynamic
3646 // linker at run time, and used by the debugger.
3647 odyn
->add_constant(elfcpp::DT_DEBUG
, 0);
3651 // Emit any relocs we saved in an attempt to avoid generating COPY
3653 if (this->copy_relocs_
.any_saved_relocs())
3654 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
3656 // For the ARM target, we need to add a PT_ARM_EXIDX segment for
3657 // the .ARM.exidx section.
3658 if (!layout
->script_options()->saw_phdrs_clause()
3659 && !parameters
->options().relocatable())
3661 Output_section
* exidx_section
=
3662 layout
->find_output_section(".ARM.exidx");
3664 if (exidx_section
!= NULL
3665 && exidx_section
->type() == elfcpp::SHT_ARM_EXIDX
)
3667 gold_assert(layout
->find_output_segment(elfcpp::PT_ARM_EXIDX
, 0, 0)
3669 Output_segment
* exidx_segment
=
3670 layout
->make_output_segment(elfcpp::PT_ARM_EXIDX
, elfcpp::PF_R
);
3671 exidx_segment
->add_output_section(exidx_section
, elfcpp::PF_R
);
3676 // Return whether a direct absolute static relocation needs to be applied.
3677 // In cases where Scan::local() or Scan::global() has created
3678 // a dynamic relocation other than R_ARM_RELATIVE, the addend
3679 // of the relocation is carried in the data, and we must not
3680 // apply the static relocation.
3682 template<bool big_endian
>
3684 Target_arm
<big_endian
>::Relocate::should_apply_static_reloc(
3685 const Sized_symbol
<32>* gsym
,
3688 Output_section
* output_section
)
3690 // If the output section is not allocated, then we didn't call
3691 // scan_relocs, we didn't create a dynamic reloc, and we must apply
3693 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
3696 // For local symbols, we will have created a non-RELATIVE dynamic
3697 // relocation only if (a) the output is position independent,
3698 // (b) the relocation is absolute (not pc- or segment-relative), and
3699 // (c) the relocation is not 32 bits wide.
3701 return !(parameters
->options().output_is_position_independent()
3702 && (ref_flags
& Symbol::ABSOLUTE_REF
)
3705 // For global symbols, we use the same helper routines used in the
3706 // scan pass. If we did not create a dynamic relocation, or if we
3707 // created a RELATIVE dynamic relocation, we should apply the static
3709 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
3710 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
3711 && gsym
->can_use_relative_reloc(ref_flags
3712 & Symbol::FUNCTION_CALL
);
3713 return !has_dyn
|| is_rel
;
3716 // Perform a relocation.
3718 template<bool big_endian
>
3720 Target_arm
<big_endian
>::Relocate::relocate(
3721 const Relocate_info
<32, big_endian
>* relinfo
,
3723 Output_section
*output_section
,
3725 const elfcpp::Rel
<32, big_endian
>& rel
,
3726 unsigned int r_type
,
3727 const Sized_symbol
<32>* gsym
,
3728 const Symbol_value
<32>* psymval
,
3729 unsigned char* view
,
3730 elfcpp::Elf_types
<32>::Elf_Addr address
,
3731 section_size_type
/* view_size */ )
3733 typedef Arm_relocate_functions
<big_endian
> Arm_relocate_functions
;
3735 r_type
= get_real_reloc_type(r_type
);
3737 // If this the symbol may be a Thumb function, set thumb bit to 1.
3738 bool has_thumb_bit
= ((gsym
!= NULL
)
3739 && (gsym
->type() == elfcpp::STT_FUNC
3740 || gsym
->type() == elfcpp::STT_ARM_TFUNC
));
3742 // Pick the value to use for symbols defined in shared objects.
3743 Symbol_value
<32> symval
;
3745 && gsym
->use_plt_offset(reloc_is_non_pic(r_type
)))
3747 symval
.set_output_value(target
->plt_section()->address()
3748 + gsym
->plt_offset());
3753 const Sized_relobj
<32, big_endian
>* object
= relinfo
->object
;
3755 // Get the GOT offset if needed.
3756 // The GOT pointer points to the end of the GOT section.
3757 // We need to subtract the size of the GOT section to get
3758 // the actual offset to use in the relocation.
3759 bool have_got_offset
= false;
3760 unsigned int got_offset
= 0;
3763 case elfcpp::R_ARM_GOT_BREL
:
3764 case elfcpp::R_ARM_GOT_PREL
:
3767 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
3768 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
3769 - target
->got_size());
3773 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3774 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
3775 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
3776 - target
->got_size());
3778 have_got_offset
= true;
3785 typename
Arm_relocate_functions::Status reloc_status
=
3786 Arm_relocate_functions::STATUS_OKAY
;
3789 case elfcpp::R_ARM_NONE
:
3792 case elfcpp::R_ARM_ABS8
:
3793 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false,
3795 reloc_status
= Arm_relocate_functions::abs8(view
, object
, psymval
);
3798 case elfcpp::R_ARM_ABS12
:
3799 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false,
3801 reloc_status
= Arm_relocate_functions::abs12(view
, object
, psymval
);
3804 case elfcpp::R_ARM_ABS16
:
3805 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false,
3807 reloc_status
= Arm_relocate_functions::abs16(view
, object
, psymval
);
3810 case elfcpp::R_ARM_ABS32
:
3811 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true,
3813 reloc_status
= Arm_relocate_functions::abs32(view
, object
, psymval
,
3817 case elfcpp::R_ARM_ABS32_NOI
:
3818 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true,
3820 // No thumb bit for this relocation: (S + A)
3821 reloc_status
= Arm_relocate_functions::abs32(view
, object
, psymval
,
3825 case elfcpp::R_ARM_MOVW_ABS_NC
:
3826 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true,
3828 reloc_status
= Arm_relocate_functions::movw_abs_nc(view
, object
,
3832 gold_error(_("relocation R_ARM_MOVW_ABS_NC cannot be used when making"
3833 "a shared object; recompile with -fPIC"));
3836 case elfcpp::R_ARM_MOVT_ABS
:
3837 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true,
3839 reloc_status
= Arm_relocate_functions::movt_abs(view
, object
, psymval
);
3841 gold_error(_("relocation R_ARM_MOVT_ABS cannot be used when making"
3842 "a shared object; recompile with -fPIC"));
3845 case elfcpp::R_ARM_THM_MOVW_ABS_NC
:
3846 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true,
3848 reloc_status
= Arm_relocate_functions::thm_movw_abs_nc(view
, object
,
3852 gold_error(_("relocation R_ARM_THM_MOVW_ABS_NC cannot be used when"
3853 "making a shared object; recompile with -fPIC"));
3856 case elfcpp::R_ARM_THM_MOVT_ABS
:
3857 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true,
3859 reloc_status
= Arm_relocate_functions::thm_movt_abs(view
, object
,
3862 gold_error(_("relocation R_ARM_THM_MOVT_ABS cannot be used when"
3863 "making a shared object; recompile with -fPIC"));
3866 case elfcpp::R_ARM_MOVW_PREL_NC
:
3867 reloc_status
= Arm_relocate_functions::movw_prel_nc(view
, object
,
3872 case elfcpp::R_ARM_MOVT_PREL
:
3873 reloc_status
= Arm_relocate_functions::movt_prel(view
, object
,
3877 case elfcpp::R_ARM_THM_MOVW_PREL_NC
:
3878 reloc_status
= Arm_relocate_functions::thm_movw_prel_nc(view
, object
,
3883 case elfcpp::R_ARM_THM_MOVT_PREL
:
3884 reloc_status
= Arm_relocate_functions::thm_movt_prel(view
, object
,
3888 case elfcpp::R_ARM_REL32
:
3889 reloc_status
= Arm_relocate_functions::rel32(view
, object
, psymval
,
3890 address
, has_thumb_bit
);
3893 case elfcpp::R_ARM_THM_ABS5
:
3894 if (should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, false,
3896 reloc_status
= Arm_relocate_functions::thm_abs5(view
, object
, psymval
);
3899 case elfcpp::R_ARM_THM_CALL
:
3900 reloc_status
= Arm_relocate_functions::thm_call(view
, object
, psymval
,
3901 address
, has_thumb_bit
);
3904 case elfcpp::R_ARM_GOTOFF32
:
3906 elfcpp::Elf_types
<32>::Elf_Addr got_origin
;
3907 got_origin
= target
->got_plt_section()->address();
3908 reloc_status
= Arm_relocate_functions::rel32(view
, object
, psymval
,
3909 got_origin
, has_thumb_bit
);
3913 case elfcpp::R_ARM_BASE_PREL
:
3916 // Get the addressing origin of the output segment defining the
3917 // symbol gsym (AAELF 4.6.1.2 Relocation types)
3918 gold_assert(gsym
!= NULL
);
3919 if (gsym
->source() == Symbol::IN_OUTPUT_SEGMENT
)
3920 origin
= gsym
->output_segment()->vaddr();
3921 else if (gsym
->source () == Symbol::IN_OUTPUT_DATA
)
3922 origin
= gsym
->output_data()->address();
3925 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3926 _("cannot find origin of R_ARM_BASE_PREL"));
3929 reloc_status
= Arm_relocate_functions::base_prel(view
, origin
, address
);
3933 case elfcpp::R_ARM_BASE_ABS
:
3935 if (!should_apply_static_reloc(gsym
, Symbol::ABSOLUTE_REF
, true,
3940 // Get the addressing origin of the output segment defining
3941 // the symbol gsym (AAELF 4.6.1.2 Relocation types).
3943 // R_ARM_BASE_ABS with the NULL symbol will give the
3944 // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
3945 // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
3946 origin
= target
->got_plt_section()->address();
3947 else if (gsym
->source() == Symbol::IN_OUTPUT_SEGMENT
)
3948 origin
= gsym
->output_segment()->vaddr();
3949 else if (gsym
->source () == Symbol::IN_OUTPUT_DATA
)
3950 origin
= gsym
->output_data()->address();
3953 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3954 _("cannot find origin of R_ARM_BASE_ABS"));
3958 reloc_status
= Arm_relocate_functions::base_abs(view
, origin
);
3962 case elfcpp::R_ARM_GOT_BREL
:
3963 gold_assert(have_got_offset
);
3964 reloc_status
= Arm_relocate_functions::got_brel(view
, got_offset
);
3967 case elfcpp::R_ARM_GOT_PREL
:
3968 gold_assert(have_got_offset
);
3969 // Get the address origin for GOT PLT, which is allocated right
3970 // after the GOT section, to calculate an absolute address of
3971 // the symbol GOT entry (got_origin + got_offset).
3972 elfcpp::Elf_types
<32>::Elf_Addr got_origin
;
3973 got_origin
= target
->got_plt_section()->address();
3974 reloc_status
= Arm_relocate_functions::got_prel(view
,
3975 got_origin
+ got_offset
,
3979 case elfcpp::R_ARM_PLT32
:
3980 gold_assert(gsym
== NULL
3981 || gsym
->has_plt_offset()
3982 || gsym
->final_value_is_known()
3983 || (gsym
->is_defined()
3984 && !gsym
->is_from_dynobj()
3985 && !gsym
->is_preemptible()));
3986 reloc_status
= Arm_relocate_functions::plt32(view
, object
, psymval
,
3987 address
, has_thumb_bit
);
3990 case elfcpp::R_ARM_CALL
:
3991 reloc_status
= Arm_relocate_functions::call(view
, object
, psymval
,
3992 address
, has_thumb_bit
);
3995 case elfcpp::R_ARM_JUMP24
:
3996 reloc_status
= Arm_relocate_functions::jump24(view
, object
, psymval
,
3997 address
, has_thumb_bit
);
4000 case elfcpp::R_ARM_PREL31
:
4001 reloc_status
= Arm_relocate_functions::prel31(view
, object
, psymval
,
4002 address
, has_thumb_bit
);
4005 case elfcpp::R_ARM_TARGET1
:
4006 // This should have been mapped to another type already.
4008 case elfcpp::R_ARM_COPY
:
4009 case elfcpp::R_ARM_GLOB_DAT
:
4010 case elfcpp::R_ARM_JUMP_SLOT
:
4011 case elfcpp::R_ARM_RELATIVE
:
4012 // These are relocations which should only be seen by the
4013 // dynamic linker, and should never be seen here.
4014 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
4015 _("unexpected reloc %u in object file"),
4020 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
4021 _("unsupported reloc %u"),
4026 // Report any errors.
4027 switch (reloc_status
)
4029 case Arm_relocate_functions::STATUS_OKAY
:
4031 case Arm_relocate_functions::STATUS_OVERFLOW
:
4032 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
4033 _("relocation overflow in relocation %u"),
4036 case Arm_relocate_functions::STATUS_BAD_RELOC
:
4037 gold_error_at_location(
4041 _("unexpected opcode while processing relocation %u"),
4051 // Relocate section data.
4053 template<bool big_endian
>
4055 Target_arm
<big_endian
>::relocate_section(
4056 const Relocate_info
<32, big_endian
>* relinfo
,
4057 unsigned int sh_type
,
4058 const unsigned char* prelocs
,
4060 Output_section
* output_section
,
4061 bool needs_special_offset_handling
,
4062 unsigned char* view
,
4063 elfcpp::Elf_types
<32>::Elf_Addr address
,
4064 section_size_type view_size
,
4065 const Reloc_symbol_changes
* reloc_symbol_changes
)
4067 typedef typename Target_arm
<big_endian
>::Relocate Arm_relocate
;
4068 gold_assert(sh_type
== elfcpp::SHT_REL
);
4070 gold::relocate_section
<32, big_endian
, Target_arm
, elfcpp::SHT_REL
,
4077 needs_special_offset_handling
,
4081 reloc_symbol_changes
);
4084 // Return the size of a relocation while scanning during a relocatable
4087 template<bool big_endian
>
4089 Target_arm
<big_endian
>::Relocatable_size_for_reloc::get_size_for_reloc(
4090 unsigned int r_type
,
4093 r_type
= get_real_reloc_type(r_type
);
4096 case elfcpp::R_ARM_NONE
:
4099 case elfcpp::R_ARM_ABS8
:
4102 case elfcpp::R_ARM_ABS16
:
4103 case elfcpp::R_ARM_THM_ABS5
:
4106 case elfcpp::R_ARM_ABS32
:
4107 case elfcpp::R_ARM_ABS32_NOI
:
4108 case elfcpp::R_ARM_ABS12
:
4109 case elfcpp::R_ARM_BASE_ABS
:
4110 case elfcpp::R_ARM_REL32
:
4111 case elfcpp::R_ARM_THM_CALL
:
4112 case elfcpp::R_ARM_GOTOFF32
:
4113 case elfcpp::R_ARM_BASE_PREL
:
4114 case elfcpp::R_ARM_GOT_BREL
:
4115 case elfcpp::R_ARM_GOT_PREL
:
4116 case elfcpp::R_ARM_PLT32
:
4117 case elfcpp::R_ARM_CALL
:
4118 case elfcpp::R_ARM_JUMP24
:
4119 case elfcpp::R_ARM_PREL31
:
4120 case elfcpp::R_ARM_MOVW_ABS_NC
:
4121 case elfcpp::R_ARM_MOVT_ABS
:
4122 case elfcpp::R_ARM_THM_MOVW_ABS_NC
:
4123 case elfcpp::R_ARM_THM_MOVT_ABS
:
4124 case elfcpp::R_ARM_MOVW_PREL_NC
:
4125 case elfcpp::R_ARM_MOVT_PREL
:
4126 case elfcpp::R_ARM_THM_MOVW_PREL_NC
:
4127 case elfcpp::R_ARM_THM_MOVT_PREL
:
4130 case elfcpp::R_ARM_TARGET1
:
4131 // This should have been mapped to another type already.
4133 case elfcpp::R_ARM_COPY
:
4134 case elfcpp::R_ARM_GLOB_DAT
:
4135 case elfcpp::R_ARM_JUMP_SLOT
:
4136 case elfcpp::R_ARM_RELATIVE
:
4137 // These are relocations which should only be seen by the
4138 // dynamic linker, and should never be seen here.
4139 gold_error(_("%s: unexpected reloc %u in object file"),
4140 object
->name().c_str(), r_type
);
4144 object
->error(_("unsupported reloc %u in object file"), r_type
);
4149 // Scan the relocs during a relocatable link.
4151 template<bool big_endian
>
4153 Target_arm
<big_endian
>::scan_relocatable_relocs(
4154 const General_options
& options
,
4155 Symbol_table
* symtab
,
4157 Sized_relobj
<32, big_endian
>* object
,
4158 unsigned int data_shndx
,
4159 unsigned int sh_type
,
4160 const unsigned char* prelocs
,
4162 Output_section
* output_section
,
4163 bool needs_special_offset_handling
,
4164 size_t local_symbol_count
,
4165 const unsigned char* plocal_symbols
,
4166 Relocatable_relocs
* rr
)
4168 gold_assert(sh_type
== elfcpp::SHT_REL
);
4170 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
4171 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
4173 gold::scan_relocatable_relocs
<32, big_endian
, elfcpp::SHT_REL
,
4174 Scan_relocatable_relocs
>(
4183 needs_special_offset_handling
,
4189 // Relocate a section during a relocatable link.
4191 template<bool big_endian
>
4193 Target_arm
<big_endian
>::relocate_for_relocatable(
4194 const Relocate_info
<32, big_endian
>* relinfo
,
4195 unsigned int sh_type
,
4196 const unsigned char* prelocs
,
4198 Output_section
* output_section
,
4199 off_t offset_in_output_section
,
4200 const Relocatable_relocs
* rr
,
4201 unsigned char* view
,
4202 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
4203 section_size_type view_size
,
4204 unsigned char* reloc_view
,
4205 section_size_type reloc_view_size
)
4207 gold_assert(sh_type
== elfcpp::SHT_REL
);
4209 gold::relocate_for_relocatable
<32, big_endian
, elfcpp::SHT_REL
>(
4214 offset_in_output_section
,
4223 // Return the value to use for a dynamic symbol which requires special
4224 // treatment. This is how we support equality comparisons of function
4225 // pointers across shared library boundaries, as described in the
4226 // processor specific ABI supplement.
4228 template<bool big_endian
>
4230 Target_arm
<big_endian
>::do_dynsym_value(const Symbol
* gsym
) const
4232 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
4233 return this->plt_section()->address() + gsym
->plt_offset();
4236 // Map platform-specific relocs to real relocs
4238 template<bool big_endian
>
4240 Target_arm
<big_endian
>::get_real_reloc_type (unsigned int r_type
)
4244 case elfcpp::R_ARM_TARGET1
:
4245 // This is either R_ARM_ABS32 or R_ARM_REL32;
4246 return elfcpp::R_ARM_ABS32
;
4248 case elfcpp::R_ARM_TARGET2
:
4249 // This can be any reloc type but ususally is R_ARM_GOT_PREL
4250 return elfcpp::R_ARM_GOT_PREL
;
4257 // The selector for arm object files.
4259 template<bool big_endian
>
4260 class Target_selector_arm
: public Target_selector
4263 Target_selector_arm()
4264 : Target_selector(elfcpp::EM_ARM
, 32, big_endian
,
4265 (big_endian
? "elf32-bigarm" : "elf32-littlearm"))
4269 do_instantiate_target()
4270 { return new Target_arm
<big_endian
>(); }
4273 Target_selector_arm
<false> target_selector_arm
;
4274 Target_selector_arm
<true> target_selector_armbe
;
4276 } // End anonymous namespace.