1 // output.cc -- manage the output file for gold
3 // Copyright 2006, 2007 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
32 #include "libiberty.h" // for unlink_if_ordinary()
34 #include "parameters.h"
44 // Output_data variables.
46 bool Output_data::sizes_are_fixed
;
48 // Output_data methods.
50 Output_data::~Output_data()
54 // Set the address and offset.
57 Output_data::set_address(uint64_t addr
, off_t off
)
59 this->address_
= addr
;
62 // Let the child class know.
63 this->do_set_address(addr
, off
);
66 // Return the default alignment for a size--32 or 64.
69 Output_data::default_alignment(int size
)
79 // Output_section_header methods. This currently assumes that the
80 // segment and section lists are complete at construction time.
82 Output_section_headers::Output_section_headers(
84 const Layout::Segment_list
* segment_list
,
85 const Layout::Section_list
* unattached_section_list
,
86 const Stringpool
* secnamepool
)
88 segment_list_(segment_list
),
89 unattached_section_list_(unattached_section_list
),
90 secnamepool_(secnamepool
)
92 // Count all the sections. Start with 1 for the null section.
94 for (Layout::Segment_list::const_iterator p
= segment_list
->begin();
95 p
!= segment_list
->end();
97 if ((*p
)->type() == elfcpp::PT_LOAD
)
98 count
+= (*p
)->output_section_count();
99 count
+= unattached_section_list
->size();
101 const int size
= parameters
->get_size();
104 shdr_size
= elfcpp::Elf_sizes
<32>::shdr_size
;
106 shdr_size
= elfcpp::Elf_sizes
<64>::shdr_size
;
110 this->set_data_size(count
* shdr_size
);
113 // Write out the section headers.
116 Output_section_headers::do_write(Output_file
* of
)
118 if (parameters
->get_size() == 32)
120 if (parameters
->is_big_endian())
122 #ifdef HAVE_TARGET_32_BIG
123 this->do_sized_write
<32, true>(of
);
130 #ifdef HAVE_TARGET_32_LITTLE
131 this->do_sized_write
<32, false>(of
);
137 else if (parameters
->get_size() == 64)
139 if (parameters
->is_big_endian())
141 #ifdef HAVE_TARGET_64_BIG
142 this->do_sized_write
<64, true>(of
);
149 #ifdef HAVE_TARGET_64_LITTLE
150 this->do_sized_write
<64, false>(of
);
160 template<int size
, bool big_endian
>
162 Output_section_headers::do_sized_write(Output_file
* of
)
164 off_t all_shdrs_size
= this->data_size();
165 unsigned char* view
= of
->get_output_view(this->offset(), all_shdrs_size
);
167 const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
168 unsigned char* v
= view
;
171 typename
elfcpp::Shdr_write
<size
, big_endian
> oshdr(v
);
172 oshdr
.put_sh_name(0);
173 oshdr
.put_sh_type(elfcpp::SHT_NULL
);
174 oshdr
.put_sh_flags(0);
175 oshdr
.put_sh_addr(0);
176 oshdr
.put_sh_offset(0);
177 oshdr
.put_sh_size(0);
178 oshdr
.put_sh_link(0);
179 oshdr
.put_sh_info(0);
180 oshdr
.put_sh_addralign(0);
181 oshdr
.put_sh_entsize(0);
187 for (Layout::Segment_list::const_iterator p
= this->segment_list_
->begin();
188 p
!= this->segment_list_
->end();
190 v
= (*p
)->write_section_headers
SELECT_SIZE_ENDIAN_NAME(size
, big_endian
) (
191 this->layout_
, this->secnamepool_
, v
, &shndx
192 SELECT_SIZE_ENDIAN(size
, big_endian
));
193 for (Layout::Section_list::const_iterator p
=
194 this->unattached_section_list_
->begin();
195 p
!= this->unattached_section_list_
->end();
198 gold_assert(shndx
== (*p
)->out_shndx());
199 elfcpp::Shdr_write
<size
, big_endian
> oshdr(v
);
200 (*p
)->write_header(this->layout_
, this->secnamepool_
, &oshdr
);
205 of
->write_output_view(this->offset(), all_shdrs_size
, view
);
208 // Output_segment_header methods.
210 Output_segment_headers::Output_segment_headers(
211 const Layout::Segment_list
& segment_list
)
212 : segment_list_(segment_list
)
214 const int size
= parameters
->get_size();
217 phdr_size
= elfcpp::Elf_sizes
<32>::phdr_size
;
219 phdr_size
= elfcpp::Elf_sizes
<64>::phdr_size
;
223 this->set_data_size(segment_list
.size() * phdr_size
);
227 Output_segment_headers::do_write(Output_file
* of
)
229 if (parameters
->get_size() == 32)
231 if (parameters
->is_big_endian())
233 #ifdef HAVE_TARGET_32_BIG
234 this->do_sized_write
<32, true>(of
);
241 #ifdef HAVE_TARGET_32_LITTLE
242 this->do_sized_write
<32, false>(of
);
248 else if (parameters
->get_size() == 64)
250 if (parameters
->is_big_endian())
252 #ifdef HAVE_TARGET_64_BIG
253 this->do_sized_write
<64, true>(of
);
260 #ifdef HAVE_TARGET_64_LITTLE
261 this->do_sized_write
<64, false>(of
);
271 template<int size
, bool big_endian
>
273 Output_segment_headers::do_sized_write(Output_file
* of
)
275 const int phdr_size
= elfcpp::Elf_sizes
<size
>::phdr_size
;
276 off_t all_phdrs_size
= this->segment_list_
.size() * phdr_size
;
277 unsigned char* view
= of
->get_output_view(this->offset(),
279 unsigned char* v
= view
;
280 for (Layout::Segment_list::const_iterator p
= this->segment_list_
.begin();
281 p
!= this->segment_list_
.end();
284 elfcpp::Phdr_write
<size
, big_endian
> ophdr(v
);
285 (*p
)->write_header(&ophdr
);
289 of
->write_output_view(this->offset(), all_phdrs_size
, view
);
292 // Output_file_header methods.
294 Output_file_header::Output_file_header(const Target
* target
,
295 const Symbol_table
* symtab
,
296 const Output_segment_headers
* osh
)
299 segment_header_(osh
),
300 section_header_(NULL
),
303 const int size
= parameters
->get_size();
306 ehdr_size
= elfcpp::Elf_sizes
<32>::ehdr_size
;
308 ehdr_size
= elfcpp::Elf_sizes
<64>::ehdr_size
;
312 this->set_data_size(ehdr_size
);
315 // Set the section table information for a file header.
318 Output_file_header::set_section_info(const Output_section_headers
* shdrs
,
319 const Output_section
* shstrtab
)
321 this->section_header_
= shdrs
;
322 this->shstrtab_
= shstrtab
;
325 // Write out the file header.
328 Output_file_header::do_write(Output_file
* of
)
330 if (parameters
->get_size() == 32)
332 if (parameters
->is_big_endian())
334 #ifdef HAVE_TARGET_32_BIG
335 this->do_sized_write
<32, true>(of
);
342 #ifdef HAVE_TARGET_32_LITTLE
343 this->do_sized_write
<32, false>(of
);
349 else if (parameters
->get_size() == 64)
351 if (parameters
->is_big_endian())
353 #ifdef HAVE_TARGET_64_BIG
354 this->do_sized_write
<64, true>(of
);
361 #ifdef HAVE_TARGET_64_LITTLE
362 this->do_sized_write
<64, false>(of
);
372 // Write out the file header with appropriate size and endianess.
374 template<int size
, bool big_endian
>
376 Output_file_header::do_sized_write(Output_file
* of
)
378 gold_assert(this->offset() == 0);
380 int ehdr_size
= elfcpp::Elf_sizes
<size
>::ehdr_size
;
381 unsigned char* view
= of
->get_output_view(0, ehdr_size
);
382 elfcpp::Ehdr_write
<size
, big_endian
> oehdr(view
);
384 unsigned char e_ident
[elfcpp::EI_NIDENT
];
385 memset(e_ident
, 0, elfcpp::EI_NIDENT
);
386 e_ident
[elfcpp::EI_MAG0
] = elfcpp::ELFMAG0
;
387 e_ident
[elfcpp::EI_MAG1
] = elfcpp::ELFMAG1
;
388 e_ident
[elfcpp::EI_MAG2
] = elfcpp::ELFMAG2
;
389 e_ident
[elfcpp::EI_MAG3
] = elfcpp::ELFMAG3
;
391 e_ident
[elfcpp::EI_CLASS
] = elfcpp::ELFCLASS32
;
393 e_ident
[elfcpp::EI_CLASS
] = elfcpp::ELFCLASS64
;
396 e_ident
[elfcpp::EI_DATA
] = (big_endian
397 ? elfcpp::ELFDATA2MSB
398 : elfcpp::ELFDATA2LSB
);
399 e_ident
[elfcpp::EI_VERSION
] = elfcpp::EV_CURRENT
;
400 // FIXME: Some targets may need to set EI_OSABI and EI_ABIVERSION.
401 oehdr
.put_e_ident(e_ident
);
405 if (parameters
->output_is_object())
406 e_type
= elfcpp::ET_REL
;
408 e_type
= elfcpp::ET_EXEC
;
409 oehdr
.put_e_type(e_type
);
411 oehdr
.put_e_machine(this->target_
->machine_code());
412 oehdr
.put_e_version(elfcpp::EV_CURRENT
);
414 // FIXME: Need to support -e, and target specific entry symbol.
415 Symbol
* sym
= this->symtab_
->lookup("_start");
416 typename Sized_symbol
<size
>::Value_type v
;
421 Sized_symbol
<size
>* ssym
;
422 ssym
= this->symtab_
->get_sized_symbol
SELECT_SIZE_NAME(size
) (
423 sym
SELECT_SIZE(size
));
426 oehdr
.put_e_entry(v
);
428 oehdr
.put_e_phoff(this->segment_header_
->offset());
429 oehdr
.put_e_shoff(this->section_header_
->offset());
431 // FIXME: The target needs to set the flags.
432 oehdr
.put_e_flags(0);
434 oehdr
.put_e_ehsize(elfcpp::Elf_sizes
<size
>::ehdr_size
);
435 oehdr
.put_e_phentsize(elfcpp::Elf_sizes
<size
>::phdr_size
);
436 oehdr
.put_e_phnum(this->segment_header_
->data_size()
437 / elfcpp::Elf_sizes
<size
>::phdr_size
);
438 oehdr
.put_e_shentsize(elfcpp::Elf_sizes
<size
>::shdr_size
);
439 oehdr
.put_e_shnum(this->section_header_
->data_size()
440 / elfcpp::Elf_sizes
<size
>::shdr_size
);
441 oehdr
.put_e_shstrndx(this->shstrtab_
->out_shndx());
443 of
->write_output_view(0, ehdr_size
, view
);
446 // Output_data_const methods.
449 Output_data_const::do_write(Output_file
* of
)
451 of
->write(this->offset(), this->data_
.data(), this->data_
.size());
454 // Output_data_const_buffer methods.
457 Output_data_const_buffer::do_write(Output_file
* of
)
459 of
->write(this->offset(), this->p_
, this->data_size());
462 // Output_section_data methods.
464 // Record the output section, and set the entry size and such.
467 Output_section_data::set_output_section(Output_section
* os
)
469 gold_assert(this->output_section_
== NULL
);
470 this->output_section_
= os
;
471 this->do_adjust_output_section(os
);
474 // Return the section index of the output section.
477 Output_section_data::do_out_shndx() const
479 gold_assert(this->output_section_
!= NULL
);
480 return this->output_section_
->out_shndx();
483 // Output_data_strtab methods.
485 // Set the address. We don't actually care about the address, but we
486 // do set our final size.
489 Output_data_strtab::do_set_address(uint64_t, off_t
)
491 this->strtab_
->set_string_offsets();
492 this->set_data_size(this->strtab_
->get_strtab_size());
495 // Write out a string table.
498 Output_data_strtab::do_write(Output_file
* of
)
500 this->strtab_
->write(of
, this->offset());
503 // Output_reloc methods.
505 // Get the symbol index of a relocation.
507 template<bool dynamic
, int size
, bool big_endian
>
509 Output_reloc
<elfcpp::SHT_REL
, dynamic
, size
, big_endian
>::get_symbol_index()
513 switch (this->local_sym_index_
)
519 if (this->u1_
.gsym
== NULL
)
522 index
= this->u1_
.gsym
->dynsym_index();
524 index
= this->u1_
.gsym
->symtab_index();
529 index
= this->u1_
.os
->dynsym_index();
531 index
= this->u1_
.os
->symtab_index();
537 // FIXME: It seems that some targets may need to generate
538 // dynamic relocations against local symbols for some
539 // reasons. This will have to be addressed at some point.
543 index
= this->u1_
.relobj
->symtab_index(this->local_sym_index_
);
546 gold_assert(index
!= -1U);
550 // Write out the offset and info fields of a Rel or Rela relocation
553 template<bool dynamic
, int size
, bool big_endian
>
554 template<typename Write_rel
>
556 Output_reloc
<elfcpp::SHT_REL
, dynamic
, size
, big_endian
>::write_rel(
559 Address address
= this->address_
;
560 if (this->shndx_
!= INVALID_CODE
)
563 Output_section
* os
= this->u2_
.relobj
->output_section(this->shndx_
,
565 gold_assert(os
!= NULL
);
566 address
+= os
->address() + off
;
568 else if (this->u2_
.od
!= NULL
)
569 address
+= this->u2_
.od
->address();
570 wr
->put_r_offset(address
);
571 wr
->put_r_info(elfcpp::elf_r_info
<size
>(this->get_symbol_index(),
575 // Write out a Rel relocation.
577 template<bool dynamic
, int size
, bool big_endian
>
579 Output_reloc
<elfcpp::SHT_REL
, dynamic
, size
, big_endian
>::write(
580 unsigned char* pov
) const
582 elfcpp::Rel_write
<size
, big_endian
> orel(pov
);
583 this->write_rel(&orel
);
586 // Write out a Rela relocation.
588 template<bool dynamic
, int size
, bool big_endian
>
590 Output_reloc
<elfcpp::SHT_RELA
, dynamic
, size
, big_endian
>::write(
591 unsigned char* pov
) const
593 elfcpp::Rela_write
<size
, big_endian
> orel(pov
);
594 this->rel_
.write_rel(&orel
);
595 orel
.put_r_addend(this->addend_
);
598 // Output_data_reloc_base methods.
600 // Adjust the output section.
602 template<int sh_type
, bool dynamic
, int size
, bool big_endian
>
604 Output_data_reloc_base
<sh_type
, dynamic
, size
, big_endian
>
605 ::do_adjust_output_section(Output_section
* os
)
607 if (sh_type
== elfcpp::SHT_REL
)
608 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rel_size
);
609 else if (sh_type
== elfcpp::SHT_RELA
)
610 os
->set_entsize(elfcpp::Elf_sizes
<size
>::rela_size
);
614 os
->set_should_link_to_dynsym();
616 os
->set_should_link_to_symtab();
619 // Write out relocation data.
621 template<int sh_type
, bool dynamic
, int size
, bool big_endian
>
623 Output_data_reloc_base
<sh_type
, dynamic
, size
, big_endian
>::do_write(
626 const off_t off
= this->offset();
627 const off_t oview_size
= this->data_size();
628 unsigned char* const oview
= of
->get_output_view(off
, oview_size
);
630 unsigned char* pov
= oview
;
631 for (typename
Relocs::const_iterator p
= this->relocs_
.begin();
632 p
!= this->relocs_
.end();
639 gold_assert(pov
- oview
== oview_size
);
641 of
->write_output_view(off
, oview_size
, oview
);
643 // We no longer need the relocation entries.
644 this->relocs_
.clear();
647 // Output_data_got::Got_entry methods.
649 // Write out the entry.
651 template<int size
, bool big_endian
>
653 Output_data_got
<size
, big_endian
>::Got_entry::write(unsigned char* pov
) const
657 switch (this->local_sym_index_
)
661 Symbol
* gsym
= this->u_
.gsym
;
663 // If the symbol is resolved locally, we need to write out its
664 // value. Otherwise we just write zero. The target code is
665 // responsible for creating a relocation entry to fill in the
667 if (gsym
->final_value_is_known())
669 Sized_symbol
<size
>* sgsym
;
670 // This cast is a bit ugly. We don't want to put a
671 // virtual method in Symbol, because we want Symbol to be
672 // as small as possible.
673 sgsym
= static_cast<Sized_symbol
<size
>*>(gsym
);
674 val
= sgsym
->value();
680 val
= this->u_
.constant
;
684 val
= this->u_
.object
->local_symbol_value(this->local_sym_index_
);
688 elfcpp::Swap
<size
, big_endian
>::writeval(pov
, val
);
691 // Output_data_got methods.
693 // Add an entry for a global symbol to the GOT. This returns true if
694 // this is a new GOT entry, false if the symbol already had a GOT
697 template<int size
, bool big_endian
>
699 Output_data_got
<size
, big_endian
>::add_global(Symbol
* gsym
)
701 if (gsym
->has_got_offset())
704 this->entries_
.push_back(Got_entry(gsym
));
705 this->set_got_size();
706 gsym
->set_got_offset(this->last_got_offset());
710 // Add an entry for a local symbol to the GOT. This returns true if
711 // this is a new GOT entry, false if the symbol already has a GOT
714 template<int size
, bool big_endian
>
716 Output_data_got
<size
, big_endian
>::add_local(
717 Sized_relobj
<size
, big_endian
>* object
,
720 if (object
->local_has_got_offset(symndx
))
722 this->entries_
.push_back(Got_entry(object
, symndx
));
723 this->set_got_size();
724 object
->set_local_got_offset(symndx
, this->last_got_offset());
728 // Write out the GOT.
730 template<int size
, bool big_endian
>
732 Output_data_got
<size
, big_endian
>::do_write(Output_file
* of
)
734 const int add
= size
/ 8;
736 const off_t off
= this->offset();
737 const off_t oview_size
= this->data_size();
738 unsigned char* const oview
= of
->get_output_view(off
, oview_size
);
740 unsigned char* pov
= oview
;
741 for (typename
Got_entries::const_iterator p
= this->entries_
.begin();
742 p
!= this->entries_
.end();
749 gold_assert(pov
- oview
== oview_size
);
751 of
->write_output_view(off
, oview_size
, oview
);
753 // We no longer need the GOT entries.
754 this->entries_
.clear();
757 // Output_data_dynamic::Dynamic_entry methods.
759 // Write out the entry.
761 template<int size
, bool big_endian
>
763 Output_data_dynamic::Dynamic_entry::write(
765 const Stringpool
* pool
766 ACCEPT_SIZE_ENDIAN
) const
768 typename
elfcpp::Elf_types
<size
>::Elf_WXword val
;
769 switch (this->classification_
)
775 case DYNAMIC_SECTION_ADDRESS
:
776 val
= this->u_
.od
->address();
779 case DYNAMIC_SECTION_SIZE
:
780 val
= this->u_
.od
->data_size();
785 const Sized_symbol
<size
>* s
=
786 static_cast<const Sized_symbol
<size
>*>(this->u_
.sym
);
792 val
= pool
->get_offset(this->u_
.str
);
799 elfcpp::Dyn_write
<size
, big_endian
> dw(pov
);
800 dw
.put_d_tag(this->tag_
);
804 // Output_data_dynamic methods.
806 // Adjust the output section to set the entry size.
809 Output_data_dynamic::do_adjust_output_section(Output_section
* os
)
811 if (parameters
->get_size() == 32)
812 os
->set_entsize(elfcpp::Elf_sizes
<32>::dyn_size
);
813 else if (parameters
->get_size() == 64)
814 os
->set_entsize(elfcpp::Elf_sizes
<64>::dyn_size
);
819 // Set the final data size.
822 Output_data_dynamic::do_set_address(uint64_t, off_t
)
824 // Add the terminating entry.
825 this->add_constant(elfcpp::DT_NULL
, 0);
828 if (parameters
->get_size() == 32)
829 dyn_size
= elfcpp::Elf_sizes
<32>::dyn_size
;
830 else if (parameters
->get_size() == 64)
831 dyn_size
= elfcpp::Elf_sizes
<64>::dyn_size
;
834 this->set_data_size(this->entries_
.size() * dyn_size
);
837 // Write out the dynamic entries.
840 Output_data_dynamic::do_write(Output_file
* of
)
842 if (parameters
->get_size() == 32)
844 if (parameters
->is_big_endian())
846 #ifdef HAVE_TARGET_32_BIG
847 this->sized_write
<32, true>(of
);
854 #ifdef HAVE_TARGET_32_LITTLE
855 this->sized_write
<32, false>(of
);
861 else if (parameters
->get_size() == 64)
863 if (parameters
->is_big_endian())
865 #ifdef HAVE_TARGET_64_BIG
866 this->sized_write
<64, true>(of
);
873 #ifdef HAVE_TARGET_64_LITTLE
874 this->sized_write
<64, false>(of
);
884 template<int size
, bool big_endian
>
886 Output_data_dynamic::sized_write(Output_file
* of
)
888 const int dyn_size
= elfcpp::Elf_sizes
<size
>::dyn_size
;
890 const off_t offset
= this->offset();
891 const off_t oview_size
= this->data_size();
892 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
894 unsigned char* pov
= oview
;
895 for (typename
Dynamic_entries::const_iterator p
= this->entries_
.begin();
896 p
!= this->entries_
.end();
899 p
->write
SELECT_SIZE_ENDIAN_NAME(size
, big_endian
)(
900 pov
, this->pool_
SELECT_SIZE_ENDIAN(size
, big_endian
));
904 gold_assert(pov
- oview
== oview_size
);
906 of
->write_output_view(offset
, oview_size
, oview
);
908 // We no longer need the dynamic entries.
909 this->entries_
.clear();
912 // Output_section::Input_section methods.
914 // Return the data size. For an input section we store the size here.
915 // For an Output_section_data, we have to ask it for the size.
918 Output_section::Input_section::data_size() const
920 if (this->is_input_section())
921 return this->u1_
.data_size
;
923 return this->u2_
.posd
->data_size();
926 // Set the address and file offset.
929 Output_section::Input_section::set_address(uint64_t addr
, off_t off
,
932 if (this->is_input_section())
933 this->u2_
.object
->set_section_offset(this->shndx_
, off
- secoff
);
935 this->u2_
.posd
->set_address(addr
, off
);
938 // Try to turn an input address into an output address.
941 Output_section::Input_section::output_address(const Relobj
* object
,
944 uint64_t output_section_address
,
945 uint64_t *poutput
) const
947 if (!this->is_input_section())
948 return this->u2_
.posd
->output_address(object
, shndx
, offset
,
949 output_section_address
, poutput
);
952 if (this->shndx_
!= shndx
953 || this->u2_
.object
!= object
)
956 Output_section
* os
= object
->output_section(shndx
, &output_offset
);
957 gold_assert(os
!= NULL
);
958 *poutput
= output_section_address
+ output_offset
+ offset
;
963 // Write out the data. We don't have to do anything for an input
964 // section--they are handled via Object::relocate--but this is where
965 // we write out the data for an Output_section_data.
968 Output_section::Input_section::write(Output_file
* of
)
970 if (!this->is_input_section())
971 this->u2_
.posd
->write(of
);
974 // Output_section methods.
976 // Construct an Output_section. NAME will point into a Stringpool.
978 Output_section::Output_section(const char* name
, elfcpp::Elf_Word type
,
979 elfcpp::Elf_Xword flags
)
993 first_input_offset_(0),
995 needs_symtab_index_(false),
996 needs_dynsym_index_(false),
997 should_link_to_symtab_(false),
998 should_link_to_dynsym_(false)
1002 Output_section::~Output_section()
1006 // Set the entry size.
1009 Output_section::set_entsize(uint64_t v
)
1011 if (this->entsize_
== 0)
1014 gold_assert(this->entsize_
== v
);
1017 // Add the input section SHNDX, with header SHDR, named SECNAME, in
1018 // OBJECT, to the Output_section. Return the offset of the input
1019 // section within the output section. We don't always keep track of
1020 // input sections for an Output_section. Instead, each Object keeps
1021 // track of the Output_section for each of its input sections.
1023 template<int size
, bool big_endian
>
1025 Output_section::add_input_section(Relobj
* object
, unsigned int shndx
,
1026 const char* secname
,
1027 const elfcpp::Shdr
<size
, big_endian
>& shdr
)
1029 elfcpp::Elf_Xword addralign
= shdr
.get_sh_addralign();
1030 if ((addralign
& (addralign
- 1)) != 0)
1032 object
->error(_("invalid alignment %lu for section \"%s\""),
1033 static_cast<unsigned long>(addralign
), secname
);
1037 if (addralign
> this->addralign_
)
1038 this->addralign_
= addralign
;
1040 // If this is a SHF_MERGE section, we pass all the input sections to
1041 // a Output_data_merge.
1042 if ((shdr
.get_sh_flags() & elfcpp::SHF_MERGE
) != 0)
1044 if (this->add_merge_input_section(object
, shndx
, shdr
.get_sh_flags(),
1045 shdr
.get_sh_entsize(),
1048 // Tell the relocation routines that they need to call the
1049 // output_address method to determine the final address.
1054 off_t offset_in_section
= this->data_size();
1055 off_t aligned_offset_in_section
= align_address(offset_in_section
,
1058 if (aligned_offset_in_section
> offset_in_section
1059 && (shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0
1060 && object
->target()->has_code_fill())
1062 // We need to add some fill data. Using fill_list_ when
1063 // possible is an optimization, since we will often have fill
1064 // sections without input sections.
1065 off_t fill_len
= aligned_offset_in_section
- offset_in_section
;
1066 if (this->input_sections_
.empty())
1067 this->fills_
.push_back(Fill(offset_in_section
, fill_len
));
1070 // FIXME: When relaxing, the size needs to adjust to
1071 // maintain a constant alignment.
1072 std::string
fill_data(object
->target()->code_fill(fill_len
));
1073 Output_data_const
* odc
= new Output_data_const(fill_data
, 1);
1074 this->input_sections_
.push_back(Input_section(odc
));
1078 this->set_data_size(aligned_offset_in_section
+ shdr
.get_sh_size());
1080 // We need to keep track of this section if we are already keeping
1081 // track of sections, or if we are relaxing. FIXME: Add test for
1083 if (!this->input_sections_
.empty())
1084 this->input_sections_
.push_back(Input_section(object
, shndx
,
1088 return aligned_offset_in_section
;
1091 // Add arbitrary data to an output section.
1094 Output_section::add_output_section_data(Output_section_data
* posd
)
1096 Input_section
inp(posd
);
1097 this->add_output_section_data(&inp
);
1100 // Add arbitrary data to an output section by Input_section.
1103 Output_section::add_output_section_data(Input_section
* inp
)
1105 if (this->input_sections_
.empty())
1106 this->first_input_offset_
= this->data_size();
1108 this->input_sections_
.push_back(*inp
);
1110 uint64_t addralign
= inp
->addralign();
1111 if (addralign
> this->addralign_
)
1112 this->addralign_
= addralign
;
1114 inp
->set_output_section(this);
1117 // Add a merge section to an output section.
1120 Output_section::add_output_merge_section(Output_section_data
* posd
,
1121 bool is_string
, uint64_t entsize
)
1123 Input_section
inp(posd
, is_string
, entsize
);
1124 this->add_output_section_data(&inp
);
1127 // Add an input section to a SHF_MERGE section.
1130 Output_section::add_merge_input_section(Relobj
* object
, unsigned int shndx
,
1131 uint64_t flags
, uint64_t entsize
,
1134 // We only merge constants if the alignment is not more than the
1135 // entry size. This could be handled, but it's unusual.
1136 if (addralign
> entsize
)
1139 bool is_string
= (flags
& elfcpp::SHF_STRINGS
) != 0;
1140 Input_section_list::iterator p
;
1141 for (p
= this->input_sections_
.begin();
1142 p
!= this->input_sections_
.end();
1144 if (p
->is_merge_section(is_string
, entsize
))
1147 // We handle the actual constant merging in Output_merge_data or
1148 // Output_merge_string_data.
1149 if (p
!= this->input_sections_
.end())
1150 p
->add_input_section(object
, shndx
);
1153 Output_section_data
* posd
;
1155 posd
= new Output_merge_data(entsize
);
1156 else if (entsize
== 1)
1157 posd
= new Output_merge_string
<char>();
1158 else if (entsize
== 2)
1159 posd
= new Output_merge_string
<uint16_t>();
1160 else if (entsize
== 4)
1161 posd
= new Output_merge_string
<uint32_t>();
1165 this->add_output_merge_section(posd
, is_string
, entsize
);
1166 posd
->add_input_section(object
, shndx
);
1172 // Return the output virtual address of OFFSET relative to the start
1173 // of input section SHNDX in object OBJECT.
1176 Output_section::output_address(const Relobj
* object
, unsigned int shndx
,
1179 uint64_t addr
= this->address() + this->first_input_offset_
;
1180 for (Input_section_list::const_iterator p
= this->input_sections_
.begin();
1181 p
!= this->input_sections_
.end();
1184 addr
= align_address(addr
, p
->addralign());
1186 if (p
->output_address(object
, shndx
, offset
, addr
, &output
))
1188 addr
+= p
->data_size();
1191 // If we get here, it means that we don't know the mapping for this
1192 // input section. This might happen in principle if
1193 // add_input_section were called before add_output_section_data.
1194 // But it should never actually happen.
1199 // Set the address of an Output_section. This is where we handle
1200 // setting the addresses of any Output_section_data objects.
1203 Output_section::do_set_address(uint64_t address
, off_t startoff
)
1205 if (this->input_sections_
.empty())
1208 off_t off
= startoff
+ this->first_input_offset_
;
1209 for (Input_section_list::iterator p
= this->input_sections_
.begin();
1210 p
!= this->input_sections_
.end();
1213 off
= align_address(off
, p
->addralign());
1214 p
->set_address(address
+ (off
- startoff
), off
, startoff
);
1215 off
+= p
->data_size();
1218 this->set_data_size(off
- startoff
);
1221 // Write the section header to *OSHDR.
1223 template<int size
, bool big_endian
>
1225 Output_section::write_header(const Layout
* layout
,
1226 const Stringpool
* secnamepool
,
1227 elfcpp::Shdr_write
<size
, big_endian
>* oshdr
) const
1229 oshdr
->put_sh_name(secnamepool
->get_offset(this->name_
));
1230 oshdr
->put_sh_type(this->type_
);
1231 oshdr
->put_sh_flags(this->flags_
);
1232 oshdr
->put_sh_addr(this->address());
1233 oshdr
->put_sh_offset(this->offset());
1234 oshdr
->put_sh_size(this->data_size());
1235 if (this->link_section_
!= NULL
)
1236 oshdr
->put_sh_link(this->link_section_
->out_shndx());
1237 else if (this->should_link_to_symtab_
)
1238 oshdr
->put_sh_link(layout
->symtab_section()->out_shndx());
1239 else if (this->should_link_to_dynsym_
)
1240 oshdr
->put_sh_link(layout
->dynsym_section()->out_shndx());
1242 oshdr
->put_sh_link(this->link_
);
1243 if (this->info_section_
!= NULL
)
1244 oshdr
->put_sh_info(this->info_section_
->out_shndx());
1246 oshdr
->put_sh_info(this->info_
);
1247 oshdr
->put_sh_addralign(this->addralign_
);
1248 oshdr
->put_sh_entsize(this->entsize_
);
1251 // Write out the data. For input sections the data is written out by
1252 // Object::relocate, but we have to handle Output_section_data objects
1256 Output_section::do_write(Output_file
* of
)
1258 off_t output_section_file_offset
= this->offset();
1259 for (Fill_list::iterator p
= this->fills_
.begin();
1260 p
!= this->fills_
.end();
1263 std::string
fill_data(of
->target()->code_fill(p
->length()));
1264 of
->write(output_section_file_offset
+ p
->section_offset(),
1265 fill_data
.data(), fill_data
.size());
1268 for (Input_section_list::iterator p
= this->input_sections_
.begin();
1269 p
!= this->input_sections_
.end();
1274 // Output segment methods.
1276 Output_segment::Output_segment(elfcpp::Elf_Word type
, elfcpp::Elf_Word flags
)
1287 is_align_known_(false)
1291 // Add an Output_section to an Output_segment.
1294 Output_segment::add_output_section(Output_section
* os
,
1295 elfcpp::Elf_Word seg_flags
,
1298 gold_assert((os
->flags() & elfcpp::SHF_ALLOC
) != 0);
1299 gold_assert(!this->is_align_known_
);
1301 // Update the segment flags.
1302 this->flags_
|= seg_flags
;
1304 Output_segment::Output_data_list
* pdl
;
1305 if (os
->type() == elfcpp::SHT_NOBITS
)
1306 pdl
= &this->output_bss_
;
1308 pdl
= &this->output_data_
;
1310 // So that PT_NOTE segments will work correctly, we need to ensure
1311 // that all SHT_NOTE sections are adjacent. This will normally
1312 // happen automatically, because all the SHT_NOTE input sections
1313 // will wind up in the same output section. However, it is possible
1314 // for multiple SHT_NOTE input sections to have different section
1315 // flags, and thus be in different output sections, but for the
1316 // different section flags to map into the same segment flags and
1317 // thus the same output segment.
1319 // Note that while there may be many input sections in an output
1320 // section, there are normally only a few output sections in an
1321 // output segment. This loop is expected to be fast.
1323 if (os
->type() == elfcpp::SHT_NOTE
&& !pdl
->empty())
1325 Output_segment::Output_data_list::iterator p
= pdl
->end();
1329 if ((*p
)->is_section_type(elfcpp::SHT_NOTE
))
1331 // We don't worry about the FRONT parameter.
1337 while (p
!= pdl
->begin());
1340 // Similarly, so that PT_TLS segments will work, we need to group
1341 // SHF_TLS sections. An SHF_TLS/SHT_NOBITS section is a special
1342 // case: we group the SHF_TLS/SHT_NOBITS sections right after the
1343 // SHF_TLS/SHT_PROGBITS sections. This lets us set up PT_TLS
1345 if ((os
->flags() & elfcpp::SHF_TLS
) != 0 && !this->output_data_
.empty())
1347 pdl
= &this->output_data_
;
1348 bool nobits
= os
->type() == elfcpp::SHT_NOBITS
;
1349 bool sawtls
= false;
1350 Output_segment::Output_data_list::iterator p
= pdl
->end();
1355 if ((*p
)->is_section_flag_set(elfcpp::SHF_TLS
))
1358 // Put a NOBITS section after the first TLS section.
1359 // But a PROGBITS section after the first TLS/PROGBITS
1361 insert
= nobits
|| !(*p
)->is_section_type(elfcpp::SHT_NOBITS
);
1365 // If we've gone past the TLS sections, but we've seen a
1366 // TLS section, then we need to insert this section now.
1372 // We don't worry about the FRONT parameter.
1378 while (p
!= pdl
->begin());
1380 // There are no TLS sections yet; put this one at the requested
1381 // location in the section list.
1385 pdl
->push_front(os
);
1390 // Add an Output_data (which is not an Output_section) to the start of
1394 Output_segment::add_initial_output_data(Output_data
* od
)
1396 gold_assert(!this->is_align_known_
);
1397 this->output_data_
.push_front(od
);
1400 // Return the maximum alignment of the Output_data in Output_segment.
1401 // Once we compute this, we prohibit new sections from being added.
1404 Output_segment::addralign()
1406 if (!this->is_align_known_
)
1410 addralign
= Output_segment::maximum_alignment(&this->output_data_
);
1411 if (addralign
> this->align_
)
1412 this->align_
= addralign
;
1414 addralign
= Output_segment::maximum_alignment(&this->output_bss_
);
1415 if (addralign
> this->align_
)
1416 this->align_
= addralign
;
1418 this->is_align_known_
= true;
1421 return this->align_
;
1424 // Return the maximum alignment of a list of Output_data.
1427 Output_segment::maximum_alignment(const Output_data_list
* pdl
)
1430 for (Output_data_list::const_iterator p
= pdl
->begin();
1434 uint64_t addralign
= (*p
)->addralign();
1435 if (addralign
> ret
)
1441 // Set the section addresses for an Output_segment. ADDR is the
1442 // address and *POFF is the file offset. Set the section indexes
1443 // starting with *PSHNDX. Return the address of the immediately
1444 // following segment. Update *POFF and *PSHNDX.
1447 Output_segment::set_section_addresses(uint64_t addr
, off_t
* poff
,
1448 unsigned int* pshndx
)
1450 gold_assert(this->type_
== elfcpp::PT_LOAD
);
1452 this->vaddr_
= addr
;
1453 this->paddr_
= addr
;
1455 off_t orig_off
= *poff
;
1456 this->offset_
= orig_off
;
1458 *poff
= align_address(*poff
, this->addralign());
1460 addr
= this->set_section_list_addresses(&this->output_data_
, addr
, poff
,
1462 this->filesz_
= *poff
- orig_off
;
1466 uint64_t ret
= this->set_section_list_addresses(&this->output_bss_
, addr
,
1468 this->memsz_
= *poff
- orig_off
;
1470 // Ignore the file offset adjustments made by the BSS Output_data
1477 // Set the addresses and file offsets in a list of Output_data
1481 Output_segment::set_section_list_addresses(Output_data_list
* pdl
,
1482 uint64_t addr
, off_t
* poff
,
1483 unsigned int* pshndx
)
1485 off_t startoff
= *poff
;
1487 off_t off
= startoff
;
1488 for (Output_data_list::iterator p
= pdl
->begin();
1492 off
= align_address(off
, (*p
)->addralign());
1493 (*p
)->set_address(addr
+ (off
- startoff
), off
);
1495 // Unless this is a PT_TLS segment, we want to ignore the size
1496 // of a SHF_TLS/SHT_NOBITS section. Such a section does not
1497 // affect the size of a PT_LOAD segment.
1498 if (this->type_
== elfcpp::PT_TLS
1499 || !(*p
)->is_section_flag_set(elfcpp::SHF_TLS
)
1500 || !(*p
)->is_section_type(elfcpp::SHT_NOBITS
))
1501 off
+= (*p
)->data_size();
1503 if ((*p
)->is_section())
1505 (*p
)->set_out_shndx(*pshndx
);
1511 return addr
+ (off
- startoff
);
1514 // For a non-PT_LOAD segment, set the offset from the sections, if
1518 Output_segment::set_offset()
1520 gold_assert(this->type_
!= elfcpp::PT_LOAD
);
1522 if (this->output_data_
.empty() && this->output_bss_
.empty())
1533 const Output_data
* first
;
1534 if (this->output_data_
.empty())
1535 first
= this->output_bss_
.front();
1537 first
= this->output_data_
.front();
1538 this->vaddr_
= first
->address();
1539 this->paddr_
= this->vaddr_
;
1540 this->offset_
= first
->offset();
1542 if (this->output_data_
.empty())
1546 const Output_data
* last_data
= this->output_data_
.back();
1547 this->filesz_
= (last_data
->address()
1548 + last_data
->data_size()
1552 const Output_data
* last
;
1553 if (this->output_bss_
.empty())
1554 last
= this->output_data_
.back();
1556 last
= this->output_bss_
.back();
1557 this->memsz_
= (last
->address()
1562 // Return the number of Output_sections in an Output_segment.
1565 Output_segment::output_section_count() const
1567 return (this->output_section_count_list(&this->output_data_
)
1568 + this->output_section_count_list(&this->output_bss_
));
1571 // Return the number of Output_sections in an Output_data_list.
1574 Output_segment::output_section_count_list(const Output_data_list
* pdl
) const
1576 unsigned int count
= 0;
1577 for (Output_data_list::const_iterator p
= pdl
->begin();
1581 if ((*p
)->is_section())
1587 // Write the segment data into *OPHDR.
1589 template<int size
, bool big_endian
>
1591 Output_segment::write_header(elfcpp::Phdr_write
<size
, big_endian
>* ophdr
)
1593 ophdr
->put_p_type(this->type_
);
1594 ophdr
->put_p_offset(this->offset_
);
1595 ophdr
->put_p_vaddr(this->vaddr_
);
1596 ophdr
->put_p_paddr(this->paddr_
);
1597 ophdr
->put_p_filesz(this->filesz_
);
1598 ophdr
->put_p_memsz(this->memsz_
);
1599 ophdr
->put_p_flags(this->flags_
);
1600 ophdr
->put_p_align(this->addralign());
1603 // Write the section headers into V.
1605 template<int size
, bool big_endian
>
1607 Output_segment::write_section_headers(const Layout
* layout
,
1608 const Stringpool
* secnamepool
,
1610 unsigned int *pshndx
1611 ACCEPT_SIZE_ENDIAN
) const
1613 // Every section that is attached to a segment must be attached to a
1614 // PT_LOAD segment, so we only write out section headers for PT_LOAD
1616 if (this->type_
!= elfcpp::PT_LOAD
)
1619 v
= this->write_section_headers_list
1620 SELECT_SIZE_ENDIAN_NAME(size
, big_endian
) (
1621 layout
, secnamepool
, &this->output_data_
, v
, pshndx
1622 SELECT_SIZE_ENDIAN(size
, big_endian
));
1623 v
= this->write_section_headers_list
1624 SELECT_SIZE_ENDIAN_NAME(size
, big_endian
) (
1625 layout
, secnamepool
, &this->output_bss_
, v
, pshndx
1626 SELECT_SIZE_ENDIAN(size
, big_endian
));
1630 template<int size
, bool big_endian
>
1632 Output_segment::write_section_headers_list(const Layout
* layout
,
1633 const Stringpool
* secnamepool
,
1634 const Output_data_list
* pdl
,
1636 unsigned int* pshndx
1637 ACCEPT_SIZE_ENDIAN
) const
1639 const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
1640 for (Output_data_list::const_iterator p
= pdl
->begin();
1644 if ((*p
)->is_section())
1646 const Output_section
* ps
= static_cast<const Output_section
*>(*p
);
1647 gold_assert(*pshndx
== ps
->out_shndx());
1648 elfcpp::Shdr_write
<size
, big_endian
> oshdr(v
);
1649 ps
->write_header(layout
, secnamepool
, &oshdr
);
1657 // Output_file methods.
1659 Output_file::Output_file(const General_options
& options
, Target
* target
)
1660 : options_(options
),
1662 name_(options
.output_file_name()),
1669 // Open the output file.
1672 Output_file::open(off_t file_size
)
1674 this->file_size_
= file_size
;
1676 // Unlink the file first; otherwise the open() may fail if the file
1677 // is busy (e.g. it's an executable that's currently being executed).
1679 // However, the linker may be part of a system where a zero-length
1680 // file is created for it to write to, with tight permissions (gcc
1681 // 2.95 did something like this). Unlinking the file would work
1682 // around those permission controls, so we only unlink if the file
1683 // has a non-zero size. We also unlink only regular files to avoid
1684 // trouble with directories/etc.
1686 // If we fail, continue; this command is merely a best-effort attempt
1687 // to improve the odds for open().
1690 if (::stat(this->name_
, &s
) == 0 && s
.st_size
!= 0)
1691 unlink_if_ordinary(this->name_
);
1693 int mode
= parameters
->output_is_object() ? 0666 : 0777;
1694 int o
= ::open(this->name_
, O_RDWR
| O_CREAT
| O_TRUNC
, mode
);
1696 gold_fatal(_("%s: open: %s"), this->name_
, strerror(errno
));
1699 // Write out one byte to make the file the right size.
1700 if (::lseek(o
, file_size
- 1, SEEK_SET
) < 0)
1701 gold_fatal(_("%s: lseek: %s"), this->name_
, strerror(errno
));
1703 if (::write(o
, &b
, 1) != 1)
1704 gold_fatal(_("%s: write: %s"), this->name_
, strerror(errno
));
1706 // Map the file into memory.
1707 void* base
= ::mmap(NULL
, file_size
, PROT_READ
| PROT_WRITE
,
1709 if (base
== MAP_FAILED
)
1710 gold_fatal(_("%s: mmap: %s"), this->name_
, strerror(errno
));
1711 this->base_
= static_cast<unsigned char*>(base
);
1714 // Close the output file.
1717 Output_file::close()
1719 if (::munmap(this->base_
, this->file_size_
) < 0)
1720 gold_error(_("%s: munmap: %s"), this->name_
, strerror(errno
));
1723 if (::close(this->o_
) < 0)
1724 gold_error(_("%s: close: %s"), this->name_
, strerror(errno
));
1728 // Instantiate the templates we need. We could use the configure
1729 // script to restrict this to only the ones for implemented targets.
1731 #ifdef HAVE_TARGET_32_LITTLE
1734 Output_section::add_input_section
<32, false>(
1737 const char* secname
,
1738 const elfcpp::Shdr
<32, false>& shdr
);
1741 #ifdef HAVE_TARGET_32_BIG
1744 Output_section::add_input_section
<32, true>(
1747 const char* secname
,
1748 const elfcpp::Shdr
<32, true>& shdr
);
1751 #ifdef HAVE_TARGET_64_LITTLE
1754 Output_section::add_input_section
<64, false>(
1757 const char* secname
,
1758 const elfcpp::Shdr
<64, false>& shdr
);
1761 #ifdef HAVE_TARGET_64_BIG
1764 Output_section::add_input_section
<64, true>(
1767 const char* secname
,
1768 const elfcpp::Shdr
<64, true>& shdr
);
1771 #ifdef HAVE_TARGET_32_LITTLE
1773 class Output_data_reloc
<elfcpp::SHT_REL
, false, 32, false>;
1776 #ifdef HAVE_TARGET_32_BIG
1778 class Output_data_reloc
<elfcpp::SHT_REL
, false, 32, true>;
1781 #ifdef HAVE_TARGET_64_LITTLE
1783 class Output_data_reloc
<elfcpp::SHT_REL
, false, 64, false>;
1786 #ifdef HAVE_TARGET_64_BIG
1788 class Output_data_reloc
<elfcpp::SHT_REL
, false, 64, true>;
1791 #ifdef HAVE_TARGET_32_LITTLE
1793 class Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false>;
1796 #ifdef HAVE_TARGET_32_BIG
1798 class Output_data_reloc
<elfcpp::SHT_REL
, true, 32, true>;
1801 #ifdef HAVE_TARGET_64_LITTLE
1803 class Output_data_reloc
<elfcpp::SHT_REL
, true, 64, false>;
1806 #ifdef HAVE_TARGET_64_BIG
1808 class Output_data_reloc
<elfcpp::SHT_REL
, true, 64, true>;
1811 #ifdef HAVE_TARGET_32_LITTLE
1813 class Output_data_reloc
<elfcpp::SHT_RELA
, false, 32, false>;
1816 #ifdef HAVE_TARGET_32_BIG
1818 class Output_data_reloc
<elfcpp::SHT_RELA
, false, 32, true>;
1821 #ifdef HAVE_TARGET_64_LITTLE
1823 class Output_data_reloc
<elfcpp::SHT_RELA
, false, 64, false>;
1826 #ifdef HAVE_TARGET_64_BIG
1828 class Output_data_reloc
<elfcpp::SHT_RELA
, false, 64, true>;
1831 #ifdef HAVE_TARGET_32_LITTLE
1833 class Output_data_reloc
<elfcpp::SHT_RELA
, true, 32, false>;
1836 #ifdef HAVE_TARGET_32_BIG
1838 class Output_data_reloc
<elfcpp::SHT_RELA
, true, 32, true>;
1841 #ifdef HAVE_TARGET_64_LITTLE
1843 class Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, false>;
1846 #ifdef HAVE_TARGET_64_BIG
1848 class Output_data_reloc
<elfcpp::SHT_RELA
, true, 64, true>;
1851 #ifdef HAVE_TARGET_32_LITTLE
1853 class Output_data_got
<32, false>;
1856 #ifdef HAVE_TARGET_32_BIG
1858 class Output_data_got
<32, true>;
1861 #ifdef HAVE_TARGET_64_LITTLE
1863 class Output_data_got
<64, false>;
1866 #ifdef HAVE_TARGET_64_BIG
1868 class Output_data_got
<64, true>;
1871 } // End namespace gold.