Fix indent for --symbols in "readelf -h"
[binutils.git] / gold / output.cc
blob63ab98c96b6789de0a75c61d034716150b1de020
1 // output.cc -- manage the output file for gold
3 // Copyright 2006, 2007, 2008, 2009 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.
23 #include "gold.h"
25 #include <cstdlib>
26 #include <cstring>
27 #include <cerrno>
28 #include <fcntl.h>
29 #include <unistd.h>
30 #include <sys/mman.h>
31 #include <sys/stat.h>
32 #include <algorithm>
33 #include "libiberty.h"
35 #include "parameters.h"
36 #include "object.h"
37 #include "symtab.h"
38 #include "reloc.h"
39 #include "merge.h"
40 #include "descriptors.h"
41 #include "output.h"
43 // Some BSD systems still use MAP_ANON instead of MAP_ANONYMOUS
44 #ifndef MAP_ANONYMOUS
45 # define MAP_ANONYMOUS MAP_ANON
46 #endif
48 #ifndef HAVE_POSIX_FALLOCATE
49 // A dummy, non general, version of posix_fallocate. Here we just set
50 // the file size and hope that there is enough disk space. FIXME: We
51 // could allocate disk space by walking block by block and writing a
52 // zero byte into each block.
53 static int
54 posix_fallocate(int o, off_t offset, off_t len)
56 return ftruncate(o, offset + len);
58 #endif // !defined(HAVE_POSIX_FALLOCATE)
60 namespace gold
63 // Output_data variables.
65 bool Output_data::allocated_sizes_are_fixed;
67 // Output_data methods.
69 Output_data::~Output_data()
73 // Return the default alignment for the target size.
75 uint64_t
76 Output_data::default_alignment()
78 return Output_data::default_alignment_for_size(
79 parameters->target().get_size());
82 // Return the default alignment for a size--32 or 64.
84 uint64_t
85 Output_data::default_alignment_for_size(int size)
87 if (size == 32)
88 return 4;
89 else if (size == 64)
90 return 8;
91 else
92 gold_unreachable();
95 // Output_section_header methods. This currently assumes that the
96 // segment and section lists are complete at construction time.
98 Output_section_headers::Output_section_headers(
99 const Layout* layout,
100 const Layout::Segment_list* segment_list,
101 const Layout::Section_list* section_list,
102 const Layout::Section_list* unattached_section_list,
103 const Stringpool* secnamepool,
104 const Output_section* shstrtab_section)
105 : layout_(layout),
106 segment_list_(segment_list),
107 section_list_(section_list),
108 unattached_section_list_(unattached_section_list),
109 secnamepool_(secnamepool),
110 shstrtab_section_(shstrtab_section)
114 // Compute the current data size.
116 off_t
117 Output_section_headers::do_size() const
119 // Count all the sections. Start with 1 for the null section.
120 off_t count = 1;
121 if (!parameters->options().relocatable())
123 for (Layout::Segment_list::const_iterator p =
124 this->segment_list_->begin();
125 p != this->segment_list_->end();
126 ++p)
127 if ((*p)->type() == elfcpp::PT_LOAD)
128 count += (*p)->output_section_count();
130 else
132 for (Layout::Section_list::const_iterator p =
133 this->section_list_->begin();
134 p != this->section_list_->end();
135 ++p)
136 if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
137 ++count;
139 count += this->unattached_section_list_->size();
141 const int size = parameters->target().get_size();
142 int shdr_size;
143 if (size == 32)
144 shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
145 else if (size == 64)
146 shdr_size = elfcpp::Elf_sizes<64>::shdr_size;
147 else
148 gold_unreachable();
150 return count * shdr_size;
153 // Write out the section headers.
155 void
156 Output_section_headers::do_write(Output_file* of)
158 switch (parameters->size_and_endianness())
160 #ifdef HAVE_TARGET_32_LITTLE
161 case Parameters::TARGET_32_LITTLE:
162 this->do_sized_write<32, false>(of);
163 break;
164 #endif
165 #ifdef HAVE_TARGET_32_BIG
166 case Parameters::TARGET_32_BIG:
167 this->do_sized_write<32, true>(of);
168 break;
169 #endif
170 #ifdef HAVE_TARGET_64_LITTLE
171 case Parameters::TARGET_64_LITTLE:
172 this->do_sized_write<64, false>(of);
173 break;
174 #endif
175 #ifdef HAVE_TARGET_64_BIG
176 case Parameters::TARGET_64_BIG:
177 this->do_sized_write<64, true>(of);
178 break;
179 #endif
180 default:
181 gold_unreachable();
185 template<int size, bool big_endian>
186 void
187 Output_section_headers::do_sized_write(Output_file* of)
189 off_t all_shdrs_size = this->data_size();
190 unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size);
192 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
193 unsigned char* v = view;
196 typename elfcpp::Shdr_write<size, big_endian> oshdr(v);
197 oshdr.put_sh_name(0);
198 oshdr.put_sh_type(elfcpp::SHT_NULL);
199 oshdr.put_sh_flags(0);
200 oshdr.put_sh_addr(0);
201 oshdr.put_sh_offset(0);
203 size_t section_count = (this->data_size()
204 / elfcpp::Elf_sizes<size>::shdr_size);
205 if (section_count < elfcpp::SHN_LORESERVE)
206 oshdr.put_sh_size(0);
207 else
208 oshdr.put_sh_size(section_count);
210 unsigned int shstrndx = this->shstrtab_section_->out_shndx();
211 if (shstrndx < elfcpp::SHN_LORESERVE)
212 oshdr.put_sh_link(0);
213 else
214 oshdr.put_sh_link(shstrndx);
216 oshdr.put_sh_info(0);
217 oshdr.put_sh_addralign(0);
218 oshdr.put_sh_entsize(0);
221 v += shdr_size;
223 unsigned int shndx = 1;
224 if (!parameters->options().relocatable())
226 for (Layout::Segment_list::const_iterator p =
227 this->segment_list_->begin();
228 p != this->segment_list_->end();
229 ++p)
230 v = (*p)->write_section_headers<size, big_endian>(this->layout_,
231 this->secnamepool_,
233 &shndx);
235 else
237 for (Layout::Section_list::const_iterator p =
238 this->section_list_->begin();
239 p != this->section_list_->end();
240 ++p)
242 // We do unallocated sections below, except that group
243 // sections have to come first.
244 if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
245 && (*p)->type() != elfcpp::SHT_GROUP)
246 continue;
247 gold_assert(shndx == (*p)->out_shndx());
248 elfcpp::Shdr_write<size, big_endian> oshdr(v);
249 (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
250 v += shdr_size;
251 ++shndx;
255 for (Layout::Section_list::const_iterator p =
256 this->unattached_section_list_->begin();
257 p != this->unattached_section_list_->end();
258 ++p)
260 // For a relocatable link, we did unallocated group sections
261 // above, since they have to come first.
262 if ((*p)->type() == elfcpp::SHT_GROUP
263 && parameters->options().relocatable())
264 continue;
265 gold_assert(shndx == (*p)->out_shndx());
266 elfcpp::Shdr_write<size, big_endian> oshdr(v);
267 (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
268 v += shdr_size;
269 ++shndx;
272 of->write_output_view(this->offset(), all_shdrs_size, view);
275 // Output_segment_header methods.
277 Output_segment_headers::Output_segment_headers(
278 const Layout::Segment_list& segment_list)
279 : segment_list_(segment_list)
283 void
284 Output_segment_headers::do_write(Output_file* of)
286 switch (parameters->size_and_endianness())
288 #ifdef HAVE_TARGET_32_LITTLE
289 case Parameters::TARGET_32_LITTLE:
290 this->do_sized_write<32, false>(of);
291 break;
292 #endif
293 #ifdef HAVE_TARGET_32_BIG
294 case Parameters::TARGET_32_BIG:
295 this->do_sized_write<32, true>(of);
296 break;
297 #endif
298 #ifdef HAVE_TARGET_64_LITTLE
299 case Parameters::TARGET_64_LITTLE:
300 this->do_sized_write<64, false>(of);
301 break;
302 #endif
303 #ifdef HAVE_TARGET_64_BIG
304 case Parameters::TARGET_64_BIG:
305 this->do_sized_write<64, true>(of);
306 break;
307 #endif
308 default:
309 gold_unreachable();
313 template<int size, bool big_endian>
314 void
315 Output_segment_headers::do_sized_write(Output_file* of)
317 const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
318 off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
319 gold_assert(all_phdrs_size == this->data_size());
320 unsigned char* view = of->get_output_view(this->offset(),
321 all_phdrs_size);
322 unsigned char* v = view;
323 for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
324 p != this->segment_list_.end();
325 ++p)
327 elfcpp::Phdr_write<size, big_endian> ophdr(v);
328 (*p)->write_header(&ophdr);
329 v += phdr_size;
332 gold_assert(v - view == all_phdrs_size);
334 of->write_output_view(this->offset(), all_phdrs_size, view);
337 off_t
338 Output_segment_headers::do_size() const
340 const int size = parameters->target().get_size();
341 int phdr_size;
342 if (size == 32)
343 phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
344 else if (size == 64)
345 phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
346 else
347 gold_unreachable();
349 return this->segment_list_.size() * phdr_size;
352 // Output_file_header methods.
354 Output_file_header::Output_file_header(const Target* target,
355 const Symbol_table* symtab,
356 const Output_segment_headers* osh,
357 const char* entry)
358 : target_(target),
359 symtab_(symtab),
360 segment_header_(osh),
361 section_header_(NULL),
362 shstrtab_(NULL),
363 entry_(entry)
365 this->set_data_size(this->do_size());
368 // Set the section table information for a file header.
370 void
371 Output_file_header::set_section_info(const Output_section_headers* shdrs,
372 const Output_section* shstrtab)
374 this->section_header_ = shdrs;
375 this->shstrtab_ = shstrtab;
378 // Write out the file header.
380 void
381 Output_file_header::do_write(Output_file* of)
383 gold_assert(this->offset() == 0);
385 switch (parameters->size_and_endianness())
387 #ifdef HAVE_TARGET_32_LITTLE
388 case Parameters::TARGET_32_LITTLE:
389 this->do_sized_write<32, false>(of);
390 break;
391 #endif
392 #ifdef HAVE_TARGET_32_BIG
393 case Parameters::TARGET_32_BIG:
394 this->do_sized_write<32, true>(of);
395 break;
396 #endif
397 #ifdef HAVE_TARGET_64_LITTLE
398 case Parameters::TARGET_64_LITTLE:
399 this->do_sized_write<64, false>(of);
400 break;
401 #endif
402 #ifdef HAVE_TARGET_64_BIG
403 case Parameters::TARGET_64_BIG:
404 this->do_sized_write<64, true>(of);
405 break;
406 #endif
407 default:
408 gold_unreachable();
412 // Write out the file header with appropriate size and endianess.
414 template<int size, bool big_endian>
415 void
416 Output_file_header::do_sized_write(Output_file* of)
418 gold_assert(this->offset() == 0);
420 int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
421 unsigned char* view = of->get_output_view(0, ehdr_size);
422 elfcpp::Ehdr_write<size, big_endian> oehdr(view);
424 unsigned char e_ident[elfcpp::EI_NIDENT];
425 memset(e_ident, 0, elfcpp::EI_NIDENT);
426 e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
427 e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
428 e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
429 e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
430 if (size == 32)
431 e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
432 else if (size == 64)
433 e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
434 else
435 gold_unreachable();
436 e_ident[elfcpp::EI_DATA] = (big_endian
437 ? elfcpp::ELFDATA2MSB
438 : elfcpp::ELFDATA2LSB);
439 e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
440 oehdr.put_e_ident(e_ident);
442 elfcpp::ET e_type;
443 if (parameters->options().relocatable())
444 e_type = elfcpp::ET_REL;
445 else if (parameters->options().output_is_position_independent())
446 e_type = elfcpp::ET_DYN;
447 else
448 e_type = elfcpp::ET_EXEC;
449 oehdr.put_e_type(e_type);
451 oehdr.put_e_machine(this->target_->machine_code());
452 oehdr.put_e_version(elfcpp::EV_CURRENT);
454 oehdr.put_e_entry(this->entry<size>());
456 if (this->segment_header_ == NULL)
457 oehdr.put_e_phoff(0);
458 else
459 oehdr.put_e_phoff(this->segment_header_->offset());
461 oehdr.put_e_shoff(this->section_header_->offset());
462 oehdr.put_e_flags(this->target_->processor_specific_flags());
463 oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
465 if (this->segment_header_ == NULL)
467 oehdr.put_e_phentsize(0);
468 oehdr.put_e_phnum(0);
470 else
472 oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
473 oehdr.put_e_phnum(this->segment_header_->data_size()
474 / elfcpp::Elf_sizes<size>::phdr_size);
477 oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
478 size_t section_count = (this->section_header_->data_size()
479 / elfcpp::Elf_sizes<size>::shdr_size);
481 if (section_count < elfcpp::SHN_LORESERVE)
482 oehdr.put_e_shnum(this->section_header_->data_size()
483 / elfcpp::Elf_sizes<size>::shdr_size);
484 else
485 oehdr.put_e_shnum(0);
487 unsigned int shstrndx = this->shstrtab_->out_shndx();
488 if (shstrndx < elfcpp::SHN_LORESERVE)
489 oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
490 else
491 oehdr.put_e_shstrndx(elfcpp::SHN_XINDEX);
493 // Let the target adjust the ELF header, e.g., to set EI_OSABI in
494 // the e_ident field.
495 parameters->target().adjust_elf_header(view, ehdr_size);
497 of->write_output_view(0, ehdr_size, view);
500 // Return the value to use for the entry address. THIS->ENTRY_ is the
501 // symbol specified on the command line, if any.
503 template<int size>
504 typename elfcpp::Elf_types<size>::Elf_Addr
505 Output_file_header::entry()
507 const bool should_issue_warning = (this->entry_ != NULL
508 && !parameters->options().relocatable()
509 && !parameters->options().shared());
511 // FIXME: Need to support target specific entry symbol.
512 const char* entry = this->entry_;
513 if (entry == NULL)
514 entry = "_start";
516 Symbol* sym = this->symtab_->lookup(entry);
518 typename Sized_symbol<size>::Value_type v;
519 if (sym != NULL)
521 Sized_symbol<size>* ssym;
522 ssym = this->symtab_->get_sized_symbol<size>(sym);
523 if (!ssym->is_defined() && should_issue_warning)
524 gold_warning("entry symbol '%s' exists but is not defined", entry);
525 v = ssym->value();
527 else
529 // We couldn't find the entry symbol. See if we can parse it as
530 // a number. This supports, e.g., -e 0x1000.
531 char* endptr;
532 v = strtoull(entry, &endptr, 0);
533 if (*endptr != '\0')
535 if (should_issue_warning)
536 gold_warning("cannot find entry symbol '%s'", entry);
537 v = 0;
541 return v;
544 // Compute the current data size.
546 off_t
547 Output_file_header::do_size() const
549 const int size = parameters->target().get_size();
550 if (size == 32)
551 return elfcpp::Elf_sizes<32>::ehdr_size;
552 else if (size == 64)
553 return elfcpp::Elf_sizes<64>::ehdr_size;
554 else
555 gold_unreachable();
558 // Output_data_const methods.
560 void
561 Output_data_const::do_write(Output_file* of)
563 of->write(this->offset(), this->data_.data(), this->data_.size());
566 // Output_data_const_buffer methods.
568 void
569 Output_data_const_buffer::do_write(Output_file* of)
571 of->write(this->offset(), this->p_, this->data_size());
574 // Output_section_data methods.
576 // Record the output section, and set the entry size and such.
578 void
579 Output_section_data::set_output_section(Output_section* os)
581 gold_assert(this->output_section_ == NULL);
582 this->output_section_ = os;
583 this->do_adjust_output_section(os);
586 // Return the section index of the output section.
588 unsigned int
589 Output_section_data::do_out_shndx() const
591 gold_assert(this->output_section_ != NULL);
592 return this->output_section_->out_shndx();
595 // Set the alignment, which means we may need to update the alignment
596 // of the output section.
598 void
599 Output_section_data::set_addralign(uint64_t addralign)
601 this->addralign_ = addralign;
602 if (this->output_section_ != NULL
603 && this->output_section_->addralign() < addralign)
604 this->output_section_->set_addralign(addralign);
607 // Output_data_strtab methods.
609 // Set the final data size.
611 void
612 Output_data_strtab::set_final_data_size()
614 this->strtab_->set_string_offsets();
615 this->set_data_size(this->strtab_->get_strtab_size());
618 // Write out a string table.
620 void
621 Output_data_strtab::do_write(Output_file* of)
623 this->strtab_->write(of, this->offset());
626 // Output_reloc methods.
628 // A reloc against a global symbol.
630 template<bool dynamic, int size, bool big_endian>
631 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
632 Symbol* gsym,
633 unsigned int type,
634 Output_data* od,
635 Address address,
636 bool is_relative)
637 : address_(address), local_sym_index_(GSYM_CODE), type_(type),
638 is_relative_(is_relative), is_section_symbol_(false), shndx_(INVALID_CODE)
640 // this->type_ is a bitfield; make sure TYPE fits.
641 gold_assert(this->type_ == type);
642 this->u1_.gsym = gsym;
643 this->u2_.od = od;
644 if (dynamic)
645 this->set_needs_dynsym_index();
648 template<bool dynamic, int size, bool big_endian>
649 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
650 Symbol* gsym,
651 unsigned int type,
652 Sized_relobj<size, big_endian>* relobj,
653 unsigned int shndx,
654 Address address,
655 bool is_relative)
656 : address_(address), local_sym_index_(GSYM_CODE), type_(type),
657 is_relative_(is_relative), is_section_symbol_(false), shndx_(shndx)
659 gold_assert(shndx != INVALID_CODE);
660 // this->type_ is a bitfield; make sure TYPE fits.
661 gold_assert(this->type_ == type);
662 this->u1_.gsym = gsym;
663 this->u2_.relobj = relobj;
664 if (dynamic)
665 this->set_needs_dynsym_index();
668 // A reloc against a local symbol.
670 template<bool dynamic, int size, bool big_endian>
671 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
672 Sized_relobj<size, big_endian>* relobj,
673 unsigned int local_sym_index,
674 unsigned int type,
675 Output_data* od,
676 Address address,
677 bool is_relative,
678 bool is_section_symbol)
679 : address_(address), local_sym_index_(local_sym_index), type_(type),
680 is_relative_(is_relative), is_section_symbol_(is_section_symbol),
681 shndx_(INVALID_CODE)
683 gold_assert(local_sym_index != GSYM_CODE
684 && local_sym_index != INVALID_CODE);
685 // this->type_ is a bitfield; make sure TYPE fits.
686 gold_assert(this->type_ == type);
687 this->u1_.relobj = relobj;
688 this->u2_.od = od;
689 if (dynamic)
690 this->set_needs_dynsym_index();
693 template<bool dynamic, int size, bool big_endian>
694 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
695 Sized_relobj<size, big_endian>* relobj,
696 unsigned int local_sym_index,
697 unsigned int type,
698 unsigned int shndx,
699 Address address,
700 bool is_relative,
701 bool is_section_symbol)
702 : address_(address), local_sym_index_(local_sym_index), type_(type),
703 is_relative_(is_relative), is_section_symbol_(is_section_symbol),
704 shndx_(shndx)
706 gold_assert(local_sym_index != GSYM_CODE
707 && local_sym_index != INVALID_CODE);
708 gold_assert(shndx != INVALID_CODE);
709 // this->type_ is a bitfield; make sure TYPE fits.
710 gold_assert(this->type_ == type);
711 this->u1_.relobj = relobj;
712 this->u2_.relobj = relobj;
713 if (dynamic)
714 this->set_needs_dynsym_index();
717 // A reloc against the STT_SECTION symbol of an output section.
719 template<bool dynamic, int size, bool big_endian>
720 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
721 Output_section* os,
722 unsigned int type,
723 Output_data* od,
724 Address address)
725 : address_(address), local_sym_index_(SECTION_CODE), type_(type),
726 is_relative_(false), is_section_symbol_(true), shndx_(INVALID_CODE)
728 // this->type_ is a bitfield; make sure TYPE fits.
729 gold_assert(this->type_ == type);
730 this->u1_.os = os;
731 this->u2_.od = od;
732 if (dynamic)
733 this->set_needs_dynsym_index();
734 else
735 os->set_needs_symtab_index();
738 template<bool dynamic, int size, bool big_endian>
739 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
740 Output_section* os,
741 unsigned int type,
742 Sized_relobj<size, big_endian>* relobj,
743 unsigned int shndx,
744 Address address)
745 : address_(address), local_sym_index_(SECTION_CODE), type_(type),
746 is_relative_(false), is_section_symbol_(true), shndx_(shndx)
748 gold_assert(shndx != INVALID_CODE);
749 // this->type_ is a bitfield; make sure TYPE fits.
750 gold_assert(this->type_ == type);
751 this->u1_.os = os;
752 this->u2_.relobj = relobj;
753 if (dynamic)
754 this->set_needs_dynsym_index();
755 else
756 os->set_needs_symtab_index();
759 // Record that we need a dynamic symbol index for this relocation.
761 template<bool dynamic, int size, bool big_endian>
762 void
763 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
764 set_needs_dynsym_index()
766 if (this->is_relative_)
767 return;
768 switch (this->local_sym_index_)
770 case INVALID_CODE:
771 gold_unreachable();
773 case GSYM_CODE:
774 this->u1_.gsym->set_needs_dynsym_entry();
775 break;
777 case SECTION_CODE:
778 this->u1_.os->set_needs_dynsym_index();
779 break;
781 case 0:
782 break;
784 default:
786 const unsigned int lsi = this->local_sym_index_;
787 if (!this->is_section_symbol_)
788 this->u1_.relobj->set_needs_output_dynsym_entry(lsi);
789 else
790 this->u1_.relobj->output_section(lsi)->set_needs_dynsym_index();
792 break;
796 // Get the symbol index of a relocation.
798 template<bool dynamic, int size, bool big_endian>
799 unsigned int
800 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
801 const
803 unsigned int index;
804 switch (this->local_sym_index_)
806 case INVALID_CODE:
807 gold_unreachable();
809 case GSYM_CODE:
810 if (this->u1_.gsym == NULL)
811 index = 0;
812 else if (dynamic)
813 index = this->u1_.gsym->dynsym_index();
814 else
815 index = this->u1_.gsym->symtab_index();
816 break;
818 case SECTION_CODE:
819 if (dynamic)
820 index = this->u1_.os->dynsym_index();
821 else
822 index = this->u1_.os->symtab_index();
823 break;
825 case 0:
826 // Relocations without symbols use a symbol index of 0.
827 index = 0;
828 break;
830 default:
832 const unsigned int lsi = this->local_sym_index_;
833 if (!this->is_section_symbol_)
835 if (dynamic)
836 index = this->u1_.relobj->dynsym_index(lsi);
837 else
838 index = this->u1_.relobj->symtab_index(lsi);
840 else
842 Output_section* os = this->u1_.relobj->output_section(lsi);
843 gold_assert(os != NULL);
844 if (dynamic)
845 index = os->dynsym_index();
846 else
847 index = os->symtab_index();
850 break;
852 gold_assert(index != -1U);
853 return index;
856 // For a local section symbol, get the address of the offset ADDEND
857 // within the input section.
859 template<bool dynamic, int size, bool big_endian>
860 typename elfcpp::Elf_types<size>::Elf_Addr
861 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
862 local_section_offset(Addend addend) const
864 gold_assert(this->local_sym_index_ != GSYM_CODE
865 && this->local_sym_index_ != SECTION_CODE
866 && this->local_sym_index_ != INVALID_CODE
867 && this->is_section_symbol_);
868 const unsigned int lsi = this->local_sym_index_;
869 Output_section* os = this->u1_.relobj->output_section(lsi);
870 gold_assert(os != NULL);
871 Address offset = this->u1_.relobj->get_output_section_offset(lsi);
872 if (offset != invalid_address)
873 return offset + addend;
874 // This is a merge section.
875 offset = os->output_address(this->u1_.relobj, lsi, addend);
876 gold_assert(offset != invalid_address);
877 return offset;
880 // Get the output address of a relocation.
882 template<bool dynamic, int size, bool big_endian>
883 typename elfcpp::Elf_types<size>::Elf_Addr
884 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_address() const
886 Address address = this->address_;
887 if (this->shndx_ != INVALID_CODE)
889 Output_section* os = this->u2_.relobj->output_section(this->shndx_);
890 gold_assert(os != NULL);
891 Address off = this->u2_.relobj->get_output_section_offset(this->shndx_);
892 if (off != invalid_address)
893 address += os->address() + off;
894 else
896 address = os->output_address(this->u2_.relobj, this->shndx_,
897 address);
898 gold_assert(address != invalid_address);
901 else if (this->u2_.od != NULL)
902 address += this->u2_.od->address();
903 return address;
906 // Write out the offset and info fields of a Rel or Rela relocation
907 // entry.
909 template<bool dynamic, int size, bool big_endian>
910 template<typename Write_rel>
911 void
912 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
913 Write_rel* wr) const
915 wr->put_r_offset(this->get_address());
916 unsigned int sym_index = this->is_relative_ ? 0 : this->get_symbol_index();
917 wr->put_r_info(elfcpp::elf_r_info<size>(sym_index, this->type_));
920 // Write out a Rel relocation.
922 template<bool dynamic, int size, bool big_endian>
923 void
924 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
925 unsigned char* pov) const
927 elfcpp::Rel_write<size, big_endian> orel(pov);
928 this->write_rel(&orel);
931 // Get the value of the symbol referred to by a Rel relocation.
933 template<bool dynamic, int size, bool big_endian>
934 typename elfcpp::Elf_types<size>::Elf_Addr
935 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::symbol_value(
936 Addend addend) const
938 if (this->local_sym_index_ == GSYM_CODE)
940 const Sized_symbol<size>* sym;
941 sym = static_cast<const Sized_symbol<size>*>(this->u1_.gsym);
942 return sym->value() + addend;
944 gold_assert(this->local_sym_index_ != SECTION_CODE
945 && this->local_sym_index_ != INVALID_CODE
946 && !this->is_section_symbol_);
947 const unsigned int lsi = this->local_sym_index_;
948 const Symbol_value<size>* symval = this->u1_.relobj->local_symbol(lsi);
949 return symval->value(this->u1_.relobj, addend);
952 // Reloc comparison. This function sorts the dynamic relocs for the
953 // benefit of the dynamic linker. First we sort all relative relocs
954 // to the front. Among relative relocs, we sort by output address.
955 // Among non-relative relocs, we sort by symbol index, then by output
956 // address.
958 template<bool dynamic, int size, bool big_endian>
960 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
961 compare(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>& r2)
962 const
964 if (this->is_relative_)
966 if (!r2.is_relative_)
967 return -1;
968 // Otherwise sort by reloc address below.
970 else if (r2.is_relative_)
971 return 1;
972 else
974 unsigned int sym1 = this->get_symbol_index();
975 unsigned int sym2 = r2.get_symbol_index();
976 if (sym1 < sym2)
977 return -1;
978 else if (sym1 > sym2)
979 return 1;
980 // Otherwise sort by reloc address.
983 section_offset_type addr1 = this->get_address();
984 section_offset_type addr2 = r2.get_address();
985 if (addr1 < addr2)
986 return -1;
987 else if (addr1 > addr2)
988 return 1;
990 // Final tie breaker, in order to generate the same output on any
991 // host: reloc type.
992 unsigned int type1 = this->type_;
993 unsigned int type2 = r2.type_;
994 if (type1 < type2)
995 return -1;
996 else if (type1 > type2)
997 return 1;
999 // These relocs appear to be exactly the same.
1000 return 0;
1003 // Write out a Rela relocation.
1005 template<bool dynamic, int size, bool big_endian>
1006 void
1007 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
1008 unsigned char* pov) const
1010 elfcpp::Rela_write<size, big_endian> orel(pov);
1011 this->rel_.write_rel(&orel);
1012 Addend addend = this->addend_;
1013 if (this->rel_.is_relative())
1014 addend = this->rel_.symbol_value(addend);
1015 else if (this->rel_.is_local_section_symbol())
1016 addend = this->rel_.local_section_offset(addend);
1017 orel.put_r_addend(addend);
1020 // Output_data_reloc_base methods.
1022 // Adjust the output section.
1024 template<int sh_type, bool dynamic, int size, bool big_endian>
1025 void
1026 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
1027 ::do_adjust_output_section(Output_section* os)
1029 if (sh_type == elfcpp::SHT_REL)
1030 os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
1031 else if (sh_type == elfcpp::SHT_RELA)
1032 os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
1033 else
1034 gold_unreachable();
1035 if (dynamic)
1036 os->set_should_link_to_dynsym();
1037 else
1038 os->set_should_link_to_symtab();
1041 // Write out relocation data.
1043 template<int sh_type, bool dynamic, int size, bool big_endian>
1044 void
1045 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
1046 Output_file* of)
1048 const off_t off = this->offset();
1049 const off_t oview_size = this->data_size();
1050 unsigned char* const oview = of->get_output_view(off, oview_size);
1052 if (this->sort_relocs_)
1054 gold_assert(dynamic);
1055 std::sort(this->relocs_.begin(), this->relocs_.end(),
1056 Sort_relocs_comparison());
1059 unsigned char* pov = oview;
1060 for (typename Relocs::const_iterator p = this->relocs_.begin();
1061 p != this->relocs_.end();
1062 ++p)
1064 p->write(pov);
1065 pov += reloc_size;
1068 gold_assert(pov - oview == oview_size);
1070 of->write_output_view(off, oview_size, oview);
1072 // We no longer need the relocation entries.
1073 this->relocs_.clear();
1076 // Class Output_relocatable_relocs.
1078 template<int sh_type, int size, bool big_endian>
1079 void
1080 Output_relocatable_relocs<sh_type, size, big_endian>::set_final_data_size()
1082 this->set_data_size(this->rr_->output_reloc_count()
1083 * Reloc_types<sh_type, size, big_endian>::reloc_size);
1086 // class Output_data_group.
1088 template<int size, bool big_endian>
1089 Output_data_group<size, big_endian>::Output_data_group(
1090 Sized_relobj<size, big_endian>* relobj,
1091 section_size_type entry_count,
1092 elfcpp::Elf_Word flags,
1093 std::vector<unsigned int>* input_shndxes)
1094 : Output_section_data(entry_count * 4, 4, false),
1095 relobj_(relobj),
1096 flags_(flags)
1098 this->input_shndxes_.swap(*input_shndxes);
1101 // Write out the section group, which means translating the section
1102 // indexes to apply to the output file.
1104 template<int size, bool big_endian>
1105 void
1106 Output_data_group<size, big_endian>::do_write(Output_file* of)
1108 const off_t off = this->offset();
1109 const section_size_type oview_size =
1110 convert_to_section_size_type(this->data_size());
1111 unsigned char* const oview = of->get_output_view(off, oview_size);
1113 elfcpp::Elf_Word* contents = reinterpret_cast<elfcpp::Elf_Word*>(oview);
1114 elfcpp::Swap<32, big_endian>::writeval(contents, this->flags_);
1115 ++contents;
1117 for (std::vector<unsigned int>::const_iterator p =
1118 this->input_shndxes_.begin();
1119 p != this->input_shndxes_.end();
1120 ++p, ++contents)
1122 Output_section* os = this->relobj_->output_section(*p);
1124 unsigned int output_shndx;
1125 if (os != NULL)
1126 output_shndx = os->out_shndx();
1127 else
1129 this->relobj_->error(_("section group retained but "
1130 "group element discarded"));
1131 output_shndx = 0;
1134 elfcpp::Swap<32, big_endian>::writeval(contents, output_shndx);
1137 size_t wrote = reinterpret_cast<unsigned char*>(contents) - oview;
1138 gold_assert(wrote == oview_size);
1140 of->write_output_view(off, oview_size, oview);
1142 // We no longer need this information.
1143 this->input_shndxes_.clear();
1146 // Output_data_got::Got_entry methods.
1148 // Write out the entry.
1150 template<int size, bool big_endian>
1151 void
1152 Output_data_got<size, big_endian>::Got_entry::write(unsigned char* pov) const
1154 Valtype val = 0;
1156 switch (this->local_sym_index_)
1158 case GSYM_CODE:
1160 // If the symbol is resolved locally, we need to write out the
1161 // link-time value, which will be relocated dynamically by a
1162 // RELATIVE relocation.
1163 Symbol* gsym = this->u_.gsym;
1164 Sized_symbol<size>* sgsym;
1165 // This cast is a bit ugly. We don't want to put a
1166 // virtual method in Symbol, because we want Symbol to be
1167 // as small as possible.
1168 sgsym = static_cast<Sized_symbol<size>*>(gsym);
1169 val = sgsym->value();
1171 break;
1173 case CONSTANT_CODE:
1174 val = this->u_.constant;
1175 break;
1177 default:
1179 const unsigned int lsi = this->local_sym_index_;
1180 const Symbol_value<size>* symval = this->u_.object->local_symbol(lsi);
1181 val = symval->value(this->u_.object, 0);
1183 break;
1186 elfcpp::Swap<size, big_endian>::writeval(pov, val);
1189 // Output_data_got methods.
1191 // Add an entry for a global symbol to the GOT. This returns true if
1192 // this is a new GOT entry, false if the symbol already had a GOT
1193 // entry.
1195 template<int size, bool big_endian>
1196 bool
1197 Output_data_got<size, big_endian>::add_global(
1198 Symbol* gsym,
1199 unsigned int got_type)
1201 if (gsym->has_got_offset(got_type))
1202 return false;
1204 this->entries_.push_back(Got_entry(gsym));
1205 this->set_got_size();
1206 gsym->set_got_offset(got_type, this->last_got_offset());
1207 return true;
1210 // Add an entry for a global symbol to the GOT, and add a dynamic
1211 // relocation of type R_TYPE for the GOT entry.
1212 template<int size, bool big_endian>
1213 void
1214 Output_data_got<size, big_endian>::add_global_with_rel(
1215 Symbol* gsym,
1216 unsigned int got_type,
1217 Rel_dyn* rel_dyn,
1218 unsigned int r_type)
1220 if (gsym->has_got_offset(got_type))
1221 return;
1223 this->entries_.push_back(Got_entry());
1224 this->set_got_size();
1225 unsigned int got_offset = this->last_got_offset();
1226 gsym->set_got_offset(got_type, got_offset);
1227 rel_dyn->add_global(gsym, r_type, this, got_offset);
1230 template<int size, bool big_endian>
1231 void
1232 Output_data_got<size, big_endian>::add_global_with_rela(
1233 Symbol* gsym,
1234 unsigned int got_type,
1235 Rela_dyn* rela_dyn,
1236 unsigned int r_type)
1238 if (gsym->has_got_offset(got_type))
1239 return;
1241 this->entries_.push_back(Got_entry());
1242 this->set_got_size();
1243 unsigned int got_offset = this->last_got_offset();
1244 gsym->set_got_offset(got_type, got_offset);
1245 rela_dyn->add_global(gsym, r_type, this, got_offset, 0);
1248 // Add a pair of entries for a global symbol to the GOT, and add
1249 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1250 // If R_TYPE_2 == 0, add the second entry with no relocation.
1251 template<int size, bool big_endian>
1252 void
1253 Output_data_got<size, big_endian>::add_global_pair_with_rel(
1254 Symbol* gsym,
1255 unsigned int got_type,
1256 Rel_dyn* rel_dyn,
1257 unsigned int r_type_1,
1258 unsigned int r_type_2)
1260 if (gsym->has_got_offset(got_type))
1261 return;
1263 this->entries_.push_back(Got_entry());
1264 unsigned int got_offset = this->last_got_offset();
1265 gsym->set_got_offset(got_type, got_offset);
1266 rel_dyn->add_global(gsym, r_type_1, this, got_offset);
1268 this->entries_.push_back(Got_entry());
1269 if (r_type_2 != 0)
1271 got_offset = this->last_got_offset();
1272 rel_dyn->add_global(gsym, r_type_2, this, got_offset);
1275 this->set_got_size();
1278 template<int size, bool big_endian>
1279 void
1280 Output_data_got<size, big_endian>::add_global_pair_with_rela(
1281 Symbol* gsym,
1282 unsigned int got_type,
1283 Rela_dyn* rela_dyn,
1284 unsigned int r_type_1,
1285 unsigned int r_type_2)
1287 if (gsym->has_got_offset(got_type))
1288 return;
1290 this->entries_.push_back(Got_entry());
1291 unsigned int got_offset = this->last_got_offset();
1292 gsym->set_got_offset(got_type, got_offset);
1293 rela_dyn->add_global(gsym, r_type_1, this, got_offset, 0);
1295 this->entries_.push_back(Got_entry());
1296 if (r_type_2 != 0)
1298 got_offset = this->last_got_offset();
1299 rela_dyn->add_global(gsym, r_type_2, this, got_offset, 0);
1302 this->set_got_size();
1305 // Add an entry for a local symbol to the GOT. This returns true if
1306 // this is a new GOT entry, false if the symbol already has a GOT
1307 // entry.
1309 template<int size, bool big_endian>
1310 bool
1311 Output_data_got<size, big_endian>::add_local(
1312 Sized_relobj<size, big_endian>* object,
1313 unsigned int symndx,
1314 unsigned int got_type)
1316 if (object->local_has_got_offset(symndx, got_type))
1317 return false;
1319 this->entries_.push_back(Got_entry(object, symndx));
1320 this->set_got_size();
1321 object->set_local_got_offset(symndx, got_type, this->last_got_offset());
1322 return true;
1325 // Add an entry for a local symbol to the GOT, and add a dynamic
1326 // relocation of type R_TYPE for the GOT entry.
1327 template<int size, bool big_endian>
1328 void
1329 Output_data_got<size, big_endian>::add_local_with_rel(
1330 Sized_relobj<size, big_endian>* object,
1331 unsigned int symndx,
1332 unsigned int got_type,
1333 Rel_dyn* rel_dyn,
1334 unsigned int r_type)
1336 if (object->local_has_got_offset(symndx, got_type))
1337 return;
1339 this->entries_.push_back(Got_entry());
1340 this->set_got_size();
1341 unsigned int got_offset = this->last_got_offset();
1342 object->set_local_got_offset(symndx, got_type, got_offset);
1343 rel_dyn->add_local(object, symndx, r_type, this, got_offset);
1346 template<int size, bool big_endian>
1347 void
1348 Output_data_got<size, big_endian>::add_local_with_rela(
1349 Sized_relobj<size, big_endian>* object,
1350 unsigned int symndx,
1351 unsigned int got_type,
1352 Rela_dyn* rela_dyn,
1353 unsigned int r_type)
1355 if (object->local_has_got_offset(symndx, got_type))
1356 return;
1358 this->entries_.push_back(Got_entry());
1359 this->set_got_size();
1360 unsigned int got_offset = this->last_got_offset();
1361 object->set_local_got_offset(symndx, got_type, got_offset);
1362 rela_dyn->add_local(object, symndx, r_type, this, got_offset, 0);
1365 // Add a pair of entries for a local symbol to the GOT, and add
1366 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1367 // If R_TYPE_2 == 0, add the second entry with no relocation.
1368 template<int size, bool big_endian>
1369 void
1370 Output_data_got<size, big_endian>::add_local_pair_with_rel(
1371 Sized_relobj<size, big_endian>* object,
1372 unsigned int symndx,
1373 unsigned int shndx,
1374 unsigned int got_type,
1375 Rel_dyn* rel_dyn,
1376 unsigned int r_type_1,
1377 unsigned int r_type_2)
1379 if (object->local_has_got_offset(symndx, got_type))
1380 return;
1382 this->entries_.push_back(Got_entry());
1383 unsigned int got_offset = this->last_got_offset();
1384 object->set_local_got_offset(symndx, got_type, got_offset);
1385 Output_section* os = object->output_section(shndx);
1386 rel_dyn->add_output_section(os, r_type_1, this, got_offset);
1388 this->entries_.push_back(Got_entry(object, symndx));
1389 if (r_type_2 != 0)
1391 got_offset = this->last_got_offset();
1392 rel_dyn->add_output_section(os, r_type_2, this, got_offset);
1395 this->set_got_size();
1398 template<int size, bool big_endian>
1399 void
1400 Output_data_got<size, big_endian>::add_local_pair_with_rela(
1401 Sized_relobj<size, big_endian>* object,
1402 unsigned int symndx,
1403 unsigned int shndx,
1404 unsigned int got_type,
1405 Rela_dyn* rela_dyn,
1406 unsigned int r_type_1,
1407 unsigned int r_type_2)
1409 if (object->local_has_got_offset(symndx, got_type))
1410 return;
1412 this->entries_.push_back(Got_entry());
1413 unsigned int got_offset = this->last_got_offset();
1414 object->set_local_got_offset(symndx, got_type, got_offset);
1415 Output_section* os = object->output_section(shndx);
1416 rela_dyn->add_output_section(os, r_type_1, this, got_offset, 0);
1418 this->entries_.push_back(Got_entry(object, symndx));
1419 if (r_type_2 != 0)
1421 got_offset = this->last_got_offset();
1422 rela_dyn->add_output_section(os, r_type_2, this, got_offset, 0);
1425 this->set_got_size();
1428 // Write out the GOT.
1430 template<int size, bool big_endian>
1431 void
1432 Output_data_got<size, big_endian>::do_write(Output_file* of)
1434 const int add = size / 8;
1436 const off_t off = this->offset();
1437 const off_t oview_size = this->data_size();
1438 unsigned char* const oview = of->get_output_view(off, oview_size);
1440 unsigned char* pov = oview;
1441 for (typename Got_entries::const_iterator p = this->entries_.begin();
1442 p != this->entries_.end();
1443 ++p)
1445 p->write(pov);
1446 pov += add;
1449 gold_assert(pov - oview == oview_size);
1451 of->write_output_view(off, oview_size, oview);
1453 // We no longer need the GOT entries.
1454 this->entries_.clear();
1457 // Output_data_dynamic::Dynamic_entry methods.
1459 // Write out the entry.
1461 template<int size, bool big_endian>
1462 void
1463 Output_data_dynamic::Dynamic_entry::write(
1464 unsigned char* pov,
1465 const Stringpool* pool) const
1467 typename elfcpp::Elf_types<size>::Elf_WXword val;
1468 switch (this->offset_)
1470 case DYNAMIC_NUMBER:
1471 val = this->u_.val;
1472 break;
1474 case DYNAMIC_SECTION_SIZE:
1475 val = this->u_.od->data_size();
1476 break;
1478 case DYNAMIC_SYMBOL:
1480 const Sized_symbol<size>* s =
1481 static_cast<const Sized_symbol<size>*>(this->u_.sym);
1482 val = s->value();
1484 break;
1486 case DYNAMIC_STRING:
1487 val = pool->get_offset(this->u_.str);
1488 break;
1490 default:
1491 val = this->u_.od->address() + this->offset_;
1492 break;
1495 elfcpp::Dyn_write<size, big_endian> dw(pov);
1496 dw.put_d_tag(this->tag_);
1497 dw.put_d_val(val);
1500 // Output_data_dynamic methods.
1502 // Adjust the output section to set the entry size.
1504 void
1505 Output_data_dynamic::do_adjust_output_section(Output_section* os)
1507 if (parameters->target().get_size() == 32)
1508 os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
1509 else if (parameters->target().get_size() == 64)
1510 os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
1511 else
1512 gold_unreachable();
1515 // Set the final data size.
1517 void
1518 Output_data_dynamic::set_final_data_size()
1520 // Add the terminating entry if it hasn't been added.
1521 // Because of relaxation, we can run this multiple times.
1522 if (this->entries_.empty()
1523 || this->entries_.rbegin()->tag() != elfcpp::DT_NULL)
1524 this->add_constant(elfcpp::DT_NULL, 0);
1526 int dyn_size;
1527 if (parameters->target().get_size() == 32)
1528 dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
1529 else if (parameters->target().get_size() == 64)
1530 dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
1531 else
1532 gold_unreachable();
1533 this->set_data_size(this->entries_.size() * dyn_size);
1536 // Write out the dynamic entries.
1538 void
1539 Output_data_dynamic::do_write(Output_file* of)
1541 switch (parameters->size_and_endianness())
1543 #ifdef HAVE_TARGET_32_LITTLE
1544 case Parameters::TARGET_32_LITTLE:
1545 this->sized_write<32, false>(of);
1546 break;
1547 #endif
1548 #ifdef HAVE_TARGET_32_BIG
1549 case Parameters::TARGET_32_BIG:
1550 this->sized_write<32, true>(of);
1551 break;
1552 #endif
1553 #ifdef HAVE_TARGET_64_LITTLE
1554 case Parameters::TARGET_64_LITTLE:
1555 this->sized_write<64, false>(of);
1556 break;
1557 #endif
1558 #ifdef HAVE_TARGET_64_BIG
1559 case Parameters::TARGET_64_BIG:
1560 this->sized_write<64, true>(of);
1561 break;
1562 #endif
1563 default:
1564 gold_unreachable();
1568 template<int size, bool big_endian>
1569 void
1570 Output_data_dynamic::sized_write(Output_file* of)
1572 const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
1574 const off_t offset = this->offset();
1575 const off_t oview_size = this->data_size();
1576 unsigned char* const oview = of->get_output_view(offset, oview_size);
1578 unsigned char* pov = oview;
1579 for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
1580 p != this->entries_.end();
1581 ++p)
1583 p->write<size, big_endian>(pov, this->pool_);
1584 pov += dyn_size;
1587 gold_assert(pov - oview == oview_size);
1589 of->write_output_view(offset, oview_size, oview);
1591 // We no longer need the dynamic entries.
1592 this->entries_.clear();
1595 // Class Output_symtab_xindex.
1597 void
1598 Output_symtab_xindex::do_write(Output_file* of)
1600 const off_t offset = this->offset();
1601 const off_t oview_size = this->data_size();
1602 unsigned char* const oview = of->get_output_view(offset, oview_size);
1604 memset(oview, 0, oview_size);
1606 if (parameters->target().is_big_endian())
1607 this->endian_do_write<true>(oview);
1608 else
1609 this->endian_do_write<false>(oview);
1611 of->write_output_view(offset, oview_size, oview);
1613 // We no longer need the data.
1614 this->entries_.clear();
1617 template<bool big_endian>
1618 void
1619 Output_symtab_xindex::endian_do_write(unsigned char* const oview)
1621 for (Xindex_entries::const_iterator p = this->entries_.begin();
1622 p != this->entries_.end();
1623 ++p)
1625 unsigned int symndx = p->first;
1626 gold_assert(symndx * 4 < this->data_size());
1627 elfcpp::Swap<32, big_endian>::writeval(oview + symndx * 4, p->second);
1631 // Output_section::Input_section methods.
1633 // Return the data size. For an input section we store the size here.
1634 // For an Output_section_data, we have to ask it for the size.
1636 off_t
1637 Output_section::Input_section::data_size() const
1639 if (this->is_input_section())
1640 return this->u1_.data_size;
1641 else
1642 return this->u2_.posd->data_size();
1645 // Set the address and file offset.
1647 void
1648 Output_section::Input_section::set_address_and_file_offset(
1649 uint64_t address,
1650 off_t file_offset,
1651 off_t section_file_offset)
1653 if (this->is_input_section())
1654 this->u2_.object->set_section_offset(this->shndx_,
1655 file_offset - section_file_offset);
1656 else
1657 this->u2_.posd->set_address_and_file_offset(address, file_offset);
1660 // Reset the address and file offset.
1662 void
1663 Output_section::Input_section::reset_address_and_file_offset()
1665 if (!this->is_input_section())
1666 this->u2_.posd->reset_address_and_file_offset();
1669 // Finalize the data size.
1671 void
1672 Output_section::Input_section::finalize_data_size()
1674 if (!this->is_input_section())
1675 this->u2_.posd->finalize_data_size();
1678 // Try to turn an input offset into an output offset. We want to
1679 // return the output offset relative to the start of this
1680 // Input_section in the output section.
1682 inline bool
1683 Output_section::Input_section::output_offset(
1684 const Relobj* object,
1685 unsigned int shndx,
1686 section_offset_type offset,
1687 section_offset_type *poutput) const
1689 if (!this->is_input_section())
1690 return this->u2_.posd->output_offset(object, shndx, offset, poutput);
1691 else
1693 if (this->shndx_ != shndx || this->u2_.object != object)
1694 return false;
1695 *poutput = offset;
1696 return true;
1700 // Return whether this is the merge section for the input section
1701 // SHNDX in OBJECT.
1703 inline bool
1704 Output_section::Input_section::is_merge_section_for(const Relobj* object,
1705 unsigned int shndx) const
1707 if (this->is_input_section())
1708 return false;
1709 return this->u2_.posd->is_merge_section_for(object, shndx);
1712 // Write out the data. We don't have to do anything for an input
1713 // section--they are handled via Object::relocate--but this is where
1714 // we write out the data for an Output_section_data.
1716 void
1717 Output_section::Input_section::write(Output_file* of)
1719 if (!this->is_input_section())
1720 this->u2_.posd->write(of);
1723 // Write the data to a buffer. As for write(), we don't have to do
1724 // anything for an input section.
1726 void
1727 Output_section::Input_section::write_to_buffer(unsigned char* buffer)
1729 if (!this->is_input_section())
1730 this->u2_.posd->write_to_buffer(buffer);
1733 // Print to a map file.
1735 void
1736 Output_section::Input_section::print_to_mapfile(Mapfile* mapfile) const
1738 switch (this->shndx_)
1740 case OUTPUT_SECTION_CODE:
1741 case MERGE_DATA_SECTION_CODE:
1742 case MERGE_STRING_SECTION_CODE:
1743 this->u2_.posd->print_to_mapfile(mapfile);
1744 break;
1746 case RELAXED_INPUT_SECTION_CODE:
1748 Output_relaxed_input_section* relaxed_section =
1749 this->relaxed_input_section();
1750 mapfile->print_input_section(relaxed_section->relobj(),
1751 relaxed_section->shndx());
1753 break;
1754 default:
1755 mapfile->print_input_section(this->u2_.object, this->shndx_);
1756 break;
1760 // Output_section methods.
1762 // Construct an Output_section. NAME will point into a Stringpool.
1764 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
1765 elfcpp::Elf_Xword flags)
1766 : name_(name),
1767 addralign_(0),
1768 entsize_(0),
1769 load_address_(0),
1770 link_section_(NULL),
1771 link_(0),
1772 info_section_(NULL),
1773 info_symndx_(NULL),
1774 info_(0),
1775 type_(type),
1776 flags_(flags),
1777 out_shndx_(-1U),
1778 symtab_index_(0),
1779 dynsym_index_(0),
1780 input_sections_(),
1781 first_input_offset_(0),
1782 fills_(),
1783 postprocessing_buffer_(NULL),
1784 needs_symtab_index_(false),
1785 needs_dynsym_index_(false),
1786 should_link_to_symtab_(false),
1787 should_link_to_dynsym_(false),
1788 after_input_sections_(false),
1789 requires_postprocessing_(false),
1790 found_in_sections_clause_(false),
1791 has_load_address_(false),
1792 info_uses_section_index_(false),
1793 may_sort_attached_input_sections_(false),
1794 must_sort_attached_input_sections_(false),
1795 attached_input_sections_are_sorted_(false),
1796 is_relro_(false),
1797 is_relro_local_(false),
1798 is_last_relro_(false),
1799 is_first_non_relro_(false),
1800 is_small_section_(false),
1801 is_large_section_(false),
1802 is_interp_(false),
1803 is_dynamic_linker_section_(false),
1804 generate_code_fills_at_write_(false),
1805 is_entsize_zero_(false),
1806 tls_offset_(0),
1807 checkpoint_(NULL),
1808 merge_section_map_(),
1809 merge_section_by_properties_map_(),
1810 relaxed_input_section_map_(),
1811 is_relaxed_input_section_map_valid_(true)
1813 // An unallocated section has no address. Forcing this means that
1814 // we don't need special treatment for symbols defined in debug
1815 // sections.
1816 if ((flags & elfcpp::SHF_ALLOC) == 0)
1817 this->set_address(0);
1820 Output_section::~Output_section()
1822 delete this->checkpoint_;
1825 // Set the entry size.
1827 void
1828 Output_section::set_entsize(uint64_t v)
1830 if (this->is_entsize_zero_)
1832 else if (this->entsize_ == 0)
1833 this->entsize_ = v;
1834 else if (this->entsize_ != v)
1836 this->entsize_ = 0;
1837 this->is_entsize_zero_ = 1;
1841 // Add the input section SHNDX, with header SHDR, named SECNAME, in
1842 // OBJECT, to the Output_section. RELOC_SHNDX is the index of a
1843 // relocation section which applies to this section, or 0 if none, or
1844 // -1U if more than one. Return the offset of the input section
1845 // within the output section. Return -1 if the input section will
1846 // receive special handling. In the normal case we don't always keep
1847 // track of input sections for an Output_section. Instead, each
1848 // Object keeps track of the Output_section for each of its input
1849 // sections. However, if HAVE_SECTIONS_SCRIPT is true, we do keep
1850 // track of input sections here; this is used when SECTIONS appears in
1851 // a linker script.
1853 template<int size, bool big_endian>
1854 off_t
1855 Output_section::add_input_section(Sized_relobj<size, big_endian>* object,
1856 unsigned int shndx,
1857 const char* secname,
1858 const elfcpp::Shdr<size, big_endian>& shdr,
1859 unsigned int reloc_shndx,
1860 bool have_sections_script)
1862 elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
1863 if ((addralign & (addralign - 1)) != 0)
1865 object->error(_("invalid alignment %lu for section \"%s\""),
1866 static_cast<unsigned long>(addralign), secname);
1867 addralign = 1;
1870 if (addralign > this->addralign_)
1871 this->addralign_ = addralign;
1873 typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
1874 uint64_t entsize = shdr.get_sh_entsize();
1876 // .debug_str is a mergeable string section, but is not always so
1877 // marked by compilers. Mark manually here so we can optimize.
1878 if (strcmp(secname, ".debug_str") == 0)
1880 sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS);
1881 entsize = 1;
1884 this->update_flags_for_input_section(sh_flags);
1885 this->set_entsize(entsize);
1887 // If this is a SHF_MERGE section, we pass all the input sections to
1888 // a Output_data_merge. We don't try to handle relocations for such
1889 // a section. We don't try to handle empty merge sections--they
1890 // mess up the mappings, and are useless anyhow.
1891 if ((sh_flags & elfcpp::SHF_MERGE) != 0
1892 && reloc_shndx == 0
1893 && shdr.get_sh_size() > 0)
1895 if (this->add_merge_input_section(object, shndx, sh_flags,
1896 entsize, addralign))
1898 // Tell the relocation routines that they need to call the
1899 // output_offset method to determine the final address.
1900 return -1;
1904 off_t offset_in_section = this->current_data_size_for_child();
1905 off_t aligned_offset_in_section = align_address(offset_in_section,
1906 addralign);
1908 // Determine if we want to delay code-fill generation until the output
1909 // section is written. When the target is relaxing, we want to delay fill
1910 // generating to avoid adjusting them during relaxation.
1911 if (!this->generate_code_fills_at_write_
1912 && !have_sections_script
1913 && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
1914 && parameters->target().has_code_fill()
1915 && parameters->target().may_relax())
1917 gold_assert(this->fills_.empty());
1918 this->generate_code_fills_at_write_ = true;
1921 if (aligned_offset_in_section > offset_in_section
1922 && !this->generate_code_fills_at_write_
1923 && !have_sections_script
1924 && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
1925 && parameters->target().has_code_fill())
1927 // We need to add some fill data. Using fill_list_ when
1928 // possible is an optimization, since we will often have fill
1929 // sections without input sections.
1930 off_t fill_len = aligned_offset_in_section - offset_in_section;
1931 if (this->input_sections_.empty())
1932 this->fills_.push_back(Fill(offset_in_section, fill_len));
1933 else
1935 std::string fill_data(parameters->target().code_fill(fill_len));
1936 Output_data_const* odc = new Output_data_const(fill_data, 1);
1937 this->input_sections_.push_back(Input_section(odc));
1941 this->set_current_data_size_for_child(aligned_offset_in_section
1942 + shdr.get_sh_size());
1944 // We need to keep track of this section if we are already keeping
1945 // track of sections, or if we are relaxing. Also, if this is a
1946 // section which requires sorting, or which may require sorting in
1947 // the future, we keep track of the sections.
1948 if (have_sections_script
1949 || !this->input_sections_.empty()
1950 || this->may_sort_attached_input_sections()
1951 || this->must_sort_attached_input_sections()
1952 || parameters->options().user_set_Map()
1953 || parameters->target().may_relax())
1954 this->input_sections_.push_back(Input_section(object, shndx,
1955 shdr.get_sh_size(),
1956 addralign));
1958 return aligned_offset_in_section;
1961 // Add arbitrary data to an output section.
1963 void
1964 Output_section::add_output_section_data(Output_section_data* posd)
1966 Input_section inp(posd);
1967 this->add_output_section_data(&inp);
1969 if (posd->is_data_size_valid())
1971 off_t offset_in_section = this->current_data_size_for_child();
1972 off_t aligned_offset_in_section = align_address(offset_in_section,
1973 posd->addralign());
1974 this->set_current_data_size_for_child(aligned_offset_in_section
1975 + posd->data_size());
1979 // Add a relaxed input section.
1981 void
1982 Output_section::add_relaxed_input_section(Output_relaxed_input_section* poris)
1984 Input_section inp(poris);
1985 this->add_output_section_data(&inp);
1986 if (this->is_relaxed_input_section_map_valid_)
1988 Input_section_specifier iss(poris->relobj(), poris->shndx());
1989 this->relaxed_input_section_map_[iss] = poris;
1992 // For a relaxed section, we use the current data size. Linker scripts
1993 // get all the input sections, including relaxed one from an output
1994 // section and add them back to them same output section to compute the
1995 // output section size. If we do not account for sizes of relaxed input
1996 // sections, an output section would be incorrectly sized.
1997 off_t offset_in_section = this->current_data_size_for_child();
1998 off_t aligned_offset_in_section = align_address(offset_in_section,
1999 poris->addralign());
2000 this->set_current_data_size_for_child(aligned_offset_in_section
2001 + poris->current_data_size());
2004 // Add arbitrary data to an output section by Input_section.
2006 void
2007 Output_section::add_output_section_data(Input_section* inp)
2009 if (this->input_sections_.empty())
2010 this->first_input_offset_ = this->current_data_size_for_child();
2012 this->input_sections_.push_back(*inp);
2014 uint64_t addralign = inp->addralign();
2015 if (addralign > this->addralign_)
2016 this->addralign_ = addralign;
2018 inp->set_output_section(this);
2021 // Add a merge section to an output section.
2023 void
2024 Output_section::add_output_merge_section(Output_section_data* posd,
2025 bool is_string, uint64_t entsize)
2027 Input_section inp(posd, is_string, entsize);
2028 this->add_output_section_data(&inp);
2031 // Add an input section to a SHF_MERGE section.
2033 bool
2034 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
2035 uint64_t flags, uint64_t entsize,
2036 uint64_t addralign)
2038 bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
2040 // We only merge strings if the alignment is not more than the
2041 // character size. This could be handled, but it's unusual.
2042 if (is_string && addralign > entsize)
2043 return false;
2045 // We cannot restore merged input section states.
2046 gold_assert(this->checkpoint_ == NULL);
2048 // Look up merge sections by required properties.
2049 Merge_section_properties msp(is_string, entsize, addralign);
2050 Merge_section_by_properties_map::const_iterator p =
2051 this->merge_section_by_properties_map_.find(msp);
2052 if (p != this->merge_section_by_properties_map_.end())
2054 Output_merge_base* merge_section = p->second;
2055 merge_section->add_input_section(object, shndx);
2056 gold_assert(merge_section->is_string() == is_string
2057 && merge_section->entsize() == entsize
2058 && merge_section->addralign() == addralign);
2060 // Link input section to found merge section.
2061 Input_section_specifier iss(object, shndx);
2062 this->merge_section_map_[iss] = merge_section;
2063 return true;
2066 // We handle the actual constant merging in Output_merge_data or
2067 // Output_merge_string_data.
2068 Output_merge_base* pomb;
2069 if (!is_string)
2070 pomb = new Output_merge_data(entsize, addralign);
2071 else
2073 switch (entsize)
2075 case 1:
2076 pomb = new Output_merge_string<char>(addralign);
2077 break;
2078 case 2:
2079 pomb = new Output_merge_string<uint16_t>(addralign);
2080 break;
2081 case 4:
2082 pomb = new Output_merge_string<uint32_t>(addralign);
2083 break;
2084 default:
2085 return false;
2089 // Add new merge section to this output section and link merge section
2090 // properties to new merge section in map.
2091 this->add_output_merge_section(pomb, is_string, entsize);
2092 this->merge_section_by_properties_map_[msp] = pomb;
2094 // Add input section to new merge section and link input section to new
2095 // merge section in map.
2096 pomb->add_input_section(object, shndx);
2097 Input_section_specifier iss(object, shndx);
2098 this->merge_section_map_[iss] = pomb;
2100 return true;
2103 // Build a relaxation map to speed up relaxation of existing input sections.
2104 // Look up to the first LIMIT elements in INPUT_SECTIONS.
2106 void
2107 Output_section::build_relaxation_map(
2108 const Input_section_list& input_sections,
2109 size_t limit,
2110 Relaxation_map* relaxation_map) const
2112 for (size_t i = 0; i < limit; ++i)
2114 const Input_section& is(input_sections[i]);
2115 if (is.is_input_section() || is.is_relaxed_input_section())
2117 Input_section_specifier iss(is.relobj(), is.shndx());
2118 (*relaxation_map)[iss] = i;
2123 // Convert regular input sections in INPUT_SECTIONS into relaxed input
2124 // sections in RELAXED_SECTIONS. MAP is a prebuilt map from input section
2125 // specifier to indices of INPUT_SECTIONS.
2127 void
2128 Output_section::convert_input_sections_in_list_to_relaxed_sections(
2129 const std::vector<Output_relaxed_input_section*>& relaxed_sections,
2130 const Relaxation_map& map,
2131 Input_section_list* input_sections)
2133 for (size_t i = 0; i < relaxed_sections.size(); ++i)
2135 Output_relaxed_input_section* poris = relaxed_sections[i];
2136 Input_section_specifier iss(poris->relobj(), poris->shndx());
2137 Relaxation_map::const_iterator p = map.find(iss);
2138 gold_assert(p != map.end());
2139 gold_assert((*input_sections)[p->second].is_input_section());
2140 (*input_sections)[p->second] = Input_section(poris);
2144 // Convert regular input sections into relaxed input sections. RELAXED_SECTIONS
2145 // is a vector of pointers to Output_relaxed_input_section or its derived
2146 // classes. The relaxed sections must correspond to existing input sections.
2148 void
2149 Output_section::convert_input_sections_to_relaxed_sections(
2150 const std::vector<Output_relaxed_input_section*>& relaxed_sections)
2152 gold_assert(parameters->target().may_relax());
2154 // We want to make sure that restore_states does not undo the effect of
2155 // this. If there is no checkpoint active, just search the current
2156 // input section list and replace the sections there. If there is
2157 // a checkpoint, also replace the sections there.
2159 // By default, we look at the whole list.
2160 size_t limit = this->input_sections_.size();
2162 if (this->checkpoint_ != NULL)
2164 // Replace input sections with relaxed input section in the saved
2165 // copy of the input section list.
2166 if (this->checkpoint_->input_sections_saved())
2168 Relaxation_map map;
2169 this->build_relaxation_map(
2170 *(this->checkpoint_->input_sections()),
2171 this->checkpoint_->input_sections()->size(),
2172 &map);
2173 this->convert_input_sections_in_list_to_relaxed_sections(
2174 relaxed_sections,
2175 map,
2176 this->checkpoint_->input_sections());
2178 else
2180 // We have not copied the input section list yet. Instead, just
2181 // look at the portion that would be saved.
2182 limit = this->checkpoint_->input_sections_size();
2186 // Convert input sections in input_section_list.
2187 Relaxation_map map;
2188 this->build_relaxation_map(this->input_sections_, limit, &map);
2189 this->convert_input_sections_in_list_to_relaxed_sections(
2190 relaxed_sections,
2191 map,
2192 &this->input_sections_);
2195 // Update the output section flags based on input section flags.
2197 void
2198 Output_section::update_flags_for_input_section(elfcpp::Elf_Xword flags)
2200 // If we created the section with SHF_ALLOC clear, we set the
2201 // address. If we are now setting the SHF_ALLOC flag, we need to
2202 // undo that.
2203 if ((this->flags_ & elfcpp::SHF_ALLOC) == 0
2204 && (flags & elfcpp::SHF_ALLOC) != 0)
2205 this->mark_address_invalid();
2207 this->flags_ |= (flags
2208 & (elfcpp::SHF_WRITE
2209 | elfcpp::SHF_ALLOC
2210 | elfcpp::SHF_EXECINSTR));
2212 if ((flags & elfcpp::SHF_MERGE) == 0)
2213 this->flags_ &=~ elfcpp::SHF_MERGE;
2214 else
2216 if (this->current_data_size_for_child() == 0)
2217 this->flags_ |= elfcpp::SHF_MERGE;
2220 if ((flags & elfcpp::SHF_STRINGS) == 0)
2221 this->flags_ &=~ elfcpp::SHF_STRINGS;
2222 else
2224 if (this->current_data_size_for_child() == 0)
2225 this->flags_ |= elfcpp::SHF_STRINGS;
2229 // Find the merge section into which an input section with index SHNDX in
2230 // OBJECT has been added. Return NULL if none found.
2232 Output_section_data*
2233 Output_section::find_merge_section(const Relobj* object,
2234 unsigned int shndx) const
2236 Input_section_specifier iss(object, shndx);
2237 Output_section_data_by_input_section_map::const_iterator p =
2238 this->merge_section_map_.find(iss);
2239 if (p != this->merge_section_map_.end())
2241 Output_section_data* posd = p->second;
2242 gold_assert(posd->is_merge_section_for(object, shndx));
2243 return posd;
2245 else
2246 return NULL;
2249 // Find an relaxed input section corresponding to an input section
2250 // in OBJECT with index SHNDX.
2252 const Output_relaxed_input_section*
2253 Output_section::find_relaxed_input_section(const Relobj* object,
2254 unsigned int shndx) const
2256 // Be careful that the map may not be valid due to input section export
2257 // to scripts or a check-point restore.
2258 if (!this->is_relaxed_input_section_map_valid_)
2260 // Rebuild the map as needed.
2261 this->relaxed_input_section_map_.clear();
2262 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2263 p != this->input_sections_.end();
2264 ++p)
2265 if (p->is_relaxed_input_section())
2267 Input_section_specifier iss(p->relobj(), p->shndx());
2268 this->relaxed_input_section_map_[iss] =
2269 p->relaxed_input_section();
2271 this->is_relaxed_input_section_map_valid_ = true;
2274 Input_section_specifier iss(object, shndx);
2275 Output_relaxed_input_section_by_input_section_map::const_iterator p =
2276 this->relaxed_input_section_map_.find(iss);
2277 if (p != this->relaxed_input_section_map_.end())
2278 return p->second;
2279 else
2280 return NULL;
2283 // Given an address OFFSET relative to the start of input section
2284 // SHNDX in OBJECT, return whether this address is being included in
2285 // the final link. This should only be called if SHNDX in OBJECT has
2286 // a special mapping.
2288 bool
2289 Output_section::is_input_address_mapped(const Relobj* object,
2290 unsigned int shndx,
2291 off_t offset) const
2293 // Look at the Output_section_data_maps first.
2294 const Output_section_data* posd = this->find_merge_section(object, shndx);
2295 if (posd == NULL)
2296 posd = this->find_relaxed_input_section(object, shndx);
2298 if (posd != NULL)
2300 section_offset_type output_offset;
2301 bool found = posd->output_offset(object, shndx, offset, &output_offset);
2302 gold_assert(found);
2303 return output_offset != -1;
2306 // Fall back to the slow look-up.
2307 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2308 p != this->input_sections_.end();
2309 ++p)
2311 section_offset_type output_offset;
2312 if (p->output_offset(object, shndx, offset, &output_offset))
2313 return output_offset != -1;
2316 // By default we assume that the address is mapped. This should
2317 // only be called after we have passed all sections to Layout. At
2318 // that point we should know what we are discarding.
2319 return true;
2322 // Given an address OFFSET relative to the start of input section
2323 // SHNDX in object OBJECT, return the output offset relative to the
2324 // start of the input section in the output section. This should only
2325 // be called if SHNDX in OBJECT has a special mapping.
2327 section_offset_type
2328 Output_section::output_offset(const Relobj* object, unsigned int shndx,
2329 section_offset_type offset) const
2331 // This can only be called meaningfully when we know the data size
2332 // of this.
2333 gold_assert(this->is_data_size_valid());
2335 // Look at the Output_section_data_maps first.
2336 const Output_section_data* posd = this->find_merge_section(object, shndx);
2337 if (posd == NULL)
2338 posd = this->find_relaxed_input_section(object, shndx);
2339 if (posd != NULL)
2341 section_offset_type output_offset;
2342 bool found = posd->output_offset(object, shndx, offset, &output_offset);
2343 gold_assert(found);
2344 return output_offset;
2347 // Fall back to the slow look-up.
2348 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2349 p != this->input_sections_.end();
2350 ++p)
2352 section_offset_type output_offset;
2353 if (p->output_offset(object, shndx, offset, &output_offset))
2354 return output_offset;
2356 gold_unreachable();
2359 // Return the output virtual address of OFFSET relative to the start
2360 // of input section SHNDX in object OBJECT.
2362 uint64_t
2363 Output_section::output_address(const Relobj* object, unsigned int shndx,
2364 off_t offset) const
2366 uint64_t addr = this->address() + this->first_input_offset_;
2368 // Look at the Output_section_data_maps first.
2369 const Output_section_data* posd = this->find_merge_section(object, shndx);
2370 if (posd == NULL)
2371 posd = this->find_relaxed_input_section(object, shndx);
2372 if (posd != NULL && posd->is_address_valid())
2374 section_offset_type output_offset;
2375 bool found = posd->output_offset(object, shndx, offset, &output_offset);
2376 gold_assert(found);
2377 return posd->address() + output_offset;
2380 // Fall back to the slow look-up.
2381 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2382 p != this->input_sections_.end();
2383 ++p)
2385 addr = align_address(addr, p->addralign());
2386 section_offset_type output_offset;
2387 if (p->output_offset(object, shndx, offset, &output_offset))
2389 if (output_offset == -1)
2390 return -1ULL;
2391 return addr + output_offset;
2393 addr += p->data_size();
2396 // If we get here, it means that we don't know the mapping for this
2397 // input section. This might happen in principle if
2398 // add_input_section were called before add_output_section_data.
2399 // But it should never actually happen.
2401 gold_unreachable();
2404 // Find the output address of the start of the merged section for
2405 // input section SHNDX in object OBJECT.
2407 bool
2408 Output_section::find_starting_output_address(const Relobj* object,
2409 unsigned int shndx,
2410 uint64_t* paddr) const
2412 // FIXME: This becomes a bottle-neck if we have many relaxed sections.
2413 // Looking up the merge section map does not always work as we sometimes
2414 // find a merge section without its address set.
2415 uint64_t addr = this->address() + this->first_input_offset_;
2416 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2417 p != this->input_sections_.end();
2418 ++p)
2420 addr = align_address(addr, p->addralign());
2422 // It would be nice if we could use the existing output_offset
2423 // method to get the output offset of input offset 0.
2424 // Unfortunately we don't know for sure that input offset 0 is
2425 // mapped at all.
2426 if (p->is_merge_section_for(object, shndx))
2428 *paddr = addr;
2429 return true;
2432 addr += p->data_size();
2435 // We couldn't find a merge output section for this input section.
2436 return false;
2439 // Set the data size of an Output_section. This is where we handle
2440 // setting the addresses of any Output_section_data objects.
2442 void
2443 Output_section::set_final_data_size()
2445 if (this->input_sections_.empty())
2447 this->set_data_size(this->current_data_size_for_child());
2448 return;
2451 if (this->must_sort_attached_input_sections())
2452 this->sort_attached_input_sections();
2454 uint64_t address = this->address();
2455 off_t startoff = this->offset();
2456 off_t off = startoff + this->first_input_offset_;
2457 for (Input_section_list::iterator p = this->input_sections_.begin();
2458 p != this->input_sections_.end();
2459 ++p)
2461 off = align_address(off, p->addralign());
2462 p->set_address_and_file_offset(address + (off - startoff), off,
2463 startoff);
2464 off += p->data_size();
2467 this->set_data_size(off - startoff);
2470 // Reset the address and file offset.
2472 void
2473 Output_section::do_reset_address_and_file_offset()
2475 // An unallocated section has no address. Forcing this means that
2476 // we don't need special treatment for symbols defined in debug
2477 // sections. We do the same in the constructor.
2478 if ((this->flags_ & elfcpp::SHF_ALLOC) == 0)
2479 this->set_address(0);
2481 for (Input_section_list::iterator p = this->input_sections_.begin();
2482 p != this->input_sections_.end();
2483 ++p)
2484 p->reset_address_and_file_offset();
2487 // Return true if address and file offset have the values after reset.
2489 bool
2490 Output_section::do_address_and_file_offset_have_reset_values() const
2492 if (this->is_offset_valid())
2493 return false;
2495 // An unallocated section has address 0 after its construction or a reset.
2496 if ((this->flags_ & elfcpp::SHF_ALLOC) == 0)
2497 return this->is_address_valid() && this->address() == 0;
2498 else
2499 return !this->is_address_valid();
2502 // Set the TLS offset. Called only for SHT_TLS sections.
2504 void
2505 Output_section::do_set_tls_offset(uint64_t tls_base)
2507 this->tls_offset_ = this->address() - tls_base;
2510 // In a few cases we need to sort the input sections attached to an
2511 // output section. This is used to implement the type of constructor
2512 // priority ordering implemented by the GNU linker, in which the
2513 // priority becomes part of the section name and the sections are
2514 // sorted by name. We only do this for an output section if we see an
2515 // attached input section matching ".ctor.*", ".dtor.*",
2516 // ".init_array.*" or ".fini_array.*".
2518 class Output_section::Input_section_sort_entry
2520 public:
2521 Input_section_sort_entry()
2522 : input_section_(), index_(-1U), section_has_name_(false),
2523 section_name_()
2526 Input_section_sort_entry(const Input_section& input_section,
2527 unsigned int index)
2528 : input_section_(input_section), index_(index),
2529 section_has_name_(input_section.is_input_section()
2530 || input_section.is_relaxed_input_section())
2532 if (this->section_has_name_)
2534 // This is only called single-threaded from Layout::finalize,
2535 // so it is OK to lock. Unfortunately we have no way to pass
2536 // in a Task token.
2537 const Task* dummy_task = reinterpret_cast<const Task*>(-1);
2538 Object* obj = (input_section.is_input_section()
2539 ? input_section.relobj()
2540 : input_section.relaxed_input_section()->relobj());
2541 Task_lock_obj<Object> tl(dummy_task, obj);
2543 // This is a slow operation, which should be cached in
2544 // Layout::layout if this becomes a speed problem.
2545 this->section_name_ = obj->section_name(input_section.shndx());
2549 // Return the Input_section.
2550 const Input_section&
2551 input_section() const
2553 gold_assert(this->index_ != -1U);
2554 return this->input_section_;
2557 // The index of this entry in the original list. This is used to
2558 // make the sort stable.
2559 unsigned int
2560 index() const
2562 gold_assert(this->index_ != -1U);
2563 return this->index_;
2566 // Whether there is a section name.
2567 bool
2568 section_has_name() const
2569 { return this->section_has_name_; }
2571 // The section name.
2572 const std::string&
2573 section_name() const
2575 gold_assert(this->section_has_name_);
2576 return this->section_name_;
2579 // Return true if the section name has a priority. This is assumed
2580 // to be true if it has a dot after the initial dot.
2581 bool
2582 has_priority() const
2584 gold_assert(this->section_has_name_);
2585 return this->section_name_.find('.', 1);
2588 // Return true if this an input file whose base name matches
2589 // FILE_NAME. The base name must have an extension of ".o", and
2590 // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
2591 // This is to match crtbegin.o as well as crtbeginS.o without
2592 // getting confused by other possibilities. Overall matching the
2593 // file name this way is a dreadful hack, but the GNU linker does it
2594 // in order to better support gcc, and we need to be compatible.
2595 bool
2596 match_file_name(const char* match_file_name) const
2598 const std::string& file_name(this->input_section_.relobj()->name());
2599 const char* base_name = lbasename(file_name.c_str());
2600 size_t match_len = strlen(match_file_name);
2601 if (strncmp(base_name, match_file_name, match_len) != 0)
2602 return false;
2603 size_t base_len = strlen(base_name);
2604 if (base_len != match_len + 2 && base_len != match_len + 3)
2605 return false;
2606 return memcmp(base_name + base_len - 2, ".o", 2) == 0;
2609 private:
2610 // The Input_section we are sorting.
2611 Input_section input_section_;
2612 // The index of this Input_section in the original list.
2613 unsigned int index_;
2614 // Whether this Input_section has a section name--it won't if this
2615 // is some random Output_section_data.
2616 bool section_has_name_;
2617 // The section name if there is one.
2618 std::string section_name_;
2621 // Return true if S1 should come before S2 in the output section.
2623 bool
2624 Output_section::Input_section_sort_compare::operator()(
2625 const Output_section::Input_section_sort_entry& s1,
2626 const Output_section::Input_section_sort_entry& s2) const
2628 // crtbegin.o must come first.
2629 bool s1_begin = s1.match_file_name("crtbegin");
2630 bool s2_begin = s2.match_file_name("crtbegin");
2631 if (s1_begin || s2_begin)
2633 if (!s1_begin)
2634 return false;
2635 if (!s2_begin)
2636 return true;
2637 return s1.index() < s2.index();
2640 // crtend.o must come last.
2641 bool s1_end = s1.match_file_name("crtend");
2642 bool s2_end = s2.match_file_name("crtend");
2643 if (s1_end || s2_end)
2645 if (!s1_end)
2646 return true;
2647 if (!s2_end)
2648 return false;
2649 return s1.index() < s2.index();
2652 // We sort all the sections with no names to the end.
2653 if (!s1.section_has_name() || !s2.section_has_name())
2655 if (s1.section_has_name())
2656 return true;
2657 if (s2.section_has_name())
2658 return false;
2659 return s1.index() < s2.index();
2662 // A section with a priority follows a section without a priority.
2663 // The GNU linker does this for all but .init_array sections; until
2664 // further notice we'll assume that that is an mistake.
2665 bool s1_has_priority = s1.has_priority();
2666 bool s2_has_priority = s2.has_priority();
2667 if (s1_has_priority && !s2_has_priority)
2668 return false;
2669 if (!s1_has_priority && s2_has_priority)
2670 return true;
2672 // Otherwise we sort by name.
2673 int compare = s1.section_name().compare(s2.section_name());
2674 if (compare != 0)
2675 return compare < 0;
2677 // Otherwise we keep the input order.
2678 return s1.index() < s2.index();
2681 // Sort the input sections attached to an output section.
2683 void
2684 Output_section::sort_attached_input_sections()
2686 if (this->attached_input_sections_are_sorted_)
2687 return;
2689 if (this->checkpoint_ != NULL
2690 && !this->checkpoint_->input_sections_saved())
2691 this->checkpoint_->save_input_sections();
2693 // The only thing we know about an input section is the object and
2694 // the section index. We need the section name. Recomputing this
2695 // is slow but this is an unusual case. If this becomes a speed
2696 // problem we can cache the names as required in Layout::layout.
2698 // We start by building a larger vector holding a copy of each
2699 // Input_section, plus its current index in the list and its name.
2700 std::vector<Input_section_sort_entry> sort_list;
2702 unsigned int i = 0;
2703 for (Input_section_list::iterator p = this->input_sections_.begin();
2704 p != this->input_sections_.end();
2705 ++p, ++i)
2706 sort_list.push_back(Input_section_sort_entry(*p, i));
2708 // Sort the input sections.
2709 std::sort(sort_list.begin(), sort_list.end(), Input_section_sort_compare());
2711 // Copy the sorted input sections back to our list.
2712 this->input_sections_.clear();
2713 for (std::vector<Input_section_sort_entry>::iterator p = sort_list.begin();
2714 p != sort_list.end();
2715 ++p)
2716 this->input_sections_.push_back(p->input_section());
2718 // Remember that we sorted the input sections, since we might get
2719 // called again.
2720 this->attached_input_sections_are_sorted_ = true;
2723 // Write the section header to *OSHDR.
2725 template<int size, bool big_endian>
2726 void
2727 Output_section::write_header(const Layout* layout,
2728 const Stringpool* secnamepool,
2729 elfcpp::Shdr_write<size, big_endian>* oshdr) const
2731 oshdr->put_sh_name(secnamepool->get_offset(this->name_));
2732 oshdr->put_sh_type(this->type_);
2734 elfcpp::Elf_Xword flags = this->flags_;
2735 if (this->info_section_ != NULL && this->info_uses_section_index_)
2736 flags |= elfcpp::SHF_INFO_LINK;
2737 oshdr->put_sh_flags(flags);
2739 oshdr->put_sh_addr(this->address());
2740 oshdr->put_sh_offset(this->offset());
2741 oshdr->put_sh_size(this->data_size());
2742 if (this->link_section_ != NULL)
2743 oshdr->put_sh_link(this->link_section_->out_shndx());
2744 else if (this->should_link_to_symtab_)
2745 oshdr->put_sh_link(layout->symtab_section()->out_shndx());
2746 else if (this->should_link_to_dynsym_)
2747 oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
2748 else
2749 oshdr->put_sh_link(this->link_);
2751 elfcpp::Elf_Word info;
2752 if (this->info_section_ != NULL)
2754 if (this->info_uses_section_index_)
2755 info = this->info_section_->out_shndx();
2756 else
2757 info = this->info_section_->symtab_index();
2759 else if (this->info_symndx_ != NULL)
2760 info = this->info_symndx_->symtab_index();
2761 else
2762 info = this->info_;
2763 oshdr->put_sh_info(info);
2765 oshdr->put_sh_addralign(this->addralign_);
2766 oshdr->put_sh_entsize(this->entsize_);
2769 // Write out the data. For input sections the data is written out by
2770 // Object::relocate, but we have to handle Output_section_data objects
2771 // here.
2773 void
2774 Output_section::do_write(Output_file* of)
2776 gold_assert(!this->requires_postprocessing());
2778 // If the target performs relaxation, we delay filler generation until now.
2779 gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
2781 off_t output_section_file_offset = this->offset();
2782 for (Fill_list::iterator p = this->fills_.begin();
2783 p != this->fills_.end();
2784 ++p)
2786 std::string fill_data(parameters->target().code_fill(p->length()));
2787 of->write(output_section_file_offset + p->section_offset(),
2788 fill_data.data(), fill_data.size());
2791 off_t off = this->offset() + this->first_input_offset_;
2792 for (Input_section_list::iterator p = this->input_sections_.begin();
2793 p != this->input_sections_.end();
2794 ++p)
2796 off_t aligned_off = align_address(off, p->addralign());
2797 if (this->generate_code_fills_at_write_ && (off != aligned_off))
2799 size_t fill_len = aligned_off - off;
2800 std::string fill_data(parameters->target().code_fill(fill_len));
2801 of->write(off, fill_data.data(), fill_data.size());
2804 p->write(of);
2805 off = aligned_off + p->data_size();
2809 // If a section requires postprocessing, create the buffer to use.
2811 void
2812 Output_section::create_postprocessing_buffer()
2814 gold_assert(this->requires_postprocessing());
2816 if (this->postprocessing_buffer_ != NULL)
2817 return;
2819 if (!this->input_sections_.empty())
2821 off_t off = this->first_input_offset_;
2822 for (Input_section_list::iterator p = this->input_sections_.begin();
2823 p != this->input_sections_.end();
2824 ++p)
2826 off = align_address(off, p->addralign());
2827 p->finalize_data_size();
2828 off += p->data_size();
2830 this->set_current_data_size_for_child(off);
2833 off_t buffer_size = this->current_data_size_for_child();
2834 this->postprocessing_buffer_ = new unsigned char[buffer_size];
2837 // Write all the data of an Output_section into the postprocessing
2838 // buffer. This is used for sections which require postprocessing,
2839 // such as compression. Input sections are handled by
2840 // Object::Relocate.
2842 void
2843 Output_section::write_to_postprocessing_buffer()
2845 gold_assert(this->requires_postprocessing());
2847 // If the target performs relaxation, we delay filler generation until now.
2848 gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
2850 unsigned char* buffer = this->postprocessing_buffer();
2851 for (Fill_list::iterator p = this->fills_.begin();
2852 p != this->fills_.end();
2853 ++p)
2855 std::string fill_data(parameters->target().code_fill(p->length()));
2856 memcpy(buffer + p->section_offset(), fill_data.data(),
2857 fill_data.size());
2860 off_t off = this->first_input_offset_;
2861 for (Input_section_list::iterator p = this->input_sections_.begin();
2862 p != this->input_sections_.end();
2863 ++p)
2865 off_t aligned_off = align_address(off, p->addralign());
2866 if (this->generate_code_fills_at_write_ && (off != aligned_off))
2868 size_t fill_len = aligned_off - off;
2869 std::string fill_data(parameters->target().code_fill(fill_len));
2870 memcpy(buffer + off, fill_data.data(), fill_data.size());
2873 p->write_to_buffer(buffer + aligned_off);
2874 off = aligned_off + p->data_size();
2878 // Get the input sections for linker script processing. We leave
2879 // behind the Output_section_data entries. Note that this may be
2880 // slightly incorrect for merge sections. We will leave them behind,
2881 // but it is possible that the script says that they should follow
2882 // some other input sections, as in:
2883 // .rodata { *(.rodata) *(.rodata.cst*) }
2884 // For that matter, we don't handle this correctly:
2885 // .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) }
2886 // With luck this will never matter.
2888 uint64_t
2889 Output_section::get_input_sections(
2890 uint64_t address,
2891 const std::string& fill,
2892 std::list<Simple_input_section>* input_sections)
2894 if (this->checkpoint_ != NULL
2895 && !this->checkpoint_->input_sections_saved())
2896 this->checkpoint_->save_input_sections();
2898 // Invalidate the relaxed input section map.
2899 this->is_relaxed_input_section_map_valid_ = false;
2901 uint64_t orig_address = address;
2903 address = align_address(address, this->addralign());
2905 Input_section_list remaining;
2906 for (Input_section_list::iterator p = this->input_sections_.begin();
2907 p != this->input_sections_.end();
2908 ++p)
2910 if (p->is_input_section())
2911 input_sections->push_back(Simple_input_section(p->relobj(),
2912 p->shndx()));
2913 else if (p->is_relaxed_input_section())
2914 input_sections->push_back(
2915 Simple_input_section(p->relaxed_input_section()));
2916 else
2918 uint64_t aligned_address = align_address(address, p->addralign());
2919 if (aligned_address != address && !fill.empty())
2921 section_size_type length =
2922 convert_to_section_size_type(aligned_address - address);
2923 std::string this_fill;
2924 this_fill.reserve(length);
2925 while (this_fill.length() + fill.length() <= length)
2926 this_fill += fill;
2927 if (this_fill.length() < length)
2928 this_fill.append(fill, 0, length - this_fill.length());
2930 Output_section_data* posd = new Output_data_const(this_fill, 0);
2931 remaining.push_back(Input_section(posd));
2933 address = aligned_address;
2935 remaining.push_back(*p);
2937 p->finalize_data_size();
2938 address += p->data_size();
2942 this->input_sections_.swap(remaining);
2943 this->first_input_offset_ = 0;
2945 uint64_t data_size = address - orig_address;
2946 this->set_current_data_size_for_child(data_size);
2947 return data_size;
2950 // Add an input section from a script.
2952 void
2953 Output_section::add_input_section_for_script(const Simple_input_section& sis,
2954 off_t data_size,
2955 uint64_t addralign)
2957 if (addralign > this->addralign_)
2958 this->addralign_ = addralign;
2960 off_t offset_in_section = this->current_data_size_for_child();
2961 off_t aligned_offset_in_section = align_address(offset_in_section,
2962 addralign);
2964 this->set_current_data_size_for_child(aligned_offset_in_section
2965 + data_size);
2967 Input_section is =
2968 (sis.is_relaxed_input_section()
2969 ? Input_section(sis.relaxed_input_section())
2970 : Input_section(sis.relobj(), sis.shndx(), data_size, addralign));
2971 this->input_sections_.push_back(is);
2976 void
2977 Output_section::save_states()
2979 gold_assert(this->checkpoint_ == NULL);
2980 Checkpoint_output_section* checkpoint =
2981 new Checkpoint_output_section(this->addralign_, this->flags_,
2982 this->input_sections_,
2983 this->first_input_offset_,
2984 this->attached_input_sections_are_sorted_);
2985 this->checkpoint_ = checkpoint;
2986 gold_assert(this->fills_.empty());
2989 void
2990 Output_section::restore_states()
2992 gold_assert(this->checkpoint_ != NULL);
2993 Checkpoint_output_section* checkpoint = this->checkpoint_;
2995 this->addralign_ = checkpoint->addralign();
2996 this->flags_ = checkpoint->flags();
2997 this->first_input_offset_ = checkpoint->first_input_offset();
2999 if (!checkpoint->input_sections_saved())
3001 // If we have not copied the input sections, just resize it.
3002 size_t old_size = checkpoint->input_sections_size();
3003 gold_assert(this->input_sections_.size() >= old_size);
3004 this->input_sections_.resize(old_size);
3006 else
3008 // We need to copy the whole list. This is not efficient for
3009 // extremely large output with hundreads of thousands of input
3010 // objects. We may need to re-think how we should pass sections
3011 // to scripts.
3012 this->input_sections_ = *checkpoint->input_sections();
3015 this->attached_input_sections_are_sorted_ =
3016 checkpoint->attached_input_sections_are_sorted();
3018 // Simply invalidate the relaxed input section map since we do not keep
3019 // track of it.
3020 this->is_relaxed_input_section_map_valid_ = false;
3023 // Print to the map file.
3025 void
3026 Output_section::do_print_to_mapfile(Mapfile* mapfile) const
3028 mapfile->print_output_section(this);
3030 for (Input_section_list::const_iterator p = this->input_sections_.begin();
3031 p != this->input_sections_.end();
3032 ++p)
3033 p->print_to_mapfile(mapfile);
3036 // Print stats for merge sections to stderr.
3038 void
3039 Output_section::print_merge_stats()
3041 Input_section_list::iterator p;
3042 for (p = this->input_sections_.begin();
3043 p != this->input_sections_.end();
3044 ++p)
3045 p->print_merge_stats(this->name_);
3048 // Output segment methods.
3050 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
3051 : output_data_(),
3052 output_bss_(),
3053 vaddr_(0),
3054 paddr_(0),
3055 memsz_(0),
3056 max_align_(0),
3057 min_p_align_(0),
3058 offset_(0),
3059 filesz_(0),
3060 type_(type),
3061 flags_(flags),
3062 is_max_align_known_(false),
3063 are_addresses_set_(false),
3064 is_large_data_segment_(false)
3066 // The ELF ABI specifies that a PT_TLS segment always has PF_R as
3067 // the flags.
3068 if (type == elfcpp::PT_TLS)
3069 this->flags_ = elfcpp::PF_R;
3072 // Add an Output_section to an Output_segment.
3074 void
3075 Output_segment::add_output_section(Output_section* os,
3076 elfcpp::Elf_Word seg_flags,
3077 bool do_sort)
3079 gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
3080 gold_assert(!this->is_max_align_known_);
3081 gold_assert(os->is_large_data_section() == this->is_large_data_segment());
3082 gold_assert(this->type() == elfcpp::PT_LOAD || !do_sort);
3084 this->update_flags_for_output_section(seg_flags);
3086 Output_segment::Output_data_list* pdl;
3087 if (os->type() == elfcpp::SHT_NOBITS)
3088 pdl = &this->output_bss_;
3089 else
3090 pdl = &this->output_data_;
3092 // Note that while there may be many input sections in an output
3093 // section, there are normally only a few output sections in an
3094 // output segment. The loops below are expected to be fast.
3096 // So that PT_NOTE segments will work correctly, we need to ensure
3097 // that all SHT_NOTE sections are adjacent.
3098 if (os->type() == elfcpp::SHT_NOTE && !pdl->empty())
3100 Output_segment::Output_data_list::iterator p = pdl->end();
3103 --p;
3104 if ((*p)->is_section_type(elfcpp::SHT_NOTE))
3106 ++p;
3107 pdl->insert(p, os);
3108 return;
3111 while (p != pdl->begin());
3114 // Similarly, so that PT_TLS segments will work, we need to group
3115 // SHF_TLS sections. An SHF_TLS/SHT_NOBITS section is a special
3116 // case: we group the SHF_TLS/SHT_NOBITS sections right after the
3117 // SHF_TLS/SHT_PROGBITS sections. This lets us set up PT_TLS
3118 // correctly. SHF_TLS sections get added to both a PT_LOAD segment
3119 // and the PT_TLS segment; we do this grouping only for the PT_LOAD
3120 // segment.
3121 if (this->type_ != elfcpp::PT_TLS
3122 && (os->flags() & elfcpp::SHF_TLS) != 0)
3124 pdl = &this->output_data_;
3125 if (!pdl->empty())
3127 bool nobits = os->type() == elfcpp::SHT_NOBITS;
3128 bool sawtls = false;
3129 Output_segment::Output_data_list::iterator p = pdl->end();
3130 gold_assert(p != pdl->begin());
3133 --p;
3134 bool insert;
3135 if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3137 sawtls = true;
3138 // Put a NOBITS section after the first TLS section.
3139 // Put a PROGBITS section after the first
3140 // TLS/PROGBITS section.
3141 insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS);
3143 else
3145 // If we've gone past the TLS sections, but we've
3146 // seen a TLS section, then we need to insert this
3147 // section now.
3148 insert = sawtls;
3151 if (insert)
3153 ++p;
3154 pdl->insert(p, os);
3155 return;
3158 while (p != pdl->begin());
3161 // There are no TLS sections yet; put this one at the requested
3162 // location in the section list.
3165 if (do_sort)
3167 // For the PT_GNU_RELRO segment, we need to group relro
3168 // sections, and we need to put them before any non-relro
3169 // sections. Any relro local sections go before relro non-local
3170 // sections. One section may be marked as the last relro
3171 // section.
3172 if (os->is_relro())
3174 gold_assert(pdl == &this->output_data_);
3175 Output_segment::Output_data_list::iterator p;
3176 for (p = pdl->begin(); p != pdl->end(); ++p)
3178 if (!(*p)->is_section())
3179 break;
3181 Output_section* pos = (*p)->output_section();
3182 if (!pos->is_relro()
3183 || (os->is_relro_local() && !pos->is_relro_local())
3184 || (!os->is_last_relro() && pos->is_last_relro()))
3185 break;
3188 pdl->insert(p, os);
3189 return;
3192 // One section may be marked as the first section which follows
3193 // the relro sections.
3194 if (os->is_first_non_relro())
3196 gold_assert(pdl == &this->output_data_);
3197 Output_segment::Output_data_list::iterator p;
3198 for (p = pdl->begin(); p != pdl->end(); ++p)
3200 if (!(*p)->is_section())
3201 break;
3203 Output_section* pos = (*p)->output_section();
3204 if (!pos->is_relro())
3205 break;
3208 pdl->insert(p, os);
3209 return;
3213 // Small data sections go at the end of the list of data sections.
3214 // If OS is not small, and there are small sections, we have to
3215 // insert it before the first small section.
3216 if (os->type() != elfcpp::SHT_NOBITS
3217 && !os->is_small_section()
3218 && !pdl->empty()
3219 && pdl->back()->is_section()
3220 && pdl->back()->output_section()->is_small_section())
3222 for (Output_segment::Output_data_list::iterator p = pdl->begin();
3223 p != pdl->end();
3224 ++p)
3226 if ((*p)->is_section()
3227 && (*p)->output_section()->is_small_section())
3229 pdl->insert(p, os);
3230 return;
3233 gold_unreachable();
3236 // A small BSS section goes at the start of the BSS sections, after
3237 // other small BSS sections.
3238 if (os->type() == elfcpp::SHT_NOBITS && os->is_small_section())
3240 for (Output_segment::Output_data_list::iterator p = pdl->begin();
3241 p != pdl->end();
3242 ++p)
3244 if (!(*p)->is_section()
3245 || !(*p)->output_section()->is_small_section())
3247 pdl->insert(p, os);
3248 return;
3253 // A large BSS section goes at the end of the BSS sections, which
3254 // means that one that is not large must come before the first large
3255 // one.
3256 if (os->type() == elfcpp::SHT_NOBITS
3257 && !os->is_large_section()
3258 && !pdl->empty()
3259 && pdl->back()->is_section()
3260 && pdl->back()->output_section()->is_large_section())
3262 for (Output_segment::Output_data_list::iterator p = pdl->begin();
3263 p != pdl->end();
3264 ++p)
3266 if ((*p)->is_section()
3267 && (*p)->output_section()->is_large_section())
3269 pdl->insert(p, os);
3270 return;
3273 gold_unreachable();
3276 // We do some further output section sorting in order to make the
3277 // generated program run more efficiently. We should only do this
3278 // when not using a linker script, so it is controled by the DO_SORT
3279 // parameter.
3280 if (do_sort)
3282 // FreeBSD requires the .interp section to be in the first page
3283 // of the executable. That is a more efficient location anyhow
3284 // for any OS, since it means that the kernel will have the data
3285 // handy after it reads the program headers.
3286 if (os->is_interp() && !pdl->empty())
3288 pdl->insert(pdl->begin(), os);
3289 return;
3292 // Put loadable non-writable notes immediately after the .interp
3293 // sections, so that the PT_NOTE segment is on the first page of
3294 // the executable.
3295 if (os->type() == elfcpp::SHT_NOTE
3296 && (os->flags() & elfcpp::SHF_WRITE) == 0
3297 && !pdl->empty())
3299 Output_segment::Output_data_list::iterator p = pdl->begin();
3300 if ((*p)->is_section() && (*p)->output_section()->is_interp())
3301 ++p;
3302 pdl->insert(p, os);
3303 return;
3306 // If this section is used by the dynamic linker, and it is not
3307 // writable, then put it first, after the .interp section and
3308 // any loadable notes. This makes it more likely that the
3309 // dynamic linker will have to read less data from the disk.
3310 if (os->is_dynamic_linker_section()
3311 && !pdl->empty()
3312 && (os->flags() & elfcpp::SHF_WRITE) == 0)
3314 bool is_reloc = (os->type() == elfcpp::SHT_REL
3315 || os->type() == elfcpp::SHT_RELA);
3316 Output_segment::Output_data_list::iterator p = pdl->begin();
3317 while (p != pdl->end()
3318 && (*p)->is_section()
3319 && ((*p)->output_section()->is_dynamic_linker_section()
3320 || (*p)->output_section()->type() == elfcpp::SHT_NOTE))
3322 // Put reloc sections after the other ones. Putting the
3323 // dynamic reloc sections first confuses BFD, notably
3324 // objcopy and strip.
3325 if (!is_reloc
3326 && ((*p)->output_section()->type() == elfcpp::SHT_REL
3327 || (*p)->output_section()->type() == elfcpp::SHT_RELA))
3328 break;
3329 ++p;
3331 pdl->insert(p, os);
3332 return;
3336 // If there were no constraints on the output section, just add it
3337 // to the end of the list.
3338 pdl->push_back(os);
3341 // Remove an Output_section from this segment. It is an error if it
3342 // is not present.
3344 void
3345 Output_segment::remove_output_section(Output_section* os)
3347 // We only need this for SHT_PROGBITS.
3348 gold_assert(os->type() == elfcpp::SHT_PROGBITS);
3349 for (Output_data_list::iterator p = this->output_data_.begin();
3350 p != this->output_data_.end();
3351 ++p)
3353 if (*p == os)
3355 this->output_data_.erase(p);
3356 return;
3359 gold_unreachable();
3362 // Add an Output_data (which need not be an Output_section) to the
3363 // start of a segment.
3365 void
3366 Output_segment::add_initial_output_data(Output_data* od)
3368 gold_assert(!this->is_max_align_known_);
3369 this->output_data_.push_front(od);
3372 // Return whether the first data section is a relro section.
3374 bool
3375 Output_segment::is_first_section_relro() const
3377 return (!this->output_data_.empty()
3378 && this->output_data_.front()->is_section()
3379 && this->output_data_.front()->output_section()->is_relro());
3382 // Return the maximum alignment of the Output_data in Output_segment.
3384 uint64_t
3385 Output_segment::maximum_alignment()
3387 if (!this->is_max_align_known_)
3389 uint64_t addralign;
3391 addralign = Output_segment::maximum_alignment_list(&this->output_data_);
3392 if (addralign > this->max_align_)
3393 this->max_align_ = addralign;
3395 addralign = Output_segment::maximum_alignment_list(&this->output_bss_);
3396 if (addralign > this->max_align_)
3397 this->max_align_ = addralign;
3399 this->is_max_align_known_ = true;
3402 return this->max_align_;
3405 // Return the maximum alignment of a list of Output_data.
3407 uint64_t
3408 Output_segment::maximum_alignment_list(const Output_data_list* pdl)
3410 uint64_t ret = 0;
3411 for (Output_data_list::const_iterator p = pdl->begin();
3412 p != pdl->end();
3413 ++p)
3415 uint64_t addralign = (*p)->addralign();
3416 if (addralign > ret)
3417 ret = addralign;
3419 return ret;
3422 // Return the number of dynamic relocs applied to this segment.
3424 unsigned int
3425 Output_segment::dynamic_reloc_count() const
3427 return (this->dynamic_reloc_count_list(&this->output_data_)
3428 + this->dynamic_reloc_count_list(&this->output_bss_));
3431 // Return the number of dynamic relocs applied to an Output_data_list.
3433 unsigned int
3434 Output_segment::dynamic_reloc_count_list(const Output_data_list* pdl) const
3436 unsigned int count = 0;
3437 for (Output_data_list::const_iterator p = pdl->begin();
3438 p != pdl->end();
3439 ++p)
3440 count += (*p)->dynamic_reloc_count();
3441 return count;
3444 // Set the section addresses for an Output_segment. If RESET is true,
3445 // reset the addresses first. ADDR is the address and *POFF is the
3446 // file offset. Set the section indexes starting with *PSHNDX.
3447 // Return the address of the immediately following segment. Update
3448 // *POFF and *PSHNDX.
3450 uint64_t
3451 Output_segment::set_section_addresses(const Layout* layout, bool reset,
3452 uint64_t addr,
3453 unsigned int increase_relro,
3454 off_t* poff,
3455 unsigned int* pshndx)
3457 gold_assert(this->type_ == elfcpp::PT_LOAD);
3459 off_t orig_off = *poff;
3461 // If we have relro sections, we need to pad forward now so that the
3462 // relro sections plus INCREASE_RELRO end on a common page boundary.
3463 if (parameters->options().relro()
3464 && this->is_first_section_relro()
3465 && (!this->are_addresses_set_ || reset))
3467 uint64_t relro_size = 0;
3468 off_t off = *poff;
3469 for (Output_data_list::iterator p = this->output_data_.begin();
3470 p != this->output_data_.end();
3471 ++p)
3473 if (!(*p)->is_section())
3474 break;
3475 Output_section* pos = (*p)->output_section();
3476 if (!pos->is_relro())
3477 break;
3478 gold_assert(!(*p)->is_section_flag_set(elfcpp::SHF_TLS));
3479 if ((*p)->is_address_valid())
3480 relro_size += (*p)->data_size();
3481 else
3483 // FIXME: This could be faster.
3484 (*p)->set_address_and_file_offset(addr + relro_size,
3485 off + relro_size);
3486 relro_size += (*p)->data_size();
3487 (*p)->reset_address_and_file_offset();
3490 relro_size += increase_relro;
3492 uint64_t page_align = parameters->target().common_pagesize();
3494 // Align to offset N such that (N + RELRO_SIZE) % PAGE_ALIGN == 0.
3495 uint64_t desired_align = page_align - (relro_size % page_align);
3496 if (desired_align < *poff % page_align)
3497 *poff += page_align - *poff % page_align;
3498 *poff += desired_align - *poff % page_align;
3499 addr += *poff - orig_off;
3500 orig_off = *poff;
3503 if (!reset && this->are_addresses_set_)
3505 gold_assert(this->paddr_ == addr);
3506 addr = this->vaddr_;
3508 else
3510 this->vaddr_ = addr;
3511 this->paddr_ = addr;
3512 this->are_addresses_set_ = true;
3515 bool in_tls = false;
3517 this->offset_ = orig_off;
3519 addr = this->set_section_list_addresses(layout, reset, &this->output_data_,
3520 addr, poff, pshndx, &in_tls);
3521 this->filesz_ = *poff - orig_off;
3523 off_t off = *poff;
3525 uint64_t ret = this->set_section_list_addresses(layout, reset,
3526 &this->output_bss_,
3527 addr, poff, pshndx,
3528 &in_tls);
3530 // If the last section was a TLS section, align upward to the
3531 // alignment of the TLS segment, so that the overall size of the TLS
3532 // segment is aligned.
3533 if (in_tls)
3535 uint64_t segment_align = layout->tls_segment()->maximum_alignment();
3536 *poff = align_address(*poff, segment_align);
3539 this->memsz_ = *poff - orig_off;
3541 // Ignore the file offset adjustments made by the BSS Output_data
3542 // objects.
3543 *poff = off;
3545 return ret;
3548 // Set the addresses and file offsets in a list of Output_data
3549 // structures.
3551 uint64_t
3552 Output_segment::set_section_list_addresses(const Layout* layout, bool reset,
3553 Output_data_list* pdl,
3554 uint64_t addr, off_t* poff,
3555 unsigned int* pshndx,
3556 bool* in_tls)
3558 off_t startoff = *poff;
3560 off_t off = startoff;
3561 for (Output_data_list::iterator p = pdl->begin();
3562 p != pdl->end();
3563 ++p)
3565 if (reset)
3566 (*p)->reset_address_and_file_offset();
3568 // When using a linker script the section will most likely
3569 // already have an address.
3570 if (!(*p)->is_address_valid())
3572 uint64_t align = (*p)->addralign();
3574 if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3576 // Give the first TLS section the alignment of the
3577 // entire TLS segment. Otherwise the TLS segment as a
3578 // whole may be misaligned.
3579 if (!*in_tls)
3581 Output_segment* tls_segment = layout->tls_segment();
3582 gold_assert(tls_segment != NULL);
3583 uint64_t segment_align = tls_segment->maximum_alignment();
3584 gold_assert(segment_align >= align);
3585 align = segment_align;
3587 *in_tls = true;
3590 else
3592 // If this is the first section after the TLS segment,
3593 // align it to at least the alignment of the TLS
3594 // segment, so that the size of the overall TLS segment
3595 // is aligned.
3596 if (*in_tls)
3598 uint64_t segment_align =
3599 layout->tls_segment()->maximum_alignment();
3600 if (segment_align > align)
3601 align = segment_align;
3603 *in_tls = false;
3607 off = align_address(off, align);
3608 (*p)->set_address_and_file_offset(addr + (off - startoff), off);
3610 else
3612 // The script may have inserted a skip forward, but it
3613 // better not have moved backward.
3614 if ((*p)->address() >= addr + (off - startoff))
3615 off += (*p)->address() - (addr + (off - startoff));
3616 else
3618 if (!layout->script_options()->saw_sections_clause())
3619 gold_unreachable();
3620 else
3622 Output_section* os = (*p)->output_section();
3624 // Cast to unsigned long long to avoid format warnings.
3625 unsigned long long previous_dot =
3626 static_cast<unsigned long long>(addr + (off - startoff));
3627 unsigned long long dot =
3628 static_cast<unsigned long long>((*p)->address());
3630 if (os == NULL)
3631 gold_error(_("dot moves backward in linker script "
3632 "from 0x%llx to 0x%llx"), previous_dot, dot);
3633 else
3634 gold_error(_("address of section '%s' moves backward "
3635 "from 0x%llx to 0x%llx"),
3636 os->name(), previous_dot, dot);
3639 (*p)->set_file_offset(off);
3640 (*p)->finalize_data_size();
3643 // We want to ignore the size of a SHF_TLS or SHT_NOBITS
3644 // section. Such a section does not affect the size of a
3645 // PT_LOAD segment.
3646 if (!(*p)->is_section_flag_set(elfcpp::SHF_TLS)
3647 || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
3648 off += (*p)->data_size();
3650 if ((*p)->is_section())
3652 (*p)->set_out_shndx(*pshndx);
3653 ++*pshndx;
3657 *poff = off;
3658 return addr + (off - startoff);
3661 // For a non-PT_LOAD segment, set the offset from the sections, if
3662 // any. Add INCREASE to the file size and the memory size.
3664 void
3665 Output_segment::set_offset(unsigned int increase)
3667 gold_assert(this->type_ != elfcpp::PT_LOAD);
3669 gold_assert(!this->are_addresses_set_);
3671 if (this->output_data_.empty() && this->output_bss_.empty())
3673 gold_assert(increase == 0);
3674 this->vaddr_ = 0;
3675 this->paddr_ = 0;
3676 this->are_addresses_set_ = true;
3677 this->memsz_ = 0;
3678 this->min_p_align_ = 0;
3679 this->offset_ = 0;
3680 this->filesz_ = 0;
3681 return;
3684 const Output_data* first;
3685 if (this->output_data_.empty())
3686 first = this->output_bss_.front();
3687 else
3688 first = this->output_data_.front();
3689 this->vaddr_ = first->address();
3690 this->paddr_ = (first->has_load_address()
3691 ? first->load_address()
3692 : this->vaddr_);
3693 this->are_addresses_set_ = true;
3694 this->offset_ = first->offset();
3696 if (this->output_data_.empty())
3697 this->filesz_ = 0;
3698 else
3700 const Output_data* last_data = this->output_data_.back();
3701 this->filesz_ = (last_data->address()
3702 + last_data->data_size()
3703 - this->vaddr_);
3706 const Output_data* last;
3707 if (this->output_bss_.empty())
3708 last = this->output_data_.back();
3709 else
3710 last = this->output_bss_.back();
3711 this->memsz_ = (last->address()
3712 + last->data_size()
3713 - this->vaddr_);
3715 this->filesz_ += increase;
3716 this->memsz_ += increase;
3718 // If this is a TLS segment, align the memory size. The code in
3719 // set_section_list ensures that the section after the TLS segment
3720 // is aligned to give us room.
3721 if (this->type_ == elfcpp::PT_TLS)
3723 uint64_t segment_align = this->maximum_alignment();
3724 gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align));
3725 this->memsz_ = align_address(this->memsz_, segment_align);
3729 // Set the TLS offsets of the sections in the PT_TLS segment.
3731 void
3732 Output_segment::set_tls_offsets()
3734 gold_assert(this->type_ == elfcpp::PT_TLS);
3736 for (Output_data_list::iterator p = this->output_data_.begin();
3737 p != this->output_data_.end();
3738 ++p)
3739 (*p)->set_tls_offset(this->vaddr_);
3741 for (Output_data_list::iterator p = this->output_bss_.begin();
3742 p != this->output_bss_.end();
3743 ++p)
3744 (*p)->set_tls_offset(this->vaddr_);
3747 // Return the address of the first section.
3749 uint64_t
3750 Output_segment::first_section_load_address() const
3752 for (Output_data_list::const_iterator p = this->output_data_.begin();
3753 p != this->output_data_.end();
3754 ++p)
3755 if ((*p)->is_section())
3756 return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
3758 for (Output_data_list::const_iterator p = this->output_bss_.begin();
3759 p != this->output_bss_.end();
3760 ++p)
3761 if ((*p)->is_section())
3762 return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
3764 gold_unreachable();
3767 // Return the number of Output_sections in an Output_segment.
3769 unsigned int
3770 Output_segment::output_section_count() const
3772 return (this->output_section_count_list(&this->output_data_)
3773 + this->output_section_count_list(&this->output_bss_));
3776 // Return the number of Output_sections in an Output_data_list.
3778 unsigned int
3779 Output_segment::output_section_count_list(const Output_data_list* pdl) const
3781 unsigned int count = 0;
3782 for (Output_data_list::const_iterator p = pdl->begin();
3783 p != pdl->end();
3784 ++p)
3786 if ((*p)->is_section())
3787 ++count;
3789 return count;
3792 // Return the section attached to the list segment with the lowest
3793 // load address. This is used when handling a PHDRS clause in a
3794 // linker script.
3796 Output_section*
3797 Output_segment::section_with_lowest_load_address() const
3799 Output_section* found = NULL;
3800 uint64_t found_lma = 0;
3801 this->lowest_load_address_in_list(&this->output_data_, &found, &found_lma);
3803 Output_section* found_data = found;
3804 this->lowest_load_address_in_list(&this->output_bss_, &found, &found_lma);
3805 if (found != found_data && found_data != NULL)
3807 gold_error(_("nobits section %s may not precede progbits section %s "
3808 "in same segment"),
3809 found->name(), found_data->name());
3810 return NULL;
3813 return found;
3816 // Look through a list for a section with a lower load address.
3818 void
3819 Output_segment::lowest_load_address_in_list(const Output_data_list* pdl,
3820 Output_section** found,
3821 uint64_t* found_lma) const
3823 for (Output_data_list::const_iterator p = pdl->begin();
3824 p != pdl->end();
3825 ++p)
3827 if (!(*p)->is_section())
3828 continue;
3829 Output_section* os = static_cast<Output_section*>(*p);
3830 uint64_t lma = (os->has_load_address()
3831 ? os->load_address()
3832 : os->address());
3833 if (*found == NULL || lma < *found_lma)
3835 *found = os;
3836 *found_lma = lma;
3841 // Write the segment data into *OPHDR.
3843 template<int size, bool big_endian>
3844 void
3845 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
3847 ophdr->put_p_type(this->type_);
3848 ophdr->put_p_offset(this->offset_);
3849 ophdr->put_p_vaddr(this->vaddr_);
3850 ophdr->put_p_paddr(this->paddr_);
3851 ophdr->put_p_filesz(this->filesz_);
3852 ophdr->put_p_memsz(this->memsz_);
3853 ophdr->put_p_flags(this->flags_);
3854 ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment()));
3857 // Write the section headers into V.
3859 template<int size, bool big_endian>
3860 unsigned char*
3861 Output_segment::write_section_headers(const Layout* layout,
3862 const Stringpool* secnamepool,
3863 unsigned char* v,
3864 unsigned int *pshndx) const
3866 // Every section that is attached to a segment must be attached to a
3867 // PT_LOAD segment, so we only write out section headers for PT_LOAD
3868 // segments.
3869 if (this->type_ != elfcpp::PT_LOAD)
3870 return v;
3872 v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
3873 &this->output_data_,
3874 v, pshndx);
3875 v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
3876 &this->output_bss_,
3877 v, pshndx);
3878 return v;
3881 template<int size, bool big_endian>
3882 unsigned char*
3883 Output_segment::write_section_headers_list(const Layout* layout,
3884 const Stringpool* secnamepool,
3885 const Output_data_list* pdl,
3886 unsigned char* v,
3887 unsigned int* pshndx) const
3889 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
3890 for (Output_data_list::const_iterator p = pdl->begin();
3891 p != pdl->end();
3892 ++p)
3894 if ((*p)->is_section())
3896 const Output_section* ps = static_cast<const Output_section*>(*p);
3897 gold_assert(*pshndx == ps->out_shndx());
3898 elfcpp::Shdr_write<size, big_endian> oshdr(v);
3899 ps->write_header(layout, secnamepool, &oshdr);
3900 v += shdr_size;
3901 ++*pshndx;
3904 return v;
3907 // Print the output sections to the map file.
3909 void
3910 Output_segment::print_sections_to_mapfile(Mapfile* mapfile) const
3912 if (this->type() != elfcpp::PT_LOAD)
3913 return;
3914 this->print_section_list_to_mapfile(mapfile, &this->output_data_);
3915 this->print_section_list_to_mapfile(mapfile, &this->output_bss_);
3918 // Print an output section list to the map file.
3920 void
3921 Output_segment::print_section_list_to_mapfile(Mapfile* mapfile,
3922 const Output_data_list* pdl) const
3924 for (Output_data_list::const_iterator p = pdl->begin();
3925 p != pdl->end();
3926 ++p)
3927 (*p)->print_to_mapfile(mapfile);
3930 // Output_file methods.
3932 Output_file::Output_file(const char* name)
3933 : name_(name),
3934 o_(-1),
3935 file_size_(0),
3936 base_(NULL),
3937 map_is_anonymous_(false),
3938 is_temporary_(false)
3942 // Try to open an existing file. Returns false if the file doesn't
3943 // exist, has a size of 0 or can't be mmapped.
3945 bool
3946 Output_file::open_for_modification()
3948 // The name "-" means "stdout".
3949 if (strcmp(this->name_, "-") == 0)
3950 return false;
3952 // Don't bother opening files with a size of zero.
3953 struct stat s;
3954 if (::stat(this->name_, &s) != 0 || s.st_size == 0)
3955 return false;
3957 int o = open_descriptor(-1, this->name_, O_RDWR, 0);
3958 if (o < 0)
3959 gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
3960 this->o_ = o;
3961 this->file_size_ = s.st_size;
3963 // If the file can't be mmapped, copying the content to an anonymous
3964 // map will probably negate the performance benefits of incremental
3965 // linking. This could be helped by using views and loading only
3966 // the necessary parts, but this is not supported as of now.
3967 if (!this->map_no_anonymous())
3969 release_descriptor(o, true);
3970 this->o_ = -1;
3971 this->file_size_ = 0;
3972 return false;
3975 return true;
3978 // Open the output file.
3980 void
3981 Output_file::open(off_t file_size)
3983 this->file_size_ = file_size;
3985 // Unlink the file first; otherwise the open() may fail if the file
3986 // is busy (e.g. it's an executable that's currently being executed).
3988 // However, the linker may be part of a system where a zero-length
3989 // file is created for it to write to, with tight permissions (gcc
3990 // 2.95 did something like this). Unlinking the file would work
3991 // around those permission controls, so we only unlink if the file
3992 // has a non-zero size. We also unlink only regular files to avoid
3993 // trouble with directories/etc.
3995 // If we fail, continue; this command is merely a best-effort attempt
3996 // to improve the odds for open().
3998 // We let the name "-" mean "stdout"
3999 if (!this->is_temporary_)
4001 if (strcmp(this->name_, "-") == 0)
4002 this->o_ = STDOUT_FILENO;
4003 else
4005 struct stat s;
4006 if (::stat(this->name_, &s) == 0
4007 && (S_ISREG (s.st_mode) || S_ISLNK (s.st_mode)))
4009 if (s.st_size != 0)
4010 ::unlink(this->name_);
4011 else if (!parameters->options().relocatable())
4013 // If we don't unlink the existing file, add execute
4014 // permission where read permissions already exist
4015 // and where the umask permits.
4016 int mask = ::umask(0);
4017 ::umask(mask);
4018 s.st_mode |= (s.st_mode & 0444) >> 2;
4019 ::chmod(this->name_, s.st_mode & ~mask);
4023 int mode = parameters->options().relocatable() ? 0666 : 0777;
4024 int o = open_descriptor(-1, this->name_, O_RDWR | O_CREAT | O_TRUNC,
4025 mode);
4026 if (o < 0)
4027 gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
4028 this->o_ = o;
4032 this->map();
4035 // Resize the output file.
4037 void
4038 Output_file::resize(off_t file_size)
4040 // If the mmap is mapping an anonymous memory buffer, this is easy:
4041 // just mremap to the new size. If it's mapping to a file, we want
4042 // to unmap to flush to the file, then remap after growing the file.
4043 if (this->map_is_anonymous_)
4045 void* base = ::mremap(this->base_, this->file_size_, file_size,
4046 MREMAP_MAYMOVE);
4047 if (base == MAP_FAILED)
4048 gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno));
4049 this->base_ = static_cast<unsigned char*>(base);
4050 this->file_size_ = file_size;
4052 else
4054 this->unmap();
4055 this->file_size_ = file_size;
4056 if (!this->map_no_anonymous())
4057 gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
4061 // Map an anonymous block of memory which will later be written to the
4062 // file. Return whether the map succeeded.
4064 bool
4065 Output_file::map_anonymous()
4067 void* base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4068 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
4069 if (base != MAP_FAILED)
4071 this->map_is_anonymous_ = true;
4072 this->base_ = static_cast<unsigned char*>(base);
4073 return true;
4075 return false;
4078 // Map the file into memory. Return whether the mapping succeeded.
4080 bool
4081 Output_file::map_no_anonymous()
4083 const int o = this->o_;
4085 // If the output file is not a regular file, don't try to mmap it;
4086 // instead, we'll mmap a block of memory (an anonymous buffer), and
4087 // then later write the buffer to the file.
4088 void* base;
4089 struct stat statbuf;
4090 if (o == STDOUT_FILENO || o == STDERR_FILENO
4091 || ::fstat(o, &statbuf) != 0
4092 || !S_ISREG(statbuf.st_mode)
4093 || this->is_temporary_)
4094 return false;
4096 // Ensure that we have disk space available for the file. If we
4097 // don't do this, it is possible that we will call munmap, close,
4098 // and exit with dirty buffers still in the cache with no assigned
4099 // disk blocks. If the disk is out of space at that point, the
4100 // output file will wind up incomplete, but we will have already
4101 // exited. The alternative to fallocate would be to use fdatasync,
4102 // but that would be a more significant performance hit.
4103 if (::posix_fallocate(o, 0, this->file_size_) < 0)
4104 gold_fatal(_("%s: %s"), this->name_, strerror(errno));
4106 // Map the file into memory.
4107 base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4108 MAP_SHARED, o, 0);
4110 // The mmap call might fail because of file system issues: the file
4111 // system might not support mmap at all, or it might not support
4112 // mmap with PROT_WRITE.
4113 if (base == MAP_FAILED)
4114 return false;
4116 this->map_is_anonymous_ = false;
4117 this->base_ = static_cast<unsigned char*>(base);
4118 return true;
4121 // Map the file into memory.
4123 void
4124 Output_file::map()
4126 if (this->map_no_anonymous())
4127 return;
4129 // The mmap call might fail because of file system issues: the file
4130 // system might not support mmap at all, or it might not support
4131 // mmap with PROT_WRITE. I'm not sure which errno values we will
4132 // see in all cases, so if the mmap fails for any reason and we
4133 // don't care about file contents, try for an anonymous map.
4134 if (this->map_anonymous())
4135 return;
4137 gold_fatal(_("%s: mmap: failed to allocate %lu bytes for output file: %s"),
4138 this->name_, static_cast<unsigned long>(this->file_size_),
4139 strerror(errno));
4142 // Unmap the file from memory.
4144 void
4145 Output_file::unmap()
4147 if (::munmap(this->base_, this->file_size_) < 0)
4148 gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
4149 this->base_ = NULL;
4152 // Close the output file.
4154 void
4155 Output_file::close()
4157 // If the map isn't file-backed, we need to write it now.
4158 if (this->map_is_anonymous_ && !this->is_temporary_)
4160 size_t bytes_to_write = this->file_size_;
4161 size_t offset = 0;
4162 while (bytes_to_write > 0)
4164 ssize_t bytes_written = ::write(this->o_, this->base_ + offset,
4165 bytes_to_write);
4166 if (bytes_written == 0)
4167 gold_error(_("%s: write: unexpected 0 return-value"), this->name_);
4168 else if (bytes_written < 0)
4169 gold_error(_("%s: write: %s"), this->name_, strerror(errno));
4170 else
4172 bytes_to_write -= bytes_written;
4173 offset += bytes_written;
4177 this->unmap();
4179 // We don't close stdout or stderr
4180 if (this->o_ != STDOUT_FILENO
4181 && this->o_ != STDERR_FILENO
4182 && !this->is_temporary_)
4183 if (::close(this->o_) < 0)
4184 gold_error(_("%s: close: %s"), this->name_, strerror(errno));
4185 this->o_ = -1;
4188 // Instantiate the templates we need. We could use the configure
4189 // script to restrict this to only the ones for implemented targets.
4191 #ifdef HAVE_TARGET_32_LITTLE
4192 template
4193 off_t
4194 Output_section::add_input_section<32, false>(
4195 Sized_relobj<32, false>* object,
4196 unsigned int shndx,
4197 const char* secname,
4198 const elfcpp::Shdr<32, false>& shdr,
4199 unsigned int reloc_shndx,
4200 bool have_sections_script);
4201 #endif
4203 #ifdef HAVE_TARGET_32_BIG
4204 template
4205 off_t
4206 Output_section::add_input_section<32, true>(
4207 Sized_relobj<32, true>* object,
4208 unsigned int shndx,
4209 const char* secname,
4210 const elfcpp::Shdr<32, true>& shdr,
4211 unsigned int reloc_shndx,
4212 bool have_sections_script);
4213 #endif
4215 #ifdef HAVE_TARGET_64_LITTLE
4216 template
4217 off_t
4218 Output_section::add_input_section<64, false>(
4219 Sized_relobj<64, false>* object,
4220 unsigned int shndx,
4221 const char* secname,
4222 const elfcpp::Shdr<64, false>& shdr,
4223 unsigned int reloc_shndx,
4224 bool have_sections_script);
4225 #endif
4227 #ifdef HAVE_TARGET_64_BIG
4228 template
4229 off_t
4230 Output_section::add_input_section<64, true>(
4231 Sized_relobj<64, true>* object,
4232 unsigned int shndx,
4233 const char* secname,
4234 const elfcpp::Shdr<64, true>& shdr,
4235 unsigned int reloc_shndx,
4236 bool have_sections_script);
4237 #endif
4239 #ifdef HAVE_TARGET_32_LITTLE
4240 template
4241 class Output_reloc<elfcpp::SHT_REL, false, 32, false>;
4242 #endif
4244 #ifdef HAVE_TARGET_32_BIG
4245 template
4246 class Output_reloc<elfcpp::SHT_REL, false, 32, true>;
4247 #endif
4249 #ifdef HAVE_TARGET_64_LITTLE
4250 template
4251 class Output_reloc<elfcpp::SHT_REL, false, 64, false>;
4252 #endif
4254 #ifdef HAVE_TARGET_64_BIG
4255 template
4256 class Output_reloc<elfcpp::SHT_REL, false, 64, true>;
4257 #endif
4259 #ifdef HAVE_TARGET_32_LITTLE
4260 template
4261 class Output_reloc<elfcpp::SHT_REL, true, 32, false>;
4262 #endif
4264 #ifdef HAVE_TARGET_32_BIG
4265 template
4266 class Output_reloc<elfcpp::SHT_REL, true, 32, true>;
4267 #endif
4269 #ifdef HAVE_TARGET_64_LITTLE
4270 template
4271 class Output_reloc<elfcpp::SHT_REL, true, 64, false>;
4272 #endif
4274 #ifdef HAVE_TARGET_64_BIG
4275 template
4276 class Output_reloc<elfcpp::SHT_REL, true, 64, true>;
4277 #endif
4279 #ifdef HAVE_TARGET_32_LITTLE
4280 template
4281 class Output_reloc<elfcpp::SHT_RELA, false, 32, false>;
4282 #endif
4284 #ifdef HAVE_TARGET_32_BIG
4285 template
4286 class Output_reloc<elfcpp::SHT_RELA, false, 32, true>;
4287 #endif
4289 #ifdef HAVE_TARGET_64_LITTLE
4290 template
4291 class Output_reloc<elfcpp::SHT_RELA, false, 64, false>;
4292 #endif
4294 #ifdef HAVE_TARGET_64_BIG
4295 template
4296 class Output_reloc<elfcpp::SHT_RELA, false, 64, true>;
4297 #endif
4299 #ifdef HAVE_TARGET_32_LITTLE
4300 template
4301 class Output_reloc<elfcpp::SHT_RELA, true, 32, false>;
4302 #endif
4304 #ifdef HAVE_TARGET_32_BIG
4305 template
4306 class Output_reloc<elfcpp::SHT_RELA, true, 32, true>;
4307 #endif
4309 #ifdef HAVE_TARGET_64_LITTLE
4310 template
4311 class Output_reloc<elfcpp::SHT_RELA, true, 64, false>;
4312 #endif
4314 #ifdef HAVE_TARGET_64_BIG
4315 template
4316 class Output_reloc<elfcpp::SHT_RELA, true, 64, true>;
4317 #endif
4319 #ifdef HAVE_TARGET_32_LITTLE
4320 template
4321 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
4322 #endif
4324 #ifdef HAVE_TARGET_32_BIG
4325 template
4326 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
4327 #endif
4329 #ifdef HAVE_TARGET_64_LITTLE
4330 template
4331 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
4332 #endif
4334 #ifdef HAVE_TARGET_64_BIG
4335 template
4336 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
4337 #endif
4339 #ifdef HAVE_TARGET_32_LITTLE
4340 template
4341 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
4342 #endif
4344 #ifdef HAVE_TARGET_32_BIG
4345 template
4346 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
4347 #endif
4349 #ifdef HAVE_TARGET_64_LITTLE
4350 template
4351 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
4352 #endif
4354 #ifdef HAVE_TARGET_64_BIG
4355 template
4356 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
4357 #endif
4359 #ifdef HAVE_TARGET_32_LITTLE
4360 template
4361 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
4362 #endif
4364 #ifdef HAVE_TARGET_32_BIG
4365 template
4366 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
4367 #endif
4369 #ifdef HAVE_TARGET_64_LITTLE
4370 template
4371 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
4372 #endif
4374 #ifdef HAVE_TARGET_64_BIG
4375 template
4376 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
4377 #endif
4379 #ifdef HAVE_TARGET_32_LITTLE
4380 template
4381 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
4382 #endif
4384 #ifdef HAVE_TARGET_32_BIG
4385 template
4386 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
4387 #endif
4389 #ifdef HAVE_TARGET_64_LITTLE
4390 template
4391 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
4392 #endif
4394 #ifdef HAVE_TARGET_64_BIG
4395 template
4396 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
4397 #endif
4399 #ifdef HAVE_TARGET_32_LITTLE
4400 template
4401 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, false>;
4402 #endif
4404 #ifdef HAVE_TARGET_32_BIG
4405 template
4406 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, true>;
4407 #endif
4409 #ifdef HAVE_TARGET_64_LITTLE
4410 template
4411 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, false>;
4412 #endif
4414 #ifdef HAVE_TARGET_64_BIG
4415 template
4416 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, true>;
4417 #endif
4419 #ifdef HAVE_TARGET_32_LITTLE
4420 template
4421 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, false>;
4422 #endif
4424 #ifdef HAVE_TARGET_32_BIG
4425 template
4426 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, true>;
4427 #endif
4429 #ifdef HAVE_TARGET_64_LITTLE
4430 template
4431 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, false>;
4432 #endif
4434 #ifdef HAVE_TARGET_64_BIG
4435 template
4436 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, true>;
4437 #endif
4439 #ifdef HAVE_TARGET_32_LITTLE
4440 template
4441 class Output_data_group<32, false>;
4442 #endif
4444 #ifdef HAVE_TARGET_32_BIG
4445 template
4446 class Output_data_group<32, true>;
4447 #endif
4449 #ifdef HAVE_TARGET_64_LITTLE
4450 template
4451 class Output_data_group<64, false>;
4452 #endif
4454 #ifdef HAVE_TARGET_64_BIG
4455 template
4456 class Output_data_group<64, true>;
4457 #endif
4459 #ifdef HAVE_TARGET_32_LITTLE
4460 template
4461 class Output_data_got<32, false>;
4462 #endif
4464 #ifdef HAVE_TARGET_32_BIG
4465 template
4466 class Output_data_got<32, true>;
4467 #endif
4469 #ifdef HAVE_TARGET_64_LITTLE
4470 template
4471 class Output_data_got<64, false>;
4472 #endif
4474 #ifdef HAVE_TARGET_64_BIG
4475 template
4476 class Output_data_got<64, true>;
4477 #endif
4479 } // End namespace gold.