Speed up relocations against local symbols in merged sections.
[deliverable/binutils-gdb.git] / gold / output.cc
1 // output.cc -- manage the output file for gold
2
3 // Copyright 2006, 2007 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5
6 // This file is part of gold.
7
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.
12
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.
17
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.
22
23 #include "gold.h"
24
25 #include <cstdlib>
26 #include <cerrno>
27 #include <fcntl.h>
28 #include <unistd.h>
29 #include <sys/mman.h>
30 #include <sys/stat.h>
31 #include <algorithm>
32 #include "libiberty.h" // for unlink_if_ordinary()
33
34 #include "parameters.h"
35 #include "object.h"
36 #include "symtab.h"
37 #include "reloc.h"
38 #include "merge.h"
39 #include "output.h"
40
41 // Some BSD systems still use MAP_ANON instead of MAP_ANONYMOUS
42 #ifndef MAP_ANONYMOUS
43 # define MAP_ANONYMOUS MAP_ANON
44 #endif
45
46 namespace gold
47 {
48
49 // Output_data variables.
50
51 bool Output_data::allocated_sizes_are_fixed;
52
53 // Output_data methods.
54
55 Output_data::~Output_data()
56 {
57 }
58
59 // Return the default alignment for the target size.
60
61 uint64_t
62 Output_data::default_alignment()
63 {
64 return Output_data::default_alignment_for_size(parameters->get_size());
65 }
66
67 // Return the default alignment for a size--32 or 64.
68
69 uint64_t
70 Output_data::default_alignment_for_size(int size)
71 {
72 if (size == 32)
73 return 4;
74 else if (size == 64)
75 return 8;
76 else
77 gold_unreachable();
78 }
79
80 // Output_section_header methods. This currently assumes that the
81 // segment and section lists are complete at construction time.
82
83 Output_section_headers::Output_section_headers(
84 const Layout* layout,
85 const Layout::Segment_list* segment_list,
86 const Layout::Section_list* unattached_section_list,
87 const Stringpool* secnamepool)
88 : layout_(layout),
89 segment_list_(segment_list),
90 unattached_section_list_(unattached_section_list),
91 secnamepool_(secnamepool)
92 {
93 // Count all the sections. Start with 1 for the null section.
94 off_t count = 1;
95 for (Layout::Segment_list::const_iterator p = segment_list->begin();
96 p != segment_list->end();
97 ++p)
98 if ((*p)->type() == elfcpp::PT_LOAD)
99 count += (*p)->output_section_count();
100 count += unattached_section_list->size();
101
102 const int size = parameters->get_size();
103 int shdr_size;
104 if (size == 32)
105 shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
106 else if (size == 64)
107 shdr_size = elfcpp::Elf_sizes<64>::shdr_size;
108 else
109 gold_unreachable();
110
111 this->set_data_size(count * shdr_size);
112 }
113
114 // Write out the section headers.
115
116 void
117 Output_section_headers::do_write(Output_file* of)
118 {
119 if (parameters->get_size() == 32)
120 {
121 if (parameters->is_big_endian())
122 {
123 #ifdef HAVE_TARGET_32_BIG
124 this->do_sized_write<32, true>(of);
125 #else
126 gold_unreachable();
127 #endif
128 }
129 else
130 {
131 #ifdef HAVE_TARGET_32_LITTLE
132 this->do_sized_write<32, false>(of);
133 #else
134 gold_unreachable();
135 #endif
136 }
137 }
138 else if (parameters->get_size() == 64)
139 {
140 if (parameters->is_big_endian())
141 {
142 #ifdef HAVE_TARGET_64_BIG
143 this->do_sized_write<64, true>(of);
144 #else
145 gold_unreachable();
146 #endif
147 }
148 else
149 {
150 #ifdef HAVE_TARGET_64_LITTLE
151 this->do_sized_write<64, false>(of);
152 #else
153 gold_unreachable();
154 #endif
155 }
156 }
157 else
158 gold_unreachable();
159 }
160
161 template<int size, bool big_endian>
162 void
163 Output_section_headers::do_sized_write(Output_file* of)
164 {
165 off_t all_shdrs_size = this->data_size();
166 unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size);
167
168 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
169 unsigned char* v = view;
170
171 {
172 typename elfcpp::Shdr_write<size, big_endian> oshdr(v);
173 oshdr.put_sh_name(0);
174 oshdr.put_sh_type(elfcpp::SHT_NULL);
175 oshdr.put_sh_flags(0);
176 oshdr.put_sh_addr(0);
177 oshdr.put_sh_offset(0);
178 oshdr.put_sh_size(0);
179 oshdr.put_sh_link(0);
180 oshdr.put_sh_info(0);
181 oshdr.put_sh_addralign(0);
182 oshdr.put_sh_entsize(0);
183 }
184
185 v += shdr_size;
186
187 unsigned shndx = 1;
188 for (Layout::Segment_list::const_iterator p = this->segment_list_->begin();
189 p != this->segment_list_->end();
190 ++p)
191 v = (*p)->write_section_headers SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
192 this->layout_, this->secnamepool_, v, &shndx
193 SELECT_SIZE_ENDIAN(size, big_endian));
194 for (Layout::Section_list::const_iterator p =
195 this->unattached_section_list_->begin();
196 p != this->unattached_section_list_->end();
197 ++p)
198 {
199 gold_assert(shndx == (*p)->out_shndx());
200 elfcpp::Shdr_write<size, big_endian> oshdr(v);
201 (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
202 v += shdr_size;
203 ++shndx;
204 }
205
206 of->write_output_view(this->offset(), all_shdrs_size, view);
207 }
208
209 // Output_segment_header methods.
210
211 Output_segment_headers::Output_segment_headers(
212 const Layout::Segment_list& segment_list)
213 : segment_list_(segment_list)
214 {
215 const int size = parameters->get_size();
216 int phdr_size;
217 if (size == 32)
218 phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
219 else if (size == 64)
220 phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
221 else
222 gold_unreachable();
223
224 this->set_data_size(segment_list.size() * phdr_size);
225 }
226
227 void
228 Output_segment_headers::do_write(Output_file* of)
229 {
230 if (parameters->get_size() == 32)
231 {
232 if (parameters->is_big_endian())
233 {
234 #ifdef HAVE_TARGET_32_BIG
235 this->do_sized_write<32, true>(of);
236 #else
237 gold_unreachable();
238 #endif
239 }
240 else
241 {
242 #ifdef HAVE_TARGET_32_LITTLE
243 this->do_sized_write<32, false>(of);
244 #else
245 gold_unreachable();
246 #endif
247 }
248 }
249 else if (parameters->get_size() == 64)
250 {
251 if (parameters->is_big_endian())
252 {
253 #ifdef HAVE_TARGET_64_BIG
254 this->do_sized_write<64, true>(of);
255 #else
256 gold_unreachable();
257 #endif
258 }
259 else
260 {
261 #ifdef HAVE_TARGET_64_LITTLE
262 this->do_sized_write<64, false>(of);
263 #else
264 gold_unreachable();
265 #endif
266 }
267 }
268 else
269 gold_unreachable();
270 }
271
272 template<int size, bool big_endian>
273 void
274 Output_segment_headers::do_sized_write(Output_file* of)
275 {
276 const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
277 off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
278 unsigned char* view = of->get_output_view(this->offset(),
279 all_phdrs_size);
280 unsigned char* v = view;
281 for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
282 p != this->segment_list_.end();
283 ++p)
284 {
285 elfcpp::Phdr_write<size, big_endian> ophdr(v);
286 (*p)->write_header(&ophdr);
287 v += phdr_size;
288 }
289
290 of->write_output_view(this->offset(), all_phdrs_size, view);
291 }
292
293 // Output_file_header methods.
294
295 Output_file_header::Output_file_header(const Target* target,
296 const Symbol_table* symtab,
297 const Output_segment_headers* osh)
298 : target_(target),
299 symtab_(symtab),
300 segment_header_(osh),
301 section_header_(NULL),
302 shstrtab_(NULL)
303 {
304 const int size = parameters->get_size();
305 int ehdr_size;
306 if (size == 32)
307 ehdr_size = elfcpp::Elf_sizes<32>::ehdr_size;
308 else if (size == 64)
309 ehdr_size = elfcpp::Elf_sizes<64>::ehdr_size;
310 else
311 gold_unreachable();
312
313 this->set_data_size(ehdr_size);
314 }
315
316 // Set the section table information for a file header.
317
318 void
319 Output_file_header::set_section_info(const Output_section_headers* shdrs,
320 const Output_section* shstrtab)
321 {
322 this->section_header_ = shdrs;
323 this->shstrtab_ = shstrtab;
324 }
325
326 // Write out the file header.
327
328 void
329 Output_file_header::do_write(Output_file* of)
330 {
331 gold_assert(this->offset() == 0);
332
333 if (parameters->get_size() == 32)
334 {
335 if (parameters->is_big_endian())
336 {
337 #ifdef HAVE_TARGET_32_BIG
338 this->do_sized_write<32, true>(of);
339 #else
340 gold_unreachable();
341 #endif
342 }
343 else
344 {
345 #ifdef HAVE_TARGET_32_LITTLE
346 this->do_sized_write<32, false>(of);
347 #else
348 gold_unreachable();
349 #endif
350 }
351 }
352 else if (parameters->get_size() == 64)
353 {
354 if (parameters->is_big_endian())
355 {
356 #ifdef HAVE_TARGET_64_BIG
357 this->do_sized_write<64, true>(of);
358 #else
359 gold_unreachable();
360 #endif
361 }
362 else
363 {
364 #ifdef HAVE_TARGET_64_LITTLE
365 this->do_sized_write<64, false>(of);
366 #else
367 gold_unreachable();
368 #endif
369 }
370 }
371 else
372 gold_unreachable();
373 }
374
375 // Write out the file header with appropriate size and endianess.
376
377 template<int size, bool big_endian>
378 void
379 Output_file_header::do_sized_write(Output_file* of)
380 {
381 gold_assert(this->offset() == 0);
382
383 int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
384 unsigned char* view = of->get_output_view(0, ehdr_size);
385 elfcpp::Ehdr_write<size, big_endian> oehdr(view);
386
387 unsigned char e_ident[elfcpp::EI_NIDENT];
388 memset(e_ident, 0, elfcpp::EI_NIDENT);
389 e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
390 e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
391 e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
392 e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
393 if (size == 32)
394 e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
395 else if (size == 64)
396 e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
397 else
398 gold_unreachable();
399 e_ident[elfcpp::EI_DATA] = (big_endian
400 ? elfcpp::ELFDATA2MSB
401 : elfcpp::ELFDATA2LSB);
402 e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
403 // FIXME: Some targets may need to set EI_OSABI and EI_ABIVERSION.
404 oehdr.put_e_ident(e_ident);
405
406 elfcpp::ET e_type;
407 if (parameters->output_is_object())
408 e_type = elfcpp::ET_REL;
409 else if (parameters->output_is_shared())
410 e_type = elfcpp::ET_DYN;
411 else
412 e_type = elfcpp::ET_EXEC;
413 oehdr.put_e_type(e_type);
414
415 oehdr.put_e_machine(this->target_->machine_code());
416 oehdr.put_e_version(elfcpp::EV_CURRENT);
417
418 // FIXME: Need to support -e, and target specific entry symbol.
419 Symbol* sym = this->symtab_->lookup("_start");
420 typename Sized_symbol<size>::Value_type v;
421 if (sym == NULL)
422 v = 0;
423 else
424 {
425 Sized_symbol<size>* ssym;
426 ssym = this->symtab_->get_sized_symbol SELECT_SIZE_NAME(size) (
427 sym SELECT_SIZE(size));
428 v = ssym->value();
429 }
430 oehdr.put_e_entry(v);
431
432 oehdr.put_e_phoff(this->segment_header_->offset());
433 oehdr.put_e_shoff(this->section_header_->offset());
434
435 // FIXME: The target needs to set the flags.
436 oehdr.put_e_flags(0);
437
438 oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
439 oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
440 oehdr.put_e_phnum(this->segment_header_->data_size()
441 / elfcpp::Elf_sizes<size>::phdr_size);
442 oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
443 oehdr.put_e_shnum(this->section_header_->data_size()
444 / elfcpp::Elf_sizes<size>::shdr_size);
445 oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
446
447 of->write_output_view(0, ehdr_size, view);
448 }
449
450 // Output_data_const methods.
451
452 void
453 Output_data_const::do_write(Output_file* of)
454 {
455 of->write(this->offset(), this->data_.data(), this->data_.size());
456 }
457
458 // Output_data_const_buffer methods.
459
460 void
461 Output_data_const_buffer::do_write(Output_file* of)
462 {
463 of->write(this->offset(), this->p_, this->data_size());
464 }
465
466 // Output_section_data methods.
467
468 // Record the output section, and set the entry size and such.
469
470 void
471 Output_section_data::set_output_section(Output_section* os)
472 {
473 gold_assert(this->output_section_ == NULL);
474 this->output_section_ = os;
475 this->do_adjust_output_section(os);
476 }
477
478 // Return the section index of the output section.
479
480 unsigned int
481 Output_section_data::do_out_shndx() const
482 {
483 gold_assert(this->output_section_ != NULL);
484 return this->output_section_->out_shndx();
485 }
486
487 // Output_data_strtab methods.
488
489 // Set the final data size.
490
491 void
492 Output_data_strtab::set_final_data_size()
493 {
494 this->strtab_->set_string_offsets();
495 this->set_data_size(this->strtab_->get_strtab_size());
496 }
497
498 // Write out a string table.
499
500 void
501 Output_data_strtab::do_write(Output_file* of)
502 {
503 this->strtab_->write(of, this->offset());
504 }
505
506 // Output_reloc methods.
507
508 // A reloc against a global symbol.
509
510 template<bool dynamic, int size, bool big_endian>
511 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
512 Symbol* gsym,
513 unsigned int type,
514 Output_data* od,
515 Address address,
516 bool is_relative)
517 : address_(address), local_sym_index_(GSYM_CODE), type_(type),
518 is_relative_(is_relative), shndx_(INVALID_CODE)
519 {
520 this->u1_.gsym = gsym;
521 this->u2_.od = od;
522 if (dynamic && !is_relative)
523 gsym->set_needs_dynsym_entry();
524 }
525
526 template<bool dynamic, int size, bool big_endian>
527 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
528 Symbol* gsym,
529 unsigned int type,
530 Relobj* relobj,
531 unsigned int shndx,
532 Address address,
533 bool is_relative)
534 : address_(address), local_sym_index_(GSYM_CODE), type_(type),
535 is_relative_(is_relative), shndx_(shndx)
536 {
537 gold_assert(shndx != INVALID_CODE);
538 this->u1_.gsym = gsym;
539 this->u2_.relobj = relobj;
540 if (dynamic && !is_relative)
541 gsym->set_needs_dynsym_entry();
542 }
543
544 // A reloc against a local symbol.
545
546 template<bool dynamic, int size, bool big_endian>
547 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
548 Sized_relobj<size, big_endian>* relobj,
549 unsigned int local_sym_index,
550 unsigned int type,
551 Output_data* od,
552 Address address,
553 bool is_relative)
554 : address_(address), local_sym_index_(local_sym_index), type_(type),
555 is_relative_(is_relative), shndx_(INVALID_CODE)
556 {
557 gold_assert(local_sym_index != GSYM_CODE
558 && local_sym_index != INVALID_CODE);
559 this->u1_.relobj = relobj;
560 this->u2_.od = od;
561 if (dynamic && !is_relative)
562 relobj->set_needs_output_dynsym_entry(local_sym_index);
563 }
564
565 template<bool dynamic, int size, bool big_endian>
566 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
567 Sized_relobj<size, big_endian>* relobj,
568 unsigned int local_sym_index,
569 unsigned int type,
570 unsigned int shndx,
571 Address address,
572 bool is_relative)
573 : address_(address), local_sym_index_(local_sym_index), type_(type),
574 is_relative_(is_relative), shndx_(shndx)
575 {
576 gold_assert(local_sym_index != GSYM_CODE
577 && local_sym_index != INVALID_CODE);
578 gold_assert(shndx != INVALID_CODE);
579 this->u1_.relobj = relobj;
580 this->u2_.relobj = relobj;
581 if (dynamic && !is_relative)
582 relobj->set_needs_output_dynsym_entry(local_sym_index);
583 }
584
585 // A reloc against the STT_SECTION symbol of an output section.
586
587 template<bool dynamic, int size, bool big_endian>
588 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
589 Output_section* os,
590 unsigned int type,
591 Output_data* od,
592 Address address)
593 : address_(address), local_sym_index_(SECTION_CODE), type_(type),
594 is_relative_(false), shndx_(INVALID_CODE)
595 {
596 this->u1_.os = os;
597 this->u2_.od = od;
598 if (dynamic)
599 os->set_needs_dynsym_index();
600 }
601
602 template<bool dynamic, int size, bool big_endian>
603 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
604 Output_section* os,
605 unsigned int type,
606 Relobj* relobj,
607 unsigned int shndx,
608 Address address)
609 : address_(address), local_sym_index_(SECTION_CODE), type_(type),
610 is_relative_(false), shndx_(shndx)
611 {
612 gold_assert(shndx != INVALID_CODE);
613 this->u1_.os = os;
614 this->u2_.relobj = relobj;
615 if (dynamic)
616 os->set_needs_dynsym_index();
617 }
618
619 // Get the symbol index of a relocation.
620
621 template<bool dynamic, int size, bool big_endian>
622 unsigned int
623 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
624 const
625 {
626 unsigned int index;
627 switch (this->local_sym_index_)
628 {
629 case INVALID_CODE:
630 gold_unreachable();
631
632 case GSYM_CODE:
633 if (this->u1_.gsym == NULL)
634 index = 0;
635 else if (dynamic)
636 index = this->u1_.gsym->dynsym_index();
637 else
638 index = this->u1_.gsym->symtab_index();
639 break;
640
641 case SECTION_CODE:
642 if (dynamic)
643 index = this->u1_.os->dynsym_index();
644 else
645 index = this->u1_.os->symtab_index();
646 break;
647
648 case 0:
649 // Relocations without symbols use a symbol index of 0.
650 index = 0;
651 break;
652
653 default:
654 if (dynamic)
655 index = this->u1_.relobj->dynsym_index(this->local_sym_index_);
656 else
657 index = this->u1_.relobj->symtab_index(this->local_sym_index_);
658 break;
659 }
660 gold_assert(index != -1U);
661 return index;
662 }
663
664 // Write out the offset and info fields of a Rel or Rela relocation
665 // entry.
666
667 template<bool dynamic, int size, bool big_endian>
668 template<typename Write_rel>
669 void
670 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
671 Write_rel* wr) const
672 {
673 Address address = this->address_;
674 if (this->shndx_ != INVALID_CODE)
675 {
676 section_offset_type off;
677 Output_section* os = this->u2_.relobj->output_section(this->shndx_,
678 &off);
679 gold_assert(os != NULL);
680 if (off != -1)
681 address += os->address() + off;
682 else
683 {
684 address = os->output_address(this->u2_.relobj, this->shndx_,
685 address);
686 gold_assert(address != -1U);
687 }
688 }
689 else if (this->u2_.od != NULL)
690 address += this->u2_.od->address();
691 wr->put_r_offset(address);
692 unsigned int sym_index = this->is_relative_ ? 0 : this->get_symbol_index();
693 wr->put_r_info(elfcpp::elf_r_info<size>(sym_index, this->type_));
694 }
695
696 // Write out a Rel relocation.
697
698 template<bool dynamic, int size, bool big_endian>
699 void
700 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
701 unsigned char* pov) const
702 {
703 elfcpp::Rel_write<size, big_endian> orel(pov);
704 this->write_rel(&orel);
705 }
706
707 // Get the value of the symbol referred to by a Rel relocation.
708
709 template<bool dynamic, int size, bool big_endian>
710 typename elfcpp::Elf_types<size>::Elf_Addr
711 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::symbol_value() const
712 {
713 if (this->local_sym_index_ == GSYM_CODE)
714 {
715 const Sized_symbol<size>* sym;
716 sym = static_cast<const Sized_symbol<size>*>(this->u1_.gsym);
717 return sym->value();
718 }
719 gold_assert(this->local_sym_index_ != SECTION_CODE
720 && this->local_sym_index_ != INVALID_CODE);
721 const Sized_relobj<size, big_endian>* relobj = this->u1_.relobj;
722 return relobj->local_symbol_value(this->local_sym_index_);
723 }
724
725 // Write out a Rela relocation.
726
727 template<bool dynamic, int size, bool big_endian>
728 void
729 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
730 unsigned char* pov) const
731 {
732 elfcpp::Rela_write<size, big_endian> orel(pov);
733 this->rel_.write_rel(&orel);
734 Addend addend = this->addend_;
735 if (rel_.is_relative())
736 addend += rel_.symbol_value();
737 orel.put_r_addend(addend);
738 }
739
740 // Output_data_reloc_base methods.
741
742 // Adjust the output section.
743
744 template<int sh_type, bool dynamic, int size, bool big_endian>
745 void
746 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
747 ::do_adjust_output_section(Output_section* os)
748 {
749 if (sh_type == elfcpp::SHT_REL)
750 os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
751 else if (sh_type == elfcpp::SHT_RELA)
752 os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
753 else
754 gold_unreachable();
755 if (dynamic)
756 os->set_should_link_to_dynsym();
757 else
758 os->set_should_link_to_symtab();
759 }
760
761 // Write out relocation data.
762
763 template<int sh_type, bool dynamic, int size, bool big_endian>
764 void
765 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
766 Output_file* of)
767 {
768 const off_t off = this->offset();
769 const off_t oview_size = this->data_size();
770 unsigned char* const oview = of->get_output_view(off, oview_size);
771
772 unsigned char* pov = oview;
773 for (typename Relocs::const_iterator p = this->relocs_.begin();
774 p != this->relocs_.end();
775 ++p)
776 {
777 p->write(pov);
778 pov += reloc_size;
779 }
780
781 gold_assert(pov - oview == oview_size);
782
783 of->write_output_view(off, oview_size, oview);
784
785 // We no longer need the relocation entries.
786 this->relocs_.clear();
787 }
788
789 // Output_data_got::Got_entry methods.
790
791 // Write out the entry.
792
793 template<int size, bool big_endian>
794 void
795 Output_data_got<size, big_endian>::Got_entry::write(unsigned char* pov) const
796 {
797 Valtype val = 0;
798
799 switch (this->local_sym_index_)
800 {
801 case GSYM_CODE:
802 {
803 // If the symbol is resolved locally, we need to write out the
804 // link-time value, which will be relocated dynamically by a
805 // RELATIVE relocation.
806 Symbol* gsym = this->u_.gsym;
807 Sized_symbol<size>* sgsym;
808 // This cast is a bit ugly. We don't want to put a
809 // virtual method in Symbol, because we want Symbol to be
810 // as small as possible.
811 sgsym = static_cast<Sized_symbol<size>*>(gsym);
812 val = sgsym->value();
813 }
814 break;
815
816 case CONSTANT_CODE:
817 val = this->u_.constant;
818 break;
819
820 default:
821 val = this->u_.object->local_symbol_value(this->local_sym_index_);
822 break;
823 }
824
825 elfcpp::Swap<size, big_endian>::writeval(pov, val);
826 }
827
828 // Output_data_got methods.
829
830 // Add an entry for a global symbol to the GOT. This returns true if
831 // this is a new GOT entry, false if the symbol already had a GOT
832 // entry.
833
834 template<int size, bool big_endian>
835 bool
836 Output_data_got<size, big_endian>::add_global(Symbol* gsym)
837 {
838 if (gsym->has_got_offset())
839 return false;
840
841 this->entries_.push_back(Got_entry(gsym));
842 this->set_got_size();
843 gsym->set_got_offset(this->last_got_offset());
844 return true;
845 }
846
847 // Add an entry for a global symbol to the GOT, and add a dynamic
848 // relocation of type R_TYPE for the GOT entry.
849 template<int size, bool big_endian>
850 void
851 Output_data_got<size, big_endian>::add_global_with_rel(
852 Symbol* gsym,
853 Rel_dyn* rel_dyn,
854 unsigned int r_type)
855 {
856 if (gsym->has_got_offset())
857 return;
858
859 this->entries_.push_back(Got_entry());
860 this->set_got_size();
861 unsigned int got_offset = this->last_got_offset();
862 gsym->set_got_offset(got_offset);
863 rel_dyn->add_global(gsym, r_type, this, got_offset);
864 }
865
866 template<int size, bool big_endian>
867 void
868 Output_data_got<size, big_endian>::add_global_with_rela(
869 Symbol* gsym,
870 Rela_dyn* rela_dyn,
871 unsigned int r_type)
872 {
873 if (gsym->has_got_offset())
874 return;
875
876 this->entries_.push_back(Got_entry());
877 this->set_got_size();
878 unsigned int got_offset = this->last_got_offset();
879 gsym->set_got_offset(got_offset);
880 rela_dyn->add_global(gsym, r_type, this, got_offset, 0);
881 }
882
883 // Add an entry for a local symbol to the GOT. This returns true if
884 // this is a new GOT entry, false if the symbol already has a GOT
885 // entry.
886
887 template<int size, bool big_endian>
888 bool
889 Output_data_got<size, big_endian>::add_local(
890 Sized_relobj<size, big_endian>* object,
891 unsigned int symndx)
892 {
893 if (object->local_has_got_offset(symndx))
894 return false;
895
896 this->entries_.push_back(Got_entry(object, symndx));
897 this->set_got_size();
898 object->set_local_got_offset(symndx, this->last_got_offset());
899 return true;
900 }
901
902 // Add an entry for a local symbol to the GOT, and add a dynamic
903 // relocation of type R_TYPE for the GOT entry.
904 template<int size, bool big_endian>
905 void
906 Output_data_got<size, big_endian>::add_local_with_rel(
907 Sized_relobj<size, big_endian>* object,
908 unsigned int symndx,
909 Rel_dyn* rel_dyn,
910 unsigned int r_type)
911 {
912 if (object->local_has_got_offset(symndx))
913 return;
914
915 this->entries_.push_back(Got_entry());
916 this->set_got_size();
917 unsigned int got_offset = this->last_got_offset();
918 object->set_local_got_offset(symndx, got_offset);
919 rel_dyn->add_local(object, symndx, r_type, this, got_offset);
920 }
921
922 template<int size, bool big_endian>
923 void
924 Output_data_got<size, big_endian>::add_local_with_rela(
925 Sized_relobj<size, big_endian>* object,
926 unsigned int symndx,
927 Rela_dyn* rela_dyn,
928 unsigned int r_type)
929 {
930 if (object->local_has_got_offset(symndx))
931 return;
932
933 this->entries_.push_back(Got_entry());
934 this->set_got_size();
935 unsigned int got_offset = this->last_got_offset();
936 object->set_local_got_offset(symndx, got_offset);
937 rela_dyn->add_local(object, symndx, r_type, this, got_offset, 0);
938 }
939
940 // Add an entry (or a pair of entries) for a global TLS symbol to the GOT.
941 // In a pair of entries, the first value in the pair will be used for the
942 // module index, and the second value will be used for the dtv-relative
943 // offset. This returns true if this is a new GOT entry, false if the symbol
944 // already has a GOT entry.
945
946 template<int size, bool big_endian>
947 bool
948 Output_data_got<size, big_endian>::add_global_tls(Symbol* gsym, bool need_pair)
949 {
950 if (gsym->has_tls_got_offset(need_pair))
951 return false;
952
953 this->entries_.push_back(Got_entry(gsym));
954 gsym->set_tls_got_offset(this->last_got_offset(), need_pair);
955 if (need_pair)
956 this->entries_.push_back(Got_entry(gsym));
957 this->set_got_size();
958 return true;
959 }
960
961 // Add an entry for a global TLS symbol to the GOT, and add a dynamic
962 // relocation of type R_TYPE.
963 template<int size, bool big_endian>
964 void
965 Output_data_got<size, big_endian>::add_global_tls_with_rel(
966 Symbol* gsym,
967 Rel_dyn* rel_dyn,
968 unsigned int r_type)
969 {
970 if (gsym->has_tls_got_offset(false))
971 return;
972
973 this->entries_.push_back(Got_entry());
974 this->set_got_size();
975 unsigned int got_offset = this->last_got_offset();
976 gsym->set_tls_got_offset(got_offset, false);
977 rel_dyn->add_global(gsym, r_type, this, got_offset);
978 }
979
980 template<int size, bool big_endian>
981 void
982 Output_data_got<size, big_endian>::add_global_tls_with_rela(
983 Symbol* gsym,
984 Rela_dyn* rela_dyn,
985 unsigned int r_type)
986 {
987 if (gsym->has_tls_got_offset(false))
988 return;
989
990 this->entries_.push_back(Got_entry());
991 this->set_got_size();
992 unsigned int got_offset = this->last_got_offset();
993 gsym->set_tls_got_offset(got_offset, false);
994 rela_dyn->add_global(gsym, r_type, this, got_offset, 0);
995 }
996
997 // Add a pair of entries for a global TLS symbol to the GOT, and add
998 // dynamic relocations of type MOD_R_TYPE and DTV_R_TYPE, respectively.
999 template<int size, bool big_endian>
1000 void
1001 Output_data_got<size, big_endian>::add_global_tls_with_rel(
1002 Symbol* gsym,
1003 Rel_dyn* rel_dyn,
1004 unsigned int mod_r_type,
1005 unsigned int dtv_r_type)
1006 {
1007 if (gsym->has_tls_got_offset(true))
1008 return;
1009
1010 this->entries_.push_back(Got_entry());
1011 unsigned int got_offset = this->last_got_offset();
1012 gsym->set_tls_got_offset(got_offset, true);
1013 rel_dyn->add_global(gsym, mod_r_type, this, got_offset);
1014
1015 this->entries_.push_back(Got_entry());
1016 this->set_got_size();
1017 got_offset = this->last_got_offset();
1018 rel_dyn->add_global(gsym, dtv_r_type, this, got_offset);
1019 }
1020
1021 template<int size, bool big_endian>
1022 void
1023 Output_data_got<size, big_endian>::add_global_tls_with_rela(
1024 Symbol* gsym,
1025 Rela_dyn* rela_dyn,
1026 unsigned int mod_r_type,
1027 unsigned int dtv_r_type)
1028 {
1029 if (gsym->has_tls_got_offset(true))
1030 return;
1031
1032 this->entries_.push_back(Got_entry());
1033 unsigned int got_offset = this->last_got_offset();
1034 gsym->set_tls_got_offset(got_offset, true);
1035 rela_dyn->add_global(gsym, mod_r_type, this, got_offset, 0);
1036
1037 this->entries_.push_back(Got_entry());
1038 this->set_got_size();
1039 got_offset = this->last_got_offset();
1040 rela_dyn->add_global(gsym, dtv_r_type, this, got_offset, 0);
1041 }
1042
1043 // Add an entry (or a pair of entries) for a local TLS symbol to the GOT.
1044 // In a pair of entries, the first value in the pair will be used for the
1045 // module index, and the second value will be used for the dtv-relative
1046 // offset. This returns true if this is a new GOT entry, false if the symbol
1047 // already has a GOT entry.
1048
1049 template<int size, bool big_endian>
1050 bool
1051 Output_data_got<size, big_endian>::add_local_tls(
1052 Sized_relobj<size, big_endian>* object,
1053 unsigned int symndx,
1054 bool need_pair)
1055 {
1056 if (object->local_has_tls_got_offset(symndx, need_pair))
1057 return false;
1058
1059 this->entries_.push_back(Got_entry(object, symndx));
1060 object->set_local_tls_got_offset(symndx, this->last_got_offset(), need_pair);
1061 if (need_pair)
1062 this->entries_.push_back(Got_entry(object, symndx));
1063 this->set_got_size();
1064 return true;
1065 }
1066
1067 // Add an entry (or pair of entries) for a local TLS symbol to the GOT,
1068 // and add a dynamic relocation of type R_TYPE for the first GOT entry.
1069 // Because this is a local symbol, the first GOT entry can be relocated
1070 // relative to a section symbol, and the second GOT entry will have an
1071 // dtv-relative value that can be computed at link time.
1072 template<int size, bool big_endian>
1073 void
1074 Output_data_got<size, big_endian>::add_local_tls_with_rel(
1075 Sized_relobj<size, big_endian>* object,
1076 unsigned int symndx,
1077 unsigned int shndx,
1078 bool need_pair,
1079 Rel_dyn* rel_dyn,
1080 unsigned int r_type)
1081 {
1082 if (object->local_has_tls_got_offset(symndx, need_pair))
1083 return;
1084
1085 this->entries_.push_back(Got_entry());
1086 unsigned int got_offset = this->last_got_offset();
1087 object->set_local_tls_got_offset(symndx, got_offset, need_pair);
1088 section_offset_type off;
1089 Output_section* os = object->output_section(shndx, &off);
1090 rel_dyn->add_output_section(os, r_type, this, got_offset);
1091
1092 // The second entry of the pair will be statically initialized
1093 // with the TLS offset of the symbol.
1094 if (need_pair)
1095 this->entries_.push_back(Got_entry(object, symndx));
1096
1097 this->set_got_size();
1098 }
1099
1100 template<int size, bool big_endian>
1101 void
1102 Output_data_got<size, big_endian>::add_local_tls_with_rela(
1103 Sized_relobj<size, big_endian>* object,
1104 unsigned int symndx,
1105 unsigned int shndx,
1106 bool need_pair,
1107 Rela_dyn* rela_dyn,
1108 unsigned int r_type)
1109 {
1110 if (object->local_has_tls_got_offset(symndx, need_pair))
1111 return;
1112
1113 this->entries_.push_back(Got_entry());
1114 unsigned int got_offset = this->last_got_offset();
1115 object->set_local_tls_got_offset(symndx, got_offset, need_pair);
1116 section_offset_type off;
1117 Output_section* os = object->output_section(shndx, &off);
1118 rela_dyn->add_output_section(os, r_type, this, got_offset, 0);
1119
1120 // The second entry of the pair will be statically initialized
1121 // with the TLS offset of the symbol.
1122 if (need_pair)
1123 this->entries_.push_back(Got_entry(object, symndx));
1124
1125 this->set_got_size();
1126 }
1127
1128 // Write out the GOT.
1129
1130 template<int size, bool big_endian>
1131 void
1132 Output_data_got<size, big_endian>::do_write(Output_file* of)
1133 {
1134 const int add = size / 8;
1135
1136 const off_t off = this->offset();
1137 const off_t oview_size = this->data_size();
1138 unsigned char* const oview = of->get_output_view(off, oview_size);
1139
1140 unsigned char* pov = oview;
1141 for (typename Got_entries::const_iterator p = this->entries_.begin();
1142 p != this->entries_.end();
1143 ++p)
1144 {
1145 p->write(pov);
1146 pov += add;
1147 }
1148
1149 gold_assert(pov - oview == oview_size);
1150
1151 of->write_output_view(off, oview_size, oview);
1152
1153 // We no longer need the GOT entries.
1154 this->entries_.clear();
1155 }
1156
1157 // Output_data_dynamic::Dynamic_entry methods.
1158
1159 // Write out the entry.
1160
1161 template<int size, bool big_endian>
1162 void
1163 Output_data_dynamic::Dynamic_entry::write(
1164 unsigned char* pov,
1165 const Stringpool* pool
1166 ACCEPT_SIZE_ENDIAN) const
1167 {
1168 typename elfcpp::Elf_types<size>::Elf_WXword val;
1169 switch (this->classification_)
1170 {
1171 case DYNAMIC_NUMBER:
1172 val = this->u_.val;
1173 break;
1174
1175 case DYNAMIC_SECTION_ADDRESS:
1176 val = this->u_.od->address();
1177 break;
1178
1179 case DYNAMIC_SECTION_SIZE:
1180 val = this->u_.od->data_size();
1181 break;
1182
1183 case DYNAMIC_SYMBOL:
1184 {
1185 const Sized_symbol<size>* s =
1186 static_cast<const Sized_symbol<size>*>(this->u_.sym);
1187 val = s->value();
1188 }
1189 break;
1190
1191 case DYNAMIC_STRING:
1192 val = pool->get_offset(this->u_.str);
1193 break;
1194
1195 default:
1196 gold_unreachable();
1197 }
1198
1199 elfcpp::Dyn_write<size, big_endian> dw(pov);
1200 dw.put_d_tag(this->tag_);
1201 dw.put_d_val(val);
1202 }
1203
1204 // Output_data_dynamic methods.
1205
1206 // Adjust the output section to set the entry size.
1207
1208 void
1209 Output_data_dynamic::do_adjust_output_section(Output_section* os)
1210 {
1211 if (parameters->get_size() == 32)
1212 os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
1213 else if (parameters->get_size() == 64)
1214 os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
1215 else
1216 gold_unreachable();
1217 }
1218
1219 // Set the final data size.
1220
1221 void
1222 Output_data_dynamic::set_final_data_size()
1223 {
1224 // Add the terminating entry.
1225 this->add_constant(elfcpp::DT_NULL, 0);
1226
1227 int dyn_size;
1228 if (parameters->get_size() == 32)
1229 dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
1230 else if (parameters->get_size() == 64)
1231 dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
1232 else
1233 gold_unreachable();
1234 this->set_data_size(this->entries_.size() * dyn_size);
1235 }
1236
1237 // Write out the dynamic entries.
1238
1239 void
1240 Output_data_dynamic::do_write(Output_file* of)
1241 {
1242 if (parameters->get_size() == 32)
1243 {
1244 if (parameters->is_big_endian())
1245 {
1246 #ifdef HAVE_TARGET_32_BIG
1247 this->sized_write<32, true>(of);
1248 #else
1249 gold_unreachable();
1250 #endif
1251 }
1252 else
1253 {
1254 #ifdef HAVE_TARGET_32_LITTLE
1255 this->sized_write<32, false>(of);
1256 #else
1257 gold_unreachable();
1258 #endif
1259 }
1260 }
1261 else if (parameters->get_size() == 64)
1262 {
1263 if (parameters->is_big_endian())
1264 {
1265 #ifdef HAVE_TARGET_64_BIG
1266 this->sized_write<64, true>(of);
1267 #else
1268 gold_unreachable();
1269 #endif
1270 }
1271 else
1272 {
1273 #ifdef HAVE_TARGET_64_LITTLE
1274 this->sized_write<64, false>(of);
1275 #else
1276 gold_unreachable();
1277 #endif
1278 }
1279 }
1280 else
1281 gold_unreachable();
1282 }
1283
1284 template<int size, bool big_endian>
1285 void
1286 Output_data_dynamic::sized_write(Output_file* of)
1287 {
1288 const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
1289
1290 const off_t offset = this->offset();
1291 const off_t oview_size = this->data_size();
1292 unsigned char* const oview = of->get_output_view(offset, oview_size);
1293
1294 unsigned char* pov = oview;
1295 for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
1296 p != this->entries_.end();
1297 ++p)
1298 {
1299 p->write SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
1300 pov, this->pool_ SELECT_SIZE_ENDIAN(size, big_endian));
1301 pov += dyn_size;
1302 }
1303
1304 gold_assert(pov - oview == oview_size);
1305
1306 of->write_output_view(offset, oview_size, oview);
1307
1308 // We no longer need the dynamic entries.
1309 this->entries_.clear();
1310 }
1311
1312 // Output_section::Input_section methods.
1313
1314 // Return the data size. For an input section we store the size here.
1315 // For an Output_section_data, we have to ask it for the size.
1316
1317 off_t
1318 Output_section::Input_section::data_size() const
1319 {
1320 if (this->is_input_section())
1321 return this->u1_.data_size;
1322 else
1323 return this->u2_.posd->data_size();
1324 }
1325
1326 // Set the address and file offset.
1327
1328 void
1329 Output_section::Input_section::set_address_and_file_offset(
1330 uint64_t address,
1331 off_t file_offset,
1332 off_t section_file_offset)
1333 {
1334 if (this->is_input_section())
1335 this->u2_.object->set_section_offset(this->shndx_,
1336 file_offset - section_file_offset);
1337 else
1338 this->u2_.posd->set_address_and_file_offset(address, file_offset);
1339 }
1340
1341 // Finalize the data size.
1342
1343 void
1344 Output_section::Input_section::finalize_data_size()
1345 {
1346 if (!this->is_input_section())
1347 this->u2_.posd->finalize_data_size();
1348 }
1349
1350 // Try to turn an input offset into an output offset. We want to
1351 // return the output offset relative to the start of this
1352 // Input_section in the output section.
1353
1354 inline bool
1355 Output_section::Input_section::output_offset(
1356 const Relobj* object,
1357 unsigned int shndx,
1358 section_offset_type offset,
1359 section_offset_type *poutput) const
1360 {
1361 if (!this->is_input_section())
1362 return this->u2_.posd->output_offset(object, shndx, offset, poutput);
1363 else
1364 {
1365 if (this->shndx_ != shndx || this->u2_.object != object)
1366 return false;
1367 *poutput = offset;
1368 return true;
1369 }
1370 }
1371
1372 // Return whether this is the merge section for the input section
1373 // SHNDX in OBJECT.
1374
1375 inline bool
1376 Output_section::Input_section::is_merge_section_for(const Relobj* object,
1377 unsigned int shndx) const
1378 {
1379 if (this->is_input_section())
1380 return false;
1381 return this->u2_.posd->is_merge_section_for(object, shndx);
1382 }
1383
1384 // Write out the data. We don't have to do anything for an input
1385 // section--they are handled via Object::relocate--but this is where
1386 // we write out the data for an Output_section_data.
1387
1388 void
1389 Output_section::Input_section::write(Output_file* of)
1390 {
1391 if (!this->is_input_section())
1392 this->u2_.posd->write(of);
1393 }
1394
1395 // Write the data to a buffer. As for write(), we don't have to do
1396 // anything for an input section.
1397
1398 void
1399 Output_section::Input_section::write_to_buffer(unsigned char* buffer)
1400 {
1401 if (!this->is_input_section())
1402 this->u2_.posd->write_to_buffer(buffer);
1403 }
1404
1405 // Output_section methods.
1406
1407 // Construct an Output_section. NAME will point into a Stringpool.
1408
1409 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
1410 elfcpp::Elf_Xword flags)
1411 : name_(name),
1412 addralign_(0),
1413 entsize_(0),
1414 link_section_(NULL),
1415 link_(0),
1416 info_section_(NULL),
1417 info_(0),
1418 type_(type),
1419 flags_(flags),
1420 out_shndx_(-1U),
1421 symtab_index_(0),
1422 dynsym_index_(0),
1423 input_sections_(),
1424 first_input_offset_(0),
1425 fills_(),
1426 postprocessing_buffer_(NULL),
1427 needs_symtab_index_(false),
1428 needs_dynsym_index_(false),
1429 should_link_to_symtab_(false),
1430 should_link_to_dynsym_(false),
1431 after_input_sections_(false),
1432 requires_postprocessing_(false),
1433 tls_offset_(0)
1434 {
1435 // An unallocated section has no address. Forcing this means that
1436 // we don't need special treatment for symbols defined in debug
1437 // sections.
1438 if ((flags & elfcpp::SHF_ALLOC) == 0)
1439 this->set_address(0);
1440 }
1441
1442 Output_section::~Output_section()
1443 {
1444 }
1445
1446 // Set the entry size.
1447
1448 void
1449 Output_section::set_entsize(uint64_t v)
1450 {
1451 if (this->entsize_ == 0)
1452 this->entsize_ = v;
1453 else
1454 gold_assert(this->entsize_ == v);
1455 }
1456
1457 // Add the input section SHNDX, with header SHDR, named SECNAME, in
1458 // OBJECT, to the Output_section. RELOC_SHNDX is the index of a
1459 // relocation section which applies to this section, or 0 if none, or
1460 // -1U if more than one. Return the offset of the input section
1461 // within the output section. Return -1 if the input section will
1462 // receive special handling. In the normal case we don't always keep
1463 // track of input sections for an Output_section. Instead, each
1464 // Object keeps track of the Output_section for each of its input
1465 // sections.
1466
1467 template<int size, bool big_endian>
1468 off_t
1469 Output_section::add_input_section(Sized_relobj<size, big_endian>* object,
1470 unsigned int shndx,
1471 const char* secname,
1472 const elfcpp::Shdr<size, big_endian>& shdr,
1473 unsigned int reloc_shndx)
1474 {
1475 elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
1476 if ((addralign & (addralign - 1)) != 0)
1477 {
1478 object->error(_("invalid alignment %lu for section \"%s\""),
1479 static_cast<unsigned long>(addralign), secname);
1480 addralign = 1;
1481 }
1482
1483 if (addralign > this->addralign_)
1484 this->addralign_ = addralign;
1485
1486 typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
1487 uint64_t entsize = shdr.get_sh_entsize();
1488
1489 // .debug_str is a mergeable string section, but is not always so
1490 // marked by compilers. Mark manually here so we can optimize.
1491 if (strcmp(secname, ".debug_str") == 0)
1492 {
1493 sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS);
1494 entsize = 1;
1495 }
1496
1497 // If this is a SHF_MERGE section, we pass all the input sections to
1498 // a Output_data_merge. We don't try to handle relocations for such
1499 // a section.
1500 if ((sh_flags & elfcpp::SHF_MERGE) != 0
1501 && reloc_shndx == 0)
1502 {
1503 if (this->add_merge_input_section(object, shndx, sh_flags,
1504 entsize, addralign))
1505 {
1506 // Tell the relocation routines that they need to call the
1507 // output_offset method to determine the final address.
1508 return -1;
1509 }
1510 }
1511
1512 off_t offset_in_section = this->current_data_size_for_child();
1513 off_t aligned_offset_in_section = align_address(offset_in_section,
1514 addralign);
1515
1516 if (aligned_offset_in_section > offset_in_section
1517 && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
1518 && object->target()->has_code_fill())
1519 {
1520 // We need to add some fill data. Using fill_list_ when
1521 // possible is an optimization, since we will often have fill
1522 // sections without input sections.
1523 off_t fill_len = aligned_offset_in_section - offset_in_section;
1524 if (this->input_sections_.empty())
1525 this->fills_.push_back(Fill(offset_in_section, fill_len));
1526 else
1527 {
1528 // FIXME: When relaxing, the size needs to adjust to
1529 // maintain a constant alignment.
1530 std::string fill_data(object->target()->code_fill(fill_len));
1531 Output_data_const* odc = new Output_data_const(fill_data, 1);
1532 this->input_sections_.push_back(Input_section(odc));
1533 }
1534 }
1535
1536 this->set_current_data_size_for_child(aligned_offset_in_section
1537 + shdr.get_sh_size());
1538
1539 // We need to keep track of this section if we are already keeping
1540 // track of sections, or if we are relaxing. FIXME: Add test for
1541 // relaxing.
1542 if (!this->input_sections_.empty())
1543 this->input_sections_.push_back(Input_section(object, shndx,
1544 shdr.get_sh_size(),
1545 addralign));
1546
1547 return aligned_offset_in_section;
1548 }
1549
1550 // Add arbitrary data to an output section.
1551
1552 void
1553 Output_section::add_output_section_data(Output_section_data* posd)
1554 {
1555 Input_section inp(posd);
1556 this->add_output_section_data(&inp);
1557 }
1558
1559 // Add arbitrary data to an output section by Input_section.
1560
1561 void
1562 Output_section::add_output_section_data(Input_section* inp)
1563 {
1564 if (this->input_sections_.empty())
1565 this->first_input_offset_ = this->current_data_size_for_child();
1566
1567 this->input_sections_.push_back(*inp);
1568
1569 uint64_t addralign = inp->addralign();
1570 if (addralign > this->addralign_)
1571 this->addralign_ = addralign;
1572
1573 inp->set_output_section(this);
1574 }
1575
1576 // Add a merge section to an output section.
1577
1578 void
1579 Output_section::add_output_merge_section(Output_section_data* posd,
1580 bool is_string, uint64_t entsize)
1581 {
1582 Input_section inp(posd, is_string, entsize);
1583 this->add_output_section_data(&inp);
1584 }
1585
1586 // Add an input section to a SHF_MERGE section.
1587
1588 bool
1589 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
1590 uint64_t flags, uint64_t entsize,
1591 uint64_t addralign)
1592 {
1593 bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
1594
1595 // We only merge strings if the alignment is not more than the
1596 // character size. This could be handled, but it's unusual.
1597 if (is_string && addralign > entsize)
1598 return false;
1599
1600 Input_section_list::iterator p;
1601 for (p = this->input_sections_.begin();
1602 p != this->input_sections_.end();
1603 ++p)
1604 if (p->is_merge_section(is_string, entsize, addralign))
1605 {
1606 p->add_input_section(object, shndx);
1607 return true;
1608 }
1609
1610 // We handle the actual constant merging in Output_merge_data or
1611 // Output_merge_string_data.
1612 Output_section_data* posd;
1613 if (!is_string)
1614 posd = new Output_merge_data(entsize, addralign);
1615 else
1616 {
1617 switch (entsize)
1618 {
1619 case 1:
1620 posd = new Output_merge_string<char>(addralign);
1621 break;
1622 case 2:
1623 posd = new Output_merge_string<uint16_t>(addralign);
1624 break;
1625 case 4:
1626 posd = new Output_merge_string<uint32_t>(addralign);
1627 break;
1628 default:
1629 return false;
1630 }
1631 }
1632
1633 this->add_output_merge_section(posd, is_string, entsize);
1634 posd->add_input_section(object, shndx);
1635
1636 return true;
1637 }
1638
1639 // Given an address OFFSET relative to the start of input section
1640 // SHNDX in OBJECT, return whether this address is being included in
1641 // the final link. This should only be called if SHNDX in OBJECT has
1642 // a special mapping.
1643
1644 bool
1645 Output_section::is_input_address_mapped(const Relobj* object,
1646 unsigned int shndx,
1647 off_t offset) const
1648 {
1649 gold_assert(object->is_section_specially_mapped(shndx));
1650
1651 for (Input_section_list::const_iterator p = this->input_sections_.begin();
1652 p != this->input_sections_.end();
1653 ++p)
1654 {
1655 section_offset_type output_offset;
1656 if (p->output_offset(object, shndx, offset, &output_offset))
1657 return output_offset != -1;
1658 }
1659
1660 // By default we assume that the address is mapped. This should
1661 // only be called after we have passed all sections to Layout. At
1662 // that point we should know what we are discarding.
1663 return true;
1664 }
1665
1666 // Given an address OFFSET relative to the start of input section
1667 // SHNDX in object OBJECT, return the output offset relative to the
1668 // start of the input section in the output section. This should only
1669 // be called if SHNDX in OBJECT has a special mapping.
1670
1671 section_offset_type
1672 Output_section::output_offset(const Relobj* object, unsigned int shndx,
1673 section_offset_type offset) const
1674 {
1675 gold_assert(object->is_section_specially_mapped(shndx));
1676 // This can only be called meaningfully when layout is complete.
1677 gold_assert(Output_data::is_layout_complete());
1678
1679 for (Input_section_list::const_iterator p = this->input_sections_.begin();
1680 p != this->input_sections_.end();
1681 ++p)
1682 {
1683 section_offset_type output_offset;
1684 if (p->output_offset(object, shndx, offset, &output_offset))
1685 return output_offset;
1686 }
1687 gold_unreachable();
1688 }
1689
1690 // Return the output virtual address of OFFSET relative to the start
1691 // of input section SHNDX in object OBJECT.
1692
1693 uint64_t
1694 Output_section::output_address(const Relobj* object, unsigned int shndx,
1695 off_t offset) const
1696 {
1697 gold_assert(object->is_section_specially_mapped(shndx));
1698 // This can only be called meaningfully when layout is complete.
1699 gold_assert(Output_data::is_layout_complete());
1700
1701 uint64_t addr = this->address() + this->first_input_offset_;
1702 for (Input_section_list::const_iterator p = this->input_sections_.begin();
1703 p != this->input_sections_.end();
1704 ++p)
1705 {
1706 addr = align_address(addr, p->addralign());
1707 section_offset_type output_offset;
1708 if (p->output_offset(object, shndx, offset, &output_offset))
1709 {
1710 if (output_offset == -1)
1711 return -1U;
1712 return addr + output_offset;
1713 }
1714 addr += p->data_size();
1715 }
1716
1717 // If we get here, it means that we don't know the mapping for this
1718 // input section. This might happen in principle if
1719 // add_input_section were called before add_output_section_data.
1720 // But it should never actually happen.
1721
1722 gold_unreachable();
1723 }
1724
1725 // Return the output address of the start of the merged section for
1726 // input section SHNDX in object OBJECT.
1727
1728 uint64_t
1729 Output_section::starting_output_address(const Relobj* object,
1730 unsigned int shndx) const
1731 {
1732 gold_assert(object->is_section_specially_mapped(shndx));
1733
1734 uint64_t addr = this->address() + this->first_input_offset_;
1735 for (Input_section_list::const_iterator p = this->input_sections_.begin();
1736 p != this->input_sections_.end();
1737 ++p)
1738 {
1739 addr = align_address(addr, p->addralign());
1740
1741 // It would be nice if we could use the existing output_offset
1742 // method to get the output offset of input offset 0.
1743 // Unfortunately we don't know for sure that input offset 0 is
1744 // mapped at all.
1745 if (p->is_merge_section_for(object, shndx))
1746 return addr;
1747
1748 addr += p->data_size();
1749 }
1750 gold_unreachable();
1751 }
1752
1753 // Set the data size of an Output_section. This is where we handle
1754 // setting the addresses of any Output_section_data objects.
1755
1756 void
1757 Output_section::set_final_data_size()
1758 {
1759 if (this->input_sections_.empty())
1760 {
1761 this->set_data_size(this->current_data_size_for_child());
1762 return;
1763 }
1764
1765 uint64_t address = this->address();
1766 off_t startoff = this->offset();
1767 off_t off = startoff + this->first_input_offset_;
1768 for (Input_section_list::iterator p = this->input_sections_.begin();
1769 p != this->input_sections_.end();
1770 ++p)
1771 {
1772 off = align_address(off, p->addralign());
1773 p->set_address_and_file_offset(address + (off - startoff), off,
1774 startoff);
1775 off += p->data_size();
1776 }
1777
1778 this->set_data_size(off - startoff);
1779 }
1780
1781 // Set the TLS offset. Called only for SHT_TLS sections.
1782
1783 void
1784 Output_section::do_set_tls_offset(uint64_t tls_base)
1785 {
1786 this->tls_offset_ = this->address() - tls_base;
1787 }
1788
1789 // Write the section header to *OSHDR.
1790
1791 template<int size, bool big_endian>
1792 void
1793 Output_section::write_header(const Layout* layout,
1794 const Stringpool* secnamepool,
1795 elfcpp::Shdr_write<size, big_endian>* oshdr) const
1796 {
1797 oshdr->put_sh_name(secnamepool->get_offset(this->name_));
1798 oshdr->put_sh_type(this->type_);
1799 oshdr->put_sh_flags(this->flags_);
1800 oshdr->put_sh_addr(this->address());
1801 oshdr->put_sh_offset(this->offset());
1802 oshdr->put_sh_size(this->data_size());
1803 if (this->link_section_ != NULL)
1804 oshdr->put_sh_link(this->link_section_->out_shndx());
1805 else if (this->should_link_to_symtab_)
1806 oshdr->put_sh_link(layout->symtab_section()->out_shndx());
1807 else if (this->should_link_to_dynsym_)
1808 oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
1809 else
1810 oshdr->put_sh_link(this->link_);
1811 if (this->info_section_ != NULL)
1812 oshdr->put_sh_info(this->info_section_->out_shndx());
1813 else
1814 oshdr->put_sh_info(this->info_);
1815 oshdr->put_sh_addralign(this->addralign_);
1816 oshdr->put_sh_entsize(this->entsize_);
1817 }
1818
1819 // Write out the data. For input sections the data is written out by
1820 // Object::relocate, but we have to handle Output_section_data objects
1821 // here.
1822
1823 void
1824 Output_section::do_write(Output_file* of)
1825 {
1826 gold_assert(!this->requires_postprocessing());
1827
1828 off_t output_section_file_offset = this->offset();
1829 for (Fill_list::iterator p = this->fills_.begin();
1830 p != this->fills_.end();
1831 ++p)
1832 {
1833 std::string fill_data(of->target()->code_fill(p->length()));
1834 of->write(output_section_file_offset + p->section_offset(),
1835 fill_data.data(), fill_data.size());
1836 }
1837
1838 for (Input_section_list::iterator p = this->input_sections_.begin();
1839 p != this->input_sections_.end();
1840 ++p)
1841 p->write(of);
1842 }
1843
1844 // If a section requires postprocessing, create the buffer to use.
1845
1846 void
1847 Output_section::create_postprocessing_buffer()
1848 {
1849 gold_assert(this->requires_postprocessing());
1850 gold_assert(this->postprocessing_buffer_ == NULL);
1851
1852 if (!this->input_sections_.empty())
1853 {
1854 off_t off = this->first_input_offset_;
1855 for (Input_section_list::iterator p = this->input_sections_.begin();
1856 p != this->input_sections_.end();
1857 ++p)
1858 {
1859 off = align_address(off, p->addralign());
1860 p->finalize_data_size();
1861 off += p->data_size();
1862 }
1863 this->set_current_data_size_for_child(off);
1864 }
1865
1866 off_t buffer_size = this->current_data_size_for_child();
1867 this->postprocessing_buffer_ = new unsigned char[buffer_size];
1868 }
1869
1870 // Write all the data of an Output_section into the postprocessing
1871 // buffer. This is used for sections which require postprocessing,
1872 // such as compression. Input sections are handled by
1873 // Object::Relocate.
1874
1875 void
1876 Output_section::write_to_postprocessing_buffer()
1877 {
1878 gold_assert(this->requires_postprocessing());
1879
1880 Target* target = parameters->target();
1881 unsigned char* buffer = this->postprocessing_buffer();
1882 for (Fill_list::iterator p = this->fills_.begin();
1883 p != this->fills_.end();
1884 ++p)
1885 {
1886 std::string fill_data(target->code_fill(p->length()));
1887 memcpy(buffer + p->section_offset(), fill_data.data(), fill_data.size());
1888 }
1889
1890 off_t off = this->first_input_offset_;
1891 for (Input_section_list::iterator p = this->input_sections_.begin();
1892 p != this->input_sections_.end();
1893 ++p)
1894 {
1895 off = align_address(off, p->addralign());
1896 p->write_to_buffer(buffer + off);
1897 off += p->data_size();
1898 }
1899 }
1900
1901 // Print stats for merge sections to stderr.
1902
1903 void
1904 Output_section::print_merge_stats()
1905 {
1906 Input_section_list::iterator p;
1907 for (p = this->input_sections_.begin();
1908 p != this->input_sections_.end();
1909 ++p)
1910 p->print_merge_stats(this->name_);
1911 }
1912
1913 // Output segment methods.
1914
1915 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
1916 : output_data_(),
1917 output_bss_(),
1918 vaddr_(0),
1919 paddr_(0),
1920 memsz_(0),
1921 align_(0),
1922 offset_(0),
1923 filesz_(0),
1924 type_(type),
1925 flags_(flags),
1926 is_align_known_(false)
1927 {
1928 }
1929
1930 // Add an Output_section to an Output_segment.
1931
1932 void
1933 Output_segment::add_output_section(Output_section* os,
1934 elfcpp::Elf_Word seg_flags,
1935 bool front)
1936 {
1937 gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
1938 gold_assert(!this->is_align_known_);
1939
1940 // Update the segment flags.
1941 this->flags_ |= seg_flags;
1942
1943 Output_segment::Output_data_list* pdl;
1944 if (os->type() == elfcpp::SHT_NOBITS)
1945 pdl = &this->output_bss_;
1946 else
1947 pdl = &this->output_data_;
1948
1949 // So that PT_NOTE segments will work correctly, we need to ensure
1950 // that all SHT_NOTE sections are adjacent. This will normally
1951 // happen automatically, because all the SHT_NOTE input sections
1952 // will wind up in the same output section. However, it is possible
1953 // for multiple SHT_NOTE input sections to have different section
1954 // flags, and thus be in different output sections, but for the
1955 // different section flags to map into the same segment flags and
1956 // thus the same output segment.
1957
1958 // Note that while there may be many input sections in an output
1959 // section, there are normally only a few output sections in an
1960 // output segment. This loop is expected to be fast.
1961
1962 if (os->type() == elfcpp::SHT_NOTE && !pdl->empty())
1963 {
1964 Output_segment::Output_data_list::iterator p = pdl->end();
1965 do
1966 {
1967 --p;
1968 if ((*p)->is_section_type(elfcpp::SHT_NOTE))
1969 {
1970 // We don't worry about the FRONT parameter.
1971 ++p;
1972 pdl->insert(p, os);
1973 return;
1974 }
1975 }
1976 while (p != pdl->begin());
1977 }
1978
1979 // Similarly, so that PT_TLS segments will work, we need to group
1980 // SHF_TLS sections. An SHF_TLS/SHT_NOBITS section is a special
1981 // case: we group the SHF_TLS/SHT_NOBITS sections right after the
1982 // SHF_TLS/SHT_PROGBITS sections. This lets us set up PT_TLS
1983 // correctly. SHF_TLS sections get added to both a PT_LOAD segment
1984 // and the PT_TLS segment -- we do this grouping only for the
1985 // PT_LOAD segment.
1986 if (this->type_ != elfcpp::PT_TLS
1987 && (os->flags() & elfcpp::SHF_TLS) != 0
1988 && !this->output_data_.empty())
1989 {
1990 pdl = &this->output_data_;
1991 bool nobits = os->type() == elfcpp::SHT_NOBITS;
1992 bool sawtls = false;
1993 Output_segment::Output_data_list::iterator p = pdl->end();
1994 do
1995 {
1996 --p;
1997 bool insert;
1998 if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
1999 {
2000 sawtls = true;
2001 // Put a NOBITS section after the first TLS section.
2002 // But a PROGBITS section after the first TLS/PROGBITS
2003 // section.
2004 insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS);
2005 }
2006 else
2007 {
2008 // If we've gone past the TLS sections, but we've seen a
2009 // TLS section, then we need to insert this section now.
2010 insert = sawtls;
2011 }
2012
2013 if (insert)
2014 {
2015 // We don't worry about the FRONT parameter.
2016 ++p;
2017 pdl->insert(p, os);
2018 return;
2019 }
2020 }
2021 while (p != pdl->begin());
2022
2023 // There are no TLS sections yet; put this one at the requested
2024 // location in the section list.
2025 }
2026
2027 if (front)
2028 pdl->push_front(os);
2029 else
2030 pdl->push_back(os);
2031 }
2032
2033 // Add an Output_data (which is not an Output_section) to the start of
2034 // a segment.
2035
2036 void
2037 Output_segment::add_initial_output_data(Output_data* od)
2038 {
2039 gold_assert(!this->is_align_known_);
2040 this->output_data_.push_front(od);
2041 }
2042
2043 // Return the maximum alignment of the Output_data in Output_segment.
2044 // Once we compute this, we prohibit new sections from being added.
2045
2046 uint64_t
2047 Output_segment::addralign()
2048 {
2049 if (!this->is_align_known_)
2050 {
2051 uint64_t addralign;
2052
2053 addralign = Output_segment::maximum_alignment(&this->output_data_);
2054 if (addralign > this->align_)
2055 this->align_ = addralign;
2056
2057 addralign = Output_segment::maximum_alignment(&this->output_bss_);
2058 if (addralign > this->align_)
2059 this->align_ = addralign;
2060
2061 this->is_align_known_ = true;
2062 }
2063
2064 return this->align_;
2065 }
2066
2067 // Return the maximum alignment of a list of Output_data.
2068
2069 uint64_t
2070 Output_segment::maximum_alignment(const Output_data_list* pdl)
2071 {
2072 uint64_t ret = 0;
2073 for (Output_data_list::const_iterator p = pdl->begin();
2074 p != pdl->end();
2075 ++p)
2076 {
2077 uint64_t addralign = (*p)->addralign();
2078 if (addralign > ret)
2079 ret = addralign;
2080 }
2081 return ret;
2082 }
2083
2084 // Return the number of dynamic relocs applied to this segment.
2085
2086 unsigned int
2087 Output_segment::dynamic_reloc_count() const
2088 {
2089 return (this->dynamic_reloc_count_list(&this->output_data_)
2090 + this->dynamic_reloc_count_list(&this->output_bss_));
2091 }
2092
2093 // Return the number of dynamic relocs applied to an Output_data_list.
2094
2095 unsigned int
2096 Output_segment::dynamic_reloc_count_list(const Output_data_list* pdl) const
2097 {
2098 unsigned int count = 0;
2099 for (Output_data_list::const_iterator p = pdl->begin();
2100 p != pdl->end();
2101 ++p)
2102 count += (*p)->dynamic_reloc_count();
2103 return count;
2104 }
2105
2106 // Set the section addresses for an Output_segment. ADDR is the
2107 // address and *POFF is the file offset. Set the section indexes
2108 // starting with *PSHNDX. Return the address of the immediately
2109 // following segment. Update *POFF and *PSHNDX.
2110
2111 uint64_t
2112 Output_segment::set_section_addresses(uint64_t addr, off_t* poff,
2113 unsigned int* pshndx)
2114 {
2115 gold_assert(this->type_ == elfcpp::PT_LOAD);
2116
2117 this->vaddr_ = addr;
2118 this->paddr_ = addr;
2119
2120 off_t orig_off = *poff;
2121 this->offset_ = orig_off;
2122
2123 *poff = align_address(*poff, this->addralign());
2124
2125 addr = this->set_section_list_addresses(&this->output_data_, addr, poff,
2126 pshndx);
2127 this->filesz_ = *poff - orig_off;
2128
2129 off_t off = *poff;
2130
2131 uint64_t ret = this->set_section_list_addresses(&this->output_bss_, addr,
2132 poff, pshndx);
2133 this->memsz_ = *poff - orig_off;
2134
2135 // Ignore the file offset adjustments made by the BSS Output_data
2136 // objects.
2137 *poff = off;
2138
2139 return ret;
2140 }
2141
2142 // Set the addresses and file offsets in a list of Output_data
2143 // structures.
2144
2145 uint64_t
2146 Output_segment::set_section_list_addresses(Output_data_list* pdl,
2147 uint64_t addr, off_t* poff,
2148 unsigned int* pshndx)
2149 {
2150 off_t startoff = *poff;
2151
2152 off_t off = startoff;
2153 for (Output_data_list::iterator p = pdl->begin();
2154 p != pdl->end();
2155 ++p)
2156 {
2157 off = align_address(off, (*p)->addralign());
2158 (*p)->set_address_and_file_offset(addr + (off - startoff), off);
2159
2160 // Unless this is a PT_TLS segment, we want to ignore the size
2161 // of a SHF_TLS/SHT_NOBITS section. Such a section does not
2162 // affect the size of a PT_LOAD segment.
2163 if (this->type_ == elfcpp::PT_TLS
2164 || !(*p)->is_section_flag_set(elfcpp::SHF_TLS)
2165 || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
2166 off += (*p)->data_size();
2167
2168 if ((*p)->is_section())
2169 {
2170 (*p)->set_out_shndx(*pshndx);
2171 ++*pshndx;
2172 }
2173 }
2174
2175 *poff = off;
2176 return addr + (off - startoff);
2177 }
2178
2179 // For a non-PT_LOAD segment, set the offset from the sections, if
2180 // any.
2181
2182 void
2183 Output_segment::set_offset()
2184 {
2185 gold_assert(this->type_ != elfcpp::PT_LOAD);
2186
2187 if (this->output_data_.empty() && this->output_bss_.empty())
2188 {
2189 this->vaddr_ = 0;
2190 this->paddr_ = 0;
2191 this->memsz_ = 0;
2192 this->align_ = 0;
2193 this->offset_ = 0;
2194 this->filesz_ = 0;
2195 return;
2196 }
2197
2198 const Output_data* first;
2199 if (this->output_data_.empty())
2200 first = this->output_bss_.front();
2201 else
2202 first = this->output_data_.front();
2203 this->vaddr_ = first->address();
2204 this->paddr_ = this->vaddr_;
2205 this->offset_ = first->offset();
2206
2207 if (this->output_data_.empty())
2208 this->filesz_ = 0;
2209 else
2210 {
2211 const Output_data* last_data = this->output_data_.back();
2212 this->filesz_ = (last_data->address()
2213 + last_data->data_size()
2214 - this->vaddr_);
2215 }
2216
2217 const Output_data* last;
2218 if (this->output_bss_.empty())
2219 last = this->output_data_.back();
2220 else
2221 last = this->output_bss_.back();
2222 this->memsz_ = (last->address()
2223 + last->data_size()
2224 - this->vaddr_);
2225 }
2226
2227 // Set the TLS offsets of the sections in the PT_TLS segment.
2228
2229 void
2230 Output_segment::set_tls_offsets()
2231 {
2232 gold_assert(this->type_ == elfcpp::PT_TLS);
2233
2234 for (Output_data_list::iterator p = this->output_data_.begin();
2235 p != this->output_data_.end();
2236 ++p)
2237 (*p)->set_tls_offset(this->vaddr_);
2238
2239 for (Output_data_list::iterator p = this->output_bss_.begin();
2240 p != this->output_bss_.end();
2241 ++p)
2242 (*p)->set_tls_offset(this->vaddr_);
2243 }
2244
2245 // Return the number of Output_sections in an Output_segment.
2246
2247 unsigned int
2248 Output_segment::output_section_count() const
2249 {
2250 return (this->output_section_count_list(&this->output_data_)
2251 + this->output_section_count_list(&this->output_bss_));
2252 }
2253
2254 // Return the number of Output_sections in an Output_data_list.
2255
2256 unsigned int
2257 Output_segment::output_section_count_list(const Output_data_list* pdl) const
2258 {
2259 unsigned int count = 0;
2260 for (Output_data_list::const_iterator p = pdl->begin();
2261 p != pdl->end();
2262 ++p)
2263 {
2264 if ((*p)->is_section())
2265 ++count;
2266 }
2267 return count;
2268 }
2269
2270 // Write the segment data into *OPHDR.
2271
2272 template<int size, bool big_endian>
2273 void
2274 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
2275 {
2276 ophdr->put_p_type(this->type_);
2277 ophdr->put_p_offset(this->offset_);
2278 ophdr->put_p_vaddr(this->vaddr_);
2279 ophdr->put_p_paddr(this->paddr_);
2280 ophdr->put_p_filesz(this->filesz_);
2281 ophdr->put_p_memsz(this->memsz_);
2282 ophdr->put_p_flags(this->flags_);
2283 ophdr->put_p_align(this->addralign());
2284 }
2285
2286 // Write the section headers into V.
2287
2288 template<int size, bool big_endian>
2289 unsigned char*
2290 Output_segment::write_section_headers(const Layout* layout,
2291 const Stringpool* secnamepool,
2292 unsigned char* v,
2293 unsigned int *pshndx
2294 ACCEPT_SIZE_ENDIAN) const
2295 {
2296 // Every section that is attached to a segment must be attached to a
2297 // PT_LOAD segment, so we only write out section headers for PT_LOAD
2298 // segments.
2299 if (this->type_ != elfcpp::PT_LOAD)
2300 return v;
2301
2302 v = this->write_section_headers_list
2303 SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
2304 layout, secnamepool, &this->output_data_, v, pshndx
2305 SELECT_SIZE_ENDIAN(size, big_endian));
2306 v = this->write_section_headers_list
2307 SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
2308 layout, secnamepool, &this->output_bss_, v, pshndx
2309 SELECT_SIZE_ENDIAN(size, big_endian));
2310 return v;
2311 }
2312
2313 template<int size, bool big_endian>
2314 unsigned char*
2315 Output_segment::write_section_headers_list(const Layout* layout,
2316 const Stringpool* secnamepool,
2317 const Output_data_list* pdl,
2318 unsigned char* v,
2319 unsigned int* pshndx
2320 ACCEPT_SIZE_ENDIAN) const
2321 {
2322 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
2323 for (Output_data_list::const_iterator p = pdl->begin();
2324 p != pdl->end();
2325 ++p)
2326 {
2327 if ((*p)->is_section())
2328 {
2329 const Output_section* ps = static_cast<const Output_section*>(*p);
2330 gold_assert(*pshndx == ps->out_shndx());
2331 elfcpp::Shdr_write<size, big_endian> oshdr(v);
2332 ps->write_header(layout, secnamepool, &oshdr);
2333 v += shdr_size;
2334 ++*pshndx;
2335 }
2336 }
2337 return v;
2338 }
2339
2340 // Output_file methods.
2341
2342 Output_file::Output_file(const General_options& options, Target* target)
2343 : options_(options),
2344 target_(target),
2345 name_(options.output_file_name()),
2346 o_(-1),
2347 file_size_(0),
2348 base_(NULL),
2349 map_is_anonymous_(false)
2350 {
2351 }
2352
2353 // Open the output file.
2354
2355 void
2356 Output_file::open(off_t file_size)
2357 {
2358 this->file_size_ = file_size;
2359
2360 // Unlink the file first; otherwise the open() may fail if the file
2361 // is busy (e.g. it's an executable that's currently being executed).
2362 //
2363 // However, the linker may be part of a system where a zero-length
2364 // file is created for it to write to, with tight permissions (gcc
2365 // 2.95 did something like this). Unlinking the file would work
2366 // around those permission controls, so we only unlink if the file
2367 // has a non-zero size. We also unlink only regular files to avoid
2368 // trouble with directories/etc.
2369 //
2370 // If we fail, continue; this command is merely a best-effort attempt
2371 // to improve the odds for open().
2372
2373 // We let the name "-" mean "stdout"
2374 if (strcmp(this->name_, "-") == 0)
2375 this->o_ = STDOUT_FILENO;
2376 else
2377 {
2378 struct stat s;
2379 if (::stat(this->name_, &s) == 0 && s.st_size != 0)
2380 unlink_if_ordinary(this->name_);
2381
2382 int mode = parameters->output_is_object() ? 0666 : 0777;
2383 int o = ::open(this->name_, O_RDWR | O_CREAT | O_TRUNC, mode);
2384 if (o < 0)
2385 gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
2386 this->o_ = o;
2387 }
2388
2389 this->map();
2390 }
2391
2392 // Resize the output file.
2393
2394 void
2395 Output_file::resize(off_t file_size)
2396 {
2397 // If the mmap is mapping an anonymous memory buffer, this is easy:
2398 // just mremap to the new size. If it's mapping to a file, we want
2399 // to unmap to flush to the file, then remap after growing the file.
2400 if (this->map_is_anonymous_)
2401 {
2402 void* base = ::mremap(this->base_, this->file_size_, file_size,
2403 MREMAP_MAYMOVE);
2404 if (base == MAP_FAILED)
2405 gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno));
2406 this->base_ = static_cast<unsigned char*>(base);
2407 this->file_size_ = file_size;
2408 }
2409 else
2410 {
2411 this->unmap();
2412 this->file_size_ = file_size;
2413 this->map();
2414 }
2415 }
2416
2417 // Map the file into memory.
2418
2419 void
2420 Output_file::map()
2421 {
2422 const int o = this->o_;
2423
2424 // If the output file is not a regular file, don't try to mmap it;
2425 // instead, we'll mmap a block of memory (an anonymous buffer), and
2426 // then later write the buffer to the file.
2427 void* base;
2428 struct stat statbuf;
2429 if (o == STDOUT_FILENO || o == STDERR_FILENO
2430 || ::fstat(o, &statbuf) != 0
2431 || !S_ISREG(statbuf.st_mode))
2432 {
2433 this->map_is_anonymous_ = true;
2434 base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
2435 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
2436 }
2437 else
2438 {
2439 // Write out one byte to make the file the right size.
2440 if (::lseek(o, this->file_size_ - 1, SEEK_SET) < 0)
2441 gold_fatal(_("%s: lseek: %s"), this->name_, strerror(errno));
2442 char b = 0;
2443 if (::write(o, &b, 1) != 1)
2444 gold_fatal(_("%s: write: %s"), this->name_, strerror(errno));
2445
2446 // Map the file into memory.
2447 this->map_is_anonymous_ = false;
2448 base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
2449 MAP_SHARED, o, 0);
2450 }
2451 if (base == MAP_FAILED)
2452 gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
2453 this->base_ = static_cast<unsigned char*>(base);
2454 }
2455
2456 // Unmap the file from memory.
2457
2458 void
2459 Output_file::unmap()
2460 {
2461 if (::munmap(this->base_, this->file_size_) < 0)
2462 gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
2463 this->base_ = NULL;
2464 }
2465
2466 // Close the output file.
2467
2468 void
2469 Output_file::close()
2470 {
2471 // If the map isn't file-backed, we need to write it now.
2472 if (this->map_is_anonymous_)
2473 {
2474 size_t bytes_to_write = this->file_size_;
2475 while (bytes_to_write > 0)
2476 {
2477 ssize_t bytes_written = ::write(this->o_, this->base_, bytes_to_write);
2478 if (bytes_written == 0)
2479 gold_error(_("%s: write: unexpected 0 return-value"), this->name_);
2480 else if (bytes_written < 0)
2481 gold_error(_("%s: write: %s"), this->name_, strerror(errno));
2482 else
2483 bytes_to_write -= bytes_written;
2484 }
2485 }
2486 this->unmap();
2487
2488 // We don't close stdout or stderr
2489 if (this->o_ != STDOUT_FILENO && this->o_ != STDERR_FILENO)
2490 if (::close(this->o_) < 0)
2491 gold_error(_("%s: close: %s"), this->name_, strerror(errno));
2492 this->o_ = -1;
2493 }
2494
2495 // Instantiate the templates we need. We could use the configure
2496 // script to restrict this to only the ones for implemented targets.
2497
2498 #ifdef HAVE_TARGET_32_LITTLE
2499 template
2500 off_t
2501 Output_section::add_input_section<32, false>(
2502 Sized_relobj<32, false>* object,
2503 unsigned int shndx,
2504 const char* secname,
2505 const elfcpp::Shdr<32, false>& shdr,
2506 unsigned int reloc_shndx);
2507 #endif
2508
2509 #ifdef HAVE_TARGET_32_BIG
2510 template
2511 off_t
2512 Output_section::add_input_section<32, true>(
2513 Sized_relobj<32, true>* object,
2514 unsigned int shndx,
2515 const char* secname,
2516 const elfcpp::Shdr<32, true>& shdr,
2517 unsigned int reloc_shndx);
2518 #endif
2519
2520 #ifdef HAVE_TARGET_64_LITTLE
2521 template
2522 off_t
2523 Output_section::add_input_section<64, false>(
2524 Sized_relobj<64, false>* object,
2525 unsigned int shndx,
2526 const char* secname,
2527 const elfcpp::Shdr<64, false>& shdr,
2528 unsigned int reloc_shndx);
2529 #endif
2530
2531 #ifdef HAVE_TARGET_64_BIG
2532 template
2533 off_t
2534 Output_section::add_input_section<64, true>(
2535 Sized_relobj<64, true>* object,
2536 unsigned int shndx,
2537 const char* secname,
2538 const elfcpp::Shdr<64, true>& shdr,
2539 unsigned int reloc_shndx);
2540 #endif
2541
2542 #ifdef HAVE_TARGET_32_LITTLE
2543 template
2544 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
2545 #endif
2546
2547 #ifdef HAVE_TARGET_32_BIG
2548 template
2549 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
2550 #endif
2551
2552 #ifdef HAVE_TARGET_64_LITTLE
2553 template
2554 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
2555 #endif
2556
2557 #ifdef HAVE_TARGET_64_BIG
2558 template
2559 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
2560 #endif
2561
2562 #ifdef HAVE_TARGET_32_LITTLE
2563 template
2564 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
2565 #endif
2566
2567 #ifdef HAVE_TARGET_32_BIG
2568 template
2569 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
2570 #endif
2571
2572 #ifdef HAVE_TARGET_64_LITTLE
2573 template
2574 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
2575 #endif
2576
2577 #ifdef HAVE_TARGET_64_BIG
2578 template
2579 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
2580 #endif
2581
2582 #ifdef HAVE_TARGET_32_LITTLE
2583 template
2584 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
2585 #endif
2586
2587 #ifdef HAVE_TARGET_32_BIG
2588 template
2589 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
2590 #endif
2591
2592 #ifdef HAVE_TARGET_64_LITTLE
2593 template
2594 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
2595 #endif
2596
2597 #ifdef HAVE_TARGET_64_BIG
2598 template
2599 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
2600 #endif
2601
2602 #ifdef HAVE_TARGET_32_LITTLE
2603 template
2604 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
2605 #endif
2606
2607 #ifdef HAVE_TARGET_32_BIG
2608 template
2609 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
2610 #endif
2611
2612 #ifdef HAVE_TARGET_64_LITTLE
2613 template
2614 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
2615 #endif
2616
2617 #ifdef HAVE_TARGET_64_BIG
2618 template
2619 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
2620 #endif
2621
2622 #ifdef HAVE_TARGET_32_LITTLE
2623 template
2624 class Output_data_got<32, false>;
2625 #endif
2626
2627 #ifdef HAVE_TARGET_32_BIG
2628 template
2629 class Output_data_got<32, true>;
2630 #endif
2631
2632 #ifdef HAVE_TARGET_64_LITTLE
2633 template
2634 class Output_data_got<64, false>;
2635 #endif
2636
2637 #ifdef HAVE_TARGET_64_BIG
2638 template
2639 class Output_data_got<64, true>;
2640 #endif
2641
2642 } // End namespace gold.
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