* config/tc-i386.h (NOP_OPCODE): Restore.
[deliverable/binutils-gdb.git] / gold / output.cc
1 // output.cc -- manage the output file for gold
2
3 #include "gold.h"
4
5 #include <cstdlib>
6 #include <cerrno>
7 #include <fcntl.h>
8 #include <unistd.h>
9 #include <sys/mman.h>
10 #include <algorithm>
11
12 #include "object.h"
13 #include "symtab.h"
14 #include "reloc.h"
15 #include "output.h"
16
17 namespace gold
18 {
19
20 // Output_data variables.
21
22 bool Output_data::sizes_are_fixed;
23
24 // Output_data methods.
25
26 Output_data::~Output_data()
27 {
28 }
29
30 // Set the address and offset.
31
32 void
33 Output_data::set_address(uint64_t addr, off_t off)
34 {
35 this->address_ = addr;
36 this->offset_ = off;
37
38 // Let the child class know.
39 this->do_set_address(addr, off);
40 }
41
42 // Return the default alignment for a size--32 or 64.
43
44 uint64_t
45 Output_data::default_alignment(int size)
46 {
47 if (size == 32)
48 return 4;
49 else if (size == 64)
50 return 8;
51 else
52 gold_unreachable();
53 }
54
55 // Output_section_header methods. This currently assumes that the
56 // segment and section lists are complete at construction time.
57
58 Output_section_headers::Output_section_headers(
59 int size,
60 bool big_endian,
61 const Layout* layout,
62 const Layout::Segment_list* segment_list,
63 const Layout::Section_list* unattached_section_list,
64 const Stringpool* secnamepool)
65 : size_(size),
66 big_endian_(big_endian),
67 layout_(layout),
68 segment_list_(segment_list),
69 unattached_section_list_(unattached_section_list),
70 secnamepool_(secnamepool)
71 {
72 // Count all the sections. Start with 1 for the null section.
73 off_t count = 1;
74 for (Layout::Segment_list::const_iterator p = segment_list->begin();
75 p != segment_list->end();
76 ++p)
77 if ((*p)->type() == elfcpp::PT_LOAD)
78 count += (*p)->output_section_count();
79 count += unattached_section_list->size();
80
81 int shdr_size;
82 if (size == 32)
83 shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
84 else if (size == 64)
85 shdr_size = elfcpp::Elf_sizes<64>::shdr_size;
86 else
87 gold_unreachable();
88
89 this->set_data_size(count * shdr_size);
90 }
91
92 // Write out the section headers.
93
94 void
95 Output_section_headers::do_write(Output_file* of)
96 {
97 if (this->size_ == 32)
98 {
99 if (this->big_endian_)
100 this->do_sized_write<32, true>(of);
101 else
102 this->do_sized_write<32, false>(of);
103 }
104 else if (this->size_ == 64)
105 {
106 if (this->big_endian_)
107 this->do_sized_write<64, true>(of);
108 else
109 this->do_sized_write<64, false>(of);
110 }
111 else
112 gold_unreachable();
113 }
114
115 template<int size, bool big_endian>
116 void
117 Output_section_headers::do_sized_write(Output_file* of)
118 {
119 off_t all_shdrs_size = this->data_size();
120 unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size);
121
122 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
123 unsigned char* v = view;
124
125 {
126 typename elfcpp::Shdr_write<size, big_endian> oshdr(v);
127 oshdr.put_sh_name(0);
128 oshdr.put_sh_type(elfcpp::SHT_NULL);
129 oshdr.put_sh_flags(0);
130 oshdr.put_sh_addr(0);
131 oshdr.put_sh_offset(0);
132 oshdr.put_sh_size(0);
133 oshdr.put_sh_link(0);
134 oshdr.put_sh_info(0);
135 oshdr.put_sh_addralign(0);
136 oshdr.put_sh_entsize(0);
137 }
138
139 v += shdr_size;
140
141 unsigned shndx = 1;
142 for (Layout::Segment_list::const_iterator p = this->segment_list_->begin();
143 p != this->segment_list_->end();
144 ++p)
145 v = (*p)->write_section_headers SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
146 this->layout_, this->secnamepool_, v, &shndx
147 SELECT_SIZE_ENDIAN(size, big_endian));
148 for (Layout::Section_list::const_iterator p =
149 this->unattached_section_list_->begin();
150 p != this->unattached_section_list_->end();
151 ++p)
152 {
153 gold_assert(shndx == (*p)->out_shndx());
154 elfcpp::Shdr_write<size, big_endian> oshdr(v);
155 (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
156 v += shdr_size;
157 ++shndx;
158 }
159
160 of->write_output_view(this->offset(), all_shdrs_size, view);
161 }
162
163 // Output_segment_header methods.
164
165 Output_segment_headers::Output_segment_headers(
166 int size,
167 bool big_endian,
168 const Layout::Segment_list& segment_list)
169 : size_(size), big_endian_(big_endian), segment_list_(segment_list)
170 {
171 int phdr_size;
172 if (size == 32)
173 phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
174 else if (size == 64)
175 phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
176 else
177 gold_unreachable();
178
179 this->set_data_size(segment_list.size() * phdr_size);
180 }
181
182 void
183 Output_segment_headers::do_write(Output_file* of)
184 {
185 if (this->size_ == 32)
186 {
187 if (this->big_endian_)
188 this->do_sized_write<32, true>(of);
189 else
190 this->do_sized_write<32, false>(of);
191 }
192 else if (this->size_ == 64)
193 {
194 if (this->big_endian_)
195 this->do_sized_write<64, true>(of);
196 else
197 this->do_sized_write<64, false>(of);
198 }
199 else
200 gold_unreachable();
201 }
202
203 template<int size, bool big_endian>
204 void
205 Output_segment_headers::do_sized_write(Output_file* of)
206 {
207 const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
208 off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
209 unsigned char* view = of->get_output_view(this->offset(),
210 all_phdrs_size);
211 unsigned char* v = view;
212 for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
213 p != this->segment_list_.end();
214 ++p)
215 {
216 elfcpp::Phdr_write<size, big_endian> ophdr(v);
217 (*p)->write_header(&ophdr);
218 v += phdr_size;
219 }
220
221 of->write_output_view(this->offset(), all_phdrs_size, view);
222 }
223
224 // Output_file_header methods.
225
226 Output_file_header::Output_file_header(int size,
227 bool big_endian,
228 const General_options& options,
229 const Target* target,
230 const Symbol_table* symtab,
231 const Output_segment_headers* osh)
232 : size_(size),
233 big_endian_(big_endian),
234 options_(options),
235 target_(target),
236 symtab_(symtab),
237 segment_header_(osh),
238 section_header_(NULL),
239 shstrtab_(NULL)
240 {
241 int ehdr_size;
242 if (size == 32)
243 ehdr_size = elfcpp::Elf_sizes<32>::ehdr_size;
244 else if (size == 64)
245 ehdr_size = elfcpp::Elf_sizes<64>::ehdr_size;
246 else
247 gold_unreachable();
248
249 this->set_data_size(ehdr_size);
250 }
251
252 // Set the section table information for a file header.
253
254 void
255 Output_file_header::set_section_info(const Output_section_headers* shdrs,
256 const Output_section* shstrtab)
257 {
258 this->section_header_ = shdrs;
259 this->shstrtab_ = shstrtab;
260 }
261
262 // Write out the file header.
263
264 void
265 Output_file_header::do_write(Output_file* of)
266 {
267 if (this->size_ == 32)
268 {
269 if (this->big_endian_)
270 this->do_sized_write<32, true>(of);
271 else
272 this->do_sized_write<32, false>(of);
273 }
274 else if (this->size_ == 64)
275 {
276 if (this->big_endian_)
277 this->do_sized_write<64, true>(of);
278 else
279 this->do_sized_write<64, false>(of);
280 }
281 else
282 gold_unreachable();
283 }
284
285 // Write out the file header with appropriate size and endianess.
286
287 template<int size, bool big_endian>
288 void
289 Output_file_header::do_sized_write(Output_file* of)
290 {
291 gold_assert(this->offset() == 0);
292
293 int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
294 unsigned char* view = of->get_output_view(0, ehdr_size);
295 elfcpp::Ehdr_write<size, big_endian> oehdr(view);
296
297 unsigned char e_ident[elfcpp::EI_NIDENT];
298 memset(e_ident, 0, elfcpp::EI_NIDENT);
299 e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
300 e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
301 e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
302 e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
303 if (size == 32)
304 e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
305 else if (size == 64)
306 e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
307 else
308 gold_unreachable();
309 e_ident[elfcpp::EI_DATA] = (big_endian
310 ? elfcpp::ELFDATA2MSB
311 : elfcpp::ELFDATA2LSB);
312 e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
313 // FIXME: Some targets may need to set EI_OSABI and EI_ABIVERSION.
314 oehdr.put_e_ident(e_ident);
315
316 elfcpp::ET e_type;
317 // FIXME: ET_DYN.
318 if (this->options_.is_relocatable())
319 e_type = elfcpp::ET_REL;
320 else
321 e_type = elfcpp::ET_EXEC;
322 oehdr.put_e_type(e_type);
323
324 oehdr.put_e_machine(this->target_->machine_code());
325 oehdr.put_e_version(elfcpp::EV_CURRENT);
326
327 // FIXME: Need to support -e, and target specific entry symbol.
328 Symbol* sym = this->symtab_->lookup("_start");
329 typename Sized_symbol<size>::Value_type v;
330 if (sym == NULL)
331 v = 0;
332 else
333 {
334 Sized_symbol<size>* ssym;
335 ssym = this->symtab_->get_sized_symbol SELECT_SIZE_NAME(size) (
336 sym SELECT_SIZE(size));
337 v = ssym->value();
338 }
339 oehdr.put_e_entry(v);
340
341 oehdr.put_e_phoff(this->segment_header_->offset());
342 oehdr.put_e_shoff(this->section_header_->offset());
343
344 // FIXME: The target needs to set the flags.
345 oehdr.put_e_flags(0);
346
347 oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
348 oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
349 oehdr.put_e_phnum(this->segment_header_->data_size()
350 / elfcpp::Elf_sizes<size>::phdr_size);
351 oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
352 oehdr.put_e_shnum(this->section_header_->data_size()
353 / elfcpp::Elf_sizes<size>::shdr_size);
354 oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
355
356 of->write_output_view(0, ehdr_size, view);
357 }
358
359 // Output_data_const methods.
360
361 void
362 Output_data_const::do_write(Output_file* of)
363 {
364 of->write(this->offset(), this->data_.data(), this->data_.size());
365 }
366
367 // Output_data_const_buffer methods.
368
369 void
370 Output_data_const_buffer::do_write(Output_file* of)
371 {
372 of->write(this->offset(), this->p_, this->data_size());
373 }
374
375 // Output_section_data methods.
376
377 // Record the output section, and set the entry size and such.
378
379 void
380 Output_section_data::set_output_section(Output_section* os)
381 {
382 gold_assert(this->output_section_ == NULL);
383 this->output_section_ = os;
384 this->do_adjust_output_section(os);
385 }
386
387 // Return the section index of the output section.
388
389 unsigned int
390 Output_section_data::do_out_shndx() const
391 {
392 gold_assert(this->output_section_ != NULL);
393 return this->output_section_->out_shndx();
394 }
395
396 // Output_data_strtab methods.
397
398 // Set the address. We don't actually care about the address, but we
399 // do set our final size.
400
401 void
402 Output_data_strtab::do_set_address(uint64_t, off_t)
403 {
404 this->strtab_->set_string_offsets();
405 this->set_data_size(this->strtab_->get_strtab_size());
406 }
407
408 // Write out a string table.
409
410 void
411 Output_data_strtab::do_write(Output_file* of)
412 {
413 this->strtab_->write(of, this->offset());
414 }
415
416 // Output_reloc methods.
417
418 // Get the symbol index of a relocation.
419
420 template<bool dynamic, int size, bool big_endian>
421 unsigned int
422 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
423 const
424 {
425 unsigned int index;
426 switch (this->local_sym_index_)
427 {
428 case INVALID_CODE:
429 gold_unreachable();
430
431 case GSYM_CODE:
432 if (this->u1_.gsym == NULL)
433 index = 0;
434 else if (dynamic)
435 index = this->u1_.gsym->dynsym_index();
436 else
437 index = this->u1_.gsym->symtab_index();
438 break;
439
440 case SECTION_CODE:
441 if (dynamic)
442 index = this->u1_.os->dynsym_index();
443 else
444 index = this->u1_.os->symtab_index();
445 break;
446
447 default:
448 if (dynamic)
449 {
450 // FIXME: It seems that some targets may need to generate
451 // dynamic relocations against local symbols for some
452 // reasons. This will have to be addressed at some point.
453 gold_unreachable();
454 }
455 else
456 index = this->u1_.relobj->symtab_index(this->local_sym_index_);
457 break;
458 }
459 gold_assert(index != -1U);
460 return index;
461 }
462
463 // Write out the offset and info fields of a Rel or Rela relocation
464 // entry.
465
466 template<bool dynamic, int size, bool big_endian>
467 template<typename Write_rel>
468 void
469 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
470 Write_rel* wr) const
471 {
472 Address address = this->address_;
473 if (this->shndx_ != INVALID_CODE)
474 {
475 off_t off;
476 Output_section* os = this->u2_.relobj->output_section(this->shndx_,
477 &off);
478 gold_assert(os != NULL);
479 address += os->address() + off;
480 }
481 else if (this->u2_.od != NULL)
482 address += this->u2_.od->address();
483 wr->put_r_offset(address);
484 wr->put_r_info(elfcpp::elf_r_info<size>(this->get_symbol_index(),
485 this->type_));
486 }
487
488 // Write out a Rel relocation.
489
490 template<bool dynamic, int size, bool big_endian>
491 void
492 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
493 unsigned char* pov) const
494 {
495 elfcpp::Rel_write<size, big_endian> orel(pov);
496 this->write_rel(&orel);
497 }
498
499 // Write out a Rela relocation.
500
501 template<bool dynamic, int size, bool big_endian>
502 void
503 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
504 unsigned char* pov) const
505 {
506 elfcpp::Rela_write<size, big_endian> orel(pov);
507 this->rel_.write_rel(&orel);
508 orel.put_r_addend(this->addend_);
509 }
510
511 // Output_data_reloc_base methods.
512
513 // Adjust the output section.
514
515 template<int sh_type, bool dynamic, int size, bool big_endian>
516 void
517 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
518 ::do_adjust_output_section(Output_section* os)
519 {
520 if (sh_type == elfcpp::SHT_REL)
521 os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
522 else if (sh_type == elfcpp::SHT_RELA)
523 os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
524 else
525 gold_unreachable();
526 if (dynamic)
527 os->set_should_link_to_dynsym();
528 else
529 os->set_should_link_to_symtab();
530 }
531
532 // Write out relocation data.
533
534 template<int sh_type, bool dynamic, int size, bool big_endian>
535 void
536 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
537 Output_file* of)
538 {
539 const off_t off = this->offset();
540 const off_t oview_size = this->data_size();
541 unsigned char* const oview = of->get_output_view(off, oview_size);
542
543 unsigned char* pov = oview;
544 for (typename Relocs::const_iterator p = this->relocs_.begin();
545 p != this->relocs_.end();
546 ++p)
547 {
548 p->write(pov);
549 pov += reloc_size;
550 }
551
552 gold_assert(pov - oview == oview_size);
553
554 of->write_output_view(off, oview_size, oview);
555
556 // We no longer need the relocation entries.
557 this->relocs_.clear();
558 }
559
560 // Output_data_got::Got_entry methods.
561
562 // Write out the entry.
563
564 template<int size, bool big_endian>
565 void
566 Output_data_got<size, big_endian>::Got_entry::write(
567 const General_options* options,
568 unsigned char* pov) const
569 {
570 Valtype val = 0;
571
572 switch (this->local_sym_index_)
573 {
574 case GSYM_CODE:
575 {
576 Symbol* gsym = this->u_.gsym;
577
578 // If the symbol is resolved locally, we need to write out its
579 // value. Otherwise we just write zero. The target code is
580 // responsible for creating a relocation entry to fill in the
581 // value at runtime.
582 if (gsym->final_value_is_known(options))
583 {
584 Sized_symbol<size>* sgsym;
585 // This cast is a bit ugly. We don't want to put a
586 // virtual method in Symbol, because we want Symbol to be
587 // as small as possible.
588 sgsym = static_cast<Sized_symbol<size>*>(gsym);
589 val = sgsym->value();
590 }
591 }
592 break;
593
594 case CONSTANT_CODE:
595 val = this->u_.constant;
596 break;
597
598 default:
599 gold_unreachable();
600 }
601
602 elfcpp::Swap<size, big_endian>::writeval(pov, val);
603 }
604
605 // Output_data_got methods.
606
607 // Add an entry for a global symbol to the GOT. This returns true if
608 // this is a new GOT entry, false if the symbol already had a GOT
609 // entry.
610
611 template<int size, bool big_endian>
612 bool
613 Output_data_got<size, big_endian>::add_global(Symbol* gsym)
614 {
615 if (gsym->has_got_offset())
616 return false;
617
618 this->entries_.push_back(Got_entry(gsym));
619 this->set_got_size();
620 gsym->set_got_offset(this->last_got_offset());
621 return true;
622 }
623
624 // Write out the GOT.
625
626 template<int size, bool big_endian>
627 void
628 Output_data_got<size, big_endian>::do_write(Output_file* of)
629 {
630 const int add = size / 8;
631
632 const off_t off = this->offset();
633 const off_t oview_size = this->data_size();
634 unsigned char* const oview = of->get_output_view(off, oview_size);
635
636 unsigned char* pov = oview;
637 for (typename Got_entries::const_iterator p = this->entries_.begin();
638 p != this->entries_.end();
639 ++p)
640 {
641 p->write(this->options_, pov);
642 pov += add;
643 }
644
645 gold_assert(pov - oview == oview_size);
646
647 of->write_output_view(off, oview_size, oview);
648
649 // We no longer need the GOT entries.
650 this->entries_.clear();
651 }
652
653 // Output_data_dynamic::Dynamic_entry methods.
654
655 // Write out the entry.
656
657 template<int size, bool big_endian>
658 void
659 Output_data_dynamic::Dynamic_entry::write(
660 unsigned char* pov,
661 const Stringpool* pool
662 ACCEPT_SIZE_ENDIAN) const
663 {
664 typename elfcpp::Elf_types<size>::Elf_WXword val;
665 switch (this->classification_)
666 {
667 case DYNAMIC_NUMBER:
668 val = this->u_.val;
669 break;
670
671 case DYNAMIC_SECTION_ADDRESS:
672 val = this->u_.od->address();
673 break;
674
675 case DYNAMIC_SECTION_SIZE:
676 val = this->u_.od->data_size();
677 break;
678
679 case DYNAMIC_SYMBOL:
680 {
681 const Sized_symbol<size>* s =
682 static_cast<const Sized_symbol<size>*>(this->u_.sym);
683 val = s->value();
684 }
685 break;
686
687 case DYNAMIC_STRING:
688 val = pool->get_offset(this->u_.str);
689 break;
690
691 default:
692 gold_unreachable();
693 }
694
695 elfcpp::Dyn_write<size, big_endian> dw(pov);
696 dw.put_d_tag(this->tag_);
697 dw.put_d_val(val);
698 }
699
700 // Output_data_dynamic methods.
701
702 // Adjust the output section to set the entry size.
703
704 void
705 Output_data_dynamic::do_adjust_output_section(Output_section* os)
706 {
707 if (this->target_->get_size() == 32)
708 os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
709 else if (this->target_->get_size() == 64)
710 os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
711 else
712 gold_unreachable();
713 }
714
715 // Set the final data size.
716
717 void
718 Output_data_dynamic::do_set_address(uint64_t, off_t)
719 {
720 // Add the terminating entry.
721 this->add_constant(elfcpp::DT_NULL, 0);
722
723 int dyn_size;
724 if (this->target_->get_size() == 32)
725 dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
726 else if (this->target_->get_size() == 64)
727 dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
728 else
729 gold_unreachable();
730 this->set_data_size(this->entries_.size() * dyn_size);
731 }
732
733 // Write out the dynamic entries.
734
735 void
736 Output_data_dynamic::do_write(Output_file* of)
737 {
738 if (this->target_->get_size() == 32)
739 {
740 if (this->target_->is_big_endian())
741 this->sized_write<32, true>(of);
742 else
743 this->sized_write<32, false>(of);
744 }
745 else if (this->target_->get_size() == 64)
746 {
747 if (this->target_->is_big_endian())
748 this->sized_write<64, true>(of);
749 else
750 this->sized_write<64, false>(of);
751 }
752 else
753 gold_unreachable();
754 }
755
756 template<int size, bool big_endian>
757 void
758 Output_data_dynamic::sized_write(Output_file* of)
759 {
760 const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
761
762 const off_t offset = this->offset();
763 const off_t oview_size = this->data_size();
764 unsigned char* const oview = of->get_output_view(offset, oview_size);
765
766 unsigned char* pov = oview;
767 for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
768 p != this->entries_.end();
769 ++p)
770 {
771 p->write SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
772 pov, this->pool_ SELECT_SIZE_ENDIAN(size, big_endian));
773 pov += dyn_size;
774 }
775
776 gold_assert(pov - oview == oview_size);
777
778 of->write_output_view(offset, oview_size, oview);
779
780 // We no longer need the dynamic entries.
781 this->entries_.clear();
782 }
783
784 // Output_section::Input_section methods.
785
786 // Return the data size. For an input section we store the size here.
787 // For an Output_section_data, we have to ask it for the size.
788
789 off_t
790 Output_section::Input_section::data_size() const
791 {
792 if (this->is_input_section())
793 return this->data_size_;
794 else
795 return this->u_.posd->data_size();
796 }
797
798 // Set the address and file offset.
799
800 void
801 Output_section::Input_section::set_address(uint64_t addr, off_t off,
802 off_t secoff)
803 {
804 if (this->is_input_section())
805 this->u_.object->set_section_offset(this->shndx_, off - secoff);
806 else
807 this->u_.posd->set_address(addr, off);
808 }
809
810 // Write out the data. We don't have to do anything for an input
811 // section--they are handled via Object::relocate--but this is where
812 // we write out the data for an Output_section_data.
813
814 void
815 Output_section::Input_section::write(Output_file* of)
816 {
817 if (!this->is_input_section())
818 this->u_.posd->write(of);
819 }
820
821 // Output_section methods.
822
823 // Construct an Output_section. NAME will point into a Stringpool.
824
825 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
826 elfcpp::Elf_Xword flags, bool may_add_data)
827 : name_(name),
828 addralign_(0),
829 entsize_(0),
830 link_section_(NULL),
831 link_(0),
832 info_section_(NULL),
833 info_(0),
834 type_(type),
835 flags_(flags),
836 out_shndx_(0),
837 symtab_index_(0),
838 dynsym_index_(0),
839 input_sections_(),
840 first_input_offset_(0),
841 may_add_data_(may_add_data),
842 needs_symtab_index_(false),
843 needs_dynsym_index_(false),
844 should_link_to_symtab_(false),
845 should_link_to_dynsym_(false)
846 {
847 }
848
849 Output_section::~Output_section()
850 {
851 }
852
853 // Set the entry size.
854
855 void
856 Output_section::set_entsize(uint64_t v)
857 {
858 if (this->entsize_ == 0)
859 this->entsize_ = v;
860 else
861 gold_assert(this->entsize_ == v);
862 }
863
864 // Add the input section SHNDX, with header SHDR, named SECNAME, in
865 // OBJECT, to the Output_section. Return the offset of the input
866 // section within the output section. We don't always keep track of
867 // input sections for an Output_section. Instead, each Object keeps
868 // track of the Output_section for each of its input sections.
869
870 template<int size, bool big_endian>
871 off_t
872 Output_section::add_input_section(Relobj* object, unsigned int shndx,
873 const char* secname,
874 const elfcpp::Shdr<size, big_endian>& shdr)
875 {
876 gold_assert(this->may_add_data_);
877
878 elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
879 if ((addralign & (addralign - 1)) != 0)
880 {
881 fprintf(stderr, _("%s: %s: invalid alignment %lu for section \"%s\"\n"),
882 program_name, object->name().c_str(),
883 static_cast<unsigned long>(addralign), secname);
884 gold_exit(false);
885 }
886
887 if (addralign > this->addralign_)
888 this->addralign_ = addralign;
889
890 off_t ssize = this->data_size();
891 ssize = align_address(ssize, addralign);
892 this->set_data_size(ssize + shdr.get_sh_size());
893
894 // We need to keep track of this section if we are already keeping
895 // track of sections, or if we are relaxing. FIXME: Add test for
896 // relaxing.
897 if (! this->input_sections_.empty())
898 this->input_sections_.push_back(Input_section(object, shndx,
899 shdr.get_sh_size(),
900 addralign));
901
902 return ssize;
903 }
904
905 // Add arbitrary data to an output section.
906
907 void
908 Output_section::add_output_section_data(Output_section_data* posd)
909 {
910 gold_assert(this->may_add_data_);
911
912 if (this->input_sections_.empty())
913 this->first_input_offset_ = this->data_size();
914
915 this->input_sections_.push_back(Input_section(posd));
916
917 uint64_t addralign = posd->addralign();
918 if (addralign > this->addralign_)
919 this->addralign_ = addralign;
920
921 posd->set_output_section(this);
922 }
923
924 // Set the address of an Output_section. This is where we handle
925 // setting the addresses of any Output_section_data objects.
926
927 void
928 Output_section::do_set_address(uint64_t address, off_t startoff)
929 {
930 if (this->input_sections_.empty())
931 return;
932
933 off_t off = startoff + this->first_input_offset_;
934 for (Input_section_list::iterator p = this->input_sections_.begin();
935 p != this->input_sections_.end();
936 ++p)
937 {
938 off = align_address(off, p->addralign());
939 p->set_address(address + (off - startoff), off, startoff);
940 off += p->data_size();
941 }
942
943 this->set_data_size(off - startoff);
944 }
945
946 // Write the section header to *OSHDR.
947
948 template<int size, bool big_endian>
949 void
950 Output_section::write_header(const Layout* layout,
951 const Stringpool* secnamepool,
952 elfcpp::Shdr_write<size, big_endian>* oshdr) const
953 {
954 oshdr->put_sh_name(secnamepool->get_offset(this->name_));
955 oshdr->put_sh_type(this->type_);
956 oshdr->put_sh_flags(this->flags_);
957 oshdr->put_sh_addr(this->address());
958 oshdr->put_sh_offset(this->offset());
959 oshdr->put_sh_size(this->data_size());
960 if (this->link_section_ != NULL)
961 oshdr->put_sh_link(this->link_section_->out_shndx());
962 else if (this->should_link_to_symtab_)
963 oshdr->put_sh_link(layout->symtab_section()->out_shndx());
964 else if (this->should_link_to_dynsym_)
965 oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
966 else
967 oshdr->put_sh_link(this->link_);
968 if (this->info_section_ != NULL)
969 oshdr->put_sh_info(this->info_section_->out_shndx());
970 else
971 oshdr->put_sh_info(this->info_);
972 oshdr->put_sh_addralign(this->addralign_);
973 oshdr->put_sh_entsize(this->entsize_);
974 }
975
976 // Write out the data. For input sections the data is written out by
977 // Object::relocate, but we have to handle Output_section_data objects
978 // here.
979
980 void
981 Output_section::do_write(Output_file* of)
982 {
983 for (Input_section_list::iterator p = this->input_sections_.begin();
984 p != this->input_sections_.end();
985 ++p)
986 p->write(of);
987 }
988
989 // Output segment methods.
990
991 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
992 : output_data_(),
993 output_bss_(),
994 vaddr_(0),
995 paddr_(0),
996 memsz_(0),
997 align_(0),
998 offset_(0),
999 filesz_(0),
1000 type_(type),
1001 flags_(flags),
1002 is_align_known_(false)
1003 {
1004 }
1005
1006 // Add an Output_section to an Output_segment.
1007
1008 void
1009 Output_segment::add_output_section(Output_section* os,
1010 elfcpp::Elf_Word seg_flags,
1011 bool front)
1012 {
1013 gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
1014 gold_assert(!this->is_align_known_);
1015
1016 // Update the segment flags.
1017 this->flags_ |= seg_flags;
1018
1019 Output_segment::Output_data_list* pdl;
1020 if (os->type() == elfcpp::SHT_NOBITS)
1021 pdl = &this->output_bss_;
1022 else
1023 pdl = &this->output_data_;
1024
1025 // So that PT_NOTE segments will work correctly, we need to ensure
1026 // that all SHT_NOTE sections are adjacent. This will normally
1027 // happen automatically, because all the SHT_NOTE input sections
1028 // will wind up in the same output section. However, it is possible
1029 // for multiple SHT_NOTE input sections to have different section
1030 // flags, and thus be in different output sections, but for the
1031 // different section flags to map into the same segment flags and
1032 // thus the same output segment.
1033
1034 // Note that while there may be many input sections in an output
1035 // section, there are normally only a few output sections in an
1036 // output segment. This loop is expected to be fast.
1037
1038 if (os->type() == elfcpp::SHT_NOTE && !pdl->empty())
1039 {
1040 Output_segment::Output_data_list::iterator p = pdl->end();
1041 do
1042 {
1043 --p;
1044 if ((*p)->is_section_type(elfcpp::SHT_NOTE))
1045 {
1046 // We don't worry about the FRONT parameter.
1047 ++p;
1048 pdl->insert(p, os);
1049 return;
1050 }
1051 }
1052 while (p != pdl->begin());
1053 }
1054
1055 // Similarly, so that PT_TLS segments will work, we need to group
1056 // SHF_TLS sections. An SHF_TLS/SHT_NOBITS section is a special
1057 // case: we group the SHF_TLS/SHT_NOBITS sections right after the
1058 // SHF_TLS/SHT_PROGBITS sections. This lets us set up PT_TLS
1059 // correctly.
1060 if ((os->flags() & elfcpp::SHF_TLS) != 0 && !this->output_data_.empty())
1061 {
1062 pdl = &this->output_data_;
1063 bool nobits = os->type() == elfcpp::SHT_NOBITS;
1064 bool sawtls = false;
1065 Output_segment::Output_data_list::iterator p = pdl->end();
1066 do
1067 {
1068 --p;
1069 bool insert;
1070 if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
1071 {
1072 sawtls = true;
1073 // Put a NOBITS section after the first TLS section.
1074 // But a PROGBITS section after the first TLS/PROGBITS
1075 // section.
1076 insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS);
1077 }
1078 else
1079 {
1080 // If we've gone past the TLS sections, but we've seen a
1081 // TLS section, then we need to insert this section now.
1082 insert = sawtls;
1083 }
1084
1085 if (insert)
1086 {
1087 // We don't worry about the FRONT parameter.
1088 ++p;
1089 pdl->insert(p, os);
1090 return;
1091 }
1092 }
1093 while (p != pdl->begin());
1094
1095 // There are no TLS sections yet; put this one at the requested
1096 // location in the section list.
1097 }
1098
1099 if (front)
1100 pdl->push_front(os);
1101 else
1102 pdl->push_back(os);
1103 }
1104
1105 // Add an Output_data (which is not an Output_section) to the start of
1106 // a segment.
1107
1108 void
1109 Output_segment::add_initial_output_data(Output_data* od)
1110 {
1111 gold_assert(!this->is_align_known_);
1112 this->output_data_.push_front(od);
1113 }
1114
1115 // Return the maximum alignment of the Output_data in Output_segment.
1116 // Once we compute this, we prohibit new sections from being added.
1117
1118 uint64_t
1119 Output_segment::addralign()
1120 {
1121 if (!this->is_align_known_)
1122 {
1123 uint64_t addralign;
1124
1125 addralign = Output_segment::maximum_alignment(&this->output_data_);
1126 if (addralign > this->align_)
1127 this->align_ = addralign;
1128
1129 addralign = Output_segment::maximum_alignment(&this->output_bss_);
1130 if (addralign > this->align_)
1131 this->align_ = addralign;
1132
1133 this->is_align_known_ = true;
1134 }
1135
1136 return this->align_;
1137 }
1138
1139 // Return the maximum alignment of a list of Output_data.
1140
1141 uint64_t
1142 Output_segment::maximum_alignment(const Output_data_list* pdl)
1143 {
1144 uint64_t ret = 0;
1145 for (Output_data_list::const_iterator p = pdl->begin();
1146 p != pdl->end();
1147 ++p)
1148 {
1149 uint64_t addralign = (*p)->addralign();
1150 if (addralign > ret)
1151 ret = addralign;
1152 }
1153 return ret;
1154 }
1155
1156 // Set the section addresses for an Output_segment. ADDR is the
1157 // address and *POFF is the file offset. Set the section indexes
1158 // starting with *PSHNDX. Return the address of the immediately
1159 // following segment. Update *POFF and *PSHNDX.
1160
1161 uint64_t
1162 Output_segment::set_section_addresses(uint64_t addr, off_t* poff,
1163 unsigned int* pshndx)
1164 {
1165 gold_assert(this->type_ == elfcpp::PT_LOAD);
1166
1167 this->vaddr_ = addr;
1168 this->paddr_ = addr;
1169
1170 off_t orig_off = *poff;
1171 this->offset_ = orig_off;
1172
1173 *poff = align_address(*poff, this->addralign());
1174
1175 addr = this->set_section_list_addresses(&this->output_data_, addr, poff,
1176 pshndx);
1177 this->filesz_ = *poff - orig_off;
1178
1179 off_t off = *poff;
1180
1181 uint64_t ret = this->set_section_list_addresses(&this->output_bss_, addr,
1182 poff, pshndx);
1183 this->memsz_ = *poff - orig_off;
1184
1185 // Ignore the file offset adjustments made by the BSS Output_data
1186 // objects.
1187 *poff = off;
1188
1189 return ret;
1190 }
1191
1192 // Set the addresses in a list of Output_data structures.
1193
1194 uint64_t
1195 Output_segment::set_section_list_addresses(Output_data_list* pdl,
1196 uint64_t addr, off_t* poff,
1197 unsigned int* pshndx)
1198 {
1199 off_t startoff = *poff;
1200
1201 off_t off = startoff;
1202 for (Output_data_list::iterator p = pdl->begin();
1203 p != pdl->end();
1204 ++p)
1205 {
1206 off = align_address(off, (*p)->addralign());
1207 (*p)->set_address(addr + (off - startoff), off);
1208
1209 // Unless this is a PT_TLS segment, we want to ignore the size
1210 // of a SHF_TLS/SHT_NOBITS section. Such a section does not
1211 // affect the size of a PT_LOAD segment.
1212 if (this->type_ == elfcpp::PT_TLS
1213 || !(*p)->is_section_flag_set(elfcpp::SHF_TLS)
1214 || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
1215 off += (*p)->data_size();
1216
1217 if ((*p)->is_section())
1218 {
1219 (*p)->set_out_shndx(*pshndx);
1220 ++*pshndx;
1221 }
1222 }
1223
1224 *poff = off;
1225 return addr + (off - startoff);
1226 }
1227
1228 // For a non-PT_LOAD segment, set the offset from the sections, if
1229 // any.
1230
1231 void
1232 Output_segment::set_offset()
1233 {
1234 gold_assert(this->type_ != elfcpp::PT_LOAD);
1235
1236 if (this->output_data_.empty() && this->output_bss_.empty())
1237 {
1238 this->vaddr_ = 0;
1239 this->paddr_ = 0;
1240 this->memsz_ = 0;
1241 this->align_ = 0;
1242 this->offset_ = 0;
1243 this->filesz_ = 0;
1244 return;
1245 }
1246
1247 const Output_data* first;
1248 if (this->output_data_.empty())
1249 first = this->output_bss_.front();
1250 else
1251 first = this->output_data_.front();
1252 this->vaddr_ = first->address();
1253 this->paddr_ = this->vaddr_;
1254 this->offset_ = first->offset();
1255
1256 if (this->output_data_.empty())
1257 this->filesz_ = 0;
1258 else
1259 {
1260 const Output_data* last_data = this->output_data_.back();
1261 this->filesz_ = (last_data->address()
1262 + last_data->data_size()
1263 - this->vaddr_);
1264 }
1265
1266 const Output_data* last;
1267 if (this->output_bss_.empty())
1268 last = this->output_data_.back();
1269 else
1270 last = this->output_bss_.back();
1271 this->memsz_ = (last->address()
1272 + last->data_size()
1273 - this->vaddr_);
1274 }
1275
1276 // Return the number of Output_sections in an Output_segment.
1277
1278 unsigned int
1279 Output_segment::output_section_count() const
1280 {
1281 return (this->output_section_count_list(&this->output_data_)
1282 + this->output_section_count_list(&this->output_bss_));
1283 }
1284
1285 // Return the number of Output_sections in an Output_data_list.
1286
1287 unsigned int
1288 Output_segment::output_section_count_list(const Output_data_list* pdl) const
1289 {
1290 unsigned int count = 0;
1291 for (Output_data_list::const_iterator p = pdl->begin();
1292 p != pdl->end();
1293 ++p)
1294 {
1295 if ((*p)->is_section())
1296 ++count;
1297 }
1298 return count;
1299 }
1300
1301 // Write the segment data into *OPHDR.
1302
1303 template<int size, bool big_endian>
1304 void
1305 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
1306 {
1307 ophdr->put_p_type(this->type_);
1308 ophdr->put_p_offset(this->offset_);
1309 ophdr->put_p_vaddr(this->vaddr_);
1310 ophdr->put_p_paddr(this->paddr_);
1311 ophdr->put_p_filesz(this->filesz_);
1312 ophdr->put_p_memsz(this->memsz_);
1313 ophdr->put_p_flags(this->flags_);
1314 ophdr->put_p_align(this->addralign());
1315 }
1316
1317 // Write the section headers into V.
1318
1319 template<int size, bool big_endian>
1320 unsigned char*
1321 Output_segment::write_section_headers(const Layout* layout,
1322 const Stringpool* secnamepool,
1323 unsigned char* v,
1324 unsigned int *pshndx
1325 ACCEPT_SIZE_ENDIAN) const
1326 {
1327 // Every section that is attached to a segment must be attached to a
1328 // PT_LOAD segment, so we only write out section headers for PT_LOAD
1329 // segments.
1330 if (this->type_ != elfcpp::PT_LOAD)
1331 return v;
1332
1333 v = this->write_section_headers_list
1334 SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1335 layout, secnamepool, &this->output_data_, v, pshndx
1336 SELECT_SIZE_ENDIAN(size, big_endian));
1337 v = this->write_section_headers_list
1338 SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
1339 layout, secnamepool, &this->output_bss_, v, pshndx
1340 SELECT_SIZE_ENDIAN(size, big_endian));
1341 return v;
1342 }
1343
1344 template<int size, bool big_endian>
1345 unsigned char*
1346 Output_segment::write_section_headers_list(const Layout* layout,
1347 const Stringpool* secnamepool,
1348 const Output_data_list* pdl,
1349 unsigned char* v,
1350 unsigned int* pshndx
1351 ACCEPT_SIZE_ENDIAN) const
1352 {
1353 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
1354 for (Output_data_list::const_iterator p = pdl->begin();
1355 p != pdl->end();
1356 ++p)
1357 {
1358 if ((*p)->is_section())
1359 {
1360 const Output_section* ps = static_cast<const Output_section*>(*p);
1361 gold_assert(*pshndx == ps->out_shndx());
1362 elfcpp::Shdr_write<size, big_endian> oshdr(v);
1363 ps->write_header(layout, secnamepool, &oshdr);
1364 v += shdr_size;
1365 ++*pshndx;
1366 }
1367 }
1368 return v;
1369 }
1370
1371 // Output_file methods.
1372
1373 Output_file::Output_file(const General_options& options)
1374 : options_(options),
1375 name_(options.output_file_name()),
1376 o_(-1),
1377 file_size_(0),
1378 base_(NULL)
1379 {
1380 }
1381
1382 // Open the output file.
1383
1384 void
1385 Output_file::open(off_t file_size)
1386 {
1387 this->file_size_ = file_size;
1388
1389 int mode = this->options_.is_relocatable() ? 0666 : 0777;
1390 int o = ::open(this->name_, O_RDWR | O_CREAT | O_TRUNC, mode);
1391 if (o < 0)
1392 {
1393 fprintf(stderr, _("%s: %s: open: %s\n"),
1394 program_name, this->name_, strerror(errno));
1395 gold_exit(false);
1396 }
1397 this->o_ = o;
1398
1399 // Write out one byte to make the file the right size.
1400 if (::lseek(o, file_size - 1, SEEK_SET) < 0)
1401 {
1402 fprintf(stderr, _("%s: %s: lseek: %s\n"),
1403 program_name, this->name_, strerror(errno));
1404 gold_exit(false);
1405 }
1406 char b = 0;
1407 if (::write(o, &b, 1) != 1)
1408 {
1409 fprintf(stderr, _("%s: %s: write: %s\n"),
1410 program_name, this->name_, strerror(errno));
1411 gold_exit(false);
1412 }
1413
1414 // Map the file into memory.
1415 void* base = ::mmap(NULL, file_size, PROT_READ | PROT_WRITE,
1416 MAP_SHARED, o, 0);
1417 if (base == MAP_FAILED)
1418 {
1419 fprintf(stderr, _("%s: %s: mmap: %s\n"),
1420 program_name, this->name_, strerror(errno));
1421 gold_exit(false);
1422 }
1423 this->base_ = static_cast<unsigned char*>(base);
1424 }
1425
1426 // Close the output file.
1427
1428 void
1429 Output_file::close()
1430 {
1431 if (::munmap(this->base_, this->file_size_) < 0)
1432 {
1433 fprintf(stderr, _("%s: %s: munmap: %s\n"),
1434 program_name, this->name_, strerror(errno));
1435 gold_exit(false);
1436 }
1437 this->base_ = NULL;
1438
1439 if (::close(this->o_) < 0)
1440 {
1441 fprintf(stderr, _("%s: %s: close: %s\n"),
1442 program_name, this->name_, strerror(errno));
1443 gold_exit(false);
1444 }
1445 this->o_ = -1;
1446 }
1447
1448 // Instantiate the templates we need. We could use the configure
1449 // script to restrict this to only the ones for implemented targets.
1450
1451 template
1452 off_t
1453 Output_section::add_input_section<32, false>(
1454 Relobj* object,
1455 unsigned int shndx,
1456 const char* secname,
1457 const elfcpp::Shdr<32, false>& shdr);
1458
1459 template
1460 off_t
1461 Output_section::add_input_section<32, true>(
1462 Relobj* object,
1463 unsigned int shndx,
1464 const char* secname,
1465 const elfcpp::Shdr<32, true>& shdr);
1466
1467 template
1468 off_t
1469 Output_section::add_input_section<64, false>(
1470 Relobj* object,
1471 unsigned int shndx,
1472 const char* secname,
1473 const elfcpp::Shdr<64, false>& shdr);
1474
1475 template
1476 off_t
1477 Output_section::add_input_section<64, true>(
1478 Relobj* object,
1479 unsigned int shndx,
1480 const char* secname,
1481 const elfcpp::Shdr<64, true>& shdr);
1482
1483 template
1484 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
1485
1486 template
1487 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
1488
1489 template
1490 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
1491
1492 template
1493 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
1494
1495 template
1496 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
1497
1498 template
1499 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
1500
1501 template
1502 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
1503
1504 template
1505 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
1506
1507 template
1508 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
1509
1510 template
1511 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
1512
1513 template
1514 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
1515
1516 template
1517 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
1518
1519 template
1520 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
1521
1522 template
1523 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
1524
1525 template
1526 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
1527
1528 template
1529 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
1530
1531 template
1532 class Output_data_got<32, false>;
1533
1534 template
1535 class Output_data_got<32, true>;
1536
1537 template
1538 class Output_data_got<64, false>;
1539
1540 template
1541 class Output_data_got<64, true>;
1542
1543 } // End namespace gold.
This page took 0.096702 seconds and 4 git commands to generate.