Add support for -pie.
[deliverable/binutils-gdb.git] / gold / output.cc
1 // output.cc -- manage the output file for gold
2
3 // Copyright 2006, 2007, 2008, 2009 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 <cstring>
27 #include <cerrno>
28 #include <fcntl.h>
29 #include <unistd.h>
30 #include <sys/mman.h>
31 #include <sys/stat.h>
32 #include <algorithm>
33 #include "libiberty.h"
34
35 #include "parameters.h"
36 #include "object.h"
37 #include "symtab.h"
38 #include "reloc.h"
39 #include "merge.h"
40 #include "descriptors.h"
41 #include "output.h"
42
43 // Some BSD systems still use MAP_ANON instead of MAP_ANONYMOUS
44 #ifndef MAP_ANONYMOUS
45 # define MAP_ANONYMOUS MAP_ANON
46 #endif
47
48 #ifndef HAVE_POSIX_FALLOCATE
49 // A dummy, non general, version of posix_fallocate. Here we just set
50 // the file size and hope that there is enough disk space. FIXME: We
51 // could allocate disk space by walking block by block and writing a
52 // zero byte into each block.
53 static int
54 posix_fallocate(int o, off_t offset, off_t len)
55 {
56 return ftruncate(o, offset + len);
57 }
58 #endif // !defined(HAVE_POSIX_FALLOCATE)
59
60 namespace gold
61 {
62
63 // Output_data variables.
64
65 bool Output_data::allocated_sizes_are_fixed;
66
67 // Output_data methods.
68
69 Output_data::~Output_data()
70 {
71 }
72
73 // Return the default alignment for the target size.
74
75 uint64_t
76 Output_data::default_alignment()
77 {
78 return Output_data::default_alignment_for_size(
79 parameters->target().get_size());
80 }
81
82 // Return the default alignment for a size--32 or 64.
83
84 uint64_t
85 Output_data::default_alignment_for_size(int size)
86 {
87 if (size == 32)
88 return 4;
89 else if (size == 64)
90 return 8;
91 else
92 gold_unreachable();
93 }
94
95 // Output_section_header methods. This currently assumes that the
96 // segment and section lists are complete at construction time.
97
98 Output_section_headers::Output_section_headers(
99 const Layout* layout,
100 const Layout::Segment_list* segment_list,
101 const Layout::Section_list* section_list,
102 const Layout::Section_list* unattached_section_list,
103 const Stringpool* secnamepool,
104 const Output_section* shstrtab_section)
105 : layout_(layout),
106 segment_list_(segment_list),
107 section_list_(section_list),
108 unattached_section_list_(unattached_section_list),
109 secnamepool_(secnamepool),
110 shstrtab_section_(shstrtab_section)
111 {
112 }
113
114 // Compute the current data size.
115
116 off_t
117 Output_section_headers::do_size() const
118 {
119 // Count all the sections. Start with 1 for the null section.
120 off_t count = 1;
121 if (!parameters->options().relocatable())
122 {
123 for (Layout::Segment_list::const_iterator p =
124 this->segment_list_->begin();
125 p != this->segment_list_->end();
126 ++p)
127 if ((*p)->type() == elfcpp::PT_LOAD)
128 count += (*p)->output_section_count();
129 }
130 else
131 {
132 for (Layout::Section_list::const_iterator p =
133 this->section_list_->begin();
134 p != this->section_list_->end();
135 ++p)
136 if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
137 ++count;
138 }
139 count += this->unattached_section_list_->size();
140
141 const int size = parameters->target().get_size();
142 int shdr_size;
143 if (size == 32)
144 shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
145 else if (size == 64)
146 shdr_size = elfcpp::Elf_sizes<64>::shdr_size;
147 else
148 gold_unreachable();
149
150 return count * shdr_size;
151 }
152
153 // Write out the section headers.
154
155 void
156 Output_section_headers::do_write(Output_file* of)
157 {
158 switch (parameters->size_and_endianness())
159 {
160 #ifdef HAVE_TARGET_32_LITTLE
161 case Parameters::TARGET_32_LITTLE:
162 this->do_sized_write<32, false>(of);
163 break;
164 #endif
165 #ifdef HAVE_TARGET_32_BIG
166 case Parameters::TARGET_32_BIG:
167 this->do_sized_write<32, true>(of);
168 break;
169 #endif
170 #ifdef HAVE_TARGET_64_LITTLE
171 case Parameters::TARGET_64_LITTLE:
172 this->do_sized_write<64, false>(of);
173 break;
174 #endif
175 #ifdef HAVE_TARGET_64_BIG
176 case Parameters::TARGET_64_BIG:
177 this->do_sized_write<64, true>(of);
178 break;
179 #endif
180 default:
181 gold_unreachable();
182 }
183 }
184
185 template<int size, bool big_endian>
186 void
187 Output_section_headers::do_sized_write(Output_file* of)
188 {
189 off_t all_shdrs_size = this->data_size();
190 unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size);
191
192 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
193 unsigned char* v = view;
194
195 {
196 typename elfcpp::Shdr_write<size, big_endian> oshdr(v);
197 oshdr.put_sh_name(0);
198 oshdr.put_sh_type(elfcpp::SHT_NULL);
199 oshdr.put_sh_flags(0);
200 oshdr.put_sh_addr(0);
201 oshdr.put_sh_offset(0);
202
203 size_t section_count = (this->data_size()
204 / elfcpp::Elf_sizes<size>::shdr_size);
205 if (section_count < elfcpp::SHN_LORESERVE)
206 oshdr.put_sh_size(0);
207 else
208 oshdr.put_sh_size(section_count);
209
210 unsigned int shstrndx = this->shstrtab_section_->out_shndx();
211 if (shstrndx < elfcpp::SHN_LORESERVE)
212 oshdr.put_sh_link(0);
213 else
214 oshdr.put_sh_link(shstrndx);
215
216 oshdr.put_sh_info(0);
217 oshdr.put_sh_addralign(0);
218 oshdr.put_sh_entsize(0);
219 }
220
221 v += shdr_size;
222
223 unsigned int shndx = 1;
224 if (!parameters->options().relocatable())
225 {
226 for (Layout::Segment_list::const_iterator p =
227 this->segment_list_->begin();
228 p != this->segment_list_->end();
229 ++p)
230 v = (*p)->write_section_headers<size, big_endian>(this->layout_,
231 this->secnamepool_,
232 v,
233 &shndx);
234 }
235 else
236 {
237 for (Layout::Section_list::const_iterator p =
238 this->section_list_->begin();
239 p != this->section_list_->end();
240 ++p)
241 {
242 // We do unallocated sections below, except that group
243 // sections have to come first.
244 if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
245 && (*p)->type() != elfcpp::SHT_GROUP)
246 continue;
247 gold_assert(shndx == (*p)->out_shndx());
248 elfcpp::Shdr_write<size, big_endian> oshdr(v);
249 (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
250 v += shdr_size;
251 ++shndx;
252 }
253 }
254
255 for (Layout::Section_list::const_iterator p =
256 this->unattached_section_list_->begin();
257 p != this->unattached_section_list_->end();
258 ++p)
259 {
260 // For a relocatable link, we did unallocated group sections
261 // above, since they have to come first.
262 if ((*p)->type() == elfcpp::SHT_GROUP
263 && parameters->options().relocatable())
264 continue;
265 gold_assert(shndx == (*p)->out_shndx());
266 elfcpp::Shdr_write<size, big_endian> oshdr(v);
267 (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
268 v += shdr_size;
269 ++shndx;
270 }
271
272 of->write_output_view(this->offset(), all_shdrs_size, view);
273 }
274
275 // Output_segment_header methods.
276
277 Output_segment_headers::Output_segment_headers(
278 const Layout::Segment_list& segment_list)
279 : segment_list_(segment_list)
280 {
281 }
282
283 void
284 Output_segment_headers::do_write(Output_file* of)
285 {
286 switch (parameters->size_and_endianness())
287 {
288 #ifdef HAVE_TARGET_32_LITTLE
289 case Parameters::TARGET_32_LITTLE:
290 this->do_sized_write<32, false>(of);
291 break;
292 #endif
293 #ifdef HAVE_TARGET_32_BIG
294 case Parameters::TARGET_32_BIG:
295 this->do_sized_write<32, true>(of);
296 break;
297 #endif
298 #ifdef HAVE_TARGET_64_LITTLE
299 case Parameters::TARGET_64_LITTLE:
300 this->do_sized_write<64, false>(of);
301 break;
302 #endif
303 #ifdef HAVE_TARGET_64_BIG
304 case Parameters::TARGET_64_BIG:
305 this->do_sized_write<64, true>(of);
306 break;
307 #endif
308 default:
309 gold_unreachable();
310 }
311 }
312
313 template<int size, bool big_endian>
314 void
315 Output_segment_headers::do_sized_write(Output_file* of)
316 {
317 const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
318 off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
319 gold_assert(all_phdrs_size == this->data_size());
320 unsigned char* view = of->get_output_view(this->offset(),
321 all_phdrs_size);
322 unsigned char* v = view;
323 for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
324 p != this->segment_list_.end();
325 ++p)
326 {
327 elfcpp::Phdr_write<size, big_endian> ophdr(v);
328 (*p)->write_header(&ophdr);
329 v += phdr_size;
330 }
331
332 gold_assert(v - view == all_phdrs_size);
333
334 of->write_output_view(this->offset(), all_phdrs_size, view);
335 }
336
337 off_t
338 Output_segment_headers::do_size() const
339 {
340 const int size = parameters->target().get_size();
341 int phdr_size;
342 if (size == 32)
343 phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
344 else if (size == 64)
345 phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
346 else
347 gold_unreachable();
348
349 return this->segment_list_.size() * phdr_size;
350 }
351
352 // Output_file_header methods.
353
354 Output_file_header::Output_file_header(const Target* target,
355 const Symbol_table* symtab,
356 const Output_segment_headers* osh,
357 const char* entry)
358 : target_(target),
359 symtab_(symtab),
360 segment_header_(osh),
361 section_header_(NULL),
362 shstrtab_(NULL),
363 entry_(entry)
364 {
365 this->set_data_size(this->do_size());
366 }
367
368 // Set the section table information for a file header.
369
370 void
371 Output_file_header::set_section_info(const Output_section_headers* shdrs,
372 const Output_section* shstrtab)
373 {
374 this->section_header_ = shdrs;
375 this->shstrtab_ = shstrtab;
376 }
377
378 // Write out the file header.
379
380 void
381 Output_file_header::do_write(Output_file* of)
382 {
383 gold_assert(this->offset() == 0);
384
385 switch (parameters->size_and_endianness())
386 {
387 #ifdef HAVE_TARGET_32_LITTLE
388 case Parameters::TARGET_32_LITTLE:
389 this->do_sized_write<32, false>(of);
390 break;
391 #endif
392 #ifdef HAVE_TARGET_32_BIG
393 case Parameters::TARGET_32_BIG:
394 this->do_sized_write<32, true>(of);
395 break;
396 #endif
397 #ifdef HAVE_TARGET_64_LITTLE
398 case Parameters::TARGET_64_LITTLE:
399 this->do_sized_write<64, false>(of);
400 break;
401 #endif
402 #ifdef HAVE_TARGET_64_BIG
403 case Parameters::TARGET_64_BIG:
404 this->do_sized_write<64, true>(of);
405 break;
406 #endif
407 default:
408 gold_unreachable();
409 }
410 }
411
412 // Write out the file header with appropriate size and endianess.
413
414 template<int size, bool big_endian>
415 void
416 Output_file_header::do_sized_write(Output_file* of)
417 {
418 gold_assert(this->offset() == 0);
419
420 int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
421 unsigned char* view = of->get_output_view(0, ehdr_size);
422 elfcpp::Ehdr_write<size, big_endian> oehdr(view);
423
424 unsigned char e_ident[elfcpp::EI_NIDENT];
425 memset(e_ident, 0, elfcpp::EI_NIDENT);
426 e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
427 e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
428 e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
429 e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
430 if (size == 32)
431 e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
432 else if (size == 64)
433 e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
434 else
435 gold_unreachable();
436 e_ident[elfcpp::EI_DATA] = (big_endian
437 ? elfcpp::ELFDATA2MSB
438 : elfcpp::ELFDATA2LSB);
439 e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
440 oehdr.put_e_ident(e_ident);
441
442 elfcpp::ET e_type;
443 if (parameters->options().relocatable())
444 e_type = elfcpp::ET_REL;
445 else if (parameters->options().output_is_position_independent())
446 e_type = elfcpp::ET_DYN;
447 else
448 e_type = elfcpp::ET_EXEC;
449 oehdr.put_e_type(e_type);
450
451 oehdr.put_e_machine(this->target_->machine_code());
452 oehdr.put_e_version(elfcpp::EV_CURRENT);
453
454 oehdr.put_e_entry(this->entry<size>());
455
456 if (this->segment_header_ == NULL)
457 oehdr.put_e_phoff(0);
458 else
459 oehdr.put_e_phoff(this->segment_header_->offset());
460
461 oehdr.put_e_shoff(this->section_header_->offset());
462
463 // FIXME: The target needs to set the flags.
464 oehdr.put_e_flags(0);
465
466 oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
467
468 if (this->segment_header_ == NULL)
469 {
470 oehdr.put_e_phentsize(0);
471 oehdr.put_e_phnum(0);
472 }
473 else
474 {
475 oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
476 oehdr.put_e_phnum(this->segment_header_->data_size()
477 / elfcpp::Elf_sizes<size>::phdr_size);
478 }
479
480 oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
481 size_t section_count = (this->section_header_->data_size()
482 / elfcpp::Elf_sizes<size>::shdr_size);
483
484 if (section_count < elfcpp::SHN_LORESERVE)
485 oehdr.put_e_shnum(this->section_header_->data_size()
486 / elfcpp::Elf_sizes<size>::shdr_size);
487 else
488 oehdr.put_e_shnum(0);
489
490 unsigned int shstrndx = this->shstrtab_->out_shndx();
491 if (shstrndx < elfcpp::SHN_LORESERVE)
492 oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
493 else
494 oehdr.put_e_shstrndx(elfcpp::SHN_XINDEX);
495
496 // Let the target adjust the ELF header, e.g., to set EI_OSABI in
497 // the e_ident field.
498 parameters->target().adjust_elf_header(view, ehdr_size);
499
500 of->write_output_view(0, ehdr_size, view);
501 }
502
503 // Return the value to use for the entry address. THIS->ENTRY_ is the
504 // symbol specified on the command line, if any.
505
506 template<int size>
507 typename elfcpp::Elf_types<size>::Elf_Addr
508 Output_file_header::entry()
509 {
510 const bool should_issue_warning = (this->entry_ != NULL
511 && !parameters->options().relocatable()
512 && !parameters->options().shared());
513
514 // FIXME: Need to support target specific entry symbol.
515 const char* entry = this->entry_;
516 if (entry == NULL)
517 entry = "_start";
518
519 Symbol* sym = this->symtab_->lookup(entry);
520
521 typename Sized_symbol<size>::Value_type v;
522 if (sym != NULL)
523 {
524 Sized_symbol<size>* ssym;
525 ssym = this->symtab_->get_sized_symbol<size>(sym);
526 if (!ssym->is_defined() && should_issue_warning)
527 gold_warning("entry symbol '%s' exists but is not defined", entry);
528 v = ssym->value();
529 }
530 else
531 {
532 // We couldn't find the entry symbol. See if we can parse it as
533 // a number. This supports, e.g., -e 0x1000.
534 char* endptr;
535 v = strtoull(entry, &endptr, 0);
536 if (*endptr != '\0')
537 {
538 if (should_issue_warning)
539 gold_warning("cannot find entry symbol '%s'", entry);
540 v = 0;
541 }
542 }
543
544 return v;
545 }
546
547 // Compute the current data size.
548
549 off_t
550 Output_file_header::do_size() const
551 {
552 const int size = parameters->target().get_size();
553 if (size == 32)
554 return elfcpp::Elf_sizes<32>::ehdr_size;
555 else if (size == 64)
556 return elfcpp::Elf_sizes<64>::ehdr_size;
557 else
558 gold_unreachable();
559 }
560
561 // Output_data_const methods.
562
563 void
564 Output_data_const::do_write(Output_file* of)
565 {
566 of->write(this->offset(), this->data_.data(), this->data_.size());
567 }
568
569 // Output_data_const_buffer methods.
570
571 void
572 Output_data_const_buffer::do_write(Output_file* of)
573 {
574 of->write(this->offset(), this->p_, this->data_size());
575 }
576
577 // Output_section_data methods.
578
579 // Record the output section, and set the entry size and such.
580
581 void
582 Output_section_data::set_output_section(Output_section* os)
583 {
584 gold_assert(this->output_section_ == NULL);
585 this->output_section_ = os;
586 this->do_adjust_output_section(os);
587 }
588
589 // Return the section index of the output section.
590
591 unsigned int
592 Output_section_data::do_out_shndx() const
593 {
594 gold_assert(this->output_section_ != NULL);
595 return this->output_section_->out_shndx();
596 }
597
598 // Set the alignment, which means we may need to update the alignment
599 // of the output section.
600
601 void
602 Output_section_data::set_addralign(uint64_t addralign)
603 {
604 this->addralign_ = addralign;
605 if (this->output_section_ != NULL
606 && this->output_section_->addralign() < addralign)
607 this->output_section_->set_addralign(addralign);
608 }
609
610 // Output_data_strtab methods.
611
612 // Set the final data size.
613
614 void
615 Output_data_strtab::set_final_data_size()
616 {
617 this->strtab_->set_string_offsets();
618 this->set_data_size(this->strtab_->get_strtab_size());
619 }
620
621 // Write out a string table.
622
623 void
624 Output_data_strtab::do_write(Output_file* of)
625 {
626 this->strtab_->write(of, this->offset());
627 }
628
629 // Output_reloc methods.
630
631 // A reloc against a global symbol.
632
633 template<bool dynamic, int size, bool big_endian>
634 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
635 Symbol* gsym,
636 unsigned int type,
637 Output_data* od,
638 Address address,
639 bool is_relative)
640 : address_(address), local_sym_index_(GSYM_CODE), type_(type),
641 is_relative_(is_relative), is_section_symbol_(false), shndx_(INVALID_CODE)
642 {
643 // this->type_ is a bitfield; make sure TYPE fits.
644 gold_assert(this->type_ == type);
645 this->u1_.gsym = gsym;
646 this->u2_.od = od;
647 if (dynamic)
648 this->set_needs_dynsym_index();
649 }
650
651 template<bool dynamic, int size, bool big_endian>
652 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
653 Symbol* gsym,
654 unsigned int type,
655 Sized_relobj<size, big_endian>* relobj,
656 unsigned int shndx,
657 Address address,
658 bool is_relative)
659 : address_(address), local_sym_index_(GSYM_CODE), type_(type),
660 is_relative_(is_relative), is_section_symbol_(false), shndx_(shndx)
661 {
662 gold_assert(shndx != INVALID_CODE);
663 // this->type_ is a bitfield; make sure TYPE fits.
664 gold_assert(this->type_ == type);
665 this->u1_.gsym = gsym;
666 this->u2_.relobj = relobj;
667 if (dynamic)
668 this->set_needs_dynsym_index();
669 }
670
671 // A reloc against a local symbol.
672
673 template<bool dynamic, int size, bool big_endian>
674 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
675 Sized_relobj<size, big_endian>* relobj,
676 unsigned int local_sym_index,
677 unsigned int type,
678 Output_data* od,
679 Address address,
680 bool is_relative,
681 bool is_section_symbol)
682 : address_(address), local_sym_index_(local_sym_index), type_(type),
683 is_relative_(is_relative), is_section_symbol_(is_section_symbol),
684 shndx_(INVALID_CODE)
685 {
686 gold_assert(local_sym_index != GSYM_CODE
687 && local_sym_index != INVALID_CODE);
688 // this->type_ is a bitfield; make sure TYPE fits.
689 gold_assert(this->type_ == type);
690 this->u1_.relobj = relobj;
691 this->u2_.od = od;
692 if (dynamic)
693 this->set_needs_dynsym_index();
694 }
695
696 template<bool dynamic, int size, bool big_endian>
697 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
698 Sized_relobj<size, big_endian>* relobj,
699 unsigned int local_sym_index,
700 unsigned int type,
701 unsigned int shndx,
702 Address address,
703 bool is_relative,
704 bool is_section_symbol)
705 : address_(address), local_sym_index_(local_sym_index), type_(type),
706 is_relative_(is_relative), is_section_symbol_(is_section_symbol),
707 shndx_(shndx)
708 {
709 gold_assert(local_sym_index != GSYM_CODE
710 && local_sym_index != INVALID_CODE);
711 gold_assert(shndx != INVALID_CODE);
712 // this->type_ is a bitfield; make sure TYPE fits.
713 gold_assert(this->type_ == type);
714 this->u1_.relobj = relobj;
715 this->u2_.relobj = relobj;
716 if (dynamic)
717 this->set_needs_dynsym_index();
718 }
719
720 // A reloc against the STT_SECTION symbol of an output section.
721
722 template<bool dynamic, int size, bool big_endian>
723 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
724 Output_section* os,
725 unsigned int type,
726 Output_data* od,
727 Address address)
728 : address_(address), local_sym_index_(SECTION_CODE), type_(type),
729 is_relative_(false), is_section_symbol_(true), shndx_(INVALID_CODE)
730 {
731 // this->type_ is a bitfield; make sure TYPE fits.
732 gold_assert(this->type_ == type);
733 this->u1_.os = os;
734 this->u2_.od = od;
735 if (dynamic)
736 this->set_needs_dynsym_index();
737 else
738 os->set_needs_symtab_index();
739 }
740
741 template<bool dynamic, int size, bool big_endian>
742 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
743 Output_section* os,
744 unsigned int type,
745 Sized_relobj<size, big_endian>* relobj,
746 unsigned int shndx,
747 Address address)
748 : address_(address), local_sym_index_(SECTION_CODE), type_(type),
749 is_relative_(false), is_section_symbol_(true), shndx_(shndx)
750 {
751 gold_assert(shndx != INVALID_CODE);
752 // this->type_ is a bitfield; make sure TYPE fits.
753 gold_assert(this->type_ == type);
754 this->u1_.os = os;
755 this->u2_.relobj = relobj;
756 if (dynamic)
757 this->set_needs_dynsym_index();
758 else
759 os->set_needs_symtab_index();
760 }
761
762 // Record that we need a dynamic symbol index for this relocation.
763
764 template<bool dynamic, int size, bool big_endian>
765 void
766 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
767 set_needs_dynsym_index()
768 {
769 if (this->is_relative_)
770 return;
771 switch (this->local_sym_index_)
772 {
773 case INVALID_CODE:
774 gold_unreachable();
775
776 case GSYM_CODE:
777 this->u1_.gsym->set_needs_dynsym_entry();
778 break;
779
780 case SECTION_CODE:
781 this->u1_.os->set_needs_dynsym_index();
782 break;
783
784 case 0:
785 break;
786
787 default:
788 {
789 const unsigned int lsi = this->local_sym_index_;
790 if (!this->is_section_symbol_)
791 this->u1_.relobj->set_needs_output_dynsym_entry(lsi);
792 else
793 this->u1_.relobj->output_section(lsi)->set_needs_dynsym_index();
794 }
795 break;
796 }
797 }
798
799 // Get the symbol index of a relocation.
800
801 template<bool dynamic, int size, bool big_endian>
802 unsigned int
803 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
804 const
805 {
806 unsigned int index;
807 switch (this->local_sym_index_)
808 {
809 case INVALID_CODE:
810 gold_unreachable();
811
812 case GSYM_CODE:
813 if (this->u1_.gsym == NULL)
814 index = 0;
815 else if (dynamic)
816 index = this->u1_.gsym->dynsym_index();
817 else
818 index = this->u1_.gsym->symtab_index();
819 break;
820
821 case SECTION_CODE:
822 if (dynamic)
823 index = this->u1_.os->dynsym_index();
824 else
825 index = this->u1_.os->symtab_index();
826 break;
827
828 case 0:
829 // Relocations without symbols use a symbol index of 0.
830 index = 0;
831 break;
832
833 default:
834 {
835 const unsigned int lsi = this->local_sym_index_;
836 if (!this->is_section_symbol_)
837 {
838 if (dynamic)
839 index = this->u1_.relobj->dynsym_index(lsi);
840 else
841 index = this->u1_.relobj->symtab_index(lsi);
842 }
843 else
844 {
845 Output_section* os = this->u1_.relobj->output_section(lsi);
846 gold_assert(os != NULL);
847 if (dynamic)
848 index = os->dynsym_index();
849 else
850 index = os->symtab_index();
851 }
852 }
853 break;
854 }
855 gold_assert(index != -1U);
856 return index;
857 }
858
859 // For a local section symbol, get the address of the offset ADDEND
860 // within the input section.
861
862 template<bool dynamic, int size, bool big_endian>
863 typename elfcpp::Elf_types<size>::Elf_Addr
864 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
865 local_section_offset(Addend addend) const
866 {
867 gold_assert(this->local_sym_index_ != GSYM_CODE
868 && this->local_sym_index_ != SECTION_CODE
869 && this->local_sym_index_ != INVALID_CODE
870 && this->is_section_symbol_);
871 const unsigned int lsi = this->local_sym_index_;
872 Output_section* os = this->u1_.relobj->output_section(lsi);
873 gold_assert(os != NULL);
874 Address offset = this->u1_.relobj->get_output_section_offset(lsi);
875 if (offset != invalid_address)
876 return offset + addend;
877 // This is a merge section.
878 offset = os->output_address(this->u1_.relobj, lsi, addend);
879 gold_assert(offset != invalid_address);
880 return offset;
881 }
882
883 // Get the output address of a relocation.
884
885 template<bool dynamic, int size, bool big_endian>
886 typename elfcpp::Elf_types<size>::Elf_Addr
887 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_address() const
888 {
889 Address address = this->address_;
890 if (this->shndx_ != INVALID_CODE)
891 {
892 Output_section* os = this->u2_.relobj->output_section(this->shndx_);
893 gold_assert(os != NULL);
894 Address off = this->u2_.relobj->get_output_section_offset(this->shndx_);
895 if (off != invalid_address)
896 address += os->address() + off;
897 else
898 {
899 address = os->output_address(this->u2_.relobj, this->shndx_,
900 address);
901 gold_assert(address != invalid_address);
902 }
903 }
904 else if (this->u2_.od != NULL)
905 address += this->u2_.od->address();
906 return address;
907 }
908
909 // Write out the offset and info fields of a Rel or Rela relocation
910 // entry.
911
912 template<bool dynamic, int size, bool big_endian>
913 template<typename Write_rel>
914 void
915 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
916 Write_rel* wr) const
917 {
918 wr->put_r_offset(this->get_address());
919 unsigned int sym_index = this->is_relative_ ? 0 : this->get_symbol_index();
920 wr->put_r_info(elfcpp::elf_r_info<size>(sym_index, this->type_));
921 }
922
923 // Write out a Rel relocation.
924
925 template<bool dynamic, int size, bool big_endian>
926 void
927 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
928 unsigned char* pov) const
929 {
930 elfcpp::Rel_write<size, big_endian> orel(pov);
931 this->write_rel(&orel);
932 }
933
934 // Get the value of the symbol referred to by a Rel relocation.
935
936 template<bool dynamic, int size, bool big_endian>
937 typename elfcpp::Elf_types<size>::Elf_Addr
938 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::symbol_value(
939 Addend addend) const
940 {
941 if (this->local_sym_index_ == GSYM_CODE)
942 {
943 const Sized_symbol<size>* sym;
944 sym = static_cast<const Sized_symbol<size>*>(this->u1_.gsym);
945 return sym->value() + addend;
946 }
947 gold_assert(this->local_sym_index_ != SECTION_CODE
948 && this->local_sym_index_ != INVALID_CODE
949 && !this->is_section_symbol_);
950 const unsigned int lsi = this->local_sym_index_;
951 const Symbol_value<size>* symval = this->u1_.relobj->local_symbol(lsi);
952 return symval->value(this->u1_.relobj, addend);
953 }
954
955 // Reloc comparison. This function sorts the dynamic relocs for the
956 // benefit of the dynamic linker. First we sort all relative relocs
957 // to the front. Among relative relocs, we sort by output address.
958 // Among non-relative relocs, we sort by symbol index, then by output
959 // address.
960
961 template<bool dynamic, int size, bool big_endian>
962 int
963 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
964 compare(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>& r2)
965 const
966 {
967 if (this->is_relative_)
968 {
969 if (!r2.is_relative_)
970 return -1;
971 // Otherwise sort by reloc address below.
972 }
973 else if (r2.is_relative_)
974 return 1;
975 else
976 {
977 unsigned int sym1 = this->get_symbol_index();
978 unsigned int sym2 = r2.get_symbol_index();
979 if (sym1 < sym2)
980 return -1;
981 else if (sym1 > sym2)
982 return 1;
983 // Otherwise sort by reloc address.
984 }
985
986 section_offset_type addr1 = this->get_address();
987 section_offset_type addr2 = r2.get_address();
988 if (addr1 < addr2)
989 return -1;
990 else if (addr1 > addr2)
991 return 1;
992
993 // Final tie breaker, in order to generate the same output on any
994 // host: reloc type.
995 unsigned int type1 = this->type_;
996 unsigned int type2 = r2.type_;
997 if (type1 < type2)
998 return -1;
999 else if (type1 > type2)
1000 return 1;
1001
1002 // These relocs appear to be exactly the same.
1003 return 0;
1004 }
1005
1006 // Write out a Rela relocation.
1007
1008 template<bool dynamic, int size, bool big_endian>
1009 void
1010 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
1011 unsigned char* pov) const
1012 {
1013 elfcpp::Rela_write<size, big_endian> orel(pov);
1014 this->rel_.write_rel(&orel);
1015 Addend addend = this->addend_;
1016 if (this->rel_.is_relative())
1017 addend = this->rel_.symbol_value(addend);
1018 else if (this->rel_.is_local_section_symbol())
1019 addend = this->rel_.local_section_offset(addend);
1020 orel.put_r_addend(addend);
1021 }
1022
1023 // Output_data_reloc_base methods.
1024
1025 // Adjust the output section.
1026
1027 template<int sh_type, bool dynamic, int size, bool big_endian>
1028 void
1029 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
1030 ::do_adjust_output_section(Output_section* os)
1031 {
1032 if (sh_type == elfcpp::SHT_REL)
1033 os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
1034 else if (sh_type == elfcpp::SHT_RELA)
1035 os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
1036 else
1037 gold_unreachable();
1038 if (dynamic)
1039 os->set_should_link_to_dynsym();
1040 else
1041 os->set_should_link_to_symtab();
1042 }
1043
1044 // Write out relocation data.
1045
1046 template<int sh_type, bool dynamic, int size, bool big_endian>
1047 void
1048 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
1049 Output_file* of)
1050 {
1051 const off_t off = this->offset();
1052 const off_t oview_size = this->data_size();
1053 unsigned char* const oview = of->get_output_view(off, oview_size);
1054
1055 if (this->sort_relocs_)
1056 {
1057 gold_assert(dynamic);
1058 std::sort(this->relocs_.begin(), this->relocs_.end(),
1059 Sort_relocs_comparison());
1060 }
1061
1062 unsigned char* pov = oview;
1063 for (typename Relocs::const_iterator p = this->relocs_.begin();
1064 p != this->relocs_.end();
1065 ++p)
1066 {
1067 p->write(pov);
1068 pov += reloc_size;
1069 }
1070
1071 gold_assert(pov - oview == oview_size);
1072
1073 of->write_output_view(off, oview_size, oview);
1074
1075 // We no longer need the relocation entries.
1076 this->relocs_.clear();
1077 }
1078
1079 // Class Output_relocatable_relocs.
1080
1081 template<int sh_type, int size, bool big_endian>
1082 void
1083 Output_relocatable_relocs<sh_type, size, big_endian>::set_final_data_size()
1084 {
1085 this->set_data_size(this->rr_->output_reloc_count()
1086 * Reloc_types<sh_type, size, big_endian>::reloc_size);
1087 }
1088
1089 // class Output_data_group.
1090
1091 template<int size, bool big_endian>
1092 Output_data_group<size, big_endian>::Output_data_group(
1093 Sized_relobj<size, big_endian>* relobj,
1094 section_size_type entry_count,
1095 elfcpp::Elf_Word flags,
1096 std::vector<unsigned int>* input_shndxes)
1097 : Output_section_data(entry_count * 4, 4, false),
1098 relobj_(relobj),
1099 flags_(flags)
1100 {
1101 this->input_shndxes_.swap(*input_shndxes);
1102 }
1103
1104 // Write out the section group, which means translating the section
1105 // indexes to apply to the output file.
1106
1107 template<int size, bool big_endian>
1108 void
1109 Output_data_group<size, big_endian>::do_write(Output_file* of)
1110 {
1111 const off_t off = this->offset();
1112 const section_size_type oview_size =
1113 convert_to_section_size_type(this->data_size());
1114 unsigned char* const oview = of->get_output_view(off, oview_size);
1115
1116 elfcpp::Elf_Word* contents = reinterpret_cast<elfcpp::Elf_Word*>(oview);
1117 elfcpp::Swap<32, big_endian>::writeval(contents, this->flags_);
1118 ++contents;
1119
1120 for (std::vector<unsigned int>::const_iterator p =
1121 this->input_shndxes_.begin();
1122 p != this->input_shndxes_.end();
1123 ++p, ++contents)
1124 {
1125 Output_section* os = this->relobj_->output_section(*p);
1126
1127 unsigned int output_shndx;
1128 if (os != NULL)
1129 output_shndx = os->out_shndx();
1130 else
1131 {
1132 this->relobj_->error(_("section group retained but "
1133 "group element discarded"));
1134 output_shndx = 0;
1135 }
1136
1137 elfcpp::Swap<32, big_endian>::writeval(contents, output_shndx);
1138 }
1139
1140 size_t wrote = reinterpret_cast<unsigned char*>(contents) - oview;
1141 gold_assert(wrote == oview_size);
1142
1143 of->write_output_view(off, oview_size, oview);
1144
1145 // We no longer need this information.
1146 this->input_shndxes_.clear();
1147 }
1148
1149 // Output_data_got::Got_entry methods.
1150
1151 // Write out the entry.
1152
1153 template<int size, bool big_endian>
1154 void
1155 Output_data_got<size, big_endian>::Got_entry::write(unsigned char* pov) const
1156 {
1157 Valtype val = 0;
1158
1159 switch (this->local_sym_index_)
1160 {
1161 case GSYM_CODE:
1162 {
1163 // If the symbol is resolved locally, we need to write out the
1164 // link-time value, which will be relocated dynamically by a
1165 // RELATIVE relocation.
1166 Symbol* gsym = this->u_.gsym;
1167 Sized_symbol<size>* sgsym;
1168 // This cast is a bit ugly. We don't want to put a
1169 // virtual method in Symbol, because we want Symbol to be
1170 // as small as possible.
1171 sgsym = static_cast<Sized_symbol<size>*>(gsym);
1172 val = sgsym->value();
1173 }
1174 break;
1175
1176 case CONSTANT_CODE:
1177 val = this->u_.constant;
1178 break;
1179
1180 default:
1181 {
1182 const unsigned int lsi = this->local_sym_index_;
1183 const Symbol_value<size>* symval = this->u_.object->local_symbol(lsi);
1184 val = symval->value(this->u_.object, 0);
1185 }
1186 break;
1187 }
1188
1189 elfcpp::Swap<size, big_endian>::writeval(pov, val);
1190 }
1191
1192 // Output_data_got methods.
1193
1194 // Add an entry for a global symbol to the GOT. This returns true if
1195 // this is a new GOT entry, false if the symbol already had a GOT
1196 // entry.
1197
1198 template<int size, bool big_endian>
1199 bool
1200 Output_data_got<size, big_endian>::add_global(
1201 Symbol* gsym,
1202 unsigned int got_type)
1203 {
1204 if (gsym->has_got_offset(got_type))
1205 return false;
1206
1207 this->entries_.push_back(Got_entry(gsym));
1208 this->set_got_size();
1209 gsym->set_got_offset(got_type, this->last_got_offset());
1210 return true;
1211 }
1212
1213 // Add an entry for a global symbol to the GOT, and add a dynamic
1214 // relocation of type R_TYPE for the GOT entry.
1215 template<int size, bool big_endian>
1216 void
1217 Output_data_got<size, big_endian>::add_global_with_rel(
1218 Symbol* gsym,
1219 unsigned int got_type,
1220 Rel_dyn* rel_dyn,
1221 unsigned int r_type)
1222 {
1223 if (gsym->has_got_offset(got_type))
1224 return;
1225
1226 this->entries_.push_back(Got_entry());
1227 this->set_got_size();
1228 unsigned int got_offset = this->last_got_offset();
1229 gsym->set_got_offset(got_type, got_offset);
1230 rel_dyn->add_global(gsym, r_type, this, got_offset);
1231 }
1232
1233 template<int size, bool big_endian>
1234 void
1235 Output_data_got<size, big_endian>::add_global_with_rela(
1236 Symbol* gsym,
1237 unsigned int got_type,
1238 Rela_dyn* rela_dyn,
1239 unsigned int r_type)
1240 {
1241 if (gsym->has_got_offset(got_type))
1242 return;
1243
1244 this->entries_.push_back(Got_entry());
1245 this->set_got_size();
1246 unsigned int got_offset = this->last_got_offset();
1247 gsym->set_got_offset(got_type, got_offset);
1248 rela_dyn->add_global(gsym, r_type, this, got_offset, 0);
1249 }
1250
1251 // Add a pair of entries for a global symbol to the GOT, and add
1252 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1253 // If R_TYPE_2 == 0, add the second entry with no relocation.
1254 template<int size, bool big_endian>
1255 void
1256 Output_data_got<size, big_endian>::add_global_pair_with_rel(
1257 Symbol* gsym,
1258 unsigned int got_type,
1259 Rel_dyn* rel_dyn,
1260 unsigned int r_type_1,
1261 unsigned int r_type_2)
1262 {
1263 if (gsym->has_got_offset(got_type))
1264 return;
1265
1266 this->entries_.push_back(Got_entry());
1267 unsigned int got_offset = this->last_got_offset();
1268 gsym->set_got_offset(got_type, got_offset);
1269 rel_dyn->add_global(gsym, r_type_1, this, got_offset);
1270
1271 this->entries_.push_back(Got_entry());
1272 if (r_type_2 != 0)
1273 {
1274 got_offset = this->last_got_offset();
1275 rel_dyn->add_global(gsym, r_type_2, this, got_offset);
1276 }
1277
1278 this->set_got_size();
1279 }
1280
1281 template<int size, bool big_endian>
1282 void
1283 Output_data_got<size, big_endian>::add_global_pair_with_rela(
1284 Symbol* gsym,
1285 unsigned int got_type,
1286 Rela_dyn* rela_dyn,
1287 unsigned int r_type_1,
1288 unsigned int r_type_2)
1289 {
1290 if (gsym->has_got_offset(got_type))
1291 return;
1292
1293 this->entries_.push_back(Got_entry());
1294 unsigned int got_offset = this->last_got_offset();
1295 gsym->set_got_offset(got_type, got_offset);
1296 rela_dyn->add_global(gsym, r_type_1, this, got_offset, 0);
1297
1298 this->entries_.push_back(Got_entry());
1299 if (r_type_2 != 0)
1300 {
1301 got_offset = this->last_got_offset();
1302 rela_dyn->add_global(gsym, r_type_2, this, got_offset, 0);
1303 }
1304
1305 this->set_got_size();
1306 }
1307
1308 // Add an entry for a local symbol to the GOT. This returns true if
1309 // this is a new GOT entry, false if the symbol already has a GOT
1310 // entry.
1311
1312 template<int size, bool big_endian>
1313 bool
1314 Output_data_got<size, big_endian>::add_local(
1315 Sized_relobj<size, big_endian>* object,
1316 unsigned int symndx,
1317 unsigned int got_type)
1318 {
1319 if (object->local_has_got_offset(symndx, got_type))
1320 return false;
1321
1322 this->entries_.push_back(Got_entry(object, symndx));
1323 this->set_got_size();
1324 object->set_local_got_offset(symndx, got_type, this->last_got_offset());
1325 return true;
1326 }
1327
1328 // Add an entry for a local symbol to the GOT, and add a dynamic
1329 // relocation of type R_TYPE for the GOT entry.
1330 template<int size, bool big_endian>
1331 void
1332 Output_data_got<size, big_endian>::add_local_with_rel(
1333 Sized_relobj<size, big_endian>* object,
1334 unsigned int symndx,
1335 unsigned int got_type,
1336 Rel_dyn* rel_dyn,
1337 unsigned int r_type)
1338 {
1339 if (object->local_has_got_offset(symndx, got_type))
1340 return;
1341
1342 this->entries_.push_back(Got_entry());
1343 this->set_got_size();
1344 unsigned int got_offset = this->last_got_offset();
1345 object->set_local_got_offset(symndx, got_type, got_offset);
1346 rel_dyn->add_local(object, symndx, r_type, this, got_offset);
1347 }
1348
1349 template<int size, bool big_endian>
1350 void
1351 Output_data_got<size, big_endian>::add_local_with_rela(
1352 Sized_relobj<size, big_endian>* object,
1353 unsigned int symndx,
1354 unsigned int got_type,
1355 Rela_dyn* rela_dyn,
1356 unsigned int r_type)
1357 {
1358 if (object->local_has_got_offset(symndx, got_type))
1359 return;
1360
1361 this->entries_.push_back(Got_entry());
1362 this->set_got_size();
1363 unsigned int got_offset = this->last_got_offset();
1364 object->set_local_got_offset(symndx, got_type, got_offset);
1365 rela_dyn->add_local(object, symndx, r_type, this, got_offset, 0);
1366 }
1367
1368 // Add a pair of entries for a local symbol to the GOT, and add
1369 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1370 // If R_TYPE_2 == 0, add the second entry with no relocation.
1371 template<int size, bool big_endian>
1372 void
1373 Output_data_got<size, big_endian>::add_local_pair_with_rel(
1374 Sized_relobj<size, big_endian>* object,
1375 unsigned int symndx,
1376 unsigned int shndx,
1377 unsigned int got_type,
1378 Rel_dyn* rel_dyn,
1379 unsigned int r_type_1,
1380 unsigned int r_type_2)
1381 {
1382 if (object->local_has_got_offset(symndx, got_type))
1383 return;
1384
1385 this->entries_.push_back(Got_entry());
1386 unsigned int got_offset = this->last_got_offset();
1387 object->set_local_got_offset(symndx, got_type, got_offset);
1388 Output_section* os = object->output_section(shndx);
1389 rel_dyn->add_output_section(os, r_type_1, this, got_offset);
1390
1391 this->entries_.push_back(Got_entry(object, symndx));
1392 if (r_type_2 != 0)
1393 {
1394 got_offset = this->last_got_offset();
1395 rel_dyn->add_output_section(os, r_type_2, this, got_offset);
1396 }
1397
1398 this->set_got_size();
1399 }
1400
1401 template<int size, bool big_endian>
1402 void
1403 Output_data_got<size, big_endian>::add_local_pair_with_rela(
1404 Sized_relobj<size, big_endian>* object,
1405 unsigned int symndx,
1406 unsigned int shndx,
1407 unsigned int got_type,
1408 Rela_dyn* rela_dyn,
1409 unsigned int r_type_1,
1410 unsigned int r_type_2)
1411 {
1412 if (object->local_has_got_offset(symndx, got_type))
1413 return;
1414
1415 this->entries_.push_back(Got_entry());
1416 unsigned int got_offset = this->last_got_offset();
1417 object->set_local_got_offset(symndx, got_type, got_offset);
1418 Output_section* os = object->output_section(shndx);
1419 rela_dyn->add_output_section(os, r_type_1, this, got_offset, 0);
1420
1421 this->entries_.push_back(Got_entry(object, symndx));
1422 if (r_type_2 != 0)
1423 {
1424 got_offset = this->last_got_offset();
1425 rela_dyn->add_output_section(os, r_type_2, this, got_offset, 0);
1426 }
1427
1428 this->set_got_size();
1429 }
1430
1431 // Write out the GOT.
1432
1433 template<int size, bool big_endian>
1434 void
1435 Output_data_got<size, big_endian>::do_write(Output_file* of)
1436 {
1437 const int add = size / 8;
1438
1439 const off_t off = this->offset();
1440 const off_t oview_size = this->data_size();
1441 unsigned char* const oview = of->get_output_view(off, oview_size);
1442
1443 unsigned char* pov = oview;
1444 for (typename Got_entries::const_iterator p = this->entries_.begin();
1445 p != this->entries_.end();
1446 ++p)
1447 {
1448 p->write(pov);
1449 pov += add;
1450 }
1451
1452 gold_assert(pov - oview == oview_size);
1453
1454 of->write_output_view(off, oview_size, oview);
1455
1456 // We no longer need the GOT entries.
1457 this->entries_.clear();
1458 }
1459
1460 // Output_data_dynamic::Dynamic_entry methods.
1461
1462 // Write out the entry.
1463
1464 template<int size, bool big_endian>
1465 void
1466 Output_data_dynamic::Dynamic_entry::write(
1467 unsigned char* pov,
1468 const Stringpool* pool) const
1469 {
1470 typename elfcpp::Elf_types<size>::Elf_WXword val;
1471 switch (this->offset_)
1472 {
1473 case DYNAMIC_NUMBER:
1474 val = this->u_.val;
1475 break;
1476
1477 case DYNAMIC_SECTION_SIZE:
1478 val = this->u_.od->data_size();
1479 break;
1480
1481 case DYNAMIC_SYMBOL:
1482 {
1483 const Sized_symbol<size>* s =
1484 static_cast<const Sized_symbol<size>*>(this->u_.sym);
1485 val = s->value();
1486 }
1487 break;
1488
1489 case DYNAMIC_STRING:
1490 val = pool->get_offset(this->u_.str);
1491 break;
1492
1493 default:
1494 val = this->u_.od->address() + this->offset_;
1495 break;
1496 }
1497
1498 elfcpp::Dyn_write<size, big_endian> dw(pov);
1499 dw.put_d_tag(this->tag_);
1500 dw.put_d_val(val);
1501 }
1502
1503 // Output_data_dynamic methods.
1504
1505 // Adjust the output section to set the entry size.
1506
1507 void
1508 Output_data_dynamic::do_adjust_output_section(Output_section* os)
1509 {
1510 if (parameters->target().get_size() == 32)
1511 os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
1512 else if (parameters->target().get_size() == 64)
1513 os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
1514 else
1515 gold_unreachable();
1516 }
1517
1518 // Set the final data size.
1519
1520 void
1521 Output_data_dynamic::set_final_data_size()
1522 {
1523 // Add the terminating entry if it hasn't been added.
1524 // Because of relaxation, we can run this multiple times.
1525 if (this->entries_.empty()
1526 || this->entries_.rbegin()->tag() != elfcpp::DT_NULL)
1527 this->add_constant(elfcpp::DT_NULL, 0);
1528
1529 int dyn_size;
1530 if (parameters->target().get_size() == 32)
1531 dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
1532 else if (parameters->target().get_size() == 64)
1533 dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
1534 else
1535 gold_unreachable();
1536 this->set_data_size(this->entries_.size() * dyn_size);
1537 }
1538
1539 // Write out the dynamic entries.
1540
1541 void
1542 Output_data_dynamic::do_write(Output_file* of)
1543 {
1544 switch (parameters->size_and_endianness())
1545 {
1546 #ifdef HAVE_TARGET_32_LITTLE
1547 case Parameters::TARGET_32_LITTLE:
1548 this->sized_write<32, false>(of);
1549 break;
1550 #endif
1551 #ifdef HAVE_TARGET_32_BIG
1552 case Parameters::TARGET_32_BIG:
1553 this->sized_write<32, true>(of);
1554 break;
1555 #endif
1556 #ifdef HAVE_TARGET_64_LITTLE
1557 case Parameters::TARGET_64_LITTLE:
1558 this->sized_write<64, false>(of);
1559 break;
1560 #endif
1561 #ifdef HAVE_TARGET_64_BIG
1562 case Parameters::TARGET_64_BIG:
1563 this->sized_write<64, true>(of);
1564 break;
1565 #endif
1566 default:
1567 gold_unreachable();
1568 }
1569 }
1570
1571 template<int size, bool big_endian>
1572 void
1573 Output_data_dynamic::sized_write(Output_file* of)
1574 {
1575 const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
1576
1577 const off_t offset = this->offset();
1578 const off_t oview_size = this->data_size();
1579 unsigned char* const oview = of->get_output_view(offset, oview_size);
1580
1581 unsigned char* pov = oview;
1582 for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
1583 p != this->entries_.end();
1584 ++p)
1585 {
1586 p->write<size, big_endian>(pov, this->pool_);
1587 pov += dyn_size;
1588 }
1589
1590 gold_assert(pov - oview == oview_size);
1591
1592 of->write_output_view(offset, oview_size, oview);
1593
1594 // We no longer need the dynamic entries.
1595 this->entries_.clear();
1596 }
1597
1598 // Class Output_symtab_xindex.
1599
1600 void
1601 Output_symtab_xindex::do_write(Output_file* of)
1602 {
1603 const off_t offset = this->offset();
1604 const off_t oview_size = this->data_size();
1605 unsigned char* const oview = of->get_output_view(offset, oview_size);
1606
1607 memset(oview, 0, oview_size);
1608
1609 if (parameters->target().is_big_endian())
1610 this->endian_do_write<true>(oview);
1611 else
1612 this->endian_do_write<false>(oview);
1613
1614 of->write_output_view(offset, oview_size, oview);
1615
1616 // We no longer need the data.
1617 this->entries_.clear();
1618 }
1619
1620 template<bool big_endian>
1621 void
1622 Output_symtab_xindex::endian_do_write(unsigned char* const oview)
1623 {
1624 for (Xindex_entries::const_iterator p = this->entries_.begin();
1625 p != this->entries_.end();
1626 ++p)
1627 {
1628 unsigned int symndx = p->first;
1629 gold_assert(symndx * 4 < this->data_size());
1630 elfcpp::Swap<32, big_endian>::writeval(oview + symndx * 4, p->second);
1631 }
1632 }
1633
1634 // Output_section::Input_section methods.
1635
1636 // Return the data size. For an input section we store the size here.
1637 // For an Output_section_data, we have to ask it for the size.
1638
1639 off_t
1640 Output_section::Input_section::data_size() const
1641 {
1642 if (this->is_input_section())
1643 return this->u1_.data_size;
1644 else
1645 return this->u2_.posd->data_size();
1646 }
1647
1648 // Set the address and file offset.
1649
1650 void
1651 Output_section::Input_section::set_address_and_file_offset(
1652 uint64_t address,
1653 off_t file_offset,
1654 off_t section_file_offset)
1655 {
1656 if (this->is_input_section())
1657 this->u2_.object->set_section_offset(this->shndx_,
1658 file_offset - section_file_offset);
1659 else
1660 this->u2_.posd->set_address_and_file_offset(address, file_offset);
1661 }
1662
1663 // Reset the address and file offset.
1664
1665 void
1666 Output_section::Input_section::reset_address_and_file_offset()
1667 {
1668 if (!this->is_input_section())
1669 this->u2_.posd->reset_address_and_file_offset();
1670 }
1671
1672 // Finalize the data size.
1673
1674 void
1675 Output_section::Input_section::finalize_data_size()
1676 {
1677 if (!this->is_input_section())
1678 this->u2_.posd->finalize_data_size();
1679 }
1680
1681 // Try to turn an input offset into an output offset. We want to
1682 // return the output offset relative to the start of this
1683 // Input_section in the output section.
1684
1685 inline bool
1686 Output_section::Input_section::output_offset(
1687 const Relobj* object,
1688 unsigned int shndx,
1689 section_offset_type offset,
1690 section_offset_type *poutput) const
1691 {
1692 if (!this->is_input_section())
1693 return this->u2_.posd->output_offset(object, shndx, offset, poutput);
1694 else
1695 {
1696 if (this->shndx_ != shndx || this->u2_.object != object)
1697 return false;
1698 *poutput = offset;
1699 return true;
1700 }
1701 }
1702
1703 // Return whether this is the merge section for the input section
1704 // SHNDX in OBJECT.
1705
1706 inline bool
1707 Output_section::Input_section::is_merge_section_for(const Relobj* object,
1708 unsigned int shndx) const
1709 {
1710 if (this->is_input_section())
1711 return false;
1712 return this->u2_.posd->is_merge_section_for(object, shndx);
1713 }
1714
1715 // Write out the data. We don't have to do anything for an input
1716 // section--they are handled via Object::relocate--but this is where
1717 // we write out the data for an Output_section_data.
1718
1719 void
1720 Output_section::Input_section::write(Output_file* of)
1721 {
1722 if (!this->is_input_section())
1723 this->u2_.posd->write(of);
1724 }
1725
1726 // Write the data to a buffer. As for write(), we don't have to do
1727 // anything for an input section.
1728
1729 void
1730 Output_section::Input_section::write_to_buffer(unsigned char* buffer)
1731 {
1732 if (!this->is_input_section())
1733 this->u2_.posd->write_to_buffer(buffer);
1734 }
1735
1736 // Print to a map file.
1737
1738 void
1739 Output_section::Input_section::print_to_mapfile(Mapfile* mapfile) const
1740 {
1741 switch (this->shndx_)
1742 {
1743 case OUTPUT_SECTION_CODE:
1744 case MERGE_DATA_SECTION_CODE:
1745 case MERGE_STRING_SECTION_CODE:
1746 this->u2_.posd->print_to_mapfile(mapfile);
1747 break;
1748
1749 case RELAXED_INPUT_SECTION_CODE:
1750 {
1751 Output_relaxed_input_section* relaxed_section =
1752 this->relaxed_input_section();
1753 mapfile->print_input_section(relaxed_section->relobj(),
1754 relaxed_section->shndx());
1755 }
1756 break;
1757 default:
1758 mapfile->print_input_section(this->u2_.object, this->shndx_);
1759 break;
1760 }
1761 }
1762
1763 // Output_section methods.
1764
1765 // Construct an Output_section. NAME will point into a Stringpool.
1766
1767 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
1768 elfcpp::Elf_Xword flags)
1769 : name_(name),
1770 addralign_(0),
1771 entsize_(0),
1772 load_address_(0),
1773 link_section_(NULL),
1774 link_(0),
1775 info_section_(NULL),
1776 info_symndx_(NULL),
1777 info_(0),
1778 type_(type),
1779 flags_(flags),
1780 out_shndx_(-1U),
1781 symtab_index_(0),
1782 dynsym_index_(0),
1783 input_sections_(),
1784 first_input_offset_(0),
1785 fills_(),
1786 postprocessing_buffer_(NULL),
1787 needs_symtab_index_(false),
1788 needs_dynsym_index_(false),
1789 should_link_to_symtab_(false),
1790 should_link_to_dynsym_(false),
1791 after_input_sections_(false),
1792 requires_postprocessing_(false),
1793 found_in_sections_clause_(false),
1794 has_load_address_(false),
1795 info_uses_section_index_(false),
1796 may_sort_attached_input_sections_(false),
1797 must_sort_attached_input_sections_(false),
1798 attached_input_sections_are_sorted_(false),
1799 is_relro_(false),
1800 is_relro_local_(false),
1801 is_small_section_(false),
1802 is_large_section_(false),
1803 tls_offset_(0),
1804 checkpoint_(NULL),
1805 merge_section_map_(),
1806 merge_section_by_properties_map_(),
1807 relaxed_input_section_map_(),
1808 is_relaxed_input_section_map_valid_(true),
1809 generate_code_fills_at_write_(false)
1810 {
1811 // An unallocated section has no address. Forcing this means that
1812 // we don't need special treatment for symbols defined in debug
1813 // sections.
1814 if ((flags & elfcpp::SHF_ALLOC) == 0)
1815 this->set_address(0);
1816 }
1817
1818 Output_section::~Output_section()
1819 {
1820 delete this->checkpoint_;
1821 }
1822
1823 // Set the entry size.
1824
1825 void
1826 Output_section::set_entsize(uint64_t v)
1827 {
1828 if (this->entsize_ == 0)
1829 this->entsize_ = v;
1830 else
1831 gold_assert(this->entsize_ == v);
1832 }
1833
1834 // Add the input section SHNDX, with header SHDR, named SECNAME, in
1835 // OBJECT, to the Output_section. RELOC_SHNDX is the index of a
1836 // relocation section which applies to this section, or 0 if none, or
1837 // -1U if more than one. Return the offset of the input section
1838 // within the output section. Return -1 if the input section will
1839 // receive special handling. In the normal case we don't always keep
1840 // track of input sections for an Output_section. Instead, each
1841 // Object keeps track of the Output_section for each of its input
1842 // sections. However, if HAVE_SECTIONS_SCRIPT is true, we do keep
1843 // track of input sections here; this is used when SECTIONS appears in
1844 // a linker script.
1845
1846 template<int size, bool big_endian>
1847 off_t
1848 Output_section::add_input_section(Sized_relobj<size, big_endian>* object,
1849 unsigned int shndx,
1850 const char* secname,
1851 const elfcpp::Shdr<size, big_endian>& shdr,
1852 unsigned int reloc_shndx,
1853 bool have_sections_script)
1854 {
1855 elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
1856 if ((addralign & (addralign - 1)) != 0)
1857 {
1858 object->error(_("invalid alignment %lu for section \"%s\""),
1859 static_cast<unsigned long>(addralign), secname);
1860 addralign = 1;
1861 }
1862
1863 if (addralign > this->addralign_)
1864 this->addralign_ = addralign;
1865
1866 typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
1867 this->update_flags_for_input_section(sh_flags);
1868
1869 uint64_t entsize = shdr.get_sh_entsize();
1870
1871 // .debug_str is a mergeable string section, but is not always so
1872 // marked by compilers. Mark manually here so we can optimize.
1873 if (strcmp(secname, ".debug_str") == 0)
1874 {
1875 sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS);
1876 entsize = 1;
1877 }
1878
1879 // If this is a SHF_MERGE section, we pass all the input sections to
1880 // a Output_data_merge. We don't try to handle relocations for such
1881 // a section. We don't try to handle empty merge sections--they
1882 // mess up the mappings, and are useless anyhow.
1883 if ((sh_flags & elfcpp::SHF_MERGE) != 0
1884 && reloc_shndx == 0
1885 && shdr.get_sh_size() > 0)
1886 {
1887 if (this->add_merge_input_section(object, shndx, sh_flags,
1888 entsize, addralign))
1889 {
1890 // Tell the relocation routines that they need to call the
1891 // output_offset method to determine the final address.
1892 return -1;
1893 }
1894 }
1895
1896 off_t offset_in_section = this->current_data_size_for_child();
1897 off_t aligned_offset_in_section = align_address(offset_in_section,
1898 addralign);
1899
1900 // Determine if we want to delay code-fill generation until the output
1901 // section is written. When the target is relaxing, we want to delay fill
1902 // generating to avoid adjusting them during relaxation.
1903 if (!this->generate_code_fills_at_write_
1904 && !have_sections_script
1905 && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
1906 && parameters->target().has_code_fill()
1907 && parameters->target().may_relax())
1908 {
1909 gold_assert(this->fills_.empty());
1910 this->generate_code_fills_at_write_ = true;
1911 }
1912
1913 if (aligned_offset_in_section > offset_in_section
1914 && !this->generate_code_fills_at_write_
1915 && !have_sections_script
1916 && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
1917 && parameters->target().has_code_fill())
1918 {
1919 // We need to add some fill data. Using fill_list_ when
1920 // possible is an optimization, since we will often have fill
1921 // sections without input sections.
1922 off_t fill_len = aligned_offset_in_section - offset_in_section;
1923 if (this->input_sections_.empty())
1924 this->fills_.push_back(Fill(offset_in_section, fill_len));
1925 else
1926 {
1927 std::string fill_data(parameters->target().code_fill(fill_len));
1928 Output_data_const* odc = new Output_data_const(fill_data, 1);
1929 this->input_sections_.push_back(Input_section(odc));
1930 }
1931 }
1932
1933 this->set_current_data_size_for_child(aligned_offset_in_section
1934 + shdr.get_sh_size());
1935
1936 // We need to keep track of this section if we are already keeping
1937 // track of sections, or if we are relaxing. Also, if this is a
1938 // section which requires sorting, or which may require sorting in
1939 // the future, we keep track of the sections.
1940 if (have_sections_script
1941 || !this->input_sections_.empty()
1942 || this->may_sort_attached_input_sections()
1943 || this->must_sort_attached_input_sections()
1944 || parameters->options().user_set_Map()
1945 || parameters->target().may_relax())
1946 this->input_sections_.push_back(Input_section(object, shndx,
1947 shdr.get_sh_size(),
1948 addralign));
1949
1950 return aligned_offset_in_section;
1951 }
1952
1953 // Add arbitrary data to an output section.
1954
1955 void
1956 Output_section::add_output_section_data(Output_section_data* posd)
1957 {
1958 Input_section inp(posd);
1959 this->add_output_section_data(&inp);
1960
1961 if (posd->is_data_size_valid())
1962 {
1963 off_t offset_in_section = this->current_data_size_for_child();
1964 off_t aligned_offset_in_section = align_address(offset_in_section,
1965 posd->addralign());
1966 this->set_current_data_size_for_child(aligned_offset_in_section
1967 + posd->data_size());
1968 }
1969 }
1970
1971 // Add a relaxed input section.
1972
1973 void
1974 Output_section::add_relaxed_input_section(Output_relaxed_input_section* poris)
1975 {
1976 Input_section inp(poris);
1977 this->add_output_section_data(&inp);
1978 if (this->is_relaxed_input_section_map_valid_)
1979 {
1980 Input_section_specifier iss(poris->relobj(), poris->shndx());
1981 this->relaxed_input_section_map_[iss] = poris;
1982 }
1983
1984 // For a relaxed section, we use the current data size. Linker scripts
1985 // get all the input sections, including relaxed one from an output
1986 // section and add them back to them same output section to compute the
1987 // output section size. If we do not account for sizes of relaxed input
1988 // sections, an output section would be incorrectly sized.
1989 off_t offset_in_section = this->current_data_size_for_child();
1990 off_t aligned_offset_in_section = align_address(offset_in_section,
1991 poris->addralign());
1992 this->set_current_data_size_for_child(aligned_offset_in_section
1993 + poris->current_data_size());
1994 }
1995
1996 // Add arbitrary data to an output section by Input_section.
1997
1998 void
1999 Output_section::add_output_section_data(Input_section* inp)
2000 {
2001 if (this->input_sections_.empty())
2002 this->first_input_offset_ = this->current_data_size_for_child();
2003
2004 this->input_sections_.push_back(*inp);
2005
2006 uint64_t addralign = inp->addralign();
2007 if (addralign > this->addralign_)
2008 this->addralign_ = addralign;
2009
2010 inp->set_output_section(this);
2011 }
2012
2013 // Add a merge section to an output section.
2014
2015 void
2016 Output_section::add_output_merge_section(Output_section_data* posd,
2017 bool is_string, uint64_t entsize)
2018 {
2019 Input_section inp(posd, is_string, entsize);
2020 this->add_output_section_data(&inp);
2021 }
2022
2023 // Add an input section to a SHF_MERGE section.
2024
2025 bool
2026 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
2027 uint64_t flags, uint64_t entsize,
2028 uint64_t addralign)
2029 {
2030 bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
2031
2032 // We only merge strings if the alignment is not more than the
2033 // character size. This could be handled, but it's unusual.
2034 if (is_string && addralign > entsize)
2035 return false;
2036
2037 // We cannot restore merged input section states.
2038 gold_assert(this->checkpoint_ == NULL);
2039
2040 // Look up merge sections by required properties.
2041 Merge_section_properties msp(is_string, entsize, addralign);
2042 Merge_section_by_properties_map::const_iterator p =
2043 this->merge_section_by_properties_map_.find(msp);
2044 if (p != this->merge_section_by_properties_map_.end())
2045 {
2046 Output_merge_base* merge_section = p->second;
2047 merge_section->add_input_section(object, shndx);
2048 gold_assert(merge_section->is_string() == is_string
2049 && merge_section->entsize() == entsize
2050 && merge_section->addralign() == addralign);
2051
2052 // Link input section to found merge section.
2053 Input_section_specifier iss(object, shndx);
2054 this->merge_section_map_[iss] = merge_section;
2055 return true;
2056 }
2057
2058 // We handle the actual constant merging in Output_merge_data or
2059 // Output_merge_string_data.
2060 Output_merge_base* pomb;
2061 if (!is_string)
2062 pomb = new Output_merge_data(entsize, addralign);
2063 else
2064 {
2065 switch (entsize)
2066 {
2067 case 1:
2068 pomb = new Output_merge_string<char>(addralign);
2069 break;
2070 case 2:
2071 pomb = new Output_merge_string<uint16_t>(addralign);
2072 break;
2073 case 4:
2074 pomb = new Output_merge_string<uint32_t>(addralign);
2075 break;
2076 default:
2077 return false;
2078 }
2079 }
2080
2081 // Add new merge section to this output section and link merge section
2082 // properties to new merge section in map.
2083 this->add_output_merge_section(pomb, is_string, entsize);
2084 this->merge_section_by_properties_map_[msp] = pomb;
2085
2086 // Add input section to new merge section and link input section to new
2087 // merge section in map.
2088 pomb->add_input_section(object, shndx);
2089 Input_section_specifier iss(object, shndx);
2090 this->merge_section_map_[iss] = pomb;
2091
2092 return true;
2093 }
2094
2095 // Build a relaxation map to speed up relaxation of existing input sections.
2096 // Look up to the first LIMIT elements in INPUT_SECTIONS.
2097
2098 void
2099 Output_section::build_relaxation_map(
2100 const Input_section_list& input_sections,
2101 size_t limit,
2102 Relaxation_map* relaxation_map) const
2103 {
2104 for (size_t i = 0; i < limit; ++i)
2105 {
2106 const Input_section& is(input_sections[i]);
2107 if (is.is_input_section() || is.is_relaxed_input_section())
2108 {
2109 Input_section_specifier iss(is.relobj(), is.shndx());
2110 (*relaxation_map)[iss] = i;
2111 }
2112 }
2113 }
2114
2115 // Convert regular input sections in INPUT_SECTIONS into relaxed input
2116 // sections in RELAXED_SECTIONS. MAP is a prebuilt map from input section
2117 // specifier to indices of INPUT_SECTIONS.
2118
2119 void
2120 Output_section::convert_input_sections_in_list_to_relaxed_sections(
2121 const std::vector<Output_relaxed_input_section*>& relaxed_sections,
2122 const Relaxation_map& map,
2123 Input_section_list* input_sections)
2124 {
2125 for (size_t i = 0; i < relaxed_sections.size(); ++i)
2126 {
2127 Output_relaxed_input_section* poris = relaxed_sections[i];
2128 Input_section_specifier iss(poris->relobj(), poris->shndx());
2129 Relaxation_map::const_iterator p = map.find(iss);
2130 gold_assert(p != map.end());
2131 gold_assert((*input_sections)[p->second].is_input_section());
2132 (*input_sections)[p->second] = Input_section(poris);
2133 }
2134 }
2135
2136 // Convert regular input sections into relaxed input sections. RELAXED_SECTIONS
2137 // is a vector of pointers to Output_relaxed_input_section or its derived
2138 // classes. The relaxed sections must correspond to existing input sections.
2139
2140 void
2141 Output_section::convert_input_sections_to_relaxed_sections(
2142 const std::vector<Output_relaxed_input_section*>& relaxed_sections)
2143 {
2144 gold_assert(parameters->target().may_relax());
2145
2146 // We want to make sure that restore_states does not undo the effect of
2147 // this. If there is no checkpoint active, just search the current
2148 // input section list and replace the sections there. If there is
2149 // a checkpoint, also replace the sections there.
2150
2151 // By default, we look at the whole list.
2152 size_t limit = this->input_sections_.size();
2153
2154 if (this->checkpoint_ != NULL)
2155 {
2156 // Replace input sections with relaxed input section in the saved
2157 // copy of the input section list.
2158 if (this->checkpoint_->input_sections_saved())
2159 {
2160 Relaxation_map map;
2161 this->build_relaxation_map(
2162 *(this->checkpoint_->input_sections()),
2163 this->checkpoint_->input_sections()->size(),
2164 &map);
2165 this->convert_input_sections_in_list_to_relaxed_sections(
2166 relaxed_sections,
2167 map,
2168 this->checkpoint_->input_sections());
2169 }
2170 else
2171 {
2172 // We have not copied the input section list yet. Instead, just
2173 // look at the portion that would be saved.
2174 limit = this->checkpoint_->input_sections_size();
2175 }
2176 }
2177
2178 // Convert input sections in input_section_list.
2179 Relaxation_map map;
2180 this->build_relaxation_map(this->input_sections_, limit, &map);
2181 this->convert_input_sections_in_list_to_relaxed_sections(
2182 relaxed_sections,
2183 map,
2184 &this->input_sections_);
2185 }
2186
2187 // Update the output section flags based on input section flags.
2188
2189 void
2190 Output_section::update_flags_for_input_section(elfcpp::Elf_Xword flags)
2191 {
2192 // If we created the section with SHF_ALLOC clear, we set the
2193 // address. If we are now setting the SHF_ALLOC flag, we need to
2194 // undo that.
2195 if ((this->flags_ & elfcpp::SHF_ALLOC) == 0
2196 && (flags & elfcpp::SHF_ALLOC) != 0)
2197 this->mark_address_invalid();
2198
2199 this->flags_ |= (flags
2200 & (elfcpp::SHF_WRITE
2201 | elfcpp::SHF_ALLOC
2202 | elfcpp::SHF_EXECINSTR));
2203 }
2204
2205 // Find the merge section into which an input section with index SHNDX in
2206 // OBJECT has been added. Return NULL if none found.
2207
2208 Output_section_data*
2209 Output_section::find_merge_section(const Relobj* object,
2210 unsigned int shndx) const
2211 {
2212 Input_section_specifier iss(object, shndx);
2213 Output_section_data_by_input_section_map::const_iterator p =
2214 this->merge_section_map_.find(iss);
2215 if (p != this->merge_section_map_.end())
2216 {
2217 Output_section_data* posd = p->second;
2218 gold_assert(posd->is_merge_section_for(object, shndx));
2219 return posd;
2220 }
2221 else
2222 return NULL;
2223 }
2224
2225 // Find an relaxed input section corresponding to an input section
2226 // in OBJECT with index SHNDX.
2227
2228 const Output_section_data*
2229 Output_section::find_relaxed_input_section(const Relobj* object,
2230 unsigned int shndx) const
2231 {
2232 // Be careful that the map may not be valid due to input section export
2233 // to scripts or a check-point restore.
2234 if (!this->is_relaxed_input_section_map_valid_)
2235 {
2236 // Rebuild the map as needed.
2237 this->relaxed_input_section_map_.clear();
2238 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2239 p != this->input_sections_.end();
2240 ++p)
2241 if (p->is_relaxed_input_section())
2242 {
2243 Input_section_specifier iss(p->relobj(), p->shndx());
2244 this->relaxed_input_section_map_[iss] =
2245 p->relaxed_input_section();
2246 }
2247 this->is_relaxed_input_section_map_valid_ = true;
2248 }
2249
2250 Input_section_specifier iss(object, shndx);
2251 Output_section_data_by_input_section_map::const_iterator p =
2252 this->relaxed_input_section_map_.find(iss);
2253 if (p != this->relaxed_input_section_map_.end())
2254 return p->second;
2255 else
2256 return NULL;
2257 }
2258
2259 // Given an address OFFSET relative to the start of input section
2260 // SHNDX in OBJECT, return whether this address is being included in
2261 // the final link. This should only be called if SHNDX in OBJECT has
2262 // a special mapping.
2263
2264 bool
2265 Output_section::is_input_address_mapped(const Relobj* object,
2266 unsigned int shndx,
2267 off_t offset) const
2268 {
2269 // Look at the Output_section_data_maps first.
2270 const Output_section_data* posd = this->find_merge_section(object, shndx);
2271 if (posd == NULL)
2272 posd = this->find_relaxed_input_section(object, shndx);
2273
2274 if (posd != NULL)
2275 {
2276 section_offset_type output_offset;
2277 bool found = posd->output_offset(object, shndx, offset, &output_offset);
2278 gold_assert(found);
2279 return output_offset != -1;
2280 }
2281
2282 // Fall back to the slow look-up.
2283 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2284 p != this->input_sections_.end();
2285 ++p)
2286 {
2287 section_offset_type output_offset;
2288 if (p->output_offset(object, shndx, offset, &output_offset))
2289 return output_offset != -1;
2290 }
2291
2292 // By default we assume that the address is mapped. This should
2293 // only be called after we have passed all sections to Layout. At
2294 // that point we should know what we are discarding.
2295 return true;
2296 }
2297
2298 // Given an address OFFSET relative to the start of input section
2299 // SHNDX in object OBJECT, return the output offset relative to the
2300 // start of the input section in the output section. This should only
2301 // be called if SHNDX in OBJECT has a special mapping.
2302
2303 section_offset_type
2304 Output_section::output_offset(const Relobj* object, unsigned int shndx,
2305 section_offset_type offset) const
2306 {
2307 // This can only be called meaningfully when we know the data size
2308 // of this.
2309 gold_assert(this->is_data_size_valid());
2310
2311 // Look at the Output_section_data_maps first.
2312 const Output_section_data* posd = this->find_merge_section(object, shndx);
2313 if (posd == NULL)
2314 posd = this->find_relaxed_input_section(object, shndx);
2315 if (posd != NULL)
2316 {
2317 section_offset_type output_offset;
2318 bool found = posd->output_offset(object, shndx, offset, &output_offset);
2319 gold_assert(found);
2320 return output_offset;
2321 }
2322
2323 // Fall back to the slow look-up.
2324 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2325 p != this->input_sections_.end();
2326 ++p)
2327 {
2328 section_offset_type output_offset;
2329 if (p->output_offset(object, shndx, offset, &output_offset))
2330 return output_offset;
2331 }
2332 gold_unreachable();
2333 }
2334
2335 // Return the output virtual address of OFFSET relative to the start
2336 // of input section SHNDX in object OBJECT.
2337
2338 uint64_t
2339 Output_section::output_address(const Relobj* object, unsigned int shndx,
2340 off_t offset) const
2341 {
2342 uint64_t addr = this->address() + this->first_input_offset_;
2343
2344 // Look at the Output_section_data_maps first.
2345 const Output_section_data* posd = this->find_merge_section(object, shndx);
2346 if (posd == NULL)
2347 posd = this->find_relaxed_input_section(object, shndx);
2348 if (posd != NULL && posd->is_address_valid())
2349 {
2350 section_offset_type output_offset;
2351 bool found = posd->output_offset(object, shndx, offset, &output_offset);
2352 gold_assert(found);
2353 return posd->address() + output_offset;
2354 }
2355
2356 // Fall back to the slow look-up.
2357 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2358 p != this->input_sections_.end();
2359 ++p)
2360 {
2361 addr = align_address(addr, p->addralign());
2362 section_offset_type output_offset;
2363 if (p->output_offset(object, shndx, offset, &output_offset))
2364 {
2365 if (output_offset == -1)
2366 return -1ULL;
2367 return addr + output_offset;
2368 }
2369 addr += p->data_size();
2370 }
2371
2372 // If we get here, it means that we don't know the mapping for this
2373 // input section. This might happen in principle if
2374 // add_input_section were called before add_output_section_data.
2375 // But it should never actually happen.
2376
2377 gold_unreachable();
2378 }
2379
2380 // Find the output address of the start of the merged section for
2381 // input section SHNDX in object OBJECT.
2382
2383 bool
2384 Output_section::find_starting_output_address(const Relobj* object,
2385 unsigned int shndx,
2386 uint64_t* paddr) const
2387 {
2388 // FIXME: This becomes a bottle-neck if we have many relaxed sections.
2389 // Looking up the merge section map does not always work as we sometimes
2390 // find a merge section without its address set.
2391 uint64_t addr = this->address() + this->first_input_offset_;
2392 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2393 p != this->input_sections_.end();
2394 ++p)
2395 {
2396 addr = align_address(addr, p->addralign());
2397
2398 // It would be nice if we could use the existing output_offset
2399 // method to get the output offset of input offset 0.
2400 // Unfortunately we don't know for sure that input offset 0 is
2401 // mapped at all.
2402 if (p->is_merge_section_for(object, shndx))
2403 {
2404 *paddr = addr;
2405 return true;
2406 }
2407
2408 addr += p->data_size();
2409 }
2410
2411 // We couldn't find a merge output section for this input section.
2412 return false;
2413 }
2414
2415 // Set the data size of an Output_section. This is where we handle
2416 // setting the addresses of any Output_section_data objects.
2417
2418 void
2419 Output_section::set_final_data_size()
2420 {
2421 if (this->input_sections_.empty())
2422 {
2423 this->set_data_size(this->current_data_size_for_child());
2424 return;
2425 }
2426
2427 if (this->must_sort_attached_input_sections())
2428 this->sort_attached_input_sections();
2429
2430 uint64_t address = this->address();
2431 off_t startoff = this->offset();
2432 off_t off = startoff + this->first_input_offset_;
2433 for (Input_section_list::iterator p = this->input_sections_.begin();
2434 p != this->input_sections_.end();
2435 ++p)
2436 {
2437 off = align_address(off, p->addralign());
2438 p->set_address_and_file_offset(address + (off - startoff), off,
2439 startoff);
2440 off += p->data_size();
2441 }
2442
2443 this->set_data_size(off - startoff);
2444 }
2445
2446 // Reset the address and file offset.
2447
2448 void
2449 Output_section::do_reset_address_and_file_offset()
2450 {
2451 // An unallocated section has no address. Forcing this means that
2452 // we don't need special treatment for symbols defined in debug
2453 // sections. We do the same in the constructor.
2454 if ((this->flags_ & elfcpp::SHF_ALLOC) == 0)
2455 this->set_address(0);
2456
2457 for (Input_section_list::iterator p = this->input_sections_.begin();
2458 p != this->input_sections_.end();
2459 ++p)
2460 p->reset_address_and_file_offset();
2461 }
2462
2463 // Return true if address and file offset have the values after reset.
2464
2465 bool
2466 Output_section::do_address_and_file_offset_have_reset_values() const
2467 {
2468 if (this->is_offset_valid())
2469 return false;
2470
2471 // An unallocated section has address 0 after its construction or a reset.
2472 if ((this->flags_ & elfcpp::SHF_ALLOC) == 0)
2473 return this->is_address_valid() && this->address() == 0;
2474 else
2475 return !this->is_address_valid();
2476 }
2477
2478 // Set the TLS offset. Called only for SHT_TLS sections.
2479
2480 void
2481 Output_section::do_set_tls_offset(uint64_t tls_base)
2482 {
2483 this->tls_offset_ = this->address() - tls_base;
2484 }
2485
2486 // In a few cases we need to sort the input sections attached to an
2487 // output section. This is used to implement the type of constructor
2488 // priority ordering implemented by the GNU linker, in which the
2489 // priority becomes part of the section name and the sections are
2490 // sorted by name. We only do this for an output section if we see an
2491 // attached input section matching ".ctor.*", ".dtor.*",
2492 // ".init_array.*" or ".fini_array.*".
2493
2494 class Output_section::Input_section_sort_entry
2495 {
2496 public:
2497 Input_section_sort_entry()
2498 : input_section_(), index_(-1U), section_has_name_(false),
2499 section_name_()
2500 { }
2501
2502 Input_section_sort_entry(const Input_section& input_section,
2503 unsigned int index)
2504 : input_section_(input_section), index_(index),
2505 section_has_name_(input_section.is_input_section()
2506 || input_section.is_relaxed_input_section())
2507 {
2508 if (this->section_has_name_)
2509 {
2510 // This is only called single-threaded from Layout::finalize,
2511 // so it is OK to lock. Unfortunately we have no way to pass
2512 // in a Task token.
2513 const Task* dummy_task = reinterpret_cast<const Task*>(-1);
2514 Object* obj = (input_section.is_input_section()
2515 ? input_section.relobj()
2516 : input_section.relaxed_input_section()->relobj());
2517 Task_lock_obj<Object> tl(dummy_task, obj);
2518
2519 // This is a slow operation, which should be cached in
2520 // Layout::layout if this becomes a speed problem.
2521 this->section_name_ = obj->section_name(input_section.shndx());
2522 }
2523 }
2524
2525 // Return the Input_section.
2526 const Input_section&
2527 input_section() const
2528 {
2529 gold_assert(this->index_ != -1U);
2530 return this->input_section_;
2531 }
2532
2533 // The index of this entry in the original list. This is used to
2534 // make the sort stable.
2535 unsigned int
2536 index() const
2537 {
2538 gold_assert(this->index_ != -1U);
2539 return this->index_;
2540 }
2541
2542 // Whether there is a section name.
2543 bool
2544 section_has_name() const
2545 { return this->section_has_name_; }
2546
2547 // The section name.
2548 const std::string&
2549 section_name() const
2550 {
2551 gold_assert(this->section_has_name_);
2552 return this->section_name_;
2553 }
2554
2555 // Return true if the section name has a priority. This is assumed
2556 // to be true if it has a dot after the initial dot.
2557 bool
2558 has_priority() const
2559 {
2560 gold_assert(this->section_has_name_);
2561 return this->section_name_.find('.', 1);
2562 }
2563
2564 // Return true if this an input file whose base name matches
2565 // FILE_NAME. The base name must have an extension of ".o", and
2566 // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
2567 // This is to match crtbegin.o as well as crtbeginS.o without
2568 // getting confused by other possibilities. Overall matching the
2569 // file name this way is a dreadful hack, but the GNU linker does it
2570 // in order to better support gcc, and we need to be compatible.
2571 bool
2572 match_file_name(const char* match_file_name) const
2573 {
2574 const std::string& file_name(this->input_section_.relobj()->name());
2575 const char* base_name = lbasename(file_name.c_str());
2576 size_t match_len = strlen(match_file_name);
2577 if (strncmp(base_name, match_file_name, match_len) != 0)
2578 return false;
2579 size_t base_len = strlen(base_name);
2580 if (base_len != match_len + 2 && base_len != match_len + 3)
2581 return false;
2582 return memcmp(base_name + base_len - 2, ".o", 2) == 0;
2583 }
2584
2585 private:
2586 // The Input_section we are sorting.
2587 Input_section input_section_;
2588 // The index of this Input_section in the original list.
2589 unsigned int index_;
2590 // Whether this Input_section has a section name--it won't if this
2591 // is some random Output_section_data.
2592 bool section_has_name_;
2593 // The section name if there is one.
2594 std::string section_name_;
2595 };
2596
2597 // Return true if S1 should come before S2 in the output section.
2598
2599 bool
2600 Output_section::Input_section_sort_compare::operator()(
2601 const Output_section::Input_section_sort_entry& s1,
2602 const Output_section::Input_section_sort_entry& s2) const
2603 {
2604 // crtbegin.o must come first.
2605 bool s1_begin = s1.match_file_name("crtbegin");
2606 bool s2_begin = s2.match_file_name("crtbegin");
2607 if (s1_begin || s2_begin)
2608 {
2609 if (!s1_begin)
2610 return false;
2611 if (!s2_begin)
2612 return true;
2613 return s1.index() < s2.index();
2614 }
2615
2616 // crtend.o must come last.
2617 bool s1_end = s1.match_file_name("crtend");
2618 bool s2_end = s2.match_file_name("crtend");
2619 if (s1_end || s2_end)
2620 {
2621 if (!s1_end)
2622 return true;
2623 if (!s2_end)
2624 return false;
2625 return s1.index() < s2.index();
2626 }
2627
2628 // We sort all the sections with no names to the end.
2629 if (!s1.section_has_name() || !s2.section_has_name())
2630 {
2631 if (s1.section_has_name())
2632 return true;
2633 if (s2.section_has_name())
2634 return false;
2635 return s1.index() < s2.index();
2636 }
2637
2638 // A section with a priority follows a section without a priority.
2639 // The GNU linker does this for all but .init_array sections; until
2640 // further notice we'll assume that that is an mistake.
2641 bool s1_has_priority = s1.has_priority();
2642 bool s2_has_priority = s2.has_priority();
2643 if (s1_has_priority && !s2_has_priority)
2644 return false;
2645 if (!s1_has_priority && s2_has_priority)
2646 return true;
2647
2648 // Otherwise we sort by name.
2649 int compare = s1.section_name().compare(s2.section_name());
2650 if (compare != 0)
2651 return compare < 0;
2652
2653 // Otherwise we keep the input order.
2654 return s1.index() < s2.index();
2655 }
2656
2657 // Sort the input sections attached to an output section.
2658
2659 void
2660 Output_section::sort_attached_input_sections()
2661 {
2662 if (this->attached_input_sections_are_sorted_)
2663 return;
2664
2665 if (this->checkpoint_ != NULL
2666 && !this->checkpoint_->input_sections_saved())
2667 this->checkpoint_->save_input_sections();
2668
2669 // The only thing we know about an input section is the object and
2670 // the section index. We need the section name. Recomputing this
2671 // is slow but this is an unusual case. If this becomes a speed
2672 // problem we can cache the names as required in Layout::layout.
2673
2674 // We start by building a larger vector holding a copy of each
2675 // Input_section, plus its current index in the list and its name.
2676 std::vector<Input_section_sort_entry> sort_list;
2677
2678 unsigned int i = 0;
2679 for (Input_section_list::iterator p = this->input_sections_.begin();
2680 p != this->input_sections_.end();
2681 ++p, ++i)
2682 sort_list.push_back(Input_section_sort_entry(*p, i));
2683
2684 // Sort the input sections.
2685 std::sort(sort_list.begin(), sort_list.end(), Input_section_sort_compare());
2686
2687 // Copy the sorted input sections back to our list.
2688 this->input_sections_.clear();
2689 for (std::vector<Input_section_sort_entry>::iterator p = sort_list.begin();
2690 p != sort_list.end();
2691 ++p)
2692 this->input_sections_.push_back(p->input_section());
2693
2694 // Remember that we sorted the input sections, since we might get
2695 // called again.
2696 this->attached_input_sections_are_sorted_ = true;
2697 }
2698
2699 // Write the section header to *OSHDR.
2700
2701 template<int size, bool big_endian>
2702 void
2703 Output_section::write_header(const Layout* layout,
2704 const Stringpool* secnamepool,
2705 elfcpp::Shdr_write<size, big_endian>* oshdr) const
2706 {
2707 oshdr->put_sh_name(secnamepool->get_offset(this->name_));
2708 oshdr->put_sh_type(this->type_);
2709
2710 elfcpp::Elf_Xword flags = this->flags_;
2711 if (this->info_section_ != NULL && this->info_uses_section_index_)
2712 flags |= elfcpp::SHF_INFO_LINK;
2713 oshdr->put_sh_flags(flags);
2714
2715 oshdr->put_sh_addr(this->address());
2716 oshdr->put_sh_offset(this->offset());
2717 oshdr->put_sh_size(this->data_size());
2718 if (this->link_section_ != NULL)
2719 oshdr->put_sh_link(this->link_section_->out_shndx());
2720 else if (this->should_link_to_symtab_)
2721 oshdr->put_sh_link(layout->symtab_section()->out_shndx());
2722 else if (this->should_link_to_dynsym_)
2723 oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
2724 else
2725 oshdr->put_sh_link(this->link_);
2726
2727 elfcpp::Elf_Word info;
2728 if (this->info_section_ != NULL)
2729 {
2730 if (this->info_uses_section_index_)
2731 info = this->info_section_->out_shndx();
2732 else
2733 info = this->info_section_->symtab_index();
2734 }
2735 else if (this->info_symndx_ != NULL)
2736 info = this->info_symndx_->symtab_index();
2737 else
2738 info = this->info_;
2739 oshdr->put_sh_info(info);
2740
2741 oshdr->put_sh_addralign(this->addralign_);
2742 oshdr->put_sh_entsize(this->entsize_);
2743 }
2744
2745 // Write out the data. For input sections the data is written out by
2746 // Object::relocate, but we have to handle Output_section_data objects
2747 // here.
2748
2749 void
2750 Output_section::do_write(Output_file* of)
2751 {
2752 gold_assert(!this->requires_postprocessing());
2753
2754 // If the target performs relaxation, we delay filler generation until now.
2755 gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
2756
2757 off_t output_section_file_offset = this->offset();
2758 for (Fill_list::iterator p = this->fills_.begin();
2759 p != this->fills_.end();
2760 ++p)
2761 {
2762 std::string fill_data(parameters->target().code_fill(p->length()));
2763 of->write(output_section_file_offset + p->section_offset(),
2764 fill_data.data(), fill_data.size());
2765 }
2766
2767 off_t off = this->offset() + this->first_input_offset_;
2768 for (Input_section_list::iterator p = this->input_sections_.begin();
2769 p != this->input_sections_.end();
2770 ++p)
2771 {
2772 off_t aligned_off = align_address(off, p->addralign());
2773 if (this->generate_code_fills_at_write_ && (off != aligned_off))
2774 {
2775 size_t fill_len = aligned_off - off;
2776 std::string fill_data(parameters->target().code_fill(fill_len));
2777 of->write(off, fill_data.data(), fill_data.size());
2778 }
2779
2780 p->write(of);
2781 off = aligned_off + p->data_size();
2782 }
2783 }
2784
2785 // If a section requires postprocessing, create the buffer to use.
2786
2787 void
2788 Output_section::create_postprocessing_buffer()
2789 {
2790 gold_assert(this->requires_postprocessing());
2791
2792 if (this->postprocessing_buffer_ != NULL)
2793 return;
2794
2795 if (!this->input_sections_.empty())
2796 {
2797 off_t off = this->first_input_offset_;
2798 for (Input_section_list::iterator p = this->input_sections_.begin();
2799 p != this->input_sections_.end();
2800 ++p)
2801 {
2802 off = align_address(off, p->addralign());
2803 p->finalize_data_size();
2804 off += p->data_size();
2805 }
2806 this->set_current_data_size_for_child(off);
2807 }
2808
2809 off_t buffer_size = this->current_data_size_for_child();
2810 this->postprocessing_buffer_ = new unsigned char[buffer_size];
2811 }
2812
2813 // Write all the data of an Output_section into the postprocessing
2814 // buffer. This is used for sections which require postprocessing,
2815 // such as compression. Input sections are handled by
2816 // Object::Relocate.
2817
2818 void
2819 Output_section::write_to_postprocessing_buffer()
2820 {
2821 gold_assert(this->requires_postprocessing());
2822
2823 // If the target performs relaxation, we delay filler generation until now.
2824 gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
2825
2826 unsigned char* buffer = this->postprocessing_buffer();
2827 for (Fill_list::iterator p = this->fills_.begin();
2828 p != this->fills_.end();
2829 ++p)
2830 {
2831 std::string fill_data(parameters->target().code_fill(p->length()));
2832 memcpy(buffer + p->section_offset(), fill_data.data(),
2833 fill_data.size());
2834 }
2835
2836 off_t off = this->first_input_offset_;
2837 for (Input_section_list::iterator p = this->input_sections_.begin();
2838 p != this->input_sections_.end();
2839 ++p)
2840 {
2841 off_t aligned_off = align_address(off, p->addralign());
2842 if (this->generate_code_fills_at_write_ && (off != aligned_off))
2843 {
2844 size_t fill_len = aligned_off - off;
2845 std::string fill_data(parameters->target().code_fill(fill_len));
2846 memcpy(buffer + off, fill_data.data(), fill_data.size());
2847 }
2848
2849 p->write_to_buffer(buffer + aligned_off);
2850 off = aligned_off + p->data_size();
2851 }
2852 }
2853
2854 // Get the input sections for linker script processing. We leave
2855 // behind the Output_section_data entries. Note that this may be
2856 // slightly incorrect for merge sections. We will leave them behind,
2857 // but it is possible that the script says that they should follow
2858 // some other input sections, as in:
2859 // .rodata { *(.rodata) *(.rodata.cst*) }
2860 // For that matter, we don't handle this correctly:
2861 // .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) }
2862 // With luck this will never matter.
2863
2864 uint64_t
2865 Output_section::get_input_sections(
2866 uint64_t address,
2867 const std::string& fill,
2868 std::list<Simple_input_section>* input_sections)
2869 {
2870 if (this->checkpoint_ != NULL
2871 && !this->checkpoint_->input_sections_saved())
2872 this->checkpoint_->save_input_sections();
2873
2874 // Invalidate the relaxed input section map.
2875 this->is_relaxed_input_section_map_valid_ = false;
2876
2877 uint64_t orig_address = address;
2878
2879 address = align_address(address, this->addralign());
2880
2881 Input_section_list remaining;
2882 for (Input_section_list::iterator p = this->input_sections_.begin();
2883 p != this->input_sections_.end();
2884 ++p)
2885 {
2886 if (p->is_input_section())
2887 input_sections->push_back(Simple_input_section(p->relobj(),
2888 p->shndx()));
2889 else if (p->is_relaxed_input_section())
2890 input_sections->push_back(
2891 Simple_input_section(p->relaxed_input_section()));
2892 else
2893 {
2894 uint64_t aligned_address = align_address(address, p->addralign());
2895 if (aligned_address != address && !fill.empty())
2896 {
2897 section_size_type length =
2898 convert_to_section_size_type(aligned_address - address);
2899 std::string this_fill;
2900 this_fill.reserve(length);
2901 while (this_fill.length() + fill.length() <= length)
2902 this_fill += fill;
2903 if (this_fill.length() < length)
2904 this_fill.append(fill, 0, length - this_fill.length());
2905
2906 Output_section_data* posd = new Output_data_const(this_fill, 0);
2907 remaining.push_back(Input_section(posd));
2908 }
2909 address = aligned_address;
2910
2911 remaining.push_back(*p);
2912
2913 p->finalize_data_size();
2914 address += p->data_size();
2915 }
2916 }
2917
2918 this->input_sections_.swap(remaining);
2919 this->first_input_offset_ = 0;
2920
2921 uint64_t data_size = address - orig_address;
2922 this->set_current_data_size_for_child(data_size);
2923 return data_size;
2924 }
2925
2926 // Add an input section from a script.
2927
2928 void
2929 Output_section::add_input_section_for_script(const Simple_input_section& sis,
2930 off_t data_size,
2931 uint64_t addralign)
2932 {
2933 if (addralign > this->addralign_)
2934 this->addralign_ = addralign;
2935
2936 off_t offset_in_section = this->current_data_size_for_child();
2937 off_t aligned_offset_in_section = align_address(offset_in_section,
2938 addralign);
2939
2940 this->set_current_data_size_for_child(aligned_offset_in_section
2941 + data_size);
2942
2943 Input_section is =
2944 (sis.is_relaxed_input_section()
2945 ? Input_section(sis.relaxed_input_section())
2946 : Input_section(sis.relobj(), sis.shndx(), data_size, addralign));
2947 this->input_sections_.push_back(is);
2948 }
2949
2950 //
2951
2952 void
2953 Output_section::save_states()
2954 {
2955 gold_assert(this->checkpoint_ == NULL);
2956 Checkpoint_output_section* checkpoint =
2957 new Checkpoint_output_section(this->addralign_, this->flags_,
2958 this->input_sections_,
2959 this->first_input_offset_,
2960 this->attached_input_sections_are_sorted_);
2961 this->checkpoint_ = checkpoint;
2962 gold_assert(this->fills_.empty());
2963 }
2964
2965 void
2966 Output_section::restore_states()
2967 {
2968 gold_assert(this->checkpoint_ != NULL);
2969 Checkpoint_output_section* checkpoint = this->checkpoint_;
2970
2971 this->addralign_ = checkpoint->addralign();
2972 this->flags_ = checkpoint->flags();
2973 this->first_input_offset_ = checkpoint->first_input_offset();
2974
2975 if (!checkpoint->input_sections_saved())
2976 {
2977 // If we have not copied the input sections, just resize it.
2978 size_t old_size = checkpoint->input_sections_size();
2979 gold_assert(this->input_sections_.size() >= old_size);
2980 this->input_sections_.resize(old_size);
2981 }
2982 else
2983 {
2984 // We need to copy the whole list. This is not efficient for
2985 // extremely large output with hundreads of thousands of input
2986 // objects. We may need to re-think how we should pass sections
2987 // to scripts.
2988 this->input_sections_ = *checkpoint->input_sections();
2989 }
2990
2991 this->attached_input_sections_are_sorted_ =
2992 checkpoint->attached_input_sections_are_sorted();
2993
2994 // Simply invalidate the relaxed input section map since we do not keep
2995 // track of it.
2996 this->is_relaxed_input_section_map_valid_ = false;
2997 }
2998
2999 // Print to the map file.
3000
3001 void
3002 Output_section::do_print_to_mapfile(Mapfile* mapfile) const
3003 {
3004 mapfile->print_output_section(this);
3005
3006 for (Input_section_list::const_iterator p = this->input_sections_.begin();
3007 p != this->input_sections_.end();
3008 ++p)
3009 p->print_to_mapfile(mapfile);
3010 }
3011
3012 // Print stats for merge sections to stderr.
3013
3014 void
3015 Output_section::print_merge_stats()
3016 {
3017 Input_section_list::iterator p;
3018 for (p = this->input_sections_.begin();
3019 p != this->input_sections_.end();
3020 ++p)
3021 p->print_merge_stats(this->name_);
3022 }
3023
3024 // Output segment methods.
3025
3026 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
3027 : output_data_(),
3028 output_bss_(),
3029 vaddr_(0),
3030 paddr_(0),
3031 memsz_(0),
3032 max_align_(0),
3033 min_p_align_(0),
3034 offset_(0),
3035 filesz_(0),
3036 type_(type),
3037 flags_(flags),
3038 is_max_align_known_(false),
3039 are_addresses_set_(false),
3040 is_large_data_segment_(false)
3041 {
3042 }
3043
3044 // Add an Output_section to an Output_segment.
3045
3046 void
3047 Output_segment::add_output_section(Output_section* os,
3048 elfcpp::Elf_Word seg_flags)
3049 {
3050 gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
3051 gold_assert(!this->is_max_align_known_);
3052 gold_assert(os->is_large_data_section() == this->is_large_data_segment());
3053
3054 // Update the segment flags.
3055 this->flags_ |= seg_flags;
3056
3057 Output_segment::Output_data_list* pdl;
3058 if (os->type() == elfcpp::SHT_NOBITS)
3059 pdl = &this->output_bss_;
3060 else
3061 pdl = &this->output_data_;
3062
3063 // So that PT_NOTE segments will work correctly, we need to ensure
3064 // that all SHT_NOTE sections are adjacent. This will normally
3065 // happen automatically, because all the SHT_NOTE input sections
3066 // will wind up in the same output section. However, it is possible
3067 // for multiple SHT_NOTE input sections to have different section
3068 // flags, and thus be in different output sections, but for the
3069 // different section flags to map into the same segment flags and
3070 // thus the same output segment.
3071
3072 // Note that while there may be many input sections in an output
3073 // section, there are normally only a few output sections in an
3074 // output segment. This loop is expected to be fast.
3075
3076 if (os->type() == elfcpp::SHT_NOTE && !pdl->empty())
3077 {
3078 Output_segment::Output_data_list::iterator p = pdl->end();
3079 do
3080 {
3081 --p;
3082 if ((*p)->is_section_type(elfcpp::SHT_NOTE))
3083 {
3084 ++p;
3085 pdl->insert(p, os);
3086 return;
3087 }
3088 }
3089 while (p != pdl->begin());
3090 }
3091
3092 // Similarly, so that PT_TLS segments will work, we need to group
3093 // SHF_TLS sections. An SHF_TLS/SHT_NOBITS section is a special
3094 // case: we group the SHF_TLS/SHT_NOBITS sections right after the
3095 // SHF_TLS/SHT_PROGBITS sections. This lets us set up PT_TLS
3096 // correctly. SHF_TLS sections get added to both a PT_LOAD segment
3097 // and the PT_TLS segment -- we do this grouping only for the
3098 // PT_LOAD segment.
3099 if (this->type_ != elfcpp::PT_TLS
3100 && (os->flags() & elfcpp::SHF_TLS) != 0)
3101 {
3102 pdl = &this->output_data_;
3103 bool nobits = os->type() == elfcpp::SHT_NOBITS;
3104 bool sawtls = false;
3105 Output_segment::Output_data_list::iterator p = pdl->end();
3106 do
3107 {
3108 --p;
3109 bool insert;
3110 if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3111 {
3112 sawtls = true;
3113 // Put a NOBITS section after the first TLS section.
3114 // Put a PROGBITS section after the first TLS/PROGBITS
3115 // section.
3116 insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS);
3117 }
3118 else
3119 {
3120 // If we've gone past the TLS sections, but we've seen a
3121 // TLS section, then we need to insert this section now.
3122 insert = sawtls;
3123 }
3124
3125 if (insert)
3126 {
3127 ++p;
3128 pdl->insert(p, os);
3129 return;
3130 }
3131 }
3132 while (p != pdl->begin());
3133
3134 // There are no TLS sections yet; put this one at the requested
3135 // location in the section list.
3136 }
3137
3138 // For the PT_GNU_RELRO segment, we need to group relro sections,
3139 // and we need to put them before any non-relro sections. Also,
3140 // relro local sections go before relro non-local sections.
3141 if (parameters->options().relro() && os->is_relro())
3142 {
3143 gold_assert(pdl == &this->output_data_);
3144 Output_segment::Output_data_list::iterator p;
3145 for (p = pdl->begin(); p != pdl->end(); ++p)
3146 {
3147 if (!(*p)->is_section())
3148 break;
3149
3150 Output_section* pos = (*p)->output_section();
3151 if (!pos->is_relro()
3152 || (os->is_relro_local() && !pos->is_relro_local()))
3153 break;
3154 }
3155
3156 pdl->insert(p, os);
3157 return;
3158 }
3159
3160 // Small data sections go at the end of the list of data sections.
3161 // If OS is not small, and there are small sections, we have to
3162 // insert it before the first small section.
3163 if (os->type() != elfcpp::SHT_NOBITS
3164 && !os->is_small_section()
3165 && !pdl->empty()
3166 && pdl->back()->is_section()
3167 && pdl->back()->output_section()->is_small_section())
3168 {
3169 for (Output_segment::Output_data_list::iterator p = pdl->begin();
3170 p != pdl->end();
3171 ++p)
3172 {
3173 if ((*p)->is_section()
3174 && (*p)->output_section()->is_small_section())
3175 {
3176 pdl->insert(p, os);
3177 return;
3178 }
3179 }
3180 gold_unreachable();
3181 }
3182
3183 // A small BSS section goes at the start of the BSS sections, after
3184 // other small BSS sections.
3185 if (os->type() == elfcpp::SHT_NOBITS && os->is_small_section())
3186 {
3187 for (Output_segment::Output_data_list::iterator p = pdl->begin();
3188 p != pdl->end();
3189 ++p)
3190 {
3191 if (!(*p)->is_section()
3192 || !(*p)->output_section()->is_small_section())
3193 {
3194 pdl->insert(p, os);
3195 return;
3196 }
3197 }
3198 }
3199
3200 // A large BSS section goes at the end of the BSS sections, which
3201 // means that one that is not large must come before the first large
3202 // one.
3203 if (os->type() == elfcpp::SHT_NOBITS
3204 && !os->is_large_section()
3205 && !pdl->empty()
3206 && pdl->back()->is_section()
3207 && pdl->back()->output_section()->is_large_section())
3208 {
3209 for (Output_segment::Output_data_list::iterator p = pdl->begin();
3210 p != pdl->end();
3211 ++p)
3212 {
3213 if ((*p)->is_section()
3214 && (*p)->output_section()->is_large_section())
3215 {
3216 pdl->insert(p, os);
3217 return;
3218 }
3219 }
3220 gold_unreachable();
3221 }
3222
3223 pdl->push_back(os);
3224 }
3225
3226 // Remove an Output_section from this segment. It is an error if it
3227 // is not present.
3228
3229 void
3230 Output_segment::remove_output_section(Output_section* os)
3231 {
3232 // We only need this for SHT_PROGBITS.
3233 gold_assert(os->type() == elfcpp::SHT_PROGBITS);
3234 for (Output_data_list::iterator p = this->output_data_.begin();
3235 p != this->output_data_.end();
3236 ++p)
3237 {
3238 if (*p == os)
3239 {
3240 this->output_data_.erase(p);
3241 return;
3242 }
3243 }
3244 gold_unreachable();
3245 }
3246
3247 // Add an Output_data (which is not an Output_section) to the start of
3248 // a segment.
3249
3250 void
3251 Output_segment::add_initial_output_data(Output_data* od)
3252 {
3253 gold_assert(!this->is_max_align_known_);
3254 this->output_data_.push_front(od);
3255 }
3256
3257 // Return whether the first data section is a relro section.
3258
3259 bool
3260 Output_segment::is_first_section_relro() const
3261 {
3262 return (!this->output_data_.empty()
3263 && this->output_data_.front()->is_section()
3264 && this->output_data_.front()->output_section()->is_relro());
3265 }
3266
3267 // Return the maximum alignment of the Output_data in Output_segment.
3268
3269 uint64_t
3270 Output_segment::maximum_alignment()
3271 {
3272 if (!this->is_max_align_known_)
3273 {
3274 uint64_t addralign;
3275
3276 addralign = Output_segment::maximum_alignment_list(&this->output_data_);
3277 if (addralign > this->max_align_)
3278 this->max_align_ = addralign;
3279
3280 addralign = Output_segment::maximum_alignment_list(&this->output_bss_);
3281 if (addralign > this->max_align_)
3282 this->max_align_ = addralign;
3283
3284 // If -z relro is in effect, and the first section in this
3285 // segment is a relro section, then the segment must be aligned
3286 // to at least the common page size. This ensures that the
3287 // PT_GNU_RELRO segment will start at a page boundary.
3288 if (this->type_ == elfcpp::PT_LOAD
3289 && parameters->options().relro()
3290 && this->is_first_section_relro())
3291 {
3292 addralign = parameters->target().common_pagesize();
3293 if (addralign > this->max_align_)
3294 this->max_align_ = addralign;
3295 }
3296
3297 this->is_max_align_known_ = true;
3298 }
3299
3300 return this->max_align_;
3301 }
3302
3303 // Return the maximum alignment of a list of Output_data.
3304
3305 uint64_t
3306 Output_segment::maximum_alignment_list(const Output_data_list* pdl)
3307 {
3308 uint64_t ret = 0;
3309 for (Output_data_list::const_iterator p = pdl->begin();
3310 p != pdl->end();
3311 ++p)
3312 {
3313 uint64_t addralign = (*p)->addralign();
3314 if (addralign > ret)
3315 ret = addralign;
3316 }
3317 return ret;
3318 }
3319
3320 // Return the number of dynamic relocs applied to this segment.
3321
3322 unsigned int
3323 Output_segment::dynamic_reloc_count() const
3324 {
3325 return (this->dynamic_reloc_count_list(&this->output_data_)
3326 + this->dynamic_reloc_count_list(&this->output_bss_));
3327 }
3328
3329 // Return the number of dynamic relocs applied to an Output_data_list.
3330
3331 unsigned int
3332 Output_segment::dynamic_reloc_count_list(const Output_data_list* pdl) const
3333 {
3334 unsigned int count = 0;
3335 for (Output_data_list::const_iterator p = pdl->begin();
3336 p != pdl->end();
3337 ++p)
3338 count += (*p)->dynamic_reloc_count();
3339 return count;
3340 }
3341
3342 // Set the section addresses for an Output_segment. If RESET is true,
3343 // reset the addresses first. ADDR is the address and *POFF is the
3344 // file offset. Set the section indexes starting with *PSHNDX.
3345 // Return the address of the immediately following segment. Update
3346 // *POFF and *PSHNDX.
3347
3348 uint64_t
3349 Output_segment::set_section_addresses(const Layout* layout, bool reset,
3350 uint64_t addr, off_t* poff,
3351 unsigned int* pshndx)
3352 {
3353 gold_assert(this->type_ == elfcpp::PT_LOAD);
3354
3355 if (!reset && this->are_addresses_set_)
3356 {
3357 gold_assert(this->paddr_ == addr);
3358 addr = this->vaddr_;
3359 }
3360 else
3361 {
3362 this->vaddr_ = addr;
3363 this->paddr_ = addr;
3364 this->are_addresses_set_ = true;
3365 }
3366
3367 bool in_tls = false;
3368
3369 bool in_relro = (parameters->options().relro()
3370 && this->is_first_section_relro());
3371
3372 off_t orig_off = *poff;
3373 this->offset_ = orig_off;
3374
3375 addr = this->set_section_list_addresses(layout, reset, &this->output_data_,
3376 addr, poff, pshndx, &in_tls,
3377 &in_relro);
3378 this->filesz_ = *poff - orig_off;
3379
3380 off_t off = *poff;
3381
3382 uint64_t ret = this->set_section_list_addresses(layout, reset,
3383 &this->output_bss_,
3384 addr, poff, pshndx,
3385 &in_tls, &in_relro);
3386
3387 // If the last section was a TLS section, align upward to the
3388 // alignment of the TLS segment, so that the overall size of the TLS
3389 // segment is aligned.
3390 if (in_tls)
3391 {
3392 uint64_t segment_align = layout->tls_segment()->maximum_alignment();
3393 *poff = align_address(*poff, segment_align);
3394 }
3395
3396 // If all the sections were relro sections, align upward to the
3397 // common page size.
3398 if (in_relro)
3399 {
3400 uint64_t page_align = parameters->target().common_pagesize();
3401 *poff = align_address(*poff, page_align);
3402 }
3403
3404 this->memsz_ = *poff - orig_off;
3405
3406 // Ignore the file offset adjustments made by the BSS Output_data
3407 // objects.
3408 *poff = off;
3409
3410 return ret;
3411 }
3412
3413 // Set the addresses and file offsets in a list of Output_data
3414 // structures.
3415
3416 uint64_t
3417 Output_segment::set_section_list_addresses(const Layout* layout, bool reset,
3418 Output_data_list* pdl,
3419 uint64_t addr, off_t* poff,
3420 unsigned int* pshndx,
3421 bool* in_tls, bool* in_relro)
3422 {
3423 off_t startoff = *poff;
3424
3425 off_t off = startoff;
3426 for (Output_data_list::iterator p = pdl->begin();
3427 p != pdl->end();
3428 ++p)
3429 {
3430 if (reset)
3431 (*p)->reset_address_and_file_offset();
3432
3433 // When using a linker script the section will most likely
3434 // already have an address.
3435 if (!(*p)->is_address_valid())
3436 {
3437 uint64_t align = (*p)->addralign();
3438
3439 if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3440 {
3441 // Give the first TLS section the alignment of the
3442 // entire TLS segment. Otherwise the TLS segment as a
3443 // whole may be misaligned.
3444 if (!*in_tls)
3445 {
3446 Output_segment* tls_segment = layout->tls_segment();
3447 gold_assert(tls_segment != NULL);
3448 uint64_t segment_align = tls_segment->maximum_alignment();
3449 gold_assert(segment_align >= align);
3450 align = segment_align;
3451
3452 *in_tls = true;
3453 }
3454 }
3455 else
3456 {
3457 // If this is the first section after the TLS segment,
3458 // align it to at least the alignment of the TLS
3459 // segment, so that the size of the overall TLS segment
3460 // is aligned.
3461 if (*in_tls)
3462 {
3463 uint64_t segment_align =
3464 layout->tls_segment()->maximum_alignment();
3465 if (segment_align > align)
3466 align = segment_align;
3467
3468 *in_tls = false;
3469 }
3470 }
3471
3472 // If this is a non-relro section after a relro section,
3473 // align it to a common page boundary so that the dynamic
3474 // linker has a page to mark as read-only.
3475 if (*in_relro
3476 && (!(*p)->is_section()
3477 || !(*p)->output_section()->is_relro()))
3478 {
3479 uint64_t page_align = parameters->target().common_pagesize();
3480 if (page_align > align)
3481 align = page_align;
3482 *in_relro = false;
3483 }
3484
3485 off = align_address(off, align);
3486 (*p)->set_address_and_file_offset(addr + (off - startoff), off);
3487 }
3488 else
3489 {
3490 // The script may have inserted a skip forward, but it
3491 // better not have moved backward.
3492 gold_assert((*p)->address() >= addr + (off - startoff));
3493 off += (*p)->address() - (addr + (off - startoff));
3494 (*p)->set_file_offset(off);
3495 (*p)->finalize_data_size();
3496 }
3497
3498 // We want to ignore the size of a SHF_TLS or SHT_NOBITS
3499 // section. Such a section does not affect the size of a
3500 // PT_LOAD segment.
3501 if (!(*p)->is_section_flag_set(elfcpp::SHF_TLS)
3502 || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
3503 off += (*p)->data_size();
3504
3505 if ((*p)->is_section())
3506 {
3507 (*p)->set_out_shndx(*pshndx);
3508 ++*pshndx;
3509 }
3510 }
3511
3512 *poff = off;
3513 return addr + (off - startoff);
3514 }
3515
3516 // For a non-PT_LOAD segment, set the offset from the sections, if
3517 // any.
3518
3519 void
3520 Output_segment::set_offset()
3521 {
3522 gold_assert(this->type_ != elfcpp::PT_LOAD);
3523
3524 gold_assert(!this->are_addresses_set_);
3525
3526 if (this->output_data_.empty() && this->output_bss_.empty())
3527 {
3528 this->vaddr_ = 0;
3529 this->paddr_ = 0;
3530 this->are_addresses_set_ = true;
3531 this->memsz_ = 0;
3532 this->min_p_align_ = 0;
3533 this->offset_ = 0;
3534 this->filesz_ = 0;
3535 return;
3536 }
3537
3538 const Output_data* first;
3539 if (this->output_data_.empty())
3540 first = this->output_bss_.front();
3541 else
3542 first = this->output_data_.front();
3543 this->vaddr_ = first->address();
3544 this->paddr_ = (first->has_load_address()
3545 ? first->load_address()
3546 : this->vaddr_);
3547 this->are_addresses_set_ = true;
3548 this->offset_ = first->offset();
3549
3550 if (this->output_data_.empty())
3551 this->filesz_ = 0;
3552 else
3553 {
3554 const Output_data* last_data = this->output_data_.back();
3555 this->filesz_ = (last_data->address()
3556 + last_data->data_size()
3557 - this->vaddr_);
3558 }
3559
3560 const Output_data* last;
3561 if (this->output_bss_.empty())
3562 last = this->output_data_.back();
3563 else
3564 last = this->output_bss_.back();
3565 this->memsz_ = (last->address()
3566 + last->data_size()
3567 - this->vaddr_);
3568
3569 // If this is a TLS segment, align the memory size. The code in
3570 // set_section_list ensures that the section after the TLS segment
3571 // is aligned to give us room.
3572 if (this->type_ == elfcpp::PT_TLS)
3573 {
3574 uint64_t segment_align = this->maximum_alignment();
3575 gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align));
3576 this->memsz_ = align_address(this->memsz_, segment_align);
3577 }
3578
3579 // If this is a RELRO segment, align the memory size. The code in
3580 // set_section_list ensures that the section after the RELRO segment
3581 // is aligned to give us room.
3582 if (this->type_ == elfcpp::PT_GNU_RELRO)
3583 {
3584 uint64_t page_align = parameters->target().common_pagesize();
3585 gold_assert(this->vaddr_ == align_address(this->vaddr_, page_align));
3586 this->memsz_ = align_address(this->memsz_, page_align);
3587 }
3588 }
3589
3590 // Set the TLS offsets of the sections in the PT_TLS segment.
3591
3592 void
3593 Output_segment::set_tls_offsets()
3594 {
3595 gold_assert(this->type_ == elfcpp::PT_TLS);
3596
3597 for (Output_data_list::iterator p = this->output_data_.begin();
3598 p != this->output_data_.end();
3599 ++p)
3600 (*p)->set_tls_offset(this->vaddr_);
3601
3602 for (Output_data_list::iterator p = this->output_bss_.begin();
3603 p != this->output_bss_.end();
3604 ++p)
3605 (*p)->set_tls_offset(this->vaddr_);
3606 }
3607
3608 // Return the address of the first section.
3609
3610 uint64_t
3611 Output_segment::first_section_load_address() const
3612 {
3613 for (Output_data_list::const_iterator p = this->output_data_.begin();
3614 p != this->output_data_.end();
3615 ++p)
3616 if ((*p)->is_section())
3617 return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
3618
3619 for (Output_data_list::const_iterator p = this->output_bss_.begin();
3620 p != this->output_bss_.end();
3621 ++p)
3622 if ((*p)->is_section())
3623 return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
3624
3625 gold_unreachable();
3626 }
3627
3628 // Return the number of Output_sections in an Output_segment.
3629
3630 unsigned int
3631 Output_segment::output_section_count() const
3632 {
3633 return (this->output_section_count_list(&this->output_data_)
3634 + this->output_section_count_list(&this->output_bss_));
3635 }
3636
3637 // Return the number of Output_sections in an Output_data_list.
3638
3639 unsigned int
3640 Output_segment::output_section_count_list(const Output_data_list* pdl) const
3641 {
3642 unsigned int count = 0;
3643 for (Output_data_list::const_iterator p = pdl->begin();
3644 p != pdl->end();
3645 ++p)
3646 {
3647 if ((*p)->is_section())
3648 ++count;
3649 }
3650 return count;
3651 }
3652
3653 // Return the section attached to the list segment with the lowest
3654 // load address. This is used when handling a PHDRS clause in a
3655 // linker script.
3656
3657 Output_section*
3658 Output_segment::section_with_lowest_load_address() const
3659 {
3660 Output_section* found = NULL;
3661 uint64_t found_lma = 0;
3662 this->lowest_load_address_in_list(&this->output_data_, &found, &found_lma);
3663
3664 Output_section* found_data = found;
3665 this->lowest_load_address_in_list(&this->output_bss_, &found, &found_lma);
3666 if (found != found_data && found_data != NULL)
3667 {
3668 gold_error(_("nobits section %s may not precede progbits section %s "
3669 "in same segment"),
3670 found->name(), found_data->name());
3671 return NULL;
3672 }
3673
3674 return found;
3675 }
3676
3677 // Look through a list for a section with a lower load address.
3678
3679 void
3680 Output_segment::lowest_load_address_in_list(const Output_data_list* pdl,
3681 Output_section** found,
3682 uint64_t* found_lma) const
3683 {
3684 for (Output_data_list::const_iterator p = pdl->begin();
3685 p != pdl->end();
3686 ++p)
3687 {
3688 if (!(*p)->is_section())
3689 continue;
3690 Output_section* os = static_cast<Output_section*>(*p);
3691 uint64_t lma = (os->has_load_address()
3692 ? os->load_address()
3693 : os->address());
3694 if (*found == NULL || lma < *found_lma)
3695 {
3696 *found = os;
3697 *found_lma = lma;
3698 }
3699 }
3700 }
3701
3702 // Write the segment data into *OPHDR.
3703
3704 template<int size, bool big_endian>
3705 void
3706 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
3707 {
3708 ophdr->put_p_type(this->type_);
3709 ophdr->put_p_offset(this->offset_);
3710 ophdr->put_p_vaddr(this->vaddr_);
3711 ophdr->put_p_paddr(this->paddr_);
3712 ophdr->put_p_filesz(this->filesz_);
3713 ophdr->put_p_memsz(this->memsz_);
3714 ophdr->put_p_flags(this->flags_);
3715 ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment()));
3716 }
3717
3718 // Write the section headers into V.
3719
3720 template<int size, bool big_endian>
3721 unsigned char*
3722 Output_segment::write_section_headers(const Layout* layout,
3723 const Stringpool* secnamepool,
3724 unsigned char* v,
3725 unsigned int *pshndx) const
3726 {
3727 // Every section that is attached to a segment must be attached to a
3728 // PT_LOAD segment, so we only write out section headers for PT_LOAD
3729 // segments.
3730 if (this->type_ != elfcpp::PT_LOAD)
3731 return v;
3732
3733 v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
3734 &this->output_data_,
3735 v, pshndx);
3736 v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
3737 &this->output_bss_,
3738 v, pshndx);
3739 return v;
3740 }
3741
3742 template<int size, bool big_endian>
3743 unsigned char*
3744 Output_segment::write_section_headers_list(const Layout* layout,
3745 const Stringpool* secnamepool,
3746 const Output_data_list* pdl,
3747 unsigned char* v,
3748 unsigned int* pshndx) const
3749 {
3750 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
3751 for (Output_data_list::const_iterator p = pdl->begin();
3752 p != pdl->end();
3753 ++p)
3754 {
3755 if ((*p)->is_section())
3756 {
3757 const Output_section* ps = static_cast<const Output_section*>(*p);
3758 gold_assert(*pshndx == ps->out_shndx());
3759 elfcpp::Shdr_write<size, big_endian> oshdr(v);
3760 ps->write_header(layout, secnamepool, &oshdr);
3761 v += shdr_size;
3762 ++*pshndx;
3763 }
3764 }
3765 return v;
3766 }
3767
3768 // Print the output sections to the map file.
3769
3770 void
3771 Output_segment::print_sections_to_mapfile(Mapfile* mapfile) const
3772 {
3773 if (this->type() != elfcpp::PT_LOAD)
3774 return;
3775 this->print_section_list_to_mapfile(mapfile, &this->output_data_);
3776 this->print_section_list_to_mapfile(mapfile, &this->output_bss_);
3777 }
3778
3779 // Print an output section list to the map file.
3780
3781 void
3782 Output_segment::print_section_list_to_mapfile(Mapfile* mapfile,
3783 const Output_data_list* pdl) const
3784 {
3785 for (Output_data_list::const_iterator p = pdl->begin();
3786 p != pdl->end();
3787 ++p)
3788 (*p)->print_to_mapfile(mapfile);
3789 }
3790
3791 // Output_file methods.
3792
3793 Output_file::Output_file(const char* name)
3794 : name_(name),
3795 o_(-1),
3796 file_size_(0),
3797 base_(NULL),
3798 map_is_anonymous_(false),
3799 is_temporary_(false)
3800 {
3801 }
3802
3803 // Try to open an existing file. Returns false if the file doesn't
3804 // exist, has a size of 0 or can't be mmapped.
3805
3806 bool
3807 Output_file::open_for_modification()
3808 {
3809 // The name "-" means "stdout".
3810 if (strcmp(this->name_, "-") == 0)
3811 return false;
3812
3813 // Don't bother opening files with a size of zero.
3814 struct stat s;
3815 if (::stat(this->name_, &s) != 0 || s.st_size == 0)
3816 return false;
3817
3818 int o = open_descriptor(-1, this->name_, O_RDWR, 0);
3819 if (o < 0)
3820 gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
3821 this->o_ = o;
3822 this->file_size_ = s.st_size;
3823
3824 // If the file can't be mmapped, copying the content to an anonymous
3825 // map will probably negate the performance benefits of incremental
3826 // linking. This could be helped by using views and loading only
3827 // the necessary parts, but this is not supported as of now.
3828 if (!this->map_no_anonymous())
3829 {
3830 release_descriptor(o, true);
3831 this->o_ = -1;
3832 this->file_size_ = 0;
3833 return false;
3834 }
3835
3836 return true;
3837 }
3838
3839 // Open the output file.
3840
3841 void
3842 Output_file::open(off_t file_size)
3843 {
3844 this->file_size_ = file_size;
3845
3846 // Unlink the file first; otherwise the open() may fail if the file
3847 // is busy (e.g. it's an executable that's currently being executed).
3848 //
3849 // However, the linker may be part of a system where a zero-length
3850 // file is created for it to write to, with tight permissions (gcc
3851 // 2.95 did something like this). Unlinking the file would work
3852 // around those permission controls, so we only unlink if the file
3853 // has a non-zero size. We also unlink only regular files to avoid
3854 // trouble with directories/etc.
3855 //
3856 // If we fail, continue; this command is merely a best-effort attempt
3857 // to improve the odds for open().
3858
3859 // We let the name "-" mean "stdout"
3860 if (!this->is_temporary_)
3861 {
3862 if (strcmp(this->name_, "-") == 0)
3863 this->o_ = STDOUT_FILENO;
3864 else
3865 {
3866 struct stat s;
3867 if (::stat(this->name_, &s) == 0
3868 && (S_ISREG (s.st_mode) || S_ISLNK (s.st_mode)))
3869 {
3870 if (s.st_size != 0)
3871 ::unlink(this->name_);
3872 else if (!parameters->options().relocatable())
3873 {
3874 // If we don't unlink the existing file, add execute
3875 // permission where read permissions already exist
3876 // and where the umask permits.
3877 int mask = ::umask(0);
3878 ::umask(mask);
3879 s.st_mode |= (s.st_mode & 0444) >> 2;
3880 ::chmod(this->name_, s.st_mode & ~mask);
3881 }
3882 }
3883
3884 int mode = parameters->options().relocatable() ? 0666 : 0777;
3885 int o = open_descriptor(-1, this->name_, O_RDWR | O_CREAT | O_TRUNC,
3886 mode);
3887 if (o < 0)
3888 gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
3889 this->o_ = o;
3890 }
3891 }
3892
3893 this->map();
3894 }
3895
3896 // Resize the output file.
3897
3898 void
3899 Output_file::resize(off_t file_size)
3900 {
3901 // If the mmap is mapping an anonymous memory buffer, this is easy:
3902 // just mremap to the new size. If it's mapping to a file, we want
3903 // to unmap to flush to the file, then remap after growing the file.
3904 if (this->map_is_anonymous_)
3905 {
3906 void* base = ::mremap(this->base_, this->file_size_, file_size,
3907 MREMAP_MAYMOVE);
3908 if (base == MAP_FAILED)
3909 gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno));
3910 this->base_ = static_cast<unsigned char*>(base);
3911 this->file_size_ = file_size;
3912 }
3913 else
3914 {
3915 this->unmap();
3916 this->file_size_ = file_size;
3917 if (!this->map_no_anonymous())
3918 gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
3919 }
3920 }
3921
3922 // Map an anonymous block of memory which will later be written to the
3923 // file. Return whether the map succeeded.
3924
3925 bool
3926 Output_file::map_anonymous()
3927 {
3928 void* base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
3929 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
3930 if (base != MAP_FAILED)
3931 {
3932 this->map_is_anonymous_ = true;
3933 this->base_ = static_cast<unsigned char*>(base);
3934 return true;
3935 }
3936 return false;
3937 }
3938
3939 // Map the file into memory. Return whether the mapping succeeded.
3940
3941 bool
3942 Output_file::map_no_anonymous()
3943 {
3944 const int o = this->o_;
3945
3946 // If the output file is not a regular file, don't try to mmap it;
3947 // instead, we'll mmap a block of memory (an anonymous buffer), and
3948 // then later write the buffer to the file.
3949 void* base;
3950 struct stat statbuf;
3951 if (o == STDOUT_FILENO || o == STDERR_FILENO
3952 || ::fstat(o, &statbuf) != 0
3953 || !S_ISREG(statbuf.st_mode)
3954 || this->is_temporary_)
3955 return false;
3956
3957 // Ensure that we have disk space available for the file. If we
3958 // don't do this, it is possible that we will call munmap, close,
3959 // and exit with dirty buffers still in the cache with no assigned
3960 // disk blocks. If the disk is out of space at that point, the
3961 // output file will wind up incomplete, but we will have already
3962 // exited. The alternative to fallocate would be to use fdatasync,
3963 // but that would be a more significant performance hit.
3964 if (::posix_fallocate(o, 0, this->file_size_) < 0)
3965 gold_fatal(_("%s: %s"), this->name_, strerror(errno));
3966
3967 // Map the file into memory.
3968 base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
3969 MAP_SHARED, o, 0);
3970
3971 // The mmap call might fail because of file system issues: the file
3972 // system might not support mmap at all, or it might not support
3973 // mmap with PROT_WRITE.
3974 if (base == MAP_FAILED)
3975 return false;
3976
3977 this->map_is_anonymous_ = false;
3978 this->base_ = static_cast<unsigned char*>(base);
3979 return true;
3980 }
3981
3982 // Map the file into memory.
3983
3984 void
3985 Output_file::map()
3986 {
3987 if (this->map_no_anonymous())
3988 return;
3989
3990 // The mmap call might fail because of file system issues: the file
3991 // system might not support mmap at all, or it might not support
3992 // mmap with PROT_WRITE. I'm not sure which errno values we will
3993 // see in all cases, so if the mmap fails for any reason and we
3994 // don't care about file contents, try for an anonymous map.
3995 if (this->map_anonymous())
3996 return;
3997
3998 gold_fatal(_("%s: mmap: failed to allocate %lu bytes for output file: %s"),
3999 this->name_, static_cast<unsigned long>(this->file_size_),
4000 strerror(errno));
4001 }
4002
4003 // Unmap the file from memory.
4004
4005 void
4006 Output_file::unmap()
4007 {
4008 if (::munmap(this->base_, this->file_size_) < 0)
4009 gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
4010 this->base_ = NULL;
4011 }
4012
4013 // Close the output file.
4014
4015 void
4016 Output_file::close()
4017 {
4018 // If the map isn't file-backed, we need to write it now.
4019 if (this->map_is_anonymous_ && !this->is_temporary_)
4020 {
4021 size_t bytes_to_write = this->file_size_;
4022 size_t offset = 0;
4023 while (bytes_to_write > 0)
4024 {
4025 ssize_t bytes_written = ::write(this->o_, this->base_ + offset,
4026 bytes_to_write);
4027 if (bytes_written == 0)
4028 gold_error(_("%s: write: unexpected 0 return-value"), this->name_);
4029 else if (bytes_written < 0)
4030 gold_error(_("%s: write: %s"), this->name_, strerror(errno));
4031 else
4032 {
4033 bytes_to_write -= bytes_written;
4034 offset += bytes_written;
4035 }
4036 }
4037 }
4038 this->unmap();
4039
4040 // We don't close stdout or stderr
4041 if (this->o_ != STDOUT_FILENO
4042 && this->o_ != STDERR_FILENO
4043 && !this->is_temporary_)
4044 if (::close(this->o_) < 0)
4045 gold_error(_("%s: close: %s"), this->name_, strerror(errno));
4046 this->o_ = -1;
4047 }
4048
4049 // Instantiate the templates we need. We could use the configure
4050 // script to restrict this to only the ones for implemented targets.
4051
4052 #ifdef HAVE_TARGET_32_LITTLE
4053 template
4054 off_t
4055 Output_section::add_input_section<32, false>(
4056 Sized_relobj<32, false>* object,
4057 unsigned int shndx,
4058 const char* secname,
4059 const elfcpp::Shdr<32, false>& shdr,
4060 unsigned int reloc_shndx,
4061 bool have_sections_script);
4062 #endif
4063
4064 #ifdef HAVE_TARGET_32_BIG
4065 template
4066 off_t
4067 Output_section::add_input_section<32, true>(
4068 Sized_relobj<32, true>* object,
4069 unsigned int shndx,
4070 const char* secname,
4071 const elfcpp::Shdr<32, true>& shdr,
4072 unsigned int reloc_shndx,
4073 bool have_sections_script);
4074 #endif
4075
4076 #ifdef HAVE_TARGET_64_LITTLE
4077 template
4078 off_t
4079 Output_section::add_input_section<64, false>(
4080 Sized_relobj<64, false>* object,
4081 unsigned int shndx,
4082 const char* secname,
4083 const elfcpp::Shdr<64, false>& shdr,
4084 unsigned int reloc_shndx,
4085 bool have_sections_script);
4086 #endif
4087
4088 #ifdef HAVE_TARGET_64_BIG
4089 template
4090 off_t
4091 Output_section::add_input_section<64, true>(
4092 Sized_relobj<64, true>* object,
4093 unsigned int shndx,
4094 const char* secname,
4095 const elfcpp::Shdr<64, true>& shdr,
4096 unsigned int reloc_shndx,
4097 bool have_sections_script);
4098 #endif
4099
4100 #ifdef HAVE_TARGET_32_LITTLE
4101 template
4102 class Output_reloc<elfcpp::SHT_REL, false, 32, false>;
4103 #endif
4104
4105 #ifdef HAVE_TARGET_32_BIG
4106 template
4107 class Output_reloc<elfcpp::SHT_REL, false, 32, true>;
4108 #endif
4109
4110 #ifdef HAVE_TARGET_64_LITTLE
4111 template
4112 class Output_reloc<elfcpp::SHT_REL, false, 64, false>;
4113 #endif
4114
4115 #ifdef HAVE_TARGET_64_BIG
4116 template
4117 class Output_reloc<elfcpp::SHT_REL, false, 64, true>;
4118 #endif
4119
4120 #ifdef HAVE_TARGET_32_LITTLE
4121 template
4122 class Output_reloc<elfcpp::SHT_REL, true, 32, false>;
4123 #endif
4124
4125 #ifdef HAVE_TARGET_32_BIG
4126 template
4127 class Output_reloc<elfcpp::SHT_REL, true, 32, true>;
4128 #endif
4129
4130 #ifdef HAVE_TARGET_64_LITTLE
4131 template
4132 class Output_reloc<elfcpp::SHT_REL, true, 64, false>;
4133 #endif
4134
4135 #ifdef HAVE_TARGET_64_BIG
4136 template
4137 class Output_reloc<elfcpp::SHT_REL, true, 64, true>;
4138 #endif
4139
4140 #ifdef HAVE_TARGET_32_LITTLE
4141 template
4142 class Output_reloc<elfcpp::SHT_RELA, false, 32, false>;
4143 #endif
4144
4145 #ifdef HAVE_TARGET_32_BIG
4146 template
4147 class Output_reloc<elfcpp::SHT_RELA, false, 32, true>;
4148 #endif
4149
4150 #ifdef HAVE_TARGET_64_LITTLE
4151 template
4152 class Output_reloc<elfcpp::SHT_RELA, false, 64, false>;
4153 #endif
4154
4155 #ifdef HAVE_TARGET_64_BIG
4156 template
4157 class Output_reloc<elfcpp::SHT_RELA, false, 64, true>;
4158 #endif
4159
4160 #ifdef HAVE_TARGET_32_LITTLE
4161 template
4162 class Output_reloc<elfcpp::SHT_RELA, true, 32, false>;
4163 #endif
4164
4165 #ifdef HAVE_TARGET_32_BIG
4166 template
4167 class Output_reloc<elfcpp::SHT_RELA, true, 32, true>;
4168 #endif
4169
4170 #ifdef HAVE_TARGET_64_LITTLE
4171 template
4172 class Output_reloc<elfcpp::SHT_RELA, true, 64, false>;
4173 #endif
4174
4175 #ifdef HAVE_TARGET_64_BIG
4176 template
4177 class Output_reloc<elfcpp::SHT_RELA, true, 64, true>;
4178 #endif
4179
4180 #ifdef HAVE_TARGET_32_LITTLE
4181 template
4182 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
4183 #endif
4184
4185 #ifdef HAVE_TARGET_32_BIG
4186 template
4187 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
4188 #endif
4189
4190 #ifdef HAVE_TARGET_64_LITTLE
4191 template
4192 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
4193 #endif
4194
4195 #ifdef HAVE_TARGET_64_BIG
4196 template
4197 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
4198 #endif
4199
4200 #ifdef HAVE_TARGET_32_LITTLE
4201 template
4202 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
4203 #endif
4204
4205 #ifdef HAVE_TARGET_32_BIG
4206 template
4207 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
4208 #endif
4209
4210 #ifdef HAVE_TARGET_64_LITTLE
4211 template
4212 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
4213 #endif
4214
4215 #ifdef HAVE_TARGET_64_BIG
4216 template
4217 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
4218 #endif
4219
4220 #ifdef HAVE_TARGET_32_LITTLE
4221 template
4222 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
4223 #endif
4224
4225 #ifdef HAVE_TARGET_32_BIG
4226 template
4227 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
4228 #endif
4229
4230 #ifdef HAVE_TARGET_64_LITTLE
4231 template
4232 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
4233 #endif
4234
4235 #ifdef HAVE_TARGET_64_BIG
4236 template
4237 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
4238 #endif
4239
4240 #ifdef HAVE_TARGET_32_LITTLE
4241 template
4242 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
4243 #endif
4244
4245 #ifdef HAVE_TARGET_32_BIG
4246 template
4247 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
4248 #endif
4249
4250 #ifdef HAVE_TARGET_64_LITTLE
4251 template
4252 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
4253 #endif
4254
4255 #ifdef HAVE_TARGET_64_BIG
4256 template
4257 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
4258 #endif
4259
4260 #ifdef HAVE_TARGET_32_LITTLE
4261 template
4262 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, false>;
4263 #endif
4264
4265 #ifdef HAVE_TARGET_32_BIG
4266 template
4267 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, true>;
4268 #endif
4269
4270 #ifdef HAVE_TARGET_64_LITTLE
4271 template
4272 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, false>;
4273 #endif
4274
4275 #ifdef HAVE_TARGET_64_BIG
4276 template
4277 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, true>;
4278 #endif
4279
4280 #ifdef HAVE_TARGET_32_LITTLE
4281 template
4282 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, false>;
4283 #endif
4284
4285 #ifdef HAVE_TARGET_32_BIG
4286 template
4287 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, true>;
4288 #endif
4289
4290 #ifdef HAVE_TARGET_64_LITTLE
4291 template
4292 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, false>;
4293 #endif
4294
4295 #ifdef HAVE_TARGET_64_BIG
4296 template
4297 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, true>;
4298 #endif
4299
4300 #ifdef HAVE_TARGET_32_LITTLE
4301 template
4302 class Output_data_group<32, false>;
4303 #endif
4304
4305 #ifdef HAVE_TARGET_32_BIG
4306 template
4307 class Output_data_group<32, true>;
4308 #endif
4309
4310 #ifdef HAVE_TARGET_64_LITTLE
4311 template
4312 class Output_data_group<64, false>;
4313 #endif
4314
4315 #ifdef HAVE_TARGET_64_BIG
4316 template
4317 class Output_data_group<64, true>;
4318 #endif
4319
4320 #ifdef HAVE_TARGET_32_LITTLE
4321 template
4322 class Output_data_got<32, false>;
4323 #endif
4324
4325 #ifdef HAVE_TARGET_32_BIG
4326 template
4327 class Output_data_got<32, true>;
4328 #endif
4329
4330 #ifdef HAVE_TARGET_64_LITTLE
4331 template
4332 class Output_data_got<64, false>;
4333 #endif
4334
4335 #ifdef HAVE_TARGET_64_BIG
4336 template
4337 class Output_data_got<64, true>;
4338 #endif
4339
4340 } // End namespace gold.
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