xref: /netbsd-src/external/gpl3/binutils/dist/gold/output.cc (revision cb63e24e8d6aae7ddac1859a9015f48b1d8bd90e)
1 // output.cc -- manage the output file for gold
2 
3 // Copyright (C) 2006-2024 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/stat.h>
31 #include <algorithm>
32 #include <uchar.h>
33 
34 #ifdef HAVE_SYS_MMAN_H
35 #include <sys/mman.h>
36 #endif
37 
38 #include "libiberty.h"
39 
40 #include "dwarf.h"
41 #include "parameters.h"
42 #include "object.h"
43 #include "symtab.h"
44 #include "reloc.h"
45 #include "merge.h"
46 #include "descriptors.h"
47 #include "layout.h"
48 #include "output.h"
49 
50 // For systems without mmap support.
51 #ifndef HAVE_MMAP
52 # define mmap gold_mmap
53 # define munmap gold_munmap
54 # define mremap gold_mremap
55 # ifndef MAP_FAILED
56 #  define MAP_FAILED (reinterpret_cast<void*>(-1))
57 # endif
58 # ifndef PROT_READ
59 #  define PROT_READ 0
60 # endif
61 # ifndef PROT_WRITE
62 #  define PROT_WRITE 0
63 # endif
64 # ifndef MAP_PRIVATE
65 #  define MAP_PRIVATE 0
66 # endif
67 # ifndef MAP_ANONYMOUS
68 #  define MAP_ANONYMOUS 0
69 # endif
70 # ifndef MAP_SHARED
71 #  define MAP_SHARED 0
72 # endif
73 
74 # ifndef ENOSYS
75 #  define ENOSYS EINVAL
76 # endif
77 
78 static void *
gold_mmap(void *,size_t,int,int,int,off_t)79 gold_mmap(void *, size_t, int, int, int, off_t)
80 {
81   errno = ENOSYS;
82   return MAP_FAILED;
83 }
84 
85 static int
gold_munmap(void *,size_t)86 gold_munmap(void *, size_t)
87 {
88   errno = ENOSYS;
89   return -1;
90 }
91 
92 static void *
gold_mremap(void *,size_t,size_t,int)93 gold_mremap(void *, size_t, size_t, int)
94 {
95   errno = ENOSYS;
96   return MAP_FAILED;
97 }
98 
99 #endif
100 
101 #if defined(HAVE_MMAP) && !defined(HAVE_MREMAP)
102 # define mremap gold_mremap
103 extern "C" void *gold_mremap(void *, size_t, size_t, int);
104 #endif
105 
106 // Some BSD systems still use MAP_ANON instead of MAP_ANONYMOUS
107 #ifndef MAP_ANONYMOUS
108 # define MAP_ANONYMOUS  MAP_ANON
109 #endif
110 
111 #ifndef MREMAP_MAYMOVE
112 # define MREMAP_MAYMOVE 1
113 #endif
114 
115 // Mingw does not have S_ISLNK.
116 #ifndef S_ISLNK
117 # define S_ISLNK(mode) 0
118 #endif
119 
120 namespace gold
121 {
122 
123 // A wrapper around posix_fallocate.  If we don't have posix_fallocate,
124 // or the --no-posix-fallocate option is set, we try the fallocate
125 // system call directly.  If that fails, we use ftruncate to set
126 // the file size and hope that there is enough disk space.
127 
128 static int
gold_fallocate(int o,off_t offset,off_t len)129 gold_fallocate(int o, off_t offset, off_t len)
130 {
131   if (len <= 0)
132     return 0;
133 
134 #ifdef HAVE_POSIX_FALLOCATE
135   if (parameters->options().posix_fallocate())
136     {
137       int err = ::posix_fallocate(o, offset, len);
138       if (err != EINVAL && err != ENOSYS && err != EOPNOTSUPP)
139 	return err;
140     }
141 #endif // defined(HAVE_POSIX_FALLOCATE)
142 
143 #ifdef HAVE_FALLOCATE
144   {
145     errno = 0;
146     int err = ::fallocate(o, 0, offset, len);
147     if (err < 0 && errno != EINVAL && errno != ENOSYS && errno != EOPNOTSUPP)
148       return errno;
149   }
150 #endif // defined(HAVE_FALLOCATE)
151 
152   errno = 0;
153   if (::ftruncate(o, offset + len) < 0)
154     return errno;
155   return 0;
156 }
157 
158 // Output_data variables.
159 
160 bool Output_data::allocated_sizes_are_fixed;
161 
162 // Output_data methods.
163 
~Output_data()164 Output_data::~Output_data()
165 {
166 }
167 
168 // Return the default alignment for the target size.
169 
170 uint64_t
default_alignment()171 Output_data::default_alignment()
172 {
173   return Output_data::default_alignment_for_size(
174       parameters->target().get_size());
175 }
176 
177 // Return the default alignment for a size--32 or 64.
178 
179 uint64_t
default_alignment_for_size(int size)180 Output_data::default_alignment_for_size(int size)
181 {
182   if (size == 32)
183     return 4;
184   else if (size == 64)
185     return 8;
186   else
187     gold_unreachable();
188 }
189 
190 // Output_section_header methods.  This currently assumes that the
191 // segment and section lists are complete at construction time.
192 
Output_section_headers(const Layout * layout,const Layout::Segment_list * segment_list,const Layout::Section_list * section_list,const Layout::Section_list * unattached_section_list,const Stringpool * secnamepool,const Output_section * shstrtab_section)193 Output_section_headers::Output_section_headers(
194     const Layout* layout,
195     const Layout::Segment_list* segment_list,
196     const Layout::Section_list* section_list,
197     const Layout::Section_list* unattached_section_list,
198     const Stringpool* secnamepool,
199     const Output_section* shstrtab_section)
200   : layout_(layout),
201     segment_list_(segment_list),
202     section_list_(section_list),
203     unattached_section_list_(unattached_section_list),
204     secnamepool_(secnamepool),
205     shstrtab_section_(shstrtab_section)
206 {
207 }
208 
209 // Compute the current data size.
210 
211 off_t
do_size() const212 Output_section_headers::do_size() const
213 {
214   // Count all the sections.  Start with 1 for the null section.
215   off_t count = 1;
216   if (!parameters->options().relocatable())
217     {
218       for (Layout::Segment_list::const_iterator p =
219 	     this->segment_list_->begin();
220 	   p != this->segment_list_->end();
221 	   ++p)
222 	if ((*p)->type() == elfcpp::PT_LOAD)
223 	  count += (*p)->output_section_count();
224     }
225   else
226     {
227       for (Layout::Section_list::const_iterator p =
228 	     this->section_list_->begin();
229 	   p != this->section_list_->end();
230 	   ++p)
231 	if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
232 	  ++count;
233     }
234   count += this->unattached_section_list_->size();
235 
236   const int size = parameters->target().get_size();
237   int shdr_size;
238   if (size == 32)
239     shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
240   else if (size == 64)
241     shdr_size = elfcpp::Elf_sizes<64>::shdr_size;
242   else
243     gold_unreachable();
244 
245   return count * shdr_size;
246 }
247 
248 // Write out the section headers.
249 
250 void
do_write(Output_file * of)251 Output_section_headers::do_write(Output_file* of)
252 {
253   switch (parameters->size_and_endianness())
254     {
255 #ifdef HAVE_TARGET_32_LITTLE
256     case Parameters::TARGET_32_LITTLE:
257       this->do_sized_write<32, false>(of);
258       break;
259 #endif
260 #ifdef HAVE_TARGET_32_BIG
261     case Parameters::TARGET_32_BIG:
262       this->do_sized_write<32, true>(of);
263       break;
264 #endif
265 #ifdef HAVE_TARGET_64_LITTLE
266     case Parameters::TARGET_64_LITTLE:
267       this->do_sized_write<64, false>(of);
268       break;
269 #endif
270 #ifdef HAVE_TARGET_64_BIG
271     case Parameters::TARGET_64_BIG:
272       this->do_sized_write<64, true>(of);
273       break;
274 #endif
275     default:
276       gold_unreachable();
277     }
278 }
279 
280 template<int size, bool big_endian>
281 void
do_sized_write(Output_file * of)282 Output_section_headers::do_sized_write(Output_file* of)
283 {
284   off_t all_shdrs_size = this->data_size();
285   unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size);
286 
287   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
288   unsigned char* v = view;
289 
290   {
291     typename elfcpp::Shdr_write<size, big_endian> oshdr(v);
292     oshdr.put_sh_name(0);
293     oshdr.put_sh_type(elfcpp::SHT_NULL);
294     oshdr.put_sh_flags(0);
295     oshdr.put_sh_addr(0);
296     oshdr.put_sh_offset(0);
297 
298     size_t section_count = (this->data_size()
299 			    / elfcpp::Elf_sizes<size>::shdr_size);
300     if (section_count < elfcpp::SHN_LORESERVE)
301       oshdr.put_sh_size(0);
302     else
303       oshdr.put_sh_size(section_count);
304 
305     unsigned int shstrndx = this->shstrtab_section_->out_shndx();
306     if (shstrndx < elfcpp::SHN_LORESERVE)
307       oshdr.put_sh_link(0);
308     else
309       oshdr.put_sh_link(shstrndx);
310 
311     size_t segment_count = this->segment_list_->size();
312     oshdr.put_sh_info(segment_count >= elfcpp::PN_XNUM ? segment_count : 0);
313 
314     oshdr.put_sh_addralign(0);
315     oshdr.put_sh_entsize(0);
316   }
317 
318   v += shdr_size;
319 
320   unsigned int shndx = 1;
321   if (!parameters->options().relocatable())
322     {
323       for (Layout::Segment_list::const_iterator p =
324 	     this->segment_list_->begin();
325 	   p != this->segment_list_->end();
326 	   ++p)
327 	v = (*p)->write_section_headers<size, big_endian>(this->layout_,
328 							  this->secnamepool_,
329 							  v,
330 							  &shndx);
331     }
332   else
333     {
334       for (Layout::Section_list::const_iterator p =
335 	     this->section_list_->begin();
336 	   p != this->section_list_->end();
337 	   ++p)
338 	{
339 	  // We do unallocated sections below, except that group
340 	  // sections have to come first.
341 	  if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
342 	      && (*p)->type() != elfcpp::SHT_GROUP)
343 	    continue;
344 	  gold_assert(shndx == (*p)->out_shndx());
345 	  elfcpp::Shdr_write<size, big_endian> oshdr(v);
346 	  (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
347 	  v += shdr_size;
348 	  ++shndx;
349 	}
350     }
351 
352   for (Layout::Section_list::const_iterator p =
353 	 this->unattached_section_list_->begin();
354        p != this->unattached_section_list_->end();
355        ++p)
356     {
357       // For a relocatable link, we did unallocated group sections
358       // above, since they have to come first.
359       if ((*p)->type() == elfcpp::SHT_GROUP
360 	  && parameters->options().relocatable())
361 	continue;
362       gold_assert(shndx == (*p)->out_shndx());
363       elfcpp::Shdr_write<size, big_endian> oshdr(v);
364       (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
365       v += shdr_size;
366       ++shndx;
367     }
368 
369   of->write_output_view(this->offset(), all_shdrs_size, view);
370 }
371 
372 // Output_segment_header methods.
373 
Output_segment_headers(const Layout::Segment_list & segment_list)374 Output_segment_headers::Output_segment_headers(
375     const Layout::Segment_list& segment_list)
376   : segment_list_(segment_list)
377 {
378   this->set_current_data_size_for_child(this->do_size());
379 }
380 
381 void
do_write(Output_file * of)382 Output_segment_headers::do_write(Output_file* of)
383 {
384   switch (parameters->size_and_endianness())
385     {
386 #ifdef HAVE_TARGET_32_LITTLE
387     case Parameters::TARGET_32_LITTLE:
388       this->do_sized_write<32, false>(of);
389       break;
390 #endif
391 #ifdef HAVE_TARGET_32_BIG
392     case Parameters::TARGET_32_BIG:
393       this->do_sized_write<32, true>(of);
394       break;
395 #endif
396 #ifdef HAVE_TARGET_64_LITTLE
397     case Parameters::TARGET_64_LITTLE:
398       this->do_sized_write<64, false>(of);
399       break;
400 #endif
401 #ifdef HAVE_TARGET_64_BIG
402     case Parameters::TARGET_64_BIG:
403       this->do_sized_write<64, true>(of);
404       break;
405 #endif
406     default:
407       gold_unreachable();
408     }
409 }
410 
411 template<int size, bool big_endian>
412 void
do_sized_write(Output_file * of)413 Output_segment_headers::do_sized_write(Output_file* of)
414 {
415   const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
416   off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
417   gold_assert(all_phdrs_size == this->data_size());
418   unsigned char* view = of->get_output_view(this->offset(),
419 					    all_phdrs_size);
420   unsigned char* v = view;
421   for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
422        p != this->segment_list_.end();
423        ++p)
424     {
425       elfcpp::Phdr_write<size, big_endian> ophdr(v);
426       (*p)->write_header(&ophdr);
427       v += phdr_size;
428     }
429 
430   gold_assert(v - view == all_phdrs_size);
431 
432   of->write_output_view(this->offset(), all_phdrs_size, view);
433 }
434 
435 off_t
do_size() const436 Output_segment_headers::do_size() const
437 {
438   const int size = parameters->target().get_size();
439   int phdr_size;
440   if (size == 32)
441     phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
442   else if (size == 64)
443     phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
444   else
445     gold_unreachable();
446 
447   return this->segment_list_.size() * phdr_size;
448 }
449 
450 // Output_file_header methods.
451 
Output_file_header(Target * target,const Symbol_table * symtab,const Output_segment_headers * osh)452 Output_file_header::Output_file_header(Target* target,
453 				       const Symbol_table* symtab,
454 				       const Output_segment_headers* osh)
455   : target_(target),
456     symtab_(symtab),
457     segment_header_(osh),
458     section_header_(NULL),
459     shstrtab_(NULL)
460 {
461   this->set_data_size(this->do_size());
462 }
463 
464 // Set the section table information for a file header.
465 
466 void
set_section_info(const Output_section_headers * shdrs,const Output_section * shstrtab)467 Output_file_header::set_section_info(const Output_section_headers* shdrs,
468 				     const Output_section* shstrtab)
469 {
470   this->section_header_ = shdrs;
471   this->shstrtab_ = shstrtab;
472 }
473 
474 // Write out the file header.
475 
476 void
do_write(Output_file * of)477 Output_file_header::do_write(Output_file* of)
478 {
479   gold_assert(this->offset() == 0);
480 
481   switch (parameters->size_and_endianness())
482     {
483 #ifdef HAVE_TARGET_32_LITTLE
484     case Parameters::TARGET_32_LITTLE:
485       this->do_sized_write<32, false>(of);
486       break;
487 #endif
488 #ifdef HAVE_TARGET_32_BIG
489     case Parameters::TARGET_32_BIG:
490       this->do_sized_write<32, true>(of);
491       break;
492 #endif
493 #ifdef HAVE_TARGET_64_LITTLE
494     case Parameters::TARGET_64_LITTLE:
495       this->do_sized_write<64, false>(of);
496       break;
497 #endif
498 #ifdef HAVE_TARGET_64_BIG
499     case Parameters::TARGET_64_BIG:
500       this->do_sized_write<64, true>(of);
501       break;
502 #endif
503     default:
504       gold_unreachable();
505     }
506 }
507 
508 // Write out the file header with appropriate size and endianness.
509 
510 template<int size, bool big_endian>
511 void
do_sized_write(Output_file * of)512 Output_file_header::do_sized_write(Output_file* of)
513 {
514   gold_assert(this->offset() == 0);
515 
516   int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
517   unsigned char* view = of->get_output_view(0, ehdr_size);
518   elfcpp::Ehdr_write<size, big_endian> oehdr(view);
519 
520   unsigned char e_ident[elfcpp::EI_NIDENT];
521   memset(e_ident, 0, elfcpp::EI_NIDENT);
522   e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
523   e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
524   e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
525   e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
526   if (size == 32)
527     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
528   else if (size == 64)
529     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
530   else
531     gold_unreachable();
532   e_ident[elfcpp::EI_DATA] = (big_endian
533 			      ? elfcpp::ELFDATA2MSB
534 			      : elfcpp::ELFDATA2LSB);
535   e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
536   oehdr.put_e_ident(e_ident);
537 
538   elfcpp::ET e_type;
539   if (parameters->options().relocatable())
540     e_type = elfcpp::ET_REL;
541   else if (parameters->options().output_is_position_independent())
542     e_type = elfcpp::ET_DYN;
543   else
544     e_type = elfcpp::ET_EXEC;
545   oehdr.put_e_type(e_type);
546 
547   oehdr.put_e_machine(this->target_->machine_code());
548   oehdr.put_e_version(elfcpp::EV_CURRENT);
549 
550   oehdr.put_e_entry(this->entry<size>());
551 
552   if (this->segment_header_ == NULL)
553     oehdr.put_e_phoff(0);
554   else
555     oehdr.put_e_phoff(this->segment_header_->offset());
556 
557   oehdr.put_e_shoff(this->section_header_->offset());
558   oehdr.put_e_flags(this->target_->processor_specific_flags());
559   oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
560 
561   if (this->segment_header_ == NULL)
562     {
563       oehdr.put_e_phentsize(0);
564       oehdr.put_e_phnum(0);
565     }
566   else
567     {
568       oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
569       size_t phnum = (this->segment_header_->data_size()
570 		      / elfcpp::Elf_sizes<size>::phdr_size);
571       if (phnum > elfcpp::PN_XNUM)
572 	phnum = elfcpp::PN_XNUM;
573       oehdr.put_e_phnum(phnum);
574     }
575 
576   oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
577   size_t section_count = (this->section_header_->data_size()
578 			  / elfcpp::Elf_sizes<size>::shdr_size);
579 
580   if (section_count < elfcpp::SHN_LORESERVE)
581     oehdr.put_e_shnum(this->section_header_->data_size()
582 		      / elfcpp::Elf_sizes<size>::shdr_size);
583   else
584     oehdr.put_e_shnum(0);
585 
586   unsigned int shstrndx = this->shstrtab_->out_shndx();
587   if (shstrndx < elfcpp::SHN_LORESERVE)
588     oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
589   else
590     oehdr.put_e_shstrndx(elfcpp::SHN_XINDEX);
591 
592   // Let the target adjust the ELF header, e.g., to set EI_OSABI in
593   // the e_ident field.
594   this->target_->adjust_elf_header(view, ehdr_size);
595 
596   of->write_output_view(0, ehdr_size, view);
597 }
598 
599 // Return the value to use for the entry address.
600 
601 template<int size>
602 typename elfcpp::Elf_types<size>::Elf_Addr
entry()603 Output_file_header::entry()
604 {
605   const bool should_issue_warning = (parameters->options().entry() != NULL
606 				     && !parameters->options().relocatable()
607 				     && !parameters->options().shared());
608   const char* entry = parameters->entry();
609   Symbol* sym = this->symtab_->lookup(entry);
610 
611   typename Sized_symbol<size>::Value_type v;
612   if (sym != NULL)
613     {
614       Sized_symbol<size>* ssym;
615       ssym = this->symtab_->get_sized_symbol<size>(sym);
616       if (!ssym->is_defined() && should_issue_warning)
617 	gold_warning("entry symbol '%s' exists but is not defined", entry);
618       v = ssym->value();
619     }
620   else
621     {
622       // We couldn't find the entry symbol.  See if we can parse it as
623       // a number.  This supports, e.g., -e 0x1000.
624       char* endptr;
625       v = strtoull(entry, &endptr, 0);
626       if (*endptr != '\0')
627 	{
628 	  if (should_issue_warning)
629 	    gold_warning("cannot find entry symbol '%s'", entry);
630 	  v = 0;
631 	}
632     }
633 
634   return v;
635 }
636 
637 // Compute the current data size.
638 
639 off_t
do_size() const640 Output_file_header::do_size() const
641 {
642   const int size = parameters->target().get_size();
643   if (size == 32)
644     return elfcpp::Elf_sizes<32>::ehdr_size;
645   else if (size == 64)
646     return elfcpp::Elf_sizes<64>::ehdr_size;
647   else
648     gold_unreachable();
649 }
650 
651 // Output_data_const methods.
652 
653 void
do_write(Output_file * of)654 Output_data_const::do_write(Output_file* of)
655 {
656   of->write(this->offset(), this->data_.data(), this->data_.size());
657 }
658 
659 // Output_data_const_buffer methods.
660 
661 void
do_write(Output_file * of)662 Output_data_const_buffer::do_write(Output_file* of)
663 {
664   of->write(this->offset(), this->p_, this->data_size());
665 }
666 
667 // Output_section_data methods.
668 
669 // Record the output section, and set the entry size and such.
670 
671 void
set_output_section(Output_section * os)672 Output_section_data::set_output_section(Output_section* os)
673 {
674   gold_assert(this->output_section_ == NULL);
675   this->output_section_ = os;
676   this->do_adjust_output_section(os);
677 }
678 
679 // Return the section index of the output section.
680 
681 unsigned int
do_out_shndx() const682 Output_section_data::do_out_shndx() const
683 {
684   gold_assert(this->output_section_ != NULL);
685   return this->output_section_->out_shndx();
686 }
687 
688 // Set the alignment, which means we may need to update the alignment
689 // of the output section.
690 
691 void
set_addralign(uint64_t addralign)692 Output_section_data::set_addralign(uint64_t addralign)
693 {
694   this->addralign_ = addralign;
695   if (this->output_section_ != NULL
696       && this->output_section_->addralign() < addralign)
697     this->output_section_->set_addralign(addralign);
698 }
699 
700 // Output_data_strtab methods.
701 
702 // Set the final data size.
703 
704 void
set_final_data_size()705 Output_data_strtab::set_final_data_size()
706 {
707   this->strtab_->set_string_offsets();
708   this->set_data_size(this->strtab_->get_strtab_size());
709 }
710 
711 // Write out a string table.
712 
713 void
do_write(Output_file * of)714 Output_data_strtab::do_write(Output_file* of)
715 {
716   this->strtab_->write(of, this->offset());
717 }
718 
719 // Output_reloc methods.
720 
721 // A reloc against a global symbol.
722 
723 template<bool dynamic, int size, bool big_endian>
Output_reloc(Symbol * gsym,unsigned int type,Output_data * od,Address address,bool is_relative,bool is_symbolless,bool use_plt_offset)724 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
725     Symbol* gsym,
726     unsigned int type,
727     Output_data* od,
728     Address address,
729     bool is_relative,
730     bool is_symbolless,
731     bool use_plt_offset)
732   : address_(address), local_sym_index_(GSYM_CODE), type_(type),
733     is_relative_(is_relative), is_symbolless_(is_symbolless),
734     is_section_symbol_(false), use_plt_offset_(use_plt_offset), shndx_(INVALID_CODE)
735 {
736   // this->type_ is a bitfield; make sure TYPE fits.
737   gold_assert(this->type_ == type);
738   this->u1_.gsym = gsym;
739   this->u2_.od = od;
740   if (dynamic)
741     this->set_needs_dynsym_index();
742 }
743 
744 template<bool dynamic, int size, bool big_endian>
Output_reloc(Symbol * gsym,unsigned int type,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address,bool is_relative,bool is_symbolless,bool use_plt_offset)745 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
746     Symbol* gsym,
747     unsigned int type,
748     Sized_relobj<size, big_endian>* relobj,
749     unsigned int shndx,
750     Address address,
751     bool is_relative,
752     bool is_symbolless,
753     bool use_plt_offset)
754   : address_(address), local_sym_index_(GSYM_CODE), type_(type),
755     is_relative_(is_relative), is_symbolless_(is_symbolless),
756     is_section_symbol_(false), use_plt_offset_(use_plt_offset), shndx_(shndx)
757 {
758   gold_assert(shndx != INVALID_CODE);
759   // this->type_ is a bitfield; make sure TYPE fits.
760   gold_assert(this->type_ == type);
761   this->u1_.gsym = gsym;
762   this->u2_.relobj = relobj;
763   if (dynamic)
764     this->set_needs_dynsym_index();
765 }
766 
767 // A reloc against a local symbol.
768 
769 template<bool dynamic, int size, bool big_endian>
Output_reloc(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,Output_data * od,Address address,bool is_relative,bool is_symbolless,bool is_section_symbol,bool use_plt_offset)770 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
771     Sized_relobj<size, big_endian>* relobj,
772     unsigned int local_sym_index,
773     unsigned int type,
774     Output_data* od,
775     Address address,
776     bool is_relative,
777     bool is_symbolless,
778     bool is_section_symbol,
779     bool use_plt_offset)
780   : address_(address), local_sym_index_(local_sym_index), type_(type),
781     is_relative_(is_relative), is_symbolless_(is_symbolless),
782     is_section_symbol_(is_section_symbol), use_plt_offset_(use_plt_offset),
783     shndx_(INVALID_CODE)
784 {
785   gold_assert(local_sym_index != GSYM_CODE
786 	      && local_sym_index != INVALID_CODE);
787   // this->type_ is a bitfield; make sure TYPE fits.
788   gold_assert(this->type_ == type);
789   this->u1_.relobj = relobj;
790   this->u2_.od = od;
791   if (dynamic)
792     this->set_needs_dynsym_index();
793 }
794 
795 template<bool dynamic, int size, bool big_endian>
Output_reloc(Sized_relobj<size,big_endian> * relobj,unsigned int local_sym_index,unsigned int type,unsigned int shndx,Address address,bool is_relative,bool is_symbolless,bool is_section_symbol,bool use_plt_offset)796 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
797     Sized_relobj<size, big_endian>* relobj,
798     unsigned int local_sym_index,
799     unsigned int type,
800     unsigned int shndx,
801     Address address,
802     bool is_relative,
803     bool is_symbolless,
804     bool is_section_symbol,
805     bool use_plt_offset)
806   : address_(address), local_sym_index_(local_sym_index), type_(type),
807     is_relative_(is_relative), is_symbolless_(is_symbolless),
808     is_section_symbol_(is_section_symbol), use_plt_offset_(use_plt_offset),
809     shndx_(shndx)
810 {
811   gold_assert(local_sym_index != GSYM_CODE
812 	      && local_sym_index != INVALID_CODE);
813   gold_assert(shndx != INVALID_CODE);
814   // this->type_ is a bitfield; make sure TYPE fits.
815   gold_assert(this->type_ == type);
816   this->u1_.relobj = relobj;
817   this->u2_.relobj = relobj;
818   if (dynamic)
819     this->set_needs_dynsym_index();
820 }
821 
822 // A reloc against the STT_SECTION symbol of an output section.
823 
824 template<bool dynamic, int size, bool big_endian>
Output_reloc(Output_section * os,unsigned int type,Output_data * od,Address address,bool is_relative)825 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
826     Output_section* os,
827     unsigned int type,
828     Output_data* od,
829     Address address,
830     bool is_relative)
831   : address_(address), local_sym_index_(SECTION_CODE), type_(type),
832     is_relative_(is_relative), is_symbolless_(is_relative),
833     is_section_symbol_(true), use_plt_offset_(false), shndx_(INVALID_CODE)
834 {
835   // this->type_ is a bitfield; make sure TYPE fits.
836   gold_assert(this->type_ == type);
837   this->u1_.os = os;
838   this->u2_.od = od;
839   if (dynamic)
840     this->set_needs_dynsym_index();
841   else
842     os->set_needs_symtab_index();
843 }
844 
845 template<bool dynamic, int size, bool big_endian>
Output_reloc(Output_section * os,unsigned int type,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address,bool is_relative)846 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
847     Output_section* os,
848     unsigned int type,
849     Sized_relobj<size, big_endian>* relobj,
850     unsigned int shndx,
851     Address address,
852     bool is_relative)
853   : address_(address), local_sym_index_(SECTION_CODE), type_(type),
854     is_relative_(is_relative), is_symbolless_(is_relative),
855     is_section_symbol_(true), use_plt_offset_(false), shndx_(shndx)
856 {
857   gold_assert(shndx != INVALID_CODE);
858   // this->type_ is a bitfield; make sure TYPE fits.
859   gold_assert(this->type_ == type);
860   this->u1_.os = os;
861   this->u2_.relobj = relobj;
862   if (dynamic)
863     this->set_needs_dynsym_index();
864   else
865     os->set_needs_symtab_index();
866 }
867 
868 // An absolute or relative relocation.
869 
870 template<bool dynamic, int size, bool big_endian>
Output_reloc(unsigned int type,Output_data * od,Address address,bool is_relative)871 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
872     unsigned int type,
873     Output_data* od,
874     Address address,
875     bool is_relative)
876   : address_(address), local_sym_index_(0), type_(type),
877     is_relative_(is_relative), is_symbolless_(false),
878     is_section_symbol_(false), use_plt_offset_(false), shndx_(INVALID_CODE)
879 {
880   // this->type_ is a bitfield; make sure TYPE fits.
881   gold_assert(this->type_ == type);
882   this->u1_.relobj = NULL;
883   this->u2_.od = od;
884 }
885 
886 template<bool dynamic, int size, bool big_endian>
Output_reloc(unsigned int type,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address,bool is_relative)887 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
888     unsigned int type,
889     Sized_relobj<size, big_endian>* relobj,
890     unsigned int shndx,
891     Address address,
892     bool is_relative)
893   : address_(address), local_sym_index_(0), type_(type),
894     is_relative_(is_relative), is_symbolless_(false),
895     is_section_symbol_(false), use_plt_offset_(false), shndx_(shndx)
896 {
897   gold_assert(shndx != INVALID_CODE);
898   // this->type_ is a bitfield; make sure TYPE fits.
899   gold_assert(this->type_ == type);
900   this->u1_.relobj = NULL;
901   this->u2_.relobj = relobj;
902 }
903 
904 // A target specific relocation.
905 
906 template<bool dynamic, int size, bool big_endian>
Output_reloc(unsigned int type,void * arg,Output_data * od,Address address)907 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
908     unsigned int type,
909     void* arg,
910     Output_data* od,
911     Address address)
912   : address_(address), local_sym_index_(TARGET_CODE), type_(type),
913     is_relative_(false), is_symbolless_(false),
914     is_section_symbol_(false), use_plt_offset_(false), shndx_(INVALID_CODE)
915 {
916   // this->type_ is a bitfield; make sure TYPE fits.
917   gold_assert(this->type_ == type);
918   this->u1_.arg = arg;
919   this->u2_.od = od;
920 }
921 
922 template<bool dynamic, int size, bool big_endian>
Output_reloc(unsigned int type,void * arg,Sized_relobj<size,big_endian> * relobj,unsigned int shndx,Address address)923 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
924     unsigned int type,
925     void* arg,
926     Sized_relobj<size, big_endian>* relobj,
927     unsigned int shndx,
928     Address address)
929   : address_(address), local_sym_index_(TARGET_CODE), type_(type),
930     is_relative_(false), is_symbolless_(false),
931     is_section_symbol_(false), use_plt_offset_(false), shndx_(shndx)
932 {
933   gold_assert(shndx != INVALID_CODE);
934   // this->type_ is a bitfield; make sure TYPE fits.
935   gold_assert(this->type_ == type);
936   this->u1_.arg = arg;
937   this->u2_.relobj = relobj;
938 }
939 
940 // Record that we need a dynamic symbol index for this relocation.
941 
942 template<bool dynamic, int size, bool big_endian>
943 void
944 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
set_needs_dynsym_index()945 set_needs_dynsym_index()
946 {
947   if (this->is_symbolless_)
948     return;
949   switch (this->local_sym_index_)
950     {
951     case INVALID_CODE:
952       gold_unreachable();
953 
954     case GSYM_CODE:
955       this->u1_.gsym->set_needs_dynsym_entry();
956       break;
957 
958     case SECTION_CODE:
959       this->u1_.os->set_needs_dynsym_index();
960       break;
961 
962     case TARGET_CODE:
963       // The target must take care of this if necessary.
964       break;
965 
966     case 0:
967       break;
968 
969     default:
970       {
971 	const unsigned int lsi = this->local_sym_index_;
972 	Sized_relobj_file<size, big_endian>* relobj =
973 	    this->u1_.relobj->sized_relobj();
974 	gold_assert(relobj != NULL);
975 	if (!this->is_section_symbol_)
976 	  relobj->set_needs_output_dynsym_entry(lsi);
977 	else
978 	  relobj->output_section(lsi)->set_needs_dynsym_index();
979       }
980       break;
981     }
982 }
983 
984 // Get the symbol index of a relocation.
985 
986 template<bool dynamic, int size, bool big_endian>
987 unsigned int
get_symbol_index() const988 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
989   const
990 {
991   unsigned int index;
992   if (this->is_symbolless_)
993     return 0;
994   switch (this->local_sym_index_)
995     {
996     case INVALID_CODE:
997       gold_unreachable();
998 
999     case GSYM_CODE:
1000       if (this->u1_.gsym == NULL)
1001 	index = 0;
1002       else if (dynamic)
1003 	index = this->u1_.gsym->dynsym_index();
1004       else
1005 	index = this->u1_.gsym->symtab_index();
1006       break;
1007 
1008     case SECTION_CODE:
1009       if (dynamic)
1010 	index = this->u1_.os->dynsym_index();
1011       else
1012 	index = this->u1_.os->symtab_index();
1013       break;
1014 
1015     case TARGET_CODE:
1016       index = parameters->target().reloc_symbol_index(this->u1_.arg,
1017 						      this->type_);
1018       break;
1019 
1020     case 0:
1021       // Relocations without symbols use a symbol index of 0.
1022       index = 0;
1023       break;
1024 
1025     default:
1026       {
1027 	const unsigned int lsi = this->local_sym_index_;
1028 	Sized_relobj_file<size, big_endian>* relobj =
1029 	    this->u1_.relobj->sized_relobj();
1030 	gold_assert(relobj != NULL);
1031 	if (!this->is_section_symbol_)
1032 	  {
1033 	    if (dynamic)
1034 	      index = relobj->dynsym_index(lsi);
1035 	    else
1036 	      index = relobj->symtab_index(lsi);
1037 	  }
1038 	else
1039 	  {
1040 	    Output_section* os = relobj->output_section(lsi);
1041 	    gold_assert(os != NULL);
1042 	    if (dynamic)
1043 	      index = os->dynsym_index();
1044 	    else
1045 	      index = os->symtab_index();
1046 	  }
1047       }
1048       break;
1049     }
1050   gold_assert(index != -1U);
1051   return index;
1052 }
1053 
1054 // For a local section symbol, get the address of the offset ADDEND
1055 // within the input section.
1056 
1057 template<bool dynamic, int size, bool big_endian>
1058 typename elfcpp::Elf_types<size>::Elf_Addr
1059 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
local_section_offset(Addend addend) const1060   local_section_offset(Addend addend) const
1061 {
1062   gold_assert(this->local_sym_index_ != GSYM_CODE
1063 	      && this->local_sym_index_ != SECTION_CODE
1064 	      && this->local_sym_index_ != TARGET_CODE
1065 	      && this->local_sym_index_ != INVALID_CODE
1066 	      && this->local_sym_index_ != 0
1067 	      && this->is_section_symbol_);
1068   const unsigned int lsi = this->local_sym_index_;
1069   Output_section* os = this->u1_.relobj->output_section(lsi);
1070   gold_assert(os != NULL);
1071   Address offset = this->u1_.relobj->get_output_section_offset(lsi);
1072   if (offset != invalid_address)
1073     return offset + addend;
1074   // This is a merge section.
1075   Sized_relobj_file<size, big_endian>* relobj =
1076       this->u1_.relobj->sized_relobj();
1077   gold_assert(relobj != NULL);
1078   offset = os->output_address(relobj, lsi, addend);
1079   gold_assert(offset != invalid_address);
1080   return offset;
1081 }
1082 
1083 // Get the output address of a relocation.
1084 
1085 template<bool dynamic, int size, bool big_endian>
1086 typename elfcpp::Elf_types<size>::Elf_Addr
get_address() const1087 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_address() const
1088 {
1089   Address address = this->address_;
1090   if (this->shndx_ != INVALID_CODE)
1091     {
1092       Output_section* os = this->u2_.relobj->output_section(this->shndx_);
1093       gold_assert(os != NULL);
1094       Address off = this->u2_.relobj->get_output_section_offset(this->shndx_);
1095       if (off != invalid_address)
1096 	address += os->address() + off;
1097       else
1098 	{
1099 	  Sized_relobj_file<size, big_endian>* relobj =
1100 	      this->u2_.relobj->sized_relobj();
1101 	  gold_assert(relobj != NULL);
1102 	  address = os->output_address(relobj, this->shndx_, address);
1103 	  gold_assert(address != invalid_address);
1104 	}
1105     }
1106   else if (this->u2_.od != NULL)
1107     address += this->u2_.od->address();
1108   return address;
1109 }
1110 
1111 // Write out the offset and info fields of a Rel or Rela relocation
1112 // entry.
1113 
1114 template<bool dynamic, int size, bool big_endian>
1115 template<typename Write_rel>
1116 void
write_rel(Write_rel * wr) const1117 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
1118     Write_rel* wr) const
1119 {
1120   wr->put_r_offset(this->get_address());
1121   unsigned int sym_index = this->get_symbol_index();
1122   wr->put_r_info(elfcpp::elf_r_info<size>(sym_index, this->type_));
1123 }
1124 
1125 // Write out a Rel relocation.
1126 
1127 template<bool dynamic, int size, bool big_endian>
1128 void
write(unsigned char * pov) const1129 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
1130     unsigned char* pov) const
1131 {
1132   elfcpp::Rel_write<size, big_endian> orel(pov);
1133   this->write_rel(&orel);
1134 }
1135 
1136 // Get the value of the symbol referred to by a Rel relocation.
1137 
1138 template<bool dynamic, int size, bool big_endian>
1139 typename elfcpp::Elf_types<size>::Elf_Addr
symbol_value(Addend addend) const1140 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::symbol_value(
1141     Addend addend) const
1142 {
1143   if (this->local_sym_index_ == GSYM_CODE)
1144     {
1145       const Sized_symbol<size>* sym;
1146       sym = static_cast<const Sized_symbol<size>*>(this->u1_.gsym);
1147       if (this->use_plt_offset_ && sym->has_plt_offset())
1148 	return parameters->target().plt_address_for_global(sym);
1149       else
1150 	return sym->value() + addend;
1151     }
1152   if (this->local_sym_index_ == SECTION_CODE)
1153     {
1154       gold_assert(!this->use_plt_offset_);
1155       return this->u1_.os->address() + addend;
1156     }
1157   gold_assert(this->local_sym_index_ != TARGET_CODE
1158 	      && this->local_sym_index_ != INVALID_CODE
1159 	      && this->local_sym_index_ != 0
1160 	      && !this->is_section_symbol_);
1161   const unsigned int lsi = this->local_sym_index_;
1162   Sized_relobj_file<size, big_endian>* relobj =
1163       this->u1_.relobj->sized_relobj();
1164   gold_assert(relobj != NULL);
1165   if (this->use_plt_offset_)
1166     return parameters->target().plt_address_for_local(relobj, lsi);
1167   const Symbol_value<size>* symval = relobj->local_symbol(lsi);
1168   return symval->value(relobj, addend);
1169 }
1170 
1171 // Reloc comparison.  This function sorts the dynamic relocs for the
1172 // benefit of the dynamic linker.  First we sort all relative relocs
1173 // to the front.  Among relative relocs, we sort by output address.
1174 // Among non-relative relocs, we sort by symbol index, then by output
1175 // address.
1176 
1177 template<bool dynamic, int size, bool big_endian>
1178 int
1179 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
compare(const Output_reloc<elfcpp::SHT_REL,dynamic,size,big_endian> & r2) const1180   compare(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>& r2)
1181     const
1182 {
1183   if (this->is_relative_)
1184     {
1185       if (!r2.is_relative_)
1186 	return -1;
1187       // Otherwise sort by reloc address below.
1188     }
1189   else if (r2.is_relative_)
1190     return 1;
1191   else
1192     {
1193       unsigned int sym1 = this->get_symbol_index();
1194       unsigned int sym2 = r2.get_symbol_index();
1195       if (sym1 < sym2)
1196 	return -1;
1197       else if (sym1 > sym2)
1198 	return 1;
1199       // Otherwise sort by reloc address.
1200     }
1201 
1202   section_offset_type addr1 = this->get_address();
1203   section_offset_type addr2 = r2.get_address();
1204   if (addr1 < addr2)
1205     return -1;
1206   else if (addr1 > addr2)
1207     return 1;
1208 
1209   // Final tie breaker, in order to generate the same output on any
1210   // host: reloc type.
1211   unsigned int type1 = this->type_;
1212   unsigned int type2 = r2.type_;
1213   if (type1 < type2)
1214     return -1;
1215   else if (type1 > type2)
1216     return 1;
1217 
1218   // These relocs appear to be exactly the same.
1219   return 0;
1220 }
1221 
1222 // Write out a Rela relocation.
1223 
1224 template<bool dynamic, int size, bool big_endian>
1225 void
write(unsigned char * pov) const1226 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
1227     unsigned char* pov) const
1228 {
1229   elfcpp::Rela_write<size, big_endian> orel(pov);
1230   this->rel_.write_rel(&orel);
1231   Addend addend = this->addend_;
1232   if (this->rel_.is_target_specific())
1233     addend = parameters->target().reloc_addend(this->rel_.target_arg(),
1234 					       this->rel_.type(), addend);
1235   else if (this->rel_.is_symbolless())
1236     addend = this->rel_.symbol_value(addend);
1237   else if (this->rel_.is_local_section_symbol())
1238     addend = this->rel_.local_section_offset(addend);
1239   orel.put_r_addend(addend);
1240 }
1241 
1242 // Output_data_reloc_base methods.
1243 
1244 // Adjust the output section.
1245 
1246 template<int sh_type, bool dynamic, int size, bool big_endian>
1247 void
1248 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
do_adjust_output_section(Output_section * os)1249     ::do_adjust_output_section(Output_section* os)
1250 {
1251   if (sh_type == elfcpp::SHT_REL)
1252     os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
1253   else if (sh_type == elfcpp::SHT_RELA)
1254     os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
1255   else
1256     gold_unreachable();
1257 
1258   // A STT_GNU_IFUNC symbol may require a IRELATIVE reloc when doing a
1259   // static link.  The backends will generate a dynamic reloc section
1260   // to hold this.  In that case we don't want to link to the dynsym
1261   // section, because there isn't one.
1262   if (!dynamic)
1263     os->set_should_link_to_symtab();
1264   else if (parameters->doing_static_link())
1265     ;
1266   else
1267     os->set_should_link_to_dynsym();
1268 }
1269 
1270 // Standard relocation writer, which just calls Output_reloc::write().
1271 
1272 template<int sh_type, bool dynamic, int size, bool big_endian>
1273 struct Output_reloc_writer
1274 {
1275   typedef Output_reloc<sh_type, dynamic, size, big_endian> Output_reloc_type;
1276   typedef std::vector<Output_reloc_type> Relocs;
1277 
1278   static void
writegold::Output_reloc_writer1279   write(typename Relocs::const_iterator p, unsigned char* pov)
1280   { p->write(pov); }
1281 };
1282 
1283 // Write out relocation data.
1284 
1285 template<int sh_type, bool dynamic, int size, bool big_endian>
1286 void
do_write(Output_file * of)1287 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
1288     Output_file* of)
1289 {
1290   typedef Output_reloc_writer<sh_type, dynamic, size, big_endian> Writer;
1291   this->do_write_generic<Writer>(of);
1292 }
1293 
1294 // Class Output_relocatable_relocs.
1295 
1296 template<int sh_type, int size, bool big_endian>
1297 void
set_final_data_size()1298 Output_relocatable_relocs<sh_type, size, big_endian>::set_final_data_size()
1299 {
1300   this->set_data_size(this->rr_->output_reloc_count()
1301 		      * Reloc_types<sh_type, size, big_endian>::reloc_size);
1302 }
1303 
1304 // class Output_data_group.
1305 
1306 template<int size, bool big_endian>
Output_data_group(Sized_relobj_file<size,big_endian> * relobj,section_size_type entry_count,elfcpp::Elf_Word flags,std::vector<unsigned int> * input_shndxes)1307 Output_data_group<size, big_endian>::Output_data_group(
1308     Sized_relobj_file<size, big_endian>* relobj,
1309     section_size_type entry_count,
1310     elfcpp::Elf_Word flags,
1311     std::vector<unsigned int>* input_shndxes)
1312   : Output_section_data(entry_count * 4, 4, false),
1313     relobj_(relobj),
1314     flags_(flags)
1315 {
1316   this->input_shndxes_.swap(*input_shndxes);
1317 }
1318 
1319 // Write out the section group, which means translating the section
1320 // indexes to apply to the output file.
1321 
1322 template<int size, bool big_endian>
1323 void
do_write(Output_file * of)1324 Output_data_group<size, big_endian>::do_write(Output_file* of)
1325 {
1326   const off_t off = this->offset();
1327   const section_size_type oview_size =
1328     convert_to_section_size_type(this->data_size());
1329   unsigned char* const oview = of->get_output_view(off, oview_size);
1330 
1331   elfcpp::Elf_Word* contents = reinterpret_cast<elfcpp::Elf_Word*>(oview);
1332   elfcpp::Swap<32, big_endian>::writeval(contents, this->flags_);
1333   ++contents;
1334 
1335   for (std::vector<unsigned int>::const_iterator p =
1336 	 this->input_shndxes_.begin();
1337        p != this->input_shndxes_.end();
1338        ++p, ++contents)
1339     {
1340       Output_section* os = this->relobj_->output_section(*p);
1341 
1342       unsigned int output_shndx;
1343       if (os != NULL)
1344 	output_shndx = os->out_shndx();
1345       else
1346 	{
1347 	  this->relobj_->error(_("section group retained but "
1348 				 "group element discarded"));
1349 	  output_shndx = 0;
1350 	}
1351 
1352       elfcpp::Swap<32, big_endian>::writeval(contents, output_shndx);
1353     }
1354 
1355   size_t wrote = reinterpret_cast<unsigned char*>(contents) - oview;
1356   gold_assert(wrote == oview_size);
1357 
1358   of->write_output_view(off, oview_size, oview);
1359 
1360   // We no longer need this information.
1361   this->input_shndxes_.clear();
1362 }
1363 
1364 // Output_data_got::Got_entry methods.
1365 
1366 // Write out the entry.
1367 
1368 template<int got_size, bool big_endian>
1369 void
write(Output_data_got_base * got,unsigned int got_indx,unsigned char * pov) const1370 Output_data_got<got_size, big_endian>::Got_entry::write(
1371     Output_data_got_base* got,
1372     unsigned int got_indx,
1373     unsigned char* pov) const
1374 {
1375   Valtype val = 0;
1376 
1377   switch (this->local_sym_index_)
1378     {
1379     case GSYM_CODE:
1380       {
1381 	// If the symbol is resolved locally, we need to write out the
1382 	// link-time value, which will be relocated dynamically by a
1383 	// RELATIVE relocation.
1384 	Symbol* gsym = this->u_.gsym;
1385 	if (this->use_plt_or_tls_offset_ && gsym->has_plt_offset())
1386 	  val = parameters->target().plt_address_for_global(gsym);
1387 	else
1388 	  {
1389 	    switch (parameters->size_and_endianness())
1390 	      {
1391 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1392 	      case Parameters::TARGET_32_LITTLE:
1393 	      case Parameters::TARGET_32_BIG:
1394 		{
1395 		  // This cast is ugly.  We don't want to put a
1396 		  // virtual method in Symbol, because we want Symbol
1397 		  // to be as small as possible.
1398 		  Sized_symbol<32>::Value_type v;
1399 		  v = static_cast<Sized_symbol<32>*>(gsym)->value();
1400 		  val = convert_types<Valtype, Sized_symbol<32>::Value_type>(v);
1401 		}
1402 		break;
1403 #endif
1404 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1405 	      case Parameters::TARGET_64_LITTLE:
1406 	      case Parameters::TARGET_64_BIG:
1407 		{
1408 		  Sized_symbol<64>::Value_type v;
1409 		  v = static_cast<Sized_symbol<64>*>(gsym)->value();
1410 		  val = convert_types<Valtype, Sized_symbol<64>::Value_type>(v);
1411 		}
1412 		break;
1413 #endif
1414 	      default:
1415 		gold_unreachable();
1416 	      }
1417 	    // If this is a GOT entry for a known value global symbol,
1418 	    // then the value should include the addend.  If the value
1419 	    // is not known leave the value as zero; The GOT entry
1420 	    // will be set by a dynamic relocation.
1421 	    if (this->addend_ && gsym->final_value_is_known())
1422 	      val += this->addend_;
1423 	    if (this->use_plt_or_tls_offset_
1424 		&& gsym->type() == elfcpp::STT_TLS)
1425 	      val += parameters->target().tls_offset_for_global(gsym,
1426 								got, got_indx,
1427 								this->addend_);
1428 	  }
1429       }
1430       break;
1431 
1432     case CONSTANT_CODE:
1433       val = this->u_.constant;
1434       break;
1435 
1436     case RESERVED_CODE:
1437       // If we're doing an incremental update, don't touch this GOT entry.
1438       if (parameters->incremental_update())
1439 	return;
1440       val = this->u_.constant;
1441       break;
1442 
1443     default:
1444       {
1445 	const Relobj* object = this->u_.object;
1446 	const unsigned int lsi = this->local_sym_index_;
1447 	bool is_tls = object->local_is_tls(lsi);
1448 	if (this->use_plt_or_tls_offset_ && !is_tls)
1449 	  val = parameters->target().plt_address_for_local(object, lsi);
1450 	else
1451 	  {
1452 	    uint64_t lval = object->local_symbol_value(lsi, this->addend_);
1453 	    val = convert_types<Valtype, uint64_t>(lval);
1454 	    if (this->use_plt_or_tls_offset_ && is_tls)
1455 	      val += parameters->target().tls_offset_for_local(object, lsi,
1456 							       got, got_indx,
1457 							       this->addend_);
1458 	  }
1459       }
1460       break;
1461     }
1462 
1463   elfcpp::Swap<got_size, big_endian>::writeval(pov, val);
1464 }
1465 
1466 // Output_data_got methods.
1467 
1468 // Add an entry for a global symbol to the GOT.  This returns true if
1469 // this is a new GOT entry, false if the symbol already had a GOT
1470 // entry.
1471 
1472 template<int got_size, bool big_endian>
1473 bool
add_global(Symbol * gsym,unsigned int got_type,uint64_t addend)1474 Output_data_got<got_size, big_endian>::add_global(Symbol* gsym,
1475 						  unsigned int got_type,
1476 						  uint64_t addend)
1477 {
1478   if (gsym->has_got_offset(got_type, addend))
1479     return false;
1480 
1481   unsigned int got_offset = this->add_got_entry(Got_entry(gsym, false, addend));
1482   gsym->set_got_offset(got_type, got_offset, addend);
1483   return true;
1484 }
1485 
1486 // Like add_global, but use the PLT offset.
1487 
1488 template<int got_size, bool big_endian>
1489 bool
add_global_plt(Symbol * gsym,unsigned int got_type,uint64_t addend)1490 Output_data_got<got_size, big_endian>::add_global_plt(Symbol* gsym,
1491 						      unsigned int got_type,
1492 						      uint64_t addend)
1493 {
1494   if (gsym->has_got_offset(got_type, addend))
1495     return false;
1496 
1497   unsigned int got_offset = this->add_got_entry(Got_entry(gsym, true, addend));
1498   gsym->set_got_offset(got_type, got_offset, addend);
1499   return true;
1500 }
1501 
1502 // Add an entry for a global symbol to the GOT, and add a dynamic
1503 // relocation of type R_TYPE for the GOT entry.
1504 
1505 template<int got_size, bool big_endian>
1506 void
add_global_with_rel(Symbol * gsym,unsigned int got_type,Output_data_reloc_generic * rel_dyn,unsigned int r_type,uint64_t addend)1507 Output_data_got<got_size, big_endian>::add_global_with_rel(
1508     Symbol* gsym,
1509     unsigned int got_type,
1510     Output_data_reloc_generic* rel_dyn,
1511     unsigned int r_type,
1512     uint64_t addend)
1513 {
1514   if (gsym->has_got_offset(got_type, addend))
1515     return;
1516 
1517   unsigned int got_offset = this->add_got_entry(Got_entry());
1518   gsym->set_got_offset(got_type, got_offset, addend);
1519   rel_dyn->add_global_generic(gsym, r_type, this, got_offset, addend);
1520 }
1521 
1522 // Add a pair of entries for a global symbol to the GOT, and add
1523 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1524 // If R_TYPE_2 == 0, add the second entry with no relocation.
1525 template<int got_size, bool big_endian>
1526 void
add_global_pair_with_rel(Symbol * gsym,unsigned int got_type,Output_data_reloc_generic * rel_dyn,unsigned int r_type_1,unsigned int r_type_2,uint64_t addend)1527 Output_data_got<got_size, big_endian>::add_global_pair_with_rel(
1528     Symbol* gsym,
1529     unsigned int got_type,
1530     Output_data_reloc_generic* rel_dyn,
1531     unsigned int r_type_1,
1532     unsigned int r_type_2,
1533     uint64_t addend)
1534 {
1535   if (gsym->has_got_offset(got_type, addend))
1536     return;
1537 
1538   unsigned int got_offset = this->add_got_entry_pair(Got_entry(), Got_entry());
1539   gsym->set_got_offset(got_type, got_offset, addend);
1540   rel_dyn->add_global_generic(gsym, r_type_1, this, got_offset, addend);
1541 
1542   if (r_type_2 != 0)
1543     rel_dyn->add_global_generic(gsym, r_type_2, this,
1544 				got_offset + got_size / 8, addend);
1545 }
1546 
1547 // Add an entry for a local symbol plus ADDEND to the GOT.  This returns
1548 // true if this is a new GOT entry, false if the symbol already has a GOT
1549 // entry.
1550 
1551 template<int got_size, bool big_endian>
1552 bool
add_local(Relobj * object,unsigned int symndx,unsigned int got_type,uint64_t addend)1553 Output_data_got<got_size, big_endian>::add_local(
1554     Relobj* object,
1555     unsigned int symndx,
1556     unsigned int got_type,
1557     uint64_t addend)
1558 {
1559   if (object->local_has_got_offset(symndx, got_type, addend))
1560     return false;
1561 
1562   unsigned int got_offset = this->add_got_entry(Got_entry(object, symndx,
1563 							  false, addend));
1564   object->set_local_got_offset(symndx, got_type, got_offset, addend);
1565   return true;
1566 }
1567 
1568 // Like add_local, but use the PLT offset.
1569 
1570 template<int got_size, bool big_endian>
1571 bool
add_local_plt(Relobj * object,unsigned int symndx,unsigned int got_type,uint64_t addend)1572 Output_data_got<got_size, big_endian>::add_local_plt(
1573     Relobj* object,
1574     unsigned int symndx,
1575     unsigned int got_type,
1576     uint64_t addend)
1577 {
1578   if (object->local_has_got_offset(symndx, got_type, addend))
1579     return false;
1580 
1581   unsigned int got_offset = this->add_got_entry(Got_entry(object, symndx,
1582 							  true, addend));
1583   object->set_local_got_offset(symndx, got_type, got_offset, addend);
1584   return true;
1585 }
1586 
1587 // Add an entry for a local symbol plus ADDEND to the GOT, and add a dynamic
1588 // relocation of type R_TYPE for the GOT entry.
1589 
1590 template<int got_size, bool big_endian>
1591 void
add_local_with_rel(Relobj * object,unsigned int symndx,unsigned int got_type,Output_data_reloc_generic * rel_dyn,unsigned int r_type,uint64_t addend)1592 Output_data_got<got_size, big_endian>::add_local_with_rel(
1593     Relobj* object,
1594     unsigned int symndx,
1595     unsigned int got_type,
1596     Output_data_reloc_generic* rel_dyn,
1597     unsigned int r_type,
1598     uint64_t addend)
1599 {
1600   if (object->local_has_got_offset(symndx, got_type, addend))
1601     return;
1602 
1603   unsigned int got_offset = this->add_got_entry(Got_entry());
1604   object->set_local_got_offset(symndx, got_type, got_offset, addend);
1605   rel_dyn->add_local_generic(object, symndx, r_type, this, got_offset,
1606                              addend);
1607 }
1608 
1609 // Add a pair of entries for a local symbol plus ADDEND to the GOT, and add
1610 // a dynamic relocation of type R_TYPE using the section symbol of
1611 // the output section to which input section SHNDX maps, on the first.
1612 // The first got entry will have a value of zero, the second the
1613 // value of the local symbol.
1614 template<int got_size, bool big_endian>
1615 void
add_local_pair_with_rel(Relobj * object,unsigned int symndx,unsigned int shndx,unsigned int got_type,Output_data_reloc_generic * rel_dyn,unsigned int r_type,uint64_t addend)1616 Output_data_got<got_size, big_endian>::add_local_pair_with_rel(
1617     Relobj* object,
1618     unsigned int symndx,
1619     unsigned int shndx,
1620     unsigned int got_type,
1621     Output_data_reloc_generic* rel_dyn,
1622     unsigned int r_type,
1623     uint64_t addend)
1624 {
1625   if (object->local_has_got_offset(symndx, got_type, addend))
1626     return;
1627 
1628   unsigned int got_offset =
1629       this->add_got_entry_pair(Got_entry(),
1630 			       Got_entry(object, symndx, false, addend));
1631   object->set_local_got_offset(symndx, got_type, got_offset, addend);
1632   Output_section* os = object->output_section(shndx);
1633   rel_dyn->add_output_section_generic(os, r_type, this, got_offset, addend);
1634 }
1635 
1636 // Add a pair of entries for a local symbol to the GOT, and add
1637 // a dynamic relocation of type R_TYPE using STN_UNDEF on the first.
1638 // The first got entry will have a value of zero, the second the
1639 // value of the local symbol offset by Target::tls_offset_for_local.
1640 template<int got_size, bool big_endian>
1641 void
add_local_tls_pair(Relobj * object,unsigned int symndx,unsigned int got_type,Output_data_reloc_generic * rel_dyn,unsigned int r_type,uint64_t addend)1642 Output_data_got<got_size, big_endian>::add_local_tls_pair(
1643     Relobj* object,
1644     unsigned int symndx,
1645     unsigned int got_type,
1646     Output_data_reloc_generic* rel_dyn,
1647     unsigned int r_type,
1648     uint64_t addend)
1649 {
1650   if (object->local_has_got_offset(symndx, got_type, addend))
1651     return;
1652 
1653   unsigned int got_offset
1654     = this->add_got_entry_pair(Got_entry(),
1655 			       Got_entry(object, symndx, true, addend));
1656   object->set_local_got_offset(symndx, got_type, got_offset, addend);
1657   rel_dyn->add_local_generic(object, 0, r_type, this, got_offset, addend);
1658 }
1659 
1660 // Reserve a slot in the GOT for a local symbol or the second slot of a pair.
1661 
1662 template<int got_size, bool big_endian>
1663 void
reserve_local(unsigned int i,Relobj * object,unsigned int sym_index,unsigned int got_type,uint64_t addend)1664 Output_data_got<got_size, big_endian>::reserve_local(
1665     unsigned int i,
1666     Relobj* object,
1667     unsigned int sym_index,
1668     unsigned int got_type,
1669     uint64_t addend)
1670 {
1671   this->do_reserve_slot(i);
1672   object->set_local_got_offset(sym_index, got_type, this->got_offset(i), addend);
1673 }
1674 
1675 // Reserve a slot in the GOT for a global symbol.
1676 
1677 template<int got_size, bool big_endian>
1678 void
reserve_global(unsigned int i,Symbol * gsym,unsigned int got_type,uint64_t addend)1679 Output_data_got<got_size, big_endian>::reserve_global(
1680     unsigned int i,
1681     Symbol* gsym,
1682     unsigned int got_type,
1683     uint64_t addend)
1684 {
1685   this->do_reserve_slot(i);
1686   gsym->set_got_offset(got_type, this->got_offset(i), addend);
1687 }
1688 
1689 // Write out the GOT.
1690 
1691 template<int got_size, bool big_endian>
1692 void
do_write(Output_file * of)1693 Output_data_got<got_size, big_endian>::do_write(Output_file* of)
1694 {
1695   const int add = got_size / 8;
1696 
1697   const off_t off = this->offset();
1698   const off_t oview_size = this->data_size();
1699   unsigned char* const oview = of->get_output_view(off, oview_size);
1700 
1701   unsigned char* pov = oview;
1702   for (unsigned int i = 0; i < this->entries_.size(); ++i)
1703     {
1704       this->entries_[i].write(this, i, pov);
1705       pov += add;
1706     }
1707 
1708   gold_assert(pov - oview == oview_size);
1709 
1710   of->write_output_view(off, oview_size, oview);
1711 
1712   // We no longer need the GOT entries.
1713   this->entries_.clear();
1714 }
1715 
1716 // Create a new GOT entry and return its offset.
1717 
1718 template<int got_size, bool big_endian>
1719 unsigned int
add_got_entry(Got_entry got_entry)1720 Output_data_got<got_size, big_endian>::add_got_entry(Got_entry got_entry)
1721 {
1722   if (!this->is_data_size_valid())
1723     {
1724       this->entries_.push_back(got_entry);
1725       this->set_got_size();
1726       return this->last_got_offset();
1727     }
1728   else
1729     {
1730       // For an incremental update, find an available slot.
1731       off_t got_offset = this->free_list_.allocate(got_size / 8,
1732 						   got_size / 8, 0);
1733       if (got_offset == -1)
1734 	gold_fallback(_("out of patch space (GOT);"
1735 			" relink with --incremental-full"));
1736       unsigned int got_index = got_offset / (got_size / 8);
1737       gold_assert(got_index < this->entries_.size());
1738       this->entries_[got_index] = got_entry;
1739       return static_cast<unsigned int>(got_offset);
1740     }
1741 }
1742 
1743 // Create a pair of new GOT entries and return the offset of the first.
1744 
1745 template<int got_size, bool big_endian>
1746 unsigned int
add_got_entry_pair(Got_entry got_entry_1,Got_entry got_entry_2)1747 Output_data_got<got_size, big_endian>::add_got_entry_pair(
1748     Got_entry got_entry_1,
1749     Got_entry got_entry_2)
1750 {
1751   if (!this->is_data_size_valid())
1752     {
1753       unsigned int got_offset;
1754       this->entries_.push_back(got_entry_1);
1755       got_offset = this->last_got_offset();
1756       this->entries_.push_back(got_entry_2);
1757       this->set_got_size();
1758       return got_offset;
1759     }
1760   else
1761     {
1762       // For an incremental update, find an available pair of slots.
1763       off_t got_offset = this->free_list_.allocate(2 * got_size / 8,
1764 						   got_size / 8, 0);
1765       if (got_offset == -1)
1766 	gold_fallback(_("out of patch space (GOT);"
1767 			" relink with --incremental-full"));
1768       unsigned int got_index = got_offset / (got_size / 8);
1769       gold_assert(got_index < this->entries_.size());
1770       this->entries_[got_index] = got_entry_1;
1771       this->entries_[got_index + 1] = got_entry_2;
1772       return static_cast<unsigned int>(got_offset);
1773     }
1774 }
1775 
1776 // Replace GOT entry I with a new value.
1777 
1778 template<int got_size, bool big_endian>
1779 void
replace_got_entry(unsigned int i,Got_entry got_entry)1780 Output_data_got<got_size, big_endian>::replace_got_entry(
1781     unsigned int i,
1782     Got_entry got_entry)
1783 {
1784   gold_assert(i < this->entries_.size());
1785   this->entries_[i] = got_entry;
1786 }
1787 
1788 // Output_data_dynamic::Dynamic_entry methods.
1789 
1790 // Write out the entry.
1791 
1792 template<int size, bool big_endian>
1793 void
write(unsigned char * pov,const Stringpool * pool) const1794 Output_data_dynamic::Dynamic_entry::write(
1795     unsigned char* pov,
1796     const Stringpool* pool) const
1797 {
1798   typename elfcpp::Elf_types<size>::Elf_WXword val;
1799   switch (this->offset_)
1800     {
1801     case DYNAMIC_NUMBER:
1802       val = this->u_.val;
1803       break;
1804 
1805     case DYNAMIC_SECTION_SIZE:
1806       val = this->u_.od->data_size();
1807       if (this->od2 != NULL)
1808 	val += this->od2->data_size();
1809       break;
1810 
1811     case DYNAMIC_SYMBOL:
1812       {
1813 	const Sized_symbol<size>* s =
1814 	  static_cast<const Sized_symbol<size>*>(this->u_.sym);
1815 	val = s->value();
1816       }
1817       break;
1818 
1819     case DYNAMIC_STRING:
1820       val = pool->get_offset(this->u_.str);
1821       break;
1822 
1823     case DYNAMIC_CUSTOM:
1824       val = parameters->target().dynamic_tag_custom_value(this->tag_);
1825       break;
1826 
1827     default:
1828       val = this->u_.od->address() + this->offset_;
1829       break;
1830     }
1831 
1832   elfcpp::Dyn_write<size, big_endian> dw(pov);
1833   dw.put_d_tag(this->tag_);
1834   dw.put_d_val(val);
1835 }
1836 
1837 // Output_data_dynamic methods.
1838 
1839 // Adjust the output section to set the entry size.
1840 
1841 void
do_adjust_output_section(Output_section * os)1842 Output_data_dynamic::do_adjust_output_section(Output_section* os)
1843 {
1844   if (parameters->target().get_size() == 32)
1845     os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
1846   else if (parameters->target().get_size() == 64)
1847     os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
1848   else
1849     gold_unreachable();
1850 }
1851 
1852 // Get a dynamic entry offset.
1853 
1854 unsigned int
get_entry_offset(elfcpp::DT tag) const1855 Output_data_dynamic::get_entry_offset(elfcpp::DT tag) const
1856 {
1857   int dyn_size;
1858 
1859   if (parameters->target().get_size() == 32)
1860     dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
1861   else if (parameters->target().get_size() == 64)
1862     dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
1863   else
1864     gold_unreachable();
1865 
1866   for (size_t i = 0; i < entries_.size(); ++i)
1867     if (entries_[i].tag() == tag)
1868       return i * dyn_size;
1869 
1870   return -1U;
1871 }
1872 
1873 // Set the final data size.
1874 
1875 void
set_final_data_size()1876 Output_data_dynamic::set_final_data_size()
1877 {
1878   // Add the terminating entry if it hasn't been added.
1879   // Because of relaxation, we can run this multiple times.
1880   if (this->entries_.empty() || this->entries_.back().tag() != elfcpp::DT_NULL)
1881     {
1882       int extra = parameters->options().spare_dynamic_tags();
1883       for (int i = 0; i < extra; ++i)
1884 	this->add_constant(elfcpp::DT_NULL, 0);
1885       this->add_constant(elfcpp::DT_NULL, 0);
1886     }
1887 
1888   int dyn_size;
1889   if (parameters->target().get_size() == 32)
1890     dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
1891   else if (parameters->target().get_size() == 64)
1892     dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
1893   else
1894     gold_unreachable();
1895   this->set_data_size(this->entries_.size() * dyn_size);
1896 }
1897 
1898 // Write out the dynamic entries.
1899 
1900 void
do_write(Output_file * of)1901 Output_data_dynamic::do_write(Output_file* of)
1902 {
1903   switch (parameters->size_and_endianness())
1904     {
1905 #ifdef HAVE_TARGET_32_LITTLE
1906     case Parameters::TARGET_32_LITTLE:
1907       this->sized_write<32, false>(of);
1908       break;
1909 #endif
1910 #ifdef HAVE_TARGET_32_BIG
1911     case Parameters::TARGET_32_BIG:
1912       this->sized_write<32, true>(of);
1913       break;
1914 #endif
1915 #ifdef HAVE_TARGET_64_LITTLE
1916     case Parameters::TARGET_64_LITTLE:
1917       this->sized_write<64, false>(of);
1918       break;
1919 #endif
1920 #ifdef HAVE_TARGET_64_BIG
1921     case Parameters::TARGET_64_BIG:
1922       this->sized_write<64, true>(of);
1923       break;
1924 #endif
1925     default:
1926       gold_unreachable();
1927     }
1928 }
1929 
1930 template<int size, bool big_endian>
1931 void
sized_write(Output_file * of)1932 Output_data_dynamic::sized_write(Output_file* of)
1933 {
1934   const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
1935 
1936   const off_t offset = this->offset();
1937   const off_t oview_size = this->data_size();
1938   unsigned char* const oview = of->get_output_view(offset, oview_size);
1939 
1940   unsigned char* pov = oview;
1941   for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
1942        p != this->entries_.end();
1943        ++p)
1944     {
1945       p->write<size, big_endian>(pov, this->pool_);
1946       pov += dyn_size;
1947     }
1948 
1949   gold_assert(pov - oview == oview_size);
1950 
1951   of->write_output_view(offset, oview_size, oview);
1952 
1953   // We no longer need the dynamic entries.
1954   this->entries_.clear();
1955 }
1956 
1957 // Class Output_symtab_xindex.
1958 
1959 void
do_write(Output_file * of)1960 Output_symtab_xindex::do_write(Output_file* of)
1961 {
1962   const off_t offset = this->offset();
1963   const off_t oview_size = this->data_size();
1964   unsigned char* const oview = of->get_output_view(offset, oview_size);
1965 
1966   memset(oview, 0, oview_size);
1967 
1968   if (parameters->target().is_big_endian())
1969     this->endian_do_write<true>(oview);
1970   else
1971     this->endian_do_write<false>(oview);
1972 
1973   of->write_output_view(offset, oview_size, oview);
1974 
1975   // We no longer need the data.
1976   this->entries_.clear();
1977 }
1978 
1979 template<bool big_endian>
1980 void
endian_do_write(unsigned char * const oview)1981 Output_symtab_xindex::endian_do_write(unsigned char* const oview)
1982 {
1983   for (Xindex_entries::const_iterator p = this->entries_.begin();
1984        p != this->entries_.end();
1985        ++p)
1986     {
1987       unsigned int symndx = p->first;
1988       gold_assert(static_cast<off_t>(symndx) * 4 < this->data_size());
1989       elfcpp::Swap<32, big_endian>::writeval(oview + symndx * 4, p->second);
1990     }
1991 }
1992 
1993 // Output_fill_debug_info methods.
1994 
1995 // Return the minimum size needed for a dummy compilation unit header.
1996 
1997 size_t
do_minimum_hole_size() const1998 Output_fill_debug_info::do_minimum_hole_size() const
1999 {
2000   // Compile unit header fields: unit_length, version, debug_abbrev_offset,
2001   // address_size.
2002   const size_t len = 4 + 2 + 4 + 1;
2003   // For type units, add type_signature, type_offset.
2004   if (this->is_debug_types_)
2005     return len + 8 + 4;
2006   return len;
2007 }
2008 
2009 // Write a dummy compilation unit header to fill a hole in the
2010 // .debug_info or .debug_types section.
2011 
2012 void
do_write(Output_file * of,off_t off,size_t len) const2013 Output_fill_debug_info::do_write(Output_file* of, off_t off, size_t len) const
2014 {
2015   gold_debug(DEBUG_INCREMENTAL, "fill_debug_info(%08lx, %08lx)",
2016 	     static_cast<long>(off), static_cast<long>(len));
2017 
2018   gold_assert(len >= this->do_minimum_hole_size());
2019 
2020   unsigned char* const oview = of->get_output_view(off, len);
2021   unsigned char* pov = oview;
2022 
2023   // Write header fields: unit_length, version, debug_abbrev_offset,
2024   // address_size.
2025   if (this->is_big_endian())
2026     {
2027       elfcpp::Swap_unaligned<32, true>::writeval(pov, len - 4);
2028       elfcpp::Swap_unaligned<16, true>::writeval(pov + 4, this->version);
2029       elfcpp::Swap_unaligned<32, true>::writeval(pov + 6, 0);
2030     }
2031   else
2032     {
2033       elfcpp::Swap_unaligned<32, false>::writeval(pov, len - 4);
2034       elfcpp::Swap_unaligned<16, false>::writeval(pov + 4, this->version);
2035       elfcpp::Swap_unaligned<32, false>::writeval(pov + 6, 0);
2036     }
2037   pov += 4 + 2 + 4;
2038   *pov++ = 4;
2039 
2040   // For type units, the additional header fields -- type_signature,
2041   // type_offset -- can be filled with zeroes.
2042 
2043   // Fill the remainder of the free space with zeroes.  The first
2044   // zero should tell the consumer there are no DIEs to read in this
2045   // compilation unit.
2046   if (pov < oview + len)
2047     memset(pov, 0, oview + len - pov);
2048 
2049   of->write_output_view(off, len, oview);
2050 }
2051 
2052 // Output_fill_debug_line methods.
2053 
2054 // Return the minimum size needed for a dummy line number program header.
2055 
2056 size_t
do_minimum_hole_size() const2057 Output_fill_debug_line::do_minimum_hole_size() const
2058 {
2059   // Line number program header fields: unit_length, version, header_length,
2060   // minimum_instruction_length, default_is_stmt, line_base, line_range,
2061   // opcode_base, standard_opcode_lengths[], include_directories, filenames.
2062   const size_t len = 4 + 2 + 4 + this->header_length;
2063   return len;
2064 }
2065 
2066 // Write a dummy line number program header to fill a hole in the
2067 // .debug_line section.
2068 
2069 void
do_write(Output_file * of,off_t off,size_t len) const2070 Output_fill_debug_line::do_write(Output_file* of, off_t off, size_t len) const
2071 {
2072   gold_debug(DEBUG_INCREMENTAL, "fill_debug_line(%08lx, %08lx)",
2073 	     static_cast<long>(off), static_cast<long>(len));
2074 
2075   gold_assert(len >= this->do_minimum_hole_size());
2076 
2077   unsigned char* const oview = of->get_output_view(off, len);
2078   unsigned char* pov = oview;
2079 
2080   // Write header fields: unit_length, version, header_length,
2081   // minimum_instruction_length, default_is_stmt, line_base, line_range,
2082   // opcode_base, standard_opcode_lengths[], include_directories, filenames.
2083   // We set the header_length field to cover the entire hole, so the
2084   // line number program is empty.
2085   if (this->is_big_endian())
2086     {
2087       elfcpp::Swap_unaligned<32, true>::writeval(pov, len - 4);
2088       elfcpp::Swap_unaligned<16, true>::writeval(pov + 4, this->version);
2089       elfcpp::Swap_unaligned<32, true>::writeval(pov + 6, len - (4 + 2 + 4));
2090     }
2091   else
2092     {
2093       elfcpp::Swap_unaligned<32, false>::writeval(pov, len - 4);
2094       elfcpp::Swap_unaligned<16, false>::writeval(pov + 4, this->version);
2095       elfcpp::Swap_unaligned<32, false>::writeval(pov + 6, len - (4 + 2 + 4));
2096     }
2097   pov += 4 + 2 + 4;
2098   *pov++ = 1;	// minimum_instruction_length
2099   *pov++ = 0;	// default_is_stmt
2100   *pov++ = 0;	// line_base
2101   *pov++ = 5;	// line_range
2102   *pov++ = 13;	// opcode_base
2103   *pov++ = 0;	// standard_opcode_lengths[1]
2104   *pov++ = 1;	// standard_opcode_lengths[2]
2105   *pov++ = 1;	// standard_opcode_lengths[3]
2106   *pov++ = 1;	// standard_opcode_lengths[4]
2107   *pov++ = 1;	// standard_opcode_lengths[5]
2108   *pov++ = 0;	// standard_opcode_lengths[6]
2109   *pov++ = 0;	// standard_opcode_lengths[7]
2110   *pov++ = 0;	// standard_opcode_lengths[8]
2111   *pov++ = 1;	// standard_opcode_lengths[9]
2112   *pov++ = 0;	// standard_opcode_lengths[10]
2113   *pov++ = 0;	// standard_opcode_lengths[11]
2114   *pov++ = 1;	// standard_opcode_lengths[12]
2115   *pov++ = 0;	// include_directories (empty)
2116   *pov++ = 0;	// filenames (empty)
2117 
2118   // Some consumers don't check the header_length field, and simply
2119   // start reading the line number program immediately following the
2120   // header.  For those consumers, we fill the remainder of the free
2121   // space with DW_LNS_set_basic_block opcodes.  These are effectively
2122   // no-ops: the resulting line table program will not create any rows.
2123   if (pov < oview + len)
2124     memset(pov, elfcpp::DW_LNS_set_basic_block, oview + len - pov);
2125 
2126   of->write_output_view(off, len, oview);
2127 }
2128 
2129 // Output_section::Input_section methods.
2130 
2131 // Return the current data size.  For an input section we store the size here.
2132 // For an Output_section_data, we have to ask it for the size.
2133 
2134 off_t
current_data_size() const2135 Output_section::Input_section::current_data_size() const
2136 {
2137   if (this->is_input_section())
2138     return this->u1_.data_size;
2139   else
2140     {
2141       this->u2_.posd->pre_finalize_data_size();
2142       return this->u2_.posd->current_data_size();
2143     }
2144 }
2145 
2146 // Return the data size.  For an input section we store the size here.
2147 // For an Output_section_data, we have to ask it for the size.
2148 
2149 off_t
data_size() const2150 Output_section::Input_section::data_size() const
2151 {
2152   if (this->is_input_section())
2153     return this->u1_.data_size;
2154   else
2155     return this->u2_.posd->data_size();
2156 }
2157 
2158 // Return the object for an input section.
2159 
2160 Relobj*
relobj() const2161 Output_section::Input_section::relobj() const
2162 {
2163   if (this->is_input_section())
2164     return this->u2_.object;
2165   else if (this->is_merge_section())
2166     {
2167       gold_assert(this->u2_.pomb->first_relobj() != NULL);
2168       return this->u2_.pomb->first_relobj();
2169     }
2170   else if (this->is_relaxed_input_section())
2171     return this->u2_.poris->relobj();
2172   else
2173     gold_unreachable();
2174 }
2175 
2176 // Return the input section index for an input section.
2177 
2178 unsigned int
shndx() const2179 Output_section::Input_section::shndx() const
2180 {
2181   if (this->is_input_section())
2182     return this->shndx_;
2183   else if (this->is_merge_section())
2184     {
2185       gold_assert(this->u2_.pomb->first_relobj() != NULL);
2186       return this->u2_.pomb->first_shndx();
2187     }
2188   else if (this->is_relaxed_input_section())
2189     return this->u2_.poris->shndx();
2190   else
2191     gold_unreachable();
2192 }
2193 
2194 // Set the address and file offset.
2195 
2196 void
set_address_and_file_offset(uint64_t address,off_t file_offset,off_t section_file_offset)2197 Output_section::Input_section::set_address_and_file_offset(
2198     uint64_t address,
2199     off_t file_offset,
2200     off_t section_file_offset)
2201 {
2202   if (this->is_input_section())
2203     this->u2_.object->set_section_offset(this->shndx_,
2204 					 file_offset - section_file_offset);
2205   else
2206     this->u2_.posd->set_address_and_file_offset(address, file_offset);
2207 }
2208 
2209 // Reset the address and file offset.
2210 
2211 void
reset_address_and_file_offset()2212 Output_section::Input_section::reset_address_and_file_offset()
2213 {
2214   if (!this->is_input_section())
2215     this->u2_.posd->reset_address_and_file_offset();
2216 }
2217 
2218 // Finalize the data size.
2219 
2220 void
finalize_data_size()2221 Output_section::Input_section::finalize_data_size()
2222 {
2223   if (!this->is_input_section())
2224     this->u2_.posd->finalize_data_size();
2225 }
2226 
2227 // Try to turn an input offset into an output offset.  We want to
2228 // return the output offset relative to the start of this
2229 // Input_section in the output section.
2230 
2231 inline bool
output_offset(const Relobj * object,unsigned int shndx,section_offset_type offset,section_offset_type * poutput) const2232 Output_section::Input_section::output_offset(
2233     const Relobj* object,
2234     unsigned int shndx,
2235     section_offset_type offset,
2236     section_offset_type* poutput) const
2237 {
2238   if (!this->is_input_section())
2239     return this->u2_.posd->output_offset(object, shndx, offset, poutput);
2240   else
2241     {
2242       if (this->shndx_ != shndx || this->u2_.object != object)
2243 	return false;
2244       *poutput = offset;
2245       return true;
2246     }
2247 }
2248 
2249 // Write out the data.  We don't have to do anything for an input
2250 // section--they are handled via Object::relocate--but this is where
2251 // we write out the data for an Output_section_data.
2252 
2253 void
write(Output_file * of)2254 Output_section::Input_section::write(Output_file* of)
2255 {
2256   if (!this->is_input_section())
2257     this->u2_.posd->write(of);
2258 }
2259 
2260 // Write the data to a buffer.  As for write(), we don't have to do
2261 // anything for an input section.
2262 
2263 void
write_to_buffer(unsigned char * buffer)2264 Output_section::Input_section::write_to_buffer(unsigned char* buffer)
2265 {
2266   if (!this->is_input_section())
2267     this->u2_.posd->write_to_buffer(buffer);
2268 }
2269 
2270 // Print to a map file.
2271 
2272 void
print_to_mapfile(Mapfile * mapfile) const2273 Output_section::Input_section::print_to_mapfile(Mapfile* mapfile) const
2274 {
2275   switch (this->shndx_)
2276     {
2277     case OUTPUT_SECTION_CODE:
2278     case MERGE_DATA_SECTION_CODE:
2279     case MERGE_STRING_SECTION_CODE:
2280       this->u2_.posd->print_to_mapfile(mapfile);
2281       break;
2282 
2283     case RELAXED_INPUT_SECTION_CODE:
2284       {
2285 	Output_relaxed_input_section* relaxed_section =
2286 	  this->relaxed_input_section();
2287 	mapfile->print_input_section(relaxed_section->relobj(),
2288 				     relaxed_section->shndx());
2289       }
2290       break;
2291     default:
2292       mapfile->print_input_section(this->u2_.object, this->shndx_);
2293       break;
2294     }
2295 }
2296 
2297 // Output_section methods.
2298 
2299 // Construct an Output_section.  NAME will point into a Stringpool.
2300 
Output_section(const char * name,elfcpp::Elf_Word type,elfcpp::Elf_Xword flags)2301 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
2302 			       elfcpp::Elf_Xword flags)
2303   : name_(name),
2304     addralign_(0),
2305     entsize_(0),
2306     load_address_(0),
2307     link_section_(NULL),
2308     link_(0),
2309     info_section_(NULL),
2310     info_symndx_(NULL),
2311     info_(0),
2312     type_(type),
2313     flags_(flags),
2314     order_(ORDER_INVALID),
2315     out_shndx_(-1U),
2316     symtab_index_(0),
2317     dynsym_index_(0),
2318     input_sections_(),
2319     first_input_offset_(0),
2320     fills_(),
2321     postprocessing_buffer_(NULL),
2322     needs_symtab_index_(false),
2323     needs_dynsym_index_(false),
2324     should_link_to_symtab_(false),
2325     should_link_to_dynsym_(false),
2326     after_input_sections_(false),
2327     requires_postprocessing_(false),
2328     found_in_sections_clause_(false),
2329     has_load_address_(false),
2330     info_uses_section_index_(false),
2331     input_section_order_specified_(false),
2332     may_sort_attached_input_sections_(false),
2333     must_sort_attached_input_sections_(false),
2334     attached_input_sections_are_sorted_(false),
2335     is_relro_(false),
2336     is_small_section_(false),
2337     is_large_section_(false),
2338     generate_code_fills_at_write_(false),
2339     is_entsize_zero_(false),
2340     section_offsets_need_adjustment_(false),
2341     is_noload_(false),
2342     always_keeps_input_sections_(false),
2343     has_fixed_layout_(false),
2344     is_patch_space_allowed_(false),
2345     is_unique_segment_(false),
2346     tls_offset_(0),
2347     extra_segment_flags_(0),
2348     segment_alignment_(0),
2349     checkpoint_(NULL),
2350     lookup_maps_(new Output_section_lookup_maps),
2351     free_list_(),
2352     free_space_fill_(NULL),
2353     patch_space_(0),
2354     reloc_section_(NULL)
2355 {
2356   // An unallocated section has no address.  Forcing this means that
2357   // we don't need special treatment for symbols defined in debug
2358   // sections.
2359   if ((flags & elfcpp::SHF_ALLOC) == 0)
2360     this->set_address(0);
2361 }
2362 
~Output_section()2363 Output_section::~Output_section()
2364 {
2365   delete this->checkpoint_;
2366 }
2367 
2368 // Set the entry size.
2369 
2370 void
set_entsize(uint64_t v)2371 Output_section::set_entsize(uint64_t v)
2372 {
2373   if (this->is_entsize_zero_)
2374     ;
2375   else if (this->entsize_ == 0)
2376     this->entsize_ = v;
2377   else if (this->entsize_ != v)
2378     {
2379       this->entsize_ = 0;
2380       this->is_entsize_zero_ = 1;
2381     }
2382 }
2383 
2384 // Add the input section SHNDX, with header SHDR, named SECNAME, in
2385 // OBJECT, to the Output_section.  RELOC_SHNDX is the index of a
2386 // relocation section which applies to this section, or 0 if none, or
2387 // -1U if more than one.  Return the offset of the input section
2388 // within the output section.  Return -1 if the input section will
2389 // receive special handling.  In the normal case we don't always keep
2390 // track of input sections for an Output_section.  Instead, each
2391 // Object keeps track of the Output_section for each of its input
2392 // sections.  However, if HAVE_SECTIONS_SCRIPT is true, we do keep
2393 // track of input sections here; this is used when SECTIONS appears in
2394 // a linker script.
2395 
2396 template<int size, bool big_endian>
2397 off_t
add_input_section(Layout * layout,Sized_relobj_file<size,big_endian> * object,unsigned int shndx,const char * secname,const elfcpp::Shdr<size,big_endian> & shdr,unsigned int reloc_shndx,bool have_sections_script)2398 Output_section::add_input_section(Layout* layout,
2399 				  Sized_relobj_file<size, big_endian>* object,
2400 				  unsigned int shndx,
2401 				  const char* secname,
2402 				  const elfcpp::Shdr<size, big_endian>& shdr,
2403 				  unsigned int reloc_shndx,
2404 				  bool have_sections_script)
2405 {
2406   section_size_type input_section_size = shdr.get_sh_size();
2407   section_size_type uncompressed_size;
2408   elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
2409   if (object->section_is_compressed(shndx, &uncompressed_size,
2410 				    &addralign))
2411     input_section_size = uncompressed_size;
2412 
2413   if ((addralign & (addralign - 1)) != 0)
2414     {
2415       object->error(_("invalid alignment %lu for section \"%s\""),
2416 		    static_cast<unsigned long>(addralign), secname);
2417       addralign = 1;
2418     }
2419 
2420   if (addralign > this->addralign_)
2421     this->addralign_ = addralign;
2422 
2423   typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
2424   uint64_t entsize = shdr.get_sh_entsize();
2425 
2426   // .debug_str is a mergeable string section, but is not always so
2427   // marked by compilers.  Mark manually here so we can optimize.
2428   if (strcmp(secname, ".debug_str") == 0)
2429     {
2430       sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS);
2431       entsize = 1;
2432     }
2433 
2434   this->update_flags_for_input_section(sh_flags);
2435   this->set_entsize(entsize);
2436 
2437   // If this is a SHF_MERGE section, we pass all the input sections to
2438   // a Output_data_merge.  We don't try to handle relocations for such
2439   // a section.  We don't try to handle empty merge sections--they
2440   // mess up the mappings, and are useless anyhow.
2441   // FIXME: Need to handle merge sections during incremental update.
2442   if ((sh_flags & elfcpp::SHF_MERGE) != 0
2443       && reloc_shndx == 0
2444       && shdr.get_sh_size() > 0
2445       && !parameters->incremental())
2446     {
2447       // Keep information about merged input sections for rebuilding fast
2448       // lookup maps if we have sections-script or we do relaxation.
2449       bool keeps_input_sections = (this->always_keeps_input_sections_
2450 				   || have_sections_script
2451 				   || parameters->target().may_relax());
2452 
2453       if (this->add_merge_input_section(object, shndx, sh_flags, entsize,
2454 					addralign, keeps_input_sections))
2455 	{
2456 	  // Tell the relocation routines that they need to call the
2457 	  // output_offset method to determine the final address.
2458 	  return -1;
2459 	}
2460     }
2461 
2462   off_t offset_in_section;
2463 
2464   if (this->has_fixed_layout())
2465     {
2466       // For incremental updates, find a chunk of unused space in the section.
2467       offset_in_section = this->free_list_.allocate(input_section_size,
2468 						    addralign, 0);
2469       if (offset_in_section == -1)
2470 	gold_fallback(_("out of patch space in section %s; "
2471 			"relink with --incremental-full"),
2472 		      this->name());
2473       return offset_in_section;
2474     }
2475 
2476   offset_in_section = this->current_data_size_for_child();
2477   off_t aligned_offset_in_section = align_address(offset_in_section,
2478 						  addralign);
2479   this->set_current_data_size_for_child(aligned_offset_in_section
2480 					+ input_section_size);
2481 
2482   // Determine if we want to delay code-fill generation until the output
2483   // section is written.  When the target is relaxing, we want to delay fill
2484   // generating to avoid adjusting them during relaxation.  Also, if we are
2485   // sorting input sections we must delay fill generation.
2486   if (!this->generate_code_fills_at_write_
2487       && !have_sections_script
2488       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2489       && parameters->target().has_code_fill()
2490       && (parameters->target().may_relax()
2491 	  || layout->is_section_ordering_specified()))
2492     {
2493       gold_assert(this->fills_.empty());
2494       this->generate_code_fills_at_write_ = true;
2495     }
2496 
2497   if (aligned_offset_in_section > offset_in_section
2498       && !this->generate_code_fills_at_write_
2499       && !have_sections_script
2500       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2501       && parameters->target().has_code_fill())
2502     {
2503       // We need to add some fill data.  Using fill_list_ when
2504       // possible is an optimization, since we will often have fill
2505       // sections without input sections.
2506       off_t fill_len = aligned_offset_in_section - offset_in_section;
2507       if (this->input_sections_.empty())
2508 	this->fills_.push_back(Fill(offset_in_section, fill_len));
2509       else
2510 	{
2511 	  std::string fill_data(parameters->target().code_fill(fill_len));
2512 	  Output_data_const* odc = new Output_data_const(fill_data, 1);
2513 	  this->input_sections_.push_back(Input_section(odc));
2514 	}
2515     }
2516 
2517   // We need to keep track of this section if we are already keeping
2518   // track of sections, or if we are relaxing.  Also, if this is a
2519   // section which requires sorting, or which may require sorting in
2520   // the future, we keep track of the sections.  If the
2521   // --section-ordering-file option is used to specify the order of
2522   // sections, we need to keep track of sections.
2523   if (this->always_keeps_input_sections_
2524       || have_sections_script
2525       || !this->input_sections_.empty()
2526       || this->may_sort_attached_input_sections()
2527       || this->must_sort_attached_input_sections()
2528       || parameters->options().user_set_Map()
2529       || parameters->target().may_relax()
2530       || layout->is_section_ordering_specified())
2531     {
2532       Input_section isecn(object, shndx, input_section_size, addralign);
2533       /* If section ordering is requested by specifying a ordering file,
2534 	 using --section-ordering-file, match the section name with
2535 	 a pattern.  */
2536       if (parameters->options().section_ordering_file())
2537 	{
2538 	  unsigned int section_order_index =
2539 	    layout->find_section_order_index(std::string(secname));
2540 	  if (section_order_index != 0)
2541 	    {
2542 	      isecn.set_section_order_index(section_order_index);
2543 	      this->set_input_section_order_specified();
2544 	    }
2545 	}
2546       this->input_sections_.push_back(isecn);
2547     }
2548 
2549   return aligned_offset_in_section;
2550 }
2551 
2552 // Add arbitrary data to an output section.
2553 
2554 void
add_output_section_data(Output_section_data * posd)2555 Output_section::add_output_section_data(Output_section_data* posd)
2556 {
2557   Input_section inp(posd);
2558   this->add_output_section_data(&inp);
2559 
2560   if (posd->is_data_size_valid())
2561     {
2562       off_t offset_in_section;
2563       if (this->has_fixed_layout())
2564 	{
2565 	  // For incremental updates, find a chunk of unused space.
2566 	  offset_in_section = this->free_list_.allocate(posd->data_size(),
2567 							posd->addralign(), 0);
2568 	  if (offset_in_section == -1)
2569 	    gold_fallback(_("out of patch space in section %s; "
2570 			    "relink with --incremental-full"),
2571 			  this->name());
2572 	  // Finalize the address and offset now.
2573 	  uint64_t addr = this->address();
2574 	  off_t offset = this->offset();
2575 	  posd->set_address_and_file_offset(addr + offset_in_section,
2576 					    offset + offset_in_section);
2577 	}
2578       else
2579 	{
2580 	  offset_in_section = this->current_data_size_for_child();
2581 	  off_t aligned_offset_in_section = align_address(offset_in_section,
2582 							  posd->addralign());
2583 	  this->set_current_data_size_for_child(aligned_offset_in_section
2584 						+ posd->data_size());
2585 	}
2586     }
2587   else if (this->has_fixed_layout())
2588     {
2589       // For incremental updates, arrange for the data to have a fixed layout.
2590       // This will mean that additions to the data must be allocated from
2591       // free space within the containing output section.
2592       uint64_t addr = this->address();
2593       posd->set_address(addr);
2594       posd->set_file_offset(0);
2595       // FIXME: This should eventually be unreachable.
2596       // gold_unreachable();
2597     }
2598 }
2599 
2600 // Add a relaxed input section.
2601 
2602 void
add_relaxed_input_section(Layout * layout,Output_relaxed_input_section * poris,const std::string & name)2603 Output_section::add_relaxed_input_section(Layout* layout,
2604 					  Output_relaxed_input_section* poris,
2605 					  const std::string& name)
2606 {
2607   Input_section inp(poris);
2608 
2609   // If the --section-ordering-file option is used to specify the order of
2610   // sections, we need to keep track of sections.
2611   if (layout->is_section_ordering_specified())
2612     {
2613       unsigned int section_order_index =
2614 	layout->find_section_order_index(name);
2615       if (section_order_index != 0)
2616 	{
2617 	  inp.set_section_order_index(section_order_index);
2618 	  this->set_input_section_order_specified();
2619 	}
2620     }
2621 
2622   this->add_output_section_data(&inp);
2623   if (this->lookup_maps_->is_valid())
2624     this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2625 						  poris->shndx(), poris);
2626 
2627   // For a relaxed section, we use the current data size.  Linker scripts
2628   // get all the input sections, including relaxed one from an output
2629   // section and add them back to the same output section to compute the
2630   // output section size.  If we do not account for sizes of relaxed input
2631   // sections, an output section would be incorrectly sized.
2632   off_t offset_in_section = this->current_data_size_for_child();
2633   off_t aligned_offset_in_section = align_address(offset_in_section,
2634 						  poris->addralign());
2635   this->set_current_data_size_for_child(aligned_offset_in_section
2636 					+ poris->current_data_size());
2637 }
2638 
2639 // Add arbitrary data to an output section by Input_section.
2640 
2641 void
add_output_section_data(Input_section * inp)2642 Output_section::add_output_section_data(Input_section* inp)
2643 {
2644   if (this->input_sections_.empty())
2645     this->first_input_offset_ = this->current_data_size_for_child();
2646 
2647   this->input_sections_.push_back(*inp);
2648 
2649   uint64_t addralign = inp->addralign();
2650   if (addralign > this->addralign_)
2651     this->addralign_ = addralign;
2652 
2653   inp->set_output_section(this);
2654 }
2655 
2656 // Add a merge section to an output section.
2657 
2658 void
add_output_merge_section(Output_section_data * posd,bool is_string,uint64_t entsize)2659 Output_section::add_output_merge_section(Output_section_data* posd,
2660 					 bool is_string, uint64_t entsize)
2661 {
2662   Input_section inp(posd, is_string, entsize);
2663   this->add_output_section_data(&inp);
2664 }
2665 
2666 // Add an input section to a SHF_MERGE section.
2667 
2668 bool
add_merge_input_section(Relobj * object,unsigned int shndx,uint64_t flags,uint64_t entsize,uint64_t addralign,bool keeps_input_sections)2669 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
2670 					uint64_t flags, uint64_t entsize,
2671 					uint64_t addralign,
2672 					bool keeps_input_sections)
2673 {
2674   // We cannot merge sections with entsize == 0.
2675   if (entsize == 0)
2676     return false;
2677 
2678   bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
2679 
2680   // We cannot restore merged input section states.
2681   gold_assert(this->checkpoint_ == NULL);
2682 
2683   // Look up merge sections by required properties.
2684   // Currently, we only invalidate the lookup maps in script processing
2685   // and relaxation.  We should not have done either when we reach here.
2686   // So we assume that the lookup maps are valid to simply code.
2687   gold_assert(this->lookup_maps_->is_valid());
2688   Merge_section_properties msp(is_string, entsize, addralign);
2689   Output_merge_base* pomb = this->lookup_maps_->find_merge_section(msp);
2690   bool is_new = false;
2691   if (pomb != NULL)
2692     {
2693       gold_assert(pomb->is_string() == is_string
2694 		  && pomb->entsize() == entsize
2695 		  && pomb->addralign() == addralign);
2696     }
2697   else
2698     {
2699       // Create a new Output_merge_data or Output_merge_string_data.
2700       if (!is_string)
2701 	pomb = new Output_merge_data(entsize, addralign);
2702       else
2703 	{
2704 	  switch (entsize)
2705 	    {
2706 	    case 1:
2707 	      pomb = new Output_merge_string<char>(addralign);
2708 	      break;
2709 	    case 2:
2710 	      pomb = new Output_merge_string<char16_t>(addralign);
2711 	      break;
2712 	    case 4:
2713 	      pomb = new Output_merge_string<char32_t>(addralign);
2714 	      break;
2715 	    default:
2716 	      return false;
2717 	    }
2718 	}
2719       // If we need to do script processing or relaxation, we need to keep
2720       // the original input sections to rebuild the fast lookup maps.
2721       if (keeps_input_sections)
2722 	pomb->set_keeps_input_sections();
2723       is_new = true;
2724     }
2725 
2726   if (pomb->add_input_section(object, shndx))
2727     {
2728       // Add new merge section to this output section and link merge
2729       // section properties to new merge section in map.
2730       if (is_new)
2731 	{
2732 	  this->add_output_merge_section(pomb, is_string, entsize);
2733 	  this->lookup_maps_->add_merge_section(msp, pomb);
2734 	}
2735 
2736       return true;
2737     }
2738   else
2739     {
2740       // If add_input_section failed, delete new merge section to avoid
2741       // exporting empty merge sections in Output_section::get_input_section.
2742       if (is_new)
2743 	delete pomb;
2744       return false;
2745     }
2746 }
2747 
2748 // Build a relaxation map to speed up relaxation of existing input sections.
2749 // Look up to the first LIMIT elements in INPUT_SECTIONS.
2750 
2751 void
build_relaxation_map(const Input_section_list & input_sections,size_t limit,Relaxation_map * relaxation_map) const2752 Output_section::build_relaxation_map(
2753   const Input_section_list& input_sections,
2754   size_t limit,
2755   Relaxation_map* relaxation_map) const
2756 {
2757   for (size_t i = 0; i < limit; ++i)
2758     {
2759       const Input_section& is(input_sections[i]);
2760       if (is.is_input_section() || is.is_relaxed_input_section())
2761 	{
2762 	  Section_id sid(is.relobj(), is.shndx());
2763 	  (*relaxation_map)[sid] = i;
2764 	}
2765     }
2766 }
2767 
2768 // Convert regular input sections in INPUT_SECTIONS into relaxed input
2769 // sections in RELAXED_SECTIONS.  MAP is a prebuilt map from section id
2770 // indices of INPUT_SECTIONS.
2771 
2772 void
convert_input_sections_in_list_to_relaxed_sections(const std::vector<Output_relaxed_input_section * > & relaxed_sections,const Relaxation_map & map,Input_section_list * input_sections)2773 Output_section::convert_input_sections_in_list_to_relaxed_sections(
2774   const std::vector<Output_relaxed_input_section*>& relaxed_sections,
2775   const Relaxation_map& map,
2776   Input_section_list* input_sections)
2777 {
2778   for (size_t i = 0; i < relaxed_sections.size(); ++i)
2779     {
2780       Output_relaxed_input_section* poris = relaxed_sections[i];
2781       Section_id sid(poris->relobj(), poris->shndx());
2782       Relaxation_map::const_iterator p = map.find(sid);
2783       gold_assert(p != map.end());
2784       gold_assert((*input_sections)[p->second].is_input_section());
2785 
2786       // Remember section order index of original input section
2787       // if it is set.  Copy it to the relaxed input section.
2788       unsigned int soi =
2789 	(*input_sections)[p->second].section_order_index();
2790       (*input_sections)[p->second] = Input_section(poris);
2791       (*input_sections)[p->second].set_section_order_index(soi);
2792     }
2793 }
2794 
2795 // Convert regular input sections into relaxed input sections. RELAXED_SECTIONS
2796 // is a vector of pointers to Output_relaxed_input_section or its derived
2797 // classes.  The relaxed sections must correspond to existing input sections.
2798 
2799 void
convert_input_sections_to_relaxed_sections(const std::vector<Output_relaxed_input_section * > & relaxed_sections)2800 Output_section::convert_input_sections_to_relaxed_sections(
2801   const std::vector<Output_relaxed_input_section*>& relaxed_sections)
2802 {
2803   gold_assert(parameters->target().may_relax());
2804 
2805   // We want to make sure that restore_states does not undo the effect of
2806   // this.  If there is no checkpoint active, just search the current
2807   // input section list and replace the sections there.  If there is
2808   // a checkpoint, also replace the sections there.
2809 
2810   // By default, we look at the whole list.
2811   size_t limit = this->input_sections_.size();
2812 
2813   if (this->checkpoint_ != NULL)
2814     {
2815       // Replace input sections with relaxed input section in the saved
2816       // copy of the input section list.
2817       if (this->checkpoint_->input_sections_saved())
2818 	{
2819 	  Relaxation_map map;
2820 	  this->build_relaxation_map(
2821 		    *(this->checkpoint_->input_sections()),
2822 		    this->checkpoint_->input_sections()->size(),
2823 		    &map);
2824 	  this->convert_input_sections_in_list_to_relaxed_sections(
2825 		    relaxed_sections,
2826 		    map,
2827 		    this->checkpoint_->input_sections());
2828 	}
2829       else
2830 	{
2831 	  // We have not copied the input section list yet.  Instead, just
2832 	  // look at the portion that would be saved.
2833 	  limit = this->checkpoint_->input_sections_size();
2834 	}
2835     }
2836 
2837   // Convert input sections in input_section_list.
2838   Relaxation_map map;
2839   this->build_relaxation_map(this->input_sections_, limit, &map);
2840   this->convert_input_sections_in_list_to_relaxed_sections(
2841 	    relaxed_sections,
2842 	    map,
2843 	    &this->input_sections_);
2844 
2845   // Update fast look-up map.
2846   if (this->lookup_maps_->is_valid())
2847     for (size_t i = 0; i < relaxed_sections.size(); ++i)
2848       {
2849 	Output_relaxed_input_section* poris = relaxed_sections[i];
2850 	this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2851 						      poris->shndx(), poris);
2852       }
2853 }
2854 
2855 // Update the output section flags based on input section flags.
2856 
2857 void
update_flags_for_input_section(elfcpp::Elf_Xword flags)2858 Output_section::update_flags_for_input_section(elfcpp::Elf_Xword flags)
2859 {
2860   // If we created the section with SHF_ALLOC clear, we set the
2861   // address.  If we are now setting the SHF_ALLOC flag, we need to
2862   // undo that.
2863   if ((this->flags_ & elfcpp::SHF_ALLOC) == 0
2864       && (flags & elfcpp::SHF_ALLOC) != 0)
2865     this->mark_address_invalid();
2866 
2867   this->flags_ |= (flags
2868 		   & (elfcpp::SHF_WRITE
2869 		      | elfcpp::SHF_ALLOC
2870 		      | elfcpp::SHF_EXECINSTR));
2871 
2872   if ((flags & elfcpp::SHF_MERGE) == 0)
2873     this->flags_ &=~ elfcpp::SHF_MERGE;
2874   else
2875     {
2876       if (this->current_data_size_for_child() == 0)
2877 	this->flags_ |= elfcpp::SHF_MERGE;
2878     }
2879 
2880   if ((flags & elfcpp::SHF_STRINGS) == 0)
2881     this->flags_ &=~ elfcpp::SHF_STRINGS;
2882   else
2883     {
2884       if (this->current_data_size_for_child() == 0)
2885 	this->flags_ |= elfcpp::SHF_STRINGS;
2886     }
2887 }
2888 
2889 // Find the merge section into which an input section with index SHNDX in
2890 // OBJECT has been added.  Return NULL if none found.
2891 
2892 const Output_section_data*
find_merge_section(const Relobj * object,unsigned int shndx) const2893 Output_section::find_merge_section(const Relobj* object,
2894 				   unsigned int shndx) const
2895 {
2896   return object->find_merge_section(shndx);
2897 }
2898 
2899 // Build the lookup maps for relaxed sections.  This needs
2900 // to be declared as a const method so that it is callable with a const
2901 // Output_section pointer.  The method only updates states of the maps.
2902 
2903 void
build_lookup_maps() const2904 Output_section::build_lookup_maps() const
2905 {
2906   this->lookup_maps_->clear();
2907   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2908        p != this->input_sections_.end();
2909        ++p)
2910     {
2911       if (p->is_relaxed_input_section())
2912 	{
2913 	  Output_relaxed_input_section* poris = p->relaxed_input_section();
2914 	  this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2915 							poris->shndx(), poris);
2916 	}
2917     }
2918 }
2919 
2920 // Find an relaxed input section corresponding to an input section
2921 // in OBJECT with index SHNDX.
2922 
2923 const Output_relaxed_input_section*
find_relaxed_input_section(const Relobj * object,unsigned int shndx) const2924 Output_section::find_relaxed_input_section(const Relobj* object,
2925 					   unsigned int shndx) const
2926 {
2927   if (!this->lookup_maps_->is_valid())
2928     this->build_lookup_maps();
2929   return this->lookup_maps_->find_relaxed_input_section(object, shndx);
2930 }
2931 
2932 // Given an address OFFSET relative to the start of input section
2933 // SHNDX in OBJECT, return whether this address is being included in
2934 // the final link.  This should only be called if SHNDX in OBJECT has
2935 // a special mapping.
2936 
2937 bool
is_input_address_mapped(const Relobj * object,unsigned int shndx,off_t offset) const2938 Output_section::is_input_address_mapped(const Relobj* object,
2939 					unsigned int shndx,
2940 					off_t offset) const
2941 {
2942   // Look at the Output_section_data_maps first.
2943   const Output_section_data* posd = this->find_merge_section(object, shndx);
2944   if (posd == NULL)
2945     posd = this->find_relaxed_input_section(object, shndx);
2946 
2947   if (posd != NULL)
2948     {
2949       section_offset_type output_offset;
2950       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2951       // By default we assume that the address is mapped. See comment at the
2952       // end.
2953       if (!found)
2954         return true;
2955       return output_offset != -1;
2956     }
2957 
2958   // Fall back to the slow look-up.
2959   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2960        p != this->input_sections_.end();
2961        ++p)
2962     {
2963       section_offset_type output_offset;
2964       if (p->output_offset(object, shndx, offset, &output_offset))
2965 	return output_offset != -1;
2966     }
2967 
2968   // By default we assume that the address is mapped.  This should
2969   // only be called after we have passed all sections to Layout.  At
2970   // that point we should know what we are discarding.
2971   return true;
2972 }
2973 
2974 // Given an address OFFSET relative to the start of input section
2975 // SHNDX in object OBJECT, return the output offset relative to the
2976 // start of the input section in the output section.  This should only
2977 // be called if SHNDX in OBJECT has a special mapping.
2978 
2979 section_offset_type
output_offset(const Relobj * object,unsigned int shndx,section_offset_type offset) const2980 Output_section::output_offset(const Relobj* object, unsigned int shndx,
2981 			      section_offset_type offset) const
2982 {
2983   // This can only be called meaningfully when we know the data size
2984   // of this.
2985   gold_assert(this->is_data_size_valid());
2986 
2987   // Look at the Output_section_data_maps first.
2988   const Output_section_data* posd = this->find_merge_section(object, shndx);
2989   if (posd == NULL)
2990     posd = this->find_relaxed_input_section(object, shndx);
2991   if (posd != NULL)
2992     {
2993       section_offset_type output_offset;
2994       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2995       gold_assert(found);
2996       return output_offset;
2997     }
2998 
2999   // Fall back to the slow look-up.
3000   for (Input_section_list::const_iterator p = this->input_sections_.begin();
3001        p != this->input_sections_.end();
3002        ++p)
3003     {
3004       section_offset_type output_offset;
3005       if (p->output_offset(object, shndx, offset, &output_offset))
3006 	return output_offset;
3007     }
3008   gold_unreachable();
3009 }
3010 
3011 // Return the output virtual address of OFFSET relative to the start
3012 // of input section SHNDX in object OBJECT.
3013 
3014 uint64_t
output_address(const Relobj * object,unsigned int shndx,off_t offset) const3015 Output_section::output_address(const Relobj* object, unsigned int shndx,
3016 			       off_t offset) const
3017 {
3018   uint64_t addr = this->address() + this->first_input_offset_;
3019 
3020   // Look at the Output_section_data_maps first.
3021   const Output_section_data* posd = this->find_merge_section(object, shndx);
3022   if (posd == NULL)
3023     posd = this->find_relaxed_input_section(object, shndx);
3024   if (posd != NULL && posd->is_address_valid())
3025     {
3026       section_offset_type output_offset;
3027       bool found = posd->output_offset(object, shndx, offset, &output_offset);
3028       gold_assert(found);
3029       return posd->address() + output_offset;
3030     }
3031 
3032   // Fall back to the slow look-up.
3033   for (Input_section_list::const_iterator p = this->input_sections_.begin();
3034        p != this->input_sections_.end();
3035        ++p)
3036     {
3037       addr = align_address(addr, p->addralign());
3038       section_offset_type output_offset;
3039       if (p->output_offset(object, shndx, offset, &output_offset))
3040 	{
3041 	  if (output_offset == -1)
3042 	    return -1ULL;
3043 	  return addr + output_offset;
3044 	}
3045       addr += p->data_size();
3046     }
3047 
3048   // If we get here, it means that we don't know the mapping for this
3049   // input section.  This might happen in principle if
3050   // add_input_section were called before add_output_section_data.
3051   // But it should never actually happen.
3052 
3053   gold_unreachable();
3054 }
3055 
3056 // Find the output address of the start of the merged section for
3057 // input section SHNDX in object OBJECT.
3058 
3059 bool
find_starting_output_address(const Relobj * object,unsigned int shndx,uint64_t * paddr) const3060 Output_section::find_starting_output_address(const Relobj* object,
3061 					     unsigned int shndx,
3062 					     uint64_t* paddr) const
3063 {
3064   const Output_section_data* data = this->find_merge_section(object, shndx);
3065   if (data == NULL)
3066     return false;
3067 
3068   // FIXME: This becomes a bottle-neck if we have many relaxed sections.
3069   // Looking up the merge section map does not always work as we sometimes
3070   // find a merge section without its address set.
3071   uint64_t addr = this->address() + this->first_input_offset_;
3072   for (Input_section_list::const_iterator p = this->input_sections_.begin();
3073        p != this->input_sections_.end();
3074        ++p)
3075     {
3076       addr = align_address(addr, p->addralign());
3077 
3078       // It would be nice if we could use the existing output_offset
3079       // method to get the output offset of input offset 0.
3080       // Unfortunately we don't know for sure that input offset 0 is
3081       // mapped at all.
3082       if (!p->is_input_section() && p->output_section_data() == data)
3083 	{
3084 	  *paddr = addr;
3085 	  return true;
3086 	}
3087 
3088       addr += p->data_size();
3089     }
3090 
3091   // We couldn't find a merge output section for this input section.
3092   return false;
3093 }
3094 
3095 // Update the data size of an Output_section.
3096 
3097 void
update_data_size()3098 Output_section::update_data_size()
3099 {
3100   if (this->input_sections_.empty())
3101       return;
3102 
3103   if (this->must_sort_attached_input_sections()
3104       || this->input_section_order_specified())
3105     this->sort_attached_input_sections();
3106 
3107   off_t off = this->first_input_offset_;
3108   for (Input_section_list::iterator p = this->input_sections_.begin();
3109        p != this->input_sections_.end();
3110        ++p)
3111     {
3112       off = align_address(off, p->addralign());
3113       off += p->current_data_size();
3114     }
3115 
3116   this->set_current_data_size_for_child(off);
3117 }
3118 
3119 // Set the data size of an Output_section.  This is where we handle
3120 // setting the addresses of any Output_section_data objects.
3121 
3122 void
set_final_data_size()3123 Output_section::set_final_data_size()
3124 {
3125   off_t data_size;
3126 
3127   if (this->input_sections_.empty())
3128     data_size = this->current_data_size_for_child();
3129   else
3130     {
3131       if (this->must_sort_attached_input_sections()
3132 	  || this->input_section_order_specified())
3133 	this->sort_attached_input_sections();
3134 
3135       uint64_t address = this->address();
3136       off_t startoff = this->offset();
3137       off_t off = this->first_input_offset_;
3138       for (Input_section_list::iterator p = this->input_sections_.begin();
3139 	   p != this->input_sections_.end();
3140 	   ++p)
3141 	{
3142 	  off = align_address(off, p->addralign());
3143 	  p->set_address_and_file_offset(address + off, startoff + off,
3144 					 startoff);
3145 	  off += p->data_size();
3146 	}
3147       data_size = off;
3148     }
3149 
3150   // For full incremental links, we want to allocate some patch space
3151   // in most sections for subsequent incremental updates.
3152   if (this->is_patch_space_allowed_ && parameters->incremental_full())
3153     {
3154       double pct = parameters->options().incremental_patch();
3155       size_t extra = static_cast<size_t>(data_size * pct);
3156       if (this->free_space_fill_ != NULL
3157 	  && this->free_space_fill_->minimum_hole_size() > extra)
3158 	extra = this->free_space_fill_->minimum_hole_size();
3159       off_t new_size = align_address(data_size + extra, this->addralign());
3160       this->patch_space_ = new_size - data_size;
3161       gold_debug(DEBUG_INCREMENTAL,
3162 		 "set_final_data_size: %08lx + %08lx: section %s",
3163 		 static_cast<long>(data_size),
3164 		 static_cast<long>(this->patch_space_),
3165 		 this->name());
3166       data_size = new_size;
3167     }
3168 
3169   this->set_data_size(data_size);
3170 }
3171 
3172 // Reset the address and file offset.
3173 
3174 void
do_reset_address_and_file_offset()3175 Output_section::do_reset_address_and_file_offset()
3176 {
3177   // An unallocated section has no address.  Forcing this means that
3178   // we don't need special treatment for symbols defined in debug
3179   // sections.  We do the same in the constructor.  This does not
3180   // apply to NOLOAD sections though.
3181   if (((this->flags_ & elfcpp::SHF_ALLOC) == 0) && !this->is_noload_)
3182      this->set_address(0);
3183 
3184   for (Input_section_list::iterator p = this->input_sections_.begin();
3185        p != this->input_sections_.end();
3186        ++p)
3187     p->reset_address_and_file_offset();
3188 
3189   // Remove any patch space that was added in set_final_data_size.
3190   if (this->patch_space_ > 0)
3191     {
3192       this->set_current_data_size_for_child(this->current_data_size_for_child()
3193 					    - this->patch_space_);
3194       this->patch_space_ = 0;
3195     }
3196 }
3197 
3198 // Return true if address and file offset have the values after reset.
3199 
3200 bool
do_address_and_file_offset_have_reset_values() const3201 Output_section::do_address_and_file_offset_have_reset_values() const
3202 {
3203   if (this->is_offset_valid())
3204     return false;
3205 
3206   // An unallocated section has address 0 after its construction or a reset.
3207   if ((this->flags_ & elfcpp::SHF_ALLOC) == 0)
3208     return this->is_address_valid() && this->address() == 0;
3209   else
3210     return !this->is_address_valid();
3211 }
3212 
3213 // Set the TLS offset.  Called only for SHT_TLS sections.
3214 
3215 void
do_set_tls_offset(uint64_t tls_base)3216 Output_section::do_set_tls_offset(uint64_t tls_base)
3217 {
3218   this->tls_offset_ = this->address() - tls_base;
3219 }
3220 
3221 // In a few cases we need to sort the input sections attached to an
3222 // output section.  This is used to implement the type of constructor
3223 // priority ordering implemented by the GNU linker, in which the
3224 // priority becomes part of the section name and the sections are
3225 // sorted by name.  We only do this for an output section if we see an
3226 // attached input section matching ".ctors.*", ".dtors.*",
3227 // ".init_array.*" or ".fini_array.*".
3228 
3229 class Output_section::Input_section_sort_entry
3230 {
3231  public:
Input_section_sort_entry()3232   Input_section_sort_entry()
3233     : input_section_(), index_(-1U), section_name_()
3234   { }
3235 
Input_section_sort_entry(const Input_section & input_section,unsigned int index,bool must_sort_attached_input_sections,const char * output_section_name)3236   Input_section_sort_entry(const Input_section& input_section,
3237 			   unsigned int index,
3238 			   bool must_sort_attached_input_sections,
3239 			   const char* output_section_name)
3240     : input_section_(input_section), index_(index), section_name_()
3241   {
3242     if ((input_section.is_input_section()
3243 	 || input_section.is_relaxed_input_section())
3244 	&& must_sort_attached_input_sections)
3245       {
3246 	// This is only called single-threaded from Layout::finalize,
3247 	// so it is OK to lock.  Unfortunately we have no way to pass
3248 	// in a Task token.
3249 	const Task* dummy_task = reinterpret_cast<const Task*>(-1);
3250 	Object* obj = (input_section.is_input_section()
3251 		       ? input_section.relobj()
3252 		       : input_section.relaxed_input_section()->relobj());
3253 	Task_lock_obj<Object> tl(dummy_task, obj);
3254 
3255 	// This is a slow operation, which should be cached in
3256 	// Layout::layout if this becomes a speed problem.
3257 	this->section_name_ = obj->section_name(input_section.shndx());
3258       }
3259     else if (input_section.is_output_section_data()
3260     	     && must_sort_attached_input_sections)
3261       {
3262 	// For linker-generated sections, use the output section name.
3263 	this->section_name_.assign(output_section_name);
3264       }
3265   }
3266 
3267   // Return the Input_section.
3268   const Input_section&
input_section() const3269   input_section() const
3270   {
3271     gold_assert(this->index_ != -1U);
3272     return this->input_section_;
3273   }
3274 
3275   // The index of this entry in the original list.  This is used to
3276   // make the sort stable.
3277   unsigned int
index() const3278   index() const
3279   {
3280     gold_assert(this->index_ != -1U);
3281     return this->index_;
3282   }
3283 
3284   // The section name.
3285   const std::string&
section_name() const3286   section_name() const
3287   {
3288     return this->section_name_;
3289   }
3290 
3291   // Return true if the section name has a priority.  This is assumed
3292   // to be true if it has a dot after the initial dot.
3293   bool
has_priority() const3294   has_priority() const
3295   {
3296     return this->section_name_.find('.', 1) != std::string::npos;
3297   }
3298 
3299   // Return the priority.  Believe it or not, gcc encodes the priority
3300   // differently for .ctors/.dtors and .init_array/.fini_array
3301   // sections.
3302   unsigned int
get_priority() const3303   get_priority() const
3304   {
3305     bool is_ctors;
3306     if (is_prefix_of(".ctors.", this->section_name_.c_str())
3307 	|| is_prefix_of(".dtors.", this->section_name_.c_str()))
3308       is_ctors = true;
3309     else if (is_prefix_of(".init_array.", this->section_name_.c_str())
3310 	     || is_prefix_of(".fini_array.", this->section_name_.c_str()))
3311       is_ctors = false;
3312     else
3313       return 0;
3314     char* end;
3315     unsigned long prio = strtoul((this->section_name_.c_str()
3316 				  + (is_ctors ? 7 : 12)),
3317 				 &end, 10);
3318     if (*end != '\0')
3319       return 0;
3320     else if (is_ctors)
3321       return 65535 - prio;
3322     else
3323       return prio;
3324   }
3325 
3326   // Return true if this an input file whose base name matches
3327   // FILE_NAME.  The base name must have an extension of ".o", and
3328   // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
3329   // This is to match crtbegin.o as well as crtbeginS.o without
3330   // getting confused by other possibilities.  Overall matching the
3331   // file name this way is a dreadful hack, but the GNU linker does it
3332   // in order to better support gcc, and we need to be compatible.
3333   bool
match_file_name(const char * file_name) const3334   match_file_name(const char* file_name) const
3335   {
3336     if (this->input_section_.is_output_section_data())
3337       return false;
3338     return Layout::match_file_name(this->input_section_.relobj(), file_name);
3339   }
3340 
3341   // Returns 1 if THIS should appear before S in section order, -1 if S
3342   // appears before THIS and 0 if they are not comparable.
3343   int
compare_section_ordering(const Input_section_sort_entry & s) const3344   compare_section_ordering(const Input_section_sort_entry& s) const
3345   {
3346     unsigned int this_secn_index = this->input_section_.section_order_index();
3347     unsigned int s_secn_index = s.input_section().section_order_index();
3348     if (this_secn_index > 0 && s_secn_index > 0)
3349       {
3350 	if (this_secn_index < s_secn_index)
3351 	  return 1;
3352 	else if (this_secn_index > s_secn_index)
3353 	  return -1;
3354       }
3355     return 0;
3356   }
3357 
3358  private:
3359   // The Input_section we are sorting.
3360   Input_section input_section_;
3361   // The index of this Input_section in the original list.
3362   unsigned int index_;
3363   // The section name if there is one.
3364   std::string section_name_;
3365 };
3366 
3367 // Return true if S1 should come before S2 in the output section.
3368 
3369 bool
operator ()(const Output_section::Input_section_sort_entry & s1,const Output_section::Input_section_sort_entry & s2) const3370 Output_section::Input_section_sort_compare::operator()(
3371     const Output_section::Input_section_sort_entry& s1,
3372     const Output_section::Input_section_sort_entry& s2) const
3373 {
3374   // crtbegin.o must come first.
3375   bool s1_begin = s1.match_file_name("crtbegin");
3376   bool s2_begin = s2.match_file_name("crtbegin");
3377   if (s1_begin || s2_begin)
3378     {
3379       if (!s1_begin)
3380 	return false;
3381       if (!s2_begin)
3382 	return true;
3383       return s1.index() < s2.index();
3384     }
3385 
3386   // crtend.o must come last.
3387   bool s1_end = s1.match_file_name("crtend");
3388   bool s2_end = s2.match_file_name("crtend");
3389   if (s1_end || s2_end)
3390     {
3391       if (!s1_end)
3392 	return true;
3393       if (!s2_end)
3394 	return false;
3395       return s1.index() < s2.index();
3396     }
3397 
3398   // A section with a priority follows a section without a priority.
3399   bool s1_has_priority = s1.has_priority();
3400   bool s2_has_priority = s2.has_priority();
3401   if (s1_has_priority && !s2_has_priority)
3402     return false;
3403   if (!s1_has_priority && s2_has_priority)
3404     return true;
3405 
3406   // Check if a section order exists for these sections through a section
3407   // ordering file.  If sequence_num is 0, an order does not exist.
3408   int sequence_num = s1.compare_section_ordering(s2);
3409   if (sequence_num != 0)
3410     return sequence_num == 1;
3411 
3412   // Otherwise we sort by name.
3413   int compare = s1.section_name().compare(s2.section_name());
3414   if (compare != 0)
3415     return compare < 0;
3416 
3417   // Otherwise we keep the input order.
3418   return s1.index() < s2.index();
3419 }
3420 
3421 // Return true if S1 should come before S2 in an .init_array or .fini_array
3422 // output section.
3423 
3424 bool
operator ()(const Output_section::Input_section_sort_entry & s1,const Output_section::Input_section_sort_entry & s2) const3425 Output_section::Input_section_sort_init_fini_compare::operator()(
3426     const Output_section::Input_section_sort_entry& s1,
3427     const Output_section::Input_section_sort_entry& s2) const
3428 {
3429   // A section without a priority follows a section with a priority.
3430   // This is the reverse of .ctors and .dtors sections.
3431   bool s1_has_priority = s1.has_priority();
3432   bool s2_has_priority = s2.has_priority();
3433   if (s1_has_priority && !s2_has_priority)
3434     return true;
3435   if (!s1_has_priority && s2_has_priority)
3436     return false;
3437 
3438   // .ctors and .dtors sections without priority come after
3439   // .init_array and .fini_array sections without priority.
3440   if (!s1_has_priority
3441       && (s1.section_name() == ".ctors" || s1.section_name() == ".dtors")
3442       && s1.section_name() != s2.section_name())
3443     return false;
3444   if (!s2_has_priority
3445       && (s2.section_name() == ".ctors" || s2.section_name() == ".dtors")
3446       && s2.section_name() != s1.section_name())
3447     return true;
3448 
3449   // Sort by priority if we can.
3450   if (s1_has_priority)
3451     {
3452       unsigned int s1_prio = s1.get_priority();
3453       unsigned int s2_prio = s2.get_priority();
3454       if (s1_prio < s2_prio)
3455 	return true;
3456       else if (s1_prio > s2_prio)
3457 	return false;
3458     }
3459 
3460   // Check if a section order exists for these sections through a section
3461   // ordering file.  If sequence_num is 0, an order does not exist.
3462   int sequence_num = s1.compare_section_ordering(s2);
3463   if (sequence_num != 0)
3464     return sequence_num == 1;
3465 
3466   // Otherwise we sort by name.
3467   int compare = s1.section_name().compare(s2.section_name());
3468   if (compare != 0)
3469     return compare < 0;
3470 
3471   // Otherwise we keep the input order.
3472   return s1.index() < s2.index();
3473 }
3474 
3475 // Return true if S1 should come before S2.  Sections that do not match
3476 // any pattern in the section ordering file are placed ahead of the sections
3477 // that match some pattern.
3478 
3479 bool
operator ()(const Output_section::Input_section_sort_entry & s1,const Output_section::Input_section_sort_entry & s2) const3480 Output_section::Input_section_sort_section_order_index_compare::operator()(
3481     const Output_section::Input_section_sort_entry& s1,
3482     const Output_section::Input_section_sort_entry& s2) const
3483 {
3484   unsigned int s1_secn_index = s1.input_section().section_order_index();
3485   unsigned int s2_secn_index = s2.input_section().section_order_index();
3486 
3487   // Keep input order if section ordering cannot determine order.
3488   if (s1_secn_index == s2_secn_index)
3489     return s1.index() < s2.index();
3490 
3491   return s1_secn_index < s2_secn_index;
3492 }
3493 
3494 // Return true if S1 should come before S2.  This is the sort comparison
3495 // function for .text to sort sections with prefixes
3496 // .text.{unlikely,exit,startup,hot} before other sections.
3497 
3498 bool
3499 Output_section::Input_section_sort_section_prefix_special_ordering_compare
operator ()(const Output_section::Input_section_sort_entry & s1,const Output_section::Input_section_sort_entry & s2) const3500   ::operator()(
3501     const Output_section::Input_section_sort_entry& s1,
3502     const Output_section::Input_section_sort_entry& s2) const
3503 {
3504   // Some input section names have special ordering requirements.
3505   const char *s1_section_name = s1.section_name().c_str();
3506   const char *s2_section_name = s2.section_name().c_str();
3507   int o1 = Layout::special_ordering_of_input_section(s1_section_name);
3508   int o2 = Layout::special_ordering_of_input_section(s2_section_name);
3509   if (o1 != o2)
3510     {
3511       if (o1 < 0)
3512 	return false;
3513       else if (o2 < 0)
3514 	return true;
3515       else
3516 	return o1 < o2;
3517     }
3518   else if (is_prefix_of(".text.sorted", s1_section_name))
3519     return strcmp(s1_section_name, s2_section_name) <= 0;
3520 
3521   // Keep input order otherwise.
3522   return s1.index() < s2.index();
3523 }
3524 
3525 // Return true if S1 should come before S2.  This is the sort comparison
3526 // function for sections to sort them by name.
3527 
3528 bool
3529 Output_section::Input_section_sort_section_name_compare
operator ()(const Output_section::Input_section_sort_entry & s1,const Output_section::Input_section_sort_entry & s2) const3530   ::operator()(
3531     const Output_section::Input_section_sort_entry& s1,
3532     const Output_section::Input_section_sort_entry& s2) const
3533 {
3534   // We sort by name.
3535   int compare = s1.section_name().compare(s2.section_name());
3536   if (compare != 0)
3537     return compare < 0;
3538 
3539   // Keep input order otherwise.
3540   return s1.index() < s2.index();
3541 }
3542 
3543 // This updates the section order index of input sections according to the
3544 // the order specified in the mapping from Section id to order index.
3545 
3546 void
update_section_layout(const Section_layout_order * order_map)3547 Output_section::update_section_layout(
3548   const Section_layout_order* order_map)
3549 {
3550   for (Input_section_list::iterator p = this->input_sections_.begin();
3551        p != this->input_sections_.end();
3552        ++p)
3553     {
3554       if (p->is_input_section()
3555 	  || p->is_relaxed_input_section())
3556 	{
3557 	  Relobj* obj = (p->is_input_section()
3558 			 ? p->relobj()
3559 			 : p->relaxed_input_section()->relobj());
3560 	  unsigned int shndx = p->shndx();
3561 	  Section_layout_order::const_iterator it
3562 	    = order_map->find(Section_id(obj, shndx));
3563 	  if (it == order_map->end())
3564 	    continue;
3565 	  unsigned int section_order_index = it->second;
3566 	  if (section_order_index != 0)
3567 	    {
3568 	      p->set_section_order_index(section_order_index);
3569 	      this->set_input_section_order_specified();
3570 	    }
3571 	}
3572     }
3573 }
3574 
3575 // Sort the input sections attached to an output section.
3576 
3577 void
sort_attached_input_sections()3578 Output_section::sort_attached_input_sections()
3579 {
3580   if (this->attached_input_sections_are_sorted_)
3581     return;
3582 
3583   if (this->checkpoint_ != NULL
3584       && !this->checkpoint_->input_sections_saved())
3585     this->checkpoint_->save_input_sections();
3586 
3587   // The only thing we know about an input section is the object and
3588   // the section index.  We need the section name.  Recomputing this
3589   // is slow but this is an unusual case.  If this becomes a speed
3590   // problem we can cache the names as required in Layout::layout.
3591 
3592   // We start by building a larger vector holding a copy of each
3593   // Input_section, plus its current index in the list and its name.
3594   std::vector<Input_section_sort_entry> sort_list;
3595 
3596   unsigned int i = 0;
3597   for (Input_section_list::iterator p = this->input_sections_.begin();
3598        p != this->input_sections_.end();
3599        ++p, ++i)
3600       sort_list.push_back(Input_section_sort_entry(*p, i,
3601 			    this->must_sort_attached_input_sections(),
3602 			    this->name()));
3603 
3604   // Sort the input sections.
3605   if (this->must_sort_attached_input_sections())
3606     {
3607       if (this->type() == elfcpp::SHT_PREINIT_ARRAY
3608 	  || this->type() == elfcpp::SHT_INIT_ARRAY
3609 	  || this->type() == elfcpp::SHT_FINI_ARRAY)
3610 	std::sort(sort_list.begin(), sort_list.end(),
3611 		  Input_section_sort_init_fini_compare());
3612       else if (strcmp(parameters->options().sort_section(), "name") == 0)
3613 	std::sort(sort_list.begin(), sort_list.end(),
3614 		  Input_section_sort_section_name_compare());
3615       else if (strcmp(this->name(), ".text") == 0)
3616 	std::sort(sort_list.begin(), sort_list.end(),
3617 		  Input_section_sort_section_prefix_special_ordering_compare());
3618       else
3619 	std::sort(sort_list.begin(), sort_list.end(),
3620 		  Input_section_sort_compare());
3621     }
3622   else
3623     {
3624       gold_assert(this->input_section_order_specified());
3625       std::sort(sort_list.begin(), sort_list.end(),
3626 		Input_section_sort_section_order_index_compare());
3627     }
3628 
3629   // Copy the sorted input sections back to our list.
3630   this->input_sections_.clear();
3631   for (std::vector<Input_section_sort_entry>::iterator p = sort_list.begin();
3632        p != sort_list.end();
3633        ++p)
3634     this->input_sections_.push_back(p->input_section());
3635   sort_list.clear();
3636 
3637   // Remember that we sorted the input sections, since we might get
3638   // called again.
3639   this->attached_input_sections_are_sorted_ = true;
3640 }
3641 
3642 // Write the section header to *OSHDR.
3643 
3644 template<int size, bool big_endian>
3645 void
write_header(const Layout * layout,const Stringpool * secnamepool,elfcpp::Shdr_write<size,big_endian> * oshdr) const3646 Output_section::write_header(const Layout* layout,
3647 			     const Stringpool* secnamepool,
3648 			     elfcpp::Shdr_write<size, big_endian>* oshdr) const
3649 {
3650   oshdr->put_sh_name(secnamepool->get_offset(this->name_));
3651   oshdr->put_sh_type(this->type_);
3652 
3653   elfcpp::Elf_Xword flags = this->flags_;
3654   if (this->info_section_ != NULL && this->info_uses_section_index_)
3655     flags |= elfcpp::SHF_INFO_LINK;
3656   oshdr->put_sh_flags(flags);
3657 
3658   oshdr->put_sh_addr(this->address());
3659   oshdr->put_sh_offset(this->offset());
3660   oshdr->put_sh_size(this->data_size());
3661   if (this->link_section_ != NULL)
3662     oshdr->put_sh_link(this->link_section_->out_shndx());
3663   else if (this->should_link_to_symtab_)
3664     oshdr->put_sh_link(layout->symtab_section_shndx());
3665   else if (this->should_link_to_dynsym_)
3666     oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
3667   else
3668     oshdr->put_sh_link(this->link_);
3669 
3670   elfcpp::Elf_Word info;
3671   if (this->info_section_ != NULL)
3672     {
3673       if (this->info_uses_section_index_)
3674 	info = this->info_section_->out_shndx();
3675       else
3676 	info = this->info_section_->symtab_index();
3677     }
3678   else if (this->info_symndx_ != NULL)
3679     info = this->info_symndx_->symtab_index();
3680   else
3681     info = this->info_;
3682   oshdr->put_sh_info(info);
3683 
3684   oshdr->put_sh_addralign(this->addralign_);
3685   oshdr->put_sh_entsize(this->entsize_);
3686 }
3687 
3688 // Write out the data.  For input sections the data is written out by
3689 // Object::relocate, but we have to handle Output_section_data objects
3690 // here.
3691 
3692 void
do_write(Output_file * of)3693 Output_section::do_write(Output_file* of)
3694 {
3695   gold_assert(!this->requires_postprocessing());
3696 
3697   // If the target performs relaxation, we delay filler generation until now.
3698   gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
3699 
3700   off_t output_section_file_offset = this->offset();
3701   for (Fill_list::iterator p = this->fills_.begin();
3702        p != this->fills_.end();
3703        ++p)
3704     {
3705       std::string fill_data(parameters->target().code_fill(p->length()));
3706       of->write(output_section_file_offset + p->section_offset(),
3707 		fill_data.data(), fill_data.size());
3708     }
3709 
3710   off_t off = this->offset() + this->first_input_offset_;
3711   for (Input_section_list::iterator p = this->input_sections_.begin();
3712        p != this->input_sections_.end();
3713        ++p)
3714     {
3715       off_t aligned_off = align_address(off, p->addralign());
3716       if (this->generate_code_fills_at_write_ && (off != aligned_off))
3717 	{
3718 	  size_t fill_len = aligned_off - off;
3719 	  std::string fill_data(parameters->target().code_fill(fill_len));
3720 	  of->write(off, fill_data.data(), fill_data.size());
3721 	}
3722 
3723       p->write(of);
3724       off = aligned_off + p->data_size();
3725     }
3726 
3727   // For incremental links, fill in unused chunks in debug sections
3728   // with dummy compilation unit headers.
3729   if (this->free_space_fill_ != NULL)
3730     {
3731       for (Free_list::Const_iterator p = this->free_list_.begin();
3732 	   p != this->free_list_.end();
3733 	   ++p)
3734 	{
3735 	  off_t off = p->start_;
3736 	  size_t len = p->end_ - off;
3737 	  this->free_space_fill_->write(of, this->offset() + off, len);
3738 	}
3739       if (this->patch_space_ > 0)
3740 	{
3741 	  off_t off = this->current_data_size_for_child() - this->patch_space_;
3742 	  this->free_space_fill_->write(of, this->offset() + off,
3743 					this->patch_space_);
3744 	}
3745     }
3746 }
3747 
3748 // If a section requires postprocessing, create the buffer to use.
3749 
3750 void
create_postprocessing_buffer()3751 Output_section::create_postprocessing_buffer()
3752 {
3753   gold_assert(this->requires_postprocessing());
3754 
3755   if (this->postprocessing_buffer_ != NULL)
3756     return;
3757 
3758   if (!this->input_sections_.empty())
3759     {
3760       off_t off = this->first_input_offset_;
3761       for (Input_section_list::iterator p = this->input_sections_.begin();
3762 	   p != this->input_sections_.end();
3763 	   ++p)
3764 	{
3765 	  off = align_address(off, p->addralign());
3766 	  p->finalize_data_size();
3767 	  off += p->data_size();
3768 	}
3769       this->set_current_data_size_for_child(off);
3770     }
3771 
3772   off_t buffer_size = this->current_data_size_for_child();
3773   this->postprocessing_buffer_ = new unsigned char[buffer_size];
3774 }
3775 
3776 // Write all the data of an Output_section into the postprocessing
3777 // buffer.  This is used for sections which require postprocessing,
3778 // such as compression.  Input sections are handled by
3779 // Object::Relocate.
3780 
3781 void
write_to_postprocessing_buffer()3782 Output_section::write_to_postprocessing_buffer()
3783 {
3784   gold_assert(this->requires_postprocessing());
3785 
3786   // If the target performs relaxation, we delay filler generation until now.
3787   gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
3788 
3789   unsigned char* buffer = this->postprocessing_buffer();
3790   for (Fill_list::iterator p = this->fills_.begin();
3791        p != this->fills_.end();
3792        ++p)
3793     {
3794       std::string fill_data(parameters->target().code_fill(p->length()));
3795       memcpy(buffer + p->section_offset(), fill_data.data(),
3796 	     fill_data.size());
3797     }
3798 
3799   off_t off = this->first_input_offset_;
3800   for (Input_section_list::iterator p = this->input_sections_.begin();
3801        p != this->input_sections_.end();
3802        ++p)
3803     {
3804       off_t aligned_off = align_address(off, p->addralign());
3805       if (this->generate_code_fills_at_write_ && (off != aligned_off))
3806 	{
3807 	  size_t fill_len = aligned_off - off;
3808 	  std::string fill_data(parameters->target().code_fill(fill_len));
3809 	  memcpy(buffer + off, fill_data.data(), fill_data.size());
3810 	}
3811 
3812       p->write_to_buffer(buffer + aligned_off);
3813       off = aligned_off + p->data_size();
3814     }
3815 }
3816 
3817 // Get the input sections for linker script processing.  We leave
3818 // behind the Output_section_data entries.  Note that this may be
3819 // slightly incorrect for merge sections.  We will leave them behind,
3820 // but it is possible that the script says that they should follow
3821 // some other input sections, as in:
3822 //    .rodata { *(.rodata) *(.rodata.cst*) }
3823 // For that matter, we don't handle this correctly:
3824 //    .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) }
3825 // With luck this will never matter.
3826 
3827 uint64_t
get_input_sections(uint64_t address,const std::string & fill,std::list<Input_section> * input_sections)3828 Output_section::get_input_sections(
3829     uint64_t address,
3830     const std::string& fill,
3831     std::list<Input_section>* input_sections)
3832 {
3833   if (this->checkpoint_ != NULL
3834       && !this->checkpoint_->input_sections_saved())
3835     this->checkpoint_->save_input_sections();
3836 
3837   // Invalidate fast look-up maps.
3838   this->lookup_maps_->invalidate();
3839 
3840   uint64_t orig_address = address;
3841 
3842   address = align_address(address, this->addralign());
3843 
3844   Input_section_list remaining;
3845   for (Input_section_list::iterator p = this->input_sections_.begin();
3846        p != this->input_sections_.end();
3847        ++p)
3848     {
3849       if (p->is_input_section()
3850 	  || p->is_relaxed_input_section()
3851 	  || p->is_merge_section())
3852 	input_sections->push_back(*p);
3853       else
3854 	{
3855 	  uint64_t aligned_address = align_address(address, p->addralign());
3856 	  if (aligned_address != address && !fill.empty())
3857 	    {
3858 	      section_size_type length =
3859 		convert_to_section_size_type(aligned_address - address);
3860 	      std::string this_fill;
3861 	      this_fill.reserve(length);
3862 	      while (this_fill.length() + fill.length() <= length)
3863 		this_fill += fill;
3864 	      if (this_fill.length() < length)
3865 		this_fill.append(fill, 0, length - this_fill.length());
3866 
3867 	      Output_section_data* posd = new Output_data_const(this_fill, 0);
3868 	      remaining.push_back(Input_section(posd));
3869 	    }
3870 	  address = aligned_address;
3871 
3872 	  remaining.push_back(*p);
3873 
3874 	  p->finalize_data_size();
3875 	  address += p->data_size();
3876 	}
3877     }
3878 
3879   this->input_sections_.swap(remaining);
3880   this->first_input_offset_ = 0;
3881 
3882   uint64_t data_size = address - orig_address;
3883   this->set_current_data_size_for_child(data_size);
3884   return data_size;
3885 }
3886 
3887 // Add a script input section.  SIS is an Output_section::Input_section,
3888 // which can be either a plain input section or a special input section like
3889 // a relaxed input section.  For a special input section, its size must be
3890 // finalized.
3891 
3892 void
add_script_input_section(const Input_section & sis)3893 Output_section::add_script_input_section(const Input_section& sis)
3894 {
3895   uint64_t data_size = sis.data_size();
3896   uint64_t addralign = sis.addralign();
3897   if (addralign > this->addralign_)
3898     this->addralign_ = addralign;
3899 
3900   off_t offset_in_section = this->current_data_size_for_child();
3901   off_t aligned_offset_in_section = align_address(offset_in_section,
3902 						  addralign);
3903 
3904   this->set_current_data_size_for_child(aligned_offset_in_section
3905 					+ data_size);
3906 
3907   this->input_sections_.push_back(sis);
3908 
3909   // Update fast lookup maps if necessary.
3910   if (this->lookup_maps_->is_valid())
3911     {
3912       if (sis.is_relaxed_input_section())
3913 	{
3914 	  Output_relaxed_input_section* poris = sis.relaxed_input_section();
3915 	  this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
3916 							poris->shndx(), poris);
3917 	}
3918     }
3919 }
3920 
3921 // Save states for relaxation.
3922 
3923 void
save_states()3924 Output_section::save_states()
3925 {
3926   gold_assert(this->checkpoint_ == NULL);
3927   Checkpoint_output_section* checkpoint =
3928     new Checkpoint_output_section(this->addralign_, this->flags_,
3929 				  this->input_sections_,
3930 				  this->first_input_offset_,
3931 				  this->attached_input_sections_are_sorted_);
3932   this->checkpoint_ = checkpoint;
3933   gold_assert(this->fills_.empty());
3934 }
3935 
3936 void
discard_states()3937 Output_section::discard_states()
3938 {
3939   gold_assert(this->checkpoint_ != NULL);
3940   delete this->checkpoint_;
3941   this->checkpoint_ = NULL;
3942   gold_assert(this->fills_.empty());
3943 
3944   // Simply invalidate the fast lookup maps since we do not keep
3945   // track of them.
3946   this->lookup_maps_->invalidate();
3947 }
3948 
3949 void
restore_states()3950 Output_section::restore_states()
3951 {
3952   gold_assert(this->checkpoint_ != NULL);
3953   Checkpoint_output_section* checkpoint = this->checkpoint_;
3954 
3955   this->addralign_ = checkpoint->addralign();
3956   this->flags_ = checkpoint->flags();
3957   this->first_input_offset_ = checkpoint->first_input_offset();
3958 
3959   if (!checkpoint->input_sections_saved())
3960     {
3961       // If we have not copied the input sections, just resize it.
3962       size_t old_size = checkpoint->input_sections_size();
3963       gold_assert(this->input_sections_.size() >= old_size);
3964       this->input_sections_.resize(old_size);
3965     }
3966   else
3967     {
3968       // We need to copy the whole list.  This is not efficient for
3969       // extremely large output with hundreads of thousands of input
3970       // objects.  We may need to re-think how we should pass sections
3971       // to scripts.
3972       this->input_sections_ = *checkpoint->input_sections();
3973     }
3974 
3975   this->attached_input_sections_are_sorted_ =
3976     checkpoint->attached_input_sections_are_sorted();
3977 
3978   // Simply invalidate the fast lookup maps since we do not keep
3979   // track of them.
3980   this->lookup_maps_->invalidate();
3981 }
3982 
3983 // Update the section offsets of input sections in this.  This is required if
3984 // relaxation causes some input sections to change sizes.
3985 
3986 void
adjust_section_offsets()3987 Output_section::adjust_section_offsets()
3988 {
3989   if (!this->section_offsets_need_adjustment_)
3990     return;
3991 
3992   off_t off = 0;
3993   for (Input_section_list::iterator p = this->input_sections_.begin();
3994        p != this->input_sections_.end();
3995        ++p)
3996     {
3997       off = align_address(off, p->addralign());
3998       if (p->is_input_section())
3999 	p->relobj()->set_section_offset(p->shndx(), off);
4000       off += p->data_size();
4001     }
4002 
4003   this->section_offsets_need_adjustment_ = false;
4004 }
4005 
4006 // Print to the map file.
4007 
4008 void
do_print_to_mapfile(Mapfile * mapfile) const4009 Output_section::do_print_to_mapfile(Mapfile* mapfile) const
4010 {
4011   mapfile->print_output_section(this);
4012 
4013   for (Input_section_list::const_iterator p = this->input_sections_.begin();
4014        p != this->input_sections_.end();
4015        ++p)
4016     p->print_to_mapfile(mapfile);
4017 }
4018 
4019 // Print stats for merge sections to stderr.
4020 
4021 void
print_merge_stats()4022 Output_section::print_merge_stats()
4023 {
4024   Input_section_list::iterator p;
4025   for (p = this->input_sections_.begin();
4026        p != this->input_sections_.end();
4027        ++p)
4028     p->print_merge_stats(this->name_);
4029 }
4030 
4031 // Set a fixed layout for the section.  Used for incremental update links.
4032 
4033 void
set_fixed_layout(uint64_t sh_addr,off_t sh_offset,off_t sh_size,uint64_t sh_addralign)4034 Output_section::set_fixed_layout(uint64_t sh_addr, off_t sh_offset,
4035 				 off_t sh_size, uint64_t sh_addralign)
4036 {
4037   this->addralign_ = sh_addralign;
4038   this->set_current_data_size(sh_size);
4039   if ((this->flags_ & elfcpp::SHF_ALLOC) != 0)
4040     this->set_address(sh_addr);
4041   this->set_file_offset(sh_offset);
4042   this->finalize_data_size();
4043   this->free_list_.init(sh_size, false);
4044   this->has_fixed_layout_ = true;
4045 }
4046 
4047 // Reserve space within the fixed layout for the section.  Used for
4048 // incremental update links.
4049 
4050 void
reserve(uint64_t sh_offset,uint64_t sh_size)4051 Output_section::reserve(uint64_t sh_offset, uint64_t sh_size)
4052 {
4053   this->free_list_.remove(sh_offset, sh_offset + sh_size);
4054 }
4055 
4056 // Allocate space from the free list for the section.  Used for
4057 // incremental update links.
4058 
4059 off_t
allocate(off_t len,uint64_t addralign)4060 Output_section::allocate(off_t len, uint64_t addralign)
4061 {
4062   return this->free_list_.allocate(len, addralign, 0);
4063 }
4064 
4065 // Output segment methods.
4066 
Output_segment(elfcpp::Elf_Word type,elfcpp::Elf_Word flags)4067 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
4068   : vaddr_(0),
4069     paddr_(0),
4070     memsz_(0),
4071     align_(0),
4072     max_align_(0),
4073     min_p_align_(0),
4074     offset_(0),
4075     filesz_(0),
4076     type_(type),
4077     flags_(flags),
4078     is_max_align_known_(false),
4079     are_addresses_set_(false),
4080     is_large_data_segment_(false),
4081     is_unique_segment_(false)
4082 {
4083   // The ELF ABI specifies that a PT_TLS segment always has PF_R as
4084   // the flags.
4085   if (type == elfcpp::PT_TLS)
4086     this->flags_ = elfcpp::PF_R;
4087 }
4088 
4089 // Add an Output_section to a PT_LOAD Output_segment.
4090 
4091 void
add_output_section_to_load(Layout * layout,Output_section * os,elfcpp::Elf_Word seg_flags)4092 Output_segment::add_output_section_to_load(Layout* layout,
4093 					   Output_section* os,
4094 					   elfcpp::Elf_Word seg_flags)
4095 {
4096   gold_assert(this->type() == elfcpp::PT_LOAD);
4097   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
4098   gold_assert(!this->is_max_align_known_);
4099   gold_assert(os->is_large_data_section() == this->is_large_data_segment());
4100 
4101   this->update_flags_for_output_section(seg_flags);
4102 
4103   // We don't want to change the ordering if we have a linker script
4104   // with a SECTIONS clause.
4105   Output_section_order order = os->order();
4106   if (layout->script_options()->saw_sections_clause())
4107     order = static_cast<Output_section_order>(0);
4108   else
4109     gold_assert(order != ORDER_INVALID);
4110 
4111   this->output_lists_[order].push_back(os);
4112 }
4113 
4114 // Add an Output_section to a non-PT_LOAD Output_segment.
4115 
4116 void
add_output_section_to_nonload(Output_section * os,elfcpp::Elf_Word seg_flags)4117 Output_segment::add_output_section_to_nonload(Output_section* os,
4118 					      elfcpp::Elf_Word seg_flags)
4119 {
4120   gold_assert(this->type() != elfcpp::PT_LOAD);
4121   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
4122   gold_assert(!this->is_max_align_known_);
4123 
4124   this->update_flags_for_output_section(seg_flags);
4125 
4126   this->output_lists_[0].push_back(os);
4127 }
4128 
4129 // Remove an Output_section from this segment.  It is an error if it
4130 // is not present.
4131 
4132 void
remove_output_section(Output_section * os)4133 Output_segment::remove_output_section(Output_section* os)
4134 {
4135   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4136     {
4137       Output_data_list* pdl = &this->output_lists_[i];
4138       for (Output_data_list::iterator p = pdl->begin(); p != pdl->end(); ++p)
4139 	{
4140 	  if (*p == os)
4141 	    {
4142 	      pdl->erase(p);
4143 	      return;
4144 	    }
4145 	}
4146     }
4147   gold_unreachable();
4148 }
4149 
4150 // Add an Output_data (which need not be an Output_section) to the
4151 // start of a segment.
4152 
4153 void
add_initial_output_data(Output_data * od)4154 Output_segment::add_initial_output_data(Output_data* od)
4155 {
4156   gold_assert(!this->is_max_align_known_);
4157   Output_data_list::iterator p = this->output_lists_[0].begin();
4158   this->output_lists_[0].insert(p, od);
4159 }
4160 
4161 // Return true if this segment has any sections which hold actual
4162 // data, rather than being a BSS section.
4163 
4164 bool
has_any_data_sections() const4165 Output_segment::has_any_data_sections() const
4166 {
4167   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4168     {
4169       const Output_data_list* pdl = &this->output_lists_[i];
4170       for (Output_data_list::const_iterator p = pdl->begin();
4171 	   p != pdl->end();
4172 	   ++p)
4173 	{
4174 	  if (!(*p)->is_section())
4175 	    return true;
4176 	  if ((*p)->output_section()->type() != elfcpp::SHT_NOBITS)
4177 	    return true;
4178 	}
4179     }
4180   return false;
4181 }
4182 
4183 // Return whether the first data section (not counting TLS sections)
4184 // is a relro section.
4185 
4186 bool
is_first_section_relro() const4187 Output_segment::is_first_section_relro() const
4188 {
4189   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4190     {
4191       if (i == static_cast<int>(ORDER_TLS_BSS))
4192 	continue;
4193       const Output_data_list* pdl = &this->output_lists_[i];
4194       if (!pdl->empty())
4195 	{
4196 	  Output_data* p = pdl->front();
4197 	  return p->is_section() && p->output_section()->is_relro();
4198 	}
4199     }
4200   return false;
4201 }
4202 
4203 // Return the maximum alignment of the Output_data in Output_segment.
4204 
4205 uint64_t
maximum_alignment()4206 Output_segment::maximum_alignment()
4207 {
4208   if (!this->is_max_align_known_)
4209     {
4210       for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4211 	{
4212 	  const Output_data_list* pdl = &this->output_lists_[i];
4213 	  uint64_t addralign = Output_segment::maximum_alignment_list(pdl);
4214 	  if (addralign > this->max_align_)
4215 	    this->max_align_ = addralign;
4216 	}
4217       this->is_max_align_known_ = true;
4218     }
4219 
4220   return this->max_align_;
4221 }
4222 
4223 // Return the maximum alignment of a list of Output_data.
4224 
4225 uint64_t
maximum_alignment_list(const Output_data_list * pdl)4226 Output_segment::maximum_alignment_list(const Output_data_list* pdl)
4227 {
4228   uint64_t ret = 0;
4229   for (Output_data_list::const_iterator p = pdl->begin();
4230        p != pdl->end();
4231        ++p)
4232     {
4233       uint64_t addralign = (*p)->addralign();
4234       if (addralign > ret)
4235 	ret = addralign;
4236     }
4237   return ret;
4238 }
4239 
4240 // Return whether this segment has any dynamic relocs.
4241 
4242 bool
has_dynamic_reloc() const4243 Output_segment::has_dynamic_reloc() const
4244 {
4245   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4246     if (this->has_dynamic_reloc_list(&this->output_lists_[i]))
4247       return true;
4248   return false;
4249 }
4250 
4251 // Return whether this Output_data_list has any dynamic relocs.
4252 
4253 bool
has_dynamic_reloc_list(const Output_data_list * pdl) const4254 Output_segment::has_dynamic_reloc_list(const Output_data_list* pdl) const
4255 {
4256   for (Output_data_list::const_iterator p = pdl->begin();
4257        p != pdl->end();
4258        ++p)
4259     if ((*p)->has_dynamic_reloc())
4260       return true;
4261   return false;
4262 }
4263 
4264 // Set the section addresses for an Output_segment.  If RESET is true,
4265 // reset the addresses first.  ADDR is the address and *POFF is the
4266 // file offset.  Set the section indexes starting with *PSHNDX.
4267 // INCREASE_RELRO is the size of the portion of the first non-relro
4268 // section that should be included in the PT_GNU_RELRO segment.
4269 // If this segment has relro sections, and has been aligned for
4270 // that purpose, set *HAS_RELRO to TRUE.  Return the address of
4271 // the immediately following segment.  Update *HAS_RELRO, *POFF,
4272 // and *PSHNDX.
4273 
4274 uint64_t
set_section_addresses(const Target * target,Layout * layout,bool reset,uint64_t addr,unsigned int * increase_relro,bool * has_relro,off_t * poff,unsigned int * pshndx)4275 Output_segment::set_section_addresses(const Target* target,
4276 				      Layout* layout, bool reset,
4277 				      uint64_t addr,
4278 				      unsigned int* increase_relro,
4279 				      bool* has_relro,
4280 				      off_t* poff,
4281 				      unsigned int* pshndx)
4282 {
4283   gold_assert(this->type_ == elfcpp::PT_LOAD);
4284 
4285   uint64_t last_relro_pad = 0;
4286   off_t orig_off = *poff;
4287 
4288   bool in_tls = false;
4289 
4290   // If we have relro sections, we need to pad forward now so that the
4291   // relro sections plus INCREASE_RELRO end on an abi page boundary.
4292   if (parameters->options().relro()
4293       && this->is_first_section_relro()
4294       && (!this->are_addresses_set_ || reset))
4295     {
4296       uint64_t relro_size = 0;
4297       off_t off = *poff;
4298       uint64_t max_align = 0;
4299       for (int i = 0; i <= static_cast<int>(ORDER_RELRO_LAST); ++i)
4300 	{
4301 	  Output_data_list* pdl = &this->output_lists_[i];
4302 	  Output_data_list::iterator p;
4303 	  for (p = pdl->begin(); p != pdl->end(); ++p)
4304 	    {
4305 	      if (!(*p)->is_section())
4306 		break;
4307 	      uint64_t align = (*p)->addralign();
4308 	      if (align > max_align)
4309 		max_align = align;
4310 	      if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
4311 		in_tls = true;
4312 	      else if (in_tls)
4313 		{
4314 		  // Align the first non-TLS section to the alignment
4315 		  // of the TLS segment.
4316 		  align = max_align;
4317 		  in_tls = false;
4318 		}
4319 	      // Ignore the size of the .tbss section.
4320 	      if ((*p)->is_section_flag_set(elfcpp::SHF_TLS)
4321 		  && (*p)->is_section_type(elfcpp::SHT_NOBITS))
4322 		continue;
4323 	      relro_size = align_address(relro_size, align);
4324 	      if ((*p)->is_address_valid())
4325 		relro_size += (*p)->data_size();
4326 	      else
4327 		{
4328 		  // FIXME: This could be faster.
4329 		  (*p)->set_address_and_file_offset(relro_size,
4330 						    relro_size);
4331 		  relro_size += (*p)->data_size();
4332 		  (*p)->reset_address_and_file_offset();
4333 		}
4334 	    }
4335 	  if (p != pdl->end())
4336 	    break;
4337 	}
4338       relro_size += *increase_relro;
4339       // Pad the total relro size to a multiple of the maximum
4340       // section alignment seen.
4341       uint64_t aligned_size = align_address(relro_size, max_align);
4342       // Note the amount of padding added after the last relro section.
4343       last_relro_pad = aligned_size - relro_size;
4344       *has_relro = true;
4345 
4346       uint64_t page_align = parameters->target().abi_pagesize();
4347 
4348       // Align to offset N such that (N + RELRO_SIZE) % PAGE_ALIGN == 0.
4349       uint64_t desired_align = page_align - (aligned_size % page_align);
4350       if (desired_align < off % page_align)
4351 	off += page_align;
4352       off += desired_align - off % page_align;
4353       addr += off - orig_off;
4354       orig_off = off;
4355       *poff = off;
4356     }
4357 
4358   if (!reset && this->are_addresses_set_)
4359     {
4360       gold_assert(this->paddr_ == addr);
4361       addr = this->vaddr_;
4362     }
4363   else
4364     {
4365       this->vaddr_ = addr;
4366       this->paddr_ = addr;
4367       this->are_addresses_set_ = true;
4368     }
4369 
4370   in_tls = false;
4371 
4372   this->offset_ = orig_off;
4373 
4374   off_t off = 0;
4375   off_t foff = *poff;
4376   uint64_t ret = 0;
4377   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4378     {
4379       if (i == static_cast<int>(ORDER_RELRO_LAST))
4380 	{
4381 	  *poff += last_relro_pad;
4382 	  foff += last_relro_pad;
4383 	  addr += last_relro_pad;
4384 	  if (this->output_lists_[i].empty())
4385 	    {
4386 	      // If there is nothing in the ORDER_RELRO_LAST list,
4387 	      // the padding will occur at the end of the relro
4388 	      // segment, and we need to add it to *INCREASE_RELRO.
4389 	      *increase_relro += last_relro_pad;
4390 	    }
4391 	}
4392       addr = this->set_section_list_addresses(layout, reset,
4393 					      &this->output_lists_[i],
4394 					      addr, poff, &foff, pshndx,
4395 					      &in_tls);
4396 
4397       // FOFF tracks the last offset used for the file image,
4398       // and *POFF tracks the last offset used for the memory image.
4399       // When not using a linker script, bss sections should all
4400       // be processed in the ORDER_SMALL_BSS and later buckets.
4401       gold_assert(*poff == foff
4402 		  || i == static_cast<int>(ORDER_TLS_BSS)
4403 		  || i >= static_cast<int>(ORDER_SMALL_BSS)
4404 		  || layout->script_options()->saw_sections_clause());
4405 
4406       this->filesz_ = foff - orig_off;
4407       off = foff;
4408 
4409       ret = addr;
4410     }
4411 
4412   // If the last section was a TLS section, align upward to the
4413   // alignment of the TLS segment, so that the overall size of the TLS
4414   // segment is aligned.
4415   if (in_tls)
4416     {
4417       uint64_t segment_align = layout->tls_segment()->maximum_alignment();
4418       *poff = align_address(*poff, segment_align);
4419     }
4420 
4421   this->memsz_ = *poff - orig_off;
4422 
4423   // Ignore the file offset adjustments made by the BSS Output_data
4424   // objects.
4425   *poff = off;
4426 
4427   // If code segments must contain only code, and this code segment is
4428   // page-aligned in the file, then fill it out to a whole page with
4429   // code fill (the tail of the segment will not be within any section).
4430   // Thus the entire code segment can be mapped from the file as whole
4431   // pages and that mapping will contain only valid instructions.
4432   if (target->isolate_execinstr() && (this->flags() & elfcpp::PF_X) != 0)
4433     {
4434       uint64_t abi_pagesize = target->abi_pagesize();
4435       if (orig_off % abi_pagesize == 0 && off % abi_pagesize != 0)
4436 	{
4437 	  size_t fill_size = abi_pagesize - (off % abi_pagesize);
4438 
4439 	  std::string fill_data;
4440 	  if (target->has_code_fill())
4441 	    fill_data = target->code_fill(fill_size);
4442 	  else
4443 	    fill_data.resize(fill_size); // Zero fill.
4444 
4445 	  Output_data_const* fill = new Output_data_const(fill_data, 0);
4446 	  fill->set_address(this->vaddr_ + this->memsz_);
4447 	  fill->set_file_offset(off);
4448 	  layout->add_relax_output(fill);
4449 
4450 	  off += fill_size;
4451 	  gold_assert(off % abi_pagesize == 0);
4452 	  ret += fill_size;
4453 	  gold_assert(ret % abi_pagesize == 0);
4454 
4455 	  gold_assert((uint64_t) this->filesz_ == this->memsz_);
4456 	  this->memsz_ = this->filesz_ += fill_size;
4457 
4458 	  *poff = off;
4459 	}
4460     }
4461 
4462   return ret;
4463 }
4464 
4465 // Set the addresses and file offsets in a list of Output_data
4466 // structures.
4467 
4468 uint64_t
set_section_list_addresses(Layout * layout,bool reset,Output_data_list * pdl,uint64_t addr,off_t * poff,off_t * pfoff,unsigned int * pshndx,bool * in_tls)4469 Output_segment::set_section_list_addresses(Layout* layout, bool reset,
4470 					   Output_data_list* pdl,
4471 					   uint64_t addr, off_t* poff,
4472 					   off_t* pfoff,
4473 					   unsigned int* pshndx,
4474 					   bool* in_tls)
4475 {
4476   off_t startoff = *poff;
4477   // For incremental updates, we may allocate non-fixed sections from
4478   // free space in the file.  This keeps track of the high-water mark.
4479   off_t maxoff = startoff;
4480 
4481   off_t off = startoff;
4482   off_t foff = *pfoff;
4483   for (Output_data_list::iterator p = pdl->begin();
4484        p != pdl->end();
4485        ++p)
4486     {
4487       bool is_bss = (*p)->is_section_type(elfcpp::SHT_NOBITS);
4488       bool is_tls = (*p)->is_section_flag_set(elfcpp::SHF_TLS);
4489 
4490       if (reset)
4491 	(*p)->reset_address_and_file_offset();
4492 
4493       // When doing an incremental update or when using a linker script,
4494       // the section will most likely already have an address.
4495       if (!(*p)->is_address_valid())
4496 	{
4497 	  uint64_t align = (*p)->addralign();
4498 
4499 	  if (is_tls)
4500 	    {
4501 	      // Give the first TLS section the alignment of the
4502 	      // entire TLS segment.  Otherwise the TLS segment as a
4503 	      // whole may be misaligned.
4504 	      if (!*in_tls)
4505 		{
4506 		  Output_segment* tls_segment = layout->tls_segment();
4507 		  gold_assert(tls_segment != NULL);
4508 		  uint64_t segment_align = tls_segment->maximum_alignment();
4509 		  gold_assert(segment_align >= align);
4510 		  align = segment_align;
4511 
4512 		  *in_tls = true;
4513 		}
4514 	    }
4515 	  else
4516 	    {
4517 	      // If this is the first section after the TLS segment,
4518 	      // align it to at least the alignment of the TLS
4519 	      // segment, so that the size of the overall TLS segment
4520 	      // is aligned.
4521 	      if (*in_tls)
4522 		{
4523 		  uint64_t segment_align =
4524 		      layout->tls_segment()->maximum_alignment();
4525 		  if (segment_align > align)
4526 		    align = segment_align;
4527 
4528 		  *in_tls = false;
4529 		}
4530 	    }
4531 
4532 	  if (!parameters->incremental_update())
4533 	    {
4534 	      gold_assert(off == foff || is_bss);
4535 	      off = align_address(off, align);
4536 	      if (is_tls || !is_bss)
4537 		foff = off;
4538 	      (*p)->set_address_and_file_offset(addr + (off - startoff), foff);
4539 	    }
4540 	  else
4541 	    {
4542 	      // Incremental update: allocate file space from free list.
4543 	      (*p)->pre_finalize_data_size();
4544 	      off_t current_size = (*p)->current_data_size();
4545 	      off = layout->allocate(current_size, align, startoff);
4546 	      foff = off;
4547 	      if (off == -1)
4548 		{
4549 		  gold_assert((*p)->output_section() != NULL);
4550 		  gold_fallback(_("out of patch space for section %s; "
4551 				  "relink with --incremental-full"),
4552 				(*p)->output_section()->name());
4553 		}
4554 	      (*p)->set_address_and_file_offset(addr + (off - startoff), foff);
4555 	      if ((*p)->data_size() > current_size)
4556 		{
4557 		  gold_assert((*p)->output_section() != NULL);
4558 		  gold_fallback(_("%s: section changed size; "
4559 				  "relink with --incremental-full"),
4560 				(*p)->output_section()->name());
4561 		}
4562 	    }
4563 	}
4564       else if (parameters->incremental_update())
4565 	{
4566 	  // For incremental updates, use the fixed offset for the
4567 	  // high-water mark computation.
4568 	  off = (*p)->offset();
4569 	  foff = off;
4570 	}
4571       else
4572 	{
4573 	  // The script may have inserted a skip forward, but it
4574 	  // better not have moved backward.
4575 	  if ((*p)->address() >= addr + (off - startoff))
4576 	    {
4577 	      if (!is_bss && off > foff)
4578 	        gold_warning(_("script places BSS section in the middle "
4579 			       "of a LOAD segment; space will be allocated "
4580 			       "in the file"));
4581 	      off += (*p)->address() - (addr + (off - startoff));
4582 	      if (is_tls || !is_bss)
4583 		foff = off;
4584 	    }
4585 	  else
4586 	    {
4587 	      if (!layout->script_options()->saw_sections_clause())
4588 		gold_unreachable();
4589 	      else
4590 		{
4591 		  Output_section* os = (*p)->output_section();
4592 
4593 		  // Cast to unsigned long long to avoid format warnings.
4594 		  unsigned long long previous_dot =
4595 		    static_cast<unsigned long long>(addr + (off - startoff));
4596 		  unsigned long long dot =
4597 		    static_cast<unsigned long long>((*p)->address());
4598 
4599 		  if (os == NULL)
4600 		    gold_error(_("dot moves backward in linker script "
4601 				 "from 0x%llx to 0x%llx"), previous_dot, dot);
4602 		  else
4603 		    gold_error(_("address of section '%s' moves backward "
4604 				 "from 0x%llx to 0x%llx"),
4605 			       os->name(), previous_dot, dot);
4606 		}
4607 	    }
4608 	  (*p)->set_file_offset(foff);
4609 	  (*p)->finalize_data_size();
4610 	}
4611 
4612       if (parameters->incremental_update())
4613 	gold_debug(DEBUG_INCREMENTAL,
4614 		   "set_section_list_addresses: %08lx %08lx %s",
4615 		   static_cast<long>(off),
4616 		   static_cast<long>((*p)->data_size()),
4617 		   ((*p)->output_section() != NULL
4618 		    ? (*p)->output_section()->name() : "(special)"));
4619 
4620       // We want to ignore the size of a SHF_TLS SHT_NOBITS
4621       // section.  Such a section does not affect the size of a
4622       // PT_LOAD segment.
4623       if (!is_tls || !is_bss)
4624 	off += (*p)->data_size();
4625 
4626       // We don't allocate space in the file for SHT_NOBITS sections,
4627       // unless a script has force-placed one in the middle of a segment.
4628       if (!is_bss)
4629 	foff = off;
4630 
4631       if (off > maxoff)
4632 	maxoff = off;
4633 
4634       if ((*p)->is_section())
4635 	{
4636 	  (*p)->set_out_shndx(*pshndx);
4637 	  ++*pshndx;
4638 	}
4639     }
4640 
4641   *poff = maxoff;
4642   *pfoff = foff;
4643   return addr + (maxoff - startoff);
4644 }
4645 
4646 // For a non-PT_LOAD segment, set the offset from the sections, if
4647 // any.  Add INCREASE to the file size and the memory size.
4648 
4649 void
set_offset(unsigned int increase)4650 Output_segment::set_offset(unsigned int increase)
4651 {
4652   gold_assert(this->type_ != elfcpp::PT_LOAD);
4653 
4654   gold_assert(!this->are_addresses_set_);
4655 
4656   // A non-load section only uses output_lists_[0].
4657 
4658   Output_data_list* pdl = &this->output_lists_[0];
4659 
4660   if (pdl->empty())
4661     {
4662       gold_assert(increase == 0);
4663       this->vaddr_ = 0;
4664       this->paddr_ = 0;
4665       this->are_addresses_set_ = true;
4666       this->memsz_ = 0;
4667       this->min_p_align_ = 0;
4668       this->offset_ = 0;
4669       this->filesz_ = 0;
4670       return;
4671     }
4672 
4673   // Find the first and last section by address.
4674   const Output_data* first = NULL;
4675   const Output_data* last_data = NULL;
4676   const Output_data* last_bss = NULL;
4677   for (Output_data_list::const_iterator p = pdl->begin();
4678        p != pdl->end();
4679        ++p)
4680     {
4681       if (first == NULL
4682 	  || (*p)->address() < first->address()
4683 	  || ((*p)->address() == first->address()
4684 	      && (*p)->data_size() < first->data_size()))
4685 	first = *p;
4686       const Output_data** plast;
4687       if ((*p)->is_section()
4688 	  && (*p)->output_section()->type() == elfcpp::SHT_NOBITS)
4689 	plast = &last_bss;
4690       else
4691 	plast = &last_data;
4692       if (*plast == NULL
4693 	  || (*p)->address() > (*plast)->address()
4694 	  || ((*p)->address() == (*plast)->address()
4695 	      && (*p)->data_size() > (*plast)->data_size()))
4696 	*plast = *p;
4697     }
4698 
4699   this->vaddr_ = first->address();
4700   this->paddr_ = (first->has_load_address()
4701 		  ? first->load_address()
4702 		  : this->vaddr_);
4703   this->are_addresses_set_ = true;
4704   this->offset_ = first->offset();
4705 
4706   if (last_data == NULL)
4707     this->filesz_ = 0;
4708   else
4709     this->filesz_ = (last_data->address()
4710 		     + last_data->data_size()
4711 		     - this->vaddr_);
4712 
4713   const Output_data* last = last_bss != NULL ? last_bss : last_data;
4714   this->memsz_ = (last->address()
4715 		  + last->data_size()
4716 		  - this->vaddr_);
4717 
4718   this->filesz_ += increase;
4719   this->memsz_ += increase;
4720 
4721   // If this is a RELRO segment, verify that the segment ends at a
4722   // page boundary.
4723   if (this->type_ == elfcpp::PT_GNU_RELRO)
4724     {
4725       uint64_t page_align = parameters->target().abi_pagesize();
4726       uint64_t segment_end = this->vaddr_ + this->memsz_;
4727       if (parameters->incremental_update())
4728 	{
4729 	  // The INCREASE_RELRO calculation is bypassed for an incremental
4730 	  // update, so we need to adjust the segment size manually here.
4731 	  segment_end = align_address(segment_end, page_align);
4732 	  this->memsz_ = segment_end - this->vaddr_;
4733 	}
4734       else
4735 	gold_assert(segment_end == align_address(segment_end, page_align));
4736     }
4737 
4738   // If this is a TLS segment, align the memory size.  The code in
4739   // set_section_list ensures that the section after the TLS segment
4740   // is aligned to give us room.
4741   if (this->type_ == elfcpp::PT_TLS)
4742     {
4743       uint64_t segment_align = this->maximum_alignment();
4744       gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align));
4745       this->memsz_ = align_address(this->memsz_, segment_align);
4746     }
4747 }
4748 
4749 // Set the TLS offsets of the sections in the PT_TLS segment.
4750 
4751 void
set_tls_offsets()4752 Output_segment::set_tls_offsets()
4753 {
4754   gold_assert(this->type_ == elfcpp::PT_TLS);
4755 
4756   for (Output_data_list::iterator p = this->output_lists_[0].begin();
4757        p != this->output_lists_[0].end();
4758        ++p)
4759     (*p)->set_tls_offset(this->vaddr_);
4760 }
4761 
4762 // Return the first section.
4763 
4764 Output_section*
first_section() const4765 Output_segment::first_section() const
4766 {
4767   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4768     {
4769       const Output_data_list* pdl = &this->output_lists_[i];
4770       for (Output_data_list::const_iterator p = pdl->begin();
4771 	   p != pdl->end();
4772 	   ++p)
4773 	{
4774 	  if ((*p)->is_section())
4775 	    return (*p)->output_section();
4776 	}
4777     }
4778   return NULL;
4779 }
4780 
4781 // Return the number of Output_sections in an Output_segment.
4782 
4783 unsigned int
output_section_count() const4784 Output_segment::output_section_count() const
4785 {
4786   unsigned int ret = 0;
4787   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4788     ret += this->output_section_count_list(&this->output_lists_[i]);
4789   return ret;
4790 }
4791 
4792 // Return the number of Output_sections in an Output_data_list.
4793 
4794 unsigned int
output_section_count_list(const Output_data_list * pdl) const4795 Output_segment::output_section_count_list(const Output_data_list* pdl) const
4796 {
4797   unsigned int count = 0;
4798   for (Output_data_list::const_iterator p = pdl->begin();
4799        p != pdl->end();
4800        ++p)
4801     {
4802       if ((*p)->is_section())
4803 	++count;
4804     }
4805   return count;
4806 }
4807 
4808 // Return the section attached to the list segment with the lowest
4809 // load address.  This is used when handling a PHDRS clause in a
4810 // linker script.
4811 
4812 Output_section*
section_with_lowest_load_address() const4813 Output_segment::section_with_lowest_load_address() const
4814 {
4815   Output_section* found = NULL;
4816   uint64_t found_lma = 0;
4817   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4818     this->lowest_load_address_in_list(&this->output_lists_[i], &found,
4819 				      &found_lma);
4820   return found;
4821 }
4822 
4823 // Look through a list for a section with a lower load address.
4824 
4825 void
lowest_load_address_in_list(const Output_data_list * pdl,Output_section ** found,uint64_t * found_lma) const4826 Output_segment::lowest_load_address_in_list(const Output_data_list* pdl,
4827 					    Output_section** found,
4828 					    uint64_t* found_lma) const
4829 {
4830   for (Output_data_list::const_iterator p = pdl->begin();
4831        p != pdl->end();
4832        ++p)
4833     {
4834       if (!(*p)->is_section())
4835 	continue;
4836       Output_section* os = static_cast<Output_section*>(*p);
4837       uint64_t lma = (os->has_load_address()
4838 		      ? os->load_address()
4839 		      : os->address());
4840       if (*found == NULL || lma < *found_lma)
4841 	{
4842 	  *found = os;
4843 	  *found_lma = lma;
4844 	}
4845     }
4846 }
4847 
4848 // Write the segment data into *OPHDR.
4849 
4850 template<int size, bool big_endian>
4851 void
write_header(elfcpp::Phdr_write<size,big_endian> * ophdr)4852 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
4853 {
4854   ophdr->put_p_type(this->type_);
4855   ophdr->put_p_offset(this->offset_);
4856   ophdr->put_p_vaddr(this->vaddr_);
4857   ophdr->put_p_paddr(this->paddr_);
4858   ophdr->put_p_filesz(this->filesz_);
4859   ophdr->put_p_memsz(this->memsz_);
4860   ophdr->put_p_flags(this->flags_);
4861   ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment()));
4862 }
4863 
4864 // Write the section headers into V.
4865 
4866 template<int size, bool big_endian>
4867 unsigned char*
write_section_headers(const Layout * layout,const Stringpool * secnamepool,unsigned char * v,unsigned int * pshndx) const4868 Output_segment::write_section_headers(const Layout* layout,
4869 				      const Stringpool* secnamepool,
4870 				      unsigned char* v,
4871 				      unsigned int* pshndx) const
4872 {
4873   // Every section that is attached to a segment must be attached to a
4874   // PT_LOAD segment, so we only write out section headers for PT_LOAD
4875   // segments.
4876   if (this->type_ != elfcpp::PT_LOAD)
4877     return v;
4878 
4879   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4880     {
4881       const Output_data_list* pdl = &this->output_lists_[i];
4882       v = this->write_section_headers_list<size, big_endian>(layout,
4883 							     secnamepool,
4884 							     pdl,
4885 							     v, pshndx);
4886     }
4887 
4888   return v;
4889 }
4890 
4891 template<int size, bool big_endian>
4892 unsigned char*
write_section_headers_list(const Layout * layout,const Stringpool * secnamepool,const Output_data_list * pdl,unsigned char * v,unsigned int * pshndx) const4893 Output_segment::write_section_headers_list(const Layout* layout,
4894 					   const Stringpool* secnamepool,
4895 					   const Output_data_list* pdl,
4896 					   unsigned char* v,
4897 					   unsigned int* pshndx) const
4898 {
4899   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
4900   for (Output_data_list::const_iterator p = pdl->begin();
4901        p != pdl->end();
4902        ++p)
4903     {
4904       if ((*p)->is_section())
4905 	{
4906 	  const Output_section* ps = static_cast<const Output_section*>(*p);
4907 	  gold_assert(*pshndx == ps->out_shndx());
4908 	  elfcpp::Shdr_write<size, big_endian> oshdr(v);
4909 	  ps->write_header(layout, secnamepool, &oshdr);
4910 	  v += shdr_size;
4911 	  ++*pshndx;
4912 	}
4913     }
4914   return v;
4915 }
4916 
4917 // Print the output sections to the map file.
4918 
4919 void
print_sections_to_mapfile(Mapfile * mapfile) const4920 Output_segment::print_sections_to_mapfile(Mapfile* mapfile) const
4921 {
4922   if (this->type() != elfcpp::PT_LOAD)
4923     return;
4924   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4925     this->print_section_list_to_mapfile(mapfile, &this->output_lists_[i]);
4926 }
4927 
4928 // Print an output section list to the map file.
4929 
4930 void
print_section_list_to_mapfile(Mapfile * mapfile,const Output_data_list * pdl) const4931 Output_segment::print_section_list_to_mapfile(Mapfile* mapfile,
4932 					      const Output_data_list* pdl) const
4933 {
4934   for (Output_data_list::const_iterator p = pdl->begin();
4935        p != pdl->end();
4936        ++p)
4937     (*p)->print_to_mapfile(mapfile);
4938 }
4939 
4940 // Output_file methods.
4941 
Output_file(const char * name)4942 Output_file::Output_file(const char* name)
4943   : name_(name),
4944     o_(-1),
4945     file_size_(0),
4946     base_(NULL),
4947     map_is_anonymous_(false),
4948     map_is_allocated_(false),
4949     is_temporary_(false)
4950 {
4951 }
4952 
4953 // Try to open an existing file.  Returns false if the file doesn't
4954 // exist, has a size of 0 or can't be mmapped.  If BASE_NAME is not
4955 // NULL, open that file as the base for incremental linking, and
4956 // copy its contents to the new output file.  This routine can
4957 // be called for incremental updates, in which case WRITABLE should
4958 // be true, or by the incremental-dump utility, in which case
4959 // WRITABLE should be false.
4960 
4961 bool
open_base_file(const char * base_name,bool writable)4962 Output_file::open_base_file(const char* base_name, bool writable)
4963 {
4964   // The name "-" means "stdout".
4965   if (strcmp(this->name_, "-") == 0)
4966     return false;
4967 
4968   bool use_base_file = base_name != NULL;
4969   if (!use_base_file)
4970     base_name = this->name_;
4971   else if (strcmp(base_name, this->name_) == 0)
4972     gold_fatal(_("%s: incremental base and output file name are the same"),
4973 	       base_name);
4974 
4975   // Don't bother opening files with a size of zero.
4976   struct stat s;
4977   if (::stat(base_name, &s) != 0)
4978     {
4979       gold_info(_("%s: stat: %s"), base_name, strerror(errno));
4980       return false;
4981     }
4982   if (s.st_size == 0)
4983     {
4984       gold_info(_("%s: incremental base file is empty"), base_name);
4985       return false;
4986     }
4987 
4988   // If we're using a base file, we want to open it read-only.
4989   if (use_base_file)
4990     writable = false;
4991 
4992   int oflags = writable ? O_RDWR : O_RDONLY;
4993   int o = open_descriptor(-1, base_name, oflags, 0);
4994   if (o < 0)
4995     {
4996       gold_info(_("%s: open: %s"), base_name, strerror(errno));
4997       return false;
4998     }
4999 
5000   // If the base file and the output file are different, open a
5001   // new output file and read the contents from the base file into
5002   // the newly-mapped region.
5003   if (use_base_file)
5004     {
5005       this->open(s.st_size);
5006       ssize_t bytes_to_read = s.st_size;
5007       unsigned char* p = this->base_;
5008       while (bytes_to_read > 0)
5009 	{
5010 	  ssize_t len = ::read(o, p, bytes_to_read);
5011 	  if (len < 0)
5012 	    {
5013 	      gold_info(_("%s: read failed: %s"), base_name, strerror(errno));
5014 	      return false;
5015 	    }
5016 	  if (len == 0)
5017 	    {
5018 	      gold_info(_("%s: file too short: read only %lld of %lld bytes"),
5019 			base_name,
5020 			static_cast<long long>(s.st_size - bytes_to_read),
5021 			static_cast<long long>(s.st_size));
5022 	      return false;
5023 	    }
5024 	  p += len;
5025 	  bytes_to_read -= len;
5026 	}
5027       ::close(o);
5028       return true;
5029     }
5030 
5031   this->o_ = o;
5032   this->file_size_ = s.st_size;
5033 
5034   if (!this->map_no_anonymous(writable))
5035     {
5036       release_descriptor(o, true);
5037       this->o_ = -1;
5038       this->file_size_ = 0;
5039       return false;
5040     }
5041 
5042   return true;
5043 }
5044 
5045 // Open the output file.
5046 
5047 void
open(off_t file_size)5048 Output_file::open(off_t file_size)
5049 {
5050   this->file_size_ = file_size;
5051 
5052   // Unlink the file first; otherwise the open() may fail if the file
5053   // is busy (e.g. it's an executable that's currently being executed).
5054   //
5055   // However, the linker may be part of a system where a zero-length
5056   // file is created for it to write to, with tight permissions (gcc
5057   // 2.95 did something like this).  Unlinking the file would work
5058   // around those permission controls, so we only unlink if the file
5059   // has a non-zero size.  We also unlink only regular files to avoid
5060   // trouble with directories/etc.
5061   //
5062   // If we fail, continue; this command is merely a best-effort attempt
5063   // to improve the odds for open().
5064 
5065   // We let the name "-" mean "stdout"
5066   if (!this->is_temporary_)
5067     {
5068       if (strcmp(this->name_, "-") == 0)
5069 	this->o_ = STDOUT_FILENO;
5070       else
5071 	{
5072 	  struct stat s;
5073 	  if (::stat(this->name_, &s) == 0
5074 	      && (S_ISREG (s.st_mode) || S_ISLNK (s.st_mode)))
5075 	    {
5076 	      if (s.st_size != 0)
5077 		::unlink(this->name_);
5078 	      else if (!parameters->options().relocatable())
5079 		{
5080 		  // If we don't unlink the existing file, add execute
5081 		  // permission where read permissions already exist
5082 		  // and where the umask permits.
5083 		  int mask = ::umask(0);
5084 		  ::umask(mask);
5085 		  s.st_mode |= (s.st_mode & 0444) >> 2;
5086 		  ::chmod(this->name_, s.st_mode & ~mask);
5087 		}
5088 	    }
5089 
5090 	  int mode = parameters->options().relocatable() ? 0666 : 0777;
5091 	  int o = open_descriptor(-1, this->name_, O_RDWR | O_CREAT | O_TRUNC,
5092 				  mode);
5093 	  if (o < 0)
5094 	    gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
5095 	  this->o_ = o;
5096 	}
5097     }
5098 
5099   this->map();
5100 }
5101 
5102 // Resize the output file.
5103 
5104 void
resize(off_t file_size)5105 Output_file::resize(off_t file_size)
5106 {
5107   // If the mmap is mapping an anonymous memory buffer, this is easy:
5108   // just mremap to the new size.  If it's mapping to a file, we want
5109   // to unmap to flush to the file, then remap after growing the file.
5110   if (this->map_is_anonymous_)
5111     {
5112       void* base;
5113       if (!this->map_is_allocated_)
5114 	{
5115 	  base = ::mremap(this->base_, this->file_size_, file_size,
5116 			  MREMAP_MAYMOVE);
5117 	  if (base == MAP_FAILED)
5118 	    gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno));
5119 	}
5120       else
5121 	{
5122 	  base = realloc(this->base_, file_size);
5123 	  if (base == NULL)
5124 	    gold_nomem();
5125 	  if (file_size > this->file_size_)
5126 	    memset(static_cast<char*>(base) + this->file_size_, 0,
5127 		   file_size - this->file_size_);
5128 	}
5129       this->base_ = static_cast<unsigned char*>(base);
5130       this->file_size_ = file_size;
5131     }
5132   else
5133     {
5134       this->unmap();
5135       this->file_size_ = file_size;
5136       if (!this->map_no_anonymous(true))
5137 	gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
5138     }
5139 }
5140 
5141 // Map an anonymous block of memory which will later be written to the
5142 // file.  Return whether the map succeeded.
5143 
5144 bool
map_anonymous()5145 Output_file::map_anonymous()
5146 {
5147   void* base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
5148 		      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
5149   if (base == MAP_FAILED)
5150     {
5151       base = malloc(this->file_size_);
5152       if (base == NULL)
5153 	return false;
5154       memset(base, 0, this->file_size_);
5155       this->map_is_allocated_ = true;
5156     }
5157   this->base_ = static_cast<unsigned char*>(base);
5158   this->map_is_anonymous_ = true;
5159   return true;
5160 }
5161 
5162 // Map the file into memory.  Return whether the mapping succeeded.
5163 // If WRITABLE is true, map with write access.
5164 
5165 bool
map_no_anonymous(bool writable)5166 Output_file::map_no_anonymous(bool writable)
5167 {
5168   const int o = this->o_;
5169 
5170   // If the output file is not a regular file, don't try to mmap it;
5171   // instead, we'll mmap a block of memory (an anonymous buffer), and
5172   // then later write the buffer to the file.
5173   void* base;
5174   struct stat statbuf;
5175   if (o == STDOUT_FILENO || o == STDERR_FILENO
5176       || ::fstat(o, &statbuf) != 0
5177       || !S_ISREG(statbuf.st_mode)
5178       || this->is_temporary_)
5179     return false;
5180 
5181   // Ensure that we have disk space available for the file.  If we
5182   // don't do this, it is possible that we will call munmap, close,
5183   // and exit with dirty buffers still in the cache with no assigned
5184   // disk blocks.  If the disk is out of space at that point, the
5185   // output file will wind up incomplete, but we will have already
5186   // exited.  The alternative to fallocate would be to use fdatasync,
5187   // but that would be a more significant performance hit.
5188   if (writable)
5189     {
5190       int err = gold_fallocate(o, 0, this->file_size_);
5191       if (err != 0)
5192        gold_fatal(_("%s: %s"), this->name_, strerror(err));
5193     }
5194 
5195   // Map the file into memory.
5196   int prot = PROT_READ;
5197   if (writable)
5198     prot |= PROT_WRITE;
5199   base = ::mmap(NULL, this->file_size_, prot, MAP_SHARED, o, 0);
5200 
5201   // The mmap call might fail because of file system issues: the file
5202   // system might not support mmap at all, or it might not support
5203   // mmap with PROT_WRITE.
5204   if (base == MAP_FAILED)
5205     return false;
5206 
5207   this->map_is_anonymous_ = false;
5208   this->base_ = static_cast<unsigned char*>(base);
5209   return true;
5210 }
5211 
5212 // Map the file into memory.
5213 
5214 void
map()5215 Output_file::map()
5216 {
5217   if (parameters->options().mmap_output_file()
5218       && this->map_no_anonymous(true))
5219     return;
5220 
5221   // The mmap call might fail because of file system issues: the file
5222   // system might not support mmap at all, or it might not support
5223   // mmap with PROT_WRITE.  I'm not sure which errno values we will
5224   // see in all cases, so if the mmap fails for any reason and we
5225   // don't care about file contents, try for an anonymous map.
5226   if (this->map_anonymous())
5227     return;
5228 
5229   gold_fatal(_("%s: mmap: failed to allocate %lu bytes for output file: %s"),
5230 	     this->name_, static_cast<unsigned long>(this->file_size_),
5231 	     strerror(errno));
5232 }
5233 
5234 // Unmap the file from memory.
5235 
5236 void
unmap()5237 Output_file::unmap()
5238 {
5239   if (this->map_is_anonymous_)
5240     {
5241       // We've already written out the data, so there is no reason to
5242       // waste time unmapping or freeing the memory.
5243     }
5244   else
5245     {
5246       if (::munmap(this->base_, this->file_size_) < 0)
5247 	gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
5248     }
5249   this->base_ = NULL;
5250 }
5251 
5252 // Close the output file.
5253 
5254 void
close()5255 Output_file::close()
5256 {
5257   // If the map isn't file-backed, we need to write it now.
5258   if (this->map_is_anonymous_ && !this->is_temporary_)
5259     {
5260       size_t bytes_to_write = this->file_size_;
5261       size_t offset = 0;
5262       while (bytes_to_write > 0)
5263 	{
5264 	  ssize_t bytes_written = ::write(this->o_, this->base_ + offset,
5265 					  bytes_to_write);
5266 	  if (bytes_written == 0)
5267 	    gold_error(_("%s: write: unexpected 0 return-value"), this->name_);
5268 	  else if (bytes_written < 0)
5269 	    gold_error(_("%s: write: %s"), this->name_, strerror(errno));
5270 	  else
5271 	    {
5272 	      bytes_to_write -= bytes_written;
5273 	      offset += bytes_written;
5274 	    }
5275 	}
5276     }
5277   this->unmap();
5278 
5279   // We don't close stdout or stderr
5280   if (this->o_ != STDOUT_FILENO
5281       && this->o_ != STDERR_FILENO
5282       && !this->is_temporary_)
5283     if (::close(this->o_) < 0)
5284       gold_error(_("%s: close: %s"), this->name_, strerror(errno));
5285   this->o_ = -1;
5286 }
5287 
5288 // Instantiate the templates we need.  We could use the configure
5289 // script to restrict this to only the ones for implemented targets.
5290 
5291 #ifdef HAVE_TARGET_32_LITTLE
5292 template
5293 off_t
5294 Output_section::add_input_section<32, false>(
5295     Layout* layout,
5296     Sized_relobj_file<32, false>* object,
5297     unsigned int shndx,
5298     const char* secname,
5299     const elfcpp::Shdr<32, false>& shdr,
5300     unsigned int reloc_shndx,
5301     bool have_sections_script);
5302 #endif
5303 
5304 #ifdef HAVE_TARGET_32_BIG
5305 template
5306 off_t
5307 Output_section::add_input_section<32, true>(
5308     Layout* layout,
5309     Sized_relobj_file<32, true>* object,
5310     unsigned int shndx,
5311     const char* secname,
5312     const elfcpp::Shdr<32, true>& shdr,
5313     unsigned int reloc_shndx,
5314     bool have_sections_script);
5315 #endif
5316 
5317 #ifdef HAVE_TARGET_64_LITTLE
5318 template
5319 off_t
5320 Output_section::add_input_section<64, false>(
5321     Layout* layout,
5322     Sized_relobj_file<64, false>* object,
5323     unsigned int shndx,
5324     const char* secname,
5325     const elfcpp::Shdr<64, false>& shdr,
5326     unsigned int reloc_shndx,
5327     bool have_sections_script);
5328 #endif
5329 
5330 #ifdef HAVE_TARGET_64_BIG
5331 template
5332 off_t
5333 Output_section::add_input_section<64, true>(
5334     Layout* layout,
5335     Sized_relobj_file<64, true>* object,
5336     unsigned int shndx,
5337     const char* secname,
5338     const elfcpp::Shdr<64, true>& shdr,
5339     unsigned int reloc_shndx,
5340     bool have_sections_script);
5341 #endif
5342 
5343 #ifdef HAVE_TARGET_32_LITTLE
5344 template
5345 class Output_reloc<elfcpp::SHT_REL, false, 32, false>;
5346 #endif
5347 
5348 #ifdef HAVE_TARGET_32_BIG
5349 template
5350 class Output_reloc<elfcpp::SHT_REL, false, 32, true>;
5351 #endif
5352 
5353 #ifdef HAVE_TARGET_64_LITTLE
5354 template
5355 class Output_reloc<elfcpp::SHT_REL, false, 64, false>;
5356 #endif
5357 
5358 #ifdef HAVE_TARGET_64_BIG
5359 template
5360 class Output_reloc<elfcpp::SHT_REL, false, 64, true>;
5361 #endif
5362 
5363 #ifdef HAVE_TARGET_32_LITTLE
5364 template
5365 class Output_reloc<elfcpp::SHT_REL, true, 32, false>;
5366 #endif
5367 
5368 #ifdef HAVE_TARGET_32_BIG
5369 template
5370 class Output_reloc<elfcpp::SHT_REL, true, 32, true>;
5371 #endif
5372 
5373 #ifdef HAVE_TARGET_64_LITTLE
5374 template
5375 class Output_reloc<elfcpp::SHT_REL, true, 64, false>;
5376 #endif
5377 
5378 #ifdef HAVE_TARGET_64_BIG
5379 template
5380 class Output_reloc<elfcpp::SHT_REL, true, 64, true>;
5381 #endif
5382 
5383 #ifdef HAVE_TARGET_32_LITTLE
5384 template
5385 class Output_reloc<elfcpp::SHT_RELA, false, 32, false>;
5386 #endif
5387 
5388 #ifdef HAVE_TARGET_32_BIG
5389 template
5390 class Output_reloc<elfcpp::SHT_RELA, false, 32, true>;
5391 #endif
5392 
5393 #ifdef HAVE_TARGET_64_LITTLE
5394 template
5395 class Output_reloc<elfcpp::SHT_RELA, false, 64, false>;
5396 #endif
5397 
5398 #ifdef HAVE_TARGET_64_BIG
5399 template
5400 class Output_reloc<elfcpp::SHT_RELA, false, 64, true>;
5401 #endif
5402 
5403 #ifdef HAVE_TARGET_32_LITTLE
5404 template
5405 class Output_reloc<elfcpp::SHT_RELA, true, 32, false>;
5406 #endif
5407 
5408 #ifdef HAVE_TARGET_32_BIG
5409 template
5410 class Output_reloc<elfcpp::SHT_RELA, true, 32, true>;
5411 #endif
5412 
5413 #ifdef HAVE_TARGET_64_LITTLE
5414 template
5415 class Output_reloc<elfcpp::SHT_RELA, true, 64, false>;
5416 #endif
5417 
5418 #ifdef HAVE_TARGET_64_BIG
5419 template
5420 class Output_reloc<elfcpp::SHT_RELA, true, 64, true>;
5421 #endif
5422 
5423 #ifdef HAVE_TARGET_32_LITTLE
5424 template
5425 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
5426 #endif
5427 
5428 #ifdef HAVE_TARGET_32_BIG
5429 template
5430 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
5431 #endif
5432 
5433 #ifdef HAVE_TARGET_64_LITTLE
5434 template
5435 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
5436 #endif
5437 
5438 #ifdef HAVE_TARGET_64_BIG
5439 template
5440 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
5441 #endif
5442 
5443 #ifdef HAVE_TARGET_32_LITTLE
5444 template
5445 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
5446 #endif
5447 
5448 #ifdef HAVE_TARGET_32_BIG
5449 template
5450 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
5451 #endif
5452 
5453 #ifdef HAVE_TARGET_64_LITTLE
5454 template
5455 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
5456 #endif
5457 
5458 #ifdef HAVE_TARGET_64_BIG
5459 template
5460 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
5461 #endif
5462 
5463 #ifdef HAVE_TARGET_32_LITTLE
5464 template
5465 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
5466 #endif
5467 
5468 #ifdef HAVE_TARGET_32_BIG
5469 template
5470 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
5471 #endif
5472 
5473 #ifdef HAVE_TARGET_64_LITTLE
5474 template
5475 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
5476 #endif
5477 
5478 #ifdef HAVE_TARGET_64_BIG
5479 template
5480 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
5481 #endif
5482 
5483 #ifdef HAVE_TARGET_32_LITTLE
5484 template
5485 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
5486 #endif
5487 
5488 #ifdef HAVE_TARGET_32_BIG
5489 template
5490 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
5491 #endif
5492 
5493 #ifdef HAVE_TARGET_64_LITTLE
5494 template
5495 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
5496 #endif
5497 
5498 #ifdef HAVE_TARGET_64_BIG
5499 template
5500 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
5501 #endif
5502 
5503 #ifdef HAVE_TARGET_32_LITTLE
5504 template
5505 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, false>;
5506 #endif
5507 
5508 #ifdef HAVE_TARGET_32_BIG
5509 template
5510 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, true>;
5511 #endif
5512 
5513 #ifdef HAVE_TARGET_64_LITTLE
5514 template
5515 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, false>;
5516 #endif
5517 
5518 #ifdef HAVE_TARGET_64_BIG
5519 template
5520 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, true>;
5521 #endif
5522 
5523 #ifdef HAVE_TARGET_32_LITTLE
5524 template
5525 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, false>;
5526 #endif
5527 
5528 #ifdef HAVE_TARGET_32_BIG
5529 template
5530 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, true>;
5531 #endif
5532 
5533 #ifdef HAVE_TARGET_64_LITTLE
5534 template
5535 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, false>;
5536 #endif
5537 
5538 #ifdef HAVE_TARGET_64_BIG
5539 template
5540 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, true>;
5541 #endif
5542 
5543 #ifdef HAVE_TARGET_32_LITTLE
5544 template
5545 class Output_data_group<32, false>;
5546 #endif
5547 
5548 #ifdef HAVE_TARGET_32_BIG
5549 template
5550 class Output_data_group<32, true>;
5551 #endif
5552 
5553 #ifdef HAVE_TARGET_64_LITTLE
5554 template
5555 class Output_data_group<64, false>;
5556 #endif
5557 
5558 #ifdef HAVE_TARGET_64_BIG
5559 template
5560 class Output_data_group<64, true>;
5561 #endif
5562 
5563 template
5564 class Output_data_got<32, false>;
5565 
5566 template
5567 class Output_data_got<32, true>;
5568 
5569 template
5570 class Output_data_got<64, false>;
5571 
5572 template
5573 class Output_data_got<64, true>;
5574 
5575 } // End namespace gold.
5576