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* options.h (class General_options): Define --check-sections.
[pf3gnuchains/pf3gnuchains3x.git] / gold / layout.cc
1 // layout.cc -- lay out output file sections for gold
2
3 // Copyright 2006, 2007, 2008 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 <cerrno>
26 #include <cstring>
27 #include <algorithm>
28 #include <iostream>
29 #include <utility>
30 #include <fcntl.h>
31 #include <unistd.h>
32 #include "libiberty.h"
33 #include "md5.h"
34 #include "sha1.h"
35
36 #include "parameters.h"
37 #include "options.h"
38 #include "mapfile.h"
39 #include "script.h"
40 #include "script-sections.h"
41 #include "output.h"
42 #include "symtab.h"
43 #include "dynobj.h"
44 #include "ehframe.h"
45 #include "compressed_output.h"
46 #include "reduced_debug_output.h"
47 #include "reloc.h"
48 #include "layout.h"
49
50 namespace gold
51 {
52
53 // Layout_task_runner methods.
54
55 // Lay out the sections.  This is called after all the input objects
56 // have been read.
57
58 void
59 Layout_task_runner::run(Workqueue* workqueue, const Task* task)
60 {
61   off_t file_size = this->layout_->finalize(this->input_objects_,
62                                             this->symtab_,
63                                             this->target_,
64                                             task);
65
66   // Now we know the final size of the output file and we know where
67   // each piece of information goes.
68
69   if (this->mapfile_ != NULL)
70     {
71       this->mapfile_->print_discarded_sections(this->input_objects_);
72       this->layout_->print_to_mapfile(this->mapfile_);
73     }
74
75   Output_file* of = new Output_file(parameters->options().output_file_name());
76   if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
77     of->set_is_temporary();
78   of->open(file_size);
79
80   // Queue up the final set of tasks.
81   gold::queue_final_tasks(this->options_, this->input_objects_,
82                           this->symtab_, this->layout_, workqueue, of);
83 }
84
85 // Layout methods.
86
87 Layout::Layout(const General_options& options, Script_options* script_options)
88   : options_(options),
89     script_options_(script_options),
90     namepool_(),
91     sympool_(),
92     dynpool_(),
93     signatures_(),
94     section_name_map_(),
95     segment_list_(),
96     section_list_(),
97     unattached_section_list_(),
98     sections_are_attached_(false),
99     special_output_list_(),
100     section_headers_(NULL),
101     tls_segment_(NULL),
102     relro_segment_(NULL),
103     symtab_section_(NULL),
104     symtab_xindex_(NULL),
105     dynsym_section_(NULL),
106     dynsym_xindex_(NULL),
107     dynamic_section_(NULL),
108     dynamic_data_(NULL),
109     eh_frame_section_(NULL),
110     eh_frame_data_(NULL),
111     added_eh_frame_data_(false),
112     eh_frame_hdr_section_(NULL),
113     build_id_note_(NULL),
114     debug_abbrev_(NULL),
115     debug_info_(NULL),
116     group_signatures_(),
117     output_file_size_(-1),
118     input_requires_executable_stack_(false),
119     input_with_gnu_stack_note_(false),
120     input_without_gnu_stack_note_(false),
121     has_static_tls_(false),
122     any_postprocessing_sections_(false)
123 {
124   // Make space for more than enough segments for a typical file.
125   // This is just for efficiency--it's OK if we wind up needing more.
126   this->segment_list_.reserve(12);
127
128   // We expect two unattached Output_data objects: the file header and
129   // the segment headers.
130   this->special_output_list_.reserve(2);
131 }
132
133 // Hash a key we use to look up an output section mapping.
134
135 size_t
136 Layout::Hash_key::operator()(const Layout::Key& k) const
137 {
138  return k.first + k.second.first + k.second.second;
139 }
140
141 // Return whether PREFIX is a prefix of STR.
142
143 static inline bool
144 is_prefix_of(const char* prefix, const char* str)
145 {
146   return strncmp(prefix, str, strlen(prefix)) == 0;
147 }
148
149 // Returns whether the given section is in the list of
150 // debug-sections-used-by-some-version-of-gdb.  Currently,
151 // we've checked versions of gdb up to and including 6.7.1.
152
153 static const char* gdb_sections[] =
154 { ".debug_abbrev",
155   // ".debug_aranges",   // not used by gdb as of 6.7.1
156   ".debug_frame",
157   ".debug_info",
158   ".debug_line",
159   ".debug_loc",
160   ".debug_macinfo",
161   // ".debug_pubnames",  // not used by gdb as of 6.7.1
162   ".debug_ranges",
163   ".debug_str",
164 };
165
166 static const char* lines_only_debug_sections[] =
167 { ".debug_abbrev",
168   // ".debug_aranges",   // not used by gdb as of 6.7.1
169   // ".debug_frame",
170   ".debug_info",
171   ".debug_line",
172   // ".debug_loc",
173   // ".debug_macinfo",
174   // ".debug_pubnames",  // not used by gdb as of 6.7.1
175   // ".debug_ranges",
176   ".debug_str",
177 };
178
179 static inline bool
180 is_gdb_debug_section(const char* str)
181 {
182   // We can do this faster: binary search or a hashtable.  But why bother?
183   for (size_t i = 0; i < sizeof(gdb_sections)/sizeof(*gdb_sections); ++i)
184     if (strcmp(str, gdb_sections[i]) == 0)
185       return true;
186   return false;
187 }
188
189 static inline bool
190 is_lines_only_debug_section(const char* str)
191 {
192   // We can do this faster: binary search or a hashtable.  But why bother?
193   for (size_t i = 0;
194        i < sizeof(lines_only_debug_sections)/sizeof(*lines_only_debug_sections);
195        ++i)
196     if (strcmp(str, lines_only_debug_sections[i]) == 0)
197       return true;
198   return false;
199 }
200
201 // Whether to include this section in the link.
202
203 template<int size, bool big_endian>
204 bool
205 Layout::include_section(Sized_relobj<size, big_endian>*, const char* name,
206                         const elfcpp::Shdr<size, big_endian>& shdr)
207 {
208   switch (shdr.get_sh_type())
209     {
210     case elfcpp::SHT_NULL:
211     case elfcpp::SHT_SYMTAB:
212     case elfcpp::SHT_DYNSYM:
213     case elfcpp::SHT_HASH:
214     case elfcpp::SHT_DYNAMIC:
215     case elfcpp::SHT_SYMTAB_SHNDX:
216       return false;
217
218     case elfcpp::SHT_STRTAB:
219       // Discard the sections which have special meanings in the ELF
220       // ABI.  Keep others (e.g., .stabstr).  We could also do this by
221       // checking the sh_link fields of the appropriate sections.
222       return (strcmp(name, ".dynstr") != 0
223               && strcmp(name, ".strtab") != 0
224               && strcmp(name, ".shstrtab") != 0);
225
226     case elfcpp::SHT_RELA:
227     case elfcpp::SHT_REL:
228     case elfcpp::SHT_GROUP:
229       // If we are emitting relocations these should be handled
230       // elsewhere.
231       gold_assert(!parameters->options().relocatable()
232                   && !parameters->options().emit_relocs());
233       return false;
234
235     case elfcpp::SHT_PROGBITS:
236       if (parameters->options().strip_debug()
237           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
238         {
239           if (is_debug_info_section(name))
240             return false;
241         }
242       if (parameters->options().strip_debug_non_line()
243           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
244         {
245           // Debugging sections can only be recognized by name.
246           if (is_prefix_of(".debug", name)
247               && !is_lines_only_debug_section(name))
248             return false;
249         }
250       if (parameters->options().strip_debug_gdb()
251           && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
252         {
253           // Debugging sections can only be recognized by name.
254           if (is_prefix_of(".debug", name)
255               && !is_gdb_debug_section(name))
256             return false;
257         }
258       return true;
259
260     default:
261       return true;
262     }
263 }
264
265 // Return an output section named NAME, or NULL if there is none.
266
267 Output_section*
268 Layout::find_output_section(const char* name) const
269 {
270   for (Section_list::const_iterator p = this->section_list_.begin();
271        p != this->section_list_.end();
272        ++p)
273     if (strcmp((*p)->name(), name) == 0)
274       return *p;
275   return NULL;
276 }
277
278 // Return an output segment of type TYPE, with segment flags SET set
279 // and segment flags CLEAR clear.  Return NULL if there is none.
280
281 Output_segment*
282 Layout::find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set,
283                             elfcpp::Elf_Word clear) const
284 {
285   for (Segment_list::const_iterator p = this->segment_list_.begin();
286        p != this->segment_list_.end();
287        ++p)
288     if (static_cast<elfcpp::PT>((*p)->type()) == type
289         && ((*p)->flags() & set) == set
290         && ((*p)->flags() & clear) == 0)
291       return *p;
292   return NULL;
293 }
294
295 // Return the output section to use for section NAME with type TYPE
296 // and section flags FLAGS.  NAME must be canonicalized in the string
297 // pool, and NAME_KEY is the key.
298
299 Output_section*
300 Layout::get_output_section(const char* name, Stringpool::Key name_key,
301                            elfcpp::Elf_Word type, elfcpp::Elf_Xword flags)
302 {
303   elfcpp::Elf_Xword lookup_flags = flags;
304
305   // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine
306   // read-write with read-only sections.  Some other ELF linkers do
307   // not do this.  FIXME: Perhaps there should be an option
308   // controlling this.
309   lookup_flags &= ~(elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR);
310
311   const Key key(name_key, std::make_pair(type, lookup_flags));
312   const std::pair<Key, Output_section*> v(key, NULL);
313   std::pair<Section_name_map::iterator, bool> ins(
314     this->section_name_map_.insert(v));
315
316   if (!ins.second)
317     return ins.first->second;
318   else
319     {
320       // This is the first time we've seen this name/type/flags
321       // combination.  For compatibility with the GNU linker, we
322       // combine sections with contents and zero flags with sections
323       // with non-zero flags.  This is a workaround for cases where
324       // assembler code forgets to set section flags.  FIXME: Perhaps
325       // there should be an option to control this.
326       Output_section* os = NULL;
327
328       if (type == elfcpp::SHT_PROGBITS)
329         {
330           if (flags == 0)
331             {
332               Output_section* same_name = this->find_output_section(name);
333               if (same_name != NULL
334                   && same_name->type() == elfcpp::SHT_PROGBITS
335                   && (same_name->flags() & elfcpp::SHF_TLS) == 0)
336                 os = same_name;
337             }
338           else if ((flags & elfcpp::SHF_TLS) == 0)
339             {
340               elfcpp::Elf_Xword zero_flags = 0;
341               const Key zero_key(name_key, std::make_pair(type, zero_flags));
342               Section_name_map::iterator p =
343                   this->section_name_map_.find(zero_key);
344               if (p != this->section_name_map_.end())
345                 os = p->second;
346             }
347         }
348
349       if (os == NULL)
350         os = this->make_output_section(name, type, flags);
351       ins.first->second = os;
352       return os;
353     }
354 }
355
356 // Pick the output section to use for section NAME, in input file
357 // RELOBJ, with type TYPE and flags FLAGS.  RELOBJ may be NULL for a
358 // linker created section.  IS_INPUT_SECTION is true if we are
359 // choosing an output section for an input section found in a input
360 // file.  This will return NULL if the input section should be
361 // discarded.
362
363 Output_section*
364 Layout::choose_output_section(const Relobj* relobj, const char* name,
365                               elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
366                               bool is_input_section)
367 {
368   // We should not see any input sections after we have attached
369   // sections to segments.
370   gold_assert(!is_input_section || !this->sections_are_attached_);
371
372   // Some flags in the input section should not be automatically
373   // copied to the output section.
374   flags &= ~ (elfcpp::SHF_INFO_LINK
375               | elfcpp::SHF_LINK_ORDER
376               | elfcpp::SHF_GROUP
377               | elfcpp::SHF_MERGE
378               | elfcpp::SHF_STRINGS);
379
380   if (this->script_options_->saw_sections_clause())
381     {
382       // We are using a SECTIONS clause, so the output section is
383       // chosen based only on the name.
384
385       Script_sections* ss = this->script_options_->script_sections();
386       const char* file_name = relobj == NULL ? NULL : relobj->name().c_str();
387       Output_section** output_section_slot;
388       name = ss->output_section_name(file_name, name, &output_section_slot);
389       if (name == NULL)
390         {
391           // The SECTIONS clause says to discard this input section.
392           return NULL;
393         }
394
395       // If this is an orphan section--one not mentioned in the linker
396       // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
397       // default processing below.
398
399       if (output_section_slot != NULL)
400         {
401           if (*output_section_slot != NULL)
402             return *output_section_slot;
403
404           // We don't put sections found in the linker script into
405           // SECTION_NAME_MAP_.  That keeps us from getting confused
406           // if an orphan section is mapped to a section with the same
407           // name as one in the linker script.
408
409           name = this->namepool_.add(name, false, NULL);
410
411           Output_section* os = this->make_output_section(name, type, flags);
412           os->set_found_in_sections_clause();
413           *output_section_slot = os;
414           return os;
415         }
416     }
417
418   // FIXME: Handle SHF_OS_NONCONFORMING somewhere.
419
420   // Turn NAME from the name of the input section into the name of the
421   // output section.
422
423   size_t len = strlen(name);
424   if (is_input_section && !parameters->options().relocatable())
425     name = Layout::output_section_name(name, &len);
426
427   Stringpool::Key name_key;
428   name = this->namepool_.add_with_length(name, len, true, &name_key);
429
430   // Find or make the output section.  The output section is selected
431   // based on the section name, type, and flags.
432   return this->get_output_section(name, name_key, type, flags);
433 }
434
435 // Return the output section to use for input section SHNDX, with name
436 // NAME, with header HEADER, from object OBJECT.  RELOC_SHNDX is the
437 // index of a relocation section which applies to this section, or 0
438 // if none, or -1U if more than one.  RELOC_TYPE is the type of the
439 // relocation section if there is one.  Set *OFF to the offset of this
440 // input section without the output section.  Return NULL if the
441 // section should be discarded.  Set *OFF to -1 if the section
442 // contents should not be written directly to the output file, but
443 // will instead receive special handling.
444
445 template<int size, bool big_endian>
446 Output_section*
447 Layout::layout(Sized_relobj<size, big_endian>* object, unsigned int shndx,
448                const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
449                unsigned int reloc_shndx, unsigned int, off_t* off)
450 {
451   *off = 0;
452
453   if (!this->include_section(object, name, shdr))
454     return NULL;
455
456   Output_section* os;
457
458   // In a relocatable link a grouped section must not be combined with
459   // any other sections.
460   if (parameters->options().relocatable()
461       && (shdr.get_sh_flags() & elfcpp::SHF_GROUP) != 0)
462     {
463       name = this->namepool_.add(name, true, NULL);
464       os = this->make_output_section(name, shdr.get_sh_type(),
465                                      shdr.get_sh_flags());
466     }
467   else
468     {
469       os = this->choose_output_section(object, name, shdr.get_sh_type(),
470                                        shdr.get_sh_flags(), true);
471       if (os == NULL)
472         return NULL;
473     }
474
475   // By default the GNU linker sorts input sections whose names match
476   // .ctor.*, .dtor.*, .init_array.*, or .fini_array.*.  The sections
477   // are sorted by name.  This is used to implement constructor
478   // priority ordering.  We are compatible.
479   if (!this->script_options_->saw_sections_clause()
480       && (is_prefix_of(".ctors.", name)
481           || is_prefix_of(".dtors.", name)
482           || is_prefix_of(".init_array.", name)
483           || is_prefix_of(".fini_array.", name)))
484     os->set_must_sort_attached_input_sections();
485
486   // FIXME: Handle SHF_LINK_ORDER somewhere.
487
488   *off = os->add_input_section(object, shndx, name, shdr, reloc_shndx,
489                                this->script_options_->saw_sections_clause());
490
491   return os;
492 }
493
494 // Handle a relocation section when doing a relocatable link.
495
496 template<int size, bool big_endian>
497 Output_section*
498 Layout::layout_reloc(Sized_relobj<size, big_endian>* object,
499                      unsigned int,
500                      const elfcpp::Shdr<size, big_endian>& shdr,
501                      Output_section* data_section,
502                      Relocatable_relocs* rr)
503 {
504   gold_assert(parameters->options().relocatable()
505               || parameters->options().emit_relocs());
506
507   int sh_type = shdr.get_sh_type();
508
509   std::string name;
510   if (sh_type == elfcpp::SHT_REL)
511     name = ".rel";
512   else if (sh_type == elfcpp::SHT_RELA)
513     name = ".rela";
514   else
515     gold_unreachable();
516   name += data_section->name();
517
518   Output_section* os = this->choose_output_section(object, name.c_str(),
519                                                    sh_type,
520                                                    shdr.get_sh_flags(),
521                                                    false);
522
523   os->set_should_link_to_symtab();
524   os->set_info_section(data_section);
525
526   Output_section_data* posd;
527   if (sh_type == elfcpp::SHT_REL)
528     {
529       os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
530       posd = new Output_relocatable_relocs<elfcpp::SHT_REL,
531                                            size,
532                                            big_endian>(rr);
533     }
534   else if (sh_type == elfcpp::SHT_RELA)
535     {
536       os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
537       posd = new Output_relocatable_relocs<elfcpp::SHT_RELA,
538                                            size,
539                                            big_endian>(rr);
540     }
541   else
542     gold_unreachable();
543
544   os->add_output_section_data(posd);
545   rr->set_output_data(posd);
546
547   return os;
548 }
549
550 // Handle a group section when doing a relocatable link.
551
552 template<int size, bool big_endian>
553 void
554 Layout::layout_group(Symbol_table* symtab,
555                      Sized_relobj<size, big_endian>* object,
556                      unsigned int,
557                      const char* group_section_name,
558                      const char* signature,
559                      const elfcpp::Shdr<size, big_endian>& shdr,
560                      elfcpp::Elf_Word flags,
561                      std::vector<unsigned int>* shndxes)
562 {
563   gold_assert(parameters->options().relocatable());
564   gold_assert(shdr.get_sh_type() == elfcpp::SHT_GROUP);
565   group_section_name = this->namepool_.add(group_section_name, true, NULL);
566   Output_section* os = this->make_output_section(group_section_name,
567                                                  elfcpp::SHT_GROUP,
568                                                  shdr.get_sh_flags());
569
570   // We need to find a symbol with the signature in the symbol table.
571   // If we don't find one now, we need to look again later.
572   Symbol* sym = symtab->lookup(signature, NULL);
573   if (sym != NULL)
574     os->set_info_symndx(sym);
575   else
576     {
577       // We will wind up using a symbol whose name is the signature.
578       // So just put the signature in the symbol name pool to save it.
579       signature = symtab->canonicalize_name(signature);
580       this->group_signatures_.push_back(Group_signature(os, signature));
581     }
582
583   os->set_should_link_to_symtab();
584   os->set_entsize(4);
585
586   section_size_type entry_count =
587     convert_to_section_size_type(shdr.get_sh_size() / 4);
588   Output_section_data* posd =
589     new Output_data_group<size, big_endian>(object, entry_count, flags,
590                                             shndxes);
591   os->add_output_section_data(posd);
592 }
593
594 // Special GNU handling of sections name .eh_frame.  They will
595 // normally hold exception frame data as defined by the C++ ABI
596 // (http://codesourcery.com/cxx-abi/).
597
598 template<int size, bool big_endian>
599 Output_section*
600 Layout::layout_eh_frame(Sized_relobj<size, big_endian>* object,
601                         const unsigned char* symbols,
602                         off_t symbols_size,
603                         const unsigned char* symbol_names,
604                         off_t symbol_names_size,
605                         unsigned int shndx,
606                         const elfcpp::Shdr<size, big_endian>& shdr,
607                         unsigned int reloc_shndx, unsigned int reloc_type,
608                         off_t* off)
609 {
610   gold_assert(shdr.get_sh_type() == elfcpp::SHT_PROGBITS);
611   gold_assert((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
612
613   const char* const name = ".eh_frame";
614   Output_section* os = this->choose_output_section(object,
615                                                    name,
616                                                    elfcpp::SHT_PROGBITS,
617                                                    elfcpp::SHF_ALLOC,
618                                                    false);
619   if (os == NULL)
620     return NULL;
621
622   if (this->eh_frame_section_ == NULL)
623     {
624       this->eh_frame_section_ = os;
625       this->eh_frame_data_ = new Eh_frame();
626
627       if (this->options_.eh_frame_hdr())
628         {
629           Output_section* hdr_os =
630             this->choose_output_section(NULL,
631                                         ".eh_frame_hdr",
632                                         elfcpp::SHT_PROGBITS,
633                                         elfcpp::SHF_ALLOC,
634                                         false);
635
636           if (hdr_os != NULL)
637             {
638               Eh_frame_hdr* hdr_posd = new Eh_frame_hdr(os,
639                                                         this->eh_frame_data_);
640               hdr_os->add_output_section_data(hdr_posd);
641
642               hdr_os->set_after_input_sections();
643
644               if (!this->script_options_->saw_phdrs_clause())
645                 {
646                   Output_segment* hdr_oseg;
647                   hdr_oseg = this->make_output_segment(elfcpp::PT_GNU_EH_FRAME,
648                                                        elfcpp::PF_R);
649                   hdr_oseg->add_output_section(hdr_os, elfcpp::PF_R);
650                 }
651
652               this->eh_frame_data_->set_eh_frame_hdr(hdr_posd);
653             }
654         }
655     }
656
657   gold_assert(this->eh_frame_section_ == os);
658
659   if (this->eh_frame_data_->add_ehframe_input_section(object,
660                                                       symbols,
661                                                       symbols_size,
662                                                       symbol_names,
663                                                       symbol_names_size,
664                                                       shndx,
665                                                       reloc_shndx,
666                                                       reloc_type))
667     {
668       os->update_flags_for_input_section(shdr.get_sh_flags());
669
670       // We found a .eh_frame section we are going to optimize, so now
671       // we can add the set of optimized sections to the output
672       // section.  We need to postpone adding this until we've found a
673       // section we can optimize so that the .eh_frame section in
674       // crtbegin.o winds up at the start of the output section.
675       if (!this->added_eh_frame_data_)
676         {
677           os->add_output_section_data(this->eh_frame_data_);
678           this->added_eh_frame_data_ = true;
679         }
680       *off = -1;
681     }
682   else
683     {
684       // We couldn't handle this .eh_frame section for some reason.
685       // Add it as a normal section.
686       bool saw_sections_clause = this->script_options_->saw_sections_clause();
687       *off = os->add_input_section(object, shndx, name, shdr, reloc_shndx,
688                                    saw_sections_clause);
689     }
690
691   return os;
692 }
693
694 // Add POSD to an output section using NAME, TYPE, and FLAGS.  Return
695 // the output section.
696
697 Output_section*
698 Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type,
699                                 elfcpp::Elf_Xword flags,
700                                 Output_section_data* posd)
701 {
702   Output_section* os = this->choose_output_section(NULL, name, type, flags,
703                                                    false);
704   if (os != NULL)
705     os->add_output_section_data(posd);
706   return os;
707 }
708
709 // Map section flags to segment flags.
710
711 elfcpp::Elf_Word
712 Layout::section_flags_to_segment(elfcpp::Elf_Xword flags)
713 {
714   elfcpp::Elf_Word ret = elfcpp::PF_R;
715   if ((flags & elfcpp::SHF_WRITE) != 0)
716     ret |= elfcpp::PF_W;
717   if ((flags & elfcpp::SHF_EXECINSTR) != 0)
718     ret |= elfcpp::PF_X;
719   return ret;
720 }
721
722 // Sometimes we compress sections.  This is typically done for
723 // sections that are not part of normal program execution (such as
724 // .debug_* sections), and where the readers of these sections know
725 // how to deal with compressed sections.  (To make it easier for them,
726 // we will rename the ouput section in such cases from .foo to
727 // .foo.zlib.nnnn, where nnnn is the uncompressed size.)  This routine
728 // doesn't say for certain whether we'll compress -- it depends on
729 // commandline options as well -- just whether this section is a
730 // candidate for compression.
731
732 static bool
733 is_compressible_debug_section(const char* secname)
734 {
735   return (strncmp(secname, ".debug", sizeof(".debug") - 1) == 0);
736 }
737
738 // Make a new Output_section, and attach it to segments as
739 // appropriate.
740
741 Output_section*
742 Layout::make_output_section(const char* name, elfcpp::Elf_Word type,
743                             elfcpp::Elf_Xword flags)
744 {
745   Output_section* os;
746   if ((flags & elfcpp::SHF_ALLOC) == 0
747       && strcmp(this->options_.compress_debug_sections(), "none") != 0
748       && is_compressible_debug_section(name))
749     os = new Output_compressed_section(&this->options_, name, type, flags);
750
751   else if ((flags & elfcpp::SHF_ALLOC) == 0
752            && this->options_.strip_debug_non_line()
753            && strcmp(".debug_abbrev", name) == 0)
754     {
755       os = this->debug_abbrev_ = new Output_reduced_debug_abbrev_section(
756           name, type, flags);
757       if (this->debug_info_)
758         this->debug_info_->set_abbreviations(this->debug_abbrev_);
759     }
760   else if ((flags & elfcpp::SHF_ALLOC) == 0
761            && this->options_.strip_debug_non_line()
762            && strcmp(".debug_info", name) == 0)
763     {
764       os = this->debug_info_ = new Output_reduced_debug_info_section(
765           name, type, flags);
766       if (this->debug_abbrev_)
767         this->debug_info_->set_abbreviations(this->debug_abbrev_);
768     }
769  else
770     os = new Output_section(name, type, flags);
771
772   this->section_list_.push_back(os);
773
774   // The GNU linker by default sorts some sections by priority, so we
775   // do the same.  We need to know that this might happen before we
776   // attach any input sections.
777   if (!this->script_options_->saw_sections_clause()
778       && (strcmp(name, ".ctors") == 0
779           || strcmp(name, ".dtors") == 0
780           || strcmp(name, ".init_array") == 0
781           || strcmp(name, ".fini_array") == 0))
782     os->set_may_sort_attached_input_sections();
783
784   // With -z relro, we have to recognize the special sections by name.
785   // There is no other way.
786   if (!this->script_options_->saw_sections_clause()
787       && parameters->options().relro()
788       && type == elfcpp::SHT_PROGBITS
789       && (flags & elfcpp::SHF_ALLOC) != 0
790       && (flags & elfcpp::SHF_WRITE) != 0)
791     {
792       if (strcmp(name, ".data.rel.ro") == 0)
793         os->set_is_relro();
794       else if (strcmp(name, ".data.rel.ro.local") == 0)
795         {
796           os->set_is_relro();
797           os->set_is_relro_local();
798         }
799     }
800
801   // If we have already attached the sections to segments, then we
802   // need to attach this one now.  This happens for sections created
803   // directly by the linker.
804   if (this->sections_are_attached_)
805     this->attach_section_to_segment(os);
806
807   return os;
808 }
809
810 // Attach output sections to segments.  This is called after we have
811 // seen all the input sections.
812
813 void
814 Layout::attach_sections_to_segments()
815 {
816   for (Section_list::iterator p = this->section_list_.begin();
817        p != this->section_list_.end();
818        ++p)
819     this->attach_section_to_segment(*p);
820
821   this->sections_are_attached_ = true;
822 }
823
824 // Attach an output section to a segment.
825
826 void
827 Layout::attach_section_to_segment(Output_section* os)
828 {
829   if ((os->flags() & elfcpp::SHF_ALLOC) == 0)
830     this->unattached_section_list_.push_back(os);
831   else
832     this->attach_allocated_section_to_segment(os);
833 }
834
835 // Attach an allocated output section to a segment.
836
837 void
838 Layout::attach_allocated_section_to_segment(Output_section* os)
839 {
840   elfcpp::Elf_Xword flags = os->flags();
841   gold_assert((flags & elfcpp::SHF_ALLOC) != 0);
842
843   if (parameters->options().relocatable())
844     return;
845
846   // If we have a SECTIONS clause, we can't handle the attachment to
847   // segments until after we've seen all the sections.
848   if (this->script_options_->saw_sections_clause())
849     return;
850
851   gold_assert(!this->script_options_->saw_phdrs_clause());
852
853   // This output section goes into a PT_LOAD segment.
854
855   elfcpp::Elf_Word seg_flags = Layout::section_flags_to_segment(flags);
856
857   // In general the only thing we really care about for PT_LOAD
858   // segments is whether or not they are writable, so that is how we
859   // search for them.  People who need segments sorted on some other
860   // basis will have to use a linker script.
861
862   Segment_list::const_iterator p;
863   for (p = this->segment_list_.begin();
864        p != this->segment_list_.end();
865        ++p)
866     {
867       if ((*p)->type() == elfcpp::PT_LOAD
868           && (parameters->options().omagic()
869               || ((*p)->flags() & elfcpp::PF_W) == (seg_flags & elfcpp::PF_W)))
870         {
871           // If -Tbss was specified, we need to separate the data
872           // and BSS segments.
873           if (this->options_.user_set_Tbss())
874             {
875               if ((os->type() == elfcpp::SHT_NOBITS)
876                   == (*p)->has_any_data_sections())
877                 continue;
878             }
879
880           (*p)->add_output_section(os, seg_flags);
881           break;
882         }
883     }
884
885   if (p == this->segment_list_.end())
886     {
887       Output_segment* oseg = this->make_output_segment(elfcpp::PT_LOAD,
888                                                        seg_flags);
889       oseg->add_output_section(os, seg_flags);
890     }
891
892   // If we see a loadable SHT_NOTE section, we create a PT_NOTE
893   // segment.
894   if (os->type() == elfcpp::SHT_NOTE)
895     {
896       // See if we already have an equivalent PT_NOTE segment.
897       for (p = this->segment_list_.begin();
898            p != segment_list_.end();
899            ++p)
900         {
901           if ((*p)->type() == elfcpp::PT_NOTE
902               && (((*p)->flags() & elfcpp::PF_W)
903                   == (seg_flags & elfcpp::PF_W)))
904             {
905               (*p)->add_output_section(os, seg_flags);
906               break;
907             }
908         }
909
910       if (p == this->segment_list_.end())
911         {
912           Output_segment* oseg = this->make_output_segment(elfcpp::PT_NOTE,
913                                                            seg_flags);
914           oseg->add_output_section(os, seg_flags);
915         }
916     }
917
918   // If we see a loadable SHF_TLS section, we create a PT_TLS
919   // segment.  There can only be one such segment.
920   if ((flags & elfcpp::SHF_TLS) != 0)
921     {
922       if (this->tls_segment_ == NULL)
923         this->tls_segment_ = this->make_output_segment(elfcpp::PT_TLS,
924                                                        seg_flags);
925       this->tls_segment_->add_output_section(os, seg_flags);
926     }
927
928   // If -z relro is in effect, and we see a relro section, we create a
929   // PT_GNU_RELRO segment.  There can only be one such segment.
930   if (os->is_relro() && parameters->options().relro())
931     {
932       gold_assert(seg_flags == (elfcpp::PF_R | elfcpp::PF_W));
933       if (this->relro_segment_ == NULL)
934         this->relro_segment_ = this->make_output_segment(elfcpp::PT_GNU_RELRO,
935                                                          seg_flags);
936       this->relro_segment_->add_output_section(os, seg_flags);
937     }
938 }
939
940 // Make an output section for a script.
941
942 Output_section*
943 Layout::make_output_section_for_script(const char* name)
944 {
945   name = this->namepool_.add(name, false, NULL);
946   Output_section* os = this->make_output_section(name, elfcpp::SHT_PROGBITS,
947                                                  elfcpp::SHF_ALLOC);
948   os->set_found_in_sections_clause();
949   return os;
950 }
951
952 // Return the number of segments we expect to see.
953
954 size_t
955 Layout::expected_segment_count() const
956 {
957   size_t ret = this->segment_list_.size();
958
959   // If we didn't see a SECTIONS clause in a linker script, we should
960   // already have the complete list of segments.  Otherwise we ask the
961   // SECTIONS clause how many segments it expects, and add in the ones
962   // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.)
963
964   if (!this->script_options_->saw_sections_clause())
965     return ret;
966   else
967     {
968       const Script_sections* ss = this->script_options_->script_sections();
969       return ret + ss->expected_segment_count(this);
970     }
971 }
972
973 // Handle the .note.GNU-stack section at layout time.  SEEN_GNU_STACK
974 // is whether we saw a .note.GNU-stack section in the object file.
975 // GNU_STACK_FLAGS is the section flags.  The flags give the
976 // protection required for stack memory.  We record this in an
977 // executable as a PT_GNU_STACK segment.  If an object file does not
978 // have a .note.GNU-stack segment, we must assume that it is an old
979 // object.  On some targets that will force an executable stack.
980
981 void
982 Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags)
983 {
984   if (!seen_gnu_stack)
985     this->input_without_gnu_stack_note_ = true;
986   else
987     {
988       this->input_with_gnu_stack_note_ = true;
989       if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0)
990         this->input_requires_executable_stack_ = true;
991     }
992 }
993
994 // Create the dynamic sections which are needed before we read the
995 // relocs.
996
997 void
998 Layout::create_initial_dynamic_sections(Symbol_table* symtab)
999 {
1000   if (parameters->doing_static_link())
1001     return;
1002
1003   this->dynamic_section_ = this->choose_output_section(NULL, ".dynamic",
1004                                                        elfcpp::SHT_DYNAMIC,
1005                                                        (elfcpp::SHF_ALLOC
1006                                                         | elfcpp::SHF_WRITE),
1007                                                        false);
1008   this->dynamic_section_->set_is_relro();
1009
1010   symtab->define_in_output_data("_DYNAMIC", NULL, this->dynamic_section_, 0, 0,
1011                                 elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
1012                                 elfcpp::STV_HIDDEN, 0, false, false);
1013
1014   this->dynamic_data_ =  new Output_data_dynamic(&this->dynpool_);
1015
1016   this->dynamic_section_->add_output_section_data(this->dynamic_data_);
1017 }
1018
1019 // For each output section whose name can be represented as C symbol,
1020 // define __start and __stop symbols for the section.  This is a GNU
1021 // extension.
1022
1023 void
1024 Layout::define_section_symbols(Symbol_table* symtab)
1025 {
1026   for (Section_list::const_iterator p = this->section_list_.begin();
1027        p != this->section_list_.end();
1028        ++p)
1029     {
1030       const char* const name = (*p)->name();
1031       if (name[strspn(name,
1032                       ("0123456789"
1033                        "ABCDEFGHIJKLMNOPWRSTUVWXYZ"
1034                        "abcdefghijklmnopqrstuvwxyz"
1035                        "_"))]
1036           == '\0')
1037         {
1038           const std::string name_string(name);
1039           const std::string start_name("__start_" + name_string);
1040           const std::string stop_name("__stop_" + name_string);
1041
1042           symtab->define_in_output_data(start_name.c_str(),
1043                                         NULL, // version
1044                                         *p,
1045                                         0, // value
1046                                         0, // symsize
1047                                         elfcpp::STT_NOTYPE,
1048                                         elfcpp::STB_GLOBAL,
1049                                         elfcpp::STV_DEFAULT,
1050                                         0, // nonvis
1051                                         false, // offset_is_from_end
1052                                         true); // only_if_ref
1053
1054           symtab->define_in_output_data(stop_name.c_str(),
1055                                         NULL, // version
1056                                         *p,
1057                                         0, // value
1058                                         0, // symsize
1059                                         elfcpp::STT_NOTYPE,
1060                                         elfcpp::STB_GLOBAL,
1061                                         elfcpp::STV_DEFAULT,
1062                                         0, // nonvis
1063                                         true, // offset_is_from_end
1064                                         true); // only_if_ref
1065         }
1066     }
1067 }
1068
1069 // Define symbols for group signatures.
1070
1071 void
1072 Layout::define_group_signatures(Symbol_table* symtab)
1073 {
1074   for (Group_signatures::iterator p = this->group_signatures_.begin();
1075        p != this->group_signatures_.end();
1076        ++p)
1077     {
1078       Symbol* sym = symtab->lookup(p->signature, NULL);
1079       if (sym != NULL)
1080         p->section->set_info_symndx(sym);
1081       else
1082         {
1083           // Force the name of the group section to the group
1084           // signature, and use the group's section symbol as the
1085           // signature symbol.
1086           if (strcmp(p->section->name(), p->signature) != 0)
1087             {
1088               const char* name = this->namepool_.add(p->signature,
1089                                                      true, NULL);
1090               p->section->set_name(name);
1091             }
1092           p->section->set_needs_symtab_index();
1093           p->section->set_info_section_symndx(p->section);
1094         }
1095     }
1096
1097   this->group_signatures_.clear();
1098 }
1099
1100 // Find the first read-only PT_LOAD segment, creating one if
1101 // necessary.
1102
1103 Output_segment*
1104 Layout::find_first_load_seg()
1105 {
1106   for (Segment_list::const_iterator p = this->segment_list_.begin();
1107        p != this->segment_list_.end();
1108        ++p)
1109     {
1110       if ((*p)->type() == elfcpp::PT_LOAD
1111           && ((*p)->flags() & elfcpp::PF_R) != 0
1112           && (parameters->options().omagic()
1113               || ((*p)->flags() & elfcpp::PF_W) == 0))
1114         return *p;
1115     }
1116
1117   gold_assert(!this->script_options_->saw_phdrs_clause());
1118
1119   Output_segment* load_seg = this->make_output_segment(elfcpp::PT_LOAD,
1120                                                        elfcpp::PF_R);
1121   return load_seg;
1122 }
1123
1124 // Finalize the layout.  When this is called, we have created all the
1125 // output sections and all the output segments which are based on
1126 // input sections.  We have several things to do, and we have to do
1127 // them in the right order, so that we get the right results correctly
1128 // and efficiently.
1129
1130 // 1) Finalize the list of output segments and create the segment
1131 // table header.
1132
1133 // 2) Finalize the dynamic symbol table and associated sections.
1134
1135 // 3) Determine the final file offset of all the output segments.
1136
1137 // 4) Determine the final file offset of all the SHF_ALLOC output
1138 // sections.
1139
1140 // 5) Create the symbol table sections and the section name table
1141 // section.
1142
1143 // 6) Finalize the symbol table: set symbol values to their final
1144 // value and make a final determination of which symbols are going
1145 // into the output symbol table.
1146
1147 // 7) Create the section table header.
1148
1149 // 8) Determine the final file offset of all the output sections which
1150 // are not SHF_ALLOC, including the section table header.
1151
1152 // 9) Finalize the ELF file header.
1153
1154 // This function returns the size of the output file.
1155
1156 off_t
1157 Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab,
1158                  Target* target, const Task* task)
1159 {
1160   target->finalize_sections(this);
1161
1162   this->count_local_symbols(task, input_objects);
1163
1164   this->create_gold_note();
1165   this->create_executable_stack_info(target);
1166   this->create_build_id();
1167
1168   Output_segment* phdr_seg = NULL;
1169   if (!parameters->options().relocatable() && !parameters->doing_static_link())
1170     {
1171       // There was a dynamic object in the link.  We need to create
1172       // some information for the dynamic linker.
1173
1174       // Create the PT_PHDR segment which will hold the program
1175       // headers.
1176       if (!this->script_options_->saw_phdrs_clause())
1177         phdr_seg = this->make_output_segment(elfcpp::PT_PHDR, elfcpp::PF_R);
1178
1179       // Create the dynamic symbol table, including the hash table.
1180       Output_section* dynstr;
1181       std::vector<Symbol*> dynamic_symbols;
1182       unsigned int local_dynamic_count;
1183       Versions versions(*this->script_options()->version_script_info(),
1184                         &this->dynpool_);
1185       this->create_dynamic_symtab(input_objects, symtab, &dynstr,
1186                                   &local_dynamic_count, &dynamic_symbols,
1187                                   &versions);
1188
1189       // Create the .interp section to hold the name of the
1190       // interpreter, and put it in a PT_INTERP segment.
1191       if (!parameters->options().shared())
1192         this->create_interp(target);
1193
1194       // Finish the .dynamic section to hold the dynamic data, and put
1195       // it in a PT_DYNAMIC segment.
1196       this->finish_dynamic_section(input_objects, symtab);
1197
1198       // We should have added everything we need to the dynamic string
1199       // table.
1200       this->dynpool_.set_string_offsets();
1201
1202       // Create the version sections.  We can't do this until the
1203       // dynamic string table is complete.
1204       this->create_version_sections(&versions, symtab, local_dynamic_count,
1205                                     dynamic_symbols, dynstr);
1206     }
1207
1208   // If there is a SECTIONS clause, put all the input sections into
1209   // the required order.
1210   Output_segment* load_seg;
1211   if (this->script_options_->saw_sections_clause())
1212     load_seg = this->set_section_addresses_from_script(symtab);
1213   else if (parameters->options().relocatable())
1214     load_seg = NULL;
1215   else
1216     load_seg = this->find_first_load_seg();
1217
1218   if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
1219     load_seg = NULL;
1220
1221   gold_assert(phdr_seg == NULL || load_seg != NULL);
1222
1223   // Lay out the segment headers.
1224   Output_segment_headers* segment_headers;
1225   if (parameters->options().relocatable())
1226     segment_headers = NULL;
1227   else
1228     {
1229       segment_headers = new Output_segment_headers(this->segment_list_);
1230       if (load_seg != NULL)
1231         load_seg->add_initial_output_data(segment_headers);
1232       if (phdr_seg != NULL)
1233         phdr_seg->add_initial_output_data(segment_headers);
1234     }
1235
1236   // Lay out the file header.
1237   Output_file_header* file_header;
1238   file_header = new Output_file_header(target, symtab, segment_headers,
1239                                        this->options_.entry());
1240   if (load_seg != NULL)
1241     load_seg->add_initial_output_data(file_header);
1242
1243   this->special_output_list_.push_back(file_header);
1244   if (segment_headers != NULL)
1245     this->special_output_list_.push_back(segment_headers);
1246
1247   if (this->script_options_->saw_phdrs_clause()
1248       && !parameters->options().relocatable())
1249     {
1250       // Support use of FILEHDRS and PHDRS attachments in a PHDRS
1251       // clause in a linker script.
1252       Script_sections* ss = this->script_options_->script_sections();
1253       ss->put_headers_in_phdrs(file_header, segment_headers);
1254     }
1255
1256   // We set the output section indexes in set_segment_offsets and
1257   // set_section_indexes.
1258   unsigned int shndx = 1;
1259
1260   // Set the file offsets of all the segments, and all the sections
1261   // they contain.
1262   off_t off;
1263   if (!parameters->options().relocatable())
1264     off = this->set_segment_offsets(target, load_seg, &shndx);
1265   else
1266     off = this->set_relocatable_section_offsets(file_header, &shndx);
1267
1268   // Set the file offsets of all the non-data sections we've seen so
1269   // far which don't have to wait for the input sections.  We need
1270   // this in order to finalize local symbols in non-allocated
1271   // sections.
1272   off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
1273
1274   // Set the section indexes of all unallocated sections seen so far,
1275   // in case any of them are somehow referenced by a symbol.
1276   shndx = this->set_section_indexes(shndx);
1277
1278   // Create the symbol table sections.
1279   this->create_symtab_sections(input_objects, symtab, shndx, &off);
1280   if (!parameters->doing_static_link())
1281     this->assign_local_dynsym_offsets(input_objects);
1282
1283   // Process any symbol assignments from a linker script.  This must
1284   // be called after the symbol table has been finalized.
1285   this->script_options_->finalize_symbols(symtab, this);
1286
1287   // Create the .shstrtab section.
1288   Output_section* shstrtab_section = this->create_shstrtab();
1289
1290   // Set the file offsets of the rest of the non-data sections which
1291   // don't have to wait for the input sections.
1292   off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
1293
1294   // Now that all sections have been created, set the section indexes
1295   // for any sections which haven't been done yet.
1296   shndx = this->set_section_indexes(shndx);
1297
1298   // Create the section table header.
1299   this->create_shdrs(shstrtab_section, &off);
1300
1301   // If there are no sections which require postprocessing, we can
1302   // handle the section names now, and avoid a resize later.
1303   if (!this->any_postprocessing_sections_)
1304     off = this->set_section_offsets(off,
1305                                     STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
1306
1307   file_header->set_section_info(this->section_headers_, shstrtab_section);
1308
1309   // Now we know exactly where everything goes in the output file
1310   // (except for non-allocated sections which require postprocessing).
1311   Output_data::layout_complete();
1312
1313   this->output_file_size_ = off;
1314
1315   return off;
1316 }
1317
1318 // Create a note header following the format defined in the ELF ABI.
1319 // NAME is the name, NOTE_TYPE is the type, DESCSZ is the size of the
1320 // descriptor.  ALLOCATE is true if the section should be allocated in
1321 // memory.  This returns the new note section.  It sets
1322 // *TRAILING_PADDING to the number of trailing zero bytes required.
1323
1324 Output_section*
1325 Layout::create_note(const char* name, int note_type, size_t descsz,
1326                     bool allocate, size_t* trailing_padding)
1327 {
1328   // Authorities all agree that the values in a .note field should
1329   // be aligned on 4-byte boundaries for 32-bit binaries.  However,
1330   // they differ on what the alignment is for 64-bit binaries.
1331   // The GABI says unambiguously they take 8-byte alignment:
1332   //    http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
1333   // Other documentation says alignment should always be 4 bytes:
1334   //    http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
1335   // GNU ld and GNU readelf both support the latter (at least as of
1336   // version 2.16.91), and glibc always generates the latter for
1337   // .note.ABI-tag (as of version 1.6), so that's the one we go with
1338   // here.
1339 #ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION   // This is not defined by default.
1340   const int size = parameters->target().get_size();
1341 #else
1342   const int size = 32;
1343 #endif
1344
1345   // The contents of the .note section.
1346   size_t namesz = strlen(name) + 1;
1347   size_t aligned_namesz = align_address(namesz, size / 8);
1348   size_t aligned_descsz = align_address(descsz, size / 8);
1349
1350   size_t notehdrsz = 3 * (size / 8) + aligned_namesz;
1351
1352   unsigned char* buffer = new unsigned char[notehdrsz];
1353   memset(buffer, 0, notehdrsz);
1354
1355   bool is_big_endian = parameters->target().is_big_endian();
1356
1357   if (size == 32)
1358     {
1359       if (!is_big_endian)
1360         {
1361           elfcpp::Swap<32, false>::writeval(buffer, namesz);
1362           elfcpp::Swap<32, false>::writeval(buffer + 4, descsz);
1363           elfcpp::Swap<32, false>::writeval(buffer + 8, note_type);
1364         }
1365       else
1366         {
1367           elfcpp::Swap<32, true>::writeval(buffer, namesz);
1368           elfcpp::Swap<32, true>::writeval(buffer + 4, descsz);
1369           elfcpp::Swap<32, true>::writeval(buffer + 8, note_type);
1370         }
1371     }
1372   else if (size == 64)
1373     {
1374       if (!is_big_endian)
1375         {
1376           elfcpp::Swap<64, false>::writeval(buffer, namesz);
1377           elfcpp::Swap<64, false>::writeval(buffer + 8, descsz);
1378           elfcpp::Swap<64, false>::writeval(buffer + 16, note_type);
1379         }
1380       else
1381         {
1382           elfcpp::Swap<64, true>::writeval(buffer, namesz);
1383           elfcpp::Swap<64, true>::writeval(buffer + 8, descsz);
1384           elfcpp::Swap<64, true>::writeval(buffer + 16, note_type);
1385         }
1386     }
1387   else
1388     gold_unreachable();
1389
1390   memcpy(buffer + 3 * (size / 8), name, namesz);
1391
1392   const char* note_name = this->namepool_.add(".note", false, NULL);
1393   elfcpp::Elf_Xword flags = 0;
1394   if (allocate)
1395     flags = elfcpp::SHF_ALLOC;
1396   Output_section* os = this->make_output_section(note_name,
1397                                                  elfcpp::SHT_NOTE,
1398                                                  flags);
1399   Output_section_data* posd = new Output_data_const_buffer(buffer, notehdrsz,
1400                                                            size / 8,
1401                                                            "** note header");
1402   os->add_output_section_data(posd);
1403
1404   *trailing_padding = aligned_descsz - descsz;
1405
1406   return os;
1407 }
1408
1409 // For an executable or shared library, create a note to record the
1410 // version of gold used to create the binary.
1411
1412 void
1413 Layout::create_gold_note()
1414 {
1415   if (parameters->options().relocatable())
1416     return;
1417
1418   std::string desc = std::string("gold ") + gold::get_version_string();
1419
1420   size_t trailing_padding;
1421   Output_section *os = this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION,
1422                                          desc.size(), false, &trailing_padding);
1423
1424   Output_section_data* posd = new Output_data_const(desc, 4);
1425   os->add_output_section_data(posd);
1426
1427   if (trailing_padding > 0)
1428     {
1429       posd = new Output_data_zero_fill(trailing_padding, 0);
1430       os->add_output_section_data(posd);
1431     }
1432 }
1433
1434 // Record whether the stack should be executable.  This can be set
1435 // from the command line using the -z execstack or -z noexecstack
1436 // options.  Otherwise, if any input file has a .note.GNU-stack
1437 // section with the SHF_EXECINSTR flag set, the stack should be
1438 // executable.  Otherwise, if at least one input file a
1439 // .note.GNU-stack section, and some input file has no .note.GNU-stack
1440 // section, we use the target default for whether the stack should be
1441 // executable.  Otherwise, we don't generate a stack note.  When
1442 // generating a object file, we create a .note.GNU-stack section with
1443 // the appropriate marking.  When generating an executable or shared
1444 // library, we create a PT_GNU_STACK segment.
1445
1446 void
1447 Layout::create_executable_stack_info(const Target* target)
1448 {
1449   bool is_stack_executable;
1450   if (this->options_.is_execstack_set())
1451     is_stack_executable = this->options_.is_stack_executable();
1452   else if (!this->input_with_gnu_stack_note_)
1453     return;
1454   else
1455     {
1456       if (this->input_requires_executable_stack_)
1457         is_stack_executable = true;
1458       else if (this->input_without_gnu_stack_note_)
1459         is_stack_executable = target->is_default_stack_executable();
1460       else
1461         is_stack_executable = false;
1462     }
1463
1464   if (parameters->options().relocatable())
1465     {
1466       const char* name = this->namepool_.add(".note.GNU-stack", false, NULL);
1467       elfcpp::Elf_Xword flags = 0;
1468       if (is_stack_executable)
1469         flags |= elfcpp::SHF_EXECINSTR;
1470       this->make_output_section(name, elfcpp::SHT_PROGBITS, flags);
1471     }
1472   else
1473     {
1474       if (this->script_options_->saw_phdrs_clause())
1475         return;
1476       int flags = elfcpp::PF_R | elfcpp::PF_W;
1477       if (is_stack_executable)
1478         flags |= elfcpp::PF_X;
1479       this->make_output_segment(elfcpp::PT_GNU_STACK, flags);
1480     }
1481 }
1482
1483 // If --build-id was used, set up the build ID note.
1484
1485 void
1486 Layout::create_build_id()
1487 {
1488   if (!parameters->options().user_set_build_id())
1489     return;
1490
1491   const char* style = parameters->options().build_id();
1492   if (strcmp(style, "none") == 0)
1493     return;
1494
1495   // Set DESCSZ to the size of the note descriptor.  When possible,
1496   // set DESC to the note descriptor contents.
1497   size_t descsz;
1498   std::string desc;
1499   if (strcmp(style, "md5") == 0)
1500     descsz = 128 / 8;
1501   else if (strcmp(style, "sha1") == 0)
1502     descsz = 160 / 8;
1503   else if (strcmp(style, "uuid") == 0)
1504     {
1505       const size_t uuidsz = 128 / 8;
1506
1507       char buffer[uuidsz];
1508       memset(buffer, 0, uuidsz);
1509
1510       int descriptor = ::open("/dev/urandom", O_RDONLY);
1511       if (descriptor < 0)
1512         gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
1513                    strerror(errno));
1514       else
1515         {
1516           ssize_t got = ::read(descriptor, buffer, uuidsz);
1517           ::close(descriptor);
1518           if (got < 0)
1519             gold_error(_("/dev/urandom: read failed: %s"), strerror(errno));
1520           else if (static_cast<size_t>(got) != uuidsz)
1521             gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"),
1522                        uuidsz, got);
1523         }
1524
1525       desc.assign(buffer, uuidsz);
1526       descsz = uuidsz;
1527     }
1528   else if (strncmp(style, "0x", 2) == 0)
1529     {
1530       hex_init();
1531       const char* p = style + 2;
1532       while (*p != '\0')
1533         {
1534           if (hex_p(p[0]) && hex_p(p[1]))
1535             {
1536               char c = (hex_value(p[0]) << 4) | hex_value(p[1]);
1537               desc += c;
1538               p += 2;
1539             }
1540           else if (*p == '-' || *p == ':')
1541             ++p;
1542           else
1543             gold_fatal(_("--build-id argument '%s' not a valid hex number"),
1544                        style);
1545         }
1546       descsz = desc.size();
1547     }
1548   else
1549     gold_fatal(_("unrecognized --build-id argument '%s'"), style);
1550
1551   // Create the note.
1552   size_t trailing_padding;
1553   Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID,
1554                                          descsz, true, &trailing_padding);
1555
1556   if (!desc.empty())
1557     {
1558       // We know the value already, so we fill it in now.
1559       gold_assert(desc.size() == descsz);
1560
1561       Output_section_data* posd = new Output_data_const(desc, 4);
1562       os->add_output_section_data(posd);
1563
1564       if (trailing_padding != 0)
1565         {
1566           posd = new Output_data_zero_fill(trailing_padding, 0);
1567           os->add_output_section_data(posd);
1568         }
1569     }
1570   else
1571     {
1572       // We need to compute a checksum after we have completed the
1573       // link.
1574       gold_assert(trailing_padding == 0);
1575       this->build_id_note_ = new Output_data_zero_fill(descsz, 4);
1576       os->add_output_section_data(this->build_id_note_);
1577       os->set_after_input_sections();
1578     }
1579 }
1580
1581 // Return whether SEG1 should be before SEG2 in the output file.  This
1582 // is based entirely on the segment type and flags.  When this is
1583 // called the segment addresses has normally not yet been set.
1584
1585 bool
1586 Layout::segment_precedes(const Output_segment* seg1,
1587                          const Output_segment* seg2)
1588 {
1589   elfcpp::Elf_Word type1 = seg1->type();
1590   elfcpp::Elf_Word type2 = seg2->type();
1591
1592   // The single PT_PHDR segment is required to precede any loadable
1593   // segment.  We simply make it always first.
1594   if (type1 == elfcpp::PT_PHDR)
1595     {
1596       gold_assert(type2 != elfcpp::PT_PHDR);
1597       return true;
1598     }
1599   if (type2 == elfcpp::PT_PHDR)
1600     return false;
1601
1602   // The single PT_INTERP segment is required to precede any loadable
1603   // segment.  We simply make it always second.
1604   if (type1 == elfcpp::PT_INTERP)
1605     {
1606       gold_assert(type2 != elfcpp::PT_INTERP);
1607       return true;
1608     }
1609   if (type2 == elfcpp::PT_INTERP)
1610     return false;
1611
1612   // We then put PT_LOAD segments before any other segments.
1613   if (type1 == elfcpp::PT_LOAD && type2 != elfcpp::PT_LOAD)
1614     return true;
1615   if (type2 == elfcpp::PT_LOAD && type1 != elfcpp::PT_LOAD)
1616     return false;
1617
1618   // We put the PT_TLS segment last except for the PT_GNU_RELRO
1619   // segment, because that is where the dynamic linker expects to find
1620   // it (this is just for efficiency; other positions would also work
1621   // correctly).
1622   if (type1 == elfcpp::PT_TLS
1623       && type2 != elfcpp::PT_TLS
1624       && type2 != elfcpp::PT_GNU_RELRO)
1625     return false;
1626   if (type2 == elfcpp::PT_TLS
1627       && type1 != elfcpp::PT_TLS
1628       && type1 != elfcpp::PT_GNU_RELRO)
1629     return true;
1630
1631   // We put the PT_GNU_RELRO segment last, because that is where the
1632   // dynamic linker expects to find it (as with PT_TLS, this is just
1633   // for efficiency).
1634   if (type1 == elfcpp::PT_GNU_RELRO && type2 != elfcpp::PT_GNU_RELRO)
1635     return false;
1636   if (type2 == elfcpp::PT_GNU_RELRO && type1 != elfcpp::PT_GNU_RELRO)
1637     return true;
1638
1639   const elfcpp::Elf_Word flags1 = seg1->flags();
1640   const elfcpp::Elf_Word flags2 = seg2->flags();
1641
1642   // The order of non-PT_LOAD segments is unimportant.  We simply sort
1643   // by the numeric segment type and flags values.  There should not
1644   // be more than one segment with the same type and flags.
1645   if (type1 != elfcpp::PT_LOAD)
1646     {
1647       if (type1 != type2)
1648         return type1 < type2;
1649       gold_assert(flags1 != flags2);
1650       return flags1 < flags2;
1651     }
1652
1653   // If the addresses are set already, sort by load address.
1654   if (seg1->are_addresses_set())
1655     {
1656       if (!seg2->are_addresses_set())
1657         return true;
1658
1659       unsigned int section_count1 = seg1->output_section_count();
1660       unsigned int section_count2 = seg2->output_section_count();
1661       if (section_count1 == 0 && section_count2 > 0)
1662         return true;
1663       if (section_count1 > 0 && section_count2 == 0)
1664         return false;
1665
1666       uint64_t paddr1 = seg1->first_section_load_address();
1667       uint64_t paddr2 = seg2->first_section_load_address();
1668       if (paddr1 != paddr2)
1669         return paddr1 < paddr2;
1670     }
1671   else if (seg2->are_addresses_set())
1672     return false;
1673
1674   // We sort PT_LOAD segments based on the flags.  Readonly segments
1675   // come before writable segments.  Then writable segments with data
1676   // come before writable segments without data.  Then executable
1677   // segments come before non-executable segments.  Then the unlikely
1678   // case of a non-readable segment comes before the normal case of a
1679   // readable segment.  If there are multiple segments with the same
1680   // type and flags, we require that the address be set, and we sort
1681   // by virtual address and then physical address.
1682   if ((flags1 & elfcpp::PF_W) != (flags2 & elfcpp::PF_W))
1683     return (flags1 & elfcpp::PF_W) == 0;
1684   if ((flags1 & elfcpp::PF_W) != 0
1685       && seg1->has_any_data_sections() != seg2->has_any_data_sections())
1686     return seg1->has_any_data_sections();
1687   if ((flags1 & elfcpp::PF_X) != (flags2 & elfcpp::PF_X))
1688     return (flags1 & elfcpp::PF_X) != 0;
1689   if ((flags1 & elfcpp::PF_R) != (flags2 & elfcpp::PF_R))
1690     return (flags1 & elfcpp::PF_R) == 0;
1691
1692   // We shouldn't get here--we shouldn't create segments which we
1693   // can't distinguish.
1694   gold_unreachable();
1695 }
1696
1697 // Set the file offsets of all the segments, and all the sections they
1698 // contain.  They have all been created.  LOAD_SEG must be be laid out
1699 // first.  Return the offset of the data to follow.
1700
1701 off_t
1702 Layout::set_segment_offsets(const Target* target, Output_segment* load_seg,
1703                             unsigned int *pshndx)
1704 {
1705   // Sort them into the final order.
1706   std::sort(this->segment_list_.begin(), this->segment_list_.end(),
1707             Layout::Compare_segments());
1708
1709   // Find the PT_LOAD segments, and set their addresses and offsets
1710   // and their section's addresses and offsets.
1711   uint64_t addr;
1712   if (this->options_.user_set_Ttext())
1713     addr = this->options_.Ttext();
1714   else if (parameters->options().shared())
1715     addr = 0;
1716   else
1717     addr = target->default_text_segment_address();
1718   off_t off = 0;
1719
1720   // If LOAD_SEG is NULL, then the file header and segment headers
1721   // will not be loadable.  But they still need to be at offset 0 in
1722   // the file.  Set their offsets now.
1723   if (load_seg == NULL)
1724     {
1725       for (Data_list::iterator p = this->special_output_list_.begin();
1726            p != this->special_output_list_.end();
1727            ++p)
1728         {
1729           off = align_address(off, (*p)->addralign());
1730           (*p)->set_address_and_file_offset(0, off);
1731           off += (*p)->data_size();
1732         }
1733     }
1734
1735   const bool check_sections = parameters->options().check_sections();
1736   Output_segment* last_load_segment = NULL;
1737
1738   bool was_readonly = false;
1739   for (Segment_list::iterator p = this->segment_list_.begin();
1740        p != this->segment_list_.end();
1741        ++p)
1742     {
1743       if ((*p)->type() == elfcpp::PT_LOAD)
1744         {
1745           if (load_seg != NULL && load_seg != *p)
1746             gold_unreachable();
1747           load_seg = NULL;
1748
1749           bool are_addresses_set = (*p)->are_addresses_set();
1750           if (are_addresses_set)
1751             {
1752               // When it comes to setting file offsets, we care about
1753               // the physical address.
1754               addr = (*p)->paddr();
1755             }
1756           else if (this->options_.user_set_Tdata()
1757                    && ((*p)->flags() & elfcpp::PF_W) != 0
1758                    && (!this->options_.user_set_Tbss()
1759                        || (*p)->has_any_data_sections()))
1760             {
1761               addr = this->options_.Tdata();
1762               are_addresses_set = true;
1763             }
1764           else if (this->options_.user_set_Tbss()
1765                    && ((*p)->flags() & elfcpp::PF_W) != 0
1766                    && !(*p)->has_any_data_sections())
1767             {
1768               addr = this->options_.Tbss();
1769               are_addresses_set = true;
1770             }
1771
1772           uint64_t orig_addr = addr;
1773           uint64_t orig_off = off;
1774
1775           uint64_t aligned_addr = 0;
1776           uint64_t abi_pagesize = target->abi_pagesize();
1777           uint64_t common_pagesize = target->common_pagesize();
1778
1779           if (!parameters->options().nmagic()
1780               && !parameters->options().omagic())
1781             (*p)->set_minimum_p_align(common_pagesize);
1782
1783           if (are_addresses_set)
1784             {
1785               if (!parameters->options().nmagic()
1786                   && !parameters->options().omagic())
1787                 {
1788                   // Adjust the file offset to the same address modulo
1789                   // the page size.
1790                   uint64_t unsigned_off = off;
1791                   uint64_t aligned_off = ((unsigned_off & ~(abi_pagesize - 1))
1792                                           | (addr & (abi_pagesize - 1)));
1793                   if (aligned_off < unsigned_off)
1794                     aligned_off += abi_pagesize;
1795                   off = aligned_off;
1796                 }
1797             }
1798           else
1799             {
1800               // If the last segment was readonly, and this one is
1801               // not, then skip the address forward one page,
1802               // maintaining the same position within the page.  This
1803               // lets us store both segments overlapping on a single
1804               // page in the file, but the loader will put them on
1805               // different pages in memory.
1806
1807               addr = align_address(addr, (*p)->maximum_alignment());
1808               aligned_addr = addr;
1809
1810               if (was_readonly && ((*p)->flags() & elfcpp::PF_W) != 0)
1811                 {
1812                   if ((addr & (abi_pagesize - 1)) != 0)
1813                     addr = addr + abi_pagesize;
1814                 }
1815
1816               off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
1817             }
1818
1819           unsigned int shndx_hold = *pshndx;
1820           uint64_t new_addr = (*p)->set_section_addresses(this, false, addr,
1821                                                           &off, pshndx);
1822
1823           // Now that we know the size of this segment, we may be able
1824           // to save a page in memory, at the cost of wasting some
1825           // file space, by instead aligning to the start of a new
1826           // page.  Here we use the real machine page size rather than
1827           // the ABI mandated page size.
1828
1829           if (!are_addresses_set && aligned_addr != addr)
1830             {
1831               uint64_t first_off = (common_pagesize
1832                                     - (aligned_addr
1833                                        & (common_pagesize - 1)));
1834               uint64_t last_off = new_addr & (common_pagesize - 1);
1835               if (first_off > 0
1836                   && last_off > 0
1837                   && ((aligned_addr & ~ (common_pagesize - 1))
1838                       != (new_addr & ~ (common_pagesize - 1)))
1839                   && first_off + last_off <= common_pagesize)
1840                 {
1841                   *pshndx = shndx_hold;
1842                   addr = align_address(aligned_addr, common_pagesize);
1843                   addr = align_address(addr, (*p)->maximum_alignment());
1844                   off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
1845                   new_addr = (*p)->set_section_addresses(this, true, addr,
1846                                                          &off, pshndx);
1847                 }
1848             }
1849
1850           addr = new_addr;
1851
1852           if (((*p)->flags() & elfcpp::PF_W) == 0)
1853             was_readonly = true;
1854
1855           // Implement --check-sections.  We know that the segments
1856           // are sorted by LMA.
1857           if (check_sections && last_load_segment != NULL)
1858             {
1859               gold_assert(last_load_segment->paddr() <= (*p)->paddr());
1860               if (last_load_segment->paddr() + last_load_segment->memsz()
1861                   > (*p)->paddr())
1862                 {
1863                   unsigned long long lb1 = last_load_segment->paddr();
1864                   unsigned long long le1 = lb1 + last_load_segment->memsz();
1865                   unsigned long long lb2 = (*p)->paddr();
1866                   unsigned long long le2 = lb2 + (*p)->memsz();
1867                   gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
1868                                "[0x%llx -> 0x%llx]"),
1869                              lb1, le1, lb2, le2);
1870                 }
1871             }
1872           last_load_segment = *p;
1873         }
1874     }
1875
1876   // Handle the non-PT_LOAD segments, setting their offsets from their
1877   // section's offsets.
1878   for (Segment_list::iterator p = this->segment_list_.begin();
1879        p != this->segment_list_.end();
1880        ++p)
1881     {
1882       if ((*p)->type() != elfcpp::PT_LOAD)
1883         (*p)->set_offset();
1884     }
1885
1886   // Set the TLS offsets for each section in the PT_TLS segment.
1887   if (this->tls_segment_ != NULL)
1888     this->tls_segment_->set_tls_offsets();
1889
1890   return off;
1891 }
1892
1893 // Set the offsets of all the allocated sections when doing a
1894 // relocatable link.  This does the same jobs as set_segment_offsets,
1895 // only for a relocatable link.
1896
1897 off_t
1898 Layout::set_relocatable_section_offsets(Output_data* file_header,
1899                                         unsigned int *pshndx)
1900 {
1901   off_t off = 0;
1902
1903   file_header->set_address_and_file_offset(0, 0);
1904   off += file_header->data_size();
1905
1906   for (Section_list::iterator p = this->section_list_.begin();
1907        p != this->section_list_.end();
1908        ++p)
1909     {
1910       // We skip unallocated sections here, except that group sections
1911       // have to come first.
1912       if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
1913           && (*p)->type() != elfcpp::SHT_GROUP)
1914         continue;
1915
1916       off = align_address(off, (*p)->addralign());
1917
1918       // The linker script might have set the address.
1919       if (!(*p)->is_address_valid())
1920         (*p)->set_address(0);
1921       (*p)->set_file_offset(off);
1922       (*p)->finalize_data_size();
1923       off += (*p)->data_size();
1924
1925       (*p)->set_out_shndx(*pshndx);
1926       ++*pshndx;
1927     }
1928
1929   return off;
1930 }
1931
1932 // Set the file offset of all the sections not associated with a
1933 // segment.
1934
1935 off_t
1936 Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass)
1937 {
1938   for (Section_list::iterator p = this->unattached_section_list_.begin();
1939        p != this->unattached_section_list_.end();
1940        ++p)
1941     {
1942       // The symtab section is handled in create_symtab_sections.
1943       if (*p == this->symtab_section_)
1944         continue;
1945
1946       // If we've already set the data size, don't set it again.
1947       if ((*p)->is_offset_valid() && (*p)->is_data_size_valid())
1948         continue;
1949
1950       if (pass == BEFORE_INPUT_SECTIONS_PASS
1951           && (*p)->requires_postprocessing())
1952         {
1953           (*p)->create_postprocessing_buffer();
1954           this->any_postprocessing_sections_ = true;
1955         }
1956
1957       if (pass == BEFORE_INPUT_SECTIONS_PASS
1958           && (*p)->after_input_sections())
1959         continue;
1960       else if (pass == POSTPROCESSING_SECTIONS_PASS
1961                && (!(*p)->after_input_sections()
1962                    || (*p)->type() == elfcpp::SHT_STRTAB))
1963         continue;
1964       else if (pass == STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
1965                && (!(*p)->after_input_sections()
1966                    || (*p)->type() != elfcpp::SHT_STRTAB))
1967         continue;
1968
1969       off = align_address(off, (*p)->addralign());
1970       (*p)->set_file_offset(off);
1971       (*p)->finalize_data_size();
1972       off += (*p)->data_size();
1973
1974       // At this point the name must be set.
1975       if (pass != STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS)
1976         this->namepool_.add((*p)->name(), false, NULL);
1977     }
1978   return off;
1979 }
1980
1981 // Set the section indexes of all the sections not associated with a
1982 // segment.
1983
1984 unsigned int
1985 Layout::set_section_indexes(unsigned int shndx)
1986 {
1987   for (Section_list::iterator p = this->unattached_section_list_.begin();
1988        p != this->unattached_section_list_.end();
1989        ++p)
1990     {
1991       if (!(*p)->has_out_shndx())
1992         {
1993           (*p)->set_out_shndx(shndx);
1994           ++shndx;
1995         }
1996     }
1997   return shndx;
1998 }
1999
2000 // Set the section addresses according to the linker script.  This is
2001 // only called when we see a SECTIONS clause.  This returns the
2002 // program segment which should hold the file header and segment
2003 // headers, if any.  It will return NULL if they should not be in a
2004 // segment.
2005
2006 Output_segment*
2007 Layout::set_section_addresses_from_script(Symbol_table* symtab)
2008 {
2009   Script_sections* ss = this->script_options_->script_sections();
2010   gold_assert(ss->saw_sections_clause());
2011
2012   // Place each orphaned output section in the script.
2013   for (Section_list::iterator p = this->section_list_.begin();
2014        p != this->section_list_.end();
2015        ++p)
2016     {
2017       if (!(*p)->found_in_sections_clause())
2018         ss->place_orphan(*p);
2019     }
2020
2021   return this->script_options_->set_section_addresses(symtab, this);
2022 }
2023
2024 // Count the local symbols in the regular symbol table and the dynamic
2025 // symbol table, and build the respective string pools.
2026
2027 void
2028 Layout::count_local_symbols(const Task* task,
2029                             const Input_objects* input_objects)
2030 {
2031   // First, figure out an upper bound on the number of symbols we'll
2032   // be inserting into each pool.  This helps us create the pools with
2033   // the right size, to avoid unnecessary hashtable resizing.
2034   unsigned int symbol_count = 0;
2035   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
2036        p != input_objects->relobj_end();
2037        ++p)
2038     symbol_count += (*p)->local_symbol_count();
2039
2040   // Go from "upper bound" to "estimate."  We overcount for two
2041   // reasons: we double-count symbols that occur in more than one
2042   // object file, and we count symbols that are dropped from the
2043   // output.  Add it all together and assume we overcount by 100%.
2044   symbol_count /= 2;
2045
2046   // We assume all symbols will go into both the sympool and dynpool.
2047   this->sympool_.reserve(symbol_count);
2048   this->dynpool_.reserve(symbol_count);
2049
2050   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
2051        p != input_objects->relobj_end();
2052        ++p)
2053     {
2054       Task_lock_obj<Object> tlo(task, *p);
2055       (*p)->count_local_symbols(&this->sympool_, &this->dynpool_);
2056     }
2057 }
2058
2059 // Create the symbol table sections.  Here we also set the final
2060 // values of the symbols.  At this point all the loadable sections are
2061 // fully laid out.  SHNUM is the number of sections so far.
2062
2063 void
2064 Layout::create_symtab_sections(const Input_objects* input_objects,
2065                                Symbol_table* symtab,
2066                                unsigned int shnum,
2067                                off_t* poff)
2068 {
2069   int symsize;
2070   unsigned int align;
2071   if (parameters->target().get_size() == 32)
2072     {
2073       symsize = elfcpp::Elf_sizes<32>::sym_size;
2074       align = 4;
2075     }
2076   else if (parameters->target().get_size() == 64)
2077     {
2078       symsize = elfcpp::Elf_sizes<64>::sym_size;
2079       align = 8;
2080     }
2081   else
2082     gold_unreachable();
2083
2084   off_t off = *poff;
2085   off = align_address(off, align);
2086   off_t startoff = off;
2087
2088   // Save space for the dummy symbol at the start of the section.  We
2089   // never bother to write this out--it will just be left as zero.
2090   off += symsize;
2091   unsigned int local_symbol_index = 1;
2092
2093   // Add STT_SECTION symbols for each Output section which needs one.
2094   for (Section_list::iterator p = this->section_list_.begin();
2095        p != this->section_list_.end();
2096        ++p)
2097     {
2098       if (!(*p)->needs_symtab_index())
2099         (*p)->set_symtab_index(-1U);
2100       else
2101         {
2102           (*p)->set_symtab_index(local_symbol_index);
2103           ++local_symbol_index;
2104           off += symsize;
2105         }
2106     }
2107
2108   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
2109        p != input_objects->relobj_end();
2110        ++p)
2111     {
2112       unsigned int index = (*p)->finalize_local_symbols(local_symbol_index,
2113                                                         off);
2114       off += (index - local_symbol_index) * symsize;
2115       local_symbol_index = index;
2116     }
2117
2118   unsigned int local_symcount = local_symbol_index;
2119   gold_assert(local_symcount * symsize == off - startoff);
2120
2121   off_t dynoff;
2122   size_t dyn_global_index;
2123   size_t dyncount;
2124   if (this->dynsym_section_ == NULL)
2125     {
2126       dynoff = 0;
2127       dyn_global_index = 0;
2128       dyncount = 0;
2129     }
2130   else
2131     {
2132       dyn_global_index = this->dynsym_section_->info();
2133       off_t locsize = dyn_global_index * this->dynsym_section_->entsize();
2134       dynoff = this->dynsym_section_->offset() + locsize;
2135       dyncount = (this->dynsym_section_->data_size() - locsize) / symsize;
2136       gold_assert(static_cast<off_t>(dyncount * symsize)
2137                   == this->dynsym_section_->data_size() - locsize);
2138     }
2139
2140   off = symtab->finalize(off, dynoff, dyn_global_index, dyncount,
2141                          &this->sympool_, &local_symcount);
2142
2143   if (!parameters->options().strip_all())
2144     {
2145       this->sympool_.set_string_offsets();
2146
2147       const char* symtab_name = this->namepool_.add(".symtab", false, NULL);
2148       Output_section* osymtab = this->make_output_section(symtab_name,
2149                                                           elfcpp::SHT_SYMTAB,
2150                                                           0);
2151       this->symtab_section_ = osymtab;
2152
2153       Output_section_data* pos = new Output_data_fixed_space(off - startoff,
2154                                                              align,
2155                                                              "** symtab");
2156       osymtab->add_output_section_data(pos);
2157
2158       // We generate a .symtab_shndx section if we have more than
2159       // SHN_LORESERVE sections.  Technically it is possible that we
2160       // don't need one, because it is possible that there are no
2161       // symbols in any of sections with indexes larger than
2162       // SHN_LORESERVE.  That is probably unusual, though, and it is
2163       // easier to always create one than to compute section indexes
2164       // twice (once here, once when writing out the symbols).
2165       if (shnum >= elfcpp::SHN_LORESERVE)
2166         {
2167           const char* symtab_xindex_name = this->namepool_.add(".symtab_shndx",
2168                                                                false, NULL);
2169           Output_section* osymtab_xindex =
2170             this->make_output_section(symtab_xindex_name,
2171                                       elfcpp::SHT_SYMTAB_SHNDX, 0);
2172
2173           size_t symcount = (off - startoff) / symsize;
2174           this->symtab_xindex_ = new Output_symtab_xindex(symcount);
2175
2176           osymtab_xindex->add_output_section_data(this->symtab_xindex_);
2177
2178           osymtab_xindex->set_link_section(osymtab);
2179           osymtab_xindex->set_addralign(4);
2180           osymtab_xindex->set_entsize(4);
2181
2182           osymtab_xindex->set_after_input_sections();
2183
2184           // This tells the driver code to wait until the symbol table
2185           // has written out before writing out the postprocessing
2186           // sections, including the .symtab_shndx section.
2187           this->any_postprocessing_sections_ = true;
2188         }
2189
2190       const char* strtab_name = this->namepool_.add(".strtab", false, NULL);
2191       Output_section* ostrtab = this->make_output_section(strtab_name,
2192                                                           elfcpp::SHT_STRTAB,
2193                                                           0);
2194
2195       Output_section_data* pstr = new Output_data_strtab(&this->sympool_);
2196       ostrtab->add_output_section_data(pstr);
2197
2198       osymtab->set_file_offset(startoff);
2199       osymtab->finalize_data_size();
2200       osymtab->set_link_section(ostrtab);
2201       osymtab->set_info(local_symcount);
2202       osymtab->set_entsize(symsize);
2203
2204       *poff = off;
2205     }
2206 }
2207
2208 // Create the .shstrtab section, which holds the names of the
2209 // sections.  At the time this is called, we have created all the
2210 // output sections except .shstrtab itself.
2211
2212 Output_section*
2213 Layout::create_shstrtab()
2214 {
2215   // FIXME: We don't need to create a .shstrtab section if we are
2216   // stripping everything.
2217
2218   const char* name = this->namepool_.add(".shstrtab", false, NULL);
2219
2220   Output_section* os = this->make_output_section(name, elfcpp::SHT_STRTAB, 0);
2221
2222   // We can't write out this section until we've set all the section
2223   // names, and we don't set the names of compressed output sections
2224   // until relocations are complete.
2225   os->set_after_input_sections();
2226
2227   Output_section_data* posd = new Output_data_strtab(&this->namepool_);
2228   os->add_output_section_data(posd);
2229
2230   return os;
2231 }
2232
2233 // Create the section headers.  SIZE is 32 or 64.  OFF is the file
2234 // offset.
2235
2236 void
2237 Layout::create_shdrs(const Output_section* shstrtab_section, off_t* poff)
2238 {
2239   Output_section_headers* oshdrs;
2240   oshdrs = new Output_section_headers(this,
2241                                       &this->segment_list_,
2242                                       &this->section_list_,
2243                                       &this->unattached_section_list_,
2244                                       &this->namepool_,
2245                                       shstrtab_section);
2246   off_t off = align_address(*poff, oshdrs->addralign());
2247   oshdrs->set_address_and_file_offset(0, off);
2248   off += oshdrs->data_size();
2249   *poff = off;
2250   this->section_headers_ = oshdrs;
2251 }
2252
2253 // Count the allocated sections.
2254
2255 size_t
2256 Layout::allocated_output_section_count() const
2257 {
2258   size_t section_count = 0;
2259   for (Segment_list::const_iterator p = this->segment_list_.begin();
2260        p != this->segment_list_.end();
2261        ++p)
2262     section_count += (*p)->output_section_count();
2263   return section_count;
2264 }
2265
2266 // Create the dynamic symbol table.
2267
2268 void
2269 Layout::create_dynamic_symtab(const Input_objects* input_objects,
2270                               Symbol_table* symtab,
2271                               Output_section **pdynstr,
2272                               unsigned int* plocal_dynamic_count,
2273                               std::vector<Symbol*>* pdynamic_symbols,
2274                               Versions* pversions)
2275 {
2276   // Count all the symbols in the dynamic symbol table, and set the
2277   // dynamic symbol indexes.
2278
2279   // Skip symbol 0, which is always all zeroes.
2280   unsigned int index = 1;
2281
2282   // Add STT_SECTION symbols for each Output section which needs one.
2283   for (Section_list::iterator p = this->section_list_.begin();
2284        p != this->section_list_.end();
2285        ++p)
2286     {
2287       if (!(*p)->needs_dynsym_index())
2288         (*p)->set_dynsym_index(-1U);
2289       else
2290         {
2291           (*p)->set_dynsym_index(index);
2292           ++index;
2293         }
2294     }
2295
2296   // Count the local symbols that need to go in the dynamic symbol table,
2297   // and set the dynamic symbol indexes.
2298   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
2299        p != input_objects->relobj_end();
2300        ++p)
2301     {
2302       unsigned int new_index = (*p)->set_local_dynsym_indexes(index);
2303       index = new_index;
2304     }
2305
2306   unsigned int local_symcount = index;
2307   *plocal_dynamic_count = local_symcount;
2308
2309   index = symtab->set_dynsym_indexes(index, pdynamic_symbols,
2310                                      &this->dynpool_, pversions);
2311
2312   int symsize;
2313   unsigned int align;
2314   const int size = parameters->target().get_size();
2315   if (size == 32)
2316     {
2317       symsize = elfcpp::Elf_sizes<32>::sym_size;
2318       align = 4;
2319     }
2320   else if (size == 64)
2321     {
2322       symsize = elfcpp::Elf_sizes<64>::sym_size;
2323       align = 8;
2324     }
2325   else
2326     gold_unreachable();
2327
2328   // Create the dynamic symbol table section.
2329
2330   Output_section* dynsym = this->choose_output_section(NULL, ".dynsym",
2331                                                        elfcpp::SHT_DYNSYM,
2332                                                        elfcpp::SHF_ALLOC,
2333                                                        false);
2334
2335   Output_section_data* odata = new Output_data_fixed_space(index * symsize,
2336                                                            align,
2337                                                            "** dynsym");
2338   dynsym->add_output_section_data(odata);
2339
2340   dynsym->set_info(local_symcount);
2341   dynsym->set_entsize(symsize);
2342   dynsym->set_addralign(align);
2343
2344   this->dynsym_section_ = dynsym;
2345
2346   Output_data_dynamic* const odyn = this->dynamic_data_;
2347   odyn->add_section_address(elfcpp::DT_SYMTAB, dynsym);
2348   odyn->add_constant(elfcpp::DT_SYMENT, symsize);
2349
2350   // If there are more than SHN_LORESERVE allocated sections, we
2351   // create a .dynsym_shndx section.  It is possible that we don't
2352   // need one, because it is possible that there are no dynamic
2353   // symbols in any of the sections with indexes larger than
2354   // SHN_LORESERVE.  This is probably unusual, though, and at this
2355   // time we don't know the actual section indexes so it is
2356   // inconvenient to check.
2357   if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE)
2358     {
2359       Output_section* dynsym_xindex =
2360         this->choose_output_section(NULL, ".dynsym_shndx",
2361                                     elfcpp::SHT_SYMTAB_SHNDX,
2362                                     elfcpp::SHF_ALLOC,
2363                                     false);
2364
2365       this->dynsym_xindex_ = new Output_symtab_xindex(index);
2366
2367       dynsym_xindex->add_output_section_data(this->dynsym_xindex_);
2368
2369       dynsym_xindex->set_link_section(dynsym);
2370       dynsym_xindex->set_addralign(4);
2371       dynsym_xindex->set_entsize(4);
2372
2373       dynsym_xindex->set_after_input_sections();
2374
2375       // This tells the driver code to wait until the symbol table has
2376       // written out before writing out the postprocessing sections,
2377       // including the .dynsym_shndx section.
2378       this->any_postprocessing_sections_ = true;
2379     }
2380
2381   // Create the dynamic string table section.
2382
2383   Output_section* dynstr = this->choose_output_section(NULL, ".dynstr",
2384                                                        elfcpp::SHT_STRTAB,
2385                                                        elfcpp::SHF_ALLOC,
2386                                                        false);
2387
2388   Output_section_data* strdata = new Output_data_strtab(&this->dynpool_);
2389   dynstr->add_output_section_data(strdata);
2390
2391   dynsym->set_link_section(dynstr);
2392   this->dynamic_section_->set_link_section(dynstr);
2393
2394   odyn->add_section_address(elfcpp::DT_STRTAB, dynstr);
2395   odyn->add_section_size(elfcpp::DT_STRSZ, dynstr);
2396
2397   *pdynstr = dynstr;
2398
2399   // Create the hash tables.
2400
2401   if (strcmp(parameters->options().hash_style(), "sysv") == 0
2402       || strcmp(parameters->options().hash_style(), "both") == 0)
2403     {
2404       unsigned char* phash;
2405       unsigned int hashlen;
2406       Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount,
2407                                     &phash, &hashlen);
2408
2409       Output_section* hashsec = this->choose_output_section(NULL, ".hash",
2410                                                             elfcpp::SHT_HASH,
2411                                                             elfcpp::SHF_ALLOC,
2412                                                             false);
2413
2414       Output_section_data* hashdata = new Output_data_const_buffer(phash,
2415                                                                    hashlen,
2416                                                                    align,
2417                                                                    "** hash");
2418       hashsec->add_output_section_data(hashdata);
2419
2420       hashsec->set_link_section(dynsym);
2421       hashsec->set_entsize(4);
2422
2423       odyn->add_section_address(elfcpp::DT_HASH, hashsec);
2424     }
2425
2426   if (strcmp(parameters->options().hash_style(), "gnu") == 0
2427       || strcmp(parameters->options().hash_style(), "both") == 0)
2428     {
2429       unsigned char* phash;
2430       unsigned int hashlen;
2431       Dynobj::create_gnu_hash_table(*pdynamic_symbols, local_symcount,
2432                                     &phash, &hashlen);
2433
2434       Output_section* hashsec = this->choose_output_section(NULL, ".gnu.hash",
2435                                                             elfcpp::SHT_GNU_HASH,
2436                                                             elfcpp::SHF_ALLOC,
2437                                                             false);
2438
2439       Output_section_data* hashdata = new Output_data_const_buffer(phash,
2440                                                                    hashlen,
2441                                                                    align,
2442                                                                    "** hash");
2443       hashsec->add_output_section_data(hashdata);
2444
2445       hashsec->set_link_section(dynsym);
2446       hashsec->set_entsize(4);
2447
2448       odyn->add_section_address(elfcpp::DT_GNU_HASH, hashsec);
2449     }
2450 }
2451
2452 // Assign offsets to each local portion of the dynamic symbol table.
2453
2454 void
2455 Layout::assign_local_dynsym_offsets(const Input_objects* input_objects)
2456 {
2457   Output_section* dynsym = this->dynsym_section_;
2458   gold_assert(dynsym != NULL);
2459
2460   off_t off = dynsym->offset();
2461
2462   // Skip the dummy symbol at the start of the section.
2463   off += dynsym->entsize();
2464
2465   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
2466        p != input_objects->relobj_end();
2467        ++p)
2468     {
2469       unsigned int count = (*p)->set_local_dynsym_offset(off);
2470       off += count * dynsym->entsize();
2471     }
2472 }
2473
2474 // Create the version sections.
2475
2476 void
2477 Layout::create_version_sections(const Versions* versions,
2478                                 const Symbol_table* symtab,
2479                                 unsigned int local_symcount,
2480                                 const std::vector<Symbol*>& dynamic_symbols,
2481                                 const Output_section* dynstr)
2482 {
2483   if (!versions->any_defs() && !versions->any_needs())
2484     return;
2485
2486   switch (parameters->size_and_endianness())
2487     {
2488 #ifdef HAVE_TARGET_32_LITTLE
2489     case Parameters::TARGET_32_LITTLE:
2490       this->sized_create_version_sections<32, false>(versions, symtab,
2491                                                      local_symcount,
2492                                                      dynamic_symbols, dynstr);
2493       break;
2494 #endif
2495 #ifdef HAVE_TARGET_32_BIG
2496     case Parameters::TARGET_32_BIG:
2497       this->sized_create_version_sections<32, true>(versions, symtab,
2498                                                     local_symcount,
2499                                                     dynamic_symbols, dynstr);
2500       break;
2501 #endif
2502 #ifdef HAVE_TARGET_64_LITTLE
2503     case Parameters::TARGET_64_LITTLE:
2504       this->sized_create_version_sections<64, false>(versions, symtab,
2505                                                      local_symcount,
2506                                                      dynamic_symbols, dynstr);
2507       break;
2508 #endif
2509 #ifdef HAVE_TARGET_64_BIG
2510     case Parameters::TARGET_64_BIG:
2511       this->sized_create_version_sections<64, true>(versions, symtab,
2512                                                     local_symcount,
2513                                                     dynamic_symbols, dynstr);
2514       break;
2515 #endif
2516     default:
2517       gold_unreachable();
2518     }
2519 }
2520
2521 // Create the version sections, sized version.
2522
2523 template<int size, bool big_endian>
2524 void
2525 Layout::sized_create_version_sections(
2526     const Versions* versions,
2527     const Symbol_table* symtab,
2528     unsigned int local_symcount,
2529     const std::vector<Symbol*>& dynamic_symbols,
2530     const Output_section* dynstr)
2531 {
2532   Output_section* vsec = this->choose_output_section(NULL, ".gnu.version",
2533                                                      elfcpp::SHT_GNU_versym,
2534                                                      elfcpp::SHF_ALLOC,
2535                                                      false);
2536
2537   unsigned char* vbuf;
2538   unsigned int vsize;
2539   versions->symbol_section_contents<size, big_endian>(symtab, &this->dynpool_,
2540                                                       local_symcount,
2541                                                       dynamic_symbols,
2542                                                       &vbuf, &vsize);
2543
2544   Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2,
2545                                                             "** versions");
2546
2547   vsec->add_output_section_data(vdata);
2548   vsec->set_entsize(2);
2549   vsec->set_link_section(this->dynsym_section_);
2550
2551   Output_data_dynamic* const odyn = this->dynamic_data_;
2552   odyn->add_section_address(elfcpp::DT_VERSYM, vsec);
2553
2554   if (versions->any_defs())
2555     {
2556       Output_section* vdsec;
2557       vdsec= this->choose_output_section(NULL, ".gnu.version_d",
2558                                          elfcpp::SHT_GNU_verdef,
2559                                          elfcpp::SHF_ALLOC,
2560                                          false);
2561
2562       unsigned char* vdbuf;
2563       unsigned int vdsize;
2564       unsigned int vdentries;
2565       versions->def_section_contents<size, big_endian>(&this->dynpool_, &vdbuf,
2566                                                        &vdsize, &vdentries);
2567
2568       Output_section_data* vddata =
2569         new Output_data_const_buffer(vdbuf, vdsize, 4, "** version defs");
2570
2571       vdsec->add_output_section_data(vddata);
2572       vdsec->set_link_section(dynstr);
2573       vdsec->set_info(vdentries);
2574
2575       odyn->add_section_address(elfcpp::DT_VERDEF, vdsec);
2576       odyn->add_constant(elfcpp::DT_VERDEFNUM, vdentries);
2577     }
2578
2579   if (versions->any_needs())
2580     {
2581       Output_section* vnsec;
2582       vnsec = this->choose_output_section(NULL, ".gnu.version_r",
2583                                           elfcpp::SHT_GNU_verneed,
2584                                           elfcpp::SHF_ALLOC,
2585                                           false);
2586
2587       unsigned char* vnbuf;
2588       unsigned int vnsize;
2589       unsigned int vnentries;
2590       versions->need_section_contents<size, big_endian>(&this->dynpool_,
2591                                                         &vnbuf, &vnsize,
2592                                                         &vnentries);
2593
2594       Output_section_data* vndata =
2595         new Output_data_const_buffer(vnbuf, vnsize, 4, "** version refs");
2596
2597       vnsec->add_output_section_data(vndata);
2598       vnsec->set_link_section(dynstr);
2599       vnsec->set_info(vnentries);
2600
2601       odyn->add_section_address(elfcpp::DT_VERNEED, vnsec);
2602       odyn->add_constant(elfcpp::DT_VERNEEDNUM, vnentries);
2603     }
2604 }
2605
2606 // Create the .interp section and PT_INTERP segment.
2607
2608 void
2609 Layout::create_interp(const Target* target)
2610 {
2611   const char* interp = this->options_.dynamic_linker();
2612   if (interp == NULL)
2613     {
2614       interp = target->dynamic_linker();
2615       gold_assert(interp != NULL);
2616     }
2617
2618   size_t len = strlen(interp) + 1;
2619
2620   Output_section_data* odata = new Output_data_const(interp, len, 1);
2621
2622   Output_section* osec = this->choose_output_section(NULL, ".interp",
2623                                                      elfcpp::SHT_PROGBITS,
2624                                                      elfcpp::SHF_ALLOC,
2625                                                      false);
2626   osec->add_output_section_data(odata);
2627
2628   if (!this->script_options_->saw_phdrs_clause())
2629     {
2630       Output_segment* oseg = this->make_output_segment(elfcpp::PT_INTERP,
2631                                                        elfcpp::PF_R);
2632       oseg->add_output_section(osec, elfcpp::PF_R);
2633     }
2634 }
2635
2636 // Finish the .dynamic section and PT_DYNAMIC segment.
2637
2638 void
2639 Layout::finish_dynamic_section(const Input_objects* input_objects,
2640                                const Symbol_table* symtab)
2641 {
2642   if (!this->script_options_->saw_phdrs_clause())
2643     {
2644       Output_segment* oseg = this->make_output_segment(elfcpp::PT_DYNAMIC,
2645                                                        (elfcpp::PF_R
2646                                                         | elfcpp::PF_W));
2647       oseg->add_output_section(this->dynamic_section_,
2648                                elfcpp::PF_R | elfcpp::PF_W);
2649     }
2650
2651   Output_data_dynamic* const odyn = this->dynamic_data_;
2652
2653   for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
2654        p != input_objects->dynobj_end();
2655        ++p)
2656     {
2657       // FIXME: Handle --as-needed.
2658       odyn->add_string(elfcpp::DT_NEEDED, (*p)->soname());
2659     }
2660
2661   if (parameters->options().shared())
2662     {
2663       const char* soname = this->options_.soname();
2664       if (soname != NULL)
2665         odyn->add_string(elfcpp::DT_SONAME, soname);
2666     }
2667
2668   // FIXME: Support --init and --fini.
2669   Symbol* sym = symtab->lookup("_init");
2670   if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
2671     odyn->add_symbol(elfcpp::DT_INIT, sym);
2672
2673   sym = symtab->lookup("_fini");
2674   if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
2675     odyn->add_symbol(elfcpp::DT_FINI, sym);
2676
2677   // FIXME: Support DT_INIT_ARRAY and DT_FINI_ARRAY.
2678
2679   // Add a DT_RPATH entry if needed.
2680   const General_options::Dir_list& rpath(this->options_.rpath());
2681   if (!rpath.empty())
2682     {
2683       std::string rpath_val;
2684       for (General_options::Dir_list::const_iterator p = rpath.begin();
2685            p != rpath.end();
2686            ++p)
2687         {
2688           if (rpath_val.empty())
2689             rpath_val = p->name();
2690           else
2691             {
2692               // Eliminate duplicates.
2693               General_options::Dir_list::const_iterator q;
2694               for (q = rpath.begin(); q != p; ++q)
2695                 if (q->name() == p->name())
2696                   break;
2697               if (q == p)
2698                 {
2699                   rpath_val += ':';
2700                   rpath_val += p->name();
2701                 }
2702             }
2703         }
2704
2705       odyn->add_string(elfcpp::DT_RPATH, rpath_val);
2706       if (parameters->options().enable_new_dtags())
2707         odyn->add_string(elfcpp::DT_RUNPATH, rpath_val);
2708     }
2709
2710   // Look for text segments that have dynamic relocations.
2711   bool have_textrel = false;
2712   if (!this->script_options_->saw_sections_clause())
2713     {
2714       for (Segment_list::const_iterator p = this->segment_list_.begin();
2715            p != this->segment_list_.end();
2716            ++p)
2717         {
2718           if (((*p)->flags() & elfcpp::PF_W) == 0
2719               && (*p)->dynamic_reloc_count() > 0)
2720             {
2721               have_textrel = true;
2722               break;
2723             }
2724         }
2725     }
2726   else
2727     {
2728       // We don't know the section -> segment mapping, so we are
2729       // conservative and just look for readonly sections with
2730       // relocations.  If those sections wind up in writable segments,
2731       // then we have created an unnecessary DT_TEXTREL entry.
2732       for (Section_list::const_iterator p = this->section_list_.begin();
2733            p != this->section_list_.end();
2734            ++p)
2735         {
2736           if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0
2737               && ((*p)->flags() & elfcpp::SHF_WRITE) == 0
2738               && ((*p)->dynamic_reloc_count() > 0))
2739             {
2740               have_textrel = true;
2741               break;
2742             }
2743         }
2744     }
2745
2746   // Add a DT_FLAGS entry. We add it even if no flags are set so that
2747   // post-link tools can easily modify these flags if desired.
2748   unsigned int flags = 0;
2749   if (have_textrel)
2750     {
2751       // Add a DT_TEXTREL for compatibility with older loaders.
2752       odyn->add_constant(elfcpp::DT_TEXTREL, 0);
2753       flags |= elfcpp::DF_TEXTREL;
2754     }
2755   if (parameters->options().shared() && this->has_static_tls())
2756     flags |= elfcpp::DF_STATIC_TLS;
2757   odyn->add_constant(elfcpp::DT_FLAGS, flags);
2758
2759   flags = 0;
2760   if (parameters->options().initfirst())
2761     flags |= elfcpp::DF_1_INITFIRST;
2762   if (parameters->options().interpose())
2763     flags |= elfcpp::DF_1_INTERPOSE;
2764   if (parameters->options().loadfltr())
2765     flags |= elfcpp::DF_1_LOADFLTR;
2766   if (parameters->options().nodefaultlib())
2767     flags |= elfcpp::DF_1_NODEFLIB;
2768   if (parameters->options().nodelete())
2769     flags |= elfcpp::DF_1_NODELETE;
2770   if (parameters->options().nodlopen())
2771     flags |= elfcpp::DF_1_NOOPEN;
2772   if (parameters->options().nodump())
2773     flags |= elfcpp::DF_1_NODUMP;
2774   if (!parameters->options().shared())
2775     flags &= ~(elfcpp::DF_1_INITFIRST
2776                | elfcpp::DF_1_NODELETE
2777                | elfcpp::DF_1_NOOPEN);
2778   if (flags)
2779     odyn->add_constant(elfcpp::DT_FLAGS_1, flags);
2780 }
2781
2782 // The mapping of .gnu.linkonce section names to real section names.
2783
2784 #define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
2785 const Layout::Linkonce_mapping Layout::linkonce_mapping[] =
2786 {
2787   MAPPING_INIT("d.rel.ro.local", ".data.rel.ro.local"), // Before "d.rel.ro".
2788   MAPPING_INIT("d.rel.ro", ".data.rel.ro"),             // Before "d".
2789   MAPPING_INIT("t", ".text"),
2790   MAPPING_INIT("r", ".rodata"),
2791   MAPPING_INIT("d", ".data"),
2792   MAPPING_INIT("b", ".bss"),
2793   MAPPING_INIT("s", ".sdata"),
2794   MAPPING_INIT("sb", ".sbss"),
2795   MAPPING_INIT("s2", ".sdata2"),
2796   MAPPING_INIT("sb2", ".sbss2"),
2797   MAPPING_INIT("wi", ".debug_info"),
2798   MAPPING_INIT("td", ".tdata"),
2799   MAPPING_INIT("tb", ".tbss"),
2800   MAPPING_INIT("lr", ".lrodata"),
2801   MAPPING_INIT("l", ".ldata"),
2802   MAPPING_INIT("lb", ".lbss"),
2803 };
2804 #undef MAPPING_INIT
2805
2806 const int Layout::linkonce_mapping_count =
2807   sizeof(Layout::linkonce_mapping) / sizeof(Layout::linkonce_mapping[0]);
2808
2809 // Return the name of the output section to use for a .gnu.linkonce
2810 // section.  This is based on the default ELF linker script of the old
2811 // GNU linker.  For example, we map a name like ".gnu.linkonce.t.foo"
2812 // to ".text".  Set *PLEN to the length of the name.  *PLEN is
2813 // initialized to the length of NAME.
2814
2815 const char*
2816 Layout::linkonce_output_name(const char* name, size_t *plen)
2817 {
2818   const char* s = name + sizeof(".gnu.linkonce") - 1;
2819   if (*s != '.')
2820     return name;
2821   ++s;
2822   const Linkonce_mapping* plm = linkonce_mapping;
2823   for (int i = 0; i < linkonce_mapping_count; ++i, ++plm)
2824     {
2825       if (strncmp(s, plm->from, plm->fromlen) == 0 && s[plm->fromlen] == '.')
2826         {
2827           *plen = plm->tolen;
2828           return plm->to;
2829         }
2830     }
2831   return name;
2832 }
2833
2834 // Choose the output section name to use given an input section name.
2835 // Set *PLEN to the length of the name.  *PLEN is initialized to the
2836 // length of NAME.
2837
2838 const char*
2839 Layout::output_section_name(const char* name, size_t* plen)
2840 {
2841   if (Layout::is_linkonce(name))
2842     {
2843       // .gnu.linkonce sections are laid out as though they were named
2844       // for the sections are placed into.
2845       return Layout::linkonce_output_name(name, plen);
2846     }
2847
2848   // gcc 4.3 generates the following sorts of section names when it
2849   // needs a section name specific to a function:
2850   //   .text.FN
2851   //   .rodata.FN
2852   //   .sdata2.FN
2853   //   .data.FN
2854   //   .data.rel.FN
2855   //   .data.rel.local.FN
2856   //   .data.rel.ro.FN
2857   //   .data.rel.ro.local.FN
2858   //   .sdata.FN
2859   //   .bss.FN
2860   //   .sbss.FN
2861   //   .tdata.FN
2862   //   .tbss.FN
2863
2864   // The GNU linker maps all of those to the part before the .FN,
2865   // except that .data.rel.local.FN is mapped to .data, and
2866   // .data.rel.ro.local.FN is mapped to .data.rel.ro.  The sections
2867   // beginning with .data.rel.ro.local are grouped together.
2868
2869   // For an anonymous namespace, the string FN can contain a '.'.
2870
2871   // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
2872   // GNU linker maps to .rodata.
2873
2874   // The .data.rel.ro sections enable a security feature triggered by
2875   // the -z relro option.  Section which need to be relocated at
2876   // program startup time but which may be readonly after startup are
2877   // grouped into .data.rel.ro.  They are then put into a PT_GNU_RELRO
2878   // segment.  The dynamic linker will make that segment writable,
2879   // perform relocations, and then make it read-only.  FIXME: We do
2880   // not yet implement this optimization.
2881
2882   // It is hard to handle this in a principled way.
2883
2884   // These are the rules we follow:
2885
2886   // If the section name has no initial '.', or no dot other than an
2887   // initial '.', we use the name unchanged (i.e., "mysection" and
2888   // ".text" are unchanged).
2889
2890   // If the name starts with ".data.rel.ro.local" we use
2891   // ".data.rel.ro.local".
2892
2893   // If the name starts with ".data.rel.ro" we use ".data.rel.ro".
2894
2895   // Otherwise, we drop the second '.' and everything that comes after
2896   // it (i.e., ".text.XXX" becomes ".text").
2897
2898   const char* s = name;
2899   if (*s != '.')
2900     return name;
2901   ++s;
2902   const char* sdot = strchr(s, '.');
2903   if (sdot == NULL)
2904     return name;
2905
2906   const char* const data_rel_ro_local = ".data.rel.ro.local";
2907   if (strncmp(name, data_rel_ro_local, strlen(data_rel_ro_local)) == 0)
2908     {
2909       *plen = strlen(data_rel_ro_local);
2910       return data_rel_ro_local;
2911     }
2912
2913   const char* const data_rel_ro = ".data.rel.ro";
2914   if (strncmp(name, data_rel_ro, strlen(data_rel_ro)) == 0)
2915     {
2916       *plen = strlen(data_rel_ro);
2917       return data_rel_ro;
2918     }
2919
2920   *plen = sdot - name;
2921   return name;
2922 }
2923
2924 // Record the signature of a comdat section, and return whether to
2925 // include it in the link.  If GROUP is true, this is a regular
2926 // section group.  If GROUP is false, this is a group signature
2927 // derived from the name of a linkonce section.  We want linkonce
2928 // signatures and group signatures to block each other, but we don't
2929 // want a linkonce signature to block another linkonce signature.
2930
2931 bool
2932 Layout::add_comdat(Relobj* object, unsigned int shndx,
2933                    const std::string& signature, bool group)
2934 {
2935   Kept_section kept(object, shndx, group);
2936   std::pair<Signatures::iterator, bool> ins(
2937     this->signatures_.insert(std::make_pair(signature, kept)));
2938
2939   if (ins.second)
2940     {
2941       // This is the first time we've seen this signature.
2942       return true;
2943     }
2944
2945   if (ins.first->second.group_)
2946     {
2947       // We've already seen a real section group with this signature.
2948       return false;
2949     }
2950   else if (group)
2951     {
2952       // This is a real section group, and we've already seen a
2953       // linkonce section with this signature.  Record that we've seen
2954       // a section group, and don't include this section group.
2955       ins.first->second.group_ = true;
2956       return false;
2957     }
2958   else
2959     {
2960       // We've already seen a linkonce section and this is a linkonce
2961       // section.  These don't block each other--this may be the same
2962       // symbol name with different section types.
2963       return true;
2964     }
2965 }
2966
2967 // Find the given comdat signature, and return the object and section
2968 // index of the kept group.
2969 Relobj*
2970 Layout::find_kept_object(const std::string& signature,
2971                          unsigned int* pshndx) const
2972 {
2973   Signatures::const_iterator p = this->signatures_.find(signature);
2974   if (p == this->signatures_.end())
2975     return NULL;
2976   if (pshndx != NULL)
2977     *pshndx = p->second.shndx_;
2978   return p->second.object_;
2979 }
2980
2981 // Store the allocated sections into the section list.
2982
2983 void
2984 Layout::get_allocated_sections(Section_list* section_list) const
2985 {
2986   for (Section_list::const_iterator p = this->section_list_.begin();
2987        p != this->section_list_.end();
2988        ++p)
2989     if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
2990       section_list->push_back(*p);
2991 }
2992
2993 // Create an output segment.
2994
2995 Output_segment*
2996 Layout::make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
2997 {
2998   gold_assert(!parameters->options().relocatable());
2999   Output_segment* oseg = new Output_segment(type, flags);
3000   this->segment_list_.push_back(oseg);
3001   return oseg;
3002 }
3003
3004 // Write out the Output_sections.  Most won't have anything to write,
3005 // since most of the data will come from input sections which are
3006 // handled elsewhere.  But some Output_sections do have Output_data.
3007
3008 void
3009 Layout::write_output_sections(Output_file* of) const
3010 {
3011   for (Section_list::const_iterator p = this->section_list_.begin();
3012        p != this->section_list_.end();
3013        ++p)
3014     {
3015       if (!(*p)->after_input_sections())
3016         (*p)->write(of);
3017     }
3018 }
3019
3020 // Write out data not associated with a section or the symbol table.
3021
3022 void
3023 Layout::write_data(const Symbol_table* symtab, Output_file* of) const
3024 {
3025   if (!parameters->options().strip_all())
3026     {
3027       const Output_section* symtab_section = this->symtab_section_;
3028       for (Section_list::const_iterator p = this->section_list_.begin();
3029            p != this->section_list_.end();
3030            ++p)
3031         {
3032           if ((*p)->needs_symtab_index())
3033             {
3034               gold_assert(symtab_section != NULL);
3035               unsigned int index = (*p)->symtab_index();
3036               gold_assert(index > 0 && index != -1U);
3037               off_t off = (symtab_section->offset()
3038                            + index * symtab_section->entsize());
3039               symtab->write_section_symbol(*p, this->symtab_xindex_, of, off);
3040             }
3041         }
3042     }
3043
3044   const Output_section* dynsym_section = this->dynsym_section_;
3045   for (Section_list::const_iterator p = this->section_list_.begin();
3046        p != this->section_list_.end();
3047        ++p)
3048     {
3049       if ((*p)->needs_dynsym_index())
3050         {
3051           gold_assert(dynsym_section != NULL);
3052           unsigned int index = (*p)->dynsym_index();
3053           gold_assert(index > 0 && index != -1U);
3054           off_t off = (dynsym_section->offset()
3055                        + index * dynsym_section->entsize());
3056           symtab->write_section_symbol(*p, this->dynsym_xindex_, of, off);
3057         }
3058     }
3059
3060   // Write out the Output_data which are not in an Output_section.
3061   for (Data_list::const_iterator p = this->special_output_list_.begin();
3062        p != this->special_output_list_.end();
3063        ++p)
3064     (*p)->write(of);
3065 }
3066
3067 // Write out the Output_sections which can only be written after the
3068 // input sections are complete.
3069
3070 void
3071 Layout::write_sections_after_input_sections(Output_file* of)
3072 {
3073   // Determine the final section offsets, and thus the final output
3074   // file size.  Note we finalize the .shstrab last, to allow the
3075   // after_input_section sections to modify their section-names before
3076   // writing.
3077   if (this->any_postprocessing_sections_)
3078     {
3079       off_t off = this->output_file_size_;
3080       off = this->set_section_offsets(off, POSTPROCESSING_SECTIONS_PASS);
3081       
3082       // Now that we've finalized the names, we can finalize the shstrab.
3083       off =
3084         this->set_section_offsets(off,
3085                                   STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
3086
3087       if (off > this->output_file_size_)
3088         {
3089           of->resize(off);
3090           this->output_file_size_ = off;
3091         }
3092     }
3093
3094   for (Section_list::const_iterator p = this->section_list_.begin();
3095        p != this->section_list_.end();
3096        ++p)
3097     {
3098       if ((*p)->after_input_sections())
3099         (*p)->write(of);
3100     }
3101
3102   this->section_headers_->write(of);
3103 }
3104
3105 // If the build ID requires computing a checksum, do so here, and
3106 // write it out.  We compute a checksum over the entire file because
3107 // that is simplest.
3108
3109 void
3110 Layout::write_build_id(Output_file* of) const
3111 {
3112   if (this->build_id_note_ == NULL)
3113     return;
3114
3115   const unsigned char* iv = of->get_input_view(0, this->output_file_size_);
3116
3117   unsigned char* ov = of->get_output_view(this->build_id_note_->offset(),
3118                                           this->build_id_note_->data_size());
3119
3120   const char* style = parameters->options().build_id();
3121   if (strcmp(style, "sha1") == 0)
3122     {
3123       sha1_ctx ctx;
3124       sha1_init_ctx(&ctx);
3125       sha1_process_bytes(iv, this->output_file_size_, &ctx);
3126       sha1_finish_ctx(&ctx, ov);
3127     }
3128   else if (strcmp(style, "md5") == 0)
3129     {
3130       md5_ctx ctx;
3131       md5_init_ctx(&ctx);
3132       md5_process_bytes(iv, this->output_file_size_, &ctx);
3133       md5_finish_ctx(&ctx, ov);
3134     }
3135   else
3136     gold_unreachable();
3137
3138   of->write_output_view(this->build_id_note_->offset(),
3139                         this->build_id_note_->data_size(),
3140                         ov);
3141
3142   of->free_input_view(0, this->output_file_size_, iv);
3143 }
3144
3145 // Write out a binary file.  This is called after the link is
3146 // complete.  IN is the temporary output file we used to generate the
3147 // ELF code.  We simply walk through the segments, read them from
3148 // their file offset in IN, and write them to their load address in
3149 // the output file.  FIXME: with a bit more work, we could support
3150 // S-records and/or Intel hex format here.
3151
3152 void
3153 Layout::write_binary(Output_file* in) const
3154 {
3155   gold_assert(this->options_.oformat_enum()
3156               == General_options::OBJECT_FORMAT_BINARY);
3157
3158   // Get the size of the binary file.
3159   uint64_t max_load_address = 0;
3160   for (Segment_list::const_iterator p = this->segment_list_.begin();
3161        p != this->segment_list_.end();
3162        ++p)
3163     {
3164       if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
3165         {
3166           uint64_t max_paddr = (*p)->paddr() + (*p)->filesz();
3167           if (max_paddr > max_load_address)
3168             max_load_address = max_paddr;
3169         }
3170     }
3171
3172   Output_file out(parameters->options().output_file_name());
3173   out.open(max_load_address);
3174
3175   for (Segment_list::const_iterator p = this->segment_list_.begin();
3176        p != this->segment_list_.end();
3177        ++p)
3178     {
3179       if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
3180         {
3181           const unsigned char* vin = in->get_input_view((*p)->offset(),
3182                                                         (*p)->filesz());
3183           unsigned char* vout = out.get_output_view((*p)->paddr(),
3184                                                     (*p)->filesz());
3185           memcpy(vout, vin, (*p)->filesz());
3186           out.write_output_view((*p)->paddr(), (*p)->filesz(), vout);
3187           in->free_input_view((*p)->offset(), (*p)->filesz(), vin);
3188         }
3189     }
3190
3191   out.close();
3192 }
3193
3194 // Print the output sections to the map file.
3195
3196 void
3197 Layout::print_to_mapfile(Mapfile* mapfile) const
3198 {
3199   for (Segment_list::const_iterator p = this->segment_list_.begin();
3200        p != this->segment_list_.end();
3201        ++p)
3202     (*p)->print_sections_to_mapfile(mapfile);
3203 }
3204
3205 // Print statistical information to stderr.  This is used for --stats.
3206
3207 void
3208 Layout::print_stats() const
3209 {
3210   this->namepool_.print_stats("section name pool");
3211   this->sympool_.print_stats("output symbol name pool");
3212   this->dynpool_.print_stats("dynamic name pool");
3213
3214   for (Section_list::const_iterator p = this->section_list_.begin();
3215        p != this->section_list_.end();
3216        ++p)
3217     (*p)->print_merge_stats();
3218 }
3219
3220 // Write_sections_task methods.
3221
3222 // We can always run this task.
3223
3224 Task_token*
3225 Write_sections_task::is_runnable()
3226 {
3227   return NULL;
3228 }
3229
3230 // We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
3231 // when finished.
3232
3233 void
3234 Write_sections_task::locks(Task_locker* tl)
3235 {
3236   tl->add(this, this->output_sections_blocker_);
3237   tl->add(this, this->final_blocker_);
3238 }
3239
3240 // Run the task--write out the data.
3241
3242 void
3243 Write_sections_task::run(Workqueue*)
3244 {
3245   this->layout_->write_output_sections(this->of_);
3246 }
3247
3248 // Write_data_task methods.
3249
3250 // We can always run this task.
3251
3252 Task_token*
3253 Write_data_task::is_runnable()
3254 {
3255   return NULL;
3256 }
3257
3258 // We need to unlock FINAL_BLOCKER when finished.
3259
3260 void
3261 Write_data_task::locks(Task_locker* tl)
3262 {
3263   tl->add(this, this->final_blocker_);
3264 }
3265
3266 // Run the task--write out the data.
3267
3268 void
3269 Write_data_task::run(Workqueue*)
3270 {
3271   this->layout_->write_data(this->symtab_, this->of_);
3272 }
3273
3274 // Write_symbols_task methods.
3275
3276 // We can always run this task.
3277
3278 Task_token*
3279 Write_symbols_task::is_runnable()
3280 {
3281   return NULL;
3282 }
3283
3284 // We need to unlock FINAL_BLOCKER when finished.
3285
3286 void
3287 Write_symbols_task::locks(Task_locker* tl)
3288 {
3289   tl->add(this, this->final_blocker_);
3290 }
3291
3292 // Run the task--write out the symbols.
3293
3294 void
3295 Write_symbols_task::run(Workqueue*)
3296 {
3297   this->symtab_->write_globals(this->input_objects_, this->sympool_,
3298                                this->dynpool_, this->layout_->symtab_xindex(),
3299                                this->layout_->dynsym_xindex(), this->of_);
3300 }
3301
3302 // Write_after_input_sections_task methods.
3303
3304 // We can only run this task after the input sections have completed.
3305
3306 Task_token*
3307 Write_after_input_sections_task::is_runnable()
3308 {
3309   if (this->input_sections_blocker_->is_blocked())
3310     return this->input_sections_blocker_;
3311   return NULL;
3312 }
3313
3314 // We need to unlock FINAL_BLOCKER when finished.
3315
3316 void
3317 Write_after_input_sections_task::locks(Task_locker* tl)
3318 {
3319   tl->add(this, this->final_blocker_);
3320 }
3321
3322 // Run the task.
3323
3324 void
3325 Write_after_input_sections_task::run(Workqueue*)
3326 {
3327   this->layout_->write_sections_after_input_sections(this->of_);
3328 }
3329
3330 // Close_task_runner methods.
3331
3332 // Run the task--close the file.
3333
3334 void
3335 Close_task_runner::run(Workqueue*, const Task*)
3336 {
3337   // If we need to compute a checksum for the BUILD if, we do so here.
3338   this->layout_->write_build_id(this->of_);
3339
3340   // If we've been asked to create a binary file, we do so here.
3341   if (this->options_->oformat_enum() != General_options::OBJECT_FORMAT_ELF)
3342     this->layout_->write_binary(this->of_);
3343
3344   this->of_->close();
3345 }
3346
3347 // Instantiate the templates we need.  We could use the configure
3348 // script to restrict this to only the ones for implemented targets.
3349
3350 #ifdef HAVE_TARGET_32_LITTLE
3351 template
3352 Output_section*
3353 Layout::layout<32, false>(Sized_relobj<32, false>* object, unsigned int shndx,
3354                           const char* name,
3355                           const elfcpp::Shdr<32, false>& shdr,
3356                           unsigned int, unsigned int, off_t*);
3357 #endif
3358
3359 #ifdef HAVE_TARGET_32_BIG
3360 template
3361 Output_section*
3362 Layout::layout<32, true>(Sized_relobj<32, true>* object, unsigned int shndx,
3363                          const char* name,
3364                          const elfcpp::Shdr<32, true>& shdr,
3365                          unsigned int, unsigned int, off_t*);
3366 #endif
3367
3368 #ifdef HAVE_TARGET_64_LITTLE
3369 template
3370 Output_section*
3371 Layout::layout<64, false>(Sized_relobj<64, false>* object, unsigned int shndx,
3372                           const char* name,
3373                           const elfcpp::Shdr<64, false>& shdr,
3374                           unsigned int, unsigned int, off_t*);
3375 #endif
3376
3377 #ifdef HAVE_TARGET_64_BIG
3378 template
3379 Output_section*
3380 Layout::layout<64, true>(Sized_relobj<64, true>* object, unsigned int shndx,
3381                          const char* name,
3382                          const elfcpp::Shdr<64, true>& shdr,
3383                          unsigned int, unsigned int, off_t*);
3384 #endif
3385
3386 #ifdef HAVE_TARGET_32_LITTLE
3387 template
3388 Output_section*
3389 Layout::layout_reloc<32, false>(Sized_relobj<32, false>* object,
3390                                 unsigned int reloc_shndx,
3391                                 const elfcpp::Shdr<32, false>& shdr,
3392                                 Output_section* data_section,
3393                                 Relocatable_relocs* rr);
3394 #endif
3395
3396 #ifdef HAVE_TARGET_32_BIG
3397 template
3398 Output_section*
3399 Layout::layout_reloc<32, true>(Sized_relobj<32, true>* object,
3400                                unsigned int reloc_shndx,
3401                                const elfcpp::Shdr<32, true>& shdr,
3402                                Output_section* data_section,
3403                                Relocatable_relocs* rr);
3404 #endif
3405
3406 #ifdef HAVE_TARGET_64_LITTLE
3407 template
3408 Output_section*
3409 Layout::layout_reloc<64, false>(Sized_relobj<64, false>* object,
3410                                 unsigned int reloc_shndx,
3411                                 const elfcpp::Shdr<64, false>& shdr,
3412                                 Output_section* data_section,
3413                                 Relocatable_relocs* rr);
3414 #endif
3415
3416 #ifdef HAVE_TARGET_64_BIG
3417 template
3418 Output_section*
3419 Layout::layout_reloc<64, true>(Sized_relobj<64, true>* object,
3420                                unsigned int reloc_shndx,
3421                                const elfcpp::Shdr<64, true>& shdr,
3422                                Output_section* data_section,
3423                                Relocatable_relocs* rr);
3424 #endif
3425
3426 #ifdef HAVE_TARGET_32_LITTLE
3427 template
3428 void
3429 Layout::layout_group<32, false>(Symbol_table* symtab,
3430                                 Sized_relobj<32, false>* object,
3431                                 unsigned int,
3432                                 const char* group_section_name,
3433                                 const char* signature,
3434                                 const elfcpp::Shdr<32, false>& shdr,
3435                                 elfcpp::Elf_Word flags,
3436                                 std::vector<unsigned int>* shndxes);
3437 #endif
3438
3439 #ifdef HAVE_TARGET_32_BIG
3440 template
3441 void
3442 Layout::layout_group<32, true>(Symbol_table* symtab,
3443                                Sized_relobj<32, true>* object,
3444                                unsigned int,
3445                                const char* group_section_name,
3446                                const char* signature,
3447                                const elfcpp::Shdr<32, true>& shdr,
3448                                elfcpp::Elf_Word flags,
3449                                std::vector<unsigned int>* shndxes);
3450 #endif
3451
3452 #ifdef HAVE_TARGET_64_LITTLE
3453 template
3454 void
3455 Layout::layout_group<64, false>(Symbol_table* symtab,
3456                                 Sized_relobj<64, false>* object,
3457                                 unsigned int,
3458                                 const char* group_section_name,
3459                                 const char* signature,
3460                                 const elfcpp::Shdr<64, false>& shdr,
3461                                 elfcpp::Elf_Word flags,
3462                                 std::vector<unsigned int>* shndxes);
3463 #endif
3464
3465 #ifdef HAVE_TARGET_64_BIG
3466 template
3467 void
3468 Layout::layout_group<64, true>(Symbol_table* symtab,
3469                                Sized_relobj<64, true>* object,
3470                                unsigned int,
3471                                const char* group_section_name,
3472                                const char* signature,
3473                                const elfcpp::Shdr<64, true>& shdr,
3474                                elfcpp::Elf_Word flags,
3475                                std::vector<unsigned int>* shndxes);
3476 #endif
3477
3478 #ifdef HAVE_TARGET_32_LITTLE
3479 template
3480 Output_section*
3481 Layout::layout_eh_frame<32, false>(Sized_relobj<32, false>* object,
3482                                    const unsigned char* symbols,
3483                                    off_t symbols_size,
3484                                    const unsigned char* symbol_names,
3485                                    off_t symbol_names_size,
3486                                    unsigned int shndx,
3487                                    const elfcpp::Shdr<32, false>& shdr,
3488                                    unsigned int reloc_shndx,
3489                                    unsigned int reloc_type,
3490                                    off_t* off);
3491 #endif
3492
3493 #ifdef HAVE_TARGET_32_BIG
3494 template
3495 Output_section*
3496 Layout::layout_eh_frame<32, true>(Sized_relobj<32, true>* object,
3497                                    const unsigned char* symbols,
3498                                    off_t symbols_size,
3499                                   const unsigned char* symbol_names,
3500                                   off_t symbol_names_size,
3501                                   unsigned int shndx,
3502                                   const elfcpp::Shdr<32, true>& shdr,
3503                                   unsigned int reloc_shndx,
3504                                   unsigned int reloc_type,
3505                                   off_t* off);
3506 #endif
3507
3508 #ifdef HAVE_TARGET_64_LITTLE
3509 template
3510 Output_section*
3511 Layout::layout_eh_frame<64, false>(Sized_relobj<64, false>* object,
3512                                    const unsigned char* symbols,
3513                                    off_t symbols_size,
3514                                    const unsigned char* symbol_names,
3515                                    off_t symbol_names_size,
3516                                    unsigned int shndx,
3517                                    const elfcpp::Shdr<64, false>& shdr,
3518                                    unsigned int reloc_shndx,
3519                                    unsigned int reloc_type,
3520                                    off_t* off);
3521 #endif
3522
3523 #ifdef HAVE_TARGET_64_BIG
3524 template
3525 Output_section*
3526 Layout::layout_eh_frame<64, true>(Sized_relobj<64, true>* object,
3527                                    const unsigned char* symbols,
3528                                    off_t symbols_size,
3529                                   const unsigned char* symbol_names,
3530                                   off_t symbol_names_size,
3531                                   unsigned int shndx,
3532                                   const elfcpp::Shdr<64, true>& shdr,
3533                                   unsigned int reloc_shndx,
3534                                   unsigned int reloc_type,
3535                                   off_t* off);
3536 #endif
3537
3538 } // End namespace gold.