PR 10147
[external/binutils.git] / gold / object.cc
1 // object.cc -- support for an object file for linking in gold
2
3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5
6 // This file is part of gold.
7
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
12
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 // GNU General Public License for more details.
17
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
22
23 #include "gold.h"
24
25 #include <cerrno>
26 #include <cstring>
27 #include <cstdarg>
28 #include "demangle.h"
29 #include "libiberty.h"
30
31 #include "gc.h"
32 #include "target-select.h"
33 #include "dwarf_reader.h"
34 #include "layout.h"
35 #include "output.h"
36 #include "symtab.h"
37 #include "cref.h"
38 #include "reloc.h"
39 #include "object.h"
40 #include "dynobj.h"
41 #include "plugin.h"
42
43 namespace gold
44 {
45
46 // Class Xindex.
47
48 // Initialize the symtab_xindex_ array.  Find the SHT_SYMTAB_SHNDX
49 // section and read it in.  SYMTAB_SHNDX is the index of the symbol
50 // table we care about.
51
52 template<int size, bool big_endian>
53 void
54 Xindex::initialize_symtab_xindex(Object* object, unsigned int symtab_shndx)
55 {
56   if (!this->symtab_xindex_.empty())
57     return;
58
59   gold_assert(symtab_shndx != 0);
60
61   // Look through the sections in reverse order, on the theory that it
62   // is more likely to be near the end than the beginning.
63   unsigned int i = object->shnum();
64   while (i > 0)
65     {
66       --i;
67       if (object->section_type(i) == elfcpp::SHT_SYMTAB_SHNDX
68           && this->adjust_shndx(object->section_link(i)) == symtab_shndx)
69         {
70           this->read_symtab_xindex<size, big_endian>(object, i, NULL);
71           return;
72         }
73     }
74
75   object->error(_("missing SHT_SYMTAB_SHNDX section"));
76 }
77
78 // Read in the symtab_xindex_ array, given the section index of the
79 // SHT_SYMTAB_SHNDX section.  If PSHDRS is not NULL, it points at the
80 // section headers.
81
82 template<int size, bool big_endian>
83 void
84 Xindex::read_symtab_xindex(Object* object, unsigned int xindex_shndx,
85                            const unsigned char* pshdrs)
86 {
87   section_size_type bytecount;
88   const unsigned char* contents;
89   if (pshdrs == NULL)
90     contents = object->section_contents(xindex_shndx, &bytecount, false);
91   else
92     {
93       const unsigned char* p = (pshdrs
94                                 + (xindex_shndx
95                                    * elfcpp::Elf_sizes<size>::shdr_size));
96       typename elfcpp::Shdr<size, big_endian> shdr(p);
97       bytecount = convert_to_section_size_type(shdr.get_sh_size());
98       contents = object->get_view(shdr.get_sh_offset(), bytecount, true, false);
99     }
100
101   gold_assert(this->symtab_xindex_.empty());
102   this->symtab_xindex_.reserve(bytecount / 4);
103   for (section_size_type i = 0; i < bytecount; i += 4)
104     {
105       unsigned int shndx = elfcpp::Swap<32, big_endian>::readval(contents + i);
106       // We preadjust the section indexes we save.
107       this->symtab_xindex_.push_back(this->adjust_shndx(shndx));
108     }
109 }
110
111 // Symbol symndx has a section of SHN_XINDEX; return the real section
112 // index.
113
114 unsigned int
115 Xindex::sym_xindex_to_shndx(Object* object, unsigned int symndx)
116 {
117   if (symndx >= this->symtab_xindex_.size())
118     {
119       object->error(_("symbol %u out of range for SHT_SYMTAB_SHNDX section"),
120                     symndx);
121       return elfcpp::SHN_UNDEF;
122     }
123   unsigned int shndx = this->symtab_xindex_[symndx];
124   if (shndx < elfcpp::SHN_LORESERVE || shndx >= object->shnum())
125     {
126       object->error(_("extended index for symbol %u out of range: %u"),
127                     symndx, shndx);
128       return elfcpp::SHN_UNDEF;
129     }
130   return shndx;
131 }
132
133 // Class Object.
134
135 // Set the target based on fields in the ELF file header.
136
137 void
138 Object::set_target(int machine, int size, bool big_endian, int osabi,
139                    int abiversion)
140 {
141   Target* target = select_target(machine, size, big_endian, osabi, abiversion);
142   if (target == NULL)
143     gold_fatal(_("%s: unsupported ELF machine number %d"),
144                this->name().c_str(), machine);
145   this->target_ = target;
146 }
147
148 // Report an error for this object file.  This is used by the
149 // elfcpp::Elf_file interface, and also called by the Object code
150 // itself.
151
152 void
153 Object::error(const char* format, ...) const
154 {
155   va_list args;
156   va_start(args, format);
157   char* buf = NULL;
158   if (vasprintf(&buf, format, args) < 0)
159     gold_nomem();
160   va_end(args);
161   gold_error(_("%s: %s"), this->name().c_str(), buf);
162   free(buf);
163 }
164
165 // Return a view of the contents of a section.
166
167 const unsigned char*
168 Object::section_contents(unsigned int shndx, section_size_type* plen,
169                          bool cache)
170 {
171   Location loc(this->do_section_contents(shndx));
172   *plen = convert_to_section_size_type(loc.data_size);
173   if (*plen == 0)
174     {
175       static const unsigned char empty[1] = { '\0' };
176       return empty;
177     }
178   return this->get_view(loc.file_offset, *plen, true, cache);
179 }
180
181 // Read the section data into SD.  This is code common to Sized_relobj
182 // and Sized_dynobj, so we put it into Object.
183
184 template<int size, bool big_endian>
185 void
186 Object::read_section_data(elfcpp::Elf_file<size, big_endian, Object>* elf_file,
187                           Read_symbols_data* sd)
188 {
189   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
190
191   // Read the section headers.
192   const off_t shoff = elf_file->shoff();
193   const unsigned int shnum = this->shnum();
194   sd->section_headers = this->get_lasting_view(shoff, shnum * shdr_size,
195                                                true, true);
196
197   // Read the section names.
198   const unsigned char* pshdrs = sd->section_headers->data();
199   const unsigned char* pshdrnames = pshdrs + elf_file->shstrndx() * shdr_size;
200   typename elfcpp::Shdr<size, big_endian> shdrnames(pshdrnames);
201
202   if (shdrnames.get_sh_type() != elfcpp::SHT_STRTAB)
203     this->error(_("section name section has wrong type: %u"),
204                 static_cast<unsigned int>(shdrnames.get_sh_type()));
205
206   sd->section_names_size =
207     convert_to_section_size_type(shdrnames.get_sh_size());
208   sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(),
209                                              sd->section_names_size, false,
210                                              false);
211 }
212
213 // If NAME is the name of a special .gnu.warning section, arrange for
214 // the warning to be issued.  SHNDX is the section index.  Return
215 // whether it is a warning section.
216
217 bool
218 Object::handle_gnu_warning_section(const char* name, unsigned int shndx,
219                                    Symbol_table* symtab)
220 {
221   const char warn_prefix[] = ".gnu.warning.";
222   const int warn_prefix_len = sizeof warn_prefix - 1;
223   if (strncmp(name, warn_prefix, warn_prefix_len) == 0)
224     {
225       // Read the section contents to get the warning text.  It would
226       // be nicer if we only did this if we have to actually issue a
227       // warning.  Unfortunately, warnings are issued as we relocate
228       // sections.  That means that we can not lock the object then,
229       // as we might try to issue the same warning multiple times
230       // simultaneously.
231       section_size_type len;
232       const unsigned char* contents = this->section_contents(shndx, &len,
233                                                              false);
234       if (len == 0)
235         {
236           const char* warning = name + warn_prefix_len;
237           contents = reinterpret_cast<const unsigned char*>(warning);
238           len = strlen(warning);
239         }
240       std::string warning(reinterpret_cast<const char*>(contents), len);
241       symtab->add_warning(name + warn_prefix_len, this, warning);
242       return true;
243     }
244   return false;
245 }
246
247 // Class Relobj
248
249 // To copy the symbols data read from the file to a local data structure.
250 // This function is called from do_layout only while doing garbage 
251 // collection.
252
253 void
254 Relobj::copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd, 
255                           unsigned int section_header_size)
256 {
257   gc_sd->section_headers_data = 
258          new unsigned char[(section_header_size)];
259   memcpy(gc_sd->section_headers_data, sd->section_headers->data(),
260          section_header_size);
261   gc_sd->section_names_data = 
262          new unsigned char[sd->section_names_size];
263   memcpy(gc_sd->section_names_data, sd->section_names->data(),
264          sd->section_names_size);
265   gc_sd->section_names_size = sd->section_names_size;
266   if (sd->symbols != NULL)
267     {
268       gc_sd->symbols_data = 
269              new unsigned char[sd->symbols_size];
270       memcpy(gc_sd->symbols_data, sd->symbols->data(),
271             sd->symbols_size);
272     }
273   else
274     {
275       gc_sd->symbols_data = NULL;
276     }
277   gc_sd->symbols_size = sd->symbols_size;
278   gc_sd->external_symbols_offset = sd->external_symbols_offset;
279   if (sd->symbol_names != NULL)
280     {
281       gc_sd->symbol_names_data =
282              new unsigned char[sd->symbol_names_size];
283       memcpy(gc_sd->symbol_names_data, sd->symbol_names->data(),
284             sd->symbol_names_size);
285     }
286   else
287     {
288       gc_sd->symbol_names_data = NULL;
289     }
290   gc_sd->symbol_names_size = sd->symbol_names_size;
291 }
292
293 // This function determines if a particular section name must be included
294 // in the link.  This is used during garbage collection to determine the
295 // roots of the worklist.
296
297 bool
298 Relobj::is_section_name_included(const char* name)
299 {
300   if (is_prefix_of(".ctors", name) 
301       || is_prefix_of(".dtors", name) 
302       || is_prefix_of(".note", name) 
303       || is_prefix_of(".init", name) 
304       || is_prefix_of(".fini", name) 
305       || is_prefix_of(".gcc_except_table", name) 
306       || is_prefix_of(".jcr", name) 
307       || is_prefix_of(".preinit_array", name) 
308       || (is_prefix_of(".text", name) 
309           && strstr(name, "personality")) 
310       || (is_prefix_of(".data", name) 
311           &&  strstr(name, "personality")) 
312       || (is_prefix_of(".gnu.linkonce.d", name) && 
313             strstr(name, "personality")))
314     {
315       return true; 
316     }
317   return false;
318 }
319
320 // Class Sized_relobj.
321
322 template<int size, bool big_endian>
323 Sized_relobj<size, big_endian>::Sized_relobj(
324     const std::string& name,
325     Input_file* input_file,
326     off_t offset,
327     const elfcpp::Ehdr<size, big_endian>& ehdr)
328   : Relobj(name, input_file, offset),
329     elf_file_(this, ehdr),
330     symtab_shndx_(-1U),
331     local_symbol_count_(0),
332     output_local_symbol_count_(0),
333     output_local_dynsym_count_(0),
334     symbols_(),
335     defined_count_(0),
336     local_symbol_offset_(0),
337     local_dynsym_offset_(0),
338     local_values_(),
339     local_got_offsets_(),
340     kept_comdat_sections_(),
341     has_eh_frame_(false),
342     discarded_eh_frame_shndx_(-1U)
343 {
344 }
345
346 template<int size, bool big_endian>
347 Sized_relobj<size, big_endian>::~Sized_relobj()
348 {
349 }
350
351 // Set up an object file based on the file header.  This sets up the
352 // target and reads the section information.
353
354 template<int size, bool big_endian>
355 void
356 Sized_relobj<size, big_endian>::setup(
357     const elfcpp::Ehdr<size, big_endian>& ehdr)
358 {
359   this->set_target(ehdr.get_e_machine(), size, big_endian,
360                    ehdr.get_e_ident()[elfcpp::EI_OSABI],
361                    ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
362
363   const unsigned int shnum = this->elf_file_.shnum();
364   this->set_shnum(shnum);
365 }
366
367 // Find the SHT_SYMTAB section, given the section headers.  The ELF
368 // standard says that maybe in the future there can be more than one
369 // SHT_SYMTAB section.  Until somebody figures out how that could
370 // work, we assume there is only one.
371
372 template<int size, bool big_endian>
373 void
374 Sized_relobj<size, big_endian>::find_symtab(const unsigned char* pshdrs)
375 {
376   const unsigned int shnum = this->shnum();
377   this->symtab_shndx_ = 0;
378   if (shnum > 0)
379     {
380       // Look through the sections in reverse order, since gas tends
381       // to put the symbol table at the end.
382       const unsigned char* p = pshdrs + shnum * This::shdr_size;
383       unsigned int i = shnum;
384       unsigned int xindex_shndx = 0;
385       unsigned int xindex_link = 0;
386       while (i > 0)
387         {
388           --i;
389           p -= This::shdr_size;
390           typename This::Shdr shdr(p);
391           if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
392             {
393               this->symtab_shndx_ = i;
394               if (xindex_shndx > 0 && xindex_link == i)
395                 {
396                   Xindex* xindex =
397                     new Xindex(this->elf_file_.large_shndx_offset());
398                   xindex->read_symtab_xindex<size, big_endian>(this,
399                                                                xindex_shndx,
400                                                                pshdrs);
401                   this->set_xindex(xindex);
402                 }
403               break;
404             }
405
406           // Try to pick up the SHT_SYMTAB_SHNDX section, if there is
407           // one.  This will work if it follows the SHT_SYMTAB
408           // section.
409           if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB_SHNDX)
410             {
411               xindex_shndx = i;
412               xindex_link = this->adjust_shndx(shdr.get_sh_link());
413             }
414         }
415     }
416 }
417
418 // Return the Xindex structure to use for object with lots of
419 // sections.
420
421 template<int size, bool big_endian>
422 Xindex*
423 Sized_relobj<size, big_endian>::do_initialize_xindex()
424 {
425   gold_assert(this->symtab_shndx_ != -1U);
426   Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset());
427   xindex->initialize_symtab_xindex<size, big_endian>(this, this->symtab_shndx_);
428   return xindex;
429 }
430
431 // Return whether SHDR has the right type and flags to be a GNU
432 // .eh_frame section.
433
434 template<int size, bool big_endian>
435 bool
436 Sized_relobj<size, big_endian>::check_eh_frame_flags(
437     const elfcpp::Shdr<size, big_endian>* shdr) const
438 {
439   return (shdr->get_sh_type() == elfcpp::SHT_PROGBITS
440           && (shdr->get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
441 }
442
443 // Return whether there is a GNU .eh_frame section, given the section
444 // headers and the section names.
445
446 template<int size, bool big_endian>
447 bool
448 Sized_relobj<size, big_endian>::find_eh_frame(
449     const unsigned char* pshdrs,
450     const char* names,
451     section_size_type names_size) const
452 {
453   const unsigned int shnum = this->shnum();
454   const unsigned char* p = pshdrs + This::shdr_size;
455   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
456     {
457       typename This::Shdr shdr(p);
458       if (this->check_eh_frame_flags(&shdr))
459         {
460           if (shdr.get_sh_name() >= names_size)
461             {
462               this->error(_("bad section name offset for section %u: %lu"),
463                           i, static_cast<unsigned long>(shdr.get_sh_name()));
464               continue;
465             }
466
467           const char* name = names + shdr.get_sh_name();
468           if (strcmp(name, ".eh_frame") == 0)
469             return true;
470         }
471     }
472   return false;
473 }
474
475 // Read the sections and symbols from an object file.
476
477 template<int size, bool big_endian>
478 void
479 Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
480 {
481   this->read_section_data(&this->elf_file_, sd);
482
483   const unsigned char* const pshdrs = sd->section_headers->data();
484
485   this->find_symtab(pshdrs);
486
487   const unsigned char* namesu = sd->section_names->data();
488   const char* names = reinterpret_cast<const char*>(namesu);
489   if (memmem(names, sd->section_names_size, ".eh_frame", 10) != NULL)
490     {
491       if (this->find_eh_frame(pshdrs, names, sd->section_names_size))
492         this->has_eh_frame_ = true;
493     }
494
495   sd->symbols = NULL;
496   sd->symbols_size = 0;
497   sd->external_symbols_offset = 0;
498   sd->symbol_names = NULL;
499   sd->symbol_names_size = 0;
500
501   if (this->symtab_shndx_ == 0)
502     {
503       // No symbol table.  Weird but legal.
504       return;
505     }
506
507   // Get the symbol table section header.
508   typename This::Shdr symtabshdr(pshdrs
509                                  + this->symtab_shndx_ * This::shdr_size);
510   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
511
512   // If this object has a .eh_frame section, we need all the symbols.
513   // Otherwise we only need the external symbols.  While it would be
514   // simpler to just always read all the symbols, I've seen object
515   // files with well over 2000 local symbols, which for a 64-bit
516   // object file format is over 5 pages that we don't need to read
517   // now.
518
519   const int sym_size = This::sym_size;
520   const unsigned int loccount = symtabshdr.get_sh_info();
521   this->local_symbol_count_ = loccount;
522   this->local_values_.resize(loccount);
523   section_offset_type locsize = loccount * sym_size;
524   off_t dataoff = symtabshdr.get_sh_offset();
525   section_size_type datasize =
526     convert_to_section_size_type(symtabshdr.get_sh_size());
527   off_t extoff = dataoff + locsize;
528   section_size_type extsize = datasize - locsize;
529
530   off_t readoff = this->has_eh_frame_ ? dataoff : extoff;
531   section_size_type readsize = this->has_eh_frame_ ? datasize : extsize;
532
533   if (readsize == 0)
534     {
535       // No external symbols.  Also weird but also legal.
536       return;
537     }
538
539   File_view* fvsymtab = this->get_lasting_view(readoff, readsize, true, false);
540
541   // Read the section header for the symbol names.
542   unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
543   if (strtab_shndx >= this->shnum())
544     {
545       this->error(_("invalid symbol table name index: %u"), strtab_shndx);
546       return;
547     }
548   typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
549   if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
550     {
551       this->error(_("symbol table name section has wrong type: %u"),
552                   static_cast<unsigned int>(strtabshdr.get_sh_type()));
553       return;
554     }
555
556   // Read the symbol names.
557   File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(),
558                                                strtabshdr.get_sh_size(),
559                                                false, true);
560
561   sd->symbols = fvsymtab;
562   sd->symbols_size = readsize;
563   sd->external_symbols_offset = this->has_eh_frame_ ? locsize : 0;
564   sd->symbol_names = fvstrtab;
565   sd->symbol_names_size =
566     convert_to_section_size_type(strtabshdr.get_sh_size());
567 }
568
569 // Return the section index of symbol SYM.  Set *VALUE to its value in
570 // the object file.  Set *IS_ORDINARY if this is an ordinary section
571 // index.  not a special cod between SHN_LORESERVE and SHN_HIRESERVE.
572 // Note that for a symbol which is not defined in this object file,
573 // this will set *VALUE to 0 and return SHN_UNDEF; it will not return
574 // the final value of the symbol in the link.
575
576 template<int size, bool big_endian>
577 unsigned int
578 Sized_relobj<size, big_endian>::symbol_section_and_value(unsigned int sym,
579                                                          Address* value,
580                                                          bool* is_ordinary)
581 {
582   section_size_type symbols_size;
583   const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
584                                                         &symbols_size,
585                                                         false);
586
587   const size_t count = symbols_size / This::sym_size;
588   gold_assert(sym < count);
589
590   elfcpp::Sym<size, big_endian> elfsym(symbols + sym * This::sym_size);
591   *value = elfsym.get_st_value();
592
593   return this->adjust_sym_shndx(sym, elfsym.get_st_shndx(), is_ordinary);
594 }
595
596 // Return whether to include a section group in the link.  LAYOUT is
597 // used to keep track of which section groups we have already seen.
598 // INDEX is the index of the section group and SHDR is the section
599 // header.  If we do not want to include this group, we set bits in
600 // OMIT for each section which should be discarded.
601
602 template<int size, bool big_endian>
603 bool
604 Sized_relobj<size, big_endian>::include_section_group(
605     Symbol_table* symtab,
606     Layout* layout,
607     unsigned int index,
608     const char* name,
609     const unsigned char* shdrs,
610     const char* section_names,
611     section_size_type section_names_size,
612     std::vector<bool>* omit)
613 {
614   // Read the section contents.
615   typename This::Shdr shdr(shdrs + index * This::shdr_size);
616   const unsigned char* pcon = this->get_view(shdr.get_sh_offset(),
617                                              shdr.get_sh_size(), true, false);
618   const elfcpp::Elf_Word* pword =
619     reinterpret_cast<const elfcpp::Elf_Word*>(pcon);
620
621   // The first word contains flags.  We only care about COMDAT section
622   // groups.  Other section groups are always included in the link
623   // just like ordinary sections.
624   elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword);
625
626   // Look up the group signature, which is the name of a symbol.  This
627   // is a lot of effort to go to to read a string.  Why didn't they
628   // just have the group signature point into the string table, rather
629   // than indirect through a symbol?
630
631   // Get the appropriate symbol table header (this will normally be
632   // the single SHT_SYMTAB section, but in principle it need not be).
633   const unsigned int link = this->adjust_shndx(shdr.get_sh_link());
634   typename This::Shdr symshdr(this, this->elf_file_.section_header(link));
635
636   // Read the symbol table entry.
637   unsigned int symndx = shdr.get_sh_info();
638   if (symndx >= symshdr.get_sh_size() / This::sym_size)
639     {
640       this->error(_("section group %u info %u out of range"),
641                   index, symndx);
642       return false;
643     }
644   off_t symoff = symshdr.get_sh_offset() + symndx * This::sym_size;
645   const unsigned char* psym = this->get_view(symoff, This::sym_size, true,
646                                              false);
647   elfcpp::Sym<size, big_endian> sym(psym);
648
649   // Read the symbol table names.
650   section_size_type symnamelen;
651   const unsigned char* psymnamesu;
652   psymnamesu = this->section_contents(this->adjust_shndx(symshdr.get_sh_link()),
653                                       &symnamelen, true);
654   const char* psymnames = reinterpret_cast<const char*>(psymnamesu);
655
656   // Get the section group signature.
657   if (sym.get_st_name() >= symnamelen)
658     {
659       this->error(_("symbol %u name offset %u out of range"),
660                   symndx, sym.get_st_name());
661       return false;
662     }
663
664   std::string signature(psymnames + sym.get_st_name());
665
666   // It seems that some versions of gas will create a section group
667   // associated with a section symbol, and then fail to give a name to
668   // the section symbol.  In such a case, use the name of the section.
669   if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION)
670     {
671       bool is_ordinary;
672       unsigned int sym_shndx = this->adjust_sym_shndx(symndx,
673                                                       sym.get_st_shndx(),
674                                                       &is_ordinary);
675       if (!is_ordinary || sym_shndx >= this->shnum())
676         {
677           this->error(_("symbol %u invalid section index %u"),
678                       symndx, sym_shndx);
679           return false;
680         }
681       typename This::Shdr member_shdr(shdrs + sym_shndx * This::shdr_size);
682       if (member_shdr.get_sh_name() < section_names_size)
683         signature = section_names + member_shdr.get_sh_name();
684     }
685
686   // Record this section group in the layout, and see whether we've already
687   // seen one with the same signature.
688   bool include_group;
689   Sized_relobj<size, big_endian>* kept_object = NULL;
690   Kept_section::Comdat_group* kept_group = NULL;
691
692   if ((flags & elfcpp::GRP_COMDAT) == 0)
693     include_group = true;
694   else
695     {
696       Kept_section this_group(this, index, true);
697       Kept_section *kept_section_group;
698       include_group = layout->find_or_add_kept_section(signature,
699                                                        &this_group,
700                                                        &kept_section_group);
701       if (include_group)
702         kept_section_group->group_sections = new Kept_section::Comdat_group;
703
704       kept_group = kept_section_group->group_sections;
705       kept_object = (static_cast<Sized_relobj<size, big_endian>*>
706                      (kept_section_group->object));
707     }
708
709   size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
710
711   std::vector<unsigned int> shndxes;
712   bool relocate_group = include_group && parameters->options().relocatable();
713   if (relocate_group)
714     shndxes.reserve(count - 1);
715
716   for (size_t i = 1; i < count; ++i)
717     {
718       elfcpp::Elf_Word secnum =
719         this->adjust_shndx(elfcpp::Swap<32, big_endian>::readval(pword + i));
720
721       if (relocate_group)
722         shndxes.push_back(secnum);
723
724       if (secnum >= this->shnum())
725         {
726           this->error(_("section %u in section group %u out of range"),
727                       secnum, index);
728           continue;
729         }
730
731       // Check for an earlier section number, since we're going to get
732       // it wrong--we may have already decided to include the section.
733       if (secnum < index)
734         this->error(_("invalid section group %u refers to earlier section %u"),
735                     index, secnum);
736
737       // Get the name of the member section.
738       typename This::Shdr member_shdr(shdrs + secnum * This::shdr_size);
739       if (member_shdr.get_sh_name() >= section_names_size)
740         {
741           // This is an error, but it will be diagnosed eventually
742           // in do_layout, so we don't need to do anything here but
743           // ignore it.
744           continue;
745         }
746       std::string mname(section_names + member_shdr.get_sh_name());
747
748       if (!include_group)
749         {
750           (*omit)[secnum] = true;
751           if (kept_group != NULL)
752             {
753               // Find the corresponding kept section, and store that info
754               // in the discarded section table.
755               Kept_section::Comdat_group::const_iterator p =
756                 kept_group->find(mname);
757               if (p != kept_group->end())
758                 {
759                   Kept_comdat_section* kept =
760                     new Kept_comdat_section(kept_object, p->second);
761                   this->set_kept_comdat_section(secnum, kept);
762                 }
763             }
764         }
765       else if (flags & elfcpp::GRP_COMDAT)
766         {
767           // Add the section to the kept group table.
768           gold_assert(kept_group != NULL);
769           kept_group->insert(std::make_pair(mname, secnum));
770         }
771     }
772
773   if (relocate_group)
774     layout->layout_group(symtab, this, index, name, signature.c_str(),
775                          shdr, flags, &shndxes);
776
777   return include_group;
778 }
779
780 // Whether to include a linkonce section in the link.  NAME is the
781 // name of the section and SHDR is the section header.
782
783 // Linkonce sections are a GNU extension implemented in the original
784 // GNU linker before section groups were defined.  The semantics are
785 // that we only include one linkonce section with a given name.  The
786 // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
787 // where T is the type of section and SYMNAME is the name of a symbol.
788 // In an attempt to make linkonce sections interact well with section
789 // groups, we try to identify SYMNAME and use it like a section group
790 // signature.  We want to block section groups with that signature,
791 // but not other linkonce sections with that signature.  We also use
792 // the full name of the linkonce section as a normal section group
793 // signature.
794
795 template<int size, bool big_endian>
796 bool
797 Sized_relobj<size, big_endian>::include_linkonce_section(
798     Layout* layout,
799     unsigned int index,
800     const char* name,
801     const elfcpp::Shdr<size, big_endian>&)
802 {
803   // In general the symbol name we want will be the string following
804   // the last '.'.  However, we have to handle the case of
805   // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
806   // some versions of gcc.  So we use a heuristic: if the name starts
807   // with ".gnu.linkonce.t.", we use everything after that.  Otherwise
808   // we look for the last '.'.  We can't always simply skip
809   // ".gnu.linkonce.X", because we have to deal with cases like
810   // ".gnu.linkonce.d.rel.ro.local".
811   const char* const linkonce_t = ".gnu.linkonce.t.";
812   const char* symname;
813   if (strncmp(name, linkonce_t, strlen(linkonce_t)) == 0)
814     symname = name + strlen(linkonce_t);
815   else
816     symname = strrchr(name, '.') + 1;
817   std::string sig1(symname);
818   std::string sig2(name);
819   Kept_section candidate1(this, index, false);
820   Kept_section candidate2(this, index, true);
821   Kept_section* kept1;
822   Kept_section* kept2;
823   bool include1 = layout->find_or_add_kept_section(sig1, &candidate1, &kept1);
824   bool include2 = layout->find_or_add_kept_section(sig2, &candidate2, &kept2);
825
826   if (!include2)
827     {
828       // The section is being discarded on the basis of its section
829       // name (i.e., the kept section was also a linkonce section).
830       // In this case, the section index stored with the layout object
831       // is the linkonce section that was kept.
832       unsigned int kept_group_index = kept2->shndx;
833       Relobj* kept_relobj = kept2->object;
834       if (kept_relobj != NULL)
835         {
836           Sized_relobj<size, big_endian>* kept_object =
837             static_cast<Sized_relobj<size, big_endian>*>(kept_relobj);
838           Kept_comdat_section* kept =
839             new Kept_comdat_section(kept_object, kept_group_index);
840           this->set_kept_comdat_section(index, kept);
841         }
842     }
843   else if (!include1)
844     {
845       // The section is being discarded on the basis of its symbol
846       // name.  This means that the corresponding kept section was
847       // part of a comdat group, and it will be difficult to identify
848       // the specific section within that group that corresponds to
849       // this linkonce section.  We'll handle the simple case where
850       // the group has only one member section.  Otherwise, it's not
851       // worth the effort.
852       Relobj* kept_relobj = kept1->object;
853       if (kept_relobj != NULL)
854         {
855           Sized_relobj<size, big_endian>* kept_object =
856             static_cast<Sized_relobj<size, big_endian>*>(kept_relobj);
857           Kept_section::Comdat_group* kept_group = kept1->group_sections;
858           if (kept_group != NULL && kept_group->size() == 1)
859             {
860               Kept_section::Comdat_group::const_iterator p =
861                 kept_group->begin();
862               gold_assert(p != kept_group->end());
863               Kept_comdat_section* kept =
864                 new Kept_comdat_section(kept_object, p->second);
865               this->set_kept_comdat_section(index, kept);
866             }
867         }
868     }
869
870   return include1 && include2;
871 }
872
873 // Layout an input section.
874
875 template<int size, bool big_endian>
876 inline void
877 Sized_relobj<size, big_endian>::layout_section(Layout* layout,
878                                                unsigned int shndx,
879                                                const char* name,
880                                                typename This::Shdr& shdr,
881                                                unsigned int reloc_shndx,
882                                                unsigned int reloc_type)
883 {
884   off_t offset;
885   Output_section* os = layout->layout(this, shndx, name, shdr,
886                                           reloc_shndx, reloc_type, &offset);
887
888   this->output_sections()[shndx] = os;
889   if (offset == -1)
890     this->section_offsets_[shndx] = invalid_address;
891   else
892     this->section_offsets_[shndx] = convert_types<Address, off_t>(offset);
893
894   // If this section requires special handling, and if there are
895   // relocs that apply to it, then we must do the special handling
896   // before we apply the relocs.
897   if (offset == -1 && reloc_shndx != 0)
898     this->set_relocs_must_follow_section_writes();
899 }
900
901 // Lay out the input sections.  We walk through the sections and check
902 // whether they should be included in the link.  If they should, we
903 // pass them to the Layout object, which will return an output section
904 // and an offset.  
905 // During garbage collection (gc-sections), this function is called
906 // twice.  When it is called the first time, it is for setting up some
907 // sections as roots to a work-list and to do comdat processing.  Actual
908 // layout happens the second time around after all the relevant sections
909 // have been determined.  The first time, is_worklist_ready is false.  
910 // It is then set to true after the worklist is processed and the relevant 
911 // sections are determined.  Then, this function is called again to 
912 // layout the sections.
913
914 template<int size, bool big_endian>
915 void
916 Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
917                                           Layout* layout,
918                                           Read_symbols_data* sd)
919 {
920   const unsigned int shnum = this->shnum();
921   bool is_gc_pass_one = (parameters->options().gc_sections() 
922                          && !symtab->gc()->is_worklist_ready());
923   bool is_gc_pass_two = (parameters->options().gc_sections() 
924                          && symtab->gc()->is_worklist_ready());
925   if (shnum == 0)
926     return;
927   Symbols_data* gc_sd = NULL;
928   if (is_gc_pass_one)
929     {
930       // During garbage collection save the symbols data to use it when 
931       // re-entering this function.   
932       gc_sd = new Symbols_data;
933       this->copy_symbols_data(gc_sd, sd, This::shdr_size * shnum);
934       this->set_symbols_data(gc_sd);
935     }
936   else if (is_gc_pass_two)
937     {
938       gc_sd = this->get_symbols_data();
939     }
940
941   const unsigned char* section_headers_data = NULL;
942   section_size_type section_names_size;
943   const unsigned char* symbols_data = NULL;
944   section_size_type symbols_size;
945   section_offset_type external_symbols_offset;
946   const unsigned char* symbol_names_data = NULL;
947   section_size_type symbol_names_size;
948  
949   if (parameters->options().gc_sections())
950     {
951       section_headers_data = gc_sd->section_headers_data;
952       section_names_size = gc_sd->section_names_size;
953       symbols_data = gc_sd->symbols_data;
954       symbols_size = gc_sd->symbols_size;
955       external_symbols_offset = gc_sd->external_symbols_offset;
956       symbol_names_data = gc_sd->symbol_names_data;
957       symbol_names_size = gc_sd->symbol_names_size;
958     }
959   else
960     {
961       section_headers_data = sd->section_headers->data();
962       section_names_size = sd->section_names_size;
963       if (sd->symbols != NULL)
964         symbols_data = sd->symbols->data();
965       symbols_size = sd->symbols_size;
966       external_symbols_offset = sd->external_symbols_offset;
967       if (sd->symbol_names != NULL)
968         symbol_names_data = sd->symbol_names->data();
969       symbol_names_size = sd->symbol_names_size;
970     }
971
972   // Get the section headers.
973   const unsigned char* shdrs = section_headers_data;
974   const unsigned char* pshdrs;
975
976   // Get the section names.
977   const unsigned char* pnamesu = parameters->options().gc_sections() ?
978                                  gc_sd->section_names_data :
979                                  sd->section_names->data();
980   const char* pnames = reinterpret_cast<const char*>(pnamesu);
981
982   // If any input files have been claimed by plugins, we need to defer
983   // actual layout until the replacement files have arrived.
984   const bool should_defer_layout =
985       (parameters->options().has_plugins()
986        && parameters->options().plugins()->should_defer_layout());
987   unsigned int num_sections_to_defer = 0;
988
989   // For each section, record the index of the reloc section if any.
990   // Use 0 to mean that there is no reloc section, -1U to mean that
991   // there is more than one.
992   std::vector<unsigned int> reloc_shndx(shnum, 0);
993   std::vector<unsigned int> reloc_type(shnum, elfcpp::SHT_NULL);
994   // Skip the first, dummy, section.
995   pshdrs = shdrs + This::shdr_size;
996   for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
997     {
998       typename This::Shdr shdr(pshdrs);
999
1000       // Count the number of sections whose layout will be deferred.
1001       if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
1002         ++num_sections_to_defer;
1003
1004       unsigned int sh_type = shdr.get_sh_type();
1005       if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
1006         {
1007           unsigned int target_shndx = this->adjust_shndx(shdr.get_sh_info());
1008           if (target_shndx == 0 || target_shndx >= shnum)
1009             {
1010               this->error(_("relocation section %u has bad info %u"),
1011                           i, target_shndx);
1012               continue;
1013             }
1014
1015           if (reloc_shndx[target_shndx] != 0)
1016             reloc_shndx[target_shndx] = -1U;
1017           else
1018             {
1019               reloc_shndx[target_shndx] = i;
1020               reloc_type[target_shndx] = sh_type;
1021             }
1022         }
1023     }
1024
1025   Output_sections& out_sections(this->output_sections());
1026   std::vector<Address>& out_section_offsets(this->section_offsets_);
1027
1028   if (!is_gc_pass_two)
1029     {
1030       out_sections.resize(shnum);
1031       out_section_offsets.resize(shnum);
1032     }
1033
1034   // If we are only linking for symbols, then there is nothing else to
1035   // do here.
1036   if (this->input_file()->just_symbols())
1037     {
1038       if (!is_gc_pass_two)
1039         {
1040           delete sd->section_headers;
1041           sd->section_headers = NULL;
1042           delete sd->section_names;
1043           sd->section_names = NULL;
1044         }
1045       return;
1046     }
1047
1048   if (num_sections_to_defer > 0)
1049     {
1050       parameters->options().plugins()->add_deferred_layout_object(this);
1051       this->deferred_layout_.reserve(num_sections_to_defer);
1052     }
1053
1054   // Whether we've seen a .note.GNU-stack section.
1055   bool seen_gnu_stack = false;
1056   // The flags of a .note.GNU-stack section.
1057   uint64_t gnu_stack_flags = 0;
1058
1059   // Keep track of which sections to omit.
1060   std::vector<bool> omit(shnum, false);
1061
1062   // Keep track of reloc sections when emitting relocations.
1063   const bool relocatable = parameters->options().relocatable();
1064   const bool emit_relocs = (relocatable
1065                             || parameters->options().emit_relocs());
1066   std::vector<unsigned int> reloc_sections;
1067
1068   // Keep track of .eh_frame sections.
1069   std::vector<unsigned int> eh_frame_sections;
1070
1071   // Skip the first, dummy, section.
1072   pshdrs = shdrs + This::shdr_size;
1073   for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
1074     {
1075       typename This::Shdr shdr(pshdrs);
1076
1077       if (shdr.get_sh_name() >= section_names_size)
1078         {
1079           this->error(_("bad section name offset for section %u: %lu"),
1080                       i, static_cast<unsigned long>(shdr.get_sh_name()));
1081           return;
1082         }
1083
1084       const char* name = pnames + shdr.get_sh_name();
1085
1086       if (!is_gc_pass_two)
1087         { 
1088           if (this->handle_gnu_warning_section(name, i, symtab))
1089             { 
1090               if (!relocatable)
1091                 omit[i] = true;
1092             }
1093
1094           // The .note.GNU-stack section is special.  It gives the
1095           // protection flags that this object file requires for the stack
1096           // in memory.
1097           if (strcmp(name, ".note.GNU-stack") == 0)
1098             {
1099               seen_gnu_stack = true;
1100               gnu_stack_flags |= shdr.get_sh_flags();
1101               omit[i] = true;
1102             }
1103
1104           bool discard = omit[i];
1105           if (!discard)
1106             {
1107               if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
1108                 {
1109                   if (!this->include_section_group(symtab, layout, i, name, 
1110                                                    shdrs, pnames, 
1111                                                    section_names_size,
1112                                                    &omit))
1113                     discard = true;
1114                 }
1115               else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
1116                        && Layout::is_linkonce(name))
1117                 {
1118                   if (!this->include_linkonce_section(layout, i, name, shdr))
1119                     discard = true;
1120                 }
1121             }
1122
1123           if (discard)
1124             {
1125               // Do not include this section in the link.
1126               out_sections[i] = NULL;
1127               out_section_offsets[i] = invalid_address;
1128               continue;
1129             }
1130         }
1131  
1132       if (is_gc_pass_one)
1133         {
1134           if (is_section_name_included(name)
1135               || shdr.get_sh_type() == elfcpp::SHT_INIT_ARRAY 
1136               || shdr.get_sh_type() == elfcpp::SHT_FINI_ARRAY)
1137             {
1138               symtab->gc()->worklist().push(Section_id(this, i)); 
1139             }
1140         }
1141
1142       // When doing a relocatable link we are going to copy input
1143       // reloc sections into the output.  We only want to copy the
1144       // ones associated with sections which are not being discarded.
1145       // However, we don't know that yet for all sections.  So save
1146       // reloc sections and process them later. Garbage collection is
1147       // not triggered when relocatable code is desired.
1148       if (emit_relocs
1149           && (shdr.get_sh_type() == elfcpp::SHT_REL
1150               || shdr.get_sh_type() == elfcpp::SHT_RELA))
1151         {
1152           reloc_sections.push_back(i);
1153           continue;
1154         }
1155
1156       if (relocatable && shdr.get_sh_type() == elfcpp::SHT_GROUP)
1157         continue;
1158
1159       // The .eh_frame section is special.  It holds exception frame
1160       // information that we need to read in order to generate the
1161       // exception frame header.  We process these after all the other
1162       // sections so that the exception frame reader can reliably
1163       // determine which sections are being discarded, and discard the
1164       // corresponding information.
1165       if (!relocatable
1166           && strcmp(name, ".eh_frame") == 0
1167           && this->check_eh_frame_flags(&shdr))
1168         {
1169           if (is_gc_pass_one)
1170             {
1171               out_sections[i] = reinterpret_cast<Output_section*>(1);
1172               out_section_offsets[i] = invalid_address;
1173             }
1174           else
1175             eh_frame_sections.push_back(i);
1176           continue;
1177         }
1178
1179       if (is_gc_pass_two)
1180         {
1181           // This is executed during the second pass of garbage 
1182           // collection. do_layout has been called before and some 
1183           // sections have been already discarded. Simply ignore 
1184           // such sections this time around.
1185           if (out_sections[i] == NULL)
1186             {
1187               gold_assert(out_section_offsets[i] == invalid_address);
1188               continue; 
1189             }
1190           if ((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
1191             if (symtab->gc()->referenced_list().find(Section_id(this,i)) 
1192                 == symtab->gc()->referenced_list().end())
1193               {
1194                 if (parameters->options().print_gc_sections())
1195                   gold_info(_("%s: removing unused section from '%s'" 
1196                               " in file '%s"),
1197                             program_name, this->section_name(i).c_str(), 
1198                             this->name().c_str());
1199                 out_sections[i] = NULL;
1200                 out_section_offsets[i] = invalid_address;
1201                 continue;
1202               }
1203         }
1204       // Defer layout here if input files are claimed by plugins.  When gc
1205       // is turned on this function is called twice.  For the second call
1206       // should_defer_layout should be false.
1207       if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
1208         {
1209           gold_assert(!is_gc_pass_two);
1210           this->deferred_layout_.push_back(Deferred_layout(i, name, 
1211                                                            pshdrs,
1212                                                            reloc_shndx[i],
1213                                                            reloc_type[i]));
1214           // Put dummy values here; real values will be supplied by
1215           // do_layout_deferred_sections.
1216           out_sections[i] = reinterpret_cast<Output_section*>(2);
1217           out_section_offsets[i] = invalid_address;
1218           continue;
1219               }
1220       // During gc_pass_two if a section that was previously deferred is
1221       // found, do not layout the section as layout_deferred_sections will
1222       // do it later from gold.cc.
1223       if (is_gc_pass_two 
1224           && (out_sections[i] == reinterpret_cast<Output_section*>(2)))
1225         continue;
1226
1227       if (is_gc_pass_one)
1228         {
1229           // This is during garbage collection. The out_sections are 
1230           // assigned in the second call to this function. 
1231           out_sections[i] = reinterpret_cast<Output_section*>(1);
1232           out_section_offsets[i] = invalid_address;
1233         }
1234       else
1235         {
1236           // When garbage collection is switched on the actual layout
1237           // only happens in the second call.
1238           this->layout_section(layout, i, name, shdr, reloc_shndx[i],
1239                                reloc_type[i]);
1240         }
1241     }
1242
1243   if (!is_gc_pass_one)
1244     layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags);
1245
1246   // When doing a relocatable link handle the reloc sections at the
1247   // end.  Garbage collection is not turned on for relocatable code. 
1248   if (emit_relocs)
1249     this->size_relocatable_relocs();
1250   gold_assert(!parameters->options().gc_sections() || reloc_sections.empty());
1251   for (std::vector<unsigned int>::const_iterator p = reloc_sections.begin();
1252        p != reloc_sections.end();
1253        ++p)
1254     {
1255       unsigned int i = *p;
1256       const unsigned char* pshdr;
1257       pshdr = section_headers_data + i * This::shdr_size;
1258       typename This::Shdr shdr(pshdr);
1259
1260       unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
1261       if (data_shndx >= shnum)
1262         {
1263           // We already warned about this above.
1264           continue;
1265         }
1266
1267       Output_section* data_section = out_sections[data_shndx];
1268       if (data_section == NULL)
1269         {
1270           out_sections[i] = NULL;
1271           out_section_offsets[i] = invalid_address;
1272           continue;
1273         }
1274
1275       Relocatable_relocs* rr = new Relocatable_relocs();
1276       this->set_relocatable_relocs(i, rr);
1277
1278       Output_section* os = layout->layout_reloc(this, i, shdr, data_section,
1279                                                 rr);
1280       out_sections[i] = os;
1281       out_section_offsets[i] = invalid_address;
1282     }
1283
1284   // Handle the .eh_frame sections at the end.
1285   gold_assert(!is_gc_pass_one || eh_frame_sections.empty());
1286   for (std::vector<unsigned int>::const_iterator p = eh_frame_sections.begin();
1287        p != eh_frame_sections.end();
1288        ++p)
1289     {
1290       gold_assert(this->has_eh_frame_);
1291       gold_assert(external_symbols_offset != 0);
1292
1293       unsigned int i = *p;
1294       const unsigned char *pshdr;
1295       pshdr = section_headers_data + i * This::shdr_size;
1296       typename This::Shdr shdr(pshdr);
1297
1298       off_t offset;
1299       Output_section* os = layout->layout_eh_frame(this,
1300                                                    symbols_data,
1301                                                    symbols_size,
1302                                                    symbol_names_data,
1303                                                    symbol_names_size,
1304                                                    i, shdr,
1305                                                    reloc_shndx[i],
1306                                                    reloc_type[i],
1307                                                    &offset);
1308       out_sections[i] = os;
1309       if (offset == -1)
1310         {
1311           // An object can contain at most one section holding exception
1312           // frame information.
1313           gold_assert(this->discarded_eh_frame_shndx_ == -1U);
1314           this->discarded_eh_frame_shndx_ = i;
1315           out_section_offsets[i] = invalid_address;
1316         }
1317       else
1318         out_section_offsets[i] = convert_types<Address, off_t>(offset);
1319
1320       // If this section requires special handling, and if there are
1321       // relocs that apply to it, then we must do the special handling
1322       // before we apply the relocs.
1323       if (offset == -1 && reloc_shndx[i] != 0)
1324         this->set_relocs_must_follow_section_writes();
1325     }
1326
1327   if (is_gc_pass_two)
1328     {
1329       delete[] gc_sd->section_headers_data;
1330       delete[] gc_sd->section_names_data;
1331       delete[] gc_sd->symbols_data;
1332       delete[] gc_sd->symbol_names_data;
1333     }
1334   else
1335     {
1336       delete sd->section_headers;
1337       sd->section_headers = NULL;
1338       delete sd->section_names;
1339       sd->section_names = NULL;
1340     }
1341 }
1342
1343 // Layout sections whose layout was deferred while waiting for
1344 // input files from a plugin.
1345
1346 template<int size, bool big_endian>
1347 void
1348 Sized_relobj<size, big_endian>::do_layout_deferred_sections(Layout* layout)
1349 {
1350   typename std::vector<Deferred_layout>::iterator deferred;
1351
1352   for (deferred = this->deferred_layout_.begin();
1353        deferred != this->deferred_layout_.end();
1354        ++deferred)
1355     {
1356       typename This::Shdr shdr(deferred->shdr_data_);
1357       this->layout_section(layout, deferred->shndx_, deferred->name_.c_str(),
1358                            shdr, deferred->reloc_shndx_, deferred->reloc_type_);
1359     }
1360
1361   this->deferred_layout_.clear();
1362 }
1363
1364 // Add the symbols to the symbol table.
1365
1366 template<int size, bool big_endian>
1367 void
1368 Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
1369                                                Read_symbols_data* sd,
1370                                                Layout*)
1371 {
1372   if (sd->symbols == NULL)
1373     {
1374       gold_assert(sd->symbol_names == NULL);
1375       return;
1376     }
1377
1378   const int sym_size = This::sym_size;
1379   size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
1380                      / sym_size);
1381   if (symcount * sym_size != sd->symbols_size - sd->external_symbols_offset)
1382     {
1383       this->error(_("size of symbols is not multiple of symbol size"));
1384       return;
1385     }
1386
1387   this->symbols_.resize(symcount);
1388
1389   const char* sym_names =
1390     reinterpret_cast<const char*>(sd->symbol_names->data());
1391   symtab->add_from_relobj(this,
1392                           sd->symbols->data() + sd->external_symbols_offset,
1393                           symcount, this->local_symbol_count_,
1394                           sym_names, sd->symbol_names_size,
1395                           &this->symbols_,
1396                           &this->defined_count_);
1397
1398   delete sd->symbols;
1399   sd->symbols = NULL;
1400   delete sd->symbol_names;
1401   sd->symbol_names = NULL;
1402 }
1403
1404 // First pass over the local symbols.  Here we add their names to
1405 // *POOL and *DYNPOOL, and we store the symbol value in
1406 // THIS->LOCAL_VALUES_.  This function is always called from a
1407 // singleton thread.  This is followed by a call to
1408 // finalize_local_symbols.
1409
1410 template<int size, bool big_endian>
1411 void
1412 Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
1413                                                        Stringpool* dynpool)
1414 {
1415   gold_assert(this->symtab_shndx_ != -1U);
1416   if (this->symtab_shndx_ == 0)
1417     {
1418       // This object has no symbols.  Weird but legal.
1419       return;
1420     }
1421
1422   // Read the symbol table section header.
1423   const unsigned int symtab_shndx = this->symtab_shndx_;
1424   typename This::Shdr symtabshdr(this,
1425                                  this->elf_file_.section_header(symtab_shndx));
1426   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1427
1428   // Read the local symbols.
1429   const int sym_size = This::sym_size;
1430   const unsigned int loccount = this->local_symbol_count_;
1431   gold_assert(loccount == symtabshdr.get_sh_info());
1432   off_t locsize = loccount * sym_size;
1433   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1434                                               locsize, true, true);
1435
1436   // Read the symbol names.
1437   const unsigned int strtab_shndx =
1438     this->adjust_shndx(symtabshdr.get_sh_link());
1439   section_size_type strtab_size;
1440   const unsigned char* pnamesu = this->section_contents(strtab_shndx,
1441                                                         &strtab_size,
1442                                                         true);
1443   const char* pnames = reinterpret_cast<const char*>(pnamesu);
1444
1445   // Loop over the local symbols.
1446
1447   const Output_sections& out_sections(this->output_sections());
1448   unsigned int shnum = this->shnum();
1449   unsigned int count = 0;
1450   unsigned int dyncount = 0;
1451   // Skip the first, dummy, symbol.
1452   psyms += sym_size;
1453   bool discard_locals = parameters->options().discard_locals();
1454   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
1455     {
1456       elfcpp::Sym<size, big_endian> sym(psyms);
1457
1458       Symbol_value<size>& lv(this->local_values_[i]);
1459
1460       bool is_ordinary;
1461       unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
1462                                                   &is_ordinary);
1463       lv.set_input_shndx(shndx, is_ordinary);
1464
1465       if (sym.get_st_type() == elfcpp::STT_SECTION)
1466         lv.set_is_section_symbol();
1467       else if (sym.get_st_type() == elfcpp::STT_TLS)
1468         lv.set_is_tls_symbol();
1469
1470       // Save the input symbol value for use in do_finalize_local_symbols().
1471       lv.set_input_value(sym.get_st_value());
1472
1473       // Decide whether this symbol should go into the output file.
1474
1475       if ((shndx < shnum && out_sections[shndx] == NULL)
1476           || (shndx == this->discarded_eh_frame_shndx_))
1477         {
1478           lv.set_no_output_symtab_entry();
1479           gold_assert(!lv.needs_output_dynsym_entry());
1480           continue;
1481         }
1482
1483       if (sym.get_st_type() == elfcpp::STT_SECTION)
1484         {
1485           lv.set_no_output_symtab_entry();
1486           gold_assert(!lv.needs_output_dynsym_entry());
1487           continue;
1488         }
1489
1490       if (sym.get_st_name() >= strtab_size)
1491         {
1492           this->error(_("local symbol %u section name out of range: %u >= %u"),
1493                       i, sym.get_st_name(),
1494                       static_cast<unsigned int>(strtab_size));
1495           lv.set_no_output_symtab_entry();
1496           continue;
1497         }
1498
1499       // If --discard-locals option is used, discard all temporary local
1500       // symbols.  These symbols start with system-specific local label
1501       // prefixes, typically .L for ELF system.  We want to be compatible
1502       // with GNU ld so here we essentially use the same check in
1503       // bfd_is_local_label().  The code is different because we already
1504       // know that:
1505       //
1506       //   - the symbol is local and thus cannot have global or weak binding.
1507       //   - the symbol is not a section symbol.
1508       //   - the symbol has a name.
1509       //
1510       // We do not discard a symbol if it needs a dynamic symbol entry.
1511       const char* name = pnames + sym.get_st_name();
1512       if (discard_locals
1513           && sym.get_st_type() != elfcpp::STT_FILE
1514           && !lv.needs_output_dynsym_entry()
1515           && parameters->target().is_local_label_name(name))
1516         {
1517           lv.set_no_output_symtab_entry();
1518           continue;
1519         }
1520
1521       // Add the symbol to the symbol table string pool.
1522       pool->add(name, true, NULL);
1523       ++count;
1524
1525       // If needed, add the symbol to the dynamic symbol table string pool.
1526       if (lv.needs_output_dynsym_entry())
1527         {
1528           dynpool->add(name, true, NULL);
1529           ++dyncount;
1530         }
1531     }
1532
1533   this->output_local_symbol_count_ = count;
1534   this->output_local_dynsym_count_ = dyncount;
1535 }
1536
1537 // Finalize the local symbols.  Here we set the final value in
1538 // THIS->LOCAL_VALUES_ and set their output symbol table indexes.
1539 // This function is always called from a singleton thread.  The actual
1540 // output of the local symbols will occur in a separate task.
1541
1542 template<int size, bool big_endian>
1543 unsigned int
1544 Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index,
1545                                                           off_t off)
1546 {
1547   gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
1548
1549   const unsigned int loccount = this->local_symbol_count_;
1550   this->local_symbol_offset_ = off;
1551
1552   const bool relocatable = parameters->options().relocatable();
1553   const Output_sections& out_sections(this->output_sections());
1554   const std::vector<Address>& out_offsets(this->section_offsets_);
1555   unsigned int shnum = this->shnum();
1556
1557   for (unsigned int i = 1; i < loccount; ++i)
1558     {
1559       Symbol_value<size>& lv(this->local_values_[i]);
1560
1561       bool is_ordinary;
1562       unsigned int shndx = lv.input_shndx(&is_ordinary);
1563
1564       // Set the output symbol value.
1565
1566       if (!is_ordinary)
1567         {
1568           if (shndx == elfcpp::SHN_ABS || Symbol::is_common_shndx(shndx))
1569             lv.set_output_value(lv.input_value());
1570           else
1571             {
1572               this->error(_("unknown section index %u for local symbol %u"),
1573                           shndx, i);
1574               lv.set_output_value(0);
1575             }
1576         }
1577       else
1578         {
1579           if (shndx >= shnum)
1580             {
1581               this->error(_("local symbol %u section index %u out of range"),
1582                           i, shndx);
1583               shndx = 0;
1584             }
1585
1586           Output_section* os = out_sections[shndx];
1587
1588           if (os == NULL)
1589             {
1590               // This local symbol belongs to a section we are discarding.
1591               // In some cases when applying relocations later, we will
1592               // attempt to match it to the corresponding kept section,
1593               // so we leave the input value unchanged here.
1594               continue;
1595             }
1596           else if (out_offsets[shndx] == invalid_address)
1597             {
1598               uint64_t start;
1599
1600               // This is a SHF_MERGE section or one which otherwise
1601               // requires special handling.
1602               if (shndx == this->discarded_eh_frame_shndx_)
1603                 {
1604                   // This local symbol belongs to a discarded .eh_frame
1605                   // section.  Just treat it like the case in which
1606                   // os == NULL above.
1607                   gold_assert(this->has_eh_frame_);
1608                   continue;
1609                 }
1610               else if (!lv.is_section_symbol())
1611                 {
1612                   // This is not a section symbol.  We can determine
1613                   // the final value now.
1614                   lv.set_output_value(os->output_address(this, shndx,
1615                                                          lv.input_value()));
1616                 }
1617               else if (!os->find_starting_output_address(this, shndx, &start))
1618                 {
1619                   // This is a section symbol, but apparently not one
1620                   // in a merged section.  Just use the start of the
1621                   // output section.  This happens with relocatable
1622                   // links when the input object has section symbols
1623                   // for arbitrary non-merge sections.
1624                   lv.set_output_value(os->address());
1625                 }
1626               else
1627                 {
1628                   // We have to consider the addend to determine the
1629                   // value to use in a relocation.  START is the start
1630                   // of this input section.
1631                   Merged_symbol_value<size>* msv =
1632                     new Merged_symbol_value<size>(lv.input_value(), start);
1633                   lv.set_merged_symbol_value(msv);
1634                 }
1635             }
1636           else if (lv.is_tls_symbol())
1637             lv.set_output_value(os->tls_offset()
1638                                 + out_offsets[shndx]
1639                                 + lv.input_value());
1640           else
1641             lv.set_output_value((relocatable ? 0 : os->address())
1642                                 + out_offsets[shndx]
1643                                 + lv.input_value());
1644         }
1645
1646       if (lv.needs_output_symtab_entry())
1647         {
1648           lv.set_output_symtab_index(index);
1649           ++index;
1650         }
1651     }
1652   return index;
1653 }
1654
1655 // Set the output dynamic symbol table indexes for the local variables.
1656
1657 template<int size, bool big_endian>
1658 unsigned int
1659 Sized_relobj<size, big_endian>::do_set_local_dynsym_indexes(unsigned int index)
1660 {
1661   const unsigned int loccount = this->local_symbol_count_;
1662   for (unsigned int i = 1; i < loccount; ++i)
1663     {
1664       Symbol_value<size>& lv(this->local_values_[i]);
1665       if (lv.needs_output_dynsym_entry())
1666         {
1667           lv.set_output_dynsym_index(index);
1668           ++index;
1669         }
1670     }
1671   return index;
1672 }
1673
1674 // Set the offset where local dynamic symbol information will be stored.
1675 // Returns the count of local symbols contributed to the symbol table by
1676 // this object.
1677
1678 template<int size, bool big_endian>
1679 unsigned int
1680 Sized_relobj<size, big_endian>::do_set_local_dynsym_offset(off_t off)
1681 {
1682   gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
1683   this->local_dynsym_offset_ = off;
1684   return this->output_local_dynsym_count_;
1685 }
1686
1687 // Write out the local symbols.
1688
1689 template<int size, bool big_endian>
1690 void
1691 Sized_relobj<size, big_endian>::write_local_symbols(
1692     Output_file* of,
1693     const Stringpool* sympool,
1694     const Stringpool* dynpool,
1695     Output_symtab_xindex* symtab_xindex,
1696     Output_symtab_xindex* dynsym_xindex)
1697 {
1698   const bool strip_all = parameters->options().strip_all();
1699   if (strip_all)
1700     {
1701       if (this->output_local_dynsym_count_ == 0)
1702         return;
1703       this->output_local_symbol_count_ = 0;
1704     }
1705
1706   gold_assert(this->symtab_shndx_ != -1U);
1707   if (this->symtab_shndx_ == 0)
1708     {
1709       // This object has no symbols.  Weird but legal.
1710       return;
1711     }
1712
1713   // Read the symbol table section header.
1714   const unsigned int symtab_shndx = this->symtab_shndx_;
1715   typename This::Shdr symtabshdr(this,
1716                                  this->elf_file_.section_header(symtab_shndx));
1717   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1718   const unsigned int loccount = this->local_symbol_count_;
1719   gold_assert(loccount == symtabshdr.get_sh_info());
1720
1721   // Read the local symbols.
1722   const int sym_size = This::sym_size;
1723   off_t locsize = loccount * sym_size;
1724   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1725                                               locsize, true, false);
1726
1727   // Read the symbol names.
1728   const unsigned int strtab_shndx =
1729     this->adjust_shndx(symtabshdr.get_sh_link());
1730   section_size_type strtab_size;
1731   const unsigned char* pnamesu = this->section_contents(strtab_shndx,
1732                                                         &strtab_size,
1733                                                         false);
1734   const char* pnames = reinterpret_cast<const char*>(pnamesu);
1735
1736   // Get views into the output file for the portions of the symbol table
1737   // and the dynamic symbol table that we will be writing.
1738   off_t output_size = this->output_local_symbol_count_ * sym_size;
1739   unsigned char* oview = NULL;
1740   if (output_size > 0)
1741     oview = of->get_output_view(this->local_symbol_offset_, output_size);
1742
1743   off_t dyn_output_size = this->output_local_dynsym_count_ * sym_size;
1744   unsigned char* dyn_oview = NULL;
1745   if (dyn_output_size > 0)
1746     dyn_oview = of->get_output_view(this->local_dynsym_offset_,
1747                                     dyn_output_size);
1748
1749   const Output_sections out_sections(this->output_sections());
1750
1751   gold_assert(this->local_values_.size() == loccount);
1752
1753   unsigned char* ov = oview;
1754   unsigned char* dyn_ov = dyn_oview;
1755   psyms += sym_size;
1756   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
1757     {
1758       elfcpp::Sym<size, big_endian> isym(psyms);
1759
1760       Symbol_value<size>& lv(this->local_values_[i]);
1761
1762       bool is_ordinary;
1763       unsigned int st_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
1764                                                      &is_ordinary);
1765       if (is_ordinary)
1766         {
1767           gold_assert(st_shndx < out_sections.size());
1768           if (out_sections[st_shndx] == NULL)
1769             continue;
1770           st_shndx = out_sections[st_shndx]->out_shndx();
1771           if (st_shndx >= elfcpp::SHN_LORESERVE)
1772             {
1773               if (lv.needs_output_symtab_entry() && !strip_all)
1774                 symtab_xindex->add(lv.output_symtab_index(), st_shndx);
1775               if (lv.needs_output_dynsym_entry())
1776                 dynsym_xindex->add(lv.output_dynsym_index(), st_shndx);
1777               st_shndx = elfcpp::SHN_XINDEX;
1778             }
1779         }
1780
1781       // Write the symbol to the output symbol table.
1782       if (!strip_all && lv.needs_output_symtab_entry())
1783         {
1784           elfcpp::Sym_write<size, big_endian> osym(ov);
1785
1786           gold_assert(isym.get_st_name() < strtab_size);
1787           const char* name = pnames + isym.get_st_name();
1788           osym.put_st_name(sympool->get_offset(name));
1789           osym.put_st_value(this->local_values_[i].value(this, 0));
1790           osym.put_st_size(isym.get_st_size());
1791           osym.put_st_info(isym.get_st_info());
1792           osym.put_st_other(isym.get_st_other());
1793           osym.put_st_shndx(st_shndx);
1794
1795           ov += sym_size;
1796         }
1797
1798       // Write the symbol to the output dynamic symbol table.
1799       if (lv.needs_output_dynsym_entry())
1800         {
1801           gold_assert(dyn_ov < dyn_oview + dyn_output_size);
1802           elfcpp::Sym_write<size, big_endian> osym(dyn_ov);
1803
1804           gold_assert(isym.get_st_name() < strtab_size);
1805           const char* name = pnames + isym.get_st_name();
1806           osym.put_st_name(dynpool->get_offset(name));
1807           osym.put_st_value(this->local_values_[i].value(this, 0));
1808           osym.put_st_size(isym.get_st_size());
1809           osym.put_st_info(isym.get_st_info());
1810           osym.put_st_other(isym.get_st_other());
1811           osym.put_st_shndx(st_shndx);
1812
1813           dyn_ov += sym_size;
1814         }
1815     }
1816
1817
1818   if (output_size > 0)
1819     {
1820       gold_assert(ov - oview == output_size);
1821       of->write_output_view(this->local_symbol_offset_, output_size, oview);
1822     }
1823
1824   if (dyn_output_size > 0)
1825     {
1826       gold_assert(dyn_ov - dyn_oview == dyn_output_size);
1827       of->write_output_view(this->local_dynsym_offset_, dyn_output_size,
1828                             dyn_oview);
1829     }
1830 }
1831
1832 // Set *INFO to symbolic information about the offset OFFSET in the
1833 // section SHNDX.  Return true if we found something, false if we
1834 // found nothing.
1835
1836 template<int size, bool big_endian>
1837 bool
1838 Sized_relobj<size, big_endian>::get_symbol_location_info(
1839     unsigned int shndx,
1840     off_t offset,
1841     Symbol_location_info* info)
1842 {
1843   if (this->symtab_shndx_ == 0)
1844     return false;
1845
1846   section_size_type symbols_size;
1847   const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
1848                                                         &symbols_size,
1849                                                         false);
1850
1851   unsigned int symbol_names_shndx =
1852     this->adjust_shndx(this->section_link(this->symtab_shndx_));
1853   section_size_type names_size;
1854   const unsigned char* symbol_names_u =
1855     this->section_contents(symbol_names_shndx, &names_size, false);
1856   const char* symbol_names = reinterpret_cast<const char*>(symbol_names_u);
1857
1858   const int sym_size = This::sym_size;
1859   const size_t count = symbols_size / sym_size;
1860
1861   const unsigned char* p = symbols;
1862   for (size_t i = 0; i < count; ++i, p += sym_size)
1863     {
1864       elfcpp::Sym<size, big_endian> sym(p);
1865
1866       if (sym.get_st_type() == elfcpp::STT_FILE)
1867         {
1868           if (sym.get_st_name() >= names_size)
1869             info->source_file = "(invalid)";
1870           else
1871             info->source_file = symbol_names + sym.get_st_name();
1872           continue;
1873         }
1874
1875       bool is_ordinary;
1876       unsigned int st_shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
1877                                                      &is_ordinary);
1878       if (is_ordinary
1879           && st_shndx == shndx
1880           && static_cast<off_t>(sym.get_st_value()) <= offset
1881           && (static_cast<off_t>(sym.get_st_value() + sym.get_st_size())
1882               > offset))
1883         {
1884           if (sym.get_st_name() > names_size)
1885             info->enclosing_symbol_name = "(invalid)";
1886           else
1887             {
1888               info->enclosing_symbol_name = symbol_names + sym.get_st_name();
1889               if (parameters->options().do_demangle())
1890                 {
1891                   char* demangled_name = cplus_demangle(
1892                       info->enclosing_symbol_name.c_str(),
1893                       DMGL_ANSI | DMGL_PARAMS);
1894                   if (demangled_name != NULL)
1895                     {
1896                       info->enclosing_symbol_name.assign(demangled_name);
1897                       free(demangled_name);
1898                     }
1899                 }
1900             }
1901           return true;
1902         }
1903     }
1904
1905   return false;
1906 }
1907
1908 // Look for a kept section corresponding to the given discarded section,
1909 // and return its output address.  This is used only for relocations in
1910 // debugging sections.  If we can't find the kept section, return 0.
1911
1912 template<int size, bool big_endian>
1913 typename Sized_relobj<size, big_endian>::Address
1914 Sized_relobj<size, big_endian>::map_to_kept_section(
1915     unsigned int shndx,
1916     bool* found) const
1917 {
1918   Kept_comdat_section *kept = this->get_kept_comdat_section(shndx);
1919   if (kept != NULL)
1920     {
1921       gold_assert(kept->object_ != NULL);
1922       *found = true;
1923       Output_section* os = kept->object_->output_section(kept->shndx_);
1924       Address offset = kept->object_->get_output_section_offset(kept->shndx_);
1925       if (os != NULL && offset != invalid_address)
1926         return os->address() + offset;
1927     }
1928   *found = false;
1929   return 0;
1930 }
1931
1932 // Get symbol counts.
1933
1934 template<int size, bool big_endian>
1935 void
1936 Sized_relobj<size, big_endian>::do_get_global_symbol_counts(
1937     const Symbol_table*,
1938     size_t* defined,
1939     size_t* used) const
1940 {
1941   *defined = this->defined_count_;
1942   size_t count = 0;
1943   for (Symbols::const_iterator p = this->symbols_.begin();
1944        p != this->symbols_.end();
1945        ++p)
1946     if (*p != NULL
1947         && (*p)->source() == Symbol::FROM_OBJECT
1948         && (*p)->object() == this
1949         && (*p)->is_defined())
1950       ++count;
1951   *used = count;
1952 }
1953
1954 // Input_objects methods.
1955
1956 // Add a regular relocatable object to the list.  Return false if this
1957 // object should be ignored.
1958
1959 bool
1960 Input_objects::add_object(Object* obj)
1961 {
1962   // Set the global target from the first object file we recognize.
1963   Target* target = obj->target();
1964   if (!parameters->target_valid())
1965     set_parameters_target(target);
1966   else if (target != &parameters->target())
1967     {
1968       obj->error(_("incompatible target"));
1969       return false;
1970     }
1971
1972   // Print the filename if the -t/--trace option is selected.
1973   if (parameters->options().trace())
1974     gold_info("%s", obj->name().c_str());
1975
1976   if (!obj->is_dynamic())
1977     this->relobj_list_.push_back(static_cast<Relobj*>(obj));
1978   else
1979     {
1980       // See if this is a duplicate SONAME.
1981       Dynobj* dynobj = static_cast<Dynobj*>(obj);
1982       const char* soname = dynobj->soname();
1983
1984       std::pair<Unordered_set<std::string>::iterator, bool> ins =
1985         this->sonames_.insert(soname);
1986       if (!ins.second)
1987         {
1988           // We have already seen a dynamic object with this soname.
1989           return false;
1990         }
1991
1992       this->dynobj_list_.push_back(dynobj);
1993     }
1994
1995   // Add this object to the cross-referencer if requested.
1996   if (parameters->options().user_set_print_symbol_counts())
1997     {
1998       if (this->cref_ == NULL)
1999         this->cref_ = new Cref();
2000       this->cref_->add_object(obj);
2001     }
2002
2003   return true;
2004 }
2005
2006 // For each dynamic object, record whether we've seen all of its
2007 // explicit dependencies.
2008
2009 void
2010 Input_objects::check_dynamic_dependencies() const
2011 {
2012   for (Dynobj_list::const_iterator p = this->dynobj_list_.begin();
2013        p != this->dynobj_list_.end();
2014        ++p)
2015     {
2016       const Dynobj::Needed& needed((*p)->needed());
2017       bool found_all = true;
2018       for (Dynobj::Needed::const_iterator pneeded = needed.begin();
2019            pneeded != needed.end();
2020            ++pneeded)
2021         {
2022           if (this->sonames_.find(*pneeded) == this->sonames_.end())
2023             {
2024               found_all = false;
2025               break;
2026             }
2027         }
2028       (*p)->set_has_unknown_needed_entries(!found_all);
2029     }
2030 }
2031
2032 // Start processing an archive.
2033
2034 void
2035 Input_objects::archive_start(Archive* archive)
2036 {
2037   if (parameters->options().user_set_print_symbol_counts())
2038     {
2039       if (this->cref_ == NULL)
2040         this->cref_ = new Cref();
2041       this->cref_->add_archive_start(archive);
2042     }
2043 }
2044
2045 // Stop processing an archive.
2046
2047 void
2048 Input_objects::archive_stop(Archive* archive)
2049 {
2050   if (parameters->options().user_set_print_symbol_counts())
2051     this->cref_->add_archive_stop(archive);
2052 }
2053
2054 // Print symbol counts
2055
2056 void
2057 Input_objects::print_symbol_counts(const Symbol_table* symtab) const
2058 {
2059   if (parameters->options().user_set_print_symbol_counts()
2060       && this->cref_ != NULL)
2061     this->cref_->print_symbol_counts(symtab);
2062 }
2063
2064 // Relocate_info methods.
2065
2066 // Return a string describing the location of a relocation.  This is
2067 // only used in error messages.
2068
2069 template<int size, bool big_endian>
2070 std::string
2071 Relocate_info<size, big_endian>::location(size_t, off_t offset) const
2072 {
2073   // See if we can get line-number information from debugging sections.
2074   std::string filename;
2075   std::string file_and_lineno;   // Better than filename-only, if available.
2076
2077   Sized_dwarf_line_info<size, big_endian> line_info(this->object);
2078   // This will be "" if we failed to parse the debug info for any reason.
2079   file_and_lineno = line_info.addr2line(this->data_shndx, offset);
2080
2081   std::string ret(this->object->name());
2082   ret += ':';
2083   Symbol_location_info info;
2084   if (this->object->get_symbol_location_info(this->data_shndx, offset, &info))
2085     {
2086       ret += " in function ";
2087       ret += info.enclosing_symbol_name;
2088       ret += ":";
2089       filename = info.source_file;
2090     }
2091
2092   if (!file_and_lineno.empty())
2093     ret += file_and_lineno;
2094   else
2095     {
2096       if (!filename.empty())
2097         ret += filename;
2098       ret += "(";
2099       ret += this->object->section_name(this->data_shndx);
2100       char buf[100];
2101       // Offsets into sections have to be positive.
2102       snprintf(buf, sizeof(buf), "+0x%lx", static_cast<long>(offset));
2103       ret += buf;
2104       ret += ")";
2105     }
2106   return ret;
2107 }
2108
2109 } // End namespace gold.
2110
2111 namespace
2112 {
2113
2114 using namespace gold;
2115
2116 // Read an ELF file with the header and return the appropriate
2117 // instance of Object.
2118
2119 template<int size, bool big_endian>
2120 Object*
2121 make_elf_sized_object(const std::string& name, Input_file* input_file,
2122                       off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
2123 {
2124   int et = ehdr.get_e_type();
2125   if (et == elfcpp::ET_REL)
2126     {
2127       Sized_relobj<size, big_endian>* obj =
2128         new Sized_relobj<size, big_endian>(name, input_file, offset, ehdr);
2129       obj->setup(ehdr);
2130       return obj;
2131     }
2132   else if (et == elfcpp::ET_DYN)
2133     {
2134       Sized_dynobj<size, big_endian>* obj =
2135         new Sized_dynobj<size, big_endian>(name, input_file, offset, ehdr);
2136       obj->setup(ehdr);
2137       return obj;
2138     }
2139   else
2140     {
2141       gold_error(_("%s: unsupported ELF file type %d"),
2142                  name.c_str(), et);
2143       return NULL;
2144     }
2145 }
2146
2147 } // End anonymous namespace.
2148
2149 namespace gold
2150 {
2151
2152 // Return whether INPUT_FILE is an ELF object.
2153
2154 bool
2155 is_elf_object(Input_file* input_file, off_t offset,
2156               const unsigned char** start, int *read_size)
2157 {
2158   off_t filesize = input_file->file().filesize();
2159   int want = elfcpp::Elf_sizes<64>::ehdr_size;
2160   if (filesize - offset < want)
2161     want = filesize - offset;
2162
2163   const unsigned char* p = input_file->file().get_view(offset, 0, want,
2164                                                        true, false);
2165   *start = p;
2166   *read_size = want;
2167
2168   if (want < 4)
2169     return false;
2170
2171   static unsigned char elfmagic[4] =
2172     {
2173       elfcpp::ELFMAG0, elfcpp::ELFMAG1,
2174       elfcpp::ELFMAG2, elfcpp::ELFMAG3
2175     };
2176   return memcmp(p, elfmagic, 4) == 0;
2177 }
2178
2179 // Read an ELF file and return the appropriate instance of Object.
2180
2181 Object*
2182 make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
2183                 const unsigned char* p, section_offset_type bytes,
2184                 bool* punconfigured)
2185 {
2186   if (punconfigured != NULL)
2187     *punconfigured = false;
2188
2189   if (bytes < elfcpp::EI_NIDENT)
2190     {
2191       gold_error(_("%s: ELF file too short"), name.c_str());
2192       return NULL;
2193     }
2194
2195   int v = p[elfcpp::EI_VERSION];
2196   if (v != elfcpp::EV_CURRENT)
2197     {
2198       if (v == elfcpp::EV_NONE)
2199         gold_error(_("%s: invalid ELF version 0"), name.c_str());
2200       else
2201         gold_error(_("%s: unsupported ELF version %d"), name.c_str(), v);
2202       return NULL;
2203     }
2204
2205   int c = p[elfcpp::EI_CLASS];
2206   if (c == elfcpp::ELFCLASSNONE)
2207     {
2208       gold_error(_("%s: invalid ELF class 0"), name.c_str());
2209       return NULL;
2210     }
2211   else if (c != elfcpp::ELFCLASS32
2212            && c != elfcpp::ELFCLASS64)
2213     {
2214       gold_error(_("%s: unsupported ELF class %d"), name.c_str(), c);
2215       return NULL;
2216     }
2217
2218   int d = p[elfcpp::EI_DATA];
2219   if (d == elfcpp::ELFDATANONE)
2220     {
2221       gold_error(_("%s: invalid ELF data encoding"), name.c_str());
2222       return NULL;
2223     }
2224   else if (d != elfcpp::ELFDATA2LSB
2225            && d != elfcpp::ELFDATA2MSB)
2226     {
2227       gold_error(_("%s: unsupported ELF data encoding %d"), name.c_str(), d);
2228       return NULL;
2229     }
2230
2231   bool big_endian = d == elfcpp::ELFDATA2MSB;
2232
2233   if (c == elfcpp::ELFCLASS32)
2234     {
2235       if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
2236         {
2237           gold_error(_("%s: ELF file too short"), name.c_str());
2238           return NULL;
2239         }
2240       if (big_endian)
2241         {
2242 #ifdef HAVE_TARGET_32_BIG
2243           elfcpp::Ehdr<32, true> ehdr(p);
2244           return make_elf_sized_object<32, true>(name, input_file,
2245                                                  offset, ehdr);
2246 #else
2247           if (punconfigured != NULL)
2248             *punconfigured = true;
2249           else
2250             gold_error(_("%s: not configured to support "
2251                          "32-bit big-endian object"),
2252                        name.c_str());
2253           return NULL;
2254 #endif
2255         }
2256       else
2257         {
2258 #ifdef HAVE_TARGET_32_LITTLE
2259           elfcpp::Ehdr<32, false> ehdr(p);
2260           return make_elf_sized_object<32, false>(name, input_file,
2261                                                   offset, ehdr);
2262 #else
2263           if (punconfigured != NULL)
2264             *punconfigured = true;
2265           else
2266             gold_error(_("%s: not configured to support "
2267                          "32-bit little-endian object"),
2268                        name.c_str());
2269           return NULL;
2270 #endif
2271         }
2272     }
2273   else
2274     {
2275       if (bytes < elfcpp::Elf_sizes<64>::ehdr_size)
2276         {
2277           gold_error(_("%s: ELF file too short"), name.c_str());
2278           return NULL;
2279         }
2280       if (big_endian)
2281         {
2282 #ifdef HAVE_TARGET_64_BIG
2283           elfcpp::Ehdr<64, true> ehdr(p);
2284           return make_elf_sized_object<64, true>(name, input_file,
2285                                                  offset, ehdr);
2286 #else
2287           if (punconfigured != NULL)
2288             *punconfigured = true;
2289           else
2290             gold_error(_("%s: not configured to support "
2291                          "64-bit big-endian object"),
2292                        name.c_str());
2293           return NULL;
2294 #endif
2295         }
2296       else
2297         {
2298 #ifdef HAVE_TARGET_64_LITTLE
2299           elfcpp::Ehdr<64, false> ehdr(p);
2300           return make_elf_sized_object<64, false>(name, input_file,
2301                                                   offset, ehdr);
2302 #else
2303           if (punconfigured != NULL)
2304             *punconfigured = true;
2305           else
2306             gold_error(_("%s: not configured to support "
2307                          "64-bit little-endian object"),
2308                        name.c_str());
2309           return NULL;
2310 #endif
2311         }
2312     }
2313 }
2314
2315 // Instantiate the templates we need.
2316
2317 #ifdef HAVE_TARGET_32_LITTLE
2318 template
2319 void
2320 Object::read_section_data<32, false>(elfcpp::Elf_file<32, false, Object>*,
2321                                      Read_symbols_data*);
2322 #endif
2323
2324 #ifdef HAVE_TARGET_32_BIG
2325 template
2326 void
2327 Object::read_section_data<32, true>(elfcpp::Elf_file<32, true, Object>*,
2328                                     Read_symbols_data*);
2329 #endif
2330
2331 #ifdef HAVE_TARGET_64_LITTLE
2332 template
2333 void
2334 Object::read_section_data<64, false>(elfcpp::Elf_file<64, false, Object>*,
2335                                      Read_symbols_data*);
2336 #endif
2337
2338 #ifdef HAVE_TARGET_64_BIG
2339 template
2340 void
2341 Object::read_section_data<64, true>(elfcpp::Elf_file<64, true, Object>*,
2342                                     Read_symbols_data*);
2343 #endif
2344
2345 #ifdef HAVE_TARGET_32_LITTLE
2346 template
2347 class Sized_relobj<32, false>;
2348 #endif
2349
2350 #ifdef HAVE_TARGET_32_BIG
2351 template
2352 class Sized_relobj<32, true>;
2353 #endif
2354
2355 #ifdef HAVE_TARGET_64_LITTLE
2356 template
2357 class Sized_relobj<64, false>;
2358 #endif
2359
2360 #ifdef HAVE_TARGET_64_BIG
2361 template
2362 class Sized_relobj<64, true>;
2363 #endif
2364
2365 #ifdef HAVE_TARGET_32_LITTLE
2366 template
2367 struct Relocate_info<32, false>;
2368 #endif
2369
2370 #ifdef HAVE_TARGET_32_BIG
2371 template
2372 struct Relocate_info<32, true>;
2373 #endif
2374
2375 #ifdef HAVE_TARGET_64_LITTLE
2376 template
2377 struct Relocate_info<64, false>;
2378 #endif
2379
2380 #ifdef HAVE_TARGET_64_BIG
2381 template
2382 struct Relocate_info<64, true>;
2383 #endif
2384
2385 } // End namespace gold.