gold/object.cc

   1 // object.cc -- support for an object file for linking in gold
   2
   3 // Copyright 2006, 2007 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
  29 #include "target-select.h"
  30 #include "layout.h"
  31 #include "output.h"
  32 #include "symtab.h"
  33 #include "object.h"
  34 #include "dynobj.h"
  35
  36 namespace gold
  37 {
  38
  39 // Class Object.
  40
  41 // Set the target based on fields in the ELF file header.
  42
  43 void
  44 Object::set_target(int machine, int size, bool big_endian, int osabi,
  45                    int abiversion)
  46 {
  47   Target* target = select_target(machine, size, big_endian, osabi, abiversion);
  48   if (target == NULL)
  49     {
  50       fprintf(stderr, _("%s: %s: unsupported ELF machine number %d\n"),
  51               program_name, this->name().c_str(), machine);
  52       gold_exit(false);
  53     }
  54   this->target_ = target;
  55 }
  56
  57 // Report an error for the elfcpp::Elf_file interface.
  58
  59 void
  60 Object::error(const char* format, ...)
  61 {
  62   va_list args;
  63
  64   fprintf(stderr, "%s: %s: ", program_name, this->name().c_str());
  65   va_start(args, format);
  66   vfprintf(stderr, format, args);
  67   va_end(args);
  68   putc('\n', stderr);
  69
  70   gold_exit(false);
  71 }
  72
  73 // Return a view of the contents of a section.
  74
  75 const unsigned char*
  76 Object::section_contents(unsigned int shndx, off_t* plen, bool cache)
  77 {
  78   Location loc(this->do_section_contents(shndx));
  79   *plen = loc.data_size;
  80   return this->get_view(loc.file_offset, loc.data_size, cache);
  81 }
  82
  83 // Read the section data into SD.  This is code common to Sized_relobj
  84 // and Sized_dynobj, so we put it into Object.
  85
  86 template<int size, bool big_endian>
  87 void
  88 Object::read_section_data(elfcpp::Elf_file<size, big_endian, Object>* elf_file,
  89                           Read_symbols_data* sd)
  90 {
  91   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
  92
  93   // Read the section headers.
  94   const off_t shoff = elf_file->shoff();
  95   const unsigned int shnum = this->shnum();
  96   sd->section_headers = this->get_lasting_view(shoff, shnum * shdr_size, true);
  97
  98   // Read the section names.
  99   const unsigned char* pshdrs = sd->section_headers->data();
 100   const unsigned char* pshdrnames = pshdrs + elf_file->shstrndx() * shdr_size;
 101   typename elfcpp::Shdr<size, big_endian> shdrnames(pshdrnames);
 102
 103   if (shdrnames.get_sh_type() != elfcpp::SHT_STRTAB)
 104     {
 105       fprintf(stderr,
 106               _("%s: %s: section name section has wrong type: %u\n"),
 107               program_name, this->name().c_str(),
 108               static_cast<unsigned int>(shdrnames.get_sh_type()));
 109       gold_exit(false);
 110     }
 111
 112   sd->section_names_size = shdrnames.get_sh_size();
 113   sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(),
 114                                              sd->section_names_size, false);
 115 }
 116
 117 // If NAME is the name of a special .gnu.warning section, arrange for
 118 // the warning to be issued.  SHNDX is the section index.  Return
 119 // whether it is a warning section.
 120
 121 bool
 122 Object::handle_gnu_warning_section(const char* name, unsigned int shndx,
 123                                    Symbol_table* symtab)
 124 {
 125   const char warn_prefix[] = ".gnu.warning.";
 126   const int warn_prefix_len = sizeof warn_prefix - 1;
 127   if (strncmp(name, warn_prefix, warn_prefix_len) == 0)
 128     {
 129       symtab->add_warning(name + warn_prefix_len, this, shndx);
 130       return true;
 131     }
 132   return false;
 133 }
 134
 135 // Class Sized_relobj.
 136
 137 template<int size, bool big_endian>
 138 Sized_relobj<size, big_endian>::Sized_relobj(
 139     const std::string& name,
 140     Input_file* input_file,
 141     off_t offset,
 142     const elfcpp::Ehdr<size, big_endian>& ehdr)
 143   : Relobj(name, input_file, offset),
 144     elf_file_(this, ehdr),
 145     symtab_shndx_(-1U),
 146     local_symbol_count_(0),
 147     output_local_symbol_count_(0),
 148     symbols_(NULL),
 149     local_symbol_offset_(0),
 150     local_values_()
 151 {
 152 }
 153
 154 template<int size, bool big_endian>
 155 Sized_relobj<size, big_endian>::~Sized_relobj()
 156 {
 157 }
 158
 159 // Set up an object file based on the file header.  This sets up the
 160 // target and reads the section information.
 161
 162 template<int size, bool big_endian>
 163 void
 164 Sized_relobj<size, big_endian>::setup(
 165     const elfcpp::Ehdr<size, big_endian>& ehdr)
 166 {
 167   this->set_target(ehdr.get_e_machine(), size, big_endian,
 168                    ehdr.get_e_ident()[elfcpp::EI_OSABI],
 169                    ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
 170
 171   const unsigned int shnum = this->elf_file_.shnum();
 172   this->set_shnum(shnum);
 173 }
 174
 175 // Find the SHT_SYMTAB section, given the section headers.  The ELF
 176 // standard says that maybe in the future there can be more than one
 177 // SHT_SYMTAB section.  Until somebody figures out how that could
 178 // work, we assume there is only one.
 179
 180 template<int size, bool big_endian>
 181 void
 182 Sized_relobj<size, big_endian>::find_symtab(const unsigned char* pshdrs)
 183 {
 184   const unsigned int shnum = this->shnum();
 185   this->symtab_shndx_ = 0;
 186   if (shnum > 0)
 187     {
 188       // Look through the sections in reverse order, since gas tends
 189       // to put the symbol table at the end.
 190       const unsigned char* p = pshdrs + shnum * This::shdr_size;
 191       unsigned int i = shnum;
 192       while (i > 0)
 193         {
 194           --i;
 195           p -= This::shdr_size;
 196           typename This::Shdr shdr(p);
 197           if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
 198             {
 199               this->symtab_shndx_ = i;
 200               break;
 201             }
 202         }
 203     }
 204 }
 205
 206 // Read the sections and symbols from an object file.
 207
 208 template<int size, bool big_endian>
 209 void
 210 Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
 211 {
 212   this->read_section_data(&this->elf_file_, sd);
 213
 214   const unsigned char* const pshdrs = sd->section_headers->data();
 215
 216   this->find_symtab(pshdrs);
 217
 218   if (this->symtab_shndx_ == 0)
 219     {
 220       // No symbol table.  Weird but legal.
 221       sd->symbols = NULL;
 222       sd->symbols_size = 0;
 223       sd->symbol_names = NULL;
 224       sd->symbol_names_size = 0;
 225       return;
 226     }
 227
 228   // Get the symbol table section header.
 229   typename This::Shdr symtabshdr(pshdrs
 230                                  + this->symtab_shndx_ * This::shdr_size);
 231   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
 232
 233   // We only need the external symbols.
 234   const int sym_size = This::sym_size;
 235   const unsigned int loccount = symtabshdr.get_sh_info();
 236   this->local_symbol_count_ = loccount;
 237   off_t locsize = loccount * sym_size;
 238   off_t extoff = symtabshdr.get_sh_offset() + locsize;
 239   off_t extsize = symtabshdr.get_sh_size() - locsize;
 240
 241   // Read the symbol table.
 242   File_view* fvsymtab = this->get_lasting_view(extoff, extsize, false);
 243
 244   // Read the section header for the symbol names.
 245   unsigned int strtab_shndx = symtabshdr.get_sh_link();
 246   if (strtab_shndx >= this->shnum())
 247     {
 248       fprintf(stderr, _("%s: %s: invalid symbol table name index: %u\n"),
 249               program_name, this->name().c_str(), strtab_shndx);
 250       gold_exit(false);
 251     }
 252   typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
 253   if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
 254     {
 255       fprintf(stderr,
 256               _("%s: %s: symbol table name section has wrong type: %u\n"),
 257               program_name, this->name().c_str(),
 258               static_cast<unsigned int>(strtabshdr.get_sh_type()));
 259       gold_exit(false);
 260     }
 261
 262   // Read the symbol names.
 263   File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(),
 264                                                strtabshdr.get_sh_size(), true);
 265
 266   sd->symbols = fvsymtab;
 267   sd->symbols_size = extsize;
 268   sd->symbol_names = fvstrtab;
 269   sd->symbol_names_size = strtabshdr.get_sh_size();
 270 }
 271
 272 // Return whether to include a section group in the link.  LAYOUT is
 273 // used to keep track of which section groups we have already seen.
 274 // INDEX is the index of the section group and SHDR is the section
 275 // header.  If we do not want to include this group, we set bits in
 276 // OMIT for each section which should be discarded.
 277
 278 template<int size, bool big_endian>
 279 bool
 280 Sized_relobj<size, big_endian>::include_section_group(
 281     Layout* layout,
 282     unsigned int index,
 283     const elfcpp::Shdr<size, big_endian>& shdr,
 284     std::vector<bool>* omit)
 285 {
 286   // Read the section contents.
 287   const unsigned char* pcon = this->get_view(shdr.get_sh_offset(),
 288                                              shdr.get_sh_size(), false);
 289   const elfcpp::Elf_Word* pword =
 290     reinterpret_cast<const elfcpp::Elf_Word*>(pcon);
 291
 292   // The first word contains flags.  We only care about COMDAT section
 293   // groups.  Other section groups are always included in the link
 294   // just like ordinary sections.
 295   elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword);
 296   if ((flags & elfcpp::GRP_COMDAT) == 0)
 297     return true;
 298
 299   // Look up the group signature, which is the name of a symbol.  This
 300   // is a lot of effort to go to to read a string.  Why didn't they
 301   // just use the name of the SHT_GROUP section as the group
 302   // signature?
 303
 304   // Get the appropriate symbol table header (this will normally be
 305   // the single SHT_SYMTAB section, but in principle it need not be).
 306   const unsigned int link = shdr.get_sh_link();
 307   typename This::Shdr symshdr(this, this->elf_file_.section_header(link));
 308
 309   // Read the symbol table entry.
 310   if (shdr.get_sh_info() >= symshdr.get_sh_size() / This::sym_size)
 311     {
 312       fprintf(stderr, _("%s: %s: section group %u info %u out of range\n"),
 313               program_name, this->name().c_str(), index, shdr.get_sh_info());
 314       gold_exit(false);
 315     }
 316   off_t symoff = symshdr.get_sh_offset() + shdr.get_sh_info() * This::sym_size;
 317   const unsigned char* psym = this->get_view(symoff, This::sym_size, true);
 318   elfcpp::Sym<size, big_endian> sym(psym);
 319
 320   // Read the symbol table names.
 321   off_t symnamelen;
 322   const unsigned char* psymnamesu;
 323   psymnamesu = this->section_contents(symshdr.get_sh_link(), &symnamelen,
 324                                       true);
 325   const char* psymnames = reinterpret_cast<const char*>(psymnamesu);
 326
 327   // Get the section group signature.
 328   if (sym.get_st_name() >= symnamelen)
 329     {
 330       fprintf(stderr, _("%s: %s: symbol %u name offset %u out of range\n"),
 331               program_name, this->name().c_str(), shdr.get_sh_info(),
 332               sym.get_st_name());
 333       gold_exit(false);
 334     }
 335
 336   const char* signature = psymnames + sym.get_st_name();
 337
 338   // It seems that some versions of gas will create a section group
 339   // associated with a section symbol, and then fail to give a name to
 340   // the section symbol.  In such a case, use the name of the section.
 341   // FIXME.
 342   std::string secname;
 343   if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION)
 344     {
 345       secname = this->section_name(sym.get_st_shndx());
 346       signature = secname.c_str();
 347     }
 348
 349   // Record this section group, and see whether we've already seen one
 350   // with the same signature.
 351   if (layout->add_comdat(signature, true))
 352     return true;
 353
 354   // This is a duplicate.  We want to discard the sections in this
 355   // group.
 356   size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
 357   for (size_t i = 1; i < count; ++i)
 358     {
 359       elfcpp::Elf_Word secnum =
 360         elfcpp::Swap<32, big_endian>::readval(pword + i);
 361       if (secnum >= this->shnum())
 362         {
 363           fprintf(stderr,
 364                   _("%s: %s: section %u in section group %u out of range"),
 365                   program_name, this->name().c_str(), secnum,
 366                   index);
 367           gold_exit(false);
 368         }
 369       (*omit)[secnum] = true;
 370     }
 371
 372   return false;
 373 }
 374
 375 // Whether to include a linkonce section in the link.  NAME is the
 376 // name of the section and SHDR is the section header.
 377
 378 // Linkonce sections are a GNU extension implemented in the original
 379 // GNU linker before section groups were defined.  The semantics are
 380 // that we only include one linkonce section with a given name.  The
 381 // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
 382 // where T is the type of section and SYMNAME is the name of a symbol.
 383 // In an attempt to make linkonce sections interact well with section
 384 // groups, we try to identify SYMNAME and use it like a section group
 385 // signature.  We want to block section groups with that signature,
 386 // but not other linkonce sections with that signature.  We also use
 387 // the full name of the linkonce section as a normal section group
 388 // signature.
 389
 390 template<int size, bool big_endian>
 391 bool
 392 Sized_relobj<size, big_endian>::include_linkonce_section(
 393     Layout* layout,
 394     const char* name,
 395     const elfcpp::Shdr<size, big_endian>&)
 396 {
 397   const char* symname = strrchr(name, '.') + 1;
 398   bool include1 = layout->add_comdat(symname, false);
 399   bool include2 = layout->add_comdat(name, true);
 400   return include1 && include2;
 401 }
 402
 403 // Lay out the input sections.  We walk through the sections and check
 404 // whether they should be included in the link.  If they should, we
 405 // pass them to the Layout object, which will return an output section
 406 // and an offset.
 407
 408 template<int size, bool big_endian>
 409 void
 410 Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
 411                                           Layout* layout,
 412                                           Read_symbols_data* sd)
 413 {
 414   const unsigned int shnum = this->shnum();
 415   if (shnum == 0)
 416     return;
 417
 418   // Get the section headers.
 419   const unsigned char* pshdrs = sd->section_headers->data();
 420
 421   // Get the section names.
 422   const unsigned char* pnamesu = sd->section_names->data();
 423   const char* pnames = reinterpret_cast<const char*>(pnamesu);
 424
 425   std::vector<Map_to_output>& map_sections(this->map_to_output());
 426   map_sections.resize(shnum);
 427
 428   // Keep track of which sections to omit.
 429   std::vector<bool> omit(shnum, false);
 430
 431   // Skip the first, dummy, section.
 432   pshdrs += This::shdr_size;
 433   for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
 434     {
 435       typename This::Shdr shdr(pshdrs);
 436
 437       if (shdr.get_sh_name() >= sd->section_names_size)
 438         {
 439           fprintf(stderr,
 440                   _("%s: %s: bad section name offset for section %u: %lu\n"),
 441                   program_name, this->name().c_str(), i,
 442                   static_cast<unsigned long>(shdr.get_sh_name()));
 443           gold_exit(false);
 444         }
 445
 446       const char* name = pnames + shdr.get_sh_name();
 447
 448       if (this->handle_gnu_warning_section(name, i, symtab))
 449         {
 450           if (!parameters->output_is_object())
 451             omit[i] = true;
 452         }
 453
 454       bool discard = omit[i];
 455       if (!discard)
 456         {
 457           if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
 458             {
 459               if (!this->include_section_group(layout, i, shdr, &omit))
 460                 discard = true;
 461             }
 462           else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
 463                    && Layout::is_linkonce(name))
 464             {
 465               if (!this->include_linkonce_section(layout, name, shdr))
 466                 discard = true;
 467             }
 468         }
 469
 470       if (discard)
 471         {
 472           // Do not include this section in the link.
 473           map_sections[i].output_section = NULL;
 474           continue;
 475         }
 476
 477       off_t offset;
 478       Output_section* os = layout->layout(this, i, name, shdr, &offset);
 479
 480       map_sections[i].output_section = os;
 481       map_sections[i].offset = offset;
 482     }
 483
 484   delete sd->section_headers;
 485   sd->section_headers = NULL;
 486   delete sd->section_names;
 487   sd->section_names = NULL;
 488 }
 489
 490 // Add the symbols to the symbol table.
 491
 492 template<int size, bool big_endian>
 493 void
 494 Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
 495                                                Read_symbols_data* sd)
 496 {
 497   if (sd->symbols == NULL)
 498     {
 499       gold_assert(sd->symbol_names == NULL);
 500       return;
 501     }
 502
 503   const int sym_size = This::sym_size;
 504   size_t symcount = sd->symbols_size / sym_size;
 505   if (symcount * sym_size != sd->symbols_size)
 506     {
 507       fprintf(stderr,
 508               _("%s: %s: size of symbols is not multiple of symbol size\n"),
 509               program_name, this->name().c_str());
 510       gold_exit(false);
 511     }
 512
 513   this->symbols_ = new Symbol*[symcount];
 514
 515   const char* sym_names =
 516     reinterpret_cast<const char*>(sd->symbol_names->data());
 517   symtab->add_from_relobj(this, sd->symbols->data(), symcount, sym_names,
 518                           sd->symbol_names_size, this->symbols_);
 519
 520   delete sd->symbols;
 521   sd->symbols = NULL;
 522   delete sd->symbol_names;
 523   sd->symbol_names = NULL;
 524 }
 525
 526 // Finalize the local symbols.  Here we record the file offset at
 527 // which they should be output, we add their names to *POOL, and we
 528 // add their values to THIS->LOCAL_VALUES_.  Return the symbol index.
 529 // This function is always called from the main thread.  The actual
 530 // output of the local symbols will occur in a separate task.
 531
 532 template<int size, bool big_endian>
 533 unsigned int
 534 Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index,
 535                                                           off_t off,
 536                                                           Stringpool* pool)
 537 {
 538   gold_assert(this->symtab_shndx_ != -1U);
 539   if (this->symtab_shndx_ == 0)
 540     {
 541       // This object has no symbols.  Weird but legal.
 542       return index;
 543     }
 544
 545   gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
 546
 547   this->local_symbol_offset_ = off;
 548
 549   // Read the symbol table section header.
 550   const unsigned int symtab_shndx = this->symtab_shndx_;
 551   typename This::Shdr symtabshdr(this,
 552                                  this->elf_file_.section_header(symtab_shndx));
 553   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
 554
 555   // Read the local symbols.
 556   const int sym_size = This::sym_size;
 557   const unsigned int loccount = this->local_symbol_count_;
 558   gold_assert(loccount == symtabshdr.get_sh_info());
 559   off_t locsize = loccount * sym_size;
 560   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
 561                                               locsize, true);
 562
 563   this->local_values_.resize(loccount);
 564
 565   // Read the symbol names.
 566   const unsigned int strtab_shndx = symtabshdr.get_sh_link();
 567   off_t strtab_size;
 568   const unsigned char* pnamesu = this->section_contents(strtab_shndx,
 569                                                         &strtab_size,
 570                                                         true);
 571   const char* pnames = reinterpret_cast<const char*>(pnamesu);
 572
 573   // Loop over the local symbols.
 574
 575   const std::vector<Map_to_output>& mo(this->map_to_output());
 576   unsigned int shnum = this->shnum();
 577   unsigned int count = 0;
 578   // Skip the first, dummy, symbol.
 579   psyms += sym_size;
 580   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
 581     {
 582       elfcpp::Sym<size, big_endian> sym(psyms);
 583
 584       Symbol_value<size>& lv(this->local_values_[i]);
 585
 586       unsigned int shndx = sym.get_st_shndx();
 587       lv.set_input_shndx(shndx);
 588
 589       if (shndx >= elfcpp::SHN_LORESERVE)
 590         {
 591           if (shndx == elfcpp::SHN_ABS)
 592             lv.set_output_value(sym.get_st_value());
 593           else
 594             {
 595               // FIXME: Handle SHN_XINDEX.
 596               fprintf(stderr,
 597                       _("%s: %s: unknown section index %u "
 598                         "for local symbol %u\n"),
 599                       program_name, this->name().c_str(), shndx, i);
 600               gold_exit(false);
 601             }
 602         }
 603       else
 604         {
 605           if (shndx >= shnum)
 606             {
 607               fprintf(stderr,
 608                       _("%s: %s: local symbol %u section index %u "
 609                         "out of range\n"),
 610                       program_name, this->name().c_str(), i, shndx);
 611               gold_exit(false);
 612             }
 613
 614           Output_section* os = mo[shndx].output_section;
 615
 616           if (os == NULL)
 617             {
 618               lv.set_output_value(0);
 619               lv.set_no_output_symtab_entry();
 620               continue;
 621             }
 622
 623           if (mo[shndx].offset == -1)
 624             lv.set_input_value(sym.get_st_value());
 625           else
 626             lv.set_output_value(mo[shndx].output_section->address()
 627                                 + mo[shndx].offset
 628                                 + sym.get_st_value());
 629         }
 630
 631       // Decide whether this symbol should go into the output file.
 632
 633       if (sym.get_st_type() == elfcpp::STT_SECTION)
 634         {
 635           lv.set_no_output_symtab_entry();
 636           continue;
 637         }
 638
 639       if (sym.get_st_name() >= strtab_size)
 640         {
 641           fprintf(stderr,
 642                   _("%s: %s: local symbol %u section name "
 643                     "out of range: %u >= %u\n"),
 644                   program_name, this->name().c_str(),
 645                   i, sym.get_st_name(),
 646                   static_cast<unsigned int>(strtab_size));
 647           gold_exit(false);
 648         }
 649
 650       const char* name = pnames + sym.get_st_name();
 651       pool->add(name, NULL);
 652       lv.set_output_symtab_index(index);
 653       ++index;
 654       ++count;
 655     }
 656
 657   this->output_local_symbol_count_ = count;
 658
 659   return index;
 660 }
 661
 662 // Return the value of a local symbol defined in input section SHNDX,
 663 // with value VALUE, adding addend ADDEND.  This handles SHF_MERGE
 664 // sections.
 665 template<int size, bool big_endian>
 666 typename elfcpp::Elf_types<size>::Elf_Addr
 667 Sized_relobj<size, big_endian>::local_value(unsigned int shndx,
 668                                             Address value,
 669                                             Address addend) const
 670 {
 671   const std::vector<Map_to_output>& mo(this->map_to_output());
 672   Output_section* os = mo[shndx].output_section;
 673   if (os == NULL)
 674     return addend;
 675   gold_assert(mo[shndx].offset == -1);
 676   return os->output_address(this, shndx, value + addend);
 677 }
 678
 679 // Write out the local symbols.
 680
 681 template<int size, bool big_endian>
 682 void
 683 Sized_relobj<size, big_endian>::write_local_symbols(Output_file* of,
 684                                                     const Stringpool* sympool)
 685 {
 686   gold_assert(this->symtab_shndx_ != -1U);
 687   if (this->symtab_shndx_ == 0)
 688     {
 689       // This object has no symbols.  Weird but legal.
 690       return;
 691     }
 692
 693   // Read the symbol table section header.
 694   const unsigned int symtab_shndx = this->symtab_shndx_;
 695   typename This::Shdr symtabshdr(this,
 696                                  this->elf_file_.section_header(symtab_shndx));
 697   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
 698   const unsigned int loccount = this->local_symbol_count_;
 699   gold_assert(loccount == symtabshdr.get_sh_info());
 700
 701   // Read the local symbols.
 702   const int sym_size = This::sym_size;
 703   off_t locsize = loccount * sym_size;
 704   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
 705                                               locsize, false);
 706
 707   // Read the symbol names.
 708   const unsigned int strtab_shndx = symtabshdr.get_sh_link();
 709   off_t strtab_size;
 710   const unsigned char* pnamesu = this->section_contents(strtab_shndx,
 711                                                         &strtab_size,
 712                                                         true);
 713   const char* pnames = reinterpret_cast<const char*>(pnamesu);
 714
 715   // Get a view into the output file.
 716   off_t output_size = this->output_local_symbol_count_ * sym_size;
 717   unsigned char* oview = of->get_output_view(this->local_symbol_offset_,
 718                                              output_size);
 719
 720   const std::vector<Map_to_output>& mo(this->map_to_output());
 721
 722   gold_assert(this->local_values_.size() == loccount);
 723
 724   unsigned char* ov = oview;
 725   psyms += sym_size;
 726   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
 727     {
 728       elfcpp::Sym<size, big_endian> isym(psyms);
 729
 730       if (!this->local_values_[i].needs_output_symtab_entry())
 731         continue;
 732
 733       unsigned int st_shndx = isym.get_st_shndx();
 734       if (st_shndx < elfcpp::SHN_LORESERVE)
 735         {
 736           gold_assert(st_shndx < mo.size());
 737           if (mo[st_shndx].output_section == NULL)
 738             continue;
 739           st_shndx = mo[st_shndx].output_section->out_shndx();
 740         }
 741
 742       elfcpp::Sym_write<size, big_endian> osym(ov);
 743
 744       gold_assert(isym.get_st_name() < strtab_size);
 745       const char* name = pnames + isym.get_st_name();
 746       osym.put_st_name(sympool->get_offset(name));
 747       osym.put_st_value(this->local_values_[i].value(this, 0));
 748       osym.put_st_size(isym.get_st_size());
 749       osym.put_st_info(isym.get_st_info());
 750       osym.put_st_other(isym.get_st_other());
 751       osym.put_st_shndx(st_shndx);
 752
 753       ov += sym_size;
 754     }
 755
 756   gold_assert(ov - oview == output_size);
 757
 758   of->write_output_view(this->local_symbol_offset_, output_size, oview);
 759 }
 760
 761 // Input_objects methods.
 762
 763 // Add a regular relocatable object to the list.  Return false if this
 764 // object should be ignored.
 765
 766 bool
 767 Input_objects::add_object(Object* obj)
 768 {
 769   if (!obj->is_dynamic())
 770     this->relobj_list_.push_back(static_cast<Relobj*>(obj));
 771   else
 772     {
 773       // See if this is a duplicate SONAME.
 774       Dynobj* dynobj = static_cast<Dynobj*>(obj);
 775
 776       std::pair<Unordered_set<std::string>::iterator, bool> ins =
 777         this->sonames_.insert(dynobj->soname());
 778       if (!ins.second)
 779         {
 780           // We have already seen a dynamic object with this soname.
 781           return false;
 782         }
 783
 784       this->dynobj_list_.push_back(dynobj);
 785     }
 786
 787   Target* target = obj->target();
 788   if (this->target_ == NULL)
 789     this->target_ = target;
 790   else if (this->target_ != target)
 791     {
 792       fprintf(stderr, "%s: %s: incompatible target\n",
 793               program_name, obj->name().c_str());
 794       gold_exit(false);
 795     }
 796
 797   set_parameters_size_and_endianness(target->get_size(),
 798                                      target->is_big_endian());
 799
 800   return true;
 801 }
 802
 803 // Relocate_info methods.
 804
 805 // Return a string describing the location of a relocation.  This is
 806 // only used in error messages.
 807
 808 template<int size, bool big_endian>
 809 std::string
 810 Relocate_info<size, big_endian>::location(size_t relnum, off_t) const
 811 {
 812   std::string ret(this->object->name());
 813   ret += ": reloc ";
 814   char buf[100];
 815   snprintf(buf, sizeof buf, "%zu", relnum);
 816   ret += buf;
 817   ret += " in reloc section ";
 818   snprintf(buf, sizeof buf, "%u", this->reloc_shndx);
 819   ret += buf;
 820   ret += " (" + this->object->section_name(this->reloc_shndx);
 821   ret += ") for section ";
 822   snprintf(buf, sizeof buf, "%u", this->data_shndx);
 823   ret += buf;
 824   ret += " (" + this->object->section_name(this->data_shndx) + ")";
 825   return ret;
 826 }
 827
 828 } // End namespace gold.
 829
 830 namespace
 831 {
 832
 833 using namespace gold;
 834
 835 // Read an ELF file with the header and return the appropriate
 836 // instance of Object.
 837
 838 template<int size, bool big_endian>
 839 Object*
 840 make_elf_sized_object(const std::string& name, Input_file* input_file,
 841                       off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
 842 {
 843   int et = ehdr.get_e_type();
 844   if (et == elfcpp::ET_REL)
 845     {
 846       Sized_relobj<size, big_endian>* obj =
 847         new Sized_relobj<size, big_endian>(name, input_file, offset, ehdr);
 848       obj->setup(ehdr);
 849       return obj;
 850     }
 851   else if (et == elfcpp::ET_DYN)
 852     {
 853       Sized_dynobj<size, big_endian>* obj =
 854         new Sized_dynobj<size, big_endian>(name, input_file, offset, ehdr);
 855       obj->setup(ehdr);
 856       return obj;
 857     }
 858   else
 859     {
 860       fprintf(stderr, _("%s: %s: unsupported ELF file type %d\n"),
 861               program_name, name.c_str(), et);
 862       gold_exit(false);
 863     }
 864 }
 865
 866 } // End anonymous namespace.
 867
 868 namespace gold
 869 {
 870
 871 // Read an ELF file and return the appropriate instance of Object.
 872
 873 Object*
 874 make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
 875                 const unsigned char* p, off_t bytes)
 876 {
 877   if (bytes < elfcpp::EI_NIDENT)
 878     {
 879       fprintf(stderr, _("%s: %s: ELF file too short\n"),
 880               program_name, name.c_str());
 881       gold_exit(false);
 882     }
 883
 884   int v = p[elfcpp::EI_VERSION];
 885   if (v != elfcpp::EV_CURRENT)
 886     {
 887       if (v == elfcpp::EV_NONE)
 888         fprintf(stderr, _("%s: %s: invalid ELF version 0\n"),
 889                 program_name, name.c_str());
 890       else
 891         fprintf(stderr, _("%s: %s: unsupported ELF version %d\n"),
 892                 program_name, name.c_str(), v);
 893       gold_exit(false);
 894     }
 895
 896   int c = p[elfcpp::EI_CLASS];
 897   if (c == elfcpp::ELFCLASSNONE)
 898     {
 899       fprintf(stderr, _("%s: %s: invalid ELF class 0\n"),
 900               program_name, name.c_str());
 901       gold_exit(false);
 902     }
 903   else if (c != elfcpp::ELFCLASS32
 904            && c != elfcpp::ELFCLASS64)
 905     {
 906       fprintf(stderr, _("%s: %s: unsupported ELF class %d\n"),
 907               program_name, name.c_str(), c);
 908       gold_exit(false);
 909     }
 910
 911   int d = p[elfcpp::EI_DATA];
 912   if (d == elfcpp::ELFDATANONE)
 913     {
 914       fprintf(stderr, _("%s: %s: invalid ELF data encoding\n"),
 915               program_name, name.c_str());
 916       gold_exit(false);
 917     }
 918   else if (d != elfcpp::ELFDATA2LSB
 919            && d != elfcpp::ELFDATA2MSB)
 920     {
 921       fprintf(stderr, _("%s: %s: unsupported ELF data encoding %d\n"),
 922               program_name, name.c_str(), d);
 923       gold_exit(false);
 924     }
 925
 926   bool big_endian = d == elfcpp::ELFDATA2MSB;
 927
 928   if (c == elfcpp::ELFCLASS32)
 929     {
 930       if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
 931         {
 932           fprintf(stderr, _("%s: %s: ELF file too short\n"),
 933                   program_name, name.c_str());
 934           gold_exit(false);
 935         }
 936       if (big_endian)
 937         {
 938 #ifdef HAVE_TARGET_32_BIG
 939           elfcpp::Ehdr<32, true> ehdr(p);
 940           return make_elf_sized_object<32, true>(name, input_file,
 941                                                  offset, ehdr);
 942 #else
 943           fprintf(stderr,
 944                   _("%s: %s: not configured to support 32-bit big-endian object\n"),
 945                   program_name, name.c_str());
 946           gold_exit(false);
 947 #endif
 948         }
 949       else
 950         {
 951 #ifdef HAVE_TARGET_32_LITTLE
 952           elfcpp::Ehdr<32, false> ehdr(p);
 953           return make_elf_sized_object<32, false>(name, input_file,
 954                                                   offset, ehdr);
 955 #else
 956           fprintf(stderr,
 957                   _("%s: %s: not configured to support 32-bit little-endian object\n"),
 958                   program_name, name.c_str());
 959           gold_exit(false);
 960 #endif
 961         }
 962     }
 963   else
 964     {
 965       if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
 966         {
 967           fprintf(stderr, _("%s: %s: ELF file too short\n"),
 968                   program_name, name.c_str());
 969           gold_exit(false);
 970         }
 971       if (big_endian)
 972         {
 973 #ifdef HAVE_TARGET_64_BIG
 974           elfcpp::Ehdr<64, true> ehdr(p);
 975           return make_elf_sized_object<64, true>(name, input_file,
 976                                                  offset, ehdr);
 977 #else
 978           fprintf(stderr,
 979                   _("%s: %s: not configured to support 64-bit big-endian object\n"),
 980                   program_name, name.c_str());
 981           gold_exit(false);
 982 #endif
 983         }
 984       else
 985         {
 986 #ifdef HAVE_TARGET_64_LITTLE
 987           elfcpp::Ehdr<64, false> ehdr(p);
 988           return make_elf_sized_object<64, false>(name, input_file,
 989                                                   offset, ehdr);
 990 #else
 991           fprintf(stderr,
 992                   _("%s: %s: not configured to support 64-bit little-endian object\n"),
 993                   program_name, name.c_str());
 994           gold_exit(false);
 995 #endif
 996         }
 997     }
 998 }
 999
1000 // Instantiate the templates we need.  We could use the configure
1001 // script to restrict this to only the ones for implemented targets.
1002
1003 #ifdef HAVE_TARGET_32_LITTLE
1004 template
1005 class Sized_relobj<32, false>;
1006 #endif
1007
1008 #ifdef HAVE_TARGET_32_BIG
1009 template
1010 class Sized_relobj<32, true>;
1011 #endif
1012
1013 #ifdef HAVE_TARGET_64_LITTLE
1014 template
1015 class Sized_relobj<64, false>;
1016 #endif
1017
1018 #ifdef HAVE_TARGET_64_BIG
1019 template
1020 class Sized_relobj<64, true>;
1021 #endif
1022
1023 #ifdef HAVE_TARGET_32_LITTLE
1024 template
1025 struct Relocate_info<32, false>;
1026 #endif
1027
1028 #ifdef HAVE_TARGET_32_BIG
1029 template
1030 struct Relocate_info<32, true>;
1031 #endif
1032
1033 #ifdef HAVE_TARGET_64_LITTLE
1034 template
1035 struct Relocate_info<64, false>;
1036 #endif
1037
1038 #ifdef HAVE_TARGET_64_BIG
1039 template
1040 struct Relocate_info<64, true>;
1041 #endif
1042
1043 } // End namespace gold.