gold/object.cc

   1 // object.cc -- support for an object file for linking in gold
   2
   3 #include "gold.h"
   4
   5 #include <cerrno>
   6 #include <cstring>
   7 #include <cassert>
   8
   9 #include "target-select.h"
  10 #include "layout.h"
  11 #include "output.h"
  12 #include "symtab.h"
  13 #include "object.h"
  14 #include "dynobj.h"
  15
  16 namespace gold
  17 {
  18
  19 // Class Sized_relobj.
  20
  21 template<int size, bool big_endian>
  22 Sized_relobj<size, big_endian>::Sized_relobj(
  23     const std::string& name,
  24     Input_file* input_file,
  25     off_t offset,
  26     const elfcpp::Ehdr<size, big_endian>& ehdr)
  27   : Relobj(name, input_file, offset),
  28     section_headers_(NULL),
  29     flags_(ehdr.get_e_flags()),
  30     shoff_(ehdr.get_e_shoff()),
  31     shstrndx_(0),
  32     symtab_shnum_(0),
  33     local_symbol_count_(0),
  34     output_local_symbol_count_(0),
  35     symbols_(NULL),
  36     local_symbol_offset_(0),
  37     values_(NULL)
  38 {
  39   if (ehdr.get_e_ehsize() != This::ehdr_size)
  40     {
  41       fprintf(stderr, _("%s: %s: bad e_ehsize field (%d != %d)\n"),
  42               program_name, this->name().c_str(), ehdr.get_e_ehsize(),
  43               This::ehdr_size);
  44       gold_exit(false);
  45     }
  46   if (ehdr.get_e_shentsize() != This::shdr_size)
  47     {
  48       fprintf(stderr, _("%s: %s: bad e_shentsize field (%d != %d)\n"),
  49               program_name, this->name().c_str(), ehdr.get_e_shentsize(),
  50               This::shdr_size);
  51       gold_exit(false);
  52     }
  53 }
  54
  55 template<int size, bool big_endian>
  56 Sized_relobj<size, big_endian>::~Sized_relobj()
  57 {
  58 }
  59
  60 // Read the section header for section SHNUM.
  61
  62 template<int size, bool big_endian>
  63 inline const unsigned char*
  64 Sized_relobj<size, big_endian>::section_header(unsigned int shnum)
  65 {
  66   assert(shnum < this->shnum());
  67   off_t symtabshdroff = this->shoff_ + shnum * This::shdr_size;
  68   return this->get_view(symtabshdroff, This::shdr_size);
  69 }
  70
  71 // Return the name of section SHNUM.  The object must already be
  72 // locked.
  73
  74 template<int size, bool big_endian>
  75 std::string
  76 Sized_relobj<size, big_endian>::do_section_name(unsigned int shnum)
  77 {
  78   // Read the section names.
  79   typename This::Shdr shdrnames(this->section_header(this->shstrndx_));
  80   const unsigned char* pnamesu = this->get_view(shdrnames.get_sh_offset(),
  81                                                 shdrnames.get_sh_size());
  82   const char* pnames = reinterpret_cast<const char*>(pnamesu);
  83
  84   typename This::Shdr shdr(this->section_header(shnum));
  85   if (shdr.get_sh_name() >= shdrnames.get_sh_size())
  86     {
  87       fprintf(stderr,
  88               _("%s: %s: bad section name offset for section %u: %lu\n"),
  89               program_name, this->name().c_str(), shnum,
  90               static_cast<unsigned long>(shdr.get_sh_name()));
  91       gold_exit(false);
  92     }
  93
  94   return std::string(pnames + shdr.get_sh_name());
  95 }
  96
  97 // Return a view of the contents of section SHNUM.  The object does
  98 // not have to be locked.
  99
 100 template<int size, bool big_endian>
 101 const unsigned char*
 102 Sized_relobj<size, big_endian>::do_section_contents(unsigned int shnum,
 103                                                     off_t* plen)
 104 {
 105   Task_locker_obj<Object> tl(*this);
 106
 107   typename This::Shdr shdr(this->section_header(shnum));
 108   *plen = shdr.get_sh_size();
 109   return this->get_view(shdr.get_sh_offset(), shdr.get_sh_size());
 110 }
 111
 112 // Set up an object file bsaed on the file header.  This sets up the
 113 // target and reads the section information.
 114
 115 template<int size, bool big_endian>
 116 void
 117 Sized_relobj<size, big_endian>::setup(
 118     const elfcpp::Ehdr<size, big_endian>& ehdr)
 119 {
 120   int machine = ehdr.get_e_machine();
 121   Target* target = select_target(machine, size, big_endian,
 122                                  ehdr.get_e_ident()[elfcpp::EI_OSABI],
 123                                  ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
 124   if (target == NULL)
 125     {
 126       fprintf(stderr, _("%s: %s: unsupported ELF machine number %d\n"),
 127               program_name, this->name().c_str(), machine);
 128       gold_exit(false);
 129     }
 130   this->set_target(target);
 131
 132   unsigned int shnum = ehdr.get_e_shnum();
 133   unsigned int shstrndx = ehdr.get_e_shstrndx();
 134   if ((shnum == 0 || shstrndx == elfcpp::SHN_XINDEX)
 135       && this->shoff_ != 0)
 136     {
 137       typename This::Shdr shdr(this->section_header(0));
 138       if (shnum == 0)
 139         shnum = shdr.get_sh_size();
 140       if (shstrndx == elfcpp::SHN_XINDEX)
 141         shstrndx = shdr.get_sh_link();
 142     }
 143   this->set_shnum(shnum);
 144   this->shstrndx_ = shstrndx;
 145
 146   if (shnum == 0)
 147     return;
 148
 149   // We store the section headers in a File_view until do_read_symbols.
 150   this->section_headers_ = this->get_lasting_view(this->shoff_,
 151                                                   shnum * This::shdr_size);
 152
 153   // Find the SHT_SYMTAB section.  The ELF standard says that maybe in
 154   // the future there can be more than one SHT_SYMTAB section.  Until
 155   // somebody figures out how that could work, we assume there is only
 156   // one.
 157   const unsigned char* p = this->section_headers_->data();
 158
 159   // Skip the first section, which is always empty.
 160   p += This::shdr_size;
 161   for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
 162     {
 163       typename This::Shdr shdr(p);
 164       if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
 165         {
 166           this->symtab_shnum_ = i;
 167           break;
 168         }
 169     }
 170 }
 171
 172 // Read the sections and symbols from an object file.
 173
 174 template<int size, bool big_endian>
 175 void
 176 Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
 177 {
 178   // Transfer our view of the section headers to SD.
 179   sd->section_headers = this->section_headers_;
 180   this->section_headers_ = NULL;
 181
 182   // Read the section names.
 183   const unsigned char* pshdrs = sd->section_headers->data();
 184   const unsigned char* pshdrnames = pshdrs + this->shstrndx_ * This::shdr_size;
 185   typename This::Shdr shdrnames(pshdrnames);
 186   sd->section_names_size = shdrnames.get_sh_size();
 187   sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(),
 188                                              sd->section_names_size);
 189
 190   if (this->symtab_shnum_ == 0)
 191     {
 192       // No symbol table.  Weird but legal.
 193       sd->symbols = NULL;
 194       sd->symbols_size = 0;
 195       sd->symbol_names = NULL;
 196       sd->symbol_names_size = 0;
 197       return;
 198     }
 199
 200   // Get the symbol table section header.
 201   typename This::Shdr symtabshdr(pshdrs
 202                                  + this->symtab_shnum_ * This::shdr_size);
 203   assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
 204
 205   // We only need the external symbols.
 206   const int sym_size = This::sym_size;
 207   const unsigned int loccount = symtabshdr.get_sh_info();
 208   this->local_symbol_count_ = loccount;
 209   off_t locsize = loccount * sym_size;
 210   off_t extoff = symtabshdr.get_sh_offset() + locsize;
 211   off_t extsize = symtabshdr.get_sh_size() - locsize;
 212
 213   // Read the symbol table.
 214   File_view* fvsymtab = this->get_lasting_view(extoff, extsize);
 215
 216   // Read the section header for the symbol names.
 217   unsigned int shnum = this->shnum();
 218   unsigned int strtab_shnum = symtabshdr.get_sh_link();
 219   if (strtab_shnum == 0 || strtab_shnum >= shnum)
 220     {
 221       fprintf(stderr, _("%s: %s: invalid symbol table name index: %u\n"),
 222               program_name, this->name().c_str(), strtab_shnum);
 223       gold_exit(false);
 224     }
 225   typename This::Shdr strtabshdr(pshdrs + strtab_shnum * This::shdr_size);
 226   if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
 227     {
 228       fprintf(stderr,
 229               _("%s: %s: symbol table name section has wrong type: %u\n"),
 230               program_name, this->name().c_str(),
 231               static_cast<unsigned int>(strtabshdr.get_sh_type()));
 232       gold_exit(false);
 233     }
 234
 235   // Read the symbol names.
 236   File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(),
 237                                                strtabshdr.get_sh_size());
 238
 239   sd->symbols = fvsymtab;
 240   sd->symbols_size = extsize;
 241   sd->symbol_names = fvstrtab;
 242   sd->symbol_names_size = strtabshdr.get_sh_size();
 243 }
 244
 245 // Return whether to include a section group in the link.  LAYOUT is
 246 // used to keep track of which section groups we have already seen.
 247 // INDEX is the index of the section group and SHDR is the section
 248 // header.  If we do not want to include this group, we set bits in
 249 // OMIT for each section which should be discarded.
 250
 251 template<int size, bool big_endian>
 252 bool
 253 Sized_relobj<size, big_endian>::include_section_group(
 254     Layout* layout,
 255     unsigned int index,
 256     const elfcpp::Shdr<size, big_endian>& shdr,
 257     std::vector<bool>* omit)
 258 {
 259   // Read the section contents.
 260   const unsigned char* pcon = this->get_view(shdr.get_sh_offset(),
 261                                              shdr.get_sh_size());
 262   const elfcpp::Elf_Word* pword =
 263     reinterpret_cast<const elfcpp::Elf_Word*>(pcon);
 264
 265   // The first word contains flags.  We only care about COMDAT section
 266   // groups.  Other section groups are always included in the link
 267   // just like ordinary sections.
 268   elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword);
 269   if ((flags & elfcpp::GRP_COMDAT) == 0)
 270     return true;
 271
 272   // Look up the group signature, which is the name of a symbol.  This
 273   // is a lot of effort to go to to read a string.  Why didn't they
 274   // just use the name of the SHT_GROUP section as the group
 275   // signature?
 276
 277   // Get the appropriate symbol table header (this will normally be
 278   // the single SHT_SYMTAB section, but in principle it need not be).
 279   if (shdr.get_sh_link() >= this->shnum())
 280     {
 281       fprintf(stderr, _("%s: %s: section group %u link %u out of range\n"),
 282               program_name, this->name().c_str(), index, shdr.get_sh_link());
 283       gold_exit(false);
 284     }
 285
 286   typename This::Shdr symshdr(this->section_header(shdr.get_sh_link()));
 287
 288   // Read the symbol table entry.
 289   if (shdr.get_sh_info() >= symshdr.get_sh_size() / This::sym_size)
 290     {
 291       fprintf(stderr, _("%s: %s: section group %u info %u out of range\n"),
 292               program_name, this->name().c_str(), index, shdr.get_sh_info());
 293       gold_exit(false);
 294     }
 295   off_t symoff = symshdr.get_sh_offset() + shdr.get_sh_info() * This::sym_size;
 296   const unsigned char* psym = this->get_view(symoff, This::sym_size);
 297   elfcpp::Sym<size, big_endian> sym(psym);
 298
 299   // Read the section header for the symbol table names.
 300   if (symshdr.get_sh_link() >= this->shnum())
 301     {
 302       fprintf(stderr, _("%s; %s: symtab section %u link %u out of range\n"),
 303               program_name, this->name().c_str(), shdr.get_sh_link(),
 304               symshdr.get_sh_link());
 305       gold_exit(false);
 306     }
 307
 308   typename This::Shdr symnamehdr(this->section_header(symshdr.get_sh_link()));
 309
 310   // Read the symbol table names.
 311   const unsigned char *psymnamesu = this->get_view(symnamehdr.get_sh_offset(),
 312                                                    symnamehdr.get_sh_size());
 313   const char* psymnames = reinterpret_cast<const char*>(psymnamesu);
 314
 315   // Get the section group signature.
 316   if (sym.get_st_name() >= symnamehdr.get_sh_size())
 317     {
 318       fprintf(stderr, _("%s: %s: symbol %u name offset %u out of range\n"),
 319               program_name, this->name().c_str(), shdr.get_sh_info(),
 320               sym.get_st_name());
 321       gold_exit(false);
 322     }
 323
 324   const char* signature = psymnames + sym.get_st_name();
 325
 326   // It seems that some versions of gas will create a section group
 327   // associated with a section symbol, and then fail to give a name to
 328   // the section symbol.  In such a case, use the name of the section.
 329   // FIXME.
 330   if (signature[0] == '\0'
 331       && sym.get_st_type() == elfcpp::STT_SECTION
 332       && sym.get_st_shndx() < this->shnum())
 333     {
 334       typename This::Shdr shdrnames(this->section_header(this->shstrndx_));
 335       const unsigned char* pnamesu = this->get_view(shdrnames.get_sh_offset(),
 336                                                     shdrnames.get_sh_size());
 337       const char* pnames = reinterpret_cast<const char*>(pnamesu);
 338
 339       typename This::Shdr sechdr(this->section_header(sym.get_st_shndx()));
 340       if (sechdr.get_sh_name() >= shdrnames.get_sh_size())
 341         {
 342           fprintf(stderr,
 343                   _("%s: %s: bad section name offset for section %u: %lu\n"),
 344                   program_name, this->name().c_str(), sym.get_st_shndx(),
 345                   static_cast<unsigned long>(sechdr.get_sh_name()));
 346           gold_exit(false);
 347         }
 348
 349       signature = pnames + sechdr.get_sh_name();
 350     }
 351
 352   // Record this section group, and see whether we've already seen one
 353   // with the same signature.
 354   if (layout->add_comdat(signature, true))
 355     return true;
 356
 357   // This is a duplicate.  We want to discard the sections in this
 358   // group.
 359   size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
 360   for (size_t i = 1; i < count; ++i)
 361     {
 362       elfcpp::Elf_Word secnum =
 363         elfcpp::Swap<32, big_endian>::readval(pword + i);
 364       if (secnum >= this->shnum())
 365         {
 366           fprintf(stderr,
 367                   _("%s: %s: section %u in section group %u out of range"),
 368                   program_name, this->name().c_str(), secnum,
 369                   index);
 370           gold_exit(false);
 371         }
 372       (*omit)[secnum] = true;
 373     }
 374
 375   return false;
 376 }
 377
 378 // Whether to include a linkonce section in the link.  NAME is the
 379 // name of the section and SHDR is the section header.
 380
 381 // Linkonce sections are a GNU extension implemented in the original
 382 // GNU linker before section groups were defined.  The semantics are
 383 // that we only include one linkonce section with a given name.  The
 384 // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
 385 // where T is the type of section and SYMNAME is the name of a symbol.
 386 // In an attempt to make linkonce sections interact well with section
 387 // groups, we try to identify SYMNAME and use it like a section group
 388 // signature.  We want to block section groups with that signature,
 389 // but not other linkonce sections with that signature.  We also use
 390 // the full name of the linkonce section as a normal section group
 391 // signature.
 392
 393 template<int size, bool big_endian>
 394 bool
 395 Sized_relobj<size, big_endian>::include_linkonce_section(
 396     Layout* layout,
 397     const char* name,
 398     const elfcpp::Shdr<size, big_endian>&)
 399 {
 400   const char* symname = strrchr(name, '.') + 1;
 401   bool include1 = layout->add_comdat(symname, false);
 402   bool include2 = layout->add_comdat(name, true);
 403   return include1 && include2;
 404 }
 405
 406 // Lay out the input sections.  We walk through the sections and check
 407 // whether they should be included in the link.  If they should, we
 408 // pass them to the Layout object, which will return an output section
 409 // and an offset.
 410
 411 template<int size, bool big_endian>
 412 void
 413 Sized_relobj<size, big_endian>::do_layout(const General_options& options,
 414                                           Symbol_table* symtab,
 415                                           Layout* layout,
 416                                           Read_symbols_data* sd)
 417 {
 418   unsigned int shnum = this->shnum();
 419   if (shnum == 0)
 420     return;
 421
 422   // Get the section headers.
 423   const unsigned char* pshdrs = sd->section_headers->data();
 424
 425   // Get the section names.
 426   const unsigned char* pnamesu = sd->section_names->data();
 427   const char* pnames = reinterpret_cast<const char*>(pnamesu);
 428
 429   std::vector<Map_to_output>& map_sections(this->map_to_output());
 430   map_sections.resize(shnum);
 431
 432   // Keep track of which sections to omit.
 433   std::vector<bool> omit(shnum, false);
 434
 435   const char warn_prefix[] = ".gnu.warning.";
 436   const int warn_prefix_len = sizeof warn_prefix - 1;
 437
 438   // Skip the first, dummy, section.
 439   pshdrs += This::shdr_size;
 440   for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
 441     {
 442       typename This::Shdr shdr(pshdrs);
 443
 444       if (shdr.get_sh_name() >= sd->section_names_size)
 445         {
 446           fprintf(stderr,
 447                   _("%s: %s: bad section name offset for section %u: %lu\n"),
 448                   program_name, this->name().c_str(), i,
 449                   static_cast<unsigned long>(shdr.get_sh_name()));
 450           gold_exit(false);
 451         }
 452
 453       const char* name = pnames + shdr.get_sh_name();
 454
 455       if (strncmp(name, warn_prefix, warn_prefix_len) == 0)
 456         {
 457           symtab->add_warning(name + warn_prefix_len, this, i);
 458           if (!options.is_relocatable())
 459             omit[i] = true;
 460         }
 461
 462       bool discard = omit[i];
 463       if (!discard)
 464         {
 465           if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
 466             {
 467               if (!this->include_section_group(layout, i, shdr, &omit))
 468                 discard = true;
 469             }
 470           else if (Layout::is_linkonce(name))
 471             {
 472               if (!this->include_linkonce_section(layout, name, shdr))
 473                 discard = true;
 474             }
 475         }
 476
 477       if (discard)
 478         {
 479           // Do not include this section in the link.
 480           map_sections[i].output_section = NULL;
 481           continue;
 482         }
 483
 484       off_t offset;
 485       Output_section* os = layout->layout(this, i, name, shdr, &offset);
 486
 487       map_sections[i].output_section = os;
 488       map_sections[i].offset = offset;
 489     }
 490
 491   delete sd->section_headers;
 492   sd->section_headers = NULL;
 493   delete sd->section_names;
 494   sd->section_names = NULL;
 495 }
 496
 497 // Add the symbols to the symbol table.
 498
 499 template<int size, bool big_endian>
 500 void
 501 Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
 502                                                Read_symbols_data* sd)
 503 {
 504   if (sd->symbols == NULL)
 505     {
 506       assert(sd->symbol_names == NULL);
 507       return;
 508     }
 509
 510   const int sym_size = This::sym_size;
 511   size_t symcount = sd->symbols_size / sym_size;
 512   if (symcount * sym_size != sd->symbols_size)
 513     {
 514       fprintf(stderr,
 515               _("%s: %s: size of symbols is not multiple of symbol size\n"),
 516               program_name, this->name().c_str());
 517       gold_exit(false);
 518     }
 519
 520   this->symbols_ = new Symbol*[symcount];
 521
 522   const char* sym_names =
 523     reinterpret_cast<const char*>(sd->symbol_names->data());
 524   symtab->add_from_object<size, big_endian>(this, sd->symbols->data(),
 525                                             symcount, sym_names,
 526                                             sd->symbol_names_size,
 527                                             this->symbols_);
 528
 529   delete sd->symbols;
 530   sd->symbols = NULL;
 531   delete sd->symbol_names;
 532   sd->symbol_names = NULL;
 533 }
 534
 535 // Finalize the local symbols.  Here we record the file offset at
 536 // which they should be output, we add their names to *POOL, and we
 537 // add their values to THIS->VALUES_.  Return the new file offset.
 538 // This function is always called from the main thread.  The actual
 539 // output of the local symbols will occur in a separate task.
 540
 541 template<int size, bool big_endian>
 542 off_t
 543 Sized_relobj<size, big_endian>::do_finalize_local_symbols(off_t off,
 544                                                           Stringpool* pool)
 545 {
 546   if (this->symtab_shnum_ == 0)
 547     {
 548       // This object has no symbols.  Weird but legal.
 549       return off;
 550     }
 551
 552   off = align_address(off, size >> 3);
 553
 554   this->local_symbol_offset_ = off;
 555
 556   // Read the symbol table section header.
 557   typename This::Shdr symtabshdr(this->section_header(this->symtab_shnum_));
 558   assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
 559
 560   // Read the local symbols.
 561   const int sym_size = This::sym_size;
 562   const unsigned int loccount = this->local_symbol_count_;
 563   assert(loccount == symtabshdr.get_sh_info());
 564   off_t locsize = loccount * sym_size;
 565   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
 566                                               locsize);
 567
 568   this->values_ = new typename elfcpp::Elf_types<size>::Elf_Addr[loccount];
 569
 570   // Read the section header for the symbol names.
 571   typename This::Shdr strtabshdr(
 572     this->section_header(symtabshdr.get_sh_link()));
 573   assert(strtabshdr.get_sh_type() == elfcpp::SHT_STRTAB);
 574
 575   // Read the symbol names.
 576   const unsigned char* pnamesu = this->get_view(strtabshdr.get_sh_offset(),
 577                                                 strtabshdr.get_sh_size());
 578   const char* pnames = reinterpret_cast<const char*>(pnamesu);
 579
 580   // Loop over the local symbols.
 581
 582   std::vector<Map_to_output>& mo(this->map_to_output());
 583   unsigned int shnum = this->shnum();
 584   unsigned int count = 0;
 585   // Skip the first, dummy, symbol.
 586   psyms += sym_size;
 587   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
 588     {
 589       elfcpp::Sym<size, big_endian> sym(psyms);
 590
 591       unsigned int shndx = sym.get_st_shndx();
 592
 593       if (shndx >= elfcpp::SHN_LORESERVE)
 594         {
 595           if (shndx == elfcpp::SHN_ABS)
 596             this->values_[i] = sym.get_st_value();
 597           else
 598             {
 599               // FIXME: Handle SHN_XINDEX.
 600               fprintf(stderr,
 601                       _("%s: %s: unknown section index %u "
 602                         "for local symbol %u\n"),
 603                       program_name, this->name().c_str(), shndx, i);
 604               gold_exit(false);
 605             }
 606         }
 607       else
 608         {
 609           if (shndx >= shnum)
 610             {
 611               fprintf(stderr,
 612                       _("%s: %s: local symbol %u section index %u "
 613                         "out of range\n"),
 614                       program_name, this->name().c_str(), i, shndx);
 615               gold_exit(false);
 616             }
 617
 618           if (mo[shndx].output_section == NULL)
 619             {
 620               this->values_[i] = 0;
 621               continue;
 622             }
 623
 624           this->values_[i] = (mo[shndx].output_section->address()
 625                               + mo[shndx].offset
 626                               + sym.get_st_value());
 627         }
 628
 629       if (sym.get_st_type() != elfcpp::STT_SECTION)
 630         {
 631           pool->add(pnames + sym.get_st_name(), NULL);
 632           off += sym_size;
 633           ++count;
 634         }
 635     }
 636
 637   this->output_local_symbol_count_ = count;
 638
 639   return off;
 640 }
 641
 642 // Write out the local symbols.
 643
 644 template<int size, bool big_endian>
 645 void
 646 Sized_relobj<size, big_endian>::write_local_symbols(Output_file* of,
 647                                                     const Stringpool* sympool)
 648 {
 649   if (this->symtab_shnum_ == 0)
 650     {
 651       // This object has no symbols.  Weird but legal.
 652       return;
 653     }
 654
 655   // Read the symbol table section header.
 656   typename This::Shdr symtabshdr(this->section_header(this->symtab_shnum_));
 657   assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
 658   const unsigned int loccount = this->local_symbol_count_;
 659   assert(loccount == symtabshdr.get_sh_info());
 660
 661   // Read the local symbols.
 662   const int sym_size = This::sym_size;
 663   off_t locsize = loccount * sym_size;
 664   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
 665                                               locsize);
 666
 667   // Read the section header for the symbol names.
 668   typename This::Shdr strtabshdr(
 669     this->section_header(symtabshdr.get_sh_link()));
 670   assert(strtabshdr.get_sh_type() == elfcpp::SHT_STRTAB);
 671
 672   // Read the symbol names.
 673   const unsigned char* pnamesu = this->get_view(strtabshdr.get_sh_offset(),
 674                                                 strtabshdr.get_sh_size());
 675   const char* pnames = reinterpret_cast<const char*>(pnamesu);
 676
 677   // Get a view into the output file.
 678   off_t output_size = this->output_local_symbol_count_ * sym_size;
 679   unsigned char* oview = of->get_output_view(this->local_symbol_offset_,
 680                                              output_size);
 681
 682   std::vector<Map_to_output>& mo(this->map_to_output());
 683
 684   psyms += sym_size;
 685   unsigned char* ov = oview;
 686   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
 687     {
 688       elfcpp::Sym<size, big_endian> isym(psyms);
 689
 690       if (isym.get_st_type() == elfcpp::STT_SECTION)
 691         continue;
 692
 693       unsigned int st_shndx = isym.get_st_shndx();
 694       if (st_shndx < elfcpp::SHN_LORESERVE)
 695         {
 696           assert(st_shndx < mo.size());
 697           if (mo[st_shndx].output_section == NULL)
 698             continue;
 699           st_shndx = mo[st_shndx].output_section->out_shndx();
 700         }
 701
 702       elfcpp::Sym_write<size, big_endian> osym(ov);
 703
 704       osym.put_st_name(sympool->get_offset(pnames + isym.get_st_name()));
 705       osym.put_st_value(this->values_[i]);
 706       osym.put_st_size(isym.get_st_size());
 707       osym.put_st_info(isym.get_st_info());
 708       osym.put_st_other(isym.get_st_other());
 709       osym.put_st_shndx(st_shndx);
 710
 711       ov += sym_size;
 712     }
 713
 714   assert(ov - oview == output_size);
 715
 716   of->write_output_view(this->local_symbol_offset_, output_size, oview);
 717 }
 718
 719 // Input_objects methods.
 720
 721 // Add a regular relocatable object to the list.
 722
 723 void
 724 Input_objects::add_object(Object* obj)
 725 {
 726   if (obj->is_dynamic())
 727     this->dynobj_list_.push_back(static_cast<Dynobj*>(obj));
 728   else
 729     this->relobj_list_.push_back(static_cast<Relobj*>(obj));
 730
 731   Target* target = obj->target();
 732   if (this->target_ == NULL)
 733     this->target_ = target;
 734   else if (this->target_ != target)
 735     {
 736       fprintf(stderr, "%s: %s: incompatible target\n",
 737               program_name, obj->name().c_str());
 738       gold_exit(false);
 739     }
 740 }
 741
 742 // Relocate_info methods.
 743
 744 // Return a string describing the location of a relocation.  This is
 745 // only used in error messages.
 746
 747 template<int size, bool big_endian>
 748 std::string
 749 Relocate_info<size, big_endian>::location(size_t relnum, off_t) const
 750 {
 751   std::string ret(this->object->name());
 752   ret += ": reloc ";
 753   char buf[100];
 754   snprintf(buf, sizeof buf, "%zu", relnum);
 755   ret += buf;
 756   ret += " in reloc section ";
 757   snprintf(buf, sizeof buf, "%u", this->reloc_shndx);
 758   ret += buf;
 759   ret += " (" + this->object->section_name(this->reloc_shndx);
 760   ret += ") for section ";
 761   snprintf(buf, sizeof buf, "%u", this->data_shndx);
 762   ret += buf;
 763   ret += " (" + this->object->section_name(this->data_shndx) + ")";
 764   return ret;
 765 }
 766
 767 } // End namespace gold.
 768
 769 namespace
 770 {
 771
 772 using namespace gold;
 773
 774 // Read an ELF file with the header and return the appropriate
 775 // instance of Object.
 776
 777 template<int size, bool big_endian>
 778 Object*
 779 make_elf_sized_object(const std::string& name, Input_file* input_file,
 780                       off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
 781 {
 782   int et = ehdr.get_e_type();
 783   if (et != elfcpp::ET_REL && et != elfcpp::ET_DYN)
 784     {
 785       fprintf(stderr, "%s: %s: unsupported ELF type %d\n",
 786               program_name, name.c_str(), static_cast<int>(et));
 787       gold_exit(false);
 788     }
 789
 790   if (et == elfcpp::ET_REL)
 791     {
 792       Sized_relobj<size, big_endian>* obj =
 793         new Sized_relobj<size, big_endian>(name, input_file, offset, ehdr);
 794       obj->setup(ehdr);
 795       return obj;
 796     }
 797   else
 798     {
 799       // elfcpp::ET_DYN
 800       fprintf(stderr, _("%s: %s: dynamic objects are not yet supported\n"),
 801               program_name, name.c_str());
 802       gold_exit(false);
 803 //       Sized_dynobj<size, big_endian>* obj =
 804 //      new Sized_dynobj<size, big_endian>(this->input_.name(), input_file,
 805 //                                         offset, ehdr);
 806 //       obj->setup(ehdr);
 807 //       return obj;
 808     }
 809 }
 810
 811 } // End anonymous namespace.
 812
 813 namespace gold
 814 {
 815
 816 // Read an ELF file and return the appropriate instance of Object.
 817
 818 Object*
 819 make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
 820                 const unsigned char* p, off_t bytes)
 821 {
 822   if (bytes < elfcpp::EI_NIDENT)
 823     {
 824       fprintf(stderr, _("%s: %s: ELF file too short\n"),
 825               program_name, name.c_str());
 826       gold_exit(false);
 827     }
 828
 829   int v = p[elfcpp::EI_VERSION];
 830   if (v != elfcpp::EV_CURRENT)
 831     {
 832       if (v == elfcpp::EV_NONE)
 833         fprintf(stderr, _("%s: %s: invalid ELF version 0\n"),
 834                 program_name, name.c_str());
 835       else
 836         fprintf(stderr, _("%s: %s: unsupported ELF version %d\n"),
 837                 program_name, name.c_str(), v);
 838       gold_exit(false);
 839     }
 840
 841   int c = p[elfcpp::EI_CLASS];
 842   if (c == elfcpp::ELFCLASSNONE)
 843     {
 844       fprintf(stderr, _("%s: %s: invalid ELF class 0\n"),
 845               program_name, name.c_str());
 846       gold_exit(false);
 847     }
 848   else if (c != elfcpp::ELFCLASS32
 849            && c != elfcpp::ELFCLASS64)
 850     {
 851       fprintf(stderr, _("%s: %s: unsupported ELF class %d\n"),
 852               program_name, name.c_str(), c);
 853       gold_exit(false);
 854     }
 855
 856   int d = p[elfcpp::EI_DATA];
 857   if (d == elfcpp::ELFDATANONE)
 858     {
 859       fprintf(stderr, _("%s: %s: invalid ELF data encoding\n"),
 860               program_name, name.c_str());
 861       gold_exit(false);
 862     }
 863   else if (d != elfcpp::ELFDATA2LSB
 864            && d != elfcpp::ELFDATA2MSB)
 865     {
 866       fprintf(stderr, _("%s: %s: unsupported ELF data encoding %d\n"),
 867               program_name, name.c_str(), d);
 868       gold_exit(false);
 869     }
 870
 871   bool big_endian = d == elfcpp::ELFDATA2MSB;
 872
 873   if (c == elfcpp::ELFCLASS32)
 874     {
 875       if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
 876         {
 877           fprintf(stderr, _("%s: %s: ELF file too short\n"),
 878                   program_name, name.c_str());
 879           gold_exit(false);
 880         }
 881       if (big_endian)
 882         {
 883           elfcpp::Ehdr<32, true> ehdr(p);
 884           return make_elf_sized_object<32, true>(name, input_file,
 885                                                  offset, ehdr);
 886         }
 887       else
 888         {
 889           elfcpp::Ehdr<32, false> ehdr(p);
 890           return make_elf_sized_object<32, false>(name, input_file,
 891                                                   offset, ehdr);
 892         }
 893     }
 894   else
 895     {
 896       if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
 897         {
 898           fprintf(stderr, _("%s: %s: ELF file too short\n"),
 899                   program_name, name.c_str());
 900           gold_exit(false);
 901         }
 902       if (big_endian)
 903         {
 904           elfcpp::Ehdr<64, true> ehdr(p);
 905           return make_elf_sized_object<64, true>(name, input_file,
 906                                                  offset, ehdr);
 907         }
 908       else
 909         {
 910           elfcpp::Ehdr<64, false> ehdr(p);
 911           return make_elf_sized_object<64, false>(name, input_file,
 912                                                   offset, ehdr);
 913         }
 914     }
 915 }
 916
 917 // Instantiate the templates we need.  We could use the configure
 918 // script to restrict this to only the ones for implemented targets.
 919
 920 template
 921 class Sized_relobj<32, false>;
 922
 923 template
 924 class Sized_relobj<32, true>;
 925
 926 template
 927 class Sized_relobj<64, false>;
 928
 929 template
 930 class Sized_relobj<64, true>;
 931
 932 template
 933 struct Relocate_info<32, false>;
 934
 935 template
 936 struct Relocate_info<32, true>;
 937
 938 template
 939 struct Relocate_info<64, false>;
 940
 941 template
 942 struct Relocate_info<64, true>;
 943
 944 } // End namespace gold.