| 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 <cstdarg> |
| 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 Object. |
| 20 | |
| 21 | // Set the target based on fields in the ELF file header. |
| 22 | |
| 23 | void |
| 24 | Object::set_target(int machine, int size, bool big_endian, int osabi, |
| 25 | int abiversion) |
| 26 | { |
| 27 | Target* target = select_target(machine, size, big_endian, osabi, abiversion); |
| 28 | if (target == NULL) |
| 29 | { |
| 30 | fprintf(stderr, _("%s: %s: unsupported ELF machine number %d\n"), |
| 31 | program_name, this->name().c_str(), machine); |
| 32 | gold_exit(false); |
| 33 | } |
| 34 | this->target_ = target; |
| 35 | } |
| 36 | |
| 37 | // Report an error for the elfcpp::Elf_file interface. |
| 38 | |
| 39 | void |
| 40 | Object::error(const char* format, ...) |
| 41 | { |
| 42 | va_list args; |
| 43 | |
| 44 | fprintf(stderr, "%s: %s: ", program_name, this->name().c_str()); |
| 45 | va_start(args, format); |
| 46 | vfprintf(stderr, format, args); |
| 47 | va_end(args); |
| 48 | putc('\n', stderr); |
| 49 | |
| 50 | gold_exit(false); |
| 51 | } |
| 52 | |
| 53 | // Return a view of the contents of a section. |
| 54 | |
| 55 | const unsigned char* |
| 56 | Object::section_contents(unsigned int shndx, off_t* plen) |
| 57 | { |
| 58 | Location loc(this->do_section_contents(shndx)); |
| 59 | *plen = loc.data_size; |
| 60 | return this->get_view(loc.file_offset, loc.data_size); |
| 61 | } |
| 62 | |
| 63 | // Read the section data into SD. This is code common to Sized_relobj |
| 64 | // and Sized_dynobj, so we put it into Object. |
| 65 | |
| 66 | template<int size, bool big_endian> |
| 67 | void |
| 68 | Object::read_section_data(elfcpp::Elf_file<size, big_endian, Object>* elf_file, |
| 69 | Read_symbols_data* sd) |
| 70 | { |
| 71 | const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size; |
| 72 | |
| 73 | // Read the section headers. |
| 74 | const off_t shoff = elf_file->shoff(); |
| 75 | const unsigned int shnum = this->shnum(); |
| 76 | sd->section_headers = this->get_lasting_view(shoff, shnum * shdr_size); |
| 77 | |
| 78 | // Read the section names. |
| 79 | const unsigned char* pshdrs = sd->section_headers->data(); |
| 80 | const unsigned char* pshdrnames = pshdrs + elf_file->shstrndx() * shdr_size; |
| 81 | typename elfcpp::Shdr<size, big_endian> shdrnames(pshdrnames); |
| 82 | |
| 83 | if (shdrnames.get_sh_type() != elfcpp::SHT_STRTAB) |
| 84 | { |
| 85 | fprintf(stderr, |
| 86 | _("%s: %s: section name section has wrong type: %u\n"), |
| 87 | program_name, this->name().c_str(), |
| 88 | static_cast<unsigned int>(shdrnames.get_sh_type())); |
| 89 | gold_exit(false); |
| 90 | } |
| 91 | |
| 92 | sd->section_names_size = shdrnames.get_sh_size(); |
| 93 | sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(), |
| 94 | sd->section_names_size); |
| 95 | } |
| 96 | |
| 97 | // If NAME is the name of a special .gnu.warning section, arrange for |
| 98 | // the warning to be issued. SHNDX is the section index. Return |
| 99 | // whether it is a warning section. |
| 100 | |
| 101 | bool |
| 102 | Object::handle_gnu_warning_section(const char* name, unsigned int shndx, |
| 103 | Symbol_table* symtab) |
| 104 | { |
| 105 | const char warn_prefix[] = ".gnu.warning."; |
| 106 | const int warn_prefix_len = sizeof warn_prefix - 1; |
| 107 | if (strncmp(name, warn_prefix, warn_prefix_len) == 0) |
| 108 | { |
| 109 | symtab->add_warning(name + warn_prefix_len, this, shndx); |
| 110 | return true; |
| 111 | } |
| 112 | return false; |
| 113 | } |
| 114 | |
| 115 | // Class Sized_relobj. |
| 116 | |
| 117 | template<int size, bool big_endian> |
| 118 | Sized_relobj<size, big_endian>::Sized_relobj( |
| 119 | const std::string& name, |
| 120 | Input_file* input_file, |
| 121 | off_t offset, |
| 122 | const elfcpp::Ehdr<size, big_endian>& ehdr) |
| 123 | : Relobj(name, input_file, offset), |
| 124 | elf_file_(this, ehdr), |
| 125 | symtab_shndx_(-1U), |
| 126 | local_symbol_count_(0), |
| 127 | output_local_symbol_count_(0), |
| 128 | symbols_(NULL), |
| 129 | local_symbol_offset_(0), |
| 130 | local_values_() |
| 131 | { |
| 132 | } |
| 133 | |
| 134 | template<int size, bool big_endian> |
| 135 | Sized_relobj<size, big_endian>::~Sized_relobj() |
| 136 | { |
| 137 | } |
| 138 | |
| 139 | // Set up an object file based on the file header. This sets up the |
| 140 | // target and reads the section information. |
| 141 | |
| 142 | template<int size, bool big_endian> |
| 143 | void |
| 144 | Sized_relobj<size, big_endian>::setup( |
| 145 | const elfcpp::Ehdr<size, big_endian>& ehdr) |
| 146 | { |
| 147 | this->set_target(ehdr.get_e_machine(), size, big_endian, |
| 148 | ehdr.get_e_ident()[elfcpp::EI_OSABI], |
| 149 | ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]); |
| 150 | |
| 151 | const unsigned int shnum = this->elf_file_.shnum(); |
| 152 | this->set_shnum(shnum); |
| 153 | } |
| 154 | |
| 155 | // Find the SHT_SYMTAB section, given the section headers. The ELF |
| 156 | // standard says that maybe in the future there can be more than one |
| 157 | // SHT_SYMTAB section. Until somebody figures out how that could |
| 158 | // work, we assume there is only one. |
| 159 | |
| 160 | template<int size, bool big_endian> |
| 161 | void |
| 162 | Sized_relobj<size, big_endian>::find_symtab(const unsigned char* pshdrs) |
| 163 | { |
| 164 | const unsigned int shnum = this->shnum(); |
| 165 | this->symtab_shndx_ = 0; |
| 166 | if (shnum > 0) |
| 167 | { |
| 168 | // Look through the sections in reverse order, since gas tends |
| 169 | // to put the symbol table at the end. |
| 170 | const unsigned char* p = pshdrs + shnum * This::shdr_size; |
| 171 | unsigned int i = shnum; |
| 172 | while (i > 0) |
| 173 | { |
| 174 | --i; |
| 175 | p -= This::shdr_size; |
| 176 | typename This::Shdr shdr(p); |
| 177 | if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB) |
| 178 | { |
| 179 | this->symtab_shndx_ = i; |
| 180 | break; |
| 181 | } |
| 182 | } |
| 183 | } |
| 184 | } |
| 185 | |
| 186 | // Read the sections and symbols from an object file. |
| 187 | |
| 188 | template<int size, bool big_endian> |
| 189 | void |
| 190 | Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd) |
| 191 | { |
| 192 | this->read_section_data(&this->elf_file_, sd); |
| 193 | |
| 194 | const unsigned char* const pshdrs = sd->section_headers->data(); |
| 195 | |
| 196 | this->find_symtab(pshdrs); |
| 197 | |
| 198 | if (this->symtab_shndx_ == 0) |
| 199 | { |
| 200 | // No symbol table. Weird but legal. |
| 201 | sd->symbols = NULL; |
| 202 | sd->symbols_size = 0; |
| 203 | sd->symbol_names = NULL; |
| 204 | sd->symbol_names_size = 0; |
| 205 | return; |
| 206 | } |
| 207 | |
| 208 | // Get the symbol table section header. |
| 209 | typename This::Shdr symtabshdr(pshdrs |
| 210 | + this->symtab_shndx_ * This::shdr_size); |
| 211 | gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB); |
| 212 | |
| 213 | // We only need the external symbols. |
| 214 | const int sym_size = This::sym_size; |
| 215 | const unsigned int loccount = symtabshdr.get_sh_info(); |
| 216 | this->local_symbol_count_ = loccount; |
| 217 | off_t locsize = loccount * sym_size; |
| 218 | off_t extoff = symtabshdr.get_sh_offset() + locsize; |
| 219 | off_t extsize = symtabshdr.get_sh_size() - locsize; |
| 220 | |
| 221 | // Read the symbol table. |
| 222 | File_view* fvsymtab = this->get_lasting_view(extoff, extsize); |
| 223 | |
| 224 | // Read the section header for the symbol names. |
| 225 | unsigned int strtab_shndx = symtabshdr.get_sh_link(); |
| 226 | if (strtab_shndx >= this->shnum()) |
| 227 | { |
| 228 | fprintf(stderr, _("%s: %s: invalid symbol table name index: %u\n"), |
| 229 | program_name, this->name().c_str(), strtab_shndx); |
| 230 | gold_exit(false); |
| 231 | } |
| 232 | typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size); |
| 233 | if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB) |
| 234 | { |
| 235 | fprintf(stderr, |
| 236 | _("%s: %s: symbol table name section has wrong type: %u\n"), |
| 237 | program_name, this->name().c_str(), |
| 238 | static_cast<unsigned int>(strtabshdr.get_sh_type())); |
| 239 | gold_exit(false); |
| 240 | } |
| 241 | |
| 242 | // Read the symbol names. |
| 243 | File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(), |
| 244 | strtabshdr.get_sh_size()); |
| 245 | |
| 246 | sd->symbols = fvsymtab; |
| 247 | sd->symbols_size = extsize; |
| 248 | sd->symbol_names = fvstrtab; |
| 249 | sd->symbol_names_size = strtabshdr.get_sh_size(); |
| 250 | } |
| 251 | |
| 252 | // Return whether to include a section group in the link. LAYOUT is |
| 253 | // used to keep track of which section groups we have already seen. |
| 254 | // INDEX is the index of the section group and SHDR is the section |
| 255 | // header. If we do not want to include this group, we set bits in |
| 256 | // OMIT for each section which should be discarded. |
| 257 | |
| 258 | template<int size, bool big_endian> |
| 259 | bool |
| 260 | Sized_relobj<size, big_endian>::include_section_group( |
| 261 | Layout* layout, |
| 262 | unsigned int index, |
| 263 | const elfcpp::Shdr<size, big_endian>& shdr, |
| 264 | std::vector<bool>* omit) |
| 265 | { |
| 266 | // Read the section contents. |
| 267 | const unsigned char* pcon = this->get_view(shdr.get_sh_offset(), |
| 268 | shdr.get_sh_size()); |
| 269 | const elfcpp::Elf_Word* pword = |
| 270 | reinterpret_cast<const elfcpp::Elf_Word*>(pcon); |
| 271 | |
| 272 | // The first word contains flags. We only care about COMDAT section |
| 273 | // groups. Other section groups are always included in the link |
| 274 | // just like ordinary sections. |
| 275 | elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword); |
| 276 | if ((flags & elfcpp::GRP_COMDAT) == 0) |
| 277 | return true; |
| 278 | |
| 279 | // Look up the group signature, which is the name of a symbol. This |
| 280 | // is a lot of effort to go to to read a string. Why didn't they |
| 281 | // just use the name of the SHT_GROUP section as the group |
| 282 | // signature? |
| 283 | |
| 284 | // Get the appropriate symbol table header (this will normally be |
| 285 | // the single SHT_SYMTAB section, but in principle it need not be). |
| 286 | const unsigned int link = shdr.get_sh_link(); |
| 287 | typename This::Shdr symshdr(this, this->elf_file_.section_header(link)); |
| 288 | |
| 289 | // Read the symbol table entry. |
| 290 | if (shdr.get_sh_info() >= symshdr.get_sh_size() / This::sym_size) |
| 291 | { |
| 292 | fprintf(stderr, _("%s: %s: section group %u info %u out of range\n"), |
| 293 | program_name, this->name().c_str(), index, shdr.get_sh_info()); |
| 294 | gold_exit(false); |
| 295 | } |
| 296 | off_t symoff = symshdr.get_sh_offset() + shdr.get_sh_info() * This::sym_size; |
| 297 | const unsigned char* psym = this->get_view(symoff, This::sym_size); |
| 298 | elfcpp::Sym<size, big_endian> sym(psym); |
| 299 | |
| 300 | // Read the symbol table names. |
| 301 | off_t symnamelen; |
| 302 | const unsigned char* psymnamesu; |
| 303 | psymnamesu = this->section_contents(symshdr.get_sh_link(), &symnamelen); |
| 304 | const char* psymnames = reinterpret_cast<const char*>(psymnamesu); |
| 305 | |
| 306 | // Get the section group signature. |
| 307 | if (sym.get_st_name() >= symnamelen) |
| 308 | { |
| 309 | fprintf(stderr, _("%s: %s: symbol %u name offset %u out of range\n"), |
| 310 | program_name, this->name().c_str(), shdr.get_sh_info(), |
| 311 | sym.get_st_name()); |
| 312 | gold_exit(false); |
| 313 | } |
| 314 | |
| 315 | const char* signature = psymnames + sym.get_st_name(); |
| 316 | |
| 317 | // It seems that some versions of gas will create a section group |
| 318 | // associated with a section symbol, and then fail to give a name to |
| 319 | // the section symbol. In such a case, use the name of the section. |
| 320 | // FIXME. |
| 321 | std::string secname; |
| 322 | if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION) |
| 323 | { |
| 324 | secname = this->section_name(sym.get_st_shndx()); |
| 325 | signature = secname.c_str(); |
| 326 | } |
| 327 | |
| 328 | // Record this section group, and see whether we've already seen one |
| 329 | // with the same signature. |
| 330 | if (layout->add_comdat(signature, true)) |
| 331 | return true; |
| 332 | |
| 333 | // This is a duplicate. We want to discard the sections in this |
| 334 | // group. |
| 335 | size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word); |
| 336 | for (size_t i = 1; i < count; ++i) |
| 337 | { |
| 338 | elfcpp::Elf_Word secnum = |
| 339 | elfcpp::Swap<32, big_endian>::readval(pword + i); |
| 340 | if (secnum >= this->shnum()) |
| 341 | { |
| 342 | fprintf(stderr, |
| 343 | _("%s: %s: section %u in section group %u out of range"), |
| 344 | program_name, this->name().c_str(), secnum, |
| 345 | index); |
| 346 | gold_exit(false); |
| 347 | } |
| 348 | (*omit)[secnum] = true; |
| 349 | } |
| 350 | |
| 351 | return false; |
| 352 | } |
| 353 | |
| 354 | // Whether to include a linkonce section in the link. NAME is the |
| 355 | // name of the section and SHDR is the section header. |
| 356 | |
| 357 | // Linkonce sections are a GNU extension implemented in the original |
| 358 | // GNU linker before section groups were defined. The semantics are |
| 359 | // that we only include one linkonce section with a given name. The |
| 360 | // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME, |
| 361 | // where T is the type of section and SYMNAME is the name of a symbol. |
| 362 | // In an attempt to make linkonce sections interact well with section |
| 363 | // groups, we try to identify SYMNAME and use it like a section group |
| 364 | // signature. We want to block section groups with that signature, |
| 365 | // but not other linkonce sections with that signature. We also use |
| 366 | // the full name of the linkonce section as a normal section group |
| 367 | // signature. |
| 368 | |
| 369 | template<int size, bool big_endian> |
| 370 | bool |
| 371 | Sized_relobj<size, big_endian>::include_linkonce_section( |
| 372 | Layout* layout, |
| 373 | const char* name, |
| 374 | const elfcpp::Shdr<size, big_endian>&) |
| 375 | { |
| 376 | const char* symname = strrchr(name, '.') + 1; |
| 377 | bool include1 = layout->add_comdat(symname, false); |
| 378 | bool include2 = layout->add_comdat(name, true); |
| 379 | return include1 && include2; |
| 380 | } |
| 381 | |
| 382 | // Lay out the input sections. We walk through the sections and check |
| 383 | // whether they should be included in the link. If they should, we |
| 384 | // pass them to the Layout object, which will return an output section |
| 385 | // and an offset. |
| 386 | |
| 387 | template<int size, bool big_endian> |
| 388 | void |
| 389 | Sized_relobj<size, big_endian>::do_layout(const General_options& options, |
| 390 | Symbol_table* symtab, |
| 391 | Layout* layout, |
| 392 | Read_symbols_data* sd) |
| 393 | { |
| 394 | const unsigned int shnum = this->shnum(); |
| 395 | if (shnum == 0) |
| 396 | return; |
| 397 | |
| 398 | // Get the section headers. |
| 399 | const unsigned char* pshdrs = sd->section_headers->data(); |
| 400 | |
| 401 | // Get the section names. |
| 402 | const unsigned char* pnamesu = sd->section_names->data(); |
| 403 | const char* pnames = reinterpret_cast<const char*>(pnamesu); |
| 404 | |
| 405 | std::vector<Map_to_output>& map_sections(this->map_to_output()); |
| 406 | map_sections.resize(shnum); |
| 407 | |
| 408 | // Keep track of which sections to omit. |
| 409 | std::vector<bool> omit(shnum, false); |
| 410 | |
| 411 | // Skip the first, dummy, section. |
| 412 | pshdrs += This::shdr_size; |
| 413 | for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size) |
| 414 | { |
| 415 | typename This::Shdr shdr(pshdrs); |
| 416 | |
| 417 | if (shdr.get_sh_name() >= sd->section_names_size) |
| 418 | { |
| 419 | fprintf(stderr, |
| 420 | _("%s: %s: bad section name offset for section %u: %lu\n"), |
| 421 | program_name, this->name().c_str(), i, |
| 422 | static_cast<unsigned long>(shdr.get_sh_name())); |
| 423 | gold_exit(false); |
| 424 | } |
| 425 | |
| 426 | const char* name = pnames + shdr.get_sh_name(); |
| 427 | |
| 428 | if (this->handle_gnu_warning_section(name, i, symtab)) |
| 429 | { |
| 430 | if (!options.is_relocatable()) |
| 431 | omit[i] = true; |
| 432 | } |
| 433 | |
| 434 | bool discard = omit[i]; |
| 435 | if (!discard) |
| 436 | { |
| 437 | if (shdr.get_sh_type() == elfcpp::SHT_GROUP) |
| 438 | { |
| 439 | if (!this->include_section_group(layout, i, shdr, &omit)) |
| 440 | discard = true; |
| 441 | } |
| 442 | else if (Layout::is_linkonce(name)) |
| 443 | { |
| 444 | if (!this->include_linkonce_section(layout, name, shdr)) |
| 445 | discard = true; |
| 446 | } |
| 447 | } |
| 448 | |
| 449 | if (discard) |
| 450 | { |
| 451 | // Do not include this section in the link. |
| 452 | map_sections[i].output_section = NULL; |
| 453 | continue; |
| 454 | } |
| 455 | |
| 456 | off_t offset; |
| 457 | Output_section* os = layout->layout(this, i, name, shdr, &offset); |
| 458 | |
| 459 | map_sections[i].output_section = os; |
| 460 | map_sections[i].offset = offset; |
| 461 | } |
| 462 | |
| 463 | delete sd->section_headers; |
| 464 | sd->section_headers = NULL; |
| 465 | delete sd->section_names; |
| 466 | sd->section_names = NULL; |
| 467 | } |
| 468 | |
| 469 | // Add the symbols to the symbol table. |
| 470 | |
| 471 | template<int size, bool big_endian> |
| 472 | void |
| 473 | Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab, |
| 474 | Read_symbols_data* sd) |
| 475 | { |
| 476 | if (sd->symbols == NULL) |
| 477 | { |
| 478 | gold_assert(sd->symbol_names == NULL); |
| 479 | return; |
| 480 | } |
| 481 | |
| 482 | const int sym_size = This::sym_size; |
| 483 | size_t symcount = sd->symbols_size / sym_size; |
| 484 | if (symcount * sym_size != sd->symbols_size) |
| 485 | { |
| 486 | fprintf(stderr, |
| 487 | _("%s: %s: size of symbols is not multiple of symbol size\n"), |
| 488 | program_name, this->name().c_str()); |
| 489 | gold_exit(false); |
| 490 | } |
| 491 | |
| 492 | this->symbols_ = new Symbol*[symcount]; |
| 493 | |
| 494 | const char* sym_names = |
| 495 | reinterpret_cast<const char*>(sd->symbol_names->data()); |
| 496 | symtab->add_from_relobj(this, sd->symbols->data(), symcount, sym_names, |
| 497 | sd->symbol_names_size, this->symbols_); |
| 498 | |
| 499 | delete sd->symbols; |
| 500 | sd->symbols = NULL; |
| 501 | delete sd->symbol_names; |
| 502 | sd->symbol_names = NULL; |
| 503 | } |
| 504 | |
| 505 | // Finalize the local symbols. Here we record the file offset at |
| 506 | // which they should be output, we add their names to *POOL, and we |
| 507 | // add their values to THIS->LOCAL_VALUES_. Return the symbol index. |
| 508 | // This function is always called from the main thread. The actual |
| 509 | // output of the local symbols will occur in a separate task. |
| 510 | |
| 511 | template<int size, bool big_endian> |
| 512 | unsigned int |
| 513 | Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index, |
| 514 | off_t off, |
| 515 | Stringpool* pool) |
| 516 | { |
| 517 | gold_assert(this->symtab_shndx_ != -1U); |
| 518 | if (this->symtab_shndx_ == 0) |
| 519 | { |
| 520 | // This object has no symbols. Weird but legal. |
| 521 | return index; |
| 522 | } |
| 523 | |
| 524 | gold_assert(off == static_cast<off_t>(align_address(off, size >> 3))); |
| 525 | |
| 526 | this->local_symbol_offset_ = off; |
| 527 | |
| 528 | // Read the symbol table section header. |
| 529 | const unsigned int symtab_shndx = this->symtab_shndx_; |
| 530 | typename This::Shdr symtabshdr(this, |
| 531 | this->elf_file_.section_header(symtab_shndx)); |
| 532 | gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB); |
| 533 | |
| 534 | // Read the local symbols. |
| 535 | const int sym_size = This::sym_size; |
| 536 | const unsigned int loccount = this->local_symbol_count_; |
| 537 | gold_assert(loccount == symtabshdr.get_sh_info()); |
| 538 | off_t locsize = loccount * sym_size; |
| 539 | const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(), |
| 540 | locsize); |
| 541 | |
| 542 | this->local_values_.resize(loccount); |
| 543 | |
| 544 | // Read the symbol names. |
| 545 | const unsigned int strtab_shndx = symtabshdr.get_sh_link(); |
| 546 | off_t strtab_size; |
| 547 | const unsigned char* pnamesu = this->section_contents(strtab_shndx, |
| 548 | &strtab_size); |
| 549 | const char* pnames = reinterpret_cast<const char*>(pnamesu); |
| 550 | |
| 551 | // Loop over the local symbols. |
| 552 | |
| 553 | const std::vector<Map_to_output>& mo(this->map_to_output()); |
| 554 | unsigned int shnum = this->shnum(); |
| 555 | unsigned int count = 0; |
| 556 | // Skip the first, dummy, symbol. |
| 557 | psyms += sym_size; |
| 558 | for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size) |
| 559 | { |
| 560 | elfcpp::Sym<size, big_endian> sym(psyms); |
| 561 | |
| 562 | Symbol_value<size>& lv(this->local_values_[i]); |
| 563 | |
| 564 | unsigned int shndx = sym.get_st_shndx(); |
| 565 | lv.set_input_shndx(shndx); |
| 566 | |
| 567 | if (shndx >= elfcpp::SHN_LORESERVE) |
| 568 | { |
| 569 | if (shndx == elfcpp::SHN_ABS) |
| 570 | lv.set_output_value(sym.get_st_value()); |
| 571 | else |
| 572 | { |
| 573 | // FIXME: Handle SHN_XINDEX. |
| 574 | fprintf(stderr, |
| 575 | _("%s: %s: unknown section index %u " |
| 576 | "for local symbol %u\n"), |
| 577 | program_name, this->name().c_str(), shndx, i); |
| 578 | gold_exit(false); |
| 579 | } |
| 580 | } |
| 581 | else |
| 582 | { |
| 583 | if (shndx >= shnum) |
| 584 | { |
| 585 | fprintf(stderr, |
| 586 | _("%s: %s: local symbol %u section index %u " |
| 587 | "out of range\n"), |
| 588 | program_name, this->name().c_str(), i, shndx); |
| 589 | gold_exit(false); |
| 590 | } |
| 591 | |
| 592 | Output_section* os = mo[shndx].output_section; |
| 593 | |
| 594 | if (os == NULL) |
| 595 | { |
| 596 | lv.set_output_value(0); |
| 597 | lv.set_no_output_symtab_entry(); |
| 598 | continue; |
| 599 | } |
| 600 | |
| 601 | if (mo[shndx].offset == -1) |
| 602 | lv.set_input_value(sym.get_st_value()); |
| 603 | else |
| 604 | lv.set_output_value(mo[shndx].output_section->address() |
| 605 | + mo[shndx].offset |
| 606 | + sym.get_st_value()); |
| 607 | } |
| 608 | |
| 609 | // Decide whether this symbol should go into the output file. |
| 610 | |
| 611 | if (sym.get_st_type() == elfcpp::STT_SECTION) |
| 612 | { |
| 613 | lv.set_no_output_symtab_entry(); |
| 614 | continue; |
| 615 | } |
| 616 | |
| 617 | if (sym.get_st_name() >= strtab_size) |
| 618 | { |
| 619 | fprintf(stderr, |
| 620 | _("%s: %s: local symbol %u section name " |
| 621 | "out of range: %u >= %u\n"), |
| 622 | program_name, this->name().c_str(), |
| 623 | i, sym.get_st_name(), |
| 624 | static_cast<unsigned int>(strtab_size)); |
| 625 | gold_exit(false); |
| 626 | } |
| 627 | |
| 628 | const char* name = pnames + sym.get_st_name(); |
| 629 | pool->add(name, NULL); |
| 630 | lv.set_output_symtab_index(index); |
| 631 | ++index; |
| 632 | ++count; |
| 633 | } |
| 634 | |
| 635 | this->output_local_symbol_count_ = count; |
| 636 | |
| 637 | return index; |
| 638 | } |
| 639 | |
| 640 | // Return the value of a local symbol defined in input section SHNDX, |
| 641 | // with value VALUE, adding addend ADDEND. This handles SHF_MERGE |
| 642 | // sections. |
| 643 | template<int size, bool big_endian> |
| 644 | typename elfcpp::Elf_types<size>::Elf_Addr |
| 645 | Sized_relobj<size, big_endian>::local_value(unsigned int shndx, |
| 646 | Address value, |
| 647 | Address addend) const |
| 648 | { |
| 649 | const std::vector<Map_to_output>& mo(this->map_to_output()); |
| 650 | Output_section* os = mo[shndx].output_section; |
| 651 | if (os == NULL) |
| 652 | return addend; |
| 653 | gold_assert(mo[shndx].offset == -1); |
| 654 | return os->output_address(this, shndx, value + addend); |
| 655 | } |
| 656 | |
| 657 | // Write out the local symbols. |
| 658 | |
| 659 | template<int size, bool big_endian> |
| 660 | void |
| 661 | Sized_relobj<size, big_endian>::write_local_symbols(Output_file* of, |
| 662 | const Stringpool* sympool) |
| 663 | { |
| 664 | gold_assert(this->symtab_shndx_ != -1U); |
| 665 | if (this->symtab_shndx_ == 0) |
| 666 | { |
| 667 | // This object has no symbols. Weird but legal. |
| 668 | return; |
| 669 | } |
| 670 | |
| 671 | // Read the symbol table section header. |
| 672 | const unsigned int symtab_shndx = this->symtab_shndx_; |
| 673 | typename This::Shdr symtabshdr(this, |
| 674 | this->elf_file_.section_header(symtab_shndx)); |
| 675 | gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB); |
| 676 | const unsigned int loccount = this->local_symbol_count_; |
| 677 | gold_assert(loccount == symtabshdr.get_sh_info()); |
| 678 | |
| 679 | // Read the local symbols. |
| 680 | const int sym_size = This::sym_size; |
| 681 | off_t locsize = loccount * sym_size; |
| 682 | const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(), |
| 683 | locsize); |
| 684 | |
| 685 | // Read the symbol names. |
| 686 | const unsigned int strtab_shndx = symtabshdr.get_sh_link(); |
| 687 | off_t strtab_size; |
| 688 | const unsigned char* pnamesu = this->section_contents(strtab_shndx, |
| 689 | &strtab_size); |
| 690 | const char* pnames = reinterpret_cast<const char*>(pnamesu); |
| 691 | |
| 692 | // Get a view into the output file. |
| 693 | off_t output_size = this->output_local_symbol_count_ * sym_size; |
| 694 | unsigned char* oview = of->get_output_view(this->local_symbol_offset_, |
| 695 | output_size); |
| 696 | |
| 697 | const std::vector<Map_to_output>& mo(this->map_to_output()); |
| 698 | |
| 699 | gold_assert(this->local_values_.size() == loccount); |
| 700 | |
| 701 | unsigned char* ov = oview; |
| 702 | psyms += sym_size; |
| 703 | for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size) |
| 704 | { |
| 705 | elfcpp::Sym<size, big_endian> isym(psyms); |
| 706 | |
| 707 | if (!this->local_values_[i].needs_output_symtab_entry()) |
| 708 | continue; |
| 709 | |
| 710 | unsigned int st_shndx = isym.get_st_shndx(); |
| 711 | if (st_shndx < elfcpp::SHN_LORESERVE) |
| 712 | { |
| 713 | gold_assert(st_shndx < mo.size()); |
| 714 | if (mo[st_shndx].output_section == NULL) |
| 715 | continue; |
| 716 | st_shndx = mo[st_shndx].output_section->out_shndx(); |
| 717 | } |
| 718 | |
| 719 | elfcpp::Sym_write<size, big_endian> osym(ov); |
| 720 | |
| 721 | gold_assert(isym.get_st_name() < strtab_size); |
| 722 | const char* name = pnames + isym.get_st_name(); |
| 723 | osym.put_st_name(sympool->get_offset(name)); |
| 724 | osym.put_st_value(this->local_values_[i].value(this, 0)); |
| 725 | osym.put_st_size(isym.get_st_size()); |
| 726 | osym.put_st_info(isym.get_st_info()); |
| 727 | osym.put_st_other(isym.get_st_other()); |
| 728 | osym.put_st_shndx(st_shndx); |
| 729 | |
| 730 | ov += sym_size; |
| 731 | } |
| 732 | |
| 733 | gold_assert(ov - oview == output_size); |
| 734 | |
| 735 | of->write_output_view(this->local_symbol_offset_, output_size, oview); |
| 736 | } |
| 737 | |
| 738 | // Input_objects methods. |
| 739 | |
| 740 | // Add a regular relocatable object to the list. Return false if this |
| 741 | // object should be ignored. |
| 742 | |
| 743 | bool |
| 744 | Input_objects::add_object(Object* obj) |
| 745 | { |
| 746 | if (!obj->is_dynamic()) |
| 747 | this->relobj_list_.push_back(static_cast<Relobj*>(obj)); |
| 748 | else |
| 749 | { |
| 750 | // See if this is a duplicate SONAME. |
| 751 | Dynobj* dynobj = static_cast<Dynobj*>(obj); |
| 752 | |
| 753 | std::pair<Unordered_set<std::string>::iterator, bool> ins = |
| 754 | this->sonames_.insert(dynobj->soname()); |
| 755 | if (!ins.second) |
| 756 | { |
| 757 | // We have already seen a dynamic object with this soname. |
| 758 | return false; |
| 759 | } |
| 760 | |
| 761 | this->dynobj_list_.push_back(dynobj); |
| 762 | } |
| 763 | |
| 764 | Target* target = obj->target(); |
| 765 | if (this->target_ == NULL) |
| 766 | this->target_ = target; |
| 767 | else if (this->target_ != target) |
| 768 | { |
| 769 | fprintf(stderr, "%s: %s: incompatible target\n", |
| 770 | program_name, obj->name().c_str()); |
| 771 | gold_exit(false); |
| 772 | } |
| 773 | |
| 774 | return true; |
| 775 | } |
| 776 | |
| 777 | // Relocate_info methods. |
| 778 | |
| 779 | // Return a string describing the location of a relocation. This is |
| 780 | // only used in error messages. |
| 781 | |
| 782 | template<int size, bool big_endian> |
| 783 | std::string |
| 784 | Relocate_info<size, big_endian>::location(size_t relnum, off_t) const |
| 785 | { |
| 786 | std::string ret(this->object->name()); |
| 787 | ret += ": reloc "; |
| 788 | char buf[100]; |
| 789 | snprintf(buf, sizeof buf, "%zu", relnum); |
| 790 | ret += buf; |
| 791 | ret += " in reloc section "; |
| 792 | snprintf(buf, sizeof buf, "%u", this->reloc_shndx); |
| 793 | ret += buf; |
| 794 | ret += " (" + this->object->section_name(this->reloc_shndx); |
| 795 | ret += ") for section "; |
| 796 | snprintf(buf, sizeof buf, "%u", this->data_shndx); |
| 797 | ret += buf; |
| 798 | ret += " (" + this->object->section_name(this->data_shndx) + ")"; |
| 799 | return ret; |
| 800 | } |
| 801 | |
| 802 | } // End namespace gold. |
| 803 | |
| 804 | namespace |
| 805 | { |
| 806 | |
| 807 | using namespace gold; |
| 808 | |
| 809 | // Read an ELF file with the header and return the appropriate |
| 810 | // instance of Object. |
| 811 | |
| 812 | template<int size, bool big_endian> |
| 813 | Object* |
| 814 | make_elf_sized_object(const std::string& name, Input_file* input_file, |
| 815 | off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr) |
| 816 | { |
| 817 | int et = ehdr.get_e_type(); |
| 818 | if (et == elfcpp::ET_REL) |
| 819 | { |
| 820 | Sized_relobj<size, big_endian>* obj = |
| 821 | new Sized_relobj<size, big_endian>(name, input_file, offset, ehdr); |
| 822 | obj->setup(ehdr); |
| 823 | return obj; |
| 824 | } |
| 825 | else if (et == elfcpp::ET_DYN) |
| 826 | { |
| 827 | Sized_dynobj<size, big_endian>* obj = |
| 828 | new Sized_dynobj<size, big_endian>(name, input_file, offset, ehdr); |
| 829 | obj->setup(ehdr); |
| 830 | return obj; |
| 831 | } |
| 832 | else |
| 833 | { |
| 834 | fprintf(stderr, _("%s: %s: unsupported ELF file type %d\n"), |
| 835 | program_name, name.c_str(), et); |
| 836 | gold_exit(false); |
| 837 | } |
| 838 | } |
| 839 | |
| 840 | } // End anonymous namespace. |
| 841 | |
| 842 | namespace gold |
| 843 | { |
| 844 | |
| 845 | // Read an ELF file and return the appropriate instance of Object. |
| 846 | |
| 847 | Object* |
| 848 | make_elf_object(const std::string& name, Input_file* input_file, off_t offset, |
| 849 | const unsigned char* p, off_t bytes) |
| 850 | { |
| 851 | if (bytes < elfcpp::EI_NIDENT) |
| 852 | { |
| 853 | fprintf(stderr, _("%s: %s: ELF file too short\n"), |
| 854 | program_name, name.c_str()); |
| 855 | gold_exit(false); |
| 856 | } |
| 857 | |
| 858 | int v = p[elfcpp::EI_VERSION]; |
| 859 | if (v != elfcpp::EV_CURRENT) |
| 860 | { |
| 861 | if (v == elfcpp::EV_NONE) |
| 862 | fprintf(stderr, _("%s: %s: invalid ELF version 0\n"), |
| 863 | program_name, name.c_str()); |
| 864 | else |
| 865 | fprintf(stderr, _("%s: %s: unsupported ELF version %d\n"), |
| 866 | program_name, name.c_str(), v); |
| 867 | gold_exit(false); |
| 868 | } |
| 869 | |
| 870 | int c = p[elfcpp::EI_CLASS]; |
| 871 | if (c == elfcpp::ELFCLASSNONE) |
| 872 | { |
| 873 | fprintf(stderr, _("%s: %s: invalid ELF class 0\n"), |
| 874 | program_name, name.c_str()); |
| 875 | gold_exit(false); |
| 876 | } |
| 877 | else if (c != elfcpp::ELFCLASS32 |
| 878 | && c != elfcpp::ELFCLASS64) |
| 879 | { |
| 880 | fprintf(stderr, _("%s: %s: unsupported ELF class %d\n"), |
| 881 | program_name, name.c_str(), c); |
| 882 | gold_exit(false); |
| 883 | } |
| 884 | |
| 885 | int d = p[elfcpp::EI_DATA]; |
| 886 | if (d == elfcpp::ELFDATANONE) |
| 887 | { |
| 888 | fprintf(stderr, _("%s: %s: invalid ELF data encoding\n"), |
| 889 | program_name, name.c_str()); |
| 890 | gold_exit(false); |
| 891 | } |
| 892 | else if (d != elfcpp::ELFDATA2LSB |
| 893 | && d != elfcpp::ELFDATA2MSB) |
| 894 | { |
| 895 | fprintf(stderr, _("%s: %s: unsupported ELF data encoding %d\n"), |
| 896 | program_name, name.c_str(), d); |
| 897 | gold_exit(false); |
| 898 | } |
| 899 | |
| 900 | bool big_endian = d == elfcpp::ELFDATA2MSB; |
| 901 | |
| 902 | if (c == elfcpp::ELFCLASS32) |
| 903 | { |
| 904 | if (bytes < elfcpp::Elf_sizes<32>::ehdr_size) |
| 905 | { |
| 906 | fprintf(stderr, _("%s: %s: ELF file too short\n"), |
| 907 | program_name, name.c_str()); |
| 908 | gold_exit(false); |
| 909 | } |
| 910 | if (big_endian) |
| 911 | { |
| 912 | elfcpp::Ehdr<32, true> ehdr(p); |
| 913 | return make_elf_sized_object<32, true>(name, input_file, |
| 914 | offset, ehdr); |
| 915 | } |
| 916 | else |
| 917 | { |
| 918 | elfcpp::Ehdr<32, false> ehdr(p); |
| 919 | return make_elf_sized_object<32, false>(name, input_file, |
| 920 | offset, ehdr); |
| 921 | } |
| 922 | } |
| 923 | else |
| 924 | { |
| 925 | if (bytes < elfcpp::Elf_sizes<32>::ehdr_size) |
| 926 | { |
| 927 | fprintf(stderr, _("%s: %s: ELF file too short\n"), |
| 928 | program_name, name.c_str()); |
| 929 | gold_exit(false); |
| 930 | } |
| 931 | if (big_endian) |
| 932 | { |
| 933 | elfcpp::Ehdr<64, true> ehdr(p); |
| 934 | return make_elf_sized_object<64, true>(name, input_file, |
| 935 | offset, ehdr); |
| 936 | } |
| 937 | else |
| 938 | { |
| 939 | elfcpp::Ehdr<64, false> ehdr(p); |
| 940 | return make_elf_sized_object<64, false>(name, input_file, |
| 941 | offset, ehdr); |
| 942 | } |
| 943 | } |
| 944 | } |
| 945 | |
| 946 | // Instantiate the templates we need. We could use the configure |
| 947 | // script to restrict this to only the ones for implemented targets. |
| 948 | |
| 949 | template |
| 950 | class Sized_relobj<32, false>; |
| 951 | |
| 952 | template |
| 953 | class Sized_relobj<32, true>; |
| 954 | |
| 955 | template |
| 956 | class Sized_relobj<64, false>; |
| 957 | |
| 958 | template |
| 959 | class Sized_relobj<64, true>; |
| 960 | |
| 961 | template |
| 962 | struct Relocate_info<32, false>; |
| 963 | |
| 964 | template |
| 965 | struct Relocate_info<32, true>; |
| 966 | |
| 967 | template |
| 968 | struct Relocate_info<64, false>; |
| 969 | |
| 970 | template |
| 971 | struct Relocate_info<64, true>; |
| 972 | |
| 973 | } // End namespace gold. |