| 1 | // object.cc -- support for an object file for linking in gold |
| 2 | |
| 3 | // Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. |
| 4 | // Written by Ian Lance Taylor <iant@google.com>. |
| 5 | |
| 6 | // This file is part of gold. |
| 7 | |
| 8 | // This program is free software; you can redistribute it and/or modify |
| 9 | // it under the terms of the GNU General Public License as published by |
| 10 | // the Free Software Foundation; either version 3 of the License, or |
| 11 | // (at your option) any later version. |
| 12 | |
| 13 | // This program is distributed in the hope that it will be useful, |
| 14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | // GNU General Public License for more details. |
| 17 | |
| 18 | // You should have received a copy of the GNU General Public License |
| 19 | // along with this program; if not, write to the Free Software |
| 20 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| 21 | // MA 02110-1301, USA. |
| 22 | |
| 23 | #include "gold.h" |
| 24 | |
| 25 | #include <cerrno> |
| 26 | #include <cstring> |
| 27 | #include <cstdarg> |
| 28 | #include "demangle.h" |
| 29 | #include "libiberty.h" |
| 30 | |
| 31 | #include "gc.h" |
| 32 | #include "target-select.h" |
| 33 | #include "dwarf_reader.h" |
| 34 | #include "layout.h" |
| 35 | #include "output.h" |
| 36 | #include "symtab.h" |
| 37 | #include "cref.h" |
| 38 | #include "reloc.h" |
| 39 | #include "object.h" |
| 40 | #include "dynobj.h" |
| 41 | #include "plugin.h" |
| 42 | |
| 43 | namespace gold |
| 44 | { |
| 45 | |
| 46 | // Struct Read_symbols_data. |
| 47 | |
| 48 | // Destroy any remaining File_view objects. |
| 49 | |
| 50 | Read_symbols_data::~Read_symbols_data() |
| 51 | { |
| 52 | if (this->section_headers != NULL) |
| 53 | delete this->section_headers; |
| 54 | if (this->section_names != NULL) |
| 55 | delete this->section_names; |
| 56 | if (this->symbols != NULL) |
| 57 | delete this->symbols; |
| 58 | if (this->symbol_names != NULL) |
| 59 | delete this->symbol_names; |
| 60 | if (this->versym != NULL) |
| 61 | delete this->versym; |
| 62 | if (this->verdef != NULL) |
| 63 | delete this->verdef; |
| 64 | if (this->verneed != NULL) |
| 65 | delete this->verneed; |
| 66 | } |
| 67 | |
| 68 | // Class Xindex. |
| 69 | |
| 70 | // Initialize the symtab_xindex_ array. Find the SHT_SYMTAB_SHNDX |
| 71 | // section and read it in. SYMTAB_SHNDX is the index of the symbol |
| 72 | // table we care about. |
| 73 | |
| 74 | template<int size, bool big_endian> |
| 75 | void |
| 76 | Xindex::initialize_symtab_xindex(Object* object, unsigned int symtab_shndx) |
| 77 | { |
| 78 | if (!this->symtab_xindex_.empty()) |
| 79 | return; |
| 80 | |
| 81 | gold_assert(symtab_shndx != 0); |
| 82 | |
| 83 | // Look through the sections in reverse order, on the theory that it |
| 84 | // is more likely to be near the end than the beginning. |
| 85 | unsigned int i = object->shnum(); |
| 86 | while (i > 0) |
| 87 | { |
| 88 | --i; |
| 89 | if (object->section_type(i) == elfcpp::SHT_SYMTAB_SHNDX |
| 90 | && this->adjust_shndx(object->section_link(i)) == symtab_shndx) |
| 91 | { |
| 92 | this->read_symtab_xindex<size, big_endian>(object, i, NULL); |
| 93 | return; |
| 94 | } |
| 95 | } |
| 96 | |
| 97 | object->error(_("missing SHT_SYMTAB_SHNDX section")); |
| 98 | } |
| 99 | |
| 100 | // Read in the symtab_xindex_ array, given the section index of the |
| 101 | // SHT_SYMTAB_SHNDX section. If PSHDRS is not NULL, it points at the |
| 102 | // section headers. |
| 103 | |
| 104 | template<int size, bool big_endian> |
| 105 | void |
| 106 | Xindex::read_symtab_xindex(Object* object, unsigned int xindex_shndx, |
| 107 | const unsigned char* pshdrs) |
| 108 | { |
| 109 | section_size_type bytecount; |
| 110 | const unsigned char* contents; |
| 111 | if (pshdrs == NULL) |
| 112 | contents = object->section_contents(xindex_shndx, &bytecount, false); |
| 113 | else |
| 114 | { |
| 115 | const unsigned char* p = (pshdrs |
| 116 | + (xindex_shndx |
| 117 | * elfcpp::Elf_sizes<size>::shdr_size)); |
| 118 | typename elfcpp::Shdr<size, big_endian> shdr(p); |
| 119 | bytecount = convert_to_section_size_type(shdr.get_sh_size()); |
| 120 | contents = object->get_view(shdr.get_sh_offset(), bytecount, true, false); |
| 121 | } |
| 122 | |
| 123 | gold_assert(this->symtab_xindex_.empty()); |
| 124 | this->symtab_xindex_.reserve(bytecount / 4); |
| 125 | for (section_size_type i = 0; i < bytecount; i += 4) |
| 126 | { |
| 127 | unsigned int shndx = elfcpp::Swap<32, big_endian>::readval(contents + i); |
| 128 | // We preadjust the section indexes we save. |
| 129 | this->symtab_xindex_.push_back(this->adjust_shndx(shndx)); |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | // Symbol symndx has a section of SHN_XINDEX; return the real section |
| 134 | // index. |
| 135 | |
| 136 | unsigned int |
| 137 | Xindex::sym_xindex_to_shndx(Object* object, unsigned int symndx) |
| 138 | { |
| 139 | if (symndx >= this->symtab_xindex_.size()) |
| 140 | { |
| 141 | object->error(_("symbol %u out of range for SHT_SYMTAB_SHNDX section"), |
| 142 | symndx); |
| 143 | return elfcpp::SHN_UNDEF; |
| 144 | } |
| 145 | unsigned int shndx = this->symtab_xindex_[symndx]; |
| 146 | if (shndx < elfcpp::SHN_LORESERVE || shndx >= object->shnum()) |
| 147 | { |
| 148 | object->error(_("extended index for symbol %u out of range: %u"), |
| 149 | symndx, shndx); |
| 150 | return elfcpp::SHN_UNDEF; |
| 151 | } |
| 152 | return shndx; |
| 153 | } |
| 154 | |
| 155 | // Class Object. |
| 156 | |
| 157 | // Report an error for this object file. This is used by the |
| 158 | // elfcpp::Elf_file interface, and also called by the Object code |
| 159 | // itself. |
| 160 | |
| 161 | void |
| 162 | Object::error(const char* format, ...) const |
| 163 | { |
| 164 | va_list args; |
| 165 | va_start(args, format); |
| 166 | char* buf = NULL; |
| 167 | if (vasprintf(&buf, format, args) < 0) |
| 168 | gold_nomem(); |
| 169 | va_end(args); |
| 170 | gold_error(_("%s: %s"), this->name().c_str(), buf); |
| 171 | free(buf); |
| 172 | } |
| 173 | |
| 174 | // Return a view of the contents of a section. |
| 175 | |
| 176 | const unsigned char* |
| 177 | Object::section_contents(unsigned int shndx, section_size_type* plen, |
| 178 | bool cache) |
| 179 | { |
| 180 | Location loc(this->do_section_contents(shndx)); |
| 181 | *plen = convert_to_section_size_type(loc.data_size); |
| 182 | if (*plen == 0) |
| 183 | { |
| 184 | static const unsigned char empty[1] = { '\0' }; |
| 185 | return empty; |
| 186 | } |
| 187 | return this->get_view(loc.file_offset, *plen, true, cache); |
| 188 | } |
| 189 | |
| 190 | // Read the section data into SD. This is code common to Sized_relobj |
| 191 | // and Sized_dynobj, so we put it into Object. |
| 192 | |
| 193 | template<int size, bool big_endian> |
| 194 | void |
| 195 | Object::read_section_data(elfcpp::Elf_file<size, big_endian, Object>* elf_file, |
| 196 | Read_symbols_data* sd) |
| 197 | { |
| 198 | const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size; |
| 199 | |
| 200 | // Read the section headers. |
| 201 | const off_t shoff = elf_file->shoff(); |
| 202 | const unsigned int shnum = this->shnum(); |
| 203 | sd->section_headers = this->get_lasting_view(shoff, shnum * shdr_size, |
| 204 | true, true); |
| 205 | |
| 206 | // Read the section names. |
| 207 | const unsigned char* pshdrs = sd->section_headers->data(); |
| 208 | const unsigned char* pshdrnames = pshdrs + elf_file->shstrndx() * shdr_size; |
| 209 | typename elfcpp::Shdr<size, big_endian> shdrnames(pshdrnames); |
| 210 | |
| 211 | if (shdrnames.get_sh_type() != elfcpp::SHT_STRTAB) |
| 212 | this->error(_("section name section has wrong type: %u"), |
| 213 | static_cast<unsigned int>(shdrnames.get_sh_type())); |
| 214 | |
| 215 | sd->section_names_size = |
| 216 | convert_to_section_size_type(shdrnames.get_sh_size()); |
| 217 | sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(), |
| 218 | sd->section_names_size, false, |
| 219 | false); |
| 220 | } |
| 221 | |
| 222 | // If NAME is the name of a special .gnu.warning section, arrange for |
| 223 | // the warning to be issued. SHNDX is the section index. Return |
| 224 | // whether it is a warning section. |
| 225 | |
| 226 | bool |
| 227 | Object::handle_gnu_warning_section(const char* name, unsigned int shndx, |
| 228 | Symbol_table* symtab) |
| 229 | { |
| 230 | const char warn_prefix[] = ".gnu.warning."; |
| 231 | const int warn_prefix_len = sizeof warn_prefix - 1; |
| 232 | if (strncmp(name, warn_prefix, warn_prefix_len) == 0) |
| 233 | { |
| 234 | // Read the section contents to get the warning text. It would |
| 235 | // be nicer if we only did this if we have to actually issue a |
| 236 | // warning. Unfortunately, warnings are issued as we relocate |
| 237 | // sections. That means that we can not lock the object then, |
| 238 | // as we might try to issue the same warning multiple times |
| 239 | // simultaneously. |
| 240 | section_size_type len; |
| 241 | const unsigned char* contents = this->section_contents(shndx, &len, |
| 242 | false); |
| 243 | if (len == 0) |
| 244 | { |
| 245 | const char* warning = name + warn_prefix_len; |
| 246 | contents = reinterpret_cast<const unsigned char*>(warning); |
| 247 | len = strlen(warning); |
| 248 | } |
| 249 | std::string warning(reinterpret_cast<const char*>(contents), len); |
| 250 | symtab->add_warning(name + warn_prefix_len, this, warning); |
| 251 | return true; |
| 252 | } |
| 253 | return false; |
| 254 | } |
| 255 | |
| 256 | // If NAME is the name of the special section which indicates that |
| 257 | // this object was compiled with -fstack-split, mark it accordingly. |
| 258 | |
| 259 | bool |
| 260 | Object::handle_split_stack_section(const char* name) |
| 261 | { |
| 262 | if (strcmp(name, ".note.GNU-split-stack") == 0) |
| 263 | { |
| 264 | this->uses_split_stack_ = true; |
| 265 | return true; |
| 266 | } |
| 267 | if (strcmp(name, ".note.GNU-no-split-stack") == 0) |
| 268 | { |
| 269 | this->has_no_split_stack_ = true; |
| 270 | return true; |
| 271 | } |
| 272 | return false; |
| 273 | } |
| 274 | |
| 275 | // Class Relobj |
| 276 | |
| 277 | // To copy the symbols data read from the file to a local data structure. |
| 278 | // This function is called from do_layout only while doing garbage |
| 279 | // collection. |
| 280 | |
| 281 | void |
| 282 | Relobj::copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd, |
| 283 | unsigned int section_header_size) |
| 284 | { |
| 285 | gc_sd->section_headers_data = |
| 286 | new unsigned char[(section_header_size)]; |
| 287 | memcpy(gc_sd->section_headers_data, sd->section_headers->data(), |
| 288 | section_header_size); |
| 289 | gc_sd->section_names_data = |
| 290 | new unsigned char[sd->section_names_size]; |
| 291 | memcpy(gc_sd->section_names_data, sd->section_names->data(), |
| 292 | sd->section_names_size); |
| 293 | gc_sd->section_names_size = sd->section_names_size; |
| 294 | if (sd->symbols != NULL) |
| 295 | { |
| 296 | gc_sd->symbols_data = |
| 297 | new unsigned char[sd->symbols_size]; |
| 298 | memcpy(gc_sd->symbols_data, sd->symbols->data(), |
| 299 | sd->symbols_size); |
| 300 | } |
| 301 | else |
| 302 | { |
| 303 | gc_sd->symbols_data = NULL; |
| 304 | } |
| 305 | gc_sd->symbols_size = sd->symbols_size; |
| 306 | gc_sd->external_symbols_offset = sd->external_symbols_offset; |
| 307 | if (sd->symbol_names != NULL) |
| 308 | { |
| 309 | gc_sd->symbol_names_data = |
| 310 | new unsigned char[sd->symbol_names_size]; |
| 311 | memcpy(gc_sd->symbol_names_data, sd->symbol_names->data(), |
| 312 | sd->symbol_names_size); |
| 313 | } |
| 314 | else |
| 315 | { |
| 316 | gc_sd->symbol_names_data = NULL; |
| 317 | } |
| 318 | gc_sd->symbol_names_size = sd->symbol_names_size; |
| 319 | } |
| 320 | |
| 321 | // This function determines if a particular section name must be included |
| 322 | // in the link. This is used during garbage collection to determine the |
| 323 | // roots of the worklist. |
| 324 | |
| 325 | bool |
| 326 | Relobj::is_section_name_included(const char* name) |
| 327 | { |
| 328 | if (is_prefix_of(".ctors", name) |
| 329 | || is_prefix_of(".dtors", name) |
| 330 | || is_prefix_of(".note", name) |
| 331 | || is_prefix_of(".init", name) |
| 332 | || is_prefix_of(".fini", name) |
| 333 | || is_prefix_of(".gcc_except_table", name) |
| 334 | || is_prefix_of(".jcr", name) |
| 335 | || is_prefix_of(".preinit_array", name) |
| 336 | || (is_prefix_of(".text", name) |
| 337 | && strstr(name, "personality")) |
| 338 | || (is_prefix_of(".data", name) |
| 339 | && strstr(name, "personality")) |
| 340 | || (is_prefix_of(".gnu.linkonce.d", name) |
| 341 | && strstr(name, "personality"))) |
| 342 | { |
| 343 | return true; |
| 344 | } |
| 345 | return false; |
| 346 | } |
| 347 | |
| 348 | // Class Sized_relobj. |
| 349 | |
| 350 | template<int size, bool big_endian> |
| 351 | Sized_relobj<size, big_endian>::Sized_relobj( |
| 352 | const std::string& name, |
| 353 | Input_file* input_file, |
| 354 | off_t offset, |
| 355 | const elfcpp::Ehdr<size, big_endian>& ehdr) |
| 356 | : Relobj(name, input_file, offset), |
| 357 | elf_file_(this, ehdr), |
| 358 | symtab_shndx_(-1U), |
| 359 | local_symbol_count_(0), |
| 360 | output_local_symbol_count_(0), |
| 361 | output_local_dynsym_count_(0), |
| 362 | symbols_(), |
| 363 | defined_count_(0), |
| 364 | local_symbol_offset_(0), |
| 365 | local_dynsym_offset_(0), |
| 366 | local_values_(), |
| 367 | local_got_offsets_(), |
| 368 | kept_comdat_sections_(), |
| 369 | has_eh_frame_(false), |
| 370 | discarded_eh_frame_shndx_(-1U) |
| 371 | { |
| 372 | } |
| 373 | |
| 374 | template<int size, bool big_endian> |
| 375 | Sized_relobj<size, big_endian>::~Sized_relobj() |
| 376 | { |
| 377 | } |
| 378 | |
| 379 | // Set up an object file based on the file header. This sets up the |
| 380 | // section information. |
| 381 | |
| 382 | template<int size, bool big_endian> |
| 383 | void |
| 384 | Sized_relobj<size, big_endian>::do_setup() |
| 385 | { |
| 386 | const unsigned int shnum = this->elf_file_.shnum(); |
| 387 | this->set_shnum(shnum); |
| 388 | } |
| 389 | |
| 390 | // Find the SHT_SYMTAB section, given the section headers. The ELF |
| 391 | // standard says that maybe in the future there can be more than one |
| 392 | // SHT_SYMTAB section. Until somebody figures out how that could |
| 393 | // work, we assume there is only one. |
| 394 | |
| 395 | template<int size, bool big_endian> |
| 396 | void |
| 397 | Sized_relobj<size, big_endian>::find_symtab(const unsigned char* pshdrs) |
| 398 | { |
| 399 | const unsigned int shnum = this->shnum(); |
| 400 | this->symtab_shndx_ = 0; |
| 401 | if (shnum > 0) |
| 402 | { |
| 403 | // Look through the sections in reverse order, since gas tends |
| 404 | // to put the symbol table at the end. |
| 405 | const unsigned char* p = pshdrs + shnum * This::shdr_size; |
| 406 | unsigned int i = shnum; |
| 407 | unsigned int xindex_shndx = 0; |
| 408 | unsigned int xindex_link = 0; |
| 409 | while (i > 0) |
| 410 | { |
| 411 | --i; |
| 412 | p -= This::shdr_size; |
| 413 | typename This::Shdr shdr(p); |
| 414 | if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB) |
| 415 | { |
| 416 | this->symtab_shndx_ = i; |
| 417 | if (xindex_shndx > 0 && xindex_link == i) |
| 418 | { |
| 419 | Xindex* xindex = |
| 420 | new Xindex(this->elf_file_.large_shndx_offset()); |
| 421 | xindex->read_symtab_xindex<size, big_endian>(this, |
| 422 | xindex_shndx, |
| 423 | pshdrs); |
| 424 | this->set_xindex(xindex); |
| 425 | } |
| 426 | break; |
| 427 | } |
| 428 | |
| 429 | // Try to pick up the SHT_SYMTAB_SHNDX section, if there is |
| 430 | // one. This will work if it follows the SHT_SYMTAB |
| 431 | // section. |
| 432 | if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB_SHNDX) |
| 433 | { |
| 434 | xindex_shndx = i; |
| 435 | xindex_link = this->adjust_shndx(shdr.get_sh_link()); |
| 436 | } |
| 437 | } |
| 438 | } |
| 439 | } |
| 440 | |
| 441 | // Return the Xindex structure to use for object with lots of |
| 442 | // sections. |
| 443 | |
| 444 | template<int size, bool big_endian> |
| 445 | Xindex* |
| 446 | Sized_relobj<size, big_endian>::do_initialize_xindex() |
| 447 | { |
| 448 | gold_assert(this->symtab_shndx_ != -1U); |
| 449 | Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset()); |
| 450 | xindex->initialize_symtab_xindex<size, big_endian>(this, this->symtab_shndx_); |
| 451 | return xindex; |
| 452 | } |
| 453 | |
| 454 | // Return whether SHDR has the right type and flags to be a GNU |
| 455 | // .eh_frame section. |
| 456 | |
| 457 | template<int size, bool big_endian> |
| 458 | bool |
| 459 | Sized_relobj<size, big_endian>::check_eh_frame_flags( |
| 460 | const elfcpp::Shdr<size, big_endian>* shdr) const |
| 461 | { |
| 462 | return (shdr->get_sh_type() == elfcpp::SHT_PROGBITS |
| 463 | && (shdr->get_sh_flags() & elfcpp::SHF_ALLOC) != 0); |
| 464 | } |
| 465 | |
| 466 | // Return whether there is a GNU .eh_frame section, given the section |
| 467 | // headers and the section names. |
| 468 | |
| 469 | template<int size, bool big_endian> |
| 470 | bool |
| 471 | Sized_relobj<size, big_endian>::find_eh_frame( |
| 472 | const unsigned char* pshdrs, |
| 473 | const char* names, |
| 474 | section_size_type names_size) const |
| 475 | { |
| 476 | const unsigned int shnum = this->shnum(); |
| 477 | const unsigned char* p = pshdrs + This::shdr_size; |
| 478 | for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size) |
| 479 | { |
| 480 | typename This::Shdr shdr(p); |
| 481 | if (this->check_eh_frame_flags(&shdr)) |
| 482 | { |
| 483 | if (shdr.get_sh_name() >= names_size) |
| 484 | { |
| 485 | this->error(_("bad section name offset for section %u: %lu"), |
| 486 | i, static_cast<unsigned long>(shdr.get_sh_name())); |
| 487 | continue; |
| 488 | } |
| 489 | |
| 490 | const char* name = names + shdr.get_sh_name(); |
| 491 | if (strcmp(name, ".eh_frame") == 0) |
| 492 | return true; |
| 493 | } |
| 494 | } |
| 495 | return false; |
| 496 | } |
| 497 | |
| 498 | // Read the sections and symbols from an object file. |
| 499 | |
| 500 | template<int size, bool big_endian> |
| 501 | void |
| 502 | Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd) |
| 503 | { |
| 504 | this->read_section_data(&this->elf_file_, sd); |
| 505 | |
| 506 | const unsigned char* const pshdrs = sd->section_headers->data(); |
| 507 | |
| 508 | this->find_symtab(pshdrs); |
| 509 | |
| 510 | const unsigned char* namesu = sd->section_names->data(); |
| 511 | const char* names = reinterpret_cast<const char*>(namesu); |
| 512 | if (memmem(names, sd->section_names_size, ".eh_frame", 10) != NULL) |
| 513 | { |
| 514 | if (this->find_eh_frame(pshdrs, names, sd->section_names_size)) |
| 515 | this->has_eh_frame_ = true; |
| 516 | } |
| 517 | |
| 518 | sd->symbols = NULL; |
| 519 | sd->symbols_size = 0; |
| 520 | sd->external_symbols_offset = 0; |
| 521 | sd->symbol_names = NULL; |
| 522 | sd->symbol_names_size = 0; |
| 523 | |
| 524 | if (this->symtab_shndx_ == 0) |
| 525 | { |
| 526 | // No symbol table. Weird but legal. |
| 527 | return; |
| 528 | } |
| 529 | |
| 530 | // Get the symbol table section header. |
| 531 | typename This::Shdr symtabshdr(pshdrs |
| 532 | + this->symtab_shndx_ * This::shdr_size); |
| 533 | gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB); |
| 534 | |
| 535 | // If this object has a .eh_frame section, we need all the symbols. |
| 536 | // Otherwise we only need the external symbols. While it would be |
| 537 | // simpler to just always read all the symbols, I've seen object |
| 538 | // files with well over 2000 local symbols, which for a 64-bit |
| 539 | // object file format is over 5 pages that we don't need to read |
| 540 | // now. |
| 541 | |
| 542 | const int sym_size = This::sym_size; |
| 543 | const unsigned int loccount = symtabshdr.get_sh_info(); |
| 544 | this->local_symbol_count_ = loccount; |
| 545 | this->local_values_.resize(loccount); |
| 546 | section_offset_type locsize = loccount * sym_size; |
| 547 | off_t dataoff = symtabshdr.get_sh_offset(); |
| 548 | section_size_type datasize = |
| 549 | convert_to_section_size_type(symtabshdr.get_sh_size()); |
| 550 | off_t extoff = dataoff + locsize; |
| 551 | section_size_type extsize = datasize - locsize; |
| 552 | |
| 553 | off_t readoff = this->has_eh_frame_ ? dataoff : extoff; |
| 554 | section_size_type readsize = this->has_eh_frame_ ? datasize : extsize; |
| 555 | |
| 556 | if (readsize == 0) |
| 557 | { |
| 558 | // No external symbols. Also weird but also legal. |
| 559 | return; |
| 560 | } |
| 561 | |
| 562 | File_view* fvsymtab = this->get_lasting_view(readoff, readsize, true, false); |
| 563 | |
| 564 | // Read the section header for the symbol names. |
| 565 | unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link()); |
| 566 | if (strtab_shndx >= this->shnum()) |
| 567 | { |
| 568 | this->error(_("invalid symbol table name index: %u"), strtab_shndx); |
| 569 | return; |
| 570 | } |
| 571 | typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size); |
| 572 | if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB) |
| 573 | { |
| 574 | this->error(_("symbol table name section has wrong type: %u"), |
| 575 | static_cast<unsigned int>(strtabshdr.get_sh_type())); |
| 576 | return; |
| 577 | } |
| 578 | |
| 579 | // Read the symbol names. |
| 580 | File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(), |
| 581 | strtabshdr.get_sh_size(), |
| 582 | false, true); |
| 583 | |
| 584 | sd->symbols = fvsymtab; |
| 585 | sd->symbols_size = readsize; |
| 586 | sd->external_symbols_offset = this->has_eh_frame_ ? locsize : 0; |
| 587 | sd->symbol_names = fvstrtab; |
| 588 | sd->symbol_names_size = |
| 589 | convert_to_section_size_type(strtabshdr.get_sh_size()); |
| 590 | } |
| 591 | |
| 592 | // Return the section index of symbol SYM. Set *VALUE to its value in |
| 593 | // the object file. Set *IS_ORDINARY if this is an ordinary section |
| 594 | // index. not a special cod between SHN_LORESERVE and SHN_HIRESERVE. |
| 595 | // Note that for a symbol which is not defined in this object file, |
| 596 | // this will set *VALUE to 0 and return SHN_UNDEF; it will not return |
| 597 | // the final value of the symbol in the link. |
| 598 | |
| 599 | template<int size, bool big_endian> |
| 600 | unsigned int |
| 601 | Sized_relobj<size, big_endian>::symbol_section_and_value(unsigned int sym, |
| 602 | Address* value, |
| 603 | bool* is_ordinary) |
| 604 | { |
| 605 | section_size_type symbols_size; |
| 606 | const unsigned char* symbols = this->section_contents(this->symtab_shndx_, |
| 607 | &symbols_size, |
| 608 | false); |
| 609 | |
| 610 | const size_t count = symbols_size / This::sym_size; |
| 611 | gold_assert(sym < count); |
| 612 | |
| 613 | elfcpp::Sym<size, big_endian> elfsym(symbols + sym * This::sym_size); |
| 614 | *value = elfsym.get_st_value(); |
| 615 | |
| 616 | return this->adjust_sym_shndx(sym, elfsym.get_st_shndx(), is_ordinary); |
| 617 | } |
| 618 | |
| 619 | // Return whether to include a section group in the link. LAYOUT is |
| 620 | // used to keep track of which section groups we have already seen. |
| 621 | // INDEX is the index of the section group and SHDR is the section |
| 622 | // header. If we do not want to include this group, we set bits in |
| 623 | // OMIT for each section which should be discarded. |
| 624 | |
| 625 | template<int size, bool big_endian> |
| 626 | bool |
| 627 | Sized_relobj<size, big_endian>::include_section_group( |
| 628 | Symbol_table* symtab, |
| 629 | Layout* layout, |
| 630 | unsigned int index, |
| 631 | const char* name, |
| 632 | const unsigned char* shdrs, |
| 633 | const char* section_names, |
| 634 | section_size_type section_names_size, |
| 635 | std::vector<bool>* omit) |
| 636 | { |
| 637 | // Read the section contents. |
| 638 | typename This::Shdr shdr(shdrs + index * This::shdr_size); |
| 639 | const unsigned char* pcon = this->get_view(shdr.get_sh_offset(), |
| 640 | shdr.get_sh_size(), true, false); |
| 641 | const elfcpp::Elf_Word* pword = |
| 642 | reinterpret_cast<const elfcpp::Elf_Word*>(pcon); |
| 643 | |
| 644 | // The first word contains flags. We only care about COMDAT section |
| 645 | // groups. Other section groups are always included in the link |
| 646 | // just like ordinary sections. |
| 647 | elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword); |
| 648 | |
| 649 | // Look up the group signature, which is the name of a symbol. This |
| 650 | // is a lot of effort to go to to read a string. Why didn't they |
| 651 | // just have the group signature point into the string table, rather |
| 652 | // than indirect through a symbol? |
| 653 | |
| 654 | // Get the appropriate symbol table header (this will normally be |
| 655 | // the single SHT_SYMTAB section, but in principle it need not be). |
| 656 | const unsigned int link = this->adjust_shndx(shdr.get_sh_link()); |
| 657 | typename This::Shdr symshdr(this, this->elf_file_.section_header(link)); |
| 658 | |
| 659 | // Read the symbol table entry. |
| 660 | unsigned int symndx = shdr.get_sh_info(); |
| 661 | if (symndx >= symshdr.get_sh_size() / This::sym_size) |
| 662 | { |
| 663 | this->error(_("section group %u info %u out of range"), |
| 664 | index, symndx); |
| 665 | return false; |
| 666 | } |
| 667 | off_t symoff = symshdr.get_sh_offset() + symndx * This::sym_size; |
| 668 | const unsigned char* psym = this->get_view(symoff, This::sym_size, true, |
| 669 | false); |
| 670 | elfcpp::Sym<size, big_endian> sym(psym); |
| 671 | |
| 672 | // Read the symbol table names. |
| 673 | section_size_type symnamelen; |
| 674 | const unsigned char* psymnamesu; |
| 675 | psymnamesu = this->section_contents(this->adjust_shndx(symshdr.get_sh_link()), |
| 676 | &symnamelen, true); |
| 677 | const char* psymnames = reinterpret_cast<const char*>(psymnamesu); |
| 678 | |
| 679 | // Get the section group signature. |
| 680 | if (sym.get_st_name() >= symnamelen) |
| 681 | { |
| 682 | this->error(_("symbol %u name offset %u out of range"), |
| 683 | symndx, sym.get_st_name()); |
| 684 | return false; |
| 685 | } |
| 686 | |
| 687 | std::string signature(psymnames + sym.get_st_name()); |
| 688 | |
| 689 | // It seems that some versions of gas will create a section group |
| 690 | // associated with a section symbol, and then fail to give a name to |
| 691 | // the section symbol. In such a case, use the name of the section. |
| 692 | if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION) |
| 693 | { |
| 694 | bool is_ordinary; |
| 695 | unsigned int sym_shndx = this->adjust_sym_shndx(symndx, |
| 696 | sym.get_st_shndx(), |
| 697 | &is_ordinary); |
| 698 | if (!is_ordinary || sym_shndx >= this->shnum()) |
| 699 | { |
| 700 | this->error(_("symbol %u invalid section index %u"), |
| 701 | symndx, sym_shndx); |
| 702 | return false; |
| 703 | } |
| 704 | typename This::Shdr member_shdr(shdrs + sym_shndx * This::shdr_size); |
| 705 | if (member_shdr.get_sh_name() < section_names_size) |
| 706 | signature = section_names + member_shdr.get_sh_name(); |
| 707 | } |
| 708 | |
| 709 | // Record this section group in the layout, and see whether we've already |
| 710 | // seen one with the same signature. |
| 711 | bool include_group; |
| 712 | bool is_comdat; |
| 713 | Kept_section* kept_section = NULL; |
| 714 | |
| 715 | if ((flags & elfcpp::GRP_COMDAT) == 0) |
| 716 | { |
| 717 | include_group = true; |
| 718 | is_comdat = false; |
| 719 | } |
| 720 | else |
| 721 | { |
| 722 | include_group = layout->find_or_add_kept_section(signature, |
| 723 | this, index, true, |
| 724 | true, &kept_section); |
| 725 | is_comdat = true; |
| 726 | } |
| 727 | |
| 728 | size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word); |
| 729 | |
| 730 | std::vector<unsigned int> shndxes; |
| 731 | bool relocate_group = include_group && parameters->options().relocatable(); |
| 732 | if (relocate_group) |
| 733 | shndxes.reserve(count - 1); |
| 734 | |
| 735 | for (size_t i = 1; i < count; ++i) |
| 736 | { |
| 737 | elfcpp::Elf_Word shndx = |
| 738 | this->adjust_shndx(elfcpp::Swap<32, big_endian>::readval(pword + i)); |
| 739 | |
| 740 | if (relocate_group) |
| 741 | shndxes.push_back(shndx); |
| 742 | |
| 743 | if (shndx >= this->shnum()) |
| 744 | { |
| 745 | this->error(_("section %u in section group %u out of range"), |
| 746 | shndx, index); |
| 747 | continue; |
| 748 | } |
| 749 | |
| 750 | // Check for an earlier section number, since we're going to get |
| 751 | // it wrong--we may have already decided to include the section. |
| 752 | if (shndx < index) |
| 753 | this->error(_("invalid section group %u refers to earlier section %u"), |
| 754 | index, shndx); |
| 755 | |
| 756 | // Get the name of the member section. |
| 757 | typename This::Shdr member_shdr(shdrs + shndx * This::shdr_size); |
| 758 | if (member_shdr.get_sh_name() >= section_names_size) |
| 759 | { |
| 760 | // This is an error, but it will be diagnosed eventually |
| 761 | // in do_layout, so we don't need to do anything here but |
| 762 | // ignore it. |
| 763 | continue; |
| 764 | } |
| 765 | std::string mname(section_names + member_shdr.get_sh_name()); |
| 766 | |
| 767 | if (include_group) |
| 768 | { |
| 769 | if (is_comdat) |
| 770 | kept_section->add_comdat_section(mname, shndx, |
| 771 | member_shdr.get_sh_size()); |
| 772 | } |
| 773 | else |
| 774 | { |
| 775 | (*omit)[shndx] = true; |
| 776 | |
| 777 | if (is_comdat) |
| 778 | { |
| 779 | Relobj* kept_object = kept_section->object(); |
| 780 | if (kept_section->is_comdat()) |
| 781 | { |
| 782 | // Find the corresponding kept section, and store |
| 783 | // that info in the discarded section table. |
| 784 | unsigned int kept_shndx; |
| 785 | uint64_t kept_size; |
| 786 | if (kept_section->find_comdat_section(mname, &kept_shndx, |
| 787 | &kept_size)) |
| 788 | { |
| 789 | // We don't keep a mapping for this section if |
| 790 | // it has a different size. The mapping is only |
| 791 | // used for relocation processing, and we don't |
| 792 | // want to treat the sections as similar if the |
| 793 | // sizes are different. Checking the section |
| 794 | // size is the approach used by the GNU linker. |
| 795 | if (kept_size == member_shdr.get_sh_size()) |
| 796 | this->set_kept_comdat_section(shndx, kept_object, |
| 797 | kept_shndx); |
| 798 | } |
| 799 | } |
| 800 | else |
| 801 | { |
| 802 | // The existing section is a linkonce section. Add |
| 803 | // a mapping if there is exactly one section in the |
| 804 | // group (which is true when COUNT == 2) and if it |
| 805 | // is the same size. |
| 806 | if (count == 2 |
| 807 | && (kept_section->linkonce_size() |
| 808 | == member_shdr.get_sh_size())) |
| 809 | this->set_kept_comdat_section(shndx, kept_object, |
| 810 | kept_section->shndx()); |
| 811 | } |
| 812 | } |
| 813 | } |
| 814 | } |
| 815 | |
| 816 | if (relocate_group) |
| 817 | layout->layout_group(symtab, this, index, name, signature.c_str(), |
| 818 | shdr, flags, &shndxes); |
| 819 | |
| 820 | return include_group; |
| 821 | } |
| 822 | |
| 823 | // Whether to include a linkonce section in the link. NAME is the |
| 824 | // name of the section and SHDR is the section header. |
| 825 | |
| 826 | // Linkonce sections are a GNU extension implemented in the original |
| 827 | // GNU linker before section groups were defined. The semantics are |
| 828 | // that we only include one linkonce section with a given name. The |
| 829 | // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME, |
| 830 | // where T is the type of section and SYMNAME is the name of a symbol. |
| 831 | // In an attempt to make linkonce sections interact well with section |
| 832 | // groups, we try to identify SYMNAME and use it like a section group |
| 833 | // signature. We want to block section groups with that signature, |
| 834 | // but not other linkonce sections with that signature. We also use |
| 835 | // the full name of the linkonce section as a normal section group |
| 836 | // signature. |
| 837 | |
| 838 | template<int size, bool big_endian> |
| 839 | bool |
| 840 | Sized_relobj<size, big_endian>::include_linkonce_section( |
| 841 | Layout* layout, |
| 842 | unsigned int index, |
| 843 | const char* name, |
| 844 | const elfcpp::Shdr<size, big_endian>& shdr) |
| 845 | { |
| 846 | typename elfcpp::Elf_types<size>::Elf_WXword sh_size = shdr.get_sh_size(); |
| 847 | // In general the symbol name we want will be the string following |
| 848 | // the last '.'. However, we have to handle the case of |
| 849 | // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by |
| 850 | // some versions of gcc. So we use a heuristic: if the name starts |
| 851 | // with ".gnu.linkonce.t.", we use everything after that. Otherwise |
| 852 | // we look for the last '.'. We can't always simply skip |
| 853 | // ".gnu.linkonce.X", because we have to deal with cases like |
| 854 | // ".gnu.linkonce.d.rel.ro.local". |
| 855 | const char* const linkonce_t = ".gnu.linkonce.t."; |
| 856 | const char* symname; |
| 857 | if (strncmp(name, linkonce_t, strlen(linkonce_t)) == 0) |
| 858 | symname = name + strlen(linkonce_t); |
| 859 | else |
| 860 | symname = strrchr(name, '.') + 1; |
| 861 | std::string sig1(symname); |
| 862 | std::string sig2(name); |
| 863 | Kept_section* kept1; |
| 864 | Kept_section* kept2; |
| 865 | bool include1 = layout->find_or_add_kept_section(sig1, this, index, false, |
| 866 | false, &kept1); |
| 867 | bool include2 = layout->find_or_add_kept_section(sig2, this, index, false, |
| 868 | true, &kept2); |
| 869 | |
| 870 | if (!include2) |
| 871 | { |
| 872 | // We are not including this section because we already saw the |
| 873 | // name of the section as a signature. This normally implies |
| 874 | // that the kept section is another linkonce section. If it is |
| 875 | // the same size, record it as the section which corresponds to |
| 876 | // this one. |
| 877 | if (kept2->object() != NULL |
| 878 | && !kept2->is_comdat() |
| 879 | && kept2->linkonce_size() == sh_size) |
| 880 | this->set_kept_comdat_section(index, kept2->object(), kept2->shndx()); |
| 881 | } |
| 882 | else if (!include1) |
| 883 | { |
| 884 | // The section is being discarded on the basis of its symbol |
| 885 | // name. This means that the corresponding kept section was |
| 886 | // part of a comdat group, and it will be difficult to identify |
| 887 | // the specific section within that group that corresponds to |
| 888 | // this linkonce section. We'll handle the simple case where |
| 889 | // the group has only one member section. Otherwise, it's not |
| 890 | // worth the effort. |
| 891 | unsigned int kept_shndx; |
| 892 | uint64_t kept_size; |
| 893 | if (kept1->object() != NULL |
| 894 | && kept1->is_comdat() |
| 895 | && kept1->find_single_comdat_section(&kept_shndx, &kept_size) |
| 896 | && kept_size == sh_size) |
| 897 | this->set_kept_comdat_section(index, kept1->object(), kept_shndx); |
| 898 | } |
| 899 | else |
| 900 | { |
| 901 | kept1->set_linkonce_size(sh_size); |
| 902 | kept2->set_linkonce_size(sh_size); |
| 903 | } |
| 904 | |
| 905 | return include1 && include2; |
| 906 | } |
| 907 | |
| 908 | // Layout an input section. |
| 909 | |
| 910 | template<int size, bool big_endian> |
| 911 | inline void |
| 912 | Sized_relobj<size, big_endian>::layout_section(Layout* layout, |
| 913 | unsigned int shndx, |
| 914 | const char* name, |
| 915 | typename This::Shdr& shdr, |
| 916 | unsigned int reloc_shndx, |
| 917 | unsigned int reloc_type) |
| 918 | { |
| 919 | off_t offset; |
| 920 | Output_section* os = layout->layout(this, shndx, name, shdr, |
| 921 | reloc_shndx, reloc_type, &offset); |
| 922 | |
| 923 | this->output_sections()[shndx] = os; |
| 924 | if (offset == -1) |
| 925 | this->section_offsets_[shndx] = invalid_address; |
| 926 | else |
| 927 | this->section_offsets_[shndx] = convert_types<Address, off_t>(offset); |
| 928 | |
| 929 | // If this section requires special handling, and if there are |
| 930 | // relocs that apply to it, then we must do the special handling |
| 931 | // before we apply the relocs. |
| 932 | if (offset == -1 && reloc_shndx != 0) |
| 933 | this->set_relocs_must_follow_section_writes(); |
| 934 | } |
| 935 | |
| 936 | // Lay out the input sections. We walk through the sections and check |
| 937 | // whether they should be included in the link. If they should, we |
| 938 | // pass them to the Layout object, which will return an output section |
| 939 | // and an offset. |
| 940 | // During garbage collection (--gc-sections) and identical code folding |
| 941 | // (--icf), this function is called twice. When it is called the first |
| 942 | // time, it is for setting up some sections as roots to a work-list for |
| 943 | // --gc-sections and to do comdat processing. Actual layout happens the |
| 944 | // second time around after all the relevant sections have been determined. |
| 945 | // The first time, is_worklist_ready or is_icf_ready is false. It is then |
| 946 | // set to true after the garbage collection worklist or identical code |
| 947 | // folding is processed and the relevant sections to be kept are |
| 948 | // determined. Then, this function is called again to layout the sections. |
| 949 | |
| 950 | template<int size, bool big_endian> |
| 951 | void |
| 952 | Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab, |
| 953 | Layout* layout, |
| 954 | Read_symbols_data* sd) |
| 955 | { |
| 956 | const unsigned int shnum = this->shnum(); |
| 957 | bool is_gc_pass_one = ((parameters->options().gc_sections() |
| 958 | && !symtab->gc()->is_worklist_ready()) |
| 959 | || (parameters->options().icf_enabled() |
| 960 | && !symtab->icf()->is_icf_ready())); |
| 961 | |
| 962 | bool is_gc_pass_two = ((parameters->options().gc_sections() |
| 963 | && symtab->gc()->is_worklist_ready()) |
| 964 | || (parameters->options().icf_enabled() |
| 965 | && symtab->icf()->is_icf_ready())); |
| 966 | |
| 967 | bool is_gc_or_icf = (parameters->options().gc_sections() |
| 968 | || parameters->options().icf_enabled()); |
| 969 | |
| 970 | // Both is_gc_pass_one and is_gc_pass_two should not be true. |
| 971 | gold_assert(!(is_gc_pass_one && is_gc_pass_two)); |
| 972 | |
| 973 | if (shnum == 0) |
| 974 | return; |
| 975 | Symbols_data* gc_sd = NULL; |
| 976 | if (is_gc_pass_one) |
| 977 | { |
| 978 | // During garbage collection save the symbols data to use it when |
| 979 | // re-entering this function. |
| 980 | gc_sd = new Symbols_data; |
| 981 | this->copy_symbols_data(gc_sd, sd, This::shdr_size * shnum); |
| 982 | this->set_symbols_data(gc_sd); |
| 983 | } |
| 984 | else if (is_gc_pass_two) |
| 985 | { |
| 986 | gc_sd = this->get_symbols_data(); |
| 987 | } |
| 988 | |
| 989 | const unsigned char* section_headers_data = NULL; |
| 990 | section_size_type section_names_size; |
| 991 | const unsigned char* symbols_data = NULL; |
| 992 | section_size_type symbols_size; |
| 993 | section_offset_type external_symbols_offset; |
| 994 | const unsigned char* symbol_names_data = NULL; |
| 995 | section_size_type symbol_names_size; |
| 996 | |
| 997 | if (is_gc_or_icf) |
| 998 | { |
| 999 | section_headers_data = gc_sd->section_headers_data; |
| 1000 | section_names_size = gc_sd->section_names_size; |
| 1001 | symbols_data = gc_sd->symbols_data; |
| 1002 | symbols_size = gc_sd->symbols_size; |
| 1003 | external_symbols_offset = gc_sd->external_symbols_offset; |
| 1004 | symbol_names_data = gc_sd->symbol_names_data; |
| 1005 | symbol_names_size = gc_sd->symbol_names_size; |
| 1006 | } |
| 1007 | else |
| 1008 | { |
| 1009 | section_headers_data = sd->section_headers->data(); |
| 1010 | section_names_size = sd->section_names_size; |
| 1011 | if (sd->symbols != NULL) |
| 1012 | symbols_data = sd->symbols->data(); |
| 1013 | symbols_size = sd->symbols_size; |
| 1014 | external_symbols_offset = sd->external_symbols_offset; |
| 1015 | if (sd->symbol_names != NULL) |
| 1016 | symbol_names_data = sd->symbol_names->data(); |
| 1017 | symbol_names_size = sd->symbol_names_size; |
| 1018 | } |
| 1019 | |
| 1020 | // Get the section headers. |
| 1021 | const unsigned char* shdrs = section_headers_data; |
| 1022 | const unsigned char* pshdrs; |
| 1023 | |
| 1024 | // Get the section names. |
| 1025 | const unsigned char* pnamesu = (is_gc_or_icf) |
| 1026 | ? gc_sd->section_names_data |
| 1027 | : sd->section_names->data(); |
| 1028 | |
| 1029 | const char* pnames = reinterpret_cast<const char*>(pnamesu); |
| 1030 | |
| 1031 | // If any input files have been claimed by plugins, we need to defer |
| 1032 | // actual layout until the replacement files have arrived. |
| 1033 | const bool should_defer_layout = |
| 1034 | (parameters->options().has_plugins() |
| 1035 | && parameters->options().plugins()->should_defer_layout()); |
| 1036 | unsigned int num_sections_to_defer = 0; |
| 1037 | |
| 1038 | // For each section, record the index of the reloc section if any. |
| 1039 | // Use 0 to mean that there is no reloc section, -1U to mean that |
| 1040 | // there is more than one. |
| 1041 | std::vector<unsigned int> reloc_shndx(shnum, 0); |
| 1042 | std::vector<unsigned int> reloc_type(shnum, elfcpp::SHT_NULL); |
| 1043 | // Skip the first, dummy, section. |
| 1044 | pshdrs = shdrs + This::shdr_size; |
| 1045 | for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size) |
| 1046 | { |
| 1047 | typename This::Shdr shdr(pshdrs); |
| 1048 | |
| 1049 | // Count the number of sections whose layout will be deferred. |
| 1050 | if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC)) |
| 1051 | ++num_sections_to_defer; |
| 1052 | |
| 1053 | unsigned int sh_type = shdr.get_sh_type(); |
| 1054 | if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA) |
| 1055 | { |
| 1056 | unsigned int target_shndx = this->adjust_shndx(shdr.get_sh_info()); |
| 1057 | if (target_shndx == 0 || target_shndx >= shnum) |
| 1058 | { |
| 1059 | this->error(_("relocation section %u has bad info %u"), |
| 1060 | i, target_shndx); |
| 1061 | continue; |
| 1062 | } |
| 1063 | |
| 1064 | if (reloc_shndx[target_shndx] != 0) |
| 1065 | reloc_shndx[target_shndx] = -1U; |
| 1066 | else |
| 1067 | { |
| 1068 | reloc_shndx[target_shndx] = i; |
| 1069 | reloc_type[target_shndx] = sh_type; |
| 1070 | } |
| 1071 | } |
| 1072 | } |
| 1073 | |
| 1074 | Output_sections& out_sections(this->output_sections()); |
| 1075 | std::vector<Address>& out_section_offsets(this->section_offsets_); |
| 1076 | |
| 1077 | if (!is_gc_pass_two) |
| 1078 | { |
| 1079 | out_sections.resize(shnum); |
| 1080 | out_section_offsets.resize(shnum); |
| 1081 | } |
| 1082 | |
| 1083 | // If we are only linking for symbols, then there is nothing else to |
| 1084 | // do here. |
| 1085 | if (this->input_file()->just_symbols()) |
| 1086 | { |
| 1087 | if (!is_gc_pass_two) |
| 1088 | { |
| 1089 | delete sd->section_headers; |
| 1090 | sd->section_headers = NULL; |
| 1091 | delete sd->section_names; |
| 1092 | sd->section_names = NULL; |
| 1093 | } |
| 1094 | return; |
| 1095 | } |
| 1096 | |
| 1097 | if (num_sections_to_defer > 0) |
| 1098 | { |
| 1099 | parameters->options().plugins()->add_deferred_layout_object(this); |
| 1100 | this->deferred_layout_.reserve(num_sections_to_defer); |
| 1101 | } |
| 1102 | |
| 1103 | // Whether we've seen a .note.GNU-stack section. |
| 1104 | bool seen_gnu_stack = false; |
| 1105 | // The flags of a .note.GNU-stack section. |
| 1106 | uint64_t gnu_stack_flags = 0; |
| 1107 | |
| 1108 | // Keep track of which sections to omit. |
| 1109 | std::vector<bool> omit(shnum, false); |
| 1110 | |
| 1111 | // Keep track of reloc sections when emitting relocations. |
| 1112 | const bool relocatable = parameters->options().relocatable(); |
| 1113 | const bool emit_relocs = (relocatable |
| 1114 | || parameters->options().emit_relocs()); |
| 1115 | std::vector<unsigned int> reloc_sections; |
| 1116 | |
| 1117 | // Keep track of .eh_frame sections. |
| 1118 | std::vector<unsigned int> eh_frame_sections; |
| 1119 | |
| 1120 | // Skip the first, dummy, section. |
| 1121 | pshdrs = shdrs + This::shdr_size; |
| 1122 | for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size) |
| 1123 | { |
| 1124 | typename This::Shdr shdr(pshdrs); |
| 1125 | |
| 1126 | if (shdr.get_sh_name() >= section_names_size) |
| 1127 | { |
| 1128 | this->error(_("bad section name offset for section %u: %lu"), |
| 1129 | i, static_cast<unsigned long>(shdr.get_sh_name())); |
| 1130 | return; |
| 1131 | } |
| 1132 | |
| 1133 | const char* name = pnames + shdr.get_sh_name(); |
| 1134 | |
| 1135 | if (!is_gc_pass_two) |
| 1136 | { |
| 1137 | if (this->handle_gnu_warning_section(name, i, symtab)) |
| 1138 | { |
| 1139 | if (!relocatable) |
| 1140 | omit[i] = true; |
| 1141 | } |
| 1142 | |
| 1143 | // The .note.GNU-stack section is special. It gives the |
| 1144 | // protection flags that this object file requires for the stack |
| 1145 | // in memory. |
| 1146 | if (strcmp(name, ".note.GNU-stack") == 0) |
| 1147 | { |
| 1148 | seen_gnu_stack = true; |
| 1149 | gnu_stack_flags |= shdr.get_sh_flags(); |
| 1150 | omit[i] = true; |
| 1151 | } |
| 1152 | |
| 1153 | // The .note.GNU-split-stack section is also special. It |
| 1154 | // indicates that the object was compiled with |
| 1155 | // -fsplit-stack. |
| 1156 | if (this->handle_split_stack_section(name)) |
| 1157 | { |
| 1158 | if (!parameters->options().relocatable() |
| 1159 | && !parameters->options().shared()) |
| 1160 | omit[i] = true; |
| 1161 | } |
| 1162 | |
| 1163 | // Skip attributes section. |
| 1164 | if (parameters->target().is_attributes_section(name)) |
| 1165 | { |
| 1166 | omit[i] = true; |
| 1167 | } |
| 1168 | |
| 1169 | bool discard = omit[i]; |
| 1170 | if (!discard) |
| 1171 | { |
| 1172 | if (shdr.get_sh_type() == elfcpp::SHT_GROUP) |
| 1173 | { |
| 1174 | if (!this->include_section_group(symtab, layout, i, name, |
| 1175 | shdrs, pnames, |
| 1176 | section_names_size, |
| 1177 | &omit)) |
| 1178 | discard = true; |
| 1179 | } |
| 1180 | else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0 |
| 1181 | && Layout::is_linkonce(name)) |
| 1182 | { |
| 1183 | if (!this->include_linkonce_section(layout, i, name, shdr)) |
| 1184 | discard = true; |
| 1185 | } |
| 1186 | } |
| 1187 | |
| 1188 | if (discard) |
| 1189 | { |
| 1190 | // Do not include this section in the link. |
| 1191 | out_sections[i] = NULL; |
| 1192 | out_section_offsets[i] = invalid_address; |
| 1193 | continue; |
| 1194 | } |
| 1195 | } |
| 1196 | |
| 1197 | if (is_gc_pass_one && parameters->options().gc_sections()) |
| 1198 | { |
| 1199 | if (is_section_name_included(name) |
| 1200 | || shdr.get_sh_type() == elfcpp::SHT_INIT_ARRAY |
| 1201 | || shdr.get_sh_type() == elfcpp::SHT_FINI_ARRAY) |
| 1202 | { |
| 1203 | symtab->gc()->worklist().push(Section_id(this, i)); |
| 1204 | } |
| 1205 | // If the section name XXX can be represented as a C identifier |
| 1206 | // it cannot be discarded if there are references to |
| 1207 | // __start_XXX and __stop_XXX symbols. These need to be |
| 1208 | // specially handled. |
| 1209 | if (is_cident(name)) |
| 1210 | { |
| 1211 | symtab->gc()->add_cident_section(name, Section_id(this, i)); |
| 1212 | } |
| 1213 | } |
| 1214 | |
| 1215 | // When doing a relocatable link we are going to copy input |
| 1216 | // reloc sections into the output. We only want to copy the |
| 1217 | // ones associated with sections which are not being discarded. |
| 1218 | // However, we don't know that yet for all sections. So save |
| 1219 | // reloc sections and process them later. Garbage collection is |
| 1220 | // not triggered when relocatable code is desired. |
| 1221 | if (emit_relocs |
| 1222 | && (shdr.get_sh_type() == elfcpp::SHT_REL |
| 1223 | || shdr.get_sh_type() == elfcpp::SHT_RELA)) |
| 1224 | { |
| 1225 | reloc_sections.push_back(i); |
| 1226 | continue; |
| 1227 | } |
| 1228 | |
| 1229 | if (relocatable && shdr.get_sh_type() == elfcpp::SHT_GROUP) |
| 1230 | continue; |
| 1231 | |
| 1232 | // The .eh_frame section is special. It holds exception frame |
| 1233 | // information that we need to read in order to generate the |
| 1234 | // exception frame header. We process these after all the other |
| 1235 | // sections so that the exception frame reader can reliably |
| 1236 | // determine which sections are being discarded, and discard the |
| 1237 | // corresponding information. |
| 1238 | if (!relocatable |
| 1239 | && strcmp(name, ".eh_frame") == 0 |
| 1240 | && this->check_eh_frame_flags(&shdr)) |
| 1241 | { |
| 1242 | if (is_gc_pass_one) |
| 1243 | { |
| 1244 | out_sections[i] = reinterpret_cast<Output_section*>(1); |
| 1245 | out_section_offsets[i] = invalid_address; |
| 1246 | } |
| 1247 | else |
| 1248 | eh_frame_sections.push_back(i); |
| 1249 | continue; |
| 1250 | } |
| 1251 | |
| 1252 | if (is_gc_pass_two && parameters->options().gc_sections()) |
| 1253 | { |
| 1254 | // This is executed during the second pass of garbage |
| 1255 | // collection. do_layout has been called before and some |
| 1256 | // sections have been already discarded. Simply ignore |
| 1257 | // such sections this time around. |
| 1258 | if (out_sections[i] == NULL) |
| 1259 | { |
| 1260 | gold_assert(out_section_offsets[i] == invalid_address); |
| 1261 | continue; |
| 1262 | } |
| 1263 | if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0) |
| 1264 | && symtab->gc()->is_section_garbage(this, i)) |
| 1265 | { |
| 1266 | if (parameters->options().print_gc_sections()) |
| 1267 | gold_info(_("%s: removing unused section from '%s'" |
| 1268 | " in file '%s'"), |
| 1269 | program_name, this->section_name(i).c_str(), |
| 1270 | this->name().c_str()); |
| 1271 | out_sections[i] = NULL; |
| 1272 | out_section_offsets[i] = invalid_address; |
| 1273 | continue; |
| 1274 | } |
| 1275 | } |
| 1276 | |
| 1277 | if (is_gc_pass_two && parameters->options().icf_enabled()) |
| 1278 | { |
| 1279 | if (out_sections[i] == NULL) |
| 1280 | { |
| 1281 | gold_assert(out_section_offsets[i] == invalid_address); |
| 1282 | continue; |
| 1283 | } |
| 1284 | if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0) |
| 1285 | && symtab->icf()->is_section_folded(this, i)) |
| 1286 | { |
| 1287 | if (parameters->options().print_icf_sections()) |
| 1288 | { |
| 1289 | Section_id folded = |
| 1290 | symtab->icf()->get_folded_section(this, i); |
| 1291 | Relobj* folded_obj = |
| 1292 | reinterpret_cast<Relobj*>(folded.first); |
| 1293 | gold_info(_("%s: ICF folding section '%s' in file '%s'" |
| 1294 | "into '%s' in file '%s'"), |
| 1295 | program_name, this->section_name(i).c_str(), |
| 1296 | this->name().c_str(), |
| 1297 | folded_obj->section_name(folded.second).c_str(), |
| 1298 | folded_obj->name().c_str()); |
| 1299 | } |
| 1300 | out_sections[i] = NULL; |
| 1301 | out_section_offsets[i] = invalid_address; |
| 1302 | continue; |
| 1303 | } |
| 1304 | } |
| 1305 | |
| 1306 | // Defer layout here if input files are claimed by plugins. When gc |
| 1307 | // is turned on this function is called twice. For the second call |
| 1308 | // should_defer_layout should be false. |
| 1309 | if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC)) |
| 1310 | { |
| 1311 | gold_assert(!is_gc_pass_two); |
| 1312 | this->deferred_layout_.push_back(Deferred_layout(i, name, |
| 1313 | pshdrs, |
| 1314 | reloc_shndx[i], |
| 1315 | reloc_type[i])); |
| 1316 | // Put dummy values here; real values will be supplied by |
| 1317 | // do_layout_deferred_sections. |
| 1318 | out_sections[i] = reinterpret_cast<Output_section*>(2); |
| 1319 | out_section_offsets[i] = invalid_address; |
| 1320 | continue; |
| 1321 | } |
| 1322 | |
| 1323 | // During gc_pass_two if a section that was previously deferred is |
| 1324 | // found, do not layout the section as layout_deferred_sections will |
| 1325 | // do it later from gold.cc. |
| 1326 | if (is_gc_pass_two |
| 1327 | && (out_sections[i] == reinterpret_cast<Output_section*>(2))) |
| 1328 | continue; |
| 1329 | |
| 1330 | if (is_gc_pass_one) |
| 1331 | { |
| 1332 | // This is during garbage collection. The out_sections are |
| 1333 | // assigned in the second call to this function. |
| 1334 | out_sections[i] = reinterpret_cast<Output_section*>(1); |
| 1335 | out_section_offsets[i] = invalid_address; |
| 1336 | } |
| 1337 | else |
| 1338 | { |
| 1339 | // When garbage collection is switched on the actual layout |
| 1340 | // only happens in the second call. |
| 1341 | this->layout_section(layout, i, name, shdr, reloc_shndx[i], |
| 1342 | reloc_type[i]); |
| 1343 | } |
| 1344 | } |
| 1345 | |
| 1346 | if (!is_gc_pass_two) |
| 1347 | layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags); |
| 1348 | |
| 1349 | // When doing a relocatable link handle the reloc sections at the |
| 1350 | // end. Garbage collection and Identical Code Folding is not |
| 1351 | // turned on for relocatable code. |
| 1352 | if (emit_relocs) |
| 1353 | this->size_relocatable_relocs(); |
| 1354 | |
| 1355 | gold_assert(!(is_gc_or_icf) || reloc_sections.empty()); |
| 1356 | |
| 1357 | for (std::vector<unsigned int>::const_iterator p = reloc_sections.begin(); |
| 1358 | p != reloc_sections.end(); |
| 1359 | ++p) |
| 1360 | { |
| 1361 | unsigned int i = *p; |
| 1362 | const unsigned char* pshdr; |
| 1363 | pshdr = section_headers_data + i * This::shdr_size; |
| 1364 | typename This::Shdr shdr(pshdr); |
| 1365 | |
| 1366 | unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info()); |
| 1367 | if (data_shndx >= shnum) |
| 1368 | { |
| 1369 | // We already warned about this above. |
| 1370 | continue; |
| 1371 | } |
| 1372 | |
| 1373 | Output_section* data_section = out_sections[data_shndx]; |
| 1374 | if (data_section == reinterpret_cast<Output_section*>(2)) |
| 1375 | { |
| 1376 | // The layout for the data section was deferred, so we need |
| 1377 | // to defer the relocation section, too. |
| 1378 | const char* name = pnames + shdr.get_sh_name(); |
| 1379 | this->deferred_layout_relocs_.push_back( |
| 1380 | Deferred_layout(i, name, pshdr, 0, elfcpp::SHT_NULL)); |
| 1381 | out_sections[i] = reinterpret_cast<Output_section*>(2); |
| 1382 | out_section_offsets[i] = invalid_address; |
| 1383 | continue; |
| 1384 | } |
| 1385 | if (data_section == NULL) |
| 1386 | { |
| 1387 | out_sections[i] = NULL; |
| 1388 | out_section_offsets[i] = invalid_address; |
| 1389 | continue; |
| 1390 | } |
| 1391 | |
| 1392 | Relocatable_relocs* rr = new Relocatable_relocs(); |
| 1393 | this->set_relocatable_relocs(i, rr); |
| 1394 | |
| 1395 | Output_section* os = layout->layout_reloc(this, i, shdr, data_section, |
| 1396 | rr); |
| 1397 | out_sections[i] = os; |
| 1398 | out_section_offsets[i] = invalid_address; |
| 1399 | } |
| 1400 | |
| 1401 | // Handle the .eh_frame sections at the end. |
| 1402 | gold_assert(!is_gc_pass_one || eh_frame_sections.empty()); |
| 1403 | for (std::vector<unsigned int>::const_iterator p = eh_frame_sections.begin(); |
| 1404 | p != eh_frame_sections.end(); |
| 1405 | ++p) |
| 1406 | { |
| 1407 | gold_assert(this->has_eh_frame_); |
| 1408 | gold_assert(external_symbols_offset != 0); |
| 1409 | |
| 1410 | unsigned int i = *p; |
| 1411 | const unsigned char *pshdr; |
| 1412 | pshdr = section_headers_data + i * This::shdr_size; |
| 1413 | typename This::Shdr shdr(pshdr); |
| 1414 | |
| 1415 | off_t offset; |
| 1416 | Output_section* os = layout->layout_eh_frame(this, |
| 1417 | symbols_data, |
| 1418 | symbols_size, |
| 1419 | symbol_names_data, |
| 1420 | symbol_names_size, |
| 1421 | i, shdr, |
| 1422 | reloc_shndx[i], |
| 1423 | reloc_type[i], |
| 1424 | &offset); |
| 1425 | out_sections[i] = os; |
| 1426 | if (os == NULL || offset == -1) |
| 1427 | { |
| 1428 | // An object can contain at most one section holding exception |
| 1429 | // frame information. |
| 1430 | gold_assert(this->discarded_eh_frame_shndx_ == -1U); |
| 1431 | this->discarded_eh_frame_shndx_ = i; |
| 1432 | out_section_offsets[i] = invalid_address; |
| 1433 | } |
| 1434 | else |
| 1435 | out_section_offsets[i] = convert_types<Address, off_t>(offset); |
| 1436 | |
| 1437 | // If this section requires special handling, and if there are |
| 1438 | // relocs that apply to it, then we must do the special handling |
| 1439 | // before we apply the relocs. |
| 1440 | if (os != NULL && offset == -1 && reloc_shndx[i] != 0) |
| 1441 | this->set_relocs_must_follow_section_writes(); |
| 1442 | } |
| 1443 | |
| 1444 | if (is_gc_pass_two) |
| 1445 | { |
| 1446 | delete[] gc_sd->section_headers_data; |
| 1447 | delete[] gc_sd->section_names_data; |
| 1448 | delete[] gc_sd->symbols_data; |
| 1449 | delete[] gc_sd->symbol_names_data; |
| 1450 | this->set_symbols_data(NULL); |
| 1451 | } |
| 1452 | else |
| 1453 | { |
| 1454 | delete sd->section_headers; |
| 1455 | sd->section_headers = NULL; |
| 1456 | delete sd->section_names; |
| 1457 | sd->section_names = NULL; |
| 1458 | } |
| 1459 | } |
| 1460 | |
| 1461 | // Layout sections whose layout was deferred while waiting for |
| 1462 | // input files from a plugin. |
| 1463 | |
| 1464 | template<int size, bool big_endian> |
| 1465 | void |
| 1466 | Sized_relobj<size, big_endian>::do_layout_deferred_sections(Layout* layout) |
| 1467 | { |
| 1468 | typename std::vector<Deferred_layout>::iterator deferred; |
| 1469 | |
| 1470 | for (deferred = this->deferred_layout_.begin(); |
| 1471 | deferred != this->deferred_layout_.end(); |
| 1472 | ++deferred) |
| 1473 | { |
| 1474 | typename This::Shdr shdr(deferred->shdr_data_); |
| 1475 | // If the section is not included, it is because the garbage collector |
| 1476 | // decided it is not needed. Avoid reverting that decision. |
| 1477 | if (!this->is_section_included(deferred->shndx_)) |
| 1478 | continue; |
| 1479 | |
| 1480 | this->layout_section(layout, deferred->shndx_, deferred->name_.c_str(), |
| 1481 | shdr, deferred->reloc_shndx_, deferred->reloc_type_); |
| 1482 | } |
| 1483 | |
| 1484 | this->deferred_layout_.clear(); |
| 1485 | |
| 1486 | // Now handle the deferred relocation sections. |
| 1487 | |
| 1488 | Output_sections& out_sections(this->output_sections()); |
| 1489 | std::vector<Address>& out_section_offsets(this->section_offsets_); |
| 1490 | |
| 1491 | for (deferred = this->deferred_layout_relocs_.begin(); |
| 1492 | deferred != this->deferred_layout_relocs_.end(); |
| 1493 | ++deferred) |
| 1494 | { |
| 1495 | unsigned int shndx = deferred->shndx_; |
| 1496 | typename This::Shdr shdr(deferred->shdr_data_); |
| 1497 | unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info()); |
| 1498 | |
| 1499 | Output_section* data_section = out_sections[data_shndx]; |
| 1500 | if (data_section == NULL) |
| 1501 | { |
| 1502 | out_sections[shndx] = NULL; |
| 1503 | out_section_offsets[shndx] = invalid_address; |
| 1504 | continue; |
| 1505 | } |
| 1506 | |
| 1507 | Relocatable_relocs* rr = new Relocatable_relocs(); |
| 1508 | this->set_relocatable_relocs(shndx, rr); |
| 1509 | |
| 1510 | Output_section* os = layout->layout_reloc(this, shndx, shdr, |
| 1511 | data_section, rr); |
| 1512 | out_sections[shndx] = os; |
| 1513 | out_section_offsets[shndx] = invalid_address; |
| 1514 | } |
| 1515 | } |
| 1516 | |
| 1517 | // Add the symbols to the symbol table. |
| 1518 | |
| 1519 | template<int size, bool big_endian> |
| 1520 | void |
| 1521 | Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab, |
| 1522 | Read_symbols_data* sd, |
| 1523 | Layout*) |
| 1524 | { |
| 1525 | if (sd->symbols == NULL) |
| 1526 | { |
| 1527 | gold_assert(sd->symbol_names == NULL); |
| 1528 | return; |
| 1529 | } |
| 1530 | |
| 1531 | const int sym_size = This::sym_size; |
| 1532 | size_t symcount = ((sd->symbols_size - sd->external_symbols_offset) |
| 1533 | / sym_size); |
| 1534 | if (symcount * sym_size != sd->symbols_size - sd->external_symbols_offset) |
| 1535 | { |
| 1536 | this->error(_("size of symbols is not multiple of symbol size")); |
| 1537 | return; |
| 1538 | } |
| 1539 | |
| 1540 | this->symbols_.resize(symcount); |
| 1541 | |
| 1542 | const char* sym_names = |
| 1543 | reinterpret_cast<const char*>(sd->symbol_names->data()); |
| 1544 | symtab->add_from_relobj(this, |
| 1545 | sd->symbols->data() + sd->external_symbols_offset, |
| 1546 | symcount, this->local_symbol_count_, |
| 1547 | sym_names, sd->symbol_names_size, |
| 1548 | &this->symbols_, |
| 1549 | &this->defined_count_); |
| 1550 | |
| 1551 | delete sd->symbols; |
| 1552 | sd->symbols = NULL; |
| 1553 | delete sd->symbol_names; |
| 1554 | sd->symbol_names = NULL; |
| 1555 | } |
| 1556 | |
| 1557 | // Find out if this object, that is a member of a lib group, should be included |
| 1558 | // in the link. We check every symbol defined by this object. If the symbol |
| 1559 | // table has a strong undefined reference to that symbol, we have to include |
| 1560 | // the object. |
| 1561 | |
| 1562 | template<int size, bool big_endian> |
| 1563 | Archive::Should_include |
| 1564 | Sized_relobj<size, big_endian>::do_should_include_member(Symbol_table* symtab, |
| 1565 | Read_symbols_data* sd, |
| 1566 | std::string* why) |
| 1567 | { |
| 1568 | char* tmpbuf = NULL; |
| 1569 | size_t tmpbuflen = 0; |
| 1570 | const char* sym_names = |
| 1571 | reinterpret_cast<const char*>(sd->symbol_names->data()); |
| 1572 | const unsigned char* syms = |
| 1573 | sd->symbols->data() + sd->external_symbols_offset; |
| 1574 | const int sym_size = elfcpp::Elf_sizes<size>::sym_size; |
| 1575 | size_t symcount = ((sd->symbols_size - sd->external_symbols_offset) |
| 1576 | / sym_size); |
| 1577 | |
| 1578 | const unsigned char* p = syms; |
| 1579 | |
| 1580 | for (size_t i = 0; i < symcount; ++i, p += sym_size) |
| 1581 | { |
| 1582 | elfcpp::Sym<size, big_endian> sym(p); |
| 1583 | unsigned int st_shndx = sym.get_st_shndx(); |
| 1584 | if (st_shndx == elfcpp::SHN_UNDEF) |
| 1585 | continue; |
| 1586 | |
| 1587 | unsigned int st_name = sym.get_st_name(); |
| 1588 | const char* name = sym_names + st_name; |
| 1589 | Symbol* symbol; |
| 1590 | Archive::Should_include t = Archive::should_include_member(symtab, name, |
| 1591 | &symbol, why, |
| 1592 | &tmpbuf, |
| 1593 | &tmpbuflen); |
| 1594 | if (t == Archive::SHOULD_INCLUDE_YES) |
| 1595 | { |
| 1596 | if (tmpbuf != NULL) |
| 1597 | free(tmpbuf); |
| 1598 | return t; |
| 1599 | } |
| 1600 | } |
| 1601 | if (tmpbuf != NULL) |
| 1602 | free(tmpbuf); |
| 1603 | return Archive::SHOULD_INCLUDE_UNKNOWN; |
| 1604 | } |
| 1605 | |
| 1606 | // First pass over the local symbols. Here we add their names to |
| 1607 | // *POOL and *DYNPOOL, and we store the symbol value in |
| 1608 | // THIS->LOCAL_VALUES_. This function is always called from a |
| 1609 | // singleton thread. This is followed by a call to |
| 1610 | // finalize_local_symbols. |
| 1611 | |
| 1612 | template<int size, bool big_endian> |
| 1613 | void |
| 1614 | Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool, |
| 1615 | Stringpool* dynpool) |
| 1616 | { |
| 1617 | gold_assert(this->symtab_shndx_ != -1U); |
| 1618 | if (this->symtab_shndx_ == 0) |
| 1619 | { |
| 1620 | // This object has no symbols. Weird but legal. |
| 1621 | return; |
| 1622 | } |
| 1623 | |
| 1624 | // Read the symbol table section header. |
| 1625 | const unsigned int symtab_shndx = this->symtab_shndx_; |
| 1626 | typename This::Shdr symtabshdr(this, |
| 1627 | this->elf_file_.section_header(symtab_shndx)); |
| 1628 | gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB); |
| 1629 | |
| 1630 | // Read the local symbols. |
| 1631 | const int sym_size = This::sym_size; |
| 1632 | const unsigned int loccount = this->local_symbol_count_; |
| 1633 | gold_assert(loccount == symtabshdr.get_sh_info()); |
| 1634 | off_t locsize = loccount * sym_size; |
| 1635 | const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(), |
| 1636 | locsize, true, true); |
| 1637 | |
| 1638 | // Read the symbol names. |
| 1639 | const unsigned int strtab_shndx = |
| 1640 | this->adjust_shndx(symtabshdr.get_sh_link()); |
| 1641 | section_size_type strtab_size; |
| 1642 | const unsigned char* pnamesu = this->section_contents(strtab_shndx, |
| 1643 | &strtab_size, |
| 1644 | true); |
| 1645 | const char* pnames = reinterpret_cast<const char*>(pnamesu); |
| 1646 | |
| 1647 | // Loop over the local symbols. |
| 1648 | |
| 1649 | const Output_sections& out_sections(this->output_sections()); |
| 1650 | unsigned int shnum = this->shnum(); |
| 1651 | unsigned int count = 0; |
| 1652 | unsigned int dyncount = 0; |
| 1653 | // Skip the first, dummy, symbol. |
| 1654 | psyms += sym_size; |
| 1655 | bool discard_all = parameters->options().discard_all(); |
| 1656 | bool discard_locals = parameters->options().discard_locals(); |
| 1657 | for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size) |
| 1658 | { |
| 1659 | elfcpp::Sym<size, big_endian> sym(psyms); |
| 1660 | |
| 1661 | Symbol_value<size>& lv(this->local_values_[i]); |
| 1662 | |
| 1663 | bool is_ordinary; |
| 1664 | unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(), |
| 1665 | &is_ordinary); |
| 1666 | lv.set_input_shndx(shndx, is_ordinary); |
| 1667 | |
| 1668 | if (sym.get_st_type() == elfcpp::STT_SECTION) |
| 1669 | lv.set_is_section_symbol(); |
| 1670 | else if (sym.get_st_type() == elfcpp::STT_TLS) |
| 1671 | lv.set_is_tls_symbol(); |
| 1672 | |
| 1673 | // Save the input symbol value for use in do_finalize_local_symbols(). |
| 1674 | lv.set_input_value(sym.get_st_value()); |
| 1675 | |
| 1676 | // Decide whether this symbol should go into the output file. |
| 1677 | |
| 1678 | if ((shndx < shnum && out_sections[shndx] == NULL) |
| 1679 | || shndx == this->discarded_eh_frame_shndx_) |
| 1680 | { |
| 1681 | lv.set_no_output_symtab_entry(); |
| 1682 | gold_assert(!lv.needs_output_dynsym_entry()); |
| 1683 | continue; |
| 1684 | } |
| 1685 | |
| 1686 | if (sym.get_st_type() == elfcpp::STT_SECTION) |
| 1687 | { |
| 1688 | lv.set_no_output_symtab_entry(); |
| 1689 | gold_assert(!lv.needs_output_dynsym_entry()); |
| 1690 | continue; |
| 1691 | } |
| 1692 | |
| 1693 | if (sym.get_st_name() >= strtab_size) |
| 1694 | { |
| 1695 | this->error(_("local symbol %u section name out of range: %u >= %u"), |
| 1696 | i, sym.get_st_name(), |
| 1697 | static_cast<unsigned int>(strtab_size)); |
| 1698 | lv.set_no_output_symtab_entry(); |
| 1699 | continue; |
| 1700 | } |
| 1701 | |
| 1702 | const char* name = pnames + sym.get_st_name(); |
| 1703 | |
| 1704 | // If needed, add the symbol to the dynamic symbol table string pool. |
| 1705 | if (lv.needs_output_dynsym_entry()) |
| 1706 | { |
| 1707 | dynpool->add(name, true, NULL); |
| 1708 | ++dyncount; |
| 1709 | } |
| 1710 | |
| 1711 | if (discard_all && lv.may_be_discarded_from_output_symtab()) |
| 1712 | { |
| 1713 | lv.set_no_output_symtab_entry(); |
| 1714 | continue; |
| 1715 | } |
| 1716 | |
| 1717 | // If --discard-locals option is used, discard all temporary local |
| 1718 | // symbols. These symbols start with system-specific local label |
| 1719 | // prefixes, typically .L for ELF system. We want to be compatible |
| 1720 | // with GNU ld so here we essentially use the same check in |
| 1721 | // bfd_is_local_label(). The code is different because we already |
| 1722 | // know that: |
| 1723 | // |
| 1724 | // - the symbol is local and thus cannot have global or weak binding. |
| 1725 | // - the symbol is not a section symbol. |
| 1726 | // - the symbol has a name. |
| 1727 | // |
| 1728 | // We do not discard a symbol if it needs a dynamic symbol entry. |
| 1729 | if (discard_locals |
| 1730 | && sym.get_st_type() != elfcpp::STT_FILE |
| 1731 | && !lv.needs_output_dynsym_entry() |
| 1732 | && lv.may_be_discarded_from_output_symtab() |
| 1733 | && parameters->target().is_local_label_name(name)) |
| 1734 | { |
| 1735 | lv.set_no_output_symtab_entry(); |
| 1736 | continue; |
| 1737 | } |
| 1738 | |
| 1739 | // Discard the local symbol if -retain_symbols_file is specified |
| 1740 | // and the local symbol is not in that file. |
| 1741 | if (!parameters->options().should_retain_symbol(name)) |
| 1742 | { |
| 1743 | lv.set_no_output_symtab_entry(); |
| 1744 | continue; |
| 1745 | } |
| 1746 | |
| 1747 | // Add the symbol to the symbol table string pool. |
| 1748 | pool->add(name, true, NULL); |
| 1749 | ++count; |
| 1750 | } |
| 1751 | |
| 1752 | this->output_local_symbol_count_ = count; |
| 1753 | this->output_local_dynsym_count_ = dyncount; |
| 1754 | } |
| 1755 | |
| 1756 | // Finalize the local symbols. Here we set the final value in |
| 1757 | // THIS->LOCAL_VALUES_ and set their output symbol table indexes. |
| 1758 | // This function is always called from a singleton thread. The actual |
| 1759 | // output of the local symbols will occur in a separate task. |
| 1760 | |
| 1761 | template<int size, bool big_endian> |
| 1762 | unsigned int |
| 1763 | Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index, |
| 1764 | off_t off, |
| 1765 | Symbol_table* symtab) |
| 1766 | { |
| 1767 | gold_assert(off == static_cast<off_t>(align_address(off, size >> 3))); |
| 1768 | |
| 1769 | const unsigned int loccount = this->local_symbol_count_; |
| 1770 | this->local_symbol_offset_ = off; |
| 1771 | |
| 1772 | const bool relocatable = parameters->options().relocatable(); |
| 1773 | const Output_sections& out_sections(this->output_sections()); |
| 1774 | const std::vector<Address>& out_offsets(this->section_offsets_); |
| 1775 | unsigned int shnum = this->shnum(); |
| 1776 | |
| 1777 | for (unsigned int i = 1; i < loccount; ++i) |
| 1778 | { |
| 1779 | Symbol_value<size>& lv(this->local_values_[i]); |
| 1780 | |
| 1781 | bool is_ordinary; |
| 1782 | unsigned int shndx = lv.input_shndx(&is_ordinary); |
| 1783 | |
| 1784 | // Set the output symbol value. |
| 1785 | |
| 1786 | if (!is_ordinary) |
| 1787 | { |
| 1788 | if (shndx == elfcpp::SHN_ABS || Symbol::is_common_shndx(shndx)) |
| 1789 | lv.set_output_value(lv.input_value()); |
| 1790 | else |
| 1791 | { |
| 1792 | this->error(_("unknown section index %u for local symbol %u"), |
| 1793 | shndx, i); |
| 1794 | lv.set_output_value(0); |
| 1795 | } |
| 1796 | } |
| 1797 | else |
| 1798 | { |
| 1799 | if (shndx >= shnum) |
| 1800 | { |
| 1801 | this->error(_("local symbol %u section index %u out of range"), |
| 1802 | i, shndx); |
| 1803 | shndx = 0; |
| 1804 | } |
| 1805 | |
| 1806 | Output_section* os = out_sections[shndx]; |
| 1807 | Address secoffset = out_offsets[shndx]; |
| 1808 | if (symtab->is_section_folded(this, shndx)) |
| 1809 | { |
| 1810 | gold_assert (os == NULL && secoffset == invalid_address); |
| 1811 | // Get the os of the section it is folded onto. |
| 1812 | Section_id folded = symtab->icf()->get_folded_section(this, |
| 1813 | shndx); |
| 1814 | gold_assert(folded.first != NULL); |
| 1815 | Sized_relobj<size, big_endian>* folded_obj = reinterpret_cast |
| 1816 | <Sized_relobj<size, big_endian>*>(folded.first); |
| 1817 | os = folded_obj->output_section(folded.second); |
| 1818 | gold_assert(os != NULL); |
| 1819 | secoffset = folded_obj->get_output_section_offset(folded.second); |
| 1820 | |
| 1821 | // This could be a relaxed input section. |
| 1822 | if (secoffset == invalid_address) |
| 1823 | { |
| 1824 | const Output_relaxed_input_section* relaxed_section = |
| 1825 | os->find_relaxed_input_section(folded_obj, folded.second); |
| 1826 | gold_assert(relaxed_section != NULL); |
| 1827 | secoffset = relaxed_section->address() - os->address(); |
| 1828 | } |
| 1829 | } |
| 1830 | |
| 1831 | if (os == NULL) |
| 1832 | { |
| 1833 | // This local symbol belongs to a section we are discarding. |
| 1834 | // In some cases when applying relocations later, we will |
| 1835 | // attempt to match it to the corresponding kept section, |
| 1836 | // so we leave the input value unchanged here. |
| 1837 | continue; |
| 1838 | } |
| 1839 | else if (secoffset == invalid_address) |
| 1840 | { |
| 1841 | uint64_t start; |
| 1842 | |
| 1843 | // This is a SHF_MERGE section or one which otherwise |
| 1844 | // requires special handling. |
| 1845 | if (shndx == this->discarded_eh_frame_shndx_) |
| 1846 | { |
| 1847 | // This local symbol belongs to a discarded .eh_frame |
| 1848 | // section. Just treat it like the case in which |
| 1849 | // os == NULL above. |
| 1850 | gold_assert(this->has_eh_frame_); |
| 1851 | continue; |
| 1852 | } |
| 1853 | else if (!lv.is_section_symbol()) |
| 1854 | { |
| 1855 | // This is not a section symbol. We can determine |
| 1856 | // the final value now. |
| 1857 | lv.set_output_value(os->output_address(this, shndx, |
| 1858 | lv.input_value())); |
| 1859 | } |
| 1860 | else if (!os->find_starting_output_address(this, shndx, &start)) |
| 1861 | { |
| 1862 | // This is a section symbol, but apparently not one in a |
| 1863 | // merged section. First check to see if this is a relaxed |
| 1864 | // input section. If so, use its address. Otherwise just |
| 1865 | // use the start of the output section. This happens with |
| 1866 | // relocatable links when the input object has section |
| 1867 | // symbols for arbitrary non-merge sections. |
| 1868 | const Output_section_data* posd = |
| 1869 | os->find_relaxed_input_section(this, shndx); |
| 1870 | if (posd != NULL) |
| 1871 | { |
| 1872 | Address relocatable_link_adjustment = |
| 1873 | relocatable ? os->address() : 0; |
| 1874 | lv.set_output_value(posd->address() |
| 1875 | - relocatable_link_adjustment); |
| 1876 | } |
| 1877 | else |
| 1878 | lv.set_output_value(os->address()); |
| 1879 | } |
| 1880 | else |
| 1881 | { |
| 1882 | // We have to consider the addend to determine the |
| 1883 | // value to use in a relocation. START is the start |
| 1884 | // of this input section. If we are doing a relocatable |
| 1885 | // link, use offset from start output section instead of |
| 1886 | // address. |
| 1887 | Address adjusted_start = |
| 1888 | relocatable ? start - os->address() : start; |
| 1889 | Merged_symbol_value<size>* msv = |
| 1890 | new Merged_symbol_value<size>(lv.input_value(), |
| 1891 | adjusted_start); |
| 1892 | lv.set_merged_symbol_value(msv); |
| 1893 | } |
| 1894 | } |
| 1895 | else if (lv.is_tls_symbol()) |
| 1896 | lv.set_output_value(os->tls_offset() |
| 1897 | + secoffset |
| 1898 | + lv.input_value()); |
| 1899 | else |
| 1900 | lv.set_output_value((relocatable ? 0 : os->address()) |
| 1901 | + secoffset |
| 1902 | + lv.input_value()); |
| 1903 | } |
| 1904 | |
| 1905 | if (!lv.is_output_symtab_index_set()) |
| 1906 | { |
| 1907 | lv.set_output_symtab_index(index); |
| 1908 | ++index; |
| 1909 | } |
| 1910 | } |
| 1911 | return index; |
| 1912 | } |
| 1913 | |
| 1914 | // Set the output dynamic symbol table indexes for the local variables. |
| 1915 | |
| 1916 | template<int size, bool big_endian> |
| 1917 | unsigned int |
| 1918 | Sized_relobj<size, big_endian>::do_set_local_dynsym_indexes(unsigned int index) |
| 1919 | { |
| 1920 | const unsigned int loccount = this->local_symbol_count_; |
| 1921 | for (unsigned int i = 1; i < loccount; ++i) |
| 1922 | { |
| 1923 | Symbol_value<size>& lv(this->local_values_[i]); |
| 1924 | if (lv.needs_output_dynsym_entry()) |
| 1925 | { |
| 1926 | lv.set_output_dynsym_index(index); |
| 1927 | ++index; |
| 1928 | } |
| 1929 | } |
| 1930 | return index; |
| 1931 | } |
| 1932 | |
| 1933 | // Set the offset where local dynamic symbol information will be stored. |
| 1934 | // Returns the count of local symbols contributed to the symbol table by |
| 1935 | // this object. |
| 1936 | |
| 1937 | template<int size, bool big_endian> |
| 1938 | unsigned int |
| 1939 | Sized_relobj<size, big_endian>::do_set_local_dynsym_offset(off_t off) |
| 1940 | { |
| 1941 | gold_assert(off == static_cast<off_t>(align_address(off, size >> 3))); |
| 1942 | this->local_dynsym_offset_ = off; |
| 1943 | return this->output_local_dynsym_count_; |
| 1944 | } |
| 1945 | |
| 1946 | // If Symbols_data is not NULL get the section flags from here otherwise |
| 1947 | // get it from the file. |
| 1948 | |
| 1949 | template<int size, bool big_endian> |
| 1950 | uint64_t |
| 1951 | Sized_relobj<size, big_endian>::do_section_flags(unsigned int shndx) |
| 1952 | { |
| 1953 | Symbols_data* sd = this->get_symbols_data(); |
| 1954 | if (sd != NULL) |
| 1955 | { |
| 1956 | const unsigned char* pshdrs = sd->section_headers_data |
| 1957 | + This::shdr_size * shndx; |
| 1958 | typename This::Shdr shdr(pshdrs); |
| 1959 | return shdr.get_sh_flags(); |
| 1960 | } |
| 1961 | // If sd is NULL, read the section header from the file. |
| 1962 | return this->elf_file_.section_flags(shndx); |
| 1963 | } |
| 1964 | |
| 1965 | // Get the section's ent size from Symbols_data. Called by get_section_contents |
| 1966 | // in icf.cc |
| 1967 | |
| 1968 | template<int size, bool big_endian> |
| 1969 | uint64_t |
| 1970 | Sized_relobj<size, big_endian>::do_section_entsize(unsigned int shndx) |
| 1971 | { |
| 1972 | Symbols_data* sd = this->get_symbols_data(); |
| 1973 | gold_assert (sd != NULL); |
| 1974 | |
| 1975 | const unsigned char* pshdrs = sd->section_headers_data |
| 1976 | + This::shdr_size * shndx; |
| 1977 | typename This::Shdr shdr(pshdrs); |
| 1978 | return shdr.get_sh_entsize(); |
| 1979 | } |
| 1980 | |
| 1981 | |
| 1982 | // Write out the local symbols. |
| 1983 | |
| 1984 | template<int size, bool big_endian> |
| 1985 | void |
| 1986 | Sized_relobj<size, big_endian>::write_local_symbols( |
| 1987 | Output_file* of, |
| 1988 | const Stringpool* sympool, |
| 1989 | const Stringpool* dynpool, |
| 1990 | Output_symtab_xindex* symtab_xindex, |
| 1991 | Output_symtab_xindex* dynsym_xindex) |
| 1992 | { |
| 1993 | const bool strip_all = parameters->options().strip_all(); |
| 1994 | if (strip_all) |
| 1995 | { |
| 1996 | if (this->output_local_dynsym_count_ == 0) |
| 1997 | return; |
| 1998 | this->output_local_symbol_count_ = 0; |
| 1999 | } |
| 2000 | |
| 2001 | gold_assert(this->symtab_shndx_ != -1U); |
| 2002 | if (this->symtab_shndx_ == 0) |
| 2003 | { |
| 2004 | // This object has no symbols. Weird but legal. |
| 2005 | return; |
| 2006 | } |
| 2007 | |
| 2008 | // Read the symbol table section header. |
| 2009 | const unsigned int symtab_shndx = this->symtab_shndx_; |
| 2010 | typename This::Shdr symtabshdr(this, |
| 2011 | this->elf_file_.section_header(symtab_shndx)); |
| 2012 | gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB); |
| 2013 | const unsigned int loccount = this->local_symbol_count_; |
| 2014 | gold_assert(loccount == symtabshdr.get_sh_info()); |
| 2015 | |
| 2016 | // Read the local symbols. |
| 2017 | const int sym_size = This::sym_size; |
| 2018 | off_t locsize = loccount * sym_size; |
| 2019 | const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(), |
| 2020 | locsize, true, false); |
| 2021 | |
| 2022 | // Read the symbol names. |
| 2023 | const unsigned int strtab_shndx = |
| 2024 | this->adjust_shndx(symtabshdr.get_sh_link()); |
| 2025 | section_size_type strtab_size; |
| 2026 | const unsigned char* pnamesu = this->section_contents(strtab_shndx, |
| 2027 | &strtab_size, |
| 2028 | false); |
| 2029 | const char* pnames = reinterpret_cast<const char*>(pnamesu); |
| 2030 | |
| 2031 | // Get views into the output file for the portions of the symbol table |
| 2032 | // and the dynamic symbol table that we will be writing. |
| 2033 | off_t output_size = this->output_local_symbol_count_ * sym_size; |
| 2034 | unsigned char* oview = NULL; |
| 2035 | if (output_size > 0) |
| 2036 | oview = of->get_output_view(this->local_symbol_offset_, output_size); |
| 2037 | |
| 2038 | off_t dyn_output_size = this->output_local_dynsym_count_ * sym_size; |
| 2039 | unsigned char* dyn_oview = NULL; |
| 2040 | if (dyn_output_size > 0) |
| 2041 | dyn_oview = of->get_output_view(this->local_dynsym_offset_, |
| 2042 | dyn_output_size); |
| 2043 | |
| 2044 | const Output_sections out_sections(this->output_sections()); |
| 2045 | |
| 2046 | gold_assert(this->local_values_.size() == loccount); |
| 2047 | |
| 2048 | unsigned char* ov = oview; |
| 2049 | unsigned char* dyn_ov = dyn_oview; |
| 2050 | psyms += sym_size; |
| 2051 | for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size) |
| 2052 | { |
| 2053 | elfcpp::Sym<size, big_endian> isym(psyms); |
| 2054 | |
| 2055 | Symbol_value<size>& lv(this->local_values_[i]); |
| 2056 | |
| 2057 | bool is_ordinary; |
| 2058 | unsigned int st_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(), |
| 2059 | &is_ordinary); |
| 2060 | if (is_ordinary) |
| 2061 | { |
| 2062 | gold_assert(st_shndx < out_sections.size()); |
| 2063 | if (out_sections[st_shndx] == NULL) |
| 2064 | continue; |
| 2065 | st_shndx = out_sections[st_shndx]->out_shndx(); |
| 2066 | if (st_shndx >= elfcpp::SHN_LORESERVE) |
| 2067 | { |
| 2068 | if (lv.has_output_symtab_entry()) |
| 2069 | symtab_xindex->add(lv.output_symtab_index(), st_shndx); |
| 2070 | if (lv.has_output_dynsym_entry()) |
| 2071 | dynsym_xindex->add(lv.output_dynsym_index(), st_shndx); |
| 2072 | st_shndx = elfcpp::SHN_XINDEX; |
| 2073 | } |
| 2074 | } |
| 2075 | |
| 2076 | // Write the symbol to the output symbol table. |
| 2077 | if (lv.has_output_symtab_entry()) |
| 2078 | { |
| 2079 | elfcpp::Sym_write<size, big_endian> osym(ov); |
| 2080 | |
| 2081 | gold_assert(isym.get_st_name() < strtab_size); |
| 2082 | const char* name = pnames + isym.get_st_name(); |
| 2083 | osym.put_st_name(sympool->get_offset(name)); |
| 2084 | osym.put_st_value(this->local_values_[i].value(this, 0)); |
| 2085 | osym.put_st_size(isym.get_st_size()); |
| 2086 | osym.put_st_info(isym.get_st_info()); |
| 2087 | osym.put_st_other(isym.get_st_other()); |
| 2088 | osym.put_st_shndx(st_shndx); |
| 2089 | |
| 2090 | ov += sym_size; |
| 2091 | } |
| 2092 | |
| 2093 | // Write the symbol to the output dynamic symbol table. |
| 2094 | if (lv.has_output_dynsym_entry()) |
| 2095 | { |
| 2096 | gold_assert(dyn_ov < dyn_oview + dyn_output_size); |
| 2097 | elfcpp::Sym_write<size, big_endian> osym(dyn_ov); |
| 2098 | |
| 2099 | gold_assert(isym.get_st_name() < strtab_size); |
| 2100 | const char* name = pnames + isym.get_st_name(); |
| 2101 | osym.put_st_name(dynpool->get_offset(name)); |
| 2102 | osym.put_st_value(this->local_values_[i].value(this, 0)); |
| 2103 | osym.put_st_size(isym.get_st_size()); |
| 2104 | osym.put_st_info(isym.get_st_info()); |
| 2105 | osym.put_st_other(isym.get_st_other()); |
| 2106 | osym.put_st_shndx(st_shndx); |
| 2107 | |
| 2108 | dyn_ov += sym_size; |
| 2109 | } |
| 2110 | } |
| 2111 | |
| 2112 | |
| 2113 | if (output_size > 0) |
| 2114 | { |
| 2115 | gold_assert(ov - oview == output_size); |
| 2116 | of->write_output_view(this->local_symbol_offset_, output_size, oview); |
| 2117 | } |
| 2118 | |
| 2119 | if (dyn_output_size > 0) |
| 2120 | { |
| 2121 | gold_assert(dyn_ov - dyn_oview == dyn_output_size); |
| 2122 | of->write_output_view(this->local_dynsym_offset_, dyn_output_size, |
| 2123 | dyn_oview); |
| 2124 | } |
| 2125 | } |
| 2126 | |
| 2127 | // Set *INFO to symbolic information about the offset OFFSET in the |
| 2128 | // section SHNDX. Return true if we found something, false if we |
| 2129 | // found nothing. |
| 2130 | |
| 2131 | template<int size, bool big_endian> |
| 2132 | bool |
| 2133 | Sized_relobj<size, big_endian>::get_symbol_location_info( |
| 2134 | unsigned int shndx, |
| 2135 | off_t offset, |
| 2136 | Symbol_location_info* info) |
| 2137 | { |
| 2138 | if (this->symtab_shndx_ == 0) |
| 2139 | return false; |
| 2140 | |
| 2141 | section_size_type symbols_size; |
| 2142 | const unsigned char* symbols = this->section_contents(this->symtab_shndx_, |
| 2143 | &symbols_size, |
| 2144 | false); |
| 2145 | |
| 2146 | unsigned int symbol_names_shndx = |
| 2147 | this->adjust_shndx(this->section_link(this->symtab_shndx_)); |
| 2148 | section_size_type names_size; |
| 2149 | const unsigned char* symbol_names_u = |
| 2150 | this->section_contents(symbol_names_shndx, &names_size, false); |
| 2151 | const char* symbol_names = reinterpret_cast<const char*>(symbol_names_u); |
| 2152 | |
| 2153 | const int sym_size = This::sym_size; |
| 2154 | const size_t count = symbols_size / sym_size; |
| 2155 | |
| 2156 | const unsigned char* p = symbols; |
| 2157 | for (size_t i = 0; i < count; ++i, p += sym_size) |
| 2158 | { |
| 2159 | elfcpp::Sym<size, big_endian> sym(p); |
| 2160 | |
| 2161 | if (sym.get_st_type() == elfcpp::STT_FILE) |
| 2162 | { |
| 2163 | if (sym.get_st_name() >= names_size) |
| 2164 | info->source_file = "(invalid)"; |
| 2165 | else |
| 2166 | info->source_file = symbol_names + sym.get_st_name(); |
| 2167 | continue; |
| 2168 | } |
| 2169 | |
| 2170 | bool is_ordinary; |
| 2171 | unsigned int st_shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(), |
| 2172 | &is_ordinary); |
| 2173 | if (is_ordinary |
| 2174 | && st_shndx == shndx |
| 2175 | && static_cast<off_t>(sym.get_st_value()) <= offset |
| 2176 | && (static_cast<off_t>(sym.get_st_value() + sym.get_st_size()) |
| 2177 | > offset)) |
| 2178 | { |
| 2179 | if (sym.get_st_name() > names_size) |
| 2180 | info->enclosing_symbol_name = "(invalid)"; |
| 2181 | else |
| 2182 | { |
| 2183 | info->enclosing_symbol_name = symbol_names + sym.get_st_name(); |
| 2184 | if (parameters->options().do_demangle()) |
| 2185 | { |
| 2186 | char* demangled_name = cplus_demangle( |
| 2187 | info->enclosing_symbol_name.c_str(), |
| 2188 | DMGL_ANSI | DMGL_PARAMS); |
| 2189 | if (demangled_name != NULL) |
| 2190 | { |
| 2191 | info->enclosing_symbol_name.assign(demangled_name); |
| 2192 | free(demangled_name); |
| 2193 | } |
| 2194 | } |
| 2195 | } |
| 2196 | return true; |
| 2197 | } |
| 2198 | } |
| 2199 | |
| 2200 | return false; |
| 2201 | } |
| 2202 | |
| 2203 | // Look for a kept section corresponding to the given discarded section, |
| 2204 | // and return its output address. This is used only for relocations in |
| 2205 | // debugging sections. If we can't find the kept section, return 0. |
| 2206 | |
| 2207 | template<int size, bool big_endian> |
| 2208 | typename Sized_relobj<size, big_endian>::Address |
| 2209 | Sized_relobj<size, big_endian>::map_to_kept_section( |
| 2210 | unsigned int shndx, |
| 2211 | bool* found) const |
| 2212 | { |
| 2213 | Relobj* kept_object; |
| 2214 | unsigned int kept_shndx; |
| 2215 | if (this->get_kept_comdat_section(shndx, &kept_object, &kept_shndx)) |
| 2216 | { |
| 2217 | Sized_relobj<size, big_endian>* kept_relobj = |
| 2218 | static_cast<Sized_relobj<size, big_endian>*>(kept_object); |
| 2219 | Output_section* os = kept_relobj->output_section(kept_shndx); |
| 2220 | Address offset = kept_relobj->get_output_section_offset(kept_shndx); |
| 2221 | if (os != NULL && offset != invalid_address) |
| 2222 | { |
| 2223 | *found = true; |
| 2224 | return os->address() + offset; |
| 2225 | } |
| 2226 | } |
| 2227 | *found = false; |
| 2228 | return 0; |
| 2229 | } |
| 2230 | |
| 2231 | // Get symbol counts. |
| 2232 | |
| 2233 | template<int size, bool big_endian> |
| 2234 | void |
| 2235 | Sized_relobj<size, big_endian>::do_get_global_symbol_counts( |
| 2236 | const Symbol_table*, |
| 2237 | size_t* defined, |
| 2238 | size_t* used) const |
| 2239 | { |
| 2240 | *defined = this->defined_count_; |
| 2241 | size_t count = 0; |
| 2242 | for (Symbols::const_iterator p = this->symbols_.begin(); |
| 2243 | p != this->symbols_.end(); |
| 2244 | ++p) |
| 2245 | if (*p != NULL |
| 2246 | && (*p)->source() == Symbol::FROM_OBJECT |
| 2247 | && (*p)->object() == this |
| 2248 | && (*p)->is_defined()) |
| 2249 | ++count; |
| 2250 | *used = count; |
| 2251 | } |
| 2252 | |
| 2253 | // Input_objects methods. |
| 2254 | |
| 2255 | // Add a regular relocatable object to the list. Return false if this |
| 2256 | // object should be ignored. |
| 2257 | |
| 2258 | bool |
| 2259 | Input_objects::add_object(Object* obj) |
| 2260 | { |
| 2261 | // Print the filename if the -t/--trace option is selected. |
| 2262 | if (parameters->options().trace()) |
| 2263 | gold_info("%s", obj->name().c_str()); |
| 2264 | |
| 2265 | if (!obj->is_dynamic()) |
| 2266 | this->relobj_list_.push_back(static_cast<Relobj*>(obj)); |
| 2267 | else |
| 2268 | { |
| 2269 | // See if this is a duplicate SONAME. |
| 2270 | Dynobj* dynobj = static_cast<Dynobj*>(obj); |
| 2271 | const char* soname = dynobj->soname(); |
| 2272 | |
| 2273 | std::pair<Unordered_set<std::string>::iterator, bool> ins = |
| 2274 | this->sonames_.insert(soname); |
| 2275 | if (!ins.second) |
| 2276 | { |
| 2277 | // We have already seen a dynamic object with this soname. |
| 2278 | return false; |
| 2279 | } |
| 2280 | |
| 2281 | this->dynobj_list_.push_back(dynobj); |
| 2282 | } |
| 2283 | |
| 2284 | // Add this object to the cross-referencer if requested. |
| 2285 | if (parameters->options().user_set_print_symbol_counts() |
| 2286 | || parameters->options().cref()) |
| 2287 | { |
| 2288 | if (this->cref_ == NULL) |
| 2289 | this->cref_ = new Cref(); |
| 2290 | this->cref_->add_object(obj); |
| 2291 | } |
| 2292 | |
| 2293 | return true; |
| 2294 | } |
| 2295 | |
| 2296 | // For each dynamic object, record whether we've seen all of its |
| 2297 | // explicit dependencies. |
| 2298 | |
| 2299 | void |
| 2300 | Input_objects::check_dynamic_dependencies() const |
| 2301 | { |
| 2302 | bool issued_copy_dt_needed_error = false; |
| 2303 | for (Dynobj_list::const_iterator p = this->dynobj_list_.begin(); |
| 2304 | p != this->dynobj_list_.end(); |
| 2305 | ++p) |
| 2306 | { |
| 2307 | const Dynobj::Needed& needed((*p)->needed()); |
| 2308 | bool found_all = true; |
| 2309 | Dynobj::Needed::const_iterator pneeded; |
| 2310 | for (pneeded = needed.begin(); pneeded != needed.end(); ++pneeded) |
| 2311 | { |
| 2312 | if (this->sonames_.find(*pneeded) == this->sonames_.end()) |
| 2313 | { |
| 2314 | found_all = false; |
| 2315 | break; |
| 2316 | } |
| 2317 | } |
| 2318 | (*p)->set_has_unknown_needed_entries(!found_all); |
| 2319 | |
| 2320 | // --copy-dt-needed-entries aka --add-needed is a GNU ld option |
| 2321 | // that gold does not support. However, they cause no trouble |
| 2322 | // unless there is a DT_NEEDED entry that we don't know about; |
| 2323 | // warn only in that case. |
| 2324 | if (!found_all |
| 2325 | && !issued_copy_dt_needed_error |
| 2326 | && (parameters->options().copy_dt_needed_entries() |
| 2327 | || parameters->options().add_needed())) |
| 2328 | { |
| 2329 | const char* optname; |
| 2330 | if (parameters->options().copy_dt_needed_entries()) |
| 2331 | optname = "--copy-dt-needed-entries"; |
| 2332 | else |
| 2333 | optname = "--add-needed"; |
| 2334 | gold_error(_("%s is not supported but is required for %s in %s"), |
| 2335 | optname, (*pneeded).c_str(), (*p)->name().c_str()); |
| 2336 | issued_copy_dt_needed_error = true; |
| 2337 | } |
| 2338 | } |
| 2339 | } |
| 2340 | |
| 2341 | // Start processing an archive. |
| 2342 | |
| 2343 | void |
| 2344 | Input_objects::archive_start(Archive* archive) |
| 2345 | { |
| 2346 | if (parameters->options().user_set_print_symbol_counts() |
| 2347 | || parameters->options().cref()) |
| 2348 | { |
| 2349 | if (this->cref_ == NULL) |
| 2350 | this->cref_ = new Cref(); |
| 2351 | this->cref_->add_archive_start(archive); |
| 2352 | } |
| 2353 | } |
| 2354 | |
| 2355 | // Stop processing an archive. |
| 2356 | |
| 2357 | void |
| 2358 | Input_objects::archive_stop(Archive* archive) |
| 2359 | { |
| 2360 | if (parameters->options().user_set_print_symbol_counts() |
| 2361 | || parameters->options().cref()) |
| 2362 | this->cref_->add_archive_stop(archive); |
| 2363 | } |
| 2364 | |
| 2365 | // Print symbol counts |
| 2366 | |
| 2367 | void |
| 2368 | Input_objects::print_symbol_counts(const Symbol_table* symtab) const |
| 2369 | { |
| 2370 | if (parameters->options().user_set_print_symbol_counts() |
| 2371 | && this->cref_ != NULL) |
| 2372 | this->cref_->print_symbol_counts(symtab); |
| 2373 | } |
| 2374 | |
| 2375 | // Print a cross reference table. |
| 2376 | |
| 2377 | void |
| 2378 | Input_objects::print_cref(const Symbol_table* symtab, FILE* f) const |
| 2379 | { |
| 2380 | if (parameters->options().cref() && this->cref_ != NULL) |
| 2381 | this->cref_->print_cref(symtab, f); |
| 2382 | } |
| 2383 | |
| 2384 | // Relocate_info methods. |
| 2385 | |
| 2386 | // Return a string describing the location of a relocation. This is |
| 2387 | // only used in error messages. |
| 2388 | |
| 2389 | template<int size, bool big_endian> |
| 2390 | std::string |
| 2391 | Relocate_info<size, big_endian>::location(size_t, off_t offset) const |
| 2392 | { |
| 2393 | // See if we can get line-number information from debugging sections. |
| 2394 | std::string filename; |
| 2395 | std::string file_and_lineno; // Better than filename-only, if available. |
| 2396 | |
| 2397 | Sized_dwarf_line_info<size, big_endian> line_info(this->object); |
| 2398 | // This will be "" if we failed to parse the debug info for any reason. |
| 2399 | file_and_lineno = line_info.addr2line(this->data_shndx, offset); |
| 2400 | |
| 2401 | std::string ret(this->object->name()); |
| 2402 | ret += ':'; |
| 2403 | Symbol_location_info info; |
| 2404 | if (this->object->get_symbol_location_info(this->data_shndx, offset, &info)) |
| 2405 | { |
| 2406 | ret += " in function "; |
| 2407 | ret += info.enclosing_symbol_name; |
| 2408 | ret += ":"; |
| 2409 | filename = info.source_file; |
| 2410 | } |
| 2411 | |
| 2412 | if (!file_and_lineno.empty()) |
| 2413 | ret += file_and_lineno; |
| 2414 | else |
| 2415 | { |
| 2416 | if (!filename.empty()) |
| 2417 | ret += filename; |
| 2418 | ret += "("; |
| 2419 | ret += this->object->section_name(this->data_shndx); |
| 2420 | char buf[100]; |
| 2421 | // Offsets into sections have to be positive. |
| 2422 | snprintf(buf, sizeof(buf), "+0x%lx", static_cast<long>(offset)); |
| 2423 | ret += buf; |
| 2424 | ret += ")"; |
| 2425 | } |
| 2426 | return ret; |
| 2427 | } |
| 2428 | |
| 2429 | } // End namespace gold. |
| 2430 | |
| 2431 | namespace |
| 2432 | { |
| 2433 | |
| 2434 | using namespace gold; |
| 2435 | |
| 2436 | // Read an ELF file with the header and return the appropriate |
| 2437 | // instance of Object. |
| 2438 | |
| 2439 | template<int size, bool big_endian> |
| 2440 | Object* |
| 2441 | make_elf_sized_object(const std::string& name, Input_file* input_file, |
| 2442 | off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr, |
| 2443 | bool* punconfigured) |
| 2444 | { |
| 2445 | Target* target = select_target(ehdr.get_e_machine(), size, big_endian, |
| 2446 | ehdr.get_e_ident()[elfcpp::EI_OSABI], |
| 2447 | ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]); |
| 2448 | if (target == NULL) |
| 2449 | gold_fatal(_("%s: unsupported ELF machine number %d"), |
| 2450 | name.c_str(), ehdr.get_e_machine()); |
| 2451 | |
| 2452 | if (!parameters->target_valid()) |
| 2453 | set_parameters_target(target); |
| 2454 | else if (target != ¶meters->target()) |
| 2455 | { |
| 2456 | if (punconfigured != NULL) |
| 2457 | *punconfigured = true; |
| 2458 | else |
| 2459 | gold_error(_("%s: incompatible target"), name.c_str()); |
| 2460 | return NULL; |
| 2461 | } |
| 2462 | |
| 2463 | return target->make_elf_object<size, big_endian>(name, input_file, offset, |
| 2464 | ehdr); |
| 2465 | } |
| 2466 | |
| 2467 | } // End anonymous namespace. |
| 2468 | |
| 2469 | namespace gold |
| 2470 | { |
| 2471 | |
| 2472 | // Return whether INPUT_FILE is an ELF object. |
| 2473 | |
| 2474 | bool |
| 2475 | is_elf_object(Input_file* input_file, off_t offset, |
| 2476 | const unsigned char** start, int *read_size) |
| 2477 | { |
| 2478 | off_t filesize = input_file->file().filesize(); |
| 2479 | int want = elfcpp::Elf_recognizer::max_header_size; |
| 2480 | if (filesize - offset < want) |
| 2481 | want = filesize - offset; |
| 2482 | |
| 2483 | const unsigned char* p = input_file->file().get_view(offset, 0, want, |
| 2484 | true, false); |
| 2485 | *start = p; |
| 2486 | *read_size = want; |
| 2487 | |
| 2488 | return elfcpp::Elf_recognizer::is_elf_file(p, want); |
| 2489 | } |
| 2490 | |
| 2491 | // Read an ELF file and return the appropriate instance of Object. |
| 2492 | |
| 2493 | Object* |
| 2494 | make_elf_object(const std::string& name, Input_file* input_file, off_t offset, |
| 2495 | const unsigned char* p, section_offset_type bytes, |
| 2496 | bool* punconfigured) |
| 2497 | { |
| 2498 | if (punconfigured != NULL) |
| 2499 | *punconfigured = false; |
| 2500 | |
| 2501 | std::string error; |
| 2502 | bool big_endian = false; |
| 2503 | int size = 0; |
| 2504 | if (!elfcpp::Elf_recognizer::is_valid_header(p, bytes, &size, |
| 2505 | &big_endian, &error)) |
| 2506 | { |
| 2507 | gold_error(_("%s: %s"), name.c_str(), error.c_str()); |
| 2508 | return NULL; |
| 2509 | } |
| 2510 | |
| 2511 | if (size == 32) |
| 2512 | { |
| 2513 | if (big_endian) |
| 2514 | { |
| 2515 | #ifdef HAVE_TARGET_32_BIG |
| 2516 | elfcpp::Ehdr<32, true> ehdr(p); |
| 2517 | return make_elf_sized_object<32, true>(name, input_file, |
| 2518 | offset, ehdr, punconfigured); |
| 2519 | #else |
| 2520 | if (punconfigured != NULL) |
| 2521 | *punconfigured = true; |
| 2522 | else |
| 2523 | gold_error(_("%s: not configured to support " |
| 2524 | "32-bit big-endian object"), |
| 2525 | name.c_str()); |
| 2526 | return NULL; |
| 2527 | #endif |
| 2528 | } |
| 2529 | else |
| 2530 | { |
| 2531 | #ifdef HAVE_TARGET_32_LITTLE |
| 2532 | elfcpp::Ehdr<32, false> ehdr(p); |
| 2533 | return make_elf_sized_object<32, false>(name, input_file, |
| 2534 | offset, ehdr, punconfigured); |
| 2535 | #else |
| 2536 | if (punconfigured != NULL) |
| 2537 | *punconfigured = true; |
| 2538 | else |
| 2539 | gold_error(_("%s: not configured to support " |
| 2540 | "32-bit little-endian object"), |
| 2541 | name.c_str()); |
| 2542 | return NULL; |
| 2543 | #endif |
| 2544 | } |
| 2545 | } |
| 2546 | else if (size == 64) |
| 2547 | { |
| 2548 | if (big_endian) |
| 2549 | { |
| 2550 | #ifdef HAVE_TARGET_64_BIG |
| 2551 | elfcpp::Ehdr<64, true> ehdr(p); |
| 2552 | return make_elf_sized_object<64, true>(name, input_file, |
| 2553 | offset, ehdr, punconfigured); |
| 2554 | #else |
| 2555 | if (punconfigured != NULL) |
| 2556 | *punconfigured = true; |
| 2557 | else |
| 2558 | gold_error(_("%s: not configured to support " |
| 2559 | "64-bit big-endian object"), |
| 2560 | name.c_str()); |
| 2561 | return NULL; |
| 2562 | #endif |
| 2563 | } |
| 2564 | else |
| 2565 | { |
| 2566 | #ifdef HAVE_TARGET_64_LITTLE |
| 2567 | elfcpp::Ehdr<64, false> ehdr(p); |
| 2568 | return make_elf_sized_object<64, false>(name, input_file, |
| 2569 | offset, ehdr, punconfigured); |
| 2570 | #else |
| 2571 | if (punconfigured != NULL) |
| 2572 | *punconfigured = true; |
| 2573 | else |
| 2574 | gold_error(_("%s: not configured to support " |
| 2575 | "64-bit little-endian object"), |
| 2576 | name.c_str()); |
| 2577 | return NULL; |
| 2578 | #endif |
| 2579 | } |
| 2580 | } |
| 2581 | else |
| 2582 | gold_unreachable(); |
| 2583 | } |
| 2584 | |
| 2585 | // Instantiate the templates we need. |
| 2586 | |
| 2587 | #ifdef HAVE_TARGET_32_LITTLE |
| 2588 | template |
| 2589 | void |
| 2590 | Object::read_section_data<32, false>(elfcpp::Elf_file<32, false, Object>*, |
| 2591 | Read_symbols_data*); |
| 2592 | #endif |
| 2593 | |
| 2594 | #ifdef HAVE_TARGET_32_BIG |
| 2595 | template |
| 2596 | void |
| 2597 | Object::read_section_data<32, true>(elfcpp::Elf_file<32, true, Object>*, |
| 2598 | Read_symbols_data*); |
| 2599 | #endif |
| 2600 | |
| 2601 | #ifdef HAVE_TARGET_64_LITTLE |
| 2602 | template |
| 2603 | void |
| 2604 | Object::read_section_data<64, false>(elfcpp::Elf_file<64, false, Object>*, |
| 2605 | Read_symbols_data*); |
| 2606 | #endif |
| 2607 | |
| 2608 | #ifdef HAVE_TARGET_64_BIG |
| 2609 | template |
| 2610 | void |
| 2611 | Object::read_section_data<64, true>(elfcpp::Elf_file<64, true, Object>*, |
| 2612 | Read_symbols_data*); |
| 2613 | #endif |
| 2614 | |
| 2615 | #ifdef HAVE_TARGET_32_LITTLE |
| 2616 | template |
| 2617 | class Sized_relobj<32, false>; |
| 2618 | #endif |
| 2619 | |
| 2620 | #ifdef HAVE_TARGET_32_BIG |
| 2621 | template |
| 2622 | class Sized_relobj<32, true>; |
| 2623 | #endif |
| 2624 | |
| 2625 | #ifdef HAVE_TARGET_64_LITTLE |
| 2626 | template |
| 2627 | class Sized_relobj<64, false>; |
| 2628 | #endif |
| 2629 | |
| 2630 | #ifdef HAVE_TARGET_64_BIG |
| 2631 | template |
| 2632 | class Sized_relobj<64, true>; |
| 2633 | #endif |
| 2634 | |
| 2635 | #ifdef HAVE_TARGET_32_LITTLE |
| 2636 | template |
| 2637 | struct Relocate_info<32, false>; |
| 2638 | #endif |
| 2639 | |
| 2640 | #ifdef HAVE_TARGET_32_BIG |
| 2641 | template |
| 2642 | struct Relocate_info<32, true>; |
| 2643 | #endif |
| 2644 | |
| 2645 | #ifdef HAVE_TARGET_64_LITTLE |
| 2646 | template |
| 2647 | struct Relocate_info<64, false>; |
| 2648 | #endif |
| 2649 | |
| 2650 | #ifdef HAVE_TARGET_64_BIG |
| 2651 | template |
| 2652 | struct Relocate_info<64, true>; |
| 2653 | #endif |
| 2654 | |
| 2655 | #ifdef HAVE_TARGET_32_LITTLE |
| 2656 | template |
| 2657 | void |
| 2658 | Xindex::initialize_symtab_xindex<32, false>(Object*, unsigned int); |
| 2659 | |
| 2660 | template |
| 2661 | void |
| 2662 | Xindex::read_symtab_xindex<32, false>(Object*, unsigned int, |
| 2663 | const unsigned char*); |
| 2664 | #endif |
| 2665 | |
| 2666 | #ifdef HAVE_TARGET_32_BIG |
| 2667 | template |
| 2668 | void |
| 2669 | Xindex::initialize_symtab_xindex<32, true>(Object*, unsigned int); |
| 2670 | |
| 2671 | template |
| 2672 | void |
| 2673 | Xindex::read_symtab_xindex<32, true>(Object*, unsigned int, |
| 2674 | const unsigned char*); |
| 2675 | #endif |
| 2676 | |
| 2677 | #ifdef HAVE_TARGET_64_LITTLE |
| 2678 | template |
| 2679 | void |
| 2680 | Xindex::initialize_symtab_xindex<64, false>(Object*, unsigned int); |
| 2681 | |
| 2682 | template |
| 2683 | void |
| 2684 | Xindex::read_symtab_xindex<64, false>(Object*, unsigned int, |
| 2685 | const unsigned char*); |
| 2686 | #endif |
| 2687 | |
| 2688 | #ifdef HAVE_TARGET_64_BIG |
| 2689 | template |
| 2690 | void |
| 2691 | Xindex::initialize_symtab_xindex<64, true>(Object*, unsigned int); |
| 2692 | |
| 2693 | template |
| 2694 | void |
| 2695 | Xindex::read_symtab_xindex<64, true>(Object*, unsigned int, |
| 2696 | const unsigned char*); |
| 2697 | #endif |
| 2698 | |
| 2699 | } // End namespace gold. |