| 1 | // object.h -- support for an object file for linking in gold -*- C++ -*- |
| 2 | |
| 3 | // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc. |
| 4 | // Written by Ian Lance Taylor <iant@google.com>. |
| 5 | |
| 6 | // This file is part of gold. |
| 7 | |
| 8 | // This program is free software; you can redistribute it and/or modify |
| 9 | // it under the terms of the GNU General Public License as published by |
| 10 | // the Free Software Foundation; either version 3 of the License, or |
| 11 | // (at your option) any later version. |
| 12 | |
| 13 | // This program is distributed in the hope that it will be useful, |
| 14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | // GNU General Public License for more details. |
| 17 | |
| 18 | // You should have received a copy of the GNU General Public License |
| 19 | // along with this program; if not, write to the Free Software |
| 20 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| 21 | // MA 02110-1301, USA. |
| 22 | |
| 23 | #ifndef GOLD_OBJECT_H |
| 24 | #define GOLD_OBJECT_H |
| 25 | |
| 26 | #include <string> |
| 27 | #include <vector> |
| 28 | |
| 29 | #include "elfcpp.h" |
| 30 | #include "elfcpp_file.h" |
| 31 | #include "fileread.h" |
| 32 | #include "target.h" |
| 33 | |
| 34 | namespace gold |
| 35 | { |
| 36 | |
| 37 | class General_options; |
| 38 | class Task; |
| 39 | class Cref; |
| 40 | class Archive; |
| 41 | class Layout; |
| 42 | class Output_section; |
| 43 | class Output_file; |
| 44 | class Output_symtab_xindex; |
| 45 | class Pluginobj; |
| 46 | class Dynobj; |
| 47 | class Object_merge_map; |
| 48 | class Relocatable_relocs; |
| 49 | class Symbols_data; |
| 50 | |
| 51 | template<typename Stringpool_char> |
| 52 | class Stringpool_template; |
| 53 | |
| 54 | // Data to pass from read_symbols() to add_symbols(). |
| 55 | |
| 56 | struct Read_symbols_data |
| 57 | { |
| 58 | // Section headers. |
| 59 | File_view* section_headers; |
| 60 | // Section names. |
| 61 | File_view* section_names; |
| 62 | // Size of section name data in bytes. |
| 63 | section_size_type section_names_size; |
| 64 | // Symbol data. |
| 65 | File_view* symbols; |
| 66 | // Size of symbol data in bytes. |
| 67 | section_size_type symbols_size; |
| 68 | // Offset of external symbols within symbol data. This structure |
| 69 | // sometimes contains only external symbols, in which case this will |
| 70 | // be zero. Sometimes it contains all symbols. |
| 71 | section_offset_type external_symbols_offset; |
| 72 | // Symbol names. |
| 73 | File_view* symbol_names; |
| 74 | // Size of symbol name data in bytes. |
| 75 | section_size_type symbol_names_size; |
| 76 | |
| 77 | // Version information. This is only used on dynamic objects. |
| 78 | // Version symbol data (from SHT_GNU_versym section). |
| 79 | File_view* versym; |
| 80 | section_size_type versym_size; |
| 81 | // Version definition data (from SHT_GNU_verdef section). |
| 82 | File_view* verdef; |
| 83 | section_size_type verdef_size; |
| 84 | unsigned int verdef_info; |
| 85 | // Needed version data (from SHT_GNU_verneed section). |
| 86 | File_view* verneed; |
| 87 | section_size_type verneed_size; |
| 88 | unsigned int verneed_info; |
| 89 | }; |
| 90 | |
| 91 | // Information used to print error messages. |
| 92 | |
| 93 | struct Symbol_location_info |
| 94 | { |
| 95 | std::string source_file; |
| 96 | std::string enclosing_symbol_name; |
| 97 | int line_number; |
| 98 | }; |
| 99 | |
| 100 | // Data about a single relocation section. This is read in |
| 101 | // read_relocs and processed in scan_relocs. |
| 102 | |
| 103 | struct Section_relocs |
| 104 | { |
| 105 | // Index of reloc section. |
| 106 | unsigned int reloc_shndx; |
| 107 | // Index of section that relocs apply to. |
| 108 | unsigned int data_shndx; |
| 109 | // Contents of reloc section. |
| 110 | File_view* contents; |
| 111 | // Reloc section type. |
| 112 | unsigned int sh_type; |
| 113 | // Number of reloc entries. |
| 114 | size_t reloc_count; |
| 115 | // Output section. |
| 116 | Output_section* output_section; |
| 117 | // Whether this section has special handling for offsets. |
| 118 | bool needs_special_offset_handling; |
| 119 | // Whether the data section is allocated (has the SHF_ALLOC flag set). |
| 120 | bool is_data_section_allocated; |
| 121 | }; |
| 122 | |
| 123 | // Relocations in an object file. This is read in read_relocs and |
| 124 | // processed in scan_relocs. |
| 125 | |
| 126 | struct Read_relocs_data |
| 127 | { |
| 128 | typedef std::vector<Section_relocs> Relocs_list; |
| 129 | // The relocations. |
| 130 | Relocs_list relocs; |
| 131 | // The local symbols. |
| 132 | File_view* local_symbols; |
| 133 | }; |
| 134 | |
| 135 | // The Xindex class manages section indexes for objects with more than |
| 136 | // 0xff00 sections. |
| 137 | |
| 138 | class Xindex |
| 139 | { |
| 140 | public: |
| 141 | Xindex(int large_shndx_offset) |
| 142 | : large_shndx_offset_(large_shndx_offset), symtab_xindex_() |
| 143 | { } |
| 144 | |
| 145 | // Initialize the symtab_xindex_ array, given the object and the |
| 146 | // section index of the symbol table to use. |
| 147 | template<int size, bool big_endian> |
| 148 | void |
| 149 | initialize_symtab_xindex(Object*, unsigned int symtab_shndx); |
| 150 | |
| 151 | // Read in the symtab_xindex_ array, given its section index. |
| 152 | // PSHDRS may optionally point to the section headers. |
| 153 | template<int size, bool big_endian> |
| 154 | void |
| 155 | read_symtab_xindex(Object*, unsigned int xindex_shndx, |
| 156 | const unsigned char* pshdrs); |
| 157 | |
| 158 | // Symbol SYMNDX in OBJECT has a section of SHN_XINDEX; return the |
| 159 | // real section index. |
| 160 | unsigned int |
| 161 | sym_xindex_to_shndx(Object* object, unsigned int symndx); |
| 162 | |
| 163 | private: |
| 164 | // The type of the array giving the real section index for symbols |
| 165 | // whose st_shndx field holds SHN_XINDEX. |
| 166 | typedef std::vector<unsigned int> Symtab_xindex; |
| 167 | |
| 168 | // Adjust a section index if necessary. This should only be called |
| 169 | // for ordinary section indexes. |
| 170 | unsigned int |
| 171 | adjust_shndx(unsigned int shndx) |
| 172 | { |
| 173 | if (shndx >= elfcpp::SHN_LORESERVE) |
| 174 | shndx += this->large_shndx_offset_; |
| 175 | return shndx; |
| 176 | } |
| 177 | |
| 178 | // Adjust to apply to large section indexes. |
| 179 | int large_shndx_offset_; |
| 180 | // The data from the SHT_SYMTAB_SHNDX section. |
| 181 | Symtab_xindex symtab_xindex_; |
| 182 | }; |
| 183 | |
| 184 | // Object is an abstract base class which represents either a 32-bit |
| 185 | // or a 64-bit input object. This can be a regular object file |
| 186 | // (ET_REL) or a shared object (ET_DYN). |
| 187 | |
| 188 | class Object |
| 189 | { |
| 190 | public: |
| 191 | // NAME is the name of the object as we would report it to the user |
| 192 | // (e.g., libfoo.a(bar.o) if this is in an archive. INPUT_FILE is |
| 193 | // used to read the file. OFFSET is the offset within the input |
| 194 | // file--0 for a .o or .so file, something else for a .a file. |
| 195 | Object(const std::string& name, Input_file* input_file, bool is_dynamic, |
| 196 | off_t offset = 0) |
| 197 | : name_(name), input_file_(input_file), offset_(offset), shnum_(-1U), |
| 198 | is_dynamic_(is_dynamic), target_(NULL), xindex_(NULL) |
| 199 | { input_file->file().add_object(); } |
| 200 | |
| 201 | virtual ~Object() |
| 202 | { this->input_file_->file().remove_object(); } |
| 203 | |
| 204 | // Return the name of the object as we would report it to the tuser. |
| 205 | const std::string& |
| 206 | name() const |
| 207 | { return this->name_; } |
| 208 | |
| 209 | // Get the offset into the file. |
| 210 | off_t |
| 211 | offset() const |
| 212 | { return this->offset_; } |
| 213 | |
| 214 | // Return whether this is a dynamic object. |
| 215 | bool |
| 216 | is_dynamic() const |
| 217 | { return this->is_dynamic_; } |
| 218 | |
| 219 | // Returns NULL for Objects that are not plugin objects. This method |
| 220 | // is overridden in the Pluginobj class. |
| 221 | Pluginobj* |
| 222 | pluginobj() |
| 223 | { return this->do_pluginobj(); } |
| 224 | |
| 225 | // Return the target structure associated with this object. |
| 226 | Target* |
| 227 | target() const |
| 228 | { return this->target_; } |
| 229 | |
| 230 | // Get the file. We pass on const-ness. |
| 231 | Input_file* |
| 232 | input_file() |
| 233 | { return this->input_file_; } |
| 234 | |
| 235 | const Input_file* |
| 236 | input_file() const |
| 237 | { return this->input_file_; } |
| 238 | |
| 239 | // Lock the underlying file. |
| 240 | void |
| 241 | lock(const Task* t) |
| 242 | { this->input_file()->file().lock(t); } |
| 243 | |
| 244 | // Unlock the underlying file. |
| 245 | void |
| 246 | unlock(const Task* t) |
| 247 | { this->input_file()->file().unlock(t); } |
| 248 | |
| 249 | // Return whether the underlying file is locked. |
| 250 | bool |
| 251 | is_locked() const |
| 252 | { return this->input_file()->file().is_locked(); } |
| 253 | |
| 254 | // Return the token, so that the task can be queued. |
| 255 | Task_token* |
| 256 | token() |
| 257 | { return this->input_file()->file().token(); } |
| 258 | |
| 259 | // Release the underlying file. |
| 260 | void |
| 261 | release() |
| 262 | { this->input_file_->file().release(); } |
| 263 | |
| 264 | // Return whether we should just read symbols from this file. |
| 265 | bool |
| 266 | just_symbols() const |
| 267 | { return this->input_file()->just_symbols(); } |
| 268 | |
| 269 | // Return the sized target structure associated with this object. |
| 270 | // This is like the target method but it returns a pointer of |
| 271 | // appropriate checked type. |
| 272 | template<int size, bool big_endian> |
| 273 | Sized_target<size, big_endian>* |
| 274 | sized_target() const; |
| 275 | |
| 276 | // Get the number of sections. |
| 277 | unsigned int |
| 278 | shnum() const |
| 279 | { return this->shnum_; } |
| 280 | |
| 281 | // Return a view of the contents of a section. Set *PLEN to the |
| 282 | // size. CACHE is a hint as in File_read::get_view. |
| 283 | const unsigned char* |
| 284 | section_contents(unsigned int shndx, section_size_type* plen, bool cache); |
| 285 | |
| 286 | // Adjust a symbol's section index as needed. SYMNDX is the index |
| 287 | // of the symbol and SHNDX is the symbol's section from |
| 288 | // get_st_shndx. This returns the section index. It sets |
| 289 | // *IS_ORDINARY to indicate whether this is a normal section index, |
| 290 | // rather than a special code between SHN_LORESERVE and |
| 291 | // SHN_HIRESERVE. |
| 292 | unsigned int |
| 293 | adjust_sym_shndx(unsigned int symndx, unsigned int shndx, bool* is_ordinary) |
| 294 | { |
| 295 | if (shndx < elfcpp::SHN_LORESERVE) |
| 296 | *is_ordinary = true; |
| 297 | else if (shndx == elfcpp::SHN_XINDEX) |
| 298 | { |
| 299 | if (this->xindex_ == NULL) |
| 300 | this->xindex_ = this->do_initialize_xindex(); |
| 301 | shndx = this->xindex_->sym_xindex_to_shndx(this, symndx); |
| 302 | *is_ordinary = true; |
| 303 | } |
| 304 | else |
| 305 | *is_ordinary = false; |
| 306 | return shndx; |
| 307 | } |
| 308 | |
| 309 | // Return the size of a section given a section index. |
| 310 | uint64_t |
| 311 | section_size(unsigned int shndx) |
| 312 | { return this->do_section_size(shndx); } |
| 313 | |
| 314 | // Return the name of a section given a section index. |
| 315 | std::string |
| 316 | section_name(unsigned int shndx) |
| 317 | { return this->do_section_name(shndx); } |
| 318 | |
| 319 | // Return the section flags given a section index. |
| 320 | uint64_t |
| 321 | section_flags(unsigned int shndx) |
| 322 | { return this->do_section_flags(shndx); } |
| 323 | |
| 324 | // Return the section address given a section index. |
| 325 | uint64_t |
| 326 | section_address(unsigned int shndx) |
| 327 | { return this->do_section_address(shndx); } |
| 328 | |
| 329 | // Return the section type given a section index. |
| 330 | unsigned int |
| 331 | section_type(unsigned int shndx) |
| 332 | { return this->do_section_type(shndx); } |
| 333 | |
| 334 | // Return the section link field given a section index. |
| 335 | unsigned int |
| 336 | section_link(unsigned int shndx) |
| 337 | { return this->do_section_link(shndx); } |
| 338 | |
| 339 | // Return the section info field given a section index. |
| 340 | unsigned int |
| 341 | section_info(unsigned int shndx) |
| 342 | { return this->do_section_info(shndx); } |
| 343 | |
| 344 | // Return the required section alignment given a section index. |
| 345 | uint64_t |
| 346 | section_addralign(unsigned int shndx) |
| 347 | { return this->do_section_addralign(shndx); } |
| 348 | |
| 349 | // Read the symbol information. |
| 350 | void |
| 351 | read_symbols(Read_symbols_data* sd) |
| 352 | { return this->do_read_symbols(sd); } |
| 353 | |
| 354 | // Pass sections which should be included in the link to the Layout |
| 355 | // object, and record where the sections go in the output file. |
| 356 | void |
| 357 | layout(Symbol_table* symtab, Layout* layout, Read_symbols_data* sd) |
| 358 | { this->do_layout(symtab, layout, sd); } |
| 359 | |
| 360 | // Add symbol information to the global symbol table. |
| 361 | void |
| 362 | add_symbols(Symbol_table* symtab, Read_symbols_data* sd, Layout *layout) |
| 363 | { this->do_add_symbols(symtab, sd, layout); } |
| 364 | |
| 365 | // Functions and types for the elfcpp::Elf_file interface. This |
| 366 | // permit us to use Object as the File template parameter for |
| 367 | // elfcpp::Elf_file. |
| 368 | |
| 369 | // The View class is returned by view. It must support a single |
| 370 | // method, data(). This is trivial, because get_view does what we |
| 371 | // need. |
| 372 | class View |
| 373 | { |
| 374 | public: |
| 375 | View(const unsigned char* p) |
| 376 | : p_(p) |
| 377 | { } |
| 378 | |
| 379 | const unsigned char* |
| 380 | data() const |
| 381 | { return this->p_; } |
| 382 | |
| 383 | private: |
| 384 | const unsigned char* p_; |
| 385 | }; |
| 386 | |
| 387 | // Return a View. |
| 388 | View |
| 389 | view(off_t file_offset, section_size_type data_size) |
| 390 | { return View(this->get_view(file_offset, data_size, true, true)); } |
| 391 | |
| 392 | // Report an error. |
| 393 | void |
| 394 | error(const char* format, ...) const ATTRIBUTE_PRINTF_2; |
| 395 | |
| 396 | // A location in the file. |
| 397 | struct Location |
| 398 | { |
| 399 | off_t file_offset; |
| 400 | off_t data_size; |
| 401 | |
| 402 | Location(off_t fo, section_size_type ds) |
| 403 | : file_offset(fo), data_size(ds) |
| 404 | { } |
| 405 | }; |
| 406 | |
| 407 | // Get a View given a Location. |
| 408 | View view(Location loc) |
| 409 | { return View(this->get_view(loc.file_offset, loc.data_size, true, true)); } |
| 410 | |
| 411 | // Get a view into the underlying file. |
| 412 | const unsigned char* |
| 413 | get_view(off_t start, section_size_type size, bool aligned, bool cache) |
| 414 | { |
| 415 | return this->input_file()->file().get_view(this->offset_, start, size, |
| 416 | aligned, cache); |
| 417 | } |
| 418 | |
| 419 | // Get a lasting view into the underlying file. |
| 420 | File_view* |
| 421 | get_lasting_view(off_t start, section_size_type size, bool aligned, |
| 422 | bool cache) |
| 423 | { |
| 424 | return this->input_file()->file().get_lasting_view(this->offset_, start, |
| 425 | size, aligned, cache); |
| 426 | } |
| 427 | |
| 428 | // Read data from the underlying file. |
| 429 | void |
| 430 | read(off_t start, section_size_type size, void* p) |
| 431 | { this->input_file()->file().read(start + this->offset_, size, p); } |
| 432 | |
| 433 | // Read multiple data from the underlying file. |
| 434 | void |
| 435 | read_multiple(const File_read::Read_multiple& rm) |
| 436 | { this->input_file()->file().read_multiple(this->offset_, rm); } |
| 437 | |
| 438 | // Stop caching views in the underlying file. |
| 439 | void |
| 440 | clear_view_cache_marks() |
| 441 | { this->input_file()->file().clear_view_cache_marks(); } |
| 442 | |
| 443 | // Get the number of global symbols defined by this object, and the |
| 444 | // number of the symbols whose final definition came from this |
| 445 | // object. |
| 446 | void |
| 447 | get_global_symbol_counts(const Symbol_table* symtab, size_t* defined, |
| 448 | size_t* used) const |
| 449 | { this->do_get_global_symbol_counts(symtab, defined, used); } |
| 450 | |
| 451 | // Set the target. |
| 452 | void |
| 453 | set_target(Target* target) |
| 454 | { this->target_ = target; } |
| 455 | |
| 456 | // Return whether this object was found in a system directory. |
| 457 | bool |
| 458 | is_in_system_directory() const |
| 459 | { return this->input_file()->is_in_system_directory(); } |
| 460 | |
| 461 | // Return whether we found this object by searching a directory. |
| 462 | bool |
| 463 | searched_for() const |
| 464 | { return this->input_file()->will_search_for(); } |
| 465 | |
| 466 | protected: |
| 467 | // Returns NULL for Objects that are not plugin objects. This method |
| 468 | // is overridden in the Pluginobj class. |
| 469 | virtual Pluginobj* |
| 470 | do_pluginobj() |
| 471 | { return NULL; } |
| 472 | |
| 473 | // Read the symbols--implemented by child class. |
| 474 | virtual void |
| 475 | do_read_symbols(Read_symbols_data*) = 0; |
| 476 | |
| 477 | // Lay out sections--implemented by child class. |
| 478 | virtual void |
| 479 | do_layout(Symbol_table*, Layout*, Read_symbols_data*) = 0; |
| 480 | |
| 481 | // Add symbol information to the global symbol table--implemented by |
| 482 | // child class. |
| 483 | virtual void |
| 484 | do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*) = 0; |
| 485 | |
| 486 | // Return the location of the contents of a section. Implemented by |
| 487 | // child class. |
| 488 | virtual Location |
| 489 | do_section_contents(unsigned int shndx) = 0; |
| 490 | |
| 491 | // Get the size of a section--implemented by child class. |
| 492 | virtual uint64_t |
| 493 | do_section_size(unsigned int shndx) = 0; |
| 494 | |
| 495 | // Get the name of a section--implemented by child class. |
| 496 | virtual std::string |
| 497 | do_section_name(unsigned int shndx) = 0; |
| 498 | |
| 499 | // Get section flags--implemented by child class. |
| 500 | virtual uint64_t |
| 501 | do_section_flags(unsigned int shndx) = 0; |
| 502 | |
| 503 | // Get section address--implemented by child class. |
| 504 | virtual uint64_t |
| 505 | do_section_address(unsigned int shndx) = 0; |
| 506 | |
| 507 | // Get section type--implemented by child class. |
| 508 | virtual unsigned int |
| 509 | do_section_type(unsigned int shndx) = 0; |
| 510 | |
| 511 | // Get section link field--implemented by child class. |
| 512 | virtual unsigned int |
| 513 | do_section_link(unsigned int shndx) = 0; |
| 514 | |
| 515 | // Get section info field--implemented by child class. |
| 516 | virtual unsigned int |
| 517 | do_section_info(unsigned int shndx) = 0; |
| 518 | |
| 519 | // Get section alignment--implemented by child class. |
| 520 | virtual uint64_t |
| 521 | do_section_addralign(unsigned int shndx) = 0; |
| 522 | |
| 523 | // Return the Xindex structure to use. |
| 524 | virtual Xindex* |
| 525 | do_initialize_xindex() = 0; |
| 526 | |
| 527 | // Implement get_global_symbol_counts--implemented by child class. |
| 528 | virtual void |
| 529 | do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const = 0; |
| 530 | |
| 531 | // Set the target. |
| 532 | void |
| 533 | set_target(int machine, int size, bool big_endian, int osabi, |
| 534 | int abiversion); |
| 535 | |
| 536 | // Set the number of sections. |
| 537 | void |
| 538 | set_shnum(int shnum) |
| 539 | { this->shnum_ = shnum; } |
| 540 | |
| 541 | // Functions used by both Sized_relobj and Sized_dynobj. |
| 542 | |
| 543 | // Read the section data into a Read_symbols_data object. |
| 544 | template<int size, bool big_endian> |
| 545 | void |
| 546 | read_section_data(elfcpp::Elf_file<size, big_endian, Object>*, |
| 547 | Read_symbols_data*); |
| 548 | |
| 549 | // Let the child class initialize the xindex object directly. |
| 550 | void |
| 551 | set_xindex(Xindex* xindex) |
| 552 | { |
| 553 | gold_assert(this->xindex_ == NULL); |
| 554 | this->xindex_ = xindex; |
| 555 | } |
| 556 | |
| 557 | // If NAME is the name of a special .gnu.warning section, arrange |
| 558 | // for the warning to be issued. SHNDX is the section index. |
| 559 | // Return whether it is a warning section. |
| 560 | bool |
| 561 | handle_gnu_warning_section(const char* name, unsigned int shndx, |
| 562 | Symbol_table*); |
| 563 | |
| 564 | private: |
| 565 | // This class may not be copied. |
| 566 | Object(const Object&); |
| 567 | Object& operator=(const Object&); |
| 568 | |
| 569 | // Name of object as printed to user. |
| 570 | std::string name_; |
| 571 | // For reading the file. |
| 572 | Input_file* input_file_; |
| 573 | // Offset within the file--0 for an object file, non-0 for an |
| 574 | // archive. |
| 575 | off_t offset_; |
| 576 | // Number of input sections. |
| 577 | unsigned int shnum_; |
| 578 | // Whether this is a dynamic object. |
| 579 | bool is_dynamic_; |
| 580 | // Target functions--may be NULL if the target is not known. |
| 581 | Target* target_; |
| 582 | // Many sections for objects with more than SHN_LORESERVE sections. |
| 583 | Xindex* xindex_; |
| 584 | }; |
| 585 | |
| 586 | // Implement sized_target inline for efficiency. This approach breaks |
| 587 | // static type checking, but is made safe using asserts. |
| 588 | |
| 589 | template<int size, bool big_endian> |
| 590 | inline Sized_target<size, big_endian>* |
| 591 | Object::sized_target() const |
| 592 | { |
| 593 | gold_assert(this->target_->get_size() == size); |
| 594 | gold_assert(this->target_->is_big_endian() ? big_endian : !big_endian); |
| 595 | return static_cast<Sized_target<size, big_endian>*>(this->target_); |
| 596 | } |
| 597 | |
| 598 | // A regular object (ET_REL). This is an abstract base class itself. |
| 599 | // The implementation is the template class Sized_relobj. |
| 600 | |
| 601 | class Relobj : public Object |
| 602 | { |
| 603 | public: |
| 604 | Relobj(const std::string& name, Input_file* input_file, off_t offset = 0) |
| 605 | : Object(name, input_file, false, offset), |
| 606 | output_sections_(), |
| 607 | map_to_relocatable_relocs_(NULL), |
| 608 | object_merge_map_(NULL), |
| 609 | relocs_must_follow_section_writes_(false) |
| 610 | { } |
| 611 | |
| 612 | // During garbage collection, the Read_symbols_data pass for |
| 613 | // each object is stored as layout needs to be done after |
| 614 | // reloc processing. |
| 615 | Symbols_data* |
| 616 | get_symbols_data() |
| 617 | { return this->sd_; } |
| 618 | |
| 619 | // Decides which section names have to be included in the worklist |
| 620 | // as roots. |
| 621 | bool |
| 622 | is_section_name_included(const char *name); |
| 623 | |
| 624 | void |
| 625 | copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd, |
| 626 | unsigned int section_header_size); |
| 627 | |
| 628 | void |
| 629 | set_symbols_data(Symbols_data* sd) |
| 630 | { this->sd_ = sd; } |
| 631 | |
| 632 | // During garbage collection, the Read_relocs pass for all objects |
| 633 | // is done before scanning the relocs. In that case, this->rd_ is |
| 634 | // used to store the information from Read_relocs for each object. |
| 635 | // This data is also used to compute the list of relevant sections. |
| 636 | Read_relocs_data* |
| 637 | get_relocs_data() |
| 638 | { return this->rd_; } |
| 639 | |
| 640 | void |
| 641 | set_relocs_data(Read_relocs_data* rd) |
| 642 | { this->rd_ = rd; } |
| 643 | |
| 644 | virtual bool |
| 645 | is_output_section_offset_invalid(unsigned int shndx) const = 0; |
| 646 | |
| 647 | // Read the relocs. |
| 648 | void |
| 649 | read_relocs(Read_relocs_data* rd) |
| 650 | { return this->do_read_relocs(rd); } |
| 651 | |
| 652 | // Process the relocs, during garbage collection only. |
| 653 | void |
| 654 | gc_process_relocs(const General_options& options, Symbol_table* symtab, |
| 655 | Layout* layout, Read_relocs_data* rd) |
| 656 | { return this->do_gc_process_relocs(options, symtab, layout, rd); } |
| 657 | |
| 658 | // Scan the relocs and adjust the symbol table. |
| 659 | void |
| 660 | scan_relocs(const General_options& options, Symbol_table* symtab, |
| 661 | Layout* layout, Read_relocs_data* rd) |
| 662 | { return this->do_scan_relocs(options, symtab, layout, rd); } |
| 663 | |
| 664 | // The number of local symbols in the input symbol table. |
| 665 | virtual unsigned int |
| 666 | local_symbol_count() const |
| 667 | { return this->do_local_symbol_count(); } |
| 668 | |
| 669 | // Initial local symbol processing: count the number of local symbols |
| 670 | // in the output symbol table and dynamic symbol table; add local symbol |
| 671 | // names to *POOL and *DYNPOOL. |
| 672 | void |
| 673 | count_local_symbols(Stringpool_template<char>* pool, |
| 674 | Stringpool_template<char>* dynpool) |
| 675 | { return this->do_count_local_symbols(pool, dynpool); } |
| 676 | |
| 677 | // Set the values of the local symbols, set the output symbol table |
| 678 | // indexes for the local variables, and set the offset where local |
| 679 | // symbol information will be stored. Returns the new local symbol index. |
| 680 | unsigned int |
| 681 | finalize_local_symbols(unsigned int index, off_t off) |
| 682 | { return this->do_finalize_local_symbols(index, off); } |
| 683 | |
| 684 | // Set the output dynamic symbol table indexes for the local variables. |
| 685 | unsigned int |
| 686 | set_local_dynsym_indexes(unsigned int index) |
| 687 | { return this->do_set_local_dynsym_indexes(index); } |
| 688 | |
| 689 | // Set the offset where local dynamic symbol information will be stored. |
| 690 | unsigned int |
| 691 | set_local_dynsym_offset(off_t off) |
| 692 | { return this->do_set_local_dynsym_offset(off); } |
| 693 | |
| 694 | // Relocate the input sections and write out the local symbols. |
| 695 | void |
| 696 | relocate(const General_options& options, const Symbol_table* symtab, |
| 697 | const Layout* layout, Output_file* of) |
| 698 | { return this->do_relocate(options, symtab, layout, of); } |
| 699 | |
| 700 | // Return whether an input section is being included in the link. |
| 701 | bool |
| 702 | is_section_included(unsigned int shndx) const |
| 703 | { |
| 704 | gold_assert(shndx < this->output_sections_.size()); |
| 705 | return this->output_sections_[shndx] != NULL; |
| 706 | } |
| 707 | |
| 708 | // Given a section index, return the corresponding Output_section. |
| 709 | // The return value will be NULL if the section is not included in |
| 710 | // the link. |
| 711 | Output_section* |
| 712 | output_section(unsigned int shndx) const |
| 713 | { |
| 714 | gold_assert(shndx < this->output_sections_.size()); |
| 715 | return this->output_sections_[shndx]; |
| 716 | } |
| 717 | |
| 718 | // Given a section index, return the offset in the Output_section. |
| 719 | // The return value will be -1U if the section is specially mapped, |
| 720 | // such as a merge section. |
| 721 | uint64_t |
| 722 | output_section_offset(unsigned int shndx) const |
| 723 | { return this->do_output_section_offset(shndx); } |
| 724 | |
| 725 | // Set the offset of an input section within its output section. |
| 726 | void |
| 727 | set_section_offset(unsigned int shndx, uint64_t off) |
| 728 | { this->do_set_section_offset(shndx, off); } |
| 729 | |
| 730 | // Return true if we need to wait for output sections to be written |
| 731 | // before we can apply relocations. This is true if the object has |
| 732 | // any relocations for sections which require special handling, such |
| 733 | // as the exception frame section. |
| 734 | bool |
| 735 | relocs_must_follow_section_writes() const |
| 736 | { return this->relocs_must_follow_section_writes_; } |
| 737 | |
| 738 | // Return the object merge map. |
| 739 | Object_merge_map* |
| 740 | merge_map() const |
| 741 | { return this->object_merge_map_; } |
| 742 | |
| 743 | // Set the object merge map. |
| 744 | void |
| 745 | set_merge_map(Object_merge_map* object_merge_map) |
| 746 | { |
| 747 | gold_assert(this->object_merge_map_ == NULL); |
| 748 | this->object_merge_map_ = object_merge_map; |
| 749 | } |
| 750 | |
| 751 | // Record the relocatable reloc info for an input reloc section. |
| 752 | void |
| 753 | set_relocatable_relocs(unsigned int reloc_shndx, Relocatable_relocs* rr) |
| 754 | { |
| 755 | gold_assert(reloc_shndx < this->shnum()); |
| 756 | (*this->map_to_relocatable_relocs_)[reloc_shndx] = rr; |
| 757 | } |
| 758 | |
| 759 | // Get the relocatable reloc info for an input reloc section. |
| 760 | Relocatable_relocs* |
| 761 | relocatable_relocs(unsigned int reloc_shndx) |
| 762 | { |
| 763 | gold_assert(reloc_shndx < this->shnum()); |
| 764 | return (*this->map_to_relocatable_relocs_)[reloc_shndx]; |
| 765 | } |
| 766 | |
| 767 | // Layout sections whose layout was deferred while waiting for |
| 768 | // input files from a plugin. |
| 769 | void |
| 770 | layout_deferred_sections(Layout* layout) |
| 771 | { this->do_layout_deferred_sections(layout); } |
| 772 | |
| 773 | protected: |
| 774 | // The output section to be used for each input section, indexed by |
| 775 | // the input section number. The output section is NULL if the |
| 776 | // input section is to be discarded. |
| 777 | typedef std::vector<Output_section*> Output_sections; |
| 778 | |
| 779 | // Read the relocs--implemented by child class. |
| 780 | virtual void |
| 781 | do_read_relocs(Read_relocs_data*) = 0; |
| 782 | |
| 783 | // Process the relocs--implemented by child class. |
| 784 | virtual void |
| 785 | do_gc_process_relocs(const General_options&, Symbol_table*, Layout*, |
| 786 | Read_relocs_data*) = 0; |
| 787 | |
| 788 | // Scan the relocs--implemented by child class. |
| 789 | virtual void |
| 790 | do_scan_relocs(const General_options&, Symbol_table*, Layout*, |
| 791 | Read_relocs_data*) = 0; |
| 792 | |
| 793 | // Return the number of local symbols--implemented by child class. |
| 794 | virtual unsigned int |
| 795 | do_local_symbol_count() const = 0; |
| 796 | |
| 797 | // Count local symbols--implemented by child class. |
| 798 | virtual void |
| 799 | do_count_local_symbols(Stringpool_template<char>*, |
| 800 | Stringpool_template<char>*) = 0; |
| 801 | |
| 802 | // Finalize the local symbols. Set the output symbol table indexes |
| 803 | // for the local variables, and set the offset where local symbol |
| 804 | // information will be stored. |
| 805 | virtual unsigned int |
| 806 | do_finalize_local_symbols(unsigned int, off_t) = 0; |
| 807 | |
| 808 | // Set the output dynamic symbol table indexes for the local variables. |
| 809 | virtual unsigned int |
| 810 | do_set_local_dynsym_indexes(unsigned int) = 0; |
| 811 | |
| 812 | // Set the offset where local dynamic symbol information will be stored. |
| 813 | virtual unsigned int |
| 814 | do_set_local_dynsym_offset(off_t) = 0; |
| 815 | |
| 816 | // Relocate the input sections and write out the local |
| 817 | // symbols--implemented by child class. |
| 818 | virtual void |
| 819 | do_relocate(const General_options& options, const Symbol_table* symtab, |
| 820 | const Layout*, Output_file* of) = 0; |
| 821 | |
| 822 | // Get the offset of a section--implemented by child class. |
| 823 | virtual uint64_t |
| 824 | do_output_section_offset(unsigned int shndx) const = 0; |
| 825 | |
| 826 | // Set the offset of a section--implemented by child class. |
| 827 | virtual void |
| 828 | do_set_section_offset(unsigned int shndx, uint64_t off) = 0; |
| 829 | |
| 830 | // Layout sections whose layout was deferred while waiting for |
| 831 | // input files from a plugin--implemented by child class. |
| 832 | virtual void |
| 833 | do_layout_deferred_sections(Layout*) = 0; |
| 834 | |
| 835 | // Return the vector mapping input sections to output sections. |
| 836 | Output_sections& |
| 837 | output_sections() |
| 838 | { return this->output_sections_; } |
| 839 | |
| 840 | const Output_sections& |
| 841 | output_sections() const |
| 842 | { return this->output_sections_; } |
| 843 | |
| 844 | // Set the size of the relocatable relocs array. |
| 845 | void |
| 846 | size_relocatable_relocs() |
| 847 | { |
| 848 | this->map_to_relocatable_relocs_ = |
| 849 | new std::vector<Relocatable_relocs*>(this->shnum()); |
| 850 | } |
| 851 | |
| 852 | // Record that we must wait for the output sections to be written |
| 853 | // before applying relocations. |
| 854 | void |
| 855 | set_relocs_must_follow_section_writes() |
| 856 | { this->relocs_must_follow_section_writes_ = true; } |
| 857 | |
| 858 | private: |
| 859 | // Mapping from input sections to output section. |
| 860 | Output_sections output_sections_; |
| 861 | // Mapping from input section index to the information recorded for |
| 862 | // the relocations. This is only used for a relocatable link. |
| 863 | std::vector<Relocatable_relocs*>* map_to_relocatable_relocs_; |
| 864 | // Mappings for merge sections. This is managed by the code in the |
| 865 | // Merge_map class. |
| 866 | Object_merge_map* object_merge_map_; |
| 867 | // Whether we need to wait for output sections to be written before |
| 868 | // we can apply relocations. |
| 869 | bool relocs_must_follow_section_writes_; |
| 870 | // Used to store the relocs data computed by the Read_relocs pass. |
| 871 | // Used during garbage collection of unused sections. |
| 872 | Read_relocs_data* rd_; |
| 873 | // Used to store the symbols data computed by the Read_symbols pass. |
| 874 | // Again used during garbage collection when laying out referenced |
| 875 | // sections. |
| 876 | gold::Symbols_data *sd_; |
| 877 | }; |
| 878 | |
| 879 | // This class is used to handle relocations against a section symbol |
| 880 | // in an SHF_MERGE section. For such a symbol, we need to know the |
| 881 | // addend of the relocation before we can determine the final value. |
| 882 | // The addend gives us the location in the input section, and we can |
| 883 | // determine how it is mapped to the output section. For a |
| 884 | // non-section symbol, we apply the addend to the final value of the |
| 885 | // symbol; that is done in finalize_local_symbols, and does not use |
| 886 | // this class. |
| 887 | |
| 888 | template<int size> |
| 889 | class Merged_symbol_value |
| 890 | { |
| 891 | public: |
| 892 | typedef typename elfcpp::Elf_types<size>::Elf_Addr Value; |
| 893 | |
| 894 | // We use a hash table to map offsets in the input section to output |
| 895 | // addresses. |
| 896 | typedef Unordered_map<section_offset_type, Value> Output_addresses; |
| 897 | |
| 898 | Merged_symbol_value(Value input_value, Value output_start_address) |
| 899 | : input_value_(input_value), output_start_address_(output_start_address), |
| 900 | output_addresses_() |
| 901 | { } |
| 902 | |
| 903 | // Initialize the hash table. |
| 904 | void |
| 905 | initialize_input_to_output_map(const Relobj*, unsigned int input_shndx); |
| 906 | |
| 907 | // Release the hash table to save space. |
| 908 | void |
| 909 | free_input_to_output_map() |
| 910 | { this->output_addresses_.clear(); } |
| 911 | |
| 912 | // Get the output value corresponding to an addend. The object and |
| 913 | // input section index are passed in because the caller will have |
| 914 | // them; otherwise we could store them here. |
| 915 | Value |
| 916 | value(const Relobj* object, unsigned int input_shndx, Value addend) const |
| 917 | { |
| 918 | // This is a relocation against a section symbol. ADDEND is the |
| 919 | // offset in the section. The result should be the start of some |
| 920 | // merge area. If the object file wants something else, it should |
| 921 | // use a regular symbol rather than a section symbol. |
| 922 | // Unfortunately, PR 6658 shows a case in which the object file |
| 923 | // refers to the section symbol, but uses a negative ADDEND to |
| 924 | // compensate for a PC relative reloc. We can't handle the |
| 925 | // general case. However, we can handle the special case of a |
| 926 | // negative addend, by assuming that it refers to the start of the |
| 927 | // section. Of course, that means that we have to guess when |
| 928 | // ADDEND is negative. It is normal to see a 32-bit value here |
| 929 | // even when the template parameter size is 64, as 64-bit object |
| 930 | // file formats have 32-bit relocations. We know this is a merge |
| 931 | // section, so we know it has to fit into memory. So we assume |
| 932 | // that we won't see a value larger than a large 32-bit unsigned |
| 933 | // value. This will break objects with very very large merge |
| 934 | // sections; they probably break in other ways anyhow. |
| 935 | Value input_offset = this->input_value_; |
| 936 | if (addend < 0xffffff00) |
| 937 | { |
| 938 | input_offset += addend; |
| 939 | addend = 0; |
| 940 | } |
| 941 | typename Output_addresses::const_iterator p = |
| 942 | this->output_addresses_.find(input_offset); |
| 943 | if (p != this->output_addresses_.end()) |
| 944 | return p->second + addend; |
| 945 | |
| 946 | return (this->value_from_output_section(object, input_shndx, input_offset) |
| 947 | + addend); |
| 948 | } |
| 949 | |
| 950 | private: |
| 951 | // Get the output value for an input offset if we couldn't find it |
| 952 | // in the hash table. |
| 953 | Value |
| 954 | value_from_output_section(const Relobj*, unsigned int input_shndx, |
| 955 | Value input_offset) const; |
| 956 | |
| 957 | // The value of the section symbol in the input file. This is |
| 958 | // normally zero, but could in principle be something else. |
| 959 | Value input_value_; |
| 960 | // The start address of this merged section in the output file. |
| 961 | Value output_start_address_; |
| 962 | // A hash table which maps offsets in the input section to output |
| 963 | // addresses. This only maps specific offsets, not all offsets. |
| 964 | Output_addresses output_addresses_; |
| 965 | }; |
| 966 | |
| 967 | // This POD class is holds the value of a symbol. This is used for |
| 968 | // local symbols, and for all symbols during relocation processing. |
| 969 | // For special sections, such as SHF_MERGE sections, this calls a |
| 970 | // function to get the final symbol value. |
| 971 | |
| 972 | template<int size> |
| 973 | class Symbol_value |
| 974 | { |
| 975 | public: |
| 976 | typedef typename elfcpp::Elf_types<size>::Elf_Addr Value; |
| 977 | |
| 978 | Symbol_value() |
| 979 | : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0), |
| 980 | is_ordinary_shndx_(false), is_section_symbol_(false), |
| 981 | is_tls_symbol_(false), has_output_value_(true) |
| 982 | { this->u_.value = 0; } |
| 983 | |
| 984 | // Get the value of this symbol. OBJECT is the object in which this |
| 985 | // symbol is defined, and ADDEND is an addend to add to the value. |
| 986 | template<bool big_endian> |
| 987 | Value |
| 988 | value(const Sized_relobj<size, big_endian>* object, Value addend) const |
| 989 | { |
| 990 | if (this->has_output_value_) |
| 991 | return this->u_.value + addend; |
| 992 | else |
| 993 | { |
| 994 | gold_assert(this->is_ordinary_shndx_); |
| 995 | return this->u_.merged_symbol_value->value(object, this->input_shndx_, |
| 996 | addend); |
| 997 | } |
| 998 | } |
| 999 | |
| 1000 | // Set the value of this symbol in the output symbol table. |
| 1001 | void |
| 1002 | set_output_value(Value value) |
| 1003 | { this->u_.value = value; } |
| 1004 | |
| 1005 | // For a section symbol in a merged section, we need more |
| 1006 | // information. |
| 1007 | void |
| 1008 | set_merged_symbol_value(Merged_symbol_value<size>* msv) |
| 1009 | { |
| 1010 | gold_assert(this->is_section_symbol_); |
| 1011 | this->has_output_value_ = false; |
| 1012 | this->u_.merged_symbol_value = msv; |
| 1013 | } |
| 1014 | |
| 1015 | // Initialize the input to output map for a section symbol in a |
| 1016 | // merged section. We also initialize the value of a non-section |
| 1017 | // symbol in a merged section. |
| 1018 | void |
| 1019 | initialize_input_to_output_map(const Relobj* object) |
| 1020 | { |
| 1021 | if (!this->has_output_value_) |
| 1022 | { |
| 1023 | gold_assert(this->is_section_symbol_ && this->is_ordinary_shndx_); |
| 1024 | Merged_symbol_value<size>* msv = this->u_.merged_symbol_value; |
| 1025 | msv->initialize_input_to_output_map(object, this->input_shndx_); |
| 1026 | } |
| 1027 | } |
| 1028 | |
| 1029 | // Free the input to output map for a section symbol in a merged |
| 1030 | // section. |
| 1031 | void |
| 1032 | free_input_to_output_map() |
| 1033 | { |
| 1034 | if (!this->has_output_value_) |
| 1035 | this->u_.merged_symbol_value->free_input_to_output_map(); |
| 1036 | } |
| 1037 | |
| 1038 | // Set the value of the symbol from the input file. This is only |
| 1039 | // called by count_local_symbols, to communicate the value to |
| 1040 | // finalize_local_symbols. |
| 1041 | void |
| 1042 | set_input_value(Value value) |
| 1043 | { this->u_.value = value; } |
| 1044 | |
| 1045 | // Return the input value. This is only called by |
| 1046 | // finalize_local_symbols and (in special cases) relocate_section. |
| 1047 | Value |
| 1048 | input_value() const |
| 1049 | { return this->u_.value; } |
| 1050 | |
| 1051 | // Return whether this symbol should go into the output symbol |
| 1052 | // table. |
| 1053 | bool |
| 1054 | needs_output_symtab_entry() const |
| 1055 | { return this->output_symtab_index_ != -1U; } |
| 1056 | |
| 1057 | // Return the index in the output symbol table. |
| 1058 | unsigned int |
| 1059 | output_symtab_index() const |
| 1060 | { |
| 1061 | gold_assert(this->output_symtab_index_ != 0); |
| 1062 | return this->output_symtab_index_; |
| 1063 | } |
| 1064 | |
| 1065 | // Set the index in the output symbol table. |
| 1066 | void |
| 1067 | set_output_symtab_index(unsigned int i) |
| 1068 | { |
| 1069 | gold_assert(this->output_symtab_index_ == 0); |
| 1070 | this->output_symtab_index_ = i; |
| 1071 | } |
| 1072 | |
| 1073 | // Record that this symbol should not go into the output symbol |
| 1074 | // table. |
| 1075 | void |
| 1076 | set_no_output_symtab_entry() |
| 1077 | { |
| 1078 | gold_assert(this->output_symtab_index_ == 0); |
| 1079 | this->output_symtab_index_ = -1U; |
| 1080 | } |
| 1081 | |
| 1082 | // Set the index in the output dynamic symbol table. |
| 1083 | void |
| 1084 | set_needs_output_dynsym_entry() |
| 1085 | { |
| 1086 | gold_assert(!this->is_section_symbol()); |
| 1087 | this->output_dynsym_index_ = 0; |
| 1088 | } |
| 1089 | |
| 1090 | // Return whether this symbol should go into the output symbol |
| 1091 | // table. |
| 1092 | bool |
| 1093 | needs_output_dynsym_entry() const |
| 1094 | { |
| 1095 | return this->output_dynsym_index_ != -1U; |
| 1096 | } |
| 1097 | |
| 1098 | // Record that this symbol should go into the dynamic symbol table. |
| 1099 | void |
| 1100 | set_output_dynsym_index(unsigned int i) |
| 1101 | { |
| 1102 | gold_assert(this->output_dynsym_index_ == 0); |
| 1103 | this->output_dynsym_index_ = i; |
| 1104 | } |
| 1105 | |
| 1106 | // Return the index in the output dynamic symbol table. |
| 1107 | unsigned int |
| 1108 | output_dynsym_index() const |
| 1109 | { |
| 1110 | gold_assert(this->output_dynsym_index_ != 0 |
| 1111 | && this->output_dynsym_index_ != -1U); |
| 1112 | return this->output_dynsym_index_; |
| 1113 | } |
| 1114 | |
| 1115 | // Set the index of the input section in the input file. |
| 1116 | void |
| 1117 | set_input_shndx(unsigned int i, bool is_ordinary) |
| 1118 | { |
| 1119 | this->input_shndx_ = i; |
| 1120 | // input_shndx_ field is a bitfield, so make sure that the value |
| 1121 | // fits. |
| 1122 | gold_assert(this->input_shndx_ == i); |
| 1123 | this->is_ordinary_shndx_ = is_ordinary; |
| 1124 | } |
| 1125 | |
| 1126 | // Return the index of the input section in the input file. |
| 1127 | unsigned int |
| 1128 | input_shndx(bool* is_ordinary) const |
| 1129 | { |
| 1130 | *is_ordinary = this->is_ordinary_shndx_; |
| 1131 | return this->input_shndx_; |
| 1132 | } |
| 1133 | |
| 1134 | // Whether this is a section symbol. |
| 1135 | bool |
| 1136 | is_section_symbol() const |
| 1137 | { return this->is_section_symbol_; } |
| 1138 | |
| 1139 | // Record that this is a section symbol. |
| 1140 | void |
| 1141 | set_is_section_symbol() |
| 1142 | { |
| 1143 | gold_assert(!this->needs_output_dynsym_entry()); |
| 1144 | this->is_section_symbol_ = true; |
| 1145 | } |
| 1146 | |
| 1147 | // Record that this is a TLS symbol. |
| 1148 | void |
| 1149 | set_is_tls_symbol() |
| 1150 | { this->is_tls_symbol_ = true; } |
| 1151 | |
| 1152 | // Return TRUE if this is a TLS symbol. |
| 1153 | bool |
| 1154 | is_tls_symbol() const |
| 1155 | { return this->is_tls_symbol_; } |
| 1156 | |
| 1157 | private: |
| 1158 | // The index of this local symbol in the output symbol table. This |
| 1159 | // will be -1 if the symbol should not go into the symbol table. |
| 1160 | unsigned int output_symtab_index_; |
| 1161 | // The index of this local symbol in the dynamic symbol table. This |
| 1162 | // will be -1 if the symbol should not go into the symbol table. |
| 1163 | unsigned int output_dynsym_index_; |
| 1164 | // The section index in the input file in which this symbol is |
| 1165 | // defined. |
| 1166 | unsigned int input_shndx_ : 28; |
| 1167 | // Whether the section index is an ordinary index, not a special |
| 1168 | // value. |
| 1169 | bool is_ordinary_shndx_ : 1; |
| 1170 | // Whether this is a STT_SECTION symbol. |
| 1171 | bool is_section_symbol_ : 1; |
| 1172 | // Whether this is a STT_TLS symbol. |
| 1173 | bool is_tls_symbol_ : 1; |
| 1174 | // Whether this symbol has a value for the output file. This is |
| 1175 | // normally set to true during Layout::finalize, by |
| 1176 | // finalize_local_symbols. It will be false for a section symbol in |
| 1177 | // a merge section, as for such symbols we can not determine the |
| 1178 | // value to use in a relocation until we see the addend. |
| 1179 | bool has_output_value_ : 1; |
| 1180 | union |
| 1181 | { |
| 1182 | // This is used if has_output_value_ is true. Between |
| 1183 | // count_local_symbols and finalize_local_symbols, this is the |
| 1184 | // value in the input file. After finalize_local_symbols, it is |
| 1185 | // the value in the output file. |
| 1186 | Value value; |
| 1187 | // This is used if has_output_value_ is false. It points to the |
| 1188 | // information we need to get the value for a merge section. |
| 1189 | Merged_symbol_value<size>* merged_symbol_value; |
| 1190 | } u_; |
| 1191 | }; |
| 1192 | |
| 1193 | // A GOT offset list. A symbol may have more than one GOT offset |
| 1194 | // (e.g., when mixing modules compiled with two different TLS models), |
| 1195 | // but will usually have at most one. GOT_TYPE identifies the type of |
| 1196 | // GOT entry; its values are specific to each target. |
| 1197 | |
| 1198 | class Got_offset_list |
| 1199 | { |
| 1200 | public: |
| 1201 | Got_offset_list() |
| 1202 | : got_type_(-1U), got_offset_(0), got_next_(NULL) |
| 1203 | { } |
| 1204 | |
| 1205 | Got_offset_list(unsigned int got_type, unsigned int got_offset) |
| 1206 | : got_type_(got_type), got_offset_(got_offset), got_next_(NULL) |
| 1207 | { } |
| 1208 | |
| 1209 | ~Got_offset_list() |
| 1210 | { |
| 1211 | if (this->got_next_ != NULL) |
| 1212 | { |
| 1213 | delete this->got_next_; |
| 1214 | this->got_next_ = NULL; |
| 1215 | } |
| 1216 | } |
| 1217 | |
| 1218 | // Initialize the fields to their default values. |
| 1219 | void |
| 1220 | init() |
| 1221 | { |
| 1222 | this->got_type_ = -1U; |
| 1223 | this->got_offset_ = 0; |
| 1224 | this->got_next_ = NULL; |
| 1225 | } |
| 1226 | |
| 1227 | // Set the offset for the GOT entry of type GOT_TYPE. |
| 1228 | void |
| 1229 | set_offset(unsigned int got_type, unsigned int got_offset) |
| 1230 | { |
| 1231 | if (this->got_type_ == -1U) |
| 1232 | { |
| 1233 | this->got_type_ = got_type; |
| 1234 | this->got_offset_ = got_offset; |
| 1235 | } |
| 1236 | else |
| 1237 | { |
| 1238 | for (Got_offset_list* g = this; g != NULL; g = g->got_next_) |
| 1239 | { |
| 1240 | if (g->got_type_ == got_type) |
| 1241 | { |
| 1242 | g->got_offset_ = got_offset; |
| 1243 | return; |
| 1244 | } |
| 1245 | } |
| 1246 | Got_offset_list* g = new Got_offset_list(got_type, got_offset); |
| 1247 | g->got_next_ = this->got_next_; |
| 1248 | this->got_next_ = g; |
| 1249 | } |
| 1250 | } |
| 1251 | |
| 1252 | // Return the offset for a GOT entry of type GOT_TYPE. |
| 1253 | unsigned int |
| 1254 | get_offset(unsigned int got_type) const |
| 1255 | { |
| 1256 | for (const Got_offset_list* g = this; g != NULL; g = g->got_next_) |
| 1257 | { |
| 1258 | if (g->got_type_ == got_type) |
| 1259 | return g->got_offset_; |
| 1260 | } |
| 1261 | return -1U; |
| 1262 | } |
| 1263 | |
| 1264 | private: |
| 1265 | unsigned int got_type_; |
| 1266 | unsigned int got_offset_; |
| 1267 | Got_offset_list* got_next_; |
| 1268 | }; |
| 1269 | |
| 1270 | // A regular object file. This is size and endian specific. |
| 1271 | |
| 1272 | template<int size, bool big_endian> |
| 1273 | class Sized_relobj : public Relobj |
| 1274 | { |
| 1275 | public: |
| 1276 | typedef typename elfcpp::Elf_types<size>::Elf_Addr Address; |
| 1277 | typedef std::vector<Symbol*> Symbols; |
| 1278 | typedef std::vector<Symbol_value<size> > Local_values; |
| 1279 | |
| 1280 | static const Address invalid_address = static_cast<Address>(0) - 1; |
| 1281 | |
| 1282 | Sized_relobj(const std::string& name, Input_file* input_file, off_t offset, |
| 1283 | const typename elfcpp::Ehdr<size, big_endian>&); |
| 1284 | |
| 1285 | ~Sized_relobj(); |
| 1286 | |
| 1287 | // Checks if the offset of input section SHNDX within its output |
| 1288 | // section is invalid. |
| 1289 | bool |
| 1290 | is_output_section_offset_invalid(unsigned int shndx) const |
| 1291 | { return this->get_output_section_offset(shndx) == invalid_address; } |
| 1292 | |
| 1293 | // Set up the object file based on the ELF header. |
| 1294 | void |
| 1295 | setup(const typename elfcpp::Ehdr<size, big_endian>&); |
| 1296 | |
| 1297 | // Return the number of symbols. This is only valid after |
| 1298 | // Object::add_symbols has been called. |
| 1299 | unsigned int |
| 1300 | symbol_count() const |
| 1301 | { return this->local_symbol_count_ + this->symbols_.size(); } |
| 1302 | |
| 1303 | // If SYM is the index of a global symbol in the object file's |
| 1304 | // symbol table, return the Symbol object. Otherwise, return NULL. |
| 1305 | Symbol* |
| 1306 | global_symbol(unsigned int sym) const |
| 1307 | { |
| 1308 | if (sym >= this->local_symbol_count_) |
| 1309 | { |
| 1310 | gold_assert(sym - this->local_symbol_count_ < this->symbols_.size()); |
| 1311 | return this->symbols_[sym - this->local_symbol_count_]; |
| 1312 | } |
| 1313 | return NULL; |
| 1314 | } |
| 1315 | |
| 1316 | // Return the section index of symbol SYM. Set *VALUE to its value |
| 1317 | // in the object file. Set *IS_ORDINARY if this is an ordinary |
| 1318 | // section index, not a special code between SHN_LORESERVE and |
| 1319 | // SHN_HIRESERVE. Note that for a symbol which is not defined in |
| 1320 | // this object file, this will set *VALUE to 0 and return SHN_UNDEF; |
| 1321 | // it will not return the final value of the symbol in the link. |
| 1322 | unsigned int |
| 1323 | symbol_section_and_value(unsigned int sym, Address* value, bool* is_ordinary); |
| 1324 | |
| 1325 | // Return a pointer to the Symbol_value structure which holds the |
| 1326 | // value of a local symbol. |
| 1327 | const Symbol_value<size>* |
| 1328 | local_symbol(unsigned int sym) const |
| 1329 | { |
| 1330 | gold_assert(sym < this->local_values_.size()); |
| 1331 | return &this->local_values_[sym]; |
| 1332 | } |
| 1333 | |
| 1334 | // Return the index of local symbol SYM in the ordinary symbol |
| 1335 | // table. A value of -1U means that the symbol is not being output. |
| 1336 | unsigned int |
| 1337 | symtab_index(unsigned int sym) const |
| 1338 | { |
| 1339 | gold_assert(sym < this->local_values_.size()); |
| 1340 | return this->local_values_[sym].output_symtab_index(); |
| 1341 | } |
| 1342 | |
| 1343 | // Return the index of local symbol SYM in the dynamic symbol |
| 1344 | // table. A value of -1U means that the symbol is not being output. |
| 1345 | unsigned int |
| 1346 | dynsym_index(unsigned int sym) const |
| 1347 | { |
| 1348 | gold_assert(sym < this->local_values_.size()); |
| 1349 | return this->local_values_[sym].output_dynsym_index(); |
| 1350 | } |
| 1351 | |
| 1352 | // Return the input section index of local symbol SYM. |
| 1353 | unsigned int |
| 1354 | local_symbol_input_shndx(unsigned int sym, bool* is_ordinary) const |
| 1355 | { |
| 1356 | gold_assert(sym < this->local_values_.size()); |
| 1357 | return this->local_values_[sym].input_shndx(is_ordinary); |
| 1358 | } |
| 1359 | |
| 1360 | // Return the appropriate Sized_target structure. |
| 1361 | Sized_target<size, big_endian>* |
| 1362 | sized_target() |
| 1363 | { return this->Object::sized_target<size, big_endian>(); } |
| 1364 | |
| 1365 | // Record that local symbol SYM needs a dynamic symbol entry. |
| 1366 | void |
| 1367 | set_needs_output_dynsym_entry(unsigned int sym) |
| 1368 | { |
| 1369 | gold_assert(sym < this->local_values_.size()); |
| 1370 | this->local_values_[sym].set_needs_output_dynsym_entry(); |
| 1371 | } |
| 1372 | |
| 1373 | // Return whether the local symbol SYMNDX has a GOT offset. |
| 1374 | // For TLS symbols, the GOT entry will hold its tp-relative offset. |
| 1375 | bool |
| 1376 | local_has_got_offset(unsigned int symndx, unsigned int got_type) const |
| 1377 | { |
| 1378 | Local_got_offsets::const_iterator p = |
| 1379 | this->local_got_offsets_.find(symndx); |
| 1380 | return (p != this->local_got_offsets_.end() |
| 1381 | && p->second->get_offset(got_type) != -1U); |
| 1382 | } |
| 1383 | |
| 1384 | // Return the GOT offset of the local symbol SYMNDX. |
| 1385 | unsigned int |
| 1386 | local_got_offset(unsigned int symndx, unsigned int got_type) const |
| 1387 | { |
| 1388 | Local_got_offsets::const_iterator p = |
| 1389 | this->local_got_offsets_.find(symndx); |
| 1390 | gold_assert(p != this->local_got_offsets_.end()); |
| 1391 | unsigned int off = p->second->get_offset(got_type); |
| 1392 | gold_assert(off != -1U); |
| 1393 | return off; |
| 1394 | } |
| 1395 | |
| 1396 | // Set the GOT offset of the local symbol SYMNDX to GOT_OFFSET. |
| 1397 | void |
| 1398 | set_local_got_offset(unsigned int symndx, unsigned int got_type, |
| 1399 | unsigned int got_offset) |
| 1400 | { |
| 1401 | Local_got_offsets::const_iterator p = |
| 1402 | this->local_got_offsets_.find(symndx); |
| 1403 | if (p != this->local_got_offsets_.end()) |
| 1404 | p->second->set_offset(got_type, got_offset); |
| 1405 | else |
| 1406 | { |
| 1407 | Got_offset_list* g = new Got_offset_list(got_type, got_offset); |
| 1408 | std::pair<Local_got_offsets::iterator, bool> ins = |
| 1409 | this->local_got_offsets_.insert(std::make_pair(symndx, g)); |
| 1410 | gold_assert(ins.second); |
| 1411 | } |
| 1412 | } |
| 1413 | |
| 1414 | // Get the offset of input section SHNDX within its output section. |
| 1415 | // This is -1 if the input section requires a special mapping, such |
| 1416 | // as a merge section. The output section can be found in the |
| 1417 | // output_sections_ field of the parent class Relobj. |
| 1418 | Address |
| 1419 | get_output_section_offset(unsigned int shndx) const |
| 1420 | { |
| 1421 | gold_assert(shndx < this->section_offsets_.size()); |
| 1422 | return this->section_offsets_[shndx]; |
| 1423 | } |
| 1424 | |
| 1425 | // Return the name of the symbol that spans the given offset in the |
| 1426 | // specified section in this object. This is used only for error |
| 1427 | // messages and is not particularly efficient. |
| 1428 | bool |
| 1429 | get_symbol_location_info(unsigned int shndx, off_t offset, |
| 1430 | Symbol_location_info* info); |
| 1431 | |
| 1432 | // Look for a kept section corresponding to the given discarded section, |
| 1433 | // and return its output address. This is used only for relocations in |
| 1434 | // debugging sections. |
| 1435 | Address |
| 1436 | map_to_kept_section(unsigned int shndx, bool* found) const; |
| 1437 | |
| 1438 | protected: |
| 1439 | // Read the symbols. |
| 1440 | void |
| 1441 | do_read_symbols(Read_symbols_data*); |
| 1442 | |
| 1443 | // Return the number of local symbols. |
| 1444 | unsigned int |
| 1445 | do_local_symbol_count() const |
| 1446 | { return this->local_symbol_count_; } |
| 1447 | |
| 1448 | // Lay out the input sections. |
| 1449 | void |
| 1450 | do_layout(Symbol_table*, Layout*, Read_symbols_data*); |
| 1451 | |
| 1452 | // Layout sections whose layout was deferred while waiting for |
| 1453 | // input files from a plugin. |
| 1454 | void |
| 1455 | do_layout_deferred_sections(Layout*); |
| 1456 | |
| 1457 | // Add the symbols to the symbol table. |
| 1458 | void |
| 1459 | do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*); |
| 1460 | |
| 1461 | // Read the relocs. |
| 1462 | void |
| 1463 | do_read_relocs(Read_relocs_data*); |
| 1464 | |
| 1465 | // Process the relocs to find list of referenced sections. Used only |
| 1466 | // during garbage collection. |
| 1467 | void |
| 1468 | do_gc_process_relocs(const General_options&, Symbol_table*, Layout*, |
| 1469 | Read_relocs_data*); |
| 1470 | |
| 1471 | // Scan the relocs and adjust the symbol table. |
| 1472 | void |
| 1473 | do_scan_relocs(const General_options&, Symbol_table*, Layout*, |
| 1474 | Read_relocs_data*); |
| 1475 | |
| 1476 | // Count the local symbols. |
| 1477 | void |
| 1478 | do_count_local_symbols(Stringpool_template<char>*, |
| 1479 | Stringpool_template<char>*); |
| 1480 | |
| 1481 | // Finalize the local symbols. |
| 1482 | unsigned int |
| 1483 | do_finalize_local_symbols(unsigned int, off_t); |
| 1484 | |
| 1485 | // Set the offset where local dynamic symbol information will be stored. |
| 1486 | unsigned int |
| 1487 | do_set_local_dynsym_indexes(unsigned int); |
| 1488 | |
| 1489 | // Set the offset where local dynamic symbol information will be stored. |
| 1490 | unsigned int |
| 1491 | do_set_local_dynsym_offset(off_t); |
| 1492 | |
| 1493 | // Relocate the input sections and write out the local symbols. |
| 1494 | void |
| 1495 | do_relocate(const General_options& options, const Symbol_table* symtab, |
| 1496 | const Layout*, Output_file* of); |
| 1497 | |
| 1498 | // Get the size of a section. |
| 1499 | uint64_t |
| 1500 | do_section_size(unsigned int shndx) |
| 1501 | { return this->elf_file_.section_size(shndx); } |
| 1502 | |
| 1503 | // Get the name of a section. |
| 1504 | std::string |
| 1505 | do_section_name(unsigned int shndx) |
| 1506 | { return this->elf_file_.section_name(shndx); } |
| 1507 | |
| 1508 | // Return the location of the contents of a section. |
| 1509 | Object::Location |
| 1510 | do_section_contents(unsigned int shndx) |
| 1511 | { return this->elf_file_.section_contents(shndx); } |
| 1512 | |
| 1513 | // Return section flags. |
| 1514 | uint64_t |
| 1515 | do_section_flags(unsigned int shndx) |
| 1516 | { return this->elf_file_.section_flags(shndx); } |
| 1517 | |
| 1518 | // Return section address. |
| 1519 | uint64_t |
| 1520 | do_section_address(unsigned int shndx) |
| 1521 | { return this->elf_file_.section_addr(shndx); } |
| 1522 | |
| 1523 | // Return section type. |
| 1524 | unsigned int |
| 1525 | do_section_type(unsigned int shndx) |
| 1526 | { return this->elf_file_.section_type(shndx); } |
| 1527 | |
| 1528 | // Return the section link field. |
| 1529 | unsigned int |
| 1530 | do_section_link(unsigned int shndx) |
| 1531 | { return this->elf_file_.section_link(shndx); } |
| 1532 | |
| 1533 | // Return the section info field. |
| 1534 | unsigned int |
| 1535 | do_section_info(unsigned int shndx) |
| 1536 | { return this->elf_file_.section_info(shndx); } |
| 1537 | |
| 1538 | // Return the section alignment. |
| 1539 | uint64_t |
| 1540 | do_section_addralign(unsigned int shndx) |
| 1541 | { return this->elf_file_.section_addralign(shndx); } |
| 1542 | |
| 1543 | // Return the Xindex structure to use. |
| 1544 | Xindex* |
| 1545 | do_initialize_xindex(); |
| 1546 | |
| 1547 | // Get symbol counts. |
| 1548 | void |
| 1549 | do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const; |
| 1550 | |
| 1551 | // Get the offset of a section. |
| 1552 | uint64_t |
| 1553 | do_output_section_offset(unsigned int shndx) const |
| 1554 | { |
| 1555 | Address off = this->get_output_section_offset(shndx); |
| 1556 | if (off == invalid_address) |
| 1557 | return -1ULL; |
| 1558 | return off; |
| 1559 | } |
| 1560 | |
| 1561 | // Set the offset of a section. |
| 1562 | void |
| 1563 | do_set_section_offset(unsigned int shndx, uint64_t off) |
| 1564 | { |
| 1565 | gold_assert(shndx < this->section_offsets_.size()); |
| 1566 | this->section_offsets_[shndx] = convert_types<Address, uint64_t>(off); |
| 1567 | } |
| 1568 | |
| 1569 | private: |
| 1570 | // For convenience. |
| 1571 | typedef Sized_relobj<size, big_endian> This; |
| 1572 | static const int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size; |
| 1573 | static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size; |
| 1574 | static const int sym_size = elfcpp::Elf_sizes<size>::sym_size; |
| 1575 | typedef elfcpp::Shdr<size, big_endian> Shdr; |
| 1576 | |
| 1577 | // To keep track of discarded comdat sections, we need to map a member |
| 1578 | // section index to the object and section index of the corresponding |
| 1579 | // kept section. |
| 1580 | struct Kept_comdat_section |
| 1581 | { |
| 1582 | Kept_comdat_section(Sized_relobj<size, big_endian>* object, |
| 1583 | unsigned int shndx) |
| 1584 | : object_(object), shndx_(shndx) |
| 1585 | { } |
| 1586 | Sized_relobj<size, big_endian>* object_; |
| 1587 | unsigned int shndx_; |
| 1588 | }; |
| 1589 | typedef std::map<unsigned int, Kept_comdat_section*> |
| 1590 | Kept_comdat_section_table; |
| 1591 | |
| 1592 | // Adjust a section index if necessary. |
| 1593 | unsigned int |
| 1594 | adjust_shndx(unsigned int shndx) |
| 1595 | { |
| 1596 | if (shndx >= elfcpp::SHN_LORESERVE) |
| 1597 | shndx += this->elf_file_.large_shndx_offset(); |
| 1598 | return shndx; |
| 1599 | } |
| 1600 | |
| 1601 | // Find the SHT_SYMTAB section, given the section headers. |
| 1602 | void |
| 1603 | find_symtab(const unsigned char* pshdrs); |
| 1604 | |
| 1605 | // Return whether SHDR has the right flags for a GNU style exception |
| 1606 | // frame section. |
| 1607 | bool |
| 1608 | check_eh_frame_flags(const elfcpp::Shdr<size, big_endian>* shdr) const; |
| 1609 | |
| 1610 | // Return whether there is a section named .eh_frame which might be |
| 1611 | // a GNU style exception frame section. |
| 1612 | bool |
| 1613 | find_eh_frame(const unsigned char* pshdrs, const char* names, |
| 1614 | section_size_type names_size) const; |
| 1615 | |
| 1616 | // Whether to include a section group in the link. |
| 1617 | bool |
| 1618 | include_section_group(Symbol_table*, Layout*, unsigned int, const char*, |
| 1619 | const unsigned char*, const char *, section_size_type, |
| 1620 | std::vector<bool>*); |
| 1621 | |
| 1622 | // Whether to include a linkonce section in the link. |
| 1623 | bool |
| 1624 | include_linkonce_section(Layout*, unsigned int, const char*, |
| 1625 | const elfcpp::Shdr<size, big_endian>&); |
| 1626 | |
| 1627 | // Layout an input section. |
| 1628 | void |
| 1629 | layout_section(Layout* layout, unsigned int shndx, const char* name, |
| 1630 | typename This::Shdr& shdr, unsigned int reloc_shndx, |
| 1631 | unsigned int reloc_type); |
| 1632 | |
| 1633 | // Views and sizes when relocating. |
| 1634 | struct View_size |
| 1635 | { |
| 1636 | unsigned char* view; |
| 1637 | typename elfcpp::Elf_types<size>::Elf_Addr address; |
| 1638 | off_t offset; |
| 1639 | section_size_type view_size; |
| 1640 | bool is_input_output_view; |
| 1641 | bool is_postprocessing_view; |
| 1642 | }; |
| 1643 | |
| 1644 | typedef std::vector<View_size> Views; |
| 1645 | |
| 1646 | // Write section data to the output file. Record the views and |
| 1647 | // sizes in VIEWS for use when relocating. |
| 1648 | void |
| 1649 | write_sections(const unsigned char* pshdrs, Output_file*, Views*); |
| 1650 | |
| 1651 | // Relocate the sections in the output file. |
| 1652 | void |
| 1653 | relocate_sections(const General_options& options, const Symbol_table*, |
| 1654 | const Layout*, const unsigned char* pshdrs, Views*); |
| 1655 | |
| 1656 | // Scan the input relocations for --emit-relocs. |
| 1657 | void |
| 1658 | emit_relocs_scan(const General_options&, Symbol_table*, Layout*, |
| 1659 | const unsigned char* plocal_syms, |
| 1660 | const Read_relocs_data::Relocs_list::iterator&); |
| 1661 | |
| 1662 | // Scan the input relocations for --emit-relocs, templatized on the |
| 1663 | // type of the relocation section. |
| 1664 | template<int sh_type> |
| 1665 | void |
| 1666 | emit_relocs_scan_reltype(const General_options&, Symbol_table*, Layout*, |
| 1667 | const unsigned char* plocal_syms, |
| 1668 | const Read_relocs_data::Relocs_list::iterator&, |
| 1669 | Relocatable_relocs*); |
| 1670 | |
| 1671 | // Emit the relocs for --emit-relocs. |
| 1672 | void |
| 1673 | emit_relocs(const Relocate_info<size, big_endian>*, unsigned int, |
| 1674 | unsigned int sh_type, const unsigned char* prelocs, |
| 1675 | size_t reloc_count, Output_section*, Address output_offset, |
| 1676 | unsigned char* view, Address address, |
| 1677 | section_size_type view_size, |
| 1678 | unsigned char* reloc_view, section_size_type reloc_view_size); |
| 1679 | |
| 1680 | // Emit the relocs for --emit-relocs, templatized on the type of the |
| 1681 | // relocation section. |
| 1682 | template<int sh_type> |
| 1683 | void |
| 1684 | emit_relocs_reltype(const Relocate_info<size, big_endian>*, unsigned int, |
| 1685 | const unsigned char* prelocs, size_t reloc_count, |
| 1686 | Output_section*, Address output_offset, |
| 1687 | unsigned char* view, Address address, |
| 1688 | section_size_type view_size, |
| 1689 | unsigned char* reloc_view, |
| 1690 | section_size_type reloc_view_size); |
| 1691 | |
| 1692 | // Initialize input to output maps for section symbols in merged |
| 1693 | // sections. |
| 1694 | void |
| 1695 | initialize_input_to_output_maps(); |
| 1696 | |
| 1697 | // Free the input to output maps for section symbols in merged |
| 1698 | // sections. |
| 1699 | void |
| 1700 | free_input_to_output_maps(); |
| 1701 | |
| 1702 | // Write out the local symbols. |
| 1703 | void |
| 1704 | write_local_symbols(Output_file*, |
| 1705 | const Stringpool_template<char>*, |
| 1706 | const Stringpool_template<char>*, |
| 1707 | Output_symtab_xindex*, |
| 1708 | Output_symtab_xindex*); |
| 1709 | |
| 1710 | // Clear the local symbol information. |
| 1711 | void |
| 1712 | clear_local_symbols() |
| 1713 | { |
| 1714 | this->local_values_.clear(); |
| 1715 | this->local_got_offsets_.clear(); |
| 1716 | } |
| 1717 | |
| 1718 | // Record a mapping from discarded section SHNDX to the corresponding |
| 1719 | // kept section. |
| 1720 | void |
| 1721 | set_kept_comdat_section(unsigned int shndx, Kept_comdat_section* kept) |
| 1722 | { |
| 1723 | this->kept_comdat_sections_[shndx] = kept; |
| 1724 | } |
| 1725 | |
| 1726 | // Find the kept section corresponding to the discarded section SHNDX. |
| 1727 | Kept_comdat_section* |
| 1728 | get_kept_comdat_section(unsigned int shndx) const |
| 1729 | { |
| 1730 | typename Kept_comdat_section_table::const_iterator p = |
| 1731 | this->kept_comdat_sections_.find(shndx); |
| 1732 | if (p == this->kept_comdat_sections_.end()) |
| 1733 | return NULL; |
| 1734 | return p->second; |
| 1735 | } |
| 1736 | |
| 1737 | // The GOT offsets of local symbols. This map also stores GOT offsets |
| 1738 | // for tp-relative offsets for TLS symbols. |
| 1739 | typedef Unordered_map<unsigned int, Got_offset_list*> Local_got_offsets; |
| 1740 | |
| 1741 | // The TLS GOT offsets of local symbols. The map stores the offsets |
| 1742 | // for either a single GOT entry that holds the module index of a TLS |
| 1743 | // symbol, or a pair of GOT entries containing the module index and |
| 1744 | // dtv-relative offset. |
| 1745 | struct Tls_got_entry |
| 1746 | { |
| 1747 | Tls_got_entry(int got_offset, bool have_pair) |
| 1748 | : got_offset_(got_offset), |
| 1749 | have_pair_(have_pair) |
| 1750 | { } |
| 1751 | int got_offset_; |
| 1752 | bool have_pair_; |
| 1753 | }; |
| 1754 | typedef Unordered_map<unsigned int, Tls_got_entry> Local_tls_got_offsets; |
| 1755 | |
| 1756 | // Saved information for sections whose layout was deferred. |
| 1757 | struct Deferred_layout |
| 1758 | { |
| 1759 | static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size; |
| 1760 | Deferred_layout(unsigned int shndx, const char* name, |
| 1761 | const unsigned char* pshdr, |
| 1762 | unsigned int reloc_shndx, unsigned int reloc_type) |
| 1763 | : shndx_(shndx), name_(name), reloc_shndx_(reloc_shndx), |
| 1764 | reloc_type_(reloc_type) |
| 1765 | { |
| 1766 | memcpy(this->shdr_data_, pshdr, shdr_size); |
| 1767 | } |
| 1768 | unsigned int shndx_; |
| 1769 | std::string name_; |
| 1770 | unsigned int reloc_shndx_; |
| 1771 | unsigned int reloc_type_; |
| 1772 | unsigned char shdr_data_[shdr_size]; |
| 1773 | }; |
| 1774 | |
| 1775 | // General access to the ELF file. |
| 1776 | elfcpp::Elf_file<size, big_endian, Object> elf_file_; |
| 1777 | // Index of SHT_SYMTAB section. |
| 1778 | unsigned int symtab_shndx_; |
| 1779 | // The number of local symbols. |
| 1780 | unsigned int local_symbol_count_; |
| 1781 | // The number of local symbols which go into the output file. |
| 1782 | unsigned int output_local_symbol_count_; |
| 1783 | // The number of local symbols which go into the output file's dynamic |
| 1784 | // symbol table. |
| 1785 | unsigned int output_local_dynsym_count_; |
| 1786 | // The entries in the symbol table for the external symbols. |
| 1787 | Symbols symbols_; |
| 1788 | // Number of symbols defined in object file itself. |
| 1789 | size_t defined_count_; |
| 1790 | // File offset for local symbols. |
| 1791 | off_t local_symbol_offset_; |
| 1792 | // File offset for local dynamic symbols. |
| 1793 | off_t local_dynsym_offset_; |
| 1794 | // Values of local symbols. |
| 1795 | Local_values local_values_; |
| 1796 | // GOT offsets for local non-TLS symbols, and tp-relative offsets |
| 1797 | // for TLS symbols, indexed by symbol number. |
| 1798 | Local_got_offsets local_got_offsets_; |
| 1799 | // For each input section, the offset of the input section in its |
| 1800 | // output section. This is INVALID_ADDRESS if the input section requires a |
| 1801 | // special mapping. |
| 1802 | std::vector<Address> section_offsets_; |
| 1803 | // Table mapping discarded comdat sections to corresponding kept sections. |
| 1804 | Kept_comdat_section_table kept_comdat_sections_; |
| 1805 | // Whether this object has a GNU style .eh_frame section. |
| 1806 | bool has_eh_frame_; |
| 1807 | // The list of sections whose layout was deferred. |
| 1808 | std::vector<Deferred_layout> deferred_layout_; |
| 1809 | }; |
| 1810 | |
| 1811 | // A class to manage the list of all objects. |
| 1812 | |
| 1813 | class Input_objects |
| 1814 | { |
| 1815 | public: |
| 1816 | Input_objects() |
| 1817 | : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL) |
| 1818 | { } |
| 1819 | |
| 1820 | // The type of the list of input relocateable objects. |
| 1821 | typedef std::vector<Relobj*> Relobj_list; |
| 1822 | typedef Relobj_list::const_iterator Relobj_iterator; |
| 1823 | |
| 1824 | // The type of the list of input dynamic objects. |
| 1825 | typedef std::vector<Dynobj*> Dynobj_list; |
| 1826 | typedef Dynobj_list::const_iterator Dynobj_iterator; |
| 1827 | |
| 1828 | // Add an object to the list. Return true if all is well, or false |
| 1829 | // if this object should be ignored. |
| 1830 | bool |
| 1831 | add_object(Object*); |
| 1832 | |
| 1833 | // Start processing an archive. |
| 1834 | void |
| 1835 | archive_start(Archive*); |
| 1836 | |
| 1837 | // Stop processing an archive. |
| 1838 | void |
| 1839 | archive_stop(Archive*); |
| 1840 | |
| 1841 | // For each dynamic object, check whether we've seen all of its |
| 1842 | // explicit dependencies. |
| 1843 | void |
| 1844 | check_dynamic_dependencies() const; |
| 1845 | |
| 1846 | // Return whether an object was found in the system library |
| 1847 | // directory. |
| 1848 | bool |
| 1849 | found_in_system_library_directory(const Object*) const; |
| 1850 | |
| 1851 | // Print symbol counts. |
| 1852 | void |
| 1853 | print_symbol_counts(const Symbol_table*) const; |
| 1854 | |
| 1855 | // Iterate over all regular objects. |
| 1856 | |
| 1857 | Relobj_iterator |
| 1858 | relobj_begin() const |
| 1859 | { return this->relobj_list_.begin(); } |
| 1860 | |
| 1861 | Relobj_iterator |
| 1862 | relobj_end() const |
| 1863 | { return this->relobj_list_.end(); } |
| 1864 | |
| 1865 | // Iterate over all dynamic objects. |
| 1866 | |
| 1867 | Dynobj_iterator |
| 1868 | dynobj_begin() const |
| 1869 | { return this->dynobj_list_.begin(); } |
| 1870 | |
| 1871 | Dynobj_iterator |
| 1872 | dynobj_end() const |
| 1873 | { return this->dynobj_list_.end(); } |
| 1874 | |
| 1875 | // Return whether we have seen any dynamic objects. |
| 1876 | bool |
| 1877 | any_dynamic() const |
| 1878 | { return !this->dynobj_list_.empty(); } |
| 1879 | |
| 1880 | // Return the number of input objects. |
| 1881 | int |
| 1882 | number_of_input_objects() const |
| 1883 | { return this->relobj_list_.size() + this->dynobj_list_.size(); } |
| 1884 | |
| 1885 | private: |
| 1886 | Input_objects(const Input_objects&); |
| 1887 | Input_objects& operator=(const Input_objects&); |
| 1888 | |
| 1889 | // The list of ordinary objects included in the link. |
| 1890 | Relobj_list relobj_list_; |
| 1891 | // The list of dynamic objects included in the link. |
| 1892 | Dynobj_list dynobj_list_; |
| 1893 | // SONAMEs that we have seen. |
| 1894 | Unordered_set<std::string> sonames_; |
| 1895 | // Manage cross-references if requested. |
| 1896 | Cref* cref_; |
| 1897 | }; |
| 1898 | |
| 1899 | // Some of the information we pass to the relocation routines. We |
| 1900 | // group this together to avoid passing a dozen different arguments. |
| 1901 | |
| 1902 | template<int size, bool big_endian> |
| 1903 | struct Relocate_info |
| 1904 | { |
| 1905 | // Command line options. |
| 1906 | const General_options* options; |
| 1907 | // Symbol table. |
| 1908 | const Symbol_table* symtab; |
| 1909 | // Layout. |
| 1910 | const Layout* layout; |
| 1911 | // Object being relocated. |
| 1912 | Sized_relobj<size, big_endian>* object; |
| 1913 | // Section index of relocation section. |
| 1914 | unsigned int reloc_shndx; |
| 1915 | // Section index of section being relocated. |
| 1916 | unsigned int data_shndx; |
| 1917 | |
| 1918 | // Return a string showing the location of a relocation. This is |
| 1919 | // only used for error messages. |
| 1920 | std::string |
| 1921 | location(size_t relnum, off_t reloffset) const; |
| 1922 | }; |
| 1923 | |
| 1924 | // Return whether INPUT_FILE contains an ELF object start at file |
| 1925 | // offset OFFSET. This sets *START to point to a view of the start of |
| 1926 | // the file. It sets *READ_SIZE to the number of bytes in the view. |
| 1927 | |
| 1928 | extern bool |
| 1929 | is_elf_object(Input_file* input_file, off_t offset, |
| 1930 | const unsigned char** start, int *read_size); |
| 1931 | |
| 1932 | // Return an Object appropriate for the input file. P is BYTES long, |
| 1933 | // and holds the ELF header. If PUNCONFIGURED is not NULL, then if |
| 1934 | // this sees an object the linker is not configured to support, it |
| 1935 | // sets *PUNCONFIGURED to true and returns NULL without giving an |
| 1936 | // error message. |
| 1937 | |
| 1938 | extern Object* |
| 1939 | make_elf_object(const std::string& name, Input_file*, |
| 1940 | off_t offset, const unsigned char* p, |
| 1941 | section_offset_type bytes, bool* punconfigured); |
| 1942 | |
| 1943 | } // end namespace gold |
| 1944 | |
| 1945 | #endif // !defined(GOLD_OBJECT_H) |