| 1 | // archive.h -- archive support for gold -*- C++ -*- |
| 2 | |
| 3 | // Copyright (C) 2006-2016 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_ARCHIVE_H |
| 24 | #define GOLD_ARCHIVE_H |
| 25 | |
| 26 | #include <string> |
| 27 | #include <vector> |
| 28 | |
| 29 | #include "fileread.h" |
| 30 | #include "workqueue.h" |
| 31 | |
| 32 | namespace gold |
| 33 | { |
| 34 | |
| 35 | class Task; |
| 36 | class Input_argument; |
| 37 | class Input_file; |
| 38 | class Input_objects; |
| 39 | class Input_group; |
| 40 | class Layout; |
| 41 | class Symbol_table; |
| 42 | class Object; |
| 43 | struct Read_symbols_data; |
| 44 | class Input_file_lib; |
| 45 | class Incremental_archive_entry; |
| 46 | |
| 47 | // An entry in the archive map of offsets to members. |
| 48 | struct Archive_member |
| 49 | { |
| 50 | Archive_member() |
| 51 | : obj_(NULL), sd_(NULL), arg_serial_(0) |
| 52 | { } |
| 53 | Archive_member(Object* obj, Read_symbols_data* sd) |
| 54 | : obj_(obj), sd_(sd), arg_serial_(0) |
| 55 | { } |
| 56 | // The object file. |
| 57 | Object* obj_; |
| 58 | // The data to pass from read_symbols() to add_symbols(). |
| 59 | Read_symbols_data* sd_; |
| 60 | // The serial number of the file in the argument list. |
| 61 | unsigned int arg_serial_; |
| 62 | }; |
| 63 | |
| 64 | // This class serves as a base class for Archive and Lib_group objects. |
| 65 | |
| 66 | class Library_base |
| 67 | { |
| 68 | public: |
| 69 | Library_base(Task* task) |
| 70 | : task_(task), incremental_info_(NULL) |
| 71 | { } |
| 72 | |
| 73 | virtual |
| 74 | ~Library_base() |
| 75 | { } |
| 76 | |
| 77 | // The file name. |
| 78 | const std::string& |
| 79 | filename() const |
| 80 | { return this->do_filename(); } |
| 81 | |
| 82 | // The modification time of the archive file. |
| 83 | Timespec |
| 84 | get_mtime() |
| 85 | { return this->do_get_mtime(); } |
| 86 | |
| 87 | // When we see a symbol in an archive we might decide to include the member, |
| 88 | // not include the member or be undecided. This enum represents these |
| 89 | // possibilities. |
| 90 | |
| 91 | enum Should_include |
| 92 | { |
| 93 | SHOULD_INCLUDE_NO, |
| 94 | SHOULD_INCLUDE_YES, |
| 95 | SHOULD_INCLUDE_UNKNOWN |
| 96 | }; |
| 97 | |
| 98 | static Should_include |
| 99 | should_include_member(Symbol_table* symtab, Layout*, const char* sym_name, |
| 100 | Symbol** symp, std::string* why, char** tmpbufp, |
| 101 | size_t* tmpbuflen); |
| 102 | |
| 103 | // Store a pointer to the incremental link info for the library. |
| 104 | void |
| 105 | set_incremental_info(Incremental_archive_entry* info) |
| 106 | { this->incremental_info_ = info; } |
| 107 | |
| 108 | // Return the pointer to the incremental link info for the library. |
| 109 | Incremental_archive_entry* |
| 110 | incremental_info() const |
| 111 | { return this->incremental_info_; } |
| 112 | |
| 113 | // Abstract base class for processing unused symbols. |
| 114 | class Symbol_visitor_base |
| 115 | { |
| 116 | public: |
| 117 | Symbol_visitor_base() |
| 118 | { } |
| 119 | |
| 120 | virtual |
| 121 | ~Symbol_visitor_base() |
| 122 | { } |
| 123 | |
| 124 | // This function will be called for each unused global |
| 125 | // symbol in a library, with a pointer to the symbol name. |
| 126 | virtual void |
| 127 | visit(const char* /* name */) = 0; |
| 128 | }; |
| 129 | |
| 130 | // Iterator for unused global symbols in the library. |
| 131 | // Calls v->visit() for each global symbol defined |
| 132 | // in each unused library member, passing a pointer to |
| 133 | // the symbol name. |
| 134 | void |
| 135 | for_all_unused_symbols(Symbol_visitor_base* v) const |
| 136 | { this->do_for_all_unused_symbols(v); } |
| 137 | |
| 138 | protected: |
| 139 | // The task reading this archive. |
| 140 | Task *task_; |
| 141 | |
| 142 | private: |
| 143 | // The file name. |
| 144 | virtual const std::string& |
| 145 | do_filename() const = 0; |
| 146 | |
| 147 | // Return the modification time of the archive file. |
| 148 | virtual Timespec |
| 149 | do_get_mtime() = 0; |
| 150 | |
| 151 | // Iterator for unused global symbols in the library. |
| 152 | virtual void |
| 153 | do_for_all_unused_symbols(Symbol_visitor_base* v) const = 0; |
| 154 | |
| 155 | // The incremental link information for this archive. |
| 156 | Incremental_archive_entry* incremental_info_; |
| 157 | }; |
| 158 | |
| 159 | // This class represents an archive--generally a libNAME.a file. |
| 160 | // Archives have a symbol table and a list of objects. |
| 161 | |
| 162 | class Archive : public Library_base |
| 163 | { |
| 164 | public: |
| 165 | Archive(const std::string& name, Input_file* input_file, |
| 166 | bool is_thin_archive, Dirsearch* dirpath, Task* task); |
| 167 | |
| 168 | // The length of the magic string at the start of an archive. |
| 169 | static const int sarmag = 8; |
| 170 | |
| 171 | // The magic string at the start of an archive. |
| 172 | static const char armag[sarmag]; |
| 173 | static const char armagt[sarmag]; |
| 174 | |
| 175 | // The string expected at the end of an archive member header. |
| 176 | static const char arfmag[2]; |
| 177 | |
| 178 | // Name of 64-bit symbol table member. |
| 179 | static const char sym64name[7]; |
| 180 | |
| 181 | // The name of the object. This is the name used on the command |
| 182 | // line; e.g., if "-lgcc" is on the command line, this will be |
| 183 | // "gcc". |
| 184 | const std::string& |
| 185 | name() const |
| 186 | { return this->name_; } |
| 187 | |
| 188 | // The input file. |
| 189 | const Input_file* |
| 190 | input_file() const |
| 191 | { return this->input_file_; } |
| 192 | |
| 193 | // Set up the archive: read the symbol map. |
| 194 | void |
| 195 | setup(); |
| 196 | |
| 197 | // Get a reference to the underlying file. |
| 198 | File_read& |
| 199 | file() |
| 200 | { return this->input_file_->file(); } |
| 201 | |
| 202 | const File_read& |
| 203 | file() const |
| 204 | { return this->input_file_->file(); } |
| 205 | |
| 206 | // Lock the underlying file. |
| 207 | void |
| 208 | lock(const Task* t) |
| 209 | { this->input_file_->file().lock(t); } |
| 210 | |
| 211 | // Unlock the underlying file. |
| 212 | void |
| 213 | unlock(const Task* t) |
| 214 | { this->input_file_->file().unlock(t); } |
| 215 | |
| 216 | // Return whether the underlying file is locked. |
| 217 | bool |
| 218 | is_locked() const |
| 219 | { return this->input_file_->file().is_locked(); } |
| 220 | |
| 221 | // Return the token, so that the task can be queued. |
| 222 | Task_token* |
| 223 | token() |
| 224 | { return this->input_file_->file().token(); } |
| 225 | |
| 226 | // Release the underlying file. |
| 227 | void |
| 228 | release() |
| 229 | { this->input_file_->file().release(); } |
| 230 | |
| 231 | // Clear uncached views in the underlying file. |
| 232 | void |
| 233 | clear_uncached_views() |
| 234 | { this->input_file_->file().clear_uncached_views(); } |
| 235 | |
| 236 | // Whether this is a thin archive. |
| 237 | bool |
| 238 | is_thin_archive() const |
| 239 | { return this->is_thin_archive_; } |
| 240 | |
| 241 | // Unlock any nested archives. |
| 242 | void |
| 243 | unlock_nested_archives(); |
| 244 | |
| 245 | // Select members from the archive as needed and add them to the |
| 246 | // link. |
| 247 | bool |
| 248 | add_symbols(Symbol_table*, Layout*, Input_objects*, Mapfile*); |
| 249 | |
| 250 | // Return whether the archive defines the symbol. |
| 251 | bool |
| 252 | defines_symbol(Symbol*) const; |
| 253 | |
| 254 | // Dump statistical information to stderr. |
| 255 | static void |
| 256 | print_stats(); |
| 257 | |
| 258 | // Return the number of members in the archive. |
| 259 | size_t |
| 260 | count_members(); |
| 261 | |
| 262 | // Return the no-export flag. |
| 263 | bool |
| 264 | no_export() |
| 265 | { return this->no_export_; } |
| 266 | |
| 267 | private: |
| 268 | Archive(const Archive&); |
| 269 | Archive& operator=(const Archive&); |
| 270 | |
| 271 | // The file name. |
| 272 | const std::string& |
| 273 | do_filename() const |
| 274 | { return this->input_file_->filename(); } |
| 275 | |
| 276 | // The modification time of the archive file. |
| 277 | Timespec |
| 278 | do_get_mtime() |
| 279 | { return this->file().get_mtime(); } |
| 280 | |
| 281 | struct Archive_header; |
| 282 | |
| 283 | // Total number of archives seen. |
| 284 | static unsigned int total_archives; |
| 285 | // Total number of archive members seen. |
| 286 | static unsigned int total_members; |
| 287 | // Number of archive members loaded. |
| 288 | static unsigned int total_members_loaded; |
| 289 | |
| 290 | // Get a view into the underlying file. |
| 291 | const unsigned char* |
| 292 | get_view(off_t start, section_size_type size, bool aligned, bool cache) |
| 293 | { return this->input_file_->file().get_view(0, start, size, aligned, cache); } |
| 294 | |
| 295 | // Read the archive symbol map. |
| 296 | template<int mapsize> |
| 297 | void |
| 298 | read_armap(off_t start, section_size_type size); |
| 299 | |
| 300 | // Read an archive member header at OFF. CACHE is whether to cache |
| 301 | // the file view. Return the size of the member, and set *PNAME to |
| 302 | // the name. |
| 303 | off_t |
| 304 | read_header(off_t off, bool cache, std::string* pname, off_t* nested_off); |
| 305 | |
| 306 | // Interpret an archive header HDR at OFF. Return the size of the |
| 307 | // member, and set *PNAME to the name. |
| 308 | off_t |
| 309 | interpret_header(const Archive_header* hdr, off_t off, std::string* pname, |
| 310 | off_t* nested_off) const; |
| 311 | |
| 312 | // Get the file and offset for an archive member, which may be an |
| 313 | // external member of a thin archive. Set *INPUT_FILE to the |
| 314 | // file containing the actual member, *MEMOFF to the offset |
| 315 | // within that file (0 if not a nested archive), and *MEMBER_NAME |
| 316 | // to the name of the archive member. Return TRUE on success. |
| 317 | bool |
| 318 | get_file_and_offset(off_t off, Input_file** input_file, off_t* memoff, |
| 319 | off_t* memsize, std::string* member_name); |
| 320 | |
| 321 | // Return an ELF object for the member at offset OFF. |
| 322 | Object* |
| 323 | get_elf_object_for_member(off_t off, bool*); |
| 324 | |
| 325 | // Read the symbols from all the archive members in the link. |
| 326 | void |
| 327 | read_all_symbols(); |
| 328 | |
| 329 | // Read the symbols from an archive member in the link. OFF is the file |
| 330 | // offset of the member header. |
| 331 | void |
| 332 | read_symbols(off_t off); |
| 333 | |
| 334 | // Include all the archive members in the link. |
| 335 | bool |
| 336 | include_all_members(Symbol_table*, Layout*, Input_objects*, Mapfile*); |
| 337 | |
| 338 | // Include an archive member in the link. |
| 339 | bool |
| 340 | include_member(Symbol_table*, Layout*, Input_objects*, off_t off, |
| 341 | Mapfile*, Symbol*, const char* why); |
| 342 | |
| 343 | // Return whether we found this archive by searching a directory. |
| 344 | bool |
| 345 | searched_for() const |
| 346 | { return this->input_file_->will_search_for(); } |
| 347 | |
| 348 | // Iterate over archive members. |
| 349 | class const_iterator; |
| 350 | |
| 351 | const_iterator |
| 352 | begin(); |
| 353 | |
| 354 | const_iterator |
| 355 | end(); |
| 356 | |
| 357 | friend class const_iterator; |
| 358 | |
| 359 | // Iterator for unused global symbols in the library. |
| 360 | void |
| 361 | do_for_all_unused_symbols(Symbol_visitor_base* v) const; |
| 362 | |
| 363 | // An entry in the archive map of symbols to object files. |
| 364 | struct Armap_entry |
| 365 | { |
| 366 | // The offset to the symbol name in armap_names_. |
| 367 | off_t name_offset; |
| 368 | // The file offset to the object in the archive. |
| 369 | off_t file_offset; |
| 370 | }; |
| 371 | |
| 372 | // A simple hash code for off_t values. |
| 373 | class Seen_hash |
| 374 | { |
| 375 | public: |
| 376 | size_t operator()(off_t val) const |
| 377 | { return static_cast<size_t>(val); } |
| 378 | }; |
| 379 | |
| 380 | // For keeping track of open nested archives in a thin archive file. |
| 381 | typedef Unordered_map<std::string, Archive*> Nested_archive_table; |
| 382 | |
| 383 | // Name of object as printed to user. |
| 384 | std::string name_; |
| 385 | // For reading the file. |
| 386 | Input_file* input_file_; |
| 387 | // The archive map. |
| 388 | std::vector<Armap_entry> armap_; |
| 389 | // The names in the archive map. |
| 390 | std::string armap_names_; |
| 391 | // The extended name table. |
| 392 | std::string extended_names_; |
| 393 | // Track which symbols in the archive map are for elements which are |
| 394 | // defined or which have already been included in the link. |
| 395 | std::vector<bool> armap_checked_; |
| 396 | // Track which elements have been included by offset. |
| 397 | Unordered_set<off_t, Seen_hash> seen_offsets_; |
| 398 | // Table of objects whose symbols have been pre-read. |
| 399 | std::map<off_t, Archive_member> members_; |
| 400 | // True if this is a thin archive. |
| 401 | const bool is_thin_archive_; |
| 402 | // True if we have included at least one object from this archive. |
| 403 | bool included_member_; |
| 404 | // Table of nested archives, indexed by filename. |
| 405 | Nested_archive_table nested_archives_; |
| 406 | // The directory search path. |
| 407 | Dirsearch* dirpath_; |
| 408 | // Number of members in this archive; |
| 409 | unsigned int num_members_; |
| 410 | // True if we exclude this library archive from automatic export. |
| 411 | bool no_export_; |
| 412 | // True if this library has been included as a --whole-archive. |
| 413 | bool included_all_members_; |
| 414 | }; |
| 415 | |
| 416 | // This class is used to read an archive and pick out the desired |
| 417 | // elements and add them to the link. |
| 418 | |
| 419 | class Add_archive_symbols : public Task |
| 420 | { |
| 421 | public: |
| 422 | Add_archive_symbols(Symbol_table* symtab, Layout* layout, |
| 423 | Input_objects* input_objects, Dirsearch* dirpath, |
| 424 | int dirindex, Mapfile* mapfile, |
| 425 | const Input_argument* input_argument, |
| 426 | Archive* archive, Input_group* input_group, |
| 427 | Task_token* this_blocker, |
| 428 | Task_token* next_blocker) |
| 429 | : symtab_(symtab), layout_(layout), input_objects_(input_objects), |
| 430 | dirpath_(dirpath), dirindex_(dirindex), mapfile_(mapfile), |
| 431 | input_argument_(input_argument), archive_(archive), |
| 432 | input_group_(input_group), this_blocker_(this_blocker), |
| 433 | next_blocker_(next_blocker) |
| 434 | { } |
| 435 | |
| 436 | ~Add_archive_symbols(); |
| 437 | |
| 438 | // The standard Task methods. |
| 439 | |
| 440 | Task_token* |
| 441 | is_runnable(); |
| 442 | |
| 443 | void |
| 444 | locks(Task_locker*); |
| 445 | |
| 446 | void |
| 447 | run(Workqueue*); |
| 448 | |
| 449 | std::string |
| 450 | get_name() const |
| 451 | { |
| 452 | if (this->archive_ == NULL) |
| 453 | return "Add_archive_symbols"; |
| 454 | return "Add_archive_symbols " + this->archive_->file().filename(); |
| 455 | } |
| 456 | |
| 457 | private: |
| 458 | Symbol_table* symtab_; |
| 459 | Layout* layout_; |
| 460 | Input_objects* input_objects_; |
| 461 | Dirsearch* dirpath_; |
| 462 | int dirindex_; |
| 463 | Mapfile* mapfile_; |
| 464 | const Input_argument* input_argument_; |
| 465 | Archive* archive_; |
| 466 | Input_group* input_group_; |
| 467 | Task_token* this_blocker_; |
| 468 | Task_token* next_blocker_; |
| 469 | }; |
| 470 | |
| 471 | // This class represents the files surrounded by a --start-lib ... --end-lib. |
| 472 | |
| 473 | class Lib_group : public Library_base |
| 474 | { |
| 475 | public: |
| 476 | Lib_group(const Input_file_lib* lib, Task* task); |
| 477 | |
| 478 | // Select members from the lib group as needed and add them to the link. |
| 479 | void |
| 480 | add_symbols(Symbol_table*, Layout*, Input_objects*); |
| 481 | |
| 482 | // Include a member of the lib group in the link. |
| 483 | void |
| 484 | include_member(Symbol_table*, Layout*, Input_objects*, const Archive_member&); |
| 485 | |
| 486 | Archive_member* |
| 487 | get_member(int i) |
| 488 | { |
| 489 | return &this->members_[i]; |
| 490 | } |
| 491 | |
| 492 | // Total number of archives seen. |
| 493 | static unsigned int total_lib_groups; |
| 494 | // Total number of archive members seen. |
| 495 | static unsigned int total_members; |
| 496 | // Number of archive members loaded. |
| 497 | static unsigned int total_members_loaded; |
| 498 | |
| 499 | // Dump statistical information to stderr. |
| 500 | static void |
| 501 | print_stats(); |
| 502 | |
| 503 | private: |
| 504 | // The file name. |
| 505 | const std::string& |
| 506 | do_filename() const; |
| 507 | |
| 508 | // A Lib_group does not have a modification time, since there is no |
| 509 | // real library file. |
| 510 | Timespec |
| 511 | do_get_mtime() |
| 512 | { return Timespec(0, 0); } |
| 513 | |
| 514 | // Iterator for unused global symbols in the library. |
| 515 | void |
| 516 | do_for_all_unused_symbols(Symbol_visitor_base*) const; |
| 517 | |
| 518 | // Table of the objects in the group. |
| 519 | std::vector<Archive_member> members_; |
| 520 | }; |
| 521 | |
| 522 | // This class is used to pick out the desired elements and add them to the link. |
| 523 | |
| 524 | class Add_lib_group_symbols : public Task |
| 525 | { |
| 526 | public: |
| 527 | Add_lib_group_symbols(Symbol_table* symtab, Layout* layout, |
| 528 | Input_objects* input_objects, |
| 529 | Lib_group* lib, Task_token* next_blocker) |
| 530 | : symtab_(symtab), layout_(layout), input_objects_(input_objects), |
| 531 | lib_(lib), readsyms_blocker_(NULL), this_blocker_(NULL), |
| 532 | next_blocker_(next_blocker) |
| 533 | { } |
| 534 | |
| 535 | ~Add_lib_group_symbols(); |
| 536 | |
| 537 | // The standard Task methods. |
| 538 | |
| 539 | Task_token* |
| 540 | is_runnable(); |
| 541 | |
| 542 | void |
| 543 | locks(Task_locker*); |
| 544 | |
| 545 | void |
| 546 | run(Workqueue*); |
| 547 | |
| 548 | // Set the blocker to use for this task. |
| 549 | void |
| 550 | set_blocker(Task_token* readsyms_blocker, Task_token* this_blocker) |
| 551 | { |
| 552 | gold_assert(this->readsyms_blocker_ == NULL && this->this_blocker_ == NULL); |
| 553 | this->readsyms_blocker_ = readsyms_blocker; |
| 554 | this->this_blocker_ = this_blocker; |
| 555 | } |
| 556 | |
| 557 | std::string |
| 558 | get_name() const |
| 559 | { |
| 560 | return "Add_lib_group_symbols"; |
| 561 | } |
| 562 | |
| 563 | private: |
| 564 | Symbol_table* symtab_; |
| 565 | Layout* layout_; |
| 566 | Input_objects* input_objects_; |
| 567 | Lib_group* lib_; |
| 568 | Task_token* readsyms_blocker_; |
| 569 | Task_token* this_blocker_; |
| 570 | Task_token* next_blocker_; |
| 571 | }; |
| 572 | |
| 573 | } // End namespace gold. |
| 574 | |
| 575 | #endif // !defined(GOLD_ARCHIVE_H) |