| 1 | // readsyms.cc -- read input file symbols for gold |
| 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 | #include "gold.h" |
| 24 | |
| 25 | #include <cstring> |
| 26 | |
| 27 | #include "elfcpp.h" |
| 28 | #include "options.h" |
| 29 | #include "dirsearch.h" |
| 30 | #include "symtab.h" |
| 31 | #include "object.h" |
| 32 | #include "archive.h" |
| 33 | #include "script.h" |
| 34 | #include "readsyms.h" |
| 35 | #include "plugin.h" |
| 36 | |
| 37 | namespace gold |
| 38 | { |
| 39 | |
| 40 | // If we fail to open the object, then we won't create an Add_symbols |
| 41 | // task. However, we still need to unblock the token, or else the |
| 42 | // link won't proceed to generate more error messages. We can only |
| 43 | // unblock tokens when the workqueue lock is held, so we need a dummy |
| 44 | // task to do that. The dummy task has to maintain the right sequence |
| 45 | // of blocks, so we need both this_blocker and next_blocker. |
| 46 | |
| 47 | class Unblock_token : public Task |
| 48 | { |
| 49 | public: |
| 50 | Unblock_token(Task_token* this_blocker, Task_token* next_blocker) |
| 51 | : this_blocker_(this_blocker), next_blocker_(next_blocker) |
| 52 | { } |
| 53 | |
| 54 | ~Unblock_token() |
| 55 | { |
| 56 | if (this->this_blocker_ != NULL) |
| 57 | delete this->this_blocker_; |
| 58 | } |
| 59 | |
| 60 | Task_token* |
| 61 | is_runnable() |
| 62 | { |
| 63 | if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) |
| 64 | return this->this_blocker_; |
| 65 | return NULL; |
| 66 | } |
| 67 | |
| 68 | void |
| 69 | locks(Task_locker* tl) |
| 70 | { tl->add(this, this->next_blocker_); } |
| 71 | |
| 72 | void |
| 73 | run(Workqueue*) |
| 74 | { } |
| 75 | |
| 76 | std::string |
| 77 | get_name() const |
| 78 | { return "Unblock_token"; } |
| 79 | |
| 80 | private: |
| 81 | Task_token* this_blocker_; |
| 82 | Task_token* next_blocker_; |
| 83 | }; |
| 84 | |
| 85 | // Class read_symbols. |
| 86 | |
| 87 | Read_symbols::~Read_symbols() |
| 88 | { |
| 89 | // The this_blocker_ and next_blocker_ pointers are passed on to the |
| 90 | // Add_symbols task. |
| 91 | } |
| 92 | |
| 93 | // If appropriate, issue a warning about skipping an incompatible |
| 94 | // file. |
| 95 | |
| 96 | void |
| 97 | Read_symbols::incompatible_warning(const Input_argument* input_argument, |
| 98 | const Input_file* input_file) |
| 99 | { |
| 100 | if (parameters->options().warn_search_mismatch()) |
| 101 | gold_warning("skipping incompatible %s while searching for %s", |
| 102 | input_file->filename().c_str(), |
| 103 | input_argument->file().name()); |
| 104 | } |
| 105 | |
| 106 | // Requeue a Read_symbols task to search for the next object with the |
| 107 | // same name. |
| 108 | |
| 109 | void |
| 110 | Read_symbols::requeue(Workqueue* workqueue, Input_objects* input_objects, |
| 111 | Symbol_table* symtab, Layout* layout, Dirsearch* dirpath, |
| 112 | int dirindex, Mapfile* mapfile, |
| 113 | const Input_argument* input_argument, |
| 114 | Input_group* input_group, Task_token* next_blocker) |
| 115 | { |
| 116 | // Bump the directory search index. |
| 117 | ++dirindex; |
| 118 | |
| 119 | // We don't need to worry about this_blocker, since we already |
| 120 | // reached it. However, we are removing the blocker on next_blocker |
| 121 | // because the calling task is completing. So we need to add a new |
| 122 | // blocker. Since next_blocker may be shared by several tasks, we |
| 123 | // need to increment the count with the workqueue lock held. |
| 124 | workqueue->add_blocker(next_blocker); |
| 125 | |
| 126 | workqueue->queue(new Read_symbols(input_objects, symtab, layout, dirpath, |
| 127 | dirindex, mapfile, input_argument, |
| 128 | input_group, NULL, next_blocker)); |
| 129 | } |
| 130 | |
| 131 | // Return whether a Read_symbols task is runnable. We can read an |
| 132 | // ordinary input file immediately. For an archive specified using |
| 133 | // -l, we have to wait until the search path is complete. |
| 134 | |
| 135 | Task_token* |
| 136 | Read_symbols::is_runnable() |
| 137 | { |
| 138 | if (this->input_argument_->is_file() |
| 139 | && this->input_argument_->file().may_need_search() |
| 140 | && this->dirpath_->token()->is_blocked()) |
| 141 | return this->dirpath_->token(); |
| 142 | |
| 143 | return NULL; |
| 144 | } |
| 145 | |
| 146 | // Return a Task_locker for a Read_symbols task. We don't need any |
| 147 | // locks here. |
| 148 | |
| 149 | void |
| 150 | Read_symbols::locks(Task_locker*) |
| 151 | { |
| 152 | } |
| 153 | |
| 154 | // Run a Read_symbols task. |
| 155 | |
| 156 | void |
| 157 | Read_symbols::run(Workqueue* workqueue) |
| 158 | { |
| 159 | // If we didn't queue a new task, then we need to explicitly unblock |
| 160 | // the token. |
| 161 | if (!this->do_read_symbols(workqueue)) |
| 162 | workqueue->queue_soon(new Unblock_token(this->this_blocker_, |
| 163 | this->next_blocker_)); |
| 164 | } |
| 165 | |
| 166 | // Open the file and read the symbols. Return true if a new task was |
| 167 | // queued, false if that could not happen due to some error. |
| 168 | |
| 169 | bool |
| 170 | Read_symbols::do_read_symbols(Workqueue* workqueue) |
| 171 | { |
| 172 | if (this->input_argument_->is_group()) |
| 173 | { |
| 174 | gold_assert(this->input_group_ == NULL); |
| 175 | this->do_group(workqueue); |
| 176 | return true; |
| 177 | } |
| 178 | |
| 179 | Input_file* input_file = new Input_file(&this->input_argument_->file()); |
| 180 | if (!input_file->open(*this->dirpath_, this, &this->dirindex_)) |
| 181 | return false; |
| 182 | |
| 183 | // Read enough of the file to pick up the entire ELF header. |
| 184 | |
| 185 | off_t filesize = input_file->file().filesize(); |
| 186 | |
| 187 | if (filesize == 0) |
| 188 | { |
| 189 | gold_error(_("%s: file is empty"), |
| 190 | input_file->file().filename().c_str()); |
| 191 | return false; |
| 192 | } |
| 193 | |
| 194 | const unsigned char* ehdr; |
| 195 | int read_size; |
| 196 | bool is_elf = is_elf_object(input_file, 0, &ehdr, &read_size); |
| 197 | |
| 198 | if (read_size >= Archive::sarmag) |
| 199 | { |
| 200 | bool is_thin_archive |
| 201 | = memcmp(ehdr, Archive::armagt, Archive::sarmag) == 0; |
| 202 | if (is_thin_archive |
| 203 | || memcmp(ehdr, Archive::armag, Archive::sarmag) == 0) |
| 204 | { |
| 205 | // This is an archive. |
| 206 | Archive* arch = new Archive(this->input_argument_->file().name(), |
| 207 | input_file, is_thin_archive, |
| 208 | this->dirpath_, this); |
| 209 | arch->setup(); |
| 210 | |
| 211 | // Unlock the archive so it can be used in the next task. |
| 212 | arch->unlock(this); |
| 213 | |
| 214 | workqueue->queue_next(new Add_archive_symbols(this->symtab_, |
| 215 | this->layout_, |
| 216 | this->input_objects_, |
| 217 | this->dirpath_, |
| 218 | this->dirindex_, |
| 219 | this->mapfile_, |
| 220 | this->input_argument_, |
| 221 | arch, |
| 222 | this->input_group_, |
| 223 | this->this_blocker_, |
| 224 | this->next_blocker_)); |
| 225 | return true; |
| 226 | } |
| 227 | } |
| 228 | |
| 229 | if (parameters->options().has_plugins()) |
| 230 | { |
| 231 | Pluginobj* obj = parameters->options().plugins()->claim_file(input_file, |
| 232 | 0, filesize); |
| 233 | if (obj != NULL) |
| 234 | { |
| 235 | // The input file was claimed by a plugin, and its symbols |
| 236 | // have been provided by the plugin. |
| 237 | |
| 238 | // We are done with the file at this point, so unlock it. |
| 239 | obj->unlock(this); |
| 240 | |
| 241 | workqueue->queue_next(new Add_symbols(this->input_objects_, |
| 242 | this->symtab_, |
| 243 | this->layout_, |
| 244 | this->dirpath_, |
| 245 | this->dirindex_, |
| 246 | this->mapfile_, |
| 247 | this->input_argument_, |
| 248 | this->input_group_, |
| 249 | obj, |
| 250 | NULL, |
| 251 | this->this_blocker_, |
| 252 | this->next_blocker_)); |
| 253 | return true; |
| 254 | } |
| 255 | } |
| 256 | |
| 257 | if (is_elf) |
| 258 | { |
| 259 | // This is an ELF object. |
| 260 | |
| 261 | bool unconfigured; |
| 262 | Object* obj = make_elf_object(input_file->filename(), |
| 263 | input_file, 0, ehdr, read_size, |
| 264 | &unconfigured); |
| 265 | if (obj == NULL) |
| 266 | { |
| 267 | if (unconfigured && input_file->will_search_for()) |
| 268 | { |
| 269 | Read_symbols::incompatible_warning(this->input_argument_, |
| 270 | input_file); |
| 271 | input_file->file().release(); |
| 272 | input_file->file().unlock(this); |
| 273 | delete input_file; |
| 274 | ++this->dirindex_; |
| 275 | return this->do_read_symbols(workqueue); |
| 276 | } |
| 277 | return false; |
| 278 | } |
| 279 | |
| 280 | Read_symbols_data* sd = new Read_symbols_data; |
| 281 | obj->read_symbols(sd); |
| 282 | |
| 283 | // Opening the file locked it, so now we need to unlock it. We |
| 284 | // need to unlock it before queuing the Add_symbols task, |
| 285 | // because the workqueue doesn't know about our lock on the |
| 286 | // file. If we queue the Add_symbols task first, it will be |
| 287 | // stuck on the end of the file lock, but since the workqueue |
| 288 | // doesn't know about that lock, it will never release the |
| 289 | // Add_symbols task. |
| 290 | |
| 291 | input_file->file().unlock(this); |
| 292 | |
| 293 | // We use queue_next because everything is cached for this |
| 294 | // task to run right away if possible. |
| 295 | |
| 296 | workqueue->queue_next(new Add_symbols(this->input_objects_, |
| 297 | this->symtab_, this->layout_, |
| 298 | this->dirpath_, |
| 299 | this->dirindex_, |
| 300 | this->mapfile_, |
| 301 | this->input_argument_, |
| 302 | this->input_group_, |
| 303 | obj, |
| 304 | sd, |
| 305 | this->this_blocker_, |
| 306 | this->next_blocker_)); |
| 307 | |
| 308 | return true; |
| 309 | } |
| 310 | |
| 311 | // Queue up a task to try to parse this file as a script. We use a |
| 312 | // separate task so that the script will be read in order with other |
| 313 | // objects named on the command line. Also so that we don't try to |
| 314 | // read multiple scripts simultaneously, which could lead to |
| 315 | // unpredictable changes to the General_options structure. |
| 316 | |
| 317 | workqueue->queue_soon(new Read_script(this->symtab_, |
| 318 | this->layout_, |
| 319 | this->dirpath_, |
| 320 | this->dirindex_, |
| 321 | this->input_objects_, |
| 322 | this->mapfile_, |
| 323 | this->input_group_, |
| 324 | this->input_argument_, |
| 325 | input_file, |
| 326 | this->this_blocker_, |
| 327 | this->next_blocker_)); |
| 328 | return true; |
| 329 | } |
| 330 | |
| 331 | // Handle a group. We need to walk through the arguments over and |
| 332 | // over until we don't see any new undefined symbols. We do this by |
| 333 | // setting off Read_symbols Tasks as usual, but recording the archive |
| 334 | // entries instead of deleting them. We also start a Finish_group |
| 335 | // Task which runs after we've read all the symbols. In that task we |
| 336 | // process the archives in a loop until we are done. |
| 337 | |
| 338 | void |
| 339 | Read_symbols::do_group(Workqueue* workqueue) |
| 340 | { |
| 341 | Input_group* input_group = new Input_group(); |
| 342 | |
| 343 | const Input_file_group* group = this->input_argument_->group(); |
| 344 | Task_token* this_blocker = this->this_blocker_; |
| 345 | |
| 346 | for (Input_file_group::const_iterator p = group->begin(); |
| 347 | p != group->end(); |
| 348 | ++p) |
| 349 | { |
| 350 | const Input_argument* arg = &*p; |
| 351 | gold_assert(arg->is_file()); |
| 352 | |
| 353 | Task_token* next_blocker = new Task_token(true); |
| 354 | next_blocker->add_blocker(); |
| 355 | workqueue->queue_soon(new Read_symbols(this->input_objects_, |
| 356 | this->symtab_, this->layout_, |
| 357 | this->dirpath_, this->dirindex_, |
| 358 | this->mapfile_, arg, input_group, |
| 359 | this_blocker, next_blocker)); |
| 360 | this_blocker = next_blocker; |
| 361 | } |
| 362 | |
| 363 | const int saw_undefined = this->symtab_->saw_undefined(); |
| 364 | workqueue->queue_soon(new Finish_group(this->input_objects_, |
| 365 | this->symtab_, |
| 366 | this->layout_, |
| 367 | this->mapfile_, |
| 368 | input_group, |
| 369 | saw_undefined, |
| 370 | this_blocker, |
| 371 | this->next_blocker_)); |
| 372 | } |
| 373 | |
| 374 | // Return a debugging name for a Read_symbols task. |
| 375 | |
| 376 | std::string |
| 377 | Read_symbols::get_name() const |
| 378 | { |
| 379 | if (!this->input_argument_->is_group()) |
| 380 | { |
| 381 | std::string ret("Read_symbols "); |
| 382 | if (this->input_argument_->file().is_lib()) |
| 383 | ret += "-l"; |
| 384 | ret += this->input_argument_->file().name(); |
| 385 | return ret; |
| 386 | } |
| 387 | |
| 388 | std::string ret("Read_symbols group ("); |
| 389 | bool add_space = false; |
| 390 | const Input_file_group* group = this->input_argument_->group(); |
| 391 | for (Input_file_group::const_iterator p = group->begin(); |
| 392 | p != group->end(); |
| 393 | ++p) |
| 394 | { |
| 395 | if (add_space) |
| 396 | ret += ' '; |
| 397 | ret += p->file().name(); |
| 398 | add_space = true; |
| 399 | } |
| 400 | return ret + ')'; |
| 401 | } |
| 402 | |
| 403 | // Class Add_symbols. |
| 404 | |
| 405 | Add_symbols::~Add_symbols() |
| 406 | { |
| 407 | if (this->this_blocker_ != NULL) |
| 408 | delete this->this_blocker_; |
| 409 | // next_blocker_ is deleted by the task associated with the next |
| 410 | // input file. |
| 411 | } |
| 412 | |
| 413 | // We are blocked by this_blocker_. We block next_blocker_. We also |
| 414 | // lock the file. |
| 415 | |
| 416 | Task_token* |
| 417 | Add_symbols::is_runnable() |
| 418 | { |
| 419 | if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) |
| 420 | return this->this_blocker_; |
| 421 | if (this->object_->is_locked()) |
| 422 | return this->object_->token(); |
| 423 | return NULL; |
| 424 | } |
| 425 | |
| 426 | void |
| 427 | Add_symbols::locks(Task_locker* tl) |
| 428 | { |
| 429 | tl->add(this, this->next_blocker_); |
| 430 | tl->add(this, this->object_->token()); |
| 431 | } |
| 432 | |
| 433 | // Add the symbols in the object to the symbol table. |
| 434 | |
| 435 | void |
| 436 | Add_symbols::run(Workqueue* workqueue) |
| 437 | { |
| 438 | Pluginobj* pluginobj = this->object_->pluginobj(); |
| 439 | if (pluginobj != NULL) |
| 440 | { |
| 441 | this->object_->add_symbols(this->symtab_, this->sd_, this->layout_); |
| 442 | return; |
| 443 | } |
| 444 | |
| 445 | // If this file has an incompatible format, try for another file |
| 446 | // with the same name. |
| 447 | if (this->object_->searched_for() |
| 448 | && !parameters->is_compatible_target(this->object_->target())) |
| 449 | { |
| 450 | Read_symbols::incompatible_warning(this->input_argument_, |
| 451 | this->object_->input_file()); |
| 452 | Read_symbols::requeue(workqueue, this->input_objects_, this->symtab_, |
| 453 | this->layout_, this->dirpath_, this->dirindex_, |
| 454 | this->mapfile_, this->input_argument_, |
| 455 | this->input_group_, this->next_blocker_); |
| 456 | this->object_->release(); |
| 457 | delete this->object_; |
| 458 | } |
| 459 | else if (!this->input_objects_->add_object(this->object_)) |
| 460 | { |
| 461 | this->object_->release(); |
| 462 | delete this->object_; |
| 463 | } |
| 464 | else |
| 465 | { |
| 466 | this->object_->layout(this->symtab_, this->layout_, this->sd_); |
| 467 | this->object_->add_symbols(this->symtab_, this->sd_, this->layout_); |
| 468 | this->object_->release(); |
| 469 | } |
| 470 | delete this->sd_; |
| 471 | this->sd_ = NULL; |
| 472 | } |
| 473 | |
| 474 | // Class Finish_group. |
| 475 | |
| 476 | Finish_group::~Finish_group() |
| 477 | { |
| 478 | if (this->this_blocker_ != NULL) |
| 479 | delete this->this_blocker_; |
| 480 | // next_blocker_ is deleted by the task associated with the next |
| 481 | // input file following the group. |
| 482 | } |
| 483 | |
| 484 | // We need to wait for THIS_BLOCKER_ and unblock NEXT_BLOCKER_. |
| 485 | |
| 486 | Task_token* |
| 487 | Finish_group::is_runnable() |
| 488 | { |
| 489 | if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) |
| 490 | return this->this_blocker_; |
| 491 | return NULL; |
| 492 | } |
| 493 | |
| 494 | void |
| 495 | Finish_group::locks(Task_locker* tl) |
| 496 | { |
| 497 | tl->add(this, this->next_blocker_); |
| 498 | } |
| 499 | |
| 500 | // Loop over the archives until there are no new undefined symbols. |
| 501 | |
| 502 | void |
| 503 | Finish_group::run(Workqueue*) |
| 504 | { |
| 505 | int saw_undefined = this->saw_undefined_; |
| 506 | while (saw_undefined != this->symtab_->saw_undefined()) |
| 507 | { |
| 508 | saw_undefined = this->symtab_->saw_undefined(); |
| 509 | |
| 510 | for (Input_group::const_iterator p = this->input_group_->begin(); |
| 511 | p != this->input_group_->end(); |
| 512 | ++p) |
| 513 | { |
| 514 | Task_lock_obj<Archive> tl(this, *p); |
| 515 | |
| 516 | (*p)->add_symbols(this->symtab_, this->layout_, |
| 517 | this->input_objects_, this->mapfile_); |
| 518 | } |
| 519 | } |
| 520 | |
| 521 | // Delete all the archives now that we no longer need them. |
| 522 | for (Input_group::const_iterator p = this->input_group_->begin(); |
| 523 | p != this->input_group_->end(); |
| 524 | ++p) |
| 525 | delete *p; |
| 526 | delete this->input_group_; |
| 527 | } |
| 528 | |
| 529 | // Class Read_script |
| 530 | |
| 531 | Read_script::~Read_script() |
| 532 | { |
| 533 | if (this->this_blocker_ != NULL) |
| 534 | delete this->this_blocker_; |
| 535 | // next_blocker_ is deleted by the task associated with the next |
| 536 | // input file. |
| 537 | } |
| 538 | |
| 539 | // We are blocked by this_blocker_. |
| 540 | |
| 541 | Task_token* |
| 542 | Read_script::is_runnable() |
| 543 | { |
| 544 | if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) |
| 545 | return this->this_blocker_; |
| 546 | return NULL; |
| 547 | } |
| 548 | |
| 549 | // We don't unlock next_blocker_ here. If the script names any input |
| 550 | // files, then the last file will be responsible for unlocking it. |
| 551 | |
| 552 | void |
| 553 | Read_script::locks(Task_locker*) |
| 554 | { |
| 555 | } |
| 556 | |
| 557 | // Read the script, if it is a script. |
| 558 | |
| 559 | void |
| 560 | Read_script::run(Workqueue* workqueue) |
| 561 | { |
| 562 | bool used_next_blocker; |
| 563 | if (!read_input_script(workqueue, this->symtab_, this->layout_, |
| 564 | this->dirpath_, this->dirindex_, this->input_objects_, |
| 565 | this->mapfile_, this->input_group_, |
| 566 | this->input_argument_, this->input_file_, |
| 567 | this->next_blocker_, &used_next_blocker)) |
| 568 | { |
| 569 | // Here we have to handle any other input file types we need. |
| 570 | gold_error(_("%s: not an object or archive"), |
| 571 | this->input_file_->file().filename().c_str()); |
| 572 | } |
| 573 | |
| 574 | if (!used_next_blocker) |
| 575 | { |
| 576 | // Queue up a task to unlock next_blocker. We can't just unlock |
| 577 | // it here, as we don't hold the workqueue lock. |
| 578 | workqueue->queue_soon(new Unblock_token(NULL, this->next_blocker_)); |
| 579 | } |
| 580 | } |
| 581 | |
| 582 | // Return a debugging name for a Read_script task. |
| 583 | |
| 584 | std::string |
| 585 | Read_script::get_name() const |
| 586 | { |
| 587 | std::string ret("Read_script "); |
| 588 | if (this->input_argument_->file().is_lib()) |
| 589 | ret += "-l"; |
| 590 | ret += this->input_argument_->file().name(); |
| 591 | return ret; |
| 592 | } |
| 593 | |
| 594 | } // End namespace gold. |