| 1 | // readsyms.cc -- read input file symbols for gold |
| 2 | |
| 3 | // Copyright 2006, 2007 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 | |
| 36 | namespace gold |
| 37 | { |
| 38 | |
| 39 | // If we fail to open the object, then we won't create an Add_symbols |
| 40 | // task. However, we still need to unblock the token, or else the |
| 41 | // link won't proceed to generate more error messages. We can only |
| 42 | // unblock tokens in the main thread, so we need a dummy task to do |
| 43 | // that. The dummy task has to maintain the right sequence of blocks, |
| 44 | // so we need both this_blocker and next_blocker. |
| 45 | |
| 46 | class Unblock_token : public Task |
| 47 | { |
| 48 | public: |
| 49 | Unblock_token(Task_token* this_blocker, Task_token* next_blocker) |
| 50 | : this_blocker_(this_blocker), next_blocker_(next_blocker) |
| 51 | { } |
| 52 | |
| 53 | ~Unblock_token() |
| 54 | { |
| 55 | if (this->this_blocker_ != NULL) |
| 56 | delete this->this_blocker_; |
| 57 | } |
| 58 | |
| 59 | Is_runnable_type |
| 60 | is_runnable(Workqueue*) |
| 61 | { |
| 62 | if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) |
| 63 | return IS_BLOCKED; |
| 64 | return IS_RUNNABLE; |
| 65 | } |
| 66 | |
| 67 | Task_locker* |
| 68 | locks(Workqueue* workqueue) |
| 69 | { return new Task_locker_block(*this->next_blocker_, workqueue); } |
| 70 | |
| 71 | void |
| 72 | run(Workqueue*) |
| 73 | { } |
| 74 | |
| 75 | std::string |
| 76 | get_name() const |
| 77 | { return "Unblock_token"; } |
| 78 | |
| 79 | private: |
| 80 | Task_token* this_blocker_; |
| 81 | Task_token* next_blocker_; |
| 82 | }; |
| 83 | |
| 84 | // Class read_symbols. |
| 85 | |
| 86 | Read_symbols::~Read_symbols() |
| 87 | { |
| 88 | // The this_blocker_ and next_blocker_ pointers are passed on to the |
| 89 | // Add_symbols task. |
| 90 | } |
| 91 | |
| 92 | // Return whether a Read_symbols task is runnable. We can read an |
| 93 | // ordinary input file immediately. For an archive specified using |
| 94 | // -l, we have to wait until the search path is complete. |
| 95 | |
| 96 | Task::Is_runnable_type |
| 97 | Read_symbols::is_runnable(Workqueue*) |
| 98 | { |
| 99 | if (this->input_argument_->is_file() |
| 100 | && this->input_argument_->file().may_need_search() |
| 101 | && this->dirpath_.token().is_blocked()) |
| 102 | return IS_BLOCKED; |
| 103 | |
| 104 | return IS_RUNNABLE; |
| 105 | } |
| 106 | |
| 107 | // Return a Task_locker for a Read_symbols task. We don't need any |
| 108 | // locks here. |
| 109 | |
| 110 | Task_locker* |
| 111 | Read_symbols::locks(Workqueue*) |
| 112 | { |
| 113 | return NULL; |
| 114 | } |
| 115 | |
| 116 | // Run a Read_symbols task. |
| 117 | |
| 118 | void |
| 119 | Read_symbols::run(Workqueue* workqueue) |
| 120 | { |
| 121 | // If we didn't queue a new task, then we need to explicitly unblock |
| 122 | // the token. |
| 123 | if (!this->do_read_symbols(workqueue)) |
| 124 | workqueue->queue_front(new Unblock_token(this->this_blocker_, |
| 125 | this->next_blocker_)); |
| 126 | } |
| 127 | |
| 128 | // Open the file and read the symbols. Return true if a new task was |
| 129 | // queued, false if that could not happen due to some error. |
| 130 | |
| 131 | bool |
| 132 | Read_symbols::do_read_symbols(Workqueue* workqueue) |
| 133 | { |
| 134 | if (this->input_argument_->is_group()) |
| 135 | { |
| 136 | gold_assert(this->input_group_ == NULL); |
| 137 | this->do_group(workqueue); |
| 138 | return true; |
| 139 | } |
| 140 | |
| 141 | Input_file* input_file = new Input_file(&this->input_argument_->file()); |
| 142 | if (!input_file->open(this->options_, this->dirpath_)) |
| 143 | return false; |
| 144 | |
| 145 | // Read enough of the file to pick up the entire ELF header. |
| 146 | |
| 147 | off_t filesize = input_file->file().filesize(); |
| 148 | |
| 149 | if (filesize == 0) |
| 150 | { |
| 151 | gold_error(_("%s: file is empty"), |
| 152 | input_file->file().filename().c_str()); |
| 153 | return false; |
| 154 | } |
| 155 | |
| 156 | unsigned char ehdr_buf[elfcpp::Elf_sizes<64>::ehdr_size]; |
| 157 | |
| 158 | int read_size = elfcpp::Elf_sizes<64>::ehdr_size; |
| 159 | if (filesize < read_size) |
| 160 | read_size = filesize; |
| 161 | |
| 162 | input_file->file().read(0, read_size, ehdr_buf); |
| 163 | |
| 164 | if (read_size >= 4) |
| 165 | { |
| 166 | static unsigned char elfmagic[4] = |
| 167 | { |
| 168 | elfcpp::ELFMAG0, elfcpp::ELFMAG1, |
| 169 | elfcpp::ELFMAG2, elfcpp::ELFMAG3 |
| 170 | }; |
| 171 | if (memcmp(ehdr_buf, elfmagic, 4) == 0) |
| 172 | { |
| 173 | // This is an ELF object. |
| 174 | |
| 175 | Object* obj = make_elf_object(input_file->filename(), |
| 176 | input_file, 0, ehdr_buf, read_size); |
| 177 | if (obj == NULL) |
| 178 | return false; |
| 179 | |
| 180 | // We don't have a way to record a non-archive in an input |
| 181 | // group. If this is an ordinary object file, we can't |
| 182 | // include it more than once anyhow. If this is a dynamic |
| 183 | // object, then including it a second time changes nothing. |
| 184 | if (this->input_group_ != NULL && !obj->is_dynamic()) |
| 185 | { |
| 186 | gold_error(_("%s: ordinary object found in input group"), |
| 187 | input_file->name()); |
| 188 | return false; |
| 189 | } |
| 190 | |
| 191 | Read_symbols_data* sd = new Read_symbols_data; |
| 192 | obj->read_symbols(sd); |
| 193 | workqueue->queue_front(new Add_symbols(this->input_objects_, |
| 194 | this->symtab_, this->layout_, |
| 195 | obj, sd, |
| 196 | this->this_blocker_, |
| 197 | this->next_blocker_)); |
| 198 | |
| 199 | // Opening the file locked it, so now we need to unlock it. |
| 200 | input_file->file().unlock(); |
| 201 | |
| 202 | return true; |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | if (read_size >= Archive::sarmag) |
| 207 | { |
| 208 | if (memcmp(ehdr_buf, Archive::armag, Archive::sarmag) == 0) |
| 209 | { |
| 210 | // This is an archive. |
| 211 | Archive* arch = new Archive(this->input_argument_->file().name(), |
| 212 | input_file); |
| 213 | arch->setup(); |
| 214 | workqueue->queue(new Add_archive_symbols(this->symtab_, |
| 215 | this->layout_, |
| 216 | this->input_objects_, |
| 217 | arch, |
| 218 | this->input_group_, |
| 219 | this->this_blocker_, |
| 220 | this->next_blocker_)); |
| 221 | return true; |
| 222 | } |
| 223 | } |
| 224 | |
| 225 | // Try to parse this file as a script. |
| 226 | if (read_input_script(workqueue, this->options_, this->symtab_, |
| 227 | this->layout_, this->dirpath_, this->input_objects_, |
| 228 | this->input_group_, this->input_argument_, input_file, |
| 229 | ehdr_buf, read_size, this->this_blocker_, |
| 230 | this->next_blocker_)) |
| 231 | return true; |
| 232 | |
| 233 | // Here we have to handle any other input file types we need. |
| 234 | gold_error(_("%s: not an object or archive"), |
| 235 | input_file->file().filename().c_str()); |
| 236 | |
| 237 | return false; |
| 238 | } |
| 239 | |
| 240 | // Handle a group. We need to walk through the arguments over and |
| 241 | // over until we don't see any new undefined symbols. We do this by |
| 242 | // setting off Read_symbols Tasks as usual, but recording the archive |
| 243 | // entries instead of deleting them. We also start a Finish_group |
| 244 | // Task which runs after we've read all the symbols. In that task we |
| 245 | // process the archives in a loop until we are done. |
| 246 | |
| 247 | void |
| 248 | Read_symbols::do_group(Workqueue* workqueue) |
| 249 | { |
| 250 | Input_group* input_group = new Input_group(); |
| 251 | |
| 252 | const Input_file_group* group = this->input_argument_->group(); |
| 253 | Task_token* this_blocker = this->this_blocker_; |
| 254 | for (Input_file_group::const_iterator p = group->begin(); |
| 255 | p != group->end(); |
| 256 | ++p) |
| 257 | { |
| 258 | const Input_argument* arg = &*p; |
| 259 | gold_assert(arg->is_file()); |
| 260 | |
| 261 | Task_token* next_blocker = new Task_token(); |
| 262 | next_blocker->add_blocker(); |
| 263 | workqueue->queue(new Read_symbols(this->options_, this->input_objects_, |
| 264 | this->symtab_, this->layout_, |
| 265 | this->dirpath_, arg, input_group, |
| 266 | this_blocker, next_blocker)); |
| 267 | this_blocker = next_blocker; |
| 268 | } |
| 269 | |
| 270 | const int saw_undefined = this->symtab_->saw_undefined(); |
| 271 | workqueue->queue(new Finish_group(this->input_objects_, |
| 272 | this->symtab_, |
| 273 | this->layout_, |
| 274 | input_group, |
| 275 | saw_undefined, |
| 276 | this_blocker, |
| 277 | this->next_blocker_)); |
| 278 | } |
| 279 | |
| 280 | // Return a debugging name for a Read_symbols task. |
| 281 | |
| 282 | std::string |
| 283 | Read_symbols::get_name() const |
| 284 | { |
| 285 | if (!this->input_argument_->is_group()) |
| 286 | { |
| 287 | std::string ret("Read_symbols "); |
| 288 | if (this->input_argument_->file().is_lib()) |
| 289 | ret += "-l"; |
| 290 | ret += this->input_argument_->file().name(); |
| 291 | return ret; |
| 292 | } |
| 293 | |
| 294 | std::string ret("Read_symbols group ("); |
| 295 | bool add_space = false; |
| 296 | const Input_file_group* group = this->input_argument_->group(); |
| 297 | for (Input_file_group::const_iterator p = group->begin(); |
| 298 | p != group->end(); |
| 299 | ++p) |
| 300 | { |
| 301 | if (add_space) |
| 302 | ret += ' '; |
| 303 | ret += p->file().name(); |
| 304 | add_space = true; |
| 305 | } |
| 306 | return ret + ')'; |
| 307 | } |
| 308 | |
| 309 | // Class Add_symbols. |
| 310 | |
| 311 | Add_symbols::~Add_symbols() |
| 312 | { |
| 313 | if (this->this_blocker_ != NULL) |
| 314 | delete this->this_blocker_; |
| 315 | // next_blocker_ is deleted by the task associated with the next |
| 316 | // input file. |
| 317 | } |
| 318 | |
| 319 | // We are blocked by this_blocker_. We block next_blocker_. We also |
| 320 | // lock the file. |
| 321 | |
| 322 | Task::Is_runnable_type |
| 323 | Add_symbols::is_runnable(Workqueue*) |
| 324 | { |
| 325 | if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) |
| 326 | return IS_BLOCKED; |
| 327 | if (this->object_->is_locked()) |
| 328 | return IS_LOCKED; |
| 329 | return IS_RUNNABLE; |
| 330 | } |
| 331 | |
| 332 | class Add_symbols::Add_symbols_locker : public Task_locker |
| 333 | { |
| 334 | public: |
| 335 | Add_symbols_locker(Task_token& token, Workqueue* workqueue, |
| 336 | Object* object) |
| 337 | : blocker_(token, workqueue), objlock_(*object) |
| 338 | { } |
| 339 | |
| 340 | private: |
| 341 | Task_locker_block blocker_; |
| 342 | Task_locker_obj<Object> objlock_; |
| 343 | }; |
| 344 | |
| 345 | Task_locker* |
| 346 | Add_symbols::locks(Workqueue* workqueue) |
| 347 | { |
| 348 | return new Add_symbols_locker(*this->next_blocker_, workqueue, |
| 349 | this->object_); |
| 350 | } |
| 351 | |
| 352 | // Add the symbols in the object to the symbol table. |
| 353 | |
| 354 | void |
| 355 | Add_symbols::run(Workqueue*) |
| 356 | { |
| 357 | if (!this->input_objects_->add_object(this->object_)) |
| 358 | { |
| 359 | // FIXME: We need to close the descriptor here. |
| 360 | delete this->object_; |
| 361 | } |
| 362 | else |
| 363 | { |
| 364 | this->object_->layout(this->symtab_, this->layout_, this->sd_); |
| 365 | this->object_->add_symbols(this->symtab_, this->sd_); |
| 366 | } |
| 367 | delete this->sd_; |
| 368 | this->sd_ = NULL; |
| 369 | } |
| 370 | |
| 371 | // Class Finish_group. |
| 372 | |
| 373 | Finish_group::~Finish_group() |
| 374 | { |
| 375 | if (this->this_blocker_ != NULL) |
| 376 | delete this->this_blocker_; |
| 377 | // next_blocker_ is deleted by the task associated with the next |
| 378 | // input file following the group. |
| 379 | } |
| 380 | |
| 381 | // We need to wait for THIS_BLOCKER_ and unblock NEXT_BLOCKER_. |
| 382 | |
| 383 | Task::Is_runnable_type |
| 384 | Finish_group::is_runnable(Workqueue*) |
| 385 | { |
| 386 | if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) |
| 387 | return IS_BLOCKED; |
| 388 | return IS_RUNNABLE; |
| 389 | } |
| 390 | |
| 391 | Task_locker* |
| 392 | Finish_group::locks(Workqueue* workqueue) |
| 393 | { |
| 394 | return new Task_locker_block(*this->next_blocker_, workqueue); |
| 395 | } |
| 396 | |
| 397 | // Loop over the archives until there are no new undefined symbols. |
| 398 | |
| 399 | void |
| 400 | Finish_group::run(Workqueue*) |
| 401 | { |
| 402 | int saw_undefined = this->saw_undefined_; |
| 403 | while (saw_undefined != this->symtab_->saw_undefined()) |
| 404 | { |
| 405 | saw_undefined = this->symtab_->saw_undefined(); |
| 406 | |
| 407 | for (Input_group::const_iterator p = this->input_group_->begin(); |
| 408 | p != this->input_group_->end(); |
| 409 | ++p) |
| 410 | { |
| 411 | Task_lock_obj<Archive> tl(**p); |
| 412 | |
| 413 | (*p)->add_symbols(this->symtab_, this->layout_, |
| 414 | this->input_objects_); |
| 415 | } |
| 416 | } |
| 417 | |
| 418 | // Delete all the archives now that we no longer need them. |
| 419 | for (Input_group::const_iterator p = this->input_group_->begin(); |
| 420 | p != this->input_group_->end(); |
| 421 | ++p) |
| 422 | delete *p; |
| 423 | delete this->input_group_; |
| 424 | } |
| 425 | |
| 426 | } // End namespace gold. |