1 // readsyms.cc -- read input file symbols for gold
3 // Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
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.
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.
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.
29 #include "dirsearch.h"
37 #include "incremental.h"
42 // If we fail to open the object, then we won't create an Add_symbols
43 // task. However, we still need to unblock the token, or else the
44 // link won't proceed to generate more error messages. We can only
45 // unblock tokens when the workqueue lock is held, so we need a dummy
46 // task to do that. The dummy task has to maintain the right sequence
47 // of blocks, so we need both this_blocker and next_blocker.
49 class Unblock_token : public Task
52 Unblock_token(Task_token* this_blocker, Task_token* next_blocker)
53 : this_blocker_(this_blocker), next_blocker_(next_blocker)
58 if (this->this_blocker_ != NULL)
59 delete this->this_blocker_;
65 if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
66 return this->this_blocker_;
71 locks(Task_locker* tl)
72 { tl->add(this, this->next_blocker_); }
80 { return "Unblock_token"; }
83 Task_token* this_blocker_;
84 Task_token* next_blocker_;
87 // Class read_symbols.
89 Read_symbols::~Read_symbols()
91 // The this_blocker_ and next_blocker_ pointers are passed on to the
95 // If appropriate, issue a warning about skipping an incompatible
99 Read_symbols::incompatible_warning(const Input_argument* input_argument,
100 const Input_file* input_file)
102 if (parameters->options().warn_search_mismatch())
103 gold_warning("skipping incompatible %s while searching for %s",
104 input_file->filename().c_str(),
105 input_argument->file().name());
108 // Requeue a Read_symbols task to search for the next object with the
112 Read_symbols::requeue(Workqueue* workqueue, Input_objects* input_objects,
113 Symbol_table* symtab, Layout* layout, Dirsearch* dirpath,
114 int dirindex, Mapfile* mapfile,
115 const Input_argument* input_argument,
116 Input_group* input_group, Task_token* next_blocker)
118 // Bump the directory search index.
121 // We don't need to worry about this_blocker, since we already
122 // reached it. However, we are removing the blocker on next_blocker
123 // because the calling task is completing. So we need to add a new
124 // blocker. Since next_blocker may be shared by several tasks, we
125 // need to increment the count with the workqueue lock held.
126 workqueue->add_blocker(next_blocker);
128 workqueue->queue(new Read_symbols(input_objects, symtab, layout, dirpath,
129 dirindex, mapfile, input_argument,
130 input_group, NULL, next_blocker));
133 // Return whether a Read_symbols task is runnable. We can read an
134 // ordinary input file immediately. For an archive specified using
135 // -l, we have to wait until the search path is complete.
138 Read_symbols::is_runnable()
140 if (this->input_argument_->is_file()
141 && this->input_argument_->file().may_need_search()
142 && this->dirpath_->token()->is_blocked())
143 return this->dirpath_->token();
148 // Return a Task_locker for a Read_symbols task. We don't need any
152 Read_symbols::locks(Task_locker*)
156 // Run a Read_symbols task.
159 Read_symbols::run(Workqueue* workqueue)
161 // If we didn't queue a new task, then we need to explicitly unblock
163 if (!this->do_read_symbols(workqueue))
164 workqueue->queue_soon(new Unblock_token(this->this_blocker_,
165 this->next_blocker_));
168 // Open the file and read the symbols. Return true if a new task was
169 // queued, false if that could not happen due to some error.
172 Read_symbols::do_read_symbols(Workqueue* workqueue)
174 if (this->input_argument_->is_group())
176 gold_assert(this->input_group_ == NULL);
177 this->do_group(workqueue);
181 Input_file* input_file = new Input_file(&this->input_argument_->file());
182 if (!input_file->open(*this->dirpath_, this, &this->dirindex_))
185 // Read enough of the file to pick up the entire ELF header.
187 off_t filesize = input_file->file().filesize();
191 gold_error(_("%s: file is empty"),
192 input_file->file().filename().c_str());
196 const unsigned char* ehdr;
198 bool is_elf = is_elf_object(input_file, 0, &ehdr, &read_size);
200 if (read_size >= Archive::sarmag)
203 = memcmp(ehdr, Archive::armagt, Archive::sarmag) == 0;
205 || memcmp(ehdr, Archive::armag, Archive::sarmag) == 0)
207 // This is an archive.
208 Archive* arch = new Archive(this->input_argument_->file().name(),
209 input_file, is_thin_archive,
210 this->dirpath_, this);
213 if (this->layout_->incremental_inputs())
215 const Input_argument* ia = this->input_argument_;
216 this->layout_->incremental_inputs()->report_archive(ia, arch);
219 // Unlock the archive so it can be used in the next task.
222 workqueue->queue_next(new Add_archive_symbols(this->symtab_,
224 this->input_objects_,
228 this->input_argument_,
232 this->next_blocker_));
237 if (parameters->options().has_plugins())
239 Pluginobj* obj = parameters->options().plugins()->claim_file(input_file,
243 // The input file was claimed by a plugin, and its symbols
244 // have been provided by the plugin.
246 // We are done with the file at this point, so unlock it.
249 workqueue->queue_next(new Add_symbols(this->input_objects_,
255 this->input_argument_,
260 this->next_blocker_));
267 // This is an ELF object.
269 bool unconfigured = false;
270 bool* punconfigured = (input_file->will_search_for()
273 Object* obj = make_elf_object(input_file->filename(),
274 input_file, 0, ehdr, read_size,
280 Read_symbols::incompatible_warning(this->input_argument_,
282 input_file->file().release();
283 input_file->file().unlock(this);
286 return this->do_read_symbols(workqueue);
291 Read_symbols_data* sd = new Read_symbols_data;
292 obj->read_symbols(sd);
294 if (this->layout_->incremental_inputs())
296 const Input_argument* ia = this->input_argument_;
297 this->layout_->incremental_inputs()->report_object(ia, obj);
300 // Opening the file locked it, so now we need to unlock it. We
301 // need to unlock it before queuing the Add_symbols task,
302 // because the workqueue doesn't know about our lock on the
303 // file. If we queue the Add_symbols task first, it will be
304 // stuck on the end of the file lock, but since the workqueue
305 // doesn't know about that lock, it will never release the
308 input_file->file().unlock(this);
310 // We use queue_next because everything is cached for this
311 // task to run right away if possible.
313 workqueue->queue_next(new Add_symbols(this->input_objects_,
314 this->symtab_, this->layout_,
318 this->input_argument_,
323 this->next_blocker_));
328 // Queue up a task to try to parse this file as a script. We use a
329 // separate task so that the script will be read in order with other
330 // objects named on the command line. Also so that we don't try to
331 // read multiple scripts simultaneously, which could lead to
332 // unpredictable changes to the General_options structure.
334 workqueue->queue_soon(new Read_script(this->symtab_,
338 this->input_objects_,
341 this->input_argument_,
344 this->next_blocker_));
348 // Handle a group. We need to walk through the arguments over and
349 // over until we don't see any new undefined symbols. We do this by
350 // setting off Read_symbols Tasks as usual, but recording the archive
351 // entries instead of deleting them. We also start a Finish_group
352 // Task which runs after we've read all the symbols. In that task we
353 // process the archives in a loop until we are done.
356 Read_symbols::do_group(Workqueue* workqueue)
358 Input_group* input_group = new Input_group();
360 const Input_file_group* group = this->input_argument_->group();
361 Task_token* this_blocker = this->this_blocker_;
363 Finish_group* finish_group = new Finish_group(this->input_objects_,
368 this->next_blocker_);
370 Task_token* next_blocker = new Task_token(true);
371 next_blocker->add_blocker();
372 workqueue->queue_soon(new Start_group(this->symtab_, finish_group,
373 this_blocker, next_blocker));
374 this_blocker = next_blocker;
376 for (Input_file_group::const_iterator p = group->begin();
380 const Input_argument* arg = &*p;
381 gold_assert(arg->is_file());
383 next_blocker = new Task_token(true);
384 next_blocker->add_blocker();
385 workqueue->queue_soon(new Read_symbols(this->input_objects_,
386 this->symtab_, this->layout_,
387 this->dirpath_, this->dirindex_,
388 this->mapfile_, arg, input_group,
389 this_blocker, next_blocker));
390 this_blocker = next_blocker;
393 finish_group->set_blocker(this_blocker);
395 workqueue->queue_soon(finish_group);
398 // Return a debugging name for a Read_symbols task.
401 Read_symbols::get_name() const
403 if (!this->input_argument_->is_group())
405 std::string ret("Read_symbols ");
406 if (this->input_argument_->file().is_lib())
408 else if (this->input_argument_->file().is_searched_file())
410 ret += this->input_argument_->file().name();
414 std::string ret("Read_symbols group (");
415 bool add_space = false;
416 const Input_file_group* group = this->input_argument_->group();
417 for (Input_file_group::const_iterator p = group->begin();
423 ret += p->file().name();
429 // Class Add_symbols.
431 Add_symbols::~Add_symbols()
433 if (this->this_blocker_ != NULL)
434 delete this->this_blocker_;
435 // next_blocker_ is deleted by the task associated with the next
439 // We are blocked by this_blocker_. We block next_blocker_. We also
443 Add_symbols::is_runnable()
445 if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
446 return this->this_blocker_;
447 if (this->object_->is_locked())
448 return this->object_->token();
453 Add_symbols::locks(Task_locker* tl)
455 tl->add(this, this->next_blocker_);
456 tl->add(this, this->object_->token());
459 // Add the symbols in the object to the symbol table.
462 Add_symbols::run(Workqueue*)
464 Pluginobj* pluginobj = this->object_->pluginobj();
465 if (pluginobj != NULL)
467 this->object_->add_symbols(this->symtab_, this->sd_, this->layout_);
471 if (!this->input_objects_->add_object(this->object_))
473 this->object_->release();
474 delete this->object_;
478 this->object_->layout(this->symtab_, this->layout_, this->sd_);
479 this->object_->add_symbols(this->symtab_, this->sd_, this->layout_);
480 this->object_->release();
486 // Class Start_group.
488 Start_group::~Start_group()
490 if (this->this_blocker_ != NULL)
491 delete this->this_blocker_;
492 // next_blocker_ is deleted by the task associated with the first
493 // file in the group.
496 // We need to wait for THIS_BLOCKER_ and unblock NEXT_BLOCKER_.
499 Start_group::is_runnable()
501 if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
502 return this->this_blocker_;
507 Start_group::locks(Task_locker* tl)
509 tl->add(this, this->next_blocker_);
512 // Store the number of undefined symbols we see now.
515 Start_group::run(Workqueue*)
517 this->finish_group_->set_saw_undefined(this->symtab_->saw_undefined());
520 // Class Finish_group.
522 Finish_group::~Finish_group()
524 if (this->this_blocker_ != NULL)
525 delete this->this_blocker_;
526 // next_blocker_ is deleted by the task associated with the next
527 // input file following the group.
530 // We need to wait for THIS_BLOCKER_ and unblock NEXT_BLOCKER_.
533 Finish_group::is_runnable()
535 if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
536 return this->this_blocker_;
541 Finish_group::locks(Task_locker* tl)
543 tl->add(this, this->next_blocker_);
546 // Loop over the archives until there are no new undefined symbols.
549 Finish_group::run(Workqueue*)
551 size_t saw_undefined = this->saw_undefined_;
552 while (saw_undefined != this->symtab_->saw_undefined())
554 saw_undefined = this->symtab_->saw_undefined();
556 for (Input_group::const_iterator p = this->input_group_->begin();
557 p != this->input_group_->end();
560 Task_lock_obj<Archive> tl(this, *p);
562 (*p)->add_symbols(this->symtab_, this->layout_,
563 this->input_objects_, this->mapfile_);
567 // Delete all the archives now that we no longer need them.
568 for (Input_group::const_iterator p = this->input_group_->begin();
569 p != this->input_group_->end();
572 delete this->input_group_;
577 Read_script::~Read_script()
579 if (this->this_blocker_ != NULL)
580 delete this->this_blocker_;
581 // next_blocker_ is deleted by the task associated with the next
585 // We are blocked by this_blocker_.
588 Read_script::is_runnable()
590 if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
591 return this->this_blocker_;
595 // We don't unlock next_blocker_ here. If the script names any input
596 // files, then the last file will be responsible for unlocking it.
599 Read_script::locks(Task_locker*)
603 // Read the script, if it is a script.
606 Read_script::run(Workqueue* workqueue)
608 bool used_next_blocker;
609 if (!read_input_script(workqueue, this->symtab_, this->layout_,
610 this->dirpath_, this->dirindex_, this->input_objects_,
611 this->mapfile_, this->input_group_,
612 this->input_argument_, this->input_file_,
613 this->next_blocker_, &used_next_blocker))
615 // Here we have to handle any other input file types we need.
616 gold_error(_("%s: not an object or archive"),
617 this->input_file_->file().filename().c_str());
620 if (!used_next_blocker)
622 // Queue up a task to unlock next_blocker. We can't just unlock
623 // it here, as we don't hold the workqueue lock.
624 workqueue->queue_soon(new Unblock_token(NULL, this->next_blocker_));
628 // Return a debugging name for a Read_script task.
631 Read_script::get_name() const
633 std::string ret("Read_script ");
634 if (this->input_argument_->file().is_lib())
636 else if (this->input_argument_->file().is_searched_file())
638 ret += this->input_argument_->file().name();
642 } // End namespace gold.