1 // readsyms.cc -- read input file symbols for gold
3 // Copyright 2006, 2007, 2008, 2009 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"
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.
47 class Unblock_token
: public Task
50 Unblock_token(Task_token
* this_blocker
, Task_token
* next_blocker
)
51 : this_blocker_(this_blocker
), next_blocker_(next_blocker
)
56 if (this->this_blocker_
!= NULL
)
57 delete this->this_blocker_
;
63 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
64 return this->this_blocker_
;
69 locks(Task_locker
* tl
)
70 { tl
->add(this, this->next_blocker_
); }
78 { return "Unblock_token"; }
81 Task_token
* this_blocker_
;
82 Task_token
* next_blocker_
;
85 // Class read_symbols.
87 Read_symbols::~Read_symbols()
89 // The this_blocker_ and next_blocker_ pointers are passed on to the
93 // If appropriate, issue a warning about skipping an incompatible
97 Read_symbols::incompatible_warning(const Input_argument
* input_argument
,
98 const Input_file
* input_file
)
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());
106 // Requeue a Read_symbols task to search for the next object with the
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
)
116 // Bump the directory search index.
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
);
126 workqueue
->queue(new Read_symbols(input_objects
, symtab
, layout
, dirpath
,
127 dirindex
, mapfile
, input_argument
,
128 input_group
, NULL
, next_blocker
));
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.
136 Read_symbols::is_runnable()
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();
146 // Return a Task_locker for a Read_symbols task. We don't need any
150 Read_symbols::locks(Task_locker
*)
154 // Run a Read_symbols task.
157 Read_symbols::run(Workqueue
* workqueue
)
159 // If we didn't queue a new task, then we need to explicitly unblock
161 if (!this->do_read_symbols(workqueue
))
162 workqueue
->queue_soon(new Unblock_token(this->this_blocker_
,
163 this->next_blocker_
));
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.
170 Read_symbols::do_read_symbols(Workqueue
* workqueue
)
172 if (this->input_argument_
->is_group())
174 gold_assert(this->input_group_
== NULL
);
175 this->do_group(workqueue
);
179 Input_file
* input_file
= new Input_file(&this->input_argument_
->file());
180 if (!input_file
->open(*this->dirpath_
, this, &this->dirindex_
))
183 // Read enough of the file to pick up the entire ELF header.
185 off_t filesize
= input_file
->file().filesize();
189 gold_error(_("%s: file is empty"),
190 input_file
->file().filename().c_str());
194 int read_size
= elfcpp::Elf_sizes
<64>::ehdr_size
;
195 if (filesize
< read_size
)
196 read_size
= filesize
;
198 const unsigned char* ehdr
= input_file
->file().get_view(0, 0, read_size
,
201 if (read_size
>= Archive::sarmag
)
204 = memcmp(ehdr
, Archive::armagt
, Archive::sarmag
) == 0;
206 || memcmp(ehdr
, Archive::armag
, Archive::sarmag
) == 0)
208 // This is an archive.
209 Archive
* arch
= new Archive(this->input_argument_
->file().name(),
210 input_file
, is_thin_archive
,
211 this->dirpath_
, this);
214 // Unlock the archive so it can be used in the next task.
217 workqueue
->queue_next(new Add_archive_symbols(this->symtab_
,
219 this->input_objects_
,
223 this->input_argument_
,
227 this->next_blocker_
));
232 if (parameters
->options().has_plugins())
234 Pluginobj
* obj
= parameters
->options().plugins()->claim_file(input_file
,
238 // The input file was claimed by a plugin, and its symbols
239 // have been provided by the plugin.
241 // We are done with the file at this point, so unlock it.
244 workqueue
->queue_next(new Add_symbols(this->input_objects_
,
250 this->input_argument_
,
255 this->next_blocker_
));
262 static unsigned char elfmagic
[4] =
264 elfcpp::ELFMAG0
, elfcpp::ELFMAG1
,
265 elfcpp::ELFMAG2
, elfcpp::ELFMAG3
267 if (memcmp(ehdr
, elfmagic
, 4) == 0)
269 // This is an ELF object.
272 Object
* obj
= make_elf_object(input_file
->filename(),
273 input_file
, 0, ehdr
, read_size
,
277 if (unconfigured
&& input_file
->will_search_for())
279 Read_symbols::incompatible_warning(this->input_argument_
,
281 input_file
->file().release();
282 input_file
->file().unlock(this);
285 return this->do_read_symbols(workqueue
);
290 Read_symbols_data
* sd
= new Read_symbols_data
;
291 obj
->read_symbols(sd
);
293 // Opening the file locked it, so now we need to unlock it.
294 // We need to unlock it before queuing the Add_symbols task,
295 // because the workqueue doesn't know about our lock on the
296 // file. If we queue the Add_symbols task first, it will be
297 // stuck on the end of the file lock, but since the
298 // workqueue doesn't know about that lock, it will never
299 // release the Add_symbols task.
301 input_file
->file().unlock(this);
303 // We use queue_next because everything is cached for this
304 // task to run right away if possible.
306 workqueue
->queue_next(new Add_symbols(this->input_objects_
,
307 this->symtab_
, this->layout_
,
311 this->input_argument_
,
316 this->next_blocker_
));
322 // Queue up a task to try to parse this file as a script. We use a
323 // separate task so that the script will be read in order with other
324 // objects named on the command line. Also so that we don't try to
325 // read multiple scripts simultaneously, which could lead to
326 // unpredictable changes to the General_options structure.
328 workqueue
->queue_soon(new Read_script(this->symtab_
,
332 this->input_objects_
,
335 this->input_argument_
,
338 this->next_blocker_
));
342 // Handle a group. We need to walk through the arguments over and
343 // over until we don't see any new undefined symbols. We do this by
344 // setting off Read_symbols Tasks as usual, but recording the archive
345 // entries instead of deleting them. We also start a Finish_group
346 // Task which runs after we've read all the symbols. In that task we
347 // process the archives in a loop until we are done.
350 Read_symbols::do_group(Workqueue
* workqueue
)
352 Input_group
* input_group
= new Input_group();
354 const Input_file_group
* group
= this->input_argument_
->group();
355 Task_token
* this_blocker
= this->this_blocker_
;
357 for (Input_file_group::const_iterator p
= group
->begin();
361 const Input_argument
* arg
= &*p
;
362 gold_assert(arg
->is_file());
364 Task_token
* next_blocker
= new Task_token(true);
365 next_blocker
->add_blocker();
366 workqueue
->queue_soon(new Read_symbols(this->input_objects_
,
367 this->symtab_
, this->layout_
,
368 this->dirpath_
, this->dirindex_
,
369 this->mapfile_
, arg
, input_group
,
370 this_blocker
, next_blocker
));
371 this_blocker
= next_blocker
;
374 const int saw_undefined
= this->symtab_
->saw_undefined();
375 workqueue
->queue_soon(new Finish_group(this->input_objects_
,
382 this->next_blocker_
));
385 // Return a debugging name for a Read_symbols task.
388 Read_symbols::get_name() const
390 if (!this->input_argument_
->is_group())
392 std::string
ret("Read_symbols ");
393 if (this->input_argument_
->file().is_lib())
395 ret
+= this->input_argument_
->file().name();
399 std::string
ret("Read_symbols group (");
400 bool add_space
= false;
401 const Input_file_group
* group
= this->input_argument_
->group();
402 for (Input_file_group::const_iterator p
= group
->begin();
408 ret
+= p
->file().name();
414 // Class Add_symbols.
416 Add_symbols::~Add_symbols()
418 if (this->this_blocker_
!= NULL
)
419 delete this->this_blocker_
;
420 // next_blocker_ is deleted by the task associated with the next
424 // We are blocked by this_blocker_. We block next_blocker_. We also
428 Add_symbols::is_runnable()
430 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
431 return this->this_blocker_
;
432 if (this->object_
->is_locked())
433 return this->object_
->token();
438 Add_symbols::locks(Task_locker
* tl
)
440 tl
->add(this, this->next_blocker_
);
441 tl
->add(this, this->object_
->token());
444 // Add the symbols in the object to the symbol table.
447 Add_symbols::run(Workqueue
* workqueue
)
449 Pluginobj
* pluginobj
= this->object_
->pluginobj();
450 if (pluginobj
!= NULL
)
452 this->object_
->add_symbols(this->symtab_
, this->sd_
, this->layout_
);
456 // If this file has an incompatible format, try for another file
457 // with the same name.
458 if (this->object_
->searched_for()
459 && !parameters
->is_compatible_target(this->object_
->target()))
461 Read_symbols::incompatible_warning(this->input_argument_
,
462 this->object_
->input_file());
463 Read_symbols::requeue(workqueue
, this->input_objects_
, this->symtab_
,
464 this->layout_
, this->dirpath_
, this->dirindex_
,
465 this->mapfile_
, this->input_argument_
,
466 this->input_group_
, this->next_blocker_
);
467 this->object_
->release();
468 delete this->object_
;
470 else if (!this->input_objects_
->add_object(this->object_
))
472 this->object_
->release();
473 delete this->object_
;
477 this->object_
->layout(this->symtab_
, this->layout_
, this->sd_
);
478 this->object_
->add_symbols(this->symtab_
, this->sd_
, this->layout_
);
479 this->object_
->release();
485 // Class Finish_group.
487 Finish_group::~Finish_group()
489 if (this->this_blocker_
!= NULL
)
490 delete this->this_blocker_
;
491 // next_blocker_ is deleted by the task associated with the next
492 // input file following the group.
495 // We need to wait for THIS_BLOCKER_ and unblock NEXT_BLOCKER_.
498 Finish_group::is_runnable()
500 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
501 return this->this_blocker_
;
506 Finish_group::locks(Task_locker
* tl
)
508 tl
->add(this, this->next_blocker_
);
511 // Loop over the archives until there are no new undefined symbols.
514 Finish_group::run(Workqueue
*)
516 int saw_undefined
= this->saw_undefined_
;
517 while (saw_undefined
!= this->symtab_
->saw_undefined())
519 saw_undefined
= this->symtab_
->saw_undefined();
521 for (Input_group::const_iterator p
= this->input_group_
->begin();
522 p
!= this->input_group_
->end();
525 Task_lock_obj
<Archive
> tl(this, *p
);
527 (*p
)->add_symbols(this->symtab_
, this->layout_
,
528 this->input_objects_
, this->mapfile_
);
532 // Delete all the archives now that we no longer need them.
533 for (Input_group::const_iterator p
= this->input_group_
->begin();
534 p
!= this->input_group_
->end();
537 delete this->input_group_
;
542 Read_script::~Read_script()
544 if (this->this_blocker_
!= NULL
)
545 delete this->this_blocker_
;
546 // next_blocker_ is deleted by the task associated with the next
550 // We are blocked by this_blocker_.
553 Read_script::is_runnable()
555 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
556 return this->this_blocker_
;
560 // We don't unlock next_blocker_ here. If the script names any input
561 // files, then the last file will be responsible for unlocking it.
564 Read_script::locks(Task_locker
*)
568 // Read the script, if it is a script.
571 Read_script::run(Workqueue
* workqueue
)
573 bool used_next_blocker
;
574 if (!read_input_script(workqueue
, this->symtab_
, this->layout_
,
575 this->dirpath_
, this->dirindex_
, this->input_objects_
,
576 this->mapfile_
, this->input_group_
,
577 this->input_argument_
, this->input_file_
,
578 this->next_blocker_
, &used_next_blocker
))
580 // Here we have to handle any other input file types we need.
581 gold_error(_("%s: not an object or archive"),
582 this->input_file_
->file().filename().c_str());
585 if (!used_next_blocker
)
587 // Queue up a task to unlock next_blocker. We can't just unlock
588 // it here, as we don't hold the workqueue lock.
589 workqueue
->queue_soon(new Unblock_token(NULL
, this->next_blocker_
));
593 // Return a debugging name for a Read_script task.
596 Read_script::get_name() const
598 std::string
ret("Read_script ");
599 if (this->input_argument_
->file().is_lib())
601 ret
+= this->input_argument_
->file().name();
605 } // End namespace gold.