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 // Return whether a Read_symbols task is runnable. We can read an
94 // ordinary input file immediately. For an archive specified using
95 // -l, we have to wait until the search path is complete.
98 Read_symbols::is_runnable()
100 if (this->input_argument_
->is_file()
101 && this->input_argument_
->file().may_need_search()
102 && this->dirpath_
->token()->is_blocked())
103 return this->dirpath_
->token();
108 // Return a Task_locker for a Read_symbols task. We don't need any
112 Read_symbols::locks(Task_locker
*)
116 // Run a Read_symbols task.
119 Read_symbols::run(Workqueue
* workqueue
)
121 // If we didn't queue a new task, then we need to explicitly unblock
123 if (!this->do_read_symbols(workqueue
))
124 workqueue
->queue_soon(new Unblock_token(this->this_blocker_
,
125 this->next_blocker_
));
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.
132 Read_symbols::do_read_symbols(Workqueue
* workqueue
)
134 if (this->input_argument_
->is_group())
136 gold_assert(this->input_group_
== NULL
);
137 this->do_group(workqueue
);
141 Input_file
* input_file
= new Input_file(&this->input_argument_
->file());
142 if (!input_file
->open(*this->dirpath_
, this))
145 // Read enough of the file to pick up the entire ELF header.
147 off_t filesize
= input_file
->file().filesize();
151 gold_error(_("%s: file is empty"),
152 input_file
->file().filename().c_str());
156 int read_size
= elfcpp::Elf_sizes
<64>::ehdr_size
;
157 if (filesize
< read_size
)
158 read_size
= filesize
;
160 const unsigned char* ehdr
= input_file
->file().get_view(0, 0, read_size
,
163 if (read_size
>= Archive::sarmag
)
166 = memcmp(ehdr
, Archive::armagt
, Archive::sarmag
) == 0;
168 || memcmp(ehdr
, Archive::armag
, Archive::sarmag
) == 0)
170 // This is an archive.
171 Archive
* arch
= new Archive(this->input_argument_
->file().name(),
172 input_file
, is_thin_archive
,
173 this->dirpath_
, this);
174 arch
->setup(this->input_objects_
);
176 // Unlock the archive so it can be used in the next task.
179 workqueue
->queue_next(new Add_archive_symbols(this->symtab_
,
181 this->input_objects_
,
186 this->next_blocker_
));
191 if (parameters
->options().has_plugins())
193 Pluginobj
* obj
= parameters
->options().plugins()->claim_file(input_file
,
197 // The input file was claimed by a plugin, and its symbols
198 // have been provided by the plugin.
200 // We are done with the file at this point, so unlock it.
203 workqueue
->queue_next(new Add_symbols(this->input_objects_
,
208 this->next_blocker_
));
215 static unsigned char elfmagic
[4] =
217 elfcpp::ELFMAG0
, elfcpp::ELFMAG1
,
218 elfcpp::ELFMAG2
, elfcpp::ELFMAG3
220 if (memcmp(ehdr
, elfmagic
, 4) == 0)
222 // This is an ELF object.
224 Object
* obj
= make_elf_object(input_file
->filename(),
225 input_file
, 0, ehdr
, read_size
);
229 Read_symbols_data
* sd
= new Read_symbols_data
;
230 obj
->read_symbols(sd
);
232 // Opening the file locked it, so now we need to unlock it.
233 // We need to unlock it before queuing the Add_symbols task,
234 // because the workqueue doesn't know about our lock on the
235 // file. If we queue the Add_symbols task first, it will be
236 // stuck on the end of the file lock, but since the
237 // workqueue doesn't know about that lock, it will never
238 // release the Add_symbols task.
240 input_file
->file().unlock(this);
242 // We use queue_next because everything is cached for this
243 // task to run right away if possible.
245 workqueue
->queue_next(new Add_symbols(this->input_objects_
,
246 this->symtab_
, this->layout_
,
249 this->next_blocker_
));
255 // Queue up a task to try to parse this file as a script. We use a
256 // separate task so that the script will be read in order with other
257 // objects named on the command line. Also so that we don't try to
258 // read multiple scripts simultaneously, which could lead to
259 // unpredictable changes to the General_options structure.
261 workqueue
->queue_soon(new Read_script(this->symtab_
,
264 this->input_objects_
,
267 this->input_argument_
,
270 this->next_blocker_
));
274 // Handle a group. We need to walk through the arguments over and
275 // over until we don't see any new undefined symbols. We do this by
276 // setting off Read_symbols Tasks as usual, but recording the archive
277 // entries instead of deleting them. We also start a Finish_group
278 // Task which runs after we've read all the symbols. In that task we
279 // process the archives in a loop until we are done.
282 Read_symbols::do_group(Workqueue
* workqueue
)
284 Input_group
* input_group
= new Input_group();
286 const Input_file_group
* group
= this->input_argument_
->group();
287 Task_token
* this_blocker
= this->this_blocker_
;
289 for (Input_file_group::const_iterator p
= group
->begin();
293 const Input_argument
* arg
= &*p
;
294 gold_assert(arg
->is_file());
296 Task_token
* next_blocker
= new Task_token(true);
297 next_blocker
->add_blocker();
298 workqueue
->queue_soon(new Read_symbols(this->input_objects_
,
299 this->symtab_
, this->layout_
,
300 this->dirpath_
, this->mapfile_
,
302 this_blocker
, next_blocker
));
303 this_blocker
= next_blocker
;
306 const int saw_undefined
= this->symtab_
->saw_undefined();
307 workqueue
->queue_soon(new Finish_group(this->input_objects_
,
314 this->next_blocker_
));
317 // Return a debugging name for a Read_symbols task.
320 Read_symbols::get_name() const
322 if (!this->input_argument_
->is_group())
324 std::string
ret("Read_symbols ");
325 if (this->input_argument_
->file().is_lib())
327 ret
+= this->input_argument_
->file().name();
331 std::string
ret("Read_symbols group (");
332 bool add_space
= false;
333 const Input_file_group
* group
= this->input_argument_
->group();
334 for (Input_file_group::const_iterator p
= group
->begin();
340 ret
+= p
->file().name();
346 // Class Add_symbols.
348 Add_symbols::~Add_symbols()
350 if (this->this_blocker_
!= NULL
)
351 delete this->this_blocker_
;
352 // next_blocker_ is deleted by the task associated with the next
356 // We are blocked by this_blocker_. We block next_blocker_. We also
360 Add_symbols::is_runnable()
362 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
363 return this->this_blocker_
;
364 if (this->object_
->is_locked())
365 return this->object_
->token();
370 Add_symbols::locks(Task_locker
* tl
)
372 tl
->add(this, this->next_blocker_
);
373 tl
->add(this, this->object_
->token());
376 // Add the symbols in the object to the symbol table.
379 Add_symbols::run(Workqueue
*)
381 Pluginobj
* pluginobj
= this->object_
->pluginobj();
382 if (pluginobj
!= NULL
)
384 this->object_
->add_symbols(this->symtab_
, this->sd_
, this->layout_
);
388 if (!this->input_objects_
->add_object(this->object_
))
390 // FIXME: We need to close the descriptor here.
391 delete this->object_
;
395 this->object_
->layout(this->symtab_
, this->layout_
, this->sd_
);
396 this->object_
->add_symbols(this->symtab_
, this->sd_
, this->layout_
);
397 this->object_
->release();
403 // Class Finish_group.
405 Finish_group::~Finish_group()
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 following the group.
413 // We need to wait for THIS_BLOCKER_ and unblock NEXT_BLOCKER_.
416 Finish_group::is_runnable()
418 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
419 return this->this_blocker_
;
424 Finish_group::locks(Task_locker
* tl
)
426 tl
->add(this, this->next_blocker_
);
429 // Loop over the archives until there are no new undefined symbols.
432 Finish_group::run(Workqueue
*)
434 int saw_undefined
= this->saw_undefined_
;
435 while (saw_undefined
!= this->symtab_
->saw_undefined())
437 saw_undefined
= this->symtab_
->saw_undefined();
439 for (Input_group::const_iterator p
= this->input_group_
->begin();
440 p
!= this->input_group_
->end();
443 Task_lock_obj
<Archive
> tl(this, *p
);
445 (*p
)->add_symbols(this->symtab_
, this->layout_
,
446 this->input_objects_
, this->mapfile_
);
450 // Delete all the archives now that we no longer need them.
451 for (Input_group::const_iterator p
= this->input_group_
->begin();
452 p
!= this->input_group_
->end();
455 delete this->input_group_
;
460 Read_script::~Read_script()
462 if (this->this_blocker_
!= NULL
)
463 delete this->this_blocker_
;
464 // next_blocker_ is deleted by the task associated with the next
468 // We are blocked by this_blocker_.
471 Read_script::is_runnable()
473 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
474 return this->this_blocker_
;
478 // We don't unlock next_blocker_ here. If the script names any input
479 // files, then the last file will be responsible for unlocking it.
482 Read_script::locks(Task_locker
*)
486 // Read the script, if it is a script.
489 Read_script::run(Workqueue
* workqueue
)
491 bool used_next_blocker
;
492 if (!read_input_script(workqueue
, this->symtab_
, this->layout_
,
493 this->dirpath_
, this->input_objects_
,
494 this->mapfile_
, this->input_group_
,
495 this->input_argument_
, this->input_file_
,
496 this->next_blocker_
, &used_next_blocker
))
498 // Here we have to handle any other input file types we need.
499 gold_error(_("%s: not an object or archive"),
500 this->input_file_
->file().filename().c_str());
503 if (!used_next_blocker
)
505 // Queue up a task to unlock next_blocker. We can't just unlock
506 // it here, as we don't hold the workqueue lock.
507 workqueue
->queue_soon(new Unblock_token(NULL
, this->next_blocker_
));
511 // Return a debugging name for a Read_script task.
514 Read_script::get_name() const
516 std::string
ret("Read_script ");
517 if (this->input_argument_
->file().is_lib())
519 ret
+= this->input_argument_
->file().name();
523 } // End namespace gold.
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