1 // readsyms.cc -- read input file symbols for gold
3 // Copyright 2006, 2007 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"
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 when the workqueue lock is held, so we need a dummy
43 // task to do that. The dummy task has to maintain the right sequence
44 // of blocks, so we need both this_blocker and next_blocker.
46 class Unblock_token
: public Task
49 Unblock_token(Task_token
* this_blocker
, Task_token
* next_blocker
)
50 : this_blocker_(this_blocker
), next_blocker_(next_blocker
)
55 if (this->this_blocker_
!= NULL
)
56 delete this->this_blocker_
;
62 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
63 return this->this_blocker_
;
68 locks(Task_locker
* tl
)
69 { tl
->add(this, this->next_blocker_
); }
77 { return "Unblock_token"; }
80 Task_token
* this_blocker_
;
81 Task_token
* next_blocker_
;
84 // Class read_symbols.
86 Read_symbols::~Read_symbols()
88 // The this_blocker_ and next_blocker_ pointers are passed on to the
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.
97 Read_symbols::is_runnable()
99 if (this->input_argument_
->is_file()
100 && this->input_argument_
->file().may_need_search()
101 && this->dirpath_
->token()->is_blocked())
102 return this->dirpath_
->token();
107 // Return a Task_locker for a Read_symbols task. We don't need any
111 Read_symbols::locks(Task_locker
*)
115 // Run a Read_symbols task.
118 Read_symbols::run(Workqueue
* workqueue
)
120 // If we didn't queue a new task, then we need to explicitly unblock
122 if (!this->do_read_symbols(workqueue
))
123 workqueue
->queue_front(new Unblock_token(this->this_blocker_
,
124 this->next_blocker_
));
127 // Open the file and read the symbols. Return true if a new task was
128 // queued, false if that could not happen due to some error.
131 Read_symbols::do_read_symbols(Workqueue
* workqueue
)
133 if (this->input_argument_
->is_group())
135 gold_assert(this->input_group_
== NULL
);
136 this->do_group(workqueue
);
140 Input_file
* input_file
= new Input_file(&this->input_argument_
->file());
141 if (!input_file
->open(this->options_
, *this->dirpath_
, this))
144 // Read enough of the file to pick up the entire ELF header.
146 off_t filesize
= input_file
->file().filesize();
150 gold_error(_("%s: file is empty"),
151 input_file
->file().filename().c_str());
155 unsigned char ehdr_buf
[elfcpp::Elf_sizes
<64>::ehdr_size
];
157 int read_size
= elfcpp::Elf_sizes
<64>::ehdr_size
;
158 if (filesize
< read_size
)
159 read_size
= filesize
;
161 input_file
->file().read(0, read_size
, ehdr_buf
);
165 static unsigned char elfmagic
[4] =
167 elfcpp::ELFMAG0
, elfcpp::ELFMAG1
,
168 elfcpp::ELFMAG2
, elfcpp::ELFMAG3
170 if (memcmp(ehdr_buf
, elfmagic
, 4) == 0)
172 // This is an ELF object.
174 Object
* obj
= make_elf_object(input_file
->filename(),
175 input_file
, 0, ehdr_buf
, read_size
);
179 // We don't have a way to record a non-archive in an input
180 // group. If this is an ordinary object file, we can't
181 // include it more than once anyhow. If this is a dynamic
182 // object, then including it a second time changes nothing.
183 if (this->input_group_
!= NULL
&& !obj
->is_dynamic())
185 gold_error(_("%s: ordinary object found in input group"),
190 Read_symbols_data
* sd
= new Read_symbols_data
;
191 obj
->read_symbols(sd
);
193 // Opening the file locked it, so now we need to unlock it.
194 // We need to unlock it before queuing the Add_symbols task,
195 // because the workqueue doesn't know about our lock on the
196 // file. If we queue the Add_symbols task first, it will be
197 // stuck on the end of the file lock, but since the
198 // workqueue doesn't know about that lock, it will never
199 // release the Add_symbols task.
201 input_file
->file().unlock(this);
203 workqueue
->queue_front(new Add_symbols(this->input_objects_
,
204 this->symtab_
, this->layout_
,
207 this->next_blocker_
));
213 if (read_size
>= Archive::sarmag
)
215 if (memcmp(ehdr_buf
, Archive::armag
, Archive::sarmag
) == 0)
217 // This is an archive.
218 Archive
* arch
= new Archive(this->input_argument_
->file().name(),
222 workqueue
->queue_front(new Add_archive_symbols(this->symtab_
,
224 this->input_objects_
,
228 this->next_blocker_
));
233 // Try to parse this file as a script.
234 if (read_input_script(workqueue
, this->options_
, this->symtab_
,
235 this->layout_
, this->dirpath_
, this->input_objects_
,
236 this->input_group_
, this->input_argument_
, input_file
,
237 ehdr_buf
, read_size
, this->this_blocker_
,
238 this->next_blocker_
))
241 // Here we have to handle any other input file types we need.
242 gold_error(_("%s: not an object or archive"),
243 input_file
->file().filename().c_str());
248 // Handle a group. We need to walk through the arguments over and
249 // over until we don't see any new undefined symbols. We do this by
250 // setting off Read_symbols Tasks as usual, but recording the archive
251 // entries instead of deleting them. We also start a Finish_group
252 // Task which runs after we've read all the symbols. In that task we
253 // process the archives in a loop until we are done.
256 Read_symbols::do_group(Workqueue
* workqueue
)
258 Input_group
* input_group
= new Input_group();
260 const Input_file_group
* group
= this->input_argument_
->group();
261 Task_token
* this_blocker
= this->this_blocker_
;
263 for (Input_file_group::const_iterator p
= group
->begin();
267 const Input_argument
* arg
= &*p
;
268 gold_assert(arg
->is_file());
270 Task_token
* next_blocker
= new Task_token(true);
271 next_blocker
->add_blocker();
272 workqueue
->queue(new Read_symbols(this->options_
, this->input_objects_
,
273 this->symtab_
, this->layout_
,
274 this->dirpath_
, arg
, input_group
,
275 this_blocker
, next_blocker
));
276 this_blocker
= next_blocker
;
279 const int saw_undefined
= this->symtab_
->saw_undefined();
280 workqueue
->queue(new Finish_group(this->input_objects_
,
286 this->next_blocker_
));
289 // Return a debugging name for a Read_symbols task.
292 Read_symbols::get_name() const
294 if (!this->input_argument_
->is_group())
296 std::string
ret("Read_symbols ");
297 if (this->input_argument_
->file().is_lib())
299 ret
+= this->input_argument_
->file().name();
303 std::string
ret("Read_symbols group (");
304 bool add_space
= false;
305 const Input_file_group
* group
= this->input_argument_
->group();
306 for (Input_file_group::const_iterator p
= group
->begin();
312 ret
+= p
->file().name();
318 // Class Add_symbols.
320 Add_symbols::~Add_symbols()
322 if (this->this_blocker_
!= NULL
)
323 delete this->this_blocker_
;
324 // next_blocker_ is deleted by the task associated with the next
328 // We are blocked by this_blocker_. We block next_blocker_. We also
332 Add_symbols::is_runnable()
334 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
335 return this->this_blocker_
;
336 if (this->object_
->is_locked())
337 return this->object_
->token();
342 Add_symbols::locks(Task_locker
* tl
)
344 tl
->add(this, this->next_blocker_
);
345 tl
->add(this, this->object_
->token());
348 // Add the symbols in the object to the symbol table.
351 Add_symbols::run(Workqueue
*)
353 if (!this->input_objects_
->add_object(this->object_
))
355 // FIXME: We need to close the descriptor here.
356 delete this->object_
;
360 this->object_
->layout(this->symtab_
, this->layout_
, this->sd_
);
361 this->object_
->add_symbols(this->symtab_
, this->sd_
);
362 this->object_
->release();
368 // Class Finish_group.
370 Finish_group::~Finish_group()
372 if (this->this_blocker_
!= NULL
)
373 delete this->this_blocker_
;
374 // next_blocker_ is deleted by the task associated with the next
375 // input file following the group.
378 // We need to wait for THIS_BLOCKER_ and unblock NEXT_BLOCKER_.
381 Finish_group::is_runnable()
383 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
384 return this->this_blocker_
;
389 Finish_group::locks(Task_locker
* tl
)
391 tl
->add(this, this->next_blocker_
);
394 // Loop over the archives until there are no new undefined symbols.
397 Finish_group::run(Workqueue
*)
399 int saw_undefined
= this->saw_undefined_
;
400 while (saw_undefined
!= this->symtab_
->saw_undefined())
402 saw_undefined
= this->symtab_
->saw_undefined();
404 for (Input_group::const_iterator p
= this->input_group_
->begin();
405 p
!= this->input_group_
->end();
408 Task_lock_obj
<Archive
> tl(this, *p
);
410 (*p
)->add_symbols(this->symtab_
, this->layout_
,
411 this->input_objects_
);
415 // Delete all the archives now that we no longer need them.
416 for (Input_group::const_iterator p
= this->input_group_
->begin();
417 p
!= this->input_group_
->end();
420 delete this->input_group_
;
423 } // End namespace gold.
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