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 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.
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_
;
60 is_runnable(Workqueue
*)
62 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
68 locks(Workqueue
* workqueue
)
69 { return new Task_locker_block(*this->next_blocker_
, workqueue
); }
76 Task_token
* this_blocker_
;
77 Task_token
* next_blocker_
;
80 // Class read_symbols.
82 Read_symbols::~Read_symbols()
84 // The this_blocker_ and next_blocker_ pointers are passed on to the
88 // Return whether a Read_symbols task is runnable. We can read an
89 // ordinary input file immediately. For an archive specified using
90 // -l, we have to wait until the search path is complete.
92 Task::Is_runnable_type
93 Read_symbols::is_runnable(Workqueue
*)
95 if (this->input_argument_
->is_file()
96 && this->input_argument_
->file().may_need_search()
97 && this->dirpath_
.token().is_blocked())
103 // Return a Task_locker for a Read_symbols task. We don't need any
107 Read_symbols::locks(Workqueue
*)
112 // Run a Read_symbols task.
115 Read_symbols::run(Workqueue
* workqueue
)
117 // If we didn't queue a new task, then we need to explicitly unblock
119 if (!this->do_read_symbols(workqueue
))
120 workqueue
->queue_front(new Unblock_token(this->this_blocker_
,
121 this->next_blocker_
));
124 // Open the file and read the symbols. Return true if a new task was
125 // queued, false if that could not happen due to some error.
128 Read_symbols::do_read_symbols(Workqueue
* workqueue
)
130 if (this->input_argument_
->is_group())
132 gold_assert(this->input_group_
== NULL
);
133 this->do_group(workqueue
);
137 Input_file
* input_file
= new Input_file(&this->input_argument_
->file());
138 if (!input_file
->open(this->options_
, this->dirpath_
))
141 // Read enough of the file to pick up the entire ELF header.
143 off_t filesize
= input_file
->file().filesize();
147 gold_error(_("%s: file is empty"),
148 input_file
->file().filename().c_str());
152 unsigned char ehdr_buf
[elfcpp::Elf_sizes
<64>::ehdr_size
];
154 int read_size
= elfcpp::Elf_sizes
<64>::ehdr_size
;
155 if (filesize
< read_size
)
156 read_size
= filesize
;
158 input_file
->file().read(0, read_size
, ehdr_buf
);
162 static unsigned char elfmagic
[4] =
164 elfcpp::ELFMAG0
, elfcpp::ELFMAG1
,
165 elfcpp::ELFMAG2
, elfcpp::ELFMAG3
167 if (memcmp(ehdr_buf
, elfmagic
, 4) == 0)
169 // This is an ELF object.
171 Object
* obj
= make_elf_object(input_file
->filename(),
172 input_file
, 0, ehdr_buf
, read_size
);
176 // We don't have a way to record a non-archive in an input
177 // group. If this is an ordinary object file, we can't
178 // include it more than once anyhow. If this is a dynamic
179 // object, then including it a second time changes nothing.
180 if (this->input_group_
!= NULL
&& !obj
->is_dynamic())
182 gold_error(_("%s: ordinary object found in input group"),
187 Read_symbols_data
* sd
= new Read_symbols_data
;
188 obj
->read_symbols(sd
);
189 workqueue
->queue_front(new Add_symbols(this->input_objects_
,
190 this->symtab_
, this->layout_
,
193 this->next_blocker_
));
195 // Opening the file locked it, so now we need to unlock it.
196 input_file
->file().unlock();
202 if (read_size
>= Archive::sarmag
)
204 if (memcmp(ehdr_buf
, Archive::armag
, Archive::sarmag
) == 0)
206 // This is an archive.
207 Archive
* arch
= new Archive(this->input_argument_
->file().name(),
210 workqueue
->queue(new Add_archive_symbols(this->symtab_
,
212 this->input_objects_
,
216 this->next_blocker_
));
221 // Try to parse this file as a script.
222 if (read_input_script(workqueue
, this->options_
, this->symtab_
,
223 this->layout_
, this->dirpath_
, this->input_objects_
,
224 this->input_group_
, this->input_argument_
, input_file
,
225 ehdr_buf
, read_size
, this->this_blocker_
,
226 this->next_blocker_
))
229 // Here we have to handle any other input file types we need.
230 gold_error(_("%s: not an object or archive"),
231 input_file
->file().filename().c_str());
236 // Handle a group. We need to walk through the arguments over and
237 // over until we don't see any new undefined symbols. We do this by
238 // setting off Read_symbols Tasks as usual, but recording the archive
239 // entries instead of deleting them. We also start a Finish_group
240 // Task which runs after we've read all the symbols. In that task we
241 // process the archives in a loop until we are done.
244 Read_symbols::do_group(Workqueue
* workqueue
)
246 Input_group
* input_group
= new Input_group();
248 const Input_file_group
* group
= this->input_argument_
->group();
249 Task_token
* this_blocker
= this->this_blocker_
;
250 for (Input_file_group::const_iterator p
= group
->begin();
254 const Input_argument
* arg
= &*p
;
255 gold_assert(arg
->is_file());
257 Task_token
* next_blocker
= new Task_token();
258 next_blocker
->add_blocker();
259 workqueue
->queue(new Read_symbols(this->options_
, this->input_objects_
,
260 this->symtab_
, this->layout_
,
261 this->dirpath_
, arg
, input_group
,
262 this_blocker
, next_blocker
));
263 this_blocker
= next_blocker
;
266 const int saw_undefined
= this->symtab_
->saw_undefined();
267 workqueue
->queue(new Finish_group(this->input_objects_
,
273 this->next_blocker_
));
276 // Class Add_symbols.
278 Add_symbols::~Add_symbols()
280 if (this->this_blocker_
!= NULL
)
281 delete this->this_blocker_
;
282 // next_blocker_ is deleted by the task associated with the next
286 // We are blocked by this_blocker_. We block next_blocker_. We also
289 Task::Is_runnable_type
290 Add_symbols::is_runnable(Workqueue
*)
292 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
294 if (this->object_
->is_locked())
299 class Add_symbols::Add_symbols_locker
: public Task_locker
302 Add_symbols_locker(Task_token
& token
, Workqueue
* workqueue
,
304 : blocker_(token
, workqueue
), objlock_(*object
)
308 Task_locker_block blocker_
;
309 Task_locker_obj
<Object
> objlock_
;
313 Add_symbols::locks(Workqueue
* workqueue
)
315 return new Add_symbols_locker(*this->next_blocker_
, workqueue
,
319 // Add the symbols in the object to the symbol table.
322 Add_symbols::run(Workqueue
*)
324 if (!this->input_objects_
->add_object(this->object_
))
326 // FIXME: We need to close the descriptor here.
327 delete this->object_
;
331 this->object_
->layout(this->symtab_
, this->layout_
, this->sd_
);
332 this->object_
->add_symbols(this->symtab_
, this->sd_
);
338 // Class Finish_group.
340 Finish_group::~Finish_group()
342 if (this->this_blocker_
!= NULL
)
343 delete this->this_blocker_
;
344 // next_blocker_ is deleted by the task associated with the next
345 // input file following the group.
348 // We need to wait for THIS_BLOCKER_ and unblock NEXT_BLOCKER_.
350 Task::Is_runnable_type
351 Finish_group::is_runnable(Workqueue
*)
353 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
359 Finish_group::locks(Workqueue
* workqueue
)
361 return new Task_locker_block(*this->next_blocker_
, workqueue
);
364 // Loop over the archives until there are no new undefined symbols.
367 Finish_group::run(Workqueue
*)
369 int saw_undefined
= this->saw_undefined_
;
370 while (saw_undefined
!= this->symtab_
->saw_undefined())
372 saw_undefined
= this->symtab_
->saw_undefined();
374 for (Input_group::const_iterator p
= this->input_group_
->begin();
375 p
!= this->input_group_
->end();
378 Task_lock_obj
<Archive
> tl(**p
);
380 (*p
)->add_symbols(this->symtab_
, this->layout_
,
381 this->input_objects_
);
385 // Delete all the archives now that we no longer need them.
386 for (Input_group::const_iterator p
= this->input_group_
->begin();
387 p
!= this->input_group_
->end();
390 delete this->input_group_
;
393 } // End namespace gold.