1 // fileread.cc -- read files 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.
30 #include "filenames.h"
33 #include "dirsearch.h"
39 // Class File_read::View.
41 File_read::View::~View()
43 gold_assert(!this->is_locked());
48 if (::munmap(const_cast<unsigned char*>(this->data_
), this->size_
) != 0)
49 gold_warning(_("munmap failed: %s"), strerror(errno
));
51 File_read::current_mapped_bytes
-= this->size_
;
56 File_read::View::lock()
62 File_read::View::unlock()
64 gold_assert(this->lock_count_
> 0);
69 File_read::View::is_locked()
71 return this->lock_count_
> 0;
76 // The File_read static variables.
77 unsigned long long File_read::total_mapped_bytes
;
78 unsigned long long File_read::current_mapped_bytes
;
79 unsigned long long File_read::maximum_mapped_bytes
;
81 // The File_read class is designed to support file descriptor caching,
82 // but this is not currently implemented.
84 File_read::~File_read()
86 gold_assert(this->token_
.is_writable());
87 if (this->descriptor_
>= 0)
89 if (close(this->descriptor_
) < 0)
90 gold_warning(_("close of %s failed: %s"),
91 this->name_
.c_str(), strerror(errno
));
92 this->descriptor_
= -1;
95 this->clear_views(true);
101 File_read::open(const Task
* task
, const std::string
& name
)
103 gold_assert(this->token_
.is_writable()
104 && this->descriptor_
< 0
105 && this->name_
.empty());
108 this->descriptor_
= ::open(this->name_
.c_str(), O_RDONLY
);
110 if (this->descriptor_
>= 0)
113 if (::fstat(this->descriptor_
, &s
) < 0)
114 gold_error(_("%s: fstat failed: %s"),
115 this->name_
.c_str(), strerror(errno
));
116 this->size_
= s
.st_size
;
119 this->token_
.add_writer(task
);
121 return this->descriptor_
>= 0;
124 // Open the file for testing purposes.
127 File_read::open(const Task
* task
, const std::string
& name
,
128 const unsigned char* contents
, off_t size
)
130 gold_assert(this->token_
.is_writable()
131 && this->descriptor_
< 0
132 && this->name_
.empty());
134 this->contents_
= contents
;
136 this->token_
.add_writer(task
);
140 // Release the file. This is called when we are done with the file in
146 gold_assert(this->is_locked());
148 File_read::total_mapped_bytes
+= this->mapped_bytes_
;
149 File_read::current_mapped_bytes
+= this->mapped_bytes_
;
150 this->mapped_bytes_
= 0;
151 if (File_read::current_mapped_bytes
> File_read::maximum_mapped_bytes
)
152 File_read::maximum_mapped_bytes
= File_read::current_mapped_bytes
;
154 this->clear_views(false);
156 this->released_
= true;
162 File_read::lock(const Task
* task
)
164 gold_assert(this->released_
);
165 this->token_
.add_writer(task
);
166 this->released_
= false;
172 File_read::unlock(const Task
* task
)
175 this->token_
.remove_writer(task
);
178 // Return whether the file is locked.
181 File_read::is_locked() const
183 if (!this->token_
.is_writable())
185 // The file is not locked, so it should have been released.
186 gold_assert(this->released_
);
190 // See if we have a view which covers the file starting at START for
191 // SIZE bytes. Return a pointer to the View if found, NULL if not.
193 inline File_read::View
*
194 File_read::find_view(off_t start
, section_size_type size
) const
196 off_t page
= File_read::page_offset(start
);
197 Views::const_iterator p
= this->views_
.find(page
);
198 if (p
== this->views_
.end())
200 if (p
->second
->size() - (start
- page
) < size
)
205 // Read SIZE bytes from the file starting at offset START. Read into
209 File_read::do_read(off_t start
, off_t size
, void* p
) const
212 if (this->contents_
!= NULL
)
214 bytes
= this->size_
- start
;
217 memcpy(p
, this->contents_
+ start
, size
);
223 bytes
= ::pread(this->descriptor_
, p
, size
, start
);
229 gold_fatal(_("%s: pread failed: %s"),
230 this->filename().c_str(), strerror(errno
));
235 gold_fatal(_("%s: file too short: read only %lld of %lld bytes at %lld"),
236 this->filename().c_str(),
237 static_cast<long long>(bytes
),
238 static_cast<long long>(size
),
239 static_cast<long long>(start
));
242 // Read data from the file.
245 File_read::read(off_t start
, off_t size
, void* p
) const
247 File_read::View
* pv
= this->find_view(start
, size
);
250 memcpy(p
, pv
->data() + (start
- pv
->start()), size
);
254 this->do_read(start
, size
, p
);
257 // Find an existing view or make a new one.
260 File_read::find_or_make_view(off_t start
, section_size_type size
, bool cache
)
262 gold_assert(!this->token_
.is_writable());
263 this->released_
= false;
265 off_t poff
= File_read::page_offset(start
);
267 File_read::View
* const vnull
= NULL
;
268 std::pair
<Views::iterator
, bool> ins
=
269 this->views_
.insert(std::make_pair(poff
, vnull
));
273 // There was an existing view at this offset.
274 File_read::View
* v
= ins
.first
->second
;
275 if (v
->size() - (start
- v
->start()) >= size
)
282 // This view is not large enough.
283 this->saved_views_
.push_back(v
);
286 // We need to read data from the file. We read full pages for
287 // greater efficiency on small files.
289 off_t psize
= File_read::pages(size
+ (start
- poff
));
291 if (poff
+ psize
>= this->size_
)
293 psize
= this->size_
- poff
;
294 gold_assert(psize
>= static_cast<off_t
>(size
));
299 if (this->contents_
!= NULL
)
301 unsigned char* p
= new unsigned char[psize
];
302 this->do_read(poff
, psize
, p
);
303 v
= new File_read::View(poff
, psize
, p
, cache
, false);
307 void* p
= ::mmap(NULL
, psize
, PROT_READ
, MAP_SHARED
,
308 this->descriptor_
, poff
);
310 gold_fatal(_("%s: mmap offset %lld size %lld failed: %s"),
311 this->filename().c_str(),
312 static_cast<long long>(poff
),
313 static_cast<long long>(psize
),
316 this->mapped_bytes_
+= psize
;
318 const unsigned char* pbytes
= static_cast<const unsigned char*>(p
);
319 v
= new File_read::View(poff
, psize
, pbytes
, cache
, true);
322 ins
.first
->second
= v
;
326 // Get a view into the file.
329 File_read::get_view(off_t start
, section_size_type size
, bool cache
)
331 File_read::View
* pv
= this->find_or_make_view(start
, size
, cache
);
332 return pv
->data() + (start
- pv
->start());
336 File_read::get_lasting_view(off_t start
, section_size_type size
, bool cache
)
338 File_read::View
* pv
= this->find_or_make_view(start
, size
, cache
);
340 return new File_view(*this, pv
, pv
->data() + (start
- pv
->start()));
343 // Remove all the file views.
346 File_read::clear_views(bool destroying
)
348 Views::iterator p
= this->views_
.begin();
349 while (p
!= this->views_
.end())
351 if (!p
->second
->is_locked()
352 && (destroying
|| !p
->second
->should_cache()))
356 // map::erase invalidates only the iterator to the deleted
358 Views::iterator pe
= p
;
360 this->views_
.erase(pe
);
364 gold_assert(!destroying
);
369 Saved_views::iterator q
= this->saved_views_
.begin();
370 while (q
!= this->saved_views_
.end())
372 if (!(*q
)->is_locked()
373 && (destroying
|| !(*q
)->should_cache()))
376 q
= this->saved_views_
.erase(q
);
380 gold_assert(!destroying
);
386 // Print statistical information to stderr. This is used for --stats.
389 File_read::print_stats()
391 fprintf(stderr
, _("%s: total bytes mapped for read: %llu\n"),
392 program_name
, File_read::total_mapped_bytes
);
393 fprintf(stderr
, _("%s: maximum bytes mapped for read at one time: %llu\n"),
394 program_name
, File_read::maximum_mapped_bytes
);
399 File_view::~File_view()
401 gold_assert(this->file_
.is_locked());
402 this->view_
->unlock();
407 // Create a file for testing.
409 Input_file::Input_file(const Task
* task
, const char* name
,
410 const unsigned char* contents
, off_t size
)
413 this->input_argument_
=
414 new Input_file_argument(name
, false, "", Position_dependent_options());
415 bool ok
= file_
.open(task
, name
, contents
, size
);
421 // If the filename is not absolute, we assume it is in the current
422 // directory *except* when:
423 // A) input_argument_->is_lib() is true; or
424 // B) input_argument_->extra_search_path() is not empty.
425 // In both cases, we look in extra_search_path + library_path to find
426 // the file location, rather than the current directory.
429 Input_file::open(const General_options
& options
, const Dirsearch
& dirpath
,
434 // Case 1: name is an absolute file, just try to open it
435 // Case 2: name is relative but is_lib is false and extra_search_path
437 if (IS_ABSOLUTE_PATH (this->input_argument_
->name())
438 || (!this->input_argument_
->is_lib()
439 && this->input_argument_
->extra_search_path() == NULL
))
441 name
= this->input_argument_
->name();
442 this->found_name_
= name
;
444 // Case 3: is_lib is true
445 else if (this->input_argument_
->is_lib())
447 // We don't yet support extra_search_path with -l.
448 gold_assert(this->input_argument_
->extra_search_path() == NULL
);
449 std::string
n1("lib");
450 n1
+= this->input_argument_
->name();
452 if (options
.is_static()
453 || this->input_argument_
->options().do_static_search())
460 name
= dirpath
.find(n1
, n2
, &this->is_in_sysroot_
);
463 gold_error(_("cannot find -l%s"),
464 this->input_argument_
->name());
467 if (n2
.empty() || name
[name
.length() - 1] == 'o')
468 this->found_name_
= n1
;
470 this->found_name_
= n2
;
472 // Case 4: extra_search_path is not empty
475 gold_assert(this->input_argument_
->extra_search_path() != NULL
);
477 // First, check extra_search_path.
478 name
= this->input_argument_
->extra_search_path();
479 if (!IS_DIR_SEPARATOR (name
[name
.length() - 1]))
481 name
+= this->input_argument_
->name();
482 struct stat dummy_stat
;
483 if (::stat(name
.c_str(), &dummy_stat
) < 0)
485 // extra_search_path failed, so check the normal search-path.
486 name
= dirpath
.find(this->input_argument_
->name(), "",
487 &this->is_in_sysroot_
);
490 gold_error(_("cannot find %s"),
491 this->input_argument_
->name());
495 this->found_name_
= this->input_argument_
->name();
498 // Now that we've figured out where the file lives, try to open it.
499 if (!this->file_
.open(task
, name
))
501 gold_error(_("cannot open %s: %s"),
502 name
.c_str(), strerror(errno
));
509 } // End namespace gold.