1 // fileread.cc -- read files for gold
3 // Copyright 2006, 2007, 2008 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.
31 #include "filenames.h"
34 #include "parameters.h"
36 #include "dirsearch.h"
44 // Class File_read::View.
46 File_read::View::~View()
48 gold_assert(!this->is_locked());
53 if (::munmap(const_cast<unsigned char*>(this->data_
), this->size_
) != 0)
54 gold_warning(_("munmap failed: %s"), strerror(errno
));
56 File_read::current_mapped_bytes
-= this->size_
;
61 File_read::View::lock()
67 File_read::View::unlock()
69 gold_assert(this->lock_count_
> 0);
74 File_read::View::is_locked()
76 return this->lock_count_
> 0;
81 // The File_read static variables.
82 unsigned long long File_read::total_mapped_bytes
;
83 unsigned long long File_read::current_mapped_bytes
;
84 unsigned long long File_read::maximum_mapped_bytes
;
86 // The File_read class is designed to support file descriptor caching,
87 // but this is not currently implemented.
89 File_read::~File_read()
91 gold_assert(this->token_
.is_writable());
92 if (this->descriptor_
>= 0)
94 if (close(this->descriptor_
) < 0)
95 gold_warning(_("close of %s failed: %s"),
96 this->name_
.c_str(), strerror(errno
));
97 this->descriptor_
= -1;
100 this->clear_views(true);
106 File_read::open(const Task
* task
, const std::string
& name
)
108 gold_assert(this->token_
.is_writable()
109 && this->descriptor_
< 0
110 && this->name_
.empty());
113 this->descriptor_
= ::open(this->name_
.c_str(), O_RDONLY
);
115 if (this->descriptor_
>= 0)
118 if (::fstat(this->descriptor_
, &s
) < 0)
119 gold_error(_("%s: fstat failed: %s"),
120 this->name_
.c_str(), strerror(errno
));
121 this->size_
= s
.st_size
;
122 gold_debug(DEBUG_FILES
, "Attempt to open %s succeeded",
123 this->name_
.c_str());
126 this->token_
.add_writer(task
);
128 return this->descriptor_
>= 0;
131 // Open the file with the contents in memory.
134 File_read::open(const Task
* task
, const std::string
& name
,
135 const unsigned char* contents
, off_t size
)
137 gold_assert(this->token_
.is_writable()
138 && this->descriptor_
< 0
139 && this->name_
.empty());
141 this->contents_
= contents
;
143 this->token_
.add_writer(task
);
147 // Release the file. This is called when we are done with the file in
153 gold_assert(this->is_locked());
155 File_read::total_mapped_bytes
+= this->mapped_bytes_
;
156 File_read::current_mapped_bytes
+= this->mapped_bytes_
;
157 this->mapped_bytes_
= 0;
158 if (File_read::current_mapped_bytes
> File_read::maximum_mapped_bytes
)
159 File_read::maximum_mapped_bytes
= File_read::current_mapped_bytes
;
161 // Only clear views if there is only one attached object. Otherwise
162 // we waste time trying to clear cached archive views.
163 if (this->object_count_
<= 1)
164 this->clear_views(false);
166 this->released_
= true;
172 File_read::lock(const Task
* task
)
174 gold_assert(this->released_
);
175 this->token_
.add_writer(task
);
176 this->released_
= false;
182 File_read::unlock(const Task
* task
)
185 this->token_
.remove_writer(task
);
188 // Return whether the file is locked.
191 File_read::is_locked() const
193 if (!this->token_
.is_writable())
195 // The file is not locked, so it should have been released.
196 gold_assert(this->released_
);
200 // See if we have a view which covers the file starting at START for
201 // SIZE bytes. Return a pointer to the View if found, NULL if not.
202 // If BYTESHIFT is not -1U, the returned View must have the specified
203 // byte shift; otherwise, it may have any byte shift. If VSHIFTED is
204 // not NULL, this sets *VSHIFTED to a view which would have worked if
205 // not for the requested BYTESHIFT.
207 inline File_read::View
*
208 File_read::find_view(off_t start
, section_size_type size
,
209 unsigned int byteshift
, File_read::View
** vshifted
) const
211 if (vshifted
!= NULL
)
214 off_t page
= File_read::page_offset(start
);
216 unsigned int bszero
= 0;
217 Views::const_iterator p
= this->views_
.upper_bound(std::make_pair(page
- 1,
220 while (p
!= this->views_
.end() && p
->first
.first
<= page
)
222 if (p
->second
->start() <= start
223 && (p
->second
->start() + static_cast<off_t
>(p
->second
->size())
224 >= start
+ static_cast<off_t
>(size
)))
226 if (byteshift
== -1U || byteshift
== p
->second
->byteshift())
228 p
->second
->set_accessed();
232 if (vshifted
!= NULL
&& *vshifted
== NULL
)
233 *vshifted
= p
->second
;
242 // Read SIZE bytes from the file starting at offset START. Read into
246 File_read::do_read(off_t start
, section_size_type size
, void* p
) const
249 if (this->contents_
!= NULL
)
251 bytes
= this->size_
- start
;
252 if (static_cast<section_size_type
>(bytes
) >= size
)
254 memcpy(p
, this->contents_
+ start
, size
);
260 bytes
= ::pread(this->descriptor_
, p
, size
, start
);
261 if (static_cast<section_size_type
>(bytes
) == size
)
266 gold_fatal(_("%s: pread failed: %s"),
267 this->filename().c_str(), strerror(errno
));
272 gold_fatal(_("%s: file too short: read only %lld of %lld bytes at %lld"),
273 this->filename().c_str(),
274 static_cast<long long>(bytes
),
275 static_cast<long long>(size
),
276 static_cast<long long>(start
));
279 // Read data from the file.
282 File_read::read(off_t start
, section_size_type size
, void* p
) const
284 const File_read::View
* pv
= this->find_view(start
, size
, -1U, NULL
);
287 memcpy(p
, pv
->data() + (start
- pv
->start() + pv
->byteshift()), size
);
291 this->do_read(start
, size
, p
);
294 // Add a new view. There may already be an existing view at this
295 // offset. If there is, the new view will be larger, and should
296 // replace the old view.
299 File_read::add_view(File_read::View
* v
)
301 std::pair
<Views::iterator
, bool> ins
=
302 this->views_
.insert(std::make_pair(std::make_pair(v
->start(),
308 // There was an existing view at this offset. It must not be large
309 // enough. We can't delete it here, since something might be using
310 // it; we put it on a list to be deleted when the file is unlocked.
311 File_read::View
* vold
= ins
.first
->second
;
312 gold_assert(vold
->size() < v
->size());
313 if (vold
->should_cache())
318 this->saved_views_
.push_back(vold
);
320 ins
.first
->second
= v
;
323 // Make a new view with a specified byteshift, reading the data from
327 File_read::make_view(off_t start
, section_size_type size
,
328 unsigned int byteshift
, bool cache
)
330 off_t poff
= File_read::page_offset(start
);
332 section_size_type psize
= File_read::pages(size
+ (start
- poff
));
334 if (poff
+ static_cast<off_t
>(psize
) >= this->size_
)
336 psize
= this->size_
- poff
;
337 gold_assert(psize
>= size
);
341 if (this->contents_
!= NULL
|| byteshift
!= 0)
343 unsigned char* p
= new unsigned char[psize
+ byteshift
];
344 memset(p
, 0, byteshift
);
345 this->do_read(poff
, psize
, p
+ byteshift
);
346 v
= new File_read::View(poff
, psize
, p
, byteshift
, cache
, false);
350 void* p
= ::mmap(NULL
, psize
, PROT_READ
, MAP_PRIVATE
,
351 this->descriptor_
, poff
);
353 gold_fatal(_("%s: mmap offset %lld size %lld failed: %s"),
354 this->filename().c_str(),
355 static_cast<long long>(poff
),
356 static_cast<long long>(psize
),
359 this->mapped_bytes_
+= psize
;
361 const unsigned char* pbytes
= static_cast<const unsigned char*>(p
);
362 v
= new File_read::View(poff
, psize
, pbytes
, 0, cache
, true);
370 // Find a View or make a new one, shifted as required by the file
371 // offset OFFSET and ALIGNED.
374 File_read::find_or_make_view(off_t offset
, off_t start
,
375 section_size_type size
, bool aligned
, bool cache
)
377 unsigned int byteshift
;
382 unsigned int target_size
= (!parameters
->target_valid()
384 : parameters
->target().get_size());
385 byteshift
= offset
& ((target_size
/ 8) - 1);
387 // Set BYTESHIFT to the number of dummy bytes which must be
388 // inserted before the data in order for this data to be
391 byteshift
= (target_size
/ 8) - byteshift
;
394 // Try to find a View with the required BYTESHIFT.
395 File_read::View
* vshifted
;
396 File_read::View
* v
= this->find_view(offset
+ start
, size
,
397 aligned
? byteshift
: -1U,
406 // If VSHIFTED is not NULL, then it has the data we need, but with
407 // the wrong byteshift.
411 gold_assert(aligned
);
413 unsigned char* pbytes
= new unsigned char[v
->size() + byteshift
];
414 memset(pbytes
, 0, byteshift
);
415 memcpy(pbytes
+ byteshift
, v
->data() + v
->byteshift(), v
->size());
417 File_read::View
* shifted_view
= new File_read::View(v
->start(), v
->size(),
421 this->add_view(shifted_view
);
425 // Make a new view. If we don't need an aligned view, use a
426 // byteshift of 0, so that we can use mmap.
427 return this->make_view(offset
+ start
, size
,
428 aligned
? byteshift
: 0,
432 // Get a view into the file.
435 File_read::get_view(off_t offset
, off_t start
, section_size_type size
,
436 bool aligned
, bool cache
)
438 File_read::View
* pv
= this->find_or_make_view(offset
, start
, size
,
440 return pv
->data() + (offset
+ start
- pv
->start() + pv
->byteshift());
444 File_read::get_lasting_view(off_t offset
, off_t start
, section_size_type size
,
445 bool aligned
, bool cache
)
447 File_read::View
* pv
= this->find_or_make_view(offset
, start
, size
,
450 return new File_view(*this, pv
,
452 + (offset
+ start
- pv
->start() + pv
->byteshift())));
455 // Use readv to read COUNT entries from RM starting at START. BASE
456 // must be added to all file offsets in RM.
459 File_read::do_readv(off_t base
, const Read_multiple
& rm
, size_t start
,
462 unsigned char discard
[File_read::page_size
];
463 iovec iov
[File_read::max_readv_entries
* 2];
464 size_t iov_index
= 0;
466 off_t first_offset
= rm
[start
].file_offset
;
467 off_t last_offset
= first_offset
;
469 for (size_t i
= 0; i
< count
; ++i
)
471 const Read_multiple_entry
& i_entry(rm
[start
+ i
]);
473 if (i_entry
.file_offset
> last_offset
)
475 size_t skip
= i_entry
.file_offset
- last_offset
;
476 gold_assert(skip
<= sizeof discard
);
478 iov
[iov_index
].iov_base
= discard
;
479 iov
[iov_index
].iov_len
= skip
;
485 iov
[iov_index
].iov_base
= i_entry
.buffer
;
486 iov
[iov_index
].iov_len
= i_entry
.size
;
489 want
+= i_entry
.size
;
491 last_offset
= i_entry
.file_offset
+ i_entry
.size
;
494 gold_assert(iov_index
< sizeof iov
/ sizeof iov
[0]);
496 if (::lseek(this->descriptor_
, base
+ first_offset
, SEEK_SET
) < 0)
497 gold_fatal(_("%s: lseek failed: %s"),
498 this->filename().c_str(), strerror(errno
));
500 ssize_t got
= ::readv(this->descriptor_
, iov
, iov_index
);
503 gold_fatal(_("%s: readv failed: %s"),
504 this->filename().c_str(), strerror(errno
));
506 gold_fatal(_("%s: file too short: read only %zd of %zd bytes at %lld"),
507 this->filename().c_str(),
508 got
, want
, static_cast<long long>(base
+ first_offset
));
511 // Read several pieces of data from the file.
514 File_read::read_multiple(off_t base
, const Read_multiple
& rm
)
516 size_t count
= rm
.size();
520 // Find up to MAX_READV_ENTRIES consecutive entries which are
521 // less than one page apart.
522 const Read_multiple_entry
& i_entry(rm
[i
]);
523 off_t i_off
= i_entry
.file_offset
;
524 off_t end_off
= i_off
+ i_entry
.size
;
526 for (j
= i
+ 1; j
< count
; ++j
)
528 if (j
- i
>= File_read::max_readv_entries
)
530 const Read_multiple_entry
& j_entry(rm
[j
]);
531 off_t j_off
= j_entry
.file_offset
;
532 gold_assert(j_off
>= end_off
);
533 off_t j_end_off
= j_off
+ j_entry
.size
;
534 if (j_end_off
- end_off
>= File_read::page_size
)
540 this->read(base
+ i_off
, i_entry
.size
, i_entry
.buffer
);
543 File_read::View
* view
= this->find_view(base
+ i_off
,
547 this->do_readv(base
, rm
, i
, j
- i
);
550 const unsigned char* v
= (view
->data()
551 + (base
+ i_off
- view
->start()
552 + view
->byteshift()));
553 for (size_t k
= i
; k
< j
; ++k
)
555 const Read_multiple_entry
& k_entry(rm
[k
]);
556 gold_assert((convert_to_section_size_type(k_entry
.file_offset
559 <= convert_to_section_size_type(end_off
561 memcpy(k_entry
.buffer
,
562 v
+ (k_entry
.file_offset
- i_off
),
572 // Mark all views as no longer cached.
575 File_read::clear_view_cache_marks()
577 // Just ignore this if there are multiple objects associated with
578 // the file. Otherwise we will wind up uncaching and freeing some
579 // views for other objects.
580 if (this->object_count_
> 1)
583 for (Views::iterator p
= this->views_
.begin();
584 p
!= this->views_
.end();
586 p
->second
->clear_cache();
587 for (Saved_views::iterator p
= this->saved_views_
.begin();
588 p
!= this->saved_views_
.end();
593 // Remove all the file views. For a file which has multiple
594 // associated objects (i.e., an archive), we keep accessed views
595 // around until next time, in the hopes that they will be useful for
599 File_read::clear_views(bool destroying
)
601 Views::iterator p
= this->views_
.begin();
602 while (p
!= this->views_
.end())
605 if (p
->second
->is_locked())
606 should_delete
= false;
608 should_delete
= true;
609 else if (p
->second
->should_cache())
610 should_delete
= false;
611 else if (this->object_count_
> 1 && p
->second
->accessed())
612 should_delete
= false;
614 should_delete
= true;
620 // map::erase invalidates only the iterator to the deleted
622 Views::iterator pe
= p
;
624 this->views_
.erase(pe
);
628 gold_assert(!destroying
);
629 p
->second
->clear_accessed();
634 Saved_views::iterator q
= this->saved_views_
.begin();
635 while (q
!= this->saved_views_
.end())
637 if (!(*q
)->is_locked())
640 q
= this->saved_views_
.erase(q
);
644 gold_assert(!destroying
);
650 // Print statistical information to stderr. This is used for --stats.
653 File_read::print_stats()
655 fprintf(stderr
, _("%s: total bytes mapped for read: %llu\n"),
656 program_name
, File_read::total_mapped_bytes
);
657 fprintf(stderr
, _("%s: maximum bytes mapped for read at one time: %llu\n"),
658 program_name
, File_read::maximum_mapped_bytes
);
663 File_view::~File_view()
665 gold_assert(this->file_
.is_locked());
666 this->view_
->unlock();
671 // Create a file for testing.
673 Input_file::Input_file(const Task
* task
, const char* name
,
674 const unsigned char* contents
, off_t size
)
677 this->input_argument_
=
678 new Input_file_argument(name
, false, "", false,
679 Position_dependent_options());
680 bool ok
= file_
.open(task
, name
, contents
, size
);
684 // Return the position dependent options in force for this file.
686 const Position_dependent_options
&
687 Input_file::options() const
689 return this->input_argument_
->options();
692 // Return the name given by the user. For -lc this will return "c".
695 Input_file::name() const
697 return this->input_argument_
->name();
700 // Return whether we are only reading symbols.
703 Input_file::just_symbols() const
705 return this->input_argument_
->just_symbols();
710 // If the filename is not absolute, we assume it is in the current
711 // directory *except* when:
712 // A) input_argument_->is_lib() is true; or
713 // B) input_argument_->extra_search_path() is not empty.
714 // In both cases, we look in extra_search_path + library_path to find
715 // the file location, rather than the current directory.
718 Input_file::open(const General_options
& options
, const Dirsearch
& dirpath
,
723 // Case 1: name is an absolute file, just try to open it
724 // Case 2: name is relative but is_lib is false and extra_search_path
726 if (IS_ABSOLUTE_PATH (this->input_argument_
->name())
727 || (!this->input_argument_
->is_lib()
728 && this->input_argument_
->extra_search_path() == NULL
))
730 name
= this->input_argument_
->name();
731 this->found_name_
= name
;
733 // Case 3: is_lib is true
734 else if (this->input_argument_
->is_lib())
736 // We don't yet support extra_search_path with -l.
737 gold_assert(this->input_argument_
->extra_search_path() == NULL
);
738 std::string
n1("lib");
739 n1
+= this->input_argument_
->name();
741 if (options
.is_static()
742 || !this->input_argument_
->options().Bdynamic())
749 name
= dirpath
.find(n1
, n2
, &this->is_in_sysroot_
);
752 gold_error(_("cannot find -l%s"),
753 this->input_argument_
->name());
756 if (n2
.empty() || name
[name
.length() - 1] == 'o')
757 this->found_name_
= n1
;
759 this->found_name_
= n2
;
761 // Case 4: extra_search_path is not empty
764 gold_assert(this->input_argument_
->extra_search_path() != NULL
);
766 // First, check extra_search_path.
767 name
= this->input_argument_
->extra_search_path();
768 if (!IS_DIR_SEPARATOR (name
[name
.length() - 1]))
770 name
+= this->input_argument_
->name();
771 struct stat dummy_stat
;
772 if (::stat(name
.c_str(), &dummy_stat
) < 0)
774 // extra_search_path failed, so check the normal search-path.
775 name
= dirpath
.find(this->input_argument_
->name(), "",
776 &this->is_in_sysroot_
);
779 gold_error(_("cannot find %s"),
780 this->input_argument_
->name());
784 this->found_name_
= this->input_argument_
->name();
787 // Now that we've figured out where the file lives, try to open it.
789 General_options::Object_format format
=
790 this->input_argument_
->options().format_enum();
792 if (format
== General_options::OBJECT_FORMAT_ELF
)
793 ok
= this->file_
.open(task
, name
);
796 gold_assert(format
== General_options::OBJECT_FORMAT_BINARY
);
797 ok
= this->open_binary(options
, task
, name
);
802 gold_error(_("cannot open %s: %s"),
803 name
.c_str(), strerror(errno
));
810 // Open a file for --format binary.
813 Input_file::open_binary(const General_options
&,
814 const Task
* task
, const std::string
& name
)
816 // In order to open a binary file, we need machine code, size, and
817 // endianness. We may not have a valid target at this point, in
818 // which case we use the default target.
819 const Target
* target
;
820 if (parameters
->target_valid())
821 target
= ¶meters
->target();
823 target
= ¶meters
->default_target();
825 Binary_to_elf
binary_to_elf(target
->machine_code(),
827 target
->is_big_endian(),
829 if (!binary_to_elf
.convert(task
))
831 return this->file_
.open(task
, name
, binary_to_elf
.converted_data_leak(),
832 binary_to_elf
.converted_size());
835 } // End namespace gold.