1 // fileread.cc -- read files for gold
2
3 // Copyright (C) 2006-2016 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5
6 // This file is part of gold.
7
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.
12
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.
17
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.
22
23 #include "gold.h"
24
25 #include <cstring>
26 #include <cerrno>
27 #include <climits>
28 #include <fcntl.h>
29 #include <unistd.h>
30
31 #ifdef HAVE_SYS_MMAN_H
32 #include <sys/mman.h>
33 #endif
34
35 #ifdef HAVE_READV
36 #include <sys/uio.h>
37 #endif
38
39 #include <sys/stat.h>
40 #include "filenames.h"
41
42 #include "debug.h"
43 #include "parameters.h"
44 #include "options.h"
45 #include "dirsearch.h"
46 #include "target.h"
47 #include "binary.h"
48 #include "descriptors.h"
49 #include "gold-threads.h"
50 #include "fileread.h"
51
52 // For systems without mmap support.
53 #ifndef HAVE_MMAP
54 # define mmap gold_mmap
55 # define munmap gold_munmap
56 # ifndef MAP_FAILED
57 # define MAP_FAILED (reinterpret_cast<void*>(-1))
58 # endif
59 # ifndef PROT_READ
60 # define PROT_READ 0
61 # endif
62 # ifndef MAP_PRIVATE
63 # define MAP_PRIVATE 0
64 # endif
65
66 # ifndef ENOSYS
67 # define ENOSYS EINVAL
68 # endif
69
70 static void *
gold_mmap(void *,size_t,int,int,int,off_t)71 gold_mmap(void *, size_t, int, int, int, off_t)
72 {
73 errno = ENOSYS;
74 return MAP_FAILED;
75 }
76
77 static int
gold_munmap(void *,size_t)78 gold_munmap(void *, size_t)
79 {
80 errno = ENOSYS;
81 return -1;
82 }
83
84 #endif
85
86 #ifndef HAVE_READV
87 struct iovec { void* iov_base; size_t iov_len; };
88 ssize_t
readv(int,const iovec *,int)89 readv(int, const iovec*, int)
90 {
91 gold_unreachable();
92 }
93 #endif
94
95 namespace gold
96 {
97
98 // Get the last modified time of an unopened file.
99
100 bool
get_mtime(const char * filename,Timespec * mtime)101 get_mtime(const char* filename, Timespec* mtime)
102 {
103 struct stat file_stat;
104
105 if (stat(filename, &file_stat) < 0)
106 return false;
107 #ifdef HAVE_STAT_ST_MTIM
108 mtime->seconds = file_stat.st_mtim.tv_sec;
109 mtime->nanoseconds = file_stat.st_mtim.tv_nsec;
110 #else
111 mtime->seconds = file_stat.st_mtime;
112 mtime->nanoseconds = 0;
113 #endif
114 return true;
115 }
116
117 // Class File_read.
118
119 // A lock for the File_read static variables.
120 static Lock* file_counts_lock = NULL;
121 static Initialize_lock file_counts_initialize_lock(&file_counts_lock);
122
123 // The File_read static variables.
124 unsigned long long File_read::total_mapped_bytes;
125 unsigned long long File_read::current_mapped_bytes;
126 unsigned long long File_read::maximum_mapped_bytes;
127
128 // Class File_read::View.
129
~View()130 File_read::View::~View()
131 {
132 gold_assert(!this->is_locked());
133 switch (this->data_ownership_)
134 {
135 case DATA_ALLOCATED_ARRAY:
136 free(const_cast<unsigned char*>(this->data_));
137 break;
138 case DATA_MMAPPED:
139 if (::munmap(const_cast<unsigned char*>(this->data_), this->size_) != 0)
140 gold_warning(_("munmap failed: %s"), strerror(errno));
141 if (!parameters->options_valid() || parameters->options().stats())
142 {
143 file_counts_initialize_lock.initialize();
144 Hold_optional_lock hl(file_counts_lock);
145 File_read::current_mapped_bytes -= this->size_;
146 }
147 break;
148 case DATA_NOT_OWNED:
149 break;
150 default:
151 gold_unreachable();
152 }
153 }
154
155 void
lock()156 File_read::View::lock()
157 {
158 ++this->lock_count_;
159 }
160
161 void
unlock()162 File_read::View::unlock()
163 {
164 gold_assert(this->lock_count_ > 0);
165 --this->lock_count_;
166 }
167
168 bool
is_locked()169 File_read::View::is_locked()
170 {
171 return this->lock_count_ > 0;
172 }
173
174 // Class File_read.
175
~File_read()176 File_read::~File_read()
177 {
178 gold_assert(this->token_.is_writable());
179 if (this->is_descriptor_opened_)
180 {
181 release_descriptor(this->descriptor_, true);
182 this->descriptor_ = -1;
183 this->is_descriptor_opened_ = false;
184 }
185 this->name_.clear();
186 this->clear_views(CLEAR_VIEWS_ALL);
187 }
188
189 // Open the file.
190
191 bool
open(const Task * task,const std::string & name)192 File_read::open(const Task* task, const std::string& name)
193 {
194 gold_assert(this->token_.is_writable()
195 && this->descriptor_ < 0
196 && !this->is_descriptor_opened_
197 && this->name_.empty());
198 this->name_ = name;
199
200 this->descriptor_ = open_descriptor(-1, this->name_.c_str(),
201 O_RDONLY);
202
203 if (this->descriptor_ >= 0)
204 {
205 this->is_descriptor_opened_ = true;
206 struct stat s;
207 if (::fstat(this->descriptor_, &s) < 0)
208 gold_error(_("%s: fstat failed: %s"),
209 this->name_.c_str(), strerror(errno));
210 this->size_ = s.st_size;
211 gold_debug(DEBUG_FILES, "Attempt to open %s succeeded",
212 this->name_.c_str());
213 this->token_.add_writer(task);
214 }
215
216 return this->descriptor_ >= 0;
217 }
218
219 // Open the file with the contents in memory.
220
221 bool
open(const Task * task,const std::string & name,const unsigned char * contents,off_t size)222 File_read::open(const Task* task, const std::string& name,
223 const unsigned char* contents, off_t size)
224 {
225 gold_assert(this->token_.is_writable()
226 && this->descriptor_ < 0
227 && !this->is_descriptor_opened_
228 && this->name_.empty());
229 this->name_ = name;
230 this->whole_file_view_ = new View(0, size, contents, 0, false,
231 View::DATA_NOT_OWNED);
232 this->add_view(this->whole_file_view_);
233 this->size_ = size;
234 this->token_.add_writer(task);
235 return true;
236 }
237
238 // Reopen a descriptor if necessary.
239
240 void
reopen_descriptor()241 File_read::reopen_descriptor()
242 {
243 if (!this->is_descriptor_opened_)
244 {
245 this->descriptor_ = open_descriptor(this->descriptor_,
246 this->name_.c_str(),
247 O_RDONLY);
248 if (this->descriptor_ < 0)
249 gold_fatal(_("could not reopen file %s"), this->name_.c_str());
250 this->is_descriptor_opened_ = true;
251 }
252 }
253
254 // Release the file. This is called when we are done with the file in
255 // a Task.
256
257 void
release()258 File_read::release()
259 {
260 gold_assert(this->is_locked());
261
262 if (!parameters->options_valid() || parameters->options().stats())
263 {
264 file_counts_initialize_lock.initialize();
265 Hold_optional_lock hl(file_counts_lock);
266 File_read::total_mapped_bytes += this->mapped_bytes_;
267 File_read::current_mapped_bytes += this->mapped_bytes_;
268 if (File_read::current_mapped_bytes > File_read::maximum_mapped_bytes)
269 File_read::maximum_mapped_bytes = File_read::current_mapped_bytes;
270 }
271
272 this->mapped_bytes_ = 0;
273
274 // Only clear views if there is only one attached object. Otherwise
275 // we waste time trying to clear cached archive views. Similarly
276 // for releasing the descriptor.
277 if (this->object_count_ <= 1)
278 {
279 this->clear_views(CLEAR_VIEWS_NORMAL);
280 if (this->is_descriptor_opened_)
281 {
282 release_descriptor(this->descriptor_, false);
283 this->is_descriptor_opened_ = false;
284 }
285 }
286
287 this->released_ = true;
288 }
289
290 // Lock the file.
291
292 void
lock(const Task * task)293 File_read::lock(const Task* task)
294 {
295 gold_assert(this->released_);
296 gold_debug(DEBUG_FILES, "Locking file \"%s\"", this->name_.c_str());
297 this->token_.add_writer(task);
298 this->released_ = false;
299 }
300
301 // Unlock the file.
302
303 void
unlock(const Task * task)304 File_read::unlock(const Task* task)
305 {
306 gold_debug(DEBUG_FILES, "Unlocking file \"%s\"", this->name_.c_str());
307 this->release();
308 this->token_.remove_writer(task);
309 }
310
311 // Return whether the file is locked.
312
313 bool
is_locked() const314 File_read::is_locked() const
315 {
316 if (!this->token_.is_writable())
317 return true;
318 // The file is not locked, so it should have been released.
319 gold_assert(this->released_);
320 return false;
321 }
322
323 // See if we have a view which covers the file starting at START for
324 // SIZE bytes. Return a pointer to the View if found, NULL if not.
325 // If BYTESHIFT is not -1U, the returned View must have the specified
326 // byte shift; otherwise, it may have any byte shift. If VSHIFTED is
327 // not NULL, this sets *VSHIFTED to a view which would have worked if
328 // not for the requested BYTESHIFT.
329
330 inline File_read::View*
find_view(off_t start,section_size_type size,unsigned int byteshift,File_read::View ** vshifted) const331 File_read::find_view(off_t start, section_size_type size,
332 unsigned int byteshift, File_read::View** vshifted) const
333 {
334 gold_assert(start <= this->size_
335 && (static_cast<unsigned long long>(size)
336 <= static_cast<unsigned long long>(this->size_ - start)));
337
338 if (vshifted != NULL)
339 *vshifted = NULL;
340
341 // If we have the whole file mmapped, and the alignment is right,
342 // we can return it.
343 if (this->whole_file_view_)
344 if (byteshift == -1U || byteshift == 0)
345 return this->whole_file_view_;
346
347 off_t page = File_read::page_offset(start);
348
349 unsigned int bszero = 0;
350 Views::const_iterator p = this->views_.upper_bound(std::make_pair(page - 1,
351 bszero));
352
353 while (p != this->views_.end() && p->first.first <= page)
354 {
355 if (p->second->start() <= start
356 && (p->second->start() + static_cast<off_t>(p->second->size())
357 >= start + static_cast<off_t>(size)))
358 {
359 if (byteshift == -1U || byteshift == p->second->byteshift())
360 {
361 p->second->set_accessed();
362 return p->second;
363 }
364
365 if (vshifted != NULL && *vshifted == NULL)
366 *vshifted = p->second;
367 }
368
369 ++p;
370 }
371
372 return NULL;
373 }
374
375 // Read SIZE bytes from the file starting at offset START. Read into
376 // the buffer at P.
377
378 void
do_read(off_t start,section_size_type size,void * p)379 File_read::do_read(off_t start, section_size_type size, void* p)
380 {
381 ssize_t bytes;
382 if (this->whole_file_view_ != NULL)
383 {
384 bytes = this->size_ - start;
385 if (static_cast<section_size_type>(bytes) >= size)
386 {
387 memcpy(p, this->whole_file_view_->data() + start, size);
388 return;
389 }
390 }
391 else
392 {
393 this->reopen_descriptor();
394
395 char *read_ptr = static_cast<char *>(p);
396 off_t read_pos = start;
397 size_t to_read = size;
398 do
399 {
400 bytes = ::pread(this->descriptor_, read_ptr, to_read, read_pos);
401 if (bytes < 0)
402 gold_fatal(_("%s: pread failed: %s"),
403 this->filename().c_str(), strerror(errno));
404
405 read_pos += bytes;
406 read_ptr += bytes;
407 to_read -= bytes;
408 if (to_read == 0)
409 return;
410 }
411 while (bytes > 0);
412
413 bytes = size - to_read;
414 }
415
416 gold_fatal(_("%s: file too short: read only %lld of %lld bytes at %lld"),
417 this->filename().c_str(),
418 static_cast<long long>(bytes),
419 static_cast<long long>(size),
420 static_cast<long long>(start));
421 }
422
423 // Read data from the file.
424
425 void
read(off_t start,section_size_type size,void * p)426 File_read::read(off_t start, section_size_type size, void* p)
427 {
428 const File_read::View* pv = this->find_view(start, size, -1U, NULL);
429 if (pv != NULL)
430 {
431 memcpy(p, pv->data() + (start - pv->start() + pv->byteshift()), size);
432 return;
433 }
434
435 this->do_read(start, size, p);
436 }
437
438 // Add a new view. There may already be an existing view at this
439 // offset. If there is, the new view will be larger, and should
440 // replace the old view.
441
442 void
add_view(File_read::View * v)443 File_read::add_view(File_read::View* v)
444 {
445 std::pair<Views::iterator, bool> ins =
446 this->views_.insert(std::make_pair(std::make_pair(v->start(),
447 v->byteshift()),
448 v));
449 if (ins.second)
450 return;
451
452 // There was an existing view at this offset. It must not be large
453 // enough. We can't delete it here, since something might be using
454 // it; we put it on a list to be deleted when the file is unlocked.
455 File_read::View* vold = ins.first->second;
456 gold_assert(vold->size() < v->size());
457 if (vold->should_cache())
458 {
459 v->set_cache();
460 vold->clear_cache();
461 }
462 this->saved_views_.push_back(vold);
463
464 ins.first->second = v;
465 }
466
467 // Make a new view with a specified byteshift, reading the data from
468 // the file.
469
470 File_read::View*
make_view(off_t start,section_size_type size,unsigned int byteshift,bool cache)471 File_read::make_view(off_t start, section_size_type size,
472 unsigned int byteshift, bool cache)
473 {
474 gold_assert(size > 0);
475 gold_assert(start <= this->size_
476 && (static_cast<unsigned long long>(size)
477 <= static_cast<unsigned long long>(this->size_ - start)));
478
479 off_t poff = File_read::page_offset(start);
480
481 section_size_type psize = File_read::pages(size + (start - poff));
482
483 if (poff + static_cast<off_t>(psize) >= this->size_)
484 {
485 psize = this->size_ - poff;
486 gold_assert(psize >= size);
487 }
488
489 void* p;
490 View::Data_ownership ownership;
491 if (byteshift != 0)
492 {
493 p = malloc(psize + byteshift);
494 if (p == NULL)
495 gold_nomem();
496 memset(p, 0, byteshift);
497 this->do_read(poff, psize, static_cast<unsigned char*>(p) + byteshift);
498 ownership = View::DATA_ALLOCATED_ARRAY;
499 }
500 else
501 {
502 this->reopen_descriptor();
503 p = ::mmap(NULL, psize, PROT_READ, MAP_PRIVATE, this->descriptor_, poff);
504 if (p != MAP_FAILED)
505 {
506 ownership = View::DATA_MMAPPED;
507 this->mapped_bytes_ += psize;
508 }
509 else
510 {
511 p = malloc(psize);
512 if (p == NULL)
513 gold_nomem();
514 this->do_read(poff, psize, p);
515 ownership = View::DATA_ALLOCATED_ARRAY;
516 }
517 }
518
519 const unsigned char* pbytes = static_cast<const unsigned char*>(p);
520 File_read::View* v = new File_read::View(poff, psize, pbytes, byteshift,
521 cache, ownership);
522
523 this->add_view(v);
524
525 return v;
526 }
527
528 // Find a View or make a new one, shifted as required by the file
529 // offset OFFSET and ALIGNED.
530
531 File_read::View*
find_or_make_view(off_t offset,off_t start,section_size_type size,bool aligned,bool cache)532 File_read::find_or_make_view(off_t offset, off_t start,
533 section_size_type size, bool aligned, bool cache)
534 {
535 // Check that start and end of the view are within the file.
536 if (start > this->size_
537 || (static_cast<unsigned long long>(size)
538 > static_cast<unsigned long long>(this->size_ - start)))
539 gold_fatal(_("%s: attempt to map %lld bytes at offset %lld exceeds "
540 "size of file; the file may be corrupt"),
541 this->filename().c_str(),
542 static_cast<long long>(size),
543 static_cast<long long>(start));
544
545 unsigned int byteshift;
546 if (offset == 0)
547 byteshift = 0;
548 else
549 {
550 unsigned int target_size = (!parameters->target_valid()
551 ? 64
552 : parameters->target().get_size());
553 byteshift = offset & ((target_size / 8) - 1);
554
555 // Set BYTESHIFT to the number of dummy bytes which must be
556 // inserted before the data in order for this data to be
557 // aligned.
558 if (byteshift != 0)
559 byteshift = (target_size / 8) - byteshift;
560 }
561
562 // If --map-whole-files is set, make sure we have a
563 // whole file view. Options may not yet be ready, e.g.,
564 // when reading a version script. We then default to
565 // --no-map-whole-files.
566 if (this->whole_file_view_ == NULL
567 && parameters->options_valid()
568 && parameters->options().map_whole_files())
569 this->whole_file_view_ = this->make_view(0, this->size_, 0, cache);
570
571 // Try to find a View with the required BYTESHIFT.
572 File_read::View* vshifted;
573 File_read::View* v = this->find_view(offset + start, size,
574 aligned ? byteshift : -1U,
575 &vshifted);
576 if (v != NULL)
577 {
578 if (cache)
579 v->set_cache();
580 return v;
581 }
582
583 // If VSHIFTED is not NULL, then it has the data we need, but with
584 // the wrong byteshift.
585 v = vshifted;
586 if (v != NULL)
587 {
588 gold_assert(aligned);
589
590 unsigned char* pbytes;
591 pbytes = static_cast<unsigned char*>(malloc(v->size() + byteshift));
592 if (pbytes == NULL)
593 gold_nomem();
594 memset(pbytes, 0, byteshift);
595 memcpy(pbytes + byteshift, v->data() + v->byteshift(), v->size());
596
597 File_read::View* shifted_view =
598 new File_read::View(v->start(), v->size(), pbytes, byteshift,
599 cache, View::DATA_ALLOCATED_ARRAY);
600
601 this->add_view(shifted_view);
602 return shifted_view;
603 }
604
605 // Make a new view. If we don't need an aligned view, use a
606 // byteshift of 0, so that we can use mmap.
607 return this->make_view(offset + start, size,
608 aligned ? byteshift : 0,
609 cache);
610 }
611
612 // Get a view into the file.
613
614 const unsigned char*
get_view(off_t offset,off_t start,section_size_type size,bool aligned,bool cache)615 File_read::get_view(off_t offset, off_t start, section_size_type size,
616 bool aligned, bool cache)
617 {
618 File_read::View* pv = this->find_or_make_view(offset, start, size,
619 aligned, cache);
620 return pv->data() + (offset + start - pv->start() + pv->byteshift());
621 }
622
623 File_view*
get_lasting_view(off_t offset,off_t start,section_size_type size,bool aligned,bool cache)624 File_read::get_lasting_view(off_t offset, off_t start, section_size_type size,
625 bool aligned, bool cache)
626 {
627 File_read::View* pv = this->find_or_make_view(offset, start, size,
628 aligned, cache);
629 pv->lock();
630 return new File_view(*this, pv,
631 (pv->data()
632 + (offset + start - pv->start() + pv->byteshift())));
633 }
634
635 // Use readv to read COUNT entries from RM starting at START. BASE
636 // must be added to all file offsets in RM.
637
638 void
do_readv(off_t base,const Read_multiple & rm,size_t start,size_t count)639 File_read::do_readv(off_t base, const Read_multiple& rm, size_t start,
640 size_t count)
641 {
642 unsigned char discard[File_read::page_size];
643 iovec iov[File_read::max_readv_entries * 2];
644 size_t iov_index = 0;
645
646 off_t first_offset = rm[start].file_offset;
647 off_t last_offset = first_offset;
648 ssize_t want = 0;
649 for (size_t i = 0; i < count; ++i)
650 {
651 const Read_multiple_entry& i_entry(rm[start + i]);
652
653 if (i_entry.file_offset > last_offset)
654 {
655 size_t skip = i_entry.file_offset - last_offset;
656 gold_assert(skip <= sizeof discard);
657
658 iov[iov_index].iov_base = discard;
659 iov[iov_index].iov_len = skip;
660 ++iov_index;
661
662 want += skip;
663 }
664
665 iov[iov_index].iov_base = i_entry.buffer;
666 iov[iov_index].iov_len = i_entry.size;
667 ++iov_index;
668
669 want += i_entry.size;
670
671 last_offset = i_entry.file_offset + i_entry.size;
672 }
673
674 this->reopen_descriptor();
675
676 gold_assert(iov_index < sizeof iov / sizeof iov[0]);
677
678 if (::lseek(this->descriptor_, base + first_offset, SEEK_SET) < 0)
679 gold_fatal(_("%s: lseek failed: %s"),
680 this->filename().c_str(), strerror(errno));
681
682 ssize_t got = ::readv(this->descriptor_, iov, iov_index);
683
684 if (got < 0)
685 gold_fatal(_("%s: readv failed: %s"),
686 this->filename().c_str(), strerror(errno));
687 if (got != want)
688 gold_fatal(_("%s: file too short: read only %zd of %zd bytes at %lld"),
689 this->filename().c_str(),
690 got, want, static_cast<long long>(base + first_offset));
691 }
692
693 // Portable IOV_MAX.
694
695 #if !defined(HAVE_READV)
696 #define GOLD_IOV_MAX 1
697 #elif defined(IOV_MAX)
698 #define GOLD_IOV_MAX IOV_MAX
699 #else
700 #define GOLD_IOV_MAX (File_read::max_readv_entries * 2)
701 #endif
702
703 // Read several pieces of data from the file.
704
705 void
read_multiple(off_t base,const Read_multiple & rm)706 File_read::read_multiple(off_t base, const Read_multiple& rm)
707 {
708 static size_t iov_max = GOLD_IOV_MAX;
709 size_t count = rm.size();
710 size_t i = 0;
711 while (i < count)
712 {
713 // Find up to MAX_READV_ENTRIES consecutive entries which are
714 // less than one page apart.
715 const Read_multiple_entry& i_entry(rm[i]);
716 off_t i_off = i_entry.file_offset;
717 off_t end_off = i_off + i_entry.size;
718 size_t j;
719 for (j = i + 1; j < count; ++j)
720 {
721 if (j - i >= File_read::max_readv_entries || j - i >= iov_max / 2)
722 break;
723 const Read_multiple_entry& j_entry(rm[j]);
724 off_t j_off = j_entry.file_offset;
725 gold_assert(j_off >= end_off);
726 off_t j_end_off = j_off + j_entry.size;
727 if (j_end_off - end_off >= File_read::page_size)
728 break;
729 end_off = j_end_off;
730 }
731
732 if (j == i + 1)
733 this->read(base + i_off, i_entry.size, i_entry.buffer);
734 else
735 {
736 File_read::View* view = this->find_view(base + i_off,
737 end_off - i_off,
738 -1U, NULL);
739 if (view == NULL)
740 this->do_readv(base, rm, i, j - i);
741 else
742 {
743 const unsigned char* v = (view->data()
744 + (base + i_off - view->start()
745 + view->byteshift()));
746 for (size_t k = i; k < j; ++k)
747 {
748 const Read_multiple_entry& k_entry(rm[k]);
749 gold_assert((convert_to_section_size_type(k_entry.file_offset
750 - i_off)
751 + k_entry.size)
752 <= convert_to_section_size_type(end_off
753 - i_off));
754 memcpy(k_entry.buffer,
755 v + (k_entry.file_offset - i_off),
756 k_entry.size);
757 }
758 }
759 }
760
761 i = j;
762 }
763 }
764
765 // Mark all views as no longer cached.
766
767 void
clear_view_cache_marks()768 File_read::clear_view_cache_marks()
769 {
770 // Just ignore this if there are multiple objects associated with
771 // the file. Otherwise we will wind up uncaching and freeing some
772 // views for other objects.
773 if (this->object_count_ > 1)
774 return;
775
776 for (Views::iterator p = this->views_.begin();
777 p != this->views_.end();
778 ++p)
779 p->second->clear_cache();
780 for (Saved_views::iterator p = this->saved_views_.begin();
781 p != this->saved_views_.end();
782 ++p)
783 (*p)->clear_cache();
784 }
785
786 // Remove all the file views. For a file which has multiple
787 // associated objects (i.e., an archive), we keep accessed views
788 // around until next time, in the hopes that they will be useful for
789 // the next object.
790
791 void
clear_views(Clear_views_mode mode)792 File_read::clear_views(Clear_views_mode mode)
793 {
794 bool keep_files_mapped = (parameters->options_valid()
795 && parameters->options().keep_files_mapped());
796 Views::iterator p = this->views_.begin();
797 while (p != this->views_.end())
798 {
799 bool should_delete;
800 if (p->second->is_locked() || p->second->is_permanent_view())
801 should_delete = false;
802 else if (mode == CLEAR_VIEWS_ALL)
803 should_delete = true;
804 else if ((p->second->should_cache()
805 || p->second == this->whole_file_view_)
806 && keep_files_mapped)
807 should_delete = false;
808 else if (this->object_count_ > 1
809 && p->second->accessed()
810 && mode != CLEAR_VIEWS_ARCHIVE)
811 should_delete = false;
812 else
813 should_delete = true;
814
815 if (should_delete)
816 {
817 if (p->second == this->whole_file_view_)
818 this->whole_file_view_ = NULL;
819 delete p->second;
820
821 // map::erase invalidates only the iterator to the deleted
822 // element.
823 Views::iterator pe = p;
824 ++p;
825 this->views_.erase(pe);
826 }
827 else
828 {
829 p->second->clear_accessed();
830 ++p;
831 }
832 }
833
834 Saved_views::iterator q = this->saved_views_.begin();
835 while (q != this->saved_views_.end())
836 {
837 if (!(*q)->is_locked())
838 {
839 delete *q;
840 q = this->saved_views_.erase(q);
841 }
842 else
843 {
844 gold_assert(mode != CLEAR_VIEWS_ALL);
845 ++q;
846 }
847 }
848 }
849
850 // Print statistical information to stderr. This is used for --stats.
851
852 void
print_stats()853 File_read::print_stats()
854 {
855 fprintf(stderr, _("%s: total bytes mapped for read: %llu\n"),
856 program_name, File_read::total_mapped_bytes);
857 fprintf(stderr, _("%s: maximum bytes mapped for read at one time: %llu\n"),
858 program_name, File_read::maximum_mapped_bytes);
859 }
860
861 // Class File_view.
862
~File_view()863 File_view::~File_view()
864 {
865 gold_assert(this->file_.is_locked());
866 this->view_->unlock();
867 }
868
869 // Class Input_file.
870
871 // Create a file given just the filename.
872
Input_file(const char * name)873 Input_file::Input_file(const char* name)
874 : found_name_(), file_(), is_in_sysroot_(false), format_(FORMAT_NONE)
875 {
876 this->input_argument_ =
877 new Input_file_argument(name, Input_file_argument::INPUT_FILE_TYPE_FILE,
878 "", false, Position_dependent_options());
879 }
880
881 // Create a file for testing.
882
Input_file(const Task * task,const char * name,const unsigned char * contents,off_t size)883 Input_file::Input_file(const Task* task, const char* name,
884 const unsigned char* contents, off_t size)
885 : file_()
886 {
887 this->input_argument_ =
888 new Input_file_argument(name, Input_file_argument::INPUT_FILE_TYPE_FILE,
889 "", false, Position_dependent_options());
890 bool ok = this->file_.open(task, name, contents, size);
891 gold_assert(ok);
892 }
893
894 // Return the position dependent options in force for this file.
895
896 const Position_dependent_options&
options() const897 Input_file::options() const
898 {
899 return this->input_argument_->options();
900 }
901
902 // Return the name given by the user. For -lc this will return "c".
903
904 const char*
name() const905 Input_file::name() const
906 {
907 return this->input_argument_->name();
908 }
909
910 // Return whether this file is in a system directory.
911
912 bool
is_in_system_directory() const913 Input_file::is_in_system_directory() const
914 {
915 if (this->is_in_sysroot())
916 return true;
917 return parameters->options().is_in_system_directory(this->filename());
918 }
919
920 // Return whether we are only reading symbols.
921
922 bool
just_symbols() const923 Input_file::just_symbols() const
924 {
925 return this->input_argument_->just_symbols();
926 }
927
928 // Return whether this is a file that we will search for in the list
929 // of directories.
930
931 bool
will_search_for() const932 Input_file::will_search_for() const
933 {
934 return (!IS_ABSOLUTE_PATH(this->input_argument_->name())
935 && (this->input_argument_->is_lib()
936 || this->input_argument_->is_searched_file()
937 || this->input_argument_->extra_search_path() != NULL));
938 }
939
940 // Return the file last modification time. Calls gold_fatal if the stat
941 // system call failed.
942
943 Timespec
get_mtime()944 File_read::get_mtime()
945 {
946 struct stat file_stat;
947 this->reopen_descriptor();
948
949 if (fstat(this->descriptor_, &file_stat) < 0)
950 gold_fatal(_("%s: stat failed: %s"), this->name_.c_str(),
951 strerror(errno));
952 #ifdef HAVE_STAT_ST_MTIM
953 return Timespec(file_stat.st_mtim.tv_sec, file_stat.st_mtim.tv_nsec);
954 #else
955 return Timespec(file_stat.st_mtime, 0);
956 #endif
957 }
958
959 // Try to find a file in the extra search dirs. Returns true on success.
960
961 bool
try_extra_search_path(int * pindex,const Input_file_argument * input_argument,std::string filename,std::string * found_name,std::string * namep)962 Input_file::try_extra_search_path(int* pindex,
963 const Input_file_argument* input_argument,
964 std::string filename, std::string* found_name,
965 std::string* namep)
966 {
967 if (input_argument->extra_search_path() == NULL)
968 return false;
969
970 std::string name = input_argument->extra_search_path();
971 if (!IS_DIR_SEPARATOR(name[name.length() - 1]))
972 name += '/';
973 name += filename;
974
975 struct stat dummy_stat;
976 if (*pindex > 0 || ::stat(name.c_str(), &dummy_stat) < 0)
977 return false;
978
979 *found_name = filename;
980 *namep = name;
981 return true;
982 }
983
984 // Find the actual file.
985 // If the filename is not absolute, we assume it is in the current
986 // directory *except* when:
987 // A) input_argument_->is_lib() is true;
988 // B) input_argument_->is_searched_file() is true; or
989 // C) input_argument_->extra_search_path() is not empty.
990 // In each, we look in extra_search_path + library_path to find
991 // the file location, rather than the current directory.
992
993 bool
find_file(const Dirsearch & dirpath,int * pindex,const Input_file_argument * input_argument,bool * is_in_sysroot,std::string * found_name,std::string * namep)994 Input_file::find_file(const Dirsearch& dirpath, int* pindex,
995 const Input_file_argument* input_argument,
996 bool* is_in_sysroot,
997 std::string* found_name, std::string* namep)
998 {
999 std::string name;
1000
1001 // Case 1: name is an absolute file, just try to open it
1002 // Case 2: name is relative but is_lib is false, is_searched_file is false,
1003 // and extra_search_path is empty
1004 if (IS_ABSOLUTE_PATH(input_argument->name())
1005 || (!input_argument->is_lib()
1006 && !input_argument->is_searched_file()
1007 && input_argument->extra_search_path() == NULL))
1008 {
1009 name = input_argument->name();
1010 *found_name = name;
1011 *namep = name;
1012 return true;
1013 }
1014 // Case 3: is_lib is true or is_searched_file is true
1015 else if (input_argument->is_lib()
1016 || input_argument->is_searched_file())
1017 {
1018 std::vector<std::string> names;
1019 names.reserve(2);
1020 if (input_argument->is_lib())
1021 {
1022 std::string prefix = "lib";
1023 prefix += input_argument->name();
1024 if (parameters->options().is_static()
1025 || !input_argument->options().Bdynamic())
1026 names.push_back(prefix + ".a");
1027 else
1028 {
1029 names.push_back(prefix + ".so");
1030 names.push_back(prefix + ".a");
1031 }
1032 }
1033 else
1034 names.push_back(input_argument->name());
1035
1036 for (std::vector<std::string>::const_iterator n = names.begin();
1037 n != names.end();
1038 ++n)
1039 if (Input_file::try_extra_search_path(pindex, input_argument, *n,
1040 found_name, namep))
1041 return true;
1042
1043 // It is not in the extra_search_path.
1044 name = dirpath.find(names, is_in_sysroot, pindex, found_name);
1045 if (name.empty())
1046 {
1047 gold_error(_("cannot find %s%s"),
1048 input_argument->is_lib() ? "-l" : "",
1049 input_argument->name());
1050 return false;
1051 }
1052 *namep = name;
1053 return true;
1054 }
1055 // Case 4: extra_search_path is not empty
1056 else
1057 {
1058 gold_assert(input_argument->extra_search_path() != NULL);
1059
1060 if (try_extra_search_path(pindex, input_argument, input_argument->name(),
1061 found_name, namep))
1062 return true;
1063
1064 // extra_search_path failed, so check the normal search-path.
1065 int index = *pindex;
1066 if (index > 0)
1067 --index;
1068 name = dirpath.find(std::vector<std::string>(1, input_argument->name()),
1069 is_in_sysroot, &index, found_name);
1070 if (name.empty())
1071 {
1072 gold_error(_("cannot find %s"),
1073 input_argument->name());
1074 return false;
1075 }
1076 *namep = name;
1077 *pindex = index + 1;
1078 return true;
1079 }
1080 }
1081
1082 // Open the file.
1083
1084 bool
open(const Dirsearch & dirpath,const Task * task,int * pindex)1085 Input_file::open(const Dirsearch& dirpath, const Task* task, int* pindex)
1086 {
1087 std::string name;
1088 if (!Input_file::find_file(dirpath, pindex, this->input_argument_,
1089 &this->is_in_sysroot_, &this->found_name_, &name))
1090 return false;
1091
1092 // Now that we've figured out where the file lives, try to open it.
1093
1094 General_options::Object_format format =
1095 this->input_argument_->options().format_enum();
1096 bool ok;
1097 if (format == General_options::OBJECT_FORMAT_ELF)
1098 {
1099 ok = this->file_.open(task, name);
1100 this->format_ = FORMAT_ELF;
1101 }
1102 else
1103 {
1104 gold_assert(format == General_options::OBJECT_FORMAT_BINARY);
1105 ok = this->open_binary(task, name);
1106 this->format_ = FORMAT_BINARY;
1107 }
1108
1109 if (!ok)
1110 {
1111 gold_error(_("cannot open %s: %s"),
1112 name.c_str(), strerror(errno));
1113 this->format_ = FORMAT_NONE;
1114 return false;
1115 }
1116
1117 return true;
1118 }
1119
1120 // Open a file for --format binary.
1121
1122 bool
open_binary(const Task * task,const std::string & name)1123 Input_file::open_binary(const Task* task, const std::string& name)
1124 {
1125 // In order to open a binary file, we need machine code, size, and
1126 // endianness. We may not have a valid target at this point, in
1127 // which case we use the default target.
1128 parameters_force_valid_target();
1129 const Target& target(parameters->target());
1130
1131 Binary_to_elf binary_to_elf(target.machine_code(),
1132 target.get_size(),
1133 target.is_big_endian(),
1134 name);
1135 if (!binary_to_elf.convert(task))
1136 return false;
1137 return this->file_.open(task, name, binary_to_elf.converted_data_leak(),
1138 binary_to_elf.converted_size());
1139 }
1140
1141 } // End namespace gold.
1142