1 // fileread.cc -- read files for gold
2
3 // Copyright (C) 2006-2020 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 std::vector<std::string> File_read::files_read;
128
129 // Class File_read::View.
130
~View()131 File_read::View::~View()
132 {
133 gold_assert(!this->is_locked());
134 switch (this->data_ownership_)
135 {
136 case DATA_ALLOCATED_ARRAY:
137 free(const_cast<unsigned char*>(this->data_));
138 break;
139 case DATA_MMAPPED:
140 if (::munmap(const_cast<unsigned char*>(this->data_), this->size_) != 0)
141 gold_warning(_("munmap failed: %s"), strerror(errno));
142 if (!parameters->options_valid() || parameters->options().stats())
143 {
144 file_counts_initialize_lock.initialize();
145 Hold_optional_lock hl(file_counts_lock);
146 File_read::current_mapped_bytes -= this->size_;
147 }
148 break;
149 case DATA_NOT_OWNED:
150 break;
151 default:
152 gold_unreachable();
153 }
154 }
155
156 void
lock()157 File_read::View::lock()
158 {
159 ++this->lock_count_;
160 }
161
162 void
unlock()163 File_read::View::unlock()
164 {
165 gold_assert(this->lock_count_ > 0);
166 --this->lock_count_;
167 }
168
169 bool
is_locked()170 File_read::View::is_locked()
171 {
172 return this->lock_count_ > 0;
173 }
174
175 // Class File_read.
176
~File_read()177 File_read::~File_read()
178 {
179 gold_assert(this->token_.is_writable());
180 if (this->is_descriptor_opened_)
181 {
182 release_descriptor(this->descriptor_, true);
183 this->descriptor_ = -1;
184 this->is_descriptor_opened_ = false;
185 }
186 this->name_.clear();
187 this->clear_views(CLEAR_VIEWS_ALL);
188 }
189
190 // Open the file.
191
192 bool
open(const Task * task,const std::string & name)193 File_read::open(const Task* task, const std::string& name)
194 {
195 gold_assert(this->token_.is_writable()
196 && this->descriptor_ < 0
197 && !this->is_descriptor_opened_
198 && this->name_.empty());
199 this->name_ = name;
200
201 this->descriptor_ = open_descriptor(-1, this->name_.c_str(),
202 O_RDONLY);
203
204 if (this->descriptor_ >= 0)
205 {
206 this->is_descriptor_opened_ = true;
207 struct stat s;
208 if (::fstat(this->descriptor_, &s) < 0)
209 gold_error(_("%s: fstat failed: %s"),
210 this->name_.c_str(), strerror(errno));
211 this->size_ = s.st_size;
212 gold_debug(DEBUG_FILES, "Attempt to open %s succeeded",
213 this->name_.c_str());
214 this->token_.add_writer(task);
215 Hold_optional_lock hl(file_counts_lock);
216 record_file_read(this->name_);
217 }
218
219 return this->descriptor_ >= 0;
220 }
221
222 // Open the file with the contents in memory.
223
224 bool
open(const Task * task,const std::string & name,const unsigned char * contents,off_t size)225 File_read::open(const Task* task, const std::string& name,
226 const unsigned char* contents, off_t size)
227 {
228 gold_assert(this->token_.is_writable()
229 && this->descriptor_ < 0
230 && !this->is_descriptor_opened_
231 && this->name_.empty());
232 this->name_ = name;
233 this->whole_file_view_ = new View(0, size, contents, 0, false,
234 View::DATA_NOT_OWNED);
235 this->add_view(this->whole_file_view_);
236 this->size_ = size;
237 this->token_.add_writer(task);
238 return true;
239 }
240
241 // Reopen a descriptor if necessary.
242
243 void
reopen_descriptor()244 File_read::reopen_descriptor()
245 {
246 if (!this->is_descriptor_opened_)
247 {
248 this->descriptor_ = open_descriptor(this->descriptor_,
249 this->name_.c_str(),
250 O_RDONLY);
251 if (this->descriptor_ < 0)
252 gold_fatal(_("could not reopen file %s"), this->name_.c_str());
253 this->is_descriptor_opened_ = true;
254 }
255 }
256
257 // Release the file. This is called when we are done with the file in
258 // a Task.
259
260 void
release()261 File_read::release()
262 {
263 gold_assert(this->is_locked());
264
265 if (!parameters->options_valid() || parameters->options().stats())
266 {
267 file_counts_initialize_lock.initialize();
268 Hold_optional_lock hl(file_counts_lock);
269 File_read::total_mapped_bytes += this->mapped_bytes_;
270 File_read::current_mapped_bytes += this->mapped_bytes_;
271 if (File_read::current_mapped_bytes > File_read::maximum_mapped_bytes)
272 File_read::maximum_mapped_bytes = File_read::current_mapped_bytes;
273 }
274
275 this->mapped_bytes_ = 0;
276
277 // Only clear views if there is only one attached object. Otherwise
278 // we waste time trying to clear cached archive views. Similarly
279 // for releasing the descriptor.
280 if (this->object_count_ <= 1)
281 {
282 this->clear_views(CLEAR_VIEWS_NORMAL);
283 if (this->is_descriptor_opened_)
284 {
285 release_descriptor(this->descriptor_, false);
286 this->is_descriptor_opened_ = false;
287 }
288 }
289
290 this->released_ = true;
291 }
292
293 // Lock the file.
294
295 void
lock(const Task * task)296 File_read::lock(const Task* task)
297 {
298 gold_assert(this->released_);
299 gold_debug(DEBUG_FILES, "Locking file \"%s\"", this->name_.c_str());
300 this->token_.add_writer(task);
301 this->released_ = false;
302 }
303
304 // Unlock the file.
305
306 void
unlock(const Task * task)307 File_read::unlock(const Task* task)
308 {
309 gold_debug(DEBUG_FILES, "Unlocking file \"%s\"", this->name_.c_str());
310 this->release();
311 this->token_.remove_writer(task);
312 }
313
314 // Return whether the file is locked.
315
316 bool
is_locked() const317 File_read::is_locked() const
318 {
319 if (!this->token_.is_writable())
320 return true;
321 // The file is not locked, so it should have been released.
322 gold_assert(this->released_);
323 return false;
324 }
325
326 // See if we have a view which covers the file starting at START for
327 // SIZE bytes. Return a pointer to the View if found, NULL if not.
328 // If BYTESHIFT is not -1U, the returned View must have the specified
329 // byte shift; otherwise, it may have any byte shift. If VSHIFTED is
330 // not NULL, this sets *VSHIFTED to a view which would have worked if
331 // not for the requested BYTESHIFT.
332
333 inline File_read::View*
find_view(off_t start,section_size_type size,unsigned int byteshift,File_read::View ** vshifted) const334 File_read::find_view(off_t start, section_size_type size,
335 unsigned int byteshift, File_read::View** vshifted) const
336 {
337 gold_assert(start <= this->size_
338 && (static_cast<unsigned long long>(size)
339 <= static_cast<unsigned long long>(this->size_ - start)));
340
341 if (vshifted != NULL)
342 *vshifted = NULL;
343
344 // If we have the whole file mmapped, and the alignment is right,
345 // we can return it.
346 if (this->whole_file_view_)
347 if (byteshift == -1U || byteshift == 0)
348 return this->whole_file_view_;
349
350 off_t page = File_read::page_offset(start);
351
352 unsigned int bszero = 0;
353 Views::const_iterator p = this->views_.upper_bound(std::make_pair(page - 1,
354 bszero));
355
356 while (p != this->views_.end() && p->first.first <= page)
357 {
358 if (p->second->start() <= start
359 && (p->second->start() + static_cast<off_t>(p->second->size())
360 >= start + static_cast<off_t>(size)))
361 {
362 if (byteshift == -1U || byteshift == p->second->byteshift())
363 {
364 p->second->set_accessed();
365 return p->second;
366 }
367
368 if (vshifted != NULL && *vshifted == NULL)
369 *vshifted = p->second;
370 }
371
372 ++p;
373 }
374
375 return NULL;
376 }
377
378 // Read SIZE bytes from the file starting at offset START. Read into
379 // the buffer at P.
380
381 void
do_read(off_t start,section_size_type size,void * p)382 File_read::do_read(off_t start, section_size_type size, void* p)
383 {
384 ssize_t bytes;
385 if (this->whole_file_view_ != NULL)
386 {
387 bytes = this->size_ - start;
388 if (static_cast<section_size_type>(bytes) >= size)
389 {
390 memcpy(p, this->whole_file_view_->data() + start, size);
391 return;
392 }
393 }
394 else
395 {
396 this->reopen_descriptor();
397
398 char *read_ptr = static_cast<char *>(p);
399 off_t read_pos = start;
400 size_t to_read = size;
401 do
402 {
403 bytes = ::pread(this->descriptor_, read_ptr, to_read, read_pos);
404 if (bytes < 0)
405 gold_fatal(_("%s: pread failed: %s"),
406 this->filename().c_str(), strerror(errno));
407
408 read_pos += bytes;
409 read_ptr += bytes;
410 to_read -= bytes;
411 if (to_read == 0)
412 return;
413 }
414 while (bytes > 0);
415
416 bytes = size - to_read;
417 }
418
419 gold_fatal(_("%s: file too short: read only %lld of %lld bytes at %lld"),
420 this->filename().c_str(),
421 static_cast<long long>(bytes),
422 static_cast<long long>(size),
423 static_cast<long long>(start));
424 }
425
426 // Read data from the file.
427
428 void
read(off_t start,section_size_type size,void * p)429 File_read::read(off_t start, section_size_type size, void* p)
430 {
431 const File_read::View* pv = this->find_view(start, size, -1U, NULL);
432 if (pv != NULL)
433 {
434 memcpy(p, pv->data() + (start - pv->start() + pv->byteshift()), size);
435 return;
436 }
437
438 this->do_read(start, size, p);
439 }
440
441 // Add a new view. There may already be an existing view at this
442 // offset. If there is, the new view will be larger, and should
443 // replace the old view.
444
445 void
add_view(File_read::View * v)446 File_read::add_view(File_read::View* v)
447 {
448 std::pair<Views::iterator, bool> ins =
449 this->views_.insert(std::make_pair(std::make_pair(v->start(),
450 v->byteshift()),
451 v));
452 if (ins.second)
453 return;
454
455 // There was an existing view at this offset. It must not be large
456 // enough. We can't delete it here, since something might be using
457 // it; we put it on a list to be deleted when the file is unlocked.
458 File_read::View* vold = ins.first->second;
459 gold_assert(vold->size() < v->size());
460 if (vold->should_cache())
461 {
462 v->set_cache();
463 vold->clear_cache();
464 }
465 this->saved_views_.push_back(vold);
466
467 ins.first->second = v;
468 }
469
470 // Make a new view with a specified byteshift, reading the data from
471 // the file.
472
473 File_read::View*
make_view(off_t start,section_size_type size,unsigned int byteshift,bool cache)474 File_read::make_view(off_t start, section_size_type size,
475 unsigned int byteshift, bool cache)
476 {
477 gold_assert(size > 0);
478 gold_assert(start <= this->size_
479 && (static_cast<unsigned long long>(size)
480 <= static_cast<unsigned long long>(this->size_ - start)));
481
482 off_t poff = File_read::page_offset(start);
483
484 section_size_type psize = File_read::pages(size + (start - poff));
485
486 if (poff + static_cast<off_t>(psize) >= this->size_)
487 {
488 psize = this->size_ - poff;
489 gold_assert(psize >= size);
490 }
491
492 void* p;
493 View::Data_ownership ownership;
494 if (byteshift != 0)
495 {
496 p = malloc(psize + byteshift);
497 if (p == NULL)
498 gold_nomem();
499 memset(p, 0, byteshift);
500 this->do_read(poff, psize, static_cast<unsigned char*>(p) + byteshift);
501 ownership = View::DATA_ALLOCATED_ARRAY;
502 }
503 else
504 {
505 this->reopen_descriptor();
506 p = ::mmap(NULL, psize, PROT_READ, MAP_PRIVATE, this->descriptor_, poff);
507 if (p != MAP_FAILED)
508 {
509 ownership = View::DATA_MMAPPED;
510 this->mapped_bytes_ += psize;
511 }
512 else
513 {
514 p = malloc(psize);
515 if (p == NULL)
516 gold_nomem();
517 this->do_read(poff, psize, p);
518 ownership = View::DATA_ALLOCATED_ARRAY;
519 }
520 }
521
522 const unsigned char* pbytes = static_cast<const unsigned char*>(p);
523 File_read::View* v = new File_read::View(poff, psize, pbytes, byteshift,
524 cache, ownership);
525
526 this->add_view(v);
527
528 return v;
529 }
530
531 // Find a View or make a new one, shifted as required by the file
532 // offset OFFSET and ALIGNED.
533
534 File_read::View*
find_or_make_view(off_t offset,off_t start,section_size_type size,bool aligned,bool cache)535 File_read::find_or_make_view(off_t offset, off_t start,
536 section_size_type size, bool aligned, bool cache)
537 {
538 // Check that start and end of the view are within the file.
539 if (start > this->size_
540 || (static_cast<unsigned long long>(size)
541 > static_cast<unsigned long long>(this->size_ - start)))
542 gold_fatal(_("%s: attempt to map %lld bytes at offset %lld exceeds "
543 "size of file; the file may be corrupt"),
544 this->filename().c_str(),
545 static_cast<long long>(size),
546 static_cast<long long>(start));
547
548 unsigned int byteshift;
549 if (offset == 0)
550 byteshift = 0;
551 else
552 {
553 unsigned int target_size = (!parameters->target_valid()
554 ? 64
555 : parameters->target().get_size());
556 byteshift = offset & ((target_size / 8) - 1);
557
558 // Set BYTESHIFT to the number of dummy bytes which must be
559 // inserted before the data in order for this data to be
560 // aligned.
561 if (byteshift != 0)
562 byteshift = (target_size / 8) - byteshift;
563 }
564
565 // If --map-whole-files is set, make sure we have a
566 // whole file view. Options may not yet be ready, e.g.,
567 // when reading a version script. We then default to
568 // --no-map-whole-files.
569 if (this->whole_file_view_ == NULL
570 && parameters->options_valid()
571 && parameters->options().map_whole_files())
572 this->whole_file_view_ = this->make_view(0, this->size_, 0, cache);
573
574 // Try to find a View with the required BYTESHIFT.
575 File_read::View* vshifted;
576 File_read::View* v = this->find_view(offset + start, size,
577 aligned ? byteshift : -1U,
578 &vshifted);
579 if (v != NULL)
580 {
581 if (cache)
582 v->set_cache();
583 return v;
584 }
585
586 // If VSHIFTED is not NULL, then it has the data we need, but with
587 // the wrong byteshift.
588 v = vshifted;
589 if (v != NULL)
590 {
591 gold_assert(aligned);
592
593 unsigned char* pbytes;
594 pbytes = static_cast<unsigned char*>(malloc(v->size() + byteshift));
595 if (pbytes == NULL)
596 gold_nomem();
597 memset(pbytes, 0, byteshift);
598 memcpy(pbytes + byteshift, v->data() + v->byteshift(), v->size());
599
600 File_read::View* shifted_view =
601 new File_read::View(v->start(), v->size(), pbytes, byteshift,
602 cache, View::DATA_ALLOCATED_ARRAY);
603
604 this->add_view(shifted_view);
605 return shifted_view;
606 }
607
608 // Make a new view. If we don't need an aligned view, use a
609 // byteshift of 0, so that we can use mmap.
610 return this->make_view(offset + start, size,
611 aligned ? byteshift : 0,
612 cache);
613 }
614
615 // Get a view into the file.
616
617 const unsigned char*
get_view(off_t offset,off_t start,section_size_type size,bool aligned,bool cache)618 File_read::get_view(off_t offset, off_t start, section_size_type size,
619 bool aligned, bool cache)
620 {
621 File_read::View* pv = this->find_or_make_view(offset, start, size,
622 aligned, cache);
623 return pv->data() + (offset + start - pv->start() + pv->byteshift());
624 }
625
626 File_view*
get_lasting_view(off_t offset,off_t start,section_size_type size,bool aligned,bool cache)627 File_read::get_lasting_view(off_t offset, off_t start, section_size_type size,
628 bool aligned, bool cache)
629 {
630 File_read::View* pv = this->find_or_make_view(offset, start, size,
631 aligned, cache);
632 pv->lock();
633 return new File_view(*this, pv,
634 (pv->data()
635 + (offset + start - pv->start() + pv->byteshift())));
636 }
637
638 // Use readv to read COUNT entries from RM starting at START. BASE
639 // must be added to all file offsets in RM.
640
641 void
do_readv(off_t base,const Read_multiple & rm,size_t start,size_t count)642 File_read::do_readv(off_t base, const Read_multiple& rm, size_t start,
643 size_t count)
644 {
645 unsigned char discard[File_read::page_size];
646 iovec iov[File_read::max_readv_entries * 2];
647 size_t iov_index = 0;
648
649 off_t first_offset = rm[start].file_offset;
650 off_t last_offset = first_offset;
651 ssize_t want = 0;
652 for (size_t i = 0; i < count; ++i)
653 {
654 const Read_multiple_entry& i_entry(rm[start + i]);
655
656 if (i_entry.file_offset > last_offset)
657 {
658 size_t skip = i_entry.file_offset - last_offset;
659 gold_assert(skip <= sizeof discard);
660
661 iov[iov_index].iov_base = discard;
662 iov[iov_index].iov_len = skip;
663 ++iov_index;
664
665 want += skip;
666 }
667
668 iov[iov_index].iov_base = i_entry.buffer;
669 iov[iov_index].iov_len = i_entry.size;
670 ++iov_index;
671
672 want += i_entry.size;
673
674 last_offset = i_entry.file_offset + i_entry.size;
675 }
676
677 this->reopen_descriptor();
678
679 gold_assert(iov_index < sizeof iov / sizeof iov[0]);
680
681 if (::lseek(this->descriptor_, base + first_offset, SEEK_SET) < 0)
682 gold_fatal(_("%s: lseek failed: %s"),
683 this->filename().c_str(), strerror(errno));
684
685 ssize_t got = ::readv(this->descriptor_, iov, iov_index);
686
687 if (got < 0)
688 gold_fatal(_("%s: readv failed: %s"),
689 this->filename().c_str(), strerror(errno));
690 if (got != want)
691 gold_fatal(_("%s: file too short: read only %zd of %zd bytes at %lld"),
692 this->filename().c_str(),
693 got, want, static_cast<long long>(base + first_offset));
694 }
695
696 // Portable IOV_MAX.
697
698 #if !defined(HAVE_READV)
699 #define GOLD_IOV_MAX 1
700 #elif defined(IOV_MAX)
701 #define GOLD_IOV_MAX IOV_MAX
702 #else
703 #define GOLD_IOV_MAX (File_read::max_readv_entries * 2)
704 #endif
705
706 // Read several pieces of data from the file.
707
708 void
read_multiple(off_t base,const Read_multiple & rm)709 File_read::read_multiple(off_t base, const Read_multiple& rm)
710 {
711 static size_t iov_max = GOLD_IOV_MAX;
712 size_t count = rm.size();
713 size_t i = 0;
714 while (i < count)
715 {
716 // Find up to MAX_READV_ENTRIES consecutive entries which are
717 // less than one page apart.
718 const Read_multiple_entry& i_entry(rm[i]);
719 off_t i_off = i_entry.file_offset;
720 off_t end_off = i_off + i_entry.size;
721 size_t j;
722 for (j = i + 1; j < count; ++j)
723 {
724 if (j - i >= File_read::max_readv_entries || j - i >= iov_max / 2)
725 break;
726 const Read_multiple_entry& j_entry(rm[j]);
727 off_t j_off = j_entry.file_offset;
728 gold_assert(j_off >= end_off);
729 off_t j_end_off = j_off + j_entry.size;
730 if (j_end_off - end_off >= File_read::page_size)
731 break;
732 end_off = j_end_off;
733 }
734
735 if (j == i + 1)
736 this->read(base + i_off, i_entry.size, i_entry.buffer);
737 else
738 {
739 File_read::View* view = this->find_view(base + i_off,
740 end_off - i_off,
741 -1U, NULL);
742 if (view == NULL)
743 this->do_readv(base, rm, i, j - i);
744 else
745 {
746 const unsigned char* v = (view->data()
747 + (base + i_off - view->start()
748 + view->byteshift()));
749 for (size_t k = i; k < j; ++k)
750 {
751 const Read_multiple_entry& k_entry(rm[k]);
752 gold_assert((convert_to_section_size_type(k_entry.file_offset
753 - i_off)
754 + k_entry.size)
755 <= convert_to_section_size_type(end_off
756 - i_off));
757 memcpy(k_entry.buffer,
758 v + (k_entry.file_offset - i_off),
759 k_entry.size);
760 }
761 }
762 }
763
764 i = j;
765 }
766 }
767
768 // Mark all views as no longer cached.
769
770 void
clear_view_cache_marks()771 File_read::clear_view_cache_marks()
772 {
773 // Just ignore this if there are multiple objects associated with
774 // the file. Otherwise we will wind up uncaching and freeing some
775 // views for other objects.
776 if (this->object_count_ > 1)
777 return;
778
779 for (Views::iterator p = this->views_.begin();
780 p != this->views_.end();
781 ++p)
782 p->second->clear_cache();
783 for (Saved_views::iterator p = this->saved_views_.begin();
784 p != this->saved_views_.end();
785 ++p)
786 (*p)->clear_cache();
787 }
788
789 // Remove all the file views. For a file which has multiple
790 // associated objects (i.e., an archive), we keep accessed views
791 // around until next time, in the hopes that they will be useful for
792 // the next object.
793
794 void
clear_views(Clear_views_mode mode)795 File_read::clear_views(Clear_views_mode mode)
796 {
797 bool keep_files_mapped = (parameters->options_valid()
798 && parameters->options().keep_files_mapped());
799 Views::iterator p = this->views_.begin();
800 while (p != this->views_.end())
801 {
802 bool should_delete;
803 if (p->second->is_locked() || p->second->is_permanent_view())
804 should_delete = false;
805 else if (mode == CLEAR_VIEWS_ALL)
806 should_delete = true;
807 else if ((p->second->should_cache()
808 || p->second == this->whole_file_view_)
809 && keep_files_mapped)
810 should_delete = false;
811 else if (this->object_count_ > 1
812 && p->second->accessed()
813 && mode != CLEAR_VIEWS_ARCHIVE)
814 should_delete = false;
815 else
816 should_delete = true;
817
818 if (should_delete)
819 {
820 if (p->second == this->whole_file_view_)
821 this->whole_file_view_ = NULL;
822 delete p->second;
823
824 // map::erase invalidates only the iterator to the deleted
825 // element.
826 Views::iterator pe = p;
827 ++p;
828 this->views_.erase(pe);
829 }
830 else
831 {
832 p->second->clear_accessed();
833 ++p;
834 }
835 }
836
837 Saved_views::iterator q = this->saved_views_.begin();
838 while (q != this->saved_views_.end())
839 {
840 if (!(*q)->is_locked())
841 {
842 delete *q;
843 q = this->saved_views_.erase(q);
844 }
845 else
846 {
847 gold_assert(mode != CLEAR_VIEWS_ALL);
848 ++q;
849 }
850 }
851 }
852
853 // Print statistical information to stderr. This is used for --stats.
854
855 void
print_stats()856 File_read::print_stats()
857 {
858 fprintf(stderr, _("%s: total bytes mapped for read: %llu\n"),
859 program_name, File_read::total_mapped_bytes);
860 fprintf(stderr, _("%s: maximum bytes mapped for read at one time: %llu\n"),
861 program_name, File_read::maximum_mapped_bytes);
862 }
863
864 // Class File_view.
865
~File_view()866 File_view::~File_view()
867 {
868 gold_assert(this->file_.is_locked());
869 this->view_->unlock();
870 }
871
872 // Class Input_file.
873
874 // Create a file given just the filename.
875
Input_file(const char * name)876 Input_file::Input_file(const char* name)
877 : found_name_(), file_(), is_in_sysroot_(false), format_(FORMAT_NONE)
878 {
879 this->input_argument_ =
880 new Input_file_argument(name, Input_file_argument::INPUT_FILE_TYPE_FILE,
881 "", false, Position_dependent_options());
882 }
883
884 // Create a file for testing.
885
Input_file(const Task * task,const char * name,const unsigned char * contents,off_t size)886 Input_file::Input_file(const Task* task, const char* name,
887 const unsigned char* contents, off_t size)
888 : file_()
889 {
890 this->input_argument_ =
891 new Input_file_argument(name, Input_file_argument::INPUT_FILE_TYPE_FILE,
892 "", false, Position_dependent_options());
893 bool ok = this->file_.open(task, name, contents, size);
894 gold_assert(ok);
895 }
896
897 // Return the position dependent options in force for this file.
898
899 const Position_dependent_options&
options() const900 Input_file::options() const
901 {
902 return this->input_argument_->options();
903 }
904
905 // Return the name given by the user. For -lc this will return "c".
906
907 const char*
name() const908 Input_file::name() const
909 {
910 return this->input_argument_->name();
911 }
912
913 // Return whether this file is in a system directory.
914
915 bool
is_in_system_directory() const916 Input_file::is_in_system_directory() const
917 {
918 if (this->is_in_sysroot())
919 return true;
920 return parameters->options().is_in_system_directory(this->filename());
921 }
922
923 // Return whether we are only reading symbols.
924
925 bool
just_symbols() const926 Input_file::just_symbols() const
927 {
928 return this->input_argument_->just_symbols();
929 }
930
931 // Return whether this is a file that we will search for in the list
932 // of directories.
933
934 bool
will_search_for() const935 Input_file::will_search_for() const
936 {
937 return (!IS_ABSOLUTE_PATH(this->input_argument_->name())
938 && (this->input_argument_->is_lib()
939 || this->input_argument_->is_searched_file()
940 || this->input_argument_->extra_search_path() != NULL));
941 }
942
943 // Return the file last modification time. Calls gold_fatal if the stat
944 // system call failed.
945
946 Timespec
get_mtime()947 File_read::get_mtime()
948 {
949 struct stat file_stat;
950 this->reopen_descriptor();
951
952 if (fstat(this->descriptor_, &file_stat) < 0)
953 gold_fatal(_("%s: stat failed: %s"), this->name_.c_str(),
954 strerror(errno));
955 #ifdef HAVE_STAT_ST_MTIM
956 return Timespec(file_stat.st_mtim.tv_sec, file_stat.st_mtim.tv_nsec);
957 #else
958 return Timespec(file_stat.st_mtime, 0);
959 #endif
960 }
961
962 // Try to find a file in the extra search dirs. Returns true on success.
963
964 bool
try_extra_search_path(int * pindex,const Input_file_argument * input_argument,std::string filename,std::string * found_name,std::string * namep)965 Input_file::try_extra_search_path(int* pindex,
966 const Input_file_argument* input_argument,
967 std::string filename, std::string* found_name,
968 std::string* namep)
969 {
970 if (input_argument->extra_search_path() == NULL)
971 return false;
972
973 std::string name = input_argument->extra_search_path();
974 if (!IS_DIR_SEPARATOR(name[name.length() - 1]))
975 name += '/';
976 name += filename;
977
978 struct stat dummy_stat;
979 if (*pindex > 0 || ::stat(name.c_str(), &dummy_stat) < 0)
980 return false;
981
982 *found_name = filename;
983 *namep = name;
984 return true;
985 }
986
987 // Find the actual file.
988 // If the filename is not absolute, we assume it is in the current
989 // directory *except* when:
990 // A) input_argument_->is_lib() is true;
991 // B) input_argument_->is_searched_file() is true; or
992 // C) input_argument_->extra_search_path() is not empty.
993 // In each, we look in extra_search_path + library_path to find
994 // the file location, rather than the current directory.
995
996 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)997 Input_file::find_file(const Dirsearch& dirpath, int* pindex,
998 const Input_file_argument* input_argument,
999 bool* is_in_sysroot,
1000 std::string* found_name, std::string* namep)
1001 {
1002 std::string name;
1003
1004 // Case 1: name is an absolute file, just try to open it
1005 // Case 2: name is relative but is_lib is false, is_searched_file is false,
1006 // and extra_search_path is empty
1007 if (IS_ABSOLUTE_PATH(input_argument->name())
1008 || (!input_argument->is_lib()
1009 && !input_argument->is_searched_file()
1010 && input_argument->extra_search_path() == NULL))
1011 {
1012 name = input_argument->name();
1013 *found_name = name;
1014 *namep = name;
1015 return true;
1016 }
1017 // Case 3: is_lib is true or is_searched_file is true
1018 else if (input_argument->is_lib()
1019 || input_argument->is_searched_file())
1020 {
1021 std::vector<std::string> names;
1022 names.reserve(2);
1023 if (input_argument->is_lib())
1024 {
1025 std::string prefix = "lib";
1026 prefix += input_argument->name();
1027 if (parameters->options().is_static()
1028 || !input_argument->options().Bdynamic())
1029 names.push_back(prefix + ".a");
1030 else
1031 {
1032 names.push_back(prefix + ".so");
1033 names.push_back(prefix + ".a");
1034 }
1035 }
1036 else
1037 names.push_back(input_argument->name());
1038
1039 for (std::vector<std::string>::const_iterator n = names.begin();
1040 n != names.end();
1041 ++n)
1042 if (Input_file::try_extra_search_path(pindex, input_argument, *n,
1043 found_name, namep))
1044 return true;
1045
1046 // It is not in the extra_search_path.
1047 name = dirpath.find(names, is_in_sysroot, pindex, found_name);
1048 if (name.empty())
1049 {
1050 gold_error(_("cannot find %s%s"),
1051 input_argument->is_lib() ? "-l" : "",
1052 input_argument->name());
1053 return false;
1054 }
1055 *namep = name;
1056 return true;
1057 }
1058 // Case 4: extra_search_path is not empty
1059 else
1060 {
1061 gold_assert(input_argument->extra_search_path() != NULL);
1062
1063 if (try_extra_search_path(pindex, input_argument, input_argument->name(),
1064 found_name, namep))
1065 return true;
1066
1067 // extra_search_path failed, so check the normal search-path.
1068 int index = *pindex;
1069 if (index > 0)
1070 --index;
1071 name = dirpath.find(std::vector<std::string>(1, input_argument->name()),
1072 is_in_sysroot, &index, found_name);
1073 if (name.empty())
1074 {
1075 gold_error(_("cannot find %s"),
1076 input_argument->name());
1077 return false;
1078 }
1079 *namep = name;
1080 *pindex = index + 1;
1081 return true;
1082 }
1083 }
1084
1085 // Open the file.
1086
1087 bool
open(const Dirsearch & dirpath,const Task * task,int * pindex)1088 Input_file::open(const Dirsearch& dirpath, const Task* task, int* pindex)
1089 {
1090 std::string name;
1091 if (!Input_file::find_file(dirpath, pindex, this->input_argument_,
1092 &this->is_in_sysroot_, &this->found_name_, &name))
1093 return false;
1094
1095 // Now that we've figured out where the file lives, try to open it.
1096
1097 General_options::Object_format format =
1098 this->input_argument_->options().format_enum();
1099 bool ok;
1100 if (format == General_options::OBJECT_FORMAT_ELF)
1101 {
1102 ok = this->file_.open(task, name);
1103 this->format_ = FORMAT_ELF;
1104 }
1105 else
1106 {
1107 gold_assert(format == General_options::OBJECT_FORMAT_BINARY);
1108 ok = this->open_binary(task, name);
1109 this->format_ = FORMAT_BINARY;
1110 }
1111
1112 if (!ok)
1113 {
1114 gold_error(_("cannot open %s: %s"),
1115 name.c_str(), strerror(errno));
1116 this->format_ = FORMAT_NONE;
1117 return false;
1118 }
1119
1120 return true;
1121 }
1122
1123 // Open a file for --format binary.
1124
1125 bool
open_binary(const Task * task,const std::string & name)1126 Input_file::open_binary(const Task* task, const std::string& name)
1127 {
1128 // In order to open a binary file, we need machine code, size, and
1129 // endianness. We may not have a valid target at this point, in
1130 // which case we use the default target.
1131 parameters_force_valid_target();
1132 const Target& target(parameters->target());
1133
1134 Binary_to_elf binary_to_elf(target.machine_code(),
1135 target.get_size(),
1136 target.is_big_endian(),
1137 name);
1138 if (!binary_to_elf.convert(task))
1139 return false;
1140 return this->file_.open(task, name, binary_to_elf.converted_data_leak(),
1141 binary_to_elf.converted_size());
1142 }
1143
1144 void
record_file_read(const std::string & name)1145 File_read::record_file_read(const std::string& name)
1146 {
1147 File_read::files_read.push_back(name);
1148 }
1149
1150 void
write_dependency_file(const char * dependency_file_name,const char * output_file_name)1151 File_read::write_dependency_file(const char* dependency_file_name,
1152 const char* output_file_name)
1153 {
1154 FILE *depfile = fopen(dependency_file_name, "w");
1155
1156 fprintf(depfile, "%s:", output_file_name);
1157 for (std::vector<std::string>::const_iterator it = files_read.begin();
1158 it != files_read.end();
1159 ++it)
1160 fprintf(depfile, " \\\n %s", it->c_str());
1161 fprintf(depfile, "\n");
1162
1163 for (std::vector<std::string>::const_iterator it = files_read.begin();
1164 it != files_read.end();
1165 ++it)
1166 fprintf(depfile, "\n%s:\n", it->c_str());
1167
1168 fclose(depfile);
1169 }
1170
1171 } // End namespace gold.
1172