xref: /netbsd-src/external/gpl3/binutils/dist/gold/fileread.cc (revision d16b7486a53dcb8072b60ec6fcb4373a2d0c27b7)
1 // fileread.cc -- read files for gold
2 
3 // Copyright (C) 2006-2022 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 *
71 gold_mmap(void *, size_t, int, int, int, off_t)
72 {
73   errno = ENOSYS;
74   return MAP_FAILED;
75 }
76 
77 static int
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
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
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 
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
157 File_read::View::lock()
158 {
159   ++this->lock_count_;
160 }
161 
162 void
163 File_read::View::unlock()
164 {
165   gold_assert(this->lock_count_ > 0);
166   --this->lock_count_;
167 }
168 
169 bool
170 File_read::View::is_locked()
171 {
172   return this->lock_count_ > 0;
173 }
174 
175 // Class File_read.
176 
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
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       file_counts_initialize_lock.initialize();
216       Hold_optional_lock hl(file_counts_lock);
217       record_file_read(this->name_);
218     }
219 
220   return this->descriptor_ >= 0;
221 }
222 
223 // Open the file with the contents in memory.
224 
225 bool
226 File_read::open(const Task* task, const std::string& name,
227 		const unsigned char* contents, off_t size)
228 {
229   gold_assert(this->token_.is_writable()
230 	      && this->descriptor_ < 0
231 	      && !this->is_descriptor_opened_
232 	      && this->name_.empty());
233   this->name_ = name;
234   this->whole_file_view_ = new View(0, size, contents, 0, false,
235 				    View::DATA_NOT_OWNED);
236   this->add_view(this->whole_file_view_);
237   this->size_ = size;
238   this->token_.add_writer(task);
239   return true;
240 }
241 
242 // Reopen a descriptor if necessary.
243 
244 void
245 File_read::reopen_descriptor()
246 {
247   if (!this->is_descriptor_opened_)
248     {
249       this->descriptor_ = open_descriptor(this->descriptor_,
250 					  this->name_.c_str(),
251 					  O_RDONLY);
252       if (this->descriptor_ < 0)
253 	gold_fatal(_("could not reopen file %s"), this->name_.c_str());
254       this->is_descriptor_opened_ = true;
255     }
256 }
257 
258 // Release the file.  This is called when we are done with the file in
259 // a Task.
260 
261 void
262 File_read::release()
263 {
264   gold_assert(this->is_locked());
265 
266   if (!parameters->options_valid() || parameters->options().stats())
267     {
268       file_counts_initialize_lock.initialize();
269       Hold_optional_lock hl(file_counts_lock);
270       File_read::total_mapped_bytes += this->mapped_bytes_;
271       File_read::current_mapped_bytes += this->mapped_bytes_;
272       if (File_read::current_mapped_bytes > File_read::maximum_mapped_bytes)
273 	File_read::maximum_mapped_bytes = File_read::current_mapped_bytes;
274     }
275 
276   this->mapped_bytes_ = 0;
277 
278   // Only clear views if there is only one attached object.  Otherwise
279   // we waste time trying to clear cached archive views.  Similarly
280   // for releasing the descriptor.
281   if (this->object_count_ <= 1)
282     {
283       this->clear_views(CLEAR_VIEWS_NORMAL);
284       if (this->is_descriptor_opened_)
285 	{
286 	  release_descriptor(this->descriptor_, false);
287 	  this->is_descriptor_opened_ = false;
288 	}
289     }
290 
291   this->released_ = true;
292 }
293 
294 // Lock the file.
295 
296 void
297 File_read::lock(const Task* task)
298 {
299   gold_assert(this->released_);
300   gold_debug(DEBUG_FILES, "Locking file \"%s\"", this->name_.c_str());
301   this->token_.add_writer(task);
302   this->released_ = false;
303 }
304 
305 // Unlock the file.
306 
307 void
308 File_read::unlock(const Task* task)
309 {
310   gold_debug(DEBUG_FILES, "Unlocking file \"%s\"", this->name_.c_str());
311   this->release();
312   this->token_.remove_writer(task);
313 }
314 
315 // Return whether the file is locked.
316 
317 bool
318 File_read::is_locked() const
319 {
320   if (!this->token_.is_writable())
321     return true;
322   // The file is not locked, so it should have been released.
323   gold_assert(this->released_);
324   return false;
325 }
326 
327 // See if we have a view which covers the file starting at START for
328 // SIZE bytes.  Return a pointer to the View if found, NULL if not.
329 // If BYTESHIFT is not -1U, the returned View must have the specified
330 // byte shift; otherwise, it may have any byte shift.  If VSHIFTED is
331 // not NULL, this sets *VSHIFTED to a view which would have worked if
332 // not for the requested BYTESHIFT.
333 
334 inline File_read::View*
335 File_read::find_view(off_t start, section_size_type size,
336 		     unsigned int byteshift, File_read::View** vshifted) const
337 {
338   gold_assert(start <= this->size_
339 	      && (static_cast<unsigned long long>(size)
340 		  <= static_cast<unsigned long long>(this->size_ - start)));
341 
342   if (vshifted != NULL)
343     *vshifted = NULL;
344 
345   // If we have the whole file mmapped, and the alignment is right,
346   // we can return it.
347   if (this->whole_file_view_)
348     if (byteshift == -1U || byteshift == 0)
349       return this->whole_file_view_;
350 
351   off_t page = File_read::page_offset(start);
352 
353   unsigned int bszero = 0;
354   Views::const_iterator p = this->views_.upper_bound(std::make_pair(page - 1,
355 								    bszero));
356 
357   while (p != this->views_.end() && p->first.first <= page)
358     {
359       if (p->second->start() <= start
360 	  && (p->second->start() + static_cast<off_t>(p->second->size())
361 	      >= start + static_cast<off_t>(size)))
362 	{
363 	  if (byteshift == -1U || byteshift == p->second->byteshift())
364 	    {
365 	      p->second->set_accessed();
366 	      return p->second;
367 	    }
368 
369 	  if (vshifted != NULL && *vshifted == NULL)
370 	    *vshifted = p->second;
371 	}
372 
373       ++p;
374     }
375 
376   return NULL;
377 }
378 
379 // Read SIZE bytes from the file starting at offset START.  Read into
380 // the buffer at P.
381 
382 void
383 File_read::do_read(off_t start, section_size_type size, void* p)
384 {
385   ssize_t bytes;
386   if (this->whole_file_view_ != NULL)
387     {
388       // See PR 23765 for an example of a testcase that triggers this error.
389       if (((ssize_t) start) < 0)
390 	gold_fatal(_("%s: read failed, starting offset (%#llx) less than zero"),
391 		   this->filename().c_str(),
392 		   static_cast<long long>(start));
393 
394       bytes = this->size_ - start;
395       if (static_cast<section_size_type>(bytes) >= size)
396 	{
397 	  memcpy(p, this->whole_file_view_->data() + start, size);
398 	  return;
399 	}
400     }
401   else
402     {
403       this->reopen_descriptor();
404 
405       char *read_ptr = static_cast<char *>(p);
406       off_t read_pos = start;
407       size_t to_read = size;
408       do
409 	{
410 	  bytes = ::pread(this->descriptor_, read_ptr, to_read, read_pos);
411 	  if (bytes < 0)
412 	    gold_fatal(_("%s: pread failed: %s"),
413 		       this->filename().c_str(), strerror(errno));
414 
415 	  read_pos += bytes;
416 	  read_ptr += bytes;
417 	  to_read -= bytes;
418 	  if (to_read == 0)
419 	    return;
420 	}
421       while (bytes > 0);
422 
423       bytes = size - to_read;
424     }
425 
426   gold_fatal(_("%s: file too short: read only %lld of %lld bytes at %lld"),
427 	     this->filename().c_str(),
428 	     static_cast<long long>(bytes),
429 	     static_cast<long long>(size),
430 	     static_cast<long long>(start));
431 }
432 
433 // Read data from the file.
434 
435 void
436 File_read::read(off_t start, section_size_type size, void* p)
437 {
438   const File_read::View* pv = this->find_view(start, size, -1U, NULL);
439   if (pv != NULL)
440     {
441       memcpy(p, pv->data() + (start - pv->start() + pv->byteshift()), size);
442       return;
443     }
444 
445   this->do_read(start, size, p);
446 }
447 
448 // Add a new view.  There may already be an existing view at this
449 // offset.  If there is, the new view will be larger, and should
450 // replace the old view.
451 
452 void
453 File_read::add_view(File_read::View* v)
454 {
455   std::pair<Views::iterator, bool> ins =
456     this->views_.insert(std::make_pair(std::make_pair(v->start(),
457 						      v->byteshift()),
458 				       v));
459   if (ins.second)
460     return;
461 
462   // There was an existing view at this offset.  It must not be large
463   // enough.  We can't delete it here, since something might be using
464   // it; we put it on a list to be deleted when the file is unlocked.
465   File_read::View* vold = ins.first->second;
466   gold_assert(vold->size() < v->size());
467   if (vold->should_cache())
468     {
469       v->set_cache();
470       vold->clear_cache();
471     }
472   this->saved_views_.push_back(vold);
473 
474   ins.first->second = v;
475 }
476 
477 // Make a new view with a specified byteshift, reading the data from
478 // the file.
479 
480 File_read::View*
481 File_read::make_view(off_t start, section_size_type size,
482 		     unsigned int byteshift, bool cache)
483 {
484   gold_assert(size > 0);
485   gold_assert(start <= this->size_
486 	      && (static_cast<unsigned long long>(size)
487 		  <= static_cast<unsigned long long>(this->size_ - start)));
488 
489   off_t poff = File_read::page_offset(start);
490 
491   section_size_type psize = File_read::pages(size + (start - poff));
492 
493   if (poff + static_cast<off_t>(psize) >= this->size_)
494     {
495       psize = this->size_ - poff;
496       gold_assert(psize >= size);
497     }
498 
499   void* p;
500   View::Data_ownership ownership;
501   if (byteshift != 0)
502     {
503       p = malloc(psize + byteshift);
504       if (p == NULL)
505 	gold_nomem();
506       memset(p, 0, byteshift);
507       this->do_read(poff, psize, static_cast<unsigned char*>(p) + byteshift);
508       ownership = View::DATA_ALLOCATED_ARRAY;
509     }
510   else
511     {
512       this->reopen_descriptor();
513       p = ::mmap(NULL, psize, PROT_READ, MAP_PRIVATE, this->descriptor_, poff);
514       if (p != MAP_FAILED)
515 	{
516 	  ownership = View::DATA_MMAPPED;
517 	  this->mapped_bytes_ += psize;
518 	}
519       else
520 	{
521 	  p = malloc(psize);
522 	  if (p == NULL)
523 	    gold_nomem();
524 	  this->do_read(poff, psize, p);
525 	  ownership = View::DATA_ALLOCATED_ARRAY;
526 	}
527     }
528 
529   const unsigned char* pbytes = static_cast<const unsigned char*>(p);
530   File_read::View* v = new File_read::View(poff, psize, pbytes, byteshift,
531 					   cache, ownership);
532 
533   this->add_view(v);
534 
535   return v;
536 }
537 
538 // Find a View or make a new one, shifted as required by the file
539 // offset OFFSET and ALIGNED.
540 
541 File_read::View*
542 File_read::find_or_make_view(off_t offset, off_t start,
543 			     section_size_type size, bool aligned, bool cache)
544 {
545   // Check that start and end of the view are within the file.
546   if (start > this->size_
547       || (static_cast<unsigned long long>(size)
548 	  > static_cast<unsigned long long>(this->size_ - start)))
549     gold_fatal(_("%s: attempt to map %lld bytes at offset %lld exceeds "
550 		 "size of file; the file may be corrupt"),
551 		   this->filename().c_str(),
552 		   static_cast<long long>(size),
553 		   static_cast<long long>(start));
554 
555   unsigned int byteshift;
556   if (offset == 0)
557     byteshift = 0;
558   else
559     {
560       unsigned int target_size = (!parameters->target_valid()
561 				  ? 64
562 				  : parameters->target().get_size());
563       byteshift = offset & ((target_size / 8) - 1);
564 
565       // Set BYTESHIFT to the number of dummy bytes which must be
566       // inserted before the data in order for this data to be
567       // aligned.
568       if (byteshift != 0)
569 	byteshift = (target_size / 8) - byteshift;
570     }
571 
572   // If --map-whole-files is set, make sure we have a
573   // whole file view.  Options may not yet be ready, e.g.,
574   // when reading a version script.  We then default to
575   // --no-map-whole-files.
576   if (this->whole_file_view_ == NULL
577       && parameters->options_valid()
578       && parameters->options().map_whole_files())
579     this->whole_file_view_ = this->make_view(0, this->size_, 0, cache);
580 
581   // Try to find a View with the required BYTESHIFT.
582   File_read::View* vshifted;
583   File_read::View* v = this->find_view(offset + start, size,
584 				       aligned ? byteshift : -1U,
585 				       &vshifted);
586   if (v != NULL)
587     {
588       if (cache)
589 	v->set_cache();
590       return v;
591     }
592 
593   // If VSHIFTED is not NULL, then it has the data we need, but with
594   // the wrong byteshift.
595   v = vshifted;
596   if (v != NULL)
597     {
598       gold_assert(aligned);
599 
600       unsigned char* pbytes;
601       pbytes = static_cast<unsigned char*>(malloc(v->size() + byteshift));
602       if (pbytes == NULL)
603 	gold_nomem();
604       memset(pbytes, 0, byteshift);
605       memcpy(pbytes + byteshift, v->data() + v->byteshift(), v->size());
606 
607       File_read::View* shifted_view =
608 	  new File_read::View(v->start(), v->size(), pbytes, byteshift,
609 			      cache, View::DATA_ALLOCATED_ARRAY);
610 
611       this->add_view(shifted_view);
612       return shifted_view;
613     }
614 
615   // Make a new view.  If we don't need an aligned view, use a
616   // byteshift of 0, so that we can use mmap.
617   return this->make_view(offset + start, size,
618 			 aligned ? byteshift : 0,
619 			 cache);
620 }
621 
622 // Get a view into the file.
623 
624 const unsigned char*
625 File_read::get_view(off_t offset, off_t start, section_size_type size,
626 		    bool aligned, bool cache)
627 {
628   File_read::View* pv = this->find_or_make_view(offset, start, size,
629 						aligned, cache);
630   return pv->data() + (offset + start - pv->start() + pv->byteshift());
631 }
632 
633 File_view*
634 File_read::get_lasting_view(off_t offset, off_t start, section_size_type size,
635 			    bool aligned, bool cache)
636 {
637   File_read::View* pv = this->find_or_make_view(offset, start, size,
638 						aligned, cache);
639   pv->lock();
640   return new File_view(*this, pv,
641 		       (pv->data()
642 			+ (offset + start - pv->start() + pv->byteshift())));
643 }
644 
645 // Use readv to read COUNT entries from RM starting at START.  BASE
646 // must be added to all file offsets in RM.
647 
648 void
649 File_read::do_readv(off_t base, const Read_multiple& rm, size_t start,
650 		    size_t count)
651 {
652   unsigned char discard[File_read::page_size];
653   iovec iov[File_read::max_readv_entries * 2];
654   size_t iov_index = 0;
655 
656   off_t first_offset = rm[start].file_offset;
657   off_t last_offset = first_offset;
658   ssize_t want = 0;
659   for (size_t i = 0; i < count; ++i)
660     {
661       const Read_multiple_entry& i_entry(rm[start + i]);
662 
663       if (i_entry.file_offset > last_offset)
664 	{
665 	  size_t skip = i_entry.file_offset - last_offset;
666 	  gold_assert(skip <= sizeof discard);
667 
668 	  iov[iov_index].iov_base = discard;
669 	  iov[iov_index].iov_len = skip;
670 	  ++iov_index;
671 
672 	  want += skip;
673 	}
674 
675       iov[iov_index].iov_base = i_entry.buffer;
676       iov[iov_index].iov_len = i_entry.size;
677       ++iov_index;
678 
679       want += i_entry.size;
680 
681       last_offset = i_entry.file_offset + i_entry.size;
682     }
683 
684   this->reopen_descriptor();
685 
686   gold_assert(iov_index < sizeof iov / sizeof iov[0]);
687 
688   if (::lseek(this->descriptor_, base + first_offset, SEEK_SET) < 0)
689     gold_fatal(_("%s: lseek failed: %s"),
690 	       this->filename().c_str(), strerror(errno));
691 
692   ssize_t got = ::readv(this->descriptor_, iov, iov_index);
693 
694   if (got < 0)
695     gold_fatal(_("%s: readv failed: %s"),
696 	       this->filename().c_str(), strerror(errno));
697   if (got != want)
698     gold_fatal(_("%s: file too short: read only %zd of %zd bytes at %lld"),
699 	       this->filename().c_str(),
700 	       got, want, static_cast<long long>(base + first_offset));
701 }
702 
703 // Portable IOV_MAX.
704 
705 #if !defined(HAVE_READV)
706 #define GOLD_IOV_MAX 1
707 #elif defined(IOV_MAX)
708 #define GOLD_IOV_MAX IOV_MAX
709 #else
710 #define GOLD_IOV_MAX (File_read::max_readv_entries * 2)
711 #endif
712 
713 // Read several pieces of data from the file.
714 
715 void
716 File_read::read_multiple(off_t base, const Read_multiple& rm)
717 {
718   static size_t iov_max = GOLD_IOV_MAX;
719   size_t count = rm.size();
720   size_t i = 0;
721   while (i < count)
722     {
723       // Find up to MAX_READV_ENTRIES consecutive entries which are
724       // less than one page apart.
725       const Read_multiple_entry& i_entry(rm[i]);
726       off_t i_off = i_entry.file_offset;
727       off_t end_off = i_off + i_entry.size;
728       size_t j;
729       for (j = i + 1; j < count; ++j)
730 	{
731 	  if (j - i >= File_read::max_readv_entries || j - i >= iov_max / 2)
732 	    break;
733 	  const Read_multiple_entry& j_entry(rm[j]);
734 	  off_t j_off = j_entry.file_offset;
735 	  gold_assert(j_off >= end_off);
736 	  off_t j_end_off = j_off + j_entry.size;
737 	  if (j_end_off - end_off >= File_read::page_size)
738 	    break;
739 	  end_off = j_end_off;
740 	}
741 
742       if (j == i + 1)
743 	this->read(base + i_off, i_entry.size, i_entry.buffer);
744       else
745 	{
746 	  File_read::View* view = this->find_view(base + i_off,
747 						  end_off - i_off,
748 						  -1U, NULL);
749 	  if (view == NULL)
750 	    this->do_readv(base, rm, i, j - i);
751 	  else
752 	    {
753 	      const unsigned char* v = (view->data()
754 					+ (base + i_off - view->start()
755 					   + view->byteshift()));
756 	      for (size_t k = i; k < j; ++k)
757 		{
758 		  const Read_multiple_entry& k_entry(rm[k]);
759 		  gold_assert((convert_to_section_size_type(k_entry.file_offset
760 							   - i_off)
761 			       + k_entry.size)
762 			      <= convert_to_section_size_type(end_off
763 							      - i_off));
764 		  memcpy(k_entry.buffer,
765 			 v + (k_entry.file_offset - i_off),
766 			 k_entry.size);
767 		}
768 	    }
769 	}
770 
771       i = j;
772     }
773 }
774 
775 // Mark all views as no longer cached.
776 
777 void
778 File_read::clear_view_cache_marks()
779 {
780   // Just ignore this if there are multiple objects associated with
781   // the file.  Otherwise we will wind up uncaching and freeing some
782   // views for other objects.
783   if (this->object_count_ > 1)
784     return;
785 
786   for (Views::iterator p = this->views_.begin();
787        p != this->views_.end();
788        ++p)
789     p->second->clear_cache();
790   for (Saved_views::iterator p = this->saved_views_.begin();
791        p != this->saved_views_.end();
792        ++p)
793     (*p)->clear_cache();
794 }
795 
796 // Remove all the file views.  For a file which has multiple
797 // associated objects (i.e., an archive), we keep accessed views
798 // around until next time, in the hopes that they will be useful for
799 // the next object.
800 
801 void
802 File_read::clear_views(Clear_views_mode mode)
803 {
804   bool keep_files_mapped = (parameters->options_valid()
805 			    && parameters->options().keep_files_mapped());
806   Views::iterator p = this->views_.begin();
807   while (p != this->views_.end())
808     {
809       bool should_delete;
810       if (p->second->is_locked() || p->second->is_permanent_view())
811 	should_delete = false;
812       else if (mode == CLEAR_VIEWS_ALL)
813 	should_delete = true;
814       else if ((p->second->should_cache()
815 		|| p->second == this->whole_file_view_)
816 	       && keep_files_mapped)
817 	should_delete = false;
818       else if (this->object_count_ > 1
819 	       && p->second->accessed()
820 	       && mode != CLEAR_VIEWS_ARCHIVE)
821 	should_delete = false;
822       else
823 	should_delete = true;
824 
825       if (should_delete)
826 	{
827 	  if (p->second == this->whole_file_view_)
828 	    this->whole_file_view_ = NULL;
829 	  delete p->second;
830 
831 	  // map::erase invalidates only the iterator to the deleted
832 	  // element.
833 	  Views::iterator pe = p;
834 	  ++p;
835 	  this->views_.erase(pe);
836 	}
837       else
838 	{
839 	  p->second->clear_accessed();
840 	  ++p;
841 	}
842     }
843 
844   Saved_views::iterator q = this->saved_views_.begin();
845   while (q != this->saved_views_.end())
846     {
847       if (!(*q)->is_locked())
848 	{
849 	  delete *q;
850 	  q = this->saved_views_.erase(q);
851 	}
852       else
853 	{
854 	  gold_assert(mode != CLEAR_VIEWS_ALL);
855 	  ++q;
856 	}
857     }
858 }
859 
860 // Print statistical information to stderr.  This is used for --stats.
861 
862 void
863 File_read::print_stats()
864 {
865   fprintf(stderr, _("%s: total bytes mapped for read: %llu\n"),
866 	  program_name, File_read::total_mapped_bytes);
867   fprintf(stderr, _("%s: maximum bytes mapped for read at one time: %llu\n"),
868 	  program_name, File_read::maximum_mapped_bytes);
869 }
870 
871 // Class File_view.
872 
873 File_view::~File_view()
874 {
875   gold_assert(this->file_.is_locked());
876   this->view_->unlock();
877 }
878 
879 // Class Input_file.
880 
881 // Create a file given just the filename.
882 
883 Input_file::Input_file(const char* name)
884   : found_name_(), file_(), is_in_sysroot_(false), format_(FORMAT_NONE)
885 {
886   this->input_argument_ =
887     new Input_file_argument(name, Input_file_argument::INPUT_FILE_TYPE_FILE,
888 			    "", false, Position_dependent_options());
889 }
890 
891 // Create a file for testing.
892 
893 Input_file::Input_file(const Task* task, const char* name,
894 		       const unsigned char* contents, off_t size)
895   : file_()
896 {
897   this->input_argument_ =
898     new Input_file_argument(name, Input_file_argument::INPUT_FILE_TYPE_FILE,
899 			    "", false, Position_dependent_options());
900   bool ok = this->file_.open(task, name, contents, size);
901   gold_assert(ok);
902 }
903 
904 // Return the position dependent options in force for this file.
905 
906 const Position_dependent_options&
907 Input_file::options() const
908 {
909   return this->input_argument_->options();
910 }
911 
912 // Return the name given by the user.  For -lc this will return "c".
913 
914 const char*
915 Input_file::name() const
916 {
917   return this->input_argument_->name();
918 }
919 
920 // Return whether this file is in a system directory.
921 
922 bool
923 Input_file::is_in_system_directory() const
924 {
925   if (this->is_in_sysroot())
926     return true;
927   return parameters->options().is_in_system_directory(this->filename());
928 }
929 
930 // Return whether we are only reading symbols.
931 
932 bool
933 Input_file::just_symbols() const
934 {
935   return this->input_argument_->just_symbols();
936 }
937 
938 // Return whether this is a file that we will search for in the list
939 // of directories.
940 
941 bool
942 Input_file::will_search_for() const
943 {
944   return (!IS_ABSOLUTE_PATH(this->input_argument_->name())
945 	  && (this->input_argument_->is_lib()
946 	      || this->input_argument_->is_searched_file()
947 	      || this->input_argument_->extra_search_path() != NULL));
948 }
949 
950 // Return the file last modification time.  Calls gold_fatal if the stat
951 // system call failed.
952 
953 Timespec
954 File_read::get_mtime()
955 {
956   struct stat file_stat;
957   this->reopen_descriptor();
958 
959   if (fstat(this->descriptor_, &file_stat) < 0)
960     gold_fatal(_("%s: stat failed: %s"), this->name_.c_str(),
961 	       strerror(errno));
962 #ifdef HAVE_STAT_ST_MTIM
963   return Timespec(file_stat.st_mtim.tv_sec, file_stat.st_mtim.tv_nsec);
964 #else
965   return Timespec(file_stat.st_mtime, 0);
966 #endif
967 }
968 
969 // Try to find a file in the extra search dirs.  Returns true on success.
970 
971 bool
972 Input_file::try_extra_search_path(int* pindex,
973 				  const Input_file_argument* input_argument,
974 				  std::string filename, std::string* found_name,
975 				  std::string* namep)
976 {
977   if (input_argument->extra_search_path() == NULL)
978     return false;
979 
980   std::string name = input_argument->extra_search_path();
981   if (!IS_DIR_SEPARATOR(name[name.length() - 1]))
982     name += '/';
983   name += filename;
984 
985   struct stat dummy_stat;
986   if (*pindex > 0 || ::stat(name.c_str(), &dummy_stat) < 0)
987     return false;
988 
989   *found_name = filename;
990   *namep = name;
991   return true;
992 }
993 
994 // Find the actual file.
995 // If the filename is not absolute, we assume it is in the current
996 // directory *except* when:
997 //    A) input_argument_->is_lib() is true;
998 //    B) input_argument_->is_searched_file() is true; or
999 //    C) input_argument_->extra_search_path() is not empty.
1000 // In each, we look in extra_search_path + library_path to find
1001 // the file location, rather than the current directory.
1002 
1003 bool
1004 Input_file::find_file(const Dirsearch& dirpath, int* pindex,
1005 		      const Input_file_argument* input_argument,
1006 		      bool* is_in_sysroot,
1007 		      std::string* found_name, std::string* namep)
1008 {
1009   std::string name;
1010 
1011   // Case 1: name is an absolute file, just try to open it
1012   // Case 2: name is relative but is_lib is false, is_searched_file is false,
1013   //         and extra_search_path is empty
1014   if (IS_ABSOLUTE_PATH(input_argument->name())
1015       || (!input_argument->is_lib()
1016 	  && !input_argument->is_searched_file()
1017 	  && input_argument->extra_search_path() == NULL))
1018     {
1019       name = input_argument->name();
1020       *found_name = name;
1021       *namep = name;
1022       return true;
1023     }
1024   // Case 3: is_lib is true or is_searched_file is true
1025   else if (input_argument->is_lib()
1026 	   || input_argument->is_searched_file())
1027     {
1028       std::vector<std::string> names;
1029       names.reserve(2);
1030       if (input_argument->is_lib())
1031 	{
1032 	  std::string prefix = "lib";
1033 	  prefix += input_argument->name();
1034 	  if (parameters->options().is_static()
1035 	      || !input_argument->options().Bdynamic())
1036 	    names.push_back(prefix + ".a");
1037 	  else
1038 	    {
1039 	      names.push_back(prefix + ".so");
1040 	      names.push_back(prefix + ".a");
1041 	    }
1042 	}
1043       else
1044 	names.push_back(input_argument->name());
1045 
1046       for (std::vector<std::string>::const_iterator n = names.begin();
1047 	   n != names.end();
1048 	   ++n)
1049 	if (Input_file::try_extra_search_path(pindex, input_argument, *n,
1050 					      found_name, namep))
1051 	  return true;
1052 
1053       // It is not in the extra_search_path.
1054       name = dirpath.find(names, is_in_sysroot, pindex, found_name);
1055       if (name.empty())
1056 	{
1057 	  gold_error(_("cannot find %s%s"),
1058 		     input_argument->is_lib() ? "-l" : "",
1059 		     input_argument->name());
1060 	  return false;
1061 	}
1062       *namep = name;
1063       return true;
1064     }
1065   // Case 4: extra_search_path is not empty
1066   else
1067     {
1068       gold_assert(input_argument->extra_search_path() != NULL);
1069 
1070       if (try_extra_search_path(pindex, input_argument, input_argument->name(),
1071 				found_name, namep))
1072 	return true;
1073 
1074       // extra_search_path failed, so check the normal search-path.
1075       int index = *pindex;
1076       if (index > 0)
1077 	--index;
1078       name = dirpath.find(std::vector<std::string>(1, input_argument->name()),
1079 			  is_in_sysroot, &index, found_name);
1080       if (name.empty())
1081 	{
1082 	  gold_error(_("cannot find %s"),
1083 		     input_argument->name());
1084 	  return false;
1085 	}
1086       *namep = name;
1087       *pindex = index + 1;
1088       return true;
1089     }
1090 }
1091 
1092 // Open the file.
1093 
1094 bool
1095 Input_file::open(const Dirsearch& dirpath, const Task* task, int* pindex)
1096 {
1097   std::string name;
1098   if (!Input_file::find_file(dirpath, pindex, this->input_argument_,
1099 			     &this->is_in_sysroot_, &this->found_name_, &name))
1100     return false;
1101 
1102   // Now that we've figured out where the file lives, try to open it.
1103 
1104   General_options::Object_format format =
1105     this->input_argument_->options().format_enum();
1106   bool ok;
1107   if (format == General_options::OBJECT_FORMAT_ELF)
1108     {
1109       ok = this->file_.open(task, name);
1110       this->format_ = FORMAT_ELF;
1111     }
1112   else
1113     {
1114       gold_assert(format == General_options::OBJECT_FORMAT_BINARY);
1115       ok = this->open_binary(task, name);
1116       this->format_ = FORMAT_BINARY;
1117     }
1118 
1119   if (!ok)
1120     {
1121       gold_error(_("cannot open %s: %s"),
1122 		 name.c_str(), strerror(errno));
1123       this->format_ = FORMAT_NONE;
1124       return false;
1125     }
1126 
1127   return true;
1128 }
1129 
1130 // Open a file for --format binary.
1131 
1132 bool
1133 Input_file::open_binary(const Task* task, const std::string& name)
1134 {
1135   // In order to open a binary file, we need machine code, size, and
1136   // endianness.  We may not have a valid target at this point, in
1137   // which case we use the default target.
1138   parameters_force_valid_target();
1139   const Target& target(parameters->target());
1140 
1141   Binary_to_elf binary_to_elf(target.machine_code(),
1142 			      target.get_size(),
1143 			      target.is_big_endian(),
1144 			      name);
1145   if (!binary_to_elf.convert(task))
1146     return false;
1147   return this->file_.open(task, name, binary_to_elf.converted_data_leak(),
1148 			  binary_to_elf.converted_size());
1149 }
1150 
1151 void
1152 File_read::record_file_read(const std::string& name)
1153 {
1154   File_read::files_read.push_back(name);
1155 }
1156 
1157 void
1158 File_read::write_dependency_file(const char* dependency_file_name,
1159 				 const char* output_file_name)
1160 {
1161   FILE *depfile = fopen(dependency_file_name, "w");
1162 
1163   fprintf(depfile, "%s:", output_file_name);
1164   for (std::vector<std::string>::const_iterator it = files_read.begin();
1165        it != files_read.end();
1166        ++it)
1167     fprintf(depfile, " \\\n  %s", it->c_str());
1168   fprintf(depfile, "\n");
1169 
1170   for (std::vector<std::string>::const_iterator it = files_read.begin();
1171        it != files_read.end();
1172        ++it)
1173     fprintf(depfile, "\n%s:\n", it->c_str());
1174 
1175   fclose(depfile);
1176 }
1177 
1178 } // End namespace gold.
1179