gold/fileread.cc

   1 // fileread.cc -- read files for gold
   2
   3 // Copyright (C) 2006-2015 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
 128 // Class File_read::View.
 129
 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
 156 File_read::View::lock()
 157 {
 158   ++this->lock_count_;
 159 }
 160
 161 void
 162 File_read::View::unlock()
 163 {
 164   gold_assert(this->lock_count_ > 0);
 165   --this->lock_count_;
 166 }
 167
 168 bool
 169 File_read::View::is_locked()
 170 {
 171   return this->lock_count_ > 0;
 172 }
 173
 174 // Class File_read.
 175
 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
 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
 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
 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
 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
 293 File_read::lock(const Task* task)
 294 {
 295   gold_assert(this->released_);
 296   this->token_.add_writer(task);
 297   this->released_ = false;
 298 }
 299
 300 // Unlock the file.
 301
 302 void
 303 File_read::unlock(const Task* task)
 304 {
 305   this->release();
 306   this->token_.remove_writer(task);
 307 }
 308
 309 // Return whether the file is locked.
 310
 311 bool
 312 File_read::is_locked() const
 313 {
 314   if (!this->token_.is_writable())
 315     return true;
 316   // The file is not locked, so it should have been released.
 317   gold_assert(this->released_);
 318   return false;
 319 }
 320
 321 // See if we have a view which covers the file starting at START for
 322 // SIZE bytes.  Return a pointer to the View if found, NULL if not.
 323 // If BYTESHIFT is not -1U, the returned View must have the specified
 324 // byte shift; otherwise, it may have any byte shift.  If VSHIFTED is
 325 // not NULL, this sets *VSHIFTED to a view which would have worked if
 326 // not for the requested BYTESHIFT.
 327
 328 inline File_read::View*
 329 File_read::find_view(off_t start, section_size_type size,
 330                      unsigned int byteshift, File_read::View** vshifted) const
 331 {
 332   gold_assert(start <= this->size_
 333               && (static_cast<unsigned long long>(size)
 334                   <= static_cast<unsigned long long>(this->size_ - start)));
 335
 336   if (vshifted != NULL)
 337     *vshifted = NULL;
 338
 339   // If we have the whole file mmapped, and the alignment is right,
 340   // we can return it.
 341   if (this->whole_file_view_)
 342     if (byteshift == -1U || byteshift == 0)
 343       return this->whole_file_view_;
 344
 345   off_t page = File_read::page_offset(start);
 346
 347   unsigned int bszero = 0;
 348   Views::const_iterator p = this->views_.upper_bound(std::make_pair(page - 1,
 349                                                                     bszero));
 350
 351   while (p != this->views_.end() && p->first.first <= page)
 352     {
 353       if (p->second->start() <= start
 354           && (p->second->start() + static_cast<off_t>(p->second->size())
 355               >= start + static_cast<off_t>(size)))
 356         {
 357           if (byteshift == -1U || byteshift == p->second->byteshift())
 358             {
 359               p->second->set_accessed();
 360               return p->second;
 361             }
 362
 363           if (vshifted != NULL && *vshifted == NULL)
 364             *vshifted = p->second;
 365         }
 366
 367       ++p;
 368     }
 369
 370   return NULL;
 371 }
 372
 373 // Read SIZE bytes from the file starting at offset START.  Read into
 374 // the buffer at P.
 375
 376 void
 377 File_read::do_read(off_t start, section_size_type size, void* p)
 378 {
 379   ssize_t bytes;
 380   if (this->whole_file_view_ != NULL)
 381     {
 382       bytes = this->size_ - start;
 383       if (static_cast<section_size_type>(bytes) >= size)
 384         {
 385           memcpy(p, this->whole_file_view_->data() + start, size);
 386           return;
 387         }
 388     }
 389   else
 390     {
 391       this->reopen_descriptor();
 392
 393       char *read_ptr = static_cast<char *>(p);
 394       off_t read_pos = start;
 395       size_t to_read = size;
 396       do
 397         {
 398           bytes = ::pread(this->descriptor_, read_ptr, to_read, read_pos);
 399           if (bytes < 0)
 400             gold_fatal(_("%s: pread failed: %s"),
 401                        this->filename().c_str(), strerror(errno));
 402
 403           read_pos += bytes;
 404           read_ptr += bytes;
 405           to_read -= bytes;
 406           if (to_read == 0)
 407             return;
 408         }
 409       while (bytes > 0);
 410
 411       bytes = size - to_read;
 412     }
 413
 414   gold_fatal(_("%s: file too short: read only %lld of %lld bytes at %lld"),
 415              this->filename().c_str(),
 416              static_cast<long long>(bytes),
 417              static_cast<long long>(size),
 418              static_cast<long long>(start));
 419 }
 420
 421 // Read data from the file.
 422
 423 void
 424 File_read::read(off_t start, section_size_type size, void* p)
 425 {
 426   const File_read::View* pv = this->find_view(start, size, -1U, NULL);
 427   if (pv != NULL)
 428     {
 429       memcpy(p, pv->data() + (start - pv->start() + pv->byteshift()), size);
 430       return;
 431     }
 432
 433   this->do_read(start, size, p);
 434 }
 435
 436 // Add a new view.  There may already be an existing view at this
 437 // offset.  If there is, the new view will be larger, and should
 438 // replace the old view.
 439
 440 void
 441 File_read::add_view(File_read::View* v)
 442 {
 443   std::pair<Views::iterator, bool> ins =
 444     this->views_.insert(std::make_pair(std::make_pair(v->start(),
 445                                                       v->byteshift()),
 446                                        v));
 447   if (ins.second)
 448     return;
 449
 450   // There was an existing view at this offset.  It must not be large
 451   // enough.  We can't delete it here, since something might be using
 452   // it; we put it on a list to be deleted when the file is unlocked.
 453   File_read::View* vold = ins.first->second;
 454   gold_assert(vold->size() < v->size());
 455   if (vold->should_cache())
 456     {
 457       v->set_cache();
 458       vold->clear_cache();
 459     }
 460   this->saved_views_.push_back(vold);
 461
 462   ins.first->second = v;
 463 }
 464
 465 // Make a new view with a specified byteshift, reading the data from
 466 // the file.
 467
 468 File_read::View*
 469 File_read::make_view(off_t start, section_size_type size,
 470                      unsigned int byteshift, bool cache)
 471 {
 472   gold_assert(size > 0);
 473   gold_assert(start <= this->size_
 474               && (static_cast<unsigned long long>(size)
 475                   <= static_cast<unsigned long long>(this->size_ - start)));
 476
 477   off_t poff = File_read::page_offset(start);
 478
 479   section_size_type psize = File_read::pages(size + (start - poff));
 480
 481   if (poff + static_cast<off_t>(psize) >= this->size_)
 482     {
 483       psize = this->size_ - poff;
 484       gold_assert(psize >= size);
 485     }
 486
 487   void* p;
 488   View::Data_ownership ownership;
 489   if (byteshift != 0)
 490     {
 491       p = malloc(psize + byteshift);
 492       if (p == NULL)
 493         gold_nomem();
 494       memset(p, 0, byteshift);
 495       this->do_read(poff, psize, static_cast<unsigned char*>(p) + byteshift);
 496       ownership = View::DATA_ALLOCATED_ARRAY;
 497     }
 498   else
 499     {
 500       this->reopen_descriptor();
 501       p = ::mmap(NULL, psize, PROT_READ, MAP_PRIVATE, this->descriptor_, poff);
 502       if (p != MAP_FAILED)
 503         {
 504           ownership = View::DATA_MMAPPED;
 505           this->mapped_bytes_ += psize;
 506         }
 507       else
 508         {
 509           p = malloc(psize);
 510           if (p == NULL)
 511             gold_nomem();
 512           this->do_read(poff, psize, p);
 513           ownership = View::DATA_ALLOCATED_ARRAY;
 514         }
 515     }
 516
 517   const unsigned char* pbytes = static_cast<const unsigned char*>(p);
 518   File_read::View* v = new File_read::View(poff, psize, pbytes, byteshift,
 519                                            cache, ownership);
 520
 521   this->add_view(v);
 522
 523   return v;
 524 }
 525
 526 // Find a View or make a new one, shifted as required by the file
 527 // offset OFFSET and ALIGNED.
 528
 529 File_read::View*
 530 File_read::find_or_make_view(off_t offset, off_t start,
 531                              section_size_type size, bool aligned, bool cache)
 532 {
 533   // Check that start and end of the view are within the file.
 534   if (start > this->size_
 535       || (static_cast<unsigned long long>(size)
 536           > static_cast<unsigned long long>(this->size_ - start)))
 537     gold_fatal(_("%s: attempt to map %lld bytes at offset %lld exceeds "
 538                  "size of file; the file may be corrupt"),
 539                    this->filename().c_str(),
 540                    static_cast<long long>(size),
 541                    static_cast<long long>(start));
 542
 543   unsigned int byteshift;
 544   if (offset == 0)
 545     byteshift = 0;
 546   else
 547     {
 548       unsigned int target_size = (!parameters->target_valid()
 549                                   ? 64
 550                                   : parameters->target().get_size());
 551       byteshift = offset & ((target_size / 8) - 1);
 552
 553       // Set BYTESHIFT to the number of dummy bytes which must be
 554       // inserted before the data in order for this data to be
 555       // aligned.
 556       if (byteshift != 0)
 557         byteshift = (target_size / 8) - byteshift;
 558     }
 559
 560   // If --map-whole-files is set, make sure we have a
 561   // whole file view.  Options may not yet be ready, e.g.,
 562   // when reading a version script.  We then default to
 563   // --no-map-whole-files.
 564   if (this->whole_file_view_ == NULL
 565       && parameters->options_valid()
 566       && parameters->options().map_whole_files())
 567     this->whole_file_view_ = this->make_view(0, this->size_, 0, cache);
 568
 569   // Try to find a View with the required BYTESHIFT.
 570   File_read::View* vshifted;
 571   File_read::View* v = this->find_view(offset + start, size,
 572                                        aligned ? byteshift : -1U,
 573                                        &vshifted);
 574   if (v != NULL)
 575     {
 576       if (cache)
 577         v->set_cache();
 578       return v;
 579     }
 580
 581   // If VSHIFTED is not NULL, then it has the data we need, but with
 582   // the wrong byteshift.
 583   v = vshifted;
 584   if (v != NULL)
 585     {
 586       gold_assert(aligned);
 587
 588       unsigned char* pbytes;
 589       pbytes = static_cast<unsigned char*>(malloc(v->size() + byteshift));
 590       if (pbytes == NULL)
 591         gold_nomem();
 592       memset(pbytes, 0, byteshift);
 593       memcpy(pbytes + byteshift, v->data() + v->byteshift(), v->size());
 594
 595       File_read::View* shifted_view =
 596           new File_read::View(v->start(), v->size(), pbytes, byteshift,
 597                               cache, View::DATA_ALLOCATED_ARRAY);
 598
 599       this->add_view(shifted_view);
 600       return shifted_view;
 601     }
 602
 603   // Make a new view.  If we don't need an aligned view, use a
 604   // byteshift of 0, so that we can use mmap.
 605   return this->make_view(offset + start, size,
 606                          aligned ? byteshift : 0,
 607                          cache);
 608 }
 609
 610 // Get a view into the file.
 611
 612 const unsigned char*
 613 File_read::get_view(off_t offset, off_t start, section_size_type size,
 614                     bool aligned, bool cache)
 615 {
 616   File_read::View* pv = this->find_or_make_view(offset, start, size,
 617                                                 aligned, cache);
 618   return pv->data() + (offset + start - pv->start() + pv->byteshift());
 619 }
 620
 621 File_view*
 622 File_read::get_lasting_view(off_t offset, off_t start, section_size_type size,
 623                             bool aligned, bool cache)
 624 {
 625   File_read::View* pv = this->find_or_make_view(offset, start, size,
 626                                                 aligned, cache);
 627   pv->lock();
 628   return new File_view(*this, pv,
 629                        (pv->data()
 630                         + (offset + start - pv->start() + pv->byteshift())));
 631 }
 632
 633 // Use readv to read COUNT entries from RM starting at START.  BASE
 634 // must be added to all file offsets in RM.
 635
 636 void
 637 File_read::do_readv(off_t base, const Read_multiple& rm, size_t start,
 638                     size_t count)
 639 {
 640   unsigned char discard[File_read::page_size];
 641   iovec iov[File_read::max_readv_entries * 2];
 642   size_t iov_index = 0;
 643
 644   off_t first_offset = rm[start].file_offset;
 645   off_t last_offset = first_offset;
 646   ssize_t want = 0;
 647   for (size_t i = 0; i < count; ++i)
 648     {
 649       const Read_multiple_entry& i_entry(rm[start + i]);
 650
 651       if (i_entry.file_offset > last_offset)
 652         {
 653           size_t skip = i_entry.file_offset - last_offset;
 654           gold_assert(skip <= sizeof discard);
 655
 656           iov[iov_index].iov_base = discard;
 657           iov[iov_index].iov_len = skip;
 658           ++iov_index;
 659
 660           want += skip;
 661         }
 662
 663       iov[iov_index].iov_base = i_entry.buffer;
 664       iov[iov_index].iov_len = i_entry.size;
 665       ++iov_index;
 666
 667       want += i_entry.size;
 668
 669       last_offset = i_entry.file_offset + i_entry.size;
 670     }
 671
 672   this->reopen_descriptor();
 673
 674   gold_assert(iov_index < sizeof iov / sizeof iov[0]);
 675
 676   if (::lseek(this->descriptor_, base + first_offset, SEEK_SET) < 0)
 677     gold_fatal(_("%s: lseek failed: %s"),
 678                this->filename().c_str(), strerror(errno));
 679
 680   ssize_t got = ::readv(this->descriptor_, iov, iov_index);
 681
 682   if (got < 0)
 683     gold_fatal(_("%s: readv failed: %s"),
 684                this->filename().c_str(), strerror(errno));
 685   if (got != want)
 686     gold_fatal(_("%s: file too short: read only %zd of %zd bytes at %lld"),
 687                this->filename().c_str(),
 688                got, want, static_cast<long long>(base + first_offset));
 689 }
 690
 691 // Portable IOV_MAX.
 692
 693 #if !defined(HAVE_READV)
 694 #define GOLD_IOV_MAX 1
 695 #elif defined(IOV_MAX)
 696 #define GOLD_IOV_MAX IOV_MAX
 697 #else
 698 #define GOLD_IOV_MAX (File_read::max_readv_entries * 2)
 699 #endif
 700
 701 // Read several pieces of data from the file.
 702
 703 void
 704 File_read::read_multiple(off_t base, const Read_multiple& rm)
 705 {
 706   static size_t iov_max = GOLD_IOV_MAX;
 707   size_t count = rm.size();
 708   size_t i = 0;
 709   while (i < count)
 710     {
 711       // Find up to MAX_READV_ENTRIES consecutive entries which are
 712       // less than one page apart.
 713       const Read_multiple_entry& i_entry(rm[i]);
 714       off_t i_off = i_entry.file_offset;
 715       off_t end_off = i_off + i_entry.size;
 716       size_t j;
 717       for (j = i + 1; j < count; ++j)
 718         {
 719           if (j - i >= File_read::max_readv_entries || j - i >= iov_max / 2)
 720             break;
 721           const Read_multiple_entry& j_entry(rm[j]);
 722           off_t j_off = j_entry.file_offset;
 723           gold_assert(j_off >= end_off);
 724           off_t j_end_off = j_off + j_entry.size;
 725           if (j_end_off - end_off >= File_read::page_size)
 726             break;
 727           end_off = j_end_off;
 728         }
 729
 730       if (j == i + 1)
 731         this->read(base + i_off, i_entry.size, i_entry.buffer);
 732       else
 733         {
 734           File_read::View* view = this->find_view(base + i_off,
 735                                                   end_off - i_off,
 736                                                   -1U, NULL);
 737           if (view == NULL)
 738             this->do_readv(base, rm, i, j - i);
 739           else
 740             {
 741               const unsigned char* v = (view->data()
 742                                         + (base + i_off - view->start()
 743                                            + view->byteshift()));
 744               for (size_t k = i; k < j; ++k)
 745                 {
 746                   const Read_multiple_entry& k_entry(rm[k]);
 747                   gold_assert((convert_to_section_size_type(k_entry.file_offset
 748                                                            - i_off)
 749                                + k_entry.size)
 750                               <= convert_to_section_size_type(end_off
 751                                                               - i_off));
 752                   memcpy(k_entry.buffer,
 753                          v + (k_entry.file_offset - i_off),
 754                          k_entry.size);
 755                 }
 756             }
 757         }
 758
 759       i = j;
 760     }
 761 }
 762
 763 // Mark all views as no longer cached.
 764
 765 void
 766 File_read::clear_view_cache_marks()
 767 {
 768   // Just ignore this if there are multiple objects associated with
 769   // the file.  Otherwise we will wind up uncaching and freeing some
 770   // views for other objects.
 771   if (this->object_count_ > 1)
 772     return;
 773
 774   for (Views::iterator p = this->views_.begin();
 775        p != this->views_.end();
 776        ++p)
 777     p->second->clear_cache();
 778   for (Saved_views::iterator p = this->saved_views_.begin();
 779        p != this->saved_views_.end();
 780        ++p)
 781     (*p)->clear_cache();
 782 }
 783
 784 // Remove all the file views.  For a file which has multiple
 785 // associated objects (i.e., an archive), we keep accessed views
 786 // around until next time, in the hopes that they will be useful for
 787 // the next object.
 788
 789 void
 790 File_read::clear_views(Clear_views_mode mode)
 791 {
 792   bool keep_files_mapped = (parameters->options_valid()
 793                             && parameters->options().keep_files_mapped());
 794   Views::iterator p = this->views_.begin();
 795   while (p != this->views_.end())
 796     {
 797       bool should_delete;
 798       if (p->second->is_locked() || p->second->is_permanent_view())
 799         should_delete = false;
 800       else if (mode == CLEAR_VIEWS_ALL)
 801         should_delete = true;
 802       else if ((p->second->should_cache()
 803                 || p->second == this->whole_file_view_)
 804                && keep_files_mapped)
 805         should_delete = false;
 806       else if (this->object_count_ > 1
 807                && p->second->accessed()
 808                && mode != CLEAR_VIEWS_ARCHIVE)
 809         should_delete = false;
 810       else
 811         should_delete = true;
 812
 813       if (should_delete)
 814         {
 815           if (p->second == this->whole_file_view_)
 816             this->whole_file_view_ = NULL;
 817           delete p->second;
 818
 819           // map::erase invalidates only the iterator to the deleted
 820           // element.
 821           Views::iterator pe = p;
 822           ++p;
 823           this->views_.erase(pe);
 824         }
 825       else
 826         {
 827           p->second->clear_accessed();
 828           ++p;
 829         }
 830     }
 831
 832   Saved_views::iterator q = this->saved_views_.begin();
 833   while (q != this->saved_views_.end())
 834     {
 835       if (!(*q)->is_locked())
 836         {
 837           delete *q;
 838           q = this->saved_views_.erase(q);
 839         }
 840       else
 841         {
 842           gold_assert(mode != CLEAR_VIEWS_ALL);
 843           ++q;
 844         }
 845     }
 846 }
 847
 848 // Print statistical information to stderr.  This is used for --stats.
 849
 850 void
 851 File_read::print_stats()
 852 {
 853   fprintf(stderr, _("%s: total bytes mapped for read: %llu\n"),
 854           program_name, File_read::total_mapped_bytes);
 855   fprintf(stderr, _("%s: maximum bytes mapped for read at one time: %llu\n"),
 856           program_name, File_read::maximum_mapped_bytes);
 857 }
 858
 859 // Class File_view.
 860
 861 File_view::~File_view()
 862 {
 863   gold_assert(this->file_.is_locked());
 864   this->view_->unlock();
 865 }
 866
 867 // Class Input_file.
 868
 869 // Create a file given just the filename.
 870
 871 Input_file::Input_file(const char* name)
 872   : found_name_(), file_(), is_in_sysroot_(false), format_(FORMAT_NONE)
 873 {
 874   this->input_argument_ =
 875     new Input_file_argument(name, Input_file_argument::INPUT_FILE_TYPE_FILE,
 876                             "", false, Position_dependent_options());
 877 }
 878
 879 // Create a file for testing.
 880
 881 Input_file::Input_file(const Task* task, const char* name,
 882                        const unsigned char* contents, off_t size)
 883   : file_()
 884 {
 885   this->input_argument_ =
 886     new Input_file_argument(name, Input_file_argument::INPUT_FILE_TYPE_FILE,
 887                             "", false, Position_dependent_options());
 888   bool ok = this->file_.open(task, name, contents, size);
 889   gold_assert(ok);
 890 }
 891
 892 // Return the position dependent options in force for this file.
 893
 894 const Position_dependent_options&
 895 Input_file::options() const
 896 {
 897   return this->input_argument_->options();
 898 }
 899
 900 // Return the name given by the user.  For -lc this will return "c".
 901
 902 const char*
 903 Input_file::name() const
 904 {
 905   return this->input_argument_->name();
 906 }
 907
 908 // Return whether this file is in a system directory.
 909
 910 bool
 911 Input_file::is_in_system_directory() const
 912 {
 913   if (this->is_in_sysroot())
 914     return true;
 915   return parameters->options().is_in_system_directory(this->filename());
 916 }
 917
 918 // Return whether we are only reading symbols.
 919
 920 bool
 921 Input_file::just_symbols() const
 922 {
 923   return this->input_argument_->just_symbols();
 924 }
 925
 926 // Return whether this is a file that we will search for in the list
 927 // of directories.
 928
 929 bool
 930 Input_file::will_search_for() const
 931 {
 932   return (!IS_ABSOLUTE_PATH(this->input_argument_->name())
 933           && (this->input_argument_->is_lib()
 934               || this->input_argument_->is_searched_file()
 935               || this->input_argument_->extra_search_path() != NULL));
 936 }
 937
 938 // Return the file last modification time.  Calls gold_fatal if the stat
 939 // system call failed.
 940
 941 Timespec
 942 File_read::get_mtime()
 943 {
 944   struct stat file_stat;
 945   this->reopen_descriptor();
 946
 947   if (fstat(this->descriptor_, &file_stat) < 0)
 948     gold_fatal(_("%s: stat failed: %s"), this->name_.c_str(),
 949                strerror(errno));
 950 #ifdef HAVE_STAT_ST_MTIM
 951   return Timespec(file_stat.st_mtim.tv_sec, file_stat.st_mtim.tv_nsec);
 952 #else
 953   return Timespec(file_stat.st_mtime, 0);
 954 #endif
 955 }
 956
 957 // Try to find a file in the extra search dirs.  Returns true on success.
 958
 959 bool
 960 Input_file::try_extra_search_path(int* pindex,
 961                                   const Input_file_argument* input_argument,
 962                                   std::string filename, std::string* found_name,
 963                                   std::string* namep)
 964 {
 965   if (input_argument->extra_search_path() == NULL)
 966     return false;
 967
 968   std::string name = input_argument->extra_search_path();
 969   if (!IS_DIR_SEPARATOR(name[name.length() - 1]))
 970     name += '/';
 971   name += filename;
 972
 973   struct stat dummy_stat;
 974   if (*pindex > 0 || ::stat(name.c_str(), &dummy_stat) < 0)
 975     return false;
 976
 977   *found_name = filename;
 978   *namep = name;
 979   return true;
 980 }
 981
 982 // Find the actual file.
 983 // If the filename is not absolute, we assume it is in the current
 984 // directory *except* when:
 985 //    A) input_argument_->is_lib() is true;
 986 //    B) input_argument_->is_searched_file() is true; or
 987 //    C) input_argument_->extra_search_path() is not empty.
 988 // In each, we look in extra_search_path + library_path to find
 989 // the file location, rather than the current directory.
 990
 991 bool
 992 Input_file::find_file(const Dirsearch& dirpath, int* pindex,
 993                       const Input_file_argument* input_argument,
 994                       bool* is_in_sysroot,
 995                       std::string* found_name, std::string* namep)
 996 {
 997   std::string name;
 998
 999   // Case 1: name is an absolute file, just try to open it
1000   // Case 2: name is relative but is_lib is false, is_searched_file is false,
1001   //         and extra_search_path is empty
1002   if (IS_ABSOLUTE_PATH(input_argument->name())
1003       || (!input_argument->is_lib()
1004           && !input_argument->is_searched_file()
1005           && input_argument->extra_search_path() == NULL))
1006     {
1007       name = input_argument->name();
1008       *found_name = name;
1009       *namep = name;
1010       return true;
1011     }
1012   // Case 3: is_lib is true or is_searched_file is true
1013   else if (input_argument->is_lib()
1014            || input_argument->is_searched_file())
1015     {
1016       std::vector<std::string> names;
1017       names.reserve(2);
1018       if (input_argument->is_lib())
1019         {
1020           std::string prefix = "lib";
1021           prefix += input_argument->name();
1022           if (parameters->options().is_static()
1023               || !input_argument->options().Bdynamic())
1024             names.push_back(prefix + ".a");
1025           else
1026             {
1027               names.push_back(prefix + ".so");
1028               names.push_back(prefix + ".a");
1029             }
1030         }
1031       else
1032         names.push_back(input_argument->name());
1033
1034       for (std::vector<std::string>::const_iterator n = names.begin();
1035            n != names.end();
1036            ++n)
1037         if (Input_file::try_extra_search_path(pindex, input_argument, *n,
1038                                               found_name, namep))
1039           return true;
1040
1041       // It is not in the extra_search_path.
1042       name = dirpath.find(names, is_in_sysroot, pindex, found_name);
1043       if (name.empty())
1044         {
1045           gold_error(_("cannot find %s%s"),
1046                      input_argument->is_lib() ? "-l" : "",
1047                      input_argument->name());
1048           return false;
1049         }
1050       *namep = name;
1051       return true;
1052     }
1053   // Case 4: extra_search_path is not empty
1054   else
1055     {
1056       gold_assert(input_argument->extra_search_path() != NULL);
1057
1058       if (try_extra_search_path(pindex, input_argument, input_argument->name(),
1059                                 found_name, namep))
1060         return true;
1061
1062       // extra_search_path failed, so check the normal search-path.
1063       int index = *pindex;
1064       if (index > 0)
1065         --index;
1066       name = dirpath.find(std::vector<std::string>(1, input_argument->name()),
1067                           is_in_sysroot, &index, found_name);
1068       if (name.empty())
1069         {
1070           gold_error(_("cannot find %s"),
1071                      input_argument->name());
1072           return false;
1073         }
1074       *namep = name;
1075       *pindex = index + 1;
1076       return true;
1077     }
1078 }
1079
1080 // Open the file.
1081
1082 bool
1083 Input_file::open(const Dirsearch& dirpath, const Task* task, int* pindex)
1084 {
1085   std::string name;
1086   if (!Input_file::find_file(dirpath, pindex, this->input_argument_,
1087                              &this->is_in_sysroot_, &this->found_name_, &name))
1088     return false;
1089
1090   // Now that we've figured out where the file lives, try to open it.
1091
1092   General_options::Object_format format =
1093     this->input_argument_->options().format_enum();
1094   bool ok;
1095   if (format == General_options::OBJECT_FORMAT_ELF)
1096     {
1097       ok = this->file_.open(task, name);
1098       this->format_ = FORMAT_ELF;
1099     }
1100   else
1101     {
1102       gold_assert(format == General_options::OBJECT_FORMAT_BINARY);
1103       ok = this->open_binary(task, name);
1104       this->format_ = FORMAT_BINARY;
1105     }
1106
1107   if (!ok)
1108     {
1109       gold_error(_("cannot open %s: %s"),
1110                  name.c_str(), strerror(errno));
1111       this->format_ = FORMAT_NONE;
1112       return false;
1113     }
1114
1115   return true;
1116 }
1117
1118 // Open a file for --format binary.
1119
1120 bool
1121 Input_file::open_binary(const Task* task, const std::string& name)
1122 {
1123   // In order to open a binary file, we need machine code, size, and
1124   // endianness.  We may not have a valid target at this point, in
1125   // which case we use the default target.
1126   parameters_force_valid_target();
1127   const Target& target(parameters->target());
1128
1129   Binary_to_elf binary_to_elf(target.machine_code(),
1130                               target.get_size(),
1131                               target.is_big_endian(),
1132                               name);
1133   if (!binary_to_elf.convert(task))
1134     return false;
1135   return this->file_.open(task, name, binary_to_elf.converted_data_leak(),
1136                           binary_to_elf.converted_size());
1137 }
1138
1139 } // End namespace gold.