gold/fileread.cc

   1 // fileread.cc -- read files for gold
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010 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 <fcntl.h>
  28 #include <unistd.h>
  29 #include <sys/mman.h>
  30 #include <sys/uio.h>
  31 #include <sys/stat.h>
  32 #include "filenames.h"
  33
  34 #include "debug.h"
  35 #include "parameters.h"
  36 #include "options.h"
  37 #include "dirsearch.h"
  38 #include "target.h"
  39 #include "binary.h"
  40 #include "descriptors.h"
  41 #include "gold-threads.h"
  42 #include "fileread.h"
  43
  44 #ifndef HAVE_READV
  45 struct iovec { void* iov_base; size_t iov_len };
  46 ssize_t
  47 readv(int, const iovec*, int)
  48 {
  49   gold_unreachable();
  50 }
  51 #endif
  52
  53 namespace gold
  54 {
  55
  56 // Class File_read::View.
  57
  58 File_read::View::~View()
  59 {
  60   gold_assert(!this->is_locked());
  61   switch (this->data_ownership_)
  62     {
  63     case DATA_ALLOCATED_ARRAY:
  64       delete[] this->data_;
  65       break;
  66     case DATA_MMAPPED:
  67       if (::munmap(const_cast<unsigned char*>(this->data_), this->size_) != 0)
  68         gold_warning(_("munmap failed: %s"), strerror(errno));
  69       File_read::current_mapped_bytes -= this->size_;
  70       break;
  71     case DATA_NOT_OWNED:
  72       break;
  73     default:
  74       gold_unreachable();
  75     }
  76 }
  77
  78 void
  79 File_read::View::lock()
  80 {
  81   ++this->lock_count_;
  82 }
  83
  84 void
  85 File_read::View::unlock()
  86 {
  87   gold_assert(this->lock_count_ > 0);
  88   --this->lock_count_;
  89 }
  90
  91 bool
  92 File_read::View::is_locked()
  93 {
  94   return this->lock_count_ > 0;
  95 }
  96
  97 // Class File_read.
  98
  99 // A lock for the File_read static variables.
 100 static Lock* file_counts_lock = NULL;
 101 static Initialize_lock file_counts_initialize_lock(&file_counts_lock);
 102
 103 // The File_read static variables.
 104 unsigned long long File_read::total_mapped_bytes;
 105 unsigned long long File_read::current_mapped_bytes;
 106 unsigned long long File_read::maximum_mapped_bytes;
 107
 108 File_read::~File_read()
 109 {
 110   gold_assert(this->token_.is_writable());
 111   if (this->is_descriptor_opened_)
 112     {
 113       release_descriptor(this->descriptor_, true);
 114       this->descriptor_ = -1;
 115       this->is_descriptor_opened_ = false;
 116     }
 117   this->name_.clear();
 118   this->clear_views(CLEAR_VIEWS_ALL);
 119 }
 120
 121 // Open the file.
 122
 123 bool
 124 File_read::open(const Task* task, const std::string& name)
 125 {
 126   gold_assert(this->token_.is_writable()
 127               && this->descriptor_ < 0
 128               && !this->is_descriptor_opened_
 129               && this->name_.empty());
 130   this->name_ = name;
 131
 132   this->descriptor_ = open_descriptor(-1, this->name_.c_str(),
 133                                       O_RDONLY);
 134
 135   if (this->descriptor_ >= 0)
 136     {
 137       this->is_descriptor_opened_ = true;
 138       struct stat s;
 139       if (::fstat(this->descriptor_, &s) < 0)
 140         gold_error(_("%s: fstat failed: %s"),
 141                    this->name_.c_str(), strerror(errno));
 142       this->size_ = s.st_size;
 143       gold_debug(DEBUG_FILES, "Attempt to open %s succeeded",
 144                  this->name_.c_str());
 145       this->token_.add_writer(task);
 146     }
 147
 148   return this->descriptor_ >= 0;
 149 }
 150
 151 // Open the file with the contents in memory.
 152
 153 bool
 154 File_read::open(const Task* task, const std::string& name,
 155                 const unsigned char* contents, off_t size)
 156 {
 157   gold_assert(this->token_.is_writable()
 158               && this->descriptor_ < 0
 159               && !this->is_descriptor_opened_
 160               && this->name_.empty());
 161   this->name_ = name;
 162   this->whole_file_view_ = new View(0, size, contents, 0, false,
 163                                     View::DATA_NOT_OWNED);
 164   this->add_view(this->whole_file_view_);
 165   this->size_ = size;
 166   this->token_.add_writer(task);
 167   return true;
 168 }
 169
 170 // Reopen a descriptor if necessary.
 171
 172 void
 173 File_read::reopen_descriptor()
 174 {
 175   if (!this->is_descriptor_opened_)
 176     {
 177       this->descriptor_ = open_descriptor(this->descriptor_,
 178                                           this->name_.c_str(),
 179                                           O_RDONLY);
 180       if (this->descriptor_ < 0)
 181         gold_fatal(_("could not reopen file %s"), this->name_.c_str());
 182       this->is_descriptor_opened_ = true;
 183     }
 184 }
 185
 186 // Release the file.  This is called when we are done with the file in
 187 // a Task.
 188
 189 void
 190 File_read::release()
 191 {
 192   gold_assert(this->is_locked());
 193
 194   if (!parameters->options_valid() || parameters->options().stats())
 195     {
 196       file_counts_initialize_lock.initialize();
 197       Hold_optional_lock hl(file_counts_lock);
 198       File_read::total_mapped_bytes += this->mapped_bytes_;
 199       File_read::current_mapped_bytes += this->mapped_bytes_;
 200       if (File_read::current_mapped_bytes > File_read::maximum_mapped_bytes)
 201         File_read::maximum_mapped_bytes = File_read::current_mapped_bytes;
 202     }
 203
 204   this->mapped_bytes_ = 0;
 205
 206   // Only clear views if there is only one attached object.  Otherwise
 207   // we waste time trying to clear cached archive views.  Similarly
 208   // for releasing the descriptor.
 209   if (this->object_count_ <= 1)
 210     {
 211       this->clear_views(CLEAR_VIEWS_NORMAL);
 212       if (this->is_descriptor_opened_)
 213         {
 214           release_descriptor(this->descriptor_, false);
 215           this->is_descriptor_opened_ = false;
 216         }
 217     }
 218
 219   this->released_ = true;
 220 }
 221
 222 // Lock the file.
 223
 224 void
 225 File_read::lock(const Task* task)
 226 {
 227   gold_assert(this->released_);
 228   this->token_.add_writer(task);
 229   this->released_ = false;
 230 }
 231
 232 // Unlock the file.
 233
 234 void
 235 File_read::unlock(const Task* task)
 236 {
 237   this->release();
 238   this->token_.remove_writer(task);
 239 }
 240
 241 // Return whether the file is locked.
 242
 243 bool
 244 File_read::is_locked() const
 245 {
 246   if (!this->token_.is_writable())
 247     return true;
 248   // The file is not locked, so it should have been released.
 249   gold_assert(this->released_);
 250   return false;
 251 }
 252
 253 // See if we have a view which covers the file starting at START for
 254 // SIZE bytes.  Return a pointer to the View if found, NULL if not.
 255 // If BYTESHIFT is not -1U, the returned View must have the specified
 256 // byte shift; otherwise, it may have any byte shift.  If VSHIFTED is
 257 // not NULL, this sets *VSHIFTED to a view which would have worked if
 258 // not for the requested BYTESHIFT.
 259
 260 inline File_read::View*
 261 File_read::find_view(off_t start, section_size_type size,
 262                      unsigned int byteshift, File_read::View** vshifted) const
 263 {
 264   if (vshifted != NULL)
 265     *vshifted = NULL;
 266
 267   // If we have the whole file mmapped, and the alignment is right,
 268   // we can return it.
 269   if (this->whole_file_view_)
 270     if (byteshift == -1U || byteshift == 0)
 271       return this->whole_file_view_;
 272
 273   off_t page = File_read::page_offset(start);
 274
 275   unsigned int bszero = 0;
 276   Views::const_iterator p = this->views_.upper_bound(std::make_pair(page - 1,
 277                                                                     bszero));
 278
 279   while (p != this->views_.end() && p->first.first <= page)
 280     {
 281       if (p->second->start() <= start
 282           && (p->second->start() + static_cast<off_t>(p->second->size())
 283               >= start + static_cast<off_t>(size)))
 284         {
 285           if (byteshift == -1U || byteshift == p->second->byteshift())
 286             {
 287               p->second->set_accessed();
 288               return p->second;
 289             }
 290
 291           if (vshifted != NULL && *vshifted == NULL)
 292             *vshifted = p->second;
 293         }
 294
 295       ++p;
 296     }
 297
 298   return NULL;
 299 }
 300
 301 // Read SIZE bytes from the file starting at offset START.  Read into
 302 // the buffer at P.
 303
 304 void
 305 File_read::do_read(off_t start, section_size_type size, void* p)
 306 {
 307   ssize_t bytes;
 308   if (this->whole_file_view_ != NULL)
 309     {
 310       bytes = this->size_ - start;
 311       if (static_cast<section_size_type>(bytes) >= size)
 312         {
 313           memcpy(p, this->whole_file_view_->data() + start, size);
 314           return;
 315         }
 316     }
 317   else
 318     {
 319       this->reopen_descriptor();
 320       bytes = ::pread(this->descriptor_, p, size, start);
 321       if (static_cast<section_size_type>(bytes) == size)
 322         return;
 323
 324       if (bytes < 0)
 325         {
 326           gold_fatal(_("%s: pread failed: %s"),
 327                      this->filename().c_str(), strerror(errno));
 328           return;
 329         }
 330     }
 331
 332   gold_fatal(_("%s: file too short: read only %lld of %lld bytes at %lld"),
 333              this->filename().c_str(),
 334              static_cast<long long>(bytes),
 335              static_cast<long long>(size),
 336              static_cast<long long>(start));
 337 }
 338
 339 // Read data from the file.
 340
 341 void
 342 File_read::read(off_t start, section_size_type size, void* p)
 343 {
 344   const File_read::View* pv = this->find_view(start, size, -1U, NULL);
 345   if (pv != NULL)
 346     {
 347       memcpy(p, pv->data() + (start - pv->start() + pv->byteshift()), size);
 348       return;
 349     }
 350
 351   this->do_read(start, size, p);
 352 }
 353
 354 // Add a new view.  There may already be an existing view at this
 355 // offset.  If there is, the new view will be larger, and should
 356 // replace the old view.
 357
 358 void
 359 File_read::add_view(File_read::View* v)
 360 {
 361   std::pair<Views::iterator, bool> ins =
 362     this->views_.insert(std::make_pair(std::make_pair(v->start(),
 363                                                       v->byteshift()),
 364                                        v));
 365   if (ins.second)
 366     return;
 367
 368   // There was an existing view at this offset.  It must not be large
 369   // enough.  We can't delete it here, since something might be using
 370   // it; we put it on a list to be deleted when the file is unlocked.
 371   File_read::View* vold = ins.first->second;
 372   gold_assert(vold->size() < v->size());
 373   if (vold->should_cache())
 374     {
 375       v->set_cache();
 376       vold->clear_cache();
 377     }
 378   this->saved_views_.push_back(vold);
 379
 380   ins.first->second = v;
 381 }
 382
 383 // Make a new view with a specified byteshift, reading the data from
 384 // the file.
 385
 386 File_read::View*
 387 File_read::make_view(off_t start, section_size_type size,
 388                      unsigned int byteshift, bool cache)
 389 {
 390   gold_assert(size > 0);
 391
 392   // Check that start and end of the view are within the file.
 393   if (start > this->size_
 394       || (static_cast<unsigned long long>(size)
 395           > static_cast<unsigned long long>(this->size_ - start)))
 396     gold_fatal(_("%s: attempt to map %lld bytes at offset %lld exceeds "
 397                  "size of file; the file may be corrupt"),
 398                    this->filename().c_str(),
 399                    static_cast<long long>(size),
 400                    static_cast<long long>(start));
 401
 402   off_t poff = File_read::page_offset(start);
 403
 404   section_size_type psize = File_read::pages(size + (start - poff));
 405
 406   if (poff + static_cast<off_t>(psize) >= this->size_)
 407     {
 408       psize = this->size_ - poff;
 409       gold_assert(psize >= size);
 410     }
 411
 412   File_read::View* v;
 413   if (byteshift != 0)
 414     {
 415       unsigned char* p = new unsigned char[psize + byteshift];
 416       memset(p, 0, byteshift);
 417       this->do_read(poff, psize, p + byteshift);
 418       v = new File_read::View(poff, psize, p, byteshift, cache,
 419                               View::DATA_ALLOCATED_ARRAY);
 420     }
 421   else
 422     {
 423       this->reopen_descriptor();
 424       void* p = ::mmap(NULL, psize, PROT_READ, MAP_PRIVATE,
 425                        this->descriptor_, poff);
 426       if (p == MAP_FAILED)
 427         gold_fatal(_("%s: mmap offset %lld size %lld failed: %s"),
 428                    this->filename().c_str(),
 429                    static_cast<long long>(poff),
 430                    static_cast<long long>(psize),
 431                    strerror(errno));
 432
 433       this->mapped_bytes_ += psize;
 434
 435       const unsigned char* pbytes = static_cast<const unsigned char*>(p);
 436       v = new File_read::View(poff, psize, pbytes, 0, cache,
 437                               View::DATA_MMAPPED);
 438     }
 439
 440   this->add_view(v);
 441
 442   return v;
 443 }
 444
 445 // Find a View or make a new one, shifted as required by the file
 446 // offset OFFSET and ALIGNED.
 447
 448 File_read::View*
 449 File_read::find_or_make_view(off_t offset, off_t start,
 450                              section_size_type size, bool aligned, bool cache)
 451 {
 452   unsigned int byteshift;
 453   if (offset == 0)
 454     byteshift = 0;
 455   else
 456     {
 457       unsigned int target_size = (!parameters->target_valid()
 458                                   ? 64
 459                                   : parameters->target().get_size());
 460       byteshift = offset & ((target_size / 8) - 1);
 461
 462       // Set BYTESHIFT to the number of dummy bytes which must be
 463       // inserted before the data in order for this data to be
 464       // aligned.
 465       if (byteshift != 0)
 466         byteshift = (target_size / 8) - byteshift;
 467     }
 468
 469   // If --map-whole-files is set, make sure we have a
 470   // whole file view.  Options may not yet be ready, e.g.,
 471   // when reading a version script.  We then default to
 472   // --no-map-whole-files.
 473   if (this->whole_file_view_ == NULL
 474       && parameters->options_valid()
 475       && parameters->options().map_whole_files())
 476     this->whole_file_view_ = this->make_view(0, this->size_, 0, cache);
 477
 478   // Try to find a View with the required BYTESHIFT.
 479   File_read::View* vshifted;
 480   File_read::View* v = this->find_view(offset + start, size,
 481                                        aligned ? byteshift : -1U,
 482                                        &vshifted);
 483   if (v != NULL)
 484     {
 485       if (cache)
 486         v->set_cache();
 487       return v;
 488     }
 489
 490   // If VSHIFTED is not NULL, then it has the data we need, but with
 491   // the wrong byteshift.
 492   v = vshifted;
 493   if (v != NULL)
 494     {
 495       gold_assert(aligned);
 496
 497       unsigned char* pbytes = new unsigned char[v->size() + byteshift];
 498       memset(pbytes, 0, byteshift);
 499       memcpy(pbytes + byteshift, v->data() + v->byteshift(), v->size());
 500
 501       File_read::View* shifted_view =
 502           new File_read::View(v->start(), v->size(), pbytes, byteshift,
 503                               cache, View::DATA_ALLOCATED_ARRAY);
 504
 505       this->add_view(shifted_view);
 506       return shifted_view;
 507     }
 508
 509   // Make a new view.  If we don't need an aligned view, use a
 510   // byteshift of 0, so that we can use mmap.
 511   return this->make_view(offset + start, size,
 512                          aligned ? byteshift : 0,
 513                          cache);
 514 }
 515
 516 // Get a view into the file.
 517
 518 const unsigned char*
 519 File_read::get_view(off_t offset, off_t start, section_size_type size,
 520                     bool aligned, bool cache)
 521 {
 522   File_read::View* pv = this->find_or_make_view(offset, start, size,
 523                                                 aligned, cache);
 524   return pv->data() + (offset + start - pv->start() + pv->byteshift());
 525 }
 526
 527 File_view*
 528 File_read::get_lasting_view(off_t offset, off_t start, section_size_type size,
 529                             bool aligned, bool cache)
 530 {
 531   File_read::View* pv = this->find_or_make_view(offset, start, size,
 532                                                 aligned, cache);
 533   pv->lock();
 534   return new File_view(*this, pv,
 535                        (pv->data()
 536                         + (offset + start - pv->start() + pv->byteshift())));
 537 }
 538
 539 // Use readv to read COUNT entries from RM starting at START.  BASE
 540 // must be added to all file offsets in RM.
 541
 542 void
 543 File_read::do_readv(off_t base, const Read_multiple& rm, size_t start,
 544                     size_t count)
 545 {
 546   unsigned char discard[File_read::page_size];
 547   iovec iov[File_read::max_readv_entries * 2];
 548   size_t iov_index = 0;
 549
 550   off_t first_offset = rm[start].file_offset;
 551   off_t last_offset = first_offset;
 552   ssize_t want = 0;
 553   for (size_t i = 0; i < count; ++i)
 554     {
 555       const Read_multiple_entry& i_entry(rm[start + i]);
 556
 557       if (i_entry.file_offset > last_offset)
 558         {
 559           size_t skip = i_entry.file_offset - last_offset;
 560           gold_assert(skip <= sizeof discard);
 561
 562           iov[iov_index].iov_base = discard;
 563           iov[iov_index].iov_len = skip;
 564           ++iov_index;
 565
 566           want += skip;
 567         }
 568
 569       iov[iov_index].iov_base = i_entry.buffer;
 570       iov[iov_index].iov_len = i_entry.size;
 571       ++iov_index;
 572
 573       want += i_entry.size;
 574
 575       last_offset = i_entry.file_offset + i_entry.size;
 576     }
 577
 578   this->reopen_descriptor();
 579
 580   gold_assert(iov_index < sizeof iov / sizeof iov[0]);
 581
 582   if (::lseek(this->descriptor_, base + first_offset, SEEK_SET) < 0)
 583     gold_fatal(_("%s: lseek failed: %s"),
 584                this->filename().c_str(), strerror(errno));
 585
 586   ssize_t got = ::readv(this->descriptor_, iov, iov_index);
 587
 588   if (got < 0)
 589     gold_fatal(_("%s: readv failed: %s"),
 590                this->filename().c_str(), strerror(errno));
 591   if (got != want)
 592     gold_fatal(_("%s: file too short: read only %zd of %zd bytes at %lld"),
 593                this->filename().c_str(),
 594                got, want, static_cast<long long>(base + first_offset));
 595 }
 596
 597 // Read several pieces of data from the file.
 598
 599 void
 600 File_read::read_multiple(off_t base, const Read_multiple& rm)
 601 {
 602   size_t count = rm.size();
 603   size_t i = 0;
 604   while (i < count)
 605     {
 606       // Find up to MAX_READV_ENTRIES consecutive entries which are
 607       // less than one page apart.
 608       const Read_multiple_entry& i_entry(rm[i]);
 609       off_t i_off = i_entry.file_offset;
 610       off_t end_off = i_off + i_entry.size;
 611       size_t j;
 612       for (j = i + 1; j < count; ++j)
 613         {
 614           if (j - i >= File_read::max_readv_entries)
 615             break;
 616           const Read_multiple_entry& j_entry(rm[j]);
 617           off_t j_off = j_entry.file_offset;
 618           gold_assert(j_off >= end_off);
 619           off_t j_end_off = j_off + j_entry.size;
 620           if (j_end_off - end_off >= File_read::page_size)
 621             break;
 622           end_off = j_end_off;
 623         }
 624
 625       if (j == i + 1)
 626         this->read(base + i_off, i_entry.size, i_entry.buffer);
 627       else
 628         {
 629           File_read::View* view = this->find_view(base + i_off,
 630                                                   end_off - i_off,
 631                                                   -1U, NULL);
 632           if (view == NULL)
 633             this->do_readv(base, rm, i, j - i);
 634           else
 635             {
 636               const unsigned char* v = (view->data()
 637                                         + (base + i_off - view->start()
 638                                            + view->byteshift()));
 639               for (size_t k = i; k < j; ++k)
 640                 {
 641                   const Read_multiple_entry& k_entry(rm[k]);
 642                   gold_assert((convert_to_section_size_type(k_entry.file_offset
 643                                                            - i_off)
 644                                + k_entry.size)
 645                               <= convert_to_section_size_type(end_off
 646                                                               - i_off));
 647                   memcpy(k_entry.buffer,
 648                          v + (k_entry.file_offset - i_off),
 649                          k_entry.size);
 650                 }
 651             }
 652         }
 653
 654       i = j;
 655     }
 656 }
 657
 658 // Mark all views as no longer cached.
 659
 660 void
 661 File_read::clear_view_cache_marks()
 662 {
 663   // Just ignore this if there are multiple objects associated with
 664   // the file.  Otherwise we will wind up uncaching and freeing some
 665   // views for other objects.
 666   if (this->object_count_ > 1)
 667     return;
 668
 669   for (Views::iterator p = this->views_.begin();
 670        p != this->views_.end();
 671        ++p)
 672     p->second->clear_cache();
 673   for (Saved_views::iterator p = this->saved_views_.begin();
 674        p != this->saved_views_.end();
 675        ++p)
 676     (*p)->clear_cache();
 677 }
 678
 679 // Remove all the file views.  For a file which has multiple
 680 // associated objects (i.e., an archive), we keep accessed views
 681 // around until next time, in the hopes that they will be useful for
 682 // the next object.
 683
 684 void
 685 File_read::clear_views(Clear_views_mode mode)
 686 {
 687   bool keep_files_mapped = (parameters->options_valid()
 688                             && parameters->options().keep_files_mapped());
 689   Views::iterator p = this->views_.begin();
 690   while (p != this->views_.end())
 691     {
 692       bool should_delete;
 693       if (p->second->is_locked() || p->second->is_permanent_view())
 694         should_delete = false;
 695       else if (mode == CLEAR_VIEWS_ALL)
 696         should_delete = true;
 697       else if (p->second->should_cache() && keep_files_mapped)
 698         should_delete = false;
 699       else if (this->object_count_ > 1
 700                && p->second->accessed()
 701                && mode != CLEAR_VIEWS_ARCHIVE)
 702         should_delete = false;
 703       else
 704         should_delete = true;
 705
 706       if (should_delete)
 707         {
 708           if (p->second == this->whole_file_view_)
 709             this->whole_file_view_ = NULL;
 710           delete p->second;
 711
 712           // map::erase invalidates only the iterator to the deleted
 713           // element.
 714           Views::iterator pe = p;
 715           ++p;
 716           this->views_.erase(pe);
 717         }
 718       else
 719         {
 720           p->second->clear_accessed();
 721           ++p;
 722         }
 723     }
 724
 725   Saved_views::iterator q = this->saved_views_.begin();
 726   while (q != this->saved_views_.end())
 727     {
 728       if (!(*q)->is_locked())
 729         {
 730           delete *q;
 731           q = this->saved_views_.erase(q);
 732         }
 733       else
 734         {
 735           gold_assert(mode != CLEAR_VIEWS_ALL);
 736           ++q;
 737         }
 738     }
 739 }
 740
 741 // Print statistical information to stderr.  This is used for --stats.
 742
 743 void
 744 File_read::print_stats()
 745 {
 746   fprintf(stderr, _("%s: total bytes mapped for read: %llu\n"),
 747           program_name, File_read::total_mapped_bytes);
 748   fprintf(stderr, _("%s: maximum bytes mapped for read at one time: %llu\n"),
 749           program_name, File_read::maximum_mapped_bytes);
 750 }
 751
 752 // Class File_view.
 753
 754 File_view::~File_view()
 755 {
 756   gold_assert(this->file_.is_locked());
 757   this->view_->unlock();
 758 }
 759
 760 // Class Input_file.
 761
 762 // Create a file for testing.
 763
 764 Input_file::Input_file(const Task* task, const char* name,
 765                        const unsigned char* contents, off_t size)
 766   : file_()
 767 {
 768   this->input_argument_ =
 769     new Input_file_argument(name, Input_file_argument::INPUT_FILE_TYPE_FILE,
 770                             "", false, Position_dependent_options());
 771   bool ok = this->file_.open(task, name, contents, size);
 772   gold_assert(ok);
 773 }
 774
 775 // Return the position dependent options in force for this file.
 776
 777 const Position_dependent_options&
 778 Input_file::options() const
 779 {
 780   return this->input_argument_->options();
 781 }
 782
 783 // Return the name given by the user.  For -lc this will return "c".
 784
 785 const char*
 786 Input_file::name() const
 787 {
 788   return this->input_argument_->name();
 789 }
 790
 791 // Return whether this file is in a system directory.
 792
 793 bool
 794 Input_file::is_in_system_directory() const
 795 {
 796   if (this->is_in_sysroot())
 797     return true;
 798   return parameters->options().is_in_system_directory(this->filename());
 799 }
 800
 801 // Return whether we are only reading symbols.
 802
 803 bool
 804 Input_file::just_symbols() const
 805 {
 806   return this->input_argument_->just_symbols();
 807 }
 808
 809 // Return whether this is a file that we will search for in the list
 810 // of directories.
 811
 812 bool
 813 Input_file::will_search_for() const
 814 {
 815   return (!IS_ABSOLUTE_PATH(this->input_argument_->name())
 816           && (this->input_argument_->is_lib()
 817               || this->input_argument_->is_searched_file()
 818               || this->input_argument_->extra_search_path() != NULL));
 819 }
 820
 821 // Return the file last modification time.  Calls gold_fatal if the stat
 822 // system call failed.
 823
 824 Timespec
 825 File_read::get_mtime()
 826 {
 827   struct stat file_stat;
 828   this->reopen_descriptor();
 829
 830   if (fstat(this->descriptor_, &file_stat) < 0)
 831     gold_fatal(_("%s: stat failed: %s"), this->name_.c_str(),
 832                strerror(errno));
 833 #ifdef HAVE_STAT_ST_MTIM
 834   return Timespec(file_stat.st_mtim.tv_sec, file_stat.st_mtim.tv_nsec);
 835 #else
 836   return Timespec(file_stat.st_mtime, 0);
 837 #endif
 838 }
 839
 840 // Open the file.
 841
 842 // If the filename is not absolute, we assume it is in the current
 843 // directory *except* when:
 844 //    A) input_argument_->is_lib() is true;
 845 //    B) input_argument_->is_searched_file() is true; or
 846 //    C) input_argument_->extra_search_path() is not empty.
 847 // In each, we look in extra_search_path + library_path to find
 848 // the file location, rather than the current directory.
 849
 850 bool
 851 Input_file::open(const Dirsearch& dirpath, const Task* task, int *pindex)
 852 {
 853   std::string name;
 854
 855   // Case 1: name is an absolute file, just try to open it
 856   // Case 2: name is relative but is_lib is false, is_searched_file is false,
 857   //         and extra_search_path is empty
 858   if (IS_ABSOLUTE_PATH(this->input_argument_->name())
 859       || (!this->input_argument_->is_lib()
 860           && !this->input_argument_->is_searched_file()
 861           && this->input_argument_->extra_search_path() == NULL))
 862     {
 863       name = this->input_argument_->name();
 864       this->found_name_ = name;
 865     }
 866   // Case 3: is_lib is true or is_searched_file is true
 867   else if (this->input_argument_->is_lib()
 868            || this->input_argument_->is_searched_file())
 869     {
 870       // We don't yet support extra_search_path with -l.
 871       gold_assert(this->input_argument_->extra_search_path() == NULL);
 872       std::string n1, n2;
 873       if (this->input_argument_->is_lib())
 874         {
 875           n1 = "lib";
 876           n1 += this->input_argument_->name();
 877           if (parameters->options().is_static()
 878               || !this->input_argument_->options().Bdynamic())
 879             n1 += ".a";
 880           else
 881             {
 882               n2 = n1 + ".a";
 883               n1 += ".so";
 884             }
 885         }
 886       else
 887         n1 = this->input_argument_->name();
 888       name = dirpath.find(n1, n2, &this->is_in_sysroot_, pindex);
 889       if (name.empty())
 890         {
 891           gold_error(_("cannot find %s%s"),
 892                      this->input_argument_->is_lib() ? "-l" : "",
 893                      this->input_argument_->name());
 894           return false;
 895         }
 896       if (n2.empty() || name[name.length() - 1] == 'o')
 897         this->found_name_ = n1;
 898       else
 899         this->found_name_ = n2;
 900     }
 901   // Case 4: extra_search_path is not empty
 902   else
 903     {
 904       gold_assert(this->input_argument_->extra_search_path() != NULL);
 905
 906       // First, check extra_search_path.
 907       name = this->input_argument_->extra_search_path();
 908       if (!IS_DIR_SEPARATOR (name[name.length() - 1]))
 909         name += '/';
 910       name += this->input_argument_->name();
 911       struct stat dummy_stat;
 912       if (*pindex > 0 || ::stat(name.c_str(), &dummy_stat) < 0)
 913         {
 914           // extra_search_path failed, so check the normal search-path.
 915           int index = *pindex;
 916           if (index > 0)
 917             --index;
 918           name = dirpath.find(this->input_argument_->name(), "",
 919                               &this->is_in_sysroot_, &index);
 920           if (name.empty())
 921             {
 922               gold_error(_("cannot find %s"),
 923                          this->input_argument_->name());
 924               return false;
 925             }
 926           *pindex = index + 1;
 927         }
 928       this->found_name_ = this->input_argument_->name();
 929     }
 930
 931   // Now that we've figured out where the file lives, try to open it.
 932
 933   General_options::Object_format format =
 934     this->input_argument_->options().format_enum();
 935   bool ok;
 936   if (format == General_options::OBJECT_FORMAT_ELF)
 937     {
 938       ok = this->file_.open(task, name);
 939       this->format_ = FORMAT_ELF;
 940     }
 941   else
 942     {
 943       gold_assert(format == General_options::OBJECT_FORMAT_BINARY);
 944       ok = this->open_binary(task, name);
 945       this->format_ = FORMAT_BINARY;
 946     }
 947
 948   if (!ok)
 949     {
 950       gold_error(_("cannot open %s: %s"),
 951                  name.c_str(), strerror(errno));
 952       this->format_ = FORMAT_NONE;
 953       return false;
 954     }
 955
 956   return true;
 957 }
 958
 959 // Open a file for --format binary.
 960
 961 bool
 962 Input_file::open_binary(const Task* task, const std::string& name)
 963 {
 964   // In order to open a binary file, we need machine code, size, and
 965   // endianness.  We may not have a valid target at this point, in
 966   // which case we use the default target.
 967   parameters_force_valid_target();
 968   const Target& target(parameters->target());
 969
 970   Binary_to_elf binary_to_elf(target.machine_code(),
 971                               target.get_size(),
 972                               target.is_big_endian(),
 973                               name);
 974   if (!binary_to_elf.convert(task))
 975     return false;
 976   return this->file_.open(task, name, binary_to_elf.converted_data_leak(),
 977                           binary_to_elf.converted_size());
 978 }
 979
 980 } // End namespace gold.