gold/fileread.cc

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