gold/fileread.cc

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