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(true);
 119   if (this->whole_file_view_)
 120     delete this->whole_file_view_;
 121 }
 122
 123 // Open the file.
 124
 125 bool
 126 File_read::open(const Task* task, const std::string& name)
 127 {
 128   gold_assert(this->token_.is_writable()
 129               && this->descriptor_ < 0
 130               && !this->is_descriptor_opened_
 131               && this->name_.empty());
 132   this->name_ = name;
 133
 134   this->descriptor_ = open_descriptor(-1, this->name_.c_str(),
 135                                       O_RDONLY);
 136
 137   if (this->descriptor_ >= 0)
 138     {
 139       this->is_descriptor_opened_ = true;
 140       struct stat s;
 141       if (::fstat(this->descriptor_, &s) < 0)
 142         gold_error(_("%s: fstat failed: %s"),
 143                    this->name_.c_str(), strerror(errno));
 144       this->size_ = s.st_size;
 145       gold_debug(DEBUG_FILES, "Attempt to open %s succeeded",
 146                  this->name_.c_str());
 147
 148       // Options may not yet be ready e.g. when reading a version
 149       // script.  We then default to --no-keep-files-mapped.
 150       if (parameters->options_valid()
 151           && parameters->options().keep_files_mapped())
 152         {
 153           const unsigned char* contents = static_cast<const unsigned char*>(
 154               ::mmap(NULL, this->size_, PROT_READ, MAP_PRIVATE,
 155                      this->descriptor_, 0));
 156           if (contents == MAP_FAILED)
 157             gold_fatal(_("%s: mmap failed: %s"), this->filename().c_str(),
 158                        strerror(errno));
 159           this->whole_file_view_ = new View(0, this->size_, contents, 0, false,
 160                                             View::DATA_MMAPPED);
 161           this->mapped_bytes_ += this->size_;
 162         }
 163
 164       this->token_.add_writer(task);
 165     }
 166
 167   return this->descriptor_ >= 0;
 168 }
 169
 170 // Open the file with the contents in memory.
 171
 172 bool
 173 File_read::open(const Task* task, const std::string& name,
 174                 const unsigned char* contents, off_t size)
 175 {
 176   gold_assert(this->token_.is_writable()
 177               && this->descriptor_ < 0
 178               && !this->is_descriptor_opened_
 179               && this->name_.empty());
 180   this->name_ = name;
 181   this->whole_file_view_ = new View(0, size, contents, 0, false,
 182                                     View::DATA_NOT_OWNED);
 183   this->size_ = size;
 184   this->token_.add_writer(task);
 185   return true;
 186 }
 187
 188 // Reopen a descriptor if necessary.
 189
 190 void
 191 File_read::reopen_descriptor()
 192 {
 193   if (!this->is_descriptor_opened_)
 194     {
 195       this->descriptor_ = open_descriptor(this->descriptor_,
 196                                           this->name_.c_str(),
 197                                           O_RDONLY);
 198       if (this->descriptor_ < 0)
 199         gold_fatal(_("could not reopen file %s"), this->name_.c_str());
 200       this->is_descriptor_opened_ = true;
 201     }
 202 }
 203
 204 // Release the file.  This is called when we are done with the file in
 205 // a Task.
 206
 207 void
 208 File_read::release()
 209 {
 210   gold_assert(this->is_locked());
 211
 212   if (!parameters->options_valid() || parameters->options().stats())
 213     {
 214       file_counts_initialize_lock.initialize();
 215       Hold_optional_lock hl(file_counts_lock);
 216       File_read::total_mapped_bytes += this->mapped_bytes_;
 217       File_read::current_mapped_bytes += this->mapped_bytes_;
 218       if (File_read::current_mapped_bytes > File_read::maximum_mapped_bytes)
 219         File_read::maximum_mapped_bytes = File_read::current_mapped_bytes;
 220     }
 221
 222   this->mapped_bytes_ = 0;
 223
 224   // Only clear views if there is only one attached object.  Otherwise
 225   // we waste time trying to clear cached archive views.  Similarly
 226   // for releasing the descriptor.
 227   if (this->object_count_ <= 1)
 228     {
 229       this->clear_views(false);
 230       if (this->is_descriptor_opened_)
 231         {
 232           release_descriptor(this->descriptor_, false);
 233           this->is_descriptor_opened_ = false;
 234         }
 235     }
 236
 237   this->released_ = true;
 238 }
 239
 240 // Lock the file.
 241
 242 void
 243 File_read::lock(const Task* task)
 244 {
 245   gold_assert(this->released_);
 246   this->token_.add_writer(task);
 247   this->released_ = false;
 248 }
 249
 250 // Unlock the file.
 251
 252 void
 253 File_read::unlock(const Task* task)
 254 {
 255   this->release();
 256   this->token_.remove_writer(task);
 257 }
 258
 259 // Return whether the file is locked.
 260
 261 bool
 262 File_read::is_locked() const
 263 {
 264   if (!this->token_.is_writable())
 265     return true;
 266   // The file is not locked, so it should have been released.
 267   gold_assert(this->released_);
 268   return false;
 269 }
 270
 271 // See if we have a view which covers the file starting at START for
 272 // SIZE bytes.  Return a pointer to the View if found, NULL if not.
 273 // If BYTESHIFT is not -1U, the returned View must have the specified
 274 // byte shift; otherwise, it may have any byte shift.  If VSHIFTED is
 275 // not NULL, this sets *VSHIFTED to a view which would have worked if
 276 // not for the requested BYTESHIFT.
 277
 278 inline File_read::View*
 279 File_read::find_view(off_t start, section_size_type size,
 280                      unsigned int byteshift, File_read::View** vshifted) const
 281 {
 282   if (vshifted != NULL)
 283     *vshifted = NULL;
 284
 285   // If we have the whole file mmapped, and the alignment is right,
 286   // we can return it.
 287   if (this->whole_file_view_)
 288     if (byteshift == -1U || byteshift == 0)
 289       return this->whole_file_view_;
 290
 291   off_t page = File_read::page_offset(start);
 292
 293   unsigned int bszero = 0;
 294   Views::const_iterator p = this->views_.upper_bound(std::make_pair(page - 1,
 295                                                                     bszero));
 296
 297   while (p != this->views_.end() && p->first.first <= page)
 298     {
 299       if (p->second->start() <= start
 300           && (p->second->start() + static_cast<off_t>(p->second->size())
 301               >= start + static_cast<off_t>(size)))
 302         {
 303           if (byteshift == -1U || byteshift == p->second->byteshift())
 304             {
 305               p->second->set_accessed();
 306               return p->second;
 307             }
 308
 309           if (vshifted != NULL && *vshifted == NULL)
 310             *vshifted = p->second;
 311         }
 312
 313       ++p;
 314     }
 315
 316   return NULL;
 317 }
 318
 319 // Read SIZE bytes from the file starting at offset START.  Read into
 320 // the buffer at P.
 321
 322 void
 323 File_read::do_read(off_t start, section_size_type size, void* p)
 324 {
 325   ssize_t bytes;
 326   if (this->whole_file_view_ != NULL)
 327     {
 328       bytes = this->size_ - start;
 329       if (static_cast<section_size_type>(bytes) >= size)
 330         {
 331           memcpy(p, this->whole_file_view_->data() + start, size);
 332           return;
 333         }
 334     }
 335   else
 336     {
 337       this->reopen_descriptor();
 338       bytes = ::pread(this->descriptor_, p, size, start);
 339       if (static_cast<section_size_type>(bytes) == size)
 340         return;
 341
 342       if (bytes < 0)
 343         {
 344           gold_fatal(_("%s: pread failed: %s"),
 345                      this->filename().c_str(), strerror(errno));
 346           return;
 347         }
 348     }
 349
 350   gold_fatal(_("%s: file too short: read only %lld of %lld bytes at %lld"),
 351              this->filename().c_str(),
 352              static_cast<long long>(bytes),
 353              static_cast<long long>(size),
 354              static_cast<long long>(start));
 355 }
 356
 357 // Read data from the file.
 358
 359 void
 360 File_read::read(off_t start, section_size_type size, void* p)
 361 {
 362   const File_read::View* pv = this->find_view(start, size, -1U, NULL);
 363   if (pv != NULL)
 364     {
 365       memcpy(p, pv->data() + (start - pv->start() + pv->byteshift()), size);
 366       return;
 367     }
 368
 369   this->do_read(start, size, p);
 370 }
 371
 372 // Add a new view.  There may already be an existing view at this
 373 // offset.  If there is, the new view will be larger, and should
 374 // replace the old view.
 375
 376 void
 377 File_read::add_view(File_read::View* v)
 378 {
 379   std::pair<Views::iterator, bool> ins =
 380     this->views_.insert(std::make_pair(std::make_pair(v->start(),
 381                                                       v->byteshift()),
 382                                        v));
 383   if (ins.second)
 384     return;
 385
 386   // There was an existing view at this offset.  It must not be large
 387   // enough.  We can't delete it here, since something might be using
 388   // it; we put it on a list to be deleted when the file is unlocked.
 389   File_read::View* vold = ins.first->second;
 390   gold_assert(vold->size() < v->size());
 391   if (vold->should_cache())
 392     {
 393       v->set_cache();
 394       vold->clear_cache();
 395     }
 396   this->saved_views_.push_back(vold);
 397
 398   ins.first->second = v;
 399 }
 400
 401 // Make a new view with a specified byteshift, reading the data from
 402 // the file.
 403
 404 File_read::View*
 405 File_read::make_view(off_t start, section_size_type size,
 406                      unsigned int byteshift, bool cache)
 407 {
 408   gold_assert(size > 0);
 409
 410   // Check that start and end of the view are within the file.
 411   if (start > this->size_
 412       || (static_cast<unsigned long long>(size)
 413           > static_cast<unsigned long long>(this->size_ - start)))
 414     gold_fatal(_("%s: attempt to map %lld bytes at offset %lld exceeds "
 415                  "size of file; the file may be corrupt"),
 416                    this->filename().c_str(),
 417                    static_cast<long long>(size),
 418                    static_cast<long long>(start));
 419
 420   off_t poff = File_read::page_offset(start);
 421
 422   section_size_type psize = File_read::pages(size + (start - poff));
 423
 424   if (poff + static_cast<off_t>(psize) >= this->size_)
 425     {
 426       psize = this->size_ - poff;
 427       gold_assert(psize >= size);
 428     }
 429
 430   File_read::View* v;
 431   if (this->whole_file_view_ != NULL || byteshift != 0)
 432     {
 433       unsigned char* p = new unsigned char[psize + byteshift];
 434       memset(p, 0, byteshift);
 435       this->do_read(poff, psize, p + byteshift);
 436       v = new File_read::View(poff, psize, p, byteshift, cache,
 437                               View::DATA_ALLOCATED_ARRAY);
 438     }
 439   else
 440     {
 441       this->reopen_descriptor();
 442       void* p = ::mmap(NULL, psize, PROT_READ, MAP_PRIVATE,
 443                        this->descriptor_, poff);
 444       if (p == MAP_FAILED)
 445         gold_fatal(_("%s: mmap offset %lld size %lld failed: %s"),
 446                    this->filename().c_str(),
 447                    static_cast<long long>(poff),
 448                    static_cast<long long>(psize),
 449                    strerror(errno));
 450
 451       this->mapped_bytes_ += psize;
 452
 453       const unsigned char* pbytes = static_cast<const unsigned char*>(p);
 454       v = new File_read::View(poff, psize, pbytes, 0, cache,
 455                               View::DATA_MMAPPED);
 456     }
 457
 458   this->add_view(v);
 459
 460   return v;
 461 }
 462
 463 // Find a View or make a new one, shifted as required by the file
 464 // offset OFFSET and ALIGNED.
 465
 466 File_read::View*
 467 File_read::find_or_make_view(off_t offset, off_t start,
 468                              section_size_type size, bool aligned, bool cache)
 469 {
 470   unsigned int byteshift;
 471   if (offset == 0)
 472     byteshift = 0;
 473   else
 474     {
 475       unsigned int target_size = (!parameters->target_valid()
 476                                   ? 64
 477                                   : parameters->target().get_size());
 478       byteshift = offset & ((target_size / 8) - 1);
 479
 480       // Set BYTESHIFT to the number of dummy bytes which must be
 481       // inserted before the data in order for this data to be
 482       // aligned.
 483       if (byteshift != 0)
 484         byteshift = (target_size / 8) - byteshift;
 485     }
 486
 487   // Try to find a View with the required BYTESHIFT.
 488   File_read::View* vshifted;
 489   File_read::View* v = this->find_view(offset + start, size,
 490                                        aligned ? byteshift : -1U,
 491                                        &vshifted);
 492   if (v != NULL)
 493     {
 494       if (cache)
 495         v->set_cache();
 496       return v;
 497     }
 498
 499   // If VSHIFTED is not NULL, then it has the data we need, but with
 500   // the wrong byteshift.
 501   v = vshifted;
 502   if (v != NULL)
 503     {
 504       gold_assert(aligned);
 505
 506       unsigned char* pbytes = new unsigned char[v->size() + byteshift];
 507       memset(pbytes, 0, byteshift);
 508       memcpy(pbytes + byteshift, v->data() + v->byteshift(), v->size());
 509
 510       File_read::View* shifted_view =
 511           new File_read::View(v->start(), v->size(), pbytes, byteshift,
 512                               cache, View::DATA_ALLOCATED_ARRAY);
 513
 514       this->add_view(shifted_view);
 515       return shifted_view;
 516     }
 517
 518   // Make a new view.  If we don't need an aligned view, use a
 519   // byteshift of 0, so that we can use mmap.
 520   return this->make_view(offset + start, size,
 521                          aligned ? byteshift : 0,
 522                          cache);
 523 }
 524
 525 // Get a view into the file.
 526
 527 const unsigned char*
 528 File_read::get_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   return pv->data() + (offset + start - pv->start() + pv->byteshift());
 534 }
 535
 536 File_view*
 537 File_read::get_lasting_view(off_t offset, off_t start, section_size_type size,
 538                             bool aligned, bool cache)
 539 {
 540   File_read::View* pv = this->find_or_make_view(offset, start, size,
 541                                                 aligned, cache);
 542   pv->lock();
 543   return new File_view(*this, pv,
 544                        (pv->data()
 545                         + (offset + start - pv->start() + pv->byteshift())));
 546 }
 547
 548 // Use readv to read COUNT entries from RM starting at START.  BASE
 549 // must be added to all file offsets in RM.
 550
 551 void
 552 File_read::do_readv(off_t base, const Read_multiple& rm, size_t start,
 553                     size_t count)
 554 {
 555   unsigned char discard[File_read::page_size];
 556   iovec iov[File_read::max_readv_entries * 2];
 557   size_t iov_index = 0;
 558
 559   off_t first_offset = rm[start].file_offset;
 560   off_t last_offset = first_offset;
 561   ssize_t want = 0;
 562   for (size_t i = 0; i < count; ++i)
 563     {
 564       const Read_multiple_entry& i_entry(rm[start + i]);
 565
 566       if (i_entry.file_offset > last_offset)
 567         {
 568           size_t skip = i_entry.file_offset - last_offset;
 569           gold_assert(skip <= sizeof discard);
 570
 571           iov[iov_index].iov_base = discard;
 572           iov[iov_index].iov_len = skip;
 573           ++iov_index;
 574
 575           want += skip;
 576         }
 577
 578       iov[iov_index].iov_base = i_entry.buffer;
 579       iov[iov_index].iov_len = i_entry.size;
 580       ++iov_index;
 581
 582       want += i_entry.size;
 583
 584       last_offset = i_entry.file_offset + i_entry.size;
 585     }
 586
 587   this->reopen_descriptor();
 588
 589   gold_assert(iov_index < sizeof iov / sizeof iov[0]);
 590
 591   if (::lseek(this->descriptor_, base + first_offset, SEEK_SET) < 0)
 592     gold_fatal(_("%s: lseek failed: %s"),
 593                this->filename().c_str(), strerror(errno));
 594
 595   ssize_t got = ::readv(this->descriptor_, iov, iov_index);
 596
 597   if (got < 0)
 598     gold_fatal(_("%s: readv failed: %s"),
 599                this->filename().c_str(), strerror(errno));
 600   if (got != want)
 601     gold_fatal(_("%s: file too short: read only %zd of %zd bytes at %lld"),
 602                this->filename().c_str(),
 603                got, want, static_cast<long long>(base + first_offset));
 604 }
 605
 606 // Read several pieces of data from the file.
 607
 608 void
 609 File_read::read_multiple(off_t base, const Read_multiple& rm)
 610 {
 611   size_t count = rm.size();
 612   size_t i = 0;
 613   while (i < count)
 614     {
 615       // Find up to MAX_READV_ENTRIES consecutive entries which are
 616       // less than one page apart.
 617       const Read_multiple_entry& i_entry(rm[i]);
 618       off_t i_off = i_entry.file_offset;
 619       off_t end_off = i_off + i_entry.size;
 620       size_t j;
 621       for (j = i + 1; j < count; ++j)
 622         {
 623           if (j - i >= File_read::max_readv_entries)
 624             break;
 625           const Read_multiple_entry& j_entry(rm[j]);
 626           off_t j_off = j_entry.file_offset;
 627           gold_assert(j_off >= end_off);
 628           off_t j_end_off = j_off + j_entry.size;
 629           if (j_end_off - end_off >= File_read::page_size)
 630             break;
 631           end_off = j_end_off;
 632         }
 633
 634       if (j == i + 1)
 635         this->read(base + i_off, i_entry.size, i_entry.buffer);
 636       else
 637         {
 638           File_read::View* view = this->find_view(base + i_off,
 639                                                   end_off - i_off,
 640                                                   -1U, NULL);
 641           if (view == NULL)
 642             this->do_readv(base, rm, i, j - i);
 643           else
 644             {
 645               const unsigned char* v = (view->data()
 646                                         + (base + i_off - view->start()
 647                                            + view->byteshift()));
 648               for (size_t k = i; k < j; ++k)
 649                 {
 650                   const Read_multiple_entry& k_entry(rm[k]);
 651                   gold_assert((convert_to_section_size_type(k_entry.file_offset
 652                                                            - i_off)
 653                                + k_entry.size)
 654                               <= convert_to_section_size_type(end_off
 655                                                               - i_off));
 656                   memcpy(k_entry.buffer,
 657                          v + (k_entry.file_offset - i_off),
 658                          k_entry.size);
 659                 }
 660             }
 661         }
 662
 663       i = j;
 664     }
 665 }
 666
 667 // Mark all views as no longer cached.
 668
 669 void
 670 File_read::clear_view_cache_marks()
 671 {
 672   // Just ignore this if there are multiple objects associated with
 673   // the file.  Otherwise we will wind up uncaching and freeing some
 674   // views for other objects.
 675   if (this->object_count_ > 1)
 676     return;
 677
 678   for (Views::iterator p = this->views_.begin();
 679        p != this->views_.end();
 680        ++p)
 681     p->second->clear_cache();
 682   for (Saved_views::iterator p = this->saved_views_.begin();
 683        p != this->saved_views_.end();
 684        ++p)
 685     (*p)->clear_cache();
 686 }
 687
 688 // Remove all the file views.  For a file which has multiple
 689 // associated objects (i.e., an archive), we keep accessed views
 690 // around until next time, in the hopes that they will be useful for
 691 // the next object.
 692
 693 void
 694 File_read::clear_views(bool destroying)
 695 {
 696   Views::iterator p = this->views_.begin();
 697   while (p != this->views_.end())
 698     {
 699       bool should_delete;
 700       if (p->second->is_locked())
 701         should_delete = false;
 702       else if (destroying)
 703         should_delete = true;
 704       else if (p->second->should_cache())
 705         should_delete = false;
 706       else if (this->object_count_ > 1 && p->second->accessed())
 707         should_delete = false;
 708       else
 709         should_delete = true;
 710
 711       if (should_delete)
 712         {
 713           delete p->second;
 714
 715           // map::erase invalidates only the iterator to the deleted
 716           // element.
 717           Views::iterator pe = p;
 718           ++p;
 719           this->views_.erase(pe);
 720         }
 721       else
 722         {
 723           gold_assert(!destroying);
 724           p->second->clear_accessed();
 725           ++p;
 726         }
 727     }
 728
 729   Saved_views::iterator q = this->saved_views_.begin();
 730   while (q != this->saved_views_.end())
 731     {
 732       if (!(*q)->is_locked())
 733         {
 734           delete *q;
 735           q = this->saved_views_.erase(q);
 736         }
 737       else
 738         {
 739           gold_assert(!destroying);
 740           ++q;
 741         }
 742     }
 743 }
 744
 745 // Print statistical information to stderr.  This is used for --stats.
 746
 747 void
 748 File_read::print_stats()
 749 {
 750   fprintf(stderr, _("%s: total bytes mapped for read: %llu\n"),
 751           program_name, File_read::total_mapped_bytes);
 752   fprintf(stderr, _("%s: maximum bytes mapped for read at one time: %llu\n"),
 753           program_name, File_read::maximum_mapped_bytes);
 754 }
 755
 756 // Class File_view.
 757
 758 File_view::~File_view()
 759 {
 760   gold_assert(this->file_.is_locked());
 761   this->view_->unlock();
 762 }
 763
 764 // Class Input_file.
 765
 766 // Create a file for testing.
 767
 768 Input_file::Input_file(const Task* task, const char* name,
 769                        const unsigned char* contents, off_t size)
 770   : file_()
 771 {
 772   this->input_argument_ =
 773     new Input_file_argument(name, Input_file_argument::INPUT_FILE_TYPE_FILE,
 774                             "", false, Position_dependent_options());
 775   bool ok = this->file_.open(task, name, contents, size);
 776   gold_assert(ok);
 777 }
 778
 779 // Return the position dependent options in force for this file.
 780
 781 const Position_dependent_options&
 782 Input_file::options() const
 783 {
 784   return this->input_argument_->options();
 785 }
 786
 787 // Return the name given by the user.  For -lc this will return "c".
 788
 789 const char*
 790 Input_file::name() const
 791 {
 792   return this->input_argument_->name();
 793 }
 794
 795 // Return whether this file is in a system directory.
 796
 797 bool
 798 Input_file::is_in_system_directory() const
 799 {
 800   if (this->is_in_sysroot())
 801     return true;
 802   return parameters->options().is_in_system_directory(this->filename());
 803 }
 804
 805 // Return whether we are only reading symbols.
 806
 807 bool
 808 Input_file::just_symbols() const
 809 {
 810   return this->input_argument_->just_symbols();
 811 }
 812
 813 // Return whether this is a file that we will search for in the list
 814 // of directories.
 815
 816 bool
 817 Input_file::will_search_for() const
 818 {
 819   return (!IS_ABSOLUTE_PATH(this->input_argument_->name())
 820           && (this->input_argument_->is_lib()
 821               || this->input_argument_->is_searched_file()
 822               || this->input_argument_->extra_search_path() != NULL));
 823 }
 824
 825 // Return the file last modification time.  Calls gold_fatal if the stat
 826 // system call failed.
 827
 828 Timespec
 829 File_read::get_mtime()
 830 {
 831   struct stat file_stat;
 832   this->reopen_descriptor();
 833
 834   if (fstat(this->descriptor_, &file_stat) < 0)
 835     gold_fatal(_("%s: stat failed: %s"), this->name_.c_str(),
 836                strerror(errno));
 837 #ifdef HAVE_STAT_ST_MTIM
 838   return Timespec(file_stat.st_mtim.tv_sec, file_stat.st_mtim.tv_nsec);
 839 #else
 840   return Timespec(file_stat.st_mtime, 0);
 841 #endif
 842 }
 843
 844 // Open the file.
 845
 846 // If the filename is not absolute, we assume it is in the current
 847 // directory *except* when:
 848 //    A) input_argument_->is_lib() is true;
 849 //    B) input_argument_->is_searched_file() is true; or
 850 //    C) input_argument_->extra_search_path() is not empty.
 851 // In each, we look in extra_search_path + library_path to find
 852 // the file location, rather than the current directory.
 853
 854 bool
 855 Input_file::open(const Dirsearch& dirpath, const Task* task, int *pindex)
 856 {
 857   std::string name;
 858
 859   // Case 1: name is an absolute file, just try to open it
 860   // Case 2: name is relative but is_lib is false, is_searched_file is false,
 861   //         and extra_search_path is empty
 862   if (IS_ABSOLUTE_PATH(this->input_argument_->name())
 863       || (!this->input_argument_->is_lib()
 864           && !this->input_argument_->is_searched_file()
 865           && this->input_argument_->extra_search_path() == NULL))
 866     {
 867       name = this->input_argument_->name();
 868       this->found_name_ = name;
 869     }
 870   // Case 3: is_lib is true or is_searched_file is true
 871   else if (this->input_argument_->is_lib()
 872            || this->input_argument_->is_searched_file())
 873     {
 874       // We don't yet support extra_search_path with -l.
 875       gold_assert(this->input_argument_->extra_search_path() == NULL);
 876       std::string n1, n2;
 877       if (this->input_argument_->is_lib())
 878         {
 879           n1 = "lib";
 880           n1 += this->input_argument_->name();
 881           if (parameters->options().is_static()
 882               || !this->input_argument_->options().Bdynamic())
 883             n1 += ".a";
 884           else
 885             {
 886               n2 = n1 + ".a";
 887               n1 += ".so";
 888             }
 889         }
 890       else
 891         n1 = this->input_argument_->name();
 892       name = dirpath.find(n1, n2, &this->is_in_sysroot_, pindex);
 893       if (name.empty())
 894         {
 895           gold_error(_("cannot find %s%s"),
 896                      this->input_argument_->is_lib() ? "-l" : "",
 897                      this->input_argument_->name());
 898           return false;
 899         }
 900       if (n2.empty() || name[name.length() - 1] == 'o')
 901         this->found_name_ = n1;
 902       else
 903         this->found_name_ = n2;
 904     }
 905   // Case 4: extra_search_path is not empty
 906   else
 907     {
 908       gold_assert(this->input_argument_->extra_search_path() != NULL);
 909
 910       // First, check extra_search_path.
 911       name = this->input_argument_->extra_search_path();
 912       if (!IS_DIR_SEPARATOR (name[name.length() - 1]))
 913         name += '/';
 914       name += this->input_argument_->name();
 915       struct stat dummy_stat;
 916       if (*pindex > 0 || ::stat(name.c_str(), &dummy_stat) < 0)
 917         {
 918           // extra_search_path failed, so check the normal search-path.
 919           int index = *pindex;
 920           if (index > 0)
 921             --index;
 922           name = dirpath.find(this->input_argument_->name(), "",
 923                               &this->is_in_sysroot_, &index);
 924           if (name.empty())
 925             {
 926               gold_error(_("cannot find %s"),
 927                          this->input_argument_->name());
 928               return false;
 929             }
 930           *pindex = index + 1;
 931         }
 932       this->found_name_ = this->input_argument_->name();
 933     }
 934
 935   // Now that we've figured out where the file lives, try to open it.
 936
 937   General_options::Object_format format =
 938     this->input_argument_->options().format_enum();
 939   bool ok;
 940   if (format == General_options::OBJECT_FORMAT_ELF)
 941     {
 942       ok = this->file_.open(task, name);
 943       this->format_ = FORMAT_ELF;
 944     }
 945   else
 946     {
 947       gold_assert(format == General_options::OBJECT_FORMAT_BINARY);
 948       ok = this->open_binary(task, name);
 949       this->format_ = FORMAT_BINARY;
 950     }
 951
 952   if (!ok)
 953     {
 954       gold_error(_("cannot open %s: %s"),
 955                  name.c_str(), strerror(errno));
 956       this->format_ = FORMAT_NONE;
 957       return false;
 958     }
 959
 960   return true;
 961 }
 962
 963 // Open a file for --format binary.
 964
 965 bool
 966 Input_file::open_binary(const Task* task, const std::string& name)
 967 {
 968   // In order to open a binary file, we need machine code, size, and
 969   // endianness.  We may not have a valid target at this point, in
 970   // which case we use the default target.
 971   parameters_force_valid_target();
 972   const Target& target(parameters->target());
 973
 974   Binary_to_elf binary_to_elf(target.machine_code(),
 975                               target.get_size(),
 976                               target.is_big_endian(),
 977                               name);
 978   if (!binary_to_elf.convert(task))
 979     return false;
 980   return this->file_.open(task, name, binary_to_elf.converted_data_leak(),
 981                           binary_to_elf.converted_size());
 982 }
 983
 984 } // End namespace gold.