gold/fileread.cc

   1 // fileread.cc -- read files for gold
   2
   3 // Copyright (C) 2006-2024 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <cstring>
  26 #include <cerrno>
  27 #include <climits>
  28 #include <fcntl.h>
  29 #include <unistd.h>
  30
  31 #ifdef HAVE_SYS_MMAN_H
  32 #include <sys/mman.h>
  33 #endif
  34
  35 #ifdef HAVE_READV
  36 #include <sys/uio.h>
  37 #endif
  38
  39 #include <sys/stat.h>
  40 #include "filenames.h"
  41
  42 #include "debug.h"
  43 #include "parameters.h"
  44 #include "options.h"
  45 #include "dirsearch.h"
  46 #include "target.h"
  47 #include "binary.h"
  48 #include "descriptors.h"
  49 #include "gold-threads.h"
  50 #include "fileread.h"
  51
  52 // For systems without mmap support.
  53 #ifndef HAVE_MMAP
  54 # define mmap gold_mmap
  55 # define munmap gold_munmap
  56 # ifndef MAP_FAILED
  57 #  define MAP_FAILED (reinterpret_cast<void*>(-1))
  58 # endif
  59 # ifndef PROT_READ
  60 #  define PROT_READ 0
  61 # endif
  62 # ifndef MAP_PRIVATE
  63 #  define MAP_PRIVATE 0
  64 # endif
  65
  66 # ifndef ENOSYS
  67 #  define ENOSYS EINVAL
  68 # endif
  69
  70 static void *
  71 gold_mmap(void *, size_t, int, int, int, off_t)
  72 {
  73   errno = ENOSYS;
  74   return MAP_FAILED;
  75 }
  76
  77 static int
  78 gold_munmap(void *, size_t)
  79 {
  80   errno = ENOSYS;
  81   return -1;
  82 }
  83
  84 #endif
  85
  86 #ifndef HAVE_READV
  87 struct iovec { void* iov_base; size_t iov_len; };
  88 ssize_t
  89 readv(int, const iovec*, int)
  90 {
  91   gold_unreachable();
  92 }
  93 #endif
  94
  95 namespace gold
  96 {
  97
  98 // Get the last modified time of an unopened file.
  99
 100 bool
 101 get_mtime(const char* filename, Timespec* mtime)
 102 {
 103   struct stat file_stat;
 104
 105   if (stat(filename, &file_stat) < 0)
 106     return false;
 107 #ifdef HAVE_STAT_ST_MTIM
 108   mtime->seconds = file_stat.st_mtim.tv_sec;
 109   mtime->nanoseconds = file_stat.st_mtim.tv_nsec;
 110 #else
 111   mtime->seconds = file_stat.st_mtime;
 112   mtime->nanoseconds = 0;
 113 #endif
 114   return true;
 115 }
 116
 117 // Class File_read.
 118
 119 // A lock for the File_read static variables.
 120 static Lock* file_counts_lock = NULL;
 121 static Initialize_lock file_counts_initialize_lock(&file_counts_lock);
 122
 123 // The File_read static variables.
 124 unsigned long long File_read::total_mapped_bytes;
 125 unsigned long long File_read::current_mapped_bytes;
 126 unsigned long long File_read::maximum_mapped_bytes;
 127 std::vector<std::string> File_read::files_read;
 128
 129 // Class File_read::View.
 130
 131 File_read::View::~View()
 132 {
 133   gold_assert(!this->is_locked());
 134   switch (this->data_ownership_)
 135     {
 136     case DATA_ALLOCATED_ARRAY:
 137       free(const_cast<unsigned char*>(this->data_));
 138       break;
 139     case DATA_MMAPPED:
 140       if (::munmap(const_cast<unsigned char*>(this->data_), this->size_) != 0)
 141         gold_warning(_("munmap failed: %s"), strerror(errno));
 142       if (!parameters->options_valid() || parameters->options().stats())
 143         {
 144           file_counts_initialize_lock.initialize();
 145           Hold_optional_lock hl(file_counts_lock);
 146           File_read::current_mapped_bytes -= this->size_;
 147         }
 148       break;
 149     case DATA_NOT_OWNED:
 150       break;
 151     default:
 152       gold_unreachable();
 153     }
 154 }
 155
 156 void
 157 File_read::View::lock()
 158 {
 159   ++this->lock_count_;
 160 }
 161
 162 void
 163 File_read::View::unlock()
 164 {
 165   gold_assert(this->lock_count_ > 0);
 166   --this->lock_count_;
 167 }
 168
 169 bool
 170 File_read::View::is_locked()
 171 {
 172   return this->lock_count_ > 0;
 173 }
 174
 175 // Class File_read.
 176
 177 File_read::~File_read()
 178 {
 179   gold_assert(this->token_.is_writable());
 180   if (this->is_descriptor_opened_)
 181     {
 182       release_descriptor(this->descriptor_, true);
 183       this->descriptor_ = -1;
 184       this->is_descriptor_opened_ = false;
 185     }
 186   this->name_.clear();
 187   this->clear_views(CLEAR_VIEWS_ALL);
 188 }
 189
 190 // Open the file.
 191
 192 bool
 193 File_read::open(const Task* task, const std::string& name)
 194 {
 195   gold_assert(this->token_.is_writable()
 196               && this->descriptor_ < 0
 197               && !this->is_descriptor_opened_
 198               && this->name_.empty());
 199   this->name_ = name;
 200
 201   this->descriptor_ = open_descriptor(-1, this->name_.c_str(),
 202                                       O_RDONLY);
 203
 204   if (this->descriptor_ >= 0)
 205     {
 206       this->is_descriptor_opened_ = true;
 207       struct stat s;
 208       if (::fstat(this->descriptor_, &s) < 0)
 209         gold_error(_("%s: fstat failed: %s"),
 210                    this->name_.c_str(), strerror(errno));
 211       this->size_ = s.st_size;
 212       gold_debug(DEBUG_FILES, "Attempt to open %s succeeded",
 213                  this->name_.c_str());
 214       this->token_.add_writer(task);
 215       file_counts_initialize_lock.initialize();
 216       Hold_optional_lock hl(file_counts_lock);
 217       record_file_read(this->name_);
 218     }
 219
 220   return this->descriptor_ >= 0;
 221 }
 222
 223 // Open the file with the contents in memory.
 224
 225 bool
 226 File_read::open(const Task* task, const std::string& name,
 227                 const unsigned char* contents, off_t size)
 228 {
 229   gold_assert(this->token_.is_writable()
 230               && this->descriptor_ < 0
 231               && !this->is_descriptor_opened_
 232               && this->name_.empty());
 233   this->name_ = name;
 234   this->whole_file_view_ = new View(0, size, contents, 0, false,
 235                                     View::DATA_NOT_OWNED);
 236   this->add_view(this->whole_file_view_);
 237   this->size_ = size;
 238   this->token_.add_writer(task);
 239   return true;
 240 }
 241
 242 // Reopen a descriptor if necessary.
 243
 244 void
 245 File_read::reopen_descriptor()
 246 {
 247   if (!this->is_descriptor_opened_)
 248     {
 249       this->descriptor_ = open_descriptor(this->descriptor_,
 250                                           this->name_.c_str(),
 251                                           O_RDONLY);
 252       if (this->descriptor_ < 0)
 253         gold_fatal(_("could not reopen file %s"), this->name_.c_str());
 254       this->is_descriptor_opened_ = true;
 255     }
 256 }
 257
 258 // Release the file.  This is called when we are done with the file in
 259 // a Task.
 260
 261 void
 262 File_read::release()
 263 {
 264   gold_assert(this->is_locked());
 265
 266   if (!parameters->options_valid() || parameters->options().stats())
 267     {
 268       file_counts_initialize_lock.initialize();
 269       Hold_optional_lock hl(file_counts_lock);
 270       File_read::total_mapped_bytes += this->mapped_bytes_;
 271       File_read::current_mapped_bytes += this->mapped_bytes_;
 272       if (File_read::current_mapped_bytes > File_read::maximum_mapped_bytes)
 273         File_read::maximum_mapped_bytes = File_read::current_mapped_bytes;
 274     }
 275
 276   this->mapped_bytes_ = 0;
 277
 278   // Only clear views if there is only one attached object.  Otherwise
 279   // we waste time trying to clear cached archive views.  Similarly
 280   // for releasing the descriptor.
 281   if (this->object_count_ <= 1)
 282     {
 283       this->clear_views(CLEAR_VIEWS_NORMAL);
 284       if (this->is_descriptor_opened_)
 285         {
 286           release_descriptor(this->descriptor_, false);
 287           this->is_descriptor_opened_ = false;
 288         }
 289     }
 290
 291   this->released_ = true;
 292 }
 293
 294 // Lock the file.
 295
 296 void
 297 File_read::lock(const Task* task)
 298 {
 299   gold_assert(this->released_);
 300   gold_debug(DEBUG_FILES, "Locking file \"%s\"", this->name_.c_str());
 301   this->token_.add_writer(task);
 302   this->released_ = false;
 303 }
 304
 305 // Unlock the file.
 306
 307 void
 308 File_read::unlock(const Task* task)
 309 {
 310   gold_debug(DEBUG_FILES, "Unlocking file \"%s\"", this->name_.c_str());
 311   this->release();
 312   this->token_.remove_writer(task);
 313 }
 314
 315 // Return whether the file is locked.
 316
 317 bool
 318 File_read::is_locked() const
 319 {
 320   if (!this->token_.is_writable())
 321     return true;
 322   // The file is not locked, so it should have been released.
 323   gold_assert(this->released_);
 324   return false;
 325 }
 326
 327 // See if we have a view which covers the file starting at START for
 328 // SIZE bytes.  Return a pointer to the View if found, NULL if not.
 329 // If BYTESHIFT is not -1U, the returned View must have the specified
 330 // byte shift; otherwise, it may have any byte shift.  If VSHIFTED is
 331 // not NULL, this sets *VSHIFTED to a view which would have worked if
 332 // not for the requested BYTESHIFT.
 333
 334 inline File_read::View*
 335 File_read::find_view(off_t start, section_size_type size,
 336                      unsigned int byteshift, File_read::View** vshifted) const
 337 {
 338   gold_assert(start <= this->size_
 339               && (static_cast<unsigned long long>(size)
 340                   <= static_cast<unsigned long long>(this->size_ - start)));
 341
 342   if (vshifted != NULL)
 343     *vshifted = NULL;
 344
 345   // If we have the whole file mmapped, and the alignment is right,
 346   // we can return it.
 347   if (this->whole_file_view_)
 348     if (byteshift == -1U || byteshift == 0)
 349       return this->whole_file_view_;
 350
 351   off_t page = File_read::page_offset(start);
 352
 353   unsigned int bszero = 0;
 354   Views::const_iterator p = this->views_.upper_bound(std::make_pair(page - 1,
 355                                                                     bszero));
 356
 357   while (p != this->views_.end() && p->first.first <= page)
 358     {
 359       if (p->second->start() <= start
 360           && (p->second->start() + static_cast<off_t>(p->second->size())
 361               >= start + static_cast<off_t>(size)))
 362         {
 363           if (byteshift == -1U || byteshift == p->second->byteshift())
 364             {
 365               p->second->set_accessed();
 366               return p->second;
 367             }
 368
 369           if (vshifted != NULL && *vshifted == NULL)
 370             *vshifted = p->second;
 371         }
 372
 373       ++p;
 374     }
 375
 376   return NULL;
 377 }
 378
 379 // Read SIZE bytes from the file starting at offset START.  Read into
 380 // the buffer at P.
 381
 382 void
 383 File_read::do_read(off_t start, section_size_type size, void* p)
 384 {
 385   ssize_t bytes;
 386   if (this->whole_file_view_ != NULL)
 387     {
 388       // See PR 23765 for an example of a testcase that triggers this error.
 389       if (((ssize_t) start) < 0)
 390         gold_fatal(_("%s: read failed, starting offset (%#llx) less than zero"),
 391                    this->filename().c_str(),
 392                    static_cast<long long>(start));
 393
 394       bytes = this->size_ - start;
 395       if (static_cast<section_size_type>(bytes) >= size)
 396         {
 397           memcpy(p, this->whole_file_view_->data() + start, size);
 398           return;
 399         }
 400     }
 401   else
 402     {
 403       this->reopen_descriptor();
 404
 405       char *read_ptr = static_cast<char *>(p);
 406       off_t read_pos = start;
 407       size_t to_read = size;
 408       do
 409         {
 410           bytes = ::pread(this->descriptor_, read_ptr, to_read, read_pos);
 411           if (bytes < 0)
 412             gold_fatal(_("%s: pread failed: %s"),
 413                        this->filename().c_str(), strerror(errno));
 414
 415           read_pos += bytes;
 416           read_ptr += bytes;
 417           to_read -= bytes;
 418           if (to_read == 0)
 419             return;
 420         }
 421       while (bytes > 0);
 422
 423       bytes = size - to_read;
 424     }
 425
 426   gold_fatal(_("%s: file too short: read only %lld of %lld bytes at %lld"),
 427              this->filename().c_str(),
 428              static_cast<long long>(bytes),
 429              static_cast<long long>(size),
 430              static_cast<long long>(start));
 431 }
 432
 433 // Read data from the file.
 434
 435 void
 436 File_read::read(off_t start, section_size_type size, void* p)
 437 {
 438   const File_read::View* pv = this->find_view(start, size, -1U, NULL);
 439   if (pv != NULL)
 440     {
 441       memcpy(p, pv->data() + (start - pv->start() + pv->byteshift()), size);
 442       return;
 443     }
 444
 445   this->do_read(start, size, p);
 446 }
 447
 448 // Add a new view.  There may already be an existing view at this
 449 // offset.  If there is, the new view will be larger, and should
 450 // replace the old view.
 451
 452 void
 453 File_read::add_view(File_read::View* v)
 454 {
 455   std::pair<Views::iterator, bool> ins =
 456     this->views_.insert(std::make_pair(std::make_pair(v->start(),
 457                                                       v->byteshift()),
 458                                        v));
 459   if (ins.second)
 460     return;
 461
 462   // There was an existing view at this offset.  It must not be large
 463   // enough.  We can't delete it here, since something might be using
 464   // it; we put it on a list to be deleted when the file is unlocked.
 465   File_read::View* vold = ins.first->second;
 466   gold_assert(vold->size() < v->size());
 467   if (vold->should_cache())
 468     {
 469       v->set_cache();
 470       vold->clear_cache();
 471     }
 472   this->saved_views_.push_back(vold);
 473
 474   ins.first->second = v;
 475 }
 476
 477 // Make a new view with a specified byteshift, reading the data from
 478 // the file.
 479
 480 File_read::View*
 481 File_read::make_view(off_t start, section_size_type size,
 482                      unsigned int byteshift, bool cache)
 483 {
 484   gold_assert(size > 0);
 485   gold_assert(start <= this->size_
 486               && (static_cast<unsigned long long>(size)
 487                   <= static_cast<unsigned long long>(this->size_ - start)));
 488
 489   off_t poff = File_read::page_offset(start);
 490
 491   section_size_type psize = File_read::pages(size + (start - poff));
 492
 493   if (poff + static_cast<off_t>(psize) >= this->size_)
 494     {
 495       psize = this->size_ - poff;
 496       gold_assert(psize >= size);
 497     }
 498
 499   void* p;
 500   View::Data_ownership ownership;
 501   if (byteshift != 0)
 502     {
 503       p = malloc(psize + byteshift);
 504       if (p == NULL)
 505         gold_nomem();
 506       memset(p, 0, byteshift);
 507       this->do_read(poff, psize, static_cast<unsigned char*>(p) + byteshift);
 508       ownership = View::DATA_ALLOCATED_ARRAY;
 509     }
 510   else
 511     {
 512       this->reopen_descriptor();
 513       p = ::mmap(NULL, psize, PROT_READ, MAP_PRIVATE, this->descriptor_, poff);
 514       if (p != MAP_FAILED)
 515         {
 516           ownership = View::DATA_MMAPPED;
 517           this->mapped_bytes_ += psize;
 518         }
 519       else
 520         {
 521           p = malloc(psize);
 522           if (p == NULL)
 523             gold_nomem();
 524           this->do_read(poff, psize, p);
 525           ownership = View::DATA_ALLOCATED_ARRAY;
 526         }
 527     }
 528
 529   const unsigned char* pbytes = static_cast<const unsigned char*>(p);
 530   File_read::View* v = new File_read::View(poff, psize, pbytes, byteshift,
 531                                            cache, ownership);
 532
 533   this->add_view(v);
 534
 535   return v;
 536 }
 537
 538 // Find a View or make a new one, shifted as required by the file
 539 // offset OFFSET and ALIGNED.
 540
 541 File_read::View*
 542 File_read::find_or_make_view(off_t offset, off_t start,
 543                              section_size_type size, bool aligned, bool cache)
 544 {
 545   // Check that start and end of the view are within the file.
 546   if (start > this->size_
 547       || (static_cast<unsigned long long>(size)
 548           > static_cast<unsigned long long>(this->size_ - start)))
 549     gold_fatal(_("%s: attempt to map %lld bytes at offset %lld exceeds "
 550                  "size of file; the file may be corrupt"),
 551                    this->filename().c_str(),
 552                    static_cast<long long>(size),
 553                    static_cast<long long>(start));
 554
 555   unsigned int byteshift;
 556   if (offset == 0)
 557     byteshift = 0;
 558   else
 559     {
 560       unsigned int target_size = (!parameters->target_valid()
 561                                   ? 64
 562                                   : parameters->target().get_size());
 563       byteshift = offset & ((target_size / 8) - 1);
 564
 565       // Set BYTESHIFT to the number of dummy bytes which must be
 566       // inserted before the data in order for this data to be
 567       // aligned.
 568       if (byteshift != 0)
 569         byteshift = (target_size / 8) - byteshift;
 570     }
 571
 572   // If --map-whole-files is set, make sure we have a
 573   // whole file view.  Options may not yet be ready, e.g.,
 574   // when reading a version script.  We then default to
 575   // --no-map-whole-files.
 576   if (this->whole_file_view_ == NULL
 577       && parameters->options_valid()
 578       && parameters->options().map_whole_files())
 579     this->whole_file_view_ = this->make_view(0, this->size_, 0, cache);
 580
 581   // Try to find a View with the required BYTESHIFT.
 582   File_read::View* vshifted;
 583   File_read::View* v = this->find_view(offset + start, size,
 584                                        aligned ? byteshift : -1U,
 585                                        &vshifted);
 586   if (v != NULL)
 587     {
 588       if (cache)
 589         v->set_cache();
 590       return v;
 591     }
 592
 593   // If VSHIFTED is not NULL, then it has the data we need, but with
 594   // the wrong byteshift.
 595   v = vshifted;
 596   if (v != NULL)
 597     {
 598       gold_assert(aligned);
 599
 600       unsigned char* pbytes;
 601       pbytes = static_cast<unsigned char*>(malloc(v->size() + byteshift));
 602       if (pbytes == NULL)
 603         gold_nomem();
 604       memset(pbytes, 0, byteshift);
 605       memcpy(pbytes + byteshift, v->data() + v->byteshift(), v->size());
 606
 607       File_read::View* shifted_view =
 608           new File_read::View(v->start(), v->size(), pbytes, byteshift,
 609                               cache, View::DATA_ALLOCATED_ARRAY);
 610
 611       this->add_view(shifted_view);
 612       return shifted_view;
 613     }
 614
 615   // Make a new view.  If we don't need an aligned view, use a
 616   // byteshift of 0, so that we can use mmap.
 617   return this->make_view(offset + start, size,
 618                          aligned ? byteshift : 0,
 619                          cache);
 620 }
 621
 622 // Get a view into the file.
 623
 624 const unsigned char*
 625 File_read::get_view(off_t offset, off_t start, section_size_type size,
 626                     bool aligned, bool cache)
 627 {
 628   File_read::View* pv = this->find_or_make_view(offset, start, size,
 629                                                 aligned, cache);
 630   return pv->data() + (offset + start - pv->start() + pv->byteshift());
 631 }
 632
 633 File_view*
 634 File_read::get_lasting_view(off_t offset, off_t start, section_size_type size,
 635                             bool aligned, bool cache)
 636 {
 637   File_read::View* pv = this->find_or_make_view(offset, start, size,
 638                                                 aligned, cache);
 639   pv->lock();
 640   return new File_view(*this, pv,
 641                        (pv->data()
 642                         + (offset + start - pv->start() + pv->byteshift())));
 643 }
 644
 645 // Use readv to read COUNT entries from RM starting at START.  BASE
 646 // must be added to all file offsets in RM.
 647
 648 void
 649 File_read::do_readv(off_t base, const Read_multiple& rm, size_t start,
 650                     size_t count)
 651 {
 652   unsigned char discard[File_read::page_size];
 653   iovec iov[File_read::max_readv_entries * 2];
 654   size_t iov_index = 0;
 655
 656   off_t first_offset = rm[start].file_offset;
 657   off_t last_offset = first_offset;
 658   ssize_t want = 0;
 659   for (size_t i = 0; i < count; ++i)
 660     {
 661       const Read_multiple_entry& i_entry(rm[start + i]);
 662
 663       if (i_entry.file_offset > last_offset)
 664         {
 665           size_t skip = i_entry.file_offset - last_offset;
 666           gold_assert(skip <= sizeof discard);
 667
 668           iov[iov_index].iov_base = discard;
 669           iov[iov_index].iov_len = skip;
 670           ++iov_index;
 671
 672           want += skip;
 673         }
 674
 675       iov[iov_index].iov_base = i_entry.buffer;
 676       iov[iov_index].iov_len = i_entry.size;
 677       ++iov_index;
 678
 679       want += i_entry.size;
 680
 681       last_offset = i_entry.file_offset + i_entry.size;
 682     }
 683
 684   this->reopen_descriptor();
 685
 686   gold_assert(iov_index < sizeof iov / sizeof iov[0]);
 687
 688   if (::lseek(this->descriptor_, base + first_offset, SEEK_SET) < 0)
 689     gold_fatal(_("%s: lseek failed: %s"),
 690                this->filename().c_str(), strerror(errno));
 691
 692   ssize_t got = ::readv(this->descriptor_, iov, iov_index);
 693
 694   if (got < 0)
 695     gold_fatal(_("%s: readv failed: %s"),
 696                this->filename().c_str(), strerror(errno));
 697   if (got != want)
 698     gold_fatal(_("%s: file too short: read only %zd of %zd bytes at %lld"),
 699                this->filename().c_str(),
 700                got, want, static_cast<long long>(base + first_offset));
 701 }
 702
 703 // Portable IOV_MAX.
 704
 705 #if !defined(HAVE_READV)
 706 #define GOLD_IOV_MAX 1
 707 #elif defined(IOV_MAX)
 708 #define GOLD_IOV_MAX IOV_MAX
 709 #else
 710 #define GOLD_IOV_MAX (File_read::max_readv_entries * 2)
 711 #endif
 712
 713 // Read several pieces of data from the file.
 714
 715 void
 716 File_read::read_multiple(off_t base, const Read_multiple& rm)
 717 {
 718   static size_t iov_max = GOLD_IOV_MAX;
 719   size_t count = rm.size();
 720   size_t i = 0;
 721   while (i < count)
 722     {
 723       // Find up to MAX_READV_ENTRIES consecutive entries which are
 724       // less than one page apart.
 725       const Read_multiple_entry& i_entry(rm[i]);
 726       off_t i_off = i_entry.file_offset;
 727       off_t end_off = i_off + i_entry.size;
 728       size_t j;
 729       for (j = i + 1; j < count; ++j)
 730         {
 731           if (j - i >= File_read::max_readv_entries || j - i >= iov_max / 2)
 732             break;
 733           const Read_multiple_entry& j_entry(rm[j]);
 734           off_t j_off = j_entry.file_offset;
 735           gold_assert(j_off >= end_off);
 736           off_t j_end_off = j_off + j_entry.size;
 737           if (j_end_off - end_off >= File_read::page_size)
 738             break;
 739           end_off = j_end_off;
 740         }
 741
 742       if (j == i + 1)
 743         this->read(base + i_off, i_entry.size, i_entry.buffer);
 744       else
 745         {
 746           File_read::View* view = this->find_view(base + i_off,
 747                                                   end_off - i_off,
 748                                                   -1U, NULL);
 749           if (view == NULL)
 750             this->do_readv(base, rm, i, j - i);
 751           else
 752             {
 753               const unsigned char* v = (view->data()
 754                                         + (base + i_off - view->start()
 755                                            + view->byteshift()));
 756               for (size_t k = i; k < j; ++k)
 757                 {
 758                   const Read_multiple_entry& k_entry(rm[k]);
 759                   gold_assert((convert_to_section_size_type(k_entry.file_offset
 760                                                            - i_off)
 761                                + k_entry.size)
 762                               <= convert_to_section_size_type(end_off
 763                                                               - i_off));
 764                   memcpy(k_entry.buffer,
 765                          v + (k_entry.file_offset - i_off),
 766                          k_entry.size);
 767                 }
 768             }
 769         }
 770
 771       i = j;
 772     }
 773 }
 774
 775 // Mark all views as no longer cached.
 776
 777 void
 778 File_read::clear_view_cache_marks()
 779 {
 780   // Just ignore this if there are multiple objects associated with
 781   // the file.  Otherwise we will wind up uncaching and freeing some
 782   // views for other objects.
 783   if (this->object_count_ > 1)
 784     return;
 785
 786   for (Views::iterator p = this->views_.begin();
 787        p != this->views_.end();
 788        ++p)
 789     p->second->clear_cache();
 790   for (Saved_views::iterator p = this->saved_views_.begin();
 791        p != this->saved_views_.end();
 792        ++p)
 793     (*p)->clear_cache();
 794 }
 795
 796 // Remove all the file views.  For a file which has multiple
 797 // associated objects (i.e., an archive), we keep accessed views
 798 // around until next time, in the hopes that they will be useful for
 799 // the next object.
 800
 801 void
 802 File_read::clear_views(Clear_views_mode mode)
 803 {
 804   bool keep_files_mapped = (parameters->options_valid()
 805                             && parameters->options().keep_files_mapped());
 806   Views::iterator p = this->views_.begin();
 807   while (p != this->views_.end())
 808     {
 809       bool should_delete;
 810       if (p->second->is_locked() || p->second->is_permanent_view())
 811         should_delete = false;
 812       else if (mode == CLEAR_VIEWS_ALL)
 813         should_delete = true;
 814       else if ((p->second->should_cache()
 815                 || p->second == this->whole_file_view_)
 816                && keep_files_mapped)
 817         should_delete = false;
 818       else if (this->object_count_ > 1
 819                && p->second->accessed()
 820                && mode != CLEAR_VIEWS_ARCHIVE)
 821         should_delete = false;
 822       else
 823         should_delete = true;
 824
 825       if (should_delete)
 826         {
 827           if (p->second == this->whole_file_view_)
 828             this->whole_file_view_ = NULL;
 829           delete p->second;
 830
 831           // map::erase invalidates only the iterator to the deleted
 832           // element.
 833           Views::iterator pe = p;
 834           ++p;
 835           this->views_.erase(pe);
 836         }
 837       else
 838         {
 839           p->second->clear_accessed();
 840           ++p;
 841         }
 842     }
 843
 844   Saved_views::iterator q = this->saved_views_.begin();
 845   while (q != this->saved_views_.end())
 846     {
 847       if (!(*q)->is_locked())
 848         {
 849           delete *q;
 850           q = this->saved_views_.erase(q);
 851         }
 852       else
 853         {
 854           gold_assert(mode != CLEAR_VIEWS_ALL);
 855           ++q;
 856         }
 857     }
 858 }
 859
 860 // Print statistical information to stderr.  This is used for --stats.
 861
 862 void
 863 File_read::print_stats()
 864 {
 865   fprintf(stderr, _("%s: total bytes mapped for read: %llu\n"),
 866           program_name, File_read::total_mapped_bytes);
 867   fprintf(stderr, _("%s: maximum bytes mapped for read at one time: %llu\n"),
 868           program_name, File_read::maximum_mapped_bytes);
 869 }
 870
 871 // Class File_view.
 872
 873 File_view::~File_view()
 874 {
 875   gold_assert(this->file_.is_locked());
 876   this->view_->unlock();
 877 }
 878
 879 // Class Input_file.
 880
 881 // Create a file given just the filename.
 882
 883 Input_file::Input_file(const char* name)
 884   : found_name_(), file_(), is_in_sysroot_(false), format_(FORMAT_NONE)
 885 {
 886   this->input_argument_ =
 887     new Input_file_argument(name, Input_file_argument::INPUT_FILE_TYPE_FILE,
 888                             "", false, Position_dependent_options());
 889 }
 890
 891 // Create a file for testing.
 892
 893 Input_file::Input_file(const Task* task, const char* name,
 894                        const unsigned char* contents, off_t size)
 895   : file_()
 896 {
 897   this->input_argument_ =
 898     new Input_file_argument(name, Input_file_argument::INPUT_FILE_TYPE_FILE,
 899                             "", false, Position_dependent_options());
 900   bool ok = this->file_.open(task, name, contents, size);
 901   gold_assert(ok);
 902 }
 903
 904 // Return the position dependent options in force for this file.
 905
 906 const Position_dependent_options&
 907 Input_file::options() const
 908 {
 909   return this->input_argument_->options();
 910 }
 911
 912 // Return the name given by the user.  For -lc this will return "c".
 913
 914 const char*
 915 Input_file::name() const
 916 {
 917   return this->input_argument_->name();
 918 }
 919
 920 // Return whether this file is in a system directory.
 921
 922 bool
 923 Input_file::is_in_system_directory() const
 924 {
 925   if (this->is_in_sysroot())
 926     return true;
 927   return parameters->options().is_in_system_directory(this->filename());
 928 }
 929
 930 // Return whether we are only reading symbols.
 931
 932 bool
 933 Input_file::just_symbols() const
 934 {
 935   return this->input_argument_->just_symbols();
 936 }
 937
 938 // Return whether this is a file that we will search for in the list
 939 // of directories.
 940
 941 bool
 942 Input_file::will_search_for() const
 943 {
 944   return (!IS_ABSOLUTE_PATH(this->input_argument_->name())
 945           && (this->input_argument_->is_lib()
 946               || this->input_argument_->is_searched_file()
 947               || this->input_argument_->extra_search_path() != NULL));
 948 }
 949
 950 // Return the file last modification time.  Calls gold_fatal if the stat
 951 // system call failed.
 952
 953 Timespec
 954 File_read::get_mtime()
 955 {
 956   struct stat file_stat;
 957   this->reopen_descriptor();
 958
 959   if (fstat(this->descriptor_, &file_stat) < 0)
 960     gold_fatal(_("%s: stat failed: %s"), this->name_.c_str(),
 961                strerror(errno));
 962 #ifdef HAVE_STAT_ST_MTIM
 963   return Timespec(file_stat.st_mtim.tv_sec, file_stat.st_mtim.tv_nsec);
 964 #else
 965   return Timespec(file_stat.st_mtime, 0);
 966 #endif
 967 }
 968
 969 // Try to find a file in the extra search dirs.  Returns true on success.
 970
 971 bool
 972 Input_file::try_extra_search_path(int* pindex,
 973                                   const Input_file_argument* input_argument,
 974                                   std::string filename, std::string* found_name,
 975                                   std::string* namep)
 976 {
 977   if (input_argument->extra_search_path() == NULL)
 978     return false;
 979
 980   std::string name = input_argument->extra_search_path();
 981   if (!IS_DIR_SEPARATOR(name[name.length() - 1]))
 982     name += '/';
 983   name += filename;
 984
 985   struct stat dummy_stat;
 986   if (*pindex > 0 || ::stat(name.c_str(), &dummy_stat) < 0)
 987     return false;
 988
 989   *found_name = filename;
 990   *namep = name;
 991   return true;
 992 }
 993
 994 // Find the actual file.
 995 // If the filename is not absolute, we assume it is in the current
 996 // directory *except* when:
 997 //    A) input_argument_->is_lib() is true;
 998 //    B) input_argument_->is_searched_file() is true; or
 999 //    C) input_argument_->extra_search_path() is not empty.
1000 // In each, we look in extra_search_path + library_path to find
1001 // the file location, rather than the current directory.
1002
1003 bool
1004 Input_file::find_file(const Dirsearch& dirpath, int* pindex,
1005                       const Input_file_argument* input_argument,
1006                       bool* is_in_sysroot,
1007                       std::string* found_name, std::string* namep)
1008 {
1009   std::string name;
1010
1011   // Case 1: name is an absolute file, just try to open it
1012   // Case 2: name is relative but is_lib is false, is_searched_file is false,
1013   //         and extra_search_path is empty
1014   if (IS_ABSOLUTE_PATH(input_argument->name())
1015       || (!input_argument->is_lib()
1016           && !input_argument->is_searched_file()
1017           && input_argument->extra_search_path() == NULL))
1018     {
1019       name = input_argument->name();
1020       *found_name = name;
1021       *namep = name;
1022       return true;
1023     }
1024   // Case 3: is_lib is true or is_searched_file is true
1025   else if (input_argument->is_lib()
1026            || input_argument->is_searched_file())
1027     {
1028       std::vector<std::string> names;
1029       names.reserve(2);
1030       if (input_argument->is_lib())
1031         {
1032           std::string prefix = "lib";
1033           prefix += input_argument->name();
1034           if (parameters->options().is_static()
1035               || !input_argument->options().Bdynamic())
1036             names.push_back(prefix + ".a");
1037           else
1038             {
1039               names.push_back(prefix + ".so");
1040               names.push_back(prefix + ".a");
1041             }
1042         }
1043       else
1044         names.push_back(input_argument->name());
1045
1046       for (std::vector<std::string>::const_iterator n = names.begin();
1047            n != names.end();
1048            ++n)
1049         if (Input_file::try_extra_search_path(pindex, input_argument, *n,
1050                                               found_name, namep))
1051           return true;
1052
1053       // It is not in the extra_search_path.
1054       name = dirpath.find(names, is_in_sysroot, pindex, found_name);
1055       if (name.empty())
1056         {
1057           gold_error(_("cannot find %s%s"),
1058                      input_argument->is_lib() ? "-l" : "",
1059                      input_argument->name());
1060           return false;
1061         }
1062       *namep = name;
1063       return true;
1064     }
1065   // Case 4: extra_search_path is not empty
1066   else
1067     {
1068       gold_assert(input_argument->extra_search_path() != NULL);
1069
1070       if (try_extra_search_path(pindex, input_argument, input_argument->name(),
1071                                 found_name, namep))
1072         return true;
1073
1074       // extra_search_path failed, so check the normal search-path.
1075       int index = *pindex;
1076       if (index > 0)
1077         --index;
1078       name = dirpath.find(std::vector<std::string>(1, input_argument->name()),
1079                           is_in_sysroot, &index, found_name);
1080       if (name.empty())
1081         {
1082           gold_error(_("cannot find %s"),
1083                      input_argument->name());
1084           return false;
1085         }
1086       *namep = name;
1087       *pindex = index + 1;
1088       return true;
1089     }
1090 }
1091
1092 // Open the file.
1093
1094 bool
1095 Input_file::open(const Dirsearch& dirpath, const Task* task, int* pindex)
1096 {
1097   std::string name;
1098   if (!Input_file::find_file(dirpath, pindex, this->input_argument_,
1099                              &this->is_in_sysroot_, &this->found_name_, &name))
1100     return false;
1101
1102   // Now that we've figured out where the file lives, try to open it.
1103
1104   General_options::Object_format format =
1105     this->input_argument_->options().format_enum();
1106   bool ok;
1107   if (format == General_options::OBJECT_FORMAT_ELF)
1108     {
1109       ok = this->file_.open(task, name);
1110       this->format_ = FORMAT_ELF;
1111     }
1112   else
1113     {
1114       gold_assert(format == General_options::OBJECT_FORMAT_BINARY);
1115       ok = this->open_binary(task, name);
1116       this->format_ = FORMAT_BINARY;
1117     }
1118
1119   if (!ok)
1120     {
1121       gold_error(_("cannot open %s: %s"),
1122                  name.c_str(), strerror(errno));
1123       this->format_ = FORMAT_NONE;
1124       return false;
1125     }
1126
1127   return true;
1128 }
1129
1130 // Open a file for --format binary.
1131
1132 bool
1133 Input_file::open_binary(const Task* task, const std::string& name)
1134 {
1135   // In order to open a binary file, we need machine code, size, and
1136   // endianness.  We may not have a valid target at this point, in
1137   // which case we use the default target.
1138   parameters_force_valid_target();
1139   const Target& target(parameters->target());
1140
1141   Binary_to_elf binary_to_elf(target.machine_code(),
1142                               target.get_size(),
1143                               target.is_big_endian(),
1144                               name);
1145   if (!binary_to_elf.convert(task))
1146     return false;
1147   return this->file_.open(task, name, binary_to_elf.converted_data_leak(),
1148                           binary_to_elf.converted_size());
1149 }
1150
1151 void
1152 File_read::record_file_read(const std::string& name)
1153 {
1154   File_read::files_read.push_back(name);
1155 }
1156
1157 void
1158 File_read::write_dependency_file(const char* dependency_file_name,
1159                                  const char* output_file_name)
1160 {
1161   FILE *depfile = fopen(dependency_file_name, "w");
1162
1163   fprintf(depfile, "%s:", output_file_name);
1164   for (std::vector<std::string>::const_iterator it = files_read.begin();
1165        it != files_read.end();
1166        ++it)
1167     fprintf(depfile, " \\\n  %s", it->c_str());
1168   fprintf(depfile, "\n");
1169
1170   for (std::vector<std::string>::const_iterator it = files_read.begin();
1171        it != files_read.end();
1172        ++it)
1173     fprintf(depfile, "\n%s:\n", it->c_str());
1174
1175   fclose(depfile);
1176 }
1177
1178 } // End namespace gold.