gold/archive.cc

   1 // archive.cc -- archive support for gold
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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 <cerrno>
  26 #include <cstring>
  27 #include <climits>
  28 #include <vector>
  29 #include "libiberty.h"
  30 #include "filenames.h"
  31
  32 #include "elfcpp.h"
  33 #include "options.h"
  34 #include "mapfile.h"
  35 #include "fileread.h"
  36 #include "readsyms.h"
  37 #include "symtab.h"
  38 #include "object.h"
  39 #include "layout.h"
  40 #include "archive.h"
  41 #include "plugin.h"
  42 #include "incremental.h"
  43
  44 namespace gold
  45 {
  46
  47 // The header of an entry in the archive.  This is all readable text,
  48 // padded with spaces where necessary.  If the contents of an archive
  49 // are all text file, the entire archive is readable.
  50
  51 struct Archive::Archive_header
  52 {
  53   // The entry name.
  54   char ar_name[16];
  55   // The file modification time.
  56   char ar_date[12];
  57   // The user's UID in decimal.
  58   char ar_uid[6];
  59   // The user's GID in decimal.
  60   char ar_gid[6];
  61   // The file mode in octal.
  62   char ar_mode[8];
  63   // The file size in decimal.
  64   char ar_size[10];
  65   // The final magic code.
  66   char ar_fmag[2];
  67 };
  68
  69 // Class Archive static variables.
  70 unsigned int Archive::total_archives;
  71 unsigned int Archive::total_members;
  72 unsigned int Archive::total_members_loaded;
  73
  74 // Archive methods.
  75
  76 const char Archive::armag[sarmag] =
  77 {
  78   '!', '<', 'a', 'r', 'c', 'h', '>', '\n'
  79 };
  80
  81 const char Archive::armagt[sarmag] =
  82 {
  83   '!', '<', 't', 'h', 'i', 'n', '>', '\n'
  84 };
  85
  86 const char Archive::arfmag[2] = { '`', '\n' };
  87
  88 Archive::Archive(const std::string& name, Input_file* input_file,
  89                  bool is_thin_archive, Dirsearch* dirpath, Task* task)
  90   : name_(name), input_file_(input_file), armap_(), armap_names_(),
  91     extended_names_(), armap_checked_(), seen_offsets_(), members_(),
  92     is_thin_archive_(is_thin_archive), included_member_(false),
  93     nested_archives_(), dirpath_(dirpath), task_(task), num_members_(0),
  94     incremental_info_(NULL)
  95 {
  96   this->no_export_ =
  97     parameters->options().check_excluded_libs(input_file->found_name());
  98 }
  99
 100 // Set up the archive: read the symbol map and the extended name
 101 // table.
 102
 103 void
 104 Archive::setup()
 105 {
 106   // We need to ignore empty archives.
 107   if (this->input_file_->file().filesize() == sarmag)
 108     return;
 109
 110   // The first member of the archive should be the symbol table.
 111   std::string armap_name;
 112   off_t header_size = this->read_header(sarmag, false, &armap_name, NULL);
 113   if (header_size == -1)
 114     return;
 115
 116   section_size_type armap_size = convert_to_section_size_type(header_size);
 117   off_t off = sarmag;
 118   if (armap_name.empty())
 119     {
 120       this->read_armap(sarmag + sizeof(Archive_header), armap_size);
 121       off = sarmag + sizeof(Archive_header) + armap_size;
 122     }
 123   else if (!this->input_file_->options().whole_archive())
 124     gold_error(_("%s: no archive symbol table (run ranlib)"),
 125                this->name().c_str());
 126
 127   // See if there is an extended name table.  We cache these views
 128   // because it is likely that we will want to read the following
 129   // header in the add_symbols routine.
 130   if ((off & 1) != 0)
 131     ++off;
 132   std::string xname;
 133   header_size = this->read_header(off, true, &xname, NULL);
 134   if (header_size == -1)
 135     return;
 136
 137   section_size_type extended_size = convert_to_section_size_type(header_size);
 138   if (xname == "/")
 139     {
 140       const unsigned char* p = this->get_view(off + sizeof(Archive_header),
 141                                               extended_size, false, true);
 142       const char* px = reinterpret_cast<const char*>(p);
 143       this->extended_names_.assign(px, extended_size);
 144     }
 145   bool preread_syms = (parameters->options().threads()
 146                        && parameters->options().preread_archive_symbols());
 147 #ifndef ENABLE_THREADS
 148   preread_syms = false;
 149 #else
 150   if (parameters->options().has_plugins())
 151     preread_syms = false;
 152 #endif
 153   if (preread_syms)
 154     this->read_all_symbols();
 155 }
 156
 157 // Unlock any nested archives.
 158
 159 void
 160 Archive::unlock_nested_archives()
 161 {
 162   for (Nested_archive_table::iterator p = this->nested_archives_.begin();
 163        p != this->nested_archives_.end();
 164        ++p)
 165     {
 166       p->second->unlock(this->task_);
 167     }
 168 }
 169
 170 // Read the archive symbol map.
 171
 172 void
 173 Archive::read_armap(off_t start, section_size_type size)
 174 {
 175   // To count the total number of archive members, we'll just count
 176   // the number of times the file offset changes.  Since most archives
 177   // group the symbols in the armap by object, this ought to give us
 178   // an accurate count.
 179   off_t last_seen_offset = -1;
 180
 181   // Read in the entire armap.
 182   const unsigned char* p = this->get_view(start, size, true, false);
 183
 184   // Numbers in the armap are always big-endian.
 185   const elfcpp::Elf_Word* pword = reinterpret_cast<const elfcpp::Elf_Word*>(p);
 186   unsigned int nsyms = elfcpp::Swap<32, true>::readval(pword);
 187   ++pword;
 188
 189   // Note that the addition is in units of sizeof(elfcpp::Elf_Word).
 190   const char* pnames = reinterpret_cast<const char*>(pword + nsyms);
 191   section_size_type names_size =
 192     reinterpret_cast<const char*>(p) + size - pnames;
 193   this->armap_names_.assign(pnames, names_size);
 194
 195   this->armap_.resize(nsyms);
 196
 197   section_offset_type name_offset = 0;
 198   for (unsigned int i = 0; i < nsyms; ++i)
 199     {
 200       this->armap_[i].name_offset = name_offset;
 201       this->armap_[i].file_offset = elfcpp::Swap<32, true>::readval(pword);
 202       name_offset += strlen(pnames + name_offset) + 1;
 203       ++pword;
 204       if (this->armap_[i].file_offset != last_seen_offset)
 205         {
 206           last_seen_offset = this->armap_[i].file_offset;
 207           ++this->num_members_;
 208         }
 209     }
 210
 211   if (static_cast<section_size_type>(name_offset) > names_size)
 212     gold_error(_("%s: bad archive symbol table names"),
 213                this->name().c_str());
 214
 215   // This array keeps track of which symbols are for archive elements
 216   // which we have already included in the link.
 217   this->armap_checked_.resize(nsyms);
 218 }
 219
 220 // Read the header of an archive member at OFF.  Fail if something
 221 // goes wrong.  Return the size of the member.  Set *PNAME to the name
 222 // of the member.
 223
 224 off_t
 225 Archive::read_header(off_t off, bool cache, std::string* pname,
 226                      off_t* nested_off)
 227 {
 228   const unsigned char* p = this->get_view(off, sizeof(Archive_header), true,
 229                                           cache);
 230   const Archive_header* hdr = reinterpret_cast<const Archive_header*>(p);
 231   return this->interpret_header(hdr, off,  pname, nested_off);
 232 }
 233
 234 // Interpret the header of HDR, the header of the archive member at
 235 // file offset OFF.  Return the size of the member, or -1 if something
 236 // has gone wrong.  Set *PNAME to the name of the member.
 237
 238 off_t
 239 Archive::interpret_header(const Archive_header* hdr, off_t off,
 240                           std::string* pname, off_t* nested_off) const
 241 {
 242   if (memcmp(hdr->ar_fmag, arfmag, sizeof arfmag) != 0)
 243     {
 244       gold_error(_("%s: malformed archive header at %zu"),
 245                  this->name().c_str(), static_cast<size_t>(off));
 246       return -1;
 247     }
 248
 249   const int size_string_size = sizeof hdr->ar_size;
 250   char size_string[size_string_size + 1];
 251   memcpy(size_string, hdr->ar_size, size_string_size);
 252   char* ps = size_string + size_string_size;
 253   while (ps[-1] == ' ')
 254     --ps;
 255   *ps = '\0';
 256
 257   errno = 0;
 258   char* end;
 259   off_t member_size = strtol(size_string, &end, 10);
 260   if (*end != '\0'
 261       || member_size < 0
 262       || (member_size == LONG_MAX && errno == ERANGE))
 263     {
 264       gold_error(_("%s: malformed archive header size at %zu"),
 265                  this->name().c_str(), static_cast<size_t>(off));
 266       return -1;
 267     }
 268
 269   if (hdr->ar_name[0] != '/')
 270     {
 271       const char* name_end = strchr(hdr->ar_name, '/');
 272       if (name_end == NULL
 273           || name_end - hdr->ar_name >= static_cast<int>(sizeof hdr->ar_name))
 274         {
 275           gold_error(_("%s: malformed archive header name at %zu"),
 276                      this->name().c_str(), static_cast<size_t>(off));
 277           return -1;
 278         }
 279       pname->assign(hdr->ar_name, name_end - hdr->ar_name);
 280       if (nested_off != NULL)
 281         *nested_off = 0;
 282     }
 283   else if (hdr->ar_name[1] == ' ')
 284     {
 285       // This is the symbol table.
 286       if (!pname->empty())
 287         pname->clear();
 288     }
 289   else if (hdr->ar_name[1] == '/')
 290     {
 291       // This is the extended name table.
 292       pname->assign(1, '/');
 293     }
 294   else
 295     {
 296       errno = 0;
 297       long x = strtol(hdr->ar_name + 1, &end, 10);
 298       long y = 0;
 299       if (*end == ':')
 300         y = strtol(end + 1, &end, 10);
 301       if (*end != ' '
 302           || x < 0
 303           || (x == LONG_MAX && errno == ERANGE)
 304           || static_cast<size_t>(x) >= this->extended_names_.size())
 305         {
 306           gold_error(_("%s: bad extended name index at %zu"),
 307                      this->name().c_str(), static_cast<size_t>(off));
 308           return -1;
 309         }
 310
 311       const char* name = this->extended_names_.data() + x;
 312       const char* name_end = strchr(name, '\n');
 313       if (static_cast<size_t>(name_end - name) > this->extended_names_.size()
 314           || name_end[-1] != '/')
 315         {
 316           gold_error(_("%s: bad extended name entry at header %zu"),
 317                      this->name().c_str(), static_cast<size_t>(off));
 318           return -1;
 319         }
 320       pname->assign(name, name_end - 1 - name);
 321       if (nested_off != NULL)
 322         *nested_off = y;
 323     }
 324
 325   return member_size;
 326 }
 327
 328 // An archive member iterator.
 329
 330 class Archive::const_iterator
 331 {
 332  public:
 333   // The header of an archive member.  This is what this iterator
 334   // points to.
 335   struct Header
 336   {
 337     // The name of the member.
 338     std::string name;
 339     // The file offset of the member.
 340     off_t off;
 341     // The file offset of a nested archive member.
 342     off_t nested_off;
 343     // The size of the member.
 344     off_t size;
 345   };
 346
 347   const_iterator(Archive* archive, off_t off)
 348     : archive_(archive), off_(off)
 349   { this->read_next_header(); }
 350
 351   const Header&
 352   operator*() const
 353   { return this->header_; }
 354
 355   const Header*
 356   operator->() const
 357   { return &this->header_; }
 358
 359   const_iterator&
 360   operator++()
 361   {
 362     if (this->off_ == this->archive_->file().filesize())
 363       return *this;
 364     this->off_ += sizeof(Archive_header);
 365     if (!this->archive_->is_thin_archive())
 366       this->off_ += this->header_.size;
 367     if ((this->off_ & 1) != 0)
 368       ++this->off_;
 369     this->read_next_header();
 370     return *this;
 371   }
 372
 373   const_iterator
 374   operator++(int)
 375   {
 376     const_iterator ret = *this;
 377     ++*this;
 378     return ret;
 379   }
 380
 381   bool
 382   operator==(const const_iterator p) const
 383   { return this->off_ == p->off; }
 384
 385   bool
 386   operator!=(const const_iterator p) const
 387   { return this->off_ != p->off; }
 388
 389  private:
 390   void
 391   read_next_header();
 392
 393   // The underlying archive.
 394   Archive* archive_;
 395   // The current offset in the file.
 396   off_t off_;
 397   // The current archive header.
 398   Header header_;
 399 };
 400
 401 // Read the next archive header.
 402
 403 void
 404 Archive::const_iterator::read_next_header()
 405 {
 406   off_t filesize = this->archive_->file().filesize();
 407   while (true)
 408     {
 409       if (filesize - this->off_ < static_cast<off_t>(sizeof(Archive_header)))
 410         {
 411           if (filesize != this->off_)
 412             {
 413               gold_error(_("%s: short archive header at %zu"),
 414                          this->archive_->filename().c_str(),
 415                          static_cast<size_t>(this->off_));
 416               this->off_ = filesize;
 417             }
 418           this->header_.off = filesize;
 419           return;
 420         }
 421
 422       unsigned char buf[sizeof(Archive_header)];
 423       this->archive_->file().read(this->off_, sizeof(Archive_header), buf);
 424
 425       const Archive_header* hdr = reinterpret_cast<const Archive_header*>(buf);
 426       off_t size = this->archive_->interpret_header(hdr, this->off_,
 427                                                     &this->header_.name,
 428                                                     &this->header_.nested_off);
 429       if (size == -1)
 430         {
 431           this->header_.off = filesize;
 432           return;
 433         }
 434
 435       this->header_.size = size;
 436       this->header_.off = this->off_;
 437
 438       // Skip special members.
 439       if (!this->header_.name.empty() && this->header_.name != "/")
 440         return;
 441
 442       this->off_ += sizeof(Archive_header) + this->header_.size;
 443       if ((this->off_ & 1) != 0)
 444         ++this->off_;
 445     }
 446 }
 447
 448 // Initial iterator.
 449
 450 Archive::const_iterator
 451 Archive::begin()
 452 {
 453   return Archive::const_iterator(this, sarmag);
 454 }
 455
 456 // Final iterator.
 457
 458 Archive::const_iterator
 459 Archive::end()
 460 {
 461   return Archive::const_iterator(this, this->input_file_->file().filesize());
 462 }
 463
 464 // Get the file and offset for an archive member, which may be an
 465 // external member of a thin archive.  Set *INPUT_FILE to the
 466 // file containing the actual member, *MEMOFF to the offset
 467 // within that file (0 if not a nested archive), and *MEMBER_NAME
 468 // to the name of the archive member.  Return TRUE on success.
 469
 470 bool
 471 Archive::get_file_and_offset(off_t off, Input_file** input_file, off_t* memoff,
 472                              off_t* memsize, std::string* member_name)
 473 {
 474   off_t nested_off;
 475
 476   *memsize = this->read_header(off, false, member_name, &nested_off);
 477   if (*memsize == -1)
 478     return false;
 479
 480   *input_file = this->input_file_;
 481   *memoff = off + static_cast<off_t>(sizeof(Archive_header));
 482
 483   if (!this->is_thin_archive_)
 484     return true;
 485
 486   // Adjust a relative pathname so that it is relative
 487   // to the directory containing the archive.
 488   if (!IS_ABSOLUTE_PATH(member_name->c_str()))
 489     {
 490       const char* arch_path = this->filename().c_str();
 491       const char* basename = lbasename(arch_path);
 492       if (basename > arch_path)
 493         member_name->replace(0, 0,
 494                              this->filename().substr(0, basename - arch_path));
 495     }
 496
 497   if (nested_off > 0)
 498     {
 499       // This is a member of a nested archive.  Open the containing
 500       // archive if we don't already have it open, then do a recursive
 501       // call to include the member from that archive.
 502       Archive* arch;
 503       Nested_archive_table::const_iterator p =
 504         this->nested_archives_.find(*member_name);
 505       if (p != this->nested_archives_.end())
 506         arch = p->second;
 507       else
 508         {
 509           Input_file_argument* input_file_arg =
 510             new Input_file_argument(member_name->c_str(),
 511                                     Input_file_argument::INPUT_FILE_TYPE_FILE,
 512                                     "", false, parameters->options());
 513           *input_file = new Input_file(input_file_arg);
 514           int dummy = 0;
 515           if (!(*input_file)->open(*this->dirpath_, this->task_, &dummy))
 516             return false;
 517           arch = new Archive(*member_name, *input_file, false, this->dirpath_,
 518                              this->task_);
 519           arch->setup();
 520           std::pair<Nested_archive_table::iterator, bool> ins =
 521             this->nested_archives_.insert(std::make_pair(*member_name, arch));
 522           gold_assert(ins.second);
 523         }
 524       return arch->get_file_and_offset(nested_off, input_file, memoff,
 525                                        memsize, member_name);
 526     }
 527
 528   // This is an external member of a thin archive.  Open the
 529   // file as a regular relocatable object file.
 530   Input_file_argument* input_file_arg =
 531       new Input_file_argument(member_name->c_str(),
 532                               Input_file_argument::INPUT_FILE_TYPE_FILE,
 533                               "", false, this->input_file_->options());
 534   *input_file = new Input_file(input_file_arg);
 535   int dummy = 0;
 536   if (!(*input_file)->open(*this->dirpath_, this->task_, &dummy))
 537     return false;
 538
 539   *memoff = 0;
 540   *memsize = (*input_file)->file().filesize();
 541   return true;
 542 }
 543
 544 // Return an ELF object for the member at offset OFF.  If
 545 // PUNCONFIGURED is not NULL, then if the ELF object has an
 546 // unsupported target type, set *PUNCONFIGURED to true and return
 547 // NULL.
 548
 549 Object*
 550 Archive::get_elf_object_for_member(off_t off, bool* punconfigured)
 551 {
 552   if (punconfigured != NULL)
 553     *punconfigured = false;
 554
 555   Input_file* input_file;
 556   off_t memoff;
 557   off_t memsize;
 558   std::string member_name;
 559   if (!this->get_file_and_offset(off, &input_file, &memoff, &memsize,
 560                                  &member_name))
 561     return NULL;
 562
 563   if (parameters->options().has_plugins())
 564     {
 565       Object* obj = parameters->options().plugins()->claim_file(input_file,
 566                                                                 memoff,
 567                                                                 memsize);
 568       if (obj != NULL)
 569         {
 570           // The input file was claimed by a plugin, and its symbols
 571           // have been provided by the plugin.
 572           return obj;
 573         }
 574     }
 575
 576   const unsigned char* ehdr;
 577   int read_size;
 578   if (!is_elf_object(input_file, memoff, &ehdr, &read_size))
 579     {
 580       gold_error(_("%s: member at %zu is not an ELF object"),
 581                  this->name().c_str(), static_cast<size_t>(off));
 582       return NULL;
 583     }
 584
 585   Object* obj = make_elf_object((std::string(this->input_file_->filename())
 586                                  + "(" + member_name + ")"),
 587                                 input_file, memoff, ehdr, read_size,
 588                                 punconfigured);
 589   if (obj == NULL)
 590     return NULL;
 591   obj->set_no_export(this->no_export());
 592   return obj;
 593 }
 594
 595 // Read the symbols from all the archive members in the link.
 596
 597 void
 598 Archive::read_all_symbols()
 599 {
 600   for (Archive::const_iterator p = this->begin();
 601        p != this->end();
 602        ++p)
 603     this->read_symbols(p->off);
 604 }
 605
 606 // Read the symbols from an archive member in the link.  OFF is the file
 607 // offset of the member header.
 608
 609 void
 610 Archive::read_symbols(off_t off)
 611 {
 612   Object* obj = this->get_elf_object_for_member(off, NULL);
 613   if (obj == NULL)
 614     return;
 615
 616   Read_symbols_data* sd = new Read_symbols_data;
 617   obj->read_symbols(sd);
 618   Archive_member member(obj, sd);
 619   this->members_[off] = member;
 620 }
 621
 622 Archive::Should_include
 623 Archive::should_include_member(Symbol_table* symtab, Layout* layout,
 624                                const char* sym_name, Symbol** symp,
 625                                std::string* why, char** tmpbufp,
 626                                size_t* tmpbuflen)
 627 {
 628   // In an object file, and therefore in an archive map, an
 629   // '@' in the name separates the symbol name from the
 630   // version name.  If there are two '@' characters, this is
 631   // the default version.
 632   char* tmpbuf = *tmpbufp;
 633   const char* ver = strchr(sym_name, '@');
 634   bool def = false;
 635   if (ver != NULL)
 636     {
 637       size_t symlen = ver - sym_name;
 638       if (symlen + 1 > *tmpbuflen)
 639         {
 640           tmpbuf = static_cast<char*>(xrealloc(tmpbuf, symlen + 1));
 641           *tmpbufp = tmpbuf;
 642           *tmpbuflen = symlen + 1;
 643         }
 644       memcpy(tmpbuf, sym_name, symlen);
 645       tmpbuf[symlen] = '\0';
 646       sym_name = tmpbuf;
 647
 648       ++ver;
 649       if (*ver == '@')
 650         {
 651           ++ver;
 652           def = true;
 653         }
 654     }
 655
 656   Symbol* sym = symtab->lookup(sym_name, ver);
 657   if (def
 658       && ver != NULL
 659       && (sym == NULL
 660           || !sym->is_undefined()
 661           || sym->binding() == elfcpp::STB_WEAK))
 662     sym = symtab->lookup(sym_name, NULL);
 663
 664   *symp = sym;
 665
 666   if (sym == NULL)
 667     {
 668       // Check whether the symbol was named in a -u option.
 669       if (parameters->options().is_undefined(sym_name))
 670         {
 671           *why = "-u ";
 672           *why += sym_name;
 673         }
 674       else if (layout->script_options()->is_referenced(sym_name))
 675         {
 676           size_t alc = 100 + strlen(sym_name);
 677           char* buf = new char[alc];
 678           snprintf(buf, alc, _("script or expression reference to %s"),
 679                    sym_name);
 680           *why = buf;
 681           delete[] buf;
 682         }
 683       else
 684         return Archive::SHOULD_INCLUDE_UNKNOWN;
 685     }
 686   else if (!sym->is_undefined())
 687     return Archive::SHOULD_INCLUDE_NO;
 688   // PR 12001: Do not include an archive when the undefined
 689   // symbol has actually been defined on the command line.
 690   else if (layout->script_options()->is_pending_assignment(sym_name))
 691     return Archive::SHOULD_INCLUDE_NO;
 692   else if (sym->binding() == elfcpp::STB_WEAK)
 693     return Archive::SHOULD_INCLUDE_UNKNOWN;
 694
 695   return Archive::SHOULD_INCLUDE_YES;
 696 }
 697
 698 // Select members from the archive and add them to the link.  We walk
 699 // through the elements in the archive map, and look each one up in
 700 // the symbol table.  If it exists as a strong undefined symbol, we
 701 // pull in the corresponding element.  We have to do this in a loop,
 702 // since pulling in one element may create new undefined symbols which
 703 // may be satisfied by other objects in the archive.  Return true in
 704 // the normal case, false if the first member we tried to add from
 705 // this archive had an incompatible target.
 706
 707 bool
 708 Archive::add_symbols(Symbol_table* symtab, Layout* layout,
 709                      Input_objects* input_objects, Mapfile* mapfile)
 710 {
 711   ++Archive::total_archives;
 712
 713   if (this->input_file_->options().whole_archive())
 714     return this->include_all_members(symtab, layout, input_objects,
 715                                      mapfile);
 716
 717   Archive::total_members += this->num_members_;
 718
 719   input_objects->archive_start(this);
 720
 721   const size_t armap_size = this->armap_.size();
 722
 723   // This is a quick optimization, since we usually see many symbols
 724   // in a row with the same offset.  last_seen_offset holds the last
 725   // offset we saw that was present in the seen_offsets_ set.
 726   off_t last_seen_offset = -1;
 727
 728   // Track which symbols in the symbol table we've already found to be
 729   // defined.
 730
 731   char* tmpbuf = NULL;
 732   size_t tmpbuflen = 0;
 733   bool added_new_object;
 734   do
 735     {
 736       added_new_object = false;
 737       for (size_t i = 0; i < armap_size; ++i)
 738         {
 739           if (this->armap_checked_[i])
 740             continue;
 741           if (this->armap_[i].file_offset == last_seen_offset)
 742             {
 743               this->armap_checked_[i] = true;
 744               continue;
 745             }
 746           if (this->seen_offsets_.find(this->armap_[i].file_offset)
 747               != this->seen_offsets_.end())
 748             {
 749               this->armap_checked_[i] = true;
 750               last_seen_offset = this->armap_[i].file_offset;
 751               continue;
 752             }
 753
 754           const char* sym_name = (this->armap_names_.data()
 755                                   + this->armap_[i].name_offset);
 756
 757           Symbol* sym;
 758           std::string why;
 759           Archive::Should_include t =
 760             Archive::should_include_member(symtab, layout, sym_name, &sym,
 761                                            &why, &tmpbuf, &tmpbuflen);
 762
 763           if (t == Archive::SHOULD_INCLUDE_NO
 764               || t == Archive::SHOULD_INCLUDE_YES)
 765             this->armap_checked_[i] = true;
 766
 767           if (t != Archive::SHOULD_INCLUDE_YES)
 768             continue;
 769
 770           // We want to include this object in the link.
 771           last_seen_offset = this->armap_[i].file_offset;
 772           this->seen_offsets_.insert(last_seen_offset);
 773
 774           if (!this->include_member(symtab, layout, input_objects,
 775                                     last_seen_offset, mapfile, sym,
 776                                     why.c_str()))
 777             {
 778               if (tmpbuf != NULL)
 779                 free(tmpbuf);
 780               return false;
 781             }
 782
 783           added_new_object = true;
 784         }
 785     }
 786   while (added_new_object);
 787
 788   if (tmpbuf != NULL)
 789     free(tmpbuf);
 790
 791   input_objects->archive_stop(this);
 792
 793   return true;
 794 }
 795
 796 // Return whether the archive includes a member which defines the
 797 // symbol SYM.
 798
 799 bool
 800 Archive::defines_symbol(Symbol* sym) const
 801 {
 802   const char* symname = sym->name();
 803   size_t symname_len = strlen(symname);
 804   size_t armap_size = this->armap_.size();
 805   for (size_t i = 0; i < armap_size; ++i)
 806     {
 807       if (this->armap_checked_[i])
 808         continue;
 809       const char* archive_symname = (this->armap_names_.data()
 810                                      + this->armap_[i].name_offset);
 811       if (strncmp(archive_symname, symname, symname_len) != 0)
 812         continue;
 813       char c = archive_symname[symname_len];
 814       if (c == '\0' && sym->version() == NULL)
 815         return true;
 816       if (c == '@')
 817         {
 818           const char* ver = archive_symname + symname_len + 1;
 819           if (*ver == '@')
 820             {
 821               if (sym->version() == NULL)
 822                 return true;
 823               ++ver;
 824             }
 825           if (sym->version() != NULL && strcmp(sym->version(), ver) == 0)
 826             return true;
 827         }
 828     }
 829   return false;
 830 }
 831
 832 // Include all the archive members in the link.  This is for --whole-archive.
 833
 834 bool
 835 Archive::include_all_members(Symbol_table* symtab, Layout* layout,
 836                              Input_objects* input_objects, Mapfile* mapfile)
 837 {
 838   input_objects->archive_start(this);
 839
 840   if (this->members_.size() > 0)
 841     {
 842       std::map<off_t, Archive_member>::const_iterator p;
 843       for (p = this->members_.begin();
 844            p != this->members_.end();
 845            ++p)
 846         {
 847           if (!this->include_member(symtab, layout, input_objects, p->first,
 848                                     mapfile, NULL, "--whole-archive"))
 849             return false;
 850           ++Archive::total_members;
 851         }
 852     }
 853   else
 854     {
 855       for (Archive::const_iterator p = this->begin();
 856            p != this->end();
 857            ++p)
 858         {
 859           if (!this->include_member(symtab, layout, input_objects, p->off,
 860                                     mapfile, NULL, "--whole-archive"))
 861             return false;
 862           ++Archive::total_members;
 863         }
 864     }
 865
 866   input_objects->archive_stop(this);
 867
 868   return true;
 869 }
 870
 871 // Return the number of members in the archive.  This is only used for
 872 // reports.
 873
 874 size_t
 875 Archive::count_members()
 876 {
 877   size_t ret = 0;
 878   for (Archive::const_iterator p = this->begin();
 879        p != this->end();
 880        ++p)
 881     ++ret;
 882   return ret;
 883 }
 884
 885 // Include an archive member in the link.  OFF is the file offset of
 886 // the member header.  WHY is the reason we are including this member.
 887 // Return true if we added the member or if we had an error, return
 888 // false if this was the first member we tried to add from this
 889 // archive and it had an incompatible format.
 890
 891 bool
 892 Archive::include_member(Symbol_table* symtab, Layout* layout,
 893                         Input_objects* input_objects, off_t off,
 894                         Mapfile* mapfile, Symbol* sym, const char* why)
 895 {
 896   ++Archive::total_members_loaded;
 897
 898   std::map<off_t, Archive_member>::const_iterator p = this->members_.find(off);
 899   if (p != this->members_.end())
 900     {
 901       Object* obj = p->second.obj_;
 902
 903       Read_symbols_data* sd = p->second.sd_;
 904       if (mapfile != NULL)
 905         mapfile->report_include_archive_member(obj->name(), sym, why);
 906       if (input_objects->add_object(obj))
 907         {
 908           obj->layout(symtab, layout, sd);
 909           obj->add_symbols(symtab, sd, layout);
 910           this->included_member_ = true;
 911         }
 912       delete sd;
 913       return true;
 914     }
 915
 916   // If this is the first object we are including from this archive,
 917   // and we searched for this archive, most likely because it was
 918   // found via a -l option, then if the target is incompatible we want
 919   // to move on to the next archive found in the search path.
 920   bool unconfigured = false;
 921   bool* punconfigured = NULL;
 922   if (!this->included_member_ && this->searched_for())
 923     punconfigured = &unconfigured;
 924
 925   Object* obj = this->get_elf_object_for_member(off, punconfigured);
 926   if (obj == NULL)
 927     {
 928       // Return false to search for another archive, true if we found
 929       // an error.
 930       return unconfigured ? false : true;
 931     }
 932
 933   if (mapfile != NULL)
 934     mapfile->report_include_archive_member(obj->name(), sym, why);
 935
 936   Pluginobj* pluginobj = obj->pluginobj();
 937   if (pluginobj != NULL)
 938     {
 939       pluginobj->add_symbols(symtab, NULL, layout);
 940       this->included_member_ = true;
 941       return true;
 942     }
 943
 944   if (!input_objects->add_object(obj))
 945     {
 946       // If this is an external member of a thin archive, unlock the
 947       // file.
 948       if (obj->offset() == 0)
 949         obj->unlock(this->task_);
 950       delete obj;
 951     }
 952   else
 953     {
 954       {
 955         if (layout->incremental_inputs() != NULL)
 956           layout->incremental_inputs()->report_object(obj, this);
 957         Read_symbols_data sd;
 958         obj->read_symbols(&sd);
 959         obj->layout(symtab, layout, &sd);
 960         obj->add_symbols(symtab, &sd, layout);
 961       }
 962
 963       // If this is an external member of a thin archive, unlock the file
 964       // for the next task.
 965       if (obj->offset() == 0)
 966         obj->unlock(this->task_);
 967
 968       this->included_member_ = true;
 969     }
 970
 971   return true;
 972 }
 973
 974 // Print statistical information to stderr.  This is used for --stats.
 975
 976 void
 977 Archive::print_stats()
 978 {
 979   fprintf(stderr, _("%s: archive libraries: %u\n"),
 980           program_name, Archive::total_archives);
 981   fprintf(stderr, _("%s: total archive members: %u\n"),
 982           program_name, Archive::total_members);
 983   fprintf(stderr, _("%s: loaded archive members: %u\n"),
 984           program_name, Archive::total_members_loaded);
 985 }
 986
 987 // Add_archive_symbols methods.
 988
 989 Add_archive_symbols::~Add_archive_symbols()
 990 {
 991   if (this->this_blocker_ != NULL)
 992     delete this->this_blocker_;
 993   // next_blocker_ is deleted by the task associated with the next
 994   // input file.
 995 }
 996
 997 // Return whether we can add the archive symbols.  We are blocked by
 998 // this_blocker_.  We block next_blocker_.  We also lock the file.
 999
1000 Task_token*
1001 Add_archive_symbols::is_runnable()
1002 {
1003   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
1004     return this->this_blocker_;
1005   return NULL;
1006 }
1007
1008 void
1009 Add_archive_symbols::locks(Task_locker* tl)
1010 {
1011   tl->add(this, this->next_blocker_);
1012   tl->add(this, this->archive_->token());
1013 }
1014
1015 void
1016 Add_archive_symbols::run(Workqueue* workqueue)
1017 {
1018   // For an incremental link, begin recording layout information.
1019   Incremental_inputs* incremental_inputs = this->layout_->incremental_inputs();
1020   if (incremental_inputs != NULL)
1021     incremental_inputs->report_archive_begin(this->archive_);
1022
1023   bool added = this->archive_->add_symbols(this->symtab_, this->layout_,
1024                                            this->input_objects_,
1025                                            this->mapfile_);
1026   this->archive_->unlock_nested_archives();
1027
1028   this->archive_->release();
1029   this->archive_->clear_uncached_views();
1030
1031   if (!added)
1032     {
1033       // This archive holds object files which are incompatible with
1034       // our output file.
1035       Read_symbols::incompatible_warning(this->input_argument_,
1036                                          this->archive_->input_file());
1037       Read_symbols::requeue(workqueue, this->input_objects_, this->symtab_,
1038                             this->layout_, this->dirpath_, this->dirindex_,
1039                             this->mapfile_, this->input_argument_,
1040                             this->input_group_, this->next_blocker_);
1041       delete this->archive_;
1042       return;
1043     }
1044
1045   if (this->input_group_ != NULL)
1046     this->input_group_->add_archive(this->archive_);
1047   else
1048     {
1049       // For an incremental link, finish recording the layout information.
1050       Incremental_inputs* incremental_inputs = this->layout_->incremental_inputs();
1051       if (incremental_inputs != NULL)
1052         incremental_inputs->report_archive_end(this->archive_);
1053
1054       if (!parameters->options().has_plugins()
1055           || this->archive_->input_file()->options().whole_archive())
1056         {
1057           // We no longer need to know about this archive.
1058           delete this->archive_;
1059         }
1060       else
1061         {
1062           // The plugin interface may want to rescan this archive.
1063           parameters->options().plugins()->save_archive(this->archive_);
1064         }
1065
1066       this->archive_ = NULL;
1067     }
1068 }
1069
1070 // Class Lib_group static variables.
1071 unsigned int Lib_group::total_lib_groups;
1072 unsigned int Lib_group::total_members;
1073 unsigned int Lib_group::total_members_loaded;
1074
1075 Lib_group::Lib_group(const Input_file_lib* lib, Task* task)
1076   : lib_(lib), task_(task), members_()
1077 {
1078   this->members_.resize(lib->size());
1079 }
1080
1081 // Select members from the lib group and add them to the link.  We walk
1082 // through the members, and check if each one up should be included.
1083 // If the object says it should be included, we do so.  We have to do
1084 // this in a loop, since including one member may create new undefined
1085 // symbols which may be satisfied by other members.
1086
1087 void
1088 Lib_group::add_symbols(Symbol_table* symtab, Layout* layout,
1089                        Input_objects* input_objects)
1090 {
1091   ++Lib_group::total_lib_groups;
1092
1093   Lib_group::total_members += this->members_.size();
1094
1095   bool added_new_object;
1096   do
1097     {
1098       added_new_object = false;
1099       unsigned int i = 0;
1100       while (i < this->members_.size())
1101         {
1102           const Archive_member& member = this->members_[i];
1103           Object* obj = member.obj_;
1104           std::string why;
1105
1106           // Skip files with no symbols. Plugin objects have
1107           // member.sd_ == NULL.
1108           if (obj != NULL
1109               && (member.sd_ == NULL || member.sd_->symbol_names != NULL))
1110             {
1111               Archive::Should_include t = obj->should_include_member(symtab,
1112                                                                      layout,
1113                                                                      member.sd_,
1114                                                                      &why);
1115
1116               if (t != Archive::SHOULD_INCLUDE_YES)
1117                 {
1118                   ++i;
1119                   continue;
1120                 }
1121
1122               this->include_member(symtab, layout, input_objects, member);
1123
1124               added_new_object = true;
1125             }
1126           else
1127             {
1128               if (member.sd_ != NULL)
1129                 {
1130                   // The file must be locked in order to destroy the views
1131                   // associated with it.
1132                   gold_assert(obj != NULL);
1133                   obj->lock(this->task_);
1134                   delete member.sd_;
1135                   obj->unlock(this->task_);
1136                 }
1137             }
1138
1139           this->members_[i] = this->members_.back();
1140           this->members_.pop_back();
1141         }
1142     }
1143   while (added_new_object);
1144 }
1145
1146 // Include a lib group member in the link.
1147
1148 void
1149 Lib_group::include_member(Symbol_table* symtab, Layout* layout,
1150                           Input_objects* input_objects,
1151                           const Archive_member& member)
1152 {
1153   ++Lib_group::total_members_loaded;
1154
1155   Object* obj = member.obj_;
1156   gold_assert(obj != NULL);
1157
1158   Pluginobj* pluginobj = obj->pluginobj();
1159   if (pluginobj != NULL)
1160     {
1161       pluginobj->add_symbols(symtab, NULL, layout);
1162       return;
1163     }
1164
1165   Read_symbols_data* sd = member.sd_;
1166   gold_assert(sd != NULL);
1167   obj->lock(this->task_);
1168   if (input_objects->add_object(obj))
1169     {
1170       // FIXME: Record incremental link info for --start-lib/--end-lib.
1171       if (layout->incremental_inputs() != NULL)
1172         layout->incremental_inputs()->report_object(obj, NULL);
1173       obj->layout(symtab, layout, sd);
1174       obj->add_symbols(symtab, sd, layout);
1175     }
1176   delete sd;
1177   // Unlock the file for the next task.
1178   obj->unlock(this->task_);
1179 }
1180
1181 // Print statistical information to stderr.  This is used for --stats.
1182
1183 void
1184 Lib_group::print_stats()
1185 {
1186   fprintf(stderr, _("%s: lib groups: %u\n"),
1187           program_name, Lib_group::total_lib_groups);
1188   fprintf(stderr, _("%s: total lib groups members: %u\n"),
1189           program_name, Lib_group::total_members);
1190   fprintf(stderr, _("%s: loaded lib groups members: %u\n"),
1191           program_name, Lib_group::total_members_loaded);
1192 }
1193
1194 Task_token*
1195 Add_lib_group_symbols::is_runnable()
1196 {
1197   if (this->readsyms_blocker_ != NULL && this->readsyms_blocker_->is_blocked())
1198     return this->readsyms_blocker_;
1199   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
1200     return this->this_blocker_;
1201   return NULL;
1202 }
1203
1204 void
1205 Add_lib_group_symbols::locks(Task_locker* tl)
1206 {
1207   tl->add(this, this->next_blocker_);
1208 }
1209
1210 void
1211 Add_lib_group_symbols::run(Workqueue*)
1212 {
1213   this->lib_->add_symbols(this->symtab_, this->layout_, this->input_objects_);
1214
1215   // FIXME: Record incremental link info for --start_lib/--end_lib.
1216 }
1217
1218 Add_lib_group_symbols::~Add_lib_group_symbols()
1219 {
1220   if (this->this_blocker_ != NULL)
1221     delete this->this_blocker_;
1222   // next_blocker_ is deleted by the task associated with the next
1223   // input file.
1224 }
1225
1226 } // End namespace gold.