gold/archive.cc

   1 // archive.cc -- archive support for gold
   2
   3 // Copyright (C) 2006-2015 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 // Library_base methods.
  48
  49 // Determine whether a definition of SYM_NAME should cause an archive
  50 // library member to be included in the link.  Returns SHOULD_INCLUDE_YES
  51 // if the symbol is referenced but not defined, SHOULD_INCLUDE_NO if the
  52 // symbol is already defined, and SHOULD_INCLUDE_UNKNOWN if the symbol is
  53 // neither referenced nor defined.
  54
  55 Library_base::Should_include
  56 Library_base::should_include_member(Symbol_table* symtab, Layout* layout,
  57                                     const char* sym_name, Symbol** symp,
  58                                     std::string* why, char** tmpbufp,
  59                                     size_t* tmpbuflen)
  60 {
  61   // In an object file, and therefore in an archive map, an
  62   // '@' in the name separates the symbol name from the
  63   // version name.  If there are two '@' characters, this is
  64   // the default version.
  65   char* tmpbuf = *tmpbufp;
  66   const char* ver = strchr(sym_name, '@');
  67   bool def = false;
  68   if (ver != NULL)
  69     {
  70       size_t symlen = ver - sym_name;
  71       if (symlen + 1 > *tmpbuflen)
  72         {
  73           tmpbuf = static_cast<char*>(xrealloc(tmpbuf, symlen + 1));
  74           *tmpbufp = tmpbuf;
  75           *tmpbuflen = symlen + 1;
  76         }
  77       memcpy(tmpbuf, sym_name, symlen);
  78       tmpbuf[symlen] = '\0';
  79       sym_name = tmpbuf;
  80
  81       ++ver;
  82       if (*ver == '@')
  83         {
  84           ++ver;
  85           def = true;
  86         }
  87     }
  88
  89   Symbol* sym = symtab->lookup(sym_name, ver);
  90   if (def
  91       && ver != NULL
  92       && (sym == NULL
  93           || !sym->is_undefined()
  94           || sym->binding() == elfcpp::STB_WEAK))
  95     sym = symtab->lookup(sym_name, NULL);
  96
  97   *symp = sym;
  98
  99   if (sym != NULL)
 100     {
 101       if (!sym->is_undefined())
 102         return Library_base::SHOULD_INCLUDE_NO;
 103
 104       // PR 12001: Do not include an archive when the undefined
 105       // symbol has actually been defined on the command line.
 106       if (layout->script_options()->is_pending_assignment(sym_name))
 107         return Library_base::SHOULD_INCLUDE_NO;
 108
 109       // If the symbol is weak undefined, we still need to check
 110       // for other reasons (like a -u option).
 111       if (sym->binding() != elfcpp::STB_WEAK)
 112         return Library_base::SHOULD_INCLUDE_YES;
 113     }
 114
 115   // Check whether the symbol was named in a -u option.
 116   if (parameters->options().is_undefined(sym_name))
 117     {
 118       *why = "-u ";
 119       *why += sym_name;
 120       return Library_base::SHOULD_INCLUDE_YES;
 121     }
 122
 123   if (parameters->options().is_export_dynamic_symbol(sym_name))
 124     {
 125       *why = "--export-dynamic-symbol ";
 126       *why += sym_name;
 127       return Library_base::SHOULD_INCLUDE_YES;
 128     }
 129
 130   if (layout->script_options()->is_referenced(sym_name))
 131     {
 132       size_t alc = 100 + strlen(sym_name);
 133       char* buf = new char[alc];
 134       snprintf(buf, alc, _("script or expression reference to %s"),
 135                sym_name);
 136       *why = buf;
 137       delete[] buf;
 138       return Library_base::SHOULD_INCLUDE_YES;
 139     }
 140
 141   if (strcmp(sym_name, parameters->entry()) == 0)
 142     {
 143       *why = "entry symbol ";
 144       *why += sym_name;
 145       return Library_base::SHOULD_INCLUDE_YES;
 146     }
 147
 148   return Library_base::SHOULD_INCLUDE_UNKNOWN;
 149 }
 150
 151 // The header of an entry in the archive.  This is all readable text,
 152 // padded with spaces where necessary.  If the contents of an archive
 153 // are all text file, the entire archive is readable.
 154
 155 struct Archive::Archive_header
 156 {
 157   // The entry name.
 158   char ar_name[16];
 159   // The file modification time.
 160   char ar_date[12];
 161   // The user's UID in decimal.
 162   char ar_uid[6];
 163   // The user's GID in decimal.
 164   char ar_gid[6];
 165   // The file mode in octal.
 166   char ar_mode[8];
 167   // The file size in decimal.
 168   char ar_size[10];
 169   // The final magic code.
 170   char ar_fmag[2];
 171 };
 172
 173 // Class Archive static variables.
 174 unsigned int Archive::total_archives;
 175 unsigned int Archive::total_members;
 176 unsigned int Archive::total_members_loaded;
 177
 178 // Archive methods.
 179
 180 const char Archive::armag[sarmag] =
 181 {
 182   '!', '<', 'a', 'r', 'c', 'h', '>', '\n'
 183 };
 184
 185 const char Archive::armagt[sarmag] =
 186 {
 187   '!', '<', 't', 'h', 'i', 'n', '>', '\n'
 188 };
 189
 190 const char Archive::arfmag[2] = { '`', '\n' };
 191
 192 Archive::Archive(const std::string& name, Input_file* input_file,
 193                  bool is_thin_archive, Dirsearch* dirpath, Task* task)
 194   : Library_base(task), name_(name), input_file_(input_file), armap_(),
 195     armap_names_(), extended_names_(), armap_checked_(), seen_offsets_(),
 196     members_(), is_thin_archive_(is_thin_archive), included_member_(false),
 197     nested_archives_(), dirpath_(dirpath), num_members_(0),
 198     included_all_members_(false)
 199 {
 200   this->no_export_ =
 201     parameters->options().check_excluded_libs(input_file->found_name());
 202 }
 203
 204 // Set up the archive: read the symbol map and the extended name
 205 // table.
 206
 207 void
 208 Archive::setup()
 209 {
 210   // We need to ignore empty archives.
 211   if (this->input_file_->file().filesize() == sarmag)
 212     return;
 213
 214   // The first member of the archive should be the symbol table.
 215   std::string armap_name;
 216   off_t header_size = this->read_header(sarmag, false, &armap_name, NULL);
 217   if (header_size == -1)
 218     return;
 219
 220   section_size_type armap_size = convert_to_section_size_type(header_size);
 221   off_t off = sarmag;
 222   if (armap_name.empty())
 223     {
 224       this->read_armap(sarmag + sizeof(Archive_header), armap_size);
 225       off = sarmag + sizeof(Archive_header) + armap_size;
 226     }
 227   else if (!this->input_file_->options().whole_archive())
 228     gold_error(_("%s: no archive symbol table (run ranlib)"),
 229                this->name().c_str());
 230
 231   // See if there is an extended name table.  We cache these views
 232   // because it is likely that we will want to read the following
 233   // header in the add_symbols routine.
 234   if ((off & 1) != 0)
 235     ++off;
 236   std::string xname;
 237   header_size = this->read_header(off, true, &xname, NULL);
 238   if (header_size == -1)
 239     return;
 240
 241   section_size_type extended_size = convert_to_section_size_type(header_size);
 242   if (xname == "/")
 243     {
 244       const unsigned char* p = this->get_view(off + sizeof(Archive_header),
 245                                               extended_size, false, true);
 246       const char* px = reinterpret_cast<const char*>(p);
 247       this->extended_names_.assign(px, extended_size);
 248     }
 249   bool preread_syms = (parameters->options().threads()
 250                        && parameters->options().preread_archive_symbols());
 251 #ifndef ENABLE_THREADS
 252   preread_syms = false;
 253 #else
 254   if (parameters->options().has_plugins())
 255     preread_syms = false;
 256 #endif
 257   if (preread_syms)
 258     this->read_all_symbols();
 259 }
 260
 261 // Unlock any nested archives.
 262
 263 void
 264 Archive::unlock_nested_archives()
 265 {
 266   for (Nested_archive_table::iterator p = this->nested_archives_.begin();
 267        p != this->nested_archives_.end();
 268        ++p)
 269     {
 270       p->second->unlock(this->task_);
 271     }
 272 }
 273
 274 // Read the archive symbol map.
 275
 276 void
 277 Archive::read_armap(off_t start, section_size_type size)
 278 {
 279   // To count the total number of archive members, we'll just count
 280   // the number of times the file offset changes.  Since most archives
 281   // group the symbols in the armap by object, this ought to give us
 282   // an accurate count.
 283   off_t last_seen_offset = -1;
 284
 285   // Read in the entire armap.
 286   const unsigned char* p = this->get_view(start, size, true, false);
 287
 288   // Numbers in the armap are always big-endian.
 289   const elfcpp::Elf_Word* pword = reinterpret_cast<const elfcpp::Elf_Word*>(p);
 290   unsigned int nsyms = elfcpp::Swap<32, true>::readval(pword);
 291   ++pword;
 292
 293   // Note that the addition is in units of sizeof(elfcpp::Elf_Word).
 294   const char* pnames = reinterpret_cast<const char*>(pword + nsyms);
 295   section_size_type names_size =
 296     reinterpret_cast<const char*>(p) + size - pnames;
 297   this->armap_names_.assign(pnames, names_size);
 298
 299   this->armap_.resize(nsyms);
 300
 301   section_offset_type name_offset = 0;
 302   for (unsigned int i = 0; i < nsyms; ++i)
 303     {
 304       this->armap_[i].name_offset = name_offset;
 305       this->armap_[i].file_offset = elfcpp::Swap<32, true>::readval(pword);
 306       name_offset += strlen(pnames + name_offset) + 1;
 307       ++pword;
 308       if (this->armap_[i].file_offset != last_seen_offset)
 309         {
 310           last_seen_offset = this->armap_[i].file_offset;
 311           ++this->num_members_;
 312         }
 313     }
 314
 315   if (static_cast<section_size_type>(name_offset) > names_size)
 316     gold_error(_("%s: bad archive symbol table names"),
 317                this->name().c_str());
 318
 319   // This array keeps track of which symbols are for archive elements
 320   // which we have already included in the link.
 321   this->armap_checked_.resize(nsyms);
 322 }
 323
 324 // Read the header of an archive member at OFF.  Fail if something
 325 // goes wrong.  Return the size of the member.  Set *PNAME to the name
 326 // of the member.
 327
 328 off_t
 329 Archive::read_header(off_t off, bool cache, std::string* pname,
 330                      off_t* nested_off)
 331 {
 332   const unsigned char* p = this->get_view(off, sizeof(Archive_header), true,
 333                                           cache);
 334   const Archive_header* hdr = reinterpret_cast<const Archive_header*>(p);
 335   return this->interpret_header(hdr, off,  pname, nested_off);
 336 }
 337
 338 // Interpret the header of HDR, the header of the archive member at
 339 // file offset OFF.  Return the size of the member, or -1 if something
 340 // has gone wrong.  Set *PNAME to the name of the member.
 341
 342 off_t
 343 Archive::interpret_header(const Archive_header* hdr, off_t off,
 344                           std::string* pname, off_t* nested_off) const
 345 {
 346   if (memcmp(hdr->ar_fmag, arfmag, sizeof arfmag) != 0)
 347     {
 348       gold_error(_("%s: malformed archive header at %zu"),
 349                  this->name().c_str(), static_cast<size_t>(off));
 350       return -1;
 351     }
 352
 353   const int size_string_size = sizeof hdr->ar_size;
 354   char size_string[size_string_size + 1];
 355   memcpy(size_string, hdr->ar_size, size_string_size);
 356   char* ps = size_string + size_string_size;
 357   while (ps[-1] == ' ')
 358     --ps;
 359   *ps = '\0';
 360
 361   errno = 0;
 362   char* end;
 363   off_t member_size = strtol(size_string, &end, 10);
 364   if (*end != '\0'
 365       || member_size < 0
 366       || (member_size == LONG_MAX && errno == ERANGE))
 367     {
 368       gold_error(_("%s: malformed archive header size at %zu"),
 369                  this->name().c_str(), static_cast<size_t>(off));
 370       return -1;
 371     }
 372
 373   if (hdr->ar_name[0] != '/')
 374     {
 375       const char* name_end = strchr(hdr->ar_name, '/');
 376       if (name_end == NULL
 377           || name_end - hdr->ar_name >= static_cast<int>(sizeof hdr->ar_name))
 378         {
 379           gold_error(_("%s: malformed archive header name at %zu"),
 380                      this->name().c_str(), static_cast<size_t>(off));
 381           return -1;
 382         }
 383       pname->assign(hdr->ar_name, name_end - hdr->ar_name);
 384       if (nested_off != NULL)
 385         *nested_off = 0;
 386     }
 387   else if (hdr->ar_name[1] == ' ')
 388     {
 389       // This is the symbol table.
 390       if (!pname->empty())
 391         pname->clear();
 392     }
 393   else if (hdr->ar_name[1] == '/')
 394     {
 395       // This is the extended name table.
 396       pname->assign(1, '/');
 397     }
 398   else
 399     {
 400       errno = 0;
 401       long x = strtol(hdr->ar_name + 1, &end, 10);
 402       long y = 0;
 403       if (*end == ':')
 404         y = strtol(end + 1, &end, 10);
 405       if (*end != ' '
 406           || x < 0
 407           || (x == LONG_MAX && errno == ERANGE)
 408           || static_cast<size_t>(x) >= this->extended_names_.size())
 409         {
 410           gold_error(_("%s: bad extended name index at %zu"),
 411                      this->name().c_str(), static_cast<size_t>(off));
 412           return -1;
 413         }
 414
 415       const char* name = this->extended_names_.data() + x;
 416       const char* name_end = strchr(name, '\n');
 417       if (static_cast<size_t>(name_end - name) > this->extended_names_.size()
 418           || name_end[-1] != '/')
 419         {
 420           gold_error(_("%s: bad extended name entry at header %zu"),
 421                      this->name().c_str(), static_cast<size_t>(off));
 422           return -1;
 423         }
 424       pname->assign(name, name_end - 1 - name);
 425       if (nested_off != NULL)
 426         *nested_off = y;
 427     }
 428
 429   return member_size;
 430 }
 431
 432 // An archive member iterator.
 433
 434 class Archive::const_iterator
 435 {
 436  public:
 437   // The header of an archive member.  This is what this iterator
 438   // points to.
 439   struct Header
 440   {
 441     // The name of the member.
 442     std::string name;
 443     // The file offset of the member.
 444     off_t off;
 445     // The file offset of a nested archive member.
 446     off_t nested_off;
 447     // The size of the member.
 448     off_t size;
 449   };
 450
 451   const_iterator(Archive* archive, off_t off)
 452     : archive_(archive), off_(off)
 453   { this->read_next_header(); }
 454
 455   const Header&
 456   operator*() const
 457   { return this->header_; }
 458
 459   const Header*
 460   operator->() const
 461   { return &this->header_; }
 462
 463   const_iterator&
 464   operator++()
 465   {
 466     if (this->off_ == this->archive_->file().filesize())
 467       return *this;
 468     this->off_ += sizeof(Archive_header);
 469     if (!this->archive_->is_thin_archive())
 470       this->off_ += this->header_.size;
 471     if ((this->off_ & 1) != 0)
 472       ++this->off_;
 473     this->read_next_header();
 474     return *this;
 475   }
 476
 477   const_iterator
 478   operator++(int)
 479   {
 480     const_iterator ret = *this;
 481     ++*this;
 482     return ret;
 483   }
 484
 485   bool
 486   operator==(const const_iterator p) const
 487   { return this->off_ == p->off; }
 488
 489   bool
 490   operator!=(const const_iterator p) const
 491   { return this->off_ != p->off; }
 492
 493  private:
 494   void
 495   read_next_header();
 496
 497   // The underlying archive.
 498   Archive* archive_;
 499   // The current offset in the file.
 500   off_t off_;
 501   // The current archive header.
 502   Header header_;
 503 };
 504
 505 // Read the next archive header.
 506
 507 void
 508 Archive::const_iterator::read_next_header()
 509 {
 510   off_t filesize = this->archive_->file().filesize();
 511   while (true)
 512     {
 513       if (filesize - this->off_ < static_cast<off_t>(sizeof(Archive_header)))
 514         {
 515           if (filesize != this->off_)
 516             {
 517               gold_error(_("%s: short archive header at %zu"),
 518                          this->archive_->filename().c_str(),
 519                          static_cast<size_t>(this->off_));
 520               this->off_ = filesize;
 521             }
 522           this->header_.off = filesize;
 523           return;
 524         }
 525
 526       unsigned char buf[sizeof(Archive_header)];
 527       this->archive_->file().read(this->off_, sizeof(Archive_header), buf);
 528
 529       const Archive_header* hdr = reinterpret_cast<const Archive_header*>(buf);
 530       off_t size = this->archive_->interpret_header(hdr, this->off_,
 531                                                     &this->header_.name,
 532                                                     &this->header_.nested_off);
 533       if (size == -1)
 534         {
 535           this->header_.off = filesize;
 536           return;
 537         }
 538
 539       this->header_.size = size;
 540       this->header_.off = this->off_;
 541
 542       // Skip special members.
 543       if (!this->header_.name.empty() && this->header_.name != "/")
 544         return;
 545
 546       this->off_ += sizeof(Archive_header) + this->header_.size;
 547       if ((this->off_ & 1) != 0)
 548         ++this->off_;
 549     }
 550 }
 551
 552 // Initial iterator.
 553
 554 Archive::const_iterator
 555 Archive::begin()
 556 {
 557   return Archive::const_iterator(this, sarmag);
 558 }
 559
 560 // Final iterator.
 561
 562 Archive::const_iterator
 563 Archive::end()
 564 {
 565   return Archive::const_iterator(this, this->input_file_->file().filesize());
 566 }
 567
 568 // Get the file and offset for an archive member, which may be an
 569 // external member of a thin archive.  Set *INPUT_FILE to the
 570 // file containing the actual member, *MEMOFF to the offset
 571 // within that file (0 if not a nested archive), and *MEMBER_NAME
 572 // to the name of the archive member.  Return TRUE on success.
 573
 574 bool
 575 Archive::get_file_and_offset(off_t off, Input_file** input_file, off_t* memoff,
 576                              off_t* memsize, std::string* member_name)
 577 {
 578   off_t nested_off;
 579
 580   *memsize = this->read_header(off, false, member_name, &nested_off);
 581   if (*memsize == -1)
 582     return false;
 583
 584   *input_file = this->input_file_;
 585   *memoff = off + static_cast<off_t>(sizeof(Archive_header));
 586
 587   if (!this->is_thin_archive_)
 588     return true;
 589
 590   // Adjust a relative pathname so that it is relative
 591   // to the directory containing the archive.
 592   if (!IS_ABSOLUTE_PATH(member_name->c_str()))
 593     {
 594       const char* arch_path = this->filename().c_str();
 595       const char* basename = lbasename(arch_path);
 596       if (basename > arch_path)
 597         member_name->replace(0, 0,
 598                              this->filename().substr(0, basename - arch_path));
 599     }
 600
 601   if (nested_off > 0)
 602     {
 603       // This is a member of a nested archive.  Open the containing
 604       // archive if we don't already have it open, then do a recursive
 605       // call to include the member from that archive.
 606       Archive* arch;
 607       Nested_archive_table::const_iterator p =
 608         this->nested_archives_.find(*member_name);
 609       if (p != this->nested_archives_.end())
 610         arch = p->second;
 611       else
 612         {
 613           Input_file_argument* input_file_arg =
 614             new Input_file_argument(member_name->c_str(),
 615                                     Input_file_argument::INPUT_FILE_TYPE_FILE,
 616                                     "", false, parameters->options());
 617           *input_file = new Input_file(input_file_arg);
 618           int dummy = 0;
 619           if (!(*input_file)->open(*this->dirpath_, this->task_, &dummy))
 620             return false;
 621           arch = new Archive(*member_name, *input_file, false, this->dirpath_,
 622                              this->task_);
 623           arch->setup();
 624           std::pair<Nested_archive_table::iterator, bool> ins =
 625             this->nested_archives_.insert(std::make_pair(*member_name, arch));
 626           gold_assert(ins.second);
 627         }
 628       return arch->get_file_and_offset(nested_off, input_file, memoff,
 629                                        memsize, member_name);
 630     }
 631
 632   // This is an external member of a thin archive.  Open the
 633   // file as a regular relocatable object file.
 634   Input_file_argument* input_file_arg =
 635       new Input_file_argument(member_name->c_str(),
 636                               Input_file_argument::INPUT_FILE_TYPE_FILE,
 637                               "", false, this->input_file_->options());
 638   *input_file = new Input_file(input_file_arg);
 639   int dummy = 0;
 640   if (!(*input_file)->open(*this->dirpath_, this->task_, &dummy))
 641     return false;
 642
 643   *memoff = 0;
 644   *memsize = (*input_file)->file().filesize();
 645   return true;
 646 }
 647
 648 // Return an ELF object for the member at offset OFF.  If
 649 // PUNCONFIGURED is not NULL, then if the ELF object has an
 650 // unsupported target type, set *PUNCONFIGURED to true and return
 651 // NULL.
 652
 653 Object*
 654 Archive::get_elf_object_for_member(off_t off, bool* punconfigured)
 655 {
 656   if (punconfigured != NULL)
 657     *punconfigured = false;
 658
 659   Input_file* input_file;
 660   off_t memoff;
 661   off_t memsize;
 662   std::string member_name;
 663   if (!this->get_file_and_offset(off, &input_file, &memoff, &memsize,
 664                                  &member_name))
 665     return NULL;
 666
 667   const unsigned char* ehdr;
 668   int read_size;
 669   Object *obj = NULL;
 670   bool is_elf_obj = false;
 671
 672   if (is_elf_object(input_file, memoff, &ehdr, &read_size))
 673     {
 674       obj = make_elf_object((std::string(this->input_file_->filename())
 675                              + "(" + member_name + ")"),
 676                             input_file, memoff, ehdr, read_size,
 677                             punconfigured);
 678       is_elf_obj = true;
 679     }
 680
 681   if (parameters->options().has_plugins())
 682     {
 683       Object* plugin_obj
 684         = parameters->options().plugins()->claim_file(input_file,
 685                                                       memoff,
 686                                                       memsize,
 687                                                       obj);
 688       if (plugin_obj != NULL)
 689         {
 690           // The input file was claimed by a plugin, and its symbols
 691           // have been provided by the plugin.
 692           // Delete its elf object.
 693           if (obj != NULL)
 694             delete obj;
 695           return plugin_obj;
 696         }
 697     }
 698
 699   if (!is_elf_obj)
 700     {
 701       gold_error(_("%s: member at %zu is not an ELF object"),
 702                  this->name().c_str(), static_cast<size_t>(off));
 703       return NULL;
 704     }
 705
 706   if (obj == NULL)
 707     return NULL;
 708   obj->set_no_export(this->no_export());
 709   return obj;
 710 }
 711
 712 // Read the symbols from all the archive members in the link.
 713
 714 void
 715 Archive::read_all_symbols()
 716 {
 717   for (Archive::const_iterator p = this->begin();
 718        p != this->end();
 719        ++p)
 720     this->read_symbols(p->off);
 721 }
 722
 723 // Read the symbols from an archive member in the link.  OFF is the file
 724 // offset of the member header.
 725
 726 void
 727 Archive::read_symbols(off_t off)
 728 {
 729   Object* obj = this->get_elf_object_for_member(off, NULL);
 730   if (obj == NULL)
 731     return;
 732
 733   Read_symbols_data* sd = new Read_symbols_data;
 734   obj->read_symbols(sd);
 735   Archive_member member(obj, sd);
 736   this->members_[off] = member;
 737 }
 738
 739 // Select members from the archive and add them to the link.  We walk
 740 // through the elements in the archive map, and look each one up in
 741 // the symbol table.  If it exists as a strong undefined symbol, we
 742 // pull in the corresponding element.  We have to do this in a loop,
 743 // since pulling in one element may create new undefined symbols which
 744 // may be satisfied by other objects in the archive.  Return true in
 745 // the normal case, false if the first member we tried to add from
 746 // this archive had an incompatible target.
 747
 748 bool
 749 Archive::add_symbols(Symbol_table* symtab, Layout* layout,
 750                      Input_objects* input_objects, Mapfile* mapfile)
 751 {
 752   ++Archive::total_archives;
 753
 754   if (this->input_file_->options().whole_archive())
 755     return this->include_all_members(symtab, layout, input_objects,
 756                                      mapfile);
 757
 758   Archive::total_members += this->num_members_;
 759
 760   input_objects->archive_start(this);
 761
 762   const size_t armap_size = this->armap_.size();
 763
 764   // This is a quick optimization, since we usually see many symbols
 765   // in a row with the same offset.  last_seen_offset holds the last
 766   // offset we saw that was present in the seen_offsets_ set.
 767   off_t last_seen_offset = -1;
 768
 769   // Track which symbols in the symbol table we've already found to be
 770   // defined.
 771
 772   char* tmpbuf = NULL;
 773   size_t tmpbuflen = 0;
 774   bool added_new_object;
 775   do
 776     {
 777       added_new_object = false;
 778       for (size_t i = 0; i < armap_size; ++i)
 779         {
 780           if (this->armap_checked_[i])
 781             continue;
 782           if (this->armap_[i].file_offset == last_seen_offset)
 783             {
 784               this->armap_checked_[i] = true;
 785               continue;
 786             }
 787           if (this->seen_offsets_.find(this->armap_[i].file_offset)
 788               != this->seen_offsets_.end())
 789             {
 790               this->armap_checked_[i] = true;
 791               last_seen_offset = this->armap_[i].file_offset;
 792               continue;
 793             }
 794
 795           const char* sym_name = (this->armap_names_.data()
 796                                   + this->armap_[i].name_offset);
 797
 798           Symbol* sym;
 799           std::string why;
 800           Archive::Should_include t =
 801             Archive::should_include_member(symtab, layout, sym_name, &sym,
 802                                            &why, &tmpbuf, &tmpbuflen);
 803
 804           if (t == Archive::SHOULD_INCLUDE_NO
 805               || t == Archive::SHOULD_INCLUDE_YES)
 806             this->armap_checked_[i] = true;
 807
 808           if (t != Archive::SHOULD_INCLUDE_YES)
 809             continue;
 810
 811           // We want to include this object in the link.
 812           last_seen_offset = this->armap_[i].file_offset;
 813           this->seen_offsets_.insert(last_seen_offset);
 814
 815           if (!this->include_member(symtab, layout, input_objects,
 816                                     last_seen_offset, mapfile, sym,
 817                                     why.c_str()))
 818             {
 819               if (tmpbuf != NULL)
 820                 free(tmpbuf);
 821               return false;
 822             }
 823
 824           added_new_object = true;
 825         }
 826     }
 827   while (added_new_object);
 828
 829   if (tmpbuf != NULL)
 830     free(tmpbuf);
 831
 832   input_objects->archive_stop(this);
 833
 834   return true;
 835 }
 836
 837 // Return whether the archive includes a member which defines the
 838 // symbol SYM.
 839
 840 bool
 841 Archive::defines_symbol(Symbol* sym) const
 842 {
 843   const char* symname = sym->name();
 844   size_t symname_len = strlen(symname);
 845   size_t armap_size = this->armap_.size();
 846   for (size_t i = 0; i < armap_size; ++i)
 847     {
 848       if (this->armap_checked_[i])
 849         continue;
 850       const char* archive_symname = (this->armap_names_.data()
 851                                      + this->armap_[i].name_offset);
 852       if (strncmp(archive_symname, symname, symname_len) != 0)
 853         continue;
 854       char c = archive_symname[symname_len];
 855       if (c == '\0' && sym->version() == NULL)
 856         return true;
 857       if (c == '@')
 858         {
 859           const char* ver = archive_symname + symname_len + 1;
 860           if (*ver == '@')
 861             {
 862               if (sym->version() == NULL)
 863                 return true;
 864               ++ver;
 865             }
 866           if (sym->version() != NULL && strcmp(sym->version(), ver) == 0)
 867             return true;
 868         }
 869     }
 870   return false;
 871 }
 872
 873 // Include all the archive members in the link.  This is for --whole-archive.
 874
 875 bool
 876 Archive::include_all_members(Symbol_table* symtab, Layout* layout,
 877                              Input_objects* input_objects, Mapfile* mapfile)
 878 {
 879   // Don't include the same archive twice.  This can happen if
 880   // --whole-archive is nested inside --start-group (PR gold/12163).
 881   if (this->included_all_members_)
 882     return true;
 883
 884   this->included_all_members_ = true;
 885
 886   input_objects->archive_start(this);
 887
 888   if (this->members_.size() > 0)
 889     {
 890       std::map<off_t, Archive_member>::const_iterator p;
 891       for (p = this->members_.begin();
 892            p != this->members_.end();
 893            ++p)
 894         {
 895           if (!this->include_member(symtab, layout, input_objects, p->first,
 896                                     mapfile, NULL, "--whole-archive"))
 897             return false;
 898           ++Archive::total_members;
 899         }
 900     }
 901   else
 902     {
 903       for (Archive::const_iterator p = this->begin();
 904            p != this->end();
 905            ++p)
 906         {
 907           if (!this->include_member(symtab, layout, input_objects, p->off,
 908                                     mapfile, NULL, "--whole-archive"))
 909             return false;
 910           ++Archive::total_members;
 911         }
 912     }
 913
 914   input_objects->archive_stop(this);
 915
 916   return true;
 917 }
 918
 919 // Return the number of members in the archive.  This is only used for
 920 // reports.
 921
 922 size_t
 923 Archive::count_members()
 924 {
 925   size_t ret = 0;
 926   for (Archive::const_iterator p = this->begin();
 927        p != this->end();
 928        ++p)
 929     ++ret;
 930   return ret;
 931 }
 932
 933 // RAII class to ensure we unlock the object if it's a member of a
 934 // thin archive. We can't use Task_lock_obj in Archive::include_member
 935 // because the object file is already locked when it's opened by
 936 // get_elf_object_for_member.
 937
 938 class Thin_archive_object_unlocker
 939 {
 940  public:
 941   Thin_archive_object_unlocker(const Task *task, Object* obj)
 942     : task_(task), obj_(obj)
 943   { }
 944
 945   ~Thin_archive_object_unlocker()
 946   {
 947     if (this->obj_->offset() == 0)
 948       this->obj_->unlock(this->task_);
 949   }
 950
 951  private:
 952   Thin_archive_object_unlocker(const Thin_archive_object_unlocker&);
 953   Thin_archive_object_unlocker& operator=(const Thin_archive_object_unlocker&);
 954
 955   const Task* task_;
 956   Object* obj_;
 957 };
 958
 959 // Include an archive member in the link.  OFF is the file offset of
 960 // the member header.  WHY is the reason we are including this member.
 961 // Return true if we added the member or if we had an error, return
 962 // false if this was the first member we tried to add from this
 963 // archive and it had an incompatible format.
 964
 965 bool
 966 Archive::include_member(Symbol_table* symtab, Layout* layout,
 967                         Input_objects* input_objects, off_t off,
 968                         Mapfile* mapfile, Symbol* sym, const char* why)
 969 {
 970   ++Archive::total_members_loaded;
 971
 972   std::map<off_t, Archive_member>::const_iterator p = this->members_.find(off);
 973   if (p != this->members_.end())
 974     {
 975       Object* obj = p->second.obj_;
 976
 977       Read_symbols_data* sd = p->second.sd_;
 978       if (mapfile != NULL)
 979         mapfile->report_include_archive_member(obj->name(), sym, why);
 980       if (input_objects->add_object(obj))
 981         {
 982           obj->layout(symtab, layout, sd);
 983           obj->add_symbols(symtab, sd, layout);
 984           this->included_member_ = true;
 985         }
 986       delete sd;
 987       return true;
 988     }
 989
 990   // If this is the first object we are including from this archive,
 991   // and we searched for this archive, most likely because it was
 992   // found via a -l option, then if the target is incompatible we want
 993   // to move on to the next archive found in the search path.
 994   bool unconfigured = false;
 995   bool* punconfigured = NULL;
 996   if (!this->included_member_ && this->searched_for())
 997     punconfigured = &unconfigured;
 998
 999   Object* obj = this->get_elf_object_for_member(off, punconfigured);
1000   if (obj == NULL)
1001     {
1002       // Return false to search for another archive, true if we found
1003       // an error.
1004       return unconfigured ? false : true;
1005     }
1006
1007   // If the object is an external member of a thin archive,
1008   // unlock it when we're done here.
1009   Thin_archive_object_unlocker unlocker(this->task_, obj);
1010
1011   if (mapfile != NULL)
1012     mapfile->report_include_archive_member(obj->name(), sym, why);
1013
1014   Pluginobj* pluginobj = obj->pluginobj();
1015   if (pluginobj != NULL)
1016     {
1017       pluginobj->add_symbols(symtab, NULL, layout);
1018       this->included_member_ = true;
1019       return true;
1020     }
1021
1022   if (!input_objects->add_object(obj))
1023     {
1024       delete obj;
1025       return true;
1026     }
1027
1028   if (layout->incremental_inputs() != NULL)
1029     layout->incremental_inputs()->report_object(obj, 0, this, NULL);
1030
1031   {
1032     Read_symbols_data sd;
1033     obj->read_symbols(&sd);
1034     obj->layout(symtab, layout, &sd);
1035     obj->add_symbols(symtab, &sd, layout);
1036   }
1037
1038   this->included_member_ = true;
1039   return true;
1040 }
1041
1042 // Iterate over all unused symbols, and call the visitor class V for each.
1043
1044 void
1045 Archive::do_for_all_unused_symbols(Symbol_visitor_base* v) const
1046 {
1047   for (std::vector<Armap_entry>::const_iterator p = this->armap_.begin();
1048        p != this->armap_.end();
1049        ++p)
1050     {
1051       if (this->seen_offsets_.find(p->file_offset)
1052           == this->seen_offsets_.end())
1053         v->visit(this->armap_names_.data() + p->name_offset);
1054     }
1055 }
1056
1057 // Print statistical information to stderr.  This is used for --stats.
1058
1059 void
1060 Archive::print_stats()
1061 {
1062   fprintf(stderr, _("%s: archive libraries: %u\n"),
1063           program_name, Archive::total_archives);
1064   fprintf(stderr, _("%s: total archive members: %u\n"),
1065           program_name, Archive::total_members);
1066   fprintf(stderr, _("%s: loaded archive members: %u\n"),
1067           program_name, Archive::total_members_loaded);
1068 }
1069
1070 // Add_archive_symbols methods.
1071
1072 Add_archive_symbols::~Add_archive_symbols()
1073 {
1074   if (this->this_blocker_ != NULL)
1075     delete this->this_blocker_;
1076   // next_blocker_ is deleted by the task associated with the next
1077   // input file.
1078 }
1079
1080 // Return whether we can add the archive symbols.  We are blocked by
1081 // this_blocker_.  We block next_blocker_.  We also lock the file.
1082
1083 Task_token*
1084 Add_archive_symbols::is_runnable()
1085 {
1086   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
1087     return this->this_blocker_;
1088   return NULL;
1089 }
1090
1091 void
1092 Add_archive_symbols::locks(Task_locker* tl)
1093 {
1094   tl->add(this, this->next_blocker_);
1095   tl->add(this, this->archive_->token());
1096 }
1097
1098 void
1099 Add_archive_symbols::run(Workqueue* workqueue)
1100 {
1101   // For an incremental link, begin recording layout information.
1102   Incremental_inputs* incremental_inputs = this->layout_->incremental_inputs();
1103   if (incremental_inputs != NULL)
1104     {
1105       unsigned int arg_serial = this->input_argument_->file().arg_serial();
1106       Script_info* script_info = this->input_argument_->script_info();
1107       incremental_inputs->report_archive_begin(this->archive_, arg_serial,
1108                                                script_info);
1109     }
1110
1111   bool added = this->archive_->add_symbols(this->symtab_, this->layout_,
1112                                            this->input_objects_,
1113                                            this->mapfile_);
1114   this->archive_->unlock_nested_archives();
1115
1116   this->archive_->release();
1117   this->archive_->clear_uncached_views();
1118
1119   if (!added)
1120     {
1121       // This archive holds object files which are incompatible with
1122       // our output file.
1123       Read_symbols::incompatible_warning(this->input_argument_,
1124                                          this->archive_->input_file());
1125       Read_symbols::requeue(workqueue, this->input_objects_, this->symtab_,
1126                             this->layout_, this->dirpath_, this->dirindex_,
1127                             this->mapfile_, this->input_argument_,
1128                             this->input_group_, this->next_blocker_);
1129       delete this->archive_;
1130       return;
1131     }
1132
1133   if (this->input_group_ != NULL)
1134     this->input_group_->add_archive(this->archive_);
1135   else
1136     {
1137       // For an incremental link, finish recording the layout information.
1138       if (incremental_inputs != NULL)
1139         incremental_inputs->report_archive_end(this->archive_);
1140
1141       if (!parameters->options().has_plugins()
1142           || this->archive_->input_file()->options().whole_archive())
1143         {
1144           // We no longer need to know about this archive.
1145           delete this->archive_;
1146         }
1147       else
1148         {
1149           // The plugin interface may want to rescan this archive.
1150           parameters->options().plugins()->save_archive(this->archive_);
1151         }
1152
1153       this->archive_ = NULL;
1154     }
1155 }
1156
1157 // Class Lib_group static variables.
1158 unsigned int Lib_group::total_lib_groups;
1159 unsigned int Lib_group::total_members;
1160 unsigned int Lib_group::total_members_loaded;
1161
1162 Lib_group::Lib_group(const Input_file_lib* lib, Task* task)
1163   : Library_base(task), members_()
1164 {
1165   this->members_.resize(lib->size());
1166 }
1167
1168 const std::string&
1169 Lib_group::do_filename() const
1170 {
1171   std::string *filename = new std::string("/group/");
1172   return *filename;
1173 }
1174
1175 // Select members from the lib group and add them to the link.  We walk
1176 // through the members, and check if each one up should be included.
1177 // If the object says it should be included, we do so.  We have to do
1178 // this in a loop, since including one member may create new undefined
1179 // symbols which may be satisfied by other members.
1180
1181 void
1182 Lib_group::add_symbols(Symbol_table* symtab, Layout* layout,
1183                        Input_objects* input_objects)
1184 {
1185   ++Lib_group::total_lib_groups;
1186
1187   Lib_group::total_members += this->members_.size();
1188
1189   bool added_new_object;
1190   do
1191     {
1192       added_new_object = false;
1193       unsigned int i = 0;
1194       while (i < this->members_.size())
1195         {
1196           const Archive_member& member = this->members_[i];
1197           Object* obj = member.obj_;
1198           std::string why;
1199
1200           // Skip files with no symbols. Plugin objects have
1201           // member.sd_ == NULL.
1202           if (obj != NULL
1203               && (member.sd_ == NULL || member.sd_->symbol_names != NULL))
1204             {
1205               Archive::Should_include t = obj->should_include_member(symtab,
1206                                                                      layout,
1207                                                                      member.sd_,
1208                                                                      &why);
1209
1210               if (t != Archive::SHOULD_INCLUDE_YES)
1211                 {
1212                   ++i;
1213                   continue;
1214                 }
1215
1216               this->include_member(symtab, layout, input_objects, member);
1217
1218               added_new_object = true;
1219             }
1220           else
1221             {
1222               if (member.sd_ != NULL)
1223                 {
1224                   // The file must be locked in order to destroy the views
1225                   // associated with it.
1226                   gold_assert(obj != NULL);
1227                   obj->lock(this->task_);
1228                   delete member.sd_;
1229                   obj->unlock(this->task_);
1230                 }
1231             }
1232
1233           this->members_[i] = this->members_.back();
1234           this->members_.pop_back();
1235         }
1236     }
1237   while (added_new_object);
1238 }
1239
1240 // Include a lib group member in the link.
1241
1242 void
1243 Lib_group::include_member(Symbol_table* symtab, Layout* layout,
1244                           Input_objects* input_objects,
1245                           const Archive_member& member)
1246 {
1247   ++Lib_group::total_members_loaded;
1248
1249   Object* obj = member.obj_;
1250   gold_assert(obj != NULL);
1251
1252   Pluginobj* pluginobj = obj->pluginobj();
1253   if (pluginobj != NULL)
1254     {
1255       pluginobj->add_symbols(symtab, NULL, layout);
1256       return;
1257     }
1258
1259   Read_symbols_data* sd = member.sd_;
1260   gold_assert(sd != NULL);
1261   obj->lock(this->task_);
1262   if (input_objects->add_object(obj))
1263     {
1264       if (layout->incremental_inputs() != NULL)
1265         layout->incremental_inputs()->report_object(obj, member.arg_serial_,
1266                                                     this, NULL);
1267       obj->layout(symtab, layout, sd);
1268       obj->add_symbols(symtab, sd, layout);
1269     }
1270   delete sd;
1271   // Unlock the file for the next task.
1272   obj->unlock(this->task_);
1273 }
1274
1275 // Iterate over all unused symbols, and call the visitor class V for each.
1276
1277 void
1278 Lib_group::do_for_all_unused_symbols(Symbol_visitor_base* v) const
1279 {
1280   // Files are removed from the members list when used, so all the
1281   // files remaining on the list are unused.
1282   for (std::vector<Archive_member>::const_iterator p = this->members_.begin();
1283        p != this->members_.end();
1284        ++p)
1285     {
1286       Object* obj = p->obj_;
1287       obj->for_all_global_symbols(p->sd_, v);
1288     }
1289 }
1290
1291 // Print statistical information to stderr.  This is used for --stats.
1292
1293 void
1294 Lib_group::print_stats()
1295 {
1296   fprintf(stderr, _("%s: lib groups: %u\n"),
1297           program_name, Lib_group::total_lib_groups);
1298   fprintf(stderr, _("%s: total lib groups members: %u\n"),
1299           program_name, Lib_group::total_members);
1300   fprintf(stderr, _("%s: loaded lib groups members: %u\n"),
1301           program_name, Lib_group::total_members_loaded);
1302 }
1303
1304 Task_token*
1305 Add_lib_group_symbols::is_runnable()
1306 {
1307   if (this->readsyms_blocker_ != NULL && this->readsyms_blocker_->is_blocked())
1308     return this->readsyms_blocker_;
1309   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
1310     return this->this_blocker_;
1311   return NULL;
1312 }
1313
1314 void
1315 Add_lib_group_symbols::locks(Task_locker* tl)
1316 {
1317   tl->add(this, this->next_blocker_);
1318 }
1319
1320 void
1321 Add_lib_group_symbols::run(Workqueue*)
1322 {
1323   // For an incremental link, begin recording layout information.
1324   Incremental_inputs* incremental_inputs = this->layout_->incremental_inputs();
1325   if (incremental_inputs != NULL)
1326     incremental_inputs->report_archive_begin(this->lib_, 0, NULL);
1327
1328   this->lib_->add_symbols(this->symtab_, this->layout_, this->input_objects_);
1329
1330   if (incremental_inputs != NULL)
1331     incremental_inputs->report_archive_end(this->lib_);
1332 }
1333
1334 Add_lib_group_symbols::~Add_lib_group_symbols()
1335 {
1336   if (this->this_blocker_ != NULL)
1337     delete this->this_blocker_;
1338   // next_blocker_ is deleted by the task associated with the next
1339   // input file.
1340 }
1341
1342 } // End namespace gold.