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