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   const unsigned char* ehdr;
 658   int read_size;
 659   Object *obj = NULL;
 660   bool is_elf_obj = false;
 661
 662   if (is_elf_object(input_file, memoff, &ehdr, &read_size))
 663     {
 664       obj = make_elf_object((std::string(this->input_file_->filename())
 665                              + "(" + member_name + ")"),
 666                             input_file, memoff, ehdr, read_size,
 667                             punconfigured);
 668       is_elf_obj = true;
 669     }
 670
 671   if (parameters->options().has_plugins())
 672     {
 673       Object* plugin_obj
 674         = parameters->options().plugins()->claim_file(input_file,
 675                                                       memoff,
 676                                                       memsize,
 677                                                       obj);
 678       if (plugin_obj != NULL)
 679         {
 680           // The input file was claimed by a plugin, and its symbols
 681           // have been provided by the plugin.
 682           // Delete its elf object.
 683           if (obj != NULL)
 684             delete obj;
 685           return plugin_obj;
 686         }
 687     }
 688
 689   if (!is_elf_obj)
 690     {
 691       gold_error(_("%s: member at %zu is not an ELF object"),
 692                  this->name().c_str(), static_cast<size_t>(off));
 693       return NULL;
 694     }
 695
 696   if (obj == NULL)
 697     return NULL;
 698   obj->set_no_export(this->no_export());
 699   return obj;
 700 }
 701
 702 // Read the symbols from all the archive members in the link.
 703
 704 void
 705 Archive::read_all_symbols()
 706 {
 707   for (Archive::const_iterator p = this->begin();
 708        p != this->end();
 709        ++p)
 710     this->read_symbols(p->off);
 711 }
 712
 713 // Read the symbols from an archive member in the link.  OFF is the file
 714 // offset of the member header.
 715
 716 void
 717 Archive::read_symbols(off_t off)
 718 {
 719   Object* obj = this->get_elf_object_for_member(off, NULL);
 720   if (obj == NULL)
 721     return;
 722
 723   Read_symbols_data* sd = new Read_symbols_data;
 724   obj->read_symbols(sd);
 725   Archive_member member(obj, sd);
 726   this->members_[off] = member;
 727 }
 728
 729 // Select members from the archive and add them to the link.  We walk
 730 // through the elements in the archive map, and look each one up in
 731 // the symbol table.  If it exists as a strong undefined symbol, we
 732 // pull in the corresponding element.  We have to do this in a loop,
 733 // since pulling in one element may create new undefined symbols which
 734 // may be satisfied by other objects in the archive.  Return true in
 735 // the normal case, false if the first member we tried to add from
 736 // this archive had an incompatible target.
 737
 738 bool
 739 Archive::add_symbols(Symbol_table* symtab, Layout* layout,
 740                      Input_objects* input_objects, Mapfile* mapfile)
 741 {
 742   ++Archive::total_archives;
 743
 744   if (this->input_file_->options().whole_archive())
 745     return this->include_all_members(symtab, layout, input_objects,
 746                                      mapfile);
 747
 748   Archive::total_members += this->num_members_;
 749
 750   input_objects->archive_start(this);
 751
 752   const size_t armap_size = this->armap_.size();
 753
 754   // This is a quick optimization, since we usually see many symbols
 755   // in a row with the same offset.  last_seen_offset holds the last
 756   // offset we saw that was present in the seen_offsets_ set.
 757   off_t last_seen_offset = -1;
 758
 759   // Track which symbols in the symbol table we've already found to be
 760   // defined.
 761
 762   char* tmpbuf = NULL;
 763   size_t tmpbuflen = 0;
 764   bool added_new_object;
 765   do
 766     {
 767       added_new_object = false;
 768       for (size_t i = 0; i < armap_size; ++i)
 769         {
 770           if (this->armap_checked_[i])
 771             continue;
 772           if (this->armap_[i].file_offset == last_seen_offset)
 773             {
 774               this->armap_checked_[i] = true;
 775               continue;
 776             }
 777           if (this->seen_offsets_.find(this->armap_[i].file_offset)
 778               != this->seen_offsets_.end())
 779             {
 780               this->armap_checked_[i] = true;
 781               last_seen_offset = this->armap_[i].file_offset;
 782               continue;
 783             }
 784
 785           const char* sym_name = (this->armap_names_.data()
 786                                   + this->armap_[i].name_offset);
 787
 788           Symbol* sym;
 789           std::string why;
 790           Archive::Should_include t =
 791             Archive::should_include_member(symtab, layout, sym_name, &sym,
 792                                            &why, &tmpbuf, &tmpbuflen);
 793
 794           if (t == Archive::SHOULD_INCLUDE_NO
 795               || t == Archive::SHOULD_INCLUDE_YES)
 796             this->armap_checked_[i] = true;
 797
 798           if (t != Archive::SHOULD_INCLUDE_YES)
 799             continue;
 800
 801           // We want to include this object in the link.
 802           last_seen_offset = this->armap_[i].file_offset;
 803           this->seen_offsets_.insert(last_seen_offset);
 804
 805           if (!this->include_member(symtab, layout, input_objects,
 806                                     last_seen_offset, mapfile, sym,
 807                                     why.c_str()))
 808             {
 809               if (tmpbuf != NULL)
 810                 free(tmpbuf);
 811               return false;
 812             }
 813
 814           added_new_object = true;
 815         }
 816     }
 817   while (added_new_object);
 818
 819   if (tmpbuf != NULL)
 820     free(tmpbuf);
 821
 822   input_objects->archive_stop(this);
 823
 824   return true;
 825 }
 826
 827 // Return whether the archive includes a member which defines the
 828 // symbol SYM.
 829
 830 bool
 831 Archive::defines_symbol(Symbol* sym) const
 832 {
 833   const char* symname = sym->name();
 834   size_t symname_len = strlen(symname);
 835   size_t armap_size = this->armap_.size();
 836   for (size_t i = 0; i < armap_size; ++i)
 837     {
 838       if (this->armap_checked_[i])
 839         continue;
 840       const char* archive_symname = (this->armap_names_.data()
 841                                      + this->armap_[i].name_offset);
 842       if (strncmp(archive_symname, symname, symname_len) != 0)
 843         continue;
 844       char c = archive_symname[symname_len];
 845       if (c == '\0' && sym->version() == NULL)
 846         return true;
 847       if (c == '@')
 848         {
 849           const char* ver = archive_symname + symname_len + 1;
 850           if (*ver == '@')
 851             {
 852               if (sym->version() == NULL)
 853                 return true;
 854               ++ver;
 855             }
 856           if (sym->version() != NULL && strcmp(sym->version(), ver) == 0)
 857             return true;
 858         }
 859     }
 860   return false;
 861 }
 862
 863 // Include all the archive members in the link.  This is for --whole-archive.
 864
 865 bool
 866 Archive::include_all_members(Symbol_table* symtab, Layout* layout,
 867                              Input_objects* input_objects, Mapfile* mapfile)
 868 {
 869   // Don't include the same archive twice.  This can happen if
 870   // --whole-archive is nested inside --start-group (PR gold/12163).
 871   if (this->included_all_members_)
 872     return true;
 873
 874   this->included_all_members_ = true;
 875
 876   input_objects->archive_start(this);
 877
 878   if (this->members_.size() > 0)
 879     {
 880       std::map<off_t, Archive_member>::const_iterator p;
 881       for (p = this->members_.begin();
 882            p != this->members_.end();
 883            ++p)
 884         {
 885           if (!this->include_member(symtab, layout, input_objects, p->first,
 886                                     mapfile, NULL, "--whole-archive"))
 887             return false;
 888           ++Archive::total_members;
 889         }
 890     }
 891   else
 892     {
 893       for (Archive::const_iterator p = this->begin();
 894            p != this->end();
 895            ++p)
 896         {
 897           if (!this->include_member(symtab, layout, input_objects, p->off,
 898                                     mapfile, NULL, "--whole-archive"))
 899             return false;
 900           ++Archive::total_members;
 901         }
 902     }
 903
 904   input_objects->archive_stop(this);
 905
 906   return true;
 907 }
 908
 909 // Return the number of members in the archive.  This is only used for
 910 // reports.
 911
 912 size_t
 913 Archive::count_members()
 914 {
 915   size_t ret = 0;
 916   for (Archive::const_iterator p = this->begin();
 917        p != this->end();
 918        ++p)
 919     ++ret;
 920   return ret;
 921 }
 922
 923 // Include an archive member in the link.  OFF is the file offset of
 924 // the member header.  WHY is the reason we are including this member.
 925 // Return true if we added the member or if we had an error, return
 926 // false if this was the first member we tried to add from this
 927 // archive and it had an incompatible format.
 928
 929 bool
 930 Archive::include_member(Symbol_table* symtab, Layout* layout,
 931                         Input_objects* input_objects, off_t off,
 932                         Mapfile* mapfile, Symbol* sym, const char* why)
 933 {
 934   ++Archive::total_members_loaded;
 935
 936   std::map<off_t, Archive_member>::const_iterator p = this->members_.find(off);
 937   if (p != this->members_.end())
 938     {
 939       Object* obj = p->second.obj_;
 940
 941       Read_symbols_data* sd = p->second.sd_;
 942       if (mapfile != NULL)
 943         mapfile->report_include_archive_member(obj->name(), sym, why);
 944       if (input_objects->add_object(obj))
 945         {
 946           obj->layout(symtab, layout, sd);
 947           obj->add_symbols(symtab, sd, layout);
 948           this->included_member_ = true;
 949         }
 950       delete sd;
 951       return true;
 952     }
 953
 954   // If this is the first object we are including from this archive,
 955   // and we searched for this archive, most likely because it was
 956   // found via a -l option, then if the target is incompatible we want
 957   // to move on to the next archive found in the search path.
 958   bool unconfigured = false;
 959   bool* punconfigured = NULL;
 960   if (!this->included_member_ && this->searched_for())
 961     punconfigured = &unconfigured;
 962
 963   Object* obj = this->get_elf_object_for_member(off, punconfigured);
 964   if (obj == NULL)
 965     {
 966       // Return false to search for another archive, true if we found
 967       // an error.
 968       return unconfigured ? false : true;
 969     }
 970
 971   if (mapfile != NULL)
 972     mapfile->report_include_archive_member(obj->name(), sym, why);
 973
 974   Pluginobj* pluginobj = obj->pluginobj();
 975   if (pluginobj != NULL)
 976     {
 977       pluginobj->add_symbols(symtab, NULL, layout);
 978       this->included_member_ = true;
 979       return true;
 980     }
 981
 982   if (!input_objects->add_object(obj))
 983     {
 984       // If this is an external member of a thin archive, unlock the
 985       // file.
 986       if (obj->offset() == 0)
 987         obj->unlock(this->task_);
 988       delete obj;
 989     }
 990   else
 991     {
 992       {
 993         if (layout->incremental_inputs() != NULL)
 994           layout->incremental_inputs()->report_object(obj, 0, this, NULL);
 995         Read_symbols_data sd;
 996         obj->read_symbols(&sd);
 997         obj->layout(symtab, layout, &sd);
 998         obj->add_symbols(symtab, &sd, layout);
 999       }
1000
1001       // If this is an external member of a thin archive, unlock the file
1002       // for the next task.
1003       if (obj->offset() == 0)
1004         obj->unlock(this->task_);
1005
1006       this->included_member_ = true;
1007     }
1008
1009   return true;
1010 }
1011
1012 // Iterate over all unused symbols, and call the visitor class V for each.
1013
1014 void
1015 Archive::do_for_all_unused_symbols(Symbol_visitor_base* v) const
1016 {
1017   for (std::vector<Armap_entry>::const_iterator p = this->armap_.begin();
1018        p != this->armap_.end();
1019        ++p)
1020     {
1021       if (this->seen_offsets_.find(p->file_offset)
1022           == this->seen_offsets_.end())
1023         v->visit(this->armap_names_.data() + p->name_offset);
1024     }
1025 }
1026
1027 // Print statistical information to stderr.  This is used for --stats.
1028
1029 void
1030 Archive::print_stats()
1031 {
1032   fprintf(stderr, _("%s: archive libraries: %u\n"),
1033           program_name, Archive::total_archives);
1034   fprintf(stderr, _("%s: total archive members: %u\n"),
1035           program_name, Archive::total_members);
1036   fprintf(stderr, _("%s: loaded archive members: %u\n"),
1037           program_name, Archive::total_members_loaded);
1038 }
1039
1040 // Add_archive_symbols methods.
1041
1042 Add_archive_symbols::~Add_archive_symbols()
1043 {
1044   if (this->this_blocker_ != NULL)
1045     delete this->this_blocker_;
1046   // next_blocker_ is deleted by the task associated with the next
1047   // input file.
1048 }
1049
1050 // Return whether we can add the archive symbols.  We are blocked by
1051 // this_blocker_.  We block next_blocker_.  We also lock the file.
1052
1053 Task_token*
1054 Add_archive_symbols::is_runnable()
1055 {
1056   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
1057     return this->this_blocker_;
1058   return NULL;
1059 }
1060
1061 void
1062 Add_archive_symbols::locks(Task_locker* tl)
1063 {
1064   tl->add(this, this->next_blocker_);
1065   tl->add(this, this->archive_->token());
1066 }
1067
1068 void
1069 Add_archive_symbols::run(Workqueue* workqueue)
1070 {
1071   // For an incremental link, begin recording layout information.
1072   Incremental_inputs* incremental_inputs = this->layout_->incremental_inputs();
1073   if (incremental_inputs != NULL)
1074     {
1075       unsigned int arg_serial = this->input_argument_->file().arg_serial();
1076       Script_info* script_info = this->input_argument_->script_info();
1077       incremental_inputs->report_archive_begin(this->archive_, arg_serial,
1078                                                script_info);
1079     }
1080
1081   bool added = this->archive_->add_symbols(this->symtab_, this->layout_,
1082                                            this->input_objects_,
1083                                            this->mapfile_);
1084   this->archive_->unlock_nested_archives();
1085
1086   this->archive_->release();
1087   this->archive_->clear_uncached_views();
1088
1089   if (!added)
1090     {
1091       // This archive holds object files which are incompatible with
1092       // our output file.
1093       Read_symbols::incompatible_warning(this->input_argument_,
1094                                          this->archive_->input_file());
1095       Read_symbols::requeue(workqueue, this->input_objects_, this->symtab_,
1096                             this->layout_, this->dirpath_, this->dirindex_,
1097                             this->mapfile_, this->input_argument_,
1098                             this->input_group_, this->next_blocker_);
1099       delete this->archive_;
1100       return;
1101     }
1102
1103   if (this->input_group_ != NULL)
1104     this->input_group_->add_archive(this->archive_);
1105   else
1106     {
1107       // For an incremental link, finish recording the layout information.
1108       if (incremental_inputs != NULL)
1109         incremental_inputs->report_archive_end(this->archive_);
1110
1111       if (!parameters->options().has_plugins()
1112           || this->archive_->input_file()->options().whole_archive())
1113         {
1114           // We no longer need to know about this archive.
1115           delete this->archive_;
1116         }
1117       else
1118         {
1119           // The plugin interface may want to rescan this archive.
1120           parameters->options().plugins()->save_archive(this->archive_);
1121         }
1122
1123       this->archive_ = NULL;
1124     }
1125 }
1126
1127 // Class Lib_group static variables.
1128 unsigned int Lib_group::total_lib_groups;
1129 unsigned int Lib_group::total_members;
1130 unsigned int Lib_group::total_members_loaded;
1131
1132 Lib_group::Lib_group(const Input_file_lib* lib, Task* task)
1133   : Library_base(task), lib_(lib), members_()
1134 {
1135   this->members_.resize(lib->size());
1136 }
1137
1138 const std::string&
1139 Lib_group::do_filename() const
1140 {
1141   std::string *filename = new std::string("/group/");
1142   return *filename;
1143 }
1144
1145 // Select members from the lib group and add them to the link.  We walk
1146 // through the members, and check if each one up should be included.
1147 // If the object says it should be included, we do so.  We have to do
1148 // this in a loop, since including one member may create new undefined
1149 // symbols which may be satisfied by other members.
1150
1151 void
1152 Lib_group::add_symbols(Symbol_table* symtab, Layout* layout,
1153                        Input_objects* input_objects)
1154 {
1155   ++Lib_group::total_lib_groups;
1156
1157   Lib_group::total_members += this->members_.size();
1158
1159   bool added_new_object;
1160   do
1161     {
1162       added_new_object = false;
1163       unsigned int i = 0;
1164       while (i < this->members_.size())
1165         {
1166           const Archive_member& member = this->members_[i];
1167           Object* obj = member.obj_;
1168           std::string why;
1169
1170           // Skip files with no symbols. Plugin objects have
1171           // member.sd_ == NULL.
1172           if (obj != NULL
1173               && (member.sd_ == NULL || member.sd_->symbol_names != NULL))
1174             {
1175               Archive::Should_include t = obj->should_include_member(symtab,
1176                                                                      layout,
1177                                                                      member.sd_,
1178                                                                      &why);
1179
1180               if (t != Archive::SHOULD_INCLUDE_YES)
1181                 {
1182                   ++i;
1183                   continue;
1184                 }
1185
1186               this->include_member(symtab, layout, input_objects, member);
1187
1188               added_new_object = true;
1189             }
1190           else
1191             {
1192               if (member.sd_ != NULL)
1193                 {
1194                   // The file must be locked in order to destroy the views
1195                   // associated with it.
1196                   gold_assert(obj != NULL);
1197                   obj->lock(this->task_);
1198                   delete member.sd_;
1199                   obj->unlock(this->task_);
1200                 }
1201             }
1202
1203           this->members_[i] = this->members_.back();
1204           this->members_.pop_back();
1205         }
1206     }
1207   while (added_new_object);
1208 }
1209
1210 // Include a lib group member in the link.
1211
1212 void
1213 Lib_group::include_member(Symbol_table* symtab, Layout* layout,
1214                           Input_objects* input_objects,
1215                           const Archive_member& member)
1216 {
1217   ++Lib_group::total_members_loaded;
1218
1219   Object* obj = member.obj_;
1220   gold_assert(obj != NULL);
1221
1222   Pluginobj* pluginobj = obj->pluginobj();
1223   if (pluginobj != NULL)
1224     {
1225       pluginobj->add_symbols(symtab, NULL, layout);
1226       return;
1227     }
1228
1229   Read_symbols_data* sd = member.sd_;
1230   gold_assert(sd != NULL);
1231   obj->lock(this->task_);
1232   if (input_objects->add_object(obj))
1233     {
1234       if (layout->incremental_inputs() != NULL)
1235         layout->incremental_inputs()->report_object(obj, member.arg_serial_,
1236                                                     this, NULL);
1237       obj->layout(symtab, layout, sd);
1238       obj->add_symbols(symtab, sd, layout);
1239     }
1240   delete sd;
1241   // Unlock the file for the next task.
1242   obj->unlock(this->task_);
1243 }
1244
1245 // Iterate over all unused symbols, and call the visitor class V for each.
1246
1247 void
1248 Lib_group::do_for_all_unused_symbols(Symbol_visitor_base* v) const
1249 {
1250   // Files are removed from the members list when used, so all the
1251   // files remaining on the list are unused.
1252   for (std::vector<Archive_member>::const_iterator p = this->members_.begin();
1253        p != this->members_.end();
1254        ++p)
1255     {
1256       Object* obj = p->obj_;
1257       obj->for_all_global_symbols(p->sd_, v);
1258     }
1259 }
1260
1261 // Print statistical information to stderr.  This is used for --stats.
1262
1263 void
1264 Lib_group::print_stats()
1265 {
1266   fprintf(stderr, _("%s: lib groups: %u\n"),
1267           program_name, Lib_group::total_lib_groups);
1268   fprintf(stderr, _("%s: total lib groups members: %u\n"),
1269           program_name, Lib_group::total_members);
1270   fprintf(stderr, _("%s: loaded lib groups members: %u\n"),
1271           program_name, Lib_group::total_members_loaded);
1272 }
1273
1274 Task_token*
1275 Add_lib_group_symbols::is_runnable()
1276 {
1277   if (this->readsyms_blocker_ != NULL && this->readsyms_blocker_->is_blocked())
1278     return this->readsyms_blocker_;
1279   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
1280     return this->this_blocker_;
1281   return NULL;
1282 }
1283
1284 void
1285 Add_lib_group_symbols::locks(Task_locker* tl)
1286 {
1287   tl->add(this, this->next_blocker_);
1288 }
1289
1290 void
1291 Add_lib_group_symbols::run(Workqueue*)
1292 {
1293   // For an incremental link, begin recording layout information.
1294   Incremental_inputs* incremental_inputs = this->layout_->incremental_inputs();
1295   if (incremental_inputs != NULL)
1296     incremental_inputs->report_archive_begin(this->lib_, 0, NULL);
1297
1298   this->lib_->add_symbols(this->symtab_, this->layout_, this->input_objects_);
1299
1300   if (incremental_inputs != NULL)
1301     incremental_inputs->report_archive_end(this->lib_);
1302 }
1303
1304 Add_lib_group_symbols::~Add_lib_group_symbols()
1305 {
1306   if (this->this_blocker_ != NULL)
1307     delete this->this_blocker_;
1308   // next_blocker_ is deleted by the task associated with the next
1309   // input file.
1310 }
1311
1312 } // End namespace gold.