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