contrib/binutils-2.27/gold/archive.cc

   1 // archive.cc -- archive support for gold
   2
   3 // Copyright (C) 2006-2016 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <cerrno>
  26 #include <cstring>
  27 #include <climits>
  28 #include <vector>
  29 #include "libiberty.h"
  30 #include "filenames.h"
  31
  32 #include "elfcpp.h"
  33 #include "options.h"
  34 #include "mapfile.h"
  35 #include "fileread.h"
  36 #include "readsyms.h"
  37 #include "symtab.h"
  38 #include "object.h"
  39 #include "layout.h"
  40 #include "archive.h"
  41 #include "plugin.h"
  42 #include "incremental.h"
  43
  44 namespace gold
  45 {
  46
  47 // Library_base methods.
  48
  49 // Determine whether a definition of SYM_NAME should cause an archive
  50 // library member to be included in the link.  Returns SHOULD_INCLUDE_YES
  51 // if the symbol is referenced but not defined, SHOULD_INCLUDE_NO if the
  52 // symbol is already defined, and SHOULD_INCLUDE_UNKNOWN if the symbol is
  53 // neither referenced nor defined.
  54
  55 Library_base::Should_include
  56 Library_base::should_include_member(Symbol_table* symtab, Layout* layout,
  57                                     const char* sym_name, Symbol** symp,
  58                                     std::string* why, char** tmpbufp,
  59                                     size_t* tmpbuflen)
  60 {
  61   // In an object file, and therefore in an archive map, an
  62   // '@' in the name separates the symbol name from the
  63   // version name.  If there are two '@' characters, this is
  64   // the default version.
  65   char* tmpbuf = *tmpbufp;
  66   const char* ver = strchr(sym_name, '@');
  67   bool def = false;
  68   if (ver != NULL)
  69     {
  70       size_t symlen = ver - sym_name;
  71       if (symlen + 1 > *tmpbuflen)
  72         {
  73           tmpbuf = static_cast<char*>(xrealloc(tmpbuf, symlen + 1));
  74           *tmpbufp = tmpbuf;
  75           *tmpbuflen = symlen + 1;
  76         }
  77       memcpy(tmpbuf, sym_name, symlen);
  78       tmpbuf[symlen] = '\0';
  79       sym_name = tmpbuf;
  80
  81       ++ver;
  82       if (*ver == '@')
  83         {
  84           ++ver;
  85           def = true;
  86         }
  87     }
  88
  89   Symbol* sym = symtab->lookup(sym_name, ver);
  90   if (def
  91       && ver != NULL
  92       && (sym == NULL
  93           || !sym->is_undefined()
  94           || sym->binding() == elfcpp::STB_WEAK))
  95     sym = symtab->lookup(sym_name, NULL);
  96
  97   *symp = sym;
  98
  99   if (sym != NULL)
 100     {
 101       if (!sym->is_undefined())
 102         return Library_base::SHOULD_INCLUDE_NO;
 103
 104       // PR 12001: Do not include an archive when the undefined
 105       // symbol has actually been defined on the command line.
 106       if (layout->script_options()->is_pending_assignment(sym_name))
 107         return Library_base::SHOULD_INCLUDE_NO;
 108
 109       // If the symbol is weak undefined, we still need to check
 110       // for other reasons (like a -u option).
 111       if (sym->binding() != elfcpp::STB_WEAK)
 112         return Library_base::SHOULD_INCLUDE_YES;
 113     }
 114
 115   // Check whether the symbol was named in a -u option.
 116   if (parameters->options().is_undefined(sym_name))
 117     {
 118       *why = "-u ";
 119       *why += sym_name;
 120       return Library_base::SHOULD_INCLUDE_YES;
 121     }
 122
 123   if (parameters->options().is_export_dynamic_symbol(sym_name))
 124     {
 125       *why = "--export-dynamic-symbol ";
 126       *why += sym_name;
 127       return Library_base::SHOULD_INCLUDE_YES;
 128     }
 129
 130   if (layout->script_options()->is_referenced(sym_name))
 131     {
 132       size_t alc = 100 + strlen(sym_name);
 133       char* buf = new char[alc];
 134       snprintf(buf, alc, _("script or expression reference to %s"),
 135                sym_name);
 136       *why = buf;
 137       delete[] buf;
 138       return Library_base::SHOULD_INCLUDE_YES;
 139     }
 140
 141   if (!parameters->options().relocatable())
 142     {
 143       const char* entry_sym = parameters->entry();
 144       if (entry_sym != NULL && strcmp(sym_name, entry_sym) == 0)
 145         {
 146           *why = "entry symbol ";
 147           *why += sym_name;
 148           return Library_base::SHOULD_INCLUDE_YES;
 149         }
 150     }
 151
 152   return Library_base::SHOULD_INCLUDE_UNKNOWN;
 153 }
 154
 155 // The header of an entry in the archive.  This is all readable text,
 156 // padded with spaces where necessary.  If the contents of an archive
 157 // are all text file, the entire archive is readable.
 158
 159 struct Archive::Archive_header
 160 {
 161   // The entry name.
 162   char ar_name[16];
 163   // The file modification time.
 164   char ar_date[12];
 165   // The user's UID in decimal.
 166   char ar_uid[6];
 167   // The user's GID in decimal.
 168   char ar_gid[6];
 169   // The file mode in octal.
 170   char ar_mode[8];
 171   // The file size in decimal.
 172   char ar_size[10];
 173   // The final magic code.
 174   char ar_fmag[2];
 175 };
 176
 177 // Class Archive static variables.
 178 unsigned int Archive::total_archives;
 179 unsigned int Archive::total_members;
 180 unsigned int Archive::total_members_loaded;
 181
 182 // Archive methods.
 183
 184 const char Archive::armag[sarmag] =
 185 {
 186   '!', '<', 'a', 'r', 'c', 'h', '>', '\n'
 187 };
 188
 189 const char Archive::armagt[sarmag] =
 190 {
 191   '!', '<', 't', 'h', 'i', 'n', '>', '\n'
 192 };
 193
 194 const char Archive::arfmag[2] = { '`', '\n' };
 195
 196 const char Archive::sym64name[7] = { '/', 'S', 'Y', 'M', '6', '4', '/' };
 197
 198 Archive::Archive(const std::string& name, Input_file* input_file,
 199                  bool is_thin_archive, Dirsearch* dirpath, Task* task)
 200   : Library_base(task), name_(name), input_file_(input_file), armap_(),
 201     armap_names_(), extended_names_(), armap_checked_(), seen_offsets_(),
 202     members_(), is_thin_archive_(is_thin_archive), included_member_(false),
 203     nested_archives_(), dirpath_(dirpath), num_members_(0),
 204     included_all_members_(false)
 205 {
 206   this->no_export_ =
 207     parameters->options().check_excluded_libs(input_file->found_name());
 208 }
 209
 210 // Set up the archive: read the symbol map and the extended name
 211 // table.
 212
 213 void
 214 Archive::setup()
 215 {
 216   // We need to ignore empty archives.
 217   if (this->input_file_->file().filesize() == sarmag)
 218     return;
 219
 220   // The first member of the archive should be the symbol table.
 221   std::string armap_name;
 222   off_t header_size = this->read_header(sarmag, false, &armap_name, NULL);
 223   if (header_size == -1)
 224     return;
 225
 226   section_size_type armap_size = convert_to_section_size_type(header_size);
 227   off_t off = sarmag;
 228   if (armap_name.empty())
 229     {
 230       this->read_armap<32>(sarmag + sizeof(Archive_header), armap_size);
 231       off = sarmag + sizeof(Archive_header) + armap_size;
 232     }
 233   else if (armap_name == "/SYM64/")
 234     {
 235       this->read_armap<64>(sarmag + sizeof(Archive_header), armap_size);
 236       off = sarmag + sizeof(Archive_header) + armap_size;
 237     }
 238   else if (!this->input_file_->options().whole_archive())
 239     gold_error(_("%s: no archive symbol table (run ranlib)"),
 240                this->name().c_str());
 241
 242   // See if there is an extended name table.  We cache these views
 243   // because it is likely that we will want to read the following
 244   // header in the add_symbols routine.
 245   if ((off & 1) != 0)
 246     ++off;
 247   std::string xname;
 248   header_size = this->read_header(off, true, &xname, NULL);
 249   if (header_size == -1)
 250     return;
 251
 252   section_size_type extended_size = convert_to_section_size_type(header_size);
 253   if (xname == "/")
 254     {
 255       const unsigned char* p = this->get_view(off + sizeof(Archive_header),
 256                                               extended_size, false, true);
 257       const char* px = reinterpret_cast<const char*>(p);
 258       this->extended_names_.assign(px, extended_size);
 259     }
 260   bool preread_syms = (parameters->options().threads()
 261                        && parameters->options().preread_archive_symbols());
 262 #ifndef ENABLE_THREADS
 263   preread_syms = false;
 264 #else
 265   if (parameters->options().has_plugins())
 266     preread_syms = false;
 267 #endif
 268   if (preread_syms)
 269     this->read_all_symbols();
 270 }
 271
 272 // Unlock any nested archives.
 273
 274 void
 275 Archive::unlock_nested_archives()
 276 {
 277   for (Nested_archive_table::iterator p = this->nested_archives_.begin();
 278        p != this->nested_archives_.end();
 279        ++p)
 280     {
 281       p->second->unlock(this->task_);
 282     }
 283 }
 284
 285 // Read the archive symbol map.
 286
 287 template<int mapsize>
 288 void
 289 Archive::read_armap(off_t start, section_size_type size)
 290 {
 291   // To count the total number of archive members, we'll just count
 292   // the number of times the file offset changes.  Since most archives
 293   // group the symbols in the armap by object, this ought to give us
 294   // an accurate count.
 295   off_t last_seen_offset = -1;
 296
 297   // Read in the entire armap.
 298   const unsigned char* p = this->get_view(start, size, true, false);
 299
 300   // Numbers in the armap are always big-endian.
 301   typedef typename elfcpp::Elf_types<mapsize>::Elf_Addr Entry_type;
 302   const Entry_type* pword = reinterpret_cast<const Entry_type*>(p);
 303   unsigned long nsyms = convert_types<unsigned long, Entry_type>(
 304     elfcpp::Swap<mapsize, true>::readval(pword));
 305   ++pword;
 306
 307   // Note that the addition is in units of sizeof(elfcpp::Elf_Word).
 308   const char* pnames = reinterpret_cast<const char*>(pword + nsyms);
 309   section_size_type names_size =
 310     reinterpret_cast<const char*>(p) + size - pnames;
 311   this->armap_names_.assign(pnames, names_size);
 312
 313   this->armap_.resize(nsyms);
 314
 315   section_offset_type name_offset = 0;
 316   for (unsigned long i = 0; i < nsyms; ++i)
 317     {
 318       this->armap_[i].name_offset = name_offset;
 319       this->armap_[i].file_offset = convert_types<off_t, Entry_type>(
 320         elfcpp::Swap<mapsize, true>::readval(pword));
 321       name_offset += strlen(pnames + name_offset) + 1;
 322       ++pword;
 323       if (this->armap_[i].file_offset != last_seen_offset)
 324         {
 325           last_seen_offset = this->armap_[i].file_offset;
 326           ++this->num_members_;
 327         }
 328     }
 329
 330   if (static_cast<section_size_type>(name_offset) > names_size)
 331     gold_error(_("%s: bad archive symbol table names"),
 332                this->name().c_str());
 333
 334   // This array keeps track of which symbols are for archive elements
 335   // which we have already included in the link.
 336   this->armap_checked_.resize(nsyms);
 337 }
 338
 339 // Read the header of an archive member at OFF.  Fail if something
 340 // goes wrong.  Return the size of the member.  Set *PNAME to the name
 341 // of the member.
 342
 343 off_t
 344 Archive::read_header(off_t off, bool cache, std::string* pname,
 345                      off_t* nested_off)
 346 {
 347   const unsigned char* p = this->get_view(off, sizeof(Archive_header), true,
 348                                           cache);
 349   const Archive_header* hdr = reinterpret_cast<const Archive_header*>(p);
 350   return this->interpret_header(hdr, off,  pname, nested_off);
 351 }
 352
 353 // Interpret the header of HDR, the header of the archive member at
 354 // file offset OFF.  Return the size of the member, or -1 if something
 355 // has gone wrong.  Set *PNAME to the name of the member.
 356
 357 off_t
 358 Archive::interpret_header(const Archive_header* hdr, off_t off,
 359                           std::string* pname, off_t* nested_off) const
 360 {
 361   if (memcmp(hdr->ar_fmag, arfmag, sizeof arfmag) != 0)
 362     {
 363       gold_error(_("%s: malformed archive header at %zu"),
 364                  this->name().c_str(), static_cast<size_t>(off));
 365       return -1;
 366     }
 367
 368   const int size_string_size = sizeof hdr->ar_size;
 369   char size_string[size_string_size + 1];
 370   memcpy(size_string, hdr->ar_size, size_string_size);
 371   char* ps = size_string + size_string_size;
 372   while (ps[-1] == ' ')
 373     --ps;
 374   *ps = '\0';
 375
 376   errno = 0;
 377   char* end;
 378   off_t member_size = strtol(size_string, &end, 10);
 379   if (*end != '\0'
 380       || member_size < 0
 381       || (member_size == LONG_MAX && errno == ERANGE))
 382     {
 383       gold_error(_("%s: malformed archive header size at %zu"),
 384                  this->name().c_str(), static_cast<size_t>(off));
 385       return -1;
 386     }
 387
 388   if (hdr->ar_name[0] != '/')
 389     {
 390       const char* name_end = strchr(hdr->ar_name, '/');
 391       if (name_end == NULL
 392           || name_end - hdr->ar_name >= static_cast<int>(sizeof hdr->ar_name))
 393         {
 394           gold_error(_("%s: malformed archive header name at %zu"),
 395                      this->name().c_str(), static_cast<size_t>(off));
 396           return -1;
 397         }
 398       pname->assign(hdr->ar_name, name_end - hdr->ar_name);
 399       if (nested_off != NULL)
 400         *nested_off = 0;
 401     }
 402   else if (hdr->ar_name[1] == ' ')
 403     {
 404       // This is the symbol table.
 405       if (!pname->empty())
 406         pname->clear();
 407     }
 408   else if (memcmp(hdr->ar_name, sym64name, sizeof sym64name) == 0)
 409     {
 410       // This is the symbol table, 64-bit version.
 411       pname->assign(sym64name, sizeof sym64name);
 412     }
 413   else if (hdr->ar_name[1] == '/')
 414     {
 415       // This is the extended name table.
 416       pname->assign(1, '/');
 417     }
 418   else
 419     {
 420       errno = 0;
 421       long x = strtol(hdr->ar_name + 1, &end, 10);
 422       long y = 0;
 423       if (*end == ':')
 424         y = strtol(end + 1, &end, 10);
 425       if (*end != ' '
 426           || x < 0
 427           || (x == LONG_MAX && errno == ERANGE)
 428           || static_cast<size_t>(x) >= this->extended_names_.size())
 429         {
 430           gold_error(_("%s: bad extended name index at %zu"),
 431                      this->name().c_str(), static_cast<size_t>(off));
 432           return -1;
 433         }
 434
 435       const char* name = this->extended_names_.data() + x;
 436       const char* name_end = strchr(name, '\n');
 437       if (static_cast<size_t>(name_end - name) > this->extended_names_.size()
 438           || name_end[-1] != '/')
 439         {
 440           gold_error(_("%s: bad extended name entry at header %zu"),
 441                      this->name().c_str(), static_cast<size_t>(off));
 442           return -1;
 443         }
 444       pname->assign(name, name_end - 1 - name);
 445       if (nested_off != NULL)
 446         *nested_off = y;
 447     }
 448
 449   return member_size;
 450 }
 451
 452 // An archive member iterator.
 453
 454 class Archive::const_iterator
 455 {
 456  public:
 457   // The header of an archive member.  This is what this iterator
 458   // points to.
 459   struct Header
 460   {
 461     // The name of the member.
 462     std::string name;
 463     // The file offset of the member.
 464     off_t off;
 465     // The file offset of a nested archive member.
 466     off_t nested_off;
 467     // The size of the member.
 468     off_t size;
 469   };
 470
 471   const_iterator(Archive* archive, off_t off)
 472     : archive_(archive), off_(off)
 473   { this->read_next_header(); }
 474
 475   const Header&
 476   operator*() const
 477   { return this->header_; }
 478
 479   const Header*
 480   operator->() const
 481   { return &this->header_; }
 482
 483   const_iterator&
 484   operator++()
 485   {
 486     if (this->off_ == this->archive_->file().filesize())
 487       return *this;
 488     this->off_ += sizeof(Archive_header);
 489     if (!this->archive_->is_thin_archive())
 490       this->off_ += this->header_.size;
 491     if ((this->off_ & 1) != 0)
 492       ++this->off_;
 493     this->read_next_header();
 494     return *this;
 495   }
 496
 497   const_iterator
 498   operator++(int)
 499   {
 500     const_iterator ret = *this;
 501     ++*this;
 502     return ret;
 503   }
 504
 505   bool
 506   operator==(const const_iterator p) const
 507   { return this->off_ == p->off; }
 508
 509   bool
 510   operator!=(const const_iterator p) const
 511   { return this->off_ != p->off; }
 512
 513  private:
 514   void
 515   read_next_header();
 516
 517   // The underlying archive.
 518   Archive* archive_;
 519   // The current offset in the file.
 520   off_t off_;
 521   // The current archive header.
 522   Header header_;
 523 };
 524
 525 // Read the next archive header.
 526
 527 void
 528 Archive::const_iterator::read_next_header()
 529 {
 530   off_t filesize = this->archive_->file().filesize();
 531   while (true)
 532     {
 533       if (filesize - this->off_ < static_cast<off_t>(sizeof(Archive_header)))
 534         {
 535           if (filesize != this->off_)
 536             {
 537               gold_error(_("%s: short archive header at %zu"),
 538                          this->archive_->filename().c_str(),
 539                          static_cast<size_t>(this->off_));
 540               this->off_ = filesize;
 541             }
 542           this->header_.off = filesize;
 543           return;
 544         }
 545
 546       unsigned char buf[sizeof(Archive_header)];
 547       this->archive_->file().read(this->off_, sizeof(Archive_header), buf);
 548
 549       const Archive_header* hdr = reinterpret_cast<const Archive_header*>(buf);
 550       off_t size = this->archive_->interpret_header(hdr, this->off_,
 551                                                     &this->header_.name,
 552                                                     &this->header_.nested_off);
 553       if (size == -1)
 554         {
 555           this->header_.off = filesize;
 556           return;
 557         }
 558
 559       this->header_.size = size;
 560       this->header_.off = this->off_;
 561
 562       // Skip special members.
 563       if (!this->header_.name.empty()
 564           && this->header_.name != "/"
 565           && this->header_.name != "/SYM64/")
 566         return;
 567
 568       this->off_ += sizeof(Archive_header) + this->header_.size;
 569       if ((this->off_ & 1) != 0)
 570         ++this->off_;
 571     }
 572 }
 573
 574 // Initial iterator.
 575
 576 Archive::const_iterator
 577 Archive::begin()
 578 {
 579   return Archive::const_iterator(this, sarmag);
 580 }
 581
 582 // Final iterator.
 583
 584 Archive::const_iterator
 585 Archive::end()
 586 {
 587   return Archive::const_iterator(this, this->input_file_->file().filesize());
 588 }
 589
 590 // Get the file and offset for an archive member, which may be an
 591 // external member of a thin archive.  Set *INPUT_FILE to the
 592 // file containing the actual member, *MEMOFF to the offset
 593 // within that file (0 if not a nested archive), and *MEMBER_NAME
 594 // to the name of the archive member.  Return TRUE on success.
 595
 596 bool
 597 Archive::get_file_and_offset(off_t off, Input_file** input_file, off_t* memoff,
 598                              off_t* memsize, std::string* member_name)
 599 {
 600   off_t nested_off;
 601
 602   *memsize = this->read_header(off, false, member_name, &nested_off);
 603   if (*memsize == -1)
 604     return false;
 605
 606   *input_file = this->input_file_;
 607   *memoff = off + static_cast<off_t>(sizeof(Archive_header));
 608
 609   if (!this->is_thin_archive_)
 610     return true;
 611
 612   // Adjust a relative pathname so that it is relative
 613   // to the directory containing the archive.
 614   if (!IS_ABSOLUTE_PATH(member_name->c_str()))
 615     {
 616       const char* arch_path = this->filename().c_str();
 617       const char* basename = lbasename(arch_path);
 618       if (basename > arch_path)
 619         member_name->replace(0, 0,
 620                              this->filename().substr(0, basename - arch_path));
 621     }
 622
 623   if (nested_off > 0)
 624     {
 625       // This is a member of a nested archive.  Open the containing
 626       // archive if we don't already have it open, then do a recursive
 627       // call to include the member from that archive.
 628       Archive* arch;
 629       Nested_archive_table::const_iterator p =
 630         this->nested_archives_.find(*member_name);
 631       if (p != this->nested_archives_.end())
 632         arch = p->second;
 633       else
 634         {
 635           Input_file_argument* input_file_arg =
 636             new Input_file_argument(member_name->c_str(),
 637                                     Input_file_argument::INPUT_FILE_TYPE_FILE,
 638                                     "", false, parameters->options());
 639           *input_file = new Input_file(input_file_arg);
 640           int dummy = 0;
 641           if (!(*input_file)->open(*this->dirpath_, this->task_, &dummy))
 642             return false;
 643           arch = new Archive(*member_name, *input_file, false, this->dirpath_,
 644                              this->task_);
 645           arch->setup();
 646           std::pair<Nested_archive_table::iterator, bool> ins =
 647             this->nested_archives_.insert(std::make_pair(*member_name, arch));
 648           gold_assert(ins.second);
 649         }
 650       return arch->get_file_and_offset(nested_off, input_file, memoff,
 651                                        memsize, member_name);
 652     }
 653
 654   // This is an external member of a thin archive.  Open the
 655   // file as a regular relocatable object file.
 656   Input_file_argument* input_file_arg =
 657       new Input_file_argument(member_name->c_str(),
 658                               Input_file_argument::INPUT_FILE_TYPE_FILE,
 659                               "", false, this->input_file_->options());
 660   *input_file = new Input_file(input_file_arg);
 661   int dummy = 0;
 662   if (!(*input_file)->open(*this->dirpath_, this->task_, &dummy))
 663     return false;
 664
 665   *memoff = 0;
 666   *memsize = (*input_file)->file().filesize();
 667   return true;
 668 }
 669
 670 // Return an ELF object for the member at offset OFF.  If
 671 // PUNCONFIGURED is not NULL, then if the ELF object has an
 672 // unsupported target type, set *PUNCONFIGURED to true and return
 673 // NULL.
 674
 675 Object*
 676 Archive::get_elf_object_for_member(off_t off, bool* punconfigured)
 677 {
 678   if (punconfigured != NULL)
 679     *punconfigured = false;
 680
 681   Input_file* input_file;
 682   off_t memoff;
 683   off_t memsize;
 684   std::string member_name;
 685   if (!this->get_file_and_offset(off, &input_file, &memoff, &memsize,
 686                                  &member_name))
 687     return NULL;
 688
 689   const unsigned char* ehdr;
 690   int read_size;
 691   Object *obj = NULL;
 692   bool is_elf_obj = false;
 693
 694   if (is_elf_object(input_file, memoff, &ehdr, &read_size))
 695     {
 696       obj = make_elf_object((std::string(this->input_file_->filename())
 697                              + "(" + member_name + ")"),
 698                             input_file, memoff, ehdr, read_size,
 699                             punconfigured);
 700       is_elf_obj = true;
 701     }
 702
 703   if (parameters->options().has_plugins())
 704     {
 705       Object* plugin_obj
 706         = parameters->options().plugins()->claim_file(input_file,
 707                                                       memoff,
 708                                                       memsize,
 709                                                       obj);
 710       if (plugin_obj != NULL)
 711         {
 712           // The input file was claimed by a plugin, and its symbols
 713           // have been provided by the plugin.
 714           // Delete its elf object.
 715           if (obj != NULL)
 716             delete obj;
 717           return plugin_obj;
 718         }
 719     }
 720
 721   if (!is_elf_obj)
 722     {
 723       gold_error(_("%s: member at %zu is not an ELF object"),
 724                  this->name().c_str(), static_cast<size_t>(off));
 725       return NULL;
 726     }
 727
 728   if (obj == NULL)
 729     return NULL;
 730   obj->set_no_export(this->no_export());
 731   return obj;
 732 }
 733
 734 // Read the symbols from all the archive members in the link.
 735
 736 void
 737 Archive::read_all_symbols()
 738 {
 739   for (Archive::const_iterator p = this->begin();
 740        p != this->end();
 741        ++p)
 742     this->read_symbols(p->off);
 743 }
 744
 745 // Read the symbols from an archive member in the link.  OFF is the file
 746 // offset of the member header.
 747
 748 void
 749 Archive::read_symbols(off_t off)
 750 {
 751   Object* obj = this->get_elf_object_for_member(off, NULL);
 752   if (obj == NULL)
 753     return;
 754
 755   Read_symbols_data* sd = new Read_symbols_data;
 756   obj->read_symbols(sd);
 757   Archive_member member(obj, sd);
 758   this->members_[off] = member;
 759 }
 760
 761 // Select members from the archive and add them to the link.  We walk
 762 // through the elements in the archive map, and look each one up in
 763 // the symbol table.  If it exists as a strong undefined symbol, we
 764 // pull in the corresponding element.  We have to do this in a loop,
 765 // since pulling in one element may create new undefined symbols which
 766 // may be satisfied by other objects in the archive.  Return true in
 767 // the normal case, false if the first member we tried to add from
 768 // this archive had an incompatible target.
 769
 770 bool
 771 Archive::add_symbols(Symbol_table* symtab, Layout* layout,
 772                      Input_objects* input_objects, Mapfile* mapfile)
 773 {
 774   ++Archive::total_archives;
 775
 776   if (this->input_file_->options().whole_archive())
 777     return this->include_all_members(symtab, layout, input_objects,
 778                                      mapfile);
 779
 780   Archive::total_members += this->num_members_;
 781
 782   input_objects->archive_start(this);
 783
 784   const size_t armap_size = this->armap_.size();
 785
 786   // This is a quick optimization, since we usually see many symbols
 787   // in a row with the same offset.  last_seen_offset holds the last
 788   // offset we saw that was present in the seen_offsets_ set.
 789   off_t last_seen_offset = -1;
 790
 791   // Track which symbols in the symbol table we've already found to be
 792   // defined.
 793
 794   char* tmpbuf = NULL;
 795   size_t tmpbuflen = 0;
 796   bool added_new_object;
 797   do
 798     {
 799       added_new_object = false;
 800       for (size_t i = 0; i < armap_size; ++i)
 801         {
 802           if (this->armap_checked_[i])
 803             continue;
 804           if (this->armap_[i].file_offset == last_seen_offset)
 805             {
 806               this->armap_checked_[i] = true;
 807               continue;
 808             }
 809           if (this->seen_offsets_.find(this->armap_[i].file_offset)
 810               != this->seen_offsets_.end())
 811             {
 812               this->armap_checked_[i] = true;
 813               last_seen_offset = this->armap_[i].file_offset;
 814               continue;
 815             }
 816
 817           const char* sym_name = (this->armap_names_.data()
 818                                   + this->armap_[i].name_offset);
 819
 820           Symbol* sym;
 821           std::string why;
 822           Archive::Should_include t =
 823             Archive::should_include_member(symtab, layout, sym_name, &sym,
 824                                            &why, &tmpbuf, &tmpbuflen);
 825
 826           if (t == Archive::SHOULD_INCLUDE_NO
 827               || t == Archive::SHOULD_INCLUDE_YES)
 828             this->armap_checked_[i] = true;
 829
 830           if (t != Archive::SHOULD_INCLUDE_YES)
 831             continue;
 832
 833           // We want to include this object in the link.
 834           last_seen_offset = this->armap_[i].file_offset;
 835           this->seen_offsets_.insert(last_seen_offset);
 836
 837           if (!this->include_member(symtab, layout, input_objects,
 838                                     last_seen_offset, mapfile, sym,
 839                                     why.c_str()))
 840             {
 841               if (tmpbuf != NULL)
 842                 free(tmpbuf);
 843               return false;
 844             }
 845
 846           added_new_object = true;
 847         }
 848     }
 849   while (added_new_object);
 850
 851   if (tmpbuf != NULL)
 852     free(tmpbuf);
 853
 854   input_objects->archive_stop(this);
 855
 856   return true;
 857 }
 858
 859 // Return whether the archive includes a member which defines the
 860 // symbol SYM.
 861
 862 bool
 863 Archive::defines_symbol(Symbol* sym) const
 864 {
 865   const char* symname = sym->name();
 866   size_t symname_len = strlen(symname);
 867   size_t armap_size = this->armap_.size();
 868   for (size_t i = 0; i < armap_size; ++i)
 869     {
 870       if (this->armap_checked_[i])
 871         continue;
 872       const char* archive_symname = (this->armap_names_.data()
 873                                      + this->armap_[i].name_offset);
 874       if (strncmp(archive_symname, symname, symname_len) != 0)
 875         continue;
 876       char c = archive_symname[symname_len];
 877       if (c == '\0' && sym->version() == NULL)
 878         return true;
 879       if (c == '@')
 880         {
 881           const char* ver = archive_symname + symname_len + 1;
 882           if (*ver == '@')
 883             {
 884               if (sym->version() == NULL)
 885                 return true;
 886               ++ver;
 887             }
 888           if (sym->version() != NULL && strcmp(sym->version(), ver) == 0)
 889             return true;
 890         }
 891     }
 892   return false;
 893 }
 894
 895 // Include all the archive members in the link.  This is for --whole-archive.
 896
 897 bool
 898 Archive::include_all_members(Symbol_table* symtab, Layout* layout,
 899                              Input_objects* input_objects, Mapfile* mapfile)
 900 {
 901   // Don't include the same archive twice.  This can happen if
 902   // --whole-archive is nested inside --start-group (PR gold/12163).
 903   if (this->included_all_members_)
 904     return true;
 905
 906   this->included_all_members_ = true;
 907
 908   input_objects->archive_start(this);
 909
 910   if (this->members_.size() > 0)
 911     {
 912       std::map<off_t, Archive_member>::const_iterator p;
 913       for (p = this->members_.begin();
 914            p != this->members_.end();
 915            ++p)
 916         {
 917           if (!this->include_member(symtab, layout, input_objects, p->first,
 918                                     mapfile, NULL, "--whole-archive"))
 919             return false;
 920           ++Archive::total_members;
 921         }
 922     }
 923   else
 924     {
 925       for (Archive::const_iterator p = this->begin();
 926            p != this->end();
 927            ++p)
 928         {
 929           if (!this->include_member(symtab, layout, input_objects, p->off,
 930                                     mapfile, NULL, "--whole-archive"))
 931             return false;
 932           ++Archive::total_members;
 933         }
 934     }
 935
 936   input_objects->archive_stop(this);
 937
 938   return true;
 939 }
 940
 941 // Return the number of members in the archive.  This is only used for
 942 // reports.
 943
 944 size_t
 945 Archive::count_members()
 946 {
 947   size_t ret = 0;
 948   for (Archive::const_iterator p = this->begin();
 949        p != this->end();
 950        ++p)
 951     ++ret;
 952   return ret;
 953 }
 954
 955 // RAII class to ensure we unlock the object if it's a member of a
 956 // thin archive. We can't use Task_lock_obj in Archive::include_member
 957 // because the object file is already locked when it's opened by
 958 // get_elf_object_for_member.
 959
 960 class Thin_archive_object_unlocker
 961 {
 962  public:
 963   Thin_archive_object_unlocker(const Task *task, Object* obj)
 964     : task_(task), obj_(obj)
 965   { }
 966
 967   ~Thin_archive_object_unlocker()
 968   {
 969     if (this->obj_->offset() == 0)
 970       this->obj_->unlock(this->task_);
 971   }
 972
 973  private:
 974   Thin_archive_object_unlocker(const Thin_archive_object_unlocker&);
 975   Thin_archive_object_unlocker& operator=(const Thin_archive_object_unlocker&);
 976
 977   const Task* task_;
 978   Object* obj_;
 979 };
 980
 981 // Include an archive member in the link.  OFF is the file offset of
 982 // the member header.  WHY is the reason we are including this member.
 983 // Return true if we added the member or if we had an error, return
 984 // false if this was the first member we tried to add from this
 985 // archive and it had an incompatible format.
 986
 987 bool
 988 Archive::include_member(Symbol_table* symtab, Layout* layout,
 989                         Input_objects* input_objects, off_t off,
 990                         Mapfile* mapfile, Symbol* sym, const char* why)
 991 {
 992   ++Archive::total_members_loaded;
 993
 994   std::map<off_t, Archive_member>::const_iterator p = this->members_.find(off);
 995   if (p != this->members_.end())
 996     {
 997       Object* obj = p->second.obj_;
 998
 999       Read_symbols_data* sd = p->second.sd_;
1000       if (mapfile != NULL)
1001         mapfile->report_include_archive_member(obj->name(), sym, why);
1002       if (input_objects->add_object(obj))
1003         {
1004           obj->layout(symtab, layout, sd);
1005           obj->add_symbols(symtab, sd, layout);
1006           this->included_member_ = true;
1007         }
1008       delete sd;
1009       return true;
1010     }
1011
1012   // If this is the first object we are including from this archive,
1013   // and we searched for this archive, most likely because it was
1014   // found via a -l option, then if the target is incompatible we want
1015   // to move on to the next archive found in the search path.
1016   bool unconfigured = false;
1017   bool* punconfigured = NULL;
1018   if (!this->included_member_ && this->searched_for())
1019     punconfigured = &unconfigured;
1020
1021   Object* obj = this->get_elf_object_for_member(off, punconfigured);
1022   if (obj == NULL)
1023     {
1024       // Return false to search for another archive, true if we found
1025       // an error.
1026       return unconfigured ? false : true;
1027     }
1028
1029   // If the object is an external member of a thin archive,
1030   // unlock it when we're done here.
1031   Thin_archive_object_unlocker unlocker(this->task_, obj);
1032
1033   if (mapfile != NULL)
1034     mapfile->report_include_archive_member(obj->name(), sym, why);
1035
1036   Pluginobj* pluginobj = obj->pluginobj();
1037   if (pluginobj != NULL)
1038     {
1039       pluginobj->add_symbols(symtab, NULL, layout);
1040       this->included_member_ = true;
1041       return true;
1042     }
1043
1044   if (!input_objects->add_object(obj))
1045     {
1046       delete obj;
1047       return true;
1048     }
1049
1050   if (layout->incremental_inputs() != NULL)
1051     layout->incremental_inputs()->report_object(obj, 0, this, NULL);
1052
1053   {
1054     Read_symbols_data sd;
1055     obj->read_symbols(&sd);
1056     obj->layout(symtab, layout, &sd);
1057     obj->add_symbols(symtab, &sd, layout);
1058   }
1059
1060   this->included_member_ = true;
1061   return true;
1062 }
1063
1064 // Iterate over all unused symbols, and call the visitor class V for each.
1065
1066 void
1067 Archive::do_for_all_unused_symbols(Symbol_visitor_base* v) const
1068 {
1069   for (std::vector<Armap_entry>::const_iterator p = this->armap_.begin();
1070        p != this->armap_.end();
1071        ++p)
1072     {
1073       if (this->seen_offsets_.find(p->file_offset)
1074           == this->seen_offsets_.end())
1075         v->visit(this->armap_names_.data() + p->name_offset);
1076     }
1077 }
1078
1079 // Print statistical information to stderr.  This is used for --stats.
1080
1081 void
1082 Archive::print_stats()
1083 {
1084   fprintf(stderr, _("%s: archive libraries: %u\n"),
1085           program_name, Archive::total_archives);
1086   fprintf(stderr, _("%s: total archive members: %u\n"),
1087           program_name, Archive::total_members);
1088   fprintf(stderr, _("%s: loaded archive members: %u\n"),
1089           program_name, Archive::total_members_loaded);
1090 }
1091
1092 // Add_archive_symbols methods.
1093
1094 Add_archive_symbols::~Add_archive_symbols()
1095 {
1096   if (this->this_blocker_ != NULL)
1097     delete this->this_blocker_;
1098   // next_blocker_ is deleted by the task associated with the next
1099   // input file.
1100 }
1101
1102 // Return whether we can add the archive symbols.  We are blocked by
1103 // this_blocker_.  We block next_blocker_.  We also lock the file.
1104
1105 Task_token*
1106 Add_archive_symbols::is_runnable()
1107 {
1108   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
1109     return this->this_blocker_;
1110   return NULL;
1111 }
1112
1113 void
1114 Add_archive_symbols::locks(Task_locker* tl)
1115 {
1116   tl->add(this, this->next_blocker_);
1117   tl->add(this, this->archive_->token());
1118 }
1119
1120 void
1121 Add_archive_symbols::run(Workqueue* workqueue)
1122 {
1123   // For an incremental link, begin recording layout information.
1124   Incremental_inputs* incremental_inputs = this->layout_->incremental_inputs();
1125   if (incremental_inputs != NULL)
1126     {
1127       unsigned int arg_serial = this->input_argument_->file().arg_serial();
1128       Script_info* script_info = this->input_argument_->script_info();
1129       incremental_inputs->report_archive_begin(this->archive_, arg_serial,
1130                                                script_info);
1131     }
1132
1133   bool added = this->archive_->add_symbols(this->symtab_, this->layout_,
1134                                            this->input_objects_,
1135                                            this->mapfile_);
1136   this->archive_->unlock_nested_archives();
1137
1138   this->archive_->release();
1139   this->archive_->clear_uncached_views();
1140
1141   if (!added)
1142     {
1143       // This archive holds object files which are incompatible with
1144       // our output file.
1145       Read_symbols::incompatible_warning(this->input_argument_,
1146                                          this->archive_->input_file());
1147       Read_symbols::requeue(workqueue, this->input_objects_, this->symtab_,
1148                             this->layout_, this->dirpath_, this->dirindex_,
1149                             this->mapfile_, this->input_argument_,
1150                             this->input_group_, this->next_blocker_);
1151       delete this->archive_;
1152       return;
1153     }
1154
1155   if (this->input_group_ != NULL)
1156     this->input_group_->add_archive(this->archive_);
1157   else
1158     {
1159       // For an incremental link, finish recording the layout information.
1160       if (incremental_inputs != NULL)
1161         incremental_inputs->report_archive_end(this->archive_);
1162
1163       if (!parameters->options().has_plugins()
1164           || this->archive_->input_file()->options().whole_archive())
1165         {
1166           // We no longer need to know about this archive.
1167           delete this->archive_;
1168         }
1169       else
1170         {
1171           // The plugin interface may want to rescan this archive.
1172           parameters->options().plugins()->save_archive(this->archive_);
1173         }
1174
1175       this->archive_ = NULL;
1176     }
1177 }
1178
1179 // Class Lib_group static variables.
1180 unsigned int Lib_group::total_lib_groups;
1181 unsigned int Lib_group::total_members;
1182 unsigned int Lib_group::total_members_loaded;
1183
1184 Lib_group::Lib_group(const Input_file_lib* lib, Task* task)
1185   : Library_base(task), members_()
1186 {
1187   this->members_.resize(lib->size());
1188 }
1189
1190 const std::string&
1191 Lib_group::do_filename() const
1192 {
1193   std::string *filename = new std::string("/group/");
1194   return *filename;
1195 }
1196
1197 // Select members from the lib group and add them to the link.  We walk
1198 // through the members, and check if each one up should be included.
1199 // If the object says it should be included, we do so.  We have to do
1200 // this in a loop, since including one member may create new undefined
1201 // symbols which may be satisfied by other members.
1202
1203 void
1204 Lib_group::add_symbols(Symbol_table* symtab, Layout* layout,
1205                        Input_objects* input_objects)
1206 {
1207   ++Lib_group::total_lib_groups;
1208
1209   Lib_group::total_members += this->members_.size();
1210
1211   bool added_new_object;
1212   do
1213     {
1214       added_new_object = false;
1215       unsigned int i = 0;
1216       while (i < this->members_.size())
1217         {
1218           const Archive_member& member = this->members_[i];
1219           Object* obj = member.obj_;
1220           std::string why;
1221
1222           // Skip files with no symbols. Plugin objects have
1223           // member.sd_ == NULL.
1224           if (obj != NULL
1225               && (member.sd_ == NULL || member.sd_->symbol_names != NULL))
1226             {
1227               Archive::Should_include t = obj->should_include_member(symtab,
1228                                                                      layout,
1229                                                                      member.sd_,
1230                                                                      &why);
1231
1232               if (t != Archive::SHOULD_INCLUDE_YES)
1233                 {
1234                   ++i;
1235                   continue;
1236                 }
1237
1238               this->include_member(symtab, layout, input_objects, member);
1239
1240               added_new_object = true;
1241             }
1242           else
1243             {
1244               if (member.sd_ != NULL)
1245                 {
1246                   // The file must be locked in order to destroy the views
1247                   // associated with it.
1248                   gold_assert(obj != NULL);
1249                   obj->lock(this->task_);
1250                   delete member.sd_;
1251                   obj->unlock(this->task_);
1252                 }
1253             }
1254
1255           this->members_[i] = this->members_.back();
1256           this->members_.pop_back();
1257         }
1258     }
1259   while (added_new_object);
1260 }
1261
1262 // Include a lib group member in the link.
1263
1264 void
1265 Lib_group::include_member(Symbol_table* symtab, Layout* layout,
1266                           Input_objects* input_objects,
1267                           const Archive_member& member)
1268 {
1269   ++Lib_group::total_members_loaded;
1270
1271   Object* obj = member.obj_;
1272   gold_assert(obj != NULL);
1273
1274   Pluginobj* pluginobj = obj->pluginobj();
1275   if (pluginobj != NULL)
1276     {
1277       pluginobj->add_symbols(symtab, NULL, layout);
1278       return;
1279     }
1280
1281   Read_symbols_data* sd = member.sd_;
1282   gold_assert(sd != NULL);
1283   obj->lock(this->task_);
1284   if (input_objects->add_object(obj))
1285     {
1286       if (layout->incremental_inputs() != NULL)
1287         layout->incremental_inputs()->report_object(obj, member.arg_serial_,
1288                                                     this, NULL);
1289       obj->layout(symtab, layout, sd);
1290       obj->add_symbols(symtab, sd, layout);
1291     }
1292   delete sd;
1293   // Unlock the file for the next task.
1294   obj->unlock(this->task_);
1295 }
1296
1297 // Iterate over all unused symbols, and call the visitor class V for each.
1298
1299 void
1300 Lib_group::do_for_all_unused_symbols(Symbol_visitor_base* v) const
1301 {
1302   // Files are removed from the members list when used, so all the
1303   // files remaining on the list are unused.
1304   for (std::vector<Archive_member>::const_iterator p = this->members_.begin();
1305        p != this->members_.end();
1306        ++p)
1307     {
1308       Object* obj = p->obj_;
1309       obj->for_all_global_symbols(p->sd_, v);
1310     }
1311 }
1312
1313 // Print statistical information to stderr.  This is used for --stats.
1314
1315 void
1316 Lib_group::print_stats()
1317 {
1318   fprintf(stderr, _("%s: lib groups: %u\n"),
1319           program_name, Lib_group::total_lib_groups);
1320   fprintf(stderr, _("%s: total lib groups members: %u\n"),
1321           program_name, Lib_group::total_members);
1322   fprintf(stderr, _("%s: loaded lib groups members: %u\n"),
1323           program_name, Lib_group::total_members_loaded);
1324 }
1325
1326 Task_token*
1327 Add_lib_group_symbols::is_runnable()
1328 {
1329   if (this->readsyms_blocker_ != NULL && this->readsyms_blocker_->is_blocked())
1330     return this->readsyms_blocker_;
1331   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
1332     return this->this_blocker_;
1333   return NULL;
1334 }
1335
1336 void
1337 Add_lib_group_symbols::locks(Task_locker* tl)
1338 {
1339   tl->add(this, this->next_blocker_);
1340 }
1341
1342 void
1343 Add_lib_group_symbols::run(Workqueue*)
1344 {
1345   // For an incremental link, begin recording layout information.
1346   Incremental_inputs* incremental_inputs = this->layout_->incremental_inputs();
1347   if (incremental_inputs != NULL)
1348     incremental_inputs->report_archive_begin(this->lib_, 0, NULL);
1349
1350   this->lib_->add_symbols(this->symtab_, this->layout_, this->input_objects_);
1351
1352   if (incremental_inputs != NULL)
1353     incremental_inputs->report_archive_end(this->lib_);
1354 }
1355
1356 Add_lib_group_symbols::~Add_lib_group_symbols()
1357 {
1358   if (this->this_blocker_ != NULL)
1359     delete this->this_blocker_;
1360   // next_blocker_ is deleted by the task associated with the next
1361   // input file.
1362 }
1363
1364 } // End namespace gold.