1 // archive.cc -- archive support for gold
3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
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.
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.
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.
29 #include "libiberty.h"
30 #include "filenames.h"
45 // The header of an entry in the archive. This is all readable text,
46 // padded with spaces where necesary. If the contents of an archive
47 // are all text file, the entire archive is readable.
49 struct Archive::Archive_header
53 // The file modification time.
55 // The user's UID in decimal.
57 // The user's GID in decimal.
59 // The file mode in octal.
61 // The file size in decimal.
63 // The final magic code.
67 // Class Archive static variables.
68 unsigned int Archive::total_archives;
69 unsigned int Archive::total_members;
70 unsigned int Archive::total_members_loaded;
74 const char Archive::armag[sarmag] =
76 '!', '<', 'a', 'r', 'c', 'h', '>', '\n'
79 const char Archive::armagt[sarmag] =
81 '!', '<', 't', 'h', 'i', 'n', '>', '\n'
84 const char Archive::arfmag[2] = { '`', '\n' };
86 // Set up the archive: read the symbol map and the extended name
90 Archive::setup(Input_objects* input_objects)
92 // We need to ignore empty archives.
93 if (this->input_file_->file().filesize() == sarmag)
96 // The first member of the archive should be the symbol table.
97 std::string armap_name;
98 section_size_type armap_size =
99 convert_to_section_size_type(this->read_header(sarmag, false,
102 if (armap_name.empty())
104 this->read_armap(sarmag + sizeof(Archive_header), armap_size);
105 off = sarmag + sizeof(Archive_header) + armap_size;
107 else if (!this->input_file_->options().whole_archive())
108 gold_error(_("%s: no archive symbol table (run ranlib)"),
109 this->name().c_str());
111 // See if there is an extended name table. We cache these views
112 // because it is likely that we will want to read the following
113 // header in the add_symbols routine.
117 section_size_type extended_size =
118 convert_to_section_size_type(this->read_header(off, true, &xname, NULL));
121 const unsigned char* p = this->get_view(off + sizeof(Archive_header),
122 extended_size, false, true);
123 const char* px = reinterpret_cast<const char*>(p);
124 this->extended_names_.assign(px, extended_size);
126 bool preread_syms = (parameters->options().threads()
127 && parameters->options().preread_archive_symbols());
128 #ifndef ENABLE_THREADS
129 preread_syms = false;
131 if (parameters->options().has_plugins())
132 preread_syms = false;
135 this->read_all_symbols(input_objects);
138 // Unlock any nested archives.
141 Archive::unlock_nested_archives()
143 for (Nested_archive_table::iterator p = this->nested_archives_.begin();
144 p != this->nested_archives_.end();
147 p->second->unlock(this->task_);
151 // Read the archive symbol map.
154 Archive::read_armap(off_t start, section_size_type size)
156 // To count the total number of archive members, we'll just count
157 // the number of times the file offset changes. Since most archives
158 // group the symbols in the armap by object, this ought to give us
159 // an accurate count.
160 off_t last_seen_offset = -1;
162 // Read in the entire armap.
163 const unsigned char* p = this->get_view(start, size, true, false);
165 // Numbers in the armap are always big-endian.
166 const elfcpp::Elf_Word* pword = reinterpret_cast<const elfcpp::Elf_Word*>(p);
167 unsigned int nsyms = elfcpp::Swap<32, true>::readval(pword);
170 // Note that the addition is in units of sizeof(elfcpp::Elf_Word).
171 const char* pnames = reinterpret_cast<const char*>(pword + nsyms);
172 section_size_type names_size =
173 reinterpret_cast<const char*>(p) + size - pnames;
174 this->armap_names_.assign(pnames, names_size);
176 this->armap_.resize(nsyms);
178 section_offset_type name_offset = 0;
179 for (unsigned int i = 0; i < nsyms; ++i)
181 this->armap_[i].name_offset = name_offset;
182 this->armap_[i].file_offset = elfcpp::Swap<32, true>::readval(pword);
183 name_offset += strlen(pnames + name_offset) + 1;
185 if (this->armap_[i].file_offset != last_seen_offset)
187 last_seen_offset = this->armap_[i].file_offset;
188 ++this->num_members_;
192 if (static_cast<section_size_type>(name_offset) > names_size)
193 gold_error(_("%s: bad archive symbol table names"),
194 this->name().c_str());
196 // This array keeps track of which symbols are for archive elements
197 // which we have already included in the link.
198 this->armap_checked_.resize(nsyms);
201 // Read the header of an archive member at OFF. Fail if something
202 // goes wrong. Return the size of the member. Set *PNAME to the name
206 Archive::read_header(off_t off, bool cache, std::string* pname,
209 const unsigned char* p = this->get_view(off, sizeof(Archive_header), true,
211 const Archive_header* hdr = reinterpret_cast<const Archive_header*>(p);
212 return this->interpret_header(hdr, off, pname, nested_off);
215 // Interpret the header of HDR, the header of the archive member at
216 // file offset OFF. Fail if something goes wrong. Return the size of
217 // the member. Set *PNAME to the name of the member.
220 Archive::interpret_header(const Archive_header* hdr, off_t off,
221 std::string* pname, off_t* nested_off) const
223 if (memcmp(hdr->ar_fmag, arfmag, sizeof arfmag) != 0)
225 gold_error(_("%s: malformed archive header at %zu"),
226 this->name().c_str(), static_cast<size_t>(off));
227 return this->input_file_->file().filesize() - off;
230 const int size_string_size = sizeof hdr->ar_size;
231 char size_string[size_string_size + 1];
232 memcpy(size_string, hdr->ar_size, size_string_size);
233 char* ps = size_string + size_string_size;
234 while (ps[-1] == ' ')
240 off_t member_size = strtol(size_string, &end, 10);
243 || (member_size == LONG_MAX && errno == ERANGE))
245 gold_error(_("%s: malformed archive header size at %zu"),
246 this->name().c_str(), static_cast<size_t>(off));
247 return this->input_file_->file().filesize() - off;
250 if (hdr->ar_name[0] != '/')
252 const char* name_end = strchr(hdr->ar_name, '/');
254 || name_end - hdr->ar_name >= static_cast<int>(sizeof hdr->ar_name))
256 gold_error(_("%s: malformed archive header name at %zu"),
257 this->name().c_str(), static_cast<size_t>(off));
258 return this->input_file_->file().filesize() - off;
260 pname->assign(hdr->ar_name, name_end - hdr->ar_name);
261 if (nested_off != NULL)
264 else if (hdr->ar_name[1] == ' ')
266 // This is the symbol table.
269 else if (hdr->ar_name[1] == '/')
271 // This is the extended name table.
272 pname->assign(1, '/');
277 long x = strtol(hdr->ar_name + 1, &end, 10);
280 y = strtol(end + 1, &end, 10);
283 || (x == LONG_MAX && errno == ERANGE)
284 || static_cast<size_t>(x) >= this->extended_names_.size())
286 gold_error(_("%s: bad extended name index at %zu"),
287 this->name().c_str(), static_cast<size_t>(off));
288 return this->input_file_->file().filesize() - off;
291 const char* name = this->extended_names_.data() + x;
292 const char* name_end = strchr(name, '\n');
293 if (static_cast<size_t>(name_end - name) > this->extended_names_.size()
294 || name_end[-1] != '/')
296 gold_error(_("%s: bad extended name entry at header %zu"),
297 this->name().c_str(), static_cast<size_t>(off));
298 return this->input_file_->file().filesize() - off;
300 pname->assign(name, name_end - 1 - name);
301 if (nested_off != NULL)
308 // An archive member iterator.
310 class Archive::const_iterator
313 // The header of an archive member. This is what this iterator
317 // The name of the member.
319 // The file offset of the member.
321 // The file offset of a nested archive member.
323 // The size of the member.
327 const_iterator(Archive* archive, off_t off)
328 : archive_(archive), off_(off)
329 { this->read_next_header(); }
333 { return this->header_; }
337 { return &this->header_; }
342 if (this->off_ == this->archive_->file().filesize())
344 this->off_ += sizeof(Archive_header);
345 if (!this->archive_->is_thin_archive())
346 this->off_ += this->header_.size;
347 if ((this->off_ & 1) != 0)
349 this->read_next_header();
356 const_iterator ret = *this;
362 operator==(const const_iterator p) const
363 { return this->off_ == p->off; }
366 operator!=(const const_iterator p) const
367 { return this->off_ != p->off; }
373 // The underlying archive.
375 // The current offset in the file.
377 // The current archive header.
381 // Read the next archive header.
384 Archive::const_iterator::read_next_header()
386 off_t filesize = this->archive_->file().filesize();
389 if (filesize - this->off_ < static_cast<off_t>(sizeof(Archive_header)))
391 if (filesize != this->off_)
393 gold_error(_("%s: short archive header at %zu"),
394 this->archive_->filename().c_str(),
395 static_cast<size_t>(this->off_));
396 this->off_ = filesize;
398 this->header_.off = filesize;
402 unsigned char buf[sizeof(Archive_header)];
403 this->archive_->file().read(this->off_, sizeof(Archive_header), buf);
405 const Archive_header* hdr = reinterpret_cast<const Archive_header*>(buf);
407 this->archive_->interpret_header(hdr, this->off_, &this->header_.name,
408 &this->header_.nested_off);
409 this->header_.off = this->off_;
411 // Skip special members.
412 if (!this->header_.name.empty() && this->header_.name != "/")
415 this->off_ += sizeof(Archive_header) + this->header_.size;
416 if ((this->off_ & 1) != 0)
423 Archive::const_iterator
426 return Archive::const_iterator(this, sarmag);
431 Archive::const_iterator
434 return Archive::const_iterator(this, this->input_file_->file().filesize());
437 // Get the file and offset for an archive member, which may be an
438 // external member of a thin archive. Set *INPUT_FILE to the
439 // file containing the actual member, *MEMOFF to the offset
440 // within that file (0 if not a nested archive), and *MEMBER_NAME
441 // to the name of the archive member. Return TRUE on success.
444 Archive::get_file_and_offset(off_t off, Input_objects* input_objects,
445 Input_file** input_file, off_t* memoff,
446 off_t* memsize, std::string* member_name)
450 *memsize = this->read_header(off, false, member_name, &nested_off);
452 *input_file = this->input_file_;
453 *memoff = off + static_cast<off_t>(sizeof(Archive_header));
455 if (!this->is_thin_archive_)
458 // Adjust a relative pathname so that it is relative
459 // to the directory containing the archive.
460 if (!IS_ABSOLUTE_PATH(member_name->c_str()))
462 const char* arch_path = this->filename().c_str();
463 const char* basename = lbasename(arch_path);
464 if (basename > arch_path)
465 member_name->replace(0, 0,
466 this->filename().substr(0, basename - arch_path));
471 // This is a member of a nested archive. Open the containing
472 // archive if we don't already have it open, then do a recursive
473 // call to include the member from that archive.
475 Nested_archive_table::const_iterator p =
476 this->nested_archives_.find(*member_name);
477 if (p != this->nested_archives_.end())
481 Input_file_argument* input_file_arg =
482 new Input_file_argument(member_name->c_str(), false, "", false,
483 parameters->options());
484 *input_file = new Input_file(input_file_arg);
485 if (!(*input_file)->open(*this->dirpath_, this->task_))
487 arch = new Archive(*member_name, *input_file, false, this->dirpath_,
489 arch->setup(input_objects);
490 std::pair<Nested_archive_table::iterator, bool> ins =
491 this->nested_archives_.insert(std::make_pair(*member_name, arch));
492 gold_assert(ins.second);
494 return arch->get_file_and_offset(nested_off, input_objects, input_file,
495 memoff, memsize, member_name);
498 // This is an external member of a thin archive. Open the
499 // file as a regular relocatable object file.
500 Input_file_argument* input_file_arg =
501 new Input_file_argument(member_name->c_str(), false, "", false,
502 this->input_file_->options());
503 *input_file = new Input_file(input_file_arg);
504 if (!(*input_file)->open(*this->dirpath_, this->task_))
508 *memsize = (*input_file)->file().filesize();
512 // Return an ELF object for the member at offset OFF. Set *MEMBER_NAME to
513 // the name of the member.
516 Archive::get_elf_object_for_member(off_t off, Input_objects* input_objects)
518 std::string member_name;
519 Input_file* input_file;
523 if (!this->get_file_and_offset(off, input_objects, &input_file, &memoff,
524 &memsize, &member_name))
527 if (parameters->options().has_plugins())
529 Object* obj = parameters->options().plugins()->claim_file(input_file,
534 // The input file was claimed by a plugin, and its symbols
535 // have been provided by the plugin.
540 off_t filesize = input_file->file().filesize();
541 int read_size = elfcpp::Elf_sizes<64>::ehdr_size;
542 if (filesize - memoff < read_size)
543 read_size = filesize - memoff;
547 gold_error(_("%s: member at %zu is not an ELF object"),
548 this->name().c_str(), static_cast<size_t>(off));
552 const unsigned char* ehdr = input_file->file().get_view(memoff, 0, read_size,
555 static unsigned char elfmagic[4] =
557 elfcpp::ELFMAG0, elfcpp::ELFMAG1,
558 elfcpp::ELFMAG2, elfcpp::ELFMAG3
560 if (memcmp(ehdr, elfmagic, 4) != 0)
562 gold_error(_("%s: member at %zu is not an ELF object"),
563 this->name().c_str(), static_cast<size_t>(off));
567 return make_elf_object((std::string(this->input_file_->filename())
568 + "(" + member_name + ")"),
569 input_file, memoff, ehdr, read_size);
572 // Read the symbols from all the archive members in the link.
575 Archive::read_all_symbols(Input_objects* input_objects)
577 for (Archive::const_iterator p = this->begin();
580 this->read_symbols(input_objects, p->off);
583 // Read the symbols from an archive member in the link. OFF is the file
584 // offset of the member header.
587 Archive::read_symbols(Input_objects* input_objects, off_t off)
589 Object* obj = this->get_elf_object_for_member(off, input_objects);
594 Read_symbols_data* sd = new Read_symbols_data;
595 obj->read_symbols(sd);
596 Archive_member member(obj, sd);
597 this->members_[off] = member;
600 // Select members from the archive and add them to the link. We walk
601 // through the elements in the archive map, and look each one up in
602 // the symbol table. If it exists as a strong undefined symbol, we
603 // pull in the corresponding element. We have to do this in a loop,
604 // since pulling in one element may create new undefined symbols which
605 // may be satisfied by other objects in the archive.
608 Archive::add_symbols(Symbol_table* symtab, Layout* layout,
609 Input_objects* input_objects, Mapfile* mapfile)
611 ++Archive::total_archives;
613 if (this->input_file_->options().whole_archive())
614 return this->include_all_members(symtab, layout, input_objects,
617 Archive::total_members += this->num_members_;
619 input_objects->archive_start(this);
621 const size_t armap_size = this->armap_.size();
623 // This is a quick optimization, since we usually see many symbols
624 // in a row with the same offset. last_seen_offset holds the last
625 // offset we saw that was present in the seen_offsets_ set.
626 off_t last_seen_offset = -1;
628 // Track which symbols in the symbol table we've already found to be
631 bool added_new_object;
634 added_new_object = false;
635 for (size_t i = 0; i < armap_size; ++i)
637 if (this->armap_checked_[i])
639 if (this->armap_[i].file_offset == last_seen_offset)
641 this->armap_checked_[i] = true;
644 if (this->seen_offsets_.find(this->armap_[i].file_offset)
645 != this->seen_offsets_.end())
647 this->armap_checked_[i] = true;
648 last_seen_offset = this->armap_[i].file_offset;
652 const char* sym_name = (this->armap_names_.data()
653 + this->armap_[i].name_offset);
654 Symbol* sym = symtab->lookup(sym_name);
657 // Check whether the symbol was named in a -u option.
658 if (!parameters->options().is_undefined(sym_name))
661 else if (!sym->is_undefined())
663 this->armap_checked_[i] = true;
666 else if (sym->binding() == elfcpp::STB_WEAK)
669 // We want to include this object in the link.
670 last_seen_offset = this->armap_[i].file_offset;
671 this->seen_offsets_.insert(last_seen_offset);
672 this->armap_checked_[i] = true;
680 this->include_member(symtab, layout, input_objects,
681 last_seen_offset, mapfile, sym, why.c_str());
683 added_new_object = true;
686 while (added_new_object);
688 input_objects->archive_stop(this);
691 // Include all the archive members in the link. This is for --whole-archive.
694 Archive::include_all_members(Symbol_table* symtab, Layout* layout,
695 Input_objects* input_objects, Mapfile* mapfile)
697 input_objects->archive_start(this);
699 if (this->members_.size() > 0)
701 std::map<off_t, Archive_member>::const_iterator p;
702 for (p = this->members_.begin();
703 p != this->members_.end();
706 this->include_member(symtab, layout, input_objects, p->first,
707 mapfile, NULL, "--whole-archive");
708 ++Archive::total_members;
713 for (Archive::const_iterator p = this->begin();
717 this->include_member(symtab, layout, input_objects, p->off,
718 mapfile, NULL, "--whole-archive");
719 ++Archive::total_members;
723 input_objects->archive_stop(this);
726 // Return the number of members in the archive. This is only used for
730 Archive::count_members()
733 for (Archive::const_iterator p = this->begin();
740 // Include an archive member in the link. OFF is the file offset of
741 // the member header. WHY is the reason we are including this member.
744 Archive::include_member(Symbol_table* symtab, Layout* layout,
745 Input_objects* input_objects, off_t off,
746 Mapfile* mapfile, Symbol* sym, const char* why)
748 ++Archive::total_members_loaded;
750 std::map<off_t, Archive_member>::const_iterator p = this->members_.find(off);
751 if (p != this->members_.end())
753 Object *obj = p->second.obj_;
754 Read_symbols_data *sd = p->second.sd_;
756 mapfile->report_include_archive_member(obj->name(), sym, why);
757 if (input_objects->add_object(obj))
759 obj->layout(symtab, layout, sd);
760 obj->add_symbols(symtab, sd, layout);
766 Object* obj = this->get_elf_object_for_member(off, input_objects);
771 mapfile->report_include_archive_member(obj->name(), sym, why);
773 Pluginobj* pluginobj = obj->pluginobj();
774 if (pluginobj != NULL)
776 pluginobj->add_symbols(symtab, NULL, layout);
780 if (input_objects->add_object(obj))
782 Read_symbols_data sd;
783 obj->read_symbols(&sd);
784 obj->layout(symtab, layout, &sd);
785 obj->add_symbols(symtab, &sd, layout);
787 // If this is an external member of a thin archive, unlock the file
788 // for the next task.
789 if (obj->offset() == 0)
790 obj->unlock(this->task_);
794 // FIXME: We need to close the descriptor here.
799 // Print statistical information to stderr. This is used for --stats.
802 Archive::print_stats()
804 fprintf(stderr, _("%s: archive libraries: %u\n"),
805 program_name, Archive::total_archives);
806 fprintf(stderr, _("%s: total archive members: %u\n"),
807 program_name, Archive::total_members);
808 fprintf(stderr, _("%s: loaded archive members: %u\n"),
809 program_name, Archive::total_members_loaded);
812 // Add_archive_symbols methods.
814 Add_archive_symbols::~Add_archive_symbols()
816 if (this->this_blocker_ != NULL)
817 delete this->this_blocker_;
818 // next_blocker_ is deleted by the task associated with the next
822 // Return whether we can add the archive symbols. We are blocked by
823 // this_blocker_. We block next_blocker_. We also lock the file.
826 Add_archive_symbols::is_runnable()
828 if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
829 return this->this_blocker_;
834 Add_archive_symbols::locks(Task_locker* tl)
836 tl->add(this, this->next_blocker_);
837 tl->add(this, this->archive_->token());
841 Add_archive_symbols::run(Workqueue*)
843 this->archive_->add_symbols(this->symtab_, this->layout_,
844 this->input_objects_, this->mapfile_);
846 this->archive_->unlock_nested_archives();
848 this->archive_->release();
849 this->archive_->clear_uncached_views();
851 if (this->input_group_ != NULL)
852 this->input_group_->add_archive(this->archive_);
855 // We no longer need to know about this archive.
856 delete this->archive_;
857 this->archive_ = NULL;
861 } // End namespace gold.