1 // archive.cc -- archive support for gold
3 // Copyright 2006, 2007, 2008 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"
44 // The header of an entry in the archive. This is all readable text,
45 // padded with spaces where necesary. If the contents of an archive
46 // are all text file, the entire archive is readable.
48 struct Archive::Archive_header
52 // The file modification time.
54 // The user's UID in decimal.
56 // The user's GID in decimal.
58 // The file mode in octal.
60 // The file size in decimal.
62 // The final magic code.
66 // Class Archive static variables.
67 unsigned int Archive::total_archives;
68 unsigned int Archive::total_members;
69 unsigned int Archive::total_members_loaded;
73 const char Archive::armag[sarmag] =
75 '!', '<', 'a', 'r', 'c', 'h', '>', '\n'
78 const char Archive::armagt[sarmag] =
80 '!', '<', 't', 'h', 'i', 'n', '>', '\n'
83 const char Archive::arfmag[2] = { '`', '\n' };
85 // Set up the archive: read the symbol map and the extended name
89 Archive::setup(Input_objects* input_objects)
91 // We need to ignore empty archives.
92 if (this->input_file_->file().filesize() == sarmag)
95 // The first member of the archive should be the symbol table.
96 std::string armap_name;
97 section_size_type armap_size =
98 convert_to_section_size_type(this->read_header(sarmag, false,
101 if (armap_name.empty())
103 this->read_armap(sarmag + sizeof(Archive_header), armap_size);
104 off = sarmag + sizeof(Archive_header) + armap_size;
106 else if (!this->input_file_->options().whole_archive())
107 gold_error(_("%s: no archive symbol table (run ranlib)"),
108 this->name().c_str());
110 // See if there is an extended name table. We cache these views
111 // because it is likely that we will want to read the following
112 // header in the add_symbols routine.
116 section_size_type extended_size =
117 convert_to_section_size_type(this->read_header(off, true, &xname, NULL));
120 const unsigned char* p = this->get_view(off + sizeof(Archive_header),
121 extended_size, false, true);
122 const char* px = reinterpret_cast<const char*>(p);
123 this->extended_names_.assign(px, extended_size);
125 bool preread_syms = (parameters->options().threads()
126 && parameters->options().preread_archive_symbols());
127 #ifndef ENABLE_THREADS
128 preread_syms = false;
131 this->read_all_symbols(input_objects);
134 // Unlock any nested archives.
137 Archive::unlock_nested_archives()
139 for (Nested_archive_table::iterator p = this->nested_archives_.begin();
140 p != this->nested_archives_.end();
143 p->second->unlock(this->task_);
147 // Read the archive symbol map.
150 Archive::read_armap(off_t start, section_size_type size)
152 // To count the total number of archive members, we'll just count
153 // the number of times the file offset changes. Since most archives
154 // group the symbols in the armap by object, this ought to give us
155 // an accurate count.
156 off_t last_seen_offset = -1;
158 // Read in the entire armap.
159 const unsigned char* p = this->get_view(start, size, true, false);
161 // Numbers in the armap are always big-endian.
162 const elfcpp::Elf_Word* pword = reinterpret_cast<const elfcpp::Elf_Word*>(p);
163 unsigned int nsyms = elfcpp::Swap<32, true>::readval(pword);
166 // Note that the addition is in units of sizeof(elfcpp::Elf_Word).
167 const char* pnames = reinterpret_cast<const char*>(pword + nsyms);
168 section_size_type names_size =
169 reinterpret_cast<const char*>(p) + size - pnames;
170 this->armap_names_.assign(pnames, names_size);
172 this->armap_.resize(nsyms);
174 section_offset_type name_offset = 0;
175 for (unsigned int i = 0; i < nsyms; ++i)
177 this->armap_[i].name_offset = name_offset;
178 this->armap_[i].file_offset = elfcpp::Swap<32, true>::readval(pword);
179 name_offset += strlen(pnames + name_offset) + 1;
181 if (this->armap_[i].file_offset != last_seen_offset)
183 last_seen_offset = this->armap_[i].file_offset;
184 ++this->num_members_;
188 if (static_cast<section_size_type>(name_offset) > names_size)
189 gold_error(_("%s: bad archive symbol table names"),
190 this->name().c_str());
192 // This array keeps track of which symbols are for archive elements
193 // which we have already included in the link.
194 this->armap_checked_.resize(nsyms);
197 // Read the header of an archive member at OFF. Fail if something
198 // goes wrong. Return the size of the member. Set *PNAME to the name
202 Archive::read_header(off_t off, bool cache, std::string* pname,
205 const unsigned char* p = this->get_view(off, sizeof(Archive_header), true,
207 const Archive_header* hdr = reinterpret_cast<const Archive_header*>(p);
208 return this->interpret_header(hdr, off, pname, nested_off);
211 // Interpret the header of HDR, the header of the archive member at
212 // file offset OFF. Fail if something goes wrong. Return the size of
213 // the member. Set *PNAME to the name of the member.
216 Archive::interpret_header(const Archive_header* hdr, off_t off,
217 std::string* pname, off_t* nested_off) const
219 if (memcmp(hdr->ar_fmag, arfmag, sizeof arfmag) != 0)
221 gold_error(_("%s: malformed archive header at %zu"),
222 this->name().c_str(), static_cast<size_t>(off));
223 return this->input_file_->file().filesize() - off;
226 const int size_string_size = sizeof hdr->ar_size;
227 char size_string[size_string_size + 1];
228 memcpy(size_string, hdr->ar_size, size_string_size);
229 char* ps = size_string + size_string_size;
230 while (ps[-1] == ' ')
236 off_t member_size = strtol(size_string, &end, 10);
239 || (member_size == LONG_MAX && errno == ERANGE))
241 gold_error(_("%s: malformed archive header size at %zu"),
242 this->name().c_str(), static_cast<size_t>(off));
243 return this->input_file_->file().filesize() - off;
246 if (hdr->ar_name[0] != '/')
248 const char* name_end = strchr(hdr->ar_name, '/');
250 || name_end - hdr->ar_name >= static_cast<int>(sizeof hdr->ar_name))
252 gold_error(_("%s: malformed archive header name at %zu"),
253 this->name().c_str(), static_cast<size_t>(off));
254 return this->input_file_->file().filesize() - off;
256 pname->assign(hdr->ar_name, name_end - hdr->ar_name);
257 if (nested_off != NULL)
260 else if (hdr->ar_name[1] == ' ')
262 // This is the symbol table.
265 else if (hdr->ar_name[1] == '/')
267 // This is the extended name table.
268 pname->assign(1, '/');
273 long x = strtol(hdr->ar_name + 1, &end, 10);
276 y = strtol(end + 1, &end, 10);
279 || (x == LONG_MAX && errno == ERANGE)
280 || static_cast<size_t>(x) >= this->extended_names_.size())
282 gold_error(_("%s: bad extended name index at %zu"),
283 this->name().c_str(), static_cast<size_t>(off));
284 return this->input_file_->file().filesize() - off;
287 const char* name = this->extended_names_.data() + x;
288 const char* name_end = strchr(name, '\n');
289 if (static_cast<size_t>(name_end - name) > this->extended_names_.size()
290 || name_end[-1] != '/')
292 gold_error(_("%s: bad extended name entry at header %zu"),
293 this->name().c_str(), static_cast<size_t>(off));
294 return this->input_file_->file().filesize() - off;
296 pname->assign(name, name_end - 1 - name);
297 if (nested_off != NULL)
304 // An archive member iterator.
306 class Archive::const_iterator
309 // The header of an archive member. This is what this iterator
313 // The name of the member.
315 // The file offset of the member.
317 // The file offset of a nested archive member.
319 // The size of the member.
323 const_iterator(Archive* archive, off_t off)
324 : archive_(archive), off_(off)
325 { this->read_next_header(); }
329 { return this->header_; }
333 { return &this->header_; }
338 if (this->off_ == this->archive_->file().filesize())
340 this->off_ += sizeof(Archive_header);
341 if (!this->archive_->is_thin_archive())
342 this->off_ += this->header_.size;
343 if ((this->off_ & 1) != 0)
345 this->read_next_header();
352 const_iterator ret = *this;
358 operator==(const const_iterator p) const
359 { return this->off_ == p->off; }
362 operator!=(const const_iterator p) const
363 { return this->off_ != p->off; }
369 // The underlying archive.
371 // The current offset in the file.
373 // The current archive header.
377 // Read the next archive header.
380 Archive::const_iterator::read_next_header()
382 off_t filesize = this->archive_->file().filesize();
385 if (filesize - this->off_ < static_cast<off_t>(sizeof(Archive_header)))
387 if (filesize != this->off_)
389 gold_error(_("%s: short archive header at %zu"),
390 this->archive_->filename().c_str(),
391 static_cast<size_t>(this->off_));
392 this->off_ = filesize;
394 this->header_.off = filesize;
398 unsigned char buf[sizeof(Archive_header)];
399 this->archive_->file().read(this->off_, sizeof(Archive_header), buf);
401 const Archive_header* hdr = reinterpret_cast<const Archive_header*>(buf);
403 this->archive_->interpret_header(hdr, this->off_, &this->header_.name,
404 &this->header_.nested_off);
405 this->header_.off = this->off_;
407 // Skip special members.
408 if (!this->header_.name.empty() && this->header_.name != "/")
411 this->off_ += sizeof(Archive_header) + this->header_.size;
412 if ((this->off_ & 1) != 0)
419 Archive::const_iterator
422 return Archive::const_iterator(this, sarmag);
427 Archive::const_iterator
430 return Archive::const_iterator(this, this->input_file_->file().filesize());
433 // Get the file and offset for an archive member, which may be an
434 // external member of a thin archive. Set *INPUT_FILE to the
435 // file containing the actual member, *MEMOFF to the offset
436 // within that file (0 if not a nested archive), and *MEMBER_NAME
437 // to the name of the archive member. Return TRUE on success.
440 Archive::get_file_and_offset(off_t off, Input_objects* input_objects,
441 Input_file** input_file, off_t* memoff,
442 std::string* member_name)
446 this->read_header(off, false, member_name, &nested_off);
448 *input_file = this->input_file_;
449 *memoff = off + static_cast<off_t>(sizeof(Archive_header));
451 if (!this->is_thin_archive_)
454 // Adjust a relative pathname so that it is relative
455 // to the directory containing the archive.
456 if (!IS_ABSOLUTE_PATH(member_name->c_str()))
458 const char* arch_path = this->name().c_str();
459 const char* basename = lbasename(arch_path);
460 if (basename > arch_path)
461 member_name->replace(0, 0,
462 this->name().substr(0, basename - arch_path));
467 // This is a member of a nested archive. Open the containing
468 // archive if we don't already have it open, then do a recursive
469 // call to include the member from that archive.
471 Nested_archive_table::const_iterator p =
472 this->nested_archives_.find(*member_name);
473 if (p != this->nested_archives_.end())
477 Input_file_argument* input_file_arg =
478 new Input_file_argument(member_name->c_str(), false, "", false,
479 parameters->options());
480 *input_file = new Input_file(input_file_arg);
481 if (!(*input_file)->open(parameters->options(), *this->dirpath_,
484 arch = new Archive(*member_name, *input_file, false, this->dirpath_,
486 arch->setup(input_objects);
487 std::pair<Nested_archive_table::iterator, bool> ins =
488 this->nested_archives_.insert(std::make_pair(*member_name, arch));
489 gold_assert(ins.second);
491 return arch->get_file_and_offset(nested_off, input_objects,
492 input_file, memoff, member_name);
495 // This is an external member of a thin archive. Open the
496 // file as a regular relocatable object file.
497 Input_file_argument* input_file_arg =
498 new Input_file_argument(member_name->c_str(), false, "", false,
499 this->input_file_->options());
500 *input_file = new Input_file(input_file_arg);
501 if (!(*input_file)->open(parameters->options(), *this->dirpath_,
509 // Return an ELF object for the member at offset OFF. Set *MEMBER_NAME to
510 // the name of the member.
513 Archive::get_elf_object_for_member(off_t off, Input_objects* input_objects)
515 std::string member_name;
516 Input_file* input_file;
519 if (!this->get_file_and_offset(off, input_objects, &input_file, &memoff,
523 off_t filesize = input_file->file().filesize();
524 int read_size = elfcpp::Elf_sizes<64>::ehdr_size;
525 if (filesize - memoff < read_size)
526 read_size = filesize - memoff;
530 gold_error(_("%s: member at %zu is not an ELF object"),
531 this->name().c_str(), static_cast<size_t>(off));
535 const unsigned char* ehdr = input_file->file().get_view(memoff, 0, read_size,
538 static unsigned char elfmagic[4] =
540 elfcpp::ELFMAG0, elfcpp::ELFMAG1,
541 elfcpp::ELFMAG2, elfcpp::ELFMAG3
543 if (memcmp(ehdr, elfmagic, 4) != 0)
545 gold_error(_("%s: member at %zu is not an ELF object"),
546 this->name().c_str(), static_cast<size_t>(off));
550 return make_elf_object((std::string(this->input_file_->filename())
551 + "(" + member_name + ")"),
552 input_file, memoff, ehdr, read_size);
555 // Read the symbols from all the archive members in the link.
558 Archive::read_all_symbols(Input_objects* input_objects)
560 for (Archive::const_iterator p = this->begin();
563 this->read_symbols(input_objects, p->off);
566 // Read the symbols from an archive member in the link. OFF is the file
567 // offset of the member header.
570 Archive::read_symbols(Input_objects* input_objects, off_t off)
572 Object* obj = this->get_elf_object_for_member(off, input_objects);
577 Read_symbols_data* sd = new Read_symbols_data;
578 obj->read_symbols(sd);
579 Archive_member member(obj, sd);
580 this->members_[off] = member;
583 // Select members from the archive and add them to the link. We walk
584 // through the elements in the archive map, and look each one up in
585 // the symbol table. If it exists as a strong undefined symbol, we
586 // pull in the corresponding element. We have to do this in a loop,
587 // since pulling in one element may create new undefined symbols which
588 // may be satisfied by other objects in the archive.
591 Archive::add_symbols(Symbol_table* symtab, Layout* layout,
592 Input_objects* input_objects, Mapfile* mapfile)
594 ++Archive::total_archives;
596 if (this->input_file_->options().whole_archive())
597 return this->include_all_members(symtab, layout, input_objects,
600 Archive::total_members += this->num_members_;
602 input_objects->archive_start(this);
604 const size_t armap_size = this->armap_.size();
606 // This is a quick optimization, since we usually see many symbols
607 // in a row with the same offset. last_seen_offset holds the last
608 // offset we saw that was present in the seen_offsets_ set.
609 off_t last_seen_offset = -1;
611 // Track which symbols in the symbol table we've already found to be
614 bool added_new_object;
617 added_new_object = false;
618 for (size_t i = 0; i < armap_size; ++i)
620 if (this->armap_checked_[i])
622 if (this->armap_[i].file_offset == last_seen_offset)
624 this->armap_checked_[i] = true;
627 if (this->seen_offsets_.find(this->armap_[i].file_offset)
628 != this->seen_offsets_.end())
630 this->armap_checked_[i] = true;
631 last_seen_offset = this->armap_[i].file_offset;
635 const char* sym_name = (this->armap_names_.data()
636 + this->armap_[i].name_offset);
637 Symbol* sym = symtab->lookup(sym_name);
640 // Check whether the symbol was named in a -u option.
641 if (!parameters->options().is_undefined(sym_name))
644 else if (!sym->is_undefined())
646 this->armap_checked_[i] = true;
649 else if (sym->binding() == elfcpp::STB_WEAK)
652 // We want to include this object in the link.
653 last_seen_offset = this->armap_[i].file_offset;
654 this->seen_offsets_.insert(last_seen_offset);
655 this->armap_checked_[i] = true;
663 this->include_member(symtab, layout, input_objects,
664 last_seen_offset, mapfile, sym, why.c_str());
666 added_new_object = true;
669 while (added_new_object);
671 input_objects->archive_stop(this);
674 // Include all the archive members in the link. This is for --whole-archive.
677 Archive::include_all_members(Symbol_table* symtab, Layout* layout,
678 Input_objects* input_objects, Mapfile* mapfile)
680 input_objects->archive_start(this);
682 if (this->members_.size() > 0)
684 std::map<off_t, Archive_member>::const_iterator p;
685 for (p = this->members_.begin();
686 p != this->members_.end();
689 this->include_member(symtab, layout, input_objects, p->first,
690 mapfile, NULL, "--whole-archive");
691 ++Archive::total_members;
696 for (Archive::const_iterator p = this->begin();
700 this->include_member(symtab, layout, input_objects, p->off,
701 mapfile, NULL, "--whole-archive");
702 ++Archive::total_members;
706 input_objects->archive_stop(this);
709 // Return the number of members in the archive. This is only used for
713 Archive::count_members()
716 for (Archive::const_iterator p = this->begin();
723 // Include an archive member in the link. OFF is the file offset of
724 // the member header. WHY is the reason we are including this member.
727 Archive::include_member(Symbol_table* symtab, Layout* layout,
728 Input_objects* input_objects, off_t off,
729 Mapfile* mapfile, Symbol* sym, const char* why)
731 ++Archive::total_members_loaded;
733 std::map<off_t, Archive_member>::const_iterator p = this->members_.find(off);
734 if (p != this->members_.end())
736 Object *obj = p->second.obj_;
737 Read_symbols_data *sd = p->second.sd_;
739 mapfile->report_include_archive_member(obj->name(), sym, why);
740 if (input_objects->add_object(obj))
742 obj->layout(symtab, layout, sd);
743 obj->add_symbols(symtab, sd);
749 Object* obj = this->get_elf_object_for_member(off, input_objects);
754 mapfile->report_include_archive_member(obj->name(), sym, why);
756 if (input_objects->add_object(obj))
758 Read_symbols_data sd;
759 obj->read_symbols(&sd);
760 obj->layout(symtab, layout, &sd);
761 obj->add_symbols(symtab, &sd);
765 // FIXME: We need to close the descriptor here.
770 // Print statistical information to stderr. This is used for --stats.
773 Archive::print_stats()
775 fprintf(stderr, _("%s: archive libraries: %u\n"),
776 program_name, Archive::total_archives);
777 fprintf(stderr, _("%s: total archive members: %u\n"),
778 program_name, Archive::total_members);
779 fprintf(stderr, _("%s: loaded archive members: %u\n"),
780 program_name, Archive::total_members_loaded);
783 // Add_archive_symbols methods.
785 Add_archive_symbols::~Add_archive_symbols()
787 if (this->this_blocker_ != NULL)
788 delete this->this_blocker_;
789 // next_blocker_ is deleted by the task associated with the next
793 // Return whether we can add the archive symbols. We are blocked by
794 // this_blocker_. We block next_blocker_. We also lock the file.
797 Add_archive_symbols::is_runnable()
799 if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
800 return this->this_blocker_;
805 Add_archive_symbols::locks(Task_locker* tl)
807 tl->add(this, this->next_blocker_);
808 tl->add(this, this->archive_->token());
812 Add_archive_symbols::run(Workqueue*)
814 this->archive_->add_symbols(this->symtab_, this->layout_,
815 this->input_objects_, this->mapfile_);
817 this->archive_->unlock_nested_archives();
819 this->archive_->release();
820 this->archive_->clear_uncached_views();
822 if (this->input_group_ != NULL)
823 this->input_group_->add_archive(this->archive_);
826 // We no longer need to know about this archive.
827 delete this->archive_;
828 this->archive_ = NULL;
832 } // End namespace gold.