// archive.cc -- archive support for gold // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. // This program is free software; you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation; either version 3 of the License, or // (at your option) any later version. // This program is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // You should have received a copy of the GNU General Public License // along with this program; if not, write to the Free Software // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, // MA 02110-1301, USA. #include "gold.h" #include #include #include #include #include "libiberty.h" #include "filenames.h" #include "elfcpp.h" #include "options.h" #include "mapfile.h" #include "fileread.h" #include "readsyms.h" #include "symtab.h" #include "object.h" #include "archive.h" #include "plugin.h" namespace gold { // The header of an entry in the archive. This is all readable text, // padded with spaces where necesary. If the contents of an archive // are all text file, the entire archive is readable. struct Archive::Archive_header { // The entry name. char ar_name[16]; // The file modification time. char ar_date[12]; // The user's UID in decimal. char ar_uid[6]; // The user's GID in decimal. char ar_gid[6]; // The file mode in octal. char ar_mode[8]; // The file size in decimal. char ar_size[10]; // The final magic code. char ar_fmag[2]; }; // Class Archive static variables. unsigned int Archive::total_archives; unsigned int Archive::total_members; unsigned int Archive::total_members_loaded; // Archive methods. const char Archive::armag[sarmag] = { '!', '<', 'a', 'r', 'c', 'h', '>', '\n' }; const char Archive::armagt[sarmag] = { '!', '<', 't', 'h', 'i', 'n', '>', '\n' }; const char Archive::arfmag[2] = { '`', '\n' }; // Set up the archive: read the symbol map and the extended name // table. void Archive::setup() { // We need to ignore empty archives. if (this->input_file_->file().filesize() == sarmag) return; // The first member of the archive should be the symbol table. std::string armap_name; section_size_type armap_size = convert_to_section_size_type(this->read_header(sarmag, false, &armap_name, NULL)); off_t off = sarmag; if (armap_name.empty()) { this->read_armap(sarmag + sizeof(Archive_header), armap_size); off = sarmag + sizeof(Archive_header) + armap_size; } else if (!this->input_file_->options().whole_archive()) gold_error(_("%s: no archive symbol table (run ranlib)"), this->name().c_str()); // See if there is an extended name table. We cache these views // because it is likely that we will want to read the following // header in the add_symbols routine. if ((off & 1) != 0) ++off; std::string xname; section_size_type extended_size = convert_to_section_size_type(this->read_header(off, true, &xname, NULL)); if (xname == "/") { const unsigned char* p = this->get_view(off + sizeof(Archive_header), extended_size, false, true); const char* px = reinterpret_cast(p); this->extended_names_.assign(px, extended_size); } bool preread_syms = (parameters->options().threads() && parameters->options().preread_archive_symbols()); #ifndef ENABLE_THREADS preread_syms = false; #else if (parameters->options().has_plugins()) preread_syms = false; #endif if (preread_syms) this->read_all_symbols(); } // Unlock any nested archives. void Archive::unlock_nested_archives() { for (Nested_archive_table::iterator p = this->nested_archives_.begin(); p != this->nested_archives_.end(); ++p) { p->second->unlock(this->task_); } } // Read the archive symbol map. void Archive::read_armap(off_t start, section_size_type size) { // To count the total number of archive members, we'll just count // the number of times the file offset changes. Since most archives // group the symbols in the armap by object, this ought to give us // an accurate count. off_t last_seen_offset = -1; // Read in the entire armap. const unsigned char* p = this->get_view(start, size, true, false); // Numbers in the armap are always big-endian. const elfcpp::Elf_Word* pword = reinterpret_cast(p); unsigned int nsyms = elfcpp::Swap<32, true>::readval(pword); ++pword; // Note that the addition is in units of sizeof(elfcpp::Elf_Word). const char* pnames = reinterpret_cast(pword + nsyms); section_size_type names_size = reinterpret_cast(p) + size - pnames; this->armap_names_.assign(pnames, names_size); this->armap_.resize(nsyms); section_offset_type name_offset = 0; for (unsigned int i = 0; i < nsyms; ++i) { this->armap_[i].name_offset = name_offset; this->armap_[i].file_offset = elfcpp::Swap<32, true>::readval(pword); name_offset += strlen(pnames + name_offset) + 1; ++pword; if (this->armap_[i].file_offset != last_seen_offset) { last_seen_offset = this->armap_[i].file_offset; ++this->num_members_; } } if (static_cast(name_offset) > names_size) gold_error(_("%s: bad archive symbol table names"), this->name().c_str()); // This array keeps track of which symbols are for archive elements // which we have already included in the link. this->armap_checked_.resize(nsyms); } // Read the header of an archive member at OFF. Fail if something // goes wrong. Return the size of the member. Set *PNAME to the name // of the member. off_t Archive::read_header(off_t off, bool cache, std::string* pname, off_t* nested_off) { const unsigned char* p = this->get_view(off, sizeof(Archive_header), true, cache); const Archive_header* hdr = reinterpret_cast(p); return this->interpret_header(hdr, off, pname, nested_off); } // Interpret the header of HDR, the header of the archive member at // file offset OFF. Fail if something goes wrong. Return the size of // the member. Set *PNAME to the name of the member. off_t Archive::interpret_header(const Archive_header* hdr, off_t off, std::string* pname, off_t* nested_off) const { if (memcmp(hdr->ar_fmag, arfmag, sizeof arfmag) != 0) { gold_error(_("%s: malformed archive header at %zu"), this->name().c_str(), static_cast(off)); return this->input_file_->file().filesize() - off; } const int size_string_size = sizeof hdr->ar_size; char size_string[size_string_size + 1]; memcpy(size_string, hdr->ar_size, size_string_size); char* ps = size_string + size_string_size; while (ps[-1] == ' ') --ps; *ps = '\0'; errno = 0; char* end; off_t member_size = strtol(size_string, &end, 10); if (*end != '\0' || member_size < 0 || (member_size == LONG_MAX && errno == ERANGE)) { gold_error(_("%s: malformed archive header size at %zu"), this->name().c_str(), static_cast(off)); return this->input_file_->file().filesize() - off; } if (hdr->ar_name[0] != '/') { const char* name_end = strchr(hdr->ar_name, '/'); if (name_end == NULL || name_end - hdr->ar_name >= static_cast(sizeof hdr->ar_name)) { gold_error(_("%s: malformed archive header name at %zu"), this->name().c_str(), static_cast(off)); return this->input_file_->file().filesize() - off; } pname->assign(hdr->ar_name, name_end - hdr->ar_name); if (nested_off != NULL) *nested_off = 0; } else if (hdr->ar_name[1] == ' ') { // This is the symbol table. pname->clear(); } else if (hdr->ar_name[1] == '/') { // This is the extended name table. pname->assign(1, '/'); } else { errno = 0; long x = strtol(hdr->ar_name + 1, &end, 10); long y = 0; if (*end == ':') y = strtol(end + 1, &end, 10); if (*end != ' ' || x < 0 || (x == LONG_MAX && errno == ERANGE) || static_cast(x) >= this->extended_names_.size()) { gold_error(_("%s: bad extended name index at %zu"), this->name().c_str(), static_cast(off)); return this->input_file_->file().filesize() - off; } const char* name = this->extended_names_.data() + x; const char* name_end = strchr(name, '\n'); if (static_cast(name_end - name) > this->extended_names_.size() || name_end[-1] != '/') { gold_error(_("%s: bad extended name entry at header %zu"), this->name().c_str(), static_cast(off)); return this->input_file_->file().filesize() - off; } pname->assign(name, name_end - 1 - name); if (nested_off != NULL) *nested_off = y; } return member_size; } // An archive member iterator. class Archive::const_iterator { public: // The header of an archive member. This is what this iterator // points to. struct Header { // The name of the member. std::string name; // The file offset of the member. off_t off; // The file offset of a nested archive member. off_t nested_off; // The size of the member. off_t size; }; const_iterator(Archive* archive, off_t off) : archive_(archive), off_(off) { this->read_next_header(); } const Header& operator*() const { return this->header_; } const Header* operator->() const { return &this->header_; } const_iterator& operator++() { if (this->off_ == this->archive_->file().filesize()) return *this; this->off_ += sizeof(Archive_header); if (!this->archive_->is_thin_archive()) this->off_ += this->header_.size; if ((this->off_ & 1) != 0) ++this->off_; this->read_next_header(); return *this; } const_iterator operator++(int) { const_iterator ret = *this; ++*this; return ret; } bool operator==(const const_iterator p) const { return this->off_ == p->off; } bool operator!=(const const_iterator p) const { return this->off_ != p->off; } private: void read_next_header(); // The underlying archive. Archive* archive_; // The current offset in the file. off_t off_; // The current archive header. Header header_; }; // Read the next archive header. void Archive::const_iterator::read_next_header() { off_t filesize = this->archive_->file().filesize(); while (true) { if (filesize - this->off_ < static_cast(sizeof(Archive_header))) { if (filesize != this->off_) { gold_error(_("%s: short archive header at %zu"), this->archive_->filename().c_str(), static_cast(this->off_)); this->off_ = filesize; } this->header_.off = filesize; return; } unsigned char buf[sizeof(Archive_header)]; this->archive_->file().read(this->off_, sizeof(Archive_header), buf); const Archive_header* hdr = reinterpret_cast(buf); this->header_.size = this->archive_->interpret_header(hdr, this->off_, &this->header_.name, &this->header_.nested_off); this->header_.off = this->off_; // Skip special members. if (!this->header_.name.empty() && this->header_.name != "/") return; this->off_ += sizeof(Archive_header) + this->header_.size; if ((this->off_ & 1) != 0) ++this->off_; } } // Initial iterator. Archive::const_iterator Archive::begin() { return Archive::const_iterator(this, sarmag); } // Final iterator. Archive::const_iterator Archive::end() { return Archive::const_iterator(this, this->input_file_->file().filesize()); } // Get the file and offset for an archive member, which may be an // external member of a thin archive. Set *INPUT_FILE to the // file containing the actual member, *MEMOFF to the offset // within that file (0 if not a nested archive), and *MEMBER_NAME // to the name of the archive member. Return TRUE on success. bool Archive::get_file_and_offset(off_t off, Input_file** input_file, off_t* memoff, off_t* memsize, std::string* member_name) { off_t nested_off; *memsize = this->read_header(off, false, member_name, &nested_off); *input_file = this->input_file_; *memoff = off + static_cast(sizeof(Archive_header)); if (!this->is_thin_archive_) return true; // Adjust a relative pathname so that it is relative // to the directory containing the archive. if (!IS_ABSOLUTE_PATH(member_name->c_str())) { const char* arch_path = this->filename().c_str(); const char* basename = lbasename(arch_path); if (basename > arch_path) member_name->replace(0, 0, this->filename().substr(0, basename - arch_path)); } if (nested_off > 0) { // This is a member of a nested archive. Open the containing // archive if we don't already have it open, then do a recursive // call to include the member from that archive. Archive* arch; Nested_archive_table::const_iterator p = this->nested_archives_.find(*member_name); if (p != this->nested_archives_.end()) arch = p->second; else { Input_file_argument* input_file_arg = new Input_file_argument(member_name->c_str(), false, "", false, parameters->options()); *input_file = new Input_file(input_file_arg); int dummy = 0; if (!(*input_file)->open(*this->dirpath_, this->task_, &dummy)) return false; arch = new Archive(*member_name, *input_file, false, this->dirpath_, this->task_); arch->setup(); std::pair ins = this->nested_archives_.insert(std::make_pair(*member_name, arch)); gold_assert(ins.second); } return arch->get_file_and_offset(nested_off, input_file, memoff, memsize, member_name); } // This is an external member of a thin archive. Open the // file as a regular relocatable object file. Input_file_argument* input_file_arg = new Input_file_argument(member_name->c_str(), false, "", false, this->input_file_->options()); *input_file = new Input_file(input_file_arg); int dummy = 0; if (!(*input_file)->open(*this->dirpath_, this->task_, &dummy)) return false; *memoff = 0; *memsize = (*input_file)->file().filesize(); return true; } // Return an ELF object for the member at offset OFF. If the ELF // object has an unsupported target type, set *PUNCONFIGURED to true // and return NULL. Object* Archive::get_elf_object_for_member(off_t off, bool* punconfigured) { *punconfigured = false; Input_file* input_file; off_t memoff; off_t memsize; std::string member_name; if (!this->get_file_and_offset(off, &input_file, &memoff, &memsize, &member_name)) return NULL; if (parameters->options().has_plugins()) { Object* obj = parameters->options().plugins()->claim_file(input_file, memoff, memsize); if (obj != NULL) { // The input file was claimed by a plugin, and its symbols // have been provided by the plugin. return obj; } } off_t filesize = input_file->file().filesize(); int read_size = elfcpp::Elf_sizes<64>::ehdr_size; if (filesize - memoff < read_size) read_size = filesize - memoff; if (read_size < 4) { gold_error(_("%s: member at %zu is not an ELF object"), this->name().c_str(), static_cast(off)); return NULL; } const unsigned char* ehdr = input_file->file().get_view(memoff, 0, read_size, true, false); static unsigned char elfmagic[4] = { elfcpp::ELFMAG0, elfcpp::ELFMAG1, elfcpp::ELFMAG2, elfcpp::ELFMAG3 }; if (memcmp(ehdr, elfmagic, 4) != 0) { gold_error(_("%s: member at %zu is not an ELF object"), this->name().c_str(), static_cast(off)); return NULL; } return make_elf_object((std::string(this->input_file_->filename()) + "(" + member_name + ")"), input_file, memoff, ehdr, read_size, punconfigured); } // Read the symbols from all the archive members in the link. void Archive::read_all_symbols() { for (Archive::const_iterator p = this->begin(); p != this->end(); ++p) this->read_symbols(p->off); } // Read the symbols from an archive member in the link. OFF is the file // offset of the member header. void Archive::read_symbols(off_t off) { bool dummy; Object* obj = this->get_elf_object_for_member(off, &dummy); if (obj == NULL) return; Read_symbols_data* sd = new Read_symbols_data; obj->read_symbols(sd); Archive_member member(obj, sd); this->members_[off] = member; } // Select members from the archive and add them to the link. We walk // through the elements in the archive map, and look each one up in // the symbol table. If it exists as a strong undefined symbol, we // pull in the corresponding element. We have to do this in a loop, // since pulling in one element may create new undefined symbols which // may be satisfied by other objects in the archive. Return true in // the normal case, false if the first member we tried to add from // this archive had an incompatible target. bool Archive::add_symbols(Symbol_table* symtab, Layout* layout, Input_objects* input_objects, Mapfile* mapfile) { ++Archive::total_archives; if (this->input_file_->options().whole_archive()) return this->include_all_members(symtab, layout, input_objects, mapfile); Archive::total_members += this->num_members_; input_objects->archive_start(this); const size_t armap_size = this->armap_.size(); // This is a quick optimization, since we usually see many symbols // in a row with the same offset. last_seen_offset holds the last // offset we saw that was present in the seen_offsets_ set. off_t last_seen_offset = -1; // Track which symbols in the symbol table we've already found to be // defined. bool added_new_object; do { added_new_object = false; for (size_t i = 0; i < armap_size; ++i) { if (this->armap_checked_[i]) continue; if (this->armap_[i].file_offset == last_seen_offset) { this->armap_checked_[i] = true; continue; } if (this->seen_offsets_.find(this->armap_[i].file_offset) != this->seen_offsets_.end()) { this->armap_checked_[i] = true; last_seen_offset = this->armap_[i].file_offset; continue; } const char* sym_name = (this->armap_names_.data() + this->armap_[i].name_offset); Symbol* sym = symtab->lookup(sym_name); if (sym == NULL) { // Check whether the symbol was named in a -u option. if (!parameters->options().is_undefined(sym_name)) continue; } else if (!sym->is_undefined()) { this->armap_checked_[i] = true; continue; } else if (sym->binding() == elfcpp::STB_WEAK) continue; // We want to include this object in the link. last_seen_offset = this->armap_[i].file_offset; this->seen_offsets_.insert(last_seen_offset); this->armap_checked_[i] = true; std::string why; if (sym == NULL) { why = "-u "; why += sym_name; } if (!this->include_member(symtab, layout, input_objects, last_seen_offset, mapfile, sym, why.c_str())) return false; added_new_object = true; } } while (added_new_object); input_objects->archive_stop(this); return true; } // Include all the archive members in the link. This is for --whole-archive. bool Archive::include_all_members(Symbol_table* symtab, Layout* layout, Input_objects* input_objects, Mapfile* mapfile) { input_objects->archive_start(this); if (this->members_.size() > 0) { std::map::const_iterator p; for (p = this->members_.begin(); p != this->members_.end(); ++p) { if (!this->include_member(symtab, layout, input_objects, p->first, mapfile, NULL, "--whole-archive")) return false; ++Archive::total_members; } } else { for (Archive::const_iterator p = this->begin(); p != this->end(); ++p) { if (!this->include_member(symtab, layout, input_objects, p->off, mapfile, NULL, "--whole-archive")) return false; ++Archive::total_members; } } input_objects->archive_stop(this); return true; } // Return the number of members in the archive. This is only used for // reports. size_t Archive::count_members() { size_t ret = 0; for (Archive::const_iterator p = this->begin(); p != this->end(); ++p) ++ret; return ret; } // Include an archive member in the link. OFF is the file offset of // the member header. WHY is the reason we are including this member. // Return true if we added the member or if we had an error, return // false if this was the first member we tried to add from this // archive and it had an incompatible format. bool Archive::include_member(Symbol_table* symtab, Layout* layout, Input_objects* input_objects, off_t off, Mapfile* mapfile, Symbol* sym, const char* why) { ++Archive::total_members_loaded; std::map::const_iterator p = this->members_.find(off); if (p != this->members_.end()) { Object *obj = p->second.obj_; if (!this->included_member_ && this->searched_for() && !parameters->is_compatible_target(obj->target())) return false; Read_symbols_data *sd = p->second.sd_; if (mapfile != NULL) mapfile->report_include_archive_member(obj->name(), sym, why); if (input_objects->add_object(obj)) { obj->layout(symtab, layout, sd); obj->add_symbols(symtab, sd, layout); this->included_member_ = true; } delete sd; return true; } bool unconfigured; Object* obj = this->get_elf_object_for_member(off, &unconfigured); if (!this->included_member_ && this->searched_for() && (obj == NULL ? unconfigured : !parameters->is_compatible_target(obj->target()))) { if (obj != NULL) delete obj; return false; } if (obj == NULL) return true; if (mapfile != NULL) mapfile->report_include_archive_member(obj->name(), sym, why); Pluginobj* pluginobj = obj->pluginobj(); if (pluginobj != NULL) { pluginobj->add_symbols(symtab, NULL, layout); this->included_member_ = true; return true; } if (!input_objects->add_object(obj)) delete obj; else { Read_symbols_data sd; obj->read_symbols(&sd); obj->layout(symtab, layout, &sd); obj->add_symbols(symtab, &sd, layout); // If this is an external member of a thin archive, unlock the file // for the next task. if (obj->offset() == 0) obj->unlock(this->task_); this->included_member_ = true; } return true; } // Print statistical information to stderr. This is used for --stats. void Archive::print_stats() { fprintf(stderr, _("%s: archive libraries: %u\n"), program_name, Archive::total_archives); fprintf(stderr, _("%s: total archive members: %u\n"), program_name, Archive::total_members); fprintf(stderr, _("%s: loaded archive members: %u\n"), program_name, Archive::total_members_loaded); } // Add_archive_symbols methods. Add_archive_symbols::~Add_archive_symbols() { if (this->this_blocker_ != NULL) delete this->this_blocker_; // next_blocker_ is deleted by the task associated with the next // input file. } // Return whether we can add the archive symbols. We are blocked by // this_blocker_. We block next_blocker_. We also lock the file. Task_token* Add_archive_symbols::is_runnable() { if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) return this->this_blocker_; return NULL; } void Add_archive_symbols::locks(Task_locker* tl) { tl->add(this, this->next_blocker_); tl->add(this, this->archive_->token()); } void Add_archive_symbols::run(Workqueue* workqueue) { bool added = this->archive_->add_symbols(this->symtab_, this->layout_, this->input_objects_, this->mapfile_); this->archive_->unlock_nested_archives(); this->archive_->release(); this->archive_->clear_uncached_views(); if (!added) { // This archive holds object files which are incompatible with // our output file. Read_symbols::incompatible_warning(this->input_argument_, this->archive_->input_file()); Read_symbols::requeue(workqueue, this->input_objects_, this->symtab_, this->layout_, this->dirpath_, this->dirindex_, this->mapfile_, this->input_argument_, this->input_group_, this->next_blocker_); delete this->archive_; return; } if (this->input_group_ != NULL) this->input_group_->add_archive(this->archive_); else { // We no longer need to know about this archive. delete this->archive_; this->archive_ = NULL; } } } // End namespace gold.