// readsyms.cc -- read input file symbols for gold // Copyright (C) 2006-2015 Free Software Foundation, Inc. // Written by Ian Lance Taylor <iant@google.com>. // 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 <cstring> #include "elfcpp.h" #include "options.h" #include "dirsearch.h" #include "symtab.h" #include "object.h" #include "archive.h" #include "script.h" #include "readsyms.h" #include "plugin.h" #include "layout.h" #include "incremental.h" namespace gold { // If we fail to open the object, then we won't create an Add_symbols // task. However, we still need to unblock the token, or else the // link won't proceed to generate more error messages. We can only // unblock tokens when the workqueue lock is held, so we need a dummy // task to do that. The dummy task has to maintain the right sequence // of blocks, so we need both this_blocker and next_blocker. class Unblock_token : public Task { public: Unblock_token(Task_token* this_blocker, Task_token* next_blocker) : this_blocker_(this_blocker), next_blocker_(next_blocker) { } ~Unblock_token() { if (this->this_blocker_ != NULL) delete this->this_blocker_; } Task_token* is_runnable() { if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) return this->this_blocker_; return NULL; } void locks(Task_locker* tl) { tl->add(this, this->next_blocker_); } void run(Workqueue*) { } std::string get_name() const { return "Unblock_token"; } private: Task_token* this_blocker_; Task_token* next_blocker_; }; // Class read_symbols. Read_symbols::~Read_symbols() { // The this_blocker_ and next_blocker_ pointers are passed on to the // Add_symbols task. } // If appropriate, issue a warning about skipping an incompatible // file. void Read_symbols::incompatible_warning(const Input_argument* input_argument, const Input_file* input_file) { if (parameters->options().warn_search_mismatch()) gold_warning("skipping incompatible %s while searching for %s", input_file->filename().c_str(), input_argument->file().name()); } // Requeue a Read_symbols task to search for the next object with the // same name. void Read_symbols::requeue(Workqueue* workqueue, Input_objects* input_objects, Symbol_table* symtab, Layout* layout, Dirsearch* dirpath, int dirindex, Mapfile* mapfile, const Input_argument* input_argument, Input_group* input_group, Task_token* next_blocker) { // Bump the directory search index. ++dirindex; // We don't need to worry about this_blocker, since we already // reached it. However, we are removing the blocker on next_blocker // because the calling task is completing. So we need to add a new // blocker. Since next_blocker may be shared by several tasks, we // need to increment the count with the workqueue lock held. workqueue->add_blocker(next_blocker); workqueue->queue(new Read_symbols(input_objects, symtab, layout, dirpath, dirindex, mapfile, input_argument, input_group, NULL, NULL, next_blocker)); } // Return whether a Read_symbols task is runnable. We can read an // ordinary input file immediately. For an archive specified using // -l, we have to wait until the search path is complete. Task_token* Read_symbols::is_runnable() { if (this->input_argument_->is_file() && this->input_argument_->file().may_need_search() && this->dirpath_->token()->is_blocked()) return this->dirpath_->token(); return NULL; } // Return a Task_locker for a Read_symbols task. We don't need any // locks here. void Read_symbols::locks(Task_locker* tl) { if (this->member_ != NULL) tl->add(this, this->next_blocker_); } // Run a Read_symbols task. void Read_symbols::run(Workqueue* workqueue) { // If we didn't queue a new task, then we need to explicitly unblock // the token. If the object is a member of a lib group, however, // the token was already added to the list of locks for the task, // and it will be unblocked automatically at the end of the task. if (!this->do_read_symbols(workqueue) && this->member_ == NULL) workqueue->queue_soon(new Unblock_token(this->this_blocker_, this->next_blocker_)); } // Handle a whole lib group. Other than collecting statistics, this just // mimics what we do for regular object files in the command line. bool Read_symbols::do_whole_lib_group(Workqueue* workqueue) { const Input_file_lib* lib_group = this->input_argument_->lib(); ++Lib_group::total_lib_groups; Task_token* this_blocker = this->this_blocker_; for (Input_file_lib::const_iterator i = lib_group->begin(); i != lib_group->end(); ++i) { ++Lib_group::total_members; ++Lib_group::total_members_loaded; const Input_argument* arg = &*i; Task_token* next_blocker; if (i != lib_group->end() - 1) { next_blocker = new Task_token(true); next_blocker->add_blocker(); } else next_blocker = this->next_blocker_; workqueue->queue_soon(new Read_symbols(this->input_objects_, this->symtab_, this->layout_, this->dirpath_, this->dirindex_, this->mapfile_, arg, NULL, NULL, this_blocker, next_blocker)); this_blocker = next_blocker; } return true; } // Handle a lib group. We set Read_symbols Tasks as usual, but have them // just record the symbol data instead of adding the objects. We also start // a Add_lib_group_symbols Task which runs after we've read all the symbols. // In that task we process the members in a loop until we are done. bool Read_symbols::do_lib_group(Workqueue* workqueue) { const Input_file_lib* lib_group = this->input_argument_->lib(); if (lib_group->options().whole_archive()) return this->do_whole_lib_group(workqueue); Lib_group* lib = new Lib_group(lib_group, this); Add_lib_group_symbols* add_lib_group_symbols = new Add_lib_group_symbols(this->symtab_, this->layout_, this->input_objects_, lib, this->next_blocker_); Task_token* next_blocker = new Task_token(true); int j = 0; for (Input_file_lib::const_iterator i = lib_group->begin(); i != lib_group->end(); ++i, ++j) { const Input_argument* arg = &*i; Archive_member* m = lib->get_member(j); next_blocker->add_blocker(); // Since this Read_symbols will not create an Add_symbols, // just pass NULL as this_blocker. workqueue->queue_soon(new Read_symbols(this->input_objects_, this->symtab_, this->layout_, this->dirpath_, this->dirindex_, this->mapfile_, arg, NULL, m, NULL, next_blocker)); } add_lib_group_symbols->set_blocker(next_blocker, this->this_blocker_); workqueue->queue_soon(add_lib_group_symbols); return true; } // Open the file and read the symbols. Return true if a new task was // queued, false if that could not happen due to some error. bool Read_symbols::do_read_symbols(Workqueue* workqueue) { if (this->input_argument_->is_group()) { gold_assert(this->input_group_ == NULL); this->do_group(workqueue); return true; } if (this->input_argument_->is_lib()) return this->do_lib_group(workqueue); Input_file* input_file = new Input_file(&this->input_argument_->file()); if (!input_file->open(*this->dirpath_, this, &this->dirindex_)) return false; // Read enough of the file to pick up the entire ELF header. off_t filesize = input_file->file().filesize(); if (filesize == 0) { gold_error(_("%s: file is empty"), input_file->file().filename().c_str()); return false; } const unsigned char* ehdr; int read_size; bool is_elf = is_elf_object(input_file, 0, &ehdr, &read_size); if (read_size >= Archive::sarmag) { bool is_thin_archive = memcmp(ehdr, Archive::armagt, Archive::sarmag) == 0; if (is_thin_archive || memcmp(ehdr, Archive::armag, Archive::sarmag) == 0) { // This is an archive. Archive* arch = new Archive(this->input_argument_->file().name(), input_file, is_thin_archive, this->dirpath_, this); arch->setup(); // Unlock the archive so it can be used in the next task. arch->unlock(this); workqueue->queue_next(new Add_archive_symbols(this->symtab_, this->layout_, this->input_objects_, this->dirpath_, this->dirindex_, this->mapfile_, this->input_argument_, arch, this->input_group_, this->this_blocker_, this->next_blocker_)); return true; } } Object* elf_obj = NULL; bool unconfigured; bool* punconfigured = NULL; if (is_elf) { // This is an ELF object. unconfigured = false; punconfigured = (input_file->will_search_for() ? &unconfigured : NULL); elf_obj = make_elf_object(input_file->filename(), input_file, 0, ehdr, read_size, punconfigured); } if (parameters->options().has_plugins()) { Pluginobj* obj = parameters->options().plugins()->claim_file(input_file, 0, filesize, elf_obj); if (obj != NULL) { // Delete the elf_obj, this file has been claimed. if (elf_obj != NULL) delete elf_obj; // The input file was claimed by a plugin, and its symbols // have been provided by the plugin. // We are done with the file at this point, so unlock it. obj->unlock(this); if (this->member_ != NULL) { this->member_->sd_ = NULL; this->member_->obj_ = obj; return true; } workqueue->queue_next(new Add_symbols(this->input_objects_, this->symtab_, this->layout_, this->dirpath_, this->dirindex_, this->mapfile_, this->input_argument_, obj, NULL, NULL, this->this_blocker_, this->next_blocker_)); return true; } } if (is_elf) { // This is an ELF object. if (elf_obj == NULL) { if (unconfigured) { Read_symbols::incompatible_warning(this->input_argument_, input_file); input_file->file().release(); input_file->file().unlock(this); delete input_file; ++this->dirindex_; return this->do_read_symbols(workqueue); } return false; } Read_symbols_data* sd = new Read_symbols_data; elf_obj->read_symbols(sd); // Opening the file locked it, so now we need to unlock it. We // need to unlock it before queuing the Add_symbols task, // because the workqueue doesn't know about our lock on the // file. If we queue the Add_symbols task first, it will be // stuck on the end of the file lock, but since the workqueue // doesn't know about that lock, it will never release the // Add_symbols task. input_file->file().unlock(this); if (this->member_ != NULL) { this->member_->sd_ = sd; this->member_->obj_ = elf_obj; this->member_->arg_serial_ = this->input_argument_->file().arg_serial(); return true; } // We use queue_next because everything is cached for this // task to run right away if possible. workqueue->queue_next(new Add_symbols(this->input_objects_, this->symtab_, this->layout_, this->dirpath_, this->dirindex_, this->mapfile_, this->input_argument_, elf_obj, NULL, sd, this->this_blocker_, this->next_blocker_)); return true; } // Queue up a task to try to parse this file as a script. We use a // separate task so that the script will be read in order with other // objects named on the command line. Also so that we don't try to // read multiple scripts simultaneously, which could lead to // unpredictable changes to the General_options structure. workqueue->queue_soon(new Read_script(this->symtab_, this->layout_, this->dirpath_, this->dirindex_, this->input_objects_, this->mapfile_, this->input_group_, this->input_argument_, input_file, this->this_blocker_, this->next_blocker_)); return true; } // Handle a group. We need to walk through the arguments over and // over until we don't see any new undefined symbols. We do this by // setting off Read_symbols Tasks as usual, but recording the archive // entries instead of deleting them. We also start a Finish_group // Task which runs after we've read all the symbols. In that task we // process the archives in a loop until we are done. void Read_symbols::do_group(Workqueue* workqueue) { Input_group* input_group = new Input_group(); const Input_file_group* group = this->input_argument_->group(); Task_token* this_blocker = this->this_blocker_; Finish_group* finish_group = new Finish_group(this->input_objects_, this->symtab_, this->layout_, this->mapfile_, input_group, this->next_blocker_); Task_token* next_blocker = new Task_token(true); next_blocker->add_blocker(); workqueue->queue_soon(new Start_group(this->symtab_, finish_group, this_blocker, next_blocker)); this_blocker = next_blocker; for (Input_file_group::const_iterator p = group->begin(); p != group->end(); ++p) { const Input_argument* arg = &*p; gold_assert(arg->is_file()); next_blocker = new Task_token(true); next_blocker->add_blocker(); workqueue->queue_soon(new Read_symbols(this->input_objects_, this->symtab_, this->layout_, this->dirpath_, this->dirindex_, this->mapfile_, arg, input_group, NULL, this_blocker, next_blocker)); this_blocker = next_blocker; } finish_group->set_blocker(this_blocker); workqueue->queue_soon(finish_group); } // Return a debugging name for a Read_symbols task. std::string Read_symbols::get_name() const { if (this->input_argument_->is_group()) { std::string ret("Read_symbols group ("); bool add_space = false; const Input_file_group* group = this->input_argument_->group(); for (Input_file_group::const_iterator p = group->begin(); p != group->end(); ++p) { if (add_space) ret += ' '; ret += p->file().name(); add_space = true; } return ret + ')'; } else if (this->input_argument_->is_lib()) { std::string ret("Read_symbols lib ("); bool add_space = false; const Input_file_lib* lib = this->input_argument_->lib(); for (Input_file_lib::const_iterator p = lib->begin(); p != lib->end(); ++p) { if (add_space) ret += ' '; ret += p->file().name(); add_space = true; } return ret + ')'; } else { std::string ret("Read_symbols "); if (this->input_argument_->file().is_lib()) ret += "-l"; else if (this->input_argument_->file().is_searched_file()) ret += "-l:"; ret += this->input_argument_->file().name(); return ret; } } // Class Add_symbols. Add_symbols::~Add_symbols() { if (this->this_blocker_ != NULL) delete this->this_blocker_; // next_blocker_ is deleted by the task associated with the next // input file. } // We are blocked by this_blocker_. We block next_blocker_. We also // lock the file. Task_token* Add_symbols::is_runnable() { if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) return this->this_blocker_; if (this->object_->is_locked()) return this->object_->token(); return NULL; } void Add_symbols::locks(Task_locker* tl) { tl->add(this, this->next_blocker_); Task_token* token = this->object_->token(); if (token != NULL) tl->add(this, token); } // Add the symbols in the object to the symbol table. void Add_symbols::run(Workqueue*) { Pluginobj* pluginobj = this->object_->pluginobj(); if (pluginobj != NULL) { this->object_->add_symbols(this->symtab_, this->sd_, this->layout_); return; } if (!this->input_objects_->add_object(this->object_)) { this->object_->discard_decompressed_sections(); gold_assert(this->sd_ != NULL); delete this->sd_; this->sd_ = NULL; this->object_->release(); delete this->object_; } else { Incremental_inputs* incremental_inputs = this->layout_->incremental_inputs(); if (incremental_inputs != NULL) { if (this->library_ != NULL && !this->library_->is_reported()) { Incremental_binary* ibase = this->layout_->incremental_base(); gold_assert(ibase != NULL); unsigned int lib_serial = this->library_->arg_serial(); unsigned int lib_index = this->library_->input_file_index(); Script_info* lib_script_info = ibase->get_script_info(lib_index); incremental_inputs->report_archive_begin(this->library_, lib_serial, lib_script_info); } unsigned int arg_serial = this->input_argument_->file().arg_serial(); Script_info* script_info = this->input_argument_->script_info(); incremental_inputs->report_object(this->object_, arg_serial, this->library_, script_info); } this->object_->layout(this->symtab_, this->layout_, this->sd_); this->object_->add_symbols(this->symtab_, this->sd_, this->layout_); this->object_->discard_decompressed_sections(); delete this->sd_; this->sd_ = NULL; this->object_->release(); } } // Class Read_member. Read_member::~Read_member() { if (this->this_blocker_ != NULL) delete this->this_blocker_; // next_blocker_ is deleted by the task associated with the next // input file. } // Return whether a Read_member task is runnable. Task_token* Read_member::is_runnable() { if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) return this->this_blocker_; return NULL; } void Read_member::locks(Task_locker* tl) { tl->add(this, this->next_blocker_); } // Run a Read_member task. void Read_member::run(Workqueue*) { // This task doesn't need to do anything for now. The Read_symbols task // that is queued for the archive library will cause the archive to be // processed from scratch. } // Class Check_script. Check_script::~Check_script() { if (this->this_blocker_ != NULL) delete this->this_blocker_; // next_blocker_ is deleted by the task associated with the next // input file. } // Return whether a Check_script task is runnable. Task_token* Check_script::is_runnable() { if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) return this->this_blocker_; return NULL; } void Check_script::locks(Task_locker* tl) { tl->add(this, this->next_blocker_); } // Run a Check_script task. void Check_script::run(Workqueue*) { Incremental_inputs* incremental_inputs = this->layout_->incremental_inputs(); gold_assert(incremental_inputs != NULL); unsigned int arg_serial = this->input_reader_->arg_serial(); Script_info* script_info = this->ibase_->get_script_info(this->input_file_index_); Timespec mtime = this->input_reader_->get_mtime(); incremental_inputs->report_script(script_info, arg_serial, mtime); } // Class Check_library. Check_library::~Check_library() { if (this->this_blocker_ != NULL) delete this->this_blocker_; // next_blocker_ is deleted by the task associated with the next // input file. } // Return whether a Check_library task is runnable. Task_token* Check_library::is_runnable() { if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) return this->this_blocker_; return NULL; } void Check_library::locks(Task_locker* tl) { tl->add(this, this->next_blocker_); } // Run a Check_library task. void Check_library::run(Workqueue*) { Incremental_inputs* incremental_inputs = this->layout_->incremental_inputs(); gold_assert(incremental_inputs != NULL); Incremental_library* lib = this->ibase_->get_library(this->input_file_index_); gold_assert(lib != NULL); lib->copy_unused_symbols(); // FIXME: Check that unused symbols remain unused. if (!lib->is_reported()) { unsigned int lib_serial = lib->arg_serial(); unsigned int lib_index = lib->input_file_index(); Script_info* script_info = this->ibase_->get_script_info(lib_index); incremental_inputs->report_archive_begin(lib, lib_serial, script_info); } incremental_inputs->report_archive_end(lib); } // Class Input_group. // When we delete an Input_group we can delete the archive // information. Input_group::~Input_group() { for (Input_group::const_iterator p = this->begin(); p != this->end(); ++p) delete *p; } // Class Start_group. Start_group::~Start_group() { if (this->this_blocker_ != NULL) delete this->this_blocker_; // next_blocker_ is deleted by the task associated with the first // file in the group. } // We need to wait for THIS_BLOCKER_ and unblock NEXT_BLOCKER_. Task_token* Start_group::is_runnable() { if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) return this->this_blocker_; return NULL; } void Start_group::locks(Task_locker* tl) { tl->add(this, this->next_blocker_); } // Store the number of undefined symbols we see now. void Start_group::run(Workqueue*) { this->finish_group_->set_saw_undefined(this->symtab_->saw_undefined()); } // Class Finish_group. Finish_group::~Finish_group() { if (this->this_blocker_ != NULL) delete this->this_blocker_; // next_blocker_ is deleted by the task associated with the next // input file following the group. } // We need to wait for THIS_BLOCKER_ and unblock NEXT_BLOCKER_. Task_token* Finish_group::is_runnable() { if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) return this->this_blocker_; return NULL; } void Finish_group::locks(Task_locker* tl) { tl->add(this, this->next_blocker_); } // Loop over the archives until there are no new undefined symbols. void Finish_group::run(Workqueue*) { size_t saw_undefined = this->saw_undefined_; while (saw_undefined != this->symtab_->saw_undefined()) { saw_undefined = this->symtab_->saw_undefined(); for (Input_group::const_iterator p = this->input_group_->begin(); p != this->input_group_->end(); ++p) { Task_lock_obj<Archive> tl(this, *p); (*p)->add_symbols(this->symtab_, this->layout_, this->input_objects_, this->mapfile_); } } // Now that we're done with the archives, record the incremental // layout information. for (Input_group::const_iterator p = this->input_group_->begin(); p != this->input_group_->end(); ++p) { // For an incremental link, finish recording the layout information. Incremental_inputs* incremental_inputs = this->layout_->incremental_inputs(); if (incremental_inputs != NULL) incremental_inputs->report_archive_end(*p); } if (parameters->options().has_plugins()) parameters->options().plugins()->save_input_group(this->input_group_); else delete this->input_group_; } // Class Read_script Read_script::~Read_script() { if (this->this_blocker_ != NULL) delete this->this_blocker_; // next_blocker_ is deleted by the task associated with the next // input file. } // We are blocked by this_blocker_. Task_token* Read_script::is_runnable() { if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) return this->this_blocker_; return NULL; } // We don't unlock next_blocker_ here. If the script names any input // files, then the last file will be responsible for unlocking it. void Read_script::locks(Task_locker*) { } // Read the script, if it is a script. void Read_script::run(Workqueue* workqueue) { bool used_next_blocker; if (!read_input_script(workqueue, this->symtab_, this->layout_, this->dirpath_, this->dirindex_, this->input_objects_, this->mapfile_, this->input_group_, this->input_argument_, this->input_file_, this->next_blocker_, &used_next_blocker)) { // Here we have to handle any other input file types we need. gold_error(_("%s: not an object or archive"), this->input_file_->file().filename().c_str()); } if (!used_next_blocker) { // Queue up a task to unlock next_blocker. We can't just unlock // it here, as we don't hold the workqueue lock. workqueue->queue_soon(new Unblock_token(NULL, this->next_blocker_)); } } // Return a debugging name for a Read_script task. std::string Read_script::get_name() const { std::string ret("Read_script "); if (this->input_argument_->file().is_lib()) ret += "-l"; else if (this->input_argument_->file().is_searched_file()) ret += "-l:"; ret += this->input_argument_->file().name(); return ret; } } // End namespace gold.