// gc.cc -- garbage collection of unused sections // Copyright (C) 2009-2020 Free Software Foundation, Inc. // Written by Sriraman Tallam <tmsriram@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 "object.h" #include "gc.h" #include "symtab.h" namespace gold { // Garbage collection uses a worklist style algorithm to determine the // transitive closure of all referenced sections. void Garbage_collection::do_transitive_closure() { while (!this->worklist().empty()) { // Add elements from the work list to the referenced list // one by one. Section_id entry = this->worklist().back(); this->worklist().pop_back(); if (!this->referenced_list().insert(entry).second) continue; Garbage_collection::Section_ref::iterator find_it = this->section_reloc_map().find(entry); if (find_it == this->section_reloc_map().end()) continue; const Garbage_collection::Sections_reachable &v = find_it->second; // Scan the vector of references for each work_list entry. for (Garbage_collection::Sections_reachable::const_iterator it_v = v.begin(); it_v != v.end(); ++it_v) { // Do not add already processed sections to the work_list. if (this->referenced_list().find(*it_v) == this->referenced_list().end()) { this->worklist().push_back(*it_v); } } } this->worklist_ready(); } } // End namespace gold.