| // gc.cc -- garbage collection of unused sections |
| |
| // Copyright (C) 2009-2021 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. |
| |