Imported binutils-2.20

[msp430-binutils.git] / gold / gc.cc

diff --git a/gold/gc.cc b/gold/gc.cc
new file mode 100644 (file)
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--- /dev/null
+++ b/gold/gc.cc
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+// gc.cc -- garbage collection of unused sections
+
+// Copyright 2009 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().front();
+      this->worklist().pop();
+      if (this->referenced_list().find(entry)
+          == this->referenced_list().end()) 
+        {
+          this->referenced_list().insert(entry);
+        }
+      else
+        {
+          continue;
+        }
+      Garbage_collection::Section_ref::iterator find_it = 
+                this->section_reloc_map().find(entry);
+      if (find_it == this->section_reloc_map().end()) 
+          continue;
+      Garbage_collection::Sections_reachable v = find_it->second;
+      // Scan the vector of references for each work_list entry. 
+      for (Garbage_collection::Sections_reachable::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(*it_v);   
+            }
+        }
+    }
+  this->worklist_ready();
+}
+
+} // End namespace gold.
+