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gc_walker.h
Go to the documentation of this file.00001 // $Id: gc_walker.h,v 1.4 2003/08/07 23:13:44 pnav Exp $ 00002 // ---------------------------------------------------------------------- 00003 // 00004 // C-Breeze 00005 // C Compiler Framework 00006 // 00007 // Copyright (c) 2000 University of Texas at Austin 00008 // 00009 // Samuel Z. Guyer 00010 // Daniel A. Jimenez 00011 // Calvin Lin 00012 // 00013 // Permission is hereby granted, free of charge, to any person 00014 // obtaining a copy of this software and associated documentation 00015 // files (the "Software"), to deal in the Software without 00016 // restriction, including without limitation the rights to use, copy, 00017 // modify, merge, publish, distribute, sublicense, and/or sell copies 00018 // of the Software, and to permit persons to whom the Software is 00019 // furnished to do so, subject to the following conditions: 00020 // 00021 // The above copyright notice and this permission notice shall be 00022 // included in all copies or substantial portions of the Software. 00023 // 00024 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 00025 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 00026 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 00027 // NONINFRINGEMENT. IN NO EVENT SHALL THE UNIVERSITY OF TEXAS AT 00028 // AUSTIN BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER 00029 // IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF 00030 // OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 00031 // THE SOFTWARE. 00032 // 00033 // We acknowledge the C-to-C Translator from MIT Laboratory for 00034 // Computer Science for inspiring parts of the C-Breeze design. 00035 // 00036 // ---------------------------------------------------------------------- 00037 00038 #ifndef CBZ_GC_WALKER_H 00039 #define CBZ_GC_WALKER_H 00040 00041 class gcWalker : public Walker { 00042 public: 00043 gcWalker (void) : Walker (Preorder, Subtree) { 00044 // mark all nodes as unvisited 00045 00046 return; 00047 for (node_list_p p=Node::nodes.begin(); 00048 p!=Node::nodes.end(); p++) { 00049 (*p)->mark = false; 00050 } 00051 } 00052 00053 static void collect (void) { 00054 return; // until we can fix the bug 00055 gcWalker g; 00056 text_list_p p; 00057 for (p=CBZ::pragmas.begin(); p!=CBZ::pragmas.end(); p++) 00058 (*p)->walk (g); 00059 unit_list_p n; 00060 for (n=CBZ::Program.begin(); n!=CBZ::Program.end(); n++) 00061 (*n)->walk (g); 00062 g.delete_nodes(); 00063 } 00064 00065 void at_unit (unitNode *u, Order) { 00066 00067 // mark all the stuff that won't get visited 00068 // by a normal tree traversal 00069 00070 00071 u->types()->mark_nodes(); 00072 u->tags()->mark_nodes(); 00073 decl_list_p p; 00074 for (p=u->undef_funcs().begin(); p!=u->undef_funcs().end(); p++) 00075 (*p)->mark = true; 00076 suespec_list_p q; 00077 for (q=u->suespecs().begin(); q!=u->suespecs().end(); q++) 00078 (*q)->mark = true; 00079 } 00080 00081 void at_binary (binaryNode *b, Order o) { 00082 b->mark = true; 00083 // because of -> and . 00084 Node *r = b->right(); 00085 if (r) { 00086 r->mark = true; 00087 r->walk (*this); 00088 } 00089 } 00090 00091 void at_node (Node *n, Order) { 00092 n->mark = true; 00093 } 00094 00095 void delete_nodes (void) { 00096 int count = 0; 00097 list <Node *> remaining; 00098 map <Node *,bool>::iterator p; 00099 list<Node *>::iterator q; 00100 for (q=Node::nodes.begin(); q!=Node::nodes.end(); ) { 00101 Node *n = *q; 00102 if (n->mark == false) { 00103 if (n->typ() == Unit) { 00104 q++; 00105 continue; 00106 } 00107 if (!Node::deleted_nodes[n]) delete n; 00108 q = Node::nodes.erase (q); 00109 count++; 00110 } else { 00111 remaining.push_back (n); 00112 q++; 00113 } 00114 } 00115 Node::deleted_nodes.clear(); 00116 cout << "deleted " << count << " nodes.\n"; 00117 } 00118 }; 00119 00120 #endif // CBZ_GC_WALKER_H