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dead.h
Go to the documentation of this file.00001 // $Id: dead.h,v 1.7 2003/08/07 23:14:13 pnav Exp $ 00002 // ---------------------------------------------------------------------- 00003 // 00004 // C-Breeze 00005 // C Compiler Framework 00006 // 00007 // Copyright (c) 2000 University of Texas at Austin 00008 // 00009 // Lipphei Adam 00010 // Samuel Z. Guyer 00011 // Daniel A. Jimenez 00012 // Calvin Lin 00013 // 00014 // Permission is hereby granted, free of charge, to any person 00015 // obtaining a copy of this software and associated documentation 00016 // files (the "Software"), to deal in the Software without 00017 // restriction, including without limitation the rights to use, copy, 00018 // modify, merge, publish, distribute, sublicense, and/or sell copies 00019 // of the Software, and to permit persons to whom the Software is 00020 // furnished to do so, subject to the following conditions: 00021 // 00022 // The above copyright notice and this permission notice shall be 00023 // included in all copies or substantial portions of the Software. 00024 // 00025 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 00026 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 00027 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 00028 // NONINFRINGEMENT. IN NO EVENT SHALL THE UNIVERSITY OF TEXAS AT 00029 // AUSTIN BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER 00030 // IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF 00031 // OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 00032 // THE SOFTWARE. 00033 // 00034 // We acknowledge the C-to-C Translator from MIT Laboratory for 00035 // Computer Science for inspiring parts of the C-Breeze design. 00036 // 00037 // ---------------------------------------------------------------------- 00038 00039 #ifndef CBZ_DEAD_H 00040 #define CBZ_DEAD_H 00041 00045 class deadCodeEliminationChanger : public Changer { 00046 private: 00047 LivenessWalker * _lw; 00048 00049 public: 00050 deadCodeEliminationChanger (); 00051 virtual Node * at_proc (procNode * proc, Order ord); 00052 virtual Node * at_threeAddr (threeAddrNode * node, Order ord); 00053 }; 00054 00055 00059 class has_struct_walker : public Walker { 00060 public: 00061 bool has_struct; 00062 00063 has_struct_walker (void) : 00064 Walker(Preorder, Subtree), has_struct(false) { } 00065 00066 void at_decl (declNode * d, Order) { 00067 has_struct = d->storage_class() == declNode::TYPEDEF; 00068 } 00069 00070 void at_sue (sueNode * s, Order) { 00071 has_struct = true; 00072 } 00073 00074 void at_func (funcNode * f, Order) { 00075 has_struct = true; 00076 } 00077 }; 00078 00079 00083 class UnusedDeclarationCleanupChanger : public Changer { 00084 private: 00085 map <declNode *, bool> used; 00086 00087 public: 00088 UnusedDeclarationCleanupChanger (void) : 00089 Changer(Both, Subtree, false) { } 00090 00091 Node * at_proc (procNode * p, Order ord) { 00092 if (ord == Preorder) 00093 used.clear(); 00094 else { 00095 blockNode * b = p->body(); 00096 decl_list_p i; 00097 for (i = b->decls().begin() ; i != b->decls().end(); ) { 00098 has_struct_walker w; 00099 (*i)->walk (w); 00100 if (w.has_struct || used[*i]) 00101 i++; 00102 else { 00103 int count = b->decls().size(); 00104 i = b->decls().erase (i); 00105 assert(count == b->decls().size() + 1); 00106 } 00107 } 00108 } 00109 return p; 00110 } 00111 00112 Node * at_id (idNode * id, Order ord) { 00113 used[id->decl()] = true; 00114 return id; 00115 } 00116 }; 00117 00118 #endif 00119