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C-Breeze C Compiler Infrastructure [ Project home page] |
dismantle-label.cc
Go to the documentation of this file.00001 // $Id: dismantle-label.cc,v 1.2 2003/08/07 23:13:43 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 // Adam Brown 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 // dismantle-label.cc 00040 // 00041 00042 #include "c_breeze.h" 00043 #include "dismantle.h" 00044 00045 LabelDismantle::LabelDismantle(void): 00046 Changer(Preorder, Subtree, false) 00047 {} 00048 00049 // All labels in dismantled code should label empty statements. 00050 // We enforce this by turning any label which labels a non-empty statement 00051 // into a block with the label (labeling an empty statement) and the original 00052 // statement that was labeled. This extra block will later be removed when 00053 // we 'flatten' the dismantled code. 00054 // 00055 // label: { ... } 00056 // => 00057 // { 00058 // label: { ; } 00059 // { ... } 00060 // } 00061 00062 Node * LabelDismantle::at_label(labelNode * the_label, Order ord) { 00063 bool empty = true; 00064 blockNode * label_block = the_label->stmt(); 00065 for( stmt_list_p p = label_block->stmts().begin(); 00066 empty && p != label_block->stmts().end(); 00067 p++ ) { 00068 if ((*p)->typ() != Expr ) 00069 empty = false; 00070 else { 00071 exprstmtNode * tmp = (exprstmtNode *) *p; 00072 if ( tmp->expr() ) // expr != NULL => not empty 00073 empty = false; 00074 } 00075 } 00076 if ( empty ) // stmt/block was empty stmt 00077 return the_label; // no change necessary 00078 blockNode * label_stmt = the_label->get_stmt(); 00079 blockNode * new_block = new blockNode(&label_stmt->decls(), 00080 &label_stmt->stmts(), 00081 the_label->coord()); 00082 the_label->stmt(DismantleUtil::empty_block()); 00083 new_block->stmts().push_front(the_label); 00084 return new_block; 00085 }