1 /* 2 * Copyright (C) 2010 Dan Carpenter. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 2 7 * of the License, or (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt 16 */ 17 18 #include "smatch.h" 19 20 static int my_id; 21 22 static void match_stmt(struct statement *stmt) 23 { 24 struct expression *expr; 25 26 if (stmt->type != STMT_EXPRESSION) 27 return; 28 expr = stmt->expression; 29 if (!expr) 30 return; 31 switch(expr->type) { 32 case EXPR_PREOP: 33 if (expr->op == '!') 34 break; 35 if (expr->op == '~') 36 break; 37 case EXPR_POSTOP: 38 case EXPR_STATEMENT: 39 case EXPR_ASSIGNMENT: 40 case EXPR_CALL: 41 case EXPR_CONDITIONAL: 42 case EXPR_SELECT: 43 case EXPR_CAST: 44 case EXPR_FORCE_CAST: 45 case EXPR_COMMA: 46 return; 47 } 48 if (in_expression_statement()) 49 return; 50 sm_warning("statement has no effect %d", expr->type); 51 } 52 53 void check_no_effect(int id) 54 { 55 my_id = id; 56 add_hook(&match_stmt, STMT_HOOK); 57 } 58