util.c

参照清华大学《编译原理》写的cmm语言语法分析程序

/** 
 * @file util.c
 * @brief  工具函数集实现
 * @author Shiquan Ye, [e-mail]
 * @date 2008-11-13
 */
/*
 * Copyright (C) 2008 - Shiquan Ye, [e-mail]
 * 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 2
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#include "globals.h"
#include "util.h"

/** 
 * @brief  创建一个新的语句节点
 * 
 * @param kind 语句类型
 * 
 * @returns 指向新节点的指针
 */
TreeNode * newStmtNode(StmtKind kind) {
      TreeNode * t = (TreeNode *)malloc(sizeof(TreeNode));
      int i;
      if (t == NULL) 
            printf("Out of memory error at line %d\n,lineno");
      else {
            for (i = 0; i < MAXCHILDREN; i++) t->child[i] = NULL;
            t->sibling = NULL;
            t->nodekind = StmtK;
            t->kind.stmt = kind;
            t->lineno = lineno;
      }
      return t;
}

/** 
 * @brief  创建一个新的表达式节点
 * 
 * @param kind 表达式类型
 * 
 * @returns 新节点的地址
 */
TreeNode * newExpNode(ExpKind kind) {
      TreeNode * t = (TreeNode *)malloc(sizeof(TreeNode));
      int i;
      if (t == NULL) {
            printf("Out of memory error at line %d\n,lineno");
      }
      else {
            for (i = 0; i < MAXCHILDREN; i++) t->child[i] = NULL;
            t->sibling = NULL;
            t->nodekind = ExpK;
            t->kind.stmt = kind;
            t->lineno = lineno;
            t->type = Void;
      }
      return t;
}

/** 
 * @brief  字符串复制函数
 * 
 * @param s 原字符串起始地址 
 * 
 * @returns 新字符串起始地址 
 */
char * copyString(char * s) {
      int n;
      char * t;
      if (s == NULL) return NULL;
      n = strlen(s) + 1;
      t = malloc(n);
      if (t == NULL) 
            printf("Out of memory error at line %d\n,lineno");
      else strcpy(t,s);
      return t;
}