/**  * @file parse.c * @brief  語法分析器的實現 * @author Shiquan Ye, yeshiquan@gmail.com * @date 2008-11-13 *//* * Copyright (C) 2008 - Shiquan Ye, yeshiquan@gmail.com * 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"#include "scan.h"#include "parse.h"static TokenType token;                         /* 保存當前的token */TreeNode * var_dec();TreeNode * program(); /**  * @brief  打印語法錯誤的提示信息 *  * @param message  */static void syntaxError(char * message) {      fprintf(listing,"\n>>>");      fprintf(listing,"Syntax error at line %d: %s",lineno,message);      Error = TRUE;}/**  * @brief  檢查當前token是否是期望的token,如果是會獲取下一個token *  * @param expected  */static void match(TokenType expected) {      if (token == expected) token = getToken();      else {            syntaxError("unexpected token -->");            printToken(token,tokenString);            fprintf(listing,"        ");      }}/**  * @brief  打印token的類型和對應的string *  * @param token  * @param tokenString  */void printToken(TokenType token, const char * tokenString) {      printf("%s\n",tokenString);}/**  * @brief  語法分析函數 *  * @returns 新生成的語法樹 */TreeNode * parse(void) {      TreeNode * t;      token = getToken();      t = program();      if (token != ENDFILE) {            syntaxError("Code ends before file\n");      }      return t;}TreeNode * program() {      TreeNode * t;      t = var_dec();      return t;}TreeNode * var_dec() {      TreeNode * t = newStmtNode(VarDecK);      if (token == INT) {            t->child[0] = newOneTokenNode(IntK);            t->child[0]->attr.type = INT;      }      else if (token == REAL) {            t->child[0] = newOneTokenNode(RealK);            t->child[0]->attr.type = REAL;      }      else {            syntaxError("unexpected token -> ");            printToken(token,tokenString);      }      token = getToken();      match(ID);      if (token = LBRACKET) token = getToken();      match(RBRACKET);      match(ASSIGN);      t->child[2] = var_init();}TreeNode * var_id() {      TreeNode * t = newVarIdNode();}TreeNode * var_init() {}TreeNode * array_init() {}TreeNode * exp() {}TreeNode * item() {}TreeNode * factor() {}