简单编译器前端的实现

其实这个程序是编译原理这门课的综合实验，前段时间我申请免试又失败了，原因是有缺课，平时分不够，早上赖床现在尝到苦果我也是醉了……没办法，逼上梁山，只好攻克这个大boss以拿下免试资格。

选了一个最简单的文法，分析了1个多星期，终于决定开始要写的时候时间已经很紧了。

去实验室通宵了一晚，在宿舍熬了一晚，睡了3个小时就起来去验收了。还好是通过了，没白费劲。

不得不说，编译原理就是烧脑，知识点都比较抽象，如果数据结构和算法的基础打得不牢的话，实现起来会感到吃力。

再次感觉到了基础的重要性，这也是一个收获吧。

总的来说，相比较之前实现形式化的des加密算法，抽象的编译器更有难度，写完也更能让你感觉到提高。

ps：程序仅供参考，时间有限，没做太多测试。

给定一个简单语言的文法描述，本程序是该语言的编译器前端。

输入一个符合该文法规则的源文件，输出三地址形式的中间代码。

具体功能有词法分析，语法分析，分析流程显示，错误提示等。

源程序：

分析过程：

生成中间代码（三地址形式）：

文法：

 文法（消除左递归后）

Program- BEGIN Stmt-List END

Stmt-List- Stmt Stmt-List

Stmt-List- Stmt Stmt-List | .

Stmt- Assign-stmt

Assign-stmt- ID = Expr

Expr- Term Expr

Expr- Add-Op Term Expr | .

Term- Factor Term

Term- Multiple-Op Factor Term | .

Factor- ( Expr ) | ID | NUM

Add-Op- + | -

Multiple-Op- * | /

 FIRST集

First(Program)={BEGIN} 

First(Stmt-List)={ID}

First(Stmt-List)={ ID,ε}

First(Stmt)={ ID}

First(Assign-stmt)={ ID}

First(Expr)={(,ID,NUM}

First(Expr)={+,-,ε}

First(Term)={(,ID,NUM}

First(Term)={*,/,ε}

First(Factor)={(,ID,NUM}

First(Add-Op)={+,-}

First(Multiple-Op)={*,/}

 FOLLOW集

Follow(Program)={$} 

Follow(Stmt-List)={END}

Follow(Stmt-List)={ END}

Follow(Stmt)={ ID,END}

Follow(Assign-stmt)={ ID,END }

Follow(Expr)={ ID,END ,)}

Follow(Expr)={ ID,END , )}

Follow(Term)={+,-, ID,END , )}

Follow(Term)={ +,-, ID,END , )}

Follow(Factor)={ *,/,+,-, ID,END , )}

Follow(Add-Op)={(,ID,NUM}

Follow(Multiple-Op)={ (,ID,NUM }

  预测分析表：

//词法分析中 代表空白字符，包括换行符，空格，制表符

//源程序格式：1、一行只能有一条语句；2、程序中可以有注释

#include iostream 

#include string.h 

#include stdio.h 

#include stack 

#include stdlib.h 

using namespace std;

char src[1000010]; //存储源代码

char TokenList_kind[1010][100]; //词法单元流 之 类别

int TokenList_value[1010]; //词法单元流 之 值

char WordList[1010][100]; //符号表 -- 由token_value指向

int LineList[1010]; //记录每一个token对应的行数 -- 由token_value指向

int TokenListPoint; //词法单元流指针

int WordListPoint; //符号表指针

int WordsPoint; //语法分析时的词法单元流指针

int tmpcnt; //三地址语句中寄存器的编号

int ExpTable[11][8] = { //用 表驱动法 读取表达式 ，状态转换表

2, -1, 1, -1, -1, -1, -1, 9,

2, -1, -1, -1, -1, -1, -1, 9,

2, -1, -1, 3, -1, -1, -1, 9,

4, 5, -1, -1, -1, -1, -1, 9,

4, -1, 8, -1, 6, -1, 10, 9,

-1, 5, 8, -1, 6, -1, 10, 9,

4, 5, -1, -1, -1, 7, -1, 9,

4, 5, -1, -1, -1, -1, -1, 9,

-1, -1, -1, -1, -1, -1, -1, -1,

-1, -1, -1, -1, -1, -1, -1, -1,

-1, -1, 8, -1, 6, -1, 10, 9

1 Program- BEGIN Stmt-List END

2 Stmt-List- Stmt Stmt-List

3 Stmt-List- Stmt Stmt-List | .

4 Stmt- Assign-stmt

5 Assign-stmt- ID = Expr

6 Expr- Term Expr

7 Expr- Add-Op Term Expr | .

8 Term- Factor Term

9 Term- Multiple-Op Factor Term | .

10 Factor- ( Expr ) | ID | NUM

11 Add-Op- + | -

12 Multiple-Op- * | /

 预测分析表

非终结符号 输入符号

 BEGIN ‘+’ ‘-’ ‘*’ ‘/’ ( ) ‘=’ ID NUM END $

Program 1

Stmt-List 2

Stmt-List 3 .

Stmt 4

Assign-stmt 5

Expr 6 6 6

Expr 7 7 . . .

Term 8 8 8

Term . . 9 9 . . .

Factor 10_1 10_210_3

Add-Op 11_1 11_2

Multiple-Op 12_1 12_2

char PreTab[12][12][100]={ //存储预测分析表

 {"BEGIN Stmt-List END","","","","","","","","","","",""},

 {"","","","","","","","","Stmt Stmt-List","","",""},

 {"","","","","","","","","Stmt Stmt-List","",".",""},

 {"","","","","","","","","Assign-stmt","","",""},

 {"","","","","","","","","ID = Expr","","",""},

 {"","","","","","Term Expr","","","Term Expr","Term Expr","",""},

 {"","Add-Op Term Expr","Add-Op Term Expr","","","",".","",".","",".",""},

 {"","","","","","Factor Term","","","Factor Term","Factor Term","",""},

 {"",".",".","Multiple-Op Factor Term","Multiple-Op Factor Term","",".","",".","",".",""},

 {"","","","","","( Expr )","","","ID","NUM","",""},

 {"","+","-","","","","","","","","",""},

 {"","","","*","/","","","","","","",""}

char Product[23][50]={ //记录产生式出现的字符串

 "Program", //0

 "Stmt-List", //1

 "Stmt-List", //2

 "Stmt", //3

 "Assign-stmt", //4

 "Expr", //5

 "Expr", //6

 "Term", //7

 "Term", //8

 "Factor", //9

 "Add-Op", //10

 "Multiple-Op", //11

 "BEGIN", //12

 "+", //13

 "-", //14

 "*", //15

 "/", //16

 "(", //17

 ")", //18

 "=", //19

 "ID", //20

 "NUM", //21

 "END" //22


 memset(src,0,sizeof(src)); //初始化源代码字符数组

 memset(TokenList_kind,0,sizeof(TokenList_kind)); //初始化词法单元流

 memset(TokenList_value,0,sizeof(TokenList_value)); //初始化词法单元流

 memset(WordList,0,sizeof(WordList)); //初始化符号表

 TokenListPoint = 1;

 WordListPoint = 1;

 WordsPoint = 1;

 //初始化指针

 root = NULL;

 now = NULL;

 p = NULL;

 tmpcnt = 1;

//--------------- 词法分析 start ---------------

void AddToken(char kind[],char value[],int line) //将 类别，值 放入token流中

 strcpy(TokenList_kind[TokenListPoint],kind);

 TokenList_value[TokenListPoint++] = WordListPoint;

 strcpy(WordList[WordListPoint],value);

 LineList[WordListPoint++] = line;

void strsub(char str1[],int start,int len,char str2[]) //截取str1的子字符串给str2

 int i=0,j;

 for(j=0;j j++){

 str2[i++] = str1[start+j];

 str2[i] = \0;

void InputString() //从文件中读取源代码，同时过滤注释，一行只能放置一条语句

 //文件读入

 FILE* fs = fopen(".\\src.txt","rb"); //源代码

 if(fs==NULL){

 printf("源代码文件 src.txt 不存在\n");

 return ;

 char s[10010]={0};

 //fscanf(fs,"%s",src);

 while(fgets(s,10010,fs)){

 if(sscanf(s,"%s",s)==-1){ //没有读到字符串，将s清空

 s[0]=\0;

 continue;

 //过滤注释

 if(s[0]==/ s[1]==/)

 continue;

 int i;

 for(i=0;s[i];i++)

 if(s[i]==/ s[i+1]==/)

 break;

 s[i]=\0;

 strcat(src,s); //连接到源代码字符串后

 strcat(src," "); //连接一个空白符

 int len = strlen(src);

 len--;

 src[len] = \0;

bool getBEGIN(int i,int line) //读取“BEGIN”

 char tmp[6];

 strsub(src,i,5,tmp);

 if(strcmp(tmp,"BEGIN")==0){

 i = i+5;

 AddToken("BEGIN","BEGIN",line); //添加token, 类别，值 

 return true;

 else

 return false;

bool getBLANK(int i) //读取“空白符”==  

 if(src[i]== ){

 i++;

 return true;

 else

 return false;

bool getEND(int i,int line) //读取“END”

 char tmp[4];

 strsub(src,i,3,tmp);

 if(strcmp(tmp,"END")==0){

 i = i+3;

 AddToken("END","END",line); //添加token, 类别，值 

 return true;

 else

 return false;

bool getExp(int i,int line) //读取表达式，遇到 结束

 int status=0;

 char tmp[10010]={0};

 char t[2]={0};

 int j=0;

 stack char 

 while(status!=8){

 if(status==-1) //跳到错误的状态号，返回false

 return false;

 if(status==9) //跳到了错误状态，返回false

 return false;

 //根据src[i]确定下一个状态，直到抵达结束状态 8

 if( (a =src[i] src[i] =z) || (A =src[i] src[i] =Z) ){

 //读取到字母

 status = ExpTable[status][0];

 tmp[j++] = src[i++];

 else if(0 =src[i] src[i] =9){

 //读取到数字

 status = ExpTable[status][1];

 tmp[j++] = src[i++];

 else{

 switch(src[i]){

 case  : //空白符

 status = ExpTable[status][2];

 if(tmp[0]!=\0){

 //如果是后来读到空白符，说明表达式该结束了

 //将读取的最后一个单词放入token

 if(j!=0){ //说明之前是一个单词或数字，否则是一个），）已经将最后一个单词放入token流中了，所以不需要处理它

 if( (a =tmp[0] tmp[0] =z) || (A =tmp[0] tmp[0] =Z) )

 AddToken("ID",tmp,line); //将这个字符代表的单词放入token流中

 else if( 0 =tmp[0] tmp[0] =9 )

 AddToken("NUM",tmp,line); //将这个字符代表的单词放入token流中

 j=0;

 line++;

 i++;

 break;

 case =: // =

 status = ExpTable[status][3];

 tmp[j] = \0;

 AddToken("ID",tmp,line); //=前面一定是标识符，放入token流

 j=0;

 AddToken("=","=",line); //将当前的=也放入token流

 i++;

 break;

 case +: //OP

 case -:

 case *:

 case /:

 status = ExpTable[status][4];

 tmp[j] = \0;

 if( (a =tmp[0] tmp[0] =z) || (A =tmp[0] tmp[0] =Z) ) //如果运算符前是字母，则说明是标识符

 AddToken("ID",tmp,line);

 else if( 0 =tmp[0] tmp[0] =9 )

 AddToken("NUM",tmp,line);

 j=0;

 t[0] = src[i];

 t[1] = \0;

 AddToken(t,t,line); //将运算符放入token流

 i++;

 break;

 case (: // (

 status = ExpTable[status][5];

 AddToken("(","(",line); //将（放入token流

 ss.push(();

 i++;

 break;

 case ): // )

 status = ExpTable[status][6];

 tmp[j] = \0;

 if( (a =tmp[0] tmp[0] =z) || (A =tmp[0] tmp[0] =Z) ) //如果)前是字母，则说明是标识符，即ID

 AddToken("ID",tmp,line);

 else if( 0 =tmp[0] tmp[0] =9 )

 AddToken("NUM",tmp,line);

 j=0;

 AddToken(")",")",line); //将（放入token流

 if(ss.empty()) //括号不匹配

 return false;

 else

 ss.pop();

 i++;

 break;

 default: //其它

 status = ExpTable[status][7];

 i++;

 break;

 if(status==8){ //正确跳出

 if(ss.empty()) //括号匹配

 return true;

 else

 return false;

 return true;

 else

 return false;

bool Lex() //进行词法分析

 printf("词法分析......\n");

 int i=0;

 int line = 1;

 InputString();

 try{

 getBEGIN(i,line)?1:throw 1;

 getBLANK(i)?line++:throw 2;

 while(1){ //读取表达式

 if(src[i]==\0) //还没检测到END，程序就结束了

 throw 3;

 char tmp[4];

 strsub(src,i,3,tmp); //截取字符串

 if(strcmp(tmp,"END")==0){

 //如果检测到END，跳出循环

 break;

 //读取表达式

 getExp(i,line)?1:throw 4;

 getEND(i,line)?1:throw 3;

 if(src[i]!=\0) //如果END结束标志之后还有输入符号，说明出错误了

 throw 5;

 catch(int err){

 printf("【词法错误】\n");

 //计算行号

 int errline = 1;

 int j;

 for(j=0;j j++)

 if(src[j]== )

 errline++;

 switch(err){

 case 1:

 printf("ERROR 1 (第%d行) : 没有读取到开始标识 BEGIN!\n",errline);

 printf("具体位置：\t%s%s\n",WordList[WordListPoint-2],WordList[WordListPoint-1]);

 printf("\t\t");

 for(j=0;j strlen(WordList[WordListPoint-2]);j++)

 printf(" ");

 printf("^\n");

 printf("\n");

 return false;

 case 2:

 printf("ERROR 2 (第%d行) : 没有读取到空白符!\n",errline);

 printf("具体位置：\t%s%s\n",WordList[WordListPoint-2],WordList[WordListPoint-1]);

 printf("\t\t");

 for(j=0;j strlen(WordList[WordListPoint-2]);j++)

 printf(" ");

 printf("^\n");

 printf("\n");

 return false;

 case 3:

 printf("ERROR 3 (第%d行) : 没有读取到结束标识 END!\n",errline);

 printf("具体位置：\t%s%s\n",WordList[WordListPoint-2],WordList[WordListPoint-1]);

 printf("\t\t");

 for(j=0;j strlen(WordList[WordListPoint-2]);j++)

 printf(" ");

 printf("^\n");

 printf("\n");

 printf("\n");

 return false;

 case 4:

 printf("ERROR 4 (第%d行) : 表达式错误。例如：标识符有误!\n",errline);

 printf("具体位置：\t%s%s\n",WordList[WordListPoint-2],WordList[WordListPoint-1]);

 printf("\t\t");

 for(j=0;j strlen(WordList[WordListPoint-2]);j++)

 printf(" ");

 printf("^\n");

 printf("\n");

 return false;

 case 5:

 printf("ERROR 5 (第%d行) : BEGIN...END 代码段格式错误!\n",errline);

 printf("具体位置：\t%s%s\n",WordList[WordListPoint-2],WordList[WordListPoint-1]);

 printf("\t\t");

 for(j=0;j strlen(WordList[WordListPoint-2]);j++)

 printf(" ");

 printf("^\n");

 printf("\n");

 return false;

 default:break;

 printf("没有词法错误\n");

 printf("\n");

 return true;

void printTokenList() //输出token流

 int i=1;

 printf("单词流：\n");

 printf(" \t类别\t,值\t \n");

 for(;i TokenListPoint;i++){

 printf(" \t%s\t,%s\t \n",TokenList_kind[i],WordList[TokenList_value[i]]);

 printf("\n");

//--------------- 词法分析 end ---------------


 char tt[200]={0};

 sprintf(tt," %s,%s ",TokenList_kind[i],WordList[TokenList_value[i]]);

 strcat(t,tt);

 j++;

 printf("%23s$",t);

void OutAction(char action[]) //输出动作

 printf(" %s\n",action);

bool seltab(int row,char f[])

 if(strcmp(TokenList_kind[WordsPoint],"BEGIN")==0){

 strcpy(f,PreTab[row][0]);

 else if(strcmp(TokenList_kind[WordsPoint],"+")==0){

 strcpy(f,PreTab[row][1]);

 else if(strcmp(TokenList_kind[WordsPoint],"-")==0){

 strcpy(f,PreTab[row][2]);

 else if(strcmp(TokenList_kind[WordsPoint],"*")==0){

 strcpy(f,PreTab[row][3]);

 else if(strcmp(TokenList_kind[WordsPoint],"/")==0){

 strcpy(f,PreTab[row][4]);

 else if(strcmp(TokenList_kind[WordsPoint],"(")==0){

 strcpy(f,PreTab[row][5]);

 else if(strcmp(TokenList_kind[WordsPoint],")")==0){

 strcpy(f,PreTab[row][6]);

 else if(strcmp(TokenList_kind[WordsPoint],"=")==0){

 strcpy(f,PreTab[row][7]);

 else if(strcmp(TokenList_kind[WordsPoint],"ID")==0){

 strcpy(f,PreTab[row][8]);

 else if(strcmp(TokenList_kind[WordsPoint],"NUM")==0){

 strcpy(f,PreTab[row][9]);

 else if(strcmp(TokenList_kind[WordsPoint],"END")==0){

 strcpy(f,PreTab[row][10]);

 else if(strcmp(TokenList_kind[WordsPoint],"$")==0){

 strcpy(f,PreTab[row][11]);

 else{

 return false;

 if(f[0]==\0) //确定的表位置为空

 return false;

 return true;

bool Parse() //语法分析阶段。输入是token流，输出分析结果

 stack char* 

 stack Node* 

 z.push(*Product);

 root = new Node("Program");

 now = root;

 printf("词法分析......\n");

 printf("【分析流程】\n");

 printf("%22s%24s%22s\n","栈","输入","动作");

 char action[100]={0};

 try{

 while(!z.empty() || WordsPoint WordListPoint){ //栈和输入串中只剩结束符号（栈空 or 指向\0）时退出循环

 //输出当前分析结果

 OutStack(z); //输出栈中内容

 OutRightStr(); //输出剩余输入字符串

 OutAction(action); //输出动作

 memset(action,0,sizeof(action));

 //预处理。例：匹配e。预处理：将e出栈，输入指针后移。

 //还没结束栈就空了

 if(z.empty())

 throw 1; //非法跳出

 if(strcmp(z.top(),TokenList_kind[WordsPoint])==0){ //栈顶元素==指针指向字符，匹配成功

 //语义动作 - 构造语法树

 while(!now- brother){ //回到有下一个兄弟节点的节点为止

 if(nz.empty()){

 if(now==root) //如果回到了根节点

 goto label;

 else

 throw 1;

 now = nz.top();

 nz.pop();

 now = now- brother;

label:

 //准备输出字符串 action

 strcat(action,"匹配");

 strcat(action,z.top());

 //出栈、指针后移

 if(!z.empty())

 z.pop();

 if(WordsPoint WordListPoint)

 WordsPoint++;

 else{ //不相等，输出推导

 //确定推导

 char f[200]={0};

 if(strcmp(z.top(),"Program")==0){

 if(!seltab(0,f)) //从表中确定推导串

 throw 2; //没有找到对应的推导

 else if(strcmp(z.top(),"Stmt-List")==0){

 if(!seltab(1,f)) //从表中确定推导串

 throw 2; //没有找到对应的推导

 else if(strcmp(z.top(),"Stmt-List")==0){

 if(!seltab(2,f)) //从表中确定推导串

 throw 2; //没有找到对应的推导

 else if(strcmp(z.top(),"Stmt")==0){

 if(!seltab(3,f)) //从表中确定推导串

 throw 2; //没有找到对应的推导

 else if(strcmp(z.top(),"Assign-stmt")==0){

 if(!seltab(4,f)) //从表中确定推导串

 throw 2; //没有找到对应的推导

 else if(strcmp(z.top(),"Expr")==0){

 if(!seltab(5,f)) //从表中确定推导串

 throw 2;

 else if(strcmp(z.top(),"Expr")==0){

 if(!seltab(6,f)) //从表中确定推导串

 throw 2;

 else if(strcmp(z.top(),"Term")==0){

 if(!seltab(7,f)) //从表中确定推导串

 throw 2;

 else if(strcmp(z.top(),"Term")==0){

 if(!seltab(8,f)) //从表中确定推导串

 throw 2;

 else if(strcmp(z.top(),"Factor")==0){

 if(!seltab(9,f)) //从表中确定推导串

 throw 2;

 else if(strcmp(z.top(),"Add-Op")==0){

 if(!seltab(10,f)) //从表中确定推导串

 throw 2;

 else if(strcmp(z.top(),"Multiple-Op")==0){

 if(!seltab(11,f)) //从表中确定推导串

 throw 2;

 else{

 throw 2;

 //准备输出字符串 action

 strcat(action,"输出");

 strcat(action,z.top());

 strcat(action,"- 

 strcat(action,f);

 //将栈顶字符串记录下来后用

 char proleft[50];

 //将栈顶元素出栈并将推导入栈

 if(!z.empty()){

 strcpy(proleft,z.top());

 z.pop();

 else

 throw 1;

 char tmp[100];

 //如果推导出来的是空，即f- .，不作处理

 if(f[0]==.){

 nz.push(now);

 now- next = new Node(".");

 now = now- next; //now指向当前产生式右边的第一个字符串

 while(!now- brother){ //回到有下一个兄弟节点的节点为止

 if(nz.empty()){

 if(now==root) //如果回到了根节点

 goto label;

 else

 throw 1;

 now = nz.top();

 nz.pop();

 now = now- brother;

 continue;

 stack char* //临时的栈

 //正向输入到临时栈中

 while(sscanf(f,"%s",tmp)!=-1){

 //语义动作 - 创建语法树

 if(strcmp(proleft,now- name)==0){

 nz.push(now); //将当前节点记录下来

 now- next = new Node(tmp);

 now = now- next; //now指向当前产生式右边的第一个字符串

 p = now;

 else{

 p- brother = new Node(tmp);

 p = p- brother;

 char* pos = strstr(f,tmp);

 strcpy(f,pos+strlen(tmp));

 if(strcmp(tmp,"Program")==0){

 tz.push(*(Product));

 else if(strcmp(tmp,"Stmt-List")==0){

 tz.push(*(Product+1));

 else if(strcmp(tmp,"Stmt-List")==0){

 tz.push(*(Product+2));

 else if(strcmp(tmp,"Stmt")==0){

 tz.push(*(Product+3));

 else if(strcmp(tmp,"Assign-stmt")==0){

 tz.push(*(Product+4));

 else if(strcmp(tmp,"Expr")==0){

 tz.push(*(Product+5));

 else if(strcmp(tmp,"Expr")==0){

 tz.push(*(Product+6));

 else if(strcmp(tmp,"Term")==0){

 tz.push(*(Product+7));

 else if(strcmp(tmp,"Term")==0){

 tz.push(*(Product+8));

 else if(strcmp(tmp,"Factor")==0){

 tz.push(*(Product+9));

 else if(strcmp(tmp,"Add-Op")==0){

 tz.push(*(Product+10));

 else if(strcmp(tmp,"Multiple-Op")==0){

 tz.push(*(Product+11));

 else if(strcmp(tmp,"BEGIN")==0){

 tz.push(*(Product+12));

 else if(strcmp(tmp,"+")==0){

 tz.push(*(Product+13));

 else if(strcmp(tmp,"-")==0){

 tz.push(*(Product+14));

 else if(strcmp(tmp,"*")==0){

 tz.push(*(Product+15));

 else if(strcmp(tmp,"/")==0){

 tz.push(*(Product+16));

 else if(strcmp(tmp,"(")==0){

 tz.push(*(Product+17));

 else if(strcmp(tmp,")")==0){

 tz.push(*(Product+18));

 else if(strcmp(tmp,"=")==0){

 tz.push(*(Product+19));

 else if(strcmp(tmp,"ID")==0){

 tz.push(*(Product+20));

 else if(strcmp(tmp,"NUM")==0){

 tz.push(*(Product+21));

 else if(strcmp(tmp,"END")==0){

 tz.push(*(Product+22));

 else{

 throw 1;

 //反向输出到真正的栈中

 while(!tz.empty()){

 if(strcmp(tz.top(),"Program")==0){

 z.push(*(Product));

 else if(strcmp(tz.top(),"Stmt-List")==0){

 z.push(*(Product+1));

 else if(strcmp(tz.top(),"Stmt-List")==0){

 z.push(*(Product+2));

 else if(strcmp(tz.top(),"Stmt")==0){

 z.push(*(Product+3));

 else if(strcmp(tz.top(),"Assign-stmt")==0){

 z.push(*(Product+4));

 else if(strcmp(tz.top(),"Expr")==0){

 z.push(*(Product+5));

 else if(strcmp(tz.top(),"Expr")==0){

 z.push(*(Product+6));

 else if(strcmp(tz.top(),"Term")==0){

 z.push(*(Product+7));

 else if(strcmp(tz.top(),"Term")==0){

 z.push(*(Product+8));

 else if(strcmp(tz.top(),"Factor")==0){

 z.push(*(Product+9));

 else if(strcmp(tz.top(),"Add-Op")==0){

 z.push(*(Product+10));

 else if(strcmp(tz.top(),"Multiple-Op")==0){

 z.push(*(Product+11));

 else if(strcmp(tz.top(),"BEGIN")==0){

 z.push(*(Product+12));

 else if(strcmp(tz.top(),"+")==0){

 z.push(*(Product+13));

 else if(strcmp(tz.top(),"-")==0){

 z.push(*(Product+14));

 else if(strcmp(tz.top(),"*")==0){

 z.push(*(Product+15));

 else if(strcmp(tz.top(),"/")==0){

 z.push(*(Product+16));

 else if(strcmp(tz.top(),"(")==0){

 z.push(*(Product+17));

 else if(strcmp(tz.top(),")")==0){

 z.push(*(Product+18));

 else if(strcmp(tz.top(),"=")==0){

 z.push(*(Product+19));

 else if(strcmp(tz.top(),"ID")==0){

 z.push(*(Product+20));

 else if(strcmp(tz.top(),"NUM")==0){

 z.push(*(Product+21));

 else if(strcmp(tz.top(),"END")==0){

 z.push(*(Product+22));

 else{

 throw 1;

 tz.pop();

 if(z.empty() WordsPoint = WordListPoint){ //正常退出循环

 //输出最后一行分析结果

 OutStack(z); //输出栈中内容

 OutRightStr(); //输出剩余输入字符串

 OutAction(action); //输出动作

 else{ //非正常情况

 throw 1;

 catch(int err){

 printf("\n");

 printf("【语法错误】\n");

 switch(err){

 case 1:

 printf("ERROR 1 (第%d行) : 非法跳出!\n",LineList[WordsPoint]);

 printf("\n");

 return false;

 case 2:

 printf("ERROR 2 (第%d行) : 没有找到 %s 对应的推导!\n",LineList[WordsPoint],z.top());

 printf("\n");

 return false;

 default:

 break;

 printf("没有语法错误\n");

 printf("\n");

 return true;

//--------------- 语法分析 end ---------------

//--------------- 生成三地址代码 start ---------------

//对语法分析树进行后序遍历，执行语义规则，一遍扫描之后，树根的code即为三地址代码


 getNext(cur- next- brother,fo);

 fprintf(fo,"%s\r\n",getNext(cur- next- brother- brother,fo));

 char* tmp = new char[2];

 tmp[0] = \0;

 return tmp;

 else if(strcmp(cur- name,"Assign-stmt")==0){

 char* tmp = new char[2];

 tmp[0] = \0;

 fprintf(fo,"%s=%s\r\n",getNext(cur- next,fo),getNext(cur- next- brother- brother,fo));

 return tmp;

 else if(strcmp(cur- name,"Term")==0){

 char* tmp = new char[150];

 tmp = getNext(cur- next- brother,fo);

 if(tmp[0]==* || tmp[0]==/){

 fprintf(fo,"t%d=%s%s\r\n",tmpcnt,getNext(cur- next,fo),tmp);

 sprintf(tmp,"t%d",tmpcnt++);

 return tmp; 

 else if(strcmp(cur- name,"Expr")==0){

 char* tmp = new char[150];

 tmp = getNext(cur- next- brother,fo);

 if(tmp[0]==+ || tmp[0]==-){

 fprintf(fo,"t%d=%s%s\r\n",tmpcnt,getNext(cur- next,fo),tmp);

 sprintf(tmp,"t%d",tmpcnt++);

 return tmp; 

 else if(strcmp(cur- name,"Term")==0){

 char* tmp = new char[150];

 if(cur- next- brother!=NULL){

 p = cur- next- brother- brother;

 if(p- next- brother!=NULL){

 tmp = getNext(cur- next- brother- brother,fo);

 if(tmp[0]==* || tmp[0]==/){

 if(*getNext(cur- next,fo)==/){ //如果最前面的是‘-’，后面的运算符应该是反的

 if(tmp[0]==/)

 tmp[0]=*;

 else

 tmp[0]=/;

 fprintf(fo,"t%d=%s%s\r\n",tmpcnt,getNext(cur- next- brother,fo),tmp);

 sprintf(tmp,"%st%d",getNext(cur- next,fo),tmpcnt++);

 return tmp; 

 else if(strcmp(cur- name,"Expr")==0){

 char* tmp = new char[150];

 if(cur- next- brother!=NULL){

 p = cur- next- brother- brother;

 if(p- next- brother!=NULL){

 tmp = getNext(cur- next- brother- brother,fo);

 if(tmp[0]==+ || tmp[0]==-){

 if(*getNext(cur- next,fo)==-){ //如果最前面的是‘-’，后面的运算符应该是反的

 if(tmp[0]==-)

 tmp[0]=+;

 else

 tmp[0]=-;

 fprintf(fo,"t%d=%s%s\r\n",tmpcnt,getNext(cur- next- brother,fo),tmp);

 sprintf(tmp,"%st%d",getNext(cur- next,fo),tmpcnt++);

 return tmp; 

 char * s = new char[150]; //new一个字符串，存储这个节点的结果

 memset(s,0,sizeof(s));

 Node* p = cur- next;

 while(p){

 strcat(s,getNext(p,fo));

 p = p- brother;

 return s;

void get3AddrCode()

 WordsPoint = 1;

 FILE* fo = fopen(".\\out.txt","wb");

 if(fo==NULL){

 printf("三地址代码生成文件 out.txt 打开失败！\n");

 return ;

 setWP(root);

 printf("生成三地址语句......\n");

 getNext(root,fo);

//--------------- 生成三地址代码 end ---------------

int main()

 bool f=true;

 Init();

 if(!Lex()) //词法分析

 f=false;

 //printTokenList();

 if(!Parse()) //语法分析

 f=false;

 if(f) //都通过了才能生成三地址代码

 get3AddrCode(); //生成三地址代码

 return 0;

}