?? 詞法編譯器.cpp
字號:
#include<iostream.h>
#include<iostream.h>
#include<string.h>
#include<ostream>
#include<stdlib.h>
#include<stdio.h>
#include<fstream.h>
#define MAX 18 //分析表的最大容量
#define MAXBUF 255
char ch =' '; // 存放讀入當前的輸入字符
int lineno=0;
struct reserve //關鍵字
{
char lexptr[MAXBUF];
int token;
};
struct reserve symtable[MAX];
char * str[]={"program","const","var","integer","long","procedure","if","then","while","do","read","write","begin","end","odd"};
void Inital() //對符號表進行初始化
{
for( int j=0; j<15; j++)
{
strcpy(symtable[j].lexptr,str[j]);
symtable[j].token=j+1;
}
}
int Search(char *temp)
{
for(int i=0; i <sizeof(symtable)/sizeof(symtable[0]); i++)
{
if(!strcmp(symtable[i].lexptr ,temp))
{
return symtable[i].token;
}
}
return 0;
}
void Syntax(FILE *fpin,FILE *fpout) //分析程序
{
char Temp[MAXBUF];
int i=0;
int j=0;
fprintf(fpout,"%s\t"," 符號 ") ;
fprintf(fpout,"%s\t","識別號") ;
fprintf(fpout,"%s\n","類別") ;
while((ch=fgetc(fpin))!=EOF) //讀入字符判斷,空格、字母、數字、界符
{
if(ch==' '||ch=='\t')
{
}
else if(ch=='\n') //如果是換行符,則行號加1
{
lineno++;
}
else if(isdigit(ch)) //如果是數字
{
while(isdigit(ch)) //判斷和讀取數字
{
Temp[j]=ch;
j++;
ch=fgetc(fpin);
}
Temp[j]='\0';
j=0;
fprintf(fpout,"%s\t%d\t",Temp,2) ;
fprintf(fpout,"%s\n","數字") ;
}
else if (isalpha(ch)) //如果是字母
{
while(isalpha(ch)||isdigit(ch))
{
Temp[j]=ch;
j++;
ch=fgetc(fpin);
}
Temp[j]='\0';
j=0;
if (Search(Temp)) //如果是關鍵字
{
fprintf(fpout,"%s\t%d\t",Temp,Search(Temp));
fprintf(fpout,"%s\n","關鍵字") ;
}
else
{
fprintf(fpout,"%s\t%d\t",Temp,34); //普通標志符
fprintf(fpout,"%s\n","標志符") ;
}
}
else if(ch==':')
{
ch=fgetc(fpin);
if(ch=='=')
{
fprintf(fpout,"%s\t%d\t",":=",30); //如果是 :=
fprintf(fpout,"%s\n","復合運算符") ;
}
else
{
fprintf(fpout,"%s\t%d\t",":",29); //如果是 :
fprintf(fpout,"%s\n","類別說明符") ;
}
}
else if (ch=='>')
{
ch=fgetc(fpin);
if(ch=='=') //如果是 >=
{
fprintf(fpout,"%s\t%d\t",">=",25);
fprintf(fpout,"%s\n","復合運算符") ;
}
else
{
fprintf(fpout,"%s\t%d\t",">",24); //如果是 >
fseek(fpin,-1L,SEEK_CUR);
}
}
else if(ch=='<')
{
ch=fgetc(fpin);
if(ch=='>')
{
fprintf(fpout,"%s\t%d\t","<>",21); // 如果是 <>
fprintf(fpout,"%s\n","復雜運算符") ;
}
else if(ch=='=')
{
fprintf(fpout,"%s\t%d\t","<=",23); //如果是 <=
fprintf(fpout,"%s\n","復合運算符") ;
}
else
{
fprintf(fpout,"%s\t%d\t","<",22); //如果是 <
fprintf(fpout,"%s\n","簡單運算符") ;
}
}
else if(ch=='/')
{
ch=fgetc(fpin);
if(ch=='*')
{
ch=fgetc(fpin);
s:
while(ch!='*')
{
ch=fgetc(fpin);
}
while(ch=='*')
{
ch=fgetc(fpin);
while(ch!='/')
{
goto s; //如果是注釋 /* */
}
}
}
else if(ch=='/')
{
ch=fgetc(fpin);
while(ch!='\n')
{
ch=fgetc(fpin); //如果是注釋 //
}
}
else
{
fprintf(fpout,"%s\t%d\t","/",24);
fprintf(fpout,"%s\n","簡單運算符") ;
}
}
else if(ch=='+')
{
fprintf(fpout,"%s\t%d\t","+",16);
fprintf(fpout,"%s\n","簡單運算符") ;
}
else if(ch=='-')
{
fprintf(fpout,"%s\t%d\t","-",17);
fprintf(fpout,"%s\n","簡單運算符") ;
}
else if(ch=='*')
{
fprintf(fpout,"%s\t%d\t","*",18);
fprintf(fpout,"%s\n","簡單運算符") ;
}
else if(ch=='(')
{
fprintf(fpout,"%s\t%d\t","(",31);
fprintf(fpout,"%s\n","簡單運算符") ;
}
else if(ch==')')
{
fprintf(fpout,"%s\t%d\t",")",32);
fprintf(fpout,"%s\n","簡單運算符") ;
}
else if(ch=='#')
{
fprintf(fpout,"%s\t%d\t","#",35);
fprintf(fpout,"%s\n","簡單運算符") ;
}
else if(ch=='.')
{
fprintf(fpout,"%s\t%d\t",".",26);
fprintf(fpout,"%s\n","程序結束符") ;
}
else if(ch==';')
{
fprintf(fpout,"%s\t%d\t",";",28);
fprintf(fpout,"%s\n","語句結束符") ;
}
else if(ch=='=')
{
fprintf(fpout,"%s\t%d\t","=",20);
fprintf(fpout,"%s\n","簡單運算符") ;
}
else if(ch==',')
{
fprintf(fpout,"%s\t%d\t",",",27);
fprintf(fpout,"%s\n","簡單運算符") ;
}
else fprintf(fpout,"無法識別的字符 %c\n",ch) ;
}
}
void main()
{
cout<<"**********************************"<<endl;
cout<<"** 詞 法 分 析 **"<<endl;
cout<<"** **"<<endl;
cout<<"** 開發者: 唐志賢 **"<<endl;
cout<<"** 學 號:20032337 **"<<endl;
cout<<"** **"<<endl;
cout<<"**********************************"<<endl;
char filenamein[10];
char filenameout[10];
cout<<"請輸入源程序的文件路徑和擴展名!"<<endl;
scanf("%s",filenamein);
cout<<"請輸入詞法分析結果輸出的文件路徑和擴展名!"<<endl;
scanf("%s",filenameout);
FILE* fpin=fopen(filenamein,"r");
FILE* fpout=fopen(filenameout,"w");
Inital();
Syntax(fpin,fpout);
fclose(fpin);
fclose(fpout);
}
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