#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#define SPACE 0x20 //空格键
#define CHANGE 'c' //转义字符
#define STRING 'S' //引号里的字符串
#define BOUNDARY 'B' //界符
#define OPERATION 'O' //运算符
#define WORD 'I' //标识符
#define KEY_WORD 'K' //关键字
#define DIGIT 'n' //数字，包括小数
#define DOTH 'd' //头文件，“.h”文件
#define INT 't'
#define VOID 'v'
#define IF 'f'
#define ELSE 'e'
#define WHILE 'w'
#define FOR 'r'
#define MAIN 'm'
#define PRINTF 'p'
#define INCLUDE 'u'
#define FLOAT 'l'
#define KEYNUM 10
#define BOUNDNUM 8
#define OPERNUM 7
#define VALUENUM 100
/************************************************************************/
/* data type */
/************************************************************************/
struct bianliang
{
int id;
char name[20];
int value;
};
struct changliang
{
int data;
};
char KeyWord[KEYNUM][8]={"int","void","if","else","while","for","main","printf","include","float"};
char Boundary[BOUNDNUM]={'"',';',',','(',')','#','{','}'};
char Operation[OPERNUM]={'+','-','*','/','=','<','>'};
char Logogram[KEYNUM]={INT,VOID,IF,ELSE,WHILE,FOR,MAIN,PRINTF,INCLUDE,FLOAT};
char Value[VALUENUM][8];
int Value_n=0;
int ErrorLine=0;
int QuotationCount=0; //计算引号的数量
int QuotationFlag=0; //引号数量为奇数时为1，偶数时为0
char LastOpera=0; //用于判断"=="号存前一个"="号
/************************************************************************/
/* function describe */
/************************************************************************/
int isKeyWord(char* s) //是关键字返回1，否则返回0
{
int i;
for (i=0;i<KEYNUM;i++)
{
if (strcmp(KeyWord[i],s)==0)
{
return i+1;
}
}
return 0;
}
int isBoundary(char ch) //是界符
{
int i;
for (i=0;i<BOUNDNUM;i++)
{
if (Boundary[i]==ch)
{
return i+1;
}
}
return 0;
}
int isOperation(char ch) //是运算符
{
int i;
for (i=0;i<OPERNUM;i++)
{
if (Operation[i]==ch)
{
return i+1;
}
}
return 0;
}
int isDigit(char *s) //是数字
{
int i,l=strlen(s);
for (i=0;i<l;i++)
{
if (!isdigit(s[i]))
{
break;
}
}
if (i>=l)
{
return 1;
}
else
{
if ('.'==s[i])
{
i++;
for (;i<l;i++)
{
if (!isdigit(s[i]))
{
break;
}
}
}
else
{
return 0;
}
if (i>=l)
return 1;
else
return 0;
}
}
int isDotH(char *s) //是头文件
{
int i,l=strlen(s);
for (i=0;i<l;i++)
{
if (!isalpha(s[i]))
{
break;
}
}
if (i>=l)
{
return 0;
}
else
{
if ('.'==s[i])
{
i++;
if(s[i]=='h')
return 1;
else
return 0;
}
else
return 0;
}
}
int isWord(char *s) //是标识符
{
int i=0,l=strlen(s);
if (isalpha(s[i]))
{
i++;
for (;i<l;i++)
{
if (!isalnum(s[i]))
{
break;
}
}
}
if (i>=l)
{
return 1;
}
else
return 0;
}
void isWhat(int *i,char *str,FILE *fileOutput,FILE *fileOutput2) //判断字符串，并把相应类型存入文件
{
int n;
struct bianliang temp;
struct changliang t;
FILE *file=fopen("num.txt","ab");
if(1!=*i)
{
str[--(*i)]='\0';
if(n=isKeyWord(str))
{
fputs(str,fileOutput);
fputc('\t',fileOutput);
fputc(KEY_WORD,fileOutput);
fputc('\t',fileOutput);
if(isKeyWord(str)>9)
fputc(isKeyWord(str)+'a'-10,fileOutput);
else
fputc(isKeyWord(str)+'0',fileOutput);
fputc('\t',fileOutput);
fputc(Logogram[n-1],fileOutput);
fputc('\n',fileOutput);
}
else if(isWord(str))
{
fputs(str,fileOutput);
fputc('\t',fileOutput);
fputc(WORD,fileOutput);
fputc('\t',fileOutput);
for(n=0;n<Value_n;n++)
{
if(0==strcmp(Value[n],str))
break;
}
if(n==Value_n)
{
n=++Value_n;
strcpy(Value[n-1],str);
temp.id=n-1;
strcpy(temp.name,str);
temp.value=0;
fwrite(&temp,sizeof(struct bianliang),1,fileOutput2);
fputc('0'+n,fileOutput);
}
else
{
fputc('0'+n+1,fileOutput);
}
fputc('\t',fileOutput);
fputc('i',fileOutput);
fputc('\n',fileOutput);
}
else if (isDotH(str))
{
fputs(str,fileOutput);
fputc('\t',fileOutput);
fputc('\t',fileOutput);
fputc('\t',fileOutput);
fputc(DOTH,fileOutput);
fputc('\n',fileOutput);
}
else if (isDigit(str))
{
fputs(str,fileOutput);
fputc('\t',fileOutput);
fputc('\t',fileOutput);
fputc('\t',fileOutput);
fputc(DIGIT,fileOutput);
fputc('\n',fileOutput);
t.data=atoi(str);
fwrite(&t,sizeof(struct changliang),1,file);
}
(*i)=0;
}
fclose(file);
}
void writeMessage(FILE *f)
{
fputs("字符\t类型\t附加值\t缩写\n",f);
}
void error()
{
printf("%d line error!\n",ErrorLine);
exit(1);
}
/************************************************************************/
/* main */
/************************************************************************/
void main()
{
FILE*fileInput;
FILE*fileOutput;
FILE*fileOutput2;
char ch,qtemp;
char str[20];
int i;
int flag=0;
fileInput=fopen("1.cpp","r");
fileOutput=fopen("object.txt","w");
fileOutput2=fopen("variable.txt","w");
writeMessage(fileOutput);
if (NULL!=fileInput)
{
i=0;
do
{
ch=fgetc(fileInput);
str[i++]=ch;
if(isBoundary(ch))
{
if(1==isBoundary(ch))
{
QuotationCount++;
if (0==QuotationCount%2)
{
QuotationFlag=0;
}
else
QuotationFlag=1;
}
isWhat(&i,str,fileOutput,fileOutput2);
fputc(ch,fileOutput);
fputc('\t',fileOutput);
fputc('B',fileOutput);
fputc('\t',fileOutput);
if(isBoundary(ch)>9)
fputc(isBoundary(ch)+'a'-10,fileOutput);
else
fputc(isBoundary(ch)+'0',fileOutput);
fputc('\t',fileOutput);
fputc(Boundary[isBoundary(ch)-1],fileOutput);
fputc('\n',fileOutput);
i=0;
}
else if(isOperation(ch))
{
if(0==QuotationCount%2)
{
isWhat(&i,str,fileOutput,fileOutput2);
if ('='==ch)
{
qtemp=fgetc(fileInput);
if ('='==qtemp)
{
fputc('=',fileOutput);
fputc('=',fileOutput);
flag=1;
}
else
{
fputc('=',fileOutput);
fseek(fileInput,-1,SEEK_CUR);
flag=0;
}
}
else
fputc(ch,fileOutput);
fputc('\t',fileOutput);
fputc(OPERATION,fileOutput);
fputc('\t',fileOutput);
if(isOperation(ch)>9)
fputc(isOperation(ch)+'a'-10,fileOutput);
else
fputc(isOperation(ch)+'0',fileOutput);
fputc('\t',fileOutput);
if (flag)
{
fputc('q',fileOutput);
}
else
fputc(Operation[isOperation(ch)-1],fileOutput);
fputc('\n',fileOutput);
i=0;
}
else
{
fputc(ch,fileOutput);
fputc('\t',fileOutput);
fputc('\t',fileOutput);
fputc('\t',fileOutput);
fputc('c',fileOutput);
fputc('\n',fileOutput);
i=0;
}
}
else if('\n'==ch)
{
isWhat(&i,str,fileOutput,fileOutput2);
ErrorLine++;
i=0;
}
else if(SPACE==ch||'\t'==ch)
{
if(1<i)
isWhat(&i,str,fileOutput,fileOutput2);
else
i=0;
}
else if ('\\'==ch)
{
if (1==QuotationFlag)
{
if (1!=i)
{
str[--i]='\0';
fputs(str,fileOutput);
fputc('\t',fileOutput);
fputc(STRING,fileOutput);
fputc('\n',fileOutput);
i=0;
}
ch=fgetc(fileInput);
if ('t'==ch)
{
fputc('\\',fileOutput);
fputc('t',fileOutput);
fputc('\t',fileOutput);
fputc('\t',fileOutput);
fputc('\t',fileOutput);
fputc(CHANGE,fileOutput);
fputc('\n',fileOutput);
i=0;
}
else if('b'==ch)
{
fputc('\\',fileOutput);
fputc('b',fileOutput);
fputc('\t',fileOutput);
fputc('\t',fileOutput);
fputc('\t',fileOutput);
fputc(CHANGE,fileOutput);
fputc('\n',fileOutput);
i=0;
}
else if ('n'==ch)
{
fputc('\\',fileOutput);
fputc('b',fileOutput);
fputc('\t',fileOutput);
fputc('\t',fileOutput);
fputc('\t',fileOutput);
fputc(CHANGE,fileOutput);
fputc('\n',fileOutput);
i=0;
}
}
else error();
}
else if (1==QuotationFlag)
{
continue;
}
else if (isalnum(ch)||ch=='.')
{
}
else if (EOF!=ch)
{
error();
}
}while(EOF!=ch);
printf("词法分析完毕\n");
fclose(fileInput);
}
fclose(fileOutput);
fclose(fileOutput2);
}
/****************************************************/
/* 1.cpp 例子文件*/
#include <stdio.h>
void main ( )
{
int i;
int j;
int m;
m=1;
for(i=0;i<5;i=i+1)
{
printf("\t",i);
for(j=0;j<i;j=j+1)
{
printf("\b",i);
}
for(j=0;j<m;j=j+1)
{
printf("*",i);
}
printf("\n",i);
m=m+2;
}
}
追问还是不太明白啊些！
追答运行下就知道了，不是编译原理实验吗？