编译原理C语言词法分析器.docx
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编译原理C语言词法分析器
编译原理C语言词法分析器(总23页)
编译原理C语言词法分析器
一、实验题目
编制并调试C词法分析程序。
a.txt源代码:
main(){
intsum=0,it=1;/*Variabledeclaration*/
if(sum==1)
it++;
else
it=it+2;
}
设计其词法分析程序,能识别出所有的关键字、标识符、常数、运算符(包括复合运算符,如++)、界符;能过滤掉源程序中的注释、空格、制表符、换行符;并且能够对一些词法规则的错误进行必要的处理,如:
标识符只能由字母、数字和下划线组成,且第一个字符必须为字母或下划线。
实验要求:
要给出所分析语言的词法说明,相应的状态转换图,单词的种别编码方案,词法分析程序的主要算法思想等。
二、实验目的
1、理解词法分析在编译程序中的作用;
2、掌握词法分析程序的实现方法和技术;
3、加深对有穷自动机模型的理解。
三、主要函数
voidload()voidchar_search(char*word)
voidmain()voidintb_search(char*word)
voidscan()voidc_search(char*word)
voidinta_search(char*word)voidcc_search(char*word)
四、设计
1.主函数voidmain()
2.初始化函数voidload()
3.保留字及标识符判断函数voidchar_search(char*word)
4.整数类型判断函数voidinta_search(char*word)
5.浮点类型判断函数voidintb_search(char*word)
6.字符串常量判断函数voidcc_search(char*word)
7.字符常量判断函数voidc_search(char*word)
同4、5函数图
8.主扫描函数voidscan()
五、关键代码
#include<>
#include<>
#include<>
char*key0[]={"","auto","break","case","char","const","continue","default","do","double","else","enum","extern","float","for","goto","if","int","long","register","return","short","signed","sizeof","static","struct","switch","typedef","_Complex","_Imaginary","union","unsigned","void","volatile","while"};
/*保留字表*/
char*key1[]={"","(",")","[","]","{","}",",",";","'"};
/*分隔符表*/
char*key2[]={"","+","-","*","/","%","<",">","==",">=","<=","!
=","!
","&&","||","<<",">>","~","|","^","&","=",":
","->","++","--",".","+=","-=","*=","/="};
/*运算符表*/
intxx0[35],xx1[10],xx2[31];
inttemp_key3=0,temp_c40=0,temp_c41=0,temp_c42=0,temp_c43=0;
/*******初始化函数*******/
voidload()
{
intmm;
for(mm=0;mm<=34;mm++)
{
xx0[mm]=0;
}
for(mm=0;mm<=9;mm++)
{
xx1[mm]=0;
}
for(mm=0;mm<=30;mm++)
{
xx2[mm]=0;
}
FILE*floading;
if((floading=fopen("","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
");
return;
}
fclose(floading);
/*建立保留字表文件:
*/
if((floading=fopen("","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
");
return;
}
/*建立分隔符表文件:
*/
if((floading=fopen("","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
");
return;
}
fclose(floading);
/*建立运算符表文件:
*/
if((floading=fopen("","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
");
return;
}
fclose(floading);
/*建立标识符表文件:
*/
if((floading=fopen("","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
");
return;
}
fclose(floading);
/*建立整数类型常量表文件:
*/
if((floading=fopen("","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
");
return;
}
fclose(floading);
/*建立浮点类型常量表文件:
*/
if((floading=fopen("","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
");
return;
}
fclose(floading);
/*建立字符类型常量表文件:
*/
if((floading=fopen("","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
");
return;
}
fclose(floading);
/*建立字符串类型常量表文件:
*/
if((floading=fopen("","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
");
return;
}
fclose(floading);
/*建立注释文件:
*/
if((floading=fopen("","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
");
return;
}
fclose(floading);
/*建立内部码文件:
*/
if((floading=fopen("temp_key1","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
temp_key1");
return;
}
fclose(floading);
/*建立保留字临时表文件:
temp_key1*/
if((floading=fopen("temp_key3","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
temp_key3");
return;
}
fclose(floading);
/*建立标识符临时文件:
temp_key3*/
if((floading=fopen("temp_c40","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
temp_c40");
return;
}
fclose(floading);
/*建立整数类型常量临时文件:
temp_c40*/
if((floading=fopen("temp_c41","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
temp_c41");
return;
}
fclose(floading);
/*建立浮点类型常量临时文件:
temp_c41*/
if((floading=fopen("temp_c42","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
temp_c42");
return;
}
fclose(floading);
/*建立字符类型常量临时文件:
temp_c42*/
if((floading=fopen("temp_c43","w"))==NULL)
{
printf("Error!
Can'tcreatefile:
temp_c43");
return;
}
fclose(floading);
/*建立字符串类型常量临时文件:
temp_c43*/
}
/*******保留字及标识符判断函数*******/
voidchar_search(char*word)
{
intm,line=0,csi=0;
intvalue=0;
intvalue2=0;
charc,cs[100];
FILE*foutput,*finput;
for(m=1;m<=34;m++)
{
if(strcmp(word,key0[m])==0)
{
value=1;
break;
}
}
if(value==1)
{
if(xx0[m]==0)
{
foutput=fopen("","a");
fprintf(foutput,"0\t%d\t\t%s\n",m,word);
fclose(foutput);
xx0[m]=1;
}
foutput=fopen("","a");
fprintf(foutput,"0\t%d\t\t%s\n",m,word);
fclose(foutput);
}
else
{
if(temp_key3==0)
{
foutput=fopen("temp_key3","a");
fprintf(foutput,"%s\n",word);
fclose(foutput);
temp_key3++;
foutput=fopen("","a");
fprintf(foutput,"3\t1\t\t%s\n",word);
fclose(foutput);
}
finput=fopen("temp_key3","r");
c=fgetc(finput);
while(c!
=EOF)
{
while(c!
='\n')
{
cs[csi++]=c;
c=fgetc(finput);
}
cs[csi]='\0';
csi=0;
line++;
if((strcmp(cs,word))==0)
{
value2=1;
break;
}
else
{
value2=0;
c=fgetc(finput);
}
}
fclose(finput);
if(value2==1)
{
foutput=fopen("","a");
fprintf(foutput,"3\t%d\t\t%s\n",line,word);
fclose(foutput);
}
else
{
foutput=fopen("temp_key3","a");
fprintf(foutput,"%s\n",word);
fclose(foutput);
temp_key3++;
foutput=fopen("","a");
fprintf(foutput,"3\t%d\t\t%s\n",temp_key3,word);
fclose(foutput);
foutput=fopen("","a");
fprintf(foutput,"3\t%d\t\t%s\n",temp_key3,word);
fclose(foutput);
}
}
}
/*******整数类型判断函数*******/
voidinta_search(char*word)
{
FILE*foutput,*finput;
charc;
charcs[100];
intcsi=0;
intline=0;
intvalue2=0;
if(temp_c40==0)
{
foutput=fopen("temp_c40","a");
fprintf(foutput,"%s\n",word);
fclose(foutput);
temp_c40++;
foutput=fopen("","a");
fprintf(foutput,"4\t0\t1\t%s\n",word);
fclose(foutput);
}
finput=fopen("temp_c40","r");
c=fgetc(finput);
while(c!
=EOF)
{
while(c!
='\n')
{
cs[csi++]=c;
c=fgetc(finput);
}
cs[csi]='\0';
csi=0;
line++;
if(strcmp(cs,word)==0)
{
value2=1;
break;
}
c=fgetc(finput);
}
fclose(finput);
if(value2==1)
{
foutput=fopen("","a");
fprintf(foutput,"4\t0\t%d\t%s\n",line,word);
fclose(foutput);
}
else
{
foutput=fopen("temp_c40","a");
fprintf(foutput,"%s\n",word);
fclose(foutput);
temp_c40++;
foutput=fopen("","a");
fprintf(foutput,"4\t0\t%d\t%s\n",temp_c40,word);
fclose(foutput);
foutput=fopen("","a");
fprintf(foutput,"4\t0\t%d\t%s\n",temp_c40,word);
fclose(foutput);
}
}
/*******浮点类型判断函数*******/
voidintb_search(char*word)
{
FILE*foutput,*finput;
charc;
charcs[100];
intcsi=0;
intline=0;
intvalue2=0;
if(temp_c41==0)
{
foutput=fopen("temp_c41","a");
fprintf(foutput,"%s\n",word);
fclose(foutput);
temp_c41++;
foutput=fopen("","a");
fprintf(foutput,"4\t1\t1\t%s\n",word);
fclose(foutput);
}
finput=fopen("temp_c41","r");
c=fgetc(finput);
while(c!
=EOF)
{
while(c!
='\n')
{
cs[csi++]=c;
c=fgetc(finput);
}
cs[csi]='\0';
csi=0;
line++;
if(strcmp(cs,word)==0)
{
value2=1;
break;
}
c=fgetc(finput);
}
fclose(finput);
if(value2==1)
{
foutput=fopen("","a");
fprintf(foutput,"4\t1\t%d\t%s\n",line,word);
fclose(foutput);
}
else
{
foutput=fopen("temp_c41","a");
fprintf(foutput,"%s\n",word);
fclose(foutput);
temp_c41++;
foutput=fopen("","a");
fprintf(foutput,"4\t1\t%d\t%s\n",temp_c41,word);
fclose(foutput);
foutput=fopen("","a");
fprintf(foutput,"4\t1\t%d\t%s\n",temp_c41,word);
fclose(foutput);
}
}
/*******字符串常量判断函数*******/
voidcc_search(char*word)
{
FILE*foutput,*finput;
charc;
charcs[100];
intcsi=0;
intline=0;
intvalue2=0;
if(temp_c43==0)
{
foutput=fopen("temp_c43","a");
fprintf(foutput,"%s\n",word);
fclose(foutput);
temp_c43++;
foutput=fopen("","a");
fprintf(foutput,"4\t3\t1\t%s\n",word);
fclose(foutput);
}
finput=fopen("temp_c43","r");
c=fgetc(finput);
while(c!
=EOF)
{
while(c!
='\n')
{
cs[csi++]=c;
c=fgetc(finput);
}
cs[csi]='\0';
csi=0;
line++;
if(strcmp(cs,word)==0)
{
value2=1;
break;
}
c=fgetc(finput);
}
fclose(finput);
if(value2==1)
{
foutput=fopen("","a");
fprintf(foutput,"4\t3\t%d\t%s\n",line,word);
fclose(foutput);
}
else
{
foutput=fopen("temp_c43","a");
fprintf(foutput,"%s\n",word);
fclose(foutput);
temp_c43++;
foutput=fopen("","a");
fprintf(foutput,"4\t3\t%d\t%s\n",temp_c43,word);
fclose(foutput);
foutput=fopen("","a");
fprintf(foutput,"4\t3\t%d\t%s\n",temp_c43,word);
fclose(foutput);
}
}
/*******字符常量判断函数*******/
voidc_search(char*word)
{
FILE*foutput,*finput;
charc;
charcs[100];
intcsi=0;
intline=0;
intvalue2=0;
if(temp_c42==0)
{
foutput=fopen("temp_c42","a");
fprintf(foutput,"%s\n",word);
fclose(foutput);
temp_c42++;
foutput=fopen("","a");
fprintf(foutput,"4\t2\t1\t%s\n",word);
fclose(foutput);
}
finput=fopen("temp_c42","r");
c=fgetc(finput);
while(c!
=EOF)
{
while(c!
='\n')
{
cs[csi++]=c;
c=fgetc(finput);
}
cs[csi]='\0';
csi=0;
line++;
if(strcmp(cs,word)==0)
{
value2=1;
break;
}
c=fgetc(finput);
}
fclose(finput);
if(value2==1)
{
foutput=fopen("","a");
fprintf(foutput,"4\t2\t%d\t%s\n",line,word);
fclose(foutput);
}
else
{
foutput=fopen("temp_c42","a");
fprintf(foutput,"%s\n",word);
fclose(foutput);
temp_c42++;
foutput=fopen("","a");
fprintf(foutput,"4\t2\t%d\t%s\n",temp_c42,word);
fclose(foutput);
foutp