cifa.c

编译原理课程设计

/***************************
         词法分析
***************************/
/*
 标识符 1
 整数   2
 关键字 3
 运算符 4
 分隔符 5
*/
#include<stdlib.h>
#include<stdio.h>
#include<string.h>
#define MAX 10000								//二元式行数
#define MAXID 8
#define MAXNUM "65535"
//保存二元式的结构体
struct ds
{
	char *idstr;								//字符串 
	int style;									//类型
};
struct ds data[MAX];
long num=0;
int wrong=0;
int line=1;
int errorno=0;
/*******************************************
 初始化函数
********************************************/
void init()
{             
    char *key[]={" ","BEGIN","END","IF","THEN","ELSE","WHILE","DO","INTEGER","VAR"};	//关键字

    char *separator[]={" ",";",".",":=",",","(",")",":"};								//分隔符
		 
    char *operation[]={" ","+","-","*","/","<","<=",">",">=","<>","="};					//运算符
    FILE *fp;
    int i;
    fp=fopen("keyword.txt","w");//创建各类此文的文本文件
    for(i=1;i<=9;i++)
       fprintf(fp,"%s\n",key[i]);
    fclose(fp);               
    fp=fopen("separator.txt","w");
    for(i=1;i<=7;i++)            
       fprintf(fp,"%s\n",separator[i]);
   fclose(fp);       
	fp=fopen("operation.txt","w");  
	for(i=1;i<=10;i++)
		fprintf(fp,"%s\n",operation[i]);
	fclose(fp);
         
    fp=fopen("id.txt","w");		//符号表
    fclose(fp);               
    fp=fopen("int.txt","w");
    fclose(fp);               
    fp=fopen("token.txt","w");
    fclose(fp);               
}


/*******************************************
 根据不同命令查表或造表函数
********************************************/
int find(char *buf,int type,int command)				//command=1 只要查表 command=2 找不到时 要加进去表中
{             
    int number=0;
    FILE *fp;
    char c;
    char temp[30];
    int i=0;
    switch(type)
    {
        
        case 1: fp=fopen("id.txt","r");break;
        case 2: fp=fopen("int.txt","r");break;
		case 3: fp=fopen("keyword.txt","r");break;
        case 4: fp=fopen("operation.txt","r"); break;
		case 5: fp=fopen("separator.txt","r");
    }
    c=fgetc(fp);
    while(c!=EOF)
    {
        while(c!='\n')
        {
            temp[i++]=c;
            c=fgetc(fp);
        }
        temp[i]='\0';
        i=0;
        number++;
        if(strcmp(temp,buf)==0)
        {  
		    fclose(fp);
			return(number);							//若找到，返回在相应表中的序号
        }
        else
           c=fgetc(fp);
     }
     if(command==1)									//找不到，当command=1，返回0
     {   
	     fclose(fp); 
		 return(0);									
     }
     switch(type)									//当command=2,向表中追加标识符 
     {
         case 1: fp=fopen("id.txt","a");break;   
         case 2: fp=fopen("int.txt","a");break;
         case 3: fp=fopen("keyword.txt","a");break;
         case 4: fp=fopen("operation.txt","a");break;
		 case 5: fp=fopen("separator.txt","a");
     }
     fprintf(fp,"%s\n",buf);
     fclose(fp);
     return(0);										//造表时，将字符串添加到表尾并返回序号值
}

/*******************************************
 整数理函数
********************************************/
void int_manage(char *buffer)
{             
    FILE *fp;
	if(strlen(buffer)>5) 
	{
	wrong=1;
	return ;
	}
    if(strlen(buffer)==5)
	{
		if(strcmp(buffer,MAXNUM)>0) 
			wrong=1;
		return ;
	}
    find(buffer,2,2);								//先查整数表，若找不到则插入整数表
    fp=fopen("token.txt","a");
	fprintf(fp,"%s\t\t\t2\n",buffer);				
	data[num].idstr =buffer;
	data[num].style =2;
	num++;
	fclose(fp);               
}

/*******************************************
 字符串处理函数 
********************************************/
void ch_manage(char *buffer)
{                     
    FILE *fp;
    int result;
	if(strlen(buffer)>8)
	{
		wrong=1;
		return ;
	}
    result=find(buffer,3,1);						  //先查关键字表
    fp=fopen("token.txt","a");
    if(result!=0)
	{
		result+=2;
		fprintf(fp,"%s\t\t\t%d\n",buffer,result);    //若找到，写入token文件
		data[num].idstr =buffer;
    	data[num].style =result;
		num++;
	}
    else
    {
        result=find(buffer,1,2);					//若找不到，则非关键字，查标识符表，还找不到则插入标识符表
        fprintf(fp,"%s\t\t\t1\n",buffer,1);
		data[num].idstr =buffer;
	    data[num].style =1;
    	num++;
    }                             
    fclose(fp);
}

/*******************************************
 出错处理函数
********************************************/
void error_manage(char error,int lineno)
{                 
    printf("error: %c ,line %d",error,lineno);    //报告出错符号和所在行数
}

/*******************************************
 扫描程序
********************************************/
void scanner()
{            
    FILE *fpin,*fpout;
    char filename[20];
    char ch;
	int k=0;
    int i=0;
    int count,result;
	char array[30];
    char *word;
	int style=0;
	int result2=0;
	printf("\n please input the source file name:");
    scanf("%s",filename);
    if((fpin=fopen(filename,"r"))==NULL)
    {
        printf("cannot open file");
        return;
    }
    ch=fgetc(fpin);	
    while(ch!=EOF)													//一直扫描到文件末尾
    {                 
        i=0;
        if(((ch>='A')&&(ch<='Z')))									//以字母开头
        {           
            while(((ch>='A')&&(ch<='Z'))||((ch>='0')&&(ch<='9')))
            {
                array[i++]=ch;
                ch=fgetc(fpin);
            }
            word=(char *)malloc((i+1)*sizeof(char));
			memcpy(word,array,i);
			word[i]='\0';
            ch_manage(word);										//处理字符串
			if(wrong) 
			{   errorno++;
				printf("\nerror:out of range :");
				for(k=0;k<i;k++) 
				 printf("%c",word[k]);   
				 printf(" ,line: %d", line);
			}
			wrong=0;
            if(ch!=EOF)
			   fseek(fpin,-1L,SEEK_CUR);							//文件指针后退一个字节
        }
        else if(ch>='0'&&ch<='9')									//以数字开头
        {         
            while(ch>='0'&&ch<='9')
            {
                array[i++]=ch;
                ch=fgetc(fpin);
            }
            word=(char *)malloc((i+1)*sizeof(char));
			memcpy(word,array,i);
			word[i]='\0';
            int_manage(word);										//处理整数
			if(wrong) 
			{   errorno++;
				printf("\n error:out of range :");
				for(k=0;k<i;k++) 
				 printf("%c",word[k]);   
				 printf(" ,line: %d", line);
			}
			wrong=0;
			
            if(ch!=EOF)
			   fseek(fpin,-1L,SEEK_CUR);
        }
        else if((ch==' ')||(ch=='\t'))
			;														//消除空格符和水平制表符
		else if(ch=='\n')
			line++;													//消除回车并记录行数
		else if(ch=='/')
        {															//消除注释
			ch=fgetc(fpin);
		    if((ch!='*')&&(ch!='/'))
            {														//若为除号，写入输出文件
                fpout=fopen("token.txt","a");
				fprintf(fpout,"/\t\t\t15\n");
					data[num].idstr ="/";
	                data[num].style =15;
                	num++;
                fclose(fpout);
				fseek(fpin,-1L,SEEK_CUR);
			}
			else if(ch=='/')										//符号为//，消除此行后面的字符
			{
				ch=fgetc(fpin);
				while(ch!='\n')
					ch=fgetc(fpin);
				line++;
			}
			else if(ch=='*')
			{														//符号为/*，消除/*和*/之间的字符
				count=0;
				ch=fgetc(fpin);
				while(count!=2)
                {													//当扫描到*且紧接着下一个字符为/,才是注释的结束*/
					count=0;
					while(ch!='*')
					{
						if(ch=='\n') 
							line++;
						ch=fgetc(fpin);
					}
					count++;
					ch=fgetc(fpin);
					if(ch=='/')
						count++;
					else
						ch=fgetc(fpin);
				}
			}
		}
		else
        {														//首字符为其它字符,即运算符或分隔符或非法字符*/
            array[0]=ch;
            ch=fgetc(fpin);										//再读入下一个字符，判断是否为双字符运算、分隔符
            if(ch!=EOF)
            {
                array[1]=ch;
				word=(char *)malloc(3*sizeof(char));
				memcpy(word,array,2);
				word[2]='\0';
                result=find(word,4,1);							//先检索是否为双字符运算符或分隔符
				result2=find(word,5,1);
				if((result==0)&&(result2==0))					//若不是
				{                         
                    word=(char *)malloc(2*sizeof(char));
					memcpy(word,array,1);
					word[1]='\0';
					result=find(word,4,1);						//检索是否为单字符运算、分隔符
					result2=find(word,5,1);
					if(result!=0) style=4;
					if(result2!=0) style=5;
					if(result==0 && result2==0)
                    {											//若还不是，则为非法字符
						printf("\n");
						error_manage(array[0],line);
						errorno++;
						fseek(fpin,-1L,SEEK_CUR);
                    }
                    else
					{											//若为单字符运算、分割符，写入token文件并将扫描文件指针回退一个字符*/
						fpout=fopen("token.txt","a");
						result+=11;
						result2+=21;
						result=(style==4)? result:result2;
						fprintf(fpout,"%s\t\t\t%d\n",word,result);
							data[num].idstr =word;
	                        data[num].style =result;
                        	num++;
						fclose(fpout);
						fseek(fpin,-1L,SEEK_CUR);				//文件指针后退一个字节
					}
				}
                else
				{												//若为双字符运算、分隔符，写token文件
					fpout=fopen("token.txt","a");
					result+=11;
					result2+=21;
					result=(result==11)?result2:result;
					fprintf(fpout,"%s\t\t\t%d\n",word,result);
					data[num].idstr =word;
	                data[num].style =result;
                	num++;
					fclose(fpout);
				}
            }
            else
				fseek(fpin,-1L,SEEK_CUR);						//文件指针后退一个字节
        }
        ch=fgetc(fpin); 
    }
	fpout=fopen("token.txt","a");
	fprintf(fpout,"#\t\t\t0\n");
	data[num].idstr="#";
	data[num].style=0;
	num++;
    fclose(fpout);
	printf("\nThere are %d error(s).\n",errorno);				//报告错误字符个数
}

void cifa()
{	
	int j=0;
	init();														//初始化
    scanner();													//扫描源程序
	printf("\n 二元式流 :\n");
	while(data[j].idstr !=NULL)								//打印二元式流
	{
		printf("%s\t\t%d\t\t\n",data[j].idstr ,data[j].style );
		j++;
	}
}