bianyi.cpp

C语言编写的简单的将汇编语言文件转化为单词二元式流文件的小软件。

#include <stdio.h> 
#include <string.h>
#include <stdlib.h>
#include <ctype.h> 
#include <malloc.h> 
#include <conio.h> 
#define g(x) (x-(x-65)*(x/(x-65+1)))%16

int line=1, row=1;
char KEY[8][6]={" ","BEGIN","THEN","DO","END","ELSE","IF","WHILE"};  //关键字表
int VAL[8]={17,1,4,7,2,5,3,6};//关键字对应种别号

int IsLetter(char ch) //判断是否是字母 
{
	if(isalpha(ch))
		return 1; 
	return 0; 
} 

int IsDigit(char ch) //判断是否为数字 
{
	if(isalnum(ch))
		return 1; 
	return 0; 
} 

int IsSpace(char ch) //判断是否为空白符（空格、换行、制表符等） 
{
	if(isspace(ch))
		return 1; 
	return 0; 
}
 
void GetChar(FILE *fp,char *ch) //读取字符送ch
{
	*ch = fgetc(fp);
	if(*ch=='\n')
	{
		line++;
		row=1;
	}
	else row++;
} 

void GetBC(FILE *fp,char *ch) //如果是空白则继续读下一个，直到不是空白 
{
	do{ 
		GetChar(fp,ch); 
	}
	while(IsSpace(*ch)&&(*ch != EOF)); 
} 

void Retract(FILE *fp,char *ch) //光标回退一位,并使 ch 为空
{
	fseek(fp,-1,1); 
	*ch = ' '; 
	row--;
}

int H(char key[]) //哈希函数：H(Key)=(L+g(key[1])+g(key[L]))%9
{
	int L = strlen(key);
	return (L+g(key[0])+g(key[L-1]))%9;
}

int Reserve(char *strToken) //返回关键字的编码（哈希函数法） 
{
	int h = H(strToken);
	if(h > 8 || h < 0)
		return 0;
	if(strcmp(strToken, KEY[h]) == 0)
		return h;
	return 0;
} 

void Concat(char *strToken, char *ch) //将ch中的字符连接到strToken后面 
{
	int i; 
	for(i=0;i<20;i++)
	{ 
		if(*strToken == NULL)
		{ 
			*strToken = *ch; 
			break; 
		} 
		strToken++; 
	} 
} 

void ErrorBranch(FILE *fp1,FILE *fp2) //出错处理分支程序
{
	char ch;
	printf("错误！非法字符！位于第%d行 第%d列\n", line, row-1);
	fprintf(fp2,"错误！非法字符！位于第%d行 第%d列\n",line,row-1);
	do{								  //跳到下一个空白符
		GetChar(fp1,&ch); 
	}
	while(!IsSpace(ch)&&(ch != EOF)); 
}

int lexSubFunc(FILE *fp1,FILE *fp2) //词法分析子程序
{
	char ch; 
	int i,code;
	char strToken[255]; 
	while(1)
	{ 
		GetBC(fp1,&ch); 
		for(i = 0;i < 255;i++)
			strToken[i] = '\0';
		if(ch == EOF)
			return 0; 
		if(IsLetter(ch))           //标识符判断
		{                          
			while(IsLetter(ch)||IsDigit(ch))
			{ 
				Concat(strToken,&ch); 
				GetChar(fp1,&ch); 
			} 
			Retract(fp1,&ch); 
			code = Reserve(strToken); 
			if(code == 0)
			{ 
				printf("<17,\"%s\">\n",strToken); 
				fprintf(fp2,"<17,\"%s\">\n",strToken);
			} 
			else
			{
				printf("<%d,\"%s\">\n",VAL[code],strToken); 
				fprintf(fp2,"<%d,\"%s\">\n",VAL[code],strToken); 
			} 
		} 
		else if(IsDigit(ch))         //整数判断
		{                      
			while (IsDigit(ch)) 
			{ 
				Concat(strToken,&ch); 
				GetChar(fp1,&ch); 
			} 
			Retract(fp1,&ch); 
			printf("<16,\"%s\">\n",strToken); 
			fprintf(fp2,"<16,\"%s\">\n",strToken); 
		} 
		else if (ch == '=')        //其他符号判断
		{                      
			GetChar(fp1,&ch);
			if(ch == '=')
			{
				printf("<12,\"==\">\n"); 
				fputs("<12,\"==\">\n",fp2); 
			}
			else 
			{
				Retract(fp1,&ch);
				printf("<8,\"=\">\n"); 
				fputs("<8,\"=\">\n",fp2); 
			}
		} 
		else if (ch == '+') 
		{ 
			printf("<9,\"+\">\n"); 
			fputs("<9,\"+\">\n",fp2); 
		} 
		else if (ch == '-') 
		{ 
			printf("<10,\"-\">\n"); 
			fputs("<10,\"-\">\n",fp2); 
		} 
		else if (ch == '<') 
		{ 
			printf("<11,\"<\">\n"); 
			fputs("<11,\"<\">\n",fp2); 
		} 
		else if (ch == '>') 
		{ 
			printf("<13,\">\">\n"); 
			fputs("<13,\">\">\n",fp2); 
		} 
		else if (ch == '.') 
		{ 
			printf("<14,\".\">\n"); 
			fputs("<14,\".\">\n",fp2); 
		} 
		else if (ch == ';') 
		{ 
			printf("<15,\";\">\n"); 
			fputs("<15,\";\">\n",fp2); 
		}
		else if(ch =='/')                 //注释符号判断
		{
			GetChar(fp1,&ch);
			if(ch =='/')
			{
				GetChar(fp1,&ch);	
				while(ch != '\n')
				{
					Concat(strToken,&ch);
					GetChar(fp1,&ch);
				}
				printf("<18,\"//%s\">\n",strToken);
				fprintf(fp2,"<18,\"//%s\">\n",strToken);
			}
			else
			if(ch == '*')
			{
				GetBC(fp1,&ch);
				while(ch !='*')
				{
					if(ch != '\n')
						Concat(strToken,&ch);
					GetBC(fp1,&ch);
				}
				GetChar(fp1,&ch);
				if(ch =='/')
				{
					printf("<19,\" %s\">\n",strToken);
					fprintf(fp2,"<19,\"%s\">\n",strToken);
				}
			}
			else
				ErrorBranch(fp1,fp2);
		}
		else
		{                                    //非法字符处理
			ErrorBranch(fp1,fp2);
		}
	} 
}

void main() 
{
	FILE *fpin,*fpout; 
	if((fpin=fopen("sourse.txt","rt"))==NULL)
	{ 
		printf("无法打开文件 sourse.txt\n");
		exit(1); 
	} 
	if((fpout=fopen("result.txt","wt+"))==NULL)
	{ 
		printf("无法创建文件 result.txt\n");
		exit(1); 
	} 
	printf("\n输出结果为：\n");
	lexSubFunc(fpin,fpout); 
	fclose(fpin); 
	fclose(fpout); 
} 




源程序sourse.txt:

BEGIN   	       //程序开始
  I=10; 
  J=I+5; 
  WHILE I= =10 DO     /*当I=10时
			          执行循环*/
			  
     BEGIN            ￥&
R=J+I;   
I=I-1
     END
END. 		      //程序结束	 




输出单词二元式流文件result.txt:

<1,"BEGIN">
<18,"//程序开始">
<17,"I">
<8,"=">
<16,"10">
<15,";">
<17,"J">
<8,"=">
<17,"I">
<9,"+">
<16,"5">
<15,";">
<17,"WHILE">
<17,"I">
<8,"=">
<8,"=">
<16,"10">
<7,"DO">
<19,"当I=10时执行循环">
<1,"BEGIN">
错误！非法字符！位于第7行 第23列
<17,"R">
<8,"=">
<17,"J">
<9,"+">
<17,"I">
<15,";">
<17,"I">
<8,"=">
<17,"I">
<10,"-">
<16,"1">
<17,"END">
<17,"END">
<14,".">
<18,"//程序结束	 ">