java-scanner.cpp

java词法分析器

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#define MAXBUFFER 256     //缓冲区大小
#define LENGTH 50

typedef struct token
{
	int label;            //种类标签
	char name[100];
	int code;             //编码
}token;	

char filename[30];  
char buffer[MAXBUFFER];   //缓冲区
int f=MAXBUFFER-1;        //缓冲中当前指针位置
FILE *sourcefin;          //源文件指针
FILE *tokenfout;          //分析结果文件指针
int currentline=1;        //当前行
int currentaddr=0;        //当前行中单词位置
int err_count=0;          //错误单词总数
int count=0;              //单词总数
char *key[LENGTH]={"abstract","boolean","break","byte","case","catch","char","class","const","continue",
                   "default","do","double","else","extends","false","final","finally","float","for",
				   "goto","if","implements","import","instanceof","int","interface","long","native","new",
				   "null","package","private","protected","public","return","short","static","super","switch",
				   "synchronized","this","throw","throws","transient","true","try","void","volatile","while"};
token currenttoken;

void load();
void scanner();
void isnumber();
void isalpha();
void isstring();
void ischar();
void isanotain();
void isesc();
void isother();
void output();
void error();


int main()
{
	scanner();
	printf("       ---------------------------------------\n");
	printf("           源文件单词个数: %d\n",count);
	printf("           源文件错误单词个数: %d\n",err_count);
	printf("       ---------------------------------------\n");
	printf("       分析完成!   o(∩_∩)o...哈哈!\n\n");
	printf("词法分析结果已经写入 scanner_output.txt 请查看详情!\n");
	return 0;
}


//---------------半缓冲读入-----------------
void load()
{
	int i;
	if(f==MAXBUFFER/2-1) 
	{
		//fread(&buffer[f+1],MAXBUFFER/2,1,sourcefin);
		for(i=128;i<256;i++) buffer[i]=fgetc(sourcefin);
		f++;
	}else if(f==MAXBUFFER-1)
	{
	//	fread(buffer,MAXBUFFER/2,1,sourcefin);
		for(i=0;i<128;i++) buffer[i]=fgetc(sourcefin);
		f=0;
	}
	else f++;
}
//---------------主程序-----------------
void scanner()
{
	printf("-------------------------\n");
	printf("    java语言词法分析器\n");
	printf("-------------------------\n");
	printf("输入源文件名：");
	scanf("%s",filename);
	if((sourcefin=fopen(filename,"rt"))==NULL) 
	{
		printf("无法打开文件%s.\n",filename);
		exit(1);
	}
	if((tokenfout=fopen("scanner_output.txt","w"))==NULL) 
	{
		printf("无法打开文件.\n");
		exit(1);
	}
	load();
	while(buffer[f]!=EOF&&buffer[f]!=NULL)
	{
		for(int i=0;i<30;i++) currenttoken.name[i]='\0';
		if((buffer[f]>47)&&(buffer[f]<58))
			isnumber();
		if(((buffer[f]>64)&&(buffer[f]<90))||((buffer[f]>96)&&(buffer[f]<123))||buffer[f]=='_'||buffer[f]=='$')
			isalpha();
		else {
			if(buffer[f]=='/') isanotain();
			else if(buffer[f]=='\\') isesc();
			else if(buffer[f]=='\"') isstring();
			else if(buffer[f]=='\'') ischar();
			else isother();
		}
	}
	fclose(sourcefin);
	fclose(tokenfout);
}
//---------------整型常量和实型常量处理----------------------
void isnumber(){
	int i=0;
	int flag=0;
	char ch;
	while((buffer[f]>47)&&(buffer[f]<58)||(buffer[f]=='e')||(buffer[f]=='E')||(buffer[f]=='F')||(buffer[f]=='X')||(buffer[f]=='x')||(buffer[f]=='L'))
	{
		currenttoken.name[i++]=buffer[f];
		load();
		if(buffer[f]=='.'||buffer[f]=='e'||buffer[f]=='E')
		{
			flag=1;
			ch=buffer[f];
			break;
		}
	}
	currenttoken.label=7;
	currenttoken.code=0x107;
	if(flag==1)
	{
		load();
		if((buffer[f]>47)&&(buffer[f]<58))
			currenttoken.name[i++]=ch;
		else error();
		while((buffer[f]>47)&&(buffer[f]<58)||buffer[f]=='F')
		{
			currenttoken.name[i++]=buffer[f];
			load();
		}
		currenttoken.label=8;
	    currenttoken.code=0x108;
		if(buffer[f]=='.')
		{
			error();
			load();
			while((buffer[f]>47)&&(buffer[f]<58))
			{
				load();
			}
		}
		if(((buffer[f]>64)&&(buffer[f]<90))||((buffer[f]>96)&&(buffer[f]<123)))
		{
			error();
			while(((buffer[f]>64)&&(buffer[f]<90))||((buffer[f]>96)&&(buffer[f]<123)))
			{
				load();
				while((buffer[f]>47)&&(buffer[f]<58)) load();
			}
		}
	}
	output();
}
//---------------关键字和标识符------------
void isalpha()
{
	int i=0,h=0;
	while(((buffer[f]>64)&&(buffer[f]<90))||((buffer[f]>96)&&(buffer[f]<123))||buffer[f]=='_'||buffer[f]=='$'||(buffer[f]>47)&&(buffer[f]<58))
	{
		currenttoken.name[i++]=buffer[f];
		load();
	}
	for(i=0;i<LENGTH;i++) 
	{
		h=strcmp(key[i],currenttoken.name);
		if(h==0) break;
	}
	if(h==0) 
	{
		currenttoken.code=0x103;
		currenttoken.label=3;    //关键字
	}
	else 
	{
		if(!(strcmp("true",currenttoken.name))&&(strcmp("false",currenttoken.name)))
		{
			currenttoken.code=0x105;
			currenttoken.label=5; //布尔型
		}
		else
		{
		currenttoken.code=0x104;
		currenttoken.label=4;    //标识符
		}
	}
	output();
}
//--------------字符串处理----------------------
void isstring()
{
	int i=0;
	for(;;)
	{
		load();
		currenttoken.code=0x109;
		currenttoken.label=9;
		for(;buffer[f]!='\"'&&buffer[f]!=EOF;load())
		{
			currenttoken.name[i++]=buffer[f];
		}
		if(buffer[f]==EOF) 
		{
			error();
			break;
		}
		else break;
	}
	output();
	load();
}
//--------------字符处理----------------------
void ischar()
{
	load();
	if(buffer[f]!='\''&&buffer[f]!=EOF&&buffer[f]!=10)
	{
		currenttoken.name[0]=buffer[f];
	}
	if(buffer[f]=='\\') 
	{
		isesc();
		if(buffer[f]=='\'') load();
	}
	else
	{
		load();
	if(buffer[f]=='\'')
	{
    currenttoken.code=0x106;
	currenttoken.label=6;
	}
	else error();
	output();
	load();
	}
}

//--------------注释处理及"/=","/"----------------------
void isanotain()
{
	char ch;
	ch=buffer[f];
	load();
	if(buffer[f]=='*')         //注释/**/处理
	{
		for(;;)
		{
			load();
			if(buffer[f]==EOF)
			{
				error();
				break;
			}
			if(buffer[f]=='*')
			{
				ch=buffer[f];
				load();
				if(buffer[f]=='/')
				{
					load();
					currenttoken.code=0x101;
		            currenttoken.label=1;
					break;
				}
			}
		}
	}
	else if(buffer[f]=='/')         //注释//处理
	{
		currenttoken.code=0x101;
	    currenttoken.label=1;
		for(;buffer[f]!='\n'&&buffer[f]!='\r'&&buffer[f]!=EOF;)
		{
			load();
		}
	}
	else if(buffer[f]=='=')         ///=处理
	{
		currenttoken.code=0x110;
		currenttoken.label=12;
		currenttoken.name[0]='/';
		currenttoken.name[1]=buffer[f];
		output();
		load();
	}
	else
	{
		currenttoken.name[0]='/';    //除号
		currenttoken.code=0x11b;
		currenttoken.label=12;
		output();
	}
}
//--------------转义字符----------------------
void isesc()
{
	int i=2,k=0;
	currenttoken.name[0]='\\';
	currenttoken.label=10;
	load();
	if(buffer[f]=='\''||buffer[f]=='\\'||buffer[f]=='r'||buffer[f]=='n'||buffer[f]=='f'||buffer[f]=='t'||buffer[f]=='b')
	{
		currenttoken.name[1]=buffer[f];
		output();
		load();
	}
	else if(buffer[f]=='u')
	{
		currenttoken.name[1]=buffer[f];
		while(1)
		{
			load();
			if((buffer[f]>47)&&(buffer[f]<58)||(buffer[f]>64)&&(buffer[f]<71)||(buffer[f]>96)&&(buffer[f]<103))
			{
				currenttoken.name[i++]=buffer[f];
				k++;
			}
			else break;
		}
		if(k>4) 
		{
			error();
			output();
		}
		else output();
	}
	else 
	{
		while(1)
		{
			load();
			if((buffer[f]>47)&&(buffer[f]<56))
			{
				currenttoken.name[i++]=buffer[f];
				k++;
			}
			else break;
		}
		if(k>3) 
		{
			error();
			output();
		}
		else output();
	}
}
//--------------其他情况----------------------
void isother()
{
	switch(buffer[f]) {
	case'[':
		currenttoken.code=0x11d;
		currenttoken.label=11;
		currenttoken.name[0]='[';
		currenttoken.name[1]='\0';
		load();
		output();
		break;
	case']':
		currenttoken.code=0x11d;
		currenttoken.label=11;
		currenttoken.name[0]=']';
		currenttoken.name[1]='\0';
		load();
		output();
		break;
	case'(':
		currenttoken.code=0x11d;