parse.h

该程序用ＶＣ实现了一个小型编译系统

/* file name:Parse.h
this file for the sentence analyzation
*/
#ifndef PARSE_H
#define PARSE_H
#include<iomanip.h>
#include "Scaner.h"
void scaner();
void program();
void declaration_list();
void declaration_stat();
void statement_list();
void statement();
void if_stat();
void while_stat();
void for_stat();
void compound_stat();
void assign_expr();
void bool_expr();
void addictive_expr();
void term();
void factor();
void read_stat();
void write_stat();
//< program>::=main(){<declaration_list><declaration_stat>}
void program()
{
      scaner();
	  if(sym==MAIN)scaner();
	  else 
	  {
		  error[index].row_error=row;
		 strcpy(error[index].p_Error,"no function 'main'  ");
		 index++;
		  return;
	  }

	if(sym==LP)scaner();
	else 
	 {
		 error[index].row_error=row; 
		 strcpy(error[index].p_Error,"missing'('after main  ");
		 index++;
		  return;
	  }
		if(sym==RP)scaner();
		else 
	  {
		  error[index].row_error=row;
		  strcpy(error[index].p_Error,"missing')',no match (  ");
	      index++;
		  return;
	  }
	 if(sym==LC)
	 {	
		 scaner();
		declaration_list();
		statement_list();
	
	}
	 else 
	  {
		 error[index].row_error=row;
		strcpy(error[index].p_Error," program not begin,missing '{' ");
	    index++;
		return;
		  
	  }
				
	
	fout<<"    STOP"<<endl;
     
	cout<<"***************************Compiler On Iminate Stack***************************"<<endl;
	cout<<"source.obj-"<<index<<" error(s)"<<endl;
	if(!index)cout<<"compile success"<<endl;
     else for(int i=0;i<index;i++)cout<<"source.txt("<<error[i].row_error<<")" <<error[i].p_Error <<endl;
}
//<declaration_list>::= {<declaration_stat>}
void declaration_list()
{
     stack[s_top++]=vartablep-1;
    while(sym==INT||sym==CHAR)
	{
		type=sym;
		declaration_stat();
	}
	cout<<"分析进入第 ("<<s_top<<")层函数嵌套。。。"<<endl;
	cout<<"此时符号栈中的变量为"<<endl;
	cout<<"类型"<<setw(8)<<"变量名"<<setw(8)<<"地址"<<endl;
	for(int i=0;i<vartablep;i++)
	cout<<varTable[i].type <<setw(8)<<varTable[i].name<<setw(8)<<varTable[i].address <<endl;
}
//claration_stat>::= @ vartable,datep->int |char ID@ name_def;
void declaration_stat()
{
	
	scaner();
	if(sym==ID)
	{
	name_def(token,type);
	scaner();
	
    if(sym!=SEMI)
	{
		
		error[index].row_error=row;
		strcpy(error[index].p_Error,"missing ';' ");
		index++;
	}
	scaner();
	}
	else 
	{
    	error[index].row_error=row;
		strcpy(error[index].p_Error,"need identifier");
		index++;
	}

}
// <statement_list>::={ <statement> }
void statement_list()
{
	while(sym!=END) 
	{
		statement();
		
	}
	
	
}
void statement()
{ 	
	if(sym==IF)if_stat();
	else if(sym==FOR)for_stat();
    else if(sym==WHILE)while_stat();
	else if(sym==LC)compound_stat();
	else if(sym==ID)assign_expr();
	else if(sym==READ)read_stat();
	else if(sym==WRITE)write_stat();
	else if(sym==RC)
	{
		int s;
		scaner();
	cout<<"分析退出第("<<s_top<<")层函数嵌套。。。"<<endl;
	 vartablep=stack[--s_top]+1;
	 datep=stack[s_top]+1;
     s=stack[s_top]+1;
	cout<<"此时符号栈中的变量为"<<endl;
    cout<<"类型"<<setw(8)<<"变量名"<<setw(8)<<"地址"<<endl;
    for(int i=0;i<s;i++)
	cout<<varTable[i].type <<setw(8)<<varTable[i].name<<setw(8)<<varTable[i].address <<endl;
	}
	
	
}
void if_stat()
{   
	int label1,label2;
	scaner();
	if(sym==LP)
		scaner();
	bool_expr();
	if(sym!=RP)
	{
		error[index].row_error=row;
		strcpy(error[index].p_Error,"missing ')' ");
		index++;
	}
        label1=labelp++;
		fout<<"    BRF Label"<<label1<<endl;//假出口指令
		scaner();
    	statement();
         label2=labelp++;
		 fout<<"    BR Label"<<label2<<endl;
			 fout<<"Label"<<label1<<":"<<endl;
		 //真出口指令及标记1
		 
	if(sym==ELSE)
	{
		scaner();
	statement();
	}
	fout<<"Label"<<label2<<":"<<endl;//设置标记 2

}
//<while_stat>::=while(<bool_expr>)<statement>
//<while_stat>::=while @SETlabel1 (<bool_expr>) @BRFlabel2 <statement> @BRlabel1@SETlabel2
void while_stat()
{
	int label1=0,label2=0;
	label1=labelp++;
	fout<<"Label"<<label1<<":"<<endl;
	scaner();
   if(sym==LP)
		scaner();
	bool_expr();
	if(sym!=RP)
	{
		error[index].row_error=row;
		strcpy(error[index].p_Error,"missing ')'");
		index++;
	}
	label2=labelp++;
	fout<<"    BRF Label"<<label2<<endl;
		scaner();
	
	  statement();
	  	fout<<"    BR Label"<<label1<<endl;
			fout<<"Label"<<label2<<":"<<endl;
}
/* 
<for_stat>::=(<assign_expr>;<bool_expr>;<assign_expr>)<statement>
 <for_stat>::=(<assign_expr>;
  @SETlabel1<bool_expr>;    设置标号1
  @BRF label2@BR label3    输出标号2和3 
	@SETlabel4<assign_expr>)@BR label1    设置标号4并输出标号1 
	@SETlabel3<statement>@BR label4        设置标号3并输出标号4
	@SETlabel2    设置标号2
*/
void for_stat()
{
	int label1,label2, label3, label4;
	scaner();
	if(sym!=LP)
	{
		error[index].row_error=row;
		strcpy(error[index].p_Error,"missing '('");
		index++;
	
	}
   scaner();
   assign_expr();
  
   label1=labelp++;
   fout<<"Label"<<label1<<":"<<endl;		
	   	bool_expr();
		label2=labelp++;
		fout<<"    BRF Label"<<label2<<endl;
		label3=labelp++;
		fout<<"    BR Label"<<label3<<endl;
	if(sym!=SEMI)
	{
		cout<<"source.txt("<<row<<")missing ';' "<<endl;
		error[index].row_error=row;
		strcpy(error[index].p_Error,"missing ';'");
		index++;
	}
	label4=labelp++;
	fout<<"Label"<<label4<<":"<<endl;
		scaner();
     	assign_expr();
			fout<<"    BR Label"<<label1<<endl;
		if(sym!=RP){
		error[index].row_error=row;
		strcpy(error[index].p_Error,"missing ')'");
		index++;
			}
		scaner();
	fout<<"Label"<<label3<<":"<<endl;
		statement();
	fout<<"    BR Label"<<label4<<endl;
	fout<<"Label"<<label2<<":"<<endl;
}
void compound_stat()
{
    /////////////////////////
	scaner();
	declaration_list();
	statement_list();
}
// <assign_expr>:: ID=<addictive>;
void assign_expr()
{
	int addr;
	char tmp[10];
	strcpy(tmp,token);
	scaner();

	if(sym==SIGN)
	{
    addr=lookup_var(tmp);
	if(addr<0){
		error[index].row_error=row;
	    strcpy(error[index].p_Error,token);
		strcat(error[index].p_Error," error :variable not declared");
		index++;
	}
	scaner();
	addictive_expr();
	if(sym==SEMI)scaner();
	fout<<"    STO "<<addr<<endl;
	}
}
// <bool_addictive>::=<addictive>(>|<|>=|<=|==|!=)<addictive>
/*
<bool_addictive>::=<addictive> > <addictive> @GT
<bool_addictive>::=<addictive> < <addictive> @LT
<bool_addictive>::=<addictive> >= <addictive> @GE
<bool_addictive>::=<addictive> <= <addictive> @LE
<bool_addictive>::=<addictive> ==<addictive> @EQ
<bool_addictive>::=<addictive> !=<addictive> @NEQ
*/
void bool_expr()
{
	int tkn;
	addictive_expr();
	if(sym==GT||sym==LT||sym==GE||sym==LE||sym==EQU||sym==NEQ)
	{
		tkn=sym;
		scaner();
        addictive_expr();
        if(tkn==GT)fout<<"    GT"<<endl;
		if(tkn==LT)fout<<"    LT"<<endl;
		if(tkn==GE)fout<<"	   GE"<<endl;
		if(tkn==LE)fout<<"	   LE"<<endl;
        if(tkn==EQU)fout<<"	   EQ"<<endl;
		if(tkn==NEQ)fout<<"	    NEQ"<<endl;

	}
}
// <addictive>::=<term>{ (+|-) <term> }
//<addictive>::=<term>{ + <term>  @ADD|- <tern> @SUB }
void addictive_expr()
{
	int tkn;
	term();
	
	while(sym==PLUS||sym==MINUS)	
	{
		tkn=sym;
		scaner();
	    term();
		if(tkn==PLUS)fout<<"    ADD"<<endl;
        if(tkn==GT)fout<<"    SUB"<<endl;
	}
}
//  <term>::=<factor>{ (*|/)<factor> }
// <term>::=<factor>{ *<factor> @MUL| /< factor > @DIV }.
void term()
{
		int tkn;
	factor();
   	while(sym==STAR||sym==DIV)	
	{
		tkn=sym;
		scaner();
	    factor();
		if(tkn==STAR)fout<<"    MUL"<<endl;
        if(tkn==DIV)fout<<"	   DIV"<<endl;
	}
}
// <factor>::=(<addictive>)|ID|NUM
//<factor>::=(<addictive>)|ID @lookup|NUM@loadi
void factor()
{
	if(sym==LP)
	{
      scaner();
     addictive_expr();
	  if(sym==RP)
       scaner();
	}
	else
	{	
		
	    if(sym==ID)
		{
			int addr;
			addr=lookup_var(token);
			if(addr<0)
			{
			error[index].row_error=row;
	    	strcpy(error[index].p_Error,token);
			strcat(error[index].p_Error," error :variable not declared");
	    	index++;
			}
			fout<<"    LOADI "<<addr<<endl;
			scaner();
		}
		if(sym==NUM){
			fout<<"    LOADI "<<token<<endl;
			scaner();
		}
	}
}
// <read_stat>::=read ID;
//<read>::=read ID lookup @IN @STI;
void read_stat()
{
	int addr;
	scaner();
	if(sym!=ID)
	{
		error[index].row_error=row;
      	strcpy(error[index].p_Error,token);
	    strcat(error[index].p_Error,"  identifer expected");
     	index++;
	}
	addr=lookup_var(token);
	if(addr<0)
	{
	error[index].row_error=row;
	strcpy(error[index].p_Error,token);
	strcat(error[index].p_Error," error :variable not declared");
	index++;
	}
	fout<<"    STI "<<addr<<endl;
	scaner();
	if(sym==SEMI)scaner();
}

// <write_stat>::=write<addictive_expr>;
// <write_stat>::=write<addictive_expr>@OUT;
void write_stat()
{
	scaner();
	addictive_expr();
     fout<<"    OUT "<<endl;
    if(sym==SEMI)scaner();
}

#endif