semantic.cpp

这是用VC6.0开发的集词法分析、语法分析、语义分析为一体的一个程序

		pFSAG1->des=this->GetIDName(pToken);

		GetNextToken(token);
		const char *str2=this->m_pWordCode[token->keycode];
		if (strcmp(str2,"<")==0 ||
			strcmp(str2,"<=")==0 ||
			strcmp(str2,">")==0 ||
			strcmp(str2,">=")==0 ||
			strcmp(str2,"=")==0 ||
			strcmp(str2,"<>")==0)
		{
			GetNextToken(token);
			if (strcmp(this->m_pWordCode[token->keycode],"identifier")==0)
			{
				PFSAG pFSAG2=new FSAG;
				pFSAG2->type=PT;
				pFSAG2->value.token=token;
				pFSAG2->des=this->GetIDName(token);				

				pTC=this->GetCurPFS();
				Gencode(this->GetOP(str2),pFSAG1,pFSAG2,NULL);
				pFC=this->GetCurPFS();
				Gencode(GetOP("j"),NULL,NULL,NULL);
			}
			else
			{
				this->AddError("条件表达式错误！");
				this->NoUseCurToken();
			}
		}
		else
		{
			this->NoUseCurToken();
			pTC=this->GetCurPFS();
			Gencode(GetOP("jnz"),pFSAG1,NULL,NULL);
			pFC=this->GetCurPFS();
			Gencode(GetOP("j"),NULL,NULL,NULL);
		}
	}
	else
	{
		this->AddError("条件表达式错误！");
		this->NoUseCurToken();
	}
}

/**
 * 根据操作符返回操作类型
 *
 * @param	char *strOp			操作符
 *
*/	
EOP CSemantic::GetOP(const char *strOp)
{
	EOP op;
	if (strcmp(strOp,"j")==0) op=OPJump;
	else if (strcmp(strOp,">")==0) op=OPJumpLarger;
	else if (strcmp(strOp,">=")==0) op=OPJumpLE;
	else if (strcmp(strOp,"jnz")==0) op=OPJumpNZero;
	else if (strcmp(strOp,"j=")==0) op=OPJumpEqual;
	else if (strcmp(strOp,"j<>")==0) op=OPJumpUEqual;
	else if (strcmp(strOp,"j<")==0) op=OPJumpSmaller;
	else if (strcmp(strOp,"j<=")==0) op=OPjumpSE;
	else if (strcmp(strOp,">")==0) op=OPLarger;
	else if (strcmp(strOp,"<")==0) op=OPSmaller;
	else if (strcmp(strOp,"=")==0) op=OPEqual;
	else if (strcmp(strOp,":=")==0) op=OPEvaluate;
	else if (strcmp(strOp,"<>")==0) op=OPUnequal;
	else if (strcmp(strOp,"+")==0) op=OPPlus;
	else if (strcmp(strOp,"-")==0) op=OPMinus;
	else if (strcmp(strOp,"*")==0) op=OPMultiply;
	else if (strcmp(strOp,"/")==0) op=OPDivide;
	else if (strcmp(strOp,"program")==0) op=OPProgram;
	else op=OPSys;

	return op;
}

/**
 * 根据操作类型返回操作符
 *
 * @param	EOP op				操作符类型
 *
 */	
char *CSemantic::GetOPStr(EOP op)
{
	switch(op)
	{
	case OPJump://无条件跳转
		return (new char[]="j");
	case OPJumpLarger://大于时跳转
		return (new char[]="j>");
	case OPJumpLE://大于等于时跳转
		return (new char[]="j>=");
	case OPJumpNZero://不等于零时跳转
		return (new char[]="jnz");
	case OPJumpEqual://等于时跳转
		return (new char[]="j=");
	case OPJumpUEqual://不等于时跳转
		return (new char[]="j<>");
	case OPJumpSmaller://小于时跳转
		return (new char[]="j<");
	case OPjumpSE://小于等于时跳转
		return (new char[]="j<=");
	case OPLarger://大于
		return (new char[]=">");
	case OPSmaller://小于
		return (new char[]="<");
	case OPEqual://等于
		return (new char[]="=");
	case OPEvaluate://赋值
		return (new char[]=":=");
	case OPUnequal://不等于
		return (new char[]="<>");
	case OPPlus://加
		return (new char[]="+");
	case OPMinus://减
		return (new char[]="-");
	case OPMultiply://乘
		return (new char[]="*");
	case OPDivide://除
		return (new char[]="/");
	case OPProgram://程序开始标识
		return (new char[]="program");
	case OPSys://程序结束标识
		return (new char[]="sys");
	}
	return NULL;
}

/**
 * 处理变量说明语句
 *
 * @param	PTokenNode pToken			token字
 *
 */	
void CSemantic::Varst(PTokenNode pToken)
{
	PTokenNode stckToken[50];
	int top=0;
	const char *str=this->m_pWordCode[pToken->keycode];
	if (strcmp(this->m_pWordCode[pToken->keycode],"identifier")!=0)
	{
		this->AddError("var后面没有变量名！");
		this->NoUseCurToken();
	}
	for (int i=0;i<50;i++) stckToken[i]=NULL;
	Ids(pToken,stckToken,top);
	GetNextToken(pToken);
	if (strcmp(this->m_pWordCode[pToken->keycode],":")!=0)
	{
		this->AddError("期待:！");
		this->NoUseCurToken();
	}
	GetNextToken(pToken);
	if (strcmp(this->m_pWordCode[pToken->keycode],"integer")!=0 &&
		strcmp(this->m_pWordCode[pToken->keycode],"bool")!=0 &&
		strcmp(this->m_pWordCode[pToken->keycode],"char")!=0 &&
		strcmp(this->m_pWordCode[pToken->keycode],"real")!=0)
	{
		this->AddError("非法类型说明！");
		this->NoUseCurToken();
	}
	GetNextToken(pToken);
	if (strcmp(this->m_pWordCode[pToken->keycode],";")!=0)
	{
		this->AddError("类型说明后面无分号！");
		this->NoUseCurToken();
	}
	for (i=0;i<top && stckToken[i]!=NULL;i++)
	{
		this->FillTokenType(stckToken[i],this->m_pWordCode[stckToken[i]->keycode]);
	}
	GetNextToken(pToken);
	if (strcmp(this->m_pWordCode[pToken->keycode],"begin")!=0 &&
		strcmp(this->m_pWordCode[pToken->keycode],"identifier")!=0)
	{
		this->AddError("变量说明中无变量或未后随begin！");
		this->NoUseCurToken();
	}
	if (strcmp(this->m_pWordCode[pToken->keycode],"identifier")==0) Varst(pToken);
	if (strcmp(this->m_pWordCode[pToken->keycode],"begin")==0) this->NoUseCurToken();

}

/**
 * 把var语句中的变量表收集到stckToken中暂存，并回送给Varst过程
 *
 * @param	PTokenNode pToken			token字
 * @param	PTokenNode stckToken[]		变量栈
 * @param	int &top					变量栈顶指针
 *
 */	
void CSemantic::Ids(PTokenNode pToken,PTokenNode stckToken[],int &top)
{
	stckToken[top++]=pToken;
	GetNextToken(pToken);
	if (strcmp(this->m_pWordCode[pToken->keycode],",")!=0 &&
		strcmp(this->m_pWordCode[pToken->keycode],":")!=0)
	{
		this->AddError("var语句中缺少“,”或“:”，已插入！");
		this->NoUseCurToken();
	}
	else if (strcmp(this->m_pWordCode[pToken->keycode],",")==0)
	{
		GetNextToken(pToken);
		if (strcmp(this->m_pWordCode[pToken->keycode],"identifier")!=0)
		{
			this->AddError("var语句中缺少变量！");
			this->NoUseCurToken();
			return;
		}
		Ids(pToken,stckToken,top);
	}
	else
	{
		this->NoUseCurToken();
	}
}

/**
 * 处理复合语句中的语句串，即匹配产生式<STL>-><S>;<STL>|e,遇到end时返回
 *
 * @param	PTokenNode pToken			token字
 *
 */	
void CSemantic::Stl(PTokenNode pToken)
{ 
	PFSymbol SChain=NULL;
	const char *str=this->m_pWordCode[pToken->keycode];
	if (strcmp(str,"identifier")==0 ||
		strcmp(str,"if")==0 ||
		strcmp(str,"for")==0 ||
		strcmp(str,"begin")==0 ||
		strcmp(str,"while")==0 ||
		strcmp(str,"repeat")==0)
	{
		SChain=Stsort(pToken);
		GetNextToken(pToken);
		if (strcmp(this->m_pWordCode[pToken->keycode],";")!=0)
		{
			this->AddError("插入分号！");
			this->NoUseCurToken();
		}
		BackPatch(SChain,GetCurPFS());
		GetNextToken(pToken);
		Stl(pToken);
	}
	else if (strcmp(str,"end")!=0)
	{
		this->AddError("非法句首符或缺end！");
		this->NoUseCurToken();
	}
}

/**
 * 处理赋值语句及散转处理各控制语句
 *
 * @param	PTokenNode pToken			token字
 *
 * @return  PFSymbol					返回S·CHAIN
 *
 */	
PFSymbol CSemantic::Stsort(PTokenNode pToken)
{
	const char *str=this->m_pWordCode[pToken->keycode];
	PFSymbol SChain=NULL;
	PFSAG pFSAG=NULL,result=NULL;

	if (strcmp(str,"identifier")==0)
	{
		if(this->m_pSymbolTable->sSubTable[pToken->strId-1].type == NULL)
		{
            this->AddError("符号/变量 未定义！");
		}
		result=new FSAG;
		result->des=this->GetIDName(pToken);
		result->type=PT;
		result->value.token=pToken;

		GetNextToken(pToken);
		if (strcmp(this->m_pWordCode[pToken->keycode],":=")!=0)
		{
			this->AddError("缺少赋值符号！");
			this->NoUseCurToken();
		}
		
		GetNextToken(pToken);
		Gencode(this->GetOP(":="),this->Ae(pToken),NULL,result);
		SChain=NULL;
	}
	else if (strcmp(str,"for")==0)
	{
		this->AddError("暂时无法识别for语句块！");
		SChain=NULL;
	}
	else if (strcmp(str,"if")==0)
	{
		SChain=Ifs();
	}
	else if (strcmp(str,"while")==0)
	{
		this->AddError("暂时无法识别while语句块！");
		SChain=NULL;
	}
	else if (strcmp(str,"repeat")==0)
	{
		this->AddError("暂时无法识别repeat语句块！");
		SChain=NULL;
	}
	else if (strcmp(str,"begin")==0)
	{
		GetNextToken(pToken);
		Stl(pToken);
		SChain=NULL;
	}
	else
	{
		this->AddError("非法句首符！");
		this->NoUseCurToken();
	}

	return SChain;
}

/**
 * 处理if语句
 *
 * @return  PFSymbol					返回S·CHAIN
 *
 */	
PFSymbol CSemantic::Ifs()
{
	PTokenNode pToken=NULL;
	PFSymbol eTC=NULL,eFC=NULL,SChain1=NULL,SChain2=NULL,SChain=NULL,q=NULL,TChain=NULL;
	GetNextToken(pToken);
	Be(pToken,eTC,eFC);
	GetNextToken(pToken);
	if (strcmp(this->m_pWordCode[pToken->keycode],"then")!=0)
	{
		this->AddError("缺then！");
		this->NoUseCurToken();
	}
	BackPatch(eTC,GetCurPFS());
	GetNextToken(pToken);
	SChain1=Stsort(pToken);
	GetNextToken(pToken);
	if (strcmp(this->m_pWordCode[pToken->keycode],";")!=0)
	{
		this->AddError("缺少分号，已插入！");
		this->NoUseCurToken();
	}
	GetNextToken(pToken);
	if (strcmp(this->m_pWordCode[pToken->keycode],"else")==0)
	{
		q=GetCurPFS();
		Gencode(GetOP("j"),NULL,NULL,NULL);
		BackPatch(eFC,GetCurPFS());
		TChain=Merg(SChain1,q);
		GetNextToken(pToken);
		SChain2=Stsort(pToken);
		SChain=Merg(TChain,SChain2);
		return SChain;
	}
	else
	{
		return Merg(SChain1,eFC);
	}
}

/**
 * SIMPLE语法制导翻译程序主控模块。
 * 说明翻译用的全称量，文件管理，处理SYNDITER开头与结束工作，直到翻译PROGRAM产生式
 *
 */		
void CSemantic::Semantic()
{
	PTokenNode pToken=NULL;
	PFSAG pFSAG=NULL;
	const char *str;
	InitPFSymbol();
	GetNextToken(pToken);
	str=this->m_pWordCode[pToken->keycode];

	if (strcmp(str,"program")!=0)
	{
		this->NoUseCurToken();
		this->AddError("程序不以program开头！");
		this->m_pMorpheme->CloseSource();
		return;
	}
	GetNextToken(pToken);
	str=this->m_pWordCode[pToken->keycode];
	if (strcmp(str,"identifier")!=0)
	{
		this->NoUseCurToken();
		this->AddError("缺程序名标示符！");
		this->m_pMorpheme->CloseSource();
		return;
	}
	//FILL(ENTRY(TOKEN),'program');
	pFSAG=new FSAG;
	pFSAG->des=this->GetIDName(pToken);
	pFSAG->type=PT;
	pFSAG->value.token=pToken;
	Gencode(this->GetOP("program"),pFSAG,NULL,NULL);

	GetNextToken(pToken);
	str=this->m_pWordCode[pToken->keycode];
	if (strcmp(str,";")!=0)
	{
		this->NoUseCurToken();
		this->AddError("缺分号，已插入！");
	}

	//开始处理var语句
	GetNextToken(pToken);
	str=this->m_pWordCode[pToken->keycode];
	if (strcmp(str,"var")!=0)
	{
		this->NoUseCurToken();
		this->AddError("缺var！");
		this->m_pMorpheme->CloseSource();
		return;
	}
	GetNextToken(pToken);
	this->Varst(pToken);

	//处理各可执行语句
	GetNextToken(pToken);
	str=this->m_pWordCode[pToken->keycode];
	if (strcmp(str,"begin")!=0)
	{
		this->NoUseCurToken();
		this->AddError("缺begin！");
		this->m_pMorpheme->CloseSource();
		return;
	}
	this->Stl(pToken);

	GetNextToken(pToken);
	str=this->m_pWordCode[pToken->keycode];
	if (strcmp(str,";")!=0)
	{
		this->NoUseCurToken();
		this->AddError("缺程序结束符，已插入！");
	}
	Gencode(GetOP("sys"),NULL,NULL,NULL);
	
	this->m_pMorpheme->CloseSource();
}

/**
 * 回填pToken类型
 *
 * @param	PTokenNode pToken			token字
 * @param	const char *type			类型字符串
 *
 */	
void CSemantic::FillTokenType(PTokenNode pToken,const char *type)
{
	if (pToken==NULL || pToken->strId==0)
	{       
		return;
	}

	if (strcmp(type,"constint")==0)
	{
		this->m_pSymbolTable->sSubTable[pToken->strId-1].type=Integer;
	}
	else if (strcmp(type,"constfloat")==0)
	{
		this->m_pSymbolTable->sSubTable[pToken->strId-1].type=Real;
	}
	else if (strcmp(type,"constchar")==0)
	{
		this->m_pSymbolTable->sSubTable[pToken->strId-1].type=Char;
	}
	else if (strcmp(type,"bool")==0)
	{
		this->m_pSymbolTable->sSubTable[pToken->strId-1].type=Bool;
	}
}