expuminus.java

来自「用Java实现的编译器。把源代码编译成SPARC汇编程序」· Java 代码 · 共 40 行

/**
*This class is used for expressions using the unary minus operation. 
*This class extends the Exp abstract class
**/
package CatDecaf.IR;
import CatDecaf.Utilities.*;
import parser.*;
import CatDecaf.Utilities.Debugger.*;
import java6035.tools.ASM.*;
public class ExpUMinus extends Exp{
	public Exp exp_;
	public int type;
	public SPARCRegister reg;
	public ExpUMinus(Exp e1){
		type = sym.INT;
		if (e1.noError() && e1.getType()!=sym.INT) 
			ErrorLog.log("Integer type expected after Uminus '-'");		
		exp_ = e1;
		reg = null;
	}
	public int getType(){return type;}	
	public boolean noError(){return !(type==sym.ERROR_TYPE);}
	public SPARCRegister getReg(){
		return reg;
	}

	public void setReg(SPARCRegister r){
		reg=r;
		reg.status = 1;
	}
	public void releaseReg(){
		reg.status = 0;
		reg= null;
	}	
	
	public void accept(Visitor v){
		v.visit(this);
    }
}