unary.java

来自「A compiler for a subset of the Java lang」· Java 代码 · 共 37 行

package inter;
import lexer.*; import symbols.*;

public class Unary extends Op {

   public Expr expr;

   public Unary(Token tok, Expr x) {    // handles minus, for ! see Not
      super(tok, null);  expr = x;
      type = Type.max(Type.Int, expr.type);
      if (type == null ) error("type error");
   }

   public Expr gen() { return new Unary(op, expr.reduce()); }

   public String toString()
   {
	   expr.toString();
	   if(expr.type == Type.Int)
	   {
		   return "ineg " + expr.lvaIdx + "\n";
	   }
	   else if(expr.type == Type.Float)
	   {
		   return "fneg " + expr.lvaIdx + "\n";
	   }
	   else if(expr.type == Type.Complex)
	   {
		   return "fneg\n" + "fstore " + LocalVarArray.curlength + "\n"
		   		+ "fneg\n" + "fload " + LocalVarArray.curlength + "\n";
	   }
	   else {
		   return null;
	   }
   }
}