/*
* @(#)BooleanExpression.java 1.15 95/11/12 Arthur van Hoff
*
* Copyright (c) 1994 Sun Microsystems, Inc. All Rights Reserved.
*
* Permission to use, copy, modify, and distribute this software
* and its documentation for NON-COMMERCIAL purposes and without
* fee is hereby granted provided that this copyright notice
* appears in all copies. Please refer to the file "copyright.html"
* for further important copyright and licensing information.
*
* SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
* THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
* TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
* PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
* ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
* DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
*/
package sun.tools.tree;
import sun.tools.java.*;
import sun.tools.asm.Assembler;
import sun.tools.asm.Label;
import java.io.PrintStream;
import java.util.Hashtable;
public
class BooleanExpression extends ConstantExpression {
boolean value;
/**
* Constructor
*/
public BooleanExpression(int where, boolean value) {
super(BOOLEANVAL, where, Type.tBoolean);
this.value = value;
}
/**
* Get the value
*/
public Object getValue() {
return new Integer(value ? 1 : 0);
}
/**
* Check if the expression is equal to a value
*/
public boolean equals(boolean b) {
return value == b;
}
/**
* Check if the expression is equal to its default static value
*/
public boolean equalsDefault() {
return !value;
}
/*
* Check a "not" expression.
*
* cvars is modified so that
* cvar.vsTrue indicates variables with a known value if
* the expression is true.
* cvars.vsFalse indicates variables with a known value if
* the expression is false
*
* For constant expressions, set the side that corresponds to our
* already known value to vset. Set the side that corresponds to the
* other way to "impossible"
*/
public void checkCondition(Environment env, Context ctx,
long vset, Hashtable exp, ConditionVars cvars) {
if (value) {
cvars.vsFalse = -1;
cvars.vsTrue = vset;
} else {
cvars.vsFalse = vset;
cvars.vsTrue = -1;
}
}
/**
* Code
*/
void codeBranch(Environment env, Context ctx, Assembler asm, Label lbl, boolean whenTrue) {
if (value == whenTrue) {
asm.add(where, opc_goto, lbl);
}
}
public void codeValue(Environment env, Context ctx, Assembler asm) {
asm.add(where, opc_ldc, new Integer(value ? 1 : 0));
}
/**
* Print
*/
public void print(PrintStream out) {
out.print(value ? "true" : "false");
}
}