/*
* Copyright (c) 1994, 2003, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package sun.tools.tree;
import sun.tools.java.*;
import sun.tools.asm.Assembler;
import sun.tools.asm.Label;
import java.util.Hashtable;
/**
* WARNING: The contents of this source file are not part of any
* supported API. Code that depends on them does so at its own risk:
* they are subject to change or removal without notice.
*/
public
class OrExpression extends BinaryLogicalExpression {
/**
* constructor
*/
public OrExpression(long where, Expression left, Expression right) {
super(OR, where, left, right);
}
/*
* Check an "or" expression.
*
* cvars is modified so that
* cvar.vsTrue indicates variables with a known value if
* either the left and right hand side isn true
* cvars.vsFalse indicates variables with a known value if
* both the left or right hand side are false
*/
public void checkCondition(Environment env, Context ctx, Vset vset,
Hashtable exp, ConditionVars cvars) {
// Find out when the left side is true/false
left.checkCondition(env, ctx, vset, exp, cvars);
left = convert(env, ctx, Type.tBoolean, left);
Vset vsTrue = cvars.vsTrue.copy();
Vset vsFalse = cvars.vsFalse.copy();
// Only look at the right side if the left side is false
right.checkCondition(env, ctx, vsFalse, exp, cvars);
right = convert(env, ctx, Type.tBoolean, right);
// cvars.vsFalse actually reports that both returned false
// cvars.vsTrue must be set back to either left side or the right
// side returning false;
cvars.vsTrue = cvars.vsTrue.join(vsTrue);
}
/**
* Evaluate
*/
Expression eval(boolean a, boolean b) {
return new BooleanExpression(where, a || b);
}
/**
* Simplify
*/
Expression simplify() {
if (right.equals(false)) {
return left;
}
if (left.equals(true)) {
return left;
}
if (left.equals(false)) {
return right;
}
if (right.equals(true)) {
// Preserve effects of left argument.
return new CommaExpression(where, left, right).simplify();
}
return this;
}
/**
* Code
*/
void codeBranch(Environment env, Context ctx, Assembler asm, Label lbl, boolean whenTrue) {
if (whenTrue) {
left.codeBranch(env, ctx, asm, lbl, true);
right.codeBranch(env, ctx, asm, lbl, true);
} else {
Label lbl2 = new Label();
left.codeBranch(env, ctx, asm, lbl2, true);
right.codeBranch(env, ctx, asm, lbl, false);
asm.add(lbl2);
}
}
}