com.google.gwt.dev.jjs.ast.JCastOperation Maven / Gradle / Ivy
/*
* Copyright 2007 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.dev.jjs.ast;
import com.google.gwt.dev.jjs.SourceInfo;
/**
* Java cast expression.
*/
public class JCastOperation extends JExpression {
private JType castType;
private JExpression expr;
public JCastOperation(SourceInfo info, JType castType, JExpression expr) {
super(info);
this.castType = castType;
this.expr = expr;
}
public JType getCastType() {
return castType;
}
public JExpression getExpr() {
return expr;
}
@Override
public JType getType() {
if (!expr.getType().canBeNull() && !castType.isNullType()) {
// Strengthen type to non null unless it has been determined that the type is not instantiable
// (and that is reflected by replacing the cast type by the null type).
return castType.strengthenToNonNull();
}
return castType;
}
@Override
public boolean hasSideEffects() {
if (castType.isPrimitiveType()) {
// Primitive casts do not throw and only have side effects if the expression has side effects.
return expr.hasSideEffects();
}
// Any live non-primitive cast operations might throw a ClassCastException
//
// TODO: revisit this when we support the concept of whether something
// can/must complete normally!
return true;
}
/**
* Resolve an external reference during AST stitching.
*/
public void resolve(JType newType) {
assert newType.replaces(castType);
castType = newType;
}
@Override
public void traverse(JVisitor visitor, Context ctx) {
if (visitor.visit(this, ctx)) {
expr = visitor.accept(expr);
}
visitor.endVisit(this, ctx);
}
}