/*
* Copyright 2008 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.impl.gflow.unreachable;
import com.google.gwt.dev.jjs.ast.JBlock;
import com.google.gwt.dev.jjs.ast.JNode;
import com.google.gwt.dev.jjs.impl.gflow.TransformationFunction.Transformation;
import com.google.gwt.dev.jjs.impl.gflow.cfg.Cfg;
import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgNode;
import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgNopNode;
import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgStatementNode;
import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgTransformer;
import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgUtil;
import com.google.gwt.thirdparty.guava.common.base.Preconditions;
class DeleteNodeTransformation implements Transformation<CfgTransformer, Cfg> {
private final Cfg graph;
private final CfgNode<?> node;
public DeleteNodeTransformation(Cfg graph, CfgNode<?> node) {
this.graph = graph;
this.node = node;
}
@Override
public CfgTransformer getGraphTransformer() {
return new CfgTransformer() {
@Override
public boolean transform(CfgNode<?> node, Cfg cfgGraph) {
if (node.getParent() == null) {
throw new IllegalArgumentException("Null parent in " + node);
}
JNode jNode = node.getJNode();
if (node instanceof CfgStatementNode<?> && !(jNode instanceof JBlock)) {
// Don't try deleting inner expressions and blocks.
// Delete statements only.
CfgNode<?> parentNode = CfgUtil.findParentOfContainingStatement(node);
JNode parentJNode = parentNode.getJNode();
boolean didChange = DeleteNodeVisitor.delete(jNode, parentJNode);
Preconditions.checkState(didChange,
"Can't delete %s (%s) from under %s (%s)", jNode, node,
parentJNode, parentNode);
return true;
}
return false;
}
};
}
@Override
public Cfg getNewSubgraph() {
CfgNode<?> newNode = new CfgNopNode(node.getParent(), node.getJNode());
return CfgUtil.createSingleNodeReplacementGraph(graph, node, newNode);
}
@Override
public String toString() {
return "DeleteNodeTransformation(node=" + node + ")";
}
}