/*
* 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.constants;
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.CfgReadNode;
import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgTransformer;
import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgUtil;
/**
* Transformation that replaces read node with Nop node in graph, and replaces
* JNode by constant value.
*/
final class FoldConstantsTransformation implements
Transformation<CfgTransformer, Cfg> {
private final ConstantsAssumption assumption;
private final Cfg graph;
private final CfgReadNode node;
FoldConstantsTransformation(ConstantsAssumption assumptions,
CfgReadNode node, Cfg graph) {
this.assumption = assumptions;
this.node = node;
this.graph = graph;
}
@Override
public CfgTransformer getGraphTransformer() {
return new FoldConstantTransformer(assumption, node);
}
@Override
public Cfg getNewSubgraph() {
CfgNode<?> newNode = new CfgNopNode(node.getParent(), node.getJNode());
return CfgUtil.createSingleNodeReplacementGraph(graph, node, newNode);
}
@Override
public String toString() {
return "FoldConstantsTransformation(node=" + node +
", assumptions=" + assumption + ")";
}
}