| /* |
| * 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.copy; |
| |
| import com.google.gwt.dev.jjs.SourceInfo; |
| import com.google.gwt.dev.jjs.ast.Context; |
| import com.google.gwt.dev.jjs.ast.JLocal; |
| import com.google.gwt.dev.jjs.ast.JLocalRef; |
| import com.google.gwt.dev.jjs.ast.JModVisitor; |
| import com.google.gwt.dev.jjs.ast.JNode; |
| import com.google.gwt.dev.jjs.ast.JParameter; |
| import com.google.gwt.dev.jjs.ast.JParameterRef; |
| import com.google.gwt.dev.jjs.ast.JVariable; |
| import com.google.gwt.dev.jjs.ast.JVariableRef; |
| import com.google.gwt.dev.jjs.impl.gflow.AssumptionMap; |
| import com.google.gwt.dev.jjs.impl.gflow.AssumptionUtil; |
| import com.google.gwt.dev.jjs.impl.gflow.IntegratedFlowFunction; |
| 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.CfgEdge; |
| import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgNode; |
| 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; |
| import com.google.gwt.dev.util.Preconditions; |
| |
| /** |
| * Integrated flow function for CopyAnalysis. Tries to replace copied vars with |
| * original ones. |
| */ |
| public class CopyIntegratedFlowFunction implements |
| IntegratedFlowFunction<CfgNode<?>, CfgEdge, CfgTransformer, Cfg, CopyAssumption> { |
| private final class CopyTransformation implements |
| Transformation<CfgTransformer, Cfg> { |
| private final CfgNode<?> node; |
| private final JVariable original; |
| private final Cfg graph; |
| |
| private CopyTransformation(CfgNode<?> node, JVariable original, |
| Cfg graph) { |
| this.node = node; |
| this.original = original; |
| this.graph = graph; |
| } |
| |
| public CfgTransformer getGraphTransformer() { |
| return new CfgTransformer() { |
| public boolean transform(final CfgNode<?> node, Cfg cfgGraph) { |
| JModVisitor visitor = new JModVisitor() { |
| @Override |
| public void endVisit(JNode x, Context ctx) { |
| if (x == node.getJNode()) { |
| ctx.replaceMe(createRef(x.getSourceInfo(), original)); |
| } |
| } |
| }; |
| CfgNode<?> parentNode = node.getParent(); |
| JNode parentJNode = parentNode.getJNode(); |
| visitor.accept(parentJNode); |
| Preconditions.checkState(visitor.didChange()); |
| return true; |
| } |
| }; |
| } |
| |
| public Cfg getNewSubgraph() { |
| CfgReadNode newNode = new CfgReadNode(node.getParent(), |
| createRef(node.getJNode().getSourceInfo(), original)); |
| return CfgUtil.createSingleNodeReplacementGraph(graph, node, newNode); |
| } |
| |
| @Override |
| public String toString() { |
| return "CopyTransformation(" + node + "," + original + ")"; |
| } |
| |
| private JVariableRef createRef(SourceInfo sourceInfo, JVariable variable) { |
| if (variable instanceof JLocal) { |
| return new JLocalRef(sourceInfo, (JLocal) variable); |
| } else if (variable instanceof JParameter) { |
| return new JParameterRef(sourceInfo, (JParameter) variable); |
| } |
| throw new IllegalArgumentException("Unsupported variable: " + |
| variable.getClass()); |
| } |
| } |
| |
| private static final CopyFlowFunction FLOW_FUNCTION = new CopyFlowFunction(); |
| |
| public Transformation<CfgTransformer, Cfg> |
| interpretOrReplace(final CfgNode<?> node, final Cfg graph, |
| AssumptionMap<CfgEdge, CopyAssumption> assumptionMap) { |
| CopyAssumption in = AssumptionUtil.join( |
| graph.getInEdges(node), assumptionMap); |
| |
| if (in != null && node instanceof CfgReadNode) { |
| JVariable v = ((CfgReadNode) node).getTarget(); |
| final JVariable original = in.getOriginal(v); |
| Preconditions.checkState(v != original, |
| "Variable is a copy of itself: %s", v); |
| if (original != null) { |
| return new CopyTransformation(node, original, graph); |
| } |
| } |
| |
| FLOW_FUNCTION.interpret(node, graph, assumptionMap); |
| return null; |
| } |
| } |