com.google.gwt.dev.jjs.impl.gflow.cfg.CfgUtil Maven / Gradle / Ivy
/*
* Copyright 2009 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.cfg;
import com.google.gwt.dev.jjs.ast.JStatement;
/**
* Utilities for working with Cfg.
*/
public class CfgUtil {
public static void addGraphEdges(Cfg originalGraph, CfgNode originalNode,
CfgNode newStartNode, CfgNode newEndNode, Cfg newSubgraph) {
for (int i = 0; i < originalGraph.getInEdges(originalNode).size(); ++i) {
CfgEdge edge = new CfgEdge();
newSubgraph.addIn(newStartNode, edge);
newSubgraph.addGraphInEdge(edge);
}
for (CfgEdge e : originalGraph.getOutEdges(originalNode)) {
CfgEdge edge = new CfgEdge(e.getRole());
newSubgraph.addOut(newEndNode, edge);
newSubgraph.addGraphOutEdge(edge);
}
}
/**
* Create a graph with single node. Resulting graph will have same amount of
* input/output edges as the original node.
*/
public static Cfg createSingleNodeReplacementGraph(
Cfg originalGraph,
CfgNode originalNode,
CfgNode newNode) {
Cfg newSubgraph = new Cfg();
newSubgraph.addNode(newNode);
addGraphEdges(originalGraph, originalNode, newNode, newNode, newSubgraph);
return newSubgraph;
}
/**
* Find CFG node corresponding to the nearest statement, containing the AST
* node of the passed node.
*/
public static CfgNode findContainingStatement(CfgNode node) {
while (!(node.getJNode() instanceof JStatement)) {
node = node.getParent();
}
return node;
}
/**
* Find parent of containing statement.
*/
public static CfgNode findParentOfContainingStatement(CfgNode node) {
CfgNode stmtNode = findContainingStatement(node);
CfgNode result = stmtNode;
while (stmtNode.getJNode() == result.getJNode()) {
result = result.getParent();
if (result == null) {
return null;
}
// Preconditions.checkNotNull(result, "Can't find parent for: %s", node);
}
return result;
}
private CfgUtil() {
//
}
}