1 files changed, 167 insertions, 0 deletions
diff --git a/plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/vars/VarVersionsGraph.java b/plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/vars/VarVersionsGraph.java
new file mode 100644
index 000000000000..f839a05819df
--- /dev/null
+++ b/plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/vars/VarVersionsGraph.java
@@ -0,0 +1,167 @@
+/*
+ * Copyright 2000-2014 JetBrains s.r.o.
+ *
+ * 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 org.jetbrains.java.decompiler.modules.decompiler.vars;
+
+import org.jetbrains.java.decompiler.modules.decompiler.decompose.GenericDominatorEngine;
+import org.jetbrains.java.decompiler.modules.decompiler.decompose.IGraph;
+import org.jetbrains.java.decompiler.modules.decompiler.decompose.IGraphNode;
+import org.jetbrains.java.decompiler.util.VBStyleCollection;
+
+import java.util.*;
+
+
+public class VarVersionsGraph {
+
+  public int counter = 0;
+
+  public VBStyleCollection<VarVersionNode, VarVersionPaar> nodes = new VBStyleCollection<VarVersionNode, VarVersionPaar>();
+
+  private GenericDominatorEngine engine;
+
+  public VarVersionNode createNode(VarVersionPaar ver) {
+    VarVersionNode node;
+    nodes.addWithKey(node = new VarVersionNode(ver.var, ver.version), ver);
+    return node;
+  }
+
+  public void addNodes(Collection<VarVersionNode> colnodes, Collection<VarVersionPaar> colpaars) {
+    nodes.addAllWithKey(colnodes, colpaars);
+  }
+
+  public boolean isDominatorSet(VarVersionNode node, HashSet<VarVersionNode> domnodes) {
+
+    if (domnodes.size() == 1) {
+      return engine.isDominator(node, domnodes.iterator().next());
+    }
+    else {
+
+      HashSet<VarVersionNode> marked = new HashSet<VarVersionNode>();
+
+      if (domnodes.contains(node)) {
+        return true;
+      }
+
+      LinkedList<VarVersionNode> lstNodes = new LinkedList<VarVersionNode>();
+      lstNodes.add(node);
+
+      while (!lstNodes.isEmpty()) {
+
+        VarVersionNode nd = lstNodes.remove(0);
+        if (marked.contains(nd)) {
+          continue;
+        }
+        else {
+          marked.add(nd);
+        }
+
+        if (nd.preds.isEmpty()) {
+          return false;
+        }
+
+        for (VarVersionEdge edge : nd.preds) {
+          VarVersionNode pred = edge.source;
+          if (!marked.contains(pred) && !domnodes.contains(pred)) {
+            lstNodes.add(pred);
+          }
+        }
+      }
+    }
+
+    return true;
+  }
+
+  public void initDominators() {
+
+    final HashSet<VarVersionNode> roots = new HashSet<VarVersionNode>();
+
+    for (VarVersionNode node : nodes) {
+      if (node.preds.isEmpty()) {
+        roots.add(node);
+      }
+    }
+
+    engine = new GenericDominatorEngine(new IGraph() {
+      public List<? extends IGraphNode> getReversePostOrderList() {
+        return getReversedPostOrder(roots);
+      }
+
+      public Set<? extends IGraphNode> getRoots() {
+        return new HashSet<IGraphNode>(roots);
+      }
+    });
+
+    engine.initialize();
+  }
+
+  private static LinkedList<VarVersionNode> getReversedPostOrder(Collection<VarVersionNode> roots) {
+
+    LinkedList<VarVersionNode> lst = new LinkedList<VarVersionNode>();
+    HashSet<VarVersionNode> setVisited = new HashSet<VarVersionNode>();
+
+    for (VarVersionNode root : roots) {
+
+      LinkedList<VarVersionNode> lstTemp = new LinkedList<VarVersionNode>();
+      addToReversePostOrderListIterative(root, lstTemp, setVisited);
+
+      lst.addAll(lstTemp);
+    }
+
+    return lst;
+  }
+
+  private static void addToReversePostOrderListIterative(VarVersionNode root, List<VarVersionNode> lst, HashSet<VarVersionNode> setVisited) {
+
+    HashMap<VarVersionNode, List<VarVersionEdge>> mapNodeSuccs = new HashMap<VarVersionNode, List<VarVersionEdge>>();
+
+    LinkedList<VarVersionNode> stackNode = new LinkedList<VarVersionNode>();
+    LinkedList<Integer> stackIndex = new LinkedList<Integer>();
+
+    stackNode.add(root);
+    stackIndex.add(0);
+
+    while (!stackNode.isEmpty()) {
+
+      VarVersionNode node = stackNode.getLast();
+      int index = stackIndex.removeLast();
+
+      setVisited.add(node);
+
+      List<VarVersionEdge> lstSuccs = mapNodeSuccs.get(node);
+      if (lstSuccs == null) {
+        mapNodeSuccs.put(node, lstSuccs = new ArrayList<VarVersionEdge>(node.succs));
+      }
+
+      for (; index < lstSuccs.size(); index++) {
+        VarVersionNode succ = lstSuccs.get(index).dest;
+
+        if (!setVisited.contains(succ)) {
+          stackIndex.add(index + 1);
+
+          stackNode.add(succ);
+          stackIndex.add(0);
+
+          break;
+        }
+      }
+
+      if (index == lstSuccs.size()) {
+        lst.add(0, node);
+
+        stackNode.removeLast();
+      }
+    }
+  }
+}