1 files changed, 184 insertions, 0 deletions
diff --git a/plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/decompose/DominatorTreeExceptionFilter.java b/plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/decompose/DominatorTreeExceptionFilter.java
new file mode 100644
index 000000000000..c11d5bf0c67e
--- /dev/null
+++ b/plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/decompose/DominatorTreeExceptionFilter.java
@@ -0,0 +1,184 @@
+/*
+ * 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.decompose;
+
+import org.jetbrains.java.decompiler.modules.decompiler.StatEdge;
+import org.jetbrains.java.decompiler.modules.decompiler.stats.Statement;
+import org.jetbrains.java.decompiler.util.VBStyleCollection;
+
+import java.util.*;
+import java.util.Map.Entry;
+
+public class DominatorTreeExceptionFilter {
+
+  private Statement statement;
+
+  // idom, nodes
+  private Map<Integer, Set<Integer>> mapTreeBranches = new HashMap<Integer, Set<Integer>>();
+
+  // handler, range nodes
+  private Map<Integer, Set<Integer>> mapExceptionRanges = new HashMap<Integer, Set<Integer>>();
+
+  // handler, head dom
+  private Map<Integer, Integer> mapExceptionDoms = new HashMap<Integer, Integer>();
+
+  // statement, handler, exit nodes
+  private Map<Integer, Map<Integer, Integer>> mapExceptionRangeUniqueExit = new HashMap<Integer, Map<Integer, Integer>>();
+
+  private DominatorEngine domEngine;
+
+  public DominatorTreeExceptionFilter(Statement statement) {
+    this.statement = statement;
+  }
+
+  public void initialize() {
+
+    domEngine = new DominatorEngine(statement);
+    domEngine.initialize();
+
+    buildDominatorTree();
+
+    buildExceptionRanges();
+
+    buildFilter(statement.getFirst().id);
+
+    // free resources
+    mapTreeBranches.clear();
+    mapExceptionRanges.clear();
+  }
+
+  public boolean acceptStatementPair(Integer head, Integer exit) {
+
+    Map<Integer, Integer> filter = mapExceptionRangeUniqueExit.get(head);
+    for (Entry<Integer, Integer> entry : filter.entrySet()) {
+      if (!head.equals(mapExceptionDoms.get(entry.getKey()))) {
+        Integer filterExit = entry.getValue();
+        if (filterExit.intValue() == -1 || !filterExit.equals(exit)) {
+          return false;
+        }
+      }
+    }
+
+    return true;
+  }
+
+  private void buildDominatorTree() {
+
+    VBStyleCollection<Integer, Integer> orderedIDoms = domEngine.getOrderedIDoms();
+
+    List<Integer> lstKeys = orderedIDoms.getLstKeys();
+    for (int index = lstKeys.size() - 1; index >= 0; index--) {
+      Integer key = lstKeys.get(index);
+      Integer idom = orderedIDoms.get(index);
+
+      Set<Integer> set = mapTreeBranches.get(idom);
+      if (set == null) {
+        mapTreeBranches.put(idom, set = new HashSet<Integer>());
+      }
+      set.add(key);
+    }
+
+    Integer firstid = statement.getFirst().id;
+    mapTreeBranches.get(firstid).remove(firstid);
+  }
+
+  private void buildExceptionRanges() {
+
+    for (Statement stat : statement.getStats()) {
+      List<Statement> lstPreds = stat.getNeighbours(StatEdge.TYPE_EXCEPTION, Statement.DIRECTION_BACKWARD);
+      if (!lstPreds.isEmpty()) {
+
+        Set<Integer> set = new HashSet<Integer>();
+
+        for (Statement st : lstPreds) {
+          set.add(st.id);
+        }
+
+        mapExceptionRanges.put(stat.id, set);
+      }
+    }
+
+    mapExceptionDoms = buildExceptionDoms(statement.getFirst().id);
+  }
+
+  private Map<Integer, Integer> buildExceptionDoms(Integer id) {
+
+    Map<Integer, Integer> map = new HashMap<Integer, Integer>();
+
+    Set<Integer> children = mapTreeBranches.get(id);
+    if (children != null) {
+      for (Integer childid : children) {
+        Map<Integer, Integer> mapChild = buildExceptionDoms(childid);
+        for (Integer handler : mapChild.keySet()) {
+          map.put(handler, map.containsKey(handler) ? id : mapChild.get(handler));
+        }
+      }
+    }
+
+    for (Entry<Integer, Set<Integer>> entry : mapExceptionRanges.entrySet()) {
+      if (entry.getValue().contains(id)) {
+        map.put(entry.getKey(), id);
+      }
+    }
+
+    return map;
+  }
+
+
+  private void buildFilter(Integer id) {
+
+    Map<Integer, Integer> map = new HashMap<Integer, Integer>();
+
+    Set<Integer> children = mapTreeBranches.get(id);
+    if (children != null) {
+      for (Integer childid : children) {
+
+        buildFilter(childid);
+
+        Map<Integer, Integer> mapChild = mapExceptionRangeUniqueExit.get(childid);
+
+        for (Entry<Integer, Set<Integer>> entry : mapExceptionRanges.entrySet()) {
+
+          Integer handler = entry.getKey();
+          Set<Integer> range = entry.getValue();
+
+          if (range.contains(id)) {
+
+            Integer exit = null;
+
+            if (!range.contains(childid)) {
+              exit = childid;
+            }
+            else {
+              // exit = map.containsKey(handler)?-1:mapChild.get(handler); FIXME: Eclipse bug?
+              exit = map.containsKey(handler) ? new Integer(-1) : mapChild.get(handler);
+            }
+
+            if (exit != null) {
+              map.put(handler, exit);
+            }
+          }
+        }
+      }
+    }
+
+    mapExceptionRangeUniqueExit.put(id, map);
+  }
+
+  public DominatorEngine getDomEngine() {
+    return domEngine;
+  }
+}