changeset 2989:70c852df047c

8130304: Inference: NodeNotFoundException thrown with deep generic method call chain Summary: Bug in Tarjan implementation is generating node ids which can overflow 32 bits Reviewed-by: vromero
author mcimadamore
date Fri, 17 Jul 2015 12:46:07 +0100
parents 02681b7c4232
children 827915d1e55e
files src/jdk.compiler/share/classes/com/sun/tools/javac/util/GraphUtils.java test/tools/javac/generics/inference/8130304/T8130304.java
diffstat 2 files changed, 121 insertions(+), 23 deletions(-) [+]
line wrap: on
line diff
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/util/GraphUtils.java	Thu Jul 16 19:31:01 2015 -0700
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/util/GraphUtils.java	Fri Jul 17 12:46:07 2015 +0100
@@ -151,32 +151,57 @@
      * directed graph in linear time. Works on TarjanNode.
      */
     public static <D, N extends TarjanNode<D, N>> List<? extends List<? extends N>> tarjan(Iterable<? extends N> nodes) {
-        ListBuffer<List<N>> cycles = new ListBuffer<>();
+        Tarjan<D, N> tarjan = new Tarjan<>();
+        return tarjan.findSCC(nodes);
+    }
+    //where
+    private static class Tarjan<D, N extends TarjanNode<D, N>> {
+
+        /** Unique node identifier. */
+        int index = 0;
+
+        /** List of SCCs found fso far. */
+        ListBuffer<List<N>> sccs = new ListBuffer<>();
+
+        /** Stack of all reacheable nodes from given root. */
         ListBuffer<N> stack = new ListBuffer<>();
-        int index = 0;
-        for (N node: nodes) {
-            if (node.index == -1) {
-                index += tarjan(node, index, stack, cycles);
+
+        private List<? extends List<? extends N>> findSCC(Iterable<? extends N> nodes) {
+            for (N node : nodes) {
+                if (node.index == -1) {
+                    findSCC(node);
+                }
+            }
+            return sccs.toList();
+        }
+
+        private void findSCC(N v) {
+            visitNode(v);
+            for (N n: v.getAllDependencies()) {
+                if (n.index == -1) {
+                    //it's the first time we see this node
+                    findSCC(n);
+                    v.lowlink = Math.min(v.lowlink, n.lowlink);
+                } else if (stack.contains(n)) {
+                    //this node is already reachable from current root
+                    v.lowlink = Math.min(v.lowlink, n.index);
+                }
+            }
+            if (v.lowlink == v.index) {
+                //v is the root of a SCC
+                addSCC(v);
             }
         }
-        return cycles.toList();
-    }
 
-    private static <D, N extends TarjanNode<D, N>> int tarjan(N v, int index, ListBuffer<N> stack, ListBuffer<List<N>> cycles) {
-        v.index = index;
-        v.lowlink = index;
-        index++;
-        stack.prepend(v);
-        v.active = true;
-        for (N n: v.getAllDependencies()) {
-            if (n.index == -1) {
-                tarjan(n, index, stack, cycles);
-                v.lowlink = Math.min(v.lowlink, n.lowlink);
-            } else if (stack.contains(n)) {
-                v.lowlink = Math.min(v.lowlink, n.index);
-            }
+        private void visitNode(N n) {
+            n.index = index;
+            n.lowlink = index;
+            index++;
+            stack.prepend(n);
+            n.active = true;
         }
-        if (v.lowlink == v.index) {
+
+        private void addSCC(N v) {
             N n;
             ListBuffer<N> cycle = new ListBuffer<>();
             do {
@@ -184,9 +209,8 @@
                 n.active = false;
                 cycle.add(n);
             } while (n != v);
-            cycles.add(cycle.toList());
+            sccs.add(cycle.toList());
         }
-        return index;
     }
 
     /**
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/tools/javac/generics/inference/8130304/T8130304.java	Fri Jul 17 12:46:07 2015 +0100
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @bug 8130304
+ * @summary Inference: NodeNotFoundException thrown with deep generic method call chain
+ * @compile T8130304.java
+ */
+class T8130304 {
+
+    void test() {
+        outer(
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner(),
+            inner());
+    }
+
+    <T> void outer(T... ts) { }
+
+    <T,V,W extends V> T inner() {
+        return null;
+    }
+}