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
--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/util/GraphUtils.java Wed Jul 05 20:42:39 2017 +0200
+++ b/langtools/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<>();
- ListBuffer<N> stack = 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;
- for (N node: nodes) {
- if (node.index == -1) {
- index += tarjan(node, index, stack, cycles);
+
+ /** 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<>();
+
+ 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/langtools/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;
+ }
+}