changeset 3248:66a7e82d10a4

8141613: Compiler fails to infer generic type Summary: Repeated capture of same expression leads to erroneous inference constraints Reviewed-by: vromero
author mcimadamore
date Tue, 10 Nov 2015 11:49:14 +0000
parents 424fba7cabb0
children 2a83d2947323
files src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Infer.java test/tools/javac/generics/inference/8141613/T8141613.java
diffstat 3 files changed, 57 insertions(+), 1 deletions(-) [+]
line wrap: on
line diff
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java	Mon Nov 09 16:03:30 2015 +0000
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java	Tue Nov 10 11:49:14 2015 +0000
@@ -1890,7 +1890,8 @@
 
             // Check that value of resulting type is admissible in the
             // current context.  Also, capture the return type
-            result = check(tree, capture(restype), KindSelector.VAL, resultInfo);
+            Type capturedRes = resultInfo.checkContext.inferenceContext().cachedCapture(tree, restype, true);
+            result = check(tree, capturedRes, KindSelector.VAL, resultInfo);
         }
         chk.validate(tree.typeargs, localEnv);
     }
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Infer.java	Mon Nov 09 16:03:30 2015 +0000
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Infer.java	Tue Nov 10 11:49:14 2015 +0000
@@ -372,6 +372,9 @@
                         resultInfo, inferenceContext);
                 }
             }
+        } else if (rsInfoInfContext.free(resultInfo.pt)) {
+            //propagation - cache captured vars
+            qtype = inferenceContext.asUndetVar(rsInfoInfContext.cachedCapture(tree, from, false));
         }
         Assert.check(allowGraphInference || !rsInfoInfContext.free(to),
                 "legacy inference engine cannot handle constraints on both sides of a subtyping assertion");
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/tools/javac/generics/inference/8141613/T8141613.java	Tue Nov 10 11:49:14 2015 +0000
@@ -0,0 +1,52 @@
+/*
+ * 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 8141613
+ * @summary Compiler fails to infer generic type
+ * @compile T8141613.java
+ */
+class T8141613 {
+
+    static class Sub<V, L> implements Sup<V, L> {
+        Sub(Bar<V> barv) { }
+    }
+
+    interface Bar<V> { }
+
+    interface Sup<V, L> { }
+
+    <L> void test() {
+        Sup<?, L> res1 = makeSub(makeBar());
+        Sup<?, L> res2 = new Sub<>(makeBar());
+    }
+
+    <S, U> Sub<S, U> makeSub(Bar<S> bars) { return null; }
+
+    <B> Bar<?> makeBar() {
+        return null;
+    }
+}