Tue, 26 May 2015 11:03:40 +0100
8055963: Inference failure with nested invocation
Summary: Revise heuristics to force eager instantiation of return inference vars
Reviewed-by: vromero
1.1 --- a/src/share/classes/com/sun/tools/javac/comp/Infer.java Thu May 21 11:14:23 2015 -0700 1.2 +++ b/src/share/classes/com/sun/tools/javac/comp/Infer.java Tue May 26 11:03:40 2015 +0100 1.3 @@ -315,11 +315,9 @@ 1.4 for (Type aLowerBound : from.getBounds(InferenceBound.LOWER)) { 1.5 for (Type anotherLowerBound : from.getBounds(InferenceBound.LOWER)) { 1.6 if (aLowerBound != anotherLowerBound && 1.7 - commonSuperWithDiffParameterization(aLowerBound, anotherLowerBound)) { 1.8 - /* self comment check if any lower bound may be and undetVar, 1.9 - * in that case the result of this call may be a false positive. 1.10 - * Should this be restricted to non free types? 1.11 - */ 1.12 + !inferenceContext.free(aLowerBound) && 1.13 + !inferenceContext.free(anotherLowerBound) && 1.14 + commonSuperWithDiffParameterization(aLowerBound, anotherLowerBound)) { 1.15 return generateReferenceToTargetConstraint(tree, from, to, 1.16 resultInfo, inferenceContext); 1.17 }
2.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 2.2 +++ b/test/tools/javac/generics/inference/8055963/T8055963.java Tue May 26 11:03:40 2015 +0100 2.3 @@ -0,0 +1,41 @@ 2.4 +/* 2.5 + * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. 2.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 2.7 + * 2.8 + * This code is free software; you can redistribute it and/or modify it 2.9 + * under the terms of the GNU General Public License version 2 only, as 2.10 + * published by the Free Software Foundation. Oracle designates this 2.11 + * particular file as subject to the "Classpath" exception as provided 2.12 + * by Oracle in the LICENSE file that accompanied this code. 2.13 + * 2.14 + * This code is distributed in the hope that it will be useful, but WITHOUT 2.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 2.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 2.17 + * version 2 for more details (a copy is included in the LICENSE file that 2.18 + * accompanied this code). 2.19 + * 2.20 + * You should have received a copy of the GNU General Public License version 2.21 + * 2 along with this work; if not, write to the Free Software Foundation, 2.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 2.23 + * 2.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 2.25 + * or visit www.oracle.com if you need additional information or have any 2.26 + * questions. 2.27 + */ 2.28 + 2.29 +/** 2.30 + * @test 2.31 + * @bug 8055963 2.32 + * @summary Inference failure with nested invocation 2.33 + * @compile T8055963.java 2.34 + */ 2.35 +class T8055963 { 2.36 + 2.37 + static class C<T> {} 2.38 + 2.39 + <T> T choose(T first, T second) { return null; } 2.40 + 2.41 + void test() { 2.42 + C<String> cs = choose(new C<String>(), new C<>()); 2.43 + } 2.44 +}