Tue, 14 May 2013 11:11:09 -0700
8012556: Implement lambda methods on interfaces as static
8006140: Javac NPE compiling Lambda expression on initialization expression of static field in interface
Summary: Lambdas occurring in static contexts or those not needing instance information should be generated into static methods. This has long been the case for classes. However, as a work-around to the lack of support for statics on interfaces, interface lambda methods have been generated into default methods. For lambdas in interface static contexts (fields and static methods) this causes an NPE in javac because there is no 'this'. MethodHandles now support static methods on interfaces. This changeset allows lambda methods to be generated as static interface methods. An existing bug in Hotspot (8013875) is exposed in a test when the "-esa" flag is used. This test and another test that already exposed this bug have been marked with @ignore.
Reviewed-by: mcimadamore
1 /*
2 * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
24 /*
25 * @test
26 * @bug 8003280
27 * @summary Add lambda tests
28 * Check that self/forward references from lambda expressions behave
29 * consistently w.r.t. local inner classes
30 */
32 import com.sun.source.util.JavacTask;
33 import java.net.URI;
34 import java.util.Arrays;
35 import javax.tools.Diagnostic;
36 import javax.tools.JavaCompiler;
37 import javax.tools.JavaFileObject;
38 import javax.tools.SimpleJavaFileObject;
39 import javax.tools.StandardJavaFileManager;
40 import javax.tools.ToolProvider;
42 public class TestSelfRef {
44 static int checkCount = 0;
46 enum RefKind {
47 SELF_LAMBDA("SAM s = x->{ System.out.println(s); };", true, false),
48 FORWARD_LAMBDA("SAM s = x->{ System.out.println(f); };\nObject f = null;", false, true),
49 SELF_ANON("Object s = new Object() { void test() { System.out.println(s); } };", true, false),
50 FORWARD_ANON("Object s = new Object() { void test() { System.out.println(f); } }; Object f = null;", false, true);
52 String refStr;
53 boolean selfRef;
54 boolean forwardRef;
56 private RefKind(String refStr, boolean selfRef, boolean forwardRef) {
57 this.refStr = refStr;
58 this.selfRef = selfRef;
59 this.forwardRef = forwardRef;
60 }
61 }
63 enum EnclosingKind {
64 TOPLEVEL("class C { #S }"),
65 MEMBER_INNER("class Outer { class C { #S } }"),
66 NESTED_INNER("class Outer { static class C { #S } }");
68 String enclStr;
70 private EnclosingKind(String enclStr) {
71 this.enclStr = enclStr;
72 }
73 }
75 enum InnerKind {
76 NONE("#R"),
77 LOCAL_NONE("class Local { #R }"),
78 LOCAL_MTH("class Local { void test() { #R } }"),
79 ANON_NONE("new Object() { #R };"),
80 ANON_MTH("new Object() { void test() { #R } };");
82 String innerStr;
84 private InnerKind(String innerStr) {
85 this.innerStr = innerStr;
86 }
88 boolean inMethodContext(SiteKind sk) {
89 switch (this) {
90 case LOCAL_MTH:
91 case ANON_MTH: return true;
92 case NONE: return sk != SiteKind.NONE;
93 default:
94 return false;
95 }
96 }
97 }
99 enum SiteKind {
100 NONE("#I"),
101 STATIC_INIT("static { #I }"),
102 INSTANCE_INIT("{ #I }"),
103 CONSTRUCTOR("C() { #I }"),
104 METHOD("void test() { #I }");
106 String siteStr;
108 private SiteKind(String siteStr) {
109 this.siteStr = siteStr;
110 }
111 }
113 public static void main(String... args) throws Exception {
115 //create default shared JavaCompiler - reused across multiple compilations
116 JavaCompiler comp = ToolProvider.getSystemJavaCompiler();
117 StandardJavaFileManager fm = comp.getStandardFileManager(null, null, null);
119 for (EnclosingKind ek : EnclosingKind.values()) {
120 for (SiteKind sk : SiteKind.values()) {
121 if (sk == SiteKind.STATIC_INIT && ek == EnclosingKind.MEMBER_INNER)
122 continue;
123 for (InnerKind ik : InnerKind.values()) {
124 if (ik != InnerKind.NONE && sk == SiteKind.NONE)
125 break;
126 for (RefKind rk : RefKind.values()) {
127 new TestSelfRef(ek, sk, ik, rk).run(comp, fm);
128 }
129 }
130 }
131 }
132 System.out.println("Total check executed: " + checkCount);
133 }
135 EnclosingKind ek;
136 SiteKind sk;
137 InnerKind ik;
138 RefKind rk;
139 JavaSource source;
140 DiagnosticChecker diagChecker;
142 TestSelfRef(EnclosingKind ek, SiteKind sk, InnerKind ik, RefKind rk) {
143 this.ek = ek;
144 this.sk = sk;
145 this.ik = ik;
146 this.rk = rk;
147 this.source = new JavaSource();
148 this.diagChecker = new DiagnosticChecker();
149 }
151 class JavaSource extends SimpleJavaFileObject {
153 String bodyTemplate = "interface SAM { void test(Object o); }\n#B";
154 String source;
156 public JavaSource() {
157 super(URI.create("myfo:/Test.java"), JavaFileObject.Kind.SOURCE);
158 source = bodyTemplate.replace("#B",
159 ek.enclStr.replace("#S", sk.siteStr.replace("#I", ik.innerStr.replace("#R", rk.refStr))));
160 }
162 @Override
163 public CharSequence getCharContent(boolean ignoreEncodingErrors) {
164 return source;
165 }
166 }
168 void run(JavaCompiler tool, StandardJavaFileManager fm) throws Exception {
169 JavacTask ct = (JavacTask)tool.getTask(null, fm, diagChecker,
170 null, null, Arrays.asList(source));
171 try {
172 ct.analyze();
173 } catch (Throwable ex) {
174 throw new AssertionError("Error thron when compiling the following code:\n" + source.getCharContent(true));
175 }
176 check();
177 }
179 void check() {
180 //illegal forward ref
181 boolean errorExpected = ik.inMethodContext(sk) &&
182 (rk.selfRef || rk.forwardRef);
183 if (diagChecker.errorFound != errorExpected) {
184 throw new Error("invalid diagnostics for source:\n" +
185 source.getCharContent(true) +
186 "\nFound error: " + diagChecker.errorFound +
187 "\nExpected error: " + errorExpected);
188 }
189 }
191 static class DiagnosticChecker implements javax.tools.DiagnosticListener<JavaFileObject> {
193 boolean errorFound;
195 public void report(Diagnostic<? extends JavaFileObject> diagnostic) {
196 if (diagnostic.getKind() == Diagnostic.Kind.ERROR) {
197 errorFound = true;
198 }
199 }
200 }
201 }