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 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
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24 */
26 /**
27 * @test
28 * @bug 8003639
29 * @summary convert lambda testng tests to jtreg and add them
30 * @run testng LambdaTranslationTest1
31 */
33 import org.testng.annotations.Test;
35 import static org.testng.Assert.assertEquals;
37 @Test
38 public class LambdaTranslationTest1 extends LT1Sub {
40 String cntxt = "blah";
42 private static final ThreadLocal<Object> result = new ThreadLocal<>();
44 private static void setResult(Object s) { result.set(s); }
45 private static void appendResult(Object s) { result.set(result.get().toString() + s); }
47 private static void assertResult(String expected) {
48 assertEquals(result.get().toString(), expected);
49 }
51 static Integer count(String s) {
52 return s.length();
53 }
55 static int icount(String s) {
56 return s.length();
57 }
59 static void eye(Integer i) {
60 setResult(String.format("I:%d", i));
61 }
63 static void ieye(int i) {
64 setResult(String.format("i:%d", i));
65 }
67 static void deye(double d) {
68 setResult(String.format("d:%f", d));
69 }
71 public void testLambdas() {
72 TBlock<Object> b = t -> {setResult("Sink0::" + t);};
73 b.apply("Howdy");
74 assertResult("Sink0::Howdy");
76 TBlock<String> b1 = t -> {setResult("Sink1::" + t);};
77 b1.apply("Rowdy");
78 assertResult("Sink1::Rowdy");
80 for (int i = 5; i < 10; ++i) {
81 TBlock<Integer> b2 = t -> {setResult("Sink2::" + t);};
82 b2.apply(i);
83 assertResult("Sink2::" + i);
84 }
86 TBlock<Integer> b3 = t -> {setResult("Sink3::" + t);};
87 for (int i = 900; i > 0; i -= 100) {
88 b3.apply(i);
89 assertResult("Sink3::" + i);
90 }
92 cntxt = "blah";
93 TBlock<String> b4 = t -> {setResult(String.format("b4: %s .. %s", cntxt, t));};
94 b4.apply("Yor");
95 assertResult("b4: blah .. Yor");
97 String flaw = "flaw";
98 TBlock<String> b5 = t -> {setResult(String.format("b5: %s .. %s", flaw, t));};
99 b5.apply("BB");
100 assertResult("b5: flaw .. BB");
102 cntxt = "flew";
103 TBlock<String> b6 = t -> {setResult(String.format("b6: %s .. %s .. %s", t, cntxt, flaw));};
104 b6.apply("flee");
105 assertResult("b6: flee .. flew .. flaw");
107 TBlock<String> b7 = t -> {setResult(String.format("b7: %s %s", t, this.protectedSuperclassMethod()));};
108 b7.apply("this:");
109 assertResult("b7: this: instance:flew");
111 TBlock<String> b8 = t -> {setResult(String.format("b8: %s %s", t, super.protectedSuperclassMethod()));};
112 b8.apply("super:");
113 assertResult("b8: super: I'm the sub");
115 TBlock<String> b7b = t -> {setResult(String.format("b9: %s %s", t, protectedSuperclassMethod()));};
116 b7b.apply("implicit this:");
117 assertResult("b9: implicit this: instance:flew");
119 TBlock<Object> b10 = t -> {setResult(String.format("b10: new LT1Thing: %s", (new LT1Thing(t)).str));};
120 b10.apply("thing");
121 assertResult("b10: new LT1Thing: thing");
123 TBlock<Object> b11 = t -> {setResult(String.format("b11: %s", (new LT1Thing(t) {
124 String get() {
125 return "*" + str.toString() + "*";
126 }
127 }).get()));};
128 b11.apply(999);
129 assertResult("b11: *999*");
130 }
132 public void testMethodRefs() {
133 LT1IA ia = LambdaTranslationTest1::eye;
134 ia.doit(1234);
135 assertResult("I:1234");
137 LT1IIA iia = LambdaTranslationTest1::ieye;
138 iia.doit(1234);
139 assertResult("i:1234");
141 LT1IA da = LambdaTranslationTest1::deye;
142 da.doit(1234);
143 assertResult("d:1234.000000");
145 LT1SA a = LambdaTranslationTest1::count;
146 assertEquals((Integer) 5, a.doit("howdy"));
148 a = LambdaTranslationTest1::icount;
149 assertEquals((Integer) 6, a.doit("shower"));
150 }
152 public void testInner() throws Exception {
153 (new In()).doInner();
154 }
156 protected String protectedSuperclassMethod() {
157 return "instance:" + cntxt;
158 }
160 private class In {
162 private int that = 1234;
164 void doInner() {
165 TBlock<String> i4 = t -> {setResult(String.format("i4: %d .. %s", that, t));};
166 i4.apply("=1234");
167 assertResult("i4: 1234 .. =1234");
169 TBlock<String> i5 = t -> {setResult(""); appendResult(t); appendResult(t);};
170 i5.apply("fruit");
171 assertResult("fruitfruit");
173 cntxt = "human";
174 TBlock<String> b4 = t -> {setResult(String.format("b4: %s .. %s", cntxt, t));};
175 b4.apply("bin");
176 assertResult("b4: human .. bin");
178 final String flaw = "flaw";
180 /**
181 Callable<String> c5 = () -> "["+flaw+"]" ;
182 System.out.printf("c5: %s\n", c5.call() );
183 **/
185 TBlock<String> b5 = t -> {setResult(String.format("b5: %s .. %s", flaw, t));};
186 b5.apply("BB");
187 assertResult("b5: flaw .. BB");
189 cntxt = "borg";
190 TBlock<String> b6 = t -> {setResult(String.format("b6: %s .. %s .. %s", t, cntxt, flaw));};
191 b6.apply("flee");
192 assertResult("b6: flee .. borg .. flaw");
194 TBlock<String> b7b = t -> {setResult(String.format("b7b: %s %s", t, protectedSuperclassMethod()));};
195 b7b.apply("implicit outer this");
196 assertResult("b7b: implicit outer this instance:borg");
198 /**
199 TBlock<Object> b9 = t -> { System.out.printf("New: %s\n", (new LT1Thing(t)).str); };
200 b9.apply("thing");
202 TBlock<Object> ba = t -> { System.out.printf("Def: %s\n", (new LT1Thing(t) { String get() { return "*" + str.toString() +"*";}}).get() ); };
203 ba.apply(999);
205 */
206 }
207 }
208 }
210 class LT1Sub {
211 protected String protectedSuperclassMethod() {
212 return "I'm the sub";
213 }
214 }
216 class LT1Thing {
217 final Object str;
219 LT1Thing(Object s) {
220 str = s;
221 }
222 }
224 interface LT1SA {
225 Integer doit(String s);
226 }
228 interface LT1IA {
229 void doit(int i);
230 }
232 interface LT1IIA {
233 void doit(Integer i);
234 }