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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26 /**
27 * @test
28 * @bug 8003639
29 * @summary convert lambda testng tests to jtreg and add them
30 * @run testng MethodReferenceTestKinds
31 */
33 import org.testng.annotations.Test;
35 import static org.testng.Assert.assertEquals;
37 /**
38 * @author Robert Field
39 */
41 @Test
42 public class MethodReferenceTestKinds extends MethodReferenceTestKindsSup {
44 interface S0 { String get(); }
45 interface S1 { String get(MethodReferenceTestKinds x); }
46 interface S2 { String get(MethodReferenceTestKinds x, MethodReferenceTestKinds y); }
48 interface SXN0 { MethodReferenceTestKindsBase make(MethodReferenceTestKinds x); }
49 interface SXN1 { MethodReferenceTestKindsBase make(MethodReferenceTestKinds x, String str); }
51 interface SN0 { MethodReferenceTestKindsBase make(); }
52 interface SN1 { MethodReferenceTestKindsBase make(String x); }
54 class In extends MethodReferenceTestKindsBase {
55 In(String val) {
56 this.val = val;
57 }
59 In() {
60 this("blank");
61 }
62 }
64 String instanceMethod0() { return "IM:0-" + this; }
65 String instanceMethod1(MethodReferenceTestKinds x) { return "IM:1-" + this + x; }
67 static String staticMethod0() { return "SM:0"; }
68 static String staticMethod1(MethodReferenceTestKinds x) { return "SM:1-" + x; }
70 MethodReferenceTestKinds(String val) {
71 super(val);
72 }
74 MethodReferenceTestKinds() {
75 super("blank");
76 }
78 MethodReferenceTestKinds inst(String val) {
79 return new MethodReferenceTestKinds(val);
80 }
82 public void testMRBound() {
83 S0 var = this::instanceMethod0;
84 assertEquals(var.get(), "IM:0-MethodReferenceTestKinds(blank)");
85 }
87 public void testMRBoundArg() {
88 S1 var = this::instanceMethod1;
89 assertEquals(var.get(inst("arg")), "IM:1-MethodReferenceTestKinds(blank)MethodReferenceTestKinds(arg)");
90 }
92 public void testMRUnbound() {
93 S1 var = MethodReferenceTestKinds::instanceMethod0;
94 assertEquals(var.get(inst("rcvr")), "IM:0-MethodReferenceTestKinds(rcvr)");
95 }
97 public void testMRUnboundArg() {
98 S2 var = MethodReferenceTestKinds::instanceMethod1;
99 assertEquals(var.get(inst("rcvr"), inst("arg")), "IM:1-MethodReferenceTestKinds(rcvr)MethodReferenceTestKinds(arg)");
100 }
102 public void testMRSuper() {
103 S0 var = super::instanceMethod0;
104 assertEquals(var.get(), "SIM:0-MethodReferenceTestKinds(blank)");
105 }
107 public void testMRSuperArg() {
108 S1 var = super::instanceMethod1;
109 assertEquals(var.get(inst("arg")), "SIM:1-MethodReferenceTestKinds(blank)MethodReferenceTestKinds(arg)");
110 }
112 public void testMRStatic() {
113 S0 var = MethodReferenceTestKinds::staticMethod0;
114 assertEquals(var.get(), "SM:0");
115 }
117 public void testMRStaticArg() {
118 S1 var = MethodReferenceTestKinds::staticMethod1;
119 assertEquals(var.get(inst("arg")), "SM:1-MethodReferenceTestKinds(arg)");
120 }
122 public void testMRTopLevel() {
123 SN0 var = MethodReferenceTestKindsBase::new;
124 assertEquals(var.make().toString(), "MethodReferenceTestKindsBase(blank)");
125 }
127 public void testMRTopLevelArg() {
128 SN1 var = MethodReferenceTestKindsBase::new;
129 assertEquals(var.make("name").toString(), "MethodReferenceTestKindsBase(name)");
130 }
132 public void testMRImplicitInner() {
133 SN0 var = MethodReferenceTestKinds.In::new;
134 assertEquals(var.make().toString(), "In(blank)");
135 }
137 public void testMRImplicitInnerArg() {
138 SN1 var = MethodReferenceTestKinds.In::new;
139 assertEquals(var.make("name").toString(), "In(name)");
140 }
142 }
145 class MethodReferenceTestKindsBase {
146 String val = "unset";
148 public String toString() {
149 return getClass().getSimpleName() + "(" + val + ")";
150 }
152 MethodReferenceTestKindsBase(String val) {
153 this.val = val;
154 }
156 MethodReferenceTestKindsBase() {
157 this("blank");
158 }
160 }
162 class MethodReferenceTestKindsSup extends MethodReferenceTestKindsBase {
163 String instanceMethod0() { return "SIM:0-" + this; }
164 String instanceMethod1(MethodReferenceTestKinds x) { return "SIM:1-" + this + x; }
166 MethodReferenceTestKindsSup(String val) {
167 super(val);
168 }
170 }