Delegated Properties: allowing type parameters for get/set methods

#KT-6253 Fixed

compiler/frontend/src/org/jetbrains/jet/lang/resolve/DelegatedPropertyResolver.java

@@ -184,7 +184,7 @@ public class DelegatedPropertyResolver {
         if (trace.getBindingContext().get(DELEGATED_PROPERTY_CALL, accessor) != null) return;
 
         OverloadResolutionResults<FunctionDescriptor> functionResults = getDelegatedPropertyConventionMethod(
-                propertyDescriptor, delegateExpression, delegateType, trace, scope, isGet);
+                propertyDescriptor, delegateExpression, delegateType, trace, scope, isGet, true);
         Call call = trace.getBindingContext().get(DELEGATED_PROPERTY_CALL, accessor);
         assert call != null : "'getDelegatedPropertyConventionMethod' didn't record a call";
 
@@ -218,14 +218,18 @@ public class DelegatedPropertyResolver {
             @NotNull JetType delegateType,
             @NotNull BindingTrace trace,
             @NotNull JetScope scope,
-            boolean isGet
+            boolean isGet,
+            boolean isComplete
     ) {
         PropertyAccessorDescriptor accessor = isGet ? propertyDescriptor.getGetter() : propertyDescriptor.getSetter();
         assert accessor != null : "Delegated property should have getter/setter " + propertyDescriptor + " " + delegateExpression.getText();
 
+        JetType expectedType = isComplete && isGet && !(propertyDescriptor.getType() instanceof DeferredType)
+                               ? propertyDescriptor.getType() : TypeUtils.NO_EXPECTED_TYPE;
+
         ExpressionTypingContext context = ExpressionTypingContext.newContext(
                 expressionTypingServices, trace, scope,
-                DataFlowInfo.EMPTY, TypeUtils.NO_EXPECTED_TYPE);
+                DataFlowInfo.EMPTY, expectedType);
 
         boolean hasThis = propertyDescriptor.getExtensionReceiverParameter() != null || propertyDescriptor.getDispatchReceiverParameter() != null;
 
@@ -318,7 +322,9 @@ public class DelegatedPropertyResolver {
                         TemporaryBindingTrace.create(trace, "Trace to resolve delegated property convention methods");
                 OverloadResolutionResults<FunctionDescriptor>
                         getMethodResults = getDelegatedPropertyConventionMethod(
-                        propertyDescriptor, delegateExpression, returnType, traceToResolveConventionMethods, accessorScope, true);
+                                propertyDescriptor, delegateExpression, returnType, traceToResolveConventionMethods, accessorScope,
+                                true, false
+                        );
 
                 if (conventionMethodFound(getMethodResults)) {
                     FunctionDescriptor descriptor = getMethodResults.getResultingDescriptor();
@@ -335,9 +341,11 @@ public class DelegatedPropertyResolver {
                 // But if the type isn't known yet, the constraint shouldn't be added (we try to infer the type of 'v' here as well).
                 if (propertyDescriptor.getReturnType() instanceof DeferredType) return;
 
-                OverloadResolutionResults<FunctionDescriptor> setMethodResults =
+                OverloadResolutionResults<FunctionDescriptor>
-                        getDelegatedPropertyConventionMethod(
+                        setMethodResults = getDelegatedPropertyConventionMethod(
-                                propertyDescriptor, delegateExpression, returnType, traceToResolveConventionMethods, accessorScope, false);
+                                propertyDescriptor, delegateExpression, returnType, traceToResolveConventionMethods, accessorScope,
+                                false, false
+                        );
 
                 if (conventionMethodFound(setMethodResults)) {
                     FunctionDescriptor descriptor = setMethodResults.getResultingDescriptor();

compiler/testData/diagnostics/tests/delegatedProperty/inference/genericMethodInGenericClass.kt

@@ -0,0 +1,25 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+class A<R>() {
+    fun <T> get(t: Any?, p: PropertyMetadata): T = null!!
+    fun <T> set(t: Any?, p: PropertyMetadata, x: T) = Unit
+}
+
+var a1: Int by <!TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>A<!>()
+var a2: Int by A<String>()
+
+class B<R>() {
+    fun <T> get(t: Any?, p: PropertyMetadata): T = null!!
+    fun set(t: Any?, p: PropertyMetadata, x: R) = Unit
+}
+
+var b1: Int by B()
+var b2: Int by B<Number>()
+
+class C<R>() {
+    fun get(t: Any?, p: PropertyMetadata): R = null!!
+    fun <T> set(t: Any?, p: PropertyMetadata, x: T) = Unit
+}
+
+var c1: Int by C()
+var c2: Int by <!DELEGATE_SPECIAL_FUNCTION_RETURN_TYPE_MISMATCH!>C<Number>()<!>

compiler/testData/diagnostics/tests/delegatedProperty/inference/genericMethodInGenericClass.txt

@@ -0,0 +1,35 @@
+package
+
+internal var a1: kotlin.Int
+internal var a2: kotlin.Int
+internal var b1: kotlin.Int
+internal var b2: kotlin.Int
+internal var c1: kotlin.Int
+internal var c2: kotlin.Int
+
+internal final class A</*0*/ R> {
+    public constructor A</*0*/ R>()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    internal final fun </*0*/ T> get(/*0*/ t: kotlin.Any?, /*1*/ p: kotlin.PropertyMetadata): T
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    internal final fun </*0*/ T> set(/*0*/ t: kotlin.Any?, /*1*/ p: kotlin.PropertyMetadata, /*2*/ x: T): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal final class B</*0*/ R> {
+    public constructor B</*0*/ R>()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    internal final fun </*0*/ T> get(/*0*/ t: kotlin.Any?, /*1*/ p: kotlin.PropertyMetadata): T
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    internal final fun set(/*0*/ t: kotlin.Any?, /*1*/ p: kotlin.PropertyMetadata, /*2*/ x: R): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal final class C</*0*/ R> {
+    public constructor C</*0*/ R>()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    internal final fun get(/*0*/ t: kotlin.Any?, /*1*/ p: kotlin.PropertyMetadata): R
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    internal final fun </*0*/ T> set(/*0*/ t: kotlin.Any?, /*1*/ p: kotlin.PropertyMetadata, /*2*/ x: T): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/delegatedProperty/inference/genericMethods.kt

@@ -0,0 +1,23 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+var a: Int by A()
+var a1 by <!DELEGATE_SPECIAL_FUNCTION_MISSING, DELEGATE_SPECIAL_FUNCTION_MISSING!>A()<!>
+
+var b: Int by B()
+
+val cObj = C()
+var c: String by cObj
+
+class A {
+  fun <T> get(t: Any?, p: PropertyMetadata): T = null!!
+  fun <T> set(t: Any?, p: PropertyMetadata, x: T) = Unit
+}
+
+class B
+
+fun <T> B.get(t: Any?, p: PropertyMetadata): T = null!!
+fun <T> B.set(t: Any?, p: PropertyMetadata, x: T) = Unit
+
+class C
+
+inline fun <reified T> C.get(t: Any?, p: PropertyMetadata): T = null!!
+inline fun <reified T> C.set(t: Any?, p: PropertyMetadata, x: T) = Unit

compiler/testData/diagnostics/tests/delegatedProperty/inference/genericMethods.txt

@@ -0,0 +1,34 @@
+package
+
+internal var a: kotlin.Int
+internal var a1: [ERROR : Type from delegate]
+internal var b: kotlin.Int
+internal var c: kotlin.String
+internal val cObj: C
+internal fun </*0*/ T> B.get(/*0*/ t: kotlin.Any?, /*1*/ p: kotlin.PropertyMetadata): T
+kotlin.inline() internal fun </*0*/ reified T> C.get(/*0*/ t: kotlin.Any?, /*1*/ p: kotlin.PropertyMetadata): T
+internal fun </*0*/ T> B.set(/*0*/ t: kotlin.Any?, /*1*/ p: kotlin.PropertyMetadata, /*2*/ x: T): kotlin.Unit
+kotlin.inline() internal fun </*0*/ reified T> C.set(/*0*/ t: kotlin.Any?, /*1*/ p: kotlin.PropertyMetadata, /*2*/ x: T): kotlin.Unit
+
+internal final class A {
+    public constructor A()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    internal final fun </*0*/ T> get(/*0*/ t: kotlin.Any?, /*1*/ p: kotlin.PropertyMetadata): T
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    internal final fun </*0*/ T> set(/*0*/ t: kotlin.Any?, /*1*/ p: kotlin.PropertyMetadata, /*2*/ x: T): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal final class B {
+    public constructor B()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal final class C {
+    public constructor C()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -3147,6 +3147,18 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                     doTest(fileName);
                 }
 
+                @TestMetadata("genericMethodInGenericClass.kt")
+                public void testGenericMethodInGenericClass() throws Exception {
+                    String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/delegatedProperty/inference/genericMethodInGenericClass.kt");
+                    doTest(fileName);
+                }
+
+                @TestMetadata("genericMethods.kt")
+                public void testGenericMethods() throws Exception {
+                    String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/delegatedProperty/inference/genericMethods.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("labeledDelegatedExpression.kt")
                 public void testLabeledDelegatedExpression() throws Exception {
                     String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/delegatedProperty/inference/labeledDelegatedExpression.kt");