Report implicit inferred Nothing only for own type parameters and in delegation resolve

^KT-47724 Fixed

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java

@@ -14228,6 +14228,12 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                     runTest("compiler/testData/diagnostics/tests/inference/nothingType/reifiedParameterWithRecursiveBound.kt");
                 }
 
+                @Test
+                @TestMetadata("reportImplicitNothingOnlyForOwnTypeParameters.kt")
+                public void testReportImplicitNothingOnlyForOwnTypeParameters() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/nothingType/reportImplicitNothingOnlyForOwnTypeParameters.kt");
+                }
+
                 @Test
                 @TestMetadata("specialCallWithMaterializeAndExpectedType.kt")
                 public void testSpecialCallWithMaterializeAndExpectedType() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsWithLightTreeTestGenerated.java

@@ -14228,6 +14228,12 @@ public class FirOldFrontendDiagnosticsWithLightTreeTestGenerated extends Abstrac
                     runTest("compiler/testData/diagnostics/tests/inference/nothingType/reifiedParameterWithRecursiveBound.kt");
                 }
 
+                @Test
+                @TestMetadata("reportImplicitNothingOnlyForOwnTypeParameters.kt")
+                public void testReportImplicitNothingOnlyForOwnTypeParameters() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/nothingType/reportImplicitNothingOnlyForOwnTypeParameters.kt");
+                }
+
                 @Test
                 @TestMetadata("specialCallWithMaterializeAndExpectedType.kt")
                 public void testSpecialCallWithMaterializeAndExpectedType() throws Exception {

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/checkers/ImplicitNothingAsTypeParameterCallChecker.kt

@@ -8,6 +8,8 @@ package org.jetbrains.kotlin.resolve.calls.checkers
 import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.builtins.isBuiltinFunctionalType
 import org.jetbrains.kotlin.builtins.isFunctionOrSuspendFunctionType
+import org.jetbrains.kotlin.descriptors.CallableDescriptor
+import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
 import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.diagnostics.reportDiagnosticOnceWrtDiagnosticFactoryList
 import org.jetbrains.kotlin.resolve.BindingContext
@@ -19,6 +21,7 @@ import org.jetbrains.kotlin.resolve.calls.model.*
 import org.jetbrains.kotlin.resolve.calls.tower.NewResolvedCallImpl
 import org.jetbrains.kotlin.resolve.calls.tower.psiExpression
 import org.jetbrains.kotlin.resolve.calls.tower.psiKotlinCall
+import org.jetbrains.kotlin.resolve.scopes.LexicalScopeKind
 import org.jetbrains.kotlin.types.DeferredType
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.TypeUtils
@@ -51,7 +54,7 @@ object ImplicitNothingAsTypeParameterCallChecker : CallChecker {
     ): Boolean {
         val resultingDescriptor = resolvedCall.resultingDescriptor
         val expectedType = context.resolutionContext.expectedType
-        val inferredReturnType = resultingDescriptor.returnType
+        val inferredReturnType = resultingDescriptor.returnType ?: return false
         val isBuiltinFunctionalType =
             resolvedCall.resultingDescriptor.dispatchReceiverParameter?.value?.type?.isBuiltinFunctionalType == true
 
@@ -61,12 +64,13 @@ object ImplicitNothingAsTypeParameterCallChecker : CallChecker {
         val lambdasFromArgumentsReturnTypes =
             resolvedCall.candidateDescriptor.valueParameters.filter { it.type.isFunctionOrSuspendFunctionType }
                 .map { it.returnType?.arguments?.last()?.type }.toSet()
-        val unsubstitutedReturnType = resultingDescriptor.original.returnType
-        val hasImplicitNothing = inferredReturnType?.isNothingOrNullableNothing() == true &&
-                unsubstitutedReturnType?.isTypeParameter() == true &&
-                (TypeUtils.noExpectedType(expectedType) || !expectedType.isNothing())
+        val unsubstitutedReturnType = resultingDescriptor.original.returnType ?: return false
+        val hasImplicitNothing = inferredReturnType.isNothingOrNullableNothing()
+                && unsubstitutedReturnType.isTypeParameter()
+                && (isOwnTypeParameter(unsubstitutedReturnType, resultingDescriptor.original) || isDelegationContext(context))
+                && (TypeUtils.noExpectedType(expectedType) || !expectedType.isNothing())
 
-        if (inferredReturnType?.isNullableNothing() == true && unsubstitutedReturnType?.isMarkedNullable == false) {
+        if (inferredReturnType.isNullableNothing() && !unsubstitutedReturnType.isMarkedNullable) {
             return false
         }
 
@@ -81,6 +85,14 @@ object ImplicitNothingAsTypeParameterCallChecker : CallChecker {
         return false
     }
 
+    private fun isOwnTypeParameter(type: KotlinType, declaration: CallableDescriptor): Boolean {
+        val typeParameter = type.constructor.declarationDescriptor as? TypeParameterDescriptor ?: return false
+        return typeParameter.containingDeclaration == declaration
+    }
+
+    private fun isDelegationContext(context: CallCheckerContext) =
+        context.resolutionContext.scope.kind == LexicalScopeKind.PROPERTY_DELEGATE_METHOD
+
     private fun ResolvedAtom.getResolvedCallAtom(bindingContext: BindingContext): ResolvedCallAtom? {
         if (this is SingleCallResolutionResult) return resultCallAtom
 

compiler/testData/diagnostics/tests/inference/nothingType/reportImplicitNothingOnlyForOwnTypeParameters.fir.kt

@@ -0,0 +1,11 @@
+fun <R> runCatching(block: () -> R) = null as Result<R>
+
+class Result<out T> {
+    fun getOrNull(): T? = null
+}
+
+fun main() {
+    runCatching {
+        null
+    }.getOrNull() // don't report IMPLICIT_NOTHING_TYPE_ARGUMENT_IN_RETURN_POSITION
+}

compiler/testData/diagnostics/tests/inference/nothingType/reportImplicitNothingOnlyForOwnTypeParameters.kt

@@ -0,0 +1,11 @@
+fun <R> runCatching(block: () -> R) = null <!CAST_NEVER_SUCCEEDS!>as<!> Result<R>
+
+class Result<out T> {
+    fun getOrNull(): T? = null
+}
+
+fun main() {
+    runCatching {
+        null
+    }.getOrNull() // don't report IMPLICIT_NOTHING_TYPE_ARGUMENT_IN_RETURN_POSITION
+}

compiler/testData/diagnostics/tests/inference/nothingType/reportImplicitNothingOnlyForOwnTypeParameters.txt

@@ -0,0 +1,12 @@
+package
+
+public fun main(): kotlin.Unit
+public fun </*0*/ R> runCatching(/*0*/ block: () -> R): Result<R>
+
+public final class Result</*0*/ out T> {
+    public constructor Result</*0*/ out T>()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final fun getOrNull(): T?
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/typeParameters/implicitNothingInReturnPosition.kt

@@ -90,7 +90,7 @@ interface Worker<out T>
 interface RenderContext<StateT, in OutputT : Any>
 
 val emptyOrNull: List<Nothing>? = null
-val x = emptyOrNull?.<!IMPLICIT_NOTHING_TYPE_ARGUMENT_IN_RETURN_POSITION!>get<!>(0)
+val x = emptyOrNull?.get(0)
 
 val errorCompletion = { e: Throwable -> throw Exception() }
 

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java

@@ -14234,6 +14234,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                     runTest("compiler/testData/diagnostics/tests/inference/nothingType/reifiedParameterWithRecursiveBound.kt");
                 }
 
+                @Test
+                @TestMetadata("reportImplicitNothingOnlyForOwnTypeParameters.kt")
+                public void testReportImplicitNothingOnlyForOwnTypeParameters() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/nothingType/reportImplicitNothingOnlyForOwnTypeParameters.kt");
+                }
+
                 @Test
                 @TestMetadata("specialCallWithMaterializeAndExpectedType.kt")
                 public void testSpecialCallWithMaterializeAndExpectedType() throws Exception {

idea/idea-frontend-fir/idea-fir-low-level-api/tests/org/jetbrains/kotlin/idea/fir/low/level/api/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java

@@ -14228,6 +14228,12 @@ public class DiagnosisCompilerTestFE10TestdataTestGenerated extends AbstractDiag
                     runTest("compiler/testData/diagnostics/tests/inference/nothingType/reifiedParameterWithRecursiveBound.kt");
                 }
 
+                @Test
+                @TestMetadata("reportImplicitNothingOnlyForOwnTypeParameters.kt")
+                public void testReportImplicitNothingOnlyForOwnTypeParameters() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/nothingType/reportImplicitNothingOnlyForOwnTypeParameters.kt");
+                }
+
                 @Test
                 @TestMetadata("specialCallWithMaterializeAndExpectedType.kt")
                 public void testSpecialCallWithMaterializeAndExpectedType() throws Exception {