From bfeb9537ee2fa2c4b1355e60ab605c03bbf934fa Mon Sep 17 00:00:00 2001
From: "victor.petukhov" <victor.petukhov@jetbrains.com>
Date: Fri, 24 May 2019 18:22:05 +0300
Subject: [PATCH] Exclude functional types for the warning reporting about
 implicitly inferred a type parameter to Nothing

---
 .../ImplicitNothingAsTypeParameterCallChecker.kt     |  6 +++++-
 .../controlStructures/notAFunctionLabel_after.kt     |  2 +-
 .../controlStructures/notAFunctionLabel_before.kt    |  2 +-
 .../typeParameters/implicitNothingAsTypeParameter.kt | 12 ++++++++++++
 4 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/checkers/ImplicitNothingAsTypeParameterCallChecker.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/checkers/ImplicitNothingAsTypeParameterCallChecker.kt
index 0abf56560d3..ba302f77e30 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/checkers/ImplicitNothingAsTypeParameterCallChecker.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/checkers/ImplicitNothingAsTypeParameterCallChecker.kt
@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.resolve.calls.checkers
 
 import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.builtins.isBuiltinFunctionalType
 import org.jetbrains.kotlin.builtins.isFunctionType
 import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
@@ -37,7 +38,10 @@ object ImplicitNothingAsTypeParameterCallChecker : CallChecker {
     override fun check(resolvedCall: ResolvedCall<*>, reportOn: PsiElement, context: CallCheckerContext) {
         val resultingDescriptor = resolvedCall.resultingDescriptor
         val inferredReturnType = resultingDescriptor.returnType
-        if (inferredReturnType is DeferredType)
+        val isBuiltinFunctionalType =
+            resolvedCall.resultingDescriptor.dispatchReceiverParameter?.value?.type?.isBuiltinFunctionalType == true
+
+        if (inferredReturnType is DeferredType || isBuiltinFunctionalType)
             return
         if (resultingDescriptor.name !in SPECIAL_FUNCTION_NAMES && resolvedCall.call.typeArguments.isEmpty()) {
             val lambdasFromArgumentsReturnTypes =
diff --git a/compiler/testData/diagnostics/tests/controlStructures/notAFunctionLabel_after.kt b/compiler/testData/diagnostics/tests/controlStructures/notAFunctionLabel_after.kt
index 01e8cb7fe8a..52d15ee4e69 100644
--- a/compiler/testData/diagnostics/tests/controlStructures/notAFunctionLabel_after.kt
+++ b/compiler/testData/diagnostics/tests/controlStructures/notAFunctionLabel_after.kt
@@ -52,7 +52,7 @@ fun testLoopLabelInReturn(xs: List<Int>) {
 
 fun testValLabelInReturn() {
     <!REDUNDANT_LABEL_WARNING!>L@<!> val fn = { <!NOT_A_FUNCTION_LABEL!>return@L<!> }
-    <!IMPLICIT_NOTHING_AS_TYPE_PARAMETER!>fn<!>()
+    fn()
 }
 
 fun testHighOrderFunctionCallLabelInReturn() {
diff --git a/compiler/testData/diagnostics/tests/controlStructures/notAFunctionLabel_before.kt b/compiler/testData/diagnostics/tests/controlStructures/notAFunctionLabel_before.kt
index df9a7999554..00a174f3a88 100644
--- a/compiler/testData/diagnostics/tests/controlStructures/notAFunctionLabel_before.kt
+++ b/compiler/testData/diagnostics/tests/controlStructures/notAFunctionLabel_before.kt
@@ -52,7 +52,7 @@ fun testLoopLabelInReturn(xs: List<Int>) {
 
 fun testValLabelInReturn() {
     <!REDUNDANT_LABEL_WARNING!>L@<!> val fn = { <!NOT_A_FUNCTION_LABEL_WARNING!>return@L<!> }
-    <!IMPLICIT_NOTHING_AS_TYPE_PARAMETER!>fn<!>()
+    fn()
 }
 
 fun testHighOrderFunctionCallLabelInReturn() {
diff --git a/compiler/testData/diagnostics/tests/typeParameters/implicitNothingAsTypeParameter.kt b/compiler/testData/diagnostics/tests/typeParameters/implicitNothingAsTypeParameter.kt
index 2c0d0e576c6..3e7657019bf 100644
--- a/compiler/testData/diagnostics/tests/typeParameters/implicitNothingAsTypeParameter.kt
+++ b/compiler/testData/diagnostics/tests/typeParameters/implicitNothingAsTypeParameter.kt
@@ -89,3 +89,15 @@ fun <InputT, OutputT : Any, RenderingT> stateless(
 interface Worker<out T>
 
 interface RenderContext<StateT, in OutputT : Any>
+
+val emptyOrNull: List<Nothing>? = null
+val x = emptyOrNull?.<!OI;IMPLICIT_NOTHING_AS_TYPE_PARAMETER!>get<!>(0)
+
+val errorCompletion = { <!OI;UNUSED_ANONYMOUS_PARAMETER!>e<!>: Throwable -> throw Exception() }
+
+fun test1() {
+    errorCompletion(Exception("fail"))
+}
+fun test2() {
+    errorCompletion.invoke(Exception("fail"))
+}