From cc6c378b68ab4333b9830dd62415e4b59b59dbc9 Mon Sep 17 00:00:00 2001
From: Dmitriy Novozhilov <dmitriy.novozhilov@jetbrains.com>
Date: Fri, 28 Apr 2023 15:51:25 +0300
Subject: [PATCH] [FIR] Don't perform suspend conversion for anonymous
 functions

^KT-58329 Fixed
---
 .../kotlin/fir/resolve/inference/InferenceUtils.kt       | 9 +++++++++
 .../inference/coerceFunctionLiteralToSuspend.fir.kt      | 6 +++---
 .../lambdaInValInitializerWithAnonymousFunctions.fir.kt  | 4 ++--
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/InferenceUtils.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/InferenceUtils.kt
index 3bd8ab07166..417731b2d21 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/InferenceUtils.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/InferenceUtils.kt
@@ -5,13 +5,16 @@
 
 package org.jetbrains.kotlin.fir.resolve.inference
 
+import org.jetbrains.kotlin.builtins.functions.FunctionTypeKind
 import org.jetbrains.kotlin.fir.declarations.FirAnonymousFunction
+import org.jetbrains.kotlin.fir.declarations.utils.isSuspend
 import org.jetbrains.kotlin.fir.diagnostics.ConeCannotInferValueParameterType
 import org.jetbrains.kotlin.fir.expressions.FirReturnExpression
 import org.jetbrains.kotlin.fir.expressions.impl.FirUnitExpression
 import org.jetbrains.kotlin.fir.resolve.BodyResolveComponents
 import org.jetbrains.kotlin.fir.resolve.calls.Candidate
 import org.jetbrains.kotlin.fir.types.*
+import org.jetbrains.kotlin.utils.addToStdlib.runIf
 
 /**
  * @return null if and only if expectedType is not function type (or flexible type with function type as bound)
@@ -39,7 +42,13 @@ fun extractLambdaInfoFromFunctionType(
         )
     }
     val expectedFunctionKind = expectedType.functionTypeKind(session) ?: return null
+
     val actualFunctionKind = session.functionTypeService.extractSingleSpecialKindForFunction(argument.symbol)
+        ?: runIf(!argument.isLambda) {
+            // There is no function -> suspend function conversions for non-lambda anonymous functions
+            // If function is suspend then functionTypeService will return SuspendFunction kind
+            FunctionTypeKind.Function
+        }
 
     val singleStatement = argument.body?.statements?.singleOrNull() as? FirReturnExpression
     if (argument.returnType == null && singleStatement != null &&
diff --git a/compiler/testData/diagnostics/tests/inference/coerceFunctionLiteralToSuspend.fir.kt b/compiler/testData/diagnostics/tests/inference/coerceFunctionLiteralToSuspend.fir.kt
index 6bd6ab8fb68..1503e4459f6 100644
--- a/compiler/testData/diagnostics/tests/inference/coerceFunctionLiteralToSuspend.fir.kt
+++ b/compiler/testData/diagnostics/tests/inference/coerceFunctionLiteralToSuspend.fir.kt
@@ -7,7 +7,7 @@ fun fail2(c: () -> Unit) {}
 fun success1(c: suspend () -> Unit) {}
 
 fun test1() {
-    fail1(fun () {})
+    fail1(<!ARGUMENT_TYPE_MISMATCH!>fun () {}<!>)
     fun fail2(c: suspend () -> Unit) {}
     fail2(fun () {})
     fun success1(c: () -> Unit) {}
@@ -21,9 +21,9 @@ suspend fun fail4(c: () -> Unit) {}
 suspend fun success2(c: suspend () -> Unit) {}
 
 suspend fun test2() {
-    fail3(fun () {})
+    fail3(<!ARGUMENT_TYPE_MISMATCH!>fun () {}<!>)
     fun fail4(c: suspend () -> Unit) {}
     fail4(fun () {})
     fun success2(c: () -> Unit) {}
     success2(fun() {})
-}
\ No newline at end of file
+}
diff --git a/compiler/testData/diagnostics/tests/inference/lambdaInValInitializerWithAnonymousFunctions.fir.kt b/compiler/testData/diagnostics/tests/inference/lambdaInValInitializerWithAnonymousFunctions.fir.kt
index 5a2ef9e81ce..cf2ba10de3f 100644
--- a/compiler/testData/diagnostics/tests/inference/lambdaInValInitializerWithAnonymousFunctions.fir.kt
+++ b/compiler/testData/diagnostics/tests/inference/lambdaInValInitializerWithAnonymousFunctions.fir.kt
@@ -1,7 +1,7 @@
 typealias SuspendFn = suspend () -> Unit
 
-val test1f: suspend () -> Unit = fun () {}
-val test2f: suspend Any.() -> Unit = fun Any.() {}
+val test1f: suspend () -> Unit = <!INITIALIZER_TYPE_MISMATCH!>fun () {}<!>
+val test2f: suspend Any.() -> Unit = <!INITIALIZER_TYPE_MISMATCH!>fun Any.() {}<!>
 
 // This is a bug in the old inference and should be fixed in new inference
 // see "Fix anonymous function literals handling in type checker" for more details