FIR: extend suspend conversion to intersection type

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/AdapterGenerator.kt

@@ -400,8 +400,8 @@ internal class AdapterGenerator(
             return this
         }
         val expectedType = parameter?.returnTypeRef?.coneType ?: return this
-        // Expect the expected type to be a suspend functional type, and the argument type is not a suspend functional type.
-        if (!expectedType.isSuspendFunctionType(session) || argument.typeRef.coneType.isSuspendFunctionType(session)) {
+        // Expect the expected type to be a suspend functional type.
+        if (!expectedType.isSuspendFunctionType(session)) {
             return this
         }
         val expectedFunctionalType = expectedType.suspendFunctionTypeToFunctionType(session)
@@ -424,22 +424,17 @@ internal class AdapterGenerator(
 
     private fun findInvokeSymbol(expectedFunctionalType: ConeClassLikeType, argument: FirExpression): IrSimpleFunctionSymbol? {
         val argumentType = argument.typeRef.coneType
-        // To avoid any remaining exotic types, e.g., intersection type, like it(FunctionN..., SuspendFunctionN...)
-        if (argumentType !is ConeClassLikeType) {
-            return null
-        }
+        val argumentTypeWithInvoke = argumentType.findSubtypeOfNonSuspendFunctionalType(session, expectedFunctionalType) ?: return null
 
-        if (argumentType.isSubtypeOfFunctionalType(session, expectedFunctionalType)) {
-            return if (argumentType.isBuiltinFunctionalType(session)) {
-                argumentType.findBaseInvokeSymbol(session, scopeSession)
-            } else {
-                argumentType.findContributedInvokeSymbol(session, scopeSession, expectedFunctionalType, shouldCalculateReturnTypesOfFakeOverrides = true)
-            }?.let {
-                declarationStorage.getIrFunctionSymbol(it) as? IrSimpleFunctionSymbol
-            }
+        return if (argumentTypeWithInvoke.isBuiltinFunctionalType(session)) {
+            (argumentTypeWithInvoke as? ConeClassLikeType)?.findBaseInvokeSymbol(session, scopeSession)
+        } else {
+            argumentTypeWithInvoke.findContributedInvokeSymbol(
+                session, scopeSession, expectedFunctionalType, shouldCalculateReturnTypesOfFakeOverrides = true
+            )
+        }?.let {
+            declarationStorage.getIrFunctionSymbol(it) as? IrSimpleFunctionSymbol
         }
-
-        return null
     }
 
     private fun createAdapterFunctionForArgument(

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/Arguments.kt

@@ -247,36 +247,30 @@ private fun argumentTypeWithSuspendConversion(
 ): ConeKotlinType? {
     // TODO: should refer to LanguageVersionSettings.SuspendConversion
 
-    // To avoid any remaining exotic types, e.g., intersection type, like it(FunctionN..., SuspendFunctionN...)
-    if (argumentType !is ConeClassLikeType) {
-        return null
-    }
-
-    // Expect the expected type to be a suspend functional type, and the argument type is not a suspend functional type.
-    if (!expectedType.isSuspendFunctionType(session) || argumentType.isSuspendFunctionType(session)) {
+    // Expect the expected type to be a suspend functional type.
+    if (!expectedType.isSuspendFunctionType(session)) {
         return null
     }
 
     // We want to check the argument type against non-suspend functional type.
     val expectedFunctionalType = expectedType.suspendFunctionTypeToFunctionType(session)
-    if (argumentType.isSubtypeOfFunctionalType(session, expectedFunctionalType)) {
-        return argumentType.findContributedInvokeSymbol(
-            session,
-            scopeSession,
-            expectedFunctionalType,
-            shouldCalculateReturnTypesOfFakeOverrides = false
-        )?.let { invokeSymbol ->
-            createFunctionalType(
-                invokeSymbol.fir.valueParameters.map { it.returnTypeRef.coneType },
-                null,
-                invokeSymbol.fir.returnTypeRef.coneType,
-                isSuspend = true,
-                isKFunctionType = argumentType.isKFunctionType(session)
-            )
-        }
-    }
 
-    return null
+    val argumentTypeWithInvoke = argumentType.findSubtypeOfNonSuspendFunctionalType(session, expectedFunctionalType)
+
+    return argumentTypeWithInvoke?.findContributedInvokeSymbol(
+        session,
+        scopeSession,
+        expectedFunctionalType,
+        shouldCalculateReturnTypesOfFakeOverrides = false
+    )?.let { invokeSymbol ->
+        createFunctionalType(
+            invokeSymbol.fir.valueParameters.map { it.returnTypeRef.coneType },
+            null,
+            invokeSymbol.fir.returnTypeRef.coneType,
+            isSuspend = true,
+            isKFunctionType = argumentType.isKFunctionType(session)
+        )
+    }
 }
 
 fun Candidate.prepareCapturedType(argumentType: ConeKotlinType, context: ResolutionContext): ConeKotlinType {

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/InferenceUtils.kt

@@ -97,6 +97,33 @@ fun ConeKotlinType.isSubtypeOfFunctionalType(session: FirSession, expectedFuncti
     return AbstractTypeChecker.isSubtypeOf(session.typeContext, this, expectedFunctionalType.replaceArgumentsWithStarProjections())
 }
 
+fun ConeKotlinType.findSubtypeOfNonSuspendFunctionalType(session: FirSession, expectedFunctionalType: ConeClassLikeType): ConeKotlinType? {
+    require(expectedFunctionalType.isBuiltinFunctionalType(session) && !expectedFunctionalType.isSuspendFunctionType(session))
+    return when (this) {
+        is ConeClassLikeType -> {
+            // Expect the argument type is not a suspend functional type.
+            if (isSuspendFunctionType(session) || !isSubtypeOfFunctionalType(session, expectedFunctionalType))
+                null
+            else
+                this
+        }
+        is ConeIntersectionType -> {
+            if (intersectedTypes.any { it.isSuspendFunctionType(session) })
+                null
+            else
+                intersectedTypes.find { it.findSubtypeOfNonSuspendFunctionalType(session, expectedFunctionalType) != null }
+        }
+        is ConeTypeParameterType -> {
+            val bounds = lookupTag.typeParameterSymbol.fir.bounds.map { it.coneType }
+            if (bounds.any { it.isSuspendFunctionType(session) })
+                null
+            else
+                bounds.find { it.findSubtypeOfNonSuspendFunctionalType(session, expectedFunctionalType) != null }
+        }
+        else -> null
+    }
+}
+
 fun ConeClassLikeType.findBaseInvokeSymbol(session: FirSession, scopeSession: ScopeSession): FirFunctionSymbol<*>? {
     require(this.isBuiltinFunctionalType(session))
     val functionN = (lookupTag.toSymbol(session)?.fir as? FirClass<*>) ?: return null

compiler/testData/codegen/box/coroutines/suspendConversion/intersectionTypeToSubtypeConversion.kt

@@ -3,7 +3,6 @@
 // WITH_COROUTINES
 // IGNORE_BACKEND: JVM, NATIVE, JS, JS_IR
 // IGNORE_BACKEND: JS_IR_ES6
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_LIGHT_ANALYSIS
 
 import helpers.*