[FE 1.0] Support suspend only SAM conversions

^KT-50477 Fixed

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

@@ -26028,6 +26028,12 @@ public class DiagnosisCompilerTestFE10TestdataTestGenerated extends AbstractDiag
                 runTest("compiler/testData/diagnostics/tests/samConversions/kt17765.kt");
             }
 
+            @Test
+            @TestMetadata("kt50477.kt")
+            public void testKt50477() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/samConversions/kt50477.kt");
+            }
+
             @Test
             @TestMetadata("OverloadPriority.kt")
             public void testOverloadPriority() throws Exception {

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

@@ -26028,6 +26028,12 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                 runTest("compiler/testData/diagnostics/tests/samConversions/kt17765.kt");
             }
 
+            @Test
+            @TestMetadata("kt50477.kt")
+            public void testKt50477() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/samConversions/kt50477.kt");
+            }
+
             @Test
             @TestMetadata("OverloadPriority.kt")
             public void testOverloadPriority() throws Exception {

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

@@ -26028,6 +26028,12 @@ public class FirOldFrontendDiagnosticsWithLightTreeTestGenerated extends Abstrac
                 runTest("compiler/testData/diagnostics/tests/samConversions/kt17765.kt");
             }
 
+            @Test
+            @TestMetadata("kt50477.kt")
+            public void testKt50477() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/samConversions/kt50477.kt");
+            }
+
             @Test
             @TestMetadata("OverloadPriority.kt")
             public void testOverloadPriority() throws Exception {

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java

@@ -44497,6 +44497,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/sam/kt50171.kt");
         }
 
+        @Test
+        @TestMetadata("kt50477Enabled.kt")
+        public void testKt50477Enabled() throws Exception {
+            runTest("compiler/testData/codegen/box/sam/kt50477Enabled.kt");
+        }
+
         @Test
         @TestMetadata("nonInlinedSamWrapper.kt")
         public void testNonInlinedSamWrapper() throws Exception {

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/SamTypeConversions.kt

@@ -5,6 +5,8 @@
 
 package org.jetbrains.kotlin.resolve.calls.components
 
+import org.jetbrains.kotlin.builtins.isFunctionOrKFunctionTypeWithAnySuspendability
+import org.jetbrains.kotlin.builtins.isFunctionOrSuspendFunctionType
 import org.jetbrains.kotlin.builtins.isFunctionType
 import org.jetbrains.kotlin.builtins.isFunctionTypeOrSubtype
 import org.jetbrains.kotlin.config.LanguageFeature
@@ -41,15 +43,23 @@ object SamTypeConversions : ParameterTypeConversion {
         return false
     }
 
-    override fun conversionIsNeededBeforeSubtypingCheck(argument: KotlinCallArgument): Boolean {
+    override fun conversionIsNeededBeforeSubtypingCheck(
+        argument: KotlinCallArgument,
+        areSuspendOnlySamConversionsSupported: Boolean
+    ): Boolean {
         return when (argument) {
             is SubKotlinCallArgument -> {
                 val stableType = argument.receiver.stableType
-                if (stableType.isFunctionType) return true
+                if (
+                    stableType.isFunctionType ||
+                    (areSuspendOnlySamConversionsSupported && stableType.isFunctionOrKFunctionTypeWithAnySuspendability)
+                ) return true
 
                 hasNonAnalyzedLambdaAsReturnType(argument.callResult.subResolvedAtoms, stableType)
             }
-            is SimpleKotlinCallArgument -> argument.receiver.stableType.isFunctionType
+            is SimpleKotlinCallArgument -> argument.receiver.stableType.run {
+                isFunctionType || (areSuspendOnlySamConversionsSupported && isFunctionOrKFunctionTypeWithAnySuspendability)
+            }
             is LambdaKotlinCallArgument, is CallableReferenceKotlinCallArgument -> true
             else -> false
         }

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/SuspendConversionUtils.kt

@@ -27,8 +27,12 @@ object SuspendTypeConversions : ParameterTypeConversion {
         return false
     }
 
-    override fun conversionIsNeededBeforeSubtypingCheck(argument: KotlinCallArgument): Boolean =
+    override fun conversionIsNeededBeforeSubtypingCheck(
-        argument is SimpleKotlinCallArgument && argument.receiver.stableType.isFunctionType
+        argument: KotlinCallArgument,
+        areSuspendOnlySamConversionsSupported: Boolean
+    ): Boolean =
+        argument is SimpleKotlinCallArgument &&
+                (argument.receiver.stableType.isFunctionType || argument.receiver.stableType.isKFunctionType)
 
     override fun conversionIsNeededAfterSubtypingCheck(argument: KotlinCallArgument): Boolean =
         argument is SimpleKotlinCallArgument && argument.receiver.stableType.isFunctionTypeOrSubtype

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/UnitTypeConversions.kt

@@ -51,7 +51,10 @@ object UnitTypeConversions : ParameterTypeConversion {
         isUnit() || isDynamic() || isNothing()
 
 
-    override fun conversionIsNeededBeforeSubtypingCheck(argument: KotlinCallArgument): Boolean =
+    override fun conversionIsNeededBeforeSubtypingCheck(
+        argument: KotlinCallArgument,
+        areSuspendOnlySamConversionsSupported: Boolean
+    ): Boolean =
         argument is SimpleKotlinCallArgument && argument.receiver.stableType.isFunctionType
 
     override fun conversionIsNeededAfterSubtypingCheck(argument: KotlinCallArgument): Boolean {

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/typeConversions.kt

@@ -5,6 +5,7 @@
 
 package org.jetbrains.kotlin.resolve.calls.components
 
+import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.descriptors.ParameterDescriptor
 import org.jetbrains.kotlin.resolve.calls.components.candidate.ResolutionCandidate
 import org.jetbrains.kotlin.resolve.calls.model.KotlinCallArgument
@@ -17,7 +18,7 @@ interface ParameterTypeConversion {
         expectedParameterType: UnwrappedType
     ): Boolean
 
-    fun conversionIsNeededBeforeSubtypingCheck(argument: KotlinCallArgument): Boolean
+    fun conversionIsNeededBeforeSubtypingCheck(argument: KotlinCallArgument, areSuspendOnlySamConversionsSupported: Boolean): Boolean
     fun conversionIsNeededAfterSubtypingCheck(argument: KotlinCallArgument): Boolean
 
     fun convertParameterType(
@@ -110,7 +111,12 @@ object TypeConversions {
         conversion: ParameterTypeConversion
     ): ConversionData {
         val conversionDefinitelyNotNeeded = conversion.conversionDefinitelyNotNeeded(candidate, argument, candidateExpectedType)
-        return if (!conversionDefinitelyNotNeeded && conversion.conversionIsNeededBeforeSubtypingCheck(argument)) {
+        val areSuspendOnlySamConversionsSupported =
+            candidate.callComponents.languageVersionSettings.supportsFeature(LanguageFeature.SuspendOnlySamConversions)
+        return if (
+            !conversionDefinitelyNotNeeded &&
+            conversion.conversionIsNeededBeforeSubtypingCheck(argument, areSuspendOnlySamConversionsSupported)
+        ) {
             ConversionData(
                 conversion.convertParameterType(candidate, argument, candidateParameter, candidateExpectedType),
                 wasConversion = true,

compiler/testData/codegen/box/sam/kt50477Enabled.kt

@@ -0,0 +1,30 @@
+// !LANGUAGE: +SuspendOnlySamConversions
+// TARGET_BACKEND: JVM_IR
+
+fun interface FI {
+    suspend fun call() // suspending now(!!!)
+}
+
+fun accept(fi: FI): Int = 1
+
+suspend fun foo() {}
+fun foo2() {}
+
+fun box(): String {
+    val fi0: () -> Unit = {}
+    accept(fi0)
+
+    val fi: suspend () -> Unit = {} // Lambda of a suspending(!!!) functional type
+    accept(fi) // ERROR: Type mismatch. Required: FI Found: suspend () → Unit
+
+    accept(::foo)
+    val x1 = ::foo
+    accept(x1) // ERROR: Type mismatch. Required: FI Found: suspend () → Unit
+
+    accept(::foo2)
+    val x2 = ::foo2
+    accept(x2) // ERROR: Type mismatch. Required: FI Found: suspend () → Unit
+
+    return "OK"
+}
+

compiler/testData/diagnostics/tests/samConversions/kt50477.fir.kt

@@ -0,0 +1,23 @@
+// !LANGUAGE: -SuspendOnlySamConversions
+
+fun interface FI {
+    suspend fun call() // suspending now(!!!)
+}
+
+fun accept(fi: FI): Int = TODO()
+
+suspend fun foo() {}
+fun foo2() {}
+
+fun main() {
+    val fi: suspend () -> Unit = {} // Lambda of a suspending(!!!) functional type
+    accept(fi) // ERROR: Type mismatch. Required: FI Found: suspend () → Unit
+
+    accept(::foo)
+    val x1 = ::foo
+    accept(x1) // ERROR: Type mismatch. Required: FI Found: suspend () → Unit
+
+    accept(::foo2)
+    val x2 = ::foo2
+    accept(x2)
+}

compiler/testData/diagnostics/tests/samConversions/kt50477.kt

@@ -0,0 +1,23 @@
+// !LANGUAGE: -SuspendOnlySamConversions
+
+fun interface FI {
+    suspend fun call() // suspending now(!!!)
+}
+
+fun accept(fi: FI): Int = TODO()
+
+suspend fun foo() {}
+fun foo2() {}
+
+fun main() {
+    val fi: suspend () -> Unit = {} // Lambda of a suspending(!!!) functional type
+    accept(<!TYPE_MISMATCH!>fi<!>) // ERROR: Type mismatch. Required: FI Found: suspend () → Unit
+
+    accept(::foo)
+    val x1 = ::foo
+    accept(<!TYPE_MISMATCH!>x1<!>) // ERROR: Type mismatch. Required: FI Found: suspend () → Unit
+
+    accept(::foo2)
+    val x2 = ::foo2
+    accept(x2)
+}

compiler/testData/diagnostics/tests/samConversions/kt50477.txt

@@ -0,0 +1,13 @@
+package
+
+public fun accept(/*0*/ fi: FI): kotlin.Int
+public suspend fun foo(): kotlin.Unit
+public fun foo2(): kotlin.Unit
+public fun main(): kotlin.Unit
+
+public fun interface FI {
+    public abstract suspend fun call(): kotlin.Unit
+    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-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java

@@ -26040,6 +26040,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 runTest("compiler/testData/diagnostics/tests/samConversions/kt17765.kt");
             }
 
+            @Test
+            @TestMetadata("kt50477.kt")
+            public void testKt50477() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/samConversions/kt50477.kt");
+            }
+
             @Test
             @TestMetadata("OverloadPriority.kt")
             public void testOverloadPriority() throws Exception {

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

@@ -44497,6 +44497,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/sam/kt50171.kt");
         }
 
+        @Test
+        @TestMetadata("kt50477Enabled.kt")
+        public void testKt50477Enabled() throws Exception {
+            runTest("compiler/testData/codegen/box/sam/kt50477Enabled.kt");
+        }
+
         @Test
         @TestMetadata("nonInlinedSamWrapper.kt")
         public void testNonInlinedSamWrapper() throws Exception {

compiler/util/src/org/jetbrains/kotlin/config/LanguageVersionSettings.kt

@@ -242,6 +242,7 @@ enum class LanguageFeature(
     ProhibitQualifiedAccessToUninitializedEnumEntry(KOTLIN_1_7, kind = BUG_FIX), // KT-41124
     ForbidRecursiveDelegateExpressions(KOTLIN_1_7, kind = BUG_FIX),
     KotlinFunInterfaceConstructorReference(KOTLIN_1_7),
+    SuspendOnlySamConversions(KOTLIN_1_7),
 
     // 1.8