JVM: Suspend converted references inherit AdaptedFunctionReference

compiler/backend/src/org/jetbrains/kotlin/codegen/ClosureCodegen.java

@@ -12,7 +12,6 @@ import kotlin.Unit;
 import kotlin.collections.CollectionsKt;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
-import org.jetbrains.kotlin.builtins.FunctionTypesKt;
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns;
 import org.jetbrains.kotlin.codegen.binding.CalculatedClosure;
 import org.jetbrains.kotlin.codegen.binding.CodegenBinding;
@@ -528,7 +527,7 @@ public class ClosureCodegen extends MemberCodegen<KtElement> {
                     PropertyReferenceCodegen.generateCallableReferenceSignature(iv, functionReferenceTarget, state);
                     int flags =
                             (isTopLevelCallableReference(functionReferenceTarget) ? 1 : 0) +
-                            (calculateFunctionReferenceFlags(functionReferenceCall, funDescriptor, classDescriptor) << 1);
+                            (calculateFunctionReferenceFlags(functionReferenceCall, funDescriptor) << 1);
                     iv.aconst(flags);
                     superCtorArgTypes.add(JAVA_CLASS_TYPE);
                     superCtorArgTypes.add(JAVA_STRING_TYPE);
@@ -553,8 +552,7 @@ public class ClosureCodegen extends MemberCodegen<KtElement> {
 
     private static int calculateFunctionReferenceFlags(
             @NotNull ResolvedCall<?> call,
-            @NotNull FunctionDescriptor anonymousAdaptedFunction,
-            @NotNull ClassDescriptor classDescriptor
+            @NotNull FunctionDescriptor anonymousAdapterFunction
     ) {
         boolean hasVarargMappedToElement = false;
         FunctionDescriptor target = (FunctionDescriptor) call.getResultingDescriptor();
@@ -562,10 +560,10 @@ public class ClosureCodegen extends MemberCodegen<KtElement> {
                 (call.getDispatchReceiver() instanceof TransientReceiver ? 1 : 0) +
                 (call.getExtensionReceiver() instanceof TransientReceiver ? 1 : 0);
         for (int i = shift;
-             i < anonymousAdaptedFunction.getValueParameters().size() && i - shift < target.getValueParameters().size();
+             i < anonymousAdapterFunction.getValueParameters().size() && i - shift < target.getValueParameters().size();
              i++) {
             ValueParameterDescriptor targetParameter = target.getValueParameters().get(i - shift);
-            ValueParameterDescriptor adaptedParameter = anonymousAdaptedFunction.getValueParameters().get(i);
+            ValueParameterDescriptor adaptedParameter = anonymousAdapterFunction.getValueParameters().get(i);
 
             // Vararg to element conversion is happening if the target parameter is vararg (e.g. `vararg xs: Int`),
             // but the adapted parameter's type is not equal to the target parameter's type (which is `IntArray`).
@@ -577,12 +575,10 @@ public class ClosureCodegen extends MemberCodegen<KtElement> {
         }
 
         //noinspection ConstantConditions
-        boolean hasCoercionToUnit = KotlinBuiltIns.isUnit(anonymousAdaptedFunction.getReturnType()) &&
+        boolean hasCoercionToUnit = KotlinBuiltIns.isUnit(anonymousAdapterFunction.getReturnType()) &&
                                     !KotlinBuiltIns.isUnit(target.getReturnType());
 
-        boolean hasSuspendConversion =
-                !target.isSuspend() &&
-                classDescriptor.getTypeConstructor().getSupertypes().stream().anyMatch(FunctionTypesKt::isSuspendFunctionType);
+        boolean hasSuspendConversion = !target.isSuspend() && anonymousAdapterFunction.isSuspend();
 
         return (hasVarargMappedToElement ? 1 : 0) +
                (hasSuspendConversion ? 2 : 0) +

compiler/backend/src/org/jetbrains/kotlin/codegen/JvmRuntimeTypes.kt

@@ -154,7 +154,7 @@ class JvmRuntimeTypes(
 
         val suspendFunctionType = if (referencedFunction.isSuspend) suspendFunctionInterface?.defaultType else null
         val superClass = when {
-            isAdaptedCallableReference -> adaptedFunctionReference
+            isAdaptedCallableReference || isSuspendConversion -> adaptedFunctionReference
             generateOptimizedCallableReferenceSuperClasses -> functionReferenceImpl
             else -> functionReference
         }

compiler/fir/fir2ir/tests/org/jetbrains/kotlin/codegen/ir/FirBlackBoxCodegenTestGenerated.java

@@ -2075,6 +2075,11 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noReflectionForAdaptedCallableReferences.kt");
             }
 
+            @TestMetadata("noReflectionForAdaptedCallableReferencesWithSuspendConversion.kt")
+            public void testNoReflectionForAdaptedCallableReferencesWithSuspendConversion() throws Exception {
+                runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noReflectionForAdaptedCallableReferencesWithSuspendConversion.kt");
+            }
+
             @TestMetadata("reflectionForVarargAsArray.kt")
             public void testReflectionForVarargAsArray() throws Exception {
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/reflectionForVarargAsArray.kt");

compiler/testData/codegen/box/callableReference/adaptedReferences/noReflectionForAdaptedCallableReferencesWithSuspendConversion.kt

@@ -0,0 +1,26 @@
+// !LANGUAGE: +SuspendConversion
+// TARGET_BACKEND: JVM
+// IGNORE_BACKEND_FIR: JVM_IR
+// WITH_RUNTIME
+
+import kotlin.reflect.KCallable
+
+private fun check(label: String, fn: Any) {
+    if (fn is KCallable<*>) {
+        throw AssertionError("$label is KCallable, ${fn::class.java.simpleName}")
+    }
+}
+
+fun checkSuspend(label: String, fn: suspend () -> Unit) = check(label, fn)
+fun checkSuspendAny(label: String, fn: suspend () -> Any) = check(label, fn)
+
+fun withSuspendConversion() {}
+
+class CCtorAsSuspend()
+
+fun box(): String {
+    checkSuspend("::withSuspendConversion", ::withSuspendConversion)
+    checkSuspendAny("::CCtorAsSuspend", ::CCtorAsSuspend)
+
+    return "OK"
+}

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -2095,6 +2095,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noReflectionForAdaptedCallableReferences.kt");
             }
 
+            @TestMetadata("noReflectionForAdaptedCallableReferencesWithSuspendConversion.kt")
+            public void testNoReflectionForAdaptedCallableReferencesWithSuspendConversion() throws Exception {
+                runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noReflectionForAdaptedCallableReferencesWithSuspendConversion.kt");
+            }
+
             @TestMetadata("reflectionForVarargAsArray.kt")
             public void testReflectionForVarargAsArray() throws Exception {
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/reflectionForVarargAsArray.kt");

compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -2095,6 +2095,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noReflectionForAdaptedCallableReferences.kt");
             }
 
+            @TestMetadata("noReflectionForAdaptedCallableReferencesWithSuspendConversion.kt")
+            public void testNoReflectionForAdaptedCallableReferencesWithSuspendConversion() throws Exception {
+                runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noReflectionForAdaptedCallableReferencesWithSuspendConversion.kt");
+            }
+
             @TestMetadata("reflectionForVarargAsArray.kt")
             public void testReflectionForVarargAsArray() throws Exception {
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/reflectionForVarargAsArray.kt");

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -2075,6 +2075,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noReflectionForAdaptedCallableReferences.kt");
             }
 
+            @TestMetadata("noReflectionForAdaptedCallableReferencesWithSuspendConversion.kt")
+            public void testNoReflectionForAdaptedCallableReferencesWithSuspendConversion() throws Exception {
+                runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noReflectionForAdaptedCallableReferencesWithSuspendConversion.kt");
+            }
+
             @TestMetadata("reflectionForVarargAsArray.kt")
             public void testReflectionForVarargAsArray() throws Exception {
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/reflectionForVarargAsArray.kt");

libraries/stdlib/jvm/runtime/kotlin/jvm/internal/FunctionReference.java

@@ -26,6 +26,11 @@ public class FunctionReference extends CallableReference implements FunctionBase
      *         fun use(f: () -> Unit) {}
      *         use(::target)
      *     </pre></ul>
+     *     <ul>2 - whether suspend conversion happened, i.e.,<pre>
+     *         fun target() {}
+     *         fun useSuspend(f: suspend () -> Unit) {}
+     *         useSuspend(::target)
+     *     </pre></ul>
      * </li>
      */
     @SinceKotlin(version = "1.4")