Do not generate references as adapted with -Xno-optimized-callable-references

The reason for this is that this flag is used right now in 'cli-common'
to workaround the problem that this module is compiled with API version
1.4, but runs with stdlib of version 1.3 (bundled to Gradle). The same
problem would appear with adapted function references, since we use
kotlin/jvm/internal/AdaptedFunctionReference in the bytecode, only
available since 1.4.

The fix is to generate adapted references in this case as subclasses of
the already existing kotlin/jvm/internal/FunctionReference. This can
change behavior in some extreme corner cases (because such references
can now be observed to have reflection capabilities), but it's an -X
argument anyway.

Another option would be to introduce another compiler argument
specifically for this, but it looks like it would only complicate things
without much benefit.

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

@@ -154,8 +154,10 @@ class JvmRuntimeTypes(
 
         val suspendFunctionType = if (referencedFunction.isSuspend) suspendFunctionInterface?.defaultType else null
         val superClass = when {
-            isAdaptedCallableReference || isSuspendConversion -> adaptedFunctionReference
-            generateOptimizedCallableReferenceSuperClasses -> functionReferenceImpl
+            generateOptimizedCallableReferenceSuperClasses -> when {
+                isAdaptedCallableReference || isSuspendConversion -> adaptedFunctionReference
+                else -> functionReferenceImpl
+            }
             else -> functionReference
         }
         return listOfNotNull(superClass.defaultType, functionType, suspendFunctionType)
@@ -178,4 +180,4 @@ class JvmRuntimeTypes(
 
         return classes[arity].defaultType
     }
-}
+}

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

@@ -2070,6 +2070,11 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/manyDefaultsAndVararg.kt");
             }
 
+            @TestMetadata("noAdaptedReferencesIfNoOptimizedReferencesEnabled.kt")
+            public void testNoAdaptedReferencesIfNoOptimizedReferencesEnabled() throws Exception {
+                runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noAdaptedReferencesIfNoOptimizedReferencesEnabled.kt");
+            }
+
             @TestMetadata("noReflectionForAdaptedCallableReferences.kt")
             public void testNoReflectionForAdaptedCallableReferences() throws Exception {
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noReflectionForAdaptedCallableReferences.kt");

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/FunctionReferenceLowering.kt

@@ -124,10 +124,7 @@ internal class FunctionReferenceLowering(private val context: JvmBackendContext)
         private val useOptimizedSuperClass =
             context.state.generateOptimizedCallableReferenceSuperClasses
 
-        private val adaptedReferenceOriginalTarget: IrFunction?
-        private val adapteeCall: IrFunctionAccessExpression?
-
-        init {
+        private val adapteeCall: IrFunctionAccessExpression? =
             if (callee.origin == IrDeclarationOrigin.ADAPTER_FOR_CALLABLE_REFERENCE) {
                 // The body of a callable reference adapter contains either only a call, or an IMPLICIT_COERCION_TO_UNIT type operator
                 // applied to a call. That call's target is the original function which we need to get owner/name/signature.
@@ -144,24 +141,26 @@ internal class FunctionReferenceLowering(private val context: JvmBackendContext)
                 if (call !is IrFunctionAccessExpression) {
                     throw UnsupportedOperationException("Unknown structure of ADAPTER_FOR_CALLABLE_REFERENCE: ${callee.render()}")
                 }
-                adapteeCall = call
-                adaptedReferenceOriginalTarget = call.symbol.owner
+                call
             } else {
-                adapteeCall = null
-                adaptedReferenceOriginalTarget = null
+                null
             }
-        }
+
+        private val adaptedReferenceOriginalTarget: IrFunction? = adapteeCall?.symbol?.owner
+        private val isAdaptedReference = adaptedReferenceOriginalTarget != null
 
         private val needToGenerateSamEqualsHashCodeMethods =
             samSuperType != null &&
                     samSuperType.getClass()?.origin != IrDeclarationOrigin.IR_EXTERNAL_JAVA_DECLARATION_STUB &&
-                    (adaptedReferenceOriginalTarget != null || !isLambda)
+                    (isAdaptedReference || !isLambda)
 
         private val superType =
             samSuperType ?: when {
-                adaptedReferenceOriginalTarget != null -> context.ir.symbols.adaptedFunctionReference
                 isLambda -> context.ir.symbols.lambdaClass
-                useOptimizedSuperClass -> context.ir.symbols.functionReferenceImpl
+                useOptimizedSuperClass -> when {
+                    isAdaptedReference -> context.ir.symbols.adaptedFunctionReference
+                    else -> context.ir.symbols.functionReferenceImpl
+                }
                 else -> context.ir.symbols.functionReference
             }.defaultType
 
@@ -258,7 +257,7 @@ internal class FunctionReferenceLowering(private val context: JvmBackendContext)
 
             SamEqualsHashCodeMethodsGenerator(backendContext, functionReferenceClass, samSuperType) { receiver ->
                 val internalClass = when {
-                    adaptedReferenceOriginalTarget != null -> backendContext.ir.symbols.adaptedFunctionReference
+                    isAdaptedReference -> backendContext.ir.symbols.adaptedFunctionReference
                     else -> backendContext.ir.symbols.functionReferenceImpl
                 }
                 val constructor = internalClass.owner.constructors.single {
@@ -299,7 +298,7 @@ internal class FunctionReferenceLowering(private val context: JvmBackendContext)
                     context.irBuiltIns.anyClass.owner.constructors.single()
                 } else {
                     val expectedArity =
-                        if (isLambda && adaptedReferenceOriginalTarget == null) 1
+                        if (isLambda && !isAdaptedReference) 1
                         else 1 + (if (boundReceiver != null) 1 else 0) + (if (useOptimizedSuperClass) 4 else 0)
                     superType.getClass()!!.constructors.single {
                         it.valueParameters.size == expectedArity
@@ -327,12 +326,8 @@ internal class FunctionReferenceLowering(private val context: JvmBackendContext)
             if (boundReceiver != null) {
                 call.putValueArgument(index++, generateBoundReceiver())
             }
-            val callableReferenceTarget = when {
-                adaptedReferenceOriginalTarget != null -> adaptedReferenceOriginalTarget
-                !isLambda && useOptimizedSuperClass -> callee
-                else -> null
-            }
-            if (callableReferenceTarget != null) {
+            if (!isLambda && useOptimizedSuperClass) {
+                val callableReferenceTarget = adaptedReferenceOriginalTarget ?: callee
                 val owner = calculateOwnerKClass(callableReferenceTarget.parent, backendContext)
                 call.putValueArgument(index++, kClassToJavaClass(owner, backendContext))
                 call.putValueArgument(index++, irString(callableReferenceTarget.originalName.asString()))

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

@@ -0,0 +1,19 @@
+// TARGET_BACKEND: JVM
+// IGNORE_BACKEND_FIR: JVM_IR
+// WITH_RUNTIME
+// KOTLIN_CONFIGURATION_FLAGS: +JVM.NO_OPTIMIZED_CALLABLE_REFERENCES
+
+class A {
+    fun target(): Int = 42
+}
+
+fun foo(f: () -> Unit): Any = f
+
+fun box(): String {
+    val o = foo(A()::target)
+    if (o is kotlin.jvm.internal.AdaptedFunctionReference ||
+        o !is kotlin.jvm.internal.FunctionReference)
+        return "Fail: we shouldn't generate reference to AdaptedFunctionReference if -Xno-optimized-callable-references is enabled"
+
+    return "OK"
+}

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

@@ -2090,6 +2090,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/manyDefaultsAndVararg.kt");
             }
 
+            @TestMetadata("noAdaptedReferencesIfNoOptimizedReferencesEnabled.kt")
+            public void testNoAdaptedReferencesIfNoOptimizedReferencesEnabled() throws Exception {
+                runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noAdaptedReferencesIfNoOptimizedReferencesEnabled.kt");
+            }
+
             @TestMetadata("noReflectionForAdaptedCallableReferences.kt")
             public void testNoReflectionForAdaptedCallableReferences() throws Exception {
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noReflectionForAdaptedCallableReferences.kt");

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

@@ -2090,6 +2090,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/manyDefaultsAndVararg.kt");
             }
 
+            @TestMetadata("noAdaptedReferencesIfNoOptimizedReferencesEnabled.kt")
+            public void testNoAdaptedReferencesIfNoOptimizedReferencesEnabled() throws Exception {
+                runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noAdaptedReferencesIfNoOptimizedReferencesEnabled.kt");
+            }
+
             @TestMetadata("noReflectionForAdaptedCallableReferences.kt")
             public void testNoReflectionForAdaptedCallableReferences() throws Exception {
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noReflectionForAdaptedCallableReferences.kt");

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

@@ -2070,6 +2070,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/manyDefaultsAndVararg.kt");
             }
 
+            @TestMetadata("noAdaptedReferencesIfNoOptimizedReferencesEnabled.kt")
+            public void testNoAdaptedReferencesIfNoOptimizedReferencesEnabled() throws Exception {
+                runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noAdaptedReferencesIfNoOptimizedReferencesEnabled.kt");
+            }
+
             @TestMetadata("noReflectionForAdaptedCallableReferences.kt")
             public void testNoReflectionForAdaptedCallableReferences() throws Exception {
                 runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/noReflectionForAdaptedCallableReferences.kt");