Expose enum .values function when generating Obj-C header

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/objcexport/ObjCExportCodeGenerator.kt

@@ -1229,6 +1229,9 @@ private fun ObjCExportCodeGenerator.createTypeAdapter(
             is ObjCGetterForKotlinEnumEntry -> {
                 classAdapters += createEnumEntryAdapter(it.irEnumEntrySymbol.owner)
             }
+            is ObjCClassMethodForKotlinEnumValues -> {
+                classAdapters += createEnumValuesAdapter(it.valuesFunctionSymbol.owner, it.selector)
+            }
             is ObjCMethodForKotlinMethod -> {} // Handled below.
         }.let {} // Force exhaustive.
     }
@@ -1473,6 +1476,21 @@ private fun ObjCExportCodeGenerator.createEnumEntryAdapter(
     }
 }
 
+private fun ObjCExportCodeGenerator.createEnumValuesAdapter(
+        valuesFunction: IrFunction,
+        selector: String
+): ObjCExportCodeGenerator.ObjCToKotlinMethodAdapter {
+    val methodBridge = MethodBridge(
+            returnBridge = MethodBridge.ReturnValue.Mapped(ReferenceBridge),
+            receiver = MethodBridgeReceiver.Static,
+            valueParameters = emptyList()
+    )
+
+    val imp = generateObjCImp(valuesFunction, valuesFunction, methodBridge, isVirtual = false)
+
+    return objCToKotlinMethodAdapter(selector, methodBridge, imp)
+}
+
 private fun List<CallableMemberDescriptor>.toMethods(): List<FunctionDescriptor> = this.flatMap {
     when (it) {
         is PropertyDescriptor -> listOfNotNull(it.getter, it.setter)

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/objcexport/ObjCExportCodeSpec.kt

@@ -10,10 +10,7 @@ import org.jetbrains.kotlin.backend.konan.descriptors.enumEntries
 import org.jetbrains.kotlin.backend.konan.descriptors.isArray
 import org.jetbrains.kotlin.backend.konan.descriptors.isInterface
 import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
-import org.jetbrains.kotlin.ir.symbols.IrConstructorSymbol
-import org.jetbrains.kotlin.ir.symbols.IrEnumEntrySymbol
-import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
+import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.util.SymbolTable
 import org.jetbrains.kotlin.resolve.descriptorUtil.getSuperClassNotAny
 
@@ -67,6 +64,13 @@ internal fun ObjCExportedInterface.createCodeSpec(symbolTable: SymbolTable): Obj
                 descriptor.enumEntries.mapTo(methods) {
                     ObjCGetterForKotlinEnumEntry(symbolTable.referenceEnumEntry(it))
                 }
+
+                descriptor.getEnumValuesFunctionDescriptor()?.let {
+                    methods += ObjCClassMethodForKotlinEnumValues(
+                            symbolTable.referenceSimpleFunction(it),
+                            namer.getEnumValuesSelector(it)
+                    )
+                }
             }
 
             val categoryMethods = categoryMembers[descriptor].orEmpty().toObjCMethods()
@@ -100,6 +104,11 @@ internal class ObjCFactoryMethodForKotlinArrayConstructor(
 
 internal class ObjCGetterForKotlinEnumEntry(val irEnumEntrySymbol: IrEnumEntrySymbol) : ObjCMethodSpec()
 
+internal class ObjCClassMethodForKotlinEnumValues(
+        val valuesFunctionSymbol: IrFunctionSymbol,
+        val selector: String
+) : ObjCMethodSpec()
+
 internal sealed class ObjCTypeSpec(val binaryName: String)
 
 internal sealed class ObjCTypeForKotlinType(

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/objcexport/ObjCExportHeaderGenerator.kt

@@ -365,6 +365,14 @@ internal class ObjCExportTranslatorImpl(
                         +ObjCProperty(entryName, it, type, listOf("class", "readonly"),
                                 declarationAttributes = listOf(swiftNameAttribute(entryName)))
                     }
+
+                    // Note: it is possible to support this function through a common machinery,
+                    // but it is very special (static and synthetic), so apparently it is much easier
+                    // to keep this ad hoc here than to add special cases to the most complicated parts
+                    // of the machinery.
+                    descriptor.getEnumValuesFunctionDescriptor()?.let { enumValues ->
+                        +buildEnumValuesMethod(enumValues, genericExportScope)
+                    }
                 }
                 else -> {
                     // Nothing special.
@@ -404,6 +412,21 @@ internal class ObjCExportTranslatorImpl(
         )
     }
 
+    private fun buildEnumValuesMethod(
+            enumValues: SimpleFunctionDescriptor,
+            genericExportScope: ObjCExportScope
+    ): ObjCMethod {
+        val selector = namer.getEnumValuesSelector(enumValues)
+        return ObjCMethod(
+                enumValues,
+                isInstanceMethod = false,
+                returnType = mapReferenceType(enumValues.returnType!!, genericExportScope),
+                selectors = splitSelector(selector),
+                parameters = emptyList(),
+                attributes = listOf(swiftNameAttribute("$selector()"))
+        )
+    }
+
     private fun ClassDescriptor.getExposedMembers(): List<CallableMemberDescriptor> =
             this.unsubstitutedMemberScope.getContributedDescriptors()
                     .asSequence()

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/objcexport/ObjCExportMapper.kt

@@ -13,6 +13,7 @@ import org.jetbrains.kotlin.backend.konan.descriptors.isArray
 import org.jetbrains.kotlin.backend.konan.descriptors.isInterface
 import org.jetbrains.kotlin.builtins.*
 import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.incremental.components.NoLookupLocation
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.resolve.deprecation.Deprecation
 import org.jetbrains.kotlin.resolve.deprecation.DeprecationLevelValue
@@ -181,6 +182,15 @@ internal fun ObjCExportMapper.isTopLevel(descriptor: CallableMemberDescriptor):
 internal fun ObjCExportMapper.isObjCProperty(property: PropertyDescriptor): Boolean =
         property.extensionReceiverParameter == null || getClassIfCategory(property) != null
 
+internal fun ClassDescriptor.getEnumValuesFunctionDescriptor(): SimpleFunctionDescriptor? {
+    require(this.kind == ClassKind.ENUM_CLASS)
+
+    return this.staticScope.getContributedFunctions(
+            StandardNames.ENUM_VALUES,
+            NoLookupLocation.FROM_BACKEND
+    ).singleOrNull { it.extensionReceiverParameter == null && it.valueParameters.size == 0 }
+}
+
 internal fun ObjCExportMapper.doesThrow(method: FunctionDescriptor): Boolean = method.allOverriddenDescriptors.any {
     it.overriddenDescriptors.isEmpty() && it.annotations.hasAnnotation(KonanFqNames.throws)
 }

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/objcexport/ObjCExportNamer.kt

@@ -11,6 +11,7 @@ import org.jetbrains.kotlin.backend.konan.descriptors.isArray
 import org.jetbrains.kotlin.backend.konan.descriptors.isInterface
 import org.jetbrains.kotlin.descriptors.konan.isNativeStdlib
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.builtins.StandardNames
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.konan.*
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation
@@ -56,6 +57,7 @@ interface ObjCExportNamer {
     fun getPropertyName(property: PropertyDescriptor): String
     fun getObjectInstanceSelector(descriptor: ClassDescriptor): String
     fun getEnumEntrySelector(descriptor: ClassDescriptor): String
+    fun getEnumValuesSelector(descriptor: FunctionDescriptor): String
     fun getTypeParameterName(typeParameterDescriptor: TypeParameterDescriptor): String
 
     fun numberBoxName(classId: ClassId): ClassOrProtocolName
@@ -328,7 +330,7 @@ internal class ObjCExportNamerImpl(
 
     private val genericTypeParameterNameMapping = GenericTypeParameterNameMapping()
 
-    private abstract inner class ClassPropertyNameMapping<T : Any> : Mapping<T, String>() {
+    private abstract inner class ClassSelectorNameMapping<T : Any> : Mapping<T, String>() {
 
         // Try to avoid clashing with NSObject class methods:
 
@@ -343,12 +345,12 @@ internal class ObjCExportNamerImpl(
         override fun reserved(name: String) = (name in reserved) || (name in cKeywords)
     }
 
-    private val objectInstanceSelectors = object : ClassPropertyNameMapping<ClassDescriptor>() {
+    private val objectInstanceSelectors = object : ClassSelectorNameMapping<ClassDescriptor>() {
         override fun conflict(first: ClassDescriptor, second: ClassDescriptor) = false
     }
 
-    private val enumEntrySelectors = object : ClassPropertyNameMapping<ClassDescriptor>() {
-        override fun conflict(first: ClassDescriptor, second: ClassDescriptor) =
+    private val enumClassSelectors = object : ClassSelectorNameMapping<DeclarationDescriptor>() {
+        override fun conflict(first: DeclarationDescriptor, second: DeclarationDescriptor) =
                 first.containingDeclaration == second.containingDeclaration
     }
 
@@ -558,7 +560,7 @@ internal class ObjCExportNamerImpl(
     override fun getEnumEntrySelector(descriptor: ClassDescriptor): String {
         assert(descriptor.kind == ClassKind.ENUM_ENTRY)
 
-        return enumEntrySelectors.getOrPut(descriptor) {
+        return enumClassSelectors.getOrPut(descriptor) {
             // FOO_BAR_BAZ -> fooBarBaz:
             val name = descriptor.name.asString().split('_').mapIndexed { index, s ->
                 val lower = s.toLowerCase()
@@ -569,6 +571,19 @@ internal class ObjCExportNamerImpl(
         }
     }
 
+    override fun getEnumValuesSelector(descriptor: FunctionDescriptor): String {
+        val containingDeclaration = descriptor.containingDeclaration
+        require(containingDeclaration is ClassDescriptor && containingDeclaration.kind == ClassKind.ENUM_CLASS)
+        require(descriptor.name == StandardNames.ENUM_VALUES)
+        require(descriptor.dispatchReceiverParameter == null) { "must be static" }
+        require(descriptor.extensionReceiverParameter == null) { "must be static" }
+        require(descriptor.valueParameters.isEmpty())
+
+        return enumClassSelectors.getOrPut(descriptor) {
+            StringBuilder(descriptor.name.asString()).mangledBySuffixUnderscores()
+        }
+    }
+
     override fun getTypeParameterName(typeParameterDescriptor: TypeParameterDescriptor): String {
         return genericTypeParameterNameMapping.getOrPut(typeParameterDescriptor) {
             StringBuilder().apply {

kotlin-native/backend.native/tests/objcexport/enumValues.kt

@@ -0,0 +1,16 @@
+package enumValues
+
+enum class EnumLeftRightUpDown {
+    LEFT, RIGHT, UP, DOWN
+}
+
+enum class EnumOneTwoThreeValues {
+    ONE, TWO, THREE, VALUES
+}
+
+enum class EnumValuesValues_ {
+    VALUES, VALUES_
+}
+
+enum class EmptyEnum {
+}

kotlin-native/backend.native/tests/objcexport/enumValues.swift

@@ -0,0 +1,47 @@
+import Kt
+
+private func testEnumValues() throws {
+    let values = EnumLeftRightUpDown.values()
+
+    try assertEquals(actual: values.size, expected: 4)
+
+    try assertSame(actual: values.get(index: 0), expected: EnumLeftRightUpDown.left)
+    try assertSame(actual: values.get(index: 1), expected: EnumLeftRightUpDown.right)
+    try assertSame(actual: values.get(index: 2), expected: EnumLeftRightUpDown.up)
+    try assertSame(actual: values.get(index: 3), expected: EnumLeftRightUpDown.down)
+}
+
+private func testEnumValuesMangled() throws {
+    let values = EnumOneTwoThreeValues.values_()
+
+    try assertEquals(actual: values.size, expected: 4)
+
+    try assertSame(actual: values.get(index: 0), expected: EnumOneTwoThreeValues.one)
+    try assertSame(actual: values.get(index: 1), expected: EnumOneTwoThreeValues.two)
+    try assertSame(actual: values.get(index: 2), expected: EnumOneTwoThreeValues.three)
+    try assertSame(actual: values.get(index: 3), expected: EnumOneTwoThreeValues.values)
+}
+
+private func testEnumValuesMangledTwice() throws {
+    let values = EnumValuesValues_.values__()
+
+    try assertEquals(actual: values.size, expected: 2)
+
+    try assertSame(actual: values.get(index: 0), expected: EnumValuesValues_.values)
+    try assertSame(actual: values.get(index: 1), expected: EnumValuesValues_.values_)
+}
+
+private func testEnumValuesEmpty() throws {
+    try assertEquals(actual: EmptyEnum.values().size, expected: 0)
+}
+
+class EnumValuesTests : SimpleTestProvider {
+    override init() {
+        super.init()
+
+        test("TestEnumValues", testEnumValues)
+        test("TestEnumValuesMangled", testEnumValuesMangled)
+        test("TestEnumValuesMangledTwice", testEnumValuesMangledTwice)
+        test("TestEnumValuesEmpty", testEnumValuesEmpty)
+    }
+}

kotlin-native/backend.native/tests/objcexport/expectedLazy.h

@@ -331,6 +331,52 @@ __attribute__((swift_name("DeallocRetainKt")))
 + (KtKotlinWeakReference<id> *)createWeakReferenceValue:(id)value __attribute__((swift_name("createWeakReference(value:)")));
 @end;
 
+__attribute__((objc_subclassing_restricted))
+__attribute__((swift_name("EnumLeftRightUpDown")))
+@interface KtEnumLeftRightUpDown : KtKotlinEnum<KtEnumLeftRightUpDown *>
++ (instancetype)alloc __attribute__((unavailable));
++ (instancetype)allocWithZone:(struct _NSZone *)zone __attribute__((unavailable));
+- (instancetype)initWithName:(NSString *)name ordinal:(int32_t)ordinal __attribute__((swift_name("init(name:ordinal:)"))) __attribute__((objc_designated_initializer)) __attribute__((unavailable));
+@property (class, readonly) KtEnumLeftRightUpDown *left __attribute__((swift_name("left")));
+@property (class, readonly) KtEnumLeftRightUpDown *right __attribute__((swift_name("right")));
+@property (class, readonly) KtEnumLeftRightUpDown *up __attribute__((swift_name("up")));
+@property (class, readonly) KtEnumLeftRightUpDown *down __attribute__((swift_name("down")));
++ (KtKotlinArray<KtEnumLeftRightUpDown *> *)values __attribute__((swift_name("values()")));
+@end;
+
+__attribute__((objc_subclassing_restricted))
+__attribute__((swift_name("EnumOneTwoThreeValues")))
+@interface KtEnumOneTwoThreeValues : KtKotlinEnum<KtEnumOneTwoThreeValues *>
++ (instancetype)alloc __attribute__((unavailable));
++ (instancetype)allocWithZone:(struct _NSZone *)zone __attribute__((unavailable));
+- (instancetype)initWithName:(NSString *)name ordinal:(int32_t)ordinal __attribute__((swift_name("init(name:ordinal:)"))) __attribute__((objc_designated_initializer)) __attribute__((unavailable));
+@property (class, readonly) KtEnumOneTwoThreeValues *one __attribute__((swift_name("one")));
+@property (class, readonly) KtEnumOneTwoThreeValues *two __attribute__((swift_name("two")));
+@property (class, readonly) KtEnumOneTwoThreeValues *three __attribute__((swift_name("three")));
+@property (class, readonly) KtEnumOneTwoThreeValues *values __attribute__((swift_name("values")));
++ (KtKotlinArray<KtEnumOneTwoThreeValues *> *)values __attribute__((swift_name("values()")));
+@end;
+
+__attribute__((objc_subclassing_restricted))
+__attribute__((swift_name("EnumValuesValues_")))
+@interface KtEnumValuesValues_ : KtKotlinEnum<KtEnumValuesValues_ *>
++ (instancetype)alloc __attribute__((unavailable));
++ (instancetype)allocWithZone:(struct _NSZone *)zone __attribute__((unavailable));
+- (instancetype)initWithName:(NSString *)name ordinal:(int32_t)ordinal __attribute__((swift_name("init(name:ordinal:)"))) __attribute__((objc_designated_initializer)) __attribute__((unavailable));
+@property (class, readonly) KtEnumValuesValues_ *values __attribute__((swift_name("values")));
+@property (class, readonly) KtEnumValuesValues_ *values __attribute__((swift_name("values")));
++ (KtKotlinArray<KtEnumValuesValues_ *> *)values __attribute__((swift_name("values()")));
+@end;
+
+__attribute__((objc_subclassing_restricted))
+__attribute__((swift_name("EmptyEnum")))
+@interface KtEmptyEnum : KtKotlinEnum<KtEmptyEnum *>
++ (instancetype)alloc __attribute__((unavailable));
++ (instancetype)allocWithZone:(struct _NSZone *)zone __attribute__((unavailable));
+- (instancetype)initWithName:(NSString *)name ordinal:(int32_t)ordinal __attribute__((swift_name("init(name:ordinal:)"))) __attribute__((objc_designated_initializer)) __attribute__((unavailable));
++ (KtKotlinArray<KtEmptyEnum *> *)values __attribute__((swift_name("values()")));
+@end;
+
 __attribute__((swift_name("FHolder")))
 @interface KtFHolder : KtBase
 - (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
@@ -696,6 +742,7 @@ __attribute__((swift_name("Enumeration")))
 @property (class, readonly) KtEnumeration *answer __attribute__((swift_name("answer")));
 @property (class, readonly) KtEnumeration *year __attribute__((swift_name("year")));
 @property (class, readonly) KtEnumeration *temperature __attribute__((swift_name("temperature")));
++ (KtKotlinArray<KtEnumeration *> *)values __attribute__((swift_name("values()")));
 @property (readonly) int32_t enumValue __attribute__((swift_name("enumValue")));
 @end;
 
@@ -1407,6 +1454,7 @@ __attribute__((swift_name("TestInvalidIdentifiers.E")))
 @property (class, readonly) KtTestInvalidIdentifiersE *_5_ __attribute__((swift_name("_5_")));
 @property (class, readonly) KtTestInvalidIdentifiersE *__ __attribute__((swift_name("__")));
 @property (class, readonly) KtTestInvalidIdentifiersE *__ __attribute__((swift_name("__")));
++ (KtKotlinArray<KtTestInvalidIdentifiersE *> *)values __attribute__((swift_name("values()")));
 @property (readonly) int32_t value __attribute__((swift_name("value")));
 @end;