Generate private interface companion object as package-private synthetic

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

@@ -482,6 +482,10 @@ public class AsmUtil {
         DeclarationDescriptor containingDeclaration = memberDescriptor.getContainingDeclaration();
         Visibility memberVisibility = memberDescriptor.getVisibility();
 
+        if (JvmCodegenUtil.isNonIntrinsicPrivateCompanionObjectInInterface(memberDescriptor)) {
+            return ACC_PUBLIC;
+        }
+
         if (memberDescriptor instanceof FunctionDescriptor &&
             isInlineClassWrapperConstructor((FunctionDescriptor) memberDescriptor, kind)) {
             return ACC_PRIVATE;

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

@@ -786,12 +786,15 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
                 state.getLanguageVersionSettings().supportsFeature(LanguageFeature.DeprecatedFieldForInvisibleCompanionObject);
         boolean properVisibilityForCompanionObjectInstanceField =
                 state.getLanguageVersionSettings().supportsFeature(LanguageFeature.ProperVisibilityForCompanionObjectInstanceField);
+        boolean hasPrivateOrProtectedProperVisibility = (properFieldVisibilityFlag & (ACC_PRIVATE | ACC_PROTECTED)) != 0;
+        boolean hasPackagePrivateProperVisibility = (properFieldVisibilityFlag & (ACC_PUBLIC | ACC_PRIVATE | ACC_PROTECTED)) == 0;
         boolean fieldShouldBeDeprecated =
                 deprecatedFieldForInvisibleCompanionObject &&
                 !properVisibilityForCompanionObjectInstanceField &&
-                (properFieldVisibilityFlag & (ACC_PRIVATE | ACC_PROTECTED)) != 0;
+                (hasPrivateOrProtectedProperVisibility || hasPackagePrivateProperVisibility ||
+                 isNonIntrinsicPrivateCompanionObjectInInterface(companionObjectDescriptor));
         boolean doNotGeneratePublic =
-                properVisibilityForCompanionObjectInstanceField && (properFieldVisibilityFlag & (ACC_PRIVATE | ACC_PROTECTED)) != 0;
+                properVisibilityForCompanionObjectInstanceField && hasPrivateOrProtectedProperVisibility;
         int fieldAccessFlags;
         if (doNotGeneratePublic) {
             fieldAccessFlags = ACC_STATIC | ACC_FINAL;
@@ -805,6 +808,11 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
         if (fieldShouldBeDeprecated) {
             fieldAccessFlags |= ACC_DEPRECATED;
         }
+        if (properVisibilityForCompanionObjectInstanceField &&
+            JvmCodegenUtil.isCompanionObjectInInterfaceNotIntrinsic(companionObjectDescriptor) &&
+            Visibilities.isPrivate(companionObjectDescriptor.getVisibility())) {
+            fieldAccessFlags |= ACC_SYNTHETIC;
+        }
         StackValue.Field field = StackValue.singleton(companionObjectDescriptor, typeMapper);
         FieldVisitor fv = v.newField(JvmDeclarationOriginKt.OtherOrigin(companionObject == null ? myClass.getPsiOrParent() : companionObject),
                                      fieldAccessFlags, field.name, field.type.getDescriptor(), null, null);

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

@@ -348,6 +348,11 @@ public class JvmCodegenUtil {
                !JvmAbi.isMappedIntrinsicCompanionObject((ClassDescriptor) companionObject);
     }
 
+    public static boolean isNonIntrinsicPrivateCompanionObjectInInterface(@NotNull DeclarationDescriptorWithVisibility companionObject) {
+        return isCompanionObjectInInterfaceNotIntrinsic(companionObject) &&
+               Visibilities.isPrivate(companionObject.getVisibility());
+    }
+
     public static boolean isDeclarationOfBigArityFunctionInvoke(@Nullable DeclarationDescriptor descriptor) {
         return descriptor instanceof FunctionInvokeDescriptor && ((FunctionInvokeDescriptor) descriptor).hasBigArity();
     }

compiler/testData/codegen/box/objects/companionObjectAccess/kt27121.kt

@@ -0,0 +1,14 @@
+// !LANGUAGE: +ProperVisibilityForCompanionObjectInstanceField
+// IGNORE_BACKEND: JS, JS_IR, JVM_IR
+
+interface A {
+    fun test() = ok()
+
+    private companion object {
+        fun ok() = "OK"
+    }
+}
+
+class C : A
+
+fun box() = C().test()

compiler/testData/codegen/bytecodeListing/companionObjectVisibility_after.kt

@@ -0,0 +1,17 @@
+// !LANGUAGE: +ProperVisibilityForCompanionObjectInstanceField
+
+open class TestProtectedCompanionInClass {
+    protected companion object
+}
+
+class TestInternalCompanionInClass {
+    internal companion object
+}
+
+class TestPrivateCompanionInClass {
+    private companion object
+}
+
+interface TestPrivateCompanionInInterface {
+    private companion object
+}

compiler/testData/codegen/bytecodeListing/companionObjectVisibility_after.txt

@@ -0,0 +1,59 @@
+@kotlin.Metadata
+public final class TestInternalCompanionInClass$Companion {
+    inner class TestInternalCompanionInClass$Companion
+    private method <init>(): void
+    public synthetic method <init>(p0: kotlin.jvm.internal.DefaultConstructorMarker): void
+}
+
+@kotlin.Metadata
+public final class TestInternalCompanionInClass {
+    public final static field Companion: TestInternalCompanionInClass$Companion
+    inner class TestInternalCompanionInClass$Companion
+    static method <clinit>(): void
+    public method <init>(): void
+}
+
+@kotlin.Metadata
+final class TestPrivateCompanionInClass$Companion {
+    inner class TestPrivateCompanionInClass$Companion
+    private method <init>(): void
+    public synthetic method <init>(p0: kotlin.jvm.internal.DefaultConstructorMarker): void
+}
+
+@kotlin.Metadata
+public final class TestPrivateCompanionInClass {
+    private final static field Companion: TestPrivateCompanionInClass$Companion
+    inner class TestPrivateCompanionInClass$Companion
+    static method <clinit>(): void
+    public method <init>(): void
+}
+
+@kotlin.Metadata
+final class TestPrivateCompanionInInterface$Companion {
+    synthetic final static field $$INSTANCE: TestPrivateCompanionInInterface$Companion
+    inner class TestPrivateCompanionInInterface$Companion
+    static method <clinit>(): void
+    private method <init>(): void
+}
+
+@kotlin.Metadata
+public interface TestPrivateCompanionInInterface {
+    public synthetic final static field Companion: TestPrivateCompanionInInterface$Companion
+    inner class TestPrivateCompanionInInterface$Companion
+    static method <clinit>(): void
+}
+
+@kotlin.Metadata
+public final class TestProtectedCompanionInClass$Companion {
+    inner class TestProtectedCompanionInClass$Companion
+    private method <init>(): void
+    public synthetic method <init>(p0: kotlin.jvm.internal.DefaultConstructorMarker): void
+}
+
+@kotlin.Metadata
+public class TestProtectedCompanionInClass {
+    protected final static field Companion: TestProtectedCompanionInClass$Companion
+    inner class TestProtectedCompanionInClass$Companion
+    static method <clinit>(): void
+    public method <init>(): void
+}

compiler/testData/codegen/bytecodeListing/companionObjectVisibility_before.kt

@@ -0,0 +1,17 @@
+// !LANGUAGE: -ProperVisibilityForCompanionObjectInstanceField
+
+open class TestProtectedCompanionInClass {
+    protected companion object
+}
+
+class TestInternalCompanionInClass {
+    internal companion object
+}
+
+class TestPrivateCompanionInClass {
+    private companion object
+}
+
+interface TestPrivateCompanionInInterface {
+    private companion object
+}

compiler/testData/codegen/bytecodeListing/companionObjectVisibility_before.txt

@@ -0,0 +1,59 @@
+@kotlin.Metadata
+public final class TestInternalCompanionInClass$Companion {
+    inner class TestInternalCompanionInClass$Companion
+    private method <init>(): void
+    public synthetic method <init>(p0: kotlin.jvm.internal.DefaultConstructorMarker): void
+}
+
+@kotlin.Metadata
+public final class TestInternalCompanionInClass {
+    public final static field Companion: TestInternalCompanionInClass$Companion
+    inner class TestInternalCompanionInClass$Companion
+    static method <clinit>(): void
+    public method <init>(): void
+}
+
+@kotlin.Metadata
+final class TestPrivateCompanionInClass$Companion {
+    inner class TestPrivateCompanionInClass$Companion
+    private method <init>(): void
+    public synthetic method <init>(p0: kotlin.jvm.internal.DefaultConstructorMarker): void
+}
+
+@kotlin.Metadata
+public final class TestPrivateCompanionInClass {
+    public deprecated final static @java.lang.Deprecated field Companion: TestPrivateCompanionInClass$Companion
+    inner class TestPrivateCompanionInClass$Companion
+    static method <clinit>(): void
+    public method <init>(): void
+}
+
+@kotlin.Metadata
+final class TestPrivateCompanionInInterface$Companion {
+    synthetic final static field $$INSTANCE: TestPrivateCompanionInInterface$Companion
+    inner class TestPrivateCompanionInInterface$Companion
+    static method <clinit>(): void
+    private method <init>(): void
+}
+
+@kotlin.Metadata
+public interface TestPrivateCompanionInInterface {
+    public deprecated final static @java.lang.Deprecated field Companion: TestPrivateCompanionInInterface$Companion
+    inner class TestPrivateCompanionInInterface$Companion
+    static method <clinit>(): void
+}
+
+@kotlin.Metadata
+public final class TestProtectedCompanionInClass$Companion {
+    inner class TestProtectedCompanionInClass$Companion
+    private method <init>(): void
+    public synthetic method <init>(p0: kotlin.jvm.internal.DefaultConstructorMarker): void
+}
+
+@kotlin.Metadata
+public class TestProtectedCompanionInClass {
+    public deprecated final static @java.lang.Deprecated field Companion: TestProtectedCompanionInClass$Companion
+    inner class TestProtectedCompanionInClass$Companion
+    static method <clinit>(): void
+    public method <init>(): void
+}

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

@@ -15123,6 +15123,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 runTest("compiler/testData/codegen/box/objects/companionObjectAccess/kt27117.kt");
             }
 
+            @TestMetadata("kt27121.kt")
+            public void testKt27121() throws Exception {
+                runTest("compiler/testData/codegen/box/objects/companionObjectAccess/kt27121.kt");
+            }
+
             @TestMetadata("privateCompanionObjectAccessedFromAnonymousObjectInNestedClass.kt")
             public void testPrivateCompanionObjectAccessedFromAnonymousObjectInNestedClass() throws Exception {
                 runTest("compiler/testData/codegen/box/objects/companionObjectAccess/privateCompanionObjectAccessedFromAnonymousObjectInNestedClass.kt");

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

@@ -38,6 +38,16 @@ public class BytecodeListingTestGenerated extends AbstractBytecodeListingTest {
         runTest("compiler/testData/codegen/bytecodeListing/callableNameIntrinsic.kt");
     }
 
+    @TestMetadata("companionObjectVisibility_after.kt")
+    public void testCompanionObjectVisibility_after() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeListing/companionObjectVisibility_after.kt");
+    }
+
+    @TestMetadata("companionObjectVisibility_before.kt")
+    public void testCompanionObjectVisibility_before() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeListing/companionObjectVisibility_before.kt");
+    }
+
     @TestMetadata("coroutineContextIntrinsic.kt")
     public void testCoroutineContextIntrinsic_1_2() throws Exception {
         runTestWithPackageReplacement("compiler/testData/codegen/bytecodeListing/coroutineContextIntrinsic.kt", "kotlin.coroutines.experimental");

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

@@ -15123,6 +15123,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
                 runTest("compiler/testData/codegen/box/objects/companionObjectAccess/kt27117.kt");
             }
 
+            @TestMetadata("kt27121.kt")
+            public void testKt27121() throws Exception {
+                runTest("compiler/testData/codegen/box/objects/companionObjectAccess/kt27121.kt");
+            }
+
             @TestMetadata("privateCompanionObjectAccessedFromAnonymousObjectInNestedClass.kt")
             public void testPrivateCompanionObjectAccessedFromAnonymousObjectInNestedClass() throws Exception {
                 runTest("compiler/testData/codegen/box/objects/companionObjectAccess/privateCompanionObjectAccessedFromAnonymousObjectInNestedClass.kt");

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

@@ -15128,6 +15128,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 runTest("compiler/testData/codegen/box/objects/companionObjectAccess/kt27117.kt");
             }
 
+            @TestMetadata("kt27121.kt")
+            public void testKt27121() throws Exception {
+                runTest("compiler/testData/codegen/box/objects/companionObjectAccess/kt27121.kt");
+            }
+
             @TestMetadata("privateCompanionObjectAccessedFromAnonymousObjectInNestedClass.kt")
             public void testPrivateCompanionObjectAccessedFromAnonymousObjectInNestedClass() throws Exception {
                 runTest("compiler/testData/codegen/box/objects/companionObjectAccess/privateCompanionObjectAccessedFromAnonymousObjectInNestedClass.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/IrJsCodegenBoxTestGenerated.java

@@ -13308,6 +13308,11 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
                 runTest("compiler/testData/codegen/box/objects/companionObjectAccess/kt27117.kt");
             }
 
+            @TestMetadata("kt27121.kt")
+            public void testKt27121() throws Exception {
+                runTest("compiler/testData/codegen/box/objects/companionObjectAccess/kt27121.kt");
+            }
+
             @TestMetadata("privateCompanionObjectAccessedFromAnonymousObjectInNestedClass.kt")
             public void testPrivateCompanionObjectAccessedFromAnonymousObjectInNestedClass() throws Exception {
                 runTest("compiler/testData/codegen/box/objects/companionObjectAccess/privateCompanionObjectAccessedFromAnonymousObjectInNestedClass.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -14353,6 +14353,11 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
                 runTest("compiler/testData/codegen/box/objects/companionObjectAccess/kt27117.kt");
             }
 
+            @TestMetadata("kt27121.kt")
+            public void testKt27121() throws Exception {
+                runTest("compiler/testData/codegen/box/objects/companionObjectAccess/kt27121.kt");
+            }
+
             @TestMetadata("privateCompanionObjectAccessedFromAnonymousObjectInNestedClass.kt")
             public void testPrivateCompanionObjectAccessedFromAnonymousObjectInNestedClass() throws Exception {
                 runTest("compiler/testData/codegen/box/objects/companionObjectAccess/privateCompanionObjectAccessedFromAnonymousObjectInNestedClass.kt");