Generate proper visibility for companion object instance field in LV1.3+

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

@@ -839,11 +839,18 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
         @Nullable KtObjectDeclaration companionObject = CollectionsKt.firstOrNull(myClass.getCompanionObjects());
 
         int properFieldVisibilityFlag = getVisibilityAccessFlag(companionObjectDescriptor);
+        boolean deprecatedFieldForInvisibleCompanionObject =
+                state.getLanguageVersionSettings().supportsFeature(LanguageFeature.DeprecatedFieldForInvisibleCompanionObject);
+        boolean properVisibilityForCompanionObjectInstanceField =
+                state.getLanguageVersionSettings().supportsFeature(LanguageFeature.ProperVisibilityForCompanionObjectInstanceField);
         boolean fieldShouldBeDeprecated =
-                state.getLanguageVersionSettings().supportsFeature(LanguageFeature.DeprecatedFieldForInvisibleCompanionObject) &&
+                deprecatedFieldForInvisibleCompanionObject &&
+                !properVisibilityForCompanionObjectInstanceField &&
                 (properFieldVisibilityFlag & (ACC_PRIVATE | ACC_PROTECTED)) != 0;
-        // TODO generate field with proper visibility in language version 1.3
         int fieldAccessFlags = ACC_PUBLIC | ACC_STATIC | ACC_FINAL;
+        if (properVisibilityForCompanionObjectInstanceField) {
+            fieldAccessFlags |= properFieldVisibilityFlag;
+        }
         if (fieldShouldBeDeprecated) {
             fieldAccessFlags |= ACC_DEPRECATED;
         }

compiler/testData/codegen/bytecodeListing/invisibleCompanionObject.kt

@@ -1,4 +1,4 @@
-// LANGUAGE_VERSION: 1.2
+// LANGUAGE_VERSION: 1.3
 
 class TestPrivateCompanion {
     private companion object Test

compiler/testData/codegen/bytecodeListing/invisibleCompanionObject.txt

@@ -22,7 +22,7 @@ final class TestPrivateCompanion$Test {
 
 @kotlin.Metadata
 public final class TestPrivateCompanion {
-    public deprecated final static @java.lang.Deprecated field Test: TestPrivateCompanion$Test
+    public private final static field Test: TestPrivateCompanion$Test
     inner class TestPrivateCompanion$Test
     static method <clinit>(): void
     public method <init>(): void
@@ -37,7 +37,7 @@ public final class TestProtectedCompanion$Test {
 
 @kotlin.Metadata
 public class TestProtectedCompanion {
-    public deprecated final static @java.lang.Deprecated field Test: TestProtectedCompanion$Test
+    public protected final static field Test: TestProtectedCompanion$Test
     inner class TestProtectedCompanion$Test
     static method <clinit>(): void
     public method <init>(): void

compiler/testData/codegen/bytecodeListing/invisibleCompanionObject_lv12.kt

@@ -0,0 +1,13 @@
+// LANGUAGE_VERSION: 1.2
+
+class TestPrivateCompanion {
+    private companion object Test
+}
+
+open class TestProtectedCompanion {
+    protected companion object Test
+}
+
+class TestInternalCompanion {
+    internal companion object Test
+}

compiler/testData/codegen/bytecodeListing/invisibleCompanionObject_lv12.txt

@@ -0,0 +1,44 @@
+@kotlin.Metadata
+public final class TestInternalCompanion$Test {
+    inner class TestInternalCompanion$Test
+    private method <init>(): void
+    public synthetic method <init>(p0: kotlin.jvm.internal.DefaultConstructorMarker): void
+}
+
+@kotlin.Metadata
+public final class TestInternalCompanion {
+    public final static field Test: TestInternalCompanion$Test
+    inner class TestInternalCompanion$Test
+    static method <clinit>(): void
+    public method <init>(): void
+}
+
+@kotlin.Metadata
+final class TestPrivateCompanion$Test {
+    inner class TestPrivateCompanion$Test
+    private method <init>(): void
+    public synthetic method <init>(p0: kotlin.jvm.internal.DefaultConstructorMarker): void
+}
+
+@kotlin.Metadata
+public final class TestPrivateCompanion {
+    public deprecated final static @java.lang.Deprecated field Test: TestPrivateCompanion$Test
+    inner class TestPrivateCompanion$Test
+    static method <clinit>(): void
+    public method <init>(): void
+}
+
+@kotlin.Metadata
+public final class TestProtectedCompanion$Test {
+    inner class TestProtectedCompanion$Test
+    private method <init>(): void
+    public synthetic method <init>(p0: kotlin.jvm.internal.DefaultConstructorMarker): void
+}
+
+@kotlin.Metadata
+public class TestProtectedCompanion {
+    public deprecated final static @java.lang.Deprecated field Test: TestProtectedCompanion$Test
+    inner class TestProtectedCompanion$Test
+    static method <clinit>(): void
+    public method <init>(): void
+}

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

@@ -108,6 +108,12 @@ public class BytecodeListingTestGenerated extends AbstractBytecodeListingTest {
         doTest(fileName);
     }
 
+    @TestMetadata("invisibleCompanionObject_lv12.kt")
+    public void testInvisibleCompanionObject_lv12() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeListing/invisibleCompanionObject_lv12.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("jvmOverloadsAndParametersAnnotations.kt")
     public void testJvmOverloadsAndParametersAnnotations() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeListing/jvmOverloadsAndParametersAnnotations.kt");

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

@@ -74,6 +74,7 @@ enum class LanguageFeature(
     ProhibitDataClassesOverridingCopy(KOTLIN_1_3),
     RestrictionOfWrongAnnotationsWithUseSiteTargetsOnTypes(KOTLIN_1_3),
     ProhibitInnerClassesOfGenericClassExtendingThrowable(KOTLIN_1_3),
+    ProperVisibilityForCompanionObjectInstanceField(KOTLIN_1_3),
 
     StrictJavaNullabilityAssertions(sinceVersion = null, defaultState = State.DISABLED),