Deprecate public access to @JvmField/const fields in private companions

#KT-25009

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

@@ -85,7 +85,6 @@ import static org.jetbrains.kotlin.types.expressions.ExpressionTypingUtils.*;
 import static org.jetbrains.org.objectweb.asm.Opcodes.*;
 
 public class FunctionCodegen {
-    private static final String JAVA_LANG_DEPRECATED = Type.getType(Deprecated.class).getDescriptor();
 
     public final GenerationState state;
     private final KotlinTypeMapper typeMapper;
@@ -225,7 +224,7 @@ public class FunctionCodegen {
                 InlineClassDescriptorResolver.isSpecializedEqualsMethod(functionDescriptor);
         generateMethodAnnotationsIfRequired(
                 functionDescriptor, asmMethod, jvmSignature, mv,
-                isCompatibilityStubInDefaultImpls ? Collections.singletonList(JAVA_LANG_DEPRECATED) : Collections.emptyList(),
+                isCompatibilityStubInDefaultImpls ? Collections.singletonList(CodegenUtilKt.JAVA_LANG_DEPRECATED) : Collections.emptyList(),
                 skipNullabilityAnnotations
         );
         GenerateJava8ParameterNamesKt.generateParameterNames(functionDescriptor, mv, jvmSignature, state, (flags & ACC_SYNTHETIC) != 0);

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

@@ -903,19 +903,26 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
     }
 
     private void generateCompanionObjectBackingFieldCopies() {
-        if (companionObjectPropertiesToCopy == null) return;
+        if (companionObjectPropertiesToCopy == null || companionObjectPropertiesToCopy.isEmpty()) return;
 
+        boolean isPrivateCompanion =
+                DescriptorVisibilities.isPrivate(
+                        ((ClassDescriptor) companionObjectPropertiesToCopy.get(0).descriptor.getContainingDeclaration()).getVisibility());
+
+        int modifiers = ACC_STATIC | ACC_FINAL | ACC_PUBLIC | (isPrivateCompanion ? ACC_DEPRECATED : 0);
+        List<String> additionalVisibleAnnotations =
+                isPrivateCompanion ? Collections.singletonList(CodegenUtilKt.JAVA_LANG_DEPRECATED) : Collections.emptyList();
         for (PropertyAndDefaultValue info : companionObjectPropertiesToCopy) {
             PropertyDescriptor property = info.descriptor;
 
             Type type = typeMapper.mapType(property);
-            int modifiers = ACC_STATIC | ACC_FINAL | ACC_PUBLIC;
+
             FieldVisitor fv = v.newField(JvmDeclarationOriginKt.Synthetic(DescriptorToSourceUtils.descriptorToDeclaration(property), property),
                                          modifiers, context.getFieldName(property, false),
                                          type.getDescriptor(), typeMapper.mapFieldSignature(property.getType(), property),
                                          info.defaultValue);
 
-            AnnotationCodegen.forField(fv, this, state).genAnnotations(property, type, null);
+            AnnotationCodegen.forField(fv, this, state).genAnnotations(property, type, null, null, additionalVisibleAnnotations);
 
             //This field are always static and final so if it has constant initializer don't do anything in clinit,
             //field would be initialized via default value in v.newField(...) - see JVM SPEC Ch.4

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

@@ -42,6 +42,7 @@ import org.jetbrains.org.objectweb.asm.Type;
 import org.jetbrains.org.objectweb.asm.commons.InstructionAdapter;
 import org.jetbrains.org.objectweb.asm.commons.Method;
 
+import java.util.Collections;
 import java.util.List;
 
 import static org.jetbrains.kotlin.codegen.DescriptorAsmUtil.getDeprecatedAccessFlag;
@@ -408,6 +409,7 @@ public class PropertyCodegen {
         ClassBuilder builder = v;
 
         FieldOwnerContext backingFieldContext = context;
+        List<String> additionalVisibleAnnotations = Collections.emptyList();
         if (DescriptorAsmUtil.isInstancePropertyWithStaticBackingField(propertyDescriptor) ) {
             modifiers |= ACC_STATIC;
 
@@ -415,6 +417,10 @@ public class PropertyCodegen {
                 ImplementationBodyCodegen codegen = (ImplementationBodyCodegen) memberCodegen.getParentCodegen();
                 builder = codegen.v;
                 backingFieldContext = codegen.context;
+                if (DescriptorVisibilities.isPrivate(((ClassDescriptor) propertyDescriptor.getContainingDeclaration()).getVisibility())) {
+                    modifiers |= ACC_DEPRECATED;
+                    additionalVisibleAnnotations = Collections.singletonList(CodegenUtilKt.JAVA_LANG_DEPRECATED);
+                }
             }
         }
         modifiers |= getVisibilityForBackingField(propertyDescriptor, isDelegate);
@@ -442,7 +448,7 @@ public class PropertyCodegen {
                         (modifiers & ACC_SYNTHETIC) != 0 ||
                         propertyDescriptor.isLateInit();
                 AnnotationCodegen.forField(fv, memberCodegen, state, skipNullabilityAnnotations)
-                        .genAnnotations(annotatedField, type, propertyDescriptor.getType());
+                        .genAnnotations(annotatedField, type, propertyDescriptor.getType(), null, additionalVisibleAnnotations);
             }
         }
     }

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

@@ -24,8 +24,8 @@ import org.jetbrains.kotlin.config.isReleaseCoroutines
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.deserialization.PLATFORM_DEPENDENT_ANNOTATION_FQ_NAME
 import org.jetbrains.kotlin.descriptors.impl.ValueParameterDescriptorImpl
-import org.jetbrains.kotlin.load.java.SpecialGenericSignatures.SpecialSignatureInfo
 import org.jetbrains.kotlin.load.java.DescriptorsJvmAbiUtil
+import org.jetbrains.kotlin.load.java.SpecialGenericSignatures.SpecialSignatureInfo
 import org.jetbrains.kotlin.load.java.descriptors.JavaCallableMemberDescriptor
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.FqName
@@ -60,8 +60,12 @@ import org.jetbrains.org.objectweb.asm.Type
 import org.jetbrains.org.objectweb.asm.commons.InstructionAdapter
 import org.jetbrains.org.objectweb.asm.commons.Method
 import org.jetbrains.org.objectweb.asm.tree.LabelNode
+import java.lang.Deprecated
 import java.util.*
 
+@JvmField
+internal val JAVA_LANG_DEPRECATED = Type.getType(Deprecated::class.java).descriptor
+
 fun generateIsCheck(
     v: InstructionAdapter,
     kotlinType: KotlinType,

compiler/testData/codegen/bytecodeListing/privateCompanionFields.kt

@@ -0,0 +1,32 @@
+// WITH_RUNTIME
+class TestClass {
+
+    private companion object {
+        @JvmField
+        var test: String = "1"
+
+        @JvmField
+        @java.lang.Deprecated
+        var test2: String = "2"
+
+        @JvmField
+        val test3: String = "3"
+
+        const val testConst = 1
+    }
+}
+
+interface TestConst {
+
+    private companion object {
+        const val testConst = 1
+    }
+}
+
+interface TestJvmField {
+
+    private companion object {
+        @JvmField
+        val test3: String = "3"
+    }
+}

compiler/testData/codegen/bytecodeListing/privateCompanionFields.txt

@@ -0,0 +1,57 @@
+@kotlin.Metadata
+final class TestClass$Companion {
+    // source: 'privateCompanionFields.kt'
+    private method <init>(): void
+    public synthetic method <init>(p0: kotlin.jvm.internal.DefaultConstructorMarker): void
+    private final inner class TestClass$Companion
+}
+
+@kotlin.Metadata
+public final class TestClass {
+    // source: 'privateCompanionFields.kt'
+    private final static @org.jetbrains.annotations.NotNull field Companion: TestClass$Companion
+    public deprecated static @java.lang.Deprecated @kotlin.jvm.JvmField @org.jetbrains.annotations.NotNull field test2: java.lang.String
+    public deprecated final static @java.lang.Deprecated @kotlin.jvm.JvmField @org.jetbrains.annotations.NotNull field test3: java.lang.String
+    public deprecated static @java.lang.Deprecated @kotlin.jvm.JvmField @org.jetbrains.annotations.NotNull field test: java.lang.String
+    public deprecated final static @java.lang.Deprecated field testConst: int
+    static method <clinit>(): void
+    public method <init>(): void
+    private final inner class TestClass$Companion
+}
+
+@kotlin.Metadata
+final class TestConst$Companion {
+    // source: 'privateCompanionFields.kt'
+    synthetic final static field $$INSTANCE: TestConst$Companion
+    public final static field testConst: int
+    static method <clinit>(): void
+    private method <init>(): void
+    public final inner class TestConst$Companion
+}
+
+@kotlin.Metadata
+public interface TestConst {
+    // source: 'privateCompanionFields.kt'
+    public synthetic final static @org.jetbrains.annotations.NotNull field Companion: TestConst$Companion
+    public deprecated final static @java.lang.Deprecated field testConst: int
+    static method <clinit>(): void
+    public final inner class TestConst$Companion
+}
+
+@kotlin.Metadata
+final class TestJvmField$Companion {
+    // source: 'privateCompanionFields.kt'
+    synthetic final static field $$INSTANCE: TestJvmField$Companion
+    private method <init>(): void
+    public synthetic method <init>(p0: kotlin.jvm.internal.DefaultConstructorMarker): void
+    public final inner class TestJvmField$Companion
+}
+
+@kotlin.Metadata
+public interface TestJvmField {
+    // source: 'privateCompanionFields.kt'
+    public synthetic final static @org.jetbrains.annotations.NotNull field Companion: TestJvmField$Companion
+    public deprecated final static @java.lang.Deprecated @kotlin.jvm.JvmField @org.jetbrains.annotations.NotNull field test3: java.lang.String
+    static method <clinit>(): void
+    public final inner class TestJvmField$Companion
+}

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

@@ -134,6 +134,11 @@ public class BytecodeListingTestGenerated extends AbstractBytecodeListingTest {
         runTest("compiler/testData/codegen/bytecodeListing/noToArrayInJava.kt");
     }
 
+    @TestMetadata("privateCompanionFields.kt")
+    public void testPrivateCompanionFields() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeListing/privateCompanionFields.kt");
+    }
+
     @TestMetadata("privateDefaultImpls.kt")
     public void testPrivateDefaultImpls() throws Exception {
         runTest("compiler/testData/codegen/bytecodeListing/privateDefaultImpls.kt");

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

@@ -134,6 +134,11 @@ public class IrBytecodeListingTestGenerated extends AbstractIrBytecodeListingTes
         runTest("compiler/testData/codegen/bytecodeListing/noToArrayInJava.kt");
     }
 
+    @TestMetadata("privateCompanionFields.kt")
+    public void testPrivateCompanionFields() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeListing/privateCompanionFields.kt");
+    }
+
     @TestMetadata("privateDefaultImpls.kt")
     public void testPrivateDefaultImpls() throws Exception {
         runTest("compiler/testData/codegen/bytecodeListing/privateDefaultImpls.kt");

idea/testData/decompiler/stubBuilder/Annotations/Annotations.txt

@@ -52,6 +52,16 @@ PsiJetFileStubImpl[package=]
                   TYPE_REFERENCE
                     USER_TYPE
                       REFERENCE_EXPRESSION[referencedName=f]
+              ANNOTATION_ENTRY[hasValueArguments=false, shortName=Deprecated]
+                ANNOTATION_TARGET[useSiteTarget=FIELD]
+                CONSTRUCTOR_CALLEE
+                  TYPE_REFERENCE
+                    USER_TYPE
+                      USER_TYPE
+                        USER_TYPE
+                          REFERENCE_EXPRESSION[referencedName=java]
+                        REFERENCE_EXPRESSION[referencedName=lang]
+                      REFERENCE_EXPRESSION[referencedName=Deprecated]
             TYPE_REFERENCE
               USER_TYPE
                 USER_TYPE