Write KotlinInterfaceDefaultImpls annotation to DefaultImpls classes

Instead of KotlinSyntheticClass with kind = TRAIT_IMPL

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

@@ -19,13 +19,13 @@ package org.jetbrains.kotlin.codegen
 import com.intellij.util.ArrayUtil
 import org.jetbrains.kotlin.backend.common.bridges.findImplementationFromInterface
 import org.jetbrains.kotlin.backend.common.bridges.firstSuperMethodFromKotlin
-import org.jetbrains.kotlin.codegen.AsmUtil.writeKotlinSyntheticClassAnnotation
 import org.jetbrains.kotlin.codegen.context.ClassContext
 import org.jetbrains.kotlin.codegen.state.GenerationState
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.impl.ClassDescriptorImpl
 import org.jetbrains.kotlin.load.java.JvmAbi
-import org.jetbrains.kotlin.load.java.JvmAnnotationNames.KotlinSyntheticClass.Kind.LOCAL_TRAIT_IMPL
+import org.jetbrains.kotlin.load.java.JvmAnnotationNames
+import org.jetbrains.kotlin.load.java.JvmAnnotationNames.KOTLIN_INTERFACE_DEFAULT_IMPLS
 import org.jetbrains.kotlin.load.java.JvmAnnotationNames.KotlinSyntheticClass.Kind.TRAIT_IMPL
 import org.jetbrains.kotlin.load.java.descriptors.JavaMethodDescriptor
 import org.jetbrains.kotlin.name.Name
@@ -35,7 +35,9 @@ import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.DelegationToTraitImpl
 import org.jetbrains.kotlin.resolve.jvm.jvmSignature.JvmMethodSignature
 import org.jetbrains.kotlin.resolve.scopes.JetScope
-import org.jetbrains.org.objectweb.asm.Opcodes.*
+import org.jetbrains.org.objectweb.asm.Opcodes.ACC_FINAL
+import org.jetbrains.org.objectweb.asm.Opcodes.ACC_PUBLIC
+import org.jetbrains.org.objectweb.asm.Opcodes.ACC_STATIC
 import org.jetbrains.org.objectweb.asm.Opcodes.V1_6
 import java.util.*
 
@@ -144,9 +146,9 @@ public class InterfaceImplBodyCodegen(
     }
 
     override fun generateKotlinAnnotation() {
-        writeKotlinSyntheticClassAnnotation(
+        val av = v.newAnnotation(AsmUtil.asmDescByFqNameWithoutInnerClasses(KOTLIN_INTERFACE_DEFAULT_IMPLS), true)
-                v,
+        av.visit(JvmAnnotationNames.VERSION_FIELD_NAME, JvmAbi.VERSION.toArray())
-                if (DescriptorUtils.isTopLevelOrInnerClass(descriptor)) TRAIT_IMPL else LOCAL_TRAIT_IMPL
+        av.visitEnd()
-        )
+        AsmUtil.writeKotlinSyntheticClassAnnotation(v, TRAIT_IMPL)
     }
 }

compiler/tests/org/jetbrains/kotlin/codegen/InlineTestUtil.kt

@@ -187,7 +187,7 @@ public object InlineTestUtil {
     private fun isClassOrPackagePartKind(header: KotlinClassHeader): Boolean {
         return header.classKind == JvmAnnotationNames.KotlinClass.Kind.CLASS
                || header.syntheticClassKind == JvmAnnotationNames.KotlinSyntheticClass.Kind.PACKAGE_PART
-               || header.syntheticClassKind == JvmAnnotationNames.KotlinSyntheticClass.Kind.TRAIT_IMPL
+               || header.isInterfaceDefaultImpls
     }
 
     private fun getClassHeader(file: OutputFile): KotlinClassHeader {

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/JvmAnnotationNames.java

@@ -34,6 +34,7 @@ public final class JvmAnnotationNames {
     public static final FqName KOTLIN_MULTIFILE_CLASS = new FqName("kotlin.jvm.internal.KotlinMultifileClass");
     public static final FqName KOTLIN_MULTIFILE_CLASS_PART = new FqName("kotlin.jvm.internal.KotlinMultifileClassPart");
     public static final FqName KOTLIN_CALLABLE = new FqName("kotlin.jvm.internal.KotlinCallable");
+    public static final FqName KOTLIN_INTERFACE_DEFAULT_IMPLS = new FqName("kotlin.jvm.internal.KotlinInterfaceDefaultImpls");
 
     public static final FqName JAVA_LANG_DEPRECATED = new FqName("java.lang.Deprecated");
 
@@ -139,6 +140,7 @@ public final class JvmAnnotationNames {
             SPECIAL_ANNOTATIONS.add(JvmClassName.byFqNameWithoutInnerClasses(fqName));
         }
         SPECIAL_ANNOTATIONS.add(KotlinSyntheticClass.CLASS_NAME);
+        SPECIAL_ANNOTATIONS.add(JvmClassName.byFqNameWithoutInnerClasses(KOTLIN_INTERFACE_DEFAULT_IMPLS));
 
         for (FqName fqName : Arrays.asList(JETBRAINS_NOT_NULL_ANNOTATION, JETBRAINS_NULLABLE_ANNOTATION)) {
             NULLABILITY_ANNOTATIONS.add(JvmClassName.byFqNameWithoutInnerClasses(fqName));

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/header/KotlinClassHeader.kt

@@ -29,7 +29,8 @@ public class KotlinClassHeader(
         public val classKind: KotlinClass.Kind?,
         public val syntheticClassKind: KotlinSyntheticClass.Kind?,
         public val filePartClassNames: Array<String>?,
-        public val multifileClassName: String?
+        public val multifileClassName: String?,
+        public val isInterfaceDefaultImpls: Boolean
 ) {
     public val isCompatibleAbiVersion: Boolean get() = AbiVersionUtil.isAbiVersionCompatible(version)
 

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/header/ReadKotlinClassHeaderAnnotationVisitor.java

@@ -68,6 +68,7 @@ public class ReadKotlinClassHeaderAnnotationVisitor implements AnnotationVisitor
     private KotlinClassHeader.Kind headerKind = null;
     private KotlinClass.Kind classKind = null;
     private KotlinSyntheticClass.Kind syntheticClassKind = null;
+    private boolean isInterfaceDefaultImpls = false;
 
     @Nullable
     public KotlinClassHeader createHeader() {
@@ -81,17 +82,17 @@ public class ReadKotlinClassHeaderAnnotationVisitor implements AnnotationVisitor
         }
 
         if (!AbiVersionUtil.isAbiVersionCompatible(version)) {
-            return new KotlinClassHeader(headerKind, version, null, strings, classKind, syntheticClassKind, null, null);
+            annotationData = null;
         }
-
+        else if (shouldHaveData() && annotationData == null) {
-        if (shouldHaveData() && annotationData == null) {
             // This means that the annotation is found and its ABI version is compatible, but there's no "data" string array in it.
             // We tell the outside world that there's really no annotation at all
             return null;
         }
 
         return new KotlinClassHeader(
-                headerKind, version, annotationData, strings, classKind, syntheticClassKind, filePartClassNames, multifileClassName
+                headerKind, version, annotationData, strings, classKind, syntheticClassKind, filePartClassNames, multifileClassName,
+                isInterfaceDefaultImpls
         );
     }
 
@@ -105,6 +106,11 @@ public class ReadKotlinClassHeaderAnnotationVisitor implements AnnotationVisitor
     @Nullable
     @Override
     public AnnotationArgumentVisitor visitAnnotation(@NotNull ClassId classId, @NotNull SourceElement source) {
+        if (KOTLIN_INTERFACE_DEFAULT_IMPLS.equals(classId.asSingleFqName())) {
+            isInterfaceDefaultImpls = true;
+            return null;
+        }
+
         if (headerKind != null) {
             // Ignore all Kotlin annotations except the first found
             return null;

core/runtime.jvm/src/kotlin/jvm/internal/KotlinInterfaceDefaultImpls.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package kotlin.jvm.internal;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+public @interface KotlinInterfaceDefaultImpls {
+    int[] version() default {};
+}

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/DecompiledUtils.kt

@@ -41,10 +41,8 @@ public fun isKotlinJvmCompiledFile(file: VirtualFile): Boolean {
         return false
     }
 
-    val header = KotlinBinaryClassCache.getKotlinBinaryClass(file)?.getClassHeader()
+    val header = KotlinBinaryClassCache.getKotlinBinaryClass(file)?.classHeader
-    return header != null &&
+    return header != null && !header.isInterfaceDefaultImpls
-           header.syntheticClassKind != KotlinSyntheticClass.Kind.TRAIT_IMPL &&
-           header.syntheticClassKind != KotlinSyntheticClass.Kind.LOCAL_TRAIT_IMPL
 }
 
 public fun isKotlinJsMetaFile(file: VirtualFile): Boolean = file.getFileType() == KotlinJavaScriptMetaFileType