Add @JvmDefault diagnostics

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/checkers/JvmDefaultChecker.kt

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.resolve.jvm.checkers
+
+import org.jetbrains.kotlin.config.JvmTarget
+import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
+import org.jetbrains.kotlin.descriptors.PropertyAccessorDescriptor
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.psi.KtDeclaration
+import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
+import org.jetbrains.kotlin.resolve.DescriptorUtils
+import org.jetbrains.kotlin.resolve.checkers.DeclarationChecker
+import org.jetbrains.kotlin.resolve.checkers.DeclarationCheckerContext
+import org.jetbrains.kotlin.resolve.jvm.diagnostics.ErrorsJvm
+
+class JvmDefaultChecker(val jvmTarget: JvmTarget) : DeclarationChecker {
+
+    companion object {
+        val JVM_DEFAULT_FQ_NAME = FqName("kotlin.jvm.JvmDefault")
+
+    }
+
+    override fun check(declaration: KtDeclaration, descriptor: DeclarationDescriptor, context: DeclarationCheckerContext) {
+
+        descriptor.annotations.findAnnotation(JVM_DEFAULT_FQ_NAME)?.let { annotationDescriptor ->
+            val reportOn = DescriptorToSourceUtils.getSourceFromAnnotation(annotationDescriptor) ?: declaration
+            if (!DescriptorUtils.isInterface(descriptor.containingDeclaration)) {
+                context.trace.report(ErrorsJvm.JVM_DEFAULT_NOT_IN_INTERFACE.on(reportOn))
+            } else if (jvmTarget == JvmTarget.JVM_1_6) {
+                context.trace.report(ErrorsJvm.JVM_DEFAULT_IN_JVM6_TARGET.on(reportOn))
+            }
+            return@check
+        }
+
+        if (!DescriptorUtils.isInterface(descriptor.containingDeclaration)) return
+        val memberDescriptor = descriptor as? CallableMemberDescriptor ?: return
+        if (descriptor is PropertyAccessorDescriptor) return
+
+        if (memberDescriptor.overriddenDescriptors.any { it.annotations.hasAnnotation(JVM_DEFAULT_FQ_NAME) }) {
+            context.trace.report(ErrorsJvm.JVM_DEFAULT_REQUIRED_FOR_OVERRIDE.on(declaration))
+        }
+    }
+}

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/DefaultErrorMessagesJvm.java

@@ -133,6 +133,10 @@ public class DefaultErrorMessagesJvm implements DefaultErrorMessages.Extension {
 
         MAP.put(ASSIGNMENT_TO_ARRAY_LOOP_VARIABLE, "Assignment to a for-in-array loop range variable. Behavior may change in Kotlin 1.3. " +
                                                    "See https://youtrack.jetbrains.com/issue/KT-21354 for more details");
+
+        MAP.put(JVM_DEFAULT_NOT_IN_INTERFACE,"'@JvmDefault' is only supported on interface members");
+        MAP.put(JVM_DEFAULT_IN_JVM6_TARGET,"'@JvmDefault' is only supported since JVM target 1.8. Recompile with '-jvm-target 1.8'");
+        MAP.put(JVM_DEFAULT_REQUIRED_FOR_OVERRIDE, "'@JvmDefault' is required for an override of a '@JvmDefault' member");
     }
 
     @NotNull

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/ErrorsJvm.java

@@ -114,6 +114,10 @@ public interface ErrorsJvm {
 
     DiagnosticFactory0<KtExpression> ASSIGNMENT_TO_ARRAY_LOOP_VARIABLE = DiagnosticFactory0.create(WARNING);
 
+    DiagnosticFactory0<PsiElement> JVM_DEFAULT_NOT_IN_INTERFACE = DiagnosticFactory0.create(ERROR);
+    DiagnosticFactory0<PsiElement> JVM_DEFAULT_IN_JVM6_TARGET = DiagnosticFactory0.create(ERROR);
+    DiagnosticFactory0<KtDeclaration> JVM_DEFAULT_REQUIRED_FOR_OVERRIDE = DiagnosticFactory0.create(ERROR, DECLARATION_SIGNATURE);
+
     enum NullabilityInformationSource {
         KOTLIN {
             @NotNull

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/platform/JvmPlatformConfigurator.kt

@@ -91,6 +91,7 @@ object JvmPlatformConfigurator : PlatformConfigurator(
         container.useImpl<JavaSyntheticScopes>()
         container.useImpl<SamConversionResolverImpl>()
         container.useImpl<InterfaceDefaultMethodCallChecker>()
+        container.useImpl<JvmDefaultChecker>()
         container.useImpl<InlinePlatformCompatibilityChecker>()
         container.useImpl<JvmModuleAccessibilityChecker>()
         container.useImpl<JvmModuleAccessibilityChecker.ClassifierUsage>()