private / protected / internal modifiers are deprecated in interfaces, relevant tests changed

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java

@@ -115,6 +115,7 @@ public interface Errors {
     DiagnosticFactory2<PsiElement, JetModifierKeywordToken, String> WRONG_MODIFIER_TARGET = DiagnosticFactory2.create(ERROR);
     DiagnosticFactory2<PsiElement, JetModifierKeywordToken, String> REDUNDANT_MODIFIER_FOR_TARGET = DiagnosticFactory2.create(WARNING);
     DiagnosticFactory2<PsiElement, JetModifierKeywordToken, String> WRONG_MODIFIER_CONTAINING_DECLARATION = DiagnosticFactory2.create(ERROR);
+    DiagnosticFactory2<PsiElement, JetModifierKeywordToken, String> DEPRECATED_MODIFIER_CONTAINING_DECLARATION = DiagnosticFactory2.create(WARNING);
     DiagnosticFactory1<JetAnnotationEntry, String> WRONG_ANNOTATION_TARGET = DiagnosticFactory1.create(ERROR);
     DiagnosticFactory2<JetAnnotationEntry, String, String> WRONG_ANNOTATION_TARGET_WITH_USE_SITE_TARGET = DiagnosticFactory2.create(ERROR);
     DiagnosticFactory0<JetAnnotationEntry> REPEATED_ANNOTATION = DiagnosticFactory0.create(ERROR);

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java

@@ -122,6 +122,7 @@ public class DefaultErrorMessages {
         MAP.put(WRONG_MODIFIER_TARGET, "Modifier ''{0}'' is not applicable to ''{1}''", TO_STRING, TO_STRING);
         MAP.put(REDUNDANT_MODIFIER_FOR_TARGET, "Modifier ''{0}'' is redundant for ''{1}''", TO_STRING, TO_STRING);
         MAP.put(WRONG_MODIFIER_CONTAINING_DECLARATION, "Modifier ''{0}'' is not applicable inside ''{1}''", TO_STRING, TO_STRING);
+        MAP.put(DEPRECATED_MODIFIER_CONTAINING_DECLARATION, "Modifier ''{0}'' is deprecated inside ''{1}''", TO_STRING, TO_STRING);
         MAP.put(WRONG_ANNOTATION_TARGET, "This annotation is not applicable to target ''{0}''", TO_STRING);
         MAP.put(WRONG_ANNOTATION_TARGET_WITH_USE_SITE_TARGET, "This annotation is not applicable to target ''{0}'' and use site target ''@{1}''", TO_STRING, TO_STRING);
         MAP.put(REPEATED_ANNOTATION, "This annotation is not repeatable");

compiler/frontend/src/org/jetbrains/kotlin/resolve/ModifiersChecker.kt

@@ -82,6 +82,12 @@ public object ModifierCheckerCore {
             COMPANION_KEYWORD to EnumSet.of(CLASS_ONLY, ENUM_CLASS, INTERFACE)
     )
 
+    private val deprecatedParentTargetMap = mapOf<JetModifierKeywordToken, Set<KotlinTarget>>(
+            PRIVATE_KEYWORD   to EnumSet.of(INTERFACE),
+            INTERNAL_KEYWORD  to EnumSet.of(INTERFACE),
+            PROTECTED_KEYWORD to EnumSet.of(INTERFACE)
+    )
+
     // First modifier in pair should be also first in declaration
     private val mutualCompatibility = buildCompatibilityMap()
 
@@ -184,6 +190,11 @@ public object ModifierCheckerCore {
             is FunctionDescriptor -> listOf(FUNCTION)
             else -> listOf(FILE)
         }
+        val deprecatedParents = deprecatedParentTargetMap[modifier]
+        if (deprecatedParents != null && actualParents.any { it in deprecatedParents }) {
+            trace.report(Errors.DEPRECATED_MODIFIER_CONTAINING_DECLARATION.on(node.psi, modifier, actualParents.firstOrNull()?.description ?: "this scope"))
+            return false
+        }
         val possibleParents = possibleParentTargetMap[modifier] ?: return true
         if (possibleParents == KotlinTarget.ALL_TARGET_SET) return true
         if (actualParents.any { it in possibleParents }) return true