JS: prohibit private members of external classes (see KT-14029)

compiler/testData/diagnostics/testsWithJsStdLib/native/privateMembers.kt

@@ -0,0 +1,55 @@
+// !DIAGNOSTICS: -NOTHING_TO_INLINE
+// TODO: should we disable NOTHING_TO_INLINE in JS backend?
+
+external class C {
+    <!EXTERNAL_CLASS_PRIVATE_MEMBER!>private fun a(): Int<!>
+
+    <!EXTERNAL_CLASS_PRIVATE_MEMBER!>private val b: String<!>
+
+    <!EXTERNAL_CLASS_PRIVATE_MEMBER!>private var c: Float<!>
+
+    <!EXTERNAL_CLASS_PRIVATE_MEMBER!>private var d: Float<!>
+        get
+        set
+
+    private inline fun inline_a(): Int = 23
+
+    private inline val inline_prop: Int
+        get() = 42
+}
+
+external object O {
+    <!EXTERNAL_CLASS_PRIVATE_MEMBER!>private fun a(): Int<!>
+
+    <!EXTERNAL_CLASS_PRIVATE_MEMBER!>private val b: String<!>
+
+    <!EXTERNAL_CLASS_PRIVATE_MEMBER!>private var c: Float<!>
+
+    <!EXTERNAL_CLASS_PRIVATE_MEMBER!>private var d: Float<!>
+        get
+        set
+
+    private inline fun inline_a(): Int = 23
+
+    private inline val inline_prop: Int
+        get() = 42
+}
+
+external class Outer {
+    class Inner {
+        <!EXTERNAL_CLASS_PRIVATE_MEMBER!>private fun a(): Int<!>
+
+        <!EXTERNAL_CLASS_PRIVATE_MEMBER!>private val b: String<!>
+
+        <!EXTERNAL_CLASS_PRIVATE_MEMBER!>private var c: Float<!>
+
+        <!EXTERNAL_CLASS_PRIVATE_MEMBER!>private var d: Float<!>
+            get
+            set
+
+        private inline fun inline_a(): Int = 23
+
+        private inline val inline_prop: Int
+            get() = 42
+    }
+}

compiler/testData/diagnostics/testsWithJsStdLib/native/privateMembers.txt

@@ -0,0 +1,47 @@
+package
+
+public final class C {
+    public constructor C()
+    private final val b: kotlin.String
+    private final var c: kotlin.Float
+    private final var d: kotlin.Float
+    private final val inline_prop: kotlin.Int
+    private final fun a(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    private final inline fun inline_a(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public object O {
+    private constructor O()
+    private final val b: kotlin.String
+    private final var c: kotlin.Float
+    private final var d: kotlin.Float
+    private final val inline_prop: kotlin.Int
+    private final fun a(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    private final inline fun inline_a(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class Outer {
+    public constructor Outer()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    public final class Inner {
+        public constructor Inner()
+        private final val b: kotlin.String
+        private final var c: kotlin.Float
+        private final var d: kotlin.Float
+        private final val inline_prop: kotlin.Int
+        private final fun a(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        private final inline fun inline_a(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+}

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestWithJsStdLibGenerated.java

@@ -539,6 +539,12 @@ public class DiagnosticsTestWithJsStdLibGenerated extends AbstractDiagnosticsTes
             doTest(fileName);
         }
 
+        @TestMetadata("privateMembers.kt")
+        public void testPrivateMembers() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithJsStdLib/native/privateMembers.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("wrongTarget.kt")
         public void testWrongTarget() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithJsStdLib/native/wrongTarget.kt");

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/DefaultErrorMessagesJs.kt

@@ -38,6 +38,7 @@ private val DIAGNOSTIC_FACTORY_TO_RENDERER by lazy {
         put(ErrorsJs.REFERENCE_TO_BUILTIN_MEMBERS_NOT_SUPPORTED, "Callable references for builtin members are not supported yet: ''{0}''", RenderFirstLineOfElementText)
         put(ErrorsJs.JSCODE_NO_JAVASCRIPT_PRODUCED, "Argument must be non-empty JavaScript code")
         put(ErrorsJs.NESTED_EXTERNAL_DECLARATION, "Non top-level `external` declaration")
+        put(ErrorsJs.EXTERNAL_CLASS_PRIVATE_MEMBER, "Private non-inline members of external classes are prohibited")
         put(ErrorsJs.JS_NAME_CLASH, "JavaScript name ({0}) generated for this declaration clashes with another declaration: {1}",
             Renderers.STRING, Renderers.COMPACT)
         put(ErrorsJs.JS_FAKE_NAME_CLASH, "JavaScript name {0} is generated for different inherited members: {1} and {2}",

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/ErrorsJs.java

@@ -41,6 +41,7 @@ public interface ErrorsJs {
     DiagnosticFactory1<KtElement, KtElement> NOT_SUPPORTED = DiagnosticFactory1.create(ERROR, DEFAULT);
     DiagnosticFactory1<KtElement, KtElement> REFERENCE_TO_BUILTIN_MEMBERS_NOT_SUPPORTED = DiagnosticFactory1.create(ERROR, DEFAULT);
     DiagnosticFactory0<KtExpression> JSCODE_NO_JAVASCRIPT_PRODUCED = DiagnosticFactory0.create(ERROR, DEFAULT);
+    DiagnosticFactory0<KtDeclaration> EXTERNAL_CLASS_PRIVATE_MEMBER = DiagnosticFactory0.create(ERROR, DECLARATION_SIGNATURE_OR_DEFAULT);
     DiagnosticFactory0<KtExpression> NESTED_EXTERNAL_DECLARATION = DiagnosticFactory0.create(ERROR, DECLARATION_SIGNATURE_OR_DEFAULT);
     DiagnosticFactory2<KtElement, String, DeclarationDescriptor> JS_NAME_CLASH = DiagnosticFactory2.create(
             ERROR, DECLARATION_SIGNATURE_OR_DEFAULT);

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsExternalChecker.kt

@@ -16,10 +16,7 @@
 
 package org.jetbrains.kotlin.js.resolve.diagnostics
 
-import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
-import org.jetbrains.kotlin.descriptors.FunctionDescriptor
-import org.jetbrains.kotlin.descriptors.PropertyAccessorDescriptor
-import org.jetbrains.kotlin.descriptors.PropertyDescriptor
+import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.js.PredefinedAnnotation
@@ -49,6 +46,9 @@ class JsExternalChecker : SimpleDeclarationChecker {
         else if (descriptor is PropertyAccessorDescriptor && isDirectlyExternal(declaration, descriptor)) {
             diagnosticHolder.report(Errors.WRONG_MODIFIER_TARGET.on(declaration, KtTokens.EXTERNAL_KEYWORD, "property accessor"))
         }
+        else if (isPrivateNonInlineMemberOfExternalClass(descriptor)) {
+            diagnosticHolder.report(ErrorsJs.EXTERNAL_CLASS_PRIVATE_MEMBER.on(declaration))
+        }
 
         if (descriptor !is PropertyAccessorDescriptor && descriptor.isExtension) {
             val target = when (descriptor) {
@@ -66,4 +66,14 @@ class JsExternalChecker : SimpleDeclarationChecker {
         return declaration.hasModifier(KtTokens.EXTERNAL_KEYWORD) ||
                AnnotationsUtils.hasAnnotation(descriptor, PredefinedAnnotation.NATIVE)
     }
+
+    private fun isPrivateNonInlineMemberOfExternalClass(descriptor: DeclarationDescriptor): Boolean {
+        if (descriptor is PropertyAccessorDescriptor) return false
+        if (descriptor !is MemberDescriptor || descriptor.visibility != Visibilities.PRIVATE) return false
+        if (descriptor is FunctionDescriptor && descriptor.isInline) return false
+        if (descriptor is PropertyDescriptor && descriptor.accessors.all { it.isInline }) return false
+
+        val containingDeclaration = descriptor.containingDeclaration as? ClassDescriptor ?: return false
+        return AnnotationsUtils.isNativeObject(containingDeclaration)
+    }
 }