Prohibit data classes with no primary constructor

compiler/backend-common/src/org/jetbrains/kotlin/backend/common/DataClassMethodGenerator.java

@@ -80,7 +80,9 @@ public abstract class DataClassMethodGenerator {
 
     private void generateComponentFunctionsForDataClasses() {
         ConstructorDescriptor constructor = classDescriptor.getUnsubstitutedPrimaryConstructor();
-        assert constructor != null : "Data class should have primary constructor";
+        // primary constructor should exist for data classes
+        // but when generating light-classes still need to check we have one
+        if (constructor == null) return;
 
         for (ValueParameterDescriptor parameter : constructor.getValueParameters()) {
             FunctionDescriptor function = bindingContext.get(BindingContext.DATA_CLASS_COMPONENT_FUNCTION, parameter);

compiler/frontend.java/src/org/jetbrains/kotlin/load/kotlin/KotlinJvmCheckerProvider.kt

@@ -65,7 +65,7 @@ import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.types.expressions.SenselessComparisonChecker
 
 public object KotlinJvmCheckerProvider : AdditionalCheckerProvider(
-        annotationCheckers = listOf(PlatformStaticAnnotationChecker(), LocalFunInlineChecker(), ReifiedTypeParameterAnnotationChecker(), NativeFunChecker()),
+        additionalAnnotationCheckers = listOf(PlatformStaticAnnotationChecker(), LocalFunInlineChecker(), ReifiedTypeParameterAnnotationChecker(), NativeFunChecker()),
         additionalCallCheckers = listOf(NeedSyntheticChecker()),
         additionalTypeCheckers = listOf(JavaNullabilityWarningsChecker())
 )

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

@@ -161,6 +161,7 @@ public interface Errors {
     DiagnosticFactory0<JetConstructorDelegationCall> PRIMARY_CONSTRUCTOR_DELEGATION_CALL_EXPECTED = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory0<PsiElement> INIT_KEYWORD_BEFORE_CLASS_INITIALIZER_EXPECTED = DiagnosticFactory0.create(WARNING);
     DiagnosticFactory0<JetConstructorDelegationCall> DELEGATION_SUPER_CALL_IN_ENUM_CONSTRUCTOR = DiagnosticFactory0.create(ERROR);
+    DiagnosticFactory0<PsiElement> PRIMARY_CONSTRUCTOR_REQUIRED_FOR_DATA_CLASS = DiagnosticFactory0.create(ERROR);
 
     // Trait-specific
 

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

@@ -418,6 +418,7 @@ public class DefaultErrorMessages {
         MAP.put(SUPERTYPE_INITIALIZED_WITHOUT_PRIMARY_CONSTRUCTOR, "Supertype initialization is impossible without primary constructor");
         MAP.put(PRIMARY_CONSTRUCTOR_DELEGATION_CALL_EXPECTED, "Primary constructor call expected");
         MAP.put(DELEGATION_SUPER_CALL_IN_ENUM_CONSTRUCTOR, "Call to super is not allowed in enum constructor");
+        MAP.put(PRIMARY_CONSTRUCTOR_REQUIRED_FOR_DATA_CLASS, "Primary constructor required for data class");
 
         MAP.put(INIT_KEYWORD_BEFORE_CLASS_INITIALIZER_EXPECTED, "Expecting 'init' keyword before class initializer");
 

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

@@ -18,15 +18,17 @@ package org.jetbrains.kotlin.resolve
 
 import org.jetbrains.kotlin.resolve.calls.checkers.*
 
+private val DEFAULT_ANNOTATION_CHECKERS = listOf(DataClassAnnotationChecker())
 private val DEFAULT_CALL_CHECKERS = listOf(CapturingInClosureChecker(), InlineCheckerWrapper(), ReifiedTypeParameterSubstitutionChecker())
 private val DEFAULT_TYPE_CHECKERS = listOf(TypeApproximator())
 
 public abstract class AdditionalCheckerProvider(
-        public val annotationCheckers: List<AnnotationChecker>,
+        additionalAnnotationCheckers: List<AnnotationChecker>,
         additionalCallCheckers: List<CallChecker>,
         additionalTypeCheckers: List<AdditionalTypeChecker>
 ) {
 
+    public val annotationCheckers: List<AnnotationChecker> = DEFAULT_ANNOTATION_CHECKERS + additionalAnnotationCheckers
     public val callCheckers: List<CallChecker> = DEFAULT_CALL_CHECKERS + additionalCallCheckers
     public val additionalTypeCheckers: List<AdditionalTypeChecker> = DEFAULT_TYPE_CHECKERS + additionalTypeCheckers
 

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

@@ -0,0 +1,36 @@
+/*
+ * 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 org.jetbrains.kotlin.resolve
+
+import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.diagnostics.*
+import org.jetbrains.kotlin.builtins.*
+
+
+public class DataClassAnnotationChecker : AnnotationChecker {
+    override fun check(declaration: JetDeclaration, descriptor: DeclarationDescriptor, diagnosticHolder: DiagnosticSink) {
+        if (descriptor !is ClassDescriptor) return
+        if (declaration !is JetClassOrObject) return
+
+        if (KotlinBuiltIns.isData(descriptor)) {
+            if (descriptor.getUnsubstitutedPrimaryConstructor() == null && descriptor.getConstructors().isNotEmpty()) {
+                diagnosticHolder.report(Errors.PRIMARY_CONSTRUCTOR_REQUIRED_FOR_DATA_CLASS.on(declaration.getNameIdentifier()));
+            }
+        }
+    }
+}

compiler/testData/diagnostics/tests/secondaryConstructors/dataClasses.kt

@@ -0,0 +1,12 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+data class A1(val x: String) {
+    constructor(): this("") {}
+}
+
+data class A2() {
+    constructor(x: String): this() {}
+}
+
+data class <!PRIMARY_CONSTRUCTOR_REQUIRED_FOR_DATA_CLASS!>A3<!> {
+    constructor() {}
+}

compiler/testData/diagnostics/tests/secondaryConstructors/dataClasses.txt

@@ -0,0 +1,28 @@
+package
+
+kotlin.data() internal final class A1 {
+    public constructor A1()
+    public constructor A1(/*0*/ x: kotlin.String)
+    internal final val x: kotlin.String
+    internal final /*synthesized*/ fun component1(): kotlin.String
+    public final /*synthesized*/ fun copy(/*0*/ x: kotlin.String = ...): A1
+    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
+}
+
+kotlin.data() internal final class A2 {
+    public constructor A2()
+    public constructor A2(/*0*/ x: kotlin.String)
+    public final /*synthesized*/ fun copy(): A2
+    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
+}
+
+kotlin.data() internal final class A3 {
+    public constructor A3()
+    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
+}

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

@@ -10469,6 +10469,12 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("dataClasses.kt")
+            public void testDataClasses() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/secondaryConstructors/dataClasses.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("enums.kt")
             public void testEnums() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/secondaryConstructors/enums.kt");

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/KotlinJsCheckerProvider.kt

@@ -34,7 +34,7 @@ import org.jetbrains.kotlin.types.typeUtil.isSubtypeOf
 import org.jetbrains.kotlin.js.resolve.diagnostics.JsCallChecker
 
 public object KotlinJsCheckerProvider : AdditionalCheckerProvider(
-        annotationCheckers = listOf(NativeInvokeChecker(), NativeGetterChecker(), NativeSetterChecker()),
+        additionalAnnotationCheckers = listOf(NativeInvokeChecker(), NativeGetterChecker(), NativeSetterChecker()),
         additionalCallCheckers = listOf(JsCallChecker()),
         additionalTypeCheckers = listOf()
 )