KT-53783 Prohibit "expect data object" syntax

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java

@@ -20830,6 +20830,12 @@ public class DiagnosisCompilerTestFE10TestdataTestGenerated extends AbstractDiag
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/tests/multiplatform"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
             }
 
+            @Test
+            @TestMetadata("expectDataObject.kt")
+            public void testExpectDataObject() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/expectDataObject.kt");
+            }
+
             @Test
             @TestMetadata("expectInterfaceApplicability.kt")
             public void testExpectInterfaceApplicability() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java

@@ -20830,6 +20830,12 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/tests/multiplatform"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
             }
 
+            @Test
+            @TestMetadata("expectDataObject.kt")
+            public void testExpectDataObject() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/expectDataObject.kt");
+            }
+
             @Test
             @TestMetadata("expectInterfaceApplicability.kt")
             public void testExpectInterfaceApplicability() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsWithLightTreeTestGenerated.java

@@ -20830,6 +20830,12 @@ public class FirOldFrontendDiagnosticsWithLightTreeTestGenerated extends Abstrac
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/tests/multiplatform"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
             }
 
+            @Test
+            @TestMetadata("expectDataObject.kt")
+            public void testExpectDataObject() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/expectDataObject.kt");
+            }
+
             @Test
             @TestMetadata("expectInterfaceApplicability.kt")
             public void testExpectInterfaceApplicability() throws Exception {

compiler/psi/src/org/jetbrains/kotlin/resolve/ModifierCheckerHelpers.kt

@@ -63,6 +63,7 @@ private fun buildCompatibilityMap(): Map<Pair<KtKeywordToken, KtKeywordToken>, C
     result += incompatibilityRegister(DATA_KEYWORD, SEALED_KEYWORD)
     result += incompatibilityRegister(DATA_KEYWORD, INLINE_KEYWORD)
     result += incompatibilityRegister(DATA_KEYWORD, VALUE_KEYWORD)
+    result += incompatibilityRegister(DATA_KEYWORD, OBJECT_KEYWORD, EXPECT_KEYWORD)
     // open is redundant to abstract & override
     result += redundantRegister(ABSTRACT_KEYWORD, OPEN_KEYWORD)
     // abstract is redundant to sealed

compiler/testData/diagnostics/tests/multiplatform/expectDataObject.fir.kt

@@ -0,0 +1,8 @@
+// LANGUAGE: +DataObjects
+// MODULE: m1-common
+// FILE: common.kt
+<!INCOMPATIBLE_MODIFIERS!>expect<!> <!INCOMPATIBLE_MODIFIERS!>data<!> object DataObject
+
+// MODULE: m1-jvm()()(m1-common)
+// FILE: jvm.kt
+actual data object DataObject

compiler/testData/diagnostics/tests/multiplatform/expectDataObject.kt

@@ -0,0 +1,8 @@
+// LANGUAGE: +DataObjects
+// MODULE: m1-common
+// FILE: common.kt
+<!INCOMPATIBLE_MODIFIERS, INCOMPATIBLE_MODIFIERS{JVM}!>expect<!> <!INCOMPATIBLE_MODIFIERS, INCOMPATIBLE_MODIFIERS{JVM}!>data<!> object DataObject
+
+// MODULE: m1-jvm()()(m1-common)
+// FILE: jvm.kt
+actual data object DataObject

compiler/testData/diagnostics/tests/multiplatform/expectDataObject.txt

@@ -0,0 +1,18 @@
+// -- Module: <m1-common> --
+package
+
+public expect data object DataObject {
+    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
+}
+
+// -- Module: <m1-jvm> --
+package
+
+public actual data object DataObject {
+    private constructor DataObject()
+    public open override /*1*/ /*synthesized*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*synthesized*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*synthesized*/ fun toString(): kotlin.String
+}

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java

@@ -20836,6 +20836,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/tests/multiplatform"), Pattern.compile("^(.*)\\.kts?$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
             }
 
+            @Test
+            @TestMetadata("expectDataObject.kt")
+            public void testExpectDataObject() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/multiplatform/expectDataObject.kt");
+            }
+
             @Test
             @TestMetadata("expectInterfaceApplicability.kt")
             public void testExpectInterfaceApplicability() throws Exception {