[WasmJs] Prohibit external classes to be a storage of an associated objects

Fix #KT-65355

compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirWasmDiagnosticsList.kt

@@ -70,4 +70,8 @@ object WASM_DIAGNOSTICS_LIST : DiagnosticList("FirWasmErrors") {
         val WASI_EXTERNAL_NOT_TOP_LEVEL_FUNCTION by error<KtElement>()
         val WASI_EXTERNAL_FUNCTION_WITHOUT_IMPORT by error<KtElement>()
     }
+
+    val ASSOCIATED_OBJECTS by object : DiagnosticGroup("Associated object") {
+        val ASSOCIATED_OBJECT_INVALID_BINDING by error<KtElement>()
+    }
 }

compiler/fir/checkers/checkers.wasm/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/wasm/FirWasmErrors.kt

@@ -55,6 +55,9 @@ object FirWasmErrors {
     val WASI_EXTERNAL_NOT_TOP_LEVEL_FUNCTION: KtDiagnosticFactory0 by error0<KtElement>()
     val WASI_EXTERNAL_FUNCTION_WITHOUT_IMPORT: KtDiagnosticFactory0 by error0<KtElement>()
 
+    // Associated object
+    val ASSOCIATED_OBJECT_INVALID_BINDING: KtDiagnosticFactory0 by error0<KtElement>()
+
     init {
         RootDiagnosticRendererFactory.registerFactory(FirWasmErrorsDefaultMessages)
     }

compiler/fir/checkers/checkers.wasm/src/org/jetbrains/kotlin/fir/analysis/diagnostics/wasm/FirWasmErrorsDefaultMessages.kt

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.diagnostics.KtDiagnosticFactoryToRendererMap
 import org.jetbrains.kotlin.diagnostics.KtDiagnosticRenderers.TO_STRING
 import org.jetbrains.kotlin.diagnostics.rendering.BaseDiagnosticRendererFactory
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirDiagnosticRenderers
+import org.jetbrains.kotlin.fir.analysis.diagnostics.wasm.FirWasmErrors.ASSOCIATED_OBJECT_INVALID_BINDING
 import org.jetbrains.kotlin.fir.analysis.diagnostics.wasm.FirWasmErrors.CALL_TO_DEFINED_EXTERNALLY_FROM_NON_EXTERNAL_DECLARATION
 import org.jetbrains.kotlin.fir.analysis.diagnostics.wasm.FirWasmErrors.EXTERNAL_TYPE_EXTENDS_NON_EXTERNAL_TYPE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.wasm.FirWasmErrors.JSCODE_INVALID_PARAMETER_NAME
@@ -42,6 +43,7 @@ object FirWasmErrorsDefaultMessages : BaseDiagnosticRendererFactory() {
             NESTED_JS_MODULE_PROHIBITED,
             "'@JsModule' cannot appear here since the file is already marked by either '@JsModule'."
         )
+
         map.put(
             NON_EXTERNAL_TYPE_EXTENDS_EXTERNAL_TYPE,
             "Non-external type extends external type ''{0}''",
@@ -100,5 +102,7 @@ object FirWasmErrorsDefaultMessages : BaseDiagnosticRendererFactory() {
 
         map.put(WASI_EXTERNAL_NOT_TOP_LEVEL_FUNCTION, "Only top-level functions can be external.")
         map.put(WASI_EXTERNAL_FUNCTION_WITHOUT_IMPORT, "External functions should be annotated with '@WasmImport'.")
+
+        map.put(ASSOCIATED_OBJECT_INVALID_BINDING, "Invalid associated object binding.")
     }
 }

compiler/fir/checkers/checkers.wasm/src/org/jetbrains/kotlin/fir/analysis/wasm/checkers/WasmDeclarationCheckers.kt

@@ -34,6 +34,7 @@ object WasmJsDeclarationCheckers : DeclarationCheckers() {
             FirJsExportAnnotationChecker,
             FirWasmJsModuleChecker,
             FirWasmExternalFileChecker,
+            FirWasmJsAssociatedObjectChecker,
         )
 }
 

compiler/fir/checkers/checkers.wasm/src/org/jetbrains/kotlin/fir/analysis/wasm/checkers/declaration/FirWasmJsAssociatedObjectChecker.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2010-2024 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * 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.fir.analysis.wasm.checkers.declaration
+
+import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.analysis.checkers.MppCheckerKind
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirBasicDeclarationChecker
+import org.jetbrains.kotlin.fir.analysis.diagnostics.wasm.FirWasmErrors.ASSOCIATED_OBJECT_INVALID_BINDING
+import org.jetbrains.kotlin.fir.declarations.FirClass
+import org.jetbrains.kotlin.fir.declarations.FirDeclaration
+import org.jetbrains.kotlin.fir.declarations.hasAnnotation
+import org.jetbrains.kotlin.fir.types.coneType
+import org.jetbrains.kotlin.fir.types.toSymbol
+import org.jetbrains.kotlin.name.StandardClassIds
+import org.jetbrains.kotlin.fir.declarations.utils.isEffectivelyExternal
+
+object FirWasmJsAssociatedObjectChecker : FirBasicDeclarationChecker(MppCheckerKind.Common) {
+    override fun check(declaration: FirDeclaration, context: CheckerContext, reporter: DiagnosticReporter) {
+        if (declaration !is FirClass) return
+        if (!declaration.symbol.isEffectivelyExternal(context.session)) return
+
+        for (annotationCall in declaration.annotations) {
+            val annotations = annotationCall.annotationTypeRef.coneType.toSymbol(context.session)?.annotations ?: continue
+            if (annotations.hasAnnotation(StandardClassIds.Annotations.AssociatedObjectKey, context.session)) {
+                reporter.reportOn(annotationCall.source, ASSOCIATED_OBJECT_INVALID_BINDING, context)
+            }
+        }
+    }
+}

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/WasmLoweringPhases.kt

@@ -678,6 +678,8 @@ val loweringList = listOf(
 
     wasmStringSwitchOptimizerLowering,
 
+    associatedObjectsLowering,
+
     complexExternalDeclarationsToTopLevelFunctionsLowering,
     complexExternalDeclarationsUsagesLowering,
 
@@ -724,8 +726,6 @@ val loweringList = listOf(
     eraseVirtualDispatchReceiverParametersTypes,
     bridgesConstructionPhase,
 
-    associatedObjectsLowering,
-
     objectDeclarationLoweringPhase,
     genericReturnTypeLowering,
     unitToVoidLowering,

compiler/testData/diagnostics/wasmTests/jsInterop/associatedObjects.kt

@@ -0,0 +1,21 @@
+// FIR_IDENTICAL
+@file:OptIn(ExperimentalAssociatedObjects::class)
+
+import kotlin.reflect.AssociatedObjectKey
+import kotlin.reflect.ExperimentalAssociatedObjects
+import kotlin.reflect.KClass
+import kotlin.reflect.findAssociatedObject
+
+@AssociatedObjectKey
+@Retention(AnnotationRetention.BINARY)
+annotation class X(val kClass: KClass<*>)
+
+object Promise
+
+<!ASSOCIATED_OBJECT_INVALID_BINDING!>@X(Promise::class)<!>
+external class Y
+
+external class OuterExternal {
+    <!ASSOCIATED_OBJECT_INVALID_BINDING!>@X(Promise::class)<!>
+    class NestedExternal
+}