FIR: forbid top-level destructuring declarations #KT-50468 Fixed

analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/transformers/LLFirDesignatedAnnotationsResolveTransformed.kt

@@ -64,7 +64,7 @@ internal class LLFirDesignatedAnnotationsResolveTransformed(
         when (declaration) {
             is FirClass, is FirTypeAlias ->
                 declaration.ensurePhase(FirResolvePhase.COMPILER_REQUIRED_ANNOTATIONS)
-            is FirFunction, is FirProperty, is FirEnumEntry, is FirField, is FirAnonymousInitializer ->
+            is FirFunction, is FirProperty, is FirEnumEntry, is FirField, is FirAnonymousInitializer, is FirErrorProperty ->
                 Unit
             else ->
                 error("Unexpected type: ${declaration::class.simpleName}")

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

@@ -512,6 +512,12 @@ public class DiagnosisCompilerFirTestdataTestGenerated extends AbstractDiagnosis
             runTest("compiler/fir/analysis-tests/testData/resolve/throwableSubclass.kt");
         }
 
+        @Test
+        @TestMetadata("topLevelDestruction.kt")
+        public void testTopLevelDestruction() throws Exception {
+            runTest("compiler/fir/analysis-tests/testData/resolve/topLevelDestruction.kt");
+        }
+
         @Test
         @TestMetadata("treeSet.kt")
         public void testTreeSet() throws Exception {

compiler/fir/analysis-tests/legacy-fir-tests/tests-gen/org/jetbrains/kotlin/fir/LazyBodyIsNotTouchedTilContractsPhaseTestGenerated.java

@@ -434,6 +434,11 @@ public class LazyBodyIsNotTouchedTilContractsPhaseTestGenerated extends Abstract
         runTest("compiler/fir/analysis-tests/testData/resolve/throwableSubclass.kt");
     }
 
+    @TestMetadata("topLevelDestruction.kt")
+    public void testTopLevelDestruction() throws Exception {
+        runTest("compiler/fir/analysis-tests/testData/resolve/topLevelDestruction.kt");
+    }
+
     @TestMetadata("treeSet.kt")
     public void testTreeSet() throws Exception {
         runTest("compiler/fir/analysis-tests/testData/resolve/treeSet.kt");

compiler/fir/analysis-tests/testData/resolve/topLevelDestruction.fir.txt

@@ -0,0 +1,2 @@
+FILE: topLevelDestruction.kt
+    <ERROR TYPE REF: Destructuring declarations are only allowed for local variables/values>

compiler/fir/analysis-tests/testData/resolve/topLevelDestruction.kt

@@ -0,0 +1 @@
+val <!SYNTAX!>(x, y)<!> = Pair(1, 2)

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

@@ -512,6 +512,12 @@ public class FirDiagnosticTestGenerated extends AbstractFirDiagnosticTest {
             runTest("compiler/fir/analysis-tests/testData/resolve/throwableSubclass.kt");
         }
 
+        @Test
+        @TestMetadata("topLevelDestruction.kt")
+        public void testTopLevelDestruction() throws Exception {
+            runTest("compiler/fir/analysis-tests/testData/resolve/topLevelDestruction.kt");
+        }
+
         @Test
         @TestMetadata("treeSet.kt")
         public void testTreeSet() throws Exception {

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

@@ -512,6 +512,12 @@ public class FirDiagnosticsWithLightTreeTestGenerated extends AbstractFirDiagnos
             runTest("compiler/fir/analysis-tests/testData/resolve/throwableSubclass.kt");
         }
 
+        @Test
+        @TestMetadata("topLevelDestruction.kt")
+        public void testTopLevelDestruction() throws Exception {
+            runTest("compiler/fir/analysis-tests/testData/resolve/topLevelDestruction.kt");
+        }
+
         @Test
         @TestMetadata("treeSet.kt")
         public void testTreeSet() throws Exception {

compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/converter/DeclarationsConverter.kt

@@ -8,11 +8,8 @@ package org.jetbrains.kotlin.fir.lightTree.converter
 import com.intellij.lang.LighterASTNode
 import com.intellij.psi.TokenType
 import com.intellij.util.diff.FlyweightCapableTreeStructure
+import org.jetbrains.kotlin.*
 import org.jetbrains.kotlin.ElementTypeUtils.isExpression
-import org.jetbrains.kotlin.KtFakeSourceElementKind
-import org.jetbrains.kotlin.KtLightSourceElement
-import org.jetbrains.kotlin.KtSourceElement
-import org.jetbrains.kotlin.KtNodeTypes
 import org.jetbrains.kotlin.KtNodeTypes.*
 import org.jetbrains.kotlin.builtins.StandardNames
 import org.jetbrains.kotlin.builtins.StandardNames.DEFAULT_VALUE_PARAMETER
@@ -22,7 +19,6 @@ import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.descriptors.Visibility
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationUseSiteTarget
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationUseSiteTarget.*
-import org.jetbrains.kotlin.fakeElement
 import org.jetbrains.kotlin.fir.*
 import org.jetbrains.kotlin.fir.builder.*
 import org.jetbrains.kotlin.fir.contracts.FirContractDescription
@@ -94,18 +90,20 @@ class DeclarationsConverter(
         val firDeclarationList = mutableListOf<FirDeclaration>()
         context.packageFqName = FqName.ROOT
         var packageDirective: FirPackageDirective? = null
-        file.forEachChildren {
-            when (it.tokenType) {
-                FILE_ANNOTATION_LIST -> fileAnnotationList += convertFileAnnotationList(it)
+        file.forEachChildren { child ->
+            @Suppress("RemoveRedundantQualifierName")
+            when (child.tokenType) {
+                FILE_ANNOTATION_LIST -> fileAnnotationList += convertFileAnnotationList(child)
                 PACKAGE_DIRECTIVE -> {
-                    packageDirective = convertPackageDirective(it).also { context.packageFqName = it.packageFqName }
+                    packageDirective = convertPackageDirective(child).also { context.packageFqName = it.packageFqName }
                 }
-                IMPORT_LIST -> importList += convertImportDirectives(it)
-                CLASS -> firDeclarationList += convertClass(it)
-                FUN -> firDeclarationList += convertFunctionDeclaration(it) as FirDeclaration
-                KtNodeTypes.PROPERTY -> firDeclarationList += convertPropertyDeclaration(it)
-                TYPEALIAS -> firDeclarationList += convertTypeAlias(it)
-                OBJECT_DECLARATION -> firDeclarationList += convertClass(it)
+                IMPORT_LIST -> importList += convertImportDirectives(child)
+                CLASS -> firDeclarationList += convertClass(child)
+                FUN -> firDeclarationList += convertFunctionDeclaration(child) as FirDeclaration
+                KtNodeTypes.PROPERTY -> firDeclarationList += convertPropertyDeclaration(child)
+                TYPEALIAS -> firDeclarationList += convertTypeAlias(child)
+                OBJECT_DECLARATION -> firDeclarationList += convertClass(child)
+                DESTRUCTURING_DECLARATION -> firDeclarationList += buildErrorTopLevelDestructuringDeclaration(child.toFirSourceElement())
                 SCRIPT -> {
                     // TODO: scripts aren't supported yet
                 }
@@ -134,6 +132,7 @@ class DeclarationsConverter(
 
     fun convertBlockExpressionWithoutBuilding(block: LighterASTNode): FirBlockBuilder {
         val firStatements = block.forEachChildrenReturnList<FirStatement> { node, container ->
+            @Suppress("RemoveRedundantQualifierName")
             when (node.tokenType) {
                 CLASS, OBJECT_DECLARATION -> container += convertClass(node) as FirStatement
                 FUN -> container += convertFunctionDeclaration(node)
@@ -791,6 +790,7 @@ class DeclarationsConverter(
      */
     private fun convertClassBody(classBody: LighterASTNode, classWrapper: ClassWrapper): List<FirDeclaration> {
         return classBody.forEachChildrenReturnList { node, container ->
+            @Suppress("RemoveRedundantQualifierName")
             when (node.tokenType) {
                 ENUM_ENTRY -> container += convertEnumEntry(node, classWrapper)
                 CLASS -> container += convertClass(node)

compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt

@@ -929,9 +929,12 @@ open class RawFirBuilder(
                     }
                 }
                 for (declaration in file.declarations) {
-                    // TODO: scripts aren't supported yet
-                    if (declaration is KtScript) continue
-                    declarations += declaration.convert<FirDeclaration>()
+                    declarations += when (declaration) {
+                        // TODO: scripts aren't supported yet
+                        is KtScript -> continue
+                        is KtDestructuringDeclaration -> buildErrorTopLevelDestructuringDeclaration(declaration.toFirSourceElement())
+                        else -> declaration.convert()
+                    }
                 }
             }
         }

compiler/fir/raw-fir/raw-fir.common/src/org/jetbrains/kotlin/fir/builder/BaseFirBuilder.kt

@@ -1261,6 +1261,17 @@ abstract class BaseFirBuilder<T>(val baseSession: FirSession, val context: Conte
         }
     }
 
+    protected fun buildErrorTopLevelDestructuringDeclaration(source: KtSourceElement) = buildErrorProperty {
+        this.source = source
+        moduleData = baseModuleData
+        origin = FirDeclarationOrigin.Source
+        name = Name.special("<destructuring>")
+        diagnostic = ConeSimpleDiagnostic(
+            "Destructuring declarations are only allowed for local variables/values", DiagnosticKind.Syntax
+        )
+        symbol = FirErrorPropertySymbol(diagnostic)
+    }
+
     enum class ValueParameterDeclaration {
         OTHER,
         LAMBDA,