[compiler] introduce dedicated Fir declaration for dangling modifier lists (KTIJ-23008)

ensure fir annotations are included in FirDanglingModifierList and resolved,
dedicated DanglingTopLevelModifierListStructureElement exists for top
level lists only, class level lists are processed by containing structure
element

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/FirDanglingModifierList.kt

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2010-2022 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.declarations
+
+import org.jetbrains.kotlin.KtSourceElement
+import org.jetbrains.kotlin.fir.FirElement
+import org.jetbrains.kotlin.fir.FirModuleData
+import org.jetbrains.kotlin.fir.diagnostics.ConeDiagnostic
+import org.jetbrains.kotlin.fir.diagnostics.FirDiagnosticHolder
+import org.jetbrains.kotlin.fir.expressions.FirAnnotation
+import org.jetbrains.kotlin.fir.symbols.impl.FirDanglingModifierSymbol
+import org.jetbrains.kotlin.fir.visitors.*
+
+/*
+ * This file was generated automatically
+ * DO NOT MODIFY IT MANUALLY
+ */
+
+abstract class FirDanglingModifierList : FirDeclaration(), FirDiagnosticHolder {
+    abstract override val source: KtSourceElement?
+    abstract override val resolvePhase: FirResolvePhase
+    abstract override val annotations: List<FirAnnotation>
+    abstract override val moduleData: FirModuleData
+    abstract override val origin: FirDeclarationOrigin
+    abstract override val attributes: FirDeclarationAttributes
+    abstract override val diagnostic: ConeDiagnostic
+    abstract override val symbol: FirDanglingModifierSymbol
+
+    override fun <R, D> accept(visitor: FirVisitor<R, D>, data: D): R = visitor.visitDanglingModifierList(this, data)
+
+    @Suppress("UNCHECKED_CAST")
+    override fun <E : FirElement, D> transform(transformer: FirTransformer<D>, data: D): E =
+        transformer.transformDanglingModifierList(this, data) as E
+
+    abstract override fun replaceResolvePhase(newResolvePhase: FirResolvePhase)
+
+    abstract override fun replaceAnnotations(newAnnotations: List<FirAnnotation>)
+
+    abstract override fun <D> transformAnnotations(transformer: FirTransformer<D>, data: D): FirDanglingModifierList
+}

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/builder/FirDanglingModifierListBuilder.kt

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2010-2022 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.
+ */
+
+@file:Suppress("DuplicatedCode")
+
+package org.jetbrains.kotlin.fir.declarations.builder
+
+import kotlin.contracts.*
+import org.jetbrains.kotlin.KtSourceElement
+import org.jetbrains.kotlin.fir.FirModuleData
+import org.jetbrains.kotlin.fir.builder.FirAnnotationContainerBuilder
+import org.jetbrains.kotlin.fir.builder.FirBuilderDsl
+import org.jetbrains.kotlin.fir.builder.toMutableOrEmpty
+import org.jetbrains.kotlin.fir.declarations.FirDanglingModifierList
+import org.jetbrains.kotlin.fir.declarations.FirDeclarationAttributes
+import org.jetbrains.kotlin.fir.declarations.FirDeclarationOrigin
+import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
+import org.jetbrains.kotlin.fir.declarations.impl.FirDanglingModifierListImpl
+import org.jetbrains.kotlin.fir.diagnostics.ConeDiagnostic
+import org.jetbrains.kotlin.fir.expressions.FirAnnotation
+import org.jetbrains.kotlin.fir.symbols.impl.FirDanglingModifierSymbol
+import org.jetbrains.kotlin.fir.visitors.*
+
+/*
+ * This file was generated automatically
+ * DO NOT MODIFY IT MANUALLY
+ */
+
+@FirBuilderDsl
+class FirDanglingModifierListBuilder : FirAnnotationContainerBuilder {
+    override var source: KtSourceElement? = null
+    var resolvePhase: FirResolvePhase = FirResolvePhase.RAW_FIR
+    override val annotations: MutableList<FirAnnotation> = mutableListOf()
+    lateinit var moduleData: FirModuleData
+    lateinit var origin: FirDeclarationOrigin
+    var attributes: FirDeclarationAttributes = FirDeclarationAttributes()
+    lateinit var diagnostic: ConeDiagnostic
+    lateinit var symbol: FirDanglingModifierSymbol
+
+    override fun build(): FirDanglingModifierList {
+        return FirDanglingModifierListImpl(
+            source,
+            resolvePhase,
+            annotations.toMutableOrEmpty(),
+            moduleData,
+            origin,
+            attributes,
+            diagnostic,
+            symbol,
+        )
+    }
+
+}
+
+@OptIn(ExperimentalContracts::class)
+inline fun buildDanglingModifierList(init: FirDanglingModifierListBuilder.() -> Unit): FirDanglingModifierList {
+    contract {
+        callsInPlace(init, kotlin.contracts.InvocationKind.EXACTLY_ONCE)
+    }
+    return FirDanglingModifierListBuilder().apply(init).build()
+}

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/impl/FirDanglingModifierListImpl.kt

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2010-2022 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.
+ */
+
+@file:Suppress("DuplicatedCode")
+
+package org.jetbrains.kotlin.fir.declarations.impl
+
+import org.jetbrains.kotlin.KtSourceElement
+import org.jetbrains.kotlin.fir.FirModuleData
+import org.jetbrains.kotlin.fir.declarations.FirDanglingModifierList
+import org.jetbrains.kotlin.fir.declarations.FirDeclarationAttributes
+import org.jetbrains.kotlin.fir.declarations.FirDeclarationOrigin
+import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
+import org.jetbrains.kotlin.fir.diagnostics.ConeDiagnostic
+import org.jetbrains.kotlin.fir.expressions.FirAnnotation
+import org.jetbrains.kotlin.fir.symbols.impl.FirDanglingModifierSymbol
+import org.jetbrains.kotlin.fir.visitors.*
+import org.jetbrains.kotlin.fir.MutableOrEmptyList
+import org.jetbrains.kotlin.fir.builder.toMutableOrEmpty
+
+/*
+ * This file was generated automatically
+ * DO NOT MODIFY IT MANUALLY
+ */
+
+internal class FirDanglingModifierListImpl(
+    override val source: KtSourceElement?,
+    @Volatile
+    override var resolvePhase: FirResolvePhase,
+    override var annotations: MutableOrEmptyList<FirAnnotation>,
+    override val moduleData: FirModuleData,
+    override val origin: FirDeclarationOrigin,
+    override val attributes: FirDeclarationAttributes,
+    override val diagnostic: ConeDiagnostic,
+    override val symbol: FirDanglingModifierSymbol,
+) : FirDanglingModifierList() {
+    init {
+        symbol.bind(this)
+    }
+
+    override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
+        annotations.forEach { it.accept(visitor, data) }
+    }
+
+    override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirDanglingModifierListImpl {
+        transformAnnotations(transformer, data)
+        return this
+    }
+
+    override fun <D> transformAnnotations(transformer: FirTransformer<D>, data: D): FirDanglingModifierListImpl {
+        annotations.transformInplace(transformer, data)
+        return this
+    }
+
+    override fun replaceResolvePhase(newResolvePhase: FirResolvePhase) {
+        resolvePhase = newResolvePhase
+    }
+
+    override fun replaceAnnotations(newAnnotations: List<FirAnnotation>) {
+        annotations = newAnnotations.toMutableOrEmpty()
+    }
+}

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/visitors/FirDefaultVisitor.kt

@@ -95,6 +95,7 @@ import org.jetbrains.kotlin.fir.expressions.FirClassReferenceExpression
 import org.jetbrains.kotlin.fir.expressions.FirErrorExpression
 import org.jetbrains.kotlin.fir.declarations.FirErrorFunction
 import org.jetbrains.kotlin.fir.declarations.FirErrorProperty
+import org.jetbrains.kotlin.fir.declarations.FirDanglingModifierList
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccessExpression
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedErrorAccessExpression
 import org.jetbrains.kotlin.fir.expressions.FirPropertyAccessExpression

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/visitors/FirDefaultVisitorVoid.kt

@@ -95,6 +95,7 @@ import org.jetbrains.kotlin.fir.expressions.FirClassReferenceExpression
 import org.jetbrains.kotlin.fir.expressions.FirErrorExpression
 import org.jetbrains.kotlin.fir.declarations.FirErrorFunction
 import org.jetbrains.kotlin.fir.declarations.FirErrorProperty
+import org.jetbrains.kotlin.fir.declarations.FirDanglingModifierList
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccessExpression
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedErrorAccessExpression
 import org.jetbrains.kotlin.fir.expressions.FirPropertyAccessExpression

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/visitors/FirTransformer.kt

@@ -95,6 +95,7 @@ import org.jetbrains.kotlin.fir.expressions.FirClassReferenceExpression
 import org.jetbrains.kotlin.fir.expressions.FirErrorExpression
 import org.jetbrains.kotlin.fir.declarations.FirErrorFunction
 import org.jetbrains.kotlin.fir.declarations.FirErrorProperty
+import org.jetbrains.kotlin.fir.declarations.FirDanglingModifierList
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccessExpression
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedErrorAccessExpression
 import org.jetbrains.kotlin.fir.expressions.FirPropertyAccessExpression
@@ -514,6 +515,10 @@ abstract class FirTransformer<in D> : FirVisitor<FirElement, D>() {
         return transformElement(errorProperty, data)
     }
 
+    open fun transformDanglingModifierList(danglingModifierList: FirDanglingModifierList, data: D): FirDanglingModifierList {
+        return transformElement(danglingModifierList, data)
+    }
+
     open fun transformQualifiedAccessExpression(qualifiedAccessExpression: FirQualifiedAccessExpression, data: D): FirStatement {
         return transformElement(qualifiedAccessExpression, data)
     }
@@ -1086,6 +1091,10 @@ abstract class FirTransformer<in D> : FirVisitor<FirElement, D>() {
         return transformErrorProperty(errorProperty, data)
     }
 
+    final override fun visitDanglingModifierList(danglingModifierList: FirDanglingModifierList, data: D): FirDanglingModifierList {
+        return transformDanglingModifierList(danglingModifierList, data)
+    }
+
     final override fun visitQualifiedAccessExpression(qualifiedAccessExpression: FirQualifiedAccessExpression, data: D): FirStatement {
         return transformQualifiedAccessExpression(qualifiedAccessExpression, data)
     }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/visitors/FirVisitor.kt

@@ -95,6 +95,7 @@ import org.jetbrains.kotlin.fir.expressions.FirClassReferenceExpression
 import org.jetbrains.kotlin.fir.expressions.FirErrorExpression
 import org.jetbrains.kotlin.fir.declarations.FirErrorFunction
 import org.jetbrains.kotlin.fir.declarations.FirErrorProperty
+import org.jetbrains.kotlin.fir.declarations.FirDanglingModifierList
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccessExpression
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedErrorAccessExpression
 import org.jetbrains.kotlin.fir.expressions.FirPropertyAccessExpression
@@ -335,6 +336,8 @@ abstract class FirVisitor<out R, in D> {
 
     open fun visitErrorProperty(errorProperty: FirErrorProperty, data: D): R  = visitElement(errorProperty, data)
 
+    open fun visitDanglingModifierList(danglingModifierList: FirDanglingModifierList, data: D): R  = visitElement(danglingModifierList, data)
+
     open fun visitQualifiedAccessExpression(qualifiedAccessExpression: FirQualifiedAccessExpression, data: D): R  = visitElement(qualifiedAccessExpression, data)
 
     open fun visitQualifiedErrorAccessExpression(qualifiedErrorAccessExpression: FirQualifiedErrorAccessExpression, data: D): R  = visitElement(qualifiedErrorAccessExpression, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/visitors/FirVisitorVoid.kt

@@ -95,6 +95,7 @@ import org.jetbrains.kotlin.fir.expressions.FirClassReferenceExpression
 import org.jetbrains.kotlin.fir.expressions.FirErrorExpression
 import org.jetbrains.kotlin.fir.declarations.FirErrorFunction
 import org.jetbrains.kotlin.fir.declarations.FirErrorProperty
+import org.jetbrains.kotlin.fir.declarations.FirDanglingModifierList
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccessExpression
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedErrorAccessExpression
 import org.jetbrains.kotlin.fir.expressions.FirPropertyAccessExpression
@@ -513,6 +514,10 @@ abstract class FirVisitorVoid : FirVisitor<Unit, Nothing?>() {
         visitElement(errorProperty)
     }
 
+    open fun visitDanglingModifierList(danglingModifierList: FirDanglingModifierList) {
+        visitElement(danglingModifierList)
+    }
+
     open fun visitQualifiedAccessExpression(qualifiedAccessExpression: FirQualifiedAccessExpression) {
         visitElement(qualifiedAccessExpression)
     }
@@ -1085,6 +1090,10 @@ abstract class FirVisitorVoid : FirVisitor<Unit, Nothing?>() {
         visitErrorProperty(errorProperty)
     }
 
+    final override fun visitDanglingModifierList(danglingModifierList: FirDanglingModifierList, data: Nothing?) {
+        visitDanglingModifierList(danglingModifierList)
+    }
+
     final override fun visitQualifiedAccessExpression(qualifiedAccessExpression: FirQualifiedAccessExpression, data: Nothing?) {
         visitQualifiedAccessExpression(qualifiedAccessExpression)
     }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/ClassMembers.kt

@@ -37,9 +37,13 @@ fun FirCallableDeclaration.containingClassLookupTag(): ConeClassLikeLookupTag? =
 fun FirRegularClass.containingClassForLocal(): ConeClassLikeLookupTag? =
     if (isLocal) containingClassForLocalAttr else null
 
+fun FirDanglingModifierList.containingClass(): ConeClassLikeLookupTag? =
+    containingClassAttr
+
 private object ContainingClassKey : FirDeclarationDataKey()
 var FirCallableDeclaration.containingClassForStaticMemberAttr: ConeClassLikeLookupTag? by FirDeclarationDataRegistry.data(ContainingClassKey)
 var FirRegularClass.containingClassForLocalAttr: ConeClassLikeLookupTag? by FirDeclarationDataRegistry.data(ContainingClassKey)
+var FirDanglingModifierList.containingClassAttr: ConeClassLikeLookupTag? by FirDeclarationDataRegistry.data(ContainingClassKey)
 
 private object IsNewPlaceForBodyGeneration : FirDeclarationDataKey()
 var FirRegularClass.isNewPlaceForBodyGeneration: Boolean? by FirDeclarationDataRegistry.data(IsNewPlaceForBodyGeneration)

compiler/fir/tree/src/org/jetbrains/kotlin/fir/diagnostics/ConeSimpleDiagnostic.kt

@@ -46,6 +46,11 @@ object ConeDestructuringDeclarationsOnTopLevel : ConeDiagnostic {
         get() = "Destructuring declarations are only allowed for local variables/values"
 }
 
+object ConeDanglingModifierOnTopLevel : ConeDiagnostic {
+    override val reason: String
+        get() = "Top level declaration expected"
+}
+
 enum class DiagnosticKind {
     Syntax,
     ExpressionExpected,

compiler/fir/tree/src/org/jetbrains/kotlin/fir/renderer/FirRenderer.kt

@@ -387,6 +387,11 @@ class FirRenderer(
             bodyRenderer?.renderBody(anonymousInitializer.body)
         }
 
+        override fun visitDanglingModifierList(danglingModifierList: FirDanglingModifierList) {
+            annotationRenderer?.render(danglingModifierList)
+            print("<DANGLING MODIFIER: ${danglingModifierList.diagnostic.reason}>")
+        }
+
         override fun visitBlock(block: FirBlock) {
             bodyRenderer?.renderBody(block)
         }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/symbols/impl/FirDanglingModifierSymbol.kt

@@ -0,0 +1,13 @@
+/*
+ * Copyright 2010-2020 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.symbols.impl
+
+import org.jetbrains.kotlin.fir.declarations.FirDanglingModifierList
+import org.jetbrains.kotlin.fir.symbols.FirBasedSymbol
+
+class FirDanglingModifierSymbol : FirBasedSymbol<FirDanglingModifierList>() {
+    override fun toString(): String = "${this::class.simpleName}"
+}

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/FirTreeBuilder.kt

@@ -118,6 +118,7 @@ object FirTreeBuilder : AbstractFirTreeBuilder() {
     val errorExpression by element(Expression, expression, diagnosticHolder)
     val errorFunction by element(Declaration, function, diagnosticHolder)
     val errorProperty by element(Declaration, variable, diagnosticHolder)
+    val danglingModifierList by element(Declaration, declaration, diagnosticHolder)
     val qualifiedAccessExpression by element(Expression, expression, qualifiedAccess)
     val qualifiedErrorAccessExpression by element(Expression, expression, diagnosticHolder)
     val propertyAccessExpression by element(Expression, qualifiedAccessExpression)

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/ImplementationConfigurator.kt

@@ -43,6 +43,7 @@ object ImplementationConfigurator : AbstractFirTreeImplementationConfigurator()
         }
 
         impl(anonymousObject)
+        impl(danglingModifierList)
         noImpl(anonymousObjectExpression)
 
         impl(typeAlias)

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/NodeConfigurator.kt

@@ -456,6 +456,10 @@ object NodeConfigurator : AbstractFieldConfigurator<FirTreeBuilder>(FirTreeBuild
             +field("dispatchReceiverType", coneSimpleKotlinTypeType, nullable = true)
         }
 
+        danglingModifierList.configure {
+            +symbol("FirDanglingModifierSymbol")
+        }
+
         file.configure {
             +field("annotationsContainer", fileAnnotationsContainer).withTransform()
             +field("packageDirective", packageDirective)