FIR2IR: convert annotations on type aliases

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrClassifierStorage.kt

@@ -49,6 +49,8 @@ class Fir2IrClassifierStorage(
 
     private val classCache = mutableMapOf<FirRegularClass, IrClass>()
 
+    private val typeAliasCache = mutableMapOf<FirTypeAlias, IrTypeAlias>()
+
     private val typeParameterCache = mutableMapOf<FirTypeParameter, IrTypeParameter>()
 
     private val typeParameterCacheForSetter = mutableMapOf<FirTypeParameter, IrTypeParameter>()
@@ -136,7 +138,7 @@ class Fir2IrClassifierStorage(
         return this
     }
 
-    fun getCachedIrClass(klass: FirClass<*>): IrClass? {
+    internal fun getCachedIrClass(klass: FirClass<*>): IrClass? {
         return if (klass is FirAnonymousObject || klass is FirRegularClass && klass.visibility == Visibilities.LOCAL) {
             localStorage.getLocalClass(klass)
         } else {
@@ -158,7 +160,7 @@ class Fir2IrClassifierStorage(
         }
     }
 
-    internal fun createIrClass(klass: FirClass<*>, parent: IrDeclarationParent? = null): IrClass {
+    private fun createIrClass(klass: FirClass<*>, parent: IrDeclarationParent? = null): IrClass {
         // NB: klass can be either FirRegularClass or FirAnonymousObject
         if (klass is FirAnonymousObject) {
             return createIrAnonymousObject(klass, irParent = parent)
@@ -193,7 +195,7 @@ class Fir2IrClassifierStorage(
         preCacheTypeParameters(typeAlias)
         return typeAlias.convertWithOffsets { startOffset, endOffset ->
             declareIrTypeAlias(signature) { symbol ->
-                IrTypeAliasImpl(
+                val irTypeAlias = IrTypeAliasImpl(
                     startOffset, endOffset, symbol,
                     typeAlias.name, typeAlias.visibility,
                     typeAlias.expandedTypeRef.toIrType(),
@@ -203,10 +205,14 @@ class Fir2IrClassifierStorage(
                     setTypeParameters(typeAlias)
                     parent.declarations += this
                 }
+                typeAliasCache[typeAlias] = irTypeAlias
+                irTypeAlias
             }
         }
     }
 
+    internal fun getCachedTypeAlias(firTypeAlias: FirTypeAlias): IrTypeAlias? = typeAliasCache[firTypeAlias]
+
     private fun declareIrClass(signature: IdSignature?, factory: (IrClassSymbol) -> IrClass): IrClass {
         if (signature == null) {
             val descriptor = WrappedClassDescriptor()
@@ -369,7 +375,7 @@ class Fir2IrClassifierStorage(
         localStorage.putLocalClass(enumEntry.initializer as FirAnonymousObject, correspondingClass)
     }
 
-    fun getCachedIrEnumEntry(enumEntry: FirEnumEntry): IrEnumEntry? = enumEntryCache[enumEntry]
+    internal fun getCachedIrEnumEntry(enumEntry: FirEnumEntry): IrEnumEntry? = enumEntryCache[enumEntry]
 
     private fun declareIrEnumEntry(signature: IdSignature?, factory: (IrEnumEntrySymbol) -> IrEnumEntry): IrEnumEntry {
         if (signature == null) {

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrVisitor.kt

@@ -100,13 +100,17 @@ class Fir2IrVisitor(
         }
     }
 
-    private fun FirDeclaration.toIrDeclaration(): IrDeclaration? {
-        if (this is FirTypeAlias) return null
-        return accept(this@Fir2IrVisitor, null) as IrDeclaration
-    }
+    private fun FirDeclaration.toIrDeclaration(): IrDeclaration? =
+        accept(this@Fir2IrVisitor, null) as IrDeclaration
 
     // ==================================================================================
 
+    override fun visitTypeAlias(typeAlias: FirTypeAlias, data: Any?): IrElement {
+        val irTypeAlias = classifierStorage.getCachedTypeAlias(typeAlias)!!
+        annotationGenerator.generate(irTypeAlias, typeAlias)
+        return irTypeAlias
+    }
+
     override fun visitEnumEntry(enumEntry: FirEnumEntry, data: Any?): IrElement {
         val irEnumEntry = classifierStorage.getCachedIrEnumEntry(enumEntry)!!
         annotationGenerator.generate(irEnumEntry, enumEntry)

compiler/testData/codegen/box/annotations/annotationsOnTypeAliases.kt

@@ -1,6 +1,4 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
-
 // WITH_RUNTIME
 // FULL_JDK
 

compiler/testData/ir/irText/declarations/annotations/typeAliasesWithAnnotations.fir.txt

@@ -1,5 +1,7 @@
 FILE fqName:<root> fileName:/typeAliasesWithAnnotations.kt
   TYPEALIAS name:TestTypeAlias visibility:public expandedType:kotlin.String
+    annotations:
+      TestAnn(x = 'TestTypeAlias')
   CLASS ANNOTATION_CLASS name:TestAnn modality:FINAL visibility:public superTypes:[kotlin.Annotation]
     annotations:
       Target(allowedTargets = [GET_ENUM 'ENUM_ENTRY IR_EXTERNAL_DECLARATION_STUB name:TYPEALIAS' type=kotlin.annotation.AnnotationTarget])