[UAST] Fix mapping types containing type aliases

#KT-27935 Fixed

core/descriptors.jvm/src/org/jetbrains/kotlin/load/kotlin/TypeMappingMode.kt

@@ -19,7 +19,8 @@ class TypeMappingMode private constructor(
     private val genericArgumentMode: TypeMappingMode? = null,
     val kotlinCollectionsToJavaCollections: Boolean = true,
     private val genericContravariantArgumentMode: TypeMappingMode? = genericArgumentMode,
-    private val genericInvariantArgumentMode: TypeMappingMode? = genericArgumentMode
+    private val genericInvariantArgumentMode: TypeMappingMode? = genericArgumentMode,
+    val mapTypeAliases: Boolean = false
 ) {
     companion object {
         /**
@@ -28,6 +29,13 @@ class TypeMappingMode private constructor(
         @JvmField
         val GENERIC_ARGUMENT = TypeMappingMode()
 
+        /**
+         * kotlin.Int is mapped to Ljava/lang/Integer;
+         * Type aliases are mapped to their expanded form
+         */
+        @JvmField
+        val GENERIC_ARGUMENT_UAST = TypeMappingMode(mapTypeAliases = true)
+
         /**
          * see KotlinTypeMapper.forceBoxedReturnType()
          * This configuration should be called only for method return type
@@ -41,6 +49,18 @@ class TypeMappingMode private constructor(
         @JvmField
         val DEFAULT = TypeMappingMode(genericArgumentMode = GENERIC_ARGUMENT, needPrimitiveBoxing = false, needInlineClassWrapping = false)
 
+        /**
+         * kotlin.Int is mapped to I
+         * Type aliases are mapped to their expanded form
+         */
+        @JvmField
+        val DEFAULT_UAST = TypeMappingMode(
+            genericArgumentMode = GENERIC_ARGUMENT_UAST,
+            needPrimitiveBoxing = false,
+            needInlineClassWrapping = false,
+            mapTypeAliases = true
+        )
+
         /**
          * kotlin.Int is mapped to I
          * inline class Foo(val x: Int) is mapped to LFoo;
@@ -133,12 +153,14 @@ class TypeMappingMode private constructor(
             skipDeclarationSiteWildcards: Boolean,
             isForAnnotationParameter: Boolean,
             needInlineClassWrapping: Boolean,
+            mapTypeAliases: Boolean,
             fallbackMode: TypeMappingMode? = null
         ) = TypeMappingMode(
             isForAnnotationParameter = isForAnnotationParameter,
             skipDeclarationSiteWildcards = skipDeclarationSiteWildcards,
             genericArgumentMode = fallbackMode,
-            needInlineClassWrapping = needInlineClassWrapping
+            needInlineClassWrapping = needInlineClassWrapping,
+            mapTypeAliases = mapTypeAliases
         )
     }
 

core/descriptors.jvm/src/org/jetbrains/kotlin/load/kotlin/typeSignatureMapping.kt

@@ -173,6 +173,10 @@ fun <T : Any> mapType(
             return type
         }
 
+        descriptor is TypeAliasDescriptor && mode.mapTypeAliases -> {
+            return mapType(descriptor.expandedType, factory, mode, typeMappingConfiguration, descriptorTypeWriter, writeGenericType)
+        }
+
         else -> throw UnsupportedOperationException("Unknown type $kotlinType")
     }
 }