KE2: Populate Kotlin type nullability and alias information

java/kotlin-extractor/src/main/kotlin/KotlinFileExtractor.kt

@@ -2776,7 +2776,7 @@ open class KotlinFileExtractor(
             val locId = tw.getLocation(ta)
             // TODO: We don't really want to generate any Java types here; we only want the KT type:
             val type = useType(ta.expandedType)
-            tw.writeKt_type_alias(id, ta.name.asString(), type.kotlinResult.id)
+            TODO() // TODO: KotType tw.writeKt_type_alias(id, ta.name.asString(), type.kotlinResult.id)
             tw.writeHasLocation(id, locId)
 
             // TODO: extract annotations

java/kotlin-extractor2/src/main/kotlin/entities/Types.kt

@@ -20,25 +20,37 @@ private fun KotlinUsesExtractor.useClassType(
 }
 
 fun KotlinUsesExtractor.useType(t: KaType?, context: TypeContext = TypeContext.OTHER): TypeResults {
-    when (t) {
+    val tr = when (t) {
         null -> {
             logger.error("Unexpected null type")
             return extractErrorType()
         }
-        is KaClassType -> return useClassType(t)
-        is KaFlexibleType -> return useType(t.lowerBound) // TODO: take a more reasoned choice here
+        is KaClassType -> useClassType(t)
+        is KaFlexibleType -> useType(t.lowerBound) // TODO: take a more reasoned choice here
         else -> TODO()
     }
-    /*
-    OLD: KE1
-            when (t) {
-                is IrSimpleType -> return useSimpleType(t, context)
-                else -> {
-                    logger.error("Unrecognised IrType: " + t.javaClass)
-                    return extractErrorType()
-                }
-            }
-    */
+    val javaResult = tr.javaResult
+    val kotlinResultBase = tr.kotlinResult
+    val abbreviation = t.abbreviatedType
+    val kotlinResultAlias = if (abbreviation == null) kotlinResultBase else {
+                                // TODO: this cast is unsafe; .symbol is actually a KaClassLikeSymbol
+                                val classId = addClassLabel(abbreviation.symbol as KaClassSymbol)
+                                val kotlinBaseTypeId = kotlinResultBase.id
+                                val kotlinAliasTypeId =
+                                    tw.getLabelFor<DbKt_type_alias>("@\"kt_type_alias;{$classId};{$kotlinBaseTypeId}\"") {
+                                        tw.writeKt_type_aliases(it, classId, kotlinBaseTypeId)
+                                    }
+                                TypeResult(kotlinAliasTypeId /* , "TODO", "TODO" */)
+                            }
+    val kotlinResultNullability = if (t.nullability.isNullable) {
+                                      val kotlinAliasTypeId = kotlinResultAlias.id
+                                      val kotlinNullableTypeId =
+                                          tw.getLabelFor<DbKt_nullable_type>("@\"kt_nullable_type;{$kotlinAliasTypeId}\"") {
+                                              tw.writeKt_nullable_types(it, kotlinAliasTypeId)
+                                          }
+                                      TypeResult(kotlinNullableTypeId /* , "TODO", "TODO" */)
+                                  } else kotlinResultAlias
+    return TypeResults(javaResult, kotlinResultNullability)
 }
 
 private fun KotlinUsesExtractor.extractJavaErrorType(): TypeResult<DbErrortype> {

java/ql/lib/config/semmlecode.dbscheme

@@ -478,12 +478,12 @@ kt_nullable_types(
 )
 
 /**
- * `id` is the Kotlin type that is the alias called `name` of `kttypeid`.
- * That is, it has been defined by `typealias name = kttypeid`.
+ * `id` is the Kotlin type that is the alias called `classid` of `kttypeid`.
+ * That is, it has been defined by `typealias classid = kttypeid`.
  */
-kt_type_alias(
+kt_type_aliases(
   unique int id: @kt_type_alias,
-  string name: string ref,
+  int classid: @reftype ref,
   int kttypeid: @kt_type ref
 )
 

java/ql/lib/semmle/code/Location.qll

@@ -42,8 +42,10 @@ predicate hasName(Element e, string name) {
   or
   modifiers(e, name)
   or
-  kt_type_alias(e, name, _)
-  or
+  // TODO: An alias declaration might have a name, but the type that
+  // uses it doesn't
+  // or
+  // kt_type_alias(e, name, _)
   ktProperties(e, name)
   or
   e instanceof ErrorType and name = "<CodeQL error type>"

java/ql/lib/semmle/code/java/KotlinType.qll

@@ -32,7 +32,9 @@ class KotlinTypeAlias extends KotlinType, @kt_type_alias {
     result = "{" + this.getKotlinType().toString() + "}" + this.getName()
   }
 
-  override string getName() { kt_type_alias(this, result, _) }
+  override string getName() { result = this.getAliasClass().getName() }
 
-  KotlinType getKotlinType() { kt_type_alias(this, _, result) }
+  Class getAliasClass() { kt_type_aliases(this, result, _) }
+
+  KotlinType getKotlinType() { kt_type_aliases(this, _, result) }
 }