Kotlin: Fix handling Unit in various places

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

@@ -354,12 +354,12 @@ open class KotlinFileExtractor(
         val paramsSignature = paramTypes.joinToString(separator = ",", prefix = "(", postfix = ")") { it.javaResult.signature!! }
 
         if (f.symbol is IrConstructorSymbol) {
-            val returnType = useType(erase(f.returnType))
+            val returnType = useType(erase(f.returnType), TypeContext.RETURN)
             val shortName = if (f.returnType.isAnonymous) "" else f.returnType.classFqName?.shortName()?.asString() ?: f.name.asString()
             @Suppress("UNCHECKED_CAST")
             tw.writeConstrs(id as Label<DbConstructor>, shortName, "$shortName$paramsSignature", returnType.javaResult.id, returnType.kotlinResult.id, parentId, id)
         } else {
-            val returnType = useType(f.returnType)
+            val returnType = useType(f.returnType, TypeContext.RETURN)
             val shortName = f.name.asString()
             @Suppress("UNCHECKED_CAST")
             tw.writeMethods(id as Label<DbMethod>, shortName, "$shortName$paramsSignature", returnType.javaResult.id, returnType.kotlinResult.id, parentId, id)

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

@@ -101,11 +101,13 @@ open class KotlinUsesExtractor(
                 this.withSourceFileOfClass(extractClass).extractClassInstance(extractClass, typeArgs)
             }
 
-            // Extract both the Kotlin and equivalent Java classes, so that we have database entries
-            // for both even if all internal references to the Kotlin type are substituted.
-            extractClassLaterIfExternal(c)
             substituteClass?.let { extractClassLaterIfExternal(it) }
         })
+        // Extract both the Kotlin and equivalent Java classes, so that we have database entries
+        // for both even if all internal references to the Kotlin type are substituted.
+        // TODO: Should we do this inside the label initialisation? That would require all
+        //       initialisers of the label to do it.
+        extractClassLaterIfExternal(c)
 
         return UseClassInstanceResult(TypeResult(classLabel, extractClass.fqNameWhenAvailable?.asString(), classId.shortName), extractClass)
     }
@@ -280,9 +282,10 @@ open class KotlinUsesExtractor(
             return classId
         }
         fun primitiveType(kotlinClass: IrClass, primitiveName: String?,
+                          otherIsPrimitive: Boolean,
                           javaPackageName: String, javaClassName: String,
                           kotlinPackageName: String, kotlinClassName: String): TypeResults {
-            val javaResult = if (context != TypeContext.GENERIC_ARGUMENT && !s.hasQuestionMark && primitiveName != null) {
+            val javaResult = if ((context == TypeContext.RETURN || (context == TypeContext.OTHER && otherIsPrimitive)) && !s.hasQuestionMark && primitiveName != null) {
                     val label: Label<DbPrimitive> = tw.getLabelFor("@\"type;$primitiveName\"", {
                         tw.writePrimitives(it, primitiveName)
                     })
@@ -327,8 +330,9 @@ XXX delete?
 */
             primitiveInfo != null -> return primitiveType(
                 s.classifier.owner as IrClass,
-                primitiveInfo.primitiveName, primitiveInfo.javaPackageName,
-                primitiveInfo.javaClassName, primitiveInfo.kotlinPackageName, primitiveInfo.kotlinClassName
+                primitiveInfo.primitiveName, primitiveInfo.otherIsPrimitive,
+                primitiveInfo.javaPackageName, primitiveInfo.javaClassName,
+                primitiveInfo.kotlinPackageName, primitiveInfo.kotlinClassName
             )
 /*
 TODO: Test case: nullable and has-question-mark type variables:
@@ -644,13 +648,13 @@ class X {
     fun useValueParameter(vp: IrValueParameter): Label<out DbParam> =
         tw.getLabelFor(getValueParameterLabel(vp))
 
-    fun getFieldLabel(p: IrField): String {
-        val parentId = useDeclarationParent(p.parent)
-        return "@\"field;{$parentId};${p.name.asString()}\""
+    fun getFieldLabel(f: IrField): String {
+        val parentId = useDeclarationParent(f.parent)
+        return "@\"field;{$parentId};${f.name.asString()}\""
     }
 
-    fun useField(p: IrField): Label<out DbField> =
-        tw.getLabelFor(getFieldLabel(p))
+    fun useField(f: IrField): Label<out DbField> =
+        tw.getLabelFor(getFieldLabel(f))
 
     fun getPropertyLabel(p: IrProperty): String {
         val parentId = useDeclarationParent(p.parent)

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

@@ -4,28 +4,29 @@ import org.jetbrains.kotlin.ir.types.IdSignatureValues
 
 data class PrimitiveTypeInfo(
     val primitiveName: String?,
+    val otherIsPrimitive: Boolean,
     val javaPackageName: String, val javaClassName: String,
     val kotlinPackageName: String, val kotlinClassName: String
 )
 
 val primitiveTypeMapping = mapOf(
-    IdSignatureValues._byte to PrimitiveTypeInfo("byte", "java.lang", "Byte", "kotlin", "Byte"),
-    IdSignatureValues._short to PrimitiveTypeInfo("short", "java.lang", "Short", "kotlin", "Short"),
-    IdSignatureValues._int to PrimitiveTypeInfo("int", "java.lang", "Integer", "kotlin", "Int"),
-    IdSignatureValues._long to PrimitiveTypeInfo("long", "java.lang", "Long", "kotlin", "Long"),
+    IdSignatureValues._byte to PrimitiveTypeInfo("byte", true, "java.lang", "Byte", "kotlin", "Byte"),
+    IdSignatureValues._short to PrimitiveTypeInfo("short", true, "java.lang", "Short", "kotlin", "Short"),
+    IdSignatureValues._int to PrimitiveTypeInfo("int", true, "java.lang", "Integer", "kotlin", "Int"),
+    IdSignatureValues._long to PrimitiveTypeInfo("long", true, "java.lang", "Long", "kotlin", "Long"),
 
-    IdSignatureValues.uByte to PrimitiveTypeInfo("byte", "kotlin", "UByte", "kotlin", "UByte"),
-    IdSignatureValues.uShort to PrimitiveTypeInfo("short", "kotlin", "UShort", "kotlin", "UShort"),
-    IdSignatureValues.uInt to PrimitiveTypeInfo("int", "kotlin", "UInt", "kotlin", "UInt"),
-    IdSignatureValues.uLong to PrimitiveTypeInfo("long", "kotlin", "ULong", "kotlin", "ULong"),
+    IdSignatureValues.uByte to PrimitiveTypeInfo("byte", true, "kotlin", "UByte", "kotlin", "UByte"),
+    IdSignatureValues.uShort to PrimitiveTypeInfo("short", true, "kotlin", "UShort", "kotlin", "UShort"),
+    IdSignatureValues.uInt to PrimitiveTypeInfo("int", true, "kotlin", "UInt", "kotlin", "UInt"),
+    IdSignatureValues.uLong to PrimitiveTypeInfo("long", true, "kotlin", "ULong", "kotlin", "ULong"),
 
-    IdSignatureValues._double to PrimitiveTypeInfo("double", "java.lang", "Double", "kotlin", "Double"),
-    IdSignatureValues._float to PrimitiveTypeInfo("float", "java.lang", "Float", "kotlin", "Float"),
+    IdSignatureValues._double to PrimitiveTypeInfo("double", true, "java.lang", "Double", "kotlin", "Double"),
+    IdSignatureValues._float to PrimitiveTypeInfo("float", true, "java.lang", "Float", "kotlin", "Float"),
 
-    IdSignatureValues._boolean to PrimitiveTypeInfo("boolean", "java.lang", "Boolean", "kotlin", "Boolean"),
+    IdSignatureValues._boolean to PrimitiveTypeInfo("boolean", true, "java.lang", "Boolean", "kotlin", "Boolean"),
 
-    IdSignatureValues._char to PrimitiveTypeInfo("char", "java.lang", "Character", "kotlin", "Char"),
+    IdSignatureValues._char to PrimitiveTypeInfo("char", true, "java.lang", "Character", "kotlin", "Char"),
 
-    IdSignatureValues.unit to PrimitiveTypeInfo("void", "java.lang", "Void", "kotlin", "Nothing"), // TODO: Is this right?
-    IdSignatureValues.nothing to PrimitiveTypeInfo(null, "java.lang", "Void", "kotlin", "Nothing"), // TODO: Is this right?
+    IdSignatureValues.unit to PrimitiveTypeInfo("void", false, "kotlin", "Unit", "kotlin", "Unit"),
+    IdSignatureValues.nothing to PrimitiveTypeInfo(null, true, "java.lang", "Void", "kotlin", "Nothing"),
 )