Kotlin: Extract an ErrorType if we fail to correctly extract a type

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

@@ -108,14 +108,26 @@ open class KotlinUsesExtractor(
     }
     data class TypeResults(val javaResult: TypeResult<DbType>, val kotlinResult: TypeResult<DbKt_type>)
 
-    fun useType(t: IrType, context: TypeContext = TypeContext.OTHER) =
+    fun useType(t: IrType, context: TypeContext = TypeContext.OTHER): TypeResults {
         when(t) {
-            is IrSimpleType -> useSimpleType(t, context)
+            is IrSimpleType -> return useSimpleType(t, context)
             else -> {
                 logger.error("Unrecognised IrType: " + t.javaClass)
-                TypeResults(TypeResult(fakeLabel(), "unknown", "unknown"), TypeResult(fakeLabel(), "unknown", "unknown"))
+                return extractErrorType()
             }
         }
+    }
+
+    private fun extractErrorType(): TypeResults {
+        val typeId = tw.getLabelFor<DbErrortype>("@\"errorType\"") {
+            tw.writeError_type(it)
+        }
+        val kotlinTypeId = tw.getLabelFor<DbKt_nullable_type>("@\"errorKotlinType\"") {
+            tw.writeKt_nullable_types(it, typeId)
+        }
+        return TypeResults(TypeResult(typeId, null, "<CodeQL error type>"),
+                           TypeResult(kotlinTypeId, null, "<CodeQL error type>"))
+    }
 
     fun getJavaEquivalentClass(c: IrClass) =
         getJavaEquivalentClassId(c)?.let { pluginContext.referenceClass(it.asSingleFqName()) }?.owner

java/ql/lib/config/semmlecode.dbscheme

@@ -332,6 +332,14 @@ modifiers(
   string nodeName: string ref
 );
 
+/**
+ * An errortype is used when the extractor is unable to extract a type
+ * correctly for some reason.
+ */
+error_type(
+  unique int id: @errortype
+);
+
 classes(
   unique int id: @class,
   string nodeName: string ref,
@@ -1012,13 +1020,13 @@ javadocText(
 @classorinterfaceorpackage = @classorinterface | @package;
 @classorinterfaceorcallable = @classorinterface | @callable;
 @boundedtype = @typevariable | @wildcard;
-@reftype = @classorinterface | @array | @boundedtype;
+@reftype = @classorinterface | @array | @boundedtype | @errortype;
 @classorarray = @class | @array;
 @type = @primitive | @reftype;
 @callable = @method | @constructor;
 
 /** A program element that has a name. */
-@element = @package | @modifier | @annotation |
+@element = @package | @modifier | @annotation | @errortype |
            @locatableElement;
 
 @locatableElement = @file | @primitive | @class | @interface | @method | @constructor | @param | @exception | @field |

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

@@ -47,6 +47,8 @@ predicate hasName(Element e, string name) {
   kt_type_alias(e, name, _)
   or
   ktProperties(e, name)
+  or
+  e instanceof ErrorType and name = "<CodeQL error type>"
 }
 
 /**

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

@@ -666,6 +666,14 @@ class RefType extends Type, Annotatable, Modifiable, @reftype {
   }
 }
 
+/**
+ * An `ErrorType` is generated when CodeQL is unable to correctly
+ * extract a type.
+ */
+class ErrorType extends RefType, @errortype {
+  override string getAPrimaryQlClass() { result = "ErrorType" }
+}
+
 /** A type that is the same as its source declaration. */
 class SrcRefType extends RefType {
   SrcRefType() { this.isSourceDeclaration() }