code review

cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/graph/OverlayNode.kt

@@ -29,4 +29,4 @@ package de.fraunhofer.aisec.cpg.graph
  * Represents an extra node added to the CPG. These nodes can live next to the CPG, typically having
  * shared edges to extend the original CPG graph.
  */
-interface OverlayNode
+abstract class OverlayNode : Node()

cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/graph/concepts/Concept.kt

@@ -28,8 +28,14 @@ package de.fraunhofer.aisec.cpg.graph.concepts
 import de.fraunhofer.aisec.cpg.graph.Node
 import de.fraunhofer.aisec.cpg.graph.OverlayNode
 
-/** A node extending the CPG and storing the corresponding/responsible [cpgNode]. */
-abstract class Concept : Node(), OverlayNode {
+/**
+ * Represents a new concept added to the CPG. This is intended for modelling "concepts" like
+ * logging, files, databases. The relevant operations on this concept are modeled as [Operation]s
+ * and stored in [ops].
+ */
+abstract class Concept() : OverlayNode() {
     /** All concept nodes are connected to an original cpg [Node] by this. */
     abstract val cpgNode: Node
+    /** All [Operation]s belonging to this concept. */
+    abstract val ops: Set<Operation>
 }

cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/graph/concepts/ConceptNode.kt → cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/graph/concepts/Operation.kt

@@ -25,11 +25,16 @@
  */
 package de.fraunhofer.aisec.cpg.graph.concepts
 
+import de.fraunhofer.aisec.cpg.graph.Node
+import de.fraunhofer.aisec.cpg.graph.OverlayNode
+
 /**
- * Represents a new concept added to the CPG. This is intended for modelling "concepts" like
- * logging, files, databases. The relevant operations on this concept are modeled as
- * [OperationNode]s and stored in [ops].
+ * Represents an operation executed on/with a [Concept] (stored in [concept]). This is typically a
+ * `write` on a file or log object or an `execute` on a database.
  */
-abstract class ConceptNode() : Concept() {
-    abstract val ops: Set<OperationNode>
+abstract class Operation : OverlayNode() {
+    /** All concept nodes are connected to an original cpg [Node] by this. */
+    abstract val cpgNode: Node
+    /** The [Concept] this operation belongs to. */
+    abstract val concept: Concept
 }