Rust: Adjust clone modeling

Author: hvitved

rust/ql/lib/codeql/rust/frameworks/stdlib/Clone.qll

@@ -18,7 +18,9 @@ final class CloneCallable extends SummarizedCallable::Range {
   final override predicate propagatesFlow(
     string input, string output, boolean preservesValue, string model
   ) {
-    input = "Argument[self]" and
+    // The `clone` method takes a `&self` parameter and dereferences it;
+    // make sure to not clone the reference itself
+    input = ["Argument[self].Reference", "Argument[self].WithoutReference"] and
     output = "ReturnValue" and
     preservesValue = true and
     model = "generated"

rust/ql/test/library-tests/dataflow/modeled/inline-flow.expected

@@ -13,24 +13,18 @@ edges
 | main.rs:12:9:12:9 | a [Some] | main.rs:14:13:14:21 | a.clone() [Some] | provenance | generated |
 | main.rs:12:13:12:28 | Some(...) [Some] | main.rs:12:9:12:9 | a [Some] | provenance |  |
 | main.rs:12:18:12:27 | source(...) | main.rs:12:13:12:28 | Some(...) [Some] | provenance |  |
-| main.rs:14:9:14:9 | b [&ref, Some] | main.rs:15:10:15:10 | b [&ref, Some] | provenance |  |
 | main.rs:14:9:14:9 | b [Some] | main.rs:15:10:15:19 | b.unwrap() | provenance | MaD:2 |
-| main.rs:14:13:14:13 | a [Some] | main.rs:14:13:14:21 | a.clone() [&ref, Some] | provenance | generated |
-| main.rs:14:13:14:21 | a.clone() [&ref, Some] | main.rs:14:9:14:9 | b [&ref, Some] | provenance |  |
+| main.rs:14:13:14:13 | a [Some] | main.rs:14:13:14:21 | a.clone() [Some] | provenance | generated |
 | main.rs:14:13:14:21 | a.clone() [Some] | main.rs:14:9:14:9 | b [Some] | provenance |  |
-| main.rs:15:10:15:10 | b [&ref, Some] | main.rs:15:10:15:19 | b.unwrap() | provenance | MaD:2 |
 | main.rs:19:9:19:9 | a [Ok] | main.rs:20:10:20:19 | a.unwrap() | provenance | MaD:5 |
 | main.rs:19:9:19:9 | a [Ok] | main.rs:21:13:21:13 | a [Ok] | provenance |  |
 | main.rs:19:9:19:9 | a [Ok] | main.rs:21:13:21:21 | a.clone() [Ok] | provenance | MaD:4 |
 | main.rs:19:9:19:9 | a [Ok] | main.rs:21:13:21:21 | a.clone() [Ok] | provenance | generated |
 | main.rs:19:31:19:44 | Ok(...) [Ok] | main.rs:19:9:19:9 | a [Ok] | provenance |  |
 | main.rs:19:34:19:43 | source(...) | main.rs:19:31:19:44 | Ok(...) [Ok] | provenance |  |
-| main.rs:21:9:21:9 | b [&ref, Ok] | main.rs:22:10:22:10 | b [&ref, Ok] | provenance |  |
 | main.rs:21:9:21:9 | b [Ok] | main.rs:22:10:22:19 | b.unwrap() | provenance | MaD:5 |
-| main.rs:21:13:21:13 | a [Ok] | main.rs:21:13:21:21 | a.clone() [&ref, Ok] | provenance | generated |
-| main.rs:21:13:21:21 | a.clone() [&ref, Ok] | main.rs:21:9:21:9 | b [&ref, Ok] | provenance |  |
+| main.rs:21:13:21:13 | a [Ok] | main.rs:21:13:21:21 | a.clone() [Ok] | provenance | generated |
 | main.rs:21:13:21:21 | a.clone() [Ok] | main.rs:21:9:21:9 | b [Ok] | provenance |  |
-| main.rs:22:10:22:10 | b [&ref, Ok] | main.rs:22:10:22:19 | b.unwrap() | provenance | MaD:5 |
 | main.rs:26:9:26:9 | a | main.rs:27:10:27:10 | a | provenance |  |
 | main.rs:26:9:26:9 | a | main.rs:28:13:28:21 | a.clone() | provenance | generated |
 | main.rs:26:13:26:22 | source(...) | main.rs:26:9:26:9 | a | provenance |  |
@@ -66,23 +60,17 @@ nodes
 | main.rs:12:13:12:28 | Some(...) [Some] | semmle.label | Some(...) [Some] |
 | main.rs:12:18:12:27 | source(...) | semmle.label | source(...) |
 | main.rs:13:10:13:19 | a.unwrap() | semmle.label | a.unwrap() |
-| main.rs:14:9:14:9 | b [&ref, Some] | semmle.label | b [&ref, Some] |
 | main.rs:14:9:14:9 | b [Some] | semmle.label | b [Some] |
 | main.rs:14:13:14:13 | a [Some] | semmle.label | a [Some] |
-| main.rs:14:13:14:21 | a.clone() [&ref, Some] | semmle.label | a.clone() [&ref, Some] |
 | main.rs:14:13:14:21 | a.clone() [Some] | semmle.label | a.clone() [Some] |
-| main.rs:15:10:15:10 | b [&ref, Some] | semmle.label | b [&ref, Some] |
 | main.rs:15:10:15:19 | b.unwrap() | semmle.label | b.unwrap() |
 | main.rs:19:9:19:9 | a [Ok] | semmle.label | a [Ok] |
 | main.rs:19:31:19:44 | Ok(...) [Ok] | semmle.label | Ok(...) [Ok] |
 | main.rs:19:34:19:43 | source(...) | semmle.label | source(...) |
 | main.rs:20:10:20:19 | a.unwrap() | semmle.label | a.unwrap() |
-| main.rs:21:9:21:9 | b [&ref, Ok] | semmle.label | b [&ref, Ok] |
 | main.rs:21:9:21:9 | b [Ok] | semmle.label | b [Ok] |
 | main.rs:21:13:21:13 | a [Ok] | semmle.label | a [Ok] |
-| main.rs:21:13:21:21 | a.clone() [&ref, Ok] | semmle.label | a.clone() [&ref, Ok] |
 | main.rs:21:13:21:21 | a.clone() [Ok] | semmle.label | a.clone() [Ok] |
-| main.rs:22:10:22:10 | b [&ref, Ok] | semmle.label | b [&ref, Ok] |
 | main.rs:22:10:22:19 | b.unwrap() | semmle.label | b.unwrap() |
 | main.rs:26:9:26:9 | a | semmle.label | a |
 | main.rs:26:13:26:22 | source(...) | semmle.label | source(...) |