sdf

Author: hvitved

rust/ql/lib/codeql/rust/internal/FunctionType.qll

@@ -186,7 +186,7 @@ class FunctionType extends TFunctionType {
    * For functions belonging to a `trait`, we use the type of the trait itself instead
    * of the implicit `Self` type parameter, as otherwise any type will match.
    *
-   * Calls will use `substituteLookupTraits` to map receiver types to the relevant
+   * Calls should use `substituteLookupTraits` to map receiver types to the relevant
    * traits when matching.
    */
   Type getTypeAt(TypePath path) {
@@ -219,3 +219,25 @@ class FunctionType extends TFunctionType {
 
   Location getLocation() { result = this.getReportingNode().getLocation() }
 }
+
+private Trait getALookupTrait(Type t) {
+  result = t.(TypeParamTypeParameter).getTypeParam().(TypeParamItemNode).resolveABound()
+  or
+  result = t.(SelfTypeParameter).getTrait()
+  or
+  result = t.(ImplTraitType).getImplTraitTypeRepr().(ImplTraitTypeReprItemNode).resolveABound()
+  or
+  result = t.(DynTraitType).getTrait()
+}
+
+/**
+ * Gets the type obtained by substituting in relevant traits in which to do function
+ * lookup, or `t` itself when no such trait exist.
+ */
+bindingset[t]
+Type substituteLookupTraits(Type t) {
+  not exists(getALookupTrait(t)) and
+  result = t
+  or
+  result = TTrait(getALookupTrait(t))
+}