inf

Author: hvitved

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

@@ -3235,7 +3235,7 @@ private Type getFieldExprLookupType(FieldExpr fe, string name, DerefChain derefC
     derefChain = DerefChain::nil()
     or
     exists(DerefImplItemNode impl, TypeParamTypeParameter tp |
-      tp.getTypeParam() = impl.resolveSelfTy().getTypeParam(0) and
+      tp = impl.getFirstSelfTypeParameter() and
       path.getHead() = tp and
       derefChain = DerefChain::singleton(impl)
     )

rust/ql/lib/codeql/rust/internal/typeinference/DerefChain.qll

@@ -41,6 +41,12 @@ class DerefImplItemNode extends ImplItemNode {
       path0.isCons(getRefTypeParameter(false), path)
     )
   }
+
+  /** Gets the first type parameter of the type being implemented, if any. */
+  pragma[nomagic]
+  TypeParamTypeParameter getFirstSelfTypeParameter() {
+    result.getTypeParam() = this.resolveSelfTy().getTypeParam(0)
+  }
 }
 
 private module UnboundListInput implements UnboundListImpl::InputSig<Location> {