From c04b615a07a7fcd128fbe5b420bc68b6b3d4ab41 Mon Sep 17 00:00:00 2001
From: Taus <tausbn@github.com>
Date: Mon, 23 Feb 2026 15:55:58 +0000
Subject: [PATCH] Python: Extend DuckTyping module

Adds `overridesMethod` and `isPropertyAccessor`.
---
 .../new/internal/DataFlowDispatch.qll         | 23 +++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/python/ql/lib/semmle/python/dataflow/new/internal/DataFlowDispatch.qll b/python/ql/lib/semmle/python/dataflow/new/internal/DataFlowDispatch.qll
index 2aaa33de159..529e90798ba 100644
--- a/python/ql/lib/semmle/python/dataflow/new/internal/DataFlowDispatch.qll
+++ b/python/ql/lib/semmle/python/dataflow/new/internal/DataFlowDispatch.qll
@@ -2111,4 +2111,27 @@ module DuckTyping {
       )
     )
   }
+
+  /**
+   * Gets the `__init__` function that will be invoked when `cls` is constructed,
+   * resolved according to the MRO.
+   */
+  Function getInit(Class cls) { result = invokedFunctionFromClassConstruction(cls, "__init__") }
+
+  /**
+   * Holds if `f` overrides a method in a superclass with the same name.
+   */
+  predicate overridesMethod(Function f) {
+    exists(Class cls | f.getScope() = cls | hasMethod(getADirectSuperclass(cls), f.getName()))
+  }
+
+  /**
+   * Holds if `f` is a property accessor (decorated with `@property`, `@name.setter`,
+   * or `@name.deleter`).
+   */
+  predicate isPropertyAccessor(Function f) {
+    exists(Attribute a | a = f.getADecorator() | a.getName() = "setter" or a.getName() = "deleter")
+    or
+    f.getADecorator().(Name).getId() = "property"
+  }
 }