[mypyc] Fix direct __dict__ access on inner functions in new Python (#16084)

Fixes #16077

Author: hauntsaninja

mypyc/codegen/emitclass.py

@@ -217,7 +217,7 @@ def generate_class(cl: ClassIR, module: str, emitter: Emitter) -> None:
     fields["tp_name"] = f'"{name}"'
 
     generate_full = not cl.is_trait and not cl.builtin_base
-    needs_getseters = cl.needs_getseters or not cl.is_generated
+    needs_getseters = cl.needs_getseters or not cl.is_generated or cl.has_dict
 
     if not cl.builtin_base:
         fields["tp_new"] = new_name
@@ -886,6 +886,9 @@ def generate_getseters_table(cl: ClassIR, name: str, emitter: Emitter) -> None:
         else:
             emitter.emit_line("NULL, NULL, NULL},")
 
+    if cl.has_dict:
+        emitter.emit_line('{"__dict__", PyObject_GenericGetDict, PyObject_GenericSetDict},')
+
     emitter.emit_line("{NULL}  /* Sentinel */")
     emitter.emit_line("};")
 

mypyc/test-data/run-functions.test

@@ -1256,3 +1256,33 @@ def foo(**kwargs: Unpack[Person]) -> None:
 foo(name='Jennifer', age=38)
 [out]
 Jennifer
+
+[case testNestedFunctionDunderDict312]
+import sys
+
+def foo() -> None:
+    def inner() -> str: return "bar"
+    print(inner.__dict__)  # type: ignore[attr-defined]
+    inner.__dict__.update({"x": 1})  # type: ignore[attr-defined]
+    print(inner.__dict__)  # type: ignore[attr-defined]
+    print(inner.x)  # type: ignore[attr-defined]
+
+if sys.version_info >= (3, 12):  # type: ignore
+    foo()
+[out]
+[out version>=3.12]
+{}
+{'x': 1}
+1
+
+[case testFunctoolsUpdateWrapper]
+import functools
+
+def bar() -> None:
+    def inner() -> str: return "bar"
+    functools.update_wrapper(inner, bar)  # type: ignore
+    print(inner.__dict__)  # type: ignore
+
+bar()
+[out]
+{'__module__': 'native', '__name__': 'bar', '__qualname__': 'bar', '__doc__': None, '__wrapped__': <built-in function bar>}