gh-115775: Compiler adds __static_attributes__ field to classes (#115913

)

Include/internal/pycore_global_strings.h

@@ -213,6 +213,7 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(__slotnames__)
         STRUCT_FOR_ID(__slots__)
         STRUCT_FOR_ID(__spec__)
+        STRUCT_FOR_ID(__static_attributes__)
         STRUCT_FOR_ID(__str__)
         STRUCT_FOR_ID(__sub__)
         STRUCT_FOR_ID(__subclasscheck__)

Lib/enum.py

@@ -2018,7 +2018,8 @@ def _test_simple_enum(checked_enum, simple_enum):
                 + list(simple_enum._member_map_.keys())
                 )
         for key in set(checked_keys + simple_keys):
-            if key in ('__module__', '_member_map_', '_value2member_map_', '__doc__'):
+            if key in ('__module__', '_member_map_', '_value2member_map_', '__doc__',
+                       '__static_attributes__'):
                 # keys known to be different, or very long
                 continue
             elif key in member_names:

Lib/pydoc.py

@@ -313,7 +313,8 @@ def visiblename(name, all=None, obj=None):
     if name in {'__author__', '__builtins__', '__cached__', '__credits__',
                 '__date__', '__doc__', '__file__', '__spec__',
                 '__loader__', '__module__', '__name__', '__package__',
-                '__path__', '__qualname__', '__slots__', '__version__'}:
+                '__path__', '__qualname__', '__slots__', '__version__',
+                '__static_attributes__'}:
         return 0
     # Private names are hidden, but special names are displayed.
     if name.startswith('__') and name.endswith('__'): return 1

Lib/test/test_compile.py

@@ -1960,6 +1960,64 @@ def test_load_super_attr(self):
         )
 
 
+class TestExpectedAttributes(unittest.TestCase):
+
+    def test_basic(self):
+        class C:
+            def f(self):
+                self.a = self.b = 42
+
+        self.assertIsInstance(C.__static_attributes__, tuple)
+        self.assertEqual(sorted(C.__static_attributes__), ['a', 'b'])
+
+    def test_nested_function(self):
+        class C:
+            def f(self):
+                self.x = 1
+                self.y = 2
+                self.x = 3   # check deduplication
+
+            def g(self, obj):
+                self.y = 4
+                self.z = 5
+
+                def h(self, a):
+                    self.u = 6
+                    self.v = 7
+
+                obj.self = 8
+
+        self.assertEqual(sorted(C.__static_attributes__), ['u', 'v', 'x', 'y', 'z'])
+
+    def test_nested_class(self):
+        class C:
+            def f(self):
+                self.x = 42
+                self.y = 42
+
+            class D:
+                def g(self):
+                    self.y = 42
+                    self.z = 42
+
+        self.assertEqual(sorted(C.__static_attributes__), ['x', 'y'])
+        self.assertEqual(sorted(C.D.__static_attributes__), ['y', 'z'])
+
+    def test_subclass(self):
+        class C:
+            def f(self):
+                self.x = 42
+                self.y = 42
+
+        class D(C):
+            def g(self):
+                self.y = 42
+                self.z = 42
+
+        self.assertEqual(sorted(C.__static_attributes__), ['x', 'y'])
+        self.assertEqual(sorted(D.__static_attributes__), ['y', 'z'])
+
+
 class TestExpressionStackSize(unittest.TestCase):
     # These tests check that the computed stack size for a code object
     # stays within reasonable bounds (see issue #21523 for an example

Lib/test/test_descr.py

@@ -5080,7 +5080,8 @@ def test_iter_keys(self):
         keys = list(it)
         keys.sort()
         self.assertEqual(keys, ['__dict__', '__doc__', '__module__',
-                                '__weakref__', 'meth'])
+                                '__static_attributes__', '__weakref__',
+                                'meth'])
 
     @unittest.skipIf(hasattr(sys, 'gettrace') and sys.gettrace(),
                         'trace function introduces __local__')
@@ -5089,7 +5090,7 @@ def test_iter_values(self):
         it = self.C.__dict__.values()
         self.assertNotIsInstance(it, list)
         values = list(it)
-        self.assertEqual(len(values), 5)
+        self.assertEqual(len(values), 6)
 
     @unittest.skipIf(hasattr(sys, 'gettrace') and sys.gettrace(),
                         'trace function introduces __local__')
@@ -5100,7 +5101,8 @@ def test_iter_items(self):
         keys = [item[0] for item in it]
         keys.sort()
         self.assertEqual(keys, ['__dict__', '__doc__', '__module__',
-                                '__weakref__', 'meth'])
+                                '__static_attributes__', '__weakref__',
+                                'meth'])
 
     def test_dict_type_with_metaclass(self):
         # Testing type of __dict__ when metaclass set...

Lib/test/test_io.py

@@ -1160,7 +1160,7 @@ class APIMismatchTest(unittest.TestCase):
     def test_RawIOBase_io_in_pyio_match(self):
         """Test that pyio RawIOBase class has all c RawIOBase methods"""
         mismatch = support.detect_api_mismatch(pyio.RawIOBase, io.RawIOBase,
-                                               ignore=('__weakref__',))
+                                               ignore=('__weakref__', '__static_attributes__'))
         self.assertEqual(mismatch, set(), msg='Python RawIOBase does not have all C RawIOBase methods')
 
     def test_RawIOBase_pyio_in_io_match(self):

Lib/test/test_metaclass.py

@@ -167,6 +167,7 @@
     d['foo'] = 4
     d['foo'] = 42
     d['bar'] = 123
+    d['__static_attributes__'] = ()
     >>>
 
 Use a metaclass that doesn't derive from type.
@@ -182,12 +183,12 @@
     ...     b = 24
     ...
     meta: C ()
-    ns: [('__module__', 'test.test_metaclass'), ('__qualname__', 'C'), ('a', 42), ('b', 24)]
+    ns: [('__module__', 'test.test_metaclass'), ('__qualname__', 'C'), ('__static_attributes__', ()), ('a', 42), ('b', 24)]
     kw: []
     >>> type(C) is dict
     True
     >>> print(sorted(C.items()))
-    [('__module__', 'test.test_metaclass'), ('__qualname__', 'C'), ('a', 42), ('b', 24)]
+    [('__module__', 'test.test_metaclass'), ('__qualname__', 'C'), ('__static_attributes__', ()), ('a', 42), ('b', 24)]
     >>>
 
 And again, with a __prepare__ attribute.
@@ -208,8 +209,9 @@
     d['a'] = 1
     d['a'] = 2
     d['b'] = 3
+    d['__static_attributes__'] = ()
     meta: C ()
-    ns: [('__module__', 'test.test_metaclass'), ('__qualname__', 'C'), ('a', 2), ('b', 3)]
+    ns: [('__module__', 'test.test_metaclass'), ('__qualname__', 'C'), ('__static_attributes__', ()), ('a', 2), ('b', 3)]
     kw: [('other', 'booh')]
     >>>
 

Lib/typing.py

@@ -1717,7 +1717,7 @@ class _TypingEllipsis:
     '__abstractmethods__', '__annotations__', '__dict__', '__doc__',
     '__init__', '__module__', '__new__', '__slots__',
     '__subclasshook__', '__weakref__', '__class_getitem__',
-    '__match_args__',
+    '__match_args__', '__static_attributes__',
 })
 
 # These special attributes will be not collected as protocol members.

Misc/NEWS.d/next/Core and Builtins/2024-02-25-14-17-25.gh-issue-115775.CNbGbJ.rst

@@ -0,0 +1,3 @@
+Compiler populates the new ``__static_attributes__`` field on a class with
+the names of attributes of this class which are accessed through self.X from
+any function in its body.

Python/compile.c

@@ -358,7 +358,8 @@ struct compiler_unit {
 
     int u_scope_type;
 
-    PyObject *u_private;        /* for private name mangling */
+    PyObject *u_private;            /* for private name mangling */
+    PyObject *u_static_attributes;  /* for class: attributes accessed via self.X */
 
     instr_sequence u_instr_sequence; /* codegen output */
 
@@ -690,9 +691,26 @@ compiler_unit_free(struct compiler_unit *u)
     Py_CLEAR(u->u_metadata.u_cellvars);
     Py_CLEAR(u->u_metadata.u_fasthidden);
     Py_CLEAR(u->u_private);
+    Py_CLEAR(u->u_static_attributes);
     PyMem_Free(u);
 }
 
+static struct compiler_unit *
+get_class_compiler_unit(struct compiler *c)
+{
+    Py_ssize_t stack_size = PyList_GET_SIZE(c->c_stack);
+    for (Py_ssize_t i = stack_size - 1; i >= 0; i--) {
+        PyObject *capsule = PyList_GET_ITEM(c->c_stack, i);
+        struct compiler_unit *u = (struct compiler_unit *)PyCapsule_GetPointer(
+                                                              capsule, CAPSULE_NAME);
+        assert(u);
+        if (u->u_scope_type == COMPILER_SCOPE_CLASS) {
+            return u;
+        }
+    }
+    return NULL;
+}
+
 static int
 compiler_set_qualname(struct compiler *c)
 {
@@ -1336,6 +1354,16 @@ compiler_enter_scope(struct compiler *c, identifier name,
     }
 
     u->u_private = NULL;
+    if (scope_type == COMPILER_SCOPE_CLASS) {
+        u->u_static_attributes = PySet_New(0);
+        if (!u->u_static_attributes) {
+            compiler_unit_free(u);
+            return ERROR;
+        }
+    }
+    else {
+        u->u_static_attributes = NULL;
+    }
 
     /* Push the old compiler_unit on the stack. */
     if (c->u) {
@@ -2517,6 +2545,18 @@ compiler_class_body(struct compiler *c, stmt_ty s, int firstlineno)
         compiler_exit_scope(c);
         return ERROR;
     }
+    assert(c->u->u_static_attributes);
+    PyObject *static_attributes = PySequence_Tuple(c->u->u_static_attributes);
+    if (static_attributes == NULL) {
+        compiler_exit_scope(c);
+        return ERROR;
+    }
+    ADDOP_LOAD_CONST(c, NO_LOCATION, static_attributes);
+    Py_CLEAR(static_attributes);
+    if (compiler_nameop(c, NO_LOCATION, &_Py_ID(__static_attributes__), Store) < 0) {
+        compiler_exit_scope(c);
+        return ERROR;
+    }
     /* The following code is artificial */
     /* Set __classdictcell__ if necessary */
     if (c->u->u_ste->ste_needs_classdict) {
@@ -2657,6 +2697,7 @@ compiler_class(struct compiler *c, stmt_ty s)
                                                          s->v.ClassDef.keywords));
 
         PyCodeObject *co = optimize_and_assemble(c, 0);
+
         compiler_exit_scope(c);
         if (co == NULL) {
             return ERROR;
@@ -6246,6 +6287,17 @@ compiler_visit_expr1(struct compiler *c, expr_ty e)
             ADDOP(c, loc, NOP);
             return SUCCESS;
         }
+        if (e->v.Attribute.value->kind == Name_kind &&
+            _PyUnicode_EqualToASCIIString(e->v.Attribute.value->v.Name.id, "self"))
+        {
+            struct compiler_unit *class_u = get_class_compiler_unit(c);
+            if (class_u != NULL) {
+                assert(class_u->u_scope_type == COMPILER_SCOPE_CLASS);
+                assert(class_u->u_static_attributes);
+                RETURN_IF_ERROR(
+                    PySet_Add(class_u->u_static_attributes, e->v.Attribute.attr));
+            }
+        }
         VISIT(c, expr, e->v.Attribute.value);
         loc = LOC(e);
         loc = update_start_location_to_match_attr(c, loc, e);