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Merged
youknowone merged 2 commits into from
Dec 10, 2025
Merged

__doc__ handing in the right way #6390

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7670655
__doc__ handing in the right way
youknowone Dec 10, 2025
32a51b1
fixit
youknowone Dec 10, 2025
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1 change: 0 additions & 1 deletion Lib/test/test_property.py
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Original file line number Diff line number Diff line change
Expand Up @@ -342,7 +342,6 @@ def documented_getter():
with self.assertRaises(AttributeError):
p = slotted_prop(documented_getter)

@unittest.expectedFailure # TODO: RUSTPYTHON
@unittest.skipIf(sys.flags.optimize >= 2,
"Docstrings are omitted with -O2 and above")
def test_property_with_slots_and_doc_slot_docstring_present(self):
Expand Down
4 changes: 2 additions & 2 deletions Lib/test/test_typing.py
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Expand Up @@ -5269,7 +5269,7 @@ def test_weakref_all(self):
for t in things:
self.assertEqual(weakref.ref(t)(), t)

@unittest.expectedFailure # TODO: RUSTPYTHON
@unittest.expectedFailure # TODO: RUSTPYTHON - __slots__ with Generic doesn't prevent new attributes
def test_parameterized_slots(self):
T = TypeVar('T')
class C(Generic[T]):
Expand All @@ -5289,7 +5289,7 @@ def foo(x: C['C']): ...
self.assertEqual(get_type_hints(foo, globals(), locals())['x'], C[C])
self.assertEqual(copy(C[int]), deepcopy(C[int]))

@unittest.expectedFailure # TODO: RUSTPYTHON
@unittest.expectedFailure # TODO: RUSTPYTHON - __slots__ with Generic doesn't prevent new attributes
def test_parameterized_slots_dict(self):
T = TypeVar('T')
class D(Generic[T]):
Expand Down
21 changes: 6 additions & 15 deletions crates/codegen/src/compile.rs
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Expand Up @@ -2679,10 +2679,12 @@ impl Compiler {
let qualname_name = self.name("__qualname__");
emit!(self, Instruction::StoreLocal(qualname_name));

// Store __doc__
self.load_docstring(doc_str);
let doc = self.name("__doc__");
emit!(self, Instruction::StoreLocal(doc));
// Store __doc__ only if there's an explicit docstring
if let Some(doc) = doc_str {
self.emit_load_const(ConstantData::Str { value: doc.into() });
let doc_name = self.name("__doc__");
emit!(self, Instruction::StoreLocal(doc_name));
}

// Store __firstlineno__ (new in Python 3.12+)
self.emit_load_const(ConstantData::Integer {
Expand Down Expand Up @@ -2876,17 +2878,6 @@ impl Compiler {
self.store_name(name)
}

fn load_docstring(&mut self, doc_str: Option<String>) {
// TODO: __doc__ must be default None and no bytecode unless it is Some
// Duplicate top of stack (the function or class object)

// Doc string value:
self.emit_load_const(match doc_str {
Some(doc) => ConstantData::Str { value: doc.into() },
None => ConstantData::None, // set docstring None if not declared
});
}

fn compile_while(&mut self, test: &Expr, body: &[Stmt], orelse: &[Stmt]) -> CompileResult<()> {
let while_block = self.new_block();
let else_block = self.new_block();
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24 changes: 17 additions & 7 deletions crates/vm/src/builtins/type.rs
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Expand Up @@ -1198,11 +1198,10 @@ impl Constructor for PyType {
member: member_def,
});

let attr_name = vm.ctx.intern_str(member.to_string());
if !typ.has_attr(attr_name) {
typ.set_attr(attr_name, member_descriptor.into());
}

let attr_name = vm.ctx.intern_str(member.as_str());
// __slots__ attributes always get a member descriptor
// (this overrides any inherited attribute from MRO)
typ.set_attr(attr_name, member_descriptor.into());
offset += 1;
}
}
Expand Down Expand Up @@ -1236,6 +1235,16 @@ impl Constructor for PyType {
}
}

// Set __doc__ to None if not already present in the type's dict
// This matches CPython's behavior in type_dict_set_doc (typeobject.c)
// which ensures every type has a __doc__ entry in its dict
{
let __doc__ = identifier!(vm, __doc__);
if !typ.attributes.read().contains_key(&__doc__) {
typ.attributes.write().insert(__doc__, vm.ctx.none());
}
}

// avoid deadlock
let attributes = typ
.attributes
Expand Down Expand Up @@ -1377,8 +1386,9 @@ impl Py<PyType> {
return Ok(vm.ctx.new_str(doc_str).into());
}

// Check if there's a __doc__ in the type's dict
if let Some(doc_attr) = self.get_attr(vm.ctx.intern_str("__doc__")) {
// Check if there's a __doc__ in THIS type's dict only (not MRO)
// CPython returns None if __doc__ is not in the type's own dict
if let Some(doc_attr) = self.get_direct_attr(vm.ctx.intern_str("__doc__")) {
// If it's a descriptor, call its __get__ method
let descr_get = doc_attr
.class()
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2 changes: 1 addition & 1 deletion extra_tests/snippets/syntax_class.py
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Expand Up @@ -186,7 +186,7 @@ def b():
class A:
pass

assert A.__doc__ == None
assert A.__doc__ is None, A.__doc__

class B:
"Docstring"
Expand Down
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