Skip to content

[mypyc] Show the reason why a class can't be a native class #19016

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 2 commits into
base: master
Choose a base branch
from
Open

[mypyc] Show the reason why a class can't be a native class #19016

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
db28023
[mypyc] Show the reason why a class can't be a native class
svalentin May 2, 2025
5f6cb7b
tuple, not Tuple
svalentin May 2, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
29 changes: 20 additions & 9 deletions mypyc/irbuild/util.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -134,13 +134,15 @@ def is_extension_class(path: str, cdef: ClassDef, errors: Errors) -> bool:
if explicit_native_class is False:
return False

implicit_extension_class = is_implicit_extension_class(cdef)
implicit_extension_class, reason = is_implicit_extension_class(cdef)

# Classes with native_class=True should be extension classes, but they might
# not be able to be due to other reasons. Print an error in that case.
if explicit_native_class is True and not implicit_extension_class:
errors.error(
"Class is marked as native_class=True but it can't be a native class", path, cdef.line
f"Class is marked as native_class=True but it can't be a native class. {reason}",
path,
cdef.line,
)

return implicit_extension_class
Expand Down Expand Up @@ -177,28 +179,37 @@ def get_explicit_native_class(path: str, cdef: ClassDef, errors: Errors) -> bool
return None


def is_implicit_extension_class(cdef: ClassDef) -> bool:
def is_implicit_extension_class(cdef: ClassDef) -> tuple[bool, str]:
"""Check if class can be extension class and return a user-friendly reason it can't be one."""

for d in cdef.decorators:
# Classes that have any decorator other than supported decorators, are not extension classes
if (
not is_trait_decorator(d)
and not is_dataclass_decorator(d)
and not get_mypyc_attr_call(d)
and not is_final_decorator(d)
):
return False
return (
False,
"Classes that have decorators other than supported decorators"
" can't be native classes.",
)

if cdef.info.typeddict_type:
return False
return False, "TypedDict classes can't be native classes."
if cdef.info.is_named_tuple:
return False
return False, "NamedTuple classes can't be native classes."
if cdef.info.metaclass_type and cdef.info.metaclass_type.type.fullname not in (
"abc.ABCMeta",
"typing.TypingMeta",
"typing.GenericMeta",
):
return False
return True
return (
False,
"Classes with a metaclass other than ABCMeta, TypingMeta or"
" GenericMeta can't be native classes.",
)
return True, ""


def get_func_def(op: FuncDef | Decorator | OverloadedFuncDef) -> FuncDef:
Expand Down
4 changes: 2 additions & 2 deletions mypyc/test-data/irbuild-classes.test
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1363,7 +1363,7 @@ def decorator(cls):

@mypyc_attr(native_class=True)
@decorator
class NonNativeClassContradiction(): # E: Class is marked as native_class=True but it can't be a native class
class NonNativeClassContradiction(): # E: Class is marked as native_class=True but it can't be a native class. Classes that have decorators other than supported decorators can't be native classes.
pass


Expand All @@ -1379,5 +1379,5 @@ class M(type): # E: Inheriting from most builtin types is unimplemented
pass

@mypyc_attr(native_class=True)
class A(metaclass=M): # E: Class is marked as native_class=True but it can't be a native class
class A(metaclass=M): # E: Class is marked as native_class=True but it can't be a native class. Classes with a metaclass other than ABCMeta, TypingMeta or GenericMeta can't be native classes.
pass