stubgenc.py

#!/usr/bin/env python3
"""Stub generator for C modules.

The public interface is via the mypy.stubgen module.
"""

from __future__ import annotations

import glob
import importlib
import inspect
import keyword
import os.path
from types import FunctionType, ModuleType
from typing import Any, Mapping

from mypy.fastparse import parse_type_comment
from mypy.moduleinspect import is_c_module
from mypy.stubdoc import (
    ArgSig,
    FunctionSig,
    Sig,
    find_unique_signatures,
    infer_arg_sig_from_anon_docstring,
    infer_prop_type_from_docstring,
    infer_ret_type_sig_from_anon_docstring,
    infer_ret_type_sig_from_docstring,
    infer_sig_from_docstring,
    parse_all_signatures,
)
from mypy.stubutil import (
    BaseStubGenerator,
    ClassInfo,
    FunctionContext,
    SignatureGenerator,
    infer_method_arg_types,
    infer_method_ret_type,
)


class ExternalSignatureGenerator(SignatureGenerator):
    def __init__(
        self, func_sigs: dict[str, str] | None = None, class_sigs: dict[str, str] | None = None
    ):
        """
        Takes a mapping of function/method names to signatures and class name to
        class signatures (usually corresponds to __init__).
        """
        self.func_sigs = func_sigs or {}
        self.class_sigs = class_sigs or {}

    @classmethod
    def from_doc_dir(cls, doc_dir: str) -> ExternalSignatureGenerator:
        """Instantiate from a directory of .rst files."""
        all_sigs: list[Sig] = []
        all_class_sigs: list[Sig] = []
        for path in glob.glob(f"{doc_dir}/*.rst"):
            with open(path) as f:
                loc_sigs, loc_class_sigs = parse_all_signatures(f.readlines())
            all_sigs += loc_sigs
            all_class_sigs += loc_class_sigs
        sigs = dict(find_unique_signatures(all_sigs))
        class_sigs = dict(find_unique_signatures(all_class_sigs))
        return ExternalSignatureGenerator(sigs, class_sigs)

    def get_function_sig(
        self, default_sig: FunctionSig, ctx: FunctionContext
    ) -> list[FunctionSig] | None:
        # method:
        if (
            ctx.class_info
            and ctx.name in ("__new__", "__init__")
            and ctx.name not in self.func_sigs
            and ctx.class_info.name in self.class_sigs
        ):
            return [
                FunctionSig(
                    name=ctx.name,
                    args=infer_arg_sig_from_anon_docstring(self.class_sigs[ctx.class_info.name]),
                    ret_type=infer_method_ret_type(ctx.name),
                )
            ]

        # function:
        if ctx.name not in self.func_sigs:
            return None

        inferred = [
            FunctionSig(
                name=ctx.name,
                args=infer_arg_sig_from_anon_docstring(self.func_sigs[ctx.name]),
                ret_type=None,
            )
        ]
        if ctx.class_info:
            return self.remove_self_type(inferred, ctx.class_info.self_var)
        else:
            return inferred

    def get_property_type(self, default_type: str | None, ctx: FunctionContext) -> str | None:
        return None


class DocstringSignatureGenerator(SignatureGenerator):
    def get_function_sig(
        self, default_sig: FunctionSig, ctx: FunctionContext
    ) -> list[FunctionSig] | None:
        inferred = infer_sig_from_docstring(ctx.docstring, ctx.name)
        if inferred:
            assert ctx.docstring is not None
            if is_pybind11_overloaded_function_docstring(ctx.docstring, ctx.name):
                # Remove pybind11 umbrella (*args, **kwargs) for overloaded functions
                del inferred[-1]

        if ctx.class_info:
            if not inferred and ctx.name == "__init__":
                # look for class-level constructor signatures of the form <class_name>(<signature>)
                inferred = infer_sig_from_docstring(ctx.class_info.docstring, ctx.class_info.name)
                if inferred:
                    inferred = [sig._replace(name="__init__") for sig in inferred]
            return self.remove_self_type(inferred, ctx.class_info.self_var)
        else:
            return inferred

    def get_property_type(self, default_type: str | None, ctx: FunctionContext) -> str | None:
        """Infer property type from docstring or docstring signature."""
        if ctx.docstring is not None:
            inferred = infer_ret_type_sig_from_anon_docstring(ctx.docstring)
            if not inferred:
                inferred = infer_ret_type_sig_from_docstring(ctx.docstring, ctx.name)
            if not inferred:
                inferred = infer_prop_type_from_docstring(ctx.docstring)
            return inferred
        else:
            return None


def is_pybind11_overloaded_function_docstring(docstring: str, name: str) -> bool:
    return docstring.startswith(f"{name}(*args, **kwargs)\nOverloaded function.\n\n")


def generate_stub_for_c_module(
    module_name: str,
    target: str,
    known_modules: list[str],
    doc_dir: str = "",
    *,
    include_private: bool = False,
    export_less: bool = False,
    include_docstrings: bool = False,
) -> None:
    """Generate stub for C module.

    Signature generators are called in order until a list of signatures is returned.  The order
    is:
    - signatures inferred from .rst documentation (if given)
    - simple runtime introspection (looking for docstrings and attributes
      with simple builtin types)
    - fallback based special method names or "(*args, **kwargs)"

    If directory for target doesn't exist it will be created. Existing stub
    will be overwritten.
    """
    subdir = os.path.dirname(target)
    if subdir and not os.path.isdir(subdir):
        os.makedirs(subdir)

    gen = InspectionStubGenerator(
        module_name,
        known_modules,
        doc_dir,
        include_private=include_private,
        export_less=export_less,
        include_docstrings=include_docstrings,
    )
    gen.generate_module()
    output = gen.output()

    with open(target, "w") as file:
        file.write(output)


class CFunctionStub:
    """
    Class that mimics a C function in order to provide parseable docstrings.
    """

    def __init__(self, name: str, doc: str, is_abstract: bool = False):
        self.__name__ = name
        self.__doc__ = doc
        self.__abstractmethod__ = is_abstract

    @classmethod
    def _from_sig(cls, sig: FunctionSig, is_abstract: bool = False) -> CFunctionStub:
        return CFunctionStub(sig.name, sig.format_sig()[:-4], is_abstract)

    @classmethod
    def _from_sigs(cls, sigs: list[FunctionSig], is_abstract: bool = False) -> CFunctionStub:
        return CFunctionStub(
            sigs[0].name, "\n".join(sig.format_sig()[:-4] for sig in sigs), is_abstract
        )

    def __get__(self) -> None:
        """
        This exists to make this object look like a method descriptor and thus
        return true for CStubGenerator.ismethod()
        """
        pass


class InspectionStubGenerator(BaseStubGenerator):
    """Stub generator that does not parse code.

    Generation is performed by inspecting the module's contents, and thus works
    for highly dynamic modules, pyc files, and C modules (via the CStubGenerator
    subclass).
    """

    def __init__(
        self,
        module_name: str,
        known_modules: list[str],
        doc_dir: str = "",
        _all_: list[str] | None = None,
        include_private: bool = False,
        export_less: bool = False,
        include_docstrings: bool = False,
        module: ModuleType | None = None,
    ) -> None:
        self.doc_dir = doc_dir
        if module is None:
            self.module = importlib.import_module(module_name)
        else:
            self.module = module
        self.is_c_module = is_c_module(self.module)
        self.known_modules = known_modules
        self.resort_members = self.is_c_module
        super().__init__(_all_, include_private, export_less, include_docstrings)
        self.module_name = module_name

    def get_default_function_sig(self, func: object, ctx: FunctionContext) -> FunctionSig:
        argspec = None
        if not self.is_c_module:
            # Get the full argument specification of the function
            try:
                argspec = inspect.getfullargspec(func)
            except TypeError:
                # some callables cannot be inspected, e.g. functools.partial
                pass
        if argspec is None:
            if ctx.class_info is not None:
                # method:
                return FunctionSig(
                    name=ctx.name,
                    args=infer_c_method_args(ctx.name, ctx.class_info.self_var),
                    ret_type=infer_method_ret_type(ctx.name),
                )
            else:
                # function:
                return FunctionSig(
                    name=ctx.name,
                    args=[ArgSig(name="*args"), ArgSig(name="**kwargs")],
                    ret_type=None,
                )

        # Extract the function arguments, defaults, and varargs
        args = argspec.args
        defaults = argspec.defaults
        varargs = argspec.varargs
        kwargs = argspec.varkw
        annotations = argspec.annotations

        def get_annotation(key: str) -> str | None:
            if key not in annotations:
                return None
            argtype = annotations[key]
            if argtype is None:
                return "None"
            if not isinstance(argtype, str):
                return self.get_type_fullname(argtype)
            return argtype

        arglist: list[ArgSig] = []
        # Add the arguments to the signature
        for i, arg in enumerate(args):
            # Check if the argument has a default value
            if defaults and i >= len(args) - len(defaults):
                default_value = defaults[i - (len(args) - len(defaults))]
                if arg in annotations:
                    argtype = annotations[arg]
                else:
                    argtype = self.get_type_annotation(default_value)
                    if argtype == "None":
                        # None is not a useful annotation, but we can infer that the arg
                        # is optional
                        incomplete = self.add_name("_typeshed.Incomplete")
                        argtype = f"{incomplete} | None"
                arglist.append(ArgSig(arg, argtype, default=True))
            else:
                arglist.append(ArgSig(arg, get_annotation(arg), default=False))

        # Add *args if present
        if varargs:
            arglist.append(ArgSig(f"*{varargs}", get_annotation(varargs)))

        # Add **kwargs if present
        if kwargs:
            arglist.append(ArgSig(f"**{kwargs}", get_annotation(kwargs)))

        # add types for known special methods
        if ctx.class_info is not None and all(
            arg.type is None and arg.default is False for arg in arglist
        ):
            new_args = infer_method_arg_types(
                ctx.name, ctx.class_info.self_var, [arg.name for arg in arglist if arg.name]
            )
            if new_args is not None:
                arglist = new_args

        ret_type = get_annotation("return") or infer_method_ret_type(ctx.name)
        return FunctionSig(ctx.name, arglist, ret_type)

    def get_sig_generators(self) -> list[SignatureGenerator]:
        if not self.is_c_module:
            return []
        else:
            sig_generators: list[SignatureGenerator] = [DocstringSignatureGenerator()]
            if self.doc_dir:
                # Collect info from docs (if given). Always check these first.
                sig_generators.insert(0, ExternalSignatureGenerator.from_doc_dir(self.doc_dir))
            return sig_generators

    def strip_or_import(self, type_name: str) -> str:
        """Strips unnecessary module names from typ.

        If typ represents a type that is inside module or is a type coming from builtins, remove
        module declaration from it. Return stripped name of the type.

        Arguments:
            typ: name of the type
        """
        local_modules = ["builtins", self.module_name]
        parsed_type = parse_type_comment(type_name, 0, 0, None)[1]
        assert parsed_type is not None, type_name
        return self.print_annotation(parsed_type, self.known_modules, local_modules)

    def get_obj_module(self, obj: object) -> str | None:
        """Return module name of the object."""
        return getattr(obj, "__module__", None)

    def is_defined_in_module(self, obj: object) -> bool:
        """Check if object is considered defined in the current module."""
        module = self.get_obj_module(obj)
        return module is None or module == self.module_name

    def generate_module(self) -> None:
        all_items = self.get_members(self.module)
        if self.resort_members:
            all_items = sorted(all_items, key=lambda x: x[0])
        items = []
        for name, obj in all_items:
            if inspect.ismodule(obj) and obj.__name__ in self.known_modules:
                module_name = obj.__name__
                if module_name.startswith(self.module_name + "."):
                    # from {.rel_name} import {mod_name} as {name}
                    pkg_name, mod_name = module_name.rsplit(".", 1)
                    rel_module = pkg_name[len(self.module_name) :] or "."
                    self.import_tracker.add_import_from(rel_module, [(mod_name, name)])
                    self.import_tracker.reexport(name)
                else:
                    # import {module_name} as {name}
                    self.import_tracker.add_import(module_name, name)
                    self.import_tracker.reexport(name)
            elif self.is_defined_in_module(obj) and not inspect.ismodule(obj):
                # process this below
                items.append((name, obj))
            else:
                # from {obj_module} import {obj_name}
                obj_module_name = self.get_obj_module(obj)
                if obj_module_name:
                    self.import_tracker.add_import_from(obj_module_name, [(name, None)])
                    if self.should_reexport(name, obj_module_name, name_is_alias=False):
                        self.import_tracker.reexport(name)

        self.set_defined_names(set([name for name, obj in all_items if not inspect.ismodule(obj)]))

        if self.resort_members:
            functions: list[str] = []
            types: list[str] = []
            variables: list[str] = []
        else:
            output: list[str] = []
            functions = types = variables = output

        for name, obj in items:
            if self.is_function(obj):
                self.generate_function_stub(name, obj, output=functions)
            elif inspect.isclass(obj):
                self.generate_class_stub(name, obj, output=types)
            else:
                self.generate_variable_stub(name, obj, output=variables)

        self._output = []

        if self.resort_members:
            for line in variables:
                self._output.append(line + "\n")
            for line in types:
                if line.startswith("class") and self._output and self._output[-1]:
                    self._output.append("\n")
                self._output.append(line + "\n")
            if self._output and functions:
                self._output.append("\n")
            for line in functions:
                self._output.append(line + "\n")
        else:
            for i, line in enumerate(output):
                if (
                    self._output
                    and line.startswith("class")
                    and (
                        not self._output[-1].startswith("class")
                        or (len(output) > i + 1 and output[i + 1].startswith("    "))
                    )
                ) or (
                    self._output
                    and self._output[-1].startswith("def")
                    and not line.startswith("def")
                ):
                    self._output.append("\n")
                self._output.append(line + "\n")
        self.check_undefined_names()

    def is_skipped_attribute(self, attr: str) -> bool:
        return (
            attr
            in (
                "__class__",
                "__getattribute__",
                "__str__",
                "__repr__",
                "__doc__",
                "__dict__",
                "__module__",
                "__weakref__",
                "__annotations__",
            )
            or attr in self.IGNORED_DUNDERS
            or is_pybind_skipped_attribute(attr)  # For pickling
            or keyword.iskeyword(attr)
        )

    def get_members(self, obj: object) -> list[tuple[str, Any]]:
        obj_dict: Mapping[str, Any] = getattr(obj, "__dict__")  # noqa: B009
        results = []
        for name in obj_dict:
            if self.is_skipped_attribute(name):
                continue
            # Try to get the value via getattr
            try:
                value = getattr(obj, name)
            except AttributeError:
                continue
            else:
                results.append((name, value))
        return results

    def get_type_annotation(self, obj: object) -> str:
        """
        Given an instance, return a string representation of its type that is valid
        to use as a type annotation.
        """
        if obj is None or obj is type(None):
            return "None"
        elif inspect.isclass(obj):
            return "type[{}]".format(self.get_type_fullname(obj))
        elif isinstance(obj, FunctionType):
            return self.add_name("typing.Callable")
        elif isinstance(obj, ModuleType):
            return self.add_name("types.ModuleType", require=False)
        else:
            return self.get_type_fullname(type(obj))

    def is_function(self, obj: object) -> bool:
        if self.is_c_module:
            return inspect.isbuiltin(obj)
        else:
            return inspect.isfunction(obj)

    def is_method(self, class_info: ClassInfo, name: str, obj: object) -> bool:
        if self.is_c_module:
            return inspect.ismethoddescriptor(obj) or type(obj) in (
                type(str.index),
                type(str.__add__),
                type(str.__new__),
            )
        else:
            # this is valid because it is only called on members of a class
            return inspect.isfunction(obj)

    def is_classmethod(self, class_info: ClassInfo, name: str, obj: object) -> bool:
        if self.is_c_module:
            return inspect.isbuiltin(obj) or type(obj).__name__ in (
                "classmethod",
                "classmethod_descriptor",
            )
        else:
            return inspect.ismethod(obj)

    def is_staticmethod(self, class_info: ClassInfo | None, name: str, obj: object) -> bool:
        if class_info is None:
            return False
        elif self.is_c_module:
            raw_lookup = getattr(class_info.cls, "__dict__")  # noqa: B009
            raw_value = raw_lookup.get(name, obj)
            return type(raw_value).__name__ == "staticmethod"
        else:
            return isinstance(inspect.getattr_static(class_info.cls, name), staticmethod)

    @staticmethod
    def is_abstract_method(obj: object) -> bool:
        return getattr(obj, "__abstractmethod__", False)

    @staticmethod
    def is_property(class_info: ClassInfo, name: str, obj: object) -> bool:
        return inspect.isdatadescriptor(obj) or hasattr(obj, "fget")

    @staticmethod
    def is_property_readonly(prop: Any) -> bool:
        return hasattr(prop, "fset") and prop.fset is None

    def is_static_property(self, obj: object) -> bool:
        """For c-modules, whether the property behaves like an attribute"""
        if self.is_c_module:
            # StaticProperty is from boost-python
            return type(obj).__name__ in ("pybind11_static_property", "StaticProperty")
        else:
            return False

    def process_inferred_sigs(self, inferred: list[FunctionSig]) -> None:
        for i, sig in enumerate(inferred):
            for arg in sig.args:
                if arg.type is not None:
                    arg.type = self.strip_or_import(arg.type)
            if sig.ret_type is not None:
                inferred[i] = sig._replace(ret_type=self.strip_or_import(sig.ret_type))

    def generate_function_stub(
        self, name: str, obj: object, *, output: list[str], class_info: ClassInfo | None = None
    ) -> None:
        """Generate stub for a single function or method.

        The result (always a single line) will be appended to 'output'.
        If necessary, any required names will be added to 'imports'.
        The 'class_name' is used to find signature of __init__ or __new__ in
        'class_sigs'.
        """
        docstring: Any = getattr(obj, "__doc__", None)
        if not isinstance(docstring, str):
            docstring = None

        ctx = FunctionContext(
            self.module_name,
            name,
            docstring=docstring,
            is_abstract=self.is_abstract_method(obj),
            class_info=class_info,
        )
        if self.is_private_name(name, ctx.fullname) or self.is_not_in_all(name):
            return

        self.record_name(ctx.name)
        default_sig = self.get_default_function_sig(obj, ctx)
        inferred = self.get_signatures(default_sig, self.sig_generators, ctx)
        self.process_inferred_sigs(inferred)

        decorators = []
        if len(inferred) > 1:
            decorators.append("@{}".format(self.add_name("typing.overload")))

        if ctx.is_abstract:
            decorators.append("@{}".format(self.add_name("abc.abstractmethod")))

        if class_info is not None:
            if self.is_staticmethod(class_info, name, obj):
                decorators.append("@staticmethod")
            else:
                for sig in inferred:
                    if not sig.args or sig.args[0].name not in ("self", "cls"):
                        sig.args.insert(0, ArgSig(name=class_info.self_var))
                # a sig generator indicates @classmethod by specifying the cls arg.
                if inferred[0].args and inferred[0].args[0].name == "cls":
                    decorators.append("@classmethod")

        output.extend(self.format_func_def(inferred, decorators=decorators, docstring=docstring))
        self._fix_iter(ctx, inferred, output)

    def _fix_iter(
        self, ctx: FunctionContext, inferred: list[FunctionSig], output: list[str]
    ) -> None:
        """Ensure that objects which implement old-style iteration via __getitem__
        are considered iterable.
        """
        if (
            ctx.class_info
            and ctx.class_info.cls is not None
            and ctx.name == "__getitem__"
            and "__iter__" not in ctx.class_info.cls.__dict__
        ):
            item_type: str | None = None
            for sig in inferred:
                if sig.args and sig.args[-1].type == "int":
                    item_type = sig.ret_type
                    break
            if item_type is None:
                return
            obj = CFunctionStub(
                "__iter__", f"def __iter__(self) -> typing.Iterator[{item_type}]\n"
            )
            self.generate_function_stub("__iter__", obj, output=output, class_info=ctx.class_info)

    def generate_property_stub(
        self,
        name: str,
        raw_obj: object,
        obj: object,
        static_properties: list[str],
        rw_properties: list[str],
        ro_properties: list[str],
        class_info: ClassInfo | None = None,
    ) -> None:
        """Generate property stub using introspection of 'obj'.

        Try to infer type from docstring, append resulting lines to 'output'.

        raw_obj : object before evaluation of descriptor (if any)
        obj : object after evaluation of descriptor
        """

        docstring = getattr(raw_obj, "__doc__", None)
        fget = getattr(raw_obj, "fget", None)
        if fget:
            alt_docstr = getattr(fget, "__doc__", None)
            if alt_docstr and docstring:
                docstring += alt_docstr
            elif alt_docstr:
                docstring = alt_docstr

        ctx = FunctionContext(
            self.module_name, name, docstring=docstring, is_abstract=False, class_info=class_info
        )

        if self.is_private_name(name, ctx.fullname) or self.is_not_in_all(name):
            return

        self.record_name(ctx.name)
        static = self.is_static_property(raw_obj)
        readonly = self.is_property_readonly(raw_obj)
        if static:
            ret_type: str | None = self.strip_or_import(self.get_type_annotation(obj))
        else:
            default_sig = self.get_default_function_sig(raw_obj, ctx)
            ret_type = default_sig.ret_type

        inferred_type = self.get_property_type(ret_type, self.sig_generators, ctx)
        if inferred_type is not None:
            inferred_type = self.strip_or_import(inferred_type)

        if static:
            classvar = self.add_name("typing.ClassVar")
            trailing_comment = "  # read-only" if readonly else ""
            if inferred_type is None:
                inferred_type = self.add_name("_typeshed.Incomplete")

            static_properties.append(
                f"{self._indent}{name}: {classvar}[{inferred_type}] = ...{trailing_comment}"
            )
        else:  # regular property
            if readonly:
                ro_properties.append(f"{self._indent}@property")
                sig = FunctionSig(name, [ArgSig("self")], inferred_type)
                ro_properties.append(sig.format_sig(indent=self._indent))
            else:
                if inferred_type is None:
                    inferred_type = self.add_name("_typeshed.Incomplete")

                rw_properties.append(f"{self._indent}{name}: {inferred_type}")

    def get_type_fullname(self, typ: type) -> str:
        """Given a type, return a string representation"""
        if typ is Any:
            return "Any"
        typename = getattr(typ, "__qualname__", typ.__name__)
        module_name = self.get_obj_module(typ)
        assert module_name is not None, typ
        if module_name != "builtins":
            typename = f"{module_name}.{typename}"
        return typename

    def get_base_types(self, obj: type) -> list[str]:
        all_bases = type.mro(obj)
        if all_bases[-1] is object:
            # TODO: Is this always object?
            del all_bases[-1]
        # remove pybind11_object. All classes generated by pybind11 have pybind11_object in their MRO,
        # which only overrides a few functions in object type
        if all_bases and all_bases[-1].__name__ == "pybind11_object":
            del all_bases[-1]
        # remove the class itself
        all_bases = all_bases[1:]
        # Remove base classes of other bases as redundant.
        bases: list[type] = []
        for base in all_bases:
            if not any(issubclass(b, base) for b in bases):
                bases.append(base)
        return [self.strip_or_import(self.get_type_fullname(base)) for base in bases]

    def generate_class_stub(self, class_name: str, cls: type, output: list[str]) -> None:
        """Generate stub for a single class using runtime introspection.

        The result lines will be appended to 'output'. If necessary, any
        required names will be added to 'imports'.
        """
        raw_lookup = getattr(cls, "__dict__")  # noqa: B009
        items = self.get_members(cls)
        if self.resort_members:
            items = sorted(items, key=lambda x: method_name_sort_key(x[0]))
        names = set(x[0] for x in items)
        methods: list[str] = []
        types: list[str] = []
        static_properties: list[str] = []
        rw_properties: list[str] = []
        ro_properties: list[str] = []
        attrs: list[tuple[str, Any]] = []

        self.record_name(class_name)
        self.indent()

        class_info = ClassInfo(class_name, "", getattr(cls, "__doc__", None), cls)

        for attr, value in items:
            # use unevaluated descriptors when dealing with property inspection
            raw_value = raw_lookup.get(attr, value)
            if self.is_method(class_info, attr, value) or self.is_classmethod(
                class_info, attr, value
            ):
                if attr == "__new__":
                    # TODO: We should support __new__.
                    if "__init__" in names:
                        # Avoid duplicate functions if both are present.
                        # But is there any case where .__new__() has a
                        # better signature than __init__() ?
                        continue
                    attr = "__init__"
                # FIXME: make this nicer
                if self.is_staticmethod(class_info, attr, value):
                    class_info.self_var = ""
                elif self.is_classmethod(class_info, attr, value):
                    class_info.self_var = "cls"
                else:
                    class_info.self_var = "self"
                self.generate_function_stub(attr, value, output=methods, class_info=class_info)
            elif self.is_property(class_info, attr, raw_value):
                self.generate_property_stub(
                    attr,
                    raw_value,
                    value,
                    static_properties,
                    rw_properties,
                    ro_properties,
                    class_info,
                )
            elif inspect.isclass(value) and self.is_defined_in_module(value):
                self.generate_class_stub(attr, value, types)
            else:
                attrs.append((attr, value))

        for attr, value in attrs:
            if attr == "__hash__" and value is None:
                # special case for __hash__
                continue
            prop_type_name = self.strip_or_import(self.get_type_annotation(value))
            classvar = self.add_name("typing.ClassVar")
            static_properties.append(f"{self._indent}{attr}: {classvar}[{prop_type_name}] = ...")

        self.dedent()

        bases = self.get_base_types(cls)
        if bases:
            bases_str = "(%s)" % ", ".join(bases)
        else:
            bases_str = ""
        if types or static_properties or rw_properties or methods or ro_properties:
            output.append(f"{self._indent}class {class_name}{bases_str}:")
            for line in types:
                if (
                    output
                    and output[-1]
                    and not output[-1].strip().startswith("class")
                    and line.strip().startswith("class")
                ):
                    output.append("")
                output.append(line)
            for line in static_properties:
                output.append(line)
            for line in rw_properties:
                output.append(line)
            for line in methods:
                output.append(line)
            for line in ro_properties:
                output.append(line)
        else:
            output.append(f"{self._indent}class {class_name}{bases_str}: ...")

    def generate_variable_stub(self, name: str, obj: object, output: list[str]) -> None:
        """Generate stub for a single variable using runtime introspection.

        The result lines will be appended to 'output'. If necessary, any
        required names will be added to 'imports'.
        """
        if self.is_private_name(name, f"{self.module_name}.{name}") or self.is_not_in_all(name):
            return
        self.record_name(name)
        type_str = self.strip_or_import(self.get_type_annotation(obj))
        output.append(f"{name}: {type_str}")


def method_name_sort_key(name: str) -> tuple[int, str]:
    """Sort methods in classes in a typical order.

    I.e.: constructor, normal methods, special methods.
    """
    if name in ("__new__", "__init__"):
        return 0, name
    if name.startswith("__") and name.endswith("__"):
        return 2, name
    return 1, name


def is_pybind_skipped_attribute(attr: str) -> bool:
    return attr.startswith("__pybind11_module_local_")


def infer_c_method_args(
    name: str, self_var: str = "self", arg_names: list[str] | None = None
) -> list[ArgSig]:
    args: list[ArgSig] | None = None
    if name.startswith("__") and name.endswith("__"):
        name = name[2:-2]
        if name in (
            "hash",
            "iter",
            "next",
            "sizeof",
            "copy",
            "deepcopy",
            "reduce",
            "getinitargs",
            "int",
            "float",
            "trunc",
            "complex",
            "bool",
            "abs",
            "bytes",
            "dir",
            "len",
            "reversed",
            "round",
            "index",
            "enter",
        ):
            args = []
        elif name == "getitem":
            args = [ArgSig(name="index")]
        elif name == "setitem":
            args = [ArgSig(name="index"), ArgSig(name="object")]
        elif name in ("delattr", "getattr"):
            args = [ArgSig(name="name")]
        elif name == "setattr":
            args = [ArgSig(name="name"), ArgSig(name="value")]
        elif name == "getstate":
            args = []
        elif name == "setstate":
            args = [ArgSig(name="state")]
        elif name in ("eq", "ne", "lt", "le", "gt", "ge"):
            args = [ArgSig(name="other", type="object")]
        elif name in (
            "add",
            "radd",
            "sub",
            "rsub",
            "mul",
            "rmul",
            "mod",
            "rmod",
            "floordiv",
            "rfloordiv",
            "truediv",
            "rtruediv",
            "divmod",
            "rdivmod",
            "pow",
            "rpow",
            "xor",
            "rxor",
            "or",
            "ror",
            "and",
            "rand",
            "lshift",
            "rlshift",
            "rshift",
            "rrshift",
            "contains",
            "delitem",
            "iadd",
            "iand",
            "ifloordiv",
            "ilshift",
            "imod",
            "imul",
            "ior",
            "ipow",
            "irshift",
            "isub",
            "itruediv",
            "ixor",
        ):
            args = [ArgSig(name="other")]
        elif name in ("neg", "pos", "invert"):
            args = []
        elif name == "get":
            args = [ArgSig(name="instance"), ArgSig(name="owner")]
        elif name == "set":
            args = [ArgSig(name="instance"), ArgSig(name="value")]
        elif name == "reduce_ex":
            args = [ArgSig(name="protocol")]
        elif name == "exit":
            args = [
                ArgSig(name="type", type="type[BaseException] | None"),
                ArgSig(name="value", type="BaseException | None"),
                ArgSig(name="traceback", type="types.TracebackType | None"),
            ]
    if args is None:
        args = infer_method_arg_types(name, self_var, arg_names)
    else:
        args = [ArgSig(name=self_var)] + args
    if args is None:
        args = [ArgSig(name="*args"), ArgSig(name="**kwargs")]
    return args