Lib/_py_warnings.py

"""Python part of the warnings subsystem."""

import sys
import _contextvars
import _thread


__all__ = ["warn", "warn_explicit", "showwarning",
           "formatwarning", "filterwarnings", "simplefilter",
           "resetwarnings", "catch_warnings", "deprecated"]


# Normally '_wm' is sys.modules['warnings'] but for unit tests it can be
# a different module.  User code is allowed to reassign global attributes
# of the 'warnings' module, commonly 'filters' or 'showwarning'. So we
# need to lookup these global attributes dynamically on the '_wm' object,
# rather than binding them earlier.  The code in this module consistently uses
# '_wm.<something>' rather than using the globals of this module.  If the
# '_warnings' C extension is in use, some globals are replaced by functions
# and variables defined in that extension.
_wm = None


def _set_module(module):
    global _wm
    _wm = module


# filters contains a sequence of filter 5-tuples
# The components of the 5-tuple are:
# - an action: error, ignore, always, all, default, module, or once
# - a compiled regex that must match the warning message
# - a class representing the warning category
# - a compiled regex that must match the module that is being warned
# - a line number for the line being warning, or 0 to mean any line
# If either if the compiled regexs are None, match anything.
filters = []


defaultaction = "default"
onceregistry = {}
_lock = _thread.RLock()
_filters_version = 1


# If true, catch_warnings() will use a context var to hold the modified
# filters list.  Otherwise, catch_warnings() will operate on the 'filters'
# global of the warnings module.
_use_context = sys.flags.context_aware_warnings


class _Context:
    def __init__(self, filters):
        self._filters = filters
        self.log = None  # if set to a list, logging is enabled

    def copy(self):
        context = _Context(self._filters[:])
        if self.log is not None:
            context.log = self.log
        return context

    def _record_warning(self, msg):
        self.log.append(msg)


class _GlobalContext(_Context):
    def __init__(self):
        self.log = None

    @property
    def _filters(self):
        # Since there is quite a lot of code that assigns to
        # warnings.filters, this needs to return the current value of
        # the module global.
        try:
            return _wm.filters
        except AttributeError:
            # 'filters' global was deleted.  Do we need to actually handle this case?
            return []


_global_context = _GlobalContext()


_warnings_context = _contextvars.ContextVar('warnings_context')


def _get_context():
    if not _use_context:
        return _global_context
    try:
        return _wm._warnings_context.get()
    except LookupError:
        return _global_context


def _set_context(context):
    assert _use_context
    _wm._warnings_context.set(context)


def _new_context():
    assert _use_context
    old_context = _wm._get_context()
    new_context = old_context.copy()
    _wm._set_context(new_context)
    return old_context, new_context


def _get_filters():
    """Return the current list of filters.  This is a non-public API used by
    module functions and by the unit tests."""
    return _wm._get_context()._filters


def _filters_mutated_lock_held():
    _wm._filters_version += 1


def showwarning(message, category, filename, lineno, file=None, line=None):
    """Hook to write a warning to a file; replace if you like."""
    msg = _wm.WarningMessage(message, category, filename, lineno, file, line)
    _wm._showwarnmsg_impl(msg)


def formatwarning(message, category, filename, lineno, line=None):
    """Function to format a warning the standard way."""
    msg = _wm.WarningMessage(message, category, filename, lineno, None, line)
    return _wm._formatwarnmsg_impl(msg)


def _showwarnmsg_impl(msg):
    context = _wm._get_context()
    if context.log is not None:
        context._record_warning(msg)
        return
    file = msg.file
    if file is None:
        file = sys.stderr
        if file is None:
            # sys.stderr is None when run with pythonw.exe:
            # warnings get lost
            return
    text = _wm._formatwarnmsg(msg)
    try:
        file.write(text)
    except OSError:
        # the file (probably stderr) is invalid - this warning gets lost.
        pass


def _formatwarnmsg_impl(msg):
    category = msg.category.__name__
    s =  f"{msg.filename}:{msg.lineno}: {category}: {msg.message}\n"

    if msg.line is None:
        try:
            import linecache
            line = linecache.getline(msg.filename, msg.lineno)
        except Exception:
            # When a warning is logged during Python shutdown, linecache
            # and the import machinery don't work anymore
            line = None
            linecache = None
    else:
        line = msg.line
    if line:
        line = line.strip()
        s += "  %s\n" % line

    if msg.source is not None:
        try:
            import tracemalloc
        # Logging a warning should not raise a new exception:
        # catch Exception, not only ImportError and RecursionError.
        except Exception:
            # don't suggest to enable tracemalloc if it's not available
            suggest_tracemalloc = False
            tb = None
        else:
            try:
                suggest_tracemalloc = not tracemalloc.is_tracing()
                tb = tracemalloc.get_object_traceback(msg.source)
            except Exception:
                # When a warning is logged during Python shutdown, tracemalloc
                # and the import machinery don't work anymore
                suggest_tracemalloc = False
                tb = None

        if tb is not None:
            s += 'Object allocated at (most recent call last):\n'
            for frame in tb:
                s += ('  File "%s", lineno %s\n'
                      % (frame.filename, frame.lineno))

                try:
                    if linecache is not None:
                        line = linecache.getline(frame.filename, frame.lineno)
                    else:
                        line = None
                except Exception:
                    line = None
                if line:
                    line = line.strip()
                    s += '    %s\n' % line
        elif suggest_tracemalloc:
            s += (f'{category}: Enable tracemalloc to get the object '
                  f'allocation traceback\n')
    return s


# Keep a reference to check if the function was replaced
_showwarning_orig = showwarning


def _showwarnmsg(msg):
    """Hook to write a warning to a file; replace if you like."""
    try:
        sw = _wm.showwarning
    except AttributeError:
        pass
    else:
        if sw is not _showwarning_orig:
            # warnings.showwarning() was replaced
            if not callable(sw):
                raise TypeError("warnings.showwarning() must be set to a "
                                "function or method")

            sw(msg.message, msg.category, msg.filename, msg.lineno,
               msg.file, msg.line)
            return
    _wm._showwarnmsg_impl(msg)


# Keep a reference to check if the function was replaced
_formatwarning_orig = formatwarning


def _formatwarnmsg(msg):
    """Function to format a warning the standard way."""
    try:
        fw = _wm.formatwarning
    except AttributeError:
        pass
    else:
        if fw is not _formatwarning_orig:
            # warnings.formatwarning() was replaced
            return fw(msg.message, msg.category,
                      msg.filename, msg.lineno, msg.line)
    return _wm._formatwarnmsg_impl(msg)


def filterwarnings(action, message="", category=Warning, module="", lineno=0,
                   append=False):
    """Insert an entry into the list of warnings filters (at the front).

    'action' -- one of "error", "ignore", "always", "all", "default", "module",
                or "once"
    'message' -- a regex that the warning message must match
    'category' -- a class that the warning must be a subclass of
    'module' -- a regex that the module name must match
    'lineno' -- an integer line number, 0 matches all warnings
    'append' -- if true, append to the list of filters
    """
    if action not in {"error", "ignore", "always", "all", "default", "module", "once"}:
        raise ValueError(f"invalid action: {action!r}")
    if not isinstance(message, str):
        raise TypeError("message must be a string")
    if not isinstance(category, type) or not issubclass(category, Warning):
        raise TypeError("category must be a Warning subclass")
    if not isinstance(module, str):
        raise TypeError("module must be a string")
    if not isinstance(lineno, int):
        raise TypeError("lineno must be an int")
    if lineno < 0:
        raise ValueError("lineno must be an int >= 0")

    if message or module:
        import re

    if message:
        message = re.compile(message, re.I)
    else:
        message = None
    if module:
        module = re.compile(module)
    else:
        module = None

    _wm._add_filter(action, message, category, module, lineno, append=append)


def simplefilter(action, category=Warning, lineno=0, append=False):
    """Insert a simple entry into the list of warnings filters (at the front).

    A simple filter matches all modules and messages.
    'action' -- one of "error", "ignore", "always", "all", "default", "module",
                or "once"
    'category' -- a class that the warning must be a subclass of
    'lineno' -- an integer line number, 0 matches all warnings
    'append' -- if true, append to the list of filters
    """
    if action not in {"error", "ignore", "always", "all", "default", "module", "once"}:
        raise ValueError(f"invalid action: {action!r}")
    if not isinstance(lineno, int):
        raise TypeError("lineno must be an int")
    if lineno < 0:
        raise ValueError("lineno must be an int >= 0")
    _wm._add_filter(action, None, category, None, lineno, append=append)


def _filters_mutated():
    # Even though this function is not part of the public API, it's used by
    # a fair amount of user code.
    with _wm._lock:
        _wm._filters_mutated_lock_held()


def _add_filter(*item, append):
    with _wm._lock:
        filters = _wm._get_filters()
        if not append:
            # Remove possible duplicate filters, so new one will be placed
            # in correct place. If append=True and duplicate exists, do nothing.
            try:
                filters.remove(item)
            except ValueError:
                pass
            filters.insert(0, item)
        else:
            if item not in filters:
                filters.append(item)
        _wm._filters_mutated_lock_held()


def resetwarnings():
    """Clear the list of warning filters, so that no filters are active."""
    with _wm._lock:
        del _wm._get_filters()[:]
        _wm._filters_mutated_lock_held()


class _OptionError(Exception):
    """Exception used by option processing helpers."""
    pass


# Helper to process -W options passed via sys.warnoptions
def _processoptions(args):
    for arg in args:
        try:
            _wm._setoption(arg)
        except _wm._OptionError as msg:
            print("Invalid -W option ignored:", msg, file=sys.stderr)


# Helper for _processoptions()
def _setoption(arg):
    parts = arg.split(':')
    if len(parts) > 5:
        raise _wm._OptionError("too many fields (max 5): %r" % (arg,))
    while len(parts) < 5:
        parts.append('')
    action, message, category, module, lineno = [s.strip()
                                                 for s in parts]
    action = _wm._getaction(action)
    category = _wm._getcategory(category)
    if message or module:
        import re
    if message:
        if len(message) >= 2 and message[0] == message[-1] == '/':
            message = message[1:-1]
        else:
            message = re.escape(message)
    if module:
        if len(module) >= 2 and module[0] == module[-1] == '/':
            module = module[1:-1]
        else:
            module = re.escape(module) + r'\z'
    if lineno:
        try:
            lineno = int(lineno)
            if lineno < 0:
                raise ValueError
        except (ValueError, OverflowError):
            raise _wm._OptionError("invalid lineno %r" % (lineno,)) from None
    else:
        lineno = 0
    try:
        _wm.filterwarnings(action, message, category, module, lineno)
    except re.PatternError if message or module else ():
        if message:
            try:
                re.compile(message)
            except re.PatternError:
                raise _wm._OptionError(f"invalid regular expression for "
                                       f"message: {message!r}") from None
        if module:
            try:
                re.compile(module)
            except re.PatternError:
                raise _wm._OptionError(f"invalid regular expression for "
                                       f"module: {module!r}") from None
        # Should never happen.
        raise


# Helper for _setoption()
def _getaction(action):
    if not action:
        return "default"
    for a in ('default', 'always', 'all', 'ignore', 'module', 'once', 'error'):
        if a.startswith(action):
            return a
    raise _wm._OptionError("invalid action: %r" % (action,))


# Helper for _setoption()
def _getcategory(category):
    if not category:
        return Warning
    if '.' not in category:
        import builtins as m
        klass = category
    else:
        module, _, klass = category.rpartition('.')
        try:
            m = __import__(module, None, None, [klass])
        except ImportError:
            raise _wm._OptionError("invalid module name: %r" % (module,)) from None
    try:
        cat = getattr(m, klass)
    except AttributeError:
        raise _wm._OptionError("unknown warning category: %r" % (category,)) from None
    if not issubclass(cat, Warning):
        raise _wm._OptionError("invalid warning category: %r" % (category,))
    return cat


def _is_internal_filename(filename):
    return 'importlib' in filename and '_bootstrap' in filename


def _is_filename_to_skip(filename, skip_file_prefixes):
    return any(filename.startswith(prefix) for prefix in skip_file_prefixes)


def _is_internal_frame(frame):
    """Signal whether the frame is an internal CPython implementation detail."""
    return _is_internal_filename(frame.f_code.co_filename)


def _next_external_frame(frame, skip_file_prefixes):
    """Find the next frame that doesn't involve Python or user internals."""
    frame = frame.f_back
    while frame is not None and (
            _is_internal_filename(filename := frame.f_code.co_filename) or
            _is_filename_to_skip(filename, skip_file_prefixes)):
        frame = frame.f_back
    return frame


# Code typically replaced by _warnings
def warn(message, category=None, stacklevel=1, source=None,
         *, skip_file_prefixes=()):
    """Issue a warning, or maybe ignore it or raise an exception."""
    # Check if message is already a Warning object
    if isinstance(message, Warning):
        category = message.__class__
    # Check category argument
    if category is None:
        category = UserWarning
    elif not isinstance(category, type):
        raise TypeError(f"category must be a Warning subclass, not "
                        f"'{type(category).__name__}'")
    elif not issubclass(category, Warning):
        raise TypeError(f"category must be a Warning subclass, not "
                        f"class '{category.__name__}'")
    if not isinstance(skip_file_prefixes, tuple):
        # The C version demands a tuple for implementation performance.
        raise TypeError('skip_file_prefixes must be a tuple of strs.')
    if skip_file_prefixes:
        stacklevel = max(2, stacklevel)
    # Get context information
    try:
        if stacklevel <= 1 or _is_internal_frame(sys._getframe(1)):
            # If frame is too small to care or if the warning originated in
            # internal code, then do not try to hide any frames.
            frame = sys._getframe(stacklevel)
        else:
            frame = sys._getframe(1)
            # Look for one frame less since the above line starts us off.
            for x in range(stacklevel-1):
                frame = _next_external_frame(frame, skip_file_prefixes)
                if frame is None:
                    raise ValueError
    except ValueError:
        globals = sys.__dict__
        filename = "<sys>"
        lineno = 0
    else:
        globals = frame.f_globals
        filename = frame.f_code.co_filename
        lineno = frame.f_lineno
    if '__name__' in globals:
        module = globals['__name__']
    else:
        module = "<string>"
    registry = globals.setdefault("__warningregistry__", {})
    _wm.warn_explicit(
        message,
        category,
        filename,
        lineno,
        module,
        registry,
        globals,
        source=source,
    )


def _match_filename(pattern, filename, *, MS_WINDOWS=(sys.platform == 'win32')):
    if not filename:
        return pattern.match('<unknown>') is not None
    if filename[0] == '<' and filename[-1] == '>':
        return pattern.match(filename) is not None

    is_py = (filename[-3:].lower() == '.py'
             if MS_WINDOWS else
             filename.endswith('.py'))
    if is_py:
        filename = filename[:-3]
    if pattern.match(filename):  # for backward compatibility
        return True
    if MS_WINDOWS:
        if not is_py and filename[-4:].lower() == '.pyw':
            filename = filename[:-4]
            is_py = True
        if is_py and filename[-9:].lower() in (r'\__init__', '/__init__'):
            filename = filename[:-9]
        filename = filename.replace('\\', '/')
    else:
        if is_py and filename.endswith('/__init__'):
            filename = filename[:-9]
    filename = filename.replace('/', '.')
    i = 0
    while True:
        if pattern.match(filename, i):
            return True
        i = filename.find('.', i) + 1
        if not i:
            return False


def warn_explicit(message, category, filename, lineno,
                  module=None, registry=None, module_globals=None,
                  source=None):
    lineno = int(lineno)
    if isinstance(message, Warning):
        text = str(message)
        category = message.__class__
    else:
        text = message
        message = category(message)
    key = (text, category, lineno)
    with _wm._lock:
        if registry is None:
            registry = {}
        if registry.get('version', 0) != _wm._filters_version:
            registry.clear()
            registry['version'] = _wm._filters_version
        # Quick test for common case
        if registry.get(key):
            return
        # Search the filters
        for item in _wm._get_filters():
            action, msg, cat, mod, ln = item
            if ((msg is None or msg.match(text)) and
                issubclass(category, cat) and
                (ln == 0 or lineno == ln) and
                (mod is None or (_match_filename(mod, filename)
                                 if module is None else
                                 mod.match(module)))):
                    break
        else:
            action = _wm.defaultaction
        # Early exit actions
        if action == "ignore":
            return

        if action == "error":
            raise message
        # Other actions
        if action == "once":
            registry[key] = 1
            oncekey = (text, category)
            if _wm.onceregistry.get(oncekey):
                return
            _wm.onceregistry[oncekey] = 1
        elif action in {"always", "all"}:
            pass
        elif action == "module":
            registry[key] = 1
            altkey = (text, category, 0)
            if registry.get(altkey):
                return
            registry[altkey] = 1
        elif action == "default":
            registry[key] = 1
        else:
            # Unrecognized actions are errors
            raise RuntimeError(
                  "Unrecognized action (%r) in warnings.filters:\n %s" %
                  (action, item))

    # Prime the linecache for formatting, in case the
    # "file" is actually in a zipfile or something.
    import linecache
    linecache.getlines(filename, module_globals)

    # Print message and context
    msg = _wm.WarningMessage(message, category, filename, lineno,
                             module=module, source=source)
    _wm._showwarnmsg(msg)


class WarningMessage(object):

    _WARNING_DETAILS = ("message", "category", "filename", "lineno", "file",
                        "line", "source", "module")

    def __init__(self, message, category, filename, lineno, file=None,
                 line=None, source=None, module=None):
        self.message = message
        self.category = category
        self.filename = filename
        self.lineno = lineno
        self.file = file
        self.line = line
        self.source = source
        self.module = module
        self._category_name = category.__name__ if category else None

    def __str__(self):
        return ("{message : %r, category : %r, module : %r, "
                "filename : %r, lineno : %s, line : %r}" % (
                    self.message, self._category_name, self.module,
                    self.filename, self.lineno, self.line))

    def __repr__(self):
        return f'<{type(self).__qualname__} {self}>'


class catch_warnings(object):

    """A context manager that copies and restores the warnings filter upon
    exiting the context.

    The 'record' argument specifies whether warnings should be captured by a
    custom implementation of warnings.showwarning() and be appended to a list
    returned by the context manager. Otherwise None is returned by the context
    manager. The objects appended to the list are arguments whose attributes
    mirror the arguments to showwarning().

    The 'module' argument is to specify an alternative module to the module
    named 'warnings' and imported under that name. This argument is only useful
    when testing the warnings module itself.

    If the 'action' argument is not None, the remaining arguments are passed
    to warnings.simplefilter() as if it were called immediately on entering the
    context.
    """

    def __init__(self, *, record=False, module=None,
                 action=None, category=Warning, lineno=0, append=False):
        """Specify whether to record warnings and if an alternative module
        should be used other than sys.modules['warnings'].

        """
        self._record = record
        self._module = sys.modules['warnings'] if module is None else module
        self._entered = False
        if action is None:
            self._filter = None
        else:
            self._filter = (action, category, lineno, append)

    def __repr__(self):
        args = []
        if self._record:
            args.append("record=True")
        if self._module is not sys.modules['warnings']:
            args.append("module=%r" % self._module)
        name = type(self).__name__
        return "%s(%s)" % (name, ", ".join(args))

    def __enter__(self):
        if self._entered:
            raise RuntimeError("Cannot enter %r twice" % self)
        self._entered = True
        with _wm._lock:
            if _use_context:
                self._saved_context, context = self._module._new_context()
            else:
                context = None
                self._filters = self._module.filters
                self._module.filters = self._filters[:]
                self._showwarnmsg_impl = self._module._showwarnmsg_impl
            self._showwarning = self._module.showwarning
            self._module._filters_mutated_lock_held()
            if self._record:
                if _use_context:
                    context.log = log = []
                else:
                    log = []
                    self._module._showwarnmsg_impl = log.append
                # Reset showwarning() to the default implementation to make sure
                # that _showwarnmsg() calls _showwarnmsg_impl()
                self._module.showwarning = self._module._showwarning_orig
            else:
                log = None
        if self._filter is not None:
            self._module.simplefilter(*self._filter)
        return log

    def __exit__(self, *exc_info):
        if not self._entered:
            raise RuntimeError("Cannot exit %r without entering first" % self)
        with _wm._lock:
            if _use_context:
                self._module._warnings_context.set(self._saved_context)
            else:
                self._module.filters = self._filters
                self._module._showwarnmsg_impl = self._showwarnmsg_impl
            self._module.showwarning = self._showwarning
            self._module._filters_mutated_lock_held()


class deprecated:
    """Indicate that a class, function or overload is deprecated.

    When this decorator is applied to an object, the type checker
    will generate a diagnostic on usage of the deprecated object.

    Usage:

        @deprecated("Use B instead")
        class A:
            pass

        @deprecated("Use g instead")
        def f():
            pass

        @overload
        @deprecated("int support is deprecated")
        def g(x: int) -> int: ...
        @overload
        def g(x: str) -> int: ...

    The warning specified by *category* will be emitted at runtime
    on use of deprecated objects. For functions, that happens on calls;
    for classes, on instantiation and on creation of subclasses.
    If the *category* is ``None``, no warning is emitted at runtime.
    The *stacklevel* determines where the
    warning is emitted. If it is ``1`` (the default), the warning
    is emitted at the direct caller of the deprecated object; if it
    is higher, it is emitted further up the stack.
    Static type checker behavior is not affected by the *category*
    and *stacklevel* arguments.

    The deprecation message passed to the decorator is saved in the
    ``__deprecated__`` attribute on the decorated object.
    If applied to an overload, the decorator
    must be after the ``@overload`` decorator for the attribute to
    exist on the overload as returned by ``get_overloads()``.

    See PEP 702 for details.

    """
    def __init__(
        self,
        message: str,
        /,
        *,
        category: type[Warning] | None = DeprecationWarning,
        stacklevel: int = 1,
    ) -> None:
        if not isinstance(message, str):
            raise TypeError(
                f"Expected an object of type str for 'message', not {type(message).__name__!r}"
            )
        self.message = message
        self.category = category
        self.stacklevel = stacklevel

    def __call__(self, arg, /):
        # Make sure the inner functions created below don't
        # retain a reference to self.
        msg = self.message
        category = self.category
        stacklevel = self.stacklevel
        if category is None:
            arg.__deprecated__ = msg
            return arg
        elif isinstance(arg, type):
            import functools
            from types import MethodType

            original_new = arg.__new__

            @functools.wraps(original_new)
            def __new__(cls, /, *args, **kwargs):
                if cls is arg:
                    _wm.warn(msg, category=category, stacklevel=stacklevel + 1)
                if original_new is not object.__new__:
                    return original_new(cls, *args, **kwargs)
                # Mirrors a similar check in object.__new__.
                elif cls.__init__ is object.__init__ and (args or kwargs):
                    raise TypeError(f"{cls.__name__}() takes no arguments")
                else:
                    return original_new(cls)

            arg.__new__ = staticmethod(__new__)

            if "__init_subclass__" in arg.__dict__:
                # __init_subclass__ is directly present on the decorated class.
                # Synthesize a wrapper that calls this method directly.
                original_init_subclass = arg.__init_subclass__
                # We need slightly different behavior if __init_subclass__
                # is a bound method (likely if it was implemented in Python).
                # Otherwise, it likely means it's a builtin such as
                # object's implementation of __init_subclass__.
                if isinstance(original_init_subclass, MethodType):
                    original_init_subclass = original_init_subclass.__func__

                @functools.wraps(original_init_subclass)
                def __init_subclass__(*args, **kwargs):
                    _wm.warn(msg, category=category, stacklevel=stacklevel + 1)
                    return original_init_subclass(*args, **kwargs)
            else:
                def __init_subclass__(cls, *args, **kwargs):
                    _wm.warn(msg, category=category, stacklevel=stacklevel + 1)
                    return super(arg, cls).__init_subclass__(*args, **kwargs)

            arg.__init_subclass__ = classmethod(__init_subclass__)

            arg.__deprecated__ = __new__.__deprecated__ = msg
            __init_subclass__.__deprecated__ = msg
            return arg
        elif callable(arg):
            import functools
            import inspect

            @functools.wraps(arg)
            def wrapper(*args, **kwargs):
                _wm.warn(msg, category=category, stacklevel=stacklevel + 1)
                return arg(*args, **kwargs)

            if inspect.iscoroutinefunction(arg):
                wrapper = inspect.markcoroutinefunction(wrapper)

            arg.__deprecated__ = wrapper.__deprecated__ = msg
            return wrapper
        else:
            raise TypeError(
                "@deprecated decorator with non-None category must be applied to "
                f"a class or callable, not {arg!r}"
            )


_DEPRECATED_MSG = "{name!r} is deprecated and slated for removal in Python {remove}"


def _deprecated(name, message=_DEPRECATED_MSG, *, remove, _version=sys.version_info,
                stacklevel=3):
    """Warn that *name* is deprecated or should be removed.

    RuntimeError is raised if *remove* specifies a major/minor tuple older than
    the current Python version or the same version but past the alpha.

    The *message* argument is formatted with *name* and *remove* as a Python
    version tuple (e.g. (3, 11)).

    """
    remove_formatted = f"{remove[0]}.{remove[1]}"
    if (_version[:2] > remove) or (_version[:2] == remove and _version[3] != "alpha"):
        msg = f"{name!r} was slated for removal after Python {remove_formatted} alpha"
        raise RuntimeError(msg)
    else:
        msg = message.format(name=name, remove=remove_formatted)
        _wm.warn(msg, DeprecationWarning, stacklevel=stacklevel)


# Private utility function called by _PyErr_WarnUnawaitedCoroutine
def _warn_unawaited_coroutine(coro):
    msg_lines = [
        f"coroutine '{coro.__qualname__}' was never awaited\n"
    ]
    if coro.cr_origin is not None:
        import linecache, traceback
        def extract():
            for filename, lineno, funcname in reversed(coro.cr_origin):
                line = linecache.getline(filename, lineno)
                yield (filename, lineno, funcname, line)
        msg_lines.append("Coroutine created at (most recent call last)\n")
        msg_lines += traceback.format_list(list(extract()))
    msg = "".join(msg_lines).rstrip("\n")
    # Passing source= here means that if the user happens to have tracemalloc
    # enabled and tracking where the coroutine was created, the warning will
    # contain that traceback. This does mean that if they have *both*
    # coroutine origin tracking *and* tracemalloc enabled, they'll get two
    # partially-redundant tracebacks. If we wanted to be clever we could
    # probably detect this case and avoid it, but for now we don't bother.
    _wm.warn(
        msg, category=RuntimeWarning, stacklevel=2, source=coro
    )


def _setup_defaults():
    # Several warning categories are ignored by default in regular builds
    if hasattr(sys, 'gettotalrefcount'):
        return
    _wm.filterwarnings("default", category=DeprecationWarning, module="__main__", append=1)
    _wm.simplefilter("ignore", category=DeprecationWarning, append=1)
    _wm.simplefilter("ignore", category=PendingDeprecationWarning, append=1)
    _wm.simplefilter("ignore", category=ImportWarning, append=1)
    _wm.simplefilter("ignore", category=ResourceWarning, append=1)