# Copyright (C) 2006, 2007, 2008, 2009 Canonical Ltd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
"""Symbol versioning
The methods here allow for api symbol versioning.
"""
__all__ = ['deprecated_function',
'deprecated_in',
'deprecated_list',
'deprecated_method',
'DEPRECATED_PARAMETER',
'deprecated_passed',
'set_warning_method',
'warn',
]
from warnings import warn
import bzrlib
DEPRECATED_PARAMETER = "A deprecated parameter marker."
def deprecated_in(version_tuple):
"""Generate a message that something was deprecated in a release.
>>> deprecated_in((1, 4, 0))
'%s was deprecated in version 1.4.0.'
"""
return ("%%s was deprecated in version %s."
% bzrlib._format_version_tuple(version_tuple))
def set_warning_method(method):
"""Set the warning method to be used by this module.
It should take a message and a warning category as warnings.warn does.
"""
global warn
warn = method
# TODO - maybe this would be easier to use as one 'smart' method that
# guess if it is a method or a class or an attribute ? If so, we can
# add that on top of the primitives, once we have all three written
# - RBC 20050105
def deprecation_string(a_callable, deprecation_version):
"""Generate an automatic deprecation string for a_callable.
:param a_callable: The callable to substitute into deprecation_version.
:param deprecation_version: A deprecation format warning string. This should
have a single %s operator in it. a_callable will be turned into a nice
python symbol and then substituted into deprecation_version.
"""
# We also want to handle old-style classes, in particular exception, and
# they don't have an im_class attribute.
if getattr(a_callable, 'im_class', None) is None:
symbol = "%s.%s" % (a_callable.__module__,
a_callable.__name__)
else:
symbol = "%s.%s.%s" % (a_callable.im_class.__module__,
a_callable.im_class.__name__,
a_callable.__name__
)
return deprecation_version % symbol
def deprecated_function(deprecation_version):
"""Decorate a function so that use of it will trigger a warning."""
def function_decorator(callable):
"""This is the function python calls to perform the decoration."""
def decorated_function(*args, **kwargs):
"""This is the decorated function."""
from bzrlib import trace
trace.mutter_callsite(4, "Deprecated function called")
warn(deprecation_string(callable, deprecation_version),
DeprecationWarning, stacklevel=2)
return callable(*args, **kwargs)
_populate_decorated(callable, deprecation_version, "function",
decorated_function)
return decorated_function
return function_decorator
def deprecated_method(deprecation_version):
"""Decorate a method so that use of it will trigger a warning.
To deprecate a static or class method, use
@staticmethod
@deprecated_function
def ...
To deprecate an entire class, decorate __init__.
"""
def method_decorator(callable):
"""This is the function python calls to perform the decoration."""
def decorated_method(self, *args, **kwargs):
"""This is the decorated method."""
from bzrlib import trace
if callable.__name__ == '__init__':
symbol = "%s.%s" % (self.__class__.__module__,
self.__class__.__name__,
)
else:
symbol = "%s.%s.%s" % (self.__class__.__module__,
self.__class__.__name__,
callable.__name__
)
trace.mutter_callsite(4, "Deprecated method called")
warn(deprecation_version % symbol, DeprecationWarning, stacklevel=2)
return callable(self, *args, **kwargs)
_populate_decorated(callable, deprecation_version, "method",
decorated_method)
return decorated_method
return method_decorator
def deprecated_passed(parameter_value):
"""Return True if parameter_value was used."""
# FIXME: it might be nice to have a parameter deprecation decorator.
# it would need to handle positional and *args and **kwargs parameters,
# which means some mechanism to describe how the parameter was being
# passed before deprecation, and some way to deprecate parameters that
# were not at the end of the arg list. Thats needed for __init__ where
# we cannot just forward to a new method name.I.e. in the following
# examples we would want to have callers that pass any value to 'bad' be
# given a warning - because we have applied:
# @deprecated_parameter('bad', deprecated_in((1, 5, 0))
#
# def __init__(self, bad=None)
# def __init__(self, bad, other)
# def __init__(self, **kwargs)
# RBC 20060116
return not parameter_value is DEPRECATED_PARAMETER
def _decorate_docstring(callable, deprecation_version, label,
decorated_callable):
if callable.__doc__:
docstring_lines = callable.__doc__.split('\n')
else:
docstring_lines = []
if len(docstring_lines) == 0:
decorated_callable.__doc__ = deprecation_version % ("This " + label)
elif len(docstring_lines) == 1:
decorated_callable.__doc__ = (callable.__doc__
+ "\n"
+ "\n"
+ deprecation_version % ("This " + label)
+ "\n")
else:
spaces = len(docstring_lines[-1])
new_doc = callable.__doc__
new_doc += "\n" + " " * spaces
new_doc += deprecation_version % ("This " + label)
new_doc += "\n" + " " * spaces
decorated_callable.__doc__ = new_doc
def _populate_decorated(callable, deprecation_version, label,
decorated_callable):
"""Populate attributes like __name__ and __doc__ on the decorated callable.
"""
_decorate_docstring(callable, deprecation_version, label,
decorated_callable)
decorated_callable.__module__ = callable.__module__
decorated_callable.__name__ = callable.__name__
decorated_callable.is_deprecated = True
def _dict_deprecation_wrapper(wrapped_method):
"""Returns a closure that emits a warning and calls the superclass"""
def cb(dep_dict, *args, **kwargs):
msg = 'access to %s' % (dep_dict._variable_name, )
msg = dep_dict._deprecation_version % (msg,)
if dep_dict._advice:
msg += ' ' + dep_dict._advice
warn(msg, DeprecationWarning, stacklevel=2)
return wrapped_method(dep_dict, *args, **kwargs)
return cb
class DeprecatedDict(dict):
"""A dictionary that complains when read or written."""
is_deprecated = True
def __init__(self,
deprecation_version,
variable_name,
initial_value,
advice,
):
"""Create a dict that warns when read or modified.
:param deprecation_version: string for the warning format to raise,
typically from deprecated_in()
:param initial_value: The contents of the dict
:param variable_name: This allows better warnings to be printed
:param advice: String of advice on what callers should do instead
of using this variable.
"""
self._deprecation_version = deprecation_version
self._variable_name = variable_name
self._advice = advice
dict.__init__(self, initial_value)
# This isn't every possible method but it should trap anyone using the
# dict -- add more if desired
__len__ = _dict_deprecation_wrapper(dict.__len__)
__getitem__ = _dict_deprecation_wrapper(dict.__getitem__)
__setitem__ = _dict_deprecation_wrapper(dict.__setitem__)
__delitem__ = _dict_deprecation_wrapper(dict.__delitem__)
keys = _dict_deprecation_wrapper(dict.keys)
__contains__ = _dict_deprecation_wrapper(dict.__contains__)
def deprecated_list(deprecation_version, variable_name,
initial_value, extra=None):
"""Create a list that warns when modified
:param deprecation_version: string for the warning format to raise,
typically from deprecated_in()
:param initial_value: The contents of the list
:param variable_name: This allows better warnings to be printed
:param extra: Extra info to print when printing a warning
"""
subst_text = 'Modifying %s' % (variable_name,)
msg = deprecation_version % (subst_text,)
if extra:
msg += ' ' + extra
class _DeprecatedList(list):
__doc__ = list.__doc__ + msg
is_deprecated = True
def _warn_deprecated(self, func, *args, **kwargs):
warn(msg, DeprecationWarning, stacklevel=3)
return func(self, *args, **kwargs)
def append(self, obj):
"""appending to %s is deprecated""" % (variable_name,)
return self._warn_deprecated(list.append, obj)
def insert(self, index, obj):
"""inserting to %s is deprecated""" % (variable_name,)
return self._warn_deprecated(list.insert, index, obj)
def extend(self, iterable):
"""extending %s is deprecated""" % (variable_name,)
return self._warn_deprecated(list.extend, iterable)
def remove(self, value):
"""removing from %s is deprecated""" % (variable_name,)
return self._warn_deprecated(list.remove, value)
def pop(self, index=None):
"""pop'ing from %s is deprecated""" % (variable_name,)
if index:
return self._warn_deprecated(list.pop, index)
else:
# Can't pass None
return self._warn_deprecated(list.pop)
return _DeprecatedList(initial_value)
def _check_for_filter(error_only):
"""Check if there is already a filter for deprecation warnings.
:param error_only: Only match an 'error' filter
:return: True if a filter is found, False otherwise
"""
import warnings
for filter in warnings.filters:
if issubclass(DeprecationWarning, filter[2]):
# This filter will effect DeprecationWarning
if not error_only or filter[0] == 'error':
return True
return False
def suppress_deprecation_warnings(override=True):
"""Call this function to suppress all deprecation warnings.
When this is a final release version, we don't want to annoy users with
lots of deprecation warnings. We only want the deprecation warnings when
running a dev or release candidate.
:param override: If True, always set the ignore, if False, only set the
ignore if there isn't already a filter.
"""
import warnings
if not override and _check_for_filter(error_only=False):
# If there is already a filter effecting suppress_deprecation_warnings,
# then skip it.
return
warnings.filterwarnings('ignore', category=DeprecationWarning)
def activate_deprecation_warnings(override=True):
"""Call this function to activate deprecation warnings.
When running in a 'final' release we suppress deprecation warnings.
However, the test suite wants to see them. So when running selftest, we
re-enable the deprecation warnings.
Note: warnings that have already been issued under 'ignore' will not be
reported after this point. The 'warnings' module has already marked them as
handled, so they don't get issued again.
:param override: If False, only add a filter if there isn't an error filter
already. (This slightly differs from suppress_deprecation_warnings, in
because it always overrides everything but -Werror).
"""
import warnings
if not override and _check_for_filter(error_only=True):
# DeprecationWarnings are already turned into errors, don't downgrade
# them to 'default'.
return
warnings.filterwarnings('default', category=DeprecationWarning)
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