# MIT License
#
# Copyright The SCons Foundation
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
"""Variable type for package Variables.
To be used whenever a 'package' may be enabled/disabled and the
package path may be specified.
Given these options ::
x11=no (disables X11 support)
x11=yes (will search for the package installation dir)
x11=/usr/local/X11 (will check this path for existence)
Can be used as a replacement for autoconf's ``--with-xxx=yyy`` ::
opts = Variables()
opts.Add(
PackageVariable(
key='x11',
help='use X11 installed here (yes = search some places)',
default='yes'
)
)
env = Environment(variables=opts)
if env['x11'] is True:
dir = ... # search X11 in some standard places ...
env['x11'] = dir
if env['x11']:
... # build with x11 ...
"""
import os
from typing import Callable, Optional, Tuple
import SCons.Errors
__all__ = ['PackageVariable',]
ENABLE_STRINGS = ('1', 'yes', 'true', 'on', 'enable', 'search')
DISABLE_STRINGS = ('0', 'no', 'false', 'off', 'disable')
[docs]def _converter(val):
"""Convert package variables.
Returns True or False if one of the recognized truthy or falsy
values is seen, else return the value unchanged (expected to
be a path string).
"""
lval = val.lower()
if lval in ENABLE_STRINGS:
return True
if lval in DISABLE_STRINGS:
return False
return val
[docs]def _validator(key, val, env, searchfunc) -> None:
"""Validate package variable for valid path.
Checks that if a path is given as the value, that pathname actually exists.
"""
# NOTE: searchfunc is currently undocumented and unsupported
if env[key] is True:
if searchfunc:
env[key] = searchfunc(key, val)
# TODO: need to check path, or be sure searchfunc raises.
elif env[key] and not os.path.exists(val):
msg = f'Path does not exist for variable {key!r}: {val!r}'
raise SCons.Errors.UserError(msg) from None
# lint: W0622: Redefining built-in 'help' (redefined-builtin)
[docs]def PackageVariable(
key: str, help: str, default, searchfunc: Optional[Callable] = None
) -> Tuple[str, str, str, Callable, Callable]:
"""Return a tuple describing a package list SCons Variable.
The input parameters describe a 'package list' variable. Returns
a tuple with the correct converter and validator appended.
The result is usable as input to :meth:`~SCons.Variables.Variables.Add`.
A 'package list' variable may either be a truthy string from
:const:`ENABLE_STRINGS`, a falsy string from
:const:`DISABLE_STRINGS`, or a pathname string.
This information is appended to *help* using only one string
each for truthy/falsy.
"""
# NB: searchfunc is currently undocumented and unsupported
help = '\n '.join((help, f'( yes | no | /path/to/{key} )'))
return (
key,
help,
default,
lambda k, v, e: _validator(k, v, e, searchfunc),
_converter,
)
# Local Variables:
# tab-width:4
# indent-tabs-mode:nil
# End:
# vim: set expandtab tabstop=4 shiftwidth=4: