mapnik/scons/scons-local-4.8.1/SCons/Variables/PathVariable.py
2024-09-09 10:56:17 +01:00

173 lines
6 KiB
Python
Vendored

# 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 path Variables.
To be used whenever a user-specified path override setting should be allowed.
Arguments to PathVariable are:
* *key* - name of this variable on the command line (e.g. "prefix")
* *help* - help string for variable
* *default* - default value for this variable
* *validator* - [optional] validator for variable value. Predefined are:
* *PathAccept* - accepts any path setting; no validation
* *PathIsDir* - path must be an existing directory
* *PathIsDirCreate* - path must be a dir; will create
* *PathIsFile* - path must be a file
* *PathExists* - path must exist (any type) [default]
The *validator* is a function that is called and which should return
True or False to indicate if the path is valid. The arguments
to the validator function are: (*key*, *val*, *env*). *key* is the
name of the variable, *val* is the path specified for the variable,
and *env* is the environment to which the Variables have been added.
Usage example::
opts = Variables()
opts.Add(
PathVariable(
'qtdir',
help='where the root of Qt is installed',
default=qtdir,
validator=PathIsDir,
)
)
opts.Add(
PathVariable(
'qt_includes',
help='where the Qt includes are installed',
default='$qtdir/includes',
validator=PathIsDirCreate,
)
)
opts.Add(
PathVariable(
'qt_libraries',
help='where the Qt library is installed',
default='$qtdir/lib',
)
)
"""
import os
import os.path
from typing import Callable, Optional, Tuple
import SCons.Errors
import SCons.Util
__all__ = ['PathVariable',]
class _PathVariableClass:
"""Class implementing path variables.
This class exists mainly to expose the validators without code having
to import the names: they will appear as methods of ``PathVariable``,
a statically created instance of this class, which is placed in
the SConscript namespace.
Instances are callable to produce a suitable variable tuple.
"""
@staticmethod
def PathAccept(key: str, val, env) -> None:
"""Validate path with no checking."""
return
@staticmethod
def PathIsDir(key: str, val, env) -> None:
"""Validate path is a directory."""
if os.path.isdir(val):
return
if os.path.isfile(val):
msg = f'Directory path for variable {key!r} is a file: {val}'
else:
msg = f'Directory path for variable {key!r} does not exist: {val}'
raise SCons.Errors.UserError(msg)
@staticmethod
def PathIsDirCreate(key: str, val, env) -> None:
"""Validate path is a directory, creating if needed."""
if os.path.isdir(val):
return
try:
os.makedirs(val, exist_ok=True)
except FileExistsError as exc:
msg = f'Path for variable {key!r} is a file, not a directory: {val}'
raise SCons.Errors.UserError(msg) from exc
except (PermissionError, OSError) as exc:
msg = f'Path for variable {key!r} could not be created: {val}'
raise SCons.Errors.UserError(msg) from exc
@staticmethod
def PathIsFile(key: str, val, env) -> None:
"""Validate path is a file."""
if not os.path.isfile(val):
if os.path.isdir(val):
msg = f'File path for variable {key!r} is a directory: {val}'
else:
msg = f'File path for variable {key!r} does not exist: {val}'
raise SCons.Errors.UserError(msg)
@staticmethod
def PathExists(key: str, val, env) -> None:
"""Validate path exists."""
if not os.path.exists(val):
msg = f'Path for variable {key!r} does not exist: {val}'
raise SCons.Errors.UserError(msg)
# lint: W0622: Redefining built-in 'help' (redefined-builtin)
def __call__(
self, key: str, help: str, default, validator: Optional[Callable] = None
) -> Tuple[str, str, str, Callable, None]:
"""Return a tuple describing a path list SCons Variable.
The input parameters describe a 'path list' variable. Returns
a tuple with the correct converter and validator appended. The
result is usable for input to :meth:`Add`.
The *default* parameter specifies the default path to use if the
user does not specify an override with this variable.
*validator* is a validator, see this file for examples
"""
if validator is None:
validator = self.PathExists
if SCons.Util.is_List(key) or SCons.Util.is_Tuple(key):
helpmsg = f'{help} ( /path/to/{key[0]} )'
else:
helpmsg = f'{help} ( /path/to/{key} )'
return key, helpmsg, default, validator, None
PathVariable = _PathVariableClass()
# Local Variables:
# tab-width:4
# indent-tabs-mode:nil
# End:
# vim: set expandtab tabstop=4 shiftwidth=4: