# MIT License
#
# Copyright The SCons Foundation
#
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# The above copyright notice and this permission notice shall be included
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"""Add user-friendly customizable variables to an SCons build. """
import os.path
import sys
from functools import cmp_to_key
import SCons.Environment
import SCons.Errors
import SCons.Util
import SCons.Warnings
from .BoolVariable import BoolVariable # okay
from .EnumVariable import EnumVariable # okay
from .ListVariable import ListVariable # naja
from .PackageVariable import PackageVariable # naja
from .PathVariable import PathVariable # okay
[docs]class Variables:
"""
Holds all the options, updates the environment with the variables,
and renders the help text.
If *is_global* is true, this is a singleton, create only once.
Args:
files (optional): List of option configuration files to load
(backward compatibility). If a single string is passed it is
automatically placed in a file list (Default value = None)
args (optional): dictionary to override values set from *files*.
(Default value = None)
is_global (optional): global instance? (Default value = True)
"""
instance = None
def __init__(self, files=None, args=None, is_global=True):
if args is None:
args = {}
self.options = []
self.args = args
if not SCons.Util.is_List(files):
if files:
files = [files,]
else:
files = []
self.files = files
self.unknown = {}
# create the singleton instance
if is_global:
self = Variables.instance
if not Variables.instance:
Variables.instance=self
[docs] def _do_add(self, key, help="", default=None, validator=None, converter=None, **kwargs) -> None:
class Variable:
pass
option = Variable()
# If we get a list or a tuple, we take the first element as the
# option key and store the remaining in aliases.
if SCons.Util.is_List(key) or SCons.Util.is_Tuple(key):
option.key = key[0]
option.aliases = list(key[1:])
else:
option.key = key
# TODO: normalize to not include key in aliases. Currently breaks tests.
option.aliases = [key,]
if not SCons.Environment.is_valid_construction_var(option.key):
raise SCons.Errors.UserError("Illegal Variables key `%s'" % str(option.key))
option.help = help
option.default = default
option.validator = validator
option.converter = converter
self.options.append(option)
# options might be added after the 'unknown' dict has been set up,
# so we remove the key and all its aliases from that dict
for alias in option.aliases + [option.key,]:
if alias in self.unknown:
del self.unknown[alias]
[docs] def keys(self) -> list:
"""Returns the keywords for the options."""
return [o.key for o in self.options]
[docs] def Add(self, key, *args, **kwargs) -> None:
r""" Add an option.
Args:
key: the name of the variable, or a 5-tuple (or list).
If a tuple, and there are no additional arguments,
the tuple is unpacked into help, default, validator, converter.
If there are additional arguments, the first word of the tuple
is taken as the key, and the remainder as aliases.
\*args: optional positional arguments
help: optional help text for the options (Default value = "")
default: optional default value for option (Default value = None)
validator: optional function called to validate the option's value
(Default value = None)
converter: optional function to be called to convert the option's
value before putting it in the environment. (Default value = None)
\*\*kwargs: keyword args, can be the arguments from \*args or
arbitrary kwargs used by a variable itself
"""
if SCons.Util.is_List(key) or SCons.Util.is_Tuple(key):
if not (len(args) or len(kwargs)):
return self._do_add(*key)
return self._do_add(key, *args, **kwargs)
[docs] def AddVariables(self, *optlist) -> None:
""" Add a list of options.
Each list element is a tuple/list of arguments to be passed on
to the underlying method for adding options.
Example::
opt.AddVariables(
('debug', '', 0),
('CC', 'The C compiler'),
('VALIDATE', 'An option for testing validation', 'notset', validator, None),
)
"""
for o in optlist:
self._do_add(*o)
[docs] def Update(self, env, args=None) -> None:
""" Update an environment with the option variables.
Args:
env: the environment to update.
args: [optional] a dictionary of keys and values to update
in *env*. If omitted, uses the variables from the commandline.
"""
values = {}
# first set the defaults:
for option in self.options:
if option.default is not None:
values[option.key] = option.default
# next set the value specified in the options file
for filename in self.files:
if os.path.exists(filename):
dir = os.path.split(os.path.abspath(filename))[0]
if dir:
sys.path.insert(0, dir)
try:
values['__name__'] = filename
with open(filename, 'r') as f:
contents = f.read()
exec(contents, {}, values)
finally:
if dir:
del sys.path[0]
del values['__name__']
# set the values specified on the command line
if args is None:
args = self.args
for arg, value in args.items():
added = False
for option in self.options:
if arg in option.aliases + [option.key,]:
values[option.key] = value
added = True
if not added:
self.unknown[arg] = value
# put the variables in the environment:
# (don't copy over variables that are not declared as options)
for option in self.options:
try:
env[option.key] = values[option.key]
except KeyError:
pass
# apply converters
for option in self.options:
if option.converter and option.key in values:
value = env.subst('${%s}'%option.key)
try:
try:
env[option.key] = option.converter(value)
except TypeError:
env[option.key] = option.converter(value, env)
except ValueError as x:
raise SCons.Errors.UserError('Error converting option: %s\n%s'%(option.key, x))
# apply validators
for option in self.options:
if option.validator and option.key in values:
option.validator(option.key, env.subst('${%s}'%option.key), env)
[docs] def UnknownVariables(self) -> dict:
""" Returns unknown variables.
Identifies options that were not known, declared options in this object.
"""
return self.unknown
[docs] def Save(self, filename, env) -> None:
""" Save the options to a file.
Saves all the options which have non-default settings
to the given file as Python expressions. This file can
then be used to load the options for a subsequent run.
This can be used to create an option cache file.
Args:
filename: Name of the file to save into
env: the environment get the option values from
"""
# Create the file and write out the header
try:
with open(filename, 'w') as fh:
# Make an assignment in the file for each option
# within the environment that was assigned a value
# other than the default. We don't want to save the
# ones set to default: in case the SConscript settings
# change you would then pick up old defaults.
for option in self.options:
try:
value = env[option.key]
try:
prepare = value.prepare_to_store
except AttributeError:
try:
eval(repr(value))
except KeyboardInterrupt:
raise
except:
# Convert stuff that has a repr() that
# cannot be evaluated into a string
value = SCons.Util.to_String(value)
else:
value = prepare()
defaultVal = env.subst(SCons.Util.to_String(option.default))
if option.converter:
try:
defaultVal = option.converter(defaultVal)
except TypeError:
defaultVal = option.converter(defaultVal, env)
if str(env.subst('${%s}' % option.key)) != str(defaultVal):
fh.write('%s = %s\n' % (option.key, repr(value)))
except KeyError:
pass
except IOError as x:
raise SCons.Errors.UserError('Error writing options to file: %s\n%s' % (filename, x))
[docs] def GenerateHelpText(self, env, sort=None) -> str:
""" Generate the help text for the options.
Args:
env: an environment that is used to get the current values
of the options.
cmp: Either a comparison function used for sorting
(must take two arguments and return -1, 0 or 1)
or a boolean to indicate if it should be sorted.
"""
if callable(sort):
options = sorted(self.options, key=cmp_to_key(lambda x, y: sort(x.key, y.key)))
elif sort is True:
options = sorted(self.options, key=lambda x: x.key)
else:
options = self.options
def format_opt(opt, self=self, env=env) -> str:
if opt.key in env:
actual = env.subst('${%s}' % opt.key)
else:
actual = None
return self.FormatVariableHelpText(env, opt.key, opt.help, opt.default, actual, opt.aliases)
lines = [_f for _f in map(format_opt, options) if _f]
return ''.join(lines)
fmt = '\n%s: %s\n default: %s\n actual: %s\n'
aliasfmt = '\n%s: %s\n default: %s\n actual: %s\n aliases: %s\n'
[docs] def FormatVariableHelpText(self, env, key, help, default, actual, aliases=None) -> str:
if aliases is None:
aliases = []
# Don't display the key name itself as an alias.
aliases = [a for a in aliases if a != key]
if aliases:
return self.aliasfmt % (key, help, default, actual, aliases)
else:
return self.fmt % (key, help, default, actual)
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