Source code for SCons.Variables

"""SCons.Variables

This file defines the Variables class that is used to add user-friendly
customizable variables to an SCons build.
"""

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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): 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 = key[1:] else: option.key = key option.aliases = [ 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 list(option.aliases) + [ option.key ]: if alias in self.unknown: del self.unknown[alias]
[docs] def keys(self): """ Returns the keywords for the options """ return [o.key for o in self.options]
[docs] def Add(self, key, help="", default=None, validator=None, converter=None, **kw): """Add an option. Args: key: the name of the variable, or a list or tuple of 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) \*\*kw: keyword args, unused. """ if SCons.Util.is_List(key) or isinstance(key, tuple): self._do_add(*key) return if not SCons.Util.is_String(key) or \ not SCons.Environment.is_valid_construction_var(key): raise SCons.Errors.UserError("Illegal Variables.Add() key `%s'" % str(key)) self._do_add(key, help, default, validator, converter)
[docs] def AddVariables(self, *optlist): """ 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): """ Update an environment with the option variables. env - the environment to update. """ 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 list(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 # Call the convert functions: for option in self.options: if option.converter and option.key in values: value = env.subst('${%s}'%option.key) try: try: env[option.key] = option.converter(value) except TypeError: env[option.key] = option.converter(value, env) except ValueError as x: raise SCons.Errors.UserError('Error converting option: %s\n%s'%(option.key, x)) # Finally validate the values: for option in self.options: if option.validator and option.key in values: option.validator(option.key, env.subst('${%s}'%option.key), env)
[docs] def UnknownVariables(self): """ Returns any options in the specified arguments lists that were not known, declared options in this object. """ return self.unknown
[docs] def Save(self, filename, env): """ Saves all the options in the given file. This file can then be used to load the options next run. This can be used to create an option cache file. 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: fh = open(filename, 'w') try: # Make an assignment in the file for each option # within the environment that was assigned a value # other than the default. 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: defaultVal = option.converter(defaultVal) if str(env.subst('${%s}' % option.key)) != str(defaultVal): fh.write('%s = %s\n' % (option.key, repr(value))) except KeyError: pass finally: fh.close() except IOError as x: raise SCons.Errors.UserError('Error writing options to file: %s\n%s' % (filename, x))
[docs] def GenerateHelpText(self, env, sort=None): """ Generate the help text for the options. env - an environment that is used to get the current values of the options. cmp - Either a function as follows: The specific sort function should take two arguments and return -1, 0 or 1 or a boolean to indicate if it should be sorted. """ if callable(sort): options = sorted(self.options, key=cmp_to_key(lambda x,y: sort(x.key,y.key))) elif sort is True: options = sorted(self.options, key=lambda x: x.key) else: options = self.options def format(opt, self=self, env=env): if opt.key in env: actual = env.subst('${%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, options) if _f] return ''.join(lines)
format = '\n%s: %s\n default: %s\n actual: %s\n' format_ = '\n%s: %s\n default: %s\n actual: %s\n aliases: %s\n'
[docs] def FormatVariableHelpText(self, env, key, help, default, actual, aliases=[]): # Don't display the key name itself as an alias. aliases = [a for a in aliases if a != key] if len(aliases)==0: return self.format % (key, help, default, actual) else: return self.format_ % (key, help, default, actual, aliases)
# Local Variables: # tab-width:4 # indent-tabs-mode:nil # End: # vim: set expandtab tabstop=4 shiftwidth=4: