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#
# __COPYRIGHT__
#
# 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.
#

__doc__ = """
SCons compatibility package for old Python versions

This subpackage holds modules that provide backwards-compatible
implementations of various things that we'd like to use in SCons but which
only show up in later versions of Python than the early, old version(s)
we still support.

This package will be imported by other code:

    import SCons.compat

But other code will not generally reference things in this package through
the SCons.compat namespace.  The modules included here add things to
the __builtin__ namespace or the global module list so that the rest
of our code can use the objects and names imported here regardless of
Python version.

Simply enough, things that go in the __builtin__ name space come from
our builtins module.

The rest of the things here will be in individual compatibility modules
that are either: 1) suitably modified copies of the future modules that
we want to use; or 2) backwards compatible re-implementations of the
specific portions of a future module's API that we want to use.

GENERAL WARNINGS:  Implementations of functions in the SCons.compat
modules are *NOT* guaranteed to be fully compliant with these functions in
later versions of Python.  We are only concerned with adding functionality
that we actually use in SCons, so be wary if you lift this code for
other uses.  (That said, making these more nearly the same as later,
official versions is still a desirable goal, we just don't need to be
obsessive about it.)

We name the compatibility modules with an initial underscore (for
example, _subprocess.py is our compatibility module for subprocess)
so that we can still try to import the real module name and fall back
to our compatibility module if we get an ImportError.  The import_as()
function defined below loads the module as the "real" name (without the
underscore), after which all of the "import {module}" statements in the
rest of our code will find our pre-loaded compatibility module.
"""

__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"

def import_as(module, name):
    """
    Imports the specified module (from our local directory) as the
    specified name.
    """
    import imp
    import os.path
    dir = os.path.split(__file__)[0]
    file, filename, suffix_mode_type = imp.find_module(module, [dir])
    imp.load_module(name, file, filename, suffix_mode_type)

import builtins

try:
    import subprocess
except ImportError:
    # Pre-2.4 Python has no subprocess module.
    import_as('_subprocess', 'subprocess')

try:
    import UserString
except ImportError:
    # Pre-1.6 Python has no UserString module.
    import_as('_UserString', 'UserString')