SysPaths.py revision 12254:e4b3baf80eb4 
1# Copyright (c) 2006 The Regents of The University of Michigan
2# All rights reserved.
3#
4# Redistribution and use in source and binary forms, with or without
5# modification, are permitted provided that the following conditions are
6# met: redistributions of source code must retain the above copyright
7# notice, this list of conditions and the following disclaimer;
8# redistributions in binary form must reproduce the above copyright
9# notice, this list of conditions and the following disclaimer in the
10# documentation and/or other materials provided with the distribution;
11# neither the name of the copyright holders nor the names of its
12# contributors may be used to endorse or promote products derived from
13# this software without specific prior written permission.
14#
15# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
18# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
19# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
21# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26#
27# Authors: Ali Saidi
28
29import os, sys
30
31config_path = os.path.dirname(os.path.abspath(__file__))
32config_root = os.path.dirname(config_path)
33
34class PathSearchFunc(object):
35    _sys_paths = None
36
37    def __init__(self, subdirs, sys_paths=None):
38        if isinstance(subdirs, basestring):
39            subdirs = [subdirs]
40        self._subdir = os.path.join(*subdirs)
41        if sys_paths:
42            self._sys_paths = sys_paths
43
44    def __call__(self, filename):
45        if self._sys_paths is None:
46            try:
47                paths = os.environ['M5_PATH'].split(':')
48            except KeyError:
49                paths = [ '/dist/m5/system', '/n/poolfs/z/dist/m5/system' ]
50
51            # expand '~' and '~user' in paths
52            paths = map(os.path.expanduser, paths)
53
54            # filter out non-existent directories
55            paths = filter(os.path.isdir, paths)
56
57            if not paths:
58                raise IOError, "Can't find a path to system files."
59
60            self._sys_paths = paths
61
62        filepath = os.path.join(self._subdir, filename)
63        paths = (os.path.join(p, filepath) for p in self._sys_paths)
64        try:
65            return next(p for p in paths if os.path.exists(p))
66        except StopIteration:
67            raise IOError, "Can't find file '%s' on path." % filename
68
69disk = PathSearchFunc('disks')
70binary = PathSearchFunc('binaries')
71script = PathSearchFunc('boot', sys_paths=[config_root])
72