SysPaths.py revision 13731:67cd980cb20f 
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
29
30from six import string_types
31import os, sys
32
33config_path = os.path.dirname(os.path.abspath(__file__))
34config_root = os.path.dirname(config_path)
35
36class PathSearchFunc(object):
37    _sys_paths = None
38
39    def __init__(self, subdirs, sys_paths=None):
40        if isinstance(subdirs, string_types):
41            subdirs = [subdirs]
42        self._subdir = os.path.join(*subdirs)
43        if sys_paths:
44            self._sys_paths = sys_paths
45
46    def __call__(self, filename):
47        if self._sys_paths is None:
48            try:
49                paths = os.environ['M5_PATH'].split(':')
50            except KeyError:
51                paths = [ '/dist/m5/system', '/n/poolfs/z/dist/m5/system' ]
52
53            # expand '~' and '~user' in paths
54            paths = map(os.path.expanduser, paths)
55
56            # filter out non-existent directories
57            paths = filter(os.path.isdir, paths)
58
59            if not paths:
60                raise IOError("Can't find a path to system files.")
61
62            self._sys_paths = list(paths)
63
64        filepath = os.path.join(self._subdir, filename)
65        paths = (os.path.join(p, filepath) for p in self._sys_paths)
66        try:
67            return next(p for p in paths if os.path.exists(p))
68        except StopIteration:
69            raise IOError("Can't find file '%s' on path." % filename)
70
71disk = PathSearchFunc('disks')
72binary = PathSearchFunc('binaries')
73script = PathSearchFunc('boot', sys_paths=[config_root])
74