configs/common/SysPaths.py

   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 import os, sys
  30
  31 config_path = os.path.dirname(os.path.abspath(__file__))
  32 config_root = os.path.dirname(config_path)
  33
  34 class 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
  69 disk = PathSearchFunc('disks')
  70 binary = PathSearchFunc('binaries')
  71 script = PathSearchFunc('boot', sys_paths=[config_root])