configs: allow fs.py and fs_bigLITTLE.py to work without M5_PATH
The requirement to have an environment variable exported to run a program
is not common, and many new users trip up on it.
Before this commit, M5_PATH was a requirement to run those scripts, or
else simulation would fail with:
IOError: Can't find a path to system files.
After this patch, as long as users indicate all required files with
command line options, M5_PATH is not needed.
This patch changes the M5_PATH semantics slightly to more closely match
PATH and so be more intuitive to users: after this commit, if the
given path contains a slash /, then the path is not searched for inside
M5_PATH, which is exactly how PATH works. Users can then select images
in the CWD with a leading ./ just as done for executables.
This is backwards incompatible if users were already specifying their paths
as ./, but this interface feels saner, because otherwise writing on the CLI
e.g.:
--disk-image path/to/my.disk
would previously fail to find the disk, even if it existed, which is very
counter-intuitive. The following will still fail however:
--disk-image my.disk
which is not ideal, but for now is a comprise between backwards
compatibility of having an M5_PATH and what users expect from CLI
interfaces.
Change-Id: Ic91e1cc20557b35b69490b6dc420e7d324fae1fc
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23672
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/configs/common/SysPaths.py b/configs/common/SysPaths.py
index e5d9f83..0a67789 100644
--- a/configs/common/SysPaths.py
+++ b/configs/common/SysPaths.py
@@ -37,6 +37,7 @@
class PathSearchFunc(object):
_sys_paths = None
+ environment_variable = 'M5_PATH'
def __init__(self, subdirs, sys_paths=None):
if isinstance(subdirs, string_types):
@@ -46,29 +47,36 @@
self._sys_paths = sys_paths
def __call__(self, filename):
- if self._sys_paths is None:
+ if os.sep in filename:
+ return filename
+ else:
+ if self._sys_paths is None:
+ try:
+ paths = os.environ[self.environment_variable].split(':')
+ except KeyError:
+ paths = [ '/dist/m5/system', '/n/poolfs/z/dist/m5/system' ]
+
+ # expand '~' and '~user' in paths
+ paths = map(os.path.expanduser, paths)
+
+ # filter out non-existent directories
+ paths = filter(os.path.isdir, paths)
+
+ if not paths:
+ raise IOError(
+ "Can't find system files directory, "
+ "check your {} environment variable"
+ .format(self.environment_variable))
+
+ self._sys_paths = list(paths)
+
+ filepath = os.path.join(self._subdir, filename)
+ paths = (os.path.join(p, filepath) for p in self._sys_paths)
try:
- paths = os.environ['M5_PATH'].split(':')
- except KeyError:
- paths = [ '/dist/m5/system', '/n/poolfs/z/dist/m5/system' ]
-
- # expand '~' and '~user' in paths
- paths = map(os.path.expanduser, paths)
-
- # filter out non-existent directories
- paths = filter(os.path.isdir, paths)
-
- if not paths:
- raise IOError("Can't find a path to system files.")
-
- self._sys_paths = list(paths)
-
- filepath = os.path.join(self._subdir, filename)
- paths = (os.path.join(p, filepath) for p in self._sys_paths)
- try:
- return next(p for p in paths if os.path.exists(p))
- except StopIteration:
- raise IOError("Can't find file '%s' on path." % filename)
+ return next(p for p in paths if os.path.exists(p))
+ except StopIteration:
+ raise IOError("Can't find file '{}' on {}."
+ .format(filename, self.environment_variable))
disk = PathSearchFunc('disks')
binary = PathSearchFunc('binaries')
