Allow conditional lit tests in Subzero, based on build flags.

pydir/ifatts.py

+#!/usr/bin/env python2
+
+import argparse
+import os
+import sys
+
+from utils import shellcmd
+
+def GetFileAttributes(Filename):
+  """Returns the set of names contained in file named Filename.
+  """
+  if not os.path.isfile(Filename):
+    raise RuntimeError("Can't open: %s" % Filename)
+  with open(Filename, 'r') as f:
+    return f.read().split()
+
+def HasFileAttributes(Filename, Attributes):
+  """Returns true if the set of names in Attributes also appear
+     in the set of names contained in file named Filename.
+  """
+  return set(Attributes) <= set(GetFileAttributes(Filename))
+
+def main():
+  """Run the specified command only if attributes are defined.
+
+     Check if the fset of attributes (i.e. names), contained in FILE,
+     contains the attributes defined by --att=ATTRIBUTE arguments. If
+     so, runs in a shell the command defined by the remaining
+     arguments.
+  """
+  argparser = argparse.ArgumentParser(
+    description='    ' + main.__doc__,
+    formatter_class=argparse.ArgumentDefaultsHelpFormatter)
+  argparser.add_argument('file', metavar='FILE',
+                         help='File defining attributes to check against.')
+  argparser.add_argument('--att', required=False, default=[],
+                         action='append', metavar='ATTRIBUTE',
+                         help='Attribute to check. May be repeated.')
+  argparser.add_argument('--echo-cmd', required=False,
+                         action='store_true',
+                         help='Trace the command before running.')
+  argparser.add_argument('--command', nargs=argparse.REMAINDER,
+                         help='Command to run if attributes found.')
+
+  args = argparser.parse_args()
+
+  # Quit early if no command to run.
+  if not args.command:
+    raise RuntimeError("No command argument(s) specified for ifatts")
+
+  if HasFileAttributes(args.file, args.att):
+    stdout_result = shellcmd(args.command, echo=args.echo_cmd)
+    if not args.echo_cmd:
+      sys.stdout.write(stdout_result)
+
+if __name__ == '__main__':
+  main()
+  sys.exit(0)