Allow custom formatting of session log file names.

Differential Revision: http://reviews.llvm.org/D20306

llvm-svn: 269793
diff --git a/lldb/packages/Python/lldbsuite/test/dotest_args.py b/lldb/packages/Python/lldbsuite/test/dotest_args.py
index 105156d..8bbc29c 100644
--- a/lldb/packages/Python/lldbsuite/test/dotest_args.py
+++ b/lldb/packages/Python/lldbsuite/test/dotest_args.py
@@ -11,6 +11,7 @@
 # Third-party modules
 
 # LLDB modules
+from . import configuration
 
 class ArgParseNamespace(object):
     pass
@@ -70,6 +71,7 @@
     group.add_argument('--framework', metavar='framework-path', help='The path to LLDB.framework')
     group.add_argument('--executable', metavar='executable-path', help='The path to the lldb executable')
     group.add_argument('-s', metavar='name', help='Specify the name of the dir created to store the session files of tests with errored or failed status. If not specified, the test driver uses the timestamp as the session dir name')
+    group.add_argument('-S', '--session-file-format', default=configuration.session_file_format, metavar='format', help='Specify session file name format.  See configuration.py for a description.')
     group.add_argument('-y', type=int, metavar='count', help="Specify the iteration count used to collect our benchmarks. An example is the number of times to do 'thread step-over' to measure stepping speed.")
     group.add_argument('-#', type=int, metavar='sharp', dest='sharp', help='Repeat the test suite for a specified number of times')
     group.add_argument('--channel', metavar='channel', dest='channels', action='append', help=textwrap.dedent("Specify the log channels (and optional categories) e.g. 'lldb all' or 'gdb-remote packets' if no categories are specified, 'default' is used"))