Fix handling of --version in lit

There's no reason why we should require a directory when asking for the version.

Differential Revision: https://reviews.llvm.org/D74553

Author: serge-sans-paille

llvm/utils/lit/lit/cl_arguments.py

@@ -15,7 +15,9 @@ def parse_args():
     parser.add_argument("--version",
             dest="show_version",
             help="Show version and exit",
-            action="store_true")
+            version="lit " + lit.__version__,
+            action="version")
+
     parser.add_argument("-j", "--threads", "--workers",
             dest="workers",
             metavar="N",

llvm/utils/lit/lit/main.py

@@ -21,10 +21,6 @@
 def main(builtin_params={}):
     opts = lit.cl_arguments.parse_args()
 
-    if opts.show_version:
-        print("lit %s" % lit.__version__)
-        return
-
     params = create_params(builtin_params, opts.user_params)
     is_windows = platform.system() == 'Windows'
 

llvm/utils/lit/tests/version.py

@@ -0,0 +1,5 @@
+# Basic sanity check that --version works.
+#
+# RUN: %{lit} --version | FileCheck %s
+#
+# CHECK: lit {{[0-9]+\.[0-9]+\.[0-9]+[a-zA-Z0-9]*}}