Support passing files/directories to git cl format

git_cl.py

Index: git_cl.py
diff --git a/git_cl.py b/git_cl.py
index d9e2d9803b0203d3203e61721d4e9b6fced0f616..b1cf7fa2695ad42fd316c3f0bfa158c0bf7c203b 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -2303,6 +2303,7 @@ def CMDowners(parser, args):
       disable_color=options.no_color).run()
 
 
+@subcommand.usage('[files or directories to diff]')
 def CMDformat(parser, args):
   """Runs clang-format on the diff."""
   CLANG_EXTS = ['.cc', '.cpp', '.h']
@@ -2311,8 +2312,6 @@ def CMDformat(parser, args):
   parser.add_option('--dry-run', action='store_true',
                     help='Don\'t modify any file on disk.')
   opts, args = parser.parse_args(args)
-  if args:
-    parser.error('Unrecognized args: %s' % ' '.join(args))
 
   # git diff generates paths against the root of the repository.  Change
   # to that directory so clang-format can find files even within subdirs.
@@ -2348,7 +2347,16 @@ def CMDformat(parser, args):
 
   # Handle source file filtering.
   diff_cmd.append('--')
-  diff_cmd += ['*' + ext for ext in CLANG_EXTS]
+  if args:
+    for arg in args:
+      if os.path.isdir(arg):
+        diff_cmd += [os.path.join(arg, '*' + ext) for ext in CLANG_EXTS]

[iannucci, 2014/01/29 06:06:03]

Is clang format interpreting these globs? Because we don't seem to be running
the command with a shell (unless RunCommand does that by default :(). It may
make sense to use the glob python module here to only pass fully-expanded stuff
on the command line, but if clang-format is expanding these then that's fine too
(if we're relying on the shell to do it, then that's less fine :)).

[enne (OOO), 2014/01/29 18:18:31]

According to
https://www.kernel.org/pub/software/scm/git/docs/gitglossary.html#def_pathspec,
"Paths relative to the directory prefix will be matched against that pattern
using fnmatch(3); in particular, * and ? can match directory separators."

So, I think git is the one interpreting these globs and not the shell or
clang-format.

+      elif os.path.isfile(arg):
+        diff_cmd.append(arg)
+      else:
+        DieWithError('Argument "%s" is not a file or a directory' % arg)
+  else:
+    diff_cmd += ['*' + ext for ext in CLANG_EXTS]
   diff_output = RunGit(diff_cmd)
 
   top_dir = os.path.normpath(