Adding 'git cl format' command for clang-format.

git_cl.py

Index: git_cl.py
diff --git a/git_cl.py b/git_cl.py
index 4e89e065e73a1d8a2b292a8b3361f0d50a6006ba..a0204785fc50326863721eced457084997a0dfc5 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -1923,6 +1923,34 @@ def CMDset_close(parser, args):
   return 0
 
 
+def CMDformat(parser, args):
+  """run clang-format on the diff"""
+  parser.add_option('--full', action='store_true', default=False)

[Greg Spencer (Chromium), 2013/05/02 18:20:11]

It might be nice to be able to specify specific files to do this to, where it
just formats the files you asked it to.

Seems like it should take a list of filenames as well, and intersect that list
with the diff output.  Probably the best way to do that is just append them
after a "--" to the diff command args.

[M-A Ruel, 2013/05/02 20:38:43]

Then, this doesn't belong to git-cl. git-cl is not a one-stop place to put all
possible features.

[agable, 2013/05/02 20:50:17]

Agreed with maruel@ here. If we want an easy command to run clang-format on
arbitrary files, that can go elsewhere. This is intended to run just on what
you've changed in your feature branch.

+  opts, args = parser.parse_args(args)
+  if args:
+    parser.error('Unrecognized args: %s' % ' '.join(args))
+  if opts.full:
+    diff = RunGit(['diff', '--name-only']).split()

[M-A Ruel, 2013/05/02 20:38:43]

I'd suggest you to list the valid extensions at the top of this file, then:

cmd.append('--')
cmd.extend('*.' + i for i in EXTENSIONS)

Then you don't have to filter afterward.

[agable, 2013/05/02 20:50:17]

I put CLANG_EXTS at the top of this function, not the file, because nothing else
in the file is clang-specific. Other than that, done, since not wasting the time
to diff non-clang files is a good idea.

+    files = [name for name in diff if
+             any([name.endswith(ext) for ext in ['.cc', '.cpp', '.h']])]
+    if not files:
+      print "Nothing to format."
+      return 0
+    cmd = ['clang-format', '-i'] + diff
+    RunCommand(cmd)
+  else:
+    diff = RunGit(['diff', '-U0', '@{u}'])

[M-A Ruel, 2013/05/02 20:38:43]

Same with filtering on the file names

+    cfd_path = os.path.join('/usr', 'lib', 'clang-format',
+                            'clang-format-diff.py')
+    if not os.path.exists(cfd_path):
+      print >> sys.stderr, 'Could not find clang-format-diff at %s.' % cfd_path
+      return 2
+    cmd = [sys.executable, '/usr/lib/clang-format/clang-format-diff.py',
+           '-style', 'Chromium']
+    RunCommand(cmd, stdin=diff)
+  return 0
+
+
 def Command(name):
   return getattr(sys.modules[__name__], 'CMD' + name, None)