Bug 1507007 - Add a clang-format hook r=ahal,Ehsan

Differential Revision: https://phabricator.services.mozilla.com/D13711

--HG--
extra : moz-landing-system : lando

tools/lint/hooks_clang_format.py

@@ -0,0 +1,48 @@
+#!/usr/bin/env python
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+import subprocess
+import sys
+
+
+here = os.path.dirname(os.path.realpath(__file__))
+topsrcdir = os.path.join(here, os.pardir, os.pardir)
+
+
+def run_clang_format(hooktype, changedFiles, args):
+    arguments = ['clang-format', '-s', '-p'] + changedFiles
+    # On windows we need this to call the command in a shell, see Bug 1511594
+    if os.name == 'nt':
+        clang_format_cmd = ['sh', 'mach'] + arguments
+    else:
+        clang_format_cmd = [os.path.join(topsrcdir, "mach")] + arguments
+    if 'commit' in hooktype:
+        # don't prevent commits, just display the clang-format results
+        subprocess.Popen(clang_format_cmd)
+        return False
+
+    print("warning: '{}' is not a valid clang-format hooktype".format(hooktype))
+    return False
+
+
+def hg(ui, repo, node, **kwargs):
+    changedFiles = [os.path.join(repo.root, file) for file in repo[node].changeset()[3]]
+    if not changedFiles:
+        # No files have been touched
+        return
+    hooktype = kwargs['hooktype']
+    return run_clang_format(hooktype, changedFiles, kwargs.get('pats', []))
+
+
+def git():
+    hooktype = os.path.basename(__file__)
+    if hooktype == 'hooks_clang_format.py':
+        hooktype = 'pre-push'
+    return run_clang_format(hooktype, [])
+
+
+if __name__ == '__main__':
+    sys.exit(git())