git-llvm: Add option to push to Github with SSH

[vchuravy]

Summary

For users with 2FA Github password challenge can be rather cumbersome
and I personally use key based authentication through SSH. This fixes
the SSH feature that was present and exposes it as a command line
option.

[merge_guards_bot]

Unit tests: pass. 60933 tests passed, 0 failed and 726 were skipped.

clang-format: pass.

Build artifacts: console-log.txt, CMakeCache.txt, test-results.xml, diff.json

[tstellar]

LGTM.

llvm/utils/git-svn/git-llvm

 
 def get_fetch_url():
     return 'https://{}'.format(GIT_URL)
 
 
 def get_push_url(user='', ssh=False):
 
     if ssh:
-        return 'ssh://{}'.format(GIT_URL)
+        return 'ssh://git@{}'.format(GIT_URL)
 
     return 'https://{}'.format(GIT_URL)
 
 
 def get_revs_to_push(branch):
     # Fetch the latest upstream to determine which commits will be pushed.
     git('fetch', get_fetch_url(), branch)
 
     commits = git('rev-list', '--ancestry-path', 'FETCH_HEAD..HEAD').splitlines()
     # Reverse the order so we commit the oldest commit first
     commits.reverse()
     return commits
 
 
-def git_push_one_rev(rev, dry_run, branch):
+def git_push_one_rev(rev, dry_run, branch, ssh):
     # Check if this a merge commit by counting the number of parent commits.
     # More than 1 parent commmit means this is a merge.
     num_parents = len(git('show', '--no-patch', '--format="%P"', rev).split())
 
     if num_parents > 1:
         raise Exception("Merge commit detected, cannot push ", rev)
 
     if num_parents != 1:
         raise Exception("Error detecting number of parents for ", rev)
 
     if dry_run:
         print("[DryRun] Would push", rev)
         return
 
     # Second push to actually push the commit
-    git('push', get_push_url(), '{}:{}'.format(rev, branch), print_raw_stderr=True)
+    git('push', get_push_url(ssh=ssh), '{}:{}'.format(rev, branch), print_raw_stderr=True)
 
 
 def cmd_push(args):
     '''Push changes to git:'''
     dry_run = args.dry_run
 
     revs = get_revs_to_push(args.branch)
 
     if not revs:
         die('Nothing to push')
 
     log('%sPushing %d commit%s:\n%s' %
         ('[DryRun] ' if dry_run else '', len(revs),
          's' if len(revs) != 1 else '',
          '\n'.join('  ' + git('show', '--oneline', '--quiet', c)
                    for c in revs)))
 
     # Ask confirmation if multiple commits are about to be pushed
     if not args.force and len(revs) > 1:
         if not ask_confirm("Are you sure you want to create %d commits?" % len(revs)):
             die("Aborting")
 
     for r in revs:
-        git_push_one_rev(r, dry_run, args.branch)
+        git_push_one_rev(r, dry_run, args.branch, args.ssh)
 
 
 if __name__ == '__main__':
     if not program_exists('git'):
         die('error: git-llvm needs git command, but git is not installed.')
 
     argv = sys.argv[1:]
     p = argparse.ArgumentParser(
parser_push.add_argument(
         '-n',
         '--dry-run',
         dest='dry_run',
         action='store_true',
         help='Do everything other than commit to svn.  Leaves junk in the svn '
         'repo, so probably will not work well if you try to commit more '
         'than one rev.')
     parser_push.add_argument(
+        '-s',
+        '--ssh',
+        dest='ssh',
+        action='store_true',
+        help='Use the SSH protocol for authentication, '
+        'instead of HTTPS with username and password.')
+    parser_push.add_argument(
         '-f',
         '--force',
         action='store_true',
         help='Do not ask for confirmation when pushing multiple commits.')
     parser_push.add_argument(
         'branch',
         metavar='GIT_BRANCH',
         type=str,