[util] Add check to git-llvm to avoid pushing to a non-trunk branch

[aykevl]

Summary

To prevent pushing to a release branch by accident, for example. This happened to me in https://reviews.llvm.org/D66379 and I'd like to make sure this doesn't happen again - at least for newer LLVM releases.

The cause was most likely that my git-llvm binary was pointing to a checkout that used to be at master but was switched to release_80, which meant that while I pushed from the master branch, it was actually pushing to release_80 due to the wrong version of git-llvm.

[hans]

I don't really know this script. I think Mehdi or James might be better reviewers.

[xbolva00]

LLVM_MONOREPO_DIR = '/trunk'

Can this be a option (default setting: trunk) ?

[aykevl]

I don't think this is relevant anymore with the move to git.

llvm/utils/git-svn/git-llvm

 
 try:
     # Python 3
     from shlex import quote
 except ImportError:
     # Python 2
     from pipes import quote
 
+LLVM_MONOREPO_DIR = '/trunk'
+
 # It's *almost* a straightforward mapping from the monorepo to svn...
 LLVM_MONOREPO_SVN_MAPPING = {
-    d: (d + '/trunk')
+    d: (d + LLVM_MONOREPO_DIR)
     for d in [
         'clang-tools-extra',
         'compiler-rt',
         'debuginfo-tests',
         'dragonegg',
         'klee',
         'libclc',
         'libcxx',
         'libcxxabi',
         'libunwind',
         'lld',
         'lldb',
         'llgo',
         'llvm',
         'openmp',
         'parallel-libs',
         'polly',
         'pstl',
     ]
 }
-LLVM_MONOREPO_SVN_MAPPING.update({'clang': 'cfe/trunk'})
-LLVM_MONOREPO_SVN_MAPPING.update({'': 'monorepo-root/trunk'})
+LLVM_MONOREPO_SVN_MAPPING.update({'clang': 'cfe' + LLVM_MONOREPO_DIR})
+LLVM_MONOREPO_SVN_MAPPING.update({'': 'monorepo-root' + LLVM_MONOREPO_DIR})
 
-SPLIT_REPO_NAMES = {'llvm-' + d: d + '/trunk'
+SPLIT_REPO_NAMES = {'llvm-' + d: d + LLVM_MONOREPO_DIR
                     for d in ['www', 'zorg', 'test-suite', 'lnt']}
 
 VERBOSE = False
 QUIET = False
 dev_null_fd = None
 
 
 def eprint(*args, **kwargs):

 
 def cmd_push(args):
     '''Push changes back to SVN: this is extracted from Justin Lebar's script
     available here: https://github.com/jlebar/llvm-repo-tools/
 
     Note: a current limitation is that git does not track file rename, so they
     will show up in SVN as delete+add.
     '''
+
+    # Check for the branch.
+    if LLVM_MONOREPO_DIR != '/trunk' and not args.force_branch:
+        die("Branch is not trunk (specify --force-branch to override)")
+
     # Get the git root
     git_root = git('rev-parse', '--show-toplevel')
     if not os.path.isdir(git_root):
         die("Can't find git root dir")
 
     # Push from the root of the git repo
     os.chdir(git_root)
 
def git_hash_by_svn_rev(svn_rev):
     return matching_hashes[0]
 
 
 def cmd_revert(args):
     '''Revert a commit by either SVN id (rNNNNNN) or git hash. This also
     populates the git commit message with both the SVN revision and git hash of
     the change being reverted.'''
 
+    # Check for the branch.
+    if LLVM_MONOREPO_DIR != '/trunk' and not args.force_branch:
+        die("Branch is not trunk (specify --force-branch to override)")
+
     # Get the git root
     git_root = git('rev-parse', '--show-toplevel')
     if not os.path.isdir(git_root):
         die("Can't find git root dir")
 
     # Run commands from the root
     os.chdir(git_root)
 
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(
+        '--force-branch',
+        dest='force_branch',
+        action='store_true',
+        help='Force pushing to a non-trunk branch.')
+    parser_push.add_argument(
         'rev_range',
         metavar='GIT_REVS',
         type=str,
         nargs='?',
         help="revs to push (default: everything not in the branch's "
         'upstream, or not in origin/master if the branch lacks '
         'an explicit upstream)')
     parser_push.set_defaults(func=cmd_push)
 
     parser_revert = subcommands.add_parser(
         'revert', description=cmd_revert.__doc__,
         help='Revert a commit locally.')
     parser_revert.add_argument(
         'revision',
         help='Revision to revert. Can either be an SVN revision number '
         "(rNNNNNN) or a git commit hash (anything that doesn't look "
         'like an SVN revision number).')
     parser_revert.add_argument(
         '-n',
         '--dry-run',
         dest='dry_run',
         action='store_true',
         help='Do everything other than perform a revert. Prints the git '
         'revert command it would have run.')
+    parser_revert.add_argument(
+        '--force-branch',
+        dest='force_branch',
+        action='store_true',
+        help='Force reverting a commit on a non-trunk branch.')
     parser_revert.set_defaults(func=cmd_revert)
 
     parser_svn_lookup = subcommands.add_parser(
         'svn-lookup', description=cmd_svn_lookup.__doc__,
         help='Find the llvm-svn revision for a given commit.')
     parser_svn_lookup.add_argument(
         'git_commit_hash',
         help='git_commit_hash for which we will look up the svn revision id.')