Add git cl split.
`git cl split` splits a branch into smaller branches and
uploads CLs.
Change-Id: Ic41cdabdd6241008ff48766e31a8d9d07995f2b0
Reviewed-on: https://chromium-review.googlesource.com/439706
Commit-Queue: Francois Pierre Doray <fdoray@chromium.org>
Reviewed-by: Aaron Gable <agable@chromium.org>
diff --git a/split_cl.py b/split_cl.py
new file mode 100644
index 0000000..7785cb8
--- /dev/null
+++ b/split_cl.py
@@ -0,0 +1,192 @@
+#!/usr/bin/env python
+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Splits a branch into smaller branches and uploads CLs."""
+
+import collections
+import os
+import re
+import subprocess2
+import sys
+import tempfile
+
+import git_footers
+import owners
+import owners_finder
+
+import git_common as git
+
+
+def ReadFile(file_path):
+ """Returns the content of |file_path|."""
+ with open(file_path) as f:
+ content = f.read()
+ return content
+
+
+def EnsureInGitRepository():
+ """Throws an exception if the current directory is not a git repository."""
+ git.run('rev-parse')
+
+
+def CreateBranchForDirectory(prefix, directory, upstream):
+ """Creates a branch named |prefix| + "_" + |directory| + "_split".
+
+ Return false if the branch already exists. |upstream| is used as upstream for
+ the created branch.
+ """
+ existing_branches = set(git.branches(use_limit = False))
+ branch_name = prefix + '_' + directory + '_split'
+ if branch_name in existing_branches:
+ return False
+ git.run('checkout', '-t', upstream, '-b', branch_name)
+ return True
+
+
+def FormatDescriptionOrComment(txt, directory):
+ """Replaces $directory with |directory| in |txt|."""
+ return txt.replace('$directory', '/' + directory)
+
+
+def AddUploadedByGitClSplitToDescription(description):
+ """Adds a 'This CL was uploaded by git cl split.' line to |description|.
+
+ The line is added before footers, or at the end of |description| if it has no
+ footers.
+ """
+ split_footers = git_footers.split_footers(description)
+ lines = split_footers[0]
+ if not lines[-1] or lines[-1].isspace():
+ lines = lines + ['']
+ lines = lines + ['This CL was uploaded by git cl split.']
+ if split_footers[1]:
+ lines += [''] + split_footers[1]
+ return '\n'.join(lines)
+
+
+def UploadCl(refactor_branch, refactor_branch_upstream, directory, files,
+ author, description, comment, owners_database, changelist,
+ cmd_upload):
+ """Uploads a CL with all changes to |files| in |refactor_branch|.
+
+ Args:
+ refactor_branch: Name of the branch that contains the changes to upload.
+ refactor_branch_upstream: Name of the upstream of |refactor_branch|.
+ directory: Path to the directory that contains the OWNERS file for which
+ to upload a CL.
+ files: List of AffectedFile instances to include in the uploaded CL.
+ author: Email address of the user running this script.
+ description: Description of the uploaded CL.
+ comment: Comment to post on the uploaded CL.
+ owners_database: An owners.Database instance.
+ changelist: The Changelist class.
+ cmd_upload: The function associated with the git cl upload command.
+ """
+
+ # Create a branch.
+ if not CreateBranchForDirectory(
+ refactor_branch, directory, refactor_branch_upstream):
+ print 'Skipping ' + directory + ' for which a branch already exists.'
+ return
+
+ # Checkout all changes to files in |files|.
+ deleted_files = [f.AbsoluteLocalPath() for f in files if f.Action() == 'D']
+ if deleted_files:
+ git.run(*['rm'] + deleted_files)
+ modified_files = [f.AbsoluteLocalPath() for f in files if f.Action() != 'D']
+ if modified_files:
+ git.run(*['checkout', refactor_branch, '--'] + modified_files)
+
+ # Commit changes. The temporary file is created with delete=False so that it
+ # can be deleted manually after git has read it rather than automatically
+ # when it is closed.
+ with tempfile.NamedTemporaryFile(delete=False) as tmp_file:
+ tmp_file.write(FormatDescriptionOrComment(description, directory))
+ # Close the file to let git open it at the next line.
+ tmp_file.close()
+ git.run('commit', '-F', tmp_file.name)
+ os.remove(tmp_file.name)
+
+ # Upload a CL.
+ reviewers = owners_database.reviewers_for(
+ [f.LocalPath() for f in files], author)
+ upload_args = ['-f', '--cq-dry-run', '-r', ','.join(reviewers)]
+ if not comment:
+ upload_args.append('--send-email')
+ print 'Uploading CL for ' + directory + '.'
+ cmd_upload(upload_args)
+ if comment:
+ changelist().AddComment(FormatDescriptionOrComment(comment, directory))
+
+
+def GetFilesSplitByOwners(owners_database, files):
+ """Returns a map of files split by OWNERS file.
+
+ Returns:
+ A map where keys are paths to directories containing an OWNERS file and
+ values are lists of files sharing an OWNERS file.
+ """
+ files_split_by_owners = collections.defaultdict(list)
+ for f in files:
+ files_split_by_owners[owners_database.enclosing_dir_with_owners(
+ f.LocalPath())].append(f)
+ return files_split_by_owners
+
+
+def SplitCl(description_file, comment_file, changelist, cmd_upload):
+ """"Splits a branch into smaller branches and uploads CLs.
+
+ Args:
+ description_file: File containing the description of uploaded CLs.
+ comment_file: File containing the comment of uploaded CLs.
+ changelist: The Changelist class.
+ cmd_upload: The function associated with the git cl upload command.
+
+ Returns:
+ 0 in case of success. 1 in case of error.
+ """
+ description = AddUploadedByGitClSplitToDescription(ReadFile(description_file))
+ comment = ReadFile(comment_file) if comment_file else None
+
+ try:
+ EnsureInGitRepository();
+
+ cl = changelist()
+ change = cl.GetChange(cl.GetCommonAncestorWithUpstream(), None)
+ files = change.AffectedFiles()
+
+ if not files:
+ print 'Cannot split an empty CL.'
+ return 1
+
+ author = git.run('config', 'user.email').strip() or None
+ refactor_branch = git.current_branch()
+ refactor_branch_upstream = git.upstream(refactor_branch)
+
+ owners_database = owners.Database(change.RepositoryRoot(), file, os.path)
+ owners_database.load_data_needed_for([f.LocalPath() for f in files])
+
+ files_split_by_owners = GetFilesSplitByOwners(
+ owners_database, files)
+
+ print ('Will split current branch (' + refactor_branch +') in ' +
+ str(len(files_split_by_owners)) + ' CLs.\n')
+
+ for directory, files in files_split_by_owners.iteritems():
+ # Use '/' as a path separator in the branch name and the CL description
+ # and comment.
+ directory = directory.replace(os.path.sep, '/')
+ # Upload the CL.
+ UploadCl(refactor_branch, refactor_branch_upstream, directory, files,
+ author, description, comment, owners_database, changelist,
+ cmd_upload)
+
+ # Go back to the original branch.
+ git.run('checkout', refactor_branch)
+
+ except subprocess2.CalledProcessError as cpe:
+ sys.stderr.write(cpe.stderr)
+ return 1
+ return 0