llvm_tools: move common functions into standalone modules

Move common functions into separate modules and update dependencies
accordingly.

BUG=chromium:1057428

TEST=local tests.

Change-Id: I40f1b613f0a41f1fc478c811379c851479aff7c3
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/2151708
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: George Burgess <gbiv@chromium.org>
Tested-by: Jian Cai <jiancai@google.com>

1 files changed, 136 insertions, 0 deletions

diff --git a/llvm_tools/git.py b/llvm_tools/git.py
new file mode 100755
index 00000000..778d9695
--- /dev/null
+++ b/llvm_tools/git.py
@@ -0,0 +1,136 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+# Copyright 2020 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Git helper functions."""
+
+from __future__ import print_function
+
+import collections
+import os
+import re
+import subprocess
+import tempfile
+
+CommitContents = collections.namedtuple('CommitContents', ['url', 'cl_number'])
+
+
+def InChroot():
+  """Returns True if currently in the chroot."""
+  return 'CROS_WORKON_SRCROOT' in os.environ
+
+
+def VerifyOutsideChroot():
+  """Checks whether the script invoked was executed in the chroot.
+
+  Raises:
+    AssertionError: The script was run inside the chroot.
+  """
+
+  assert not InChroot(), 'Script should be run outside the chroot.'
+
+
+def CreateBranch(repo, branch):
+  """Creates a branch in the given repo.
+
+  Args:
+    repo: The absolute path to the repo.
+    branch: The name of the branch to create.
+
+  Raises:
+    ValueError: Failed to create a repo in that directory.
+  """
+
+  if not os.path.isdir(repo):
+    raise ValueError('Invalid directory path provided: %s' % repo)
+
+  subprocess.check_output(['git', '-C', repo, 'reset', 'HEAD', '--hard'],
+                          encoding='utf-8')
+
+  subprocess.check_output(['repo', 'start', branch], cwd=repo, encoding='utf-8')
+
+
+def DeleteBranch(repo, branch):
+  """Deletes a branch in the given repo.
+
+  Args:
+    repo: The absolute path of the repo.
+    branch: The name of the branch to delete.
+
+  Raises:
+    ValueError: Failed to delete the repo in that directory.
+  """
+
+  if not os.path.isdir(repo):
+    raise ValueError('Invalid directory path provided: %s' % repo)
+
+  subprocess.check_output(['git', '-C', repo, 'checkout', 'cros/master'],
+                          encoding='utf-8')
+
+  subprocess.check_output(['git', '-C', repo, 'reset', 'HEAD', '--hard'],
+                          encoding='utf-8')
+
+  subprocess.check_output(['git', '-C', repo, 'branch', '-D', branch],
+                          encoding='utf-8')
+
+
+def UploadChanges(repo, branch, commit_messages):
+  """Uploads the changes in the specifed branch of the given repo for review.
+
+  Args:
+    repo: The absolute path to the repo where changes were made.
+    branch: The name of the branch to upload.
+    commit_messages: A string of commit message(s) (i.e. '[message]'
+    of the changes made.
+
+  Returns:
+    A nametuple that has two (key, value) pairs, where the first pair is the
+    Gerrit commit URL and the second pair is the change list number.
+
+  Raises:
+    ValueError: Failed to create a commit or failed to upload the
+    changes for review.
+  """
+
+  if not os.path.isdir(repo):
+    raise ValueError('Invalid path provided: %s' % repo)
+
+  # Create a git commit.
+  with tempfile.NamedTemporaryFile(mode='w+t') as f:
+    f.write('\n'.join(commit_messages))
+    f.flush()
+
+    subprocess.check_output(['git', 'commit', '-F', f.name],
+                            cwd=repo,
+                            encoding='utf-8')
+
+  # Upload the changes for review.
+  # Pylint currently doesn't lint things in py3 mode, and py2 didn't allow
+  # users to specify `encoding`s for Popen. Hence, pylint is "wrong" here.
+  # pylint: disable=unexpected-keyword-arg
+  # The CL URL is sent to 'stderr', so need to redirect 'stderr' to 'stdout'.
+  upload_changes_obj = subprocess.Popen(
+      ['repo', 'upload', '--yes', '--ne', '--no-verify',
+       '--br=%s' % branch],
+      cwd=repo,
+      stdout=subprocess.PIPE,
+      stderr=subprocess.STDOUT,
+      encoding='utf-8')
+
+  out, _ = upload_changes_obj.communicate()
+
+  if upload_changes_obj.returncode:  # Failed to upload changes.
+    print(out)
+    raise ValueError('Failed to upload changes for review')
+
+  found_url = re.search(
+      r'https://chromium-review.googlesource.com/c/'
+      r'chromiumos/overlays/chromiumos-overlay/\+/([0-9]+)', out.rstrip())
+
+  if not found_url:
+    raise ValueError('Failed to find change list URL.')
+
+  return CommitContents(
+      url=found_url.group(0), cl_number=int(found_url.group(1)))