1 files changed, 159 insertions, 0 deletions
diff --git a/cros_utils/git_utils.py b/cros_utils/git_utils.py
new file mode 100644
index 00000000..d8c11d0a
--- /dev/null
+++ b/cros_utils/git_utils.py
@@ -0,0 +1,159 @@
+# Copyright 2024 The ChromiumOS Authors
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Shared utilities for working with git."""
+
+import contextlib
+import logging
+from pathlib import Path
+import re
+import shlex
+import subprocess
+import tempfile
+from typing import Generator, Iterable, List
+
+
+# Email address used to tag the detective as a reviewer.
+REVIEWER_DETECTIVE = "c-compiler-chrome@google.com"
+
+
+def _parse_cls_from_upload_output(upload_output: str) -> List[int]:
+    """Returns the CL number in the given upload output."""
+    id_regex = re.compile(
+        r"^remote:\s+https://"
+        r"(?:chromium|chrome-internal)"
+        r"-review\S+/\+/(\d+)\s",
+        re.MULTILINE,
+    )
+
+    results = id_regex.findall(upload_output)
+    if not results:
+        raise ValueError(
+            f"Wanted at least one match for {id_regex} in {upload_output!r}; "
+            "found 0"
+        )
+    return [int(x) for x in results]
+
+
+def upload_to_gerrit(
+    git_repo: Path,
+    remote: str,
+    branch: str,
+    reviewers: Iterable[str] = (),
+    cc: Iterable[str] = (),
+    ref: str = "HEAD",
+) -> List[int]:
+    """Uploads `ref` to gerrit, optionally adding reviewers/CCs."""
+    # https://gerrit-review.googlesource.com/Documentation/user-upload.html#reviewers
+    # for more info on the `%` params.
+    option_list = [f"r={x}" for x in reviewers]
+    option_list += (f"cc={x}" for x in cc)
+    if option_list:
+        trailing_options = "%" + ",".join(option_list)
+    else:
+        trailing_options = ""
+
+    run_result = subprocess.run(
+        [
+            "git",
+            "push",
+            remote,
+            # https://gerrit-review.googlesource.com/Documentation/user-upload.html#reviewers
+            # for more info on the `%` params.
+            f"{ref}:refs/for/{branch}{trailing_options}",
+        ],
+        cwd=git_repo,
+        check=False,
+        stdin=subprocess.DEVNULL,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT,
+        encoding="utf-8",
+    )
+
+    logging.info(
+        "`git push`ing %s to %s/%s had this output:\n%s",
+        ref,
+        remote,
+        branch,
+        run_result.stdout,
+    )
+    run_result.check_returncode()
+    return _parse_cls_from_upload_output(run_result.stdout)
+
+
+def try_set_autosubmit_labels(cwd: Path, cl_id: int) -> None:
+    """Sets autosubmit on a CL. Logs - not raises - on failure.
+
+    This sets a series of convenience labels on the given cl_number, so landing
+    it (e.g., for the detective) is as easy as possible.
+
+    Args:
+        cwd: the directory that the `gerrit` tool should be run in. Anywhere in
+            a ChromeOS tree will do. The `gerrit` command fails if it isn't run
+            from within a ChromeOS tree.
+        cl_id: The CL number to apply labels to.
+    """
+    gerrit_cl_id = str(cl_id)
+    gerrit_commands = (
+        ["gerrit", "label-as", gerrit_cl_id, "1"],
+        ["gerrit", "label-cq", gerrit_cl_id, "1"],
+        ["gerrit", "label-v", gerrit_cl_id, "1"],
+    )
+    for cmd in gerrit_commands:
+        # Run the gerrit commands inside of toolchain_utils, since `gerrit`
+        # needs to be run inside of a ChromeOS tree to work. While
+        # `toolchain-utils` can be checked out on its own, that's not how this
+        # script is expeted to be used.
+        return_code = subprocess.run(
+            cmd,
+            cwd=cwd,
+            check=False,
+            stdin=subprocess.DEVNULL,
+        ).returncode
+        if return_code:
+            logging.warning(
+                "Failed to run gerrit command %s. Ignoring.",
+                shlex.join(cmd),
+            )
+
+
+@contextlib.contextmanager
+def create_worktree(git_directory: Path) -> Generator[Path, None, None]:
+    """Creates a temp worktree of `git_directory`, yielding the result."""
+    with tempfile.TemporaryDirectory(prefix="update_kernel_afdo_") as t:
+        tempdir = Path(t)
+        logging.info(
+            "Establishing worktree of %s in %s", git_directory, tempdir
+        )
+        subprocess.run(
+            [
+                "git",
+                "worktree",
+                "add",
+                "--detach",
+                "--force",
+                tempdir,
+            ],
+            cwd=git_directory,
+            check=True,
+            stdin=subprocess.DEVNULL,
+        )
+
+        try:
+            yield tempdir
+        finally:
+            # Explicitly `git worktree remove` here, so the parent worktree's
+            # metadata is cleaned up promptly.
+            subprocess.run(
+                [
+                    "git",
+                    "worktree",
+                    "remove",
+                    "--force",
+                    tempdir,
+                ],
+                cwd=git_directory,
+                check=False,
+                stdin=subprocess.DEVNULL,
+            )