[rust] [depot_tools] Minimal `rustfmt` support for `git cl format`.
This CL provides minimal `git cl format` support to enforce correct Rust
formatting in presubmit checks. For now the files are always fully
formatted - there is no support at this point for formatting only the
changed lines.
Manual tests (after temporarily, artificially introducing a formatting
error to one of .rs files under build/rest/tests):
*) git cl presubmit
Result: The src directory requires source formatting.
Please run: git cl format
*) git cl format --dry-run
Result: Pretty/colorful diff printed out.
*) git cl format
Result: Temporary formatting errors are fixed.
Bug: chromium:1231317
Change-Id: I114ece90630476f27871ebcd170162caa92c0871
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3054980
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Reviewed-by: Adrian Taylor <adetaylor@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@google.com>
Reviewed-by: danakj <danakj@chromium.org>
diff --git a/rustfmt.py b/rustfmt.py
new file mode 100755
index 0000000..4da2cc9
--- /dev/null
+++ b/rustfmt.py
@@ -0,0 +1,73 @@
+#!/usr/bin/env python3
+# Copyright 2021 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.
+"""Redirects to the version of rustfmt present in the Chrome tree.
+
+Rust binaries are pulled down from Google Cloud Storage whenever you sync
+Chrome. This script knows how to locate those tools, assuming the script is
+invoked from inside a Chromium checkout."""
+
+import gclient_paths
+import os
+import subprocess
+import sys
+
+
+class NotFoundError(Exception):
+ """A file could not be found."""
+
+ def __init__(self, e):
+ Exception.__init__(
+ self, 'Problem while looking for rustfmt in Chromium source tree:\n'
+ '%s' % e)
+
+
+def FindRustfmtToolInChromiumTree():
+ """Return a path to the rustfmt executable, or die trying."""
+ chromium_src_path = gclient_paths.GetPrimarySolutionPath()
+ if not chromium_src_path:
+ raise NotFoundError(
+ 'Could not find checkout in any parent of the current path.\n'
+ 'Set CHROMIUM_BUILDTOOLS_PATH to use outside of a chromium checkout.')
+
+ # TODO(lukasza): Deduplicate the is-Rust-supported and find-Rust-binaries code
+ # by somehow sharing the `rust_prefix` variable from //build/config/rust.gni
+ tool_path = os.path.join(chromium_src_path, 'third_party',
+ 'android_rust_toolchain', 'toolchain', 'bin',
+ 'rustfmt' + gclient_paths.GetExeSuffix())
+ if not os.path.exists(tool_path):
+ raise NotFoundError('File does not exist: %s' % tool_path)
+ return tool_path
+
+
+def IsRustfmtSupported():
+ try:
+ FindRustfmtToolInChromiumTree()
+ return True
+ except NotFoundError:
+ return False
+
+
+def main(args):
+ try:
+ tool = FindRustfmtToolInChromiumTree()
+ except NotFoundError as e:
+ sys.stderr.write("%s\n" % str(e))
+ return 1
+
+ # Add some visibility to --help showing where the tool lives, since this
+ # redirection can be a little opaque.
+ help_syntax = ('-h', '--help', '-help', '-help-list', '--help-list')
+ if any(match in args for match in help_syntax):
+ print('\nDepot tools redirects you to the rustfmt at:\n %s\n' % tool)
+
+ return subprocess.call([tool] + args)
+
+
+if __name__ == '__main__':
+ try:
+ sys.exit(main(sys.argv[1:]))
+ except KeyboardInterrupt:
+ sys.stderr.write('interrupted\n')
+ sys.exit(1)