Add script applying the clang-format diff

Our lint target already provides a target for the diff obtained
from clang format. Add a convenience script computing and applying
that patch.

2 files changed, 23 insertions, 3 deletions

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index f8d86251..6badaf33 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -15,8 +15,9 @@ pass; the global test suite is `["@", "just tests", "", "ALL"]`.
 Code is formatted with `clang-format` and linted with `clang-tidy`;
 the corresponding configuration files can be found in the top-level
 directory of this repository. The top-level lint target is
-`["@", "lint", "", ""]`; formatting issues can be fixed by building
-and applying the patch `["@", "lint", "", "format.diff"]`.
+`["@", "lint", "", ""]`. Formatting issues can be fixed by building
+and applying the patch `["@", "lint", "", "format.diff"]`; the script
+`bin/format-code.sh` does precisely this.
 
 *NOTE:* In order for everyone to use the same version of the linting
 tools, the `"lint"` repository
@@ -25,7 +26,7 @@ the required tools; the configuration variable `"TOOLCHAIN_CONFIG"`
 is honored. As a consequence, (transitively) depending on the
 `"lint"` repository pulls in quite some sources and linting the
 first time requires a significant amount of time to build the tools
-from first principles.
+from first principles. This is also true when calling `bin/format-code.sh`.
 
 Changes should be organized as a patch series, i.e., as a sequence of
 small changes that are easy to review, but nevertheless self-contained
diff --git a/bin/format-code.sh b/bin/format-code.sh
new file mode 100755
index 00000000..aa4e5f5b
--- /dev/null
+++ b/bin/format-code.sh
@@ -0,0 +1,19 @@
+#!/bin/sh
+# Copyright 2025 Huawei Cloud Computing Technology Co., Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+: ${JUST_MR:=just-mr}
+
+cd $(readlink -f $(dirname $0)/..)
+${JUST_MR} --main lint build -p format.diff | (patch -p1)