Enforce clang-format #160

	# Copyright (c) 2023 Sebastian Pipping <sebastian@pipping.org>
	# SPDX-License-Identifier: Apache-2.0

	name: Enforce clang-format

	# Drop permissions to minimum, for security
	permissions:
	contents: read

	on:
	pull_request:
	push:
	schedule:
	- cron: '0 2 * * 5' # Every Friday at 2am
	workflow_dispatch:

	jobs:
	clang-format:
	name: Enforce clang-format
	runs-on: ubuntu-22.04
	env:
	CLANG_MAJOR_VERSION: 18
	steps:

	- uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7

	- name: Add Clang/LLVM repositories
	run: \|-
	set -x
	source /etc/os-release
	wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key \| sudo apt-key add -
	sudo add-apt-repository "deb http://apt.llvm.org/${UBUNTU_CODENAME}/ llvm-toolchain-${UBUNTU_CODENAME}-${CLANG_MAJOR_VERSION} main"

	- name: Install clang-format
	run: \|-
	set -x
	sudo apt-get update
	sudo apt-get install --yes --no-install-recommends -V \
	clang-format-${CLANG_MAJOR_VERSION}

	- name: Enforce clang-format
	run: \|-
	set -x
	clang-format-${CLANG_MAJOR_VERSION} --version
	clang-format-${CLANG_MAJOR_VERSION} -i *.c
	git diff --exit-code # i.e. reject non-empty diff

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