Add a clang-format check to GH actions #1

	name: "clang format"

	# if .{cpp,hpp} files are touched in a PR, lint them!

	on:
	pull_request:
	branches: ["master"]
	paths:
	- 'components/eamxx/*/.cpp'
	- 'components/eamxx/*/.hpp'

	concurrency:
	group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number \|\| github.run_id }}
	cancel-in-progress: true

	jobs:
	clang-format-linter:
	if: ${{ github.repository == 'E3SM-Project/E3SM' }}
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4
	with:
	fetch-depth: 0
	- uses: tj-actions/changed-files@v46
	id: changed-files
	with:
	files: 'components/eamxx/*/.{cpp,hpp}'
	separator: " "
	# 1. runs clang-format on the files changed by this PR, and returns pass/fail
	# error code.
	# 2. prints the diff to screen (action log), comparing to the changes
	# that would be made
	# 3. the mjschmidt modification to DoozyX/clang-format-lint-action@v0.20
	# adds a Step summary to the workflow page, and, on failure, lists the
	# files that fail the clang-format test
	- uses: mjschmidt271/clang-format-lint-action@v1.0.0
	with:
	source: ${{ steps.changed-files.outputs.all_changed_files }}
	exclude: ''
	extensions: 'hpp,cpp'
	clangFormatVersion: 14
	style: 'file:components/eamxx/.clang-format'

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