tools/format-cpp: use a group of `echo` lines with a single `>& 2`

[babeltrace.git] / tools / format-cpp

#!/bin/bash
#
# SPDX-License-Identifier: GPL-2.0-only
#
# Copyright (C) 2020-2022 Philippe Proulx <pproulx@efficios.com>

expected_formatter_major_version=15

# Runs the formatter, making sure it's the expected version.
format_cpp() {
	local formatter=("$@")
	local version

	if ! version=$("${formatter[@]}" --version); then
		echo "Cannot execute \`${formatter[*]} --version\`." >&2
		return 1
	fi

	if [[ "$version" != *"clang-format version $expected_formatter_major_version"* ]]; then
		{
			echo "Expecting clang-format $expected_formatter_major_version."
			echo
			echo Got:
			echo
			echo "$version"
		} >& 2

		return 1
	fi

	local root_dir

	root_dir="$(dirname "${BASH_SOURCE[0]}")/.."

	# Using xargs to fail as soon as the formatter fails (`-exec`
	# won't stop if its subprocess fails).
	find "$root_dir" \( -name '*.cpp' -o -name '*.hpp' \) \
		! -wholename '*/cpp-common/optional.hpp' \
		! -wholename '*/cpp-common/string_view.hpp' \
		! -wholename '*/cpp-common/nlohmann/json.hpp' \
		-print0 | xargs -P"$(nproc)" -n1 -t -0 "${formatter[@]}"
}

if [[ -n "$FORMATTER" ]]; then
	# Try using environment-provided formatter
	read -ra formatter <<< "$FORMATTER"
elif command -v clang-format-$expected_formatter_major_version &> /dev/null; then
	# Try using the expected version of clang-format
	formatter=("clang-format-$expected_formatter_major_version" -i)
else
	# Try using `clang-format` as is
	formatter=(clang-format -i)
fi

# Try to format files
format_cpp "${formatter[@]}"