#!/bin/sh
# SPDX-License-Identifier: GPL-2.0

scm_version()
{
	# Check for git and a git repo.
	if test -z "$(git rev-parse --show-cdup 2>/dev/null)" &&
	   head="$(git rev-parse --verify HEAD 2>/dev/null)"; then
		# If we are at a tagged commit, we ignore it.
		if [ -z "$(git describe --exact-match 2>/dev/null)" ]; then
			# Add -g and 8 hex chars.
			printf -- '-g%.8s' "$head"
		fi
		# Check for uncommitted changes.
		# This script must avoid any write attempt to the source tree,
		# which might be read-only.
		# You cannot use 'git describe --dirty' because it tries to
		# create .git/index.lock .
		# First, with git-status, but --no-optional-locks is only
		# supported in git >= 2.14, so fall back to git-diff-index if
		# it fails. Note that git-diff-index does not refresh the
		# index, so it may give misleading results. See
		# git-update-index(1), git-diff-index(1), and git-status(1).
		if {
			git --no-optional-locks status -uno --porcelain 2>/dev/null ||
			git diff-index --name-only HEAD
		} | read dummy; then
			printf '%s' -dirty
		fi
	fi
}

if [ -n "$EROFS_UTILS_VERSION" ]; then
	echo "$EROFS_UTILS_VERSION"
else
	echo $(head -n1 VERSION)$(scm_version)
fi