Git version to C file

.gitignore

version.h
module
*.o

Makefile

VERSION = 0.1

version.h: FORCE
	@echo "$(VERSION)$(shell $(PWD)/setlocalversion $(PWD))"
	@echo "#define VERSION \"$(VERSION)$(shell $(PWD)/setlocalversion $(PWD))\"" > version.h


module.o: version.h

all: module
	@$(PWD)/module

clean:
	@rm module module.o version.h

FORCE:

.PHONY: FORCE

module.c

#include <stdio.h>

#include "version.h"

int main(int argc, char *argv[])
{
	printf("Our version is: %s\n", VERSION);
	return 0;
}

setlocalversion

#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
#
# This scripts adds local version information from the version
# control systems git, mercurial (hg) and subversion (svn).
#

usage() {
	echo "Usage: $0 [srctree]" >&2
	exit 1
}

if test $# -gt 0; then
	srctree=$1
	shift
fi
if test $# -gt 0 -o ! -d "$srctree"; then
	usage
fi

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 --short HEAD 2>/dev/null); then

		# If we are at a tagged commit (like "v2.6.30-rc6"), we ignore
		# it, because this version is defined in the top level Makefile.
		if [ -z "$(git describe --exact-match 2>/dev/null)" ]; then
			printf '%s%s' -g $head
		fi

		# Is this git on svn?
		if git config --get svn-remote.svn.url >/dev/null; then
			printf -- '-svn%s' "$(git svn find-rev $head)"
		fi

		# Check for uncommitted changes.
		# 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
		} | grep -qvE '^(.. )?scripts/package'; then
			printf '%s' -dirty
		fi

		# All done with git
		return
	fi

	# Check for mercurial and a mercurial repo.
	if test -d .hg && hgid=$(hg id 2>/dev/null); then
		# Do we have an tagged version?  If so, latesttagdistance == 1
		if [ "$(hg log -r . --template '{latesttagdistance}')" = "1" ]; then
			id=$(hg log -r . --template '{latesttag}')
			printf '%s%s' -hg "$id"
		else
			tag=$(printf '%s' "$hgid" | cut -d' ' -f2)
			if [ -z "$tag" -o "$tag" = tip ]; then
				id=$(printf '%s' "$hgid" | sed 's/[+ ].*//')
				printf '%s%s' -hg "$id"
			fi
		fi

		# Are there uncommitted changes?
		# These are represented by + after the changeset id.
		case "$hgid" in
			*+|*+\ *) printf '%s' -dirty ;;
		esac

		# All done with mercurial
		return
	fi

	# Check for svn and a svn repo.
	if rev=$(LANG= LC_ALL= LC_MESSAGES=C svn info 2>/dev/null | grep '^Last Changed Rev'); then
		rev=$(echo $rev | awk '{print $NF}')
		printf -- '-svn%s' "$rev"

		# All done with svn
		return
	fi
}

# full scm version string
echo "$(scm_version)"