1 files changed, 78 insertions, 0 deletions
diff --git a/scripts/make_gitrev.sh b/scripts/make_gitrev.sh
new file mode 100755
index 0000000000000..f5c743b137991
--- /dev/null
+++ b/scripts/make_gitrev.sh
@@ -0,0 +1,78 @@
+#!/bin/sh
+
+#
+# CDDL HEADER START
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+# CDDL HEADER END
+#
+
+# Copyright (c) 2018 by Delphix. All rights reserved.
+# Copyright (c) 2018 by Matthew Thode. All rights reserved.
+
+#
+# Generate zfs_gitrev.h.  Note that we need to do this for every
+# invocation of `make`, including for incremental builds.  Therefore we
+# can't use a zfs_gitrev.h.in file which would be processed only when
+# `configure` is run.
+#
+
+set -e -u
+
+dist=no
+distdir=.
+while getopts D: flag
+do
+	case $flag in
+		\?) echo "Usage: $0 [-D distdir] [file]" >&2; exit 1;;
+		D)  dist=yes; distdir=${OPTARG};;
+	esac
+done
+shift $((OPTIND - 1))
+
+top_srcdir="$(dirname "$0")/.."
+GITREV="${1:-include/zfs_gitrev.h}"
+
+# GITREV should be a relative path (relative to top_builddir or distdir)
+case "${GITREV}" in
+	/*) echo "Error: ${GITREV} should be a relative path" >&2
+	    exit 1;;
+esac
+
+ZFS_GITREV=$({ cd "${top_srcdir}" &&
+	git describe --always --long --dirty 2>/dev/null; } || :)
+
+if [ "x${ZFS_GITREV}" = x ]
+then
+	# If the source directory is not a git repository, check if the file
+	# already exists (in the source)
+	if [ -f "${top_srcdir}/${GITREV}" ]
+	then
+		ZFS_GITREV="$(sed -n \
+			'1s/^#define[[:blank:]]ZFS_META_GITREV "\([^"]*\)"$/\1/p' \
+			"${top_srcdir}/${GITREV}")"
+	fi
+elif [ ${dist} = yes ]
+then
+	# Append -dist when creating distributed sources from a git repository
+	ZFS_GITREV="${ZFS_GITREV}-dist"
+fi
+ZFS_GITREV=${ZFS_GITREV:-unknown}
+
+GITREVTMP="${GITREV}~"
+printf '#define\tZFS_META_GITREV "%s"\n' "${ZFS_GITREV}" >"${GITREVTMP}"
+GITREV="${distdir}/${GITREV}"
+if cmp -s "${GITREV}" "${GITREVTMP}"
+then
+	rm -f "${GITREVTMP}"
+else
+	mv -f "${GITREVTMP}" "${GITREV}"
+fi