From c2001e22815747620307c32aaf688b38d84ee207 Mon Sep 17 00:00:00 2001
From: Peter Hyman <pete@peterhyman.com>
Date: Thu, 24 Dec 2020 10:37:13 -0600
Subject: [PATCH] Use git describe to present version number to configure.ac

gitdesc.sh assumes tag will have format v#.### and will return
major version, minor version, and micro version depending on
command.
gitdesc.sh will also add tag revision and HEAD commit if tag is
not equal to HEAD. So lrzip version may appear as
`#.###' or
`#.###-R-#######'
where `R' is count of commits since last tag.
usage
gitdesc.sh command [-r]
where command is one of:
all - entire git describe
commit - commit, omitting v
tagrev - tag revision count
major - major release version
ninor - minor release version
micro - micro release version + [tag release count-HEAD commit]
version - M.mic
-r -- get release tag only
---
 configure.ac    |   6 +--
 util/gitdesc.sh | 105 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 108 insertions(+), 3 deletions(-)
 create mode 100755 util/gitdesc.sh

diff --git a/configure.ac b/configure.ac
index a84c9d1..e4c3de9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,8 +1,8 @@
 ##--##--##--##--##--##--##--##--##--##--##--##--##--##--##--##--##
 ##--##--##--##--##--##--##--##--##--##--##--##--##--##--##--##--##
-m4_define([v_maj], [0])
-m4_define([v_min], [6])
-m4_define([v_mic], [31])
+m4_define([v_maj], [m4_esyscmd_s([./util/gitdesc.sh major])])
+m4_define([v_min], [m4_esyscmd_s([./util/gitdesc.sh minor])])
+m4_define([v_mic],[m4_esyscmd_s([./util/gitdesc.sh micro])])
 ##--##--##--##--##--##--##--##--##--##--##--##--##--##--##--##--##
 m4_define([v_v], m4_join([], v_min, v_mic))
 m4_define([v_ver], [v_maj.v_v])
diff --git a/util/gitdesc.sh b/util/gitdesc.sh
new file mode 100755
index 0000000..06f6aa8
--- /dev/null
+++ b/util/gitdesc.sh
@@ -0,0 +1,105 @@
+#?bin/sh
+# Peter Hyman, pete@peterhyman.com
+# December 2020
+
+# This program will return commit references based on Tags and Annotated Tags from git describe
+
+usage() {
+cat >&2  <<EOF
+$(basename $0) command [-r]
+all - entire git describe
+commit - commit, omitting v
+tagrev - tag revision count
+major - major release version
+ninor - minor release version
+micro - micro release version
+version - M.mic + [tag release count-HEAD commit]
+-r -- get release tag only
+EOF
+exit 1
+}
+
+# showw message and usage
+die() {
+	echo "$1"
+	usage
+}
+
+# return variables
+# everything, with leading `v' and leading `g' for commits
+describe_tag=
+# abbreviated commit
+commit=
+# count of commits from last tag
+tagrev=
+# major version
+major=
+# minor version
+minor=
+# micro version
+micro=
+# get release or tag?
+tagopt="--tags"
+
+# get whole commit and parse
+# if tagrev > 0 then add it and commit to micro version
+# Expected format is:
+# v#.###-g#######
+init() {
+	describe_tag=$(git describe $tagopt --long --abbrev=7)
+	describe_tag=${describe_tag/v/}
+	describe_tag=${describe_tag/g/}
+	commit=$(echo $describe_tag | cut -d- -f3)
+	tagrev=$(echo $describe_tag | cut -d- -f2)
+	version=$(echo $describe_tag | cut -d- -f1)
+	micro=${version: -2}
+	[ $tagrev -gt 0 ] && micro=$micro-$tagrev-$commit
+	minor=${version: -3:1}
+	major=$(echo $version | cut -d. -f1)
+}
+
+[ ! $(which git) ] && die "Something very wrong: git not found."
+
+[ $# -eq 0 ] && die "Must provide a command and optional argument."
+
+# are we getting a release only?
+if [ $# -eq 2 ]; then
+	if [ $2 = "-r" ]; then
+		tagopt=""
+	else
+		die "Invalid option. Must be -r or nothing."
+	fi
+fi
+
+init
+
+case "$1" in
+	"all" )
+		retval=$describe_tag
+		;;
+	"commit" )
+		retval=$commit
+		;;
+	"tagrev" )
+		retval=$tagrev
+		;;
+	"version" )
+		retval=$version
+		;;
+	"major" )
+		retval=$major
+		;;
+	"minor" )
+		retval=$minor
+		;;
+	"micro" )
+		retval=$micro
+		;;
+	* )
+		die "Invalid command."
+		;;
+esac
+
+echo $retval
+
+exit 0