From 5867f263e2f8d60aab3592300204d5619d61c761 Mon Sep 17 00:00:00 2001
From: Mike Gerwitz <gerwitzm@lovullo.com>
Date: Tue, 15 Aug 2017 15:18:21 -0400
Subject: [PATCH] Generate version number from git state

Copies script from GNU ease.js.

* .gitignore: Do not ignore `build-aux/vergen'.
* build-aux/vergen: Add file from GNU ease.js.
* configure.ac: Use `vergen' to generate version string.
---
 .gitignore       |  3 ++-
 build-aux/vergen | 44 ++++++++++++++++++++++++++++++++++++++++++++
 configure.ac     |  5 ++++-
 3 files changed, 50 insertions(+), 2 deletions(-)
 create mode 100755 build-aux/vergen

diff --git a/.gitignore b/.gitignore
index 7634d5d..89c1bde 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 # generated by autotools
-build-aux/
+build-aux/*
+!build-aux/vergen
 aclocal.m4
 autom4te.cache
 configure
diff --git a/build-aux/vergen b/build-aux/vergen
new file mode 100755
index 0000000..efef66c
--- /dev/null
+++ b/build-aux/vergen
@@ -0,0 +1,44 @@
+#!/bin/sh
+# Generates version string
+#
+#  Copyright (C) 2012, 2013, 2014 Free Software Foundation, Inc.
+#
+#  This file is part of GNU ease.js.
+#
+#  This program is free software: you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation, either version 3 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This script has been modified slightly by LoVullo Associates to support
+# liza's versioning scheme (`v'-prefixed).
+##
+
+# for distributions
+if [ -s version ]; then
+  cat version
+  exit
+fi
+
+git rev-parse --show-toplevel >/dev/null 2>&1 || {
+  echo 'fatal: git repository is not available'
+}
+
+version=$(
+  git describe --match='v[0-9]\.*' --abbrev=7 HEAD 2>/dev/null \
+    | sed 's/^v//'
+)
+
+git update-index -q --refresh
+test -z "$( git diff-index --name-only HEAD)" || version="$version-dirty"
+
+echo -n "$version"
+
diff --git a/configure.ac b/configure.ac
index fb8d969..cc58591 100644
--- a/configure.ac
+++ b/configure.ac
@@ -18,7 +18,10 @@
 #  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ##
 
-AC_INIT([liza], [1.3.0], [dev@lovullo.com])
+m4_define([ver], m4_esyscmd(build-aux/vergen))
+m4_if(ver, [], [m4_exit(1)])
+
+AC_INIT([liza], [ver], [dev@lovullo.com])
 AC_CONFIG_AUX_DIR([build-aux])
 AM_INIT_AUTOMAKE([foreign])