autotools: Make petitboot autoreconfable

The standard way to regenerate the autotools bits is with 'autoreconf',
but that doesn't work with our custom bootstrap script. We only need the
bootstrap script to generate the version in configure.ac, which we can
easily do with m4_esyscmd_s instead.

This change allows autoreconfiguration with `autoreconf -f -i`.

Includes changes proposed by Yann E. Morin <yann.morin.1998@free.fr>,
and modifications from the original patch from
Jeremy Kerr <jk@ozlabs.org>

Signed-off-by: Jeff Bailey <jeffbailey@google.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

1 files changed, 34 insertions, 0 deletions

diff --git a/version.sh b/version.sh
new file mode 100755
index 0000000..eed8d3a
--- /dev/null
+++ b/version.sh
@@ -0,0 +1,34 @@
+#! /bin/bash
+#
+# version.sh: create a version string for use by configure.ac
+
+version=
+
+if head=$(git rev-parse --short --verify HEAD 2>/dev/null); then
+
+	# If available, use the git commit revision for the package version.
+
+	# Add a date prefix for easy reading.
+	# date='2010-11-30 16:36:09 -0800'
+
+	date=$(git log --pretty=format:"%ci" -1 HEAD)
+	date=${date##20}
+	date=${date%%:[0-9][0-9] *}
+	date=${date//-/.}
+	date=${date// /.}
+	date=${date//:/.}
+
+	version=$(printf '%s-%s%s' ${date} g ${head})
+
+	# Add a '-dirty' postfix for uncommitted changes.
+
+	if git diff-index HEAD | read dummy; then
+		version=`printf '%s%s' ${version} -dirty`
+	fi
+else
+	# Default to current date and time.
+
+	version="dev-$(date +%y.%m.%d-%H.%M.%S)"
+fi
+
+echo $version