How to add a git revision string when using automake

Andy Alt · 06-26-2019, 04:01 AM

I was just trying to figure out how to add a git revision string to VERSION. After some searching, I wasn't quite happy with any of the answers so I combined some of what I read into this:

in Makefile.am

Code:

git_rev := $(shell \
if test -f @top_srcdir@/.git/refs/heads/master; then	\
	expr substr `cat @top_srcdir@/.git/refs/heads/master` 1 7;	\
else	\
	echo "unknown";	\
fi)

Add this to your DEFS:

Code:

-DGIT_REV=\"$(git_rev)\"

Probably will want a condition not to append GIT_REV to VERSION when issuing releases though.

GazL · 06-26-2019, 06:24 AM

This is what I like to use.

Code:

$ #  linux tree at tagged release
$ cd /usr/src/linux
$ version=$( git describe 2>/dev/null || git rev-parse HEAD 2>/dev/null || echo 'unknown' )
$ echo $version
v5.1.15
$
$ #  My personal dwm branch, 8 commits past tagged release 
$ cd ~/projects/dwm/
$ version=$( git describe 2>/dev/null || git rev-parse HEAD 2>/dev/null || echo 'unknown' )
$ echo $version
6.0.2-8-g2f4bc6b
$ 
$ # Another project of mine with no tags as yet
$ cd ../xtc
$ version=$( git describe 2>/dev/null || git rev-parse HEAD 2>/dev/null || echo 'unknown' )
$ echo $version
a80500cda681caf5854e9e31cab4d0f8dce0b645
$

You can also add '--short' to git rev-parse if you don't want the full ref, and the '--long' option of git describe will force it to always include the number of commits since the last tag, and the ref, even when HEAD is at that tag.

Andy Alt · 07-01-2019, 05:41 PM

I'll have to rewrite mine a bit. After I turned -Wall on for the automake options, I get warnings that using ':=' as an assignment operator isn't portable. And on osx, I there are "syntax errors" when encountering the 'expr' command.

My goal is to keep related code out of configure.ac so autoconf wouldn't need to be run whenever the rev changes.