How to insert Git-based version in autoconf-managed project?

Question

How can I assign a dynamic, git-based version number to an autoconf project? Autoconf requires a static string argument to

AC_INIT([Title],[version],[name])

AC_INIT documentation says that one can use M4 to supply a shell-based version. M4 is beyond my ken. I'd like to version my software according to the results of this command

version=`git describe --abbrev=7 --dirty --always --tags`

This produces something like 4.6.6-alpha07-9-ga3e01a8 .

I may not understand high level answers. I need a solution like "cut and paste this into your autoconf.ac and/or acinclude.m4".

Any help appreciated.

Answer 1

How about:

AC_INIT([Title], [m4_esyscmd_s([git describe --abbrev=7 --dirty --always --tags])])

should work for you.

Answer 2

Just running git describe in m4_esyscmd for the AC_INIT version still leaves a few things to be desired:

• What version to use if you build a dist tarball? There is no git describe useful output to be had here at all.

• What version to use if you have just committed a change? Do you update the configure version from git describe , or just continue to build with the existing version?

For my own packages (such as ndim-utils ), I have solved these issues (and a few more) by

• Having a special build-helpers/package-version script which determines the version to use from a version-stamp file if found, or git describe . configure.ac AC_INIT will m4_esyscmd that script.

• Having a special build-helpers/package-version.mk to include from the top-level Makefile.am which generates a version-stamp file for dist tarballs, checks whether the current git describe output differs from what configure has stored, and a few other things.

• Having a GNUmakefile.in which updates the version stored in configure internals from git describe when necessary.

And I probably have forgotten a few issues addressed in that solution.

I am not certain that those scripts are ready to just copy over to your project, but I wanted to mention here that there are a few more things to consider.