Re: Dynamic package version numbers with Autoconf and Automake

[Robert Boehne]

On 08/15/12 08:45, Bob Friesenhahn wrote:
> On Wed, 15 Aug 2012, Miles Bader wrote:
> > (3) The final version info is updated (using VCS info and/or autoconf
> >    version info) at make time using a script, and when it changes,
> >    only causes a source file (e.g., version.c) to change.
> >
> >    This means that although some things are rebuilt after a commit
> >    (version.o, and relinking of any binaries that use it), the amount
> >    of rebuilding is relatively minor while still yielding accurate
> >    info.
>
> Likewise, GraphicsMagick configures a "version.h" as well as a version 
> file used for non-autotools builds under Windows.  With the currently 
> used mechanism, only the few files depending on version.h need to be 
> rebuilt but the whole project relinks.
>
> If the project "config.h" was to be re-generated (seems to be 
> necessary with new AC_INIT), then all of the source modules would need 
> to be recompiled and relinked since everything depends on the 
> configuration header.
>
> Bpb

I've had a similar complaint when using Autotest.  In my project, the 
test suite depends on an M4 input file that has the project version 
encoded in it.
 cat test_suite/package.m4
# Signature of the current package.
m4_define([AT_PACKAGE_NAME],  [my_server])
m4_define([AT_PACKAGE_TARNAME],  [my_server])
m4_define([AT_PACKAGE_MINOR_VERSION], 4.18)
m4_define([AT_PACKAGE_VERSION],  [4.18.5])
m4_define([AT_PACKAGE_STRING],  [my_server 4.18.5])

Which is created by a makefile rule as suggested in the autoconf 
documentation:

http://www.gnu.org/software/autoconf/manual/autoconf.html#Making-testsuite-Scripts

So when I change the version of the package, I autoreconf, then make 
then autoreconf again.

Scenario #2 -

I have inherited a library versioning scheme that doesn't play nice with 
Libtool  (an absolute requirement)
when the Automake name is not encoded with the version -

  lib_LTLIBRARIES = libmy_server-4.18.la

 So every time I change the version argument to AC_INIT, I have to 
search around my makefiles for anything
that references each library and make the same changes there.

So I would be very interested in a solution to these issues.

Cheers,

Robert