Re: Autoconf/Automake is not using version from AC_INIT

[Peter Johansson]

Hi Bob,

On 13/1/21 12:35 am, Bob Friesenhahn wrote:
> On Tue, 12 Jan 2021, Peter Johansson wrote:
> > The problem is that there is no dependency in the Makefile telling 
> > that autoconf need to be rerun when the version has changed. Automake 
> > has the variable 'CONFIGURE_DEPENDENCIES' for this purpose, so adding
> >
> > CONFIGURE_DEPENDENCIES = ChangeLog
> >
> > would solve the issue but will cause a rerun of autoconf every time 
> > you touch ChangeLog. Rather you want a stamp file, whose timestamp 
> > only changes when the output of 'version.sh packageversion' changes. 
> > Something along the lines:
> >
> > $(srcdir)/.version: ChangeLog
> >     cd $(srcdir) && ./version packageversion > .version-tmp && 
> > move-if-change .version-tmp .version
> >
> > EXTRA_DIST = $(srcdir)/.version
> >
> > I don't see any way without a specific file holding the timestamp on 
> > when the version was last updated.
>
> This is very helpful advice (and adds to valuable advice offered in 
> private emails by others).  I don't really like hidden files but I do 
> have a version.h header file which could already be used for this 
> purpose.  The version.h header file is currently produced from 
> version.h.in using config.status and it gets copied to the source 
> directory (if necessary) if the file has changed.

I think that will have the unwanted effect that autoconf is triggered 
when building from a tarball. Since version.h is not included in the 
tarball, it will be built by the user and have a newer timestamp than 
configure, and hence the rule is triggered. I think the advice one of 
the automake maintainers (probably Ralf) gave many years ago is that 
files listed in CONFIGURE_DEPENDENCIES should be distributed.

Peter