* Bruno Haible wrote on Wed, Dec 20, 2006 at 02:51:01PM CET:
> Ralf Wildenhues wrote:
> > > it creates the new files in the build
> > > directory. I know the reason why: if a source distribution is installed
> > > in a
> > > read-only location, the build in a VPATH should not touch any file in the
> > > source directory.
> >
> > That's not what I'd say. You can only expect compiling from a read-only
> > location to work right if that read-only location happens to contain up
> > to date files. If a bison input file is updated there, then one can
> > rightly expect other files to need updated there as well.
>
> Good! So please, can you fix automake to behave like this?
[...]
> The fix should be that in the cited circumstances po-gram-gen.c and
> po-gram-gen.h should be updated in $(srcdir).
Currently Automake seems not to place a restriction on whether the
package author wants bison output updated in the source tree or in the
build tree.
I mean, you can make it work with updates in the build tree by
- adjusting cpp include path to mention the build tree path first
(in your case already done by DEFAULT_INCLUDES).
- adjusting all other references to the generated files inside rules
to _prefer_ the file in the build tree location over one in the source
tree location. E.g.:
test -f $$input || input=$(srcdir)/$$input; \
[...]
I don't see a convincing argument that Automake need to restrict package
authors to only use one or the other possibility.
> > How about this patch to force updates in srcdir?
> > (Some BSD make cannot infer that file and $(srcdir)/file are
> > the same target with VPATH = $(srcdir).)
>
> This misses the point,
Bzzt. I was explaining here why my patch did not just add the minimal
amount of changes needed to fix the above issue. Read it again.
> because
> - we are not discussing BSD make here, but GNU make on a glibc system, and
What? Can you not build gettext with a BSD make any more?
Can you not build gettext on a non-glibc system?
If yes to both, then of course my patch could be made smaller, without
breakage (but as it is it wouldn't harm either).
> - a patch to gettext's Makefile.am will not affect the instantiations of
> automake's .y.c rule in other packages than gettext.
Certainly.
Cheers,
Ralf
