Re: cygwin build problem with m4 HEAD

[Ralf Wildenhues]

[ taking libtool-patches back out ]

Hi Eric,

* Eric Blake wrote on Fri, Sep 09, 2005 at 01:31:30PM CEST:
> According to Ralf Wildenhues on 9/9/2005 1:31 AM:
> >
> > If not, then the patch below should work as
> > well, I believe (untested with newlib), and is less work than providing
> > argz_add as well.  Could you confirm this?  If ok, I'll apply this CVS
> > HEAD and backport to branch-1-5.
> 
> Don't apply the patch as is - I've thought about it a bit more.  I think a
> better patch, in the spirit of gnulib, is to update m4/argz.m4 to do a
> configure-time run test to see if the system argz_insert is broken, in
> which case libtool's argz_insert is used instead.  Leave libtool's ltdl.c
> alone - no need to dirty it with workarounds that can be solved by fixing
> argz_insert instead.  Besides, if any other project uses gnulib's argz
> module, they should get correct behavior as well.  Unfortunately, I
> imagine that such a fix to the argz.m4 file will have to be pessimistic
> during cross-compiles, and is further complicated by the fact that argz.c
> should probably provide only a replacement argz_insert that falls back on
> the system argz_append if it was only the system argz_insert that is
> broken.

I hate runtime checks.  This one will mean hopeless complication of
things, and worse results for any kind of cross compilation.  And all of
this for a system where people are unlikely to run year-old
installations anyway.  Besides, the workaround costs like what?  Two
lines of code.  Multiply by a hundred for the test + replacement.

> However, my employer has not signed a copyright disclaimer,
> despite my repeated requests (although I'm making progress, and hope to
> get it one of these days), and the amount of m4 magic needed to add a
> runtime check and improve argz.c is most likely beyond the trivial patch
> limits.

I could attempt such a patch, but do not see its value outweighing its
costs, see above.  In matters like these, I would _by far_ prefer a
documentation of such limitations, in the spirit of the Autoconf manual.

> > By the way, how does the m4 testsuite fare on cygwin with this fixed?
> 
> It dropped from 76 failures (ie. every single test) down to 9 failures
> (I'll post further info to the m4 lists).

Quite a relief.  Thanks for checking.

Cheers,
Ralf

> >     * libltdl/ltdl.c (lt_argz_insert): Work around newlib argz_insert bug.
> >         * Makefile.am (VERSION_INFO): Bumped revision.
> >         Reported by Eric Blake <address@hidden>.