Re: prepare for autoconf-2.60

[Jim Meyering]

Ralf Wildenhues <address@hidden> wrote:
> * Paul Eggert wrote on Thu, Apr 20, 2006 at 01:50:48AM CEST:
>> Bruno Haible <address@hidden> writes:
>>
>> > + But about AC_CHECK_DECLS_ONCE: note that in
>> > + autoconf >= 2.60 the symbol separator is a comma, whereas here it is
>> > + whitespace.
>>
>> I hadn't noticed this incompatibility.  It is a real hassle.
>
> One solution is to forbid _any_ Gnulib (or other non-Autoconf-provided)
> macro to start with `AC_'.  I thought this was a convention agreed upon
> long ago (much longer than, say, `build-aux' as a directory name).  Then
> one could even write an autoupdate rule to transform gl_CHECK_DECLS_ONCE
> into AC_CHECK_DECLS_ONCE and change the white-space separated list into
> a M4 list at the same time (with reasonably safe heuristics).[1]

That sounds fine, but there is a small downside.  I've found it useful
to provide fixed/improved versions of autoconf-defined AC_* macros.
All I need to do is include a new .m4 file that undefs and redefines the
offending macro.  Then, once an official version of autoconf is available
with the fix, I simply remove the interim .m4 file.  That way, there is
no need to rename every use of the AC_ macro in question, then to rename
them back, once it's fixed.

But with any luck, autoconf is stable enough these days that even if we
do have to rename things once in a while, it won't be much of a burden.