Re: autoreconf and m4_pattern_allow

[Robert Lowe]

Noah Misch wrote:
> On Wed, Feb 08, 2006 at 11:47:37PM -0600, Robert Lowe wrote:
>
> > Hi,
> >
> > Until today I had never tried autoreconf.  I have always used a simple
> > shell script like:
>
>
> <snipped>
>
> > The script runs just fine, but autoreconf complained about my use of
> > AC_CREATE_STDINT_H, insisting that I use m4_pattern_allow, which I
> > did, and the problem vanished.  But, would anyone explain what
> > happened and why?  Does it perhaps have anything to do with the fact
> > that this macro is the only one I am using named AC_*, rather than say
> > ACX_*?
>
>
> The `autoconf' program presents this warning; I suspect the cause is a
> difference in the way your bootstrap script and autoreconf call `aclocal'.
>
> After `autoconf' generates your configure script, it greps the script for
> strings that look like typical macro names.  If `configure' contains the literal
> name of a macro, that is often a sign of either excessive m4 quoting or missing
> macro definitions.
>
> I'll guess that in this case, AC_CREATE_STDINT_H is a macro defined by a file in
> your `m4' directory. 

Yes.

> When you invoke `autoreconf', it does not pass `-I m4' to
> `aclocal', so `autoconf' never has the definition of that macro.  Using
> m4_pattern_allow clears the warning, but it does not yield a fully functional
> configure script.  The fix, if you use Automake, is to put `ACLOCAL_AMFLAGS = -I
> m4' in Makefile.am.  If you do not use Automake, there is no good solution at
> this time.  `autoreconf' should support that case better.  In the mean time,
> you may wish to retain your custom script.

No, I use automake, so all is well.  BTW, after the addition of
ACLOCAL_AMFLAGS to Makefile.am it was necessary to remove the
m4_pattern_allow statement from configure.ac.

I have not been using these tools long, and I must admit I still
feel a sense of awe just watching them work.  So for what it's
worth, I want to express my appreciation to all who build,
maintain and support them!  Thank you!

-Robert