Re: Bug#395466: AM_PATH_CHECK causes "possibly undefined macro" errors

[Ralf Wildenhues]

[ http://bugs.debian.org/395466 ]

Hello Josh,

* Josh Triplett wrote on Fri, Oct 27, 2006 at 09:33:30AM CEST:
>
> --- check.m4.orig     2006-10-13 12:24:41.000000000 -0700
> +++ check.m4  2006-10-26 23:55:54.000000000 -0700
> @@ -4,8 +4,9 @@
>  
>  AC_DEFUN([AM_PATH_CHECK],
>  [
> -  AC_MSG_WARN([[AM_PATH_CHECK() is deprecated]])
> -  AC_MSG_WARN([[use PKG_CHECK_MODULES([CHECK], [check >= 0.9.4]) instead]])
> +  empty=
> +  AC_MSG_WARN([A${empty}M_PATH_CHECK() is deprecated])
> +  AC_MSG_WARN([[use P${empty}KG_CHECK_MODULES([CHECK], [check >= 0.9.4]) 
> instead]])
>    AC_ARG_WITH([check],
>    [  --with-check=PATH       prefix where check is installed [default=auto]])
>   

Yuck three times.  1. Learn to use Quadrigraphs:
  AC_MSG_WARN([[AM@&address@hidden() is deprecated]])

http://www.gnu.org/software/autoconf/manual/html_node/Quadrigraphs.html

2. Double quotation [[ ]] does successfully prevent expansion of macros,
iff all macros calling this one have been quoted correctly, i.e., once.

3. m4_pattern_forbid was invented to forbid some patterns.  User macros
should simply not begin with 'AM_'.  That prefix is reserved for
Automake, and also used by a set of legacy macros from some other
packages.  When you invent new names, use a different prefix, like
'jt_', or, for pkg-config, 'PKG_'.  I reckon that the damage is already
done with AM_PATH_CHECK though.  Which is the name of the package that
defines it?  It is broken, the bug should be moved to this package, and
to fix it, the package should add something like
  m4_pattern_allow([^AM_PATH_CHECK$])
to its macro.

Hope that helps.

Cheers,
Ralf