Re: [PATCH] maint: be more robust to gnulib's FOO_H variables

[Jim Meyering]

Akim Demaille wrote:
> With the current master, I have failures about sched.h, which
> should be lib/sched.h.  We have too much dependency on the
> state of gnulib inside configure.ac.  I propose the following
> simple change.  It is optimistic (i.e., one can easily forge cases
> where it would break), but I'm not sure we need to be more
> cautious.  A better alternative, of course, would be to have
> a means to have gnulib natively support such a package layout.
>
>
> From dcac080fea88d13cb714cf29556624a7717a7cac Mon Sep 17 00:00:00 2001
> From: Akim Demaille <address@hidden>
> Date: Fri, 20 Jan 2012 13:47:11 +0100
> Subject: [PATCH] maint: be more robust to gnulib's FOO_H variables.
>
>       * configure.ac: Instead of listing gnulib's variables, look for
>       them among AC_SUBST variables.

Nice.  That is much more maintainable.

>  configure.ac |   12 ++++++++----
>  1 files changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/configure.ac b/configure.ac
> index 78284e9..a99b45f 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -168,11 +168,15 @@ gt_JAVAEXEC
>  # We use gnulib, but from lib/local.mk instead of lib/Makefile.am.
>  # So prefix paths with lib/.  See also etc/prefix-gnulib-mk.
>  gl_LIBOBJS=`echo "$gl_LIBOBJS" | sed -e 's, , lib/,g'`
> -for ac_var in ALLOCA_H ERRNO_H FCNTL_H GETOPT_H INTTYPES_H \
> -              LIBUNISTRING_UNITYPES_H LIBUNISTRING_UNIWIDTH_H \
> -              STDBOOL_H STDINT_H SYS_WAIT_H WCHAR_H WCTYPE_H
> +# Listing the name of the variables to prefix is error-prone.  Rather,

s/name/names/

> +# fetch all the AC_SUBST variables whose name ends in '_H', and whose

s/fetch/adjust/

> +# content ends in '.h'.
> +for ac_var in $ac_subst_vars
>  do
> -  eval "test x\$$ac_var = x || $ac_var=lib/\$$ac_var"
> +  eval "ac_val=\$$ac_var"
> +  case $ac_var=$ac_val in
> +    (*_H=*.h) eval "$ac_var=lib/\$$ac_var";;
> +  esac
>  done
>  AC_CONFIG_FILES([Makefile
>                   po/Makefile.in