Re: [PATCH] Fix use of ENABLE_NLS (which is not always defined)

[Bruno Haible]

Hi,

Grégoire Sutre wrote:
> ENABLE_NLS is defined in AM_GNU_GETTEXT and the documentation of this 
> macro [2] does not require ENABLE_NLS to be defined when gettext is not 
> available.

Correct: ENABLE_NLS is not meant to be defined to empty. It is meant to
be undefined or defined to 0 (both equivalent) or be defined to 1.

> However, uses of ENABLE_NLS assume it to be defined, which  
> is not correct.

No. The only assumption being made about ENABLE_NLS is that is it either
undefined or expands to a valid preprocessor integer expression (like 0 or 1).

> [1] http://lists.gnu.org/archive/html/grub-devel/2010-01/msg00288.html

Citing it: "The problem only occurs ... when compiling with -Wundef -Werror".

The problem is the use of -Wundef. Gnulib does not support use of -Wundef.
In fact, any package which makes good use of Autoconf cannot support -Wundef.
(Well, you can use this warning option, but don't bother us with the result.)

The <libintl.h> of GNU gettext will be changed to support -Wundef in the
next release [1], because <libintl.h> is also useful in projects that don't
use Autoconf. But this does not extend to gettext.h or any other files from
Gnulib.

Bruno

[1] http://lists.gnu.org/archive/html/bug-gnu-utils/2008-09/msg00033.html