Re: [PATCH] lib/gettext.h: fix warning if gettext is already present

[Giulio Benetti <giulio.benetti@benettiengineering.com>]

Hi Bruno,

sorry I'm following too many things in parallel and I've made a mess on 
explaining!

On 1/27/20 6:38 PM, Bruno Haible wrote:
> Giulio Benetti wrote:
>>> Since you reported a redefinition warning regarding 'gettext_noop',
>>> gettext_noop must have been defined as a macro already elsewhere. Where?
>>
>> gettext_noop() is defined in environment gettext.h
> 
> What do you mean by "environment gettext.h"??
> 
> The documentation [1] says
>    "Do not install the gettext.h file in public locations. Every package
>     that needs it should contain a copy of it on its own."
> 
> There should not be a <gettext.h> in public include file directories!

Indeed there is not, there is <libintl.h> and it is part of uclibc:
https://cgit.uclibc-ng.org/cgi/cgit/uclibc-ng.git/tree/include/libintl.h

>> and in
>> libbytesize/configure.ac they define:
>> CFLAGS="${CFLAGS} -DENABLE_NLS"
>> ...
>> libbytesize should define ENABLE_NLS according to host gettext presence
> 
> This is perfectly OK. It implies that their package won't compile if
> gettext() is not contained in libc or GNU gettext was not installed.
> But it is NOT the cause of the warning that you are seeing.

AFAIK ENABLE_NLS is emitted in any case, there is not check.
I'm using Buildroot test-pkg and it fails with uClibc-ng that contains 
libintl.h where they already:
#undef gettext_noop
#define gettext_noop()

but in your gettext.h:
#include <libintl.h>
and after:
#define gettext_noop(String) String

without before:
#undef gettext_noop

so you get that gettext_noop() is redefined.

What I was proposing at the beginning was to add:
#undef gettext_noop

the same way uClibc does.

So now libbytesize PR I've opened makes sense.

I've explained myself very bad, sorry, hope now it's clear.

Best regards
-- 
Giulio Benetti
Benetti Engineering sas

>> the problem to be fixed is in libbytesize and
>> it's not fixed by the PR I've already open, I need to modify
>> configure.ac to emit ENABLE_NLS according to host gettext presence.
> 
> No, libbytesize is OK.
> 
>> only once, it's enough to see gettext_noop() redefined, since it's
>> defined in host.
> 
> The "host" that you are alluding to is the problem.
> 
> Bruno
> 
> [1] https://www.gnu.org/software/gettext/manual/html_node/lib_002fgettext_002eh.html
>