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

[Giulio Benetti]

Hi Bruno,

On 1/27/20 2:41 AM, Bruno Haible wrote:
> Giulio Benetti wrote:
> > In my specific case I'm adding package libbytesize
> > [1], where they add src/gettext.h
>
> But libbytesize uses gettext.h as they should: They use the file internally,
> without installing it in public locations upon "make install".
>
> 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 and in 
libbytesize/configure.ac they define:
CFLAGS="${CFLAGS} -DENABLE_NLS"
without taking into account if we already are in an environment where 
gettext is already installed. So I think that this is problem, 
libbytesize should define ENABLE_NLS according to host gettext presence 
otherwise host gettext could be indirectly included(like in my case) and 
expose gettext_noop() and when local "gettext.h" is included and 
ENABLE_NLS is defined(because there are no checks on environment) 
gettext_noop() will be defined twice.

> > but they define ENABLE_NLS in any case
>
> Defining ENABLE_NLS several times to the same value 1 is a no-brainer.
> It does not produce GCC warnings.

Here I meant that in libbytesize they define ENABLE_NLS in configure.c 
without guarding for host gettext presence. So if you define ENABLE_NLS 
only once, it's enough to see gettext_noop() redefined, since it's 
defined in host.

Anyway gnulib is correct, 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.

Sorry for the noise

Best and kind regards
--
Giulio Benetti
Benetti Engineering sas

> Bruno