snprintf warnings

snprintf warnings

[Eli Zaretskii]

When I build GDB with DJGPP, GCC whines like so:

    remote.c: In function `remote_xfer_partial':
    remote.c:4920: warning: implicit declaration of function `snprintf'

(I see this warning for other source files as well.)

This happens because DJGPP doesn't have `snprintf' in its library, so
the libiberty version is used.  But there's no prototype for the
libiberty `snprintf' anywhere, thus the warning.  The code seems to be
relying on getting the prototype from stdio.h, but if the library
doesn't have the function, we cannot expect to have the prototype on a
standard header.

What would be the canonical way to fix that?

Re: snprintf warnings

[Andrew Cagney]

Eli Zaretskii wrote:
> When I build GDB with DJGPP, GCC whines like so:
> 
>     remote.c: In function `remote_xfer_partial':
>     remote.c:4920: warning: implicit declaration of function `snprintf'
> 
> (I see this warning for other source files as well.)
> 
> This happens because DJGPP doesn't have `snprintf' in its library, so
> the libiberty version is used.  But there's no prototype for the
> libiberty `snprintf' anywhere, thus the warning.  The code seems to be
> relying on getting the prototype from stdio.h, but if the library
> doesn't have the function, we cannot expect to have the prototype on a
> standard header.
> 
> What would be the canonical way to fix that?

include/libiberty.h, for instance:

> #if !HAVE_DECL_ASPRINTF
> /* Like sprintf but provides a pointer to malloc'd storage, which must
>    be freed by the caller.  */
> 
> extern int asprintf PARAMS ((char **, const char *, ...)) ATTRIBUTE_PRINTF_2;
> #endif

Andrew

Re: snprintf warnings

[Eli Zaretskii]

> Date: Mon, 15 Nov 2004 19:36:45 -0500
> From: Andrew Cagney <cagney@gnu.org>
> Cc: gdb@sources.redhat.com
> 
> include/libiberty.h, for instance:
> 
> > #if !HAVE_DECL_ASPRINTF
> > /* Like sprintf but provides a pointer to malloc'd storage, which must
> >    be freed by the caller.  */
> > 
> > extern int asprintf PARAMS ((char **, const char *, ...)) ATTRIBUTE_PRINTF_2;
> > #endif

So you are saying that we should add some configury stuff to produce
HAVE_DECL_SNPRINTF, and then add a fragment similar to the above to
libiberty.h that specifies the prototype for snprintf, yes?

Re: snprintf warnings

[Daniel Jacobowitz]

On Tue, Nov 16, 2004 at 06:53:48AM +0200, Eli Zaretskii wrote:
> > Date: Mon, 15 Nov 2004 19:36:45 -0500
> > From: Andrew Cagney <cagney@gnu.org>
> > Cc: gdb@sources.redhat.com
> > 
> > include/libiberty.h, for instance:
> > 
> > > #if !HAVE_DECL_ASPRINTF
> > > /* Like sprintf but provides a pointer to malloc'd storage, which must
> > >    be freed by the caller.  */
> > > 
> > > extern int asprintf PARAMS ((char **, const char *, ...)) ATTRIBUTE_PRINTF_2;
> > > #endif
> 
> So you are saying that we should add some configury stuff to produce
> HAVE_DECL_SNPRINTF, and then add a fragment similar to the above to
> libiberty.h that specifies the prototype for snprintf, yes?

Yes, that sounds like a good idea.

-- 
Daniel Jacobowitz