Re: xalloc: missing prototype

[Akim Demaille]

Hi Paul,

Le 6 déc. 2012 à 18:48, Paul Eggert <address@hidden> a écrit :

> In file included from ../../../lib/mbschr.c:23:0:
> ../../../lib/mbschr.c: At top level:
> ../../../lib/mbuiter.h:201:181: warning: '__inline_memset_chk' is static but 
> used in inline function 'mbuiter_multi_copy' which is not static [enabled by 
> default]
>     memset (&new_iter->state, 0, sizeof (mbstate_t));
> 
> This (and similar warnings) appear to be a bug in the
> build environment.  It ought to be OK
> to invoke memset from an extern inline function.
> My guess is that the warning can be safely ignored.
> You might want to file a bug report with Apple or
> whoever.

That's good old GCC, every version I can run from 4.3 to 4.8.
This is a stripped down version of the code from gnulib on
my platform.

$ cat mbschr.i
static __inline int
iswcntrl(int wc)
{
  return wc;
}

inline int
mb_width_aux (int wc)
{
  return iswcntrl (wc);
}
$ gcc-mp-4.3  -c mbschr.i
$ gcc-mp-4.3 -std=gnu99 -c mbschr.i
mbschr.i: In function 'mb_width_aux':
mbschr.i:10: warning: 'iswcntrl' is static but used in inline function 
'mb_width_aux' which is not static
$ gcc-mp-4.3 -std=c99 -c mbschr.i
mbschr.i: In function 'mb_width_aux':
mbschr.i:10: warning: 'iswcntrl' is static but used in inline function 
'mb_width_aux' which is not static
$ gcc-mp-4.8 -std=gnu99 -c mbschr.i
mbschr.i:10:10: warning: 'iswcntrl' is static but used in inline function 
'mb_width_aux' which is not static [enabled by default]
   return iswcntrl (wc);
          ^

The prototype comes from /usr/include/_wctype.h:


> #ifndef __DARWIN_WCTYPE_TOP_static_inline
> #define __DARWIN_WCTYPE_TOP_static_inline static __inline
> #endif
> 
...
> 
> __DARWIN_WCTYPE_TOP_static_inline int
> iswcntrl(wint_t _wc)
> {
>       return (__istype(_wc, _CTYPE_C));
> }

The warning is legitimate, as 6.7.4.3 in C99 reads:

        • An inline definition of a function with external linkage shall not 
contain a definition of a modifiable object with static storage duration, and 
shall not contain a reference to an identifier with internal linkage.

The problem is the prototype of iswcntrl which is incompatible
with the use in an inline function.  Yet I don't understand
why GCC does not accept that inline functions call static
functions that are inline too.