Re: Inconsistency with coreutils: _Static_assert()

[Corinna Vinschen <corinna-cygwin at cygwin dot com>]

On May 21 17:59, Denis Excoffier wrote:
> Hello,
> 
> I compile coreutils-8.21 under Cygwin (Windows XP). I'm using
> gcc-4.8.0 with no problem, except that under _any_ snapshot
> posterior to
> plain 1.7.18, i obtain the following (with plain 1.7.18, or under
> gcc-4.5.3 it works perfectly):
> 
> ---------------
> ...
> depbase=`echo src/chroot.o | sed 's|[^/]*$|.deps/&|;s|\.o$||'`;\
> gcc -std=gnu99  -I. -I./lib  -Ilib -I./lib -Isrc -I./src    -g -O2
> -MT src/chroot.o -MD -MP -MF $depbase.Tpo -c -o src/chroot.o
> src/chroot.c &&\
> mv -f $depbase.Tpo $depbase.Po
> In file included from /usr/include/sys/stdio.h:14:0,
>                  from /usr/include/stdio.h:62,
>                  from ./lib/stdio.h:43,
>                  from src/chroot.c:21:
> src/chroot.c: In function 'set_additional_groups':
> ./lib/verify.h:181:8: error: expected specifier-qualifier-list
> before 'typedef'
>         _Static_assert (R, DIAGNOSTIC);          \
>         ^
> ./lib/verify.h:166:16: note: in expansion of macro '_GL_VERIFY_TYPE'
>      (!!sizeof (_GL_VERIFY_TYPE (R, DIAGNOSTIC)))
>                 ^
> ./lib/verify.h:230:25: note: in expansion of macro '_GL_VERIFY_TRUE'
>  # define verify_true(R) _GL_VERIFY_TRUE (R, "verify_true (" #R ")")
>                          ^
> src/system.h:247:35: note: in expansion of macro 'verify_true'
>  #define X2NREALLOC(P, PN) ((void) verify_true (sizeof *(P) != 1), \
>                                    ^
> src/chroot.c:103:16: note: in expansion of macro 'X2NREALLOC'
>          gids = X2NREALLOC (gids, &n_gids_allocated);
>                 ^
> Makefile:6662: recipe for target 'src/chroot.o' failed
> make: *** [src/chroot.o] Error 1
> ---------------
> 
> I have narrowed the problem down to /usr/include/sys/cdefs.h, where
> (line 271) you have _Static_assert defined:
> #define _Static_assert(x, y)  __Static_assert(x, __COUNTER__)
> 
> This definition occurs even under GCC 4.6.0 (and later) where
> _Static_assert() indeed works. As a consequence, it no longer works as
> expected in coreutils-8.21/lib/verify.h (lines 24 and 181).

Sorry, but I don't grok this sentence.  Since the cdefs.h version
works as expected, it does not work in coreutils' verify.h?  Who
exactly is wrong, cdefs.h or verify.h?  And *what* exactly is wrong
with the definition?


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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