On Sat, 7 Oct 2006, Glynn Clements wrote:
>
> Robert P. J. Day wrote:
>
> > sort of a combination of a C and gcc question but what's the rules
> > these days on the following (ripped from the linux kernel source, from
> > asm/semaphore.h)?
> >
> > ===
> > static inline void sema_init (struct semaphore *sem, int val)
> > {
> > /*
> > * *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
> > *
> > * i'd rather use the more flexible initialization above, but sadly
> > * GCC 2.7.2.3 emits a bogus warning. EGCS doesn't. Oh well.
> > */
> > atomic_set(&sem->count, val);
> > sem->sleepers = 0;
> > init_waitqueue_head(&sem->wait);
> > }
> > ===
> >
> > i recall that earlier compilers complained about that first example
> > of pointer indirection as the target of an assignment. is that legal
> > these days?
>
> The problem with the first example is that the
> __SEMAPHORE_INITIALIZER macro uses C99 features, which probably
> aren't supported in gcc 2.7.x.
>
> The LHS has nothing to do with it.
ah, sorry, i didn't look closely enough. so if one could count on a
C99-compilant compiler being available, then the first form would be
perfectly acceptable? thanks.
rday
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