Re: [PATCH] jit: Ensure ssize_t is defined.

[Jakub Jelinek <jakub@redhat.com>]

On Tue, Jun 11, 2024 at 09:27:37AM +0200, Richard Biener wrote:
> On Tue, 11 Jun 2024, FX Coudert wrote:
> 
> > Hi
> > 
> > I can’t seem to get a review of this one-line patch. Could a global reviewer help?
> 
> While stdio.h can be relied on to exist I do not think you can assume
> the same for sys/types.h without "configury", but libgccjit.h is an
> installed API.  I would assume including stdlib.h gets you ssize_t as 
> well?

If stdlib.h includes sys/types.h like often on Linux, yes, but not
necessarily.  ssize_t is a POSIX type and it might be solely in sys/types.h.

Perhaps libgccjit.h could use
#ifdef __has_include
#if __has_include (<sys/types.h>)
#include <sys/types.h>
#endif
#endif
instead of just #include <sys/types.h>.
When compiled by gcc, one can use hacks like
#define unsigned signed
typedef __SIZE_TYPE__ gcc_jit_ssize_t;
#undef unsigned
but that might not work with other compilers and is perhaps
just too ugly.

>  In fact the C11 standard doesn't even mention ssize_t so the
> API should probably avoid using it and instead use size_t for
> 
> /* Given type "T", get its size.
>    This API entrypoint was added in LIBGCCJIT_ABI_20; you can test for its
>    presence using
>      #ifdef LIBGCCJIT_HAVE_SIZED_INTEGERS  */
> extern ssize_t
> gcc_jit_type_get_size (gcc_jit_type *type);

	Jakub