On 08/04/2010 09:58 AM, Massimiliano Cialdi wrote: > Il giorno mar, 03/08/2010 alle 17.03 +0100, Andrew Haley ha scritto: >>> This looks incredible to me. I wonder why. >>> Is it a bug? >> >> I don't think it is. gcc uses ssize_t (or, to be precise, a signed >> integer type beased on sizetype) internally when constructing the size >> of an array. Given that array offsets can be negative or positive. >> this seems reasonable enough. > > So why if I write: > big_dummy_t *p = (big_dummy_t*)0; > uint16_t p = (uint16_t)&(p->singledata); > > I get NO warning? Because the first is constant folded, the second isn't. Not that it matters, because your program is undefined anyway, since you're dereferencing a null pointer. Andrew.
