Re: [PATCH] ctype: Fix bitfield types on 16-bit targets

> On Jul 20, 2018, at 1:37 PM, Hans-Bernhard Bröker <[email protected]> wrote:
> 
> Am 20.07.2018 um 13:07 schrieb Sebastian Huber:
>> -  unsigned int first: 24; -  unsigned short delta; +  uint_least32_t
>> first: 24; +  uint_least16_t delta;
> 
> Unfortunately that makes the code's correctness implementation-defined,
> because it now depends on what the underlying implementation's take on
> the constraint C99 6.7.2.1p4 is:
> 
> 	A bit-field shall have a type that is a qualified or unqualified
> 	version of _Bool, signed int, unsigned int, or some other	
> 	implementation-defined type.
> 
> I.e. compilers are not required to allow uint32_least_t in this place.

Yes, but the original code was just as implementation-dependent, because it depended on "int" having at least 24 bits.  And indeed that is not true (or not necessarily true) on 16-bit targets.

Does "qualified" mean "long int" is allowed?  If so, that would be an alternative.  But the proposed patch has the advantage that it explicitly calls for a long-enough type.  

While legally speaking the standard doesn't require that to work, is it plausible that any real world compiler would object?

	paul