Re: wrong decltype( INTN_C(value) )?

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

On 27-03-2016 17:54, Yaron Cohen-Tal wrote:
> Hi,
> 
> I was wondering: according to the C99 standard (I couldn't get hold of
> the C11 standard) it seems like e.g. "INT8_C" should have the type
> "int_least8_t". From section 7.18.4.1:
> 
> "The macro INTN_C(value) shall expand to a signed integer constant
> with the specified value and type int_leastN_t"
> 
> However, on my system (Debian 8 x64) "INT8_C(1)" expands to "1" which
> has type "int" (which is 32 bit) whereas "int_least8_t" has type
> "signed char" (which is 8 bit). So is glibc not conformant to the
> standard here, or there's anything I misunderstand? I'd expact it to
> expand to "((signed char)1)".
> 

My understanding is it falls to:

7.18.4 Macros for integer constants

3. Each invocation of one of these macros shall expand to an integer
   constant expression suitable for use in #if preprocessing directives.
   The type of the expression shall have the same type as would an
   expression of the corresponding type *converted according to the
   integer promotions*. The value of the expression shall be that of
   the argument.

Since it it should use default C99 integer promotions the macro should
not promote to smaller than int types.