Problem with int types persists on nettle 2.4 and gnutls 3.0.19 on Solaris 9 Sparc

[Dagobert Michelsen]

Hi Niels,

(adding bug-gnulib@)

Am 27.04.2012 um 17:24 schrieb Niels Möller:
> Simon Josefsson <simon at josefsson.org> writes:
>> Yes. Understanding what the differences is, and which one is right,
>> seems useful first though. If the problem is in gnulib, we can fix
>> that and GnuTLS will have the new variant soon.
> 
> Quoting my investigation from an old (off-list) email thread, from
> November last year:
> 
>  And the problem seems to be that inttypes.h doesn't define int_fast8_t
>  types. And then AX_CREATE_STDINT_H (used by nettle) and gnulib (used by
>  gnutls) both decide to define them, and they do that in an incompatible
>  way.
> 
> ---
> 
>  From a quick look at gl/stdint.h.in and on posted error messages, I
>  think glib uses long for all of int_fast8_t, int_fast16_t and
>  int_fast32_t, and int64_t for int_fast64_t, while nettle uses int8_t,
>  int, int32_t and int64_t.
> 
> ---
> 
>>> Actually, one ought to have a look at the definitions in the stdint.h
>>> provided by gcc (and at the definitions in the solaris10 stdint.h), and
>>> make sure the definitions of the int_fast* types are equivalent.
>>> Otherwise one might end up with subtle ABI differences and errors when
>>> linking together code compiled by different compilers.
>> 
>> Agreed.
> 
>  I did a quick check. The following seems to be the correct sizes:
> 
>  int_fast8_t: 1
>  int_fast16_t: 4
>  int_fast32_t: 4
>  int_fast64_t: 8
> 
>  This is using sizeof on the types defined in stdint.h, trying:
> 
>  gcc -m32 on solaris 9
>  gcc -m64 on solaris 9
>  cc -m32 on solaris 10
>  cc -m64 on solaris 10
> 
>  Remarkably enough, they all agree. I also get the same sizes from
>  nettle-stdint.h, for both 32 bit and 64 bit configurations. So I think
>  nettle (or really, AX_CREATE_STDINT_H) gets this right.
> 
>  While if I understand gl correctly, it uses 4,4,4,8 for a 32-bit build
>  and 8,8,8,8 for a 64-bit build (the size of long is different). This
>  seems wrong. Sure, these are perfectly ok sizes according to C99, but
>  they differ from the sparc conventions (and possibly conventions for
>  other architectures as well).

I see different possibilities on how this can be resolved:

1. nettle uses the gnulib definitions
2. gnulib changes the definitions to conform to nettle

Maybe someone from the gnulib list can give some more advice on this?


Best regards

  -- Dago

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