Re: [pkcs11] Updated Proposal: All constants should have UL suffix

[Michael StJohns <msj@nthpermutation.com>]

On 6/12/2013 5:12 PM, Stef Walter wrote:
> On 12.06.2013 22:31, Michael StJohns wrote:
> > What I started to mumble about on the web site was whether this should
> > actually be a #define or a "static const".   I don't actually have a
> > strong opinion, and this might be too much of a change, but if we're
> > turning these into actual ULs, then it may make sense to change these to
> > compilable objects for type safety.
> Unfortunately C and C++ handle 'static const' quite differently. For
> eaxmple 'static const' variables cannot be used in switch statements in
> C. And there are notable between compilers/linkers, and versions of C.
>
> See following for an example of just one of the things that would break.
>
> Cheers,

You would think by now (20years after C 89) they would have fixed things 
like this.

Fair enough - comment withdrawn.

Mike



> Stef
>
>
> example:
>
> #include <assert.h>
> #include <stdlib.h>
>
> #define ONE 1
> #define TWO 2UL
> static const unsigned long THREE = 3UL;
>
> int
> main (int argc,
>        char *argv[])
> {
> 	assert (argc == 2);
> 	switch (atoi(argv[1])) {
> 	case ONE:
> 	case TWO:
> 	case THREE:
> 		return 0;
> 	default:
> 		return 1;
> 	}
> }
>
>
> $ gcc -Wall ./test.c
> ./test.c: In function ‘main’:
> ./test.c:16:2: error: case label does not reduce to an integer constant
>    case THREE: