an oldie but a goodie .. ISO C90 does not support 'long long'

[Michael Wojcik]

> From: openssl-users <openssl-users-bounces at openssl.org> On Behalf Of raf via
> openssl-users
> Sent: Friday, 4 November, 2022 18:54
> 
> On Wed, Nov 02, 2022 at 06:29:45PM +0000, Michael Wojcik via openssl-users
> <openssl-users at openssl.org> wrote:
> 
> >
> > I'm inclined to agree. While there's an argument for backward compatibility,
> > C99 was standardized nearly a quarter of a century ago. OpenSSL 1.x is
> > younger than C99. It doesn't seem like an unreasonable requirement.
> 
> Would this be a choice between backwards-compatibility with C90
> compilers and compatibility with 32-bit architectures?

I don't see how.

It's a question of the C implementation, not the underlying architecture. A C implementation for a 32-bit system can certainly provide a 64-bit integer type. If that C implementation conforms to C99 or later, it ought to do so using long long and unsigned long long. (I'm excluding C implementations for exotic systems where, for example, CHAR_BIT != 8, such as some DSPs; those aren't going to be viable targets for OpenSSL anyway.)

> Is there another way to get 64-bit integers on 32-bit systems?

Sure. There's a standard one, which is to include <stdint.h> and use int64_t and uint64_t. That also requires C99 or later and an implementation which provides those types; they're not required.

And for some implementations there are implementation-specific extensions, which by definition are not standard.

And you can roll your own. In a non-OO language like C, this would be intrusive for the parts of the source base that rely on a 64-bit integer type.

> I suspect that that there are more 32-bit systems than there are
> C90 compilers.

Perhaps, but I don't think it's relevant here. In any case, OpenSSL is not in the business of supporting every platform and C implementation in existence. There are the platforms supported by the project, and there are contributed platforms which are included in the code base and supported by the community (hopefully), and there are unsupported platforms.

If someone wants OpenSSL on an unsupported platform, then it's up to them to do the work.

-- 
Michael Wojcik