Architectural diversity - was Re: Pair of Twiggys

[Toby Thain]

On 2017-03-16 5:09 PM, Ethan Dicks wrote:
> On Wed, Mar 15, 2017 at 6:55 PM, Toby Thain via cctalk
> <cctalk at classiccmp.org> wrote:
>> On 2017-03-15 5:17 PM, Peter Coghlan via cctalk wrote:
>>> Has anybody else noticed that the meaning of "portable code" seems to have
>>> morphed into "can be built on two or three different flavours of Linux"?
>>
>> 1983. All the world's a VAX.
>
> And about 2 years later, I learned C on a VAX...
>
>> 1993. No sorry, all the world's a SPARC.
>>
>> 2013. Oops, no, all the world's an x86.
>
>>From 1997-1999, I worked at Lucent where we ran SPARC, NCR x86 boxes,
> DEC Alpha, and a couple of lonely VAXen... One of the interesting
> episodes in that transitional time was when some app/utility program
> written by the group "worked on the NCR" but "failed on the SPARC",
> which was proof to some of them that something was wrong with the
> SPARC or at least "better" about the x86... what was really going on
> was someone did a strlen() of a pointer which was NULL, and really
> didn't understand that when the man page says that behavior is
> "undefined", that *both* machines were doing the right thing (they
> figured it should act only like strlen() of a pointer to a NULL and
> return 0, rather than segfault for attempting to dereference a pointer
> to 0x00000000...)
>
> I politely suggested they should go back and read up on what
> "undefined" means and then go fix their code...

Porting to diverse architectures is still a great way to find latent bugs.

--Toby

>
> -ethan
>