Nicholas Clark schrieb:
On Sun, Jun 03, 2007 at 08:00:18AM -0700, Bernhard Schmalhofer via RT wrote:
I have looked at the 'more_memory.patch' and I'm wondering about the
portability.
In that patch loops where pointers are explicitly set to NULL
are replaced with a
memset( start, 0, len);
What happens when NULL is not a consective series of '\0' chars?
I think that it breaks.
Are there such platforms and are they releavant for parrot?
I believe that this assumption is endemic in Perl 5, and it's never hindered
Perl 5's portability. The C FAQ gives examples of platforms where NULL is not
all bits zero - http://c-faq.com/null/machexamp.html - and I've never
encountered anyone using them.
(As an aside, I think that Perl 5 also (mostly?) doesn't assume 2s complement
storage of integers. IIRC a bug report from a Ahmdal mainframes gave the
impression that it was using sign and magnitude. However, we've not heard
about anyone using Ahmdal mainframes in years. Likewise no-one has missed the
removal of memory model support from Configure, so presumably no-one is
compiling on a PDP-11 anymore. We did discover nasal daemons, or something
similarly painful, on Irix64, until we removed assumptions about signed
integer overflow. (It's undefined behaviour. It will bite))
Nicholas Clark
