Re: Analysis of remaining xm-host headers

[Sam TH <sam at uchicago dot edu>]

On Wed, Mar 14, 2001 at 02:00:10AM -0800, Zack Weinberg wrote:
> On Wed, Mar 14, 2001 at 03:33:35AM -0600, Sam TH wrote:
> > On Wed, Mar 14, 2001 at 12:43:54AM -0800, Zack Weinberg wrote:
> > > i386/xm-beos.h, rs6000/xm-beos.h: A shocking amount of crud which
> > > makes sense only if beos can't run configure.  I'm 99% sure this is
> > > not the case.  The only necessary bits appear to be the
> > > include-directory adjustments, and an unconditional #define
> > > USE_C_ALLOCA.  On the latter, aomment explains that beos stacks are
> > > permanently limited to 64KB, but it says "may change after DR9" so it
> > > may be obsolete.
> > 
> > BeOS R 4.5 can definitely run configure on both of these platforms
> > (and lots more, to boot).  I don't know about earlier versions, but
> > 4.5 is something like 18 months old, and since upgrades are free, and
> > BeOS is only a desktop system, I think that assuming that configure
> > runs on BeOS is quite safe.  
> 
> This is good to know.  If I feed you a patch, can you test it?

I'll see what I can do.  The two Be machines that I have access two
are both really old and slow, and I only have remote access to them.
But I'll see what I can do.

> 
> > What would be a good way to test the max stack size?
> 
> Something like
> 
> #include <stddef.h>
> #include <string.h>
> 
> void func(size_t n)
> {
>   char *p = __builtin_alloca(n);
>   memset (p, 0x5A, n);
> }
> 
> int main(void)
> {
>   size_t i;
>   for (i = 1024; i < 8 * 1024 * 1024; i <<= 1)
>     func(i);
>   return 0;
> }
> 
> run that under the debugger and see what i is when you crash for lack
> of stack space.  8MB is the default stack limit on Linux, which means
> that if GCC commonly wanted more than that, people would be screaming.

Ok, off to compile GDB. :-)
           
sam th --- sam@uchicago.edu --- http://www.abisource.com/~sam/
OpenPGP Key: CABD33FC --- http://samth.dyndns.org/key
DeCSS: http://samth.dynds.org/decss

PGP signature