Re: Problem with building XS module on AS 1401

I was able to resolve the problem. Although I ran into another, eh, 
interesting issue.

The problem was that in my Makefile.pl I had:

    'CCFLAGS'     => '/MT /W3', # Debug-flag: '/Zi',
    'OPTIMIZE'     => '/O2',

That is, I entirely overrode whatever came with $Config. I got away with
it for a long time, but finally time caught up with me. I changed this to:

   my $ccflags = $Config{'ccflags'};
   my $optimize = $Config{'optimize'};
   $ccflags =~ s/-MD\b/-MT/;
   $optimize =~ s/-MD\b/-MT/;
   $ccflags =~ s/-O1\b/-O2/;
   $optimize =~ s/-O1\b/-O2/;

And everything works fine. Exactly what in $Config{'ccflags'} that was 
crucial I did not investigate. (But I don't use time_t.)

So why do I insist on /MT and /O2? Originally, I distributed the MSCVRT file 
in my binary distribution and put in the same directory as my own DLL. But 
this did not work when you used my module from IIS. I asked some C++ MVPs 
for advice, and they suggested /MT.

On the other hand, there is no particular thought behind /O2, as I recall. 
"Optimize for speed" sounded good, I thought some time long ago. So why not 
stick with the default then? This is where we come to the interesting part. 
One of my test scripts fail when I use /O1 on AS1401 and x86 (and again only 
that build). But the failure is very strange. I have an XS routine with 
this signature:

   int
   executebatch(sqlsrv, rows_affected = NULL)
    SV * sqlsrv;
    SV * rows_affected;

In one place in one test script, this XS routine returns undef. This is a
core routine, so it is called well over thousand times in the test suite.
And in one specific case it returns undef. I've traced it so far that the
underlying C++ function does really execute to the end and returns TRUE.

Apparently something goes wrong in the part that comes after? Why? Maybe 
something was clobbered, so maybe I have a bad pointer somewhere. But 
they usually cause a lot more problem than a single miss in 1000 executions.

Anyway, that's why I stick with -O2.

-- 
Erland Sommarskog, Stockholm, [email protected]