OpenEuphoria

Re: Modifying the Euphoria interpreter

• Posted by CChris <christian.cuvier at agriculture.gouv.fr> Jun 12, 2007
• 537 views

Pete Lomax wrote:
> 
> CChris wrote:
> > No, it's even worse than that.
> > Remember that, if ex.exe tries to compile a program which mentions
> > open_dll(), it errors out even though the the function won't ever be
> > executed because the call is protected by a "if platform()=??? then".
> > The error is generated before the platform dependent code is removed.
> > But replacing the call with "machine_func(50,"kernel32.dll") won't hurt.
> 
> As well as the same things others have tried, I just tested this here:
> }}}
<eucode>
> constant k32=open_dll("kernel32")
> constant k32=machine_func(50,"kernel32")
> </eucode>
{{{

> Despite beginning to mistrust myself, I was right. Both the above fail equally
> on ex.exe, since you cannot put a platform() check around either.
> It is true, btw, to say that you cannot use constant definitions like the
> above
> in platform independent code. Instead you must use atom vars.
> 
> The point I am trying to make here is that you seem to be locked into using
> a direct call to machine_func when it will make no significant difference -
> see the definition of open_dll() in dll.e. It is the machine_func call itself
> which fails on ex.exe, NOT the trivial open_dll() wrapper... you can even
> prove
> this by putting a display inside open_dll just before the call to
> machine_func:
> it will show fine, just before ex.exe crashes.
> 
> Regards,
> Pete

Of course I know the wrapper is trivial, and makes no difference.
I thought I remembered that, if running a program using ex.exe, and if 
that program had lines like

atom k32
if platform()=WINDOWS then
k32=open_dll("kernel32.dll")
end if

I was getting an error for open_dll() not being supported under DOS. And then
of course the wrapper would make a difference, since no one could object to
a machine_func() call at compile time.

But again, I'll have to check what actually happens.
And as you said, the entry point can't be a constant, as it must appear
inside an if block.
CChris