[ODE] Using exceptions to catch errors

[Jon Watte]

I believe the C++ standard specifies that throws propagate through 
C linkage (without exception data) without specific object unwinding 
for objects active on the stack in those functions.

A very simple test should also show you what's happening in this 
case.

Cheers,

			/ h+


-----Original Message-----
From: ode-bounces at q12.org [mailto:ode-bounces at q12.org]On Behalf Of Adam
Paul Coates
Sent: Thursday, August 12, 2004 2:22 AM
To: Shamyl Zakariya
Cc: ode at q12.org
Subject: RE: [ODE] Using exceptions to catch errors


I've not been watching this thread until now, so maybe this has been
asked.  Does it make a difference that dError is linked as a C-style
function?  I'm not sure how the gcc linker handles this situation, but is
it possible that, to avoid throwing an exception to external C code, it
either allows execution to continue, or instead calls the global
unexpected() or terminate() functions (whose default behavior is to call
abort() I believe)?

A quick experiment might be in order to test this if it sounds reasonable.
You can install your own unexpected() and terminate() handlers via
set_unexpected() and set_terminate().

Hope that helps;  I'd be curious to know whether this is the reason.

Adam C.


> extern "C" void dError (int num, const char *msg, ...)
> {
>    va_list ap;
>    va_start (ap,msg);
>    if (error_function) error_function (num,msg,ap);
>    else printMessage (num,"ODE Error",msg,ap);
>    exit (1);
> }



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