I've written a small exception demo in C and tried to avoid macros as
far as possible.
> C code *may*, if it chooses, install a generic exception override,
> and we'll have a routine for this. Something like:
>
> EXCEPTION_OVERRIDE(&exception_frame);
> EXCEPTION_RELEASE(&exception_frame);
This is implemented this way:
ex_scope ex;
ex_scope_begin( ex );
if( !ex_occured( ex ) ) {
printf( "throwing exception 123...\n" );
ex_throw( 123 );
printf( "error\n" );
} else {
printf( "fetched exception #%d\n", ex_type() );
}
ex_scope_end( ex );
It uses only a single macro "ex_scope_begin" (which calls setjmp).
The code has been tested with gcc2.96 and 3.0.4 on RH Linux, gcc 2.95.1
on Solaris and MS VC 6 on Windows 2000 (I think,
do not use windows myself).
The sourcecode is available here: http://jbs.t0c.de/parrot/
In exception.h is a "struct ex_info_t", which at the moment just
contains a field "type"; "Language", "Class", "Object" etc can be
added there easily.
