setjmp/longjmp question

[Sir Hoyt]

I am considering using setjmp/longjmp to implement exception handling in C.
It would be used like this:

int foo()
{
 /* variable allocation here */
 if (setjmp( ... ))
 { /* clean up the variables */ }
 else
 { /* normal codes */ }
}

Normal codes would including calling other subroutines.  When error occurs,
longjmp() will be used to jump back to foo().

I am aware that on the Sun, all register variables cannot be trusted after a
longjmp().

What I want to know is the behavior of setjmp/longjmp on other machines.
Would longjmp() clober all local variables if assuming RISC machine, and
automatic register allocation?

 -Thomas Wang ("I am, therefore I am."
                 - Akira               )
                                                     ttwang at polyslo.calpoly.edu