throw c++ exceptions from signal handler and -fnon-call-exceptions

Mon Jun 12 02:04:00 GMT 2006

Hi all,
I saw an example in libjava/include/i386_signal.h, in macro
MAKE_THROW_FRAME, upon trapping instructions we advance eip by 2 and
throw C++ exceptions from signal handler. My question is:
Why we advance eip by a fixed value 2 here? Does this work for any
trapping instructions for invalid memory access on ia32? I tested with:
__asm__ ("movl 0ドルx4,0xffffffe8(%eax)"); //suppose eax=0 for invalid
memory access
which is a 7 bytes instruction but looks it does not work anymore,
neither did when advancing eip by 2 or 7.
Thanks a lot
Miaobo