Daniel Jacobowitz <[EMAIL PROTECTED]> writes:
> > The following program illustrates that __builtin_return_address seg faults
> > when
> > you reach the top of the stack rather than returning 0 as it is specified in
> > the gcc manual.
> >
> > I see the same behaviour with both gcc 2.95 and gcc 3.0.
>
> GCC 3.2 says:
> On some machines it may be impossible to determine the return
> address of any function other than the current one; in such cases,
> or when the top of the stack has been reached, this function will
> return `0' or a random value. In addition,
> `__builtin_frame_address' may be used to determine if the top of
> the stack has been reached.
Well, that's not what my documentation from GCC 2.95 says:
On some machines it may be impossible to determine the return
address of any function other than the current one; in such cases,
or when the top of the stack has been reached, this function will
return `0'.
I'm puzzled why I can use __builtin_frame_address to determine if the top of
the stack has been reached but gcc's builtin can't do the same for me. I must
be missing something, how do gdb and other tools happily decode stack traces
all the time without crashing?
--
greg
