Re: Stepping over longjmp presumably broken for glibc

Eli Zaretskii
2005-12-26T05:19:35Z

> Date: Sun, 25 Dec 2005 20:06:42 -0800
> From: Jim Blandy <jimb@red-bean.com>
> Cc: gdb@sourceware.org
>
> On 12/24/05, Eli Zaretskii <eliz@gnu.org> wrote:
> > I also don't see any significant difference between dependencies on
> > intimate details of the runtime library and the details of the ABI,
> > like function prologue emitted by GCC. We depend on that in lots of
> > places.
>
> Like fork and malloc, the ABI is a published, documented interface. I
> think it's all right to depend on that.

It's not that simple, you know: we allow the architecture to specify
an arbitrary name for the malloc function. I also remember that we
sometimes look for several known names of a function, but I cannot for
the moment find it in the sources. I did find proc-events.c, which
seems to list all the syscall names on a certain platform.

> The details of the function prologues emitted by GCC are not a public
> interface, and are, again, a constant source of troubles.

How do other debuggers do things for which we need the function
prologues? If they also have intimate knowledge of the prologues,
then I think it's okay for us as well.

My point was that we already depend on all kinds of ad-hoc knowledge
of the ABI and the runtime, so adding one more dependency would not
hurt too much, although I'd applaud to changes to do that without any
such dependencies.