Re: [Qemu-devel] [PATCH] Fix compiler warning (always return a value), introduce qemu_abort?

[Stefan Weil]

Am 26.10.2011 14:54, schrieb Stefan Hajnoczi:
> On Mon, Oct 24, 2011 at 10:18:43PM +0200, Stefan Weil wrote:
> > For compilations with -DNDEBUG, the default case did not return
> > a value which caused a compiler warning.
> >
> > Signed-off-by: Stefan Weil <address@hidden>
> > ---
> > hw/ppce500_spin.c | 11 ++++++++---
> > 1 files changed, 8 insertions(+), 3 deletions(-)
> >
> > diff --git a/hw/ppce500_spin.c b/hw/ppce500_spin.c
> > index cccd940..5b5ffe0 100644
> > --- a/hw/ppce500_spin.c
> > +++ b/hw/ppce500_spin.c
> > @@ -168,17 +168,22 @@ static uint64_t spin_read(void *opaque, 
> > target_phys_addr_t addr, unsigned len)
> > {
> > SpinState *s = opaque;
> > uint8_t *spin_p = &((uint8_t*)s->spin)[addr];
> > + uint64_t result = 0;
> >
> > switch (len) {
> > case 1:
> > - return ldub_p(spin_p);
> > + result = ldub_p(spin_p);
> > + break;
> > case 2:
> > - return lduw_p(spin_p);
> > + result = lduw_p(spin_p);
> > + break;
> > case 4:
> > - return ldl_p(spin_p);
> > + result = ldl_p(spin_p);
> > + break;
> > default:
> > assert(0);
>
> I would replace assert(3) with abort(3). If this ever happens the
> program is broken - returning 0 instead of an undefined value doesn't
> help.
>
> Stefan

Alex, do you agree on replacing assert() by abort()?

I personally don't like abort() because it does not show the
reason for the failure.

Most users don't know how to get a core dump or how to
use gdb. And even for those who know, a crash caused
by an abort() which cannot be reproduced usually happens
on a system were ulimit disables core dumps...

I'd like to have a qemu_abort() macro in qemu-common.h which
replaces all abort() calls used today:

#define qemu_abort() \
  do { \
    fprintf(stderr, "QEMU aborted in %s, %s:%u\n", __func__, __FILE__, 
__LINE__);
    abort();
  } while (0)

(The macro could also call a function which handles fprintf and abort).

Cheers,
Stefan W.