On 08/03/2017 10:55 AM, Eric Blake wrote:
On 08/03/2017 08:34 AM, Philippe Mathieu-Daudé wrote:
Hi Greg,
On 08/02/2017 11:47 AM, Greg Kurz wrote:
Building QEMU on fedora26 with the latest gcc package fails:
CC ppc64-softmmu/target/ppc/kvm.o
In file included from include/sysemu/hw_accel.h:16:0,
from target/ppc/kvm.c:31:
target/ppc/kvm.c: In function ‘kvmppc_booke_watchdog_enable’:
include/sysemu/kvm.h:449:35: error: ‘args_tmp[i]’ may be used
uninitialized
This sizeof() use looks unnatural to me. I wonder why not use size_t,
since this is about sizeof()/ARRAY_SIZE(). The problem seems to come
from the commit this cast was introduced (61c7bbd236):
target-ppc/kvm.c:1302:21: error: comparison of unsigned expression < 0
is always false [-Werror=type-limits]
So I'd rather suggest this code, which looks more natural to read to me:
if (ARRAY_SIZE(args_tmp)) {
for (i = 0; i < ARRAY_SIZE(args_tmp) && ...
Oops I forgot to suggest size_t i.
For that matter, the existing code is doing:
int i;
i < (int)ARRAY_SIZE(args_tmp)
but wouldn't that be better as:
size_t i;
i < ARRAY_SIZE(args_temp)
I guess we have both the old compilers (per commit 61c7bbd2) and the new
to worry about; although I was unable to reproduce it on Fedora 26 on
x86_64 (is this an architecture-dependent compiler bug?)
Ok so let's stop losing time about compiler incoherent warnings, using
-Wno-type-limits for GCC < 5...
So we can keep a sane/understandable codebase, using size_t and no (int)
cast.
Phil.
