https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78503
jbeulich at novell dot com changed:
What |Removed |Added
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CC| |jbeulich at novell dot com
--- Comment #1 from jbeulich at novell dot com ---
We have something similar in the Xen hypervisor sources:
#define __compat_access_ok(d, addr, size) \
__compat_addr_ok(d, (unsigned long)(addr) + ((size) ? (size) - 1 : 0))
#define compat_access_ok(addr, size) \
__compat_access_ok(current->domain, addr, size)
#define compat_array_access_ok(addr,count,size) \
(likely((count) < (~0U / (size))) && \
compat_access_ok(addr, (count) * (size)))
Instead of != 0 (which seems rather strange to not have the same effect of
producing a warning) for now we're adding in zero, but the example shows
clearly that replacing * by && is not an option here just like in the original
example.
Assuming that there's no intention to eliminate such false positives, could we
at least get a workaround allowing to suppress the warning which is going to be
usable also on future compiler versions (just like I'd expect the
presence/absence of != 0 to make not difference, I could imagine the + 0 to get
eliminated before inspecting the expression for whether to emit the warning).
Disabling the warning altogether does not seem to be desirable.
