Messages in this thread |  | | Date | Sat, 21 Jan 2023 23:00:38 -0800 | Subject | Re: [PATCH: 1/1] sh4: avoid spurious gcc warning | From | Randy Dunlap <> |
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Hi--
It's just sh: AFAICT. The patch fixes the build error for me on sh2, using gcc 12.1.0 from the kernel.org crosstool builds.
On 1/21/23 16:15, Michael.Karcher wrote: > Prevent sizeof-pointer-div warning in SH4 intc macros > > Gcc warns about the pattern sizeof(void*)/sizeof(void), as it looks like > the abuse of a pattern to calculate the array size. This pattern appears > in the unevaluated part of the ternary operator in _INTC_ARRAY if the > parameter is NULL. > > The replacement uses an alternate approach to return 0 in case of NULL > which does not generate the pattern sizeof(void*)/sizeof(void), but still > emits the warning if _INTC_ARRAY is called with a nonarray parameter. > > This patch is required for successful compilation with -Werror enabled. > > The idea to use _Generic for type distinction is taken from Comment #7 > in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108483 by Jakub Jelinek > > Signed-off-by: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de> > --- > > diff --git a/include/linux/sh_intc.h b/include/linux/sh_intc.h > index c255273b0281..d7a7ffb60a34 100644 > --- a/include/linux/sh_intc.h > +++ b/include/linux/sh_intc.h > @@ -97,7 +97,7 @@ struct intc_hw_desc { > unsigned int nr_subgroups; > }; > > -#define _INTC_ARRAY(a) a, __same_type(a, NULL) ? 0 : sizeof(a)/sizeof(*a) > +#define _INTC_ARRAY(a) a, sizeof(a)/(_Generic((a), typeof(NULL): 0xFFFFFFFFU, default: sizeof(*a)))
s/: / : / in 2 places.
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
How far back in gcc versions does this work?
Thanks.
> > #define INTC_HW_DESC(vectors, groups, mask_regs, \ > prio_regs, sense_regs, ack_regs) \ >
-- ~Randy
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