Messages in this thread Patch in this message |  | | Date | Sun, 22 Jan 2023 21:51:39 +0100 | From | Michael Karcher <> | Subject | [PATCH v3 1/1] arch/sh: avoid spurious sizeof-pointer-div warning |
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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> --- History: v3: - I had a stern discussion with Thunderbird about not mangling the space characters in my email, and I hope spaces get sent as standard spaces now v2: - improve title and remove mostly redundant first sentence of the description - adjust formatting of the _Generic construction
diff --git a/include/linux/sh_intc.h b/include/linux/sh_intc.h index c255273b0281..98d1da0d8e36 100644 --- a/include/linux/sh_intc.h +++ b/include/linux/sh_intc.h @@ -97,7 +97,9 @@ 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): (size_t)-1, \ + default: sizeof(*a)))
#define INTC_HW_DESC(vectors, groups, mask_regs, \ prio_regs, sense_regs, ack_regs) \
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