Messages in this thread | | | Date | Tue, 24 Jan 2023 08:41:21 -0800 | Subject | Re: [PATCH v5 1/1] arch/sh: avoid spurious sizeof-pointer-div warning | From | Randy Dunlap <> |
| |
On 1/24/23 00:11, John Paul Adrian Glaubitz wrote: > Hello! > > On 1/23/23 21:05, Michael Karcher wrote: >> 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 >> inhttps://gcc.gnu.org/bugzilla/show_bug.cgi?id=108483 by Jakub Jelinek >> >> Signed-off-by: Michael Karcher<kernel@mkarcher.dialup.fu-berlin.de> >> --- >> History: >> v5: >> - Cleanly generated the patch >> v4: >> - Put the case distinction into the numerator instead of the denominator >> - Refactor the case disctinction into a second macro >> 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..37ad81058d6a 100644 >> --- a/include/linux/sh_intc.h >> +++ b/include/linux/sh_intc.h >> @@ -97,7 +97,10 @@ struct intc_hw_desc { >> unsigned int nr_subgroups; >> }; >> >> -#define _INTC_ARRAY(a) a, __same_type(a, NULL) ? 0 : sizeof(a)/sizeof(*a) >> +#define _INTC_SIZEOF_OR_ZERO(a) (_Generic(a, \ >> + typeof(NULL): 0, \ >> + default: sizeof(a))) >> +#define _INTC_ARRAY(a) a, _INTC_SIZEOF_OR_ZERO(a)/sizeof(*a) >> >> #define INTC_HW_DESC(vectors, groups, mask_regs, \ >> prio_regs, sense_regs, ack_regs) \ > > Can anyone suggest which tree to pick this up through until we have established a > new linux-sh tree? > > Shall this go through Andrew's tree?
I think Andrew or Arnd could merge it.
-- ~Randy
| |