Messages in this thread | | | Date | Wed, 26 Feb 2014 20:32:07 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH V2] sparse: Allow override of sizeof(bool) warning |
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On 02/26/2014 08:26 PM, Ben Pfaff wrote: > >> Because sizeof(_Bool) is a little bit special compare to sizeof(long). >> In the case of long, all sizeof(long) * 8 bits are use in the actual value. >> But for the _Bool, only the 1 bit is used in the 8 bits size. In other words, >> the _Bool has a special case of the actual bit size is not a multiple of 8.
Quite frankly, this is silly in my opinion, *and* it is not guaranteed by C either (read about "trap representations").
>> Sparse has two hats, it is a C compiler front end, and more often it is >> used in the Linux kernel source sanitize checking. Depending on the sizeof >> _Bool sounds a little bit suspicious in the kernel. I would love to the heard >> your actual usage case of the sizeof(_Bool). Why do you care about this >> warning?
Anything that moves data around in a generic fashion. It can be as simple as:
memcpy(foo, bar, sizeof *foo);
-hpa
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