Messages in this thread | | | Subject | Re: drivers/infiniband/hw/qib/qib_sysfs.c:413:1: error: static_assert expression is not an integral constant expression | From | Nathan Chancellor <> | Date | Mon, 13 Sep 2021 12:13:45 -0700 |
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On 9/13/2021 12:02 PM, Jason Gunthorpe wrote: > On Mon, Sep 13, 2021 at 11:53:25AM -0700, Nathan Chancellor wrote: >> On Mon, Sep 13, 2021 at 03:38:13PM -0300, Jason Gunthorpe wrote: >>> On Mon, Sep 13, 2021 at 10:00:02AM -0700, Nick Desaulniers wrote: >>> >>>>> This macro would like to know that the passed in member name has a u64 >>>>> type, all the things I've come up with fail on clang - but many work >>>>> fine on gcc. Frankly I think this case is a clang bug myself.. >>>> >>>> Perhaps, though this assertion looks a bit like offsetof() to me. I >>>> wonder if that can help here? >>> >>> The assertion would logically like to be this: >>> >>> static_assert(typecheck(((struct qib_port *)0)->N, u64)) >> >> This works for me with both GCC and clang, if that is acceptable to you? >> It fails if you change one of the variables to 'u32'. > > Yes, thanks. Can't say I've even heard of __same_type before :\ would > be nice if this was in typecheck.h along with the other variations of > the same idea. Presumably it is a little bit different from those > somehow?
Good question... commit d2c123c27db8 ("module_param: add __same_type convenience wrapper for __builtin_types_compatible_p") introduced it so that it could be used in commit fddd52012295 ("module_param: allow 'bool' module_params to be bool, not just int."); I am guessing that typecheck() could not be used in those cases. Perhaps all instances of typecheck() could be converted to __same_type()?
Do you want me to send a formal patch for that diff?
Cheers, Nathan
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