Messages in this thread | | | Date | Fri, 19 Jun 2020 16:12:37 +0200 | From | Luc Van Oostenryck <> | Subject | Re: [PATCH] sparse: use the _Generic() version of __unqual_scalar_typeof() |
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On Fri, Jun 19, 2020 at 11:51:05AM +0200, Marco Elver wrote: > On Fri, Jun 19, 2020 at 12:26AM +0200, Luc Van Oostenryck wrote: > > If the file is being checked with sparse, use the version of > > __unqual_scalar_typeof() using _Generic(), leaving the unoptimized > > version only for the oldest versions of GCC. > > > > This reverts commit > > b398ace5d2ea ("compiler_types.h: Use unoptimized __unqual_scalar_typeof for sparse") > > > > Note: a recent version of sparse will be needed (minimum v0.6.2-rc2 > > or later than 2020-05-28). > > > > Cc: Marco Elver <elver@google.com> > > Cc: Borislav Petkov <bp@suse.de> > > Cc: Will Deacon <will@kernel.org> > > Link: https://marc.info/?l=linux-sparse&m=159233481816454 > > Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> > > Definitely support this change, so in principle: > > Acked-by: Marco Elver <elver@google.com> > > But, I think sparse still isn't entirely happy with all legal uses of > _Generic. Running latest sparse on:
Indeed.
> Whereas GCC or Clang accept this as expected. I can't find the > standardese right now, but in [1] we have: > > "[...] The conversion is performed in type domain only: it > discards the top-level cvr-qualifiers and atomicity and applies > array-to-pointer/function-to-pointer transformations to the type > of the controlling expression [...]" > > [1] https://en.cppreference.com/w/c/language/generic
Yes, these are the rules following the resolution of DR481, which are now used for C17 and also by gcc & clang for C11 but were not present the C11 standard.
This should be fixed now but I'm waiting for the tests results.
Thanks for reporting this. -- Luc
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