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 <el...@google.com>
> > Cc: Borislav Petkov <b...@suse.de>
> > Cc: Will Deacon <w...@kernel.org>
> > Link: https://marc.info/?l=linux-sparse&m=159233481816454
> > Signed-off-by: Luc Van Oostenryck <luc.vanoostenr...@gmail.com>
>
> Definitely support this change, so in principle:
>
> Acked-by: Marco Elver <el...@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
