On Wed, May 24, 2017 at 10:20 AM, Jonathan Wakely <jwak...@redhat.com> wrote: > On 23/05/17 16:26 -0400, Jason Merrill wrote: >> >> On Tue, May 23, 2017 at 2:00 PM, Jonathan Wakely <jwak...@redhat.com> >> wrote: >>> >>> On 19/05/17 15:14 -0400, Jason Merrill wrote: >>>> >>>> >>>> On Thu, Apr 27, 2017 at 12:59 PM, Jonathan Wakely <jwak...@redhat.com> >>>> wrote: >>>>> >>>>> >>>>> I also tried to add a warning like EDG's (see the PR) but it gave a >>>>> false positive for direct-list-init of scoped enums (P0138R2, r240449) >>>>> because that code goes through build_c_cast to perform the conversion, >>>>> so looks like a cast to my new warning. >>>> >>>> >>>> >>>> The enum init code could strip the cv-quals when calling build_c_cast >>>> to avoid the warning. >>> >>> >>> >>> Thanks, that works. I don't think this warning fits under any existing >>> option, so I'll add a new one. -Wuseless-cast-qual maybe? Or is that >>> too close to -Wuseless-cast and -Wcast-qual and would cause confusion? >> >> >> -Wcast-rvalue-qual ? > > > I realised that -Wignored-qualifiers is a good fit. That warns about > ignored cv-qualifiers on return types, which is a very similar case. > > This patch adds a new function to conditionally warn and calls that > from the build_*_cast functions after they produce a valid result. I > originally put the warnings next to the cv_unqualified calls that > strip the quals, but was getting duplicate warnings when build_cp_cast > calls more than one of the build_*_cast_1 functions. > > This also removes the unnecessary check for reference types that > Nathan pointed out. > > Tested x86_64-linux and powerpc64-linux. OK for trunk?
> +/* > + Warns if the cast ignores cv-qualifiers on TYPE. > + */ The GCC sources don't put /* and */ on their own line. OK with that change, thanks! Jason
