Re: [PATCH 3/4] configure: propagate --extra-cflags and --extra-ldflags to meson compile tests

[Paolo Bonzini <pbonzini@redhat.com>]

On 11/8/21 10:11, Thomas Huth wrote:
>> +    EXTRA_CXXFLAGS="$EXTRA_CXXFLAGS $optarg"
> 
> I'd rather drop that EXTRA_CXXFLAGS line here - I think that calls for 
> trouble otherwise if a user is trying to add a C compiler option that is 
> not supported in C++ mode.
> If the users have some options that need to be passed to both, C and 
> C++, they should simply use --extra-cxxflags in addition instead.

True, but that is needed to preserve previous behavior, where 
QEMU_CXXFLAGS is initialized with QEMU_CFLAGS in update_cxxflags.

update_cxxflags does not do any filtering either, except for some -W 
options that shouldn't be in --extra-cflags.  So (apart from those -W 
options) a C-only option wouldn't have worked before with 
--extra-cflags, either.

Paolo