> I'd like to ping the > https://gcc.gnu.org/pipermail/gcc-patches/2025-March/679182.html > patch. > I know it is quite controversial and if clang wouldn't be the first > to implement this I'd certainly not go that way; I am willing to change > the warning option names or move the maybe one from -Wextra to -Wall > if there is agreement on that. Unfortunately there seems to be > quite a lot of code in the wild that uses this attribute already > and without this patch GCC 15 will simply not be able to compile that > (whether it is firefox (skia etc.), protobuf, ...).
FWIW the patch looks good to me. > > The only other option is IMHO to drop the musttail attribute support > for GCC 15 or name it differently with different semantics. > But not sure projects in the wild will like to annotate their calls > with two different musttail like attributes if they satisfy behavior > of both. Projects that are serious about the performance will also need to use __attribute__((no_callee_saved_registers)) and that is different than the clang equivalent. So some ifdefery is needed anyways. -Andi
