On Tue, 9 Apr 2024, Jan Hubicka wrote: > > The following adjusts -flto option processing in lto-wrapper to have > > link-time -flto override any compile time setting. > > > > LTO-boostrapped on x86_64-unknown-linux-gnu, testing in progress. > > > > OK for trunk and branches? GCC 11 seems to be unaffected by this. > > > > Thanks, > > Richard. > > > > PR lto/114655 > > * lto-wrapper.cc (merge_flto_options): Add force argument. > > (merge_and_complain): Do not force here. > > (run_gcc): But here to make the link-time -flto option override > > any compile-time one. > Looks good to me. I am actually surprised we propagate -flto settings > from compile time at all. I guess I never tried it since I never > assumed it to work :)
We do magic now ;) I think this was done because while people manage to use CFLAGS=-flto they eventually fail to adjust LDFLAGS and without plugin auto-loading you won't get LTO and in particular not -flto=auto. I checked that it now works as expected - fortunately -v now displays the make invocation command, so it was easy to verify. Richard.
