On Sat, Oct 29, 2016 at 12:41:43PM -0400, Jason Merrill wrote: > On Sat, Oct 29, 2016 at 12:09 PM, Jakub Jelinek <ja...@redhat.com> wrote: > > Apparently the driver reorders the options, -std=* options come before > > all -f* options, so both of the following patches work the same, except > > when cc1plus is invoked by hand. The first (inlined) patch solves it > > more in line how e.g. -fgnu-keywords and similar options are handled, so I > > think > > it is preferable (and I've successfully bootstrapped/regtested it on > > x86_64-linux and i686-linux). The second (attached) patch handles it > > by not clearing -fext-numeric-literals during option processing > > for -std=* options, just in post option handling clears it for the > > strict c++11+ modes if the option is not specified explicitly. > > If the driver wouldn't reorder the options, it would handle better > > cases like -fext-numeric-literals -std=c++11 to mean the same thing > > as -std=c++11 -fext-numeric-literals etc., but due to the reordering > > it isn't needed and for consistency we'd also need to change -fgnu-keywords > > etc. > > I lean toward the second patch because it keeps the logic in a single > place, but it looks like it doesn't currently handle C++98 > differently. I don't think we need to change the handling of other > options to match.
The second patch has that + /* Unless -f{,no-}ext-numeric-literals has been used explicitly, + for -std=c++{11,14,1z} default to -fno-ext-numeric-literals. */ + if (flag_iso && !global_options_set.x_flag_ext_numeric_literals) + cpp_opts->ext_numeric_literals = 0; in a block guarded with cxx_dialect >= cxx11. So for -std=c++98 it will just not disable them (the same as the other patch, and the same as vanilla trunk/6/5 if just using -std=c++98 and not -std=c++11 -std=c++98; or do you want to change behavior of -std=c++98 to reject those unless using -std=gnu++98 or -std=c++98 -fext-numeric-literals? Pedantically they are GNU extensions, but if we want to be pedantic, -pedantic/-pedantic-errors already rejects those anyway. Jakub