On Sat, 16 Jun 2018 at 13:38, U.Mutlu <um@xxxxxxxxxxx> wrote:
> Jonathan Wakely wrote on 06/16/2018 02:10 PM:
> > On Sat, 16 Jun 2018 at 13:08, U.Mutlu <um@xxxxxxxxxxx> wrote:
> >
> >> I've successfully built a bootstrap version and installed it under
> >> /usr/local, and set the environment vars (in ~/.bashrc) appropriately,
> >> so that the new compiler can be used.
> >>
> >> Now, after that step I do another build, but now with the
> >> --disable-bootstrap
> >> option.
> >> But in this case it uses the system-compiler(!). I think this is a bug
> b/c
> >> if I do a full bootstrap build instead, then that new one gets compiled
> >> with
> >> the new compiler, as it should.
> >>
> >>
> >> I can verify it from the output of this:
> >> $ echo "int main() { return 0; }" | g++-latest -Q -v -x c++ -Ofast -
> >>
> >> (g++-latest being the name of the new compiler)
> >>
> >>
> >> If the compiler was generated w/o --disable-bootstrap (ie. a full
> build),
> >> it says:
> >> compiled by GNU C version 9.0.0 20180616 (experimental) [trunk
> >> revision 261680], GMP version 6.1.0, MPFR version 3.1.4, MPC version
> >> 1.0.3,
> >> isl version isl-0.18-GMP
> >>
> >> If the compiler was generated with --disable-bootstrap, it says:
> >> compiled by GNU C version 4.9.2, GMP version 6.1.0, MPFR
> version
> >> 3.1.4, MPC version 1.0.3, isl version isl-0.18-GMP
> >>
> >> (4.9.2 being the system-compiler)
> >>
> >>
> >> I would like to have all subsequent builds use the newly generated
> >> compiler.
> >> As said above, this works only if --disable-bootstrap was not given, ie.
> >> with
> >> full builds.
> >>
> >> Why does it in one of the two cases switch back to the old system
> compiler?
> >> Is this inconsistency a possible bug?
> >>
> >
> > No, it's what bootstrap means.
> >
> > If you do a full bootstrap then the system compiler is used to build the
> > new GCC, then the new GCC is used to build itself (twice, to compare them
> > and ensure they are the same).
> >
> > If you disable bootstrap then GCC is just built once by the system
> compiler.
> >
> > What you're seeing is exactly what is supposed to happen. If you want GCC
> > to be built by the new compiler then don't use --disable-bootstrap.
>
> Yes, but the full-build takes a whoppy ~ 111 minutes here, whereas
> the non-bootstrap build takes only 12 minutes to make. A big difference.
>
> How can I use the quick build variant with the new compiler?
>
How do you expect to use the new compiler without building the new compiler?
> If I don't use --disable-bootstrap, as you suggest, then it takes,
> as said, ~ 111 minutes to make... :-(
>
>
>
