Re: Can we make gfortran the default Fortran?

[David Holland <dholland-pkgtech%netbsd.org@localhost>]

On Mon, Jan 01, 2018 at 07:59:15PM +0000, coypu%sdf.org@localhost wrote:
 > > Also I have a feeling that on various vintage platforms bootstrapping
 > > to gcc5 will require multiple stages...
 > 
 > It won't require multiple stages, it will require multiple hours-days of
 > work to restore support that was removed entirely.

...?

 > this all boils down to some people not believing gcc's libraries are
 > somewhat backwards compatible, at least to a sensible degree.

You yourself just posted in chat an example of a program that was
linked to two different versions of libstdc++ at once. That doesn't
work. It may run, partly, or sometimes, depending on what's actually
incompatible between the two libstdc++ versions, but any success you
see is entirely by luck.

 > if we make this assumption we cannot use pkgsrc GCC at all,
 > because base libraries might also be linked to libgcc, and so a new gcc
 > comes with a new libgcc, which you claim is not backwards compatible.

The big issue is libstdc++, not libgcc.

Ending up with two incompatible versions of libgcc at once would also
be a problem, and yes if that happens you're SOL. Is this an issue in
practice? Do you have any binaries that have gotten linked to multiple
libgcc versions?

-- 
David A. Holland
dholland%netbsd.org@localhost