On Thu, Nov 27, 2008 at 1:34 AM, Duncan <[EMAIL PROTECTED]> wrote: > It's also worth noting that due to Gentoo's gcc slotting, one can use > gcc-config to switch between gcc versions. Thus using a new and still > masked gcc isn't as much of a problem as it might be, since you can use > the new version for most things and switch to the old version for > anything that's still broken with the new version. When an > emerge --emptytree @system @world works just using the new version, you > can then unmerge the old version. > > I've done this over several gcc upgrades, now. > > It works well for C programs, but there can be issues with C++ > occasionally, since gcc provides libstdc++ which must remain compatible. > Over the versions I've done this with, it has been mostly compatible, but > not always 100%. At one point some stuff in KDE would break if I was > switched to the older gcc, since I had compiled it with the newer gcc, > with a mostly compatible libstdc++, but one that added a few new > functions. So anything that used the new functions would break when > switched to the old gcc and thus the old libstdc++. But most of KDE > would work, so I'd switch to the old version just long enough to compile > whatever package wouldn't yet compile with the new gcc, and wouldn't use > the KDE stuff that was broken (basically anything having to do with the > web, IDR whether it was just the web, or all Internet functionality) > while I did so. Then I'd switch back to the newer gcc, and everything > would work again.
Thanks for sharing this option. I gave it a try, so far so good. martindesktop ~ # cat /etc/portage/package.keywords (..) =sys-devel/gcc-4.3.2 =sys-libs/glibc-2.7-r2 Next emerge gcc, output: * If you have issues with packages unable to locate libstdc++.la, * then try running 'fix_libtool_files.sh' on the old gcc versions. martindesktop ~ # cat /etc/make.conf (..) # gcc < 4.2.0 #CFLAGS="-march=nocona -O2 -pipe" # gcc >= 4.2.0 CFLAGS="-march=native -O2 -pipe" (..) Martin
