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On Thu, Nov 27, 2008 at 1:34 AM, Duncan <1i5t5.duncan@×××.net> wrote: |
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> It's also worth noting that due to Gentoo's gcc slotting, one can use |
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> gcc-config to switch between gcc versions. Thus using a new and still |
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> masked gcc isn't as much of a problem as it might be, since you can use |
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> the new version for most things and switch to the old version for |
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> anything that's still broken with the new version. When an |
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> emerge --emptytree @system @world works just using the new version, you |
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> can then unmerge the old version. |
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> |
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> I've done this over several gcc upgrades, now. |
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> |
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> It works well for C programs, but there can be issues with C++ |
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> occasionally, since gcc provides libstdc++ which must remain compatible. |
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> Over the versions I've done this with, it has been mostly compatible, but |
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> not always 100%. At one point some stuff in KDE would break if I was |
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> switched to the older gcc, since I had compiled it with the newer gcc, |
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> with a mostly compatible libstdc++, but one that added a few new |
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> functions. So anything that used the new functions would break when |
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> switched to the old gcc and thus the old libstdc++. But most of KDE |
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> would work, so I'd switch to the old version just long enough to compile |
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> whatever package wouldn't yet compile with the new gcc, and wouldn't use |
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> the KDE stuff that was broken (basically anything having to do with the |
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> web, IDR whether it was just the web, or all Internet functionality) |
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> while I did so. Then I'd switch back to the newer gcc, and everything |
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> would work again. |
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Thanks for sharing this option. I gave it a try, so far so good. |
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martindesktop ~ # cat /etc/portage/package.keywords |
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(..) |
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=sys-devel/gcc-4.3.2 |
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=sys-libs/glibc-2.7-r2 |
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Next emerge gcc, output: |
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* If you have issues with packages unable to locate libstdc++.la, |
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* then try running 'fix_libtool_files.sh' on the old gcc versions. |
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martindesktop ~ # cat /etc/make.conf |
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(..) |
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# gcc < 4.2.0 |
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#CFLAGS="-march=nocona -O2 -pipe" |
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# gcc >= 4.2.0 |
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CFLAGS="-march=native -O2 -pipe" |
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(..) |
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Martin |
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