On Sat, Aug 15, 2009 at 8:50 AM, Alan McKinnon<[email protected]> wrote: > On Saturday 15 August 2009 02:33:56 [email protected] wrote: >> This being 4.3.4 to 4.1.1 looks like a major version change according >> to the upgrade guide. It doesn't mention what a switch manual takes, >> but it does list a whole series of steps such as remerging system and >> world without saying exactly when they or how much are necessary. I'd >> just as soon not do that unless necessary, but I'd much more regret >> not doing it if I should have. > > All you need to do for this gcc-config is select the new compiler for the > system, but only if you choose to. > > There are no other steps. If a system rebuild is necessary, the upgrade guide > will say so in terms that make for no confusion, and the ebuild elog will say > the same. They do not, so there is no need. > > Look, the amount of confusion in gentoo-land about gcc upgrades defies belief. > The upgrade guide explicitly says it is talking about going from a named > version X to another named version Y, and somehow vast numbers of people morph > this into somehow meaning that it must always be done. This is not true. > > It only needs to be done when the compiler introduces ABI changes that make > new object code incompatible with old object code that the new code intends to > use. And it is always well-publicised when this happens (it couldn't be any > other way, the dev's reputations depends on them doing exactly that.) > > -- > alan dot mckinnon at gmail dot com > > Alan, I agree with your description, but I disagree that the upgrade guide is actually very clear about this. It has us upgrade the compiler (OK), switch to the new compiler (OK), rebuild the libtool stuff (OK) then then states:
http://www.gentoo.org/doc/en/gcc-upgrading.xml <QUOTE> To be completely safe that your system is in a sane state, you must rebuild the toolchain and then world to make use of the new compiler. Code Listing 2.2: Rebuilding system # emerge -eav system # emerge -eav world </QUOTE> Who, reading this, wouldn't want to be safe and sane? I doesn't say 'might', 'could' or even 'should'. It says 'must'. I agree that in the case of 4.3 to 4.4 it *probably* isn't necessary, but that isn't what the guide says. In fact, a bit earlier on it specifically states that bug fix releases - 3.3.5 to 3.3.6 - *should be* safe, implying to me that something bigger than a bug fix (4.3 to 4.4?) might not be. Now, I'm not arguing with you in the least, but I think that if my reading of the guide isn't correct in terms of simply understanding what the words say then someone with the proper background needs to work on the doc a bit. - Mark
