Re: [gentoo-user] Re: How does Gentoo deal with GCC's header fixes?

[Alan McKinnon <alan.mckinnon@gmail.com>]

Apparently, though unproven, at 18:26 on Thursday 09 September 2010, Volker 
Armin Hemmann did opine thusly:

> On Thursday 09 September 2010, walt wrote:
> > On 09/08/2010 03:10 PM, Nikos Chantziaras wrote:
> > > When building GCC, it will scan all headers in /usr/include and apply
> > > fixes to them, and then copy them and use the modified versions.  Now a
> > > binary distro (AFAIK) will ship the GCC modified headers, so there's no
> > > problem.
> > > 
> > > Gentoo on the other hand will work as intended by GCC only if the user
> > > re-emerges GCC after every time a package is emerged that installs
> > > headers. Obviously, no user does that.
> > > 
> > > So the question is simple; does Gentoo deal with this problem in any
> > > way?
> > 
> > Maybe I misunderstand your question, but AFAIK the only reason to
> > re-compile any package is if the libraries it links to have changed, no?
> > 
> > AFAICS gcc links only to libraries installed by glibc. therefore in the
> > case of recompiling gcc itself, it should need/use only the headers
> > installed by glibc.
> > 
> > (And the only reason to re-compile an existing glibc is if the linux
> > kernel headers change.  I always re-compile glibc when the linux kernel
> > headers change, but I never thought about re-compiling gcc as well. 
> > Maybe I should.)
> > 
> > Corrections are requested if I'm wrong about all of this.
> 
> hm, I never recompile glibc after a header update.... or anything else....


Me neither :-)

I know I should, and why. But don't.

I think the glibc and toolchain devs think the same way and go to 
extraordinary lengths to make sure stuff still works no matter hwo you go 
about it.



-- 
alan dot mckinnon at gmail dot com