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

[Nikos Chantziaras]

On 09/09/2010 10:17 PM, Alan McKinnon wrote:
> 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.

Just want to point out that this was about GCC's fixed headers, not 
glibc, which makes it off-topic and completely unrelated to the original 
topic :)