Re: RFC: drop support for gcc < 4.0

[Segher Boessenkool <segher@kernel.crashing.org>]

>>> How many people e.g. test -rc kernels compiled with gcc 3.2?
>>
>> Why would that matter?  It either works or not.  If it doesn't
>> work, it can either be fixed, or support for that old compiler
>> version can be removed.
>
> One bug report "kernel doesn't work / crash / ... when compiled with
> gcc 3.2, but works when compiled with gcc 4.2" will most likely be lost
> in the big pile of unhandled bugs, not cause the removal of gcc 3.2
> support...

While that might be true, it's a separate problem.

>> The only other policy than "only remove support if things are
>> badly broken" would be "only support what the GCC team supports",
>> which would be >= 4.1 now; and there are very good arguments for
>> supporting more than that with the Linux kernel.
>
> No, it's not about bugs in gcc, it's about kernel+gcc combinations that
> are mostly untested but officially supported.

What does "officially supported" mean?  Especially the
"officially" part.  Is this documented somewhere?

> E.g. how many kernel developers use kernels compiled without
> unit-at-a-time? And unit-at-a-time does paper over some bugs,
> e.g. at about half a dozen section mismatch bugs I've fixed
> recently are not present with it.

If any developer is interested in supporting some certain old
compiler version, he should be testing regularly with it.  Sounds
like that's you ;-)

If no developer is interested, we shouldn't claim to support
using that compiler version.

> But as the discussions have shown gcc 4.0 is currently too high for
> making a cut, and it is not yet the right time for raising the minimum
> required gcc version.

Agreed.


Segher