Re: [PATCH] kernel: add support for gcc 5

Re: [PATCH] kernel: add support for gcc 5

[Andrew Morton]

On Thu,  4 Sep 2014 11:37:19 -0400 Sasha Levin <sasha.levin@oracle.com> wrote:

> We're missing include/linux/compiler-gcc5.h which is required now
> because gcc branched off to v5 in trunk.
> 
> Just copy the relevant bits out of include/linux/compiler-gcc4.h,
> no new code is added as of now.
> 
> This fixes a build error when using gcc 5.

I think I'll stick a cc:stable on this one, as people will presumably
wish to compile older kernels with newer gcc's at some time in the
future.

Re: [PATCH] kernel: add support for gcc 5

[Richard Weinberger]

On Thu, Sep 4, 2014 at 11:12 PM, Andrew Morton
<akpm@linux-foundation.org> wrote:
> On Thu,  4 Sep 2014 11:37:19 -0400 Sasha Levin <sasha.levin@oracle.com> wrote:
>
>> We're missing include/linux/compiler-gcc5.h which is required now
>> because gcc branched off to v5 in trunk.
>>
>> Just copy the relevant bits out of include/linux/compiler-gcc4.h,
>> no new code is added as of now.
>>
>> This fixes a build error when using gcc 5.
>
> I think I'll stick a cc:stable on this one, as people will presumably
> wish to compile older kernels with newer gcc's at some time in the
> future.

CC'ing Hannes, he sent a much simpler gcc5 patch a few days ago.
https://lkml.org/lkml/2014/8/26/710

-- 
Thanks,
//richard

Re: [PATCH] kernel: add support for gcc 5

[Andrew Morton]

On Thu, 4 Sep 2014 23:19:34 +0200 Richard Weinberger <richard.weinberger@gmail.com> wrote:

> On Thu, Sep 4, 2014 at 11:12 PM, Andrew Morton
> <akpm@linux-foundation.org> wrote:
> > On Thu,  4 Sep 2014 11:37:19 -0400 Sasha Levin <sasha.levin@oracle.com> wrote:
> >
> >> We're missing include/linux/compiler-gcc5.h which is required now
> >> because gcc branched off to v5 in trunk.
> >>
> >> Just copy the relevant bits out of include/linux/compiler-gcc4.h,
> >> no new code is added as of now.
> >>
> >> This fixes a build error when using gcc 5.
> >
> > I think I'll stick a cc:stable on this one, as people will presumably
> > wish to compile older kernels with newer gcc's at some time in the
> > future.
> 
> CC'ing Hannes, he sent a much simpler gcc5 patch a few days ago.
> https://lkml.org/lkml/2014/8/26/710

That approach won't last for long - as soon as we add some
gcc5-specific thing, we'll need a new file.

Let history be a guide:

diff -u include/linux/compiler-gcc3.h include/linux/compiler-gcc4.h

Re: [PATCH] kernel: add support for gcc 5

[Sasha Levin]

On 09/04/2014 05:25 PM, Andrew Morton wrote:
> On Thu, 4 Sep 2014 23:19:34 +0200 Richard Weinberger <richard.weinberger@gmail.com> wrote:
> 
>> On Thu, Sep 4, 2014 at 11:12 PM, Andrew Morton
>> <akpm@linux-foundation.org> wrote:
>>> On Thu,  4 Sep 2014 11:37:19 -0400 Sasha Levin <sasha.levin@oracle.com> wrote:
>>>
>>>> We're missing include/linux/compiler-gcc5.h which is required now
>>>> because gcc branched off to v5 in trunk.
>>>>
>>>> Just copy the relevant bits out of include/linux/compiler-gcc4.h,
>>>> no new code is added as of now.
>>>>
>>>> This fixes a build error when using gcc 5.
>>>
>>> I think I'll stick a cc:stable on this one, as people will presumably
>>> wish to compile older kernels with newer gcc's at some time in the
>>> future.
>>
>> CC'ing Hannes, he sent a much simpler gcc5 patch a few days ago.
>> https://lkml.org/lkml/2014/8/26/710
> 
> That approach won't last for long - as soon as we add some
> gcc5-specific thing, we'll need a new file.
> 
> Let history be a guide:
> 
> diff -u include/linux/compiler-gcc3.h include/linux/compiler-gcc4.h

I didn't see Hannes version before sending mine, apologies for that.

Right now something in gcc5 seems to be broken since my test VMs refuse
to even load up their *very* trivial userspace properly (/bin/bash just
hangs) so I suspect we'll have changes to that file even before the first
official version of gcc5 is out.


Thanks,
Sasha

Re: [PATCH] kernel: add support for gcc 5

[H. Peter Anvin]

On 09/04/2014 02:25 PM, Andrew Morton wrote:
>>
>> CC'ing Hannes, he sent a much simpler gcc5 patch a few days ago.
>> https://lkml.org/lkml/2014/8/26/710
> 
> That approach won't last for long - as soon as we add some
> gcc5-specific thing, we'll need a new file.
> 
> Let history be a guide:
> 
> diff -u include/linux/compiler-gcc3.h include/linux/compiler-gcc4.h

It seems much saner to do that branching when we actually need to.  In
the meantime I suspect that a handful of redefinitions would actually be
cleaner.

	-hpa