gcc 4.9 build warnings (was: Re: next build: 2674 warnings 1 failures (next/next-20141022))

[Russell King - ARM Linux]

On Fri, Oct 24, 2014 at 11:13:27AM +0200, Arnd Bergmann wrote:
> Ok, that also explains the problems with the missing __linux__ macro, given
> Ard's reply about bare-metal gcc.
> 
> I think we have two choices here:
> 
> a) change the buildall script so it actually builds a compiler that behaves
>    in the way we expect for the kernel (__SIZE_TYPE__ and __linux__ at least,
>    possibly others)
> 
> b) change the kernel to work with the way the bare-metal compiler is built,
>    adding -D__linux__ in the ARM Makefile and applying Ard's workaround for
>    __SIZE_TYPE__/__INT32_TYPE__/__UINT32_TYPE__/__UINTPTR_TYPE__.
> 
> Both options are a little hacky and I don't really like them, but I think
> it makes sense to do one of them.

Well, (a) is probably the right answer.  EABI had (or still has) the
idea that enums can be a dynamic size, and this was taken out of the
Linux version of EABI.  What this means is that an enum used across an
interface between a compiler targetting Linux and one not targetting
Linux may not be compatible.

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