Re: [Qemu-devel] [PATCH] build: Use $(CC) for compiling .S files

[Richard Henderson <rth@twiddle.net>]

On 06/20/2016 06:43 AM, Peter Maydell wrote:
> On 18 June 2016 at 07:47, Richard Henderson <rth@twiddle.net> wrote:
>> We fail to pass to AS all of the different flags that
>> may be required for a given set of CFLAGS.  Rather than
>> figuring out the host-specific mapping, it's better to
>> allow the compiler driver to do that.
>>
>> This fixes e.g. ../configure --cpu=i686, but would also
>> be required for ppc and sparc.
>>
>> Signed-off-by: Richard Henderson <rth@twiddle.net>
>
> This is basically reverting commit 3dd46c78525a30e98c68 from
> 2013, which explicitly switched to using separate CPP and
> AS steps "because the C compiler could be unsuitable", by
> which I think it means the failure described here:
> https://lists.gnu.org/archive/html/qemu-devel/2013-01/msg00558.html
> where if the compiler is clang it might not be able to
> handle some of the code we use in the optionrom assembly
> even though 'as' can.
>
> Does that no longer apply ?

Ah, well, no.

But that report is for building ROMs, where AS plus all of the options are 
easily controllable.  Whereas this current problem is where we are linking 
assembly (safe-syscall.S) into the qemu executable.

These are two completely different usages, and ought to be treated as such.


r~