Re: [Qemu-devel] [PATCH] Drop QEMU_GNUC_PREREQ() checks for gcc older than 4.1

[Paolo Bonzini <pbonzini@redhat.com>]

On 31/01/2017 11:58, Peter Maydell wrote:
> On 31 January 2017 at 16:55, Daniel P. Berrange <berrange@redhat.com> wrote:
>> On Tue, Jan 31, 2017 at 04:14:47PM +0000, Peter Maydell wrote:
>>> We already require gcc 4.1 or newer (for the atomic
>>> support), so the fallback codepaths for older gcc
>>> versions than that are now dead code and we can
>>> just delete them.
>>
>> Do we have any explicit check alreadu for 4.1, or do we
>> just let the build fail on the atomic code ?
>>
>> IOW, is there any use in having..
>>
>> #if !QEMU_GNUC_PREREQ(4, 1)
>> # error "QEMU requires GCC >= 4.1 or CLang"
>> #endif
> 
> I guess we just barf in the atomics. An explicit check might
> not be a bad idea I guess, though it depends a bit on how
> many releases we've been implicitly requiring 4.1 for. I
> suppose it would act as documentation of our current
> minimum req.

We have:

- first occurrence on Linux hosts: 0.13.0 (for vhost)

- first occurrence on non-Linux hosts: 0.15.0 (simpletrace backend),
then backed out in 1.0

- next occurrence on all hosts, but only in tests: 1.4.0

- finally, first occurrence on all hosts with simple ./configure &&
make: 2.0.0

Paolo