Re: [Qemu-devel] [PATCH for-4.0] compiler.h: Add an explicit check for the compiler version

[Paolo Bonzini <pbonzini@redhat.com>]

On 30/11/18 11:43, Thomas Huth wrote:
> The questions about our minimum compiler requirement pops up every
> couple of months, and we then have to recall the details each time.
> So let's document this in a proper way, by adding a comment and
> check for the right compiler version to our compiler.h header.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  include/qemu/compiler.h | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
> index ca9bc85..775446b 100644
> --- a/include/qemu/compiler.h
> +++ b/include/qemu/compiler.h
> @@ -22,6 +22,14 @@
>  # define QEMU_GNUC_PREREQ(maj, min) 0
>  #endif
>  
> +/*
> + * We need at least GCC 4.1 for atomics support. Clang also supports these,
> + * and reports itself as GCC 4.2, so it passes this check, too.
> + */
> +#if !QEMU_GNUC_PREREQ(4, 1)
> +#error QEMU needs a compiler that is compatible with GCC v4.1 or newer
> +#endif
> +
>  #define QEMU_NORETURN __attribute__ ((__noreturn__))
>  
>  #define QEMU_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
> 

Queued, thanks.

Paolo