Re: [Qemu-devel] [PATCH v2] build: include sys/sysmacros.h for major() and minor()

From: Eric Blake <eblake@redhat.com>
To: Christopher Covington <cov@codeaurora.org>, qemu-devel@nongnu.org
Cc: "Marc-André Lureau" <marcandre.lureau@gmail.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v2] build: include sys/sysmacros.h for major() and minor()
Date: Wed, 28 Dec 2016 10:10:56 -0600	[thread overview]
Message-ID: <2a940dc2-05a0-2e91-afc0-eeb560f6ce32@redhat.com> (raw)
In-Reply-To: <20161228145344.30819-1-cov@codeaurora.org>

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On 12/28/2016 08:53 AM, Christopher Covington wrote:
> The definition of the major() and minor() macros are moving within glibc to
> <sys/sysmacros.h>. Include this header to avoid the following sorts of
> build-stopping messages:
> 

> The additional include allows the build to complete on Fedora 26 (Rawhide)
> with glibc version 2.24.90.
> 
> Signed-off-by: Christopher Covington <cov@codeaurora.org>
> ---
>  include/sysemu/os-posix.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/include/sysemu/os-posix.h b/include/sysemu/os-posix.h
> index b0a6c0695b..772d58f7ed 100644
> --- a/include/sysemu/os-posix.h
> +++ b/include/sysemu/os-posix.h
> @@ -28,6 +28,7 @@
>  
>  #include <sys/mman.h>
>  #include <sys/socket.h>
> +#include <sys/sysmacros.h>

I repeat what I said on v1:

Works for glibc; but <sys/sysmacros.h> is non-standard and not present
on some other systems, so this may fail to build elsewhere.  You'll
probably need a configure probe.  Autoconf also says that some platforms
have <sys/mkdev.h> instead of <sys/sysmacros.h> (per its AC_HEADER_MAJOR
macro).

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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