Re: [PATCH] ARC: Add guard macro to uapi/asm/unistd.h

[Chen Gang <gang.chen.5i5j@gmail.com>]

On 11/21/2013 06:29 PM, Vineet Gupta wrote:
> Chen originally proposed this as "right thing to do" however I
> actually ran into this when building perf tools. Some of the utils
> include unistd.h as well as linux/unistd.h. Since -I includes kernel
> headers too, we end up including the ARC unistd.h twice, leading to
> redefinition nwarnings.
> 
> ------------------>8-------------------
>     CC bench/sched-pipe.o
> In file included from ~/kernel/arch/arc/include/uapi/asm/unistd.h:21:0,
>                  from ~/kernel/include/uapi/linux/unistd.h:7,
>                  from bench/sched-pipe.c:24:
> ~/kernel/include/uapi/asm-generic/unistd.h:889:0: error: "__NR_fcntl64"
> redefined [-Werror]
>  #define __NR_fcntl64 __NR3264_fcntl
>  ^
> In file included from
> ~/gnu/arc-linux-uclibc/sys-include/sys/syscall.h:24:0,
>                  from bench/../perf.h:112,
>                  from bench/sched-pipe.c:13:
> ~/gnu/arc-linux-uclibc/include/bits/sysnum.h:761:0: note: this is the
> location of the previous definition
> ------------------>8-------------------
> 
> Verified that make headers_install works fine with this.
> 
> Suggested-by: Chen Gang <gang.chen.5i5j@gmail.com>
> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
> Cc: David Howells <dhowells@redhat.com>
> ---
> I will be adding this to arc tree for 3.13
> ---
>  arch/arc/include/uapi/asm/unistd.h | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/arc/include/uapi/asm/unistd.h b/arch/arc/include/uapi/asm/unistd.h
> index 6f30484f34b7..68125dd766c6 100644
> --- a/arch/arc/include/uapi/asm/unistd.h
> +++ b/arch/arc/include/uapi/asm/unistd.h
> @@ -8,6 +8,9 @@
>  
>  /******** no-legacy-syscalls-ABI *******/
>  
> +#ifndef _UAPI_ASM_ARC_UNISTD_H
> +#define _UAPI_ASM_ARC_UNISTD_H
> +
>  #define __ARCH_WANT_SYS_EXECVE
>  #define __ARCH_WANT_SYS_CLONE
>  #define __ARCH_WANT_SYS_VFORK
> @@ -32,3 +35,5 @@ __SYSCALL(__NR_arc_gettls, sys_arc_gettls)
>  /* Generic syscall (fs/filesystems.c - lost in asm-generic/unistd.h */
>  #define __NR_sysfs		(__NR_arch_specific_syscall + 3)
>  __SYSCALL(__NR_sysfs, sys_sysfs)
> +
> +#endif
> 

Is it better to append comment for "#endif"?

e.g. "#endif /* _UAPI_ASM_ARC_UNISTD_H */"


Thanks.
-- 
Chen Gang