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SubjectRe: [PATCH v2 2/4] linux/const.h: move UL() macro to include/linux/const.h
Date
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> diff --git a/include/uapi/linux/const.h b/include/uapi/linux/const.h
> index c872bfd..76fb0f9 100644
> --- a/include/uapi/linux/const.h
> +++ b/include/uapi/linux/const.h
> @@ -1,7 +1,7 @@
> /* const.h: Macros for dealing with constants. */
>
> -#ifndef _LINUX_CONST_H
> -#define _LINUX_CONST_H
> +#ifndef _UAPI_LINUX_CONST_H
> +#define _UAPI_LINUX_CONST_H

You need to be very careful doing this. Some userspace stuff depends on the
guard macro names on the kernel header files.

> /* Some constant macros are used in both assembler and
> * C code. Therefore we cannot annotate them always with
> @@ -21,7 +21,10 @@
> #define _AT(T,X) ((T)(X))
> #endif
>
> +#define _UL(x) (_AC(x, UL))
> +#define _ULL(x) (_AC(x, ULL))

How likely is this to collide with existing userspace code somewhere? It
looks like the sort of thing that could collide with a C library.

David

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