Re: [PATCH 05/47] MdePkg/Include/Base.h: introduce the ARRAY_SIZE() function-like macro

["Kinney, Michael D" <michael.d.kinney@intel.com>]

Hi Laszlo,

One comment inline below.

Mike

> -----Original Message-----
> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Laszlo Ersek
> Sent: Wednesday, October 26, 2016 12:04 PM
> To: edk2-devel-01 <edk2-devel@ml01.01.org>
> Cc: Ni, Ruiyu <ruiyu.ni@intel.com>; Tim He <tim.he@intel.com>; Tian, Feng
> <feng.tian@intel.com>; Kinney, Michael D <michael.d.kinney@intel.com>; Dong, Eric
> <eric.dong@intel.com>; Cecil Sheng <cecil.sheng@hpe.com>; Ard Biesheuvel
> <ard.biesheuvel@linaro.org>; Justen, Jordan L <jordan.l.justen@intel.com>; Gao, Liming
> <liming.gao@intel.com>; Bi, Dandan <dandan.bi@intel.com>; Wu, Jiaxin
> <jiaxin.wu@intel.com>; Gary Lin <glin@suse.com>; Zeng, Star <star.zeng@intel.com>;
> Daryl McDaniel <edk2-lists@mc2research.org>; Carsey, Jaben <jaben.carsey@intel.com>;
> Fu, Siyuan <siyuan.fu@intel.com>; Fan, Jeff <jeff.fan@intel.com>; Zhang, Chao B
> <chao.b.zhang@intel.com>; Wei, David <david.wei@intel.com>
> Subject: [edk2] [PATCH 05/47] MdePkg/Include/Base.h: introduce the ARRAY_SIZE()
> function-like macro
> 
> Several modules use ARRAY_SIZE() already; centralize the definition. (The
> module-specific macro definitions are guarded by #ifndef directives at
> this point.)
> 
> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Cc: Cecil Sheng <cecil.sheng@hpe.com>
> Cc: Chao Zhang <chao.b.zhang@intel.com>
> Cc: Dandan Bi <dandan.bi@intel.com>
> Cc: Daryl McDaniel <edk2-lists@mc2research.org>
> Cc: David Wei <david.wei@intel.com>
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Feng Tian <feng.tian@intel.com>
> Cc: Gary Lin <glin@suse.com>
> Cc: Jaben Carsey <jaben.carsey@intel.com>
> Cc: Jeff Fan <jeff.fan@intel.com>
> Cc: Jiaxin Wu <jiaxin.wu@intel.com>
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Liming Gao <liming.gao@intel.com>
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Cc: Ruiyu Ni <ruiyu.ni@intel.com>
> Cc: Siyuan Fu <siyuan.fu@intel.com>
> Cc: Star Zeng <star.zeng@intel.com>
> Cc: Tim He <tim.he@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
> ---
>  MdePkg/Include/Base.h | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/MdePkg/Include/Base.h b/MdePkg/Include/Base.h
> index c66614846488..8bdb257e37bd 100644
> --- a/MdePkg/Include/Base.h
> +++ b/MdePkg/Include/Base.h
> @@ -1211,5 +1211,18 @@ typedef UINTN RETURN_STATUS;
>    #define RETURN_ADDRESS(L)     ((VOID *) 0)
>  #endif
> 
> +/**
> +  Return the number of elements in an array.
> +
> +  @param  Array  An object of array type. Array is only used as an argument to
> +                 the sizeof operator, therefore Array is never evaluated. The
> +                 caller is responsible for ensuring that Array's type is not
> +                 incomplete; that is, Array must have known constant size.
> +
> +  @return The number of elements in Array. The result has type UINTN.
> +
> +**/
> +#define ARRAY_SIZE(Array) (sizeof (Array) / sizeof (Array)[0])
 
I think adding one extra set of () makes this clearer:

#define ARRAY_SIZE(Array) (sizeof (Array) / sizeof ((Array)[0]))

> +
>  #endif
> 
> --
> 2.9.2
> 
> 
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