Re: [PATCH v2 1/6] MdePkg/BaseLib: Refine (Ascii)StrnLenS functions logic

["Gao, Liming" <liming.gao@intel.com>]

Reviewed-by: Liming Gao <liming.gao@intel.com>

> -----Original Message-----
> From: Wu, Hao A
> Sent: Friday, December 16, 2016 11:38 AM
> To: edk2-devel@lists.01.org
> Cc: Wu, Hao A <hao.a.wu@intel.com>; Yao, Jiewen <jiewen.yao@intel.com>;
> Gao, Liming <liming.gao@intel.com>; Kinney, Michael D
> <michael.d.kinney@intel.com>
> Subject: [PATCH v2 1/6] MdePkg/BaseLib: Refine (Ascii)StrnLenS functions
> logic
> 
> This commit refines the logic for AsciiStrnLenS and StrnLenS. It makes the
> logic more straightforward to prevent possible mis-reports by static code
> checkers.
> 
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Liming Gao <liming.gao@intel.com>
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Hao Wu <hao.a.wu@intel.com>
> ---
>  MdePkg/Library/BaseLib/SafeString.c | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/MdePkg/Library/BaseLib/SafeString.c
> b/MdePkg/Library/BaseLib/SafeString.c
> index ede2f4c..e4c0759 100644
> --- a/MdePkg/Library/BaseLib/SafeString.c
> +++ b/MdePkg/Library/BaseLib/SafeString.c
> @@ -143,8 +143,12 @@ StrnLenS (
>    // String then StrnLenS returns MaxSize. At most the first MaxSize
> characters of String shall
>    // be accessed by StrnLenS.
>    //
> -  for (Length = 0; (Length < MaxSize) && (*String != 0); String++, Length++) {
> -    ;
> +  Length = 0;
> +  while (String[Length] != 0) {
> +    if (Length >= MaxSize - 1) {
> +      return MaxSize;
> +    }
> +    Length++;
>    }
>    return Length;
>  }
> @@ -571,8 +575,12 @@ AsciiStrnLenS (
>    // String then AsciiStrnLenS returns MaxSize. At most the first MaxSize
> characters of String shall
>    // be accessed by AsciiStrnLenS.
>    //
> -  for (Length = 0; (Length < MaxSize) && (*String != 0); String++, Length++) {
> -    ;
> +  Length = 0;
> +  while (String[Length] != 0) {
> +    if (Length >= MaxSize - 1) {
> +      return MaxSize;
> +    }
> +    Length++;
>    }
>    return Length;
>  }
> --
> 1.9.5.msysgit.0