Re: [PATCH 3/6] MdePkg/MemoryLib: Refine InternalMemSetMem16|32|64 functions logic

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

Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>

> -----Original Message-----
> From: Wu, Hao A
> Sent: Wednesday, December 14, 2016 3:27 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 3/6] MdePkg/MemoryLib: Refine InternalMemSetMem16|32|64 functions
> logic
> 
> This commit refines the logic for InternalMemSetMem16|32|64 functions. It
> avoids using the decrement operator '--' for array index to prevent
> possible mis-reports by static code checkers.
> 
> Please note that those modified functions are only consumed within
> MemoryLib by APIs SetMem16|32|64, and those APIs will handle the case when
> the input number of bytes to set is 0. Hence, the behavior of APIs
> SetMem16|32|64 is not changed.
> 
> 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/BaseMemoryLib/MemLibGeneric.c | 18 +++++++++---------
>  MdePkg/Library/PeiMemoryLib/MemLibGeneric.c  | 18 +++++++++---------
>  MdePkg/Library/UefiMemoryLib/MemLibGeneric.c | 18 +++++++++---------
>  3 files changed, 27 insertions(+), 27 deletions(-)
> 
> diff --git a/MdePkg/Library/BaseMemoryLib/MemLibGeneric.c
> b/MdePkg/Library/BaseMemoryLib/MemLibGeneric.c
> index b058be8..cf40ace 100644
> --- a/MdePkg/Library/BaseMemoryLib/MemLibGeneric.c
> +++ b/MdePkg/Library/BaseMemoryLib/MemLibGeneric.c
> @@ -37,9 +37,9 @@ InternalMemSetMem16 (
>    IN      UINT16                    Value
>    )
>  {
> -  do {
> -    ((UINT16*)Buffer)[--Length] = Value;
> -  } while (Length != 0);
> +  for (; Length != 0; Length--) {
> +    ((UINT16*)Buffer)[Length - 1] = Value;
> +  }
>    return Buffer;
>  }
> 
> @@ -61,9 +61,9 @@ InternalMemSetMem32 (
>    IN      UINT32                    Value
>    )
>  {
> -  do {
> -    ((UINT32*)Buffer)[--Length] = Value;
> -  } while (Length != 0);
> +  for (; Length != 0; Length--) {
> +    ((UINT32*)Buffer)[Length - 1] = Value;
> +  }
>    return Buffer;
>  }
> 
> @@ -85,9 +85,9 @@ InternalMemSetMem64 (
>    IN      UINT64                    Value
>    )
>  {
> -  do {
> -    ((UINT64*)Buffer)[--Length] = Value;
> -  } while (Length != 0);
> +  for (; Length != 0; Length--) {
> +    ((UINT64*)Buffer)[Length - 1] = Value;
> +  }
>    return Buffer;
>  }
> 
> diff --git a/MdePkg/Library/PeiMemoryLib/MemLibGeneric.c
> b/MdePkg/Library/PeiMemoryLib/MemLibGeneric.c
> index 490b244..ed18b57 100644
> --- a/MdePkg/Library/PeiMemoryLib/MemLibGeneric.c
> +++ b/MdePkg/Library/PeiMemoryLib/MemLibGeneric.c
> @@ -37,9 +37,9 @@ InternalMemSetMem16 (
>    IN      UINT16                    Value
>    )
>  {
> -  do {
> -    ((UINT16*)Buffer)[--Length] = Value;
> -  } while (Length != 0);
> +  for (; Length != 0; Length--) {
> +    ((UINT16*)Buffer)[Length - 1] = Value;
> +  }
>    return Buffer;
>  }
> 
> @@ -61,9 +61,9 @@ InternalMemSetMem32 (
>    IN      UINT32                    Value
>    )
>  {
> -  do {
> -    ((UINT32*)Buffer)[--Length] = Value;
> -  } while (Length != 0);
> +  for (; Length != 0; Length--) {
> +    ((UINT32*)Buffer)[Length - 1] = Value;
> +  }
>    return Buffer;
>  }
> 
> @@ -85,9 +85,9 @@ InternalMemSetMem64 (
>    IN      UINT64                    Value
>    )
>  {
> -  do {
> -    ((UINT64*)Buffer)[--Length] = Value;
> -  } while (Length != 0);
> +  for (; Length != 0; Length--) {
> +    ((UINT64*)Buffer)[Length - 1] = Value;
> +  }
>    return Buffer;
>  }
> 
> diff --git a/MdePkg/Library/UefiMemoryLib/MemLibGeneric.c
> b/MdePkg/Library/UefiMemoryLib/MemLibGeneric.c
> index da02b6c..f1efdbb 100644
> --- a/MdePkg/Library/UefiMemoryLib/MemLibGeneric.c
> +++ b/MdePkg/Library/UefiMemoryLib/MemLibGeneric.c
> @@ -37,9 +37,9 @@ InternalMemSetMem16 (
>    IN      UINT16                    Value
>    )
>  {
> -  do {
> -    ((UINT16*)Buffer)[--Length] = Value;
> -  } while (Length != 0);
> +  for (; Length != 0; Length--) {
> +    ((UINT16*)Buffer)[Length - 1] = Value;
> +  }
>    return Buffer;
>  }
> 
> @@ -61,9 +61,9 @@ InternalMemSetMem32 (
>    IN      UINT32                    Value
>    )
>  {
> -  do {
> -    ((UINT32*)Buffer)[--Length] = Value;
> -  } while (Length != 0);
> +  for (; Length != 0; Length--) {
> +    ((UINT32*)Buffer)[Length - 1] = Value;
> +  }
>    return Buffer;
>  }
> 
> @@ -85,9 +85,9 @@ InternalMemSetMem64 (
>    IN      UINT64                    Value
>    )
>  {
> -  do {
> -    ((UINT64*)Buffer)[--Length] = Value;
> -  } while (Length != 0);
> +  for (; Length != 0; Length--) {
> +    ((UINT64*)Buffer)[Length - 1] = Value;
> +  }
>    return Buffer;
>  }
> 
> --
> 1.9.5.msysgit.0