Re: [PATCH v1 18/19] ArmPlatformPkg: Fix comparison of constants warning

["Leif Lindholm" <leif.lindholm@linaro.org>]

On Fri, Aug 23, 2019 at 11:55:38 +0100, Sami Mujawar wrote:
> The VS2017 compiler reports 'warning C6326: potential
> comparison of a constant with another constant' when
> a fixed PCD value is compared with a constant value.
> 
> The faulting code is as marked by '-->' below:
> 
> --> if (FixedPcdGet32 (PL011UartInteger) != 0) {
>       Integer = FixedPcdGet32 (PL011UartInteger);
>       Fractional = FixedPcdGet32 (PL011UartFractional);
>     } else {
>     ...
> 
> The macro FixedPcdGet32 (PL011UartInteger) evaluates
> to a macro _PCD_VALUE_PL011UartInteger that is defined
> by the build system to represent the UART Integer
> value. Therefore, the VS2017 compiler reports the above
> warning.
> 
> Fix this warning by enclosing the code in appropriate
>  #if .. #else .. #endif directives.
> 
> Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>

Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

> ---
>  ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c b/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c
> index 2d3c279cce49304959953ec4a34b50e09a7d0045..dabf099b9bc82e1fb1bd5a2eae3fa4b5878a9e07 100644
> --- a/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c
> +++ b/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c
> @@ -174,10 +174,10 @@ PL011UartInitializePort (
>    //
>  
>    // If PL011 Integer value has been defined then always ignore the BAUD rate
> -  if (FixedPcdGet32 (PL011UartInteger) != 0) {
> +#if (FixedPcdGet32 (PL011UartInteger) != 0)
>      Integer = FixedPcdGet32 (PL011UartInteger);
>      Fractional = FixedPcdGet32 (PL011UartFractional);
> -  } else {
> +#else
>      // If BAUD rate is zero then replace it with the system default value
>      if (*BaudRate == 0) {
>        *BaudRate = FixedPcdGet32 (PcdSerialBaudRate);
> @@ -197,7 +197,7 @@ PL011UartInitializePort (
>      Divisor = (UINT32)DivisorValue;
>      Integer = Divisor >> FRACTION_PART_SIZE_IN_BITS;
>      Fractional = Divisor & FRACTION_PART_MASK;
> -  }
> +#endif
>  
>    //
>    // If PL011 is already initialized, check the current settings
> -- 
> 'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'
> 
>