Re: [edk2-devel] [PATCH v1] MdePkg: Use __builtin_offset with CLANGPDB toolchain

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 11/28/19 6:56 AM, Alex James via Groups.Io wrote:
> CLANGPDB does not define __GNUC__, but it does define __clang__. Check
> for the __clang__ preprocessor definition to use __builtin_offsetof to
> implement the OFFSET_OF macro.
> 
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Cc: Liming Gao <liming.gao@intel.com>
> Signed-off-by: Alex James <theracermaster@gmail.com>
> ---
>   MdePkg/Include/Base.h | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/MdePkg/Include/Base.h b/MdePkg/Include/Base.h
> index 4680e64136..e0bcd0ae67 100644
> --- a/MdePkg/Include/Base.h
> +++ b/MdePkg/Include/Base.h
> @@ -781,11 +781,9 @@ typedef UINTN  *BASE_LIST;
>     @return  Offset, in bytes, of field.
>   
>   **/
> -#ifdef __GNUC__
> -#if __GNUC__ >= 4
> +#if (defined(__GNUC__) && __GNUC__ >= 4) || defined(__clang__)
>   #define OFFSET_OF(TYPE, Field) ((UINTN) __builtin_offsetof(TYPE, Field))
>   #endif
> -#endif
>   
>   #ifndef OFFSET_OF
>   #define OFFSET_OF(TYPE, Field) ((UINTN) &(((TYPE *)0)->Field))
> 

Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>