Re: [PATCH v6 14/22] ArmPkg: Add Universal/Smbios/ProcessorSubClassDxe

["Leif Lindholm" <leif@nuviainc.com>]

On Wed, Jan 27, 2021 at 21:53:57 -0700, Rebecca Cran wrote:
> On 1/25/21 12:04 PM, Leif Lindholm wrote:
> > On Thu, Jan 14, 2021 at 09:36:20 -0700, Rebecca Cran wrote:
> > > +// Sets the HII variable `x` if `pcd` isn't empty
> > > +#define SET_HII_STRING_IF_PCD_NOT_EMPTY(pcd, x)               \
> > > +    x##Str = (CHAR16 *)PcdGetPtr (pcd); \
> > > +    if (StrLen (x##Str) > 0) {                                \
> > > +      HiiSetString (mHiiHandle, x, x##Str, NULL);             \
> > > +    }                                                         \
> > 
> > I am not a fan of preprocessor macros that require local variables
> > with magic names to exist.
> > Can this be rewritten as a helper function?
> 
> Unfortunately PcdGetPtr uses token pasting, so a helper function won't work.
> 
> Would the following be better?
> 
> #define SetHiiStringIfPcdNotEmpty(Pcd, StringId) { \
>   CHAR16 *Str = (CHAR16*)PcdGetPtr (Pcd); \
>   if (StrLen (Str) > 0) { \
>     HiiSetString (mHiiHandle, StringId, Str, NULL); \
>   } \
> }

I'm mostly OK with that. I'd say it technically violates the coding
style because of assigning a value to Str on definition, but I can't
convince myself to care about that for a macro.

However, it still needs to have the name indicate that it's a macro,
so SET_HII_STRING_IF_PCD_NOT_EMPTY.

Best Regards,

Leif