[cfe-commits] r130381 - in /cfe/trunk: lib/Sema/SemaTemplate.cpp test/Parser/MicrosoftExtensions.cpp

[John McCall]

On Apr 27, 2011, at 9:39 PM, Francois Pichet wrote:

> Author: fpichet
> Date: Wed Apr 27 23:39:50 2011
> New Revision: 130381
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=130381&view=rev
> Log:
> Support &__uuidof(type) as a non type template argument.
> This idiom is used everywhere in MFC/COM code and as such this patch removes hundreds of errors when parsing MFC code with clang.
> 
> Example: 
> template <class T, const GUID* g = &__uuidof(T)>
> class ComTemplate  { };
> 
> typedef ComTemplate<struct_with_uuid, &__uuidof(struct_with_uuid)> COM_TYPE;
> 
> Of course this is just parsing support. Trying to use this in CodeGen will generate:
> error: cannot yet mangle expression type CXXUuidofExpr
> 
> Modified:
>    cfe/trunk/lib/Sema/SemaTemplate.cpp
>    cfe/trunk/test/Parser/MicrosoftExtensions.cpp
> 
> Modified: cfe/trunk/lib/Sema/SemaTemplate.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplate.cpp?rev=130381&r1=130380&r2=130381&view=diff
> ==============================================================================
> --- cfe/trunk/lib/Sema/SemaTemplate.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaTemplate.cpp Wed Apr 27 23:39:50 2011
> @@ -3093,6 +3093,15 @@
>   bool AddressTaken = false;
>   SourceLocation AddrOpLoc;
>   if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
> +
> +    // Support &__uuidof(class_with_uuid) as a non-type template argument.
> +    // Very common in Microsoft COM headers.
> +    if (S.getLangOptions().Microsoft && 
> +      isa<CXXUuidofExpr>(UnOp->getSubExpr())) {
> +      Converted = TemplateArgument(ArgIn);
> +      return false;
> +    }
> +

You need to actually check for UO_AddrOf here.  I assume most unary operators don't work on the GUID type, but __extension__ does, and it's good to be future-proof.

You should also make sure this works for reference template parameters;  maybe that never actually happens in the MFC headers, but it's good to get this right.

John.