[clang] [SYCL] Basic diagnostics for the sycl_kernel_entry_point attribute. (PR #120327)

[Aaron Ballman via cfe-commits]

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@@ -1550,6 +1550,8 @@ NamedDecl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
     IdResolver.AddDecl(Param);
   }
 
+  ProcessDeclAttributes(S, Param, D);
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AaronBallman wrote:

We definitely need some changes because we drop the attributes on the floor: https://godbolt.org/z/oEr7bneaE

However, this is interesting:
https://eel.is/c++draft/temp#nt:template-parameter
https://eel.is/c++draft/dcl.fct#nt:parameter-declaration

So I would expect us to handle NTTPs the same as other parameter declarations. But... are NTTP's a parameter? If so, our Attr.td and corresponding tablegen might need some updates to distinguish between function parameters and non-function parameters because of things like https://eel.is/c++draft/dcl.attr.depend or https://eel.is/c++draft/dcl.attr.indet because they're specific about function parameters.

So I don't think this code is *wrong*, but I do think we may need to take another look at how we process NTTPs because I would have expected them to use the parameter declaration parsing code, which should automatically handle processing attributes correctly.

https://github.com/llvm/llvm-project/pull/120327