[clang] [HLSL] Implement `SpirvType` and `SpirvOpaqueType` (PR #134034)

[Steven Perron via cfe-commits]

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@@ -4855,6 +4857,17 @@ LinkageInfo LinkageComputer::computeTypeLinkageInfo(const Type *T) {
     return computeTypeLinkageInfo(cast<HLSLAttributedResourceType>(T)
                                       ->getContainedType()
                                       ->getCanonicalTypeInternal());
+  case Type::HLSLInlineSpirv:
+    return LinkageInfo::external();
+    {
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s-perron wrote:

I don't know if we can have different linkages on types in HLSL. You cannot put a type in the  anonymous namespace. You can't use `__attribute__((internal_linkage))`. I'm not sure how we would test this properly.

In the HLSL source, this is a type with a templates that build the type. Change the template parameters, change the type. I don't know if this causes it to be classified as a dependent type, and should always return `external` as is done for all dependent types. If that is true, then we should label this as a dependent type in TypeNodes.td.

The argument for the removing the return is that if one of the templates is say an internal type, then the vk::SpirvType should be internal too, as is done for functions with a parameter type that is internal. As I said before, we would not be able to test this.

@llvm-beanz @AaronBallman Let me know if you know the right way to do this.

FYI: Cassie is no longer working on this. I'll see if I can fix it up.

https://github.com/llvm/llvm-project/pull/134034