[clang] [HLSL] Make HLSLAttributedResourceType canonical and add code paths to convert HLSL types to DirectX target types (PR #110327)

[Helena Kotas via cfe-commits]

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@@ -4488,6 +4488,30 @@ void CXXNameMangler::mangleType(const ArrayParameterType *T) {
   mangleType(cast<ConstantArrayType>(T));
 }
 
+void CXXNameMangler::mangleType(const HLSLAttributedResourceType *T) {
+  mangleType(T->getWrappedType());
+  const HLSLAttributedResourceType::Attributes &Attrs = T->getAttrs();
+  switch (Attrs.ResourceClass) {
+  case llvm::dxil::ResourceClass::UAV:
+    Out << 'U';
+    break;
+  case llvm::dxil::ResourceClass::SRV:
+    Out << 'T';
+    break;
+  case llvm::dxil::ResourceClass::CBuffer:
+    Out << 'C';
+    break;
+  case llvm::dxil::ResourceClass::Sampler:
+    Out << 'S';
+    break;
+  }
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hekota wrote:

This is intentional. If add a default case, there'll be a warning `Default label in switch which covers all enumeration values`. If a new value is added to ResourceClass, there'll be a warning that this switch does not cover all enum values.

https://github.com/llvm/llvm-project/pull/110327