[clang] Implement resource binding type prefix mismatch diagnostic infrastructure (PR #97103)

[Joshua Batista via cfe-commits]

================
@@ -459,7 +467,412 @@ void SemaHLSL::handleResourceClassAttr(Decl *D, const ParsedAttr &AL) {
   D->addAttr(HLSLResourceClassAttr::Create(getASTContext(), RC, ArgLoc));
 }
 
-void SemaHLSL::handleResourceBindingAttr(Decl *D, const ParsedAttr &AL) {
+struct RegisterBindingFlags {
+  bool Resource = false;
+  bool UDT = false;
+  bool Other = false;
+  bool Basic = false;
+
+  bool SRV = false;
+  bool UAV = false;
+  bool CBV = false;
+  bool Sampler = false;
+
+  bool ContainsNumeric = false;
+  bool DefaultGlobals = false;
+};
+
+static bool isDeclaredWithinCOrTBuffer(const Decl *TheDecl) {
+  if (!TheDecl)
+    return false;
+
+  // Traverse up the parent contexts
+  const DeclContext *context = TheDecl->getDeclContext();
+  if (isa<HLSLBufferDecl>(context)) {
+    return true;
+  }
+
+  return false;
+}
+
+// get the record decl from a var decl that we expect
+// represents a resource
+static CXXRecordDecl *getRecordDeclFromVarDecl(VarDecl *VD) {
+  const Type *Ty = VD->getType()->getPointeeOrArrayElementType();
+  assert(Ty && "Resource must have an element type.");
+
+  if (const auto *TheBuiltinTy = dyn_cast<BuiltinType>(Ty))
+    return nullptr;
+
+  CXXRecordDecl *TheRecordDecl = Ty->getAsCXXRecordDecl();
+  assert(TheRecordDecl && "Resource should have a resource type declaration.");
+  return TheRecordDecl;
+}
+
+static void setResourceClassFlagsFromDeclResourceClass(
+    RegisterBindingFlags &Flags, llvm::hlsl::ResourceClass DeclResourceClass) {
+  switch (DeclResourceClass) {
+  case llvm::hlsl::ResourceClass::SRV:
+    Flags.SRV = true;
+    break;
+  case llvm::hlsl::ResourceClass::UAV:
+    Flags.UAV = true;
+    break;
+  case llvm::hlsl::ResourceClass::CBuffer:
+    Flags.CBV = true;
+    break;
+  case llvm::hlsl::ResourceClass::Sampler:
+    Flags.Sampler = true;
+    break;
+  }
+}
+
+template <typename T>
+static const T *
+getSpecifiedHLSLAttrFromVarDeclOrRecordDecl(VarDecl *VD,
+                                            RecordDecl *TheRecordDecl) {
----------------
bob80905 wrote:

1. Sounds good.
2. I'll see if this works.
3. It should be ok that the first attribute is all that's detected. We don't expect users to use user-defined resources that have made use of the spellable attributes, and have defined more than one resource class for said attribute. All HLSL resources should have exactly one resource class attribute, so there will never be a valid case where there are 2 attributes and we should've picked the second one. 

https://github.com/llvm/llvm-project/pull/97103