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

[Helena Kotas via cfe-commits]

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@@ -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) {
----------------
hekota wrote:

I agree with @damyanp. This function seems to always be called with one of the arguments null. Why not have `getAttributeFromVarDecl` and `getAttributeFromRecordDecl`, and the first one would call the other in the `VarDecl` case?

Additionally, `getAttributeFromRecordDecl` could also detect the attibute on the record decl itself, avoiding the separate check on line 598 (with comment `// otherwise, check if the member of the UDT itself has a resource class attr`).

Also, this seems to find just the first instance of the attribute. Is that ok? What if there are more and with conflicting resource classes? Have you considered passing in the `RegisterBindingFlags` by reference and let the function fill in the resource class and other info, instead of extracting a single attribute?

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