[clang] [HLSL] Collect explicit resource binding information (PR #111203)

[Justin Bogner via cfe-commits]

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@@ -985,88 +1026,92 @@ SemaHLSL::TakeLocForHLSLAttribute(const HLSLAttributedResourceType *RT) {
   return LocInfo;
 }
 
-// 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 (Ty->isBuiltinType())
-    return nullptr;
-
-  CXXRecordDecl *TheRecordDecl = Ty->getAsCXXRecordDecl();
-  assert(TheRecordDecl && "Resource should have a resource type declaration.");
-  return TheRecordDecl;
-}
-
+// Returns handle type of a resource, if the type is a resource
 static const HLSLAttributedResourceType *
-findAttributedResourceTypeOnField(VarDecl *VD) {
-  assert(VD != nullptr && "expected VarDecl");
-  if (RecordDecl *RD = getRecordDeclFromVarDecl(VD)) {
-    for (auto *FD : RD->fields()) {
-      if (const HLSLAttributedResourceType *AttrResType =
-              dyn_cast<HLSLAttributedResourceType>(FD->getType().getTypePtr()))
-        return AttrResType;
+FindHandleTypeOnResource(const Type *Ty) {
+  // If Ty is a resource class, the first field must
+  // be the resource handle of type HLSLAttributedResourceType
+  if (RecordDecl *RD = Ty->getAsCXXRecordDecl()) {
+    if (!RD->fields().empty()) {
+      const auto &FirstFD = RD->fields().begin();
+      return dyn_cast<HLSLAttributedResourceType>(
+          FirstFD->getType().getTypePtr());
     }
   }
   return nullptr;
 }
 
-// Iterate over RecordType fields and return true if any of them matched the
-// register type
-static bool ContainsResourceForRegisterType(Sema &S, const RecordType *RT,
-                                            RegisterType RegType) {
-  llvm::SmallVector<const Type *> TypesToScan;
-  TypesToScan.emplace_back(RT);
-
-  while (!TypesToScan.empty()) {
-    const Type *T = TypesToScan.pop_back_val();
-    while (T->isArrayType())
-      T = T->getArrayElementTypeNoTypeQual();
-    if (T->isIntegralOrEnumerationType() || T->isFloatingType()) {
-      if (RegType == RegisterType::C)
-        return true;
+// Returns handle type of a resource, if the VarDecl is a resource
+static const HLSLAttributedResourceType *
+FindHandleTypeOnResource(const VarDecl *VD) {
+  assert(VD != nullptr && "expected VarDecl");
+  return FindHandleTypeOnResource(VD->getType().getTypePtr());
+}
+
+// Walks though the global variable declaration, collects all resource binding
+// requirements and adds them to Bindings
+void SemaHLSL::FindResourcesOnUserRecordDecl(const VarDecl *VD,
+                                             const RecordType *RT, int Size) {
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bogner wrote:

Might be better to call this "collectResourcesOnUserRecordDecl" - the verb "find" doesn't sound like it's going to mutate anything to me.

Also what is size here? It could probably use a mention in the comment.

https://github.com/llvm/llvm-project/pull/111203