[clang] [HLSL] Collect explicit resource binding information (part 1) (PR #111203)

[Joshua Batista via cfe-commits]

================
@@ -2228,3 +2242,62 @@ QualType SemaHLSL::getInoutParameterType(QualType Ty) {
   Ty.addRestrict();
   return Ty;
 }
+
+// Walks though existing explicit bindings, finds the actual resource class
+// decl the binding applies to and sets it to attr->ResourceField.
+// Additional processing of resource binding can be added here later on,
+// such as preparation for overapping resource detection or implicit binding.
+void SemaHLSL::ProcessResourceBindingOnDecl(VarDecl *D) {
+  if (!D->hasGlobalStorage())
+    return;
+  
+  for (Attr *A : D->attrs()) {
+    HLSLResourceBindingAttr *RBA = dyn_cast<HLSLResourceBindingAttr>(A);
+    if (!RBA)
+      continue;
+
+    // // Cbuffers and Tbuffers are HLSLBufferDecl types
+    if (const HLSLBufferDecl *CBufferOrTBuffer = dyn_cast<HLSLBufferDecl>(D)) {
+      assert(RBA->getRegisterType() ==
+                 getRegisterType(CBufferOrTBuffer->isCBuffer()
+                                     ? ResourceClass::CBuffer
+                                     : ResourceClass::SRV) &&
+             "this should have been handled in DiagnoseLocalRegisterBinding");
+      // should we handle HLSLBufferDecl here?
+      continue;
+    }
+
+    // Samplers, UAVs, and SRVs are VarDecl types
+    assert(isa<VarDecl>(D) && "D is expected to be VarDecl or HLSLBufferDecl");
+    const VarDecl *VD = cast<VarDecl>(D);
+
+    // Register binding directly on global resource class variable
+    if (const HLSLAttributedResourceType *AttrResType =
+            FindHandleTypeOnResource(VD)) {
+      // FIXME: if array, calculate the binding size from the array dimensions
+      // (or unbounded for unsized array)
+      assert(RBA->getResourceField() == nullptr);
+      continue;
----------------
bob80905 wrote:

So, at some point in the future, you'd have something like `RBA->setResourceField(D)` here right? But it depends first on the FIXME?

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