[clang] [HLSL][Sema] Validate that occupied register numbers never exceed UINT32_MAX (PR #174028)

[Finn Plummer via cfe-commits]

================
@@ -2419,12 +2498,24 @@ void SemaHLSL::handleResourceBindingAttr(Decl *TheDecl, const ParsedAttr &AL) {
       Diag(SlotLoc, diag::warn_hlsl_deprecated_register_type_i);
       return;
     }
-    StringRef SlotNumStr = Slot.substr(1);
+    const StringRef SlotNumStr = Slot.substr(1);
+
     unsigned N;
-    if (SlotNumStr.getAsInteger(10, N)) {
+
+    // validate that the slot number is a non-empty number
+    if (SlotNumStr.empty() || !llvm::all_of(SlotNumStr, llvm::isDigit)) {
       Diag(SlotLoc, diag::err_hlsl_unsupported_register_number);
       return;
     }
+
+    // Validate register number. It should not exceed UINT32_MAX,
+    // including if the resource type is an array that starts
+    // before UINT32_MAX, but ends afterwards.
+    if (ValidateRegisterNumber(SlotNumStr, TheDecl, getASTContext(), N)) {
----------------
inbelic wrote:

Take it or leave it nit:
```suggestion
   uint64_t N;
    if (SlotNumStr.getAsInteger(10, N) || ValidateRegisterNumber(N, TheDecl, getASTContext())) {
    ...
    }
    SlotNum = (uint32_t)N;
```

https://github.com/llvm/llvm-project/pull/174028