[clang] counter var3 (PR #162291)

[Helena Kotas via cfe-commits]

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@@ -2978,6 +2987,25 @@ bool SemaHLSL::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
     TheCall->setType(ResourceTy);
     break;
   }
+  case Builtin::BI__builtin_hlsl_resource_counterhandlefromimplicitbinding: {
+    ASTContext &AST = SemaRef.getASTContext();
+    if (SemaRef.checkArgCount(TheCall, 3) ||
+        CheckResourceHandle(&SemaRef, TheCall, 0) ||
+        CheckArgTypeMatches(&SemaRef, TheCall->getArg(1), AST.UnsignedIntTy) ||
+        CheckArgTypeMatches(&SemaRef, TheCall->getArg(2), AST.UnsignedIntTy))
+      return true;
+
+    QualType MainHandleTy = TheCall->getArg(0)->getType();
+    auto *MainResType = MainHandleTy->getAs<HLSLAttributedResourceType>();
+    auto MainAttrs = MainResType->getAttrs();
+    assert(!MainAttrs.IsCounter && "cannot create a counter from a counter");
+    MainAttrs.IsCounter = true;
+    QualType CounterHandleTy = getASTContext().getHLSLAttributedResourceType(
----------------
hekota wrote:

```suggestion
    QualType CounterHandleTy = AST.getHLSLAttributedResourceType(
```

https://github.com/llvm/llvm-project/pull/162291