[clang] [llvm] [HLSL] Implement Texture2D::operator[] (PR #186110)

[Helena Kotas via cfe-commits]

================
@@ -3350,6 +3350,44 @@ static bool CheckVectorSelect(Sema *S, CallExpr *TheCall) {
   return false;
 }
 
+static bool CheckIndexType(Sema *S, CallExpr *TheCall, unsigned IndexArgIndex) {
+  assert(TheCall->getNumArgs() > IndexArgIndex && "Index argument missing");
+  QualType ArgType = TheCall->getArg(IndexArgIndex)->getType();
+  QualType IndexTy = ArgType;
+  unsigned int ActualDim = 1;
+  if (const auto *VTy = IndexTy->getAs<VectorType>()) {
+    ActualDim = VTy->getNumElements();
+    IndexTy = VTy->getElementType();
+  }
+  if (!IndexTy->isIntegerType()) {
+    S->Diag(TheCall->getArg(IndexArgIndex)->getBeginLoc(),
+            diag::err_typecheck_expect_int)
+        << ArgType;
+    return true;
+  }
+
+  QualType ResourceArgTy = TheCall->getArg(0)->getType();
+  const HLSLAttributedResourceType *ResTy =
+      ResourceArgTy.getTypePtr()->getAs<HLSLAttributedResourceType>();
+  assert(ResTy && "Resource argument must be a resource");
+  HLSLAttributedResourceType::Attributes ResAttrs = ResTy->getAttrs();
+
+  unsigned int ExpectedDim = 1;
+  if (ResAttrs.ResourceDimension != llvm::dxil::ResourceDimension::Unknown) {
+    ExpectedDim = getResourceDimensions(ResAttrs.ResourceDimension);
+  }
----------------
hekota wrote:

```suggestion
  if (ResAttrs.ResourceDimension != llvm::dxil::ResourceDimension::Unknown)
    ExpectedDim = getResourceDimensions(ResAttrs.ResourceDimension);
```

https://github.com/llvm/llvm-project/pull/186110