[llvm-branch-commits] [clang] [HLSL] Global resource arrays element access (PR #152454)

[Joshua Batista via llvm-branch-commits]

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@@ -84,6 +84,124 @@ void addRootSignature(llvm::dxbc::RootSignatureVersion RootSigVer,
   RootSignatureValMD->addOperand(MDVals);
 }
 
+// If the specified expr is a simple decay from an array to pointer,
+// return the array subexpression. Otherwise, return nullptr.
+static const Expr *getSubExprFromArrayDecayOperand(const Expr *E) {
+  const auto *CE = dyn_cast<CastExpr>(E);
+  if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
+    return nullptr;
+  return CE->getSubExpr();
+}
+
+// Find array variable declaration from nested array subscript AST nodes
+static const ValueDecl *getArrayDecl(const ArraySubscriptExpr *ASE) {
+  const Expr *E = nullptr;
+  while (ASE != nullptr) {
+    E = getSubExprFromArrayDecayOperand(ASE->getBase());
+    if (!E)
+      return nullptr;
+    ASE = dyn_cast<ArraySubscriptExpr>(E);
+  }
+  if (const DeclRefExpr *DRE = dyn_cast_or_null<DeclRefExpr>(E))
+    return DRE->getDecl();
+  return nullptr;
+}
+
+// Get the total size of the array, or -1 if the array is unbounded.
+static int getTotalArraySize(const clang::Type *Ty) {
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bob80905 wrote:

Would this be better named `getArrayDimension`?
Looks like it counts the dimension of the array.

https://github.com/llvm/llvm-project/pull/152454