[llvm-branch-commits] [llvm] [DirectX] Improve error handling and validation in root signature parsing (PR #144577)

[Chris B via llvm-branch-commits]

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@@ -48,6 +48,71 @@ static bool reportValueError(LLVMContext *Ctx, Twine ParamName,
   return true;
 }
 
+// Template function to get formatted type string based on C++ type
+template <typename T> std::string getTypeFormatted() {
+  if constexpr (std::is_same_v<T, MDString>) {
+    return "string";
+  } else if constexpr (std::is_same_v<T, MDNode *> ||
+                       std::is_same_v<T, const MDNode *>) {
+    return "metadata";
+  } else if constexpr (std::is_same_v<T, ConstantAsMetadata *> ||
+                       std::is_same_v<T, const ConstantAsMetadata *>) {
+    return "constant";
+  } else if constexpr (std::is_same_v<T, ConstantAsMetadata>) {
+    return "constant";
+  } else if constexpr (std::is_same_v<T, ConstantInt *> ||
+                       std::is_same_v<T, const ConstantInt *>) {
+    return "constant int";
+  } else if constexpr (std::is_same_v<T, ConstantInt>) {
+    return "constant int";
+  }
+  return "unknown";
+}
+
+// Helper function to get the actual type of a metadata operand
+std::string getActualMDType(const MDNode *Node, unsigned Index) {
+  if (!Node || Index >= Node->getNumOperands())
+    return "null";
+
+  Metadata *Op = Node->getOperand(Index);
+  if (!Op)
+    return "null";
+
+  if (isa<MDString>(Op))
+    return getTypeFormatted<MDString>();
+
+  if (isa<ConstantAsMetadata>(Op)) {
+    if (auto *CAM = dyn_cast<ConstantAsMetadata>(Op)) {
+      Type *T = CAM->getValue()->getType();
+      if (T->isIntegerTy())
+        return (Twine("i") + Twine(T->getIntegerBitWidth())).str();
+      if (T->isFloatingPointTy())
+        return T->isFloatTy()    ? getTypeFormatted<float>()
+               : T->isDoubleTy() ? getTypeFormatted<double>()
+                                 : "fp";
+
+      return getTypeFormatted<ConstantAsMetadata>();
+    }
+  }
+  if (isa<MDNode>(Op))
+    return getTypeFormatted<MDNode *>();
+
+  return "unknown";
+}
+
+// Helper function to simplify error reporting for invalid metadata values
+template <typename ET>
+auto reportInvalidTypeError(LLVMContext *Ctx, Twine ParamName,
----------------
llvm-beanz wrote:

`auto` as a return type rarely meets LLVM's coding standards:
see: https://llvm.org/docs/CodingStandards.html#use-auto-type-deduction-to-make-code-more-readable

https://github.com/llvm/llvm-project/pull/144577