[llvm] [DirectX] Error handling improve in root signature metadata Parser (PR #149232)

[Chris B via llvm-commits]

================
@@ -26,6 +28,80 @@ class Metadata;
 namespace hlsl {
 namespace rootsig {
 
+template <typename T>
+class RootSignatureValidationError
+    : public ErrorInfo<RootSignatureValidationError<T>> {
+public:
+  static char ID;
+  std::string ParamName;
+  T Value;
+
+  RootSignatureValidationError(StringRef ParamName, T Value)
+      : ParamName(ParamName.str()), Value(Value) {}
+
+  void log(raw_ostream &OS) const override {
+    OS << "Invalid value for " << ParamName << ": " << Value;
+  }
+
+  std::error_code convertToErrorCode() const override {
+    return llvm::inconvertibleErrorCode();
+  }
+};
+
+class GenericRSMetadataError : public ErrorInfo<GenericRSMetadataError> {
+public:
+  static char ID;
+  Twine Message;
+  MDNode *MD;
+
+  GenericRSMetadataError(Twine Message, MDNode *MD)
+      : Message(Message), MD(MD) {}
+
+  void log(raw_ostream &OS) const override {
+    OS << Message;
+    if (MD) {
+      OS << "\n";
+      MD->printTree(OS);
+    }
+  }
+
+  std::error_code convertToErrorCode() const override {
+    return llvm::inconvertibleErrorCode();
+  }
+};
+
+class InvalidRSMetadataFormat : public ErrorInfo<InvalidRSMetadataFormat> {
+public:
+  static char ID;
+  StringRef ElementName;
+
+  InvalidRSMetadataFormat(StringRef ElementName) : ElementName(ElementName) {}
+
+  void log(raw_ostream &OS) const override {
+    OS << "Invalid format for  " << ElementName;
+  }
+
+  std::error_code convertToErrorCode() const override {
+    return llvm::inconvertibleErrorCode();
+  }
+};
+
+class InvalidRSMetadataValue : public ErrorInfo<InvalidRSMetadataValue> {
+public:
+  static char ID;
+  std::string ParamName;
+
+  InvalidRSMetadataValue(StringRef ParamName) : ParamName(ParamName.str()) {}
----------------
llvm-beanz wrote:

```suggestion
  InvalidRSMetadataValue(StringRef ParamName) : ParamName(ParamName) {}
```

https://github.com/llvm/llvm-project/pull/149232