diff --git a/mlir/include/mlir/IR/Diagnostics.h b/mlir/include/mlir/IR/Diagnostics.h
--- a/mlir/include/mlir/IR/Diagnostics.h
+++ b/mlir/include/mlir/IR/Diagnostics.h
@@ -265,6 +265,9 @@
   /// Allow a diagnostic to be converted to 'failure'.
   operator LogicalResult() const;
 
+  /// Allow a diagnostic to be converted to 'failure'.
+  operator ParseResult() const { return ParseResult(LogicalResult(*this)); }
+
   /// Allow a diagnostic to be converted to FailureOr<T>. Always results in
   /// 'failure' because this cast cannot possibly return an object of 'T'.
   template <typename T>
@@ -354,6 +357,10 @@
   /// 'success' if this is an empty diagnostic.
   operator LogicalResult() const;
 
+  /// Allow an inflight diagnostic to be converted to 'failure', otherwise
+  /// 'success' if this is an empty diagnostic.
+  operator ParseResult() const { return ParseResult(LogicalResult(*this)); }
+
   /// Allow an inflight diagnostic to be converted to FailureOr<T>. Always
   /// results in 'failure' because this cast cannot possibly return an object of
   /// 'T'.
diff --git a/mlir/include/mlir/IR/OpDefinition.h b/mlir/include/mlir/IR/OpDefinition.h
--- a/mlir/include/mlir/IR/OpDefinition.h
+++ b/mlir/include/mlir/IR/OpDefinition.h
@@ -29,21 +29,6 @@
 class Builder;
 class OpBuilder;
 
-/// This class represents success/failure for operation parsing. It is
-/// essentially a simple wrapper class around LogicalResult that allows for
-/// explicit conversion to bool. This allows for the parser to chain together
-/// parse rules without the clutter of "failed/succeeded".
-class ParseResult : public LogicalResult {
-public:
-  ParseResult(LogicalResult result = success()) : LogicalResult(result) {}
-
-  // Allow diagnostics emitted during parsing to be converted to failure.
-  ParseResult(const InFlightDiagnostic &) : LogicalResult(failure()) {}
-  ParseResult(const Diagnostic &) : LogicalResult(failure()) {}
-
-  /// Failure is true in a boolean context.
-  explicit operator bool() const { return failed(); }
-};
 /// This class implements `Optional` functionality for ParseResult. We don't
 /// directly use Optional here, because it provides an implicit conversion
 /// to 'bool' which we want to avoid. This class is used to implement tri-state
diff --git a/mlir/include/mlir/Support/LogicalResult.h b/mlir/include/mlir/Support/LogicalResult.h
--- a/mlir/include/mlir/Support/LogicalResult.h
+++ b/mlir/include/mlir/Support/LogicalResult.h
@@ -71,6 +71,18 @@
 /// to a failure value.
 inline bool failed(LogicalResult result) { return result.failed(); }
 
+/// This class represents success/failure for operation parsing. It is
+/// essentially a simple wrapper class around LogicalResult that allows for
+/// explicit conversion to bool. This allows for the parser to chain together
+/// parse rules without the clutter of "failed/succeeded".
+class ParseResult : public LogicalResult {
+public:
+  ParseResult(LogicalResult result = success()) : LogicalResult(result) {}
+
+  /// Failure is true in a boolean context.
+  explicit operator bool() const { return failed(); }
+};
+
 /// This class provides support for representing a failure result, or a valid
 /// value of type `T`. This allows for integrating with LogicalResult, while
 /// also providing a value on the success path.
diff --git a/mlir/lib/Tools/PDLL/AST/Diagnostic.cpp b/mlir/lib/Tools/PDLL/AST/Diagnostic.cpp
--- a/mlir/lib/Tools/PDLL/AST/Diagnostic.cpp
+++ b/mlir/lib/Tools/PDLL/AST/Diagnostic.cpp
@@ -15,7 +15,7 @@
 // InFlightDiagnostic
 //===----------------------------------------------------------------------===//
 
-void InFlightDiagnostic::report() {
+void mlir::pdll::ast::InFlightDiagnostic::report() {
   // If this diagnostic is still inflight and it hasn't been abandoned, then
   // report it.
   if (isInFlight()) {