diff --git a/clang/include/clang/Lex/Preprocessor.h b/clang/include/clang/Lex/Preprocessor.h
--- a/clang/include/clang/Lex/Preprocessor.h
+++ b/clang/include/clang/Lex/Preprocessor.h
@@ -1375,6 +1375,11 @@
   StringRef getLastMacroWithSpelling(SourceLocation Loc,
                                      ArrayRef<TokenValue> Tokens) const;
 
+  /// Get the predefines for this processor.
+  /// Used by some third-party tools to inspect and add predefines (see
+  /// https://github.com/llvm/llvm-project/issues/57483).
+  const std::string &getPredefines() const { return Predefines; }
+
   /// Set the predefines for this Preprocessor.
   ///
   /// These predefines are automatically injected when parsing the main file.