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diff --git a/include/llvm/MC/YAML.h b/include/llvm/MC/YAML.h
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+#ifndef LLVM_MC_YAML_H
+#define LLVM_MC_YAML_H
+
+#include "llvm/Support/YAMLTraits.h"
+
+namespace llvm {
+namespace yaml {
+/// \brief Specialized YAMLIO scalar type for representing a binary blob.
+///
+/// A typical use case would be to represent the content of a section in a
+/// binary file.
+/// This class has custom YAMLIO traits for convenient reading and writing.
+/// It renders as a string of hex digits in a YAML file.
+/// For example, it might render as `DEADBEEFCAFEBABE` (YAML does not
+/// require the quotation marks, so for simplicity when outputting they are
+/// omitted).
+/// When reading, any string whose content is an even number of hex digits
+/// will be accepted.
+/// For example, all of the following are acceptable:
+/// `DEADBEEF`, `"DeADbEeF"`, `"\x44EADBEEF"` (Note: '\x44' == 'D')
+///
+/// A significant advantage of using this class is that it never allocates
+/// temporary strings or buffers for any of its functionality.
+///
+/// Example:
+///
+/// The YAML mapping:
+/// \code
+/// Foo: DEADBEEFCAFEBABE
+/// \endcode
+///
+/// Could be modeled in YAMLIO by the struct:
+/// \code
+/// struct FooHolder {
+///   BinaryRef Foo;
+/// };
+/// namespace llvm {
+/// namespace yaml {
+/// template <>
+/// struct MappingTraits<FooHolder> {
+///   static void mapping(IO &IO, FooHolder &FH) {
+///     IO.mapRequired("Foo", FH.Foo);
+///   }
+/// };
+/// } // end namespace yaml
+/// } // end namespace llvm
+/// \endcode
+class BinaryRef {
+  friend bool operator==(const BinaryRef &LHS, const BinaryRef &RHS);
+  /// \brief Either raw binary data, or a string of hex bytes (must always
+  /// be an even number of characters).
+  ArrayRef<uint8_t> Data;
+  /// \brief Discriminator between the two states of the `Data` member.
+  bool DataIsHexString;
+
+public:
+  BinaryRef(ArrayRef<uint8_t> Data) : Data(Data), DataIsHexString(false) {}
+  BinaryRef(StringRef Data)
+      : Data(reinterpret_cast<const uint8_t *>(Data.data()), Data.size()),
+        DataIsHexString(true) {}
+  BinaryRef() : DataIsHexString(true) {}
+  /// \brief The number of bytes that are represented by this BinaryRef.
+  /// This is the number of bytes that writeAsBinary() will write.
+  ArrayRef<uint8_t>::size_type binary_size() const {
+    if (DataIsHexString)
+      return Data.size() / 2;
+    return Data.size();
+  }
+  /// \brief Write the contents (regardless of whether it is binary or a
+  /// hex string) as binary to the given raw_ostream.
+  void writeAsBinary(raw_ostream &OS) const;
+  /// \brief Write the contents (regardless of whether it is binary or a
+  /// hex string) as hex to the given raw_ostream.
+  ///
+  /// For example, a possible output could be `DEADBEEFCAFEBABE`.
+  void writeAsHex(raw_ostream &OS) const;
+};
+
+inline bool operator==(const BinaryRef &LHS, const BinaryRef &RHS) {
+  // Special case for default constructed BinaryRef.
+  if (LHS.Data.empty() && RHS.Data.empty())
+    return true;
+
+  return LHS.DataIsHexString == RHS.DataIsHexString && LHS.Data == RHS.Data;
+}
+
+template <> struct ScalarTraits<BinaryRef> {
+  static void output(const BinaryRef &, void *, llvm::raw_ostream &);
+  static StringRef input(StringRef, void *, BinaryRef &);
+  static bool mustQuote(StringRef S) { return needsQuotes(S); }
+};
+}
+}
+#endif