X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FSupport%2FYAMLTraits.h;h=c04294a5e87a735b3bf79b3475d60f47d01afab3;hb=00552e3875ee5f382db6c98286a241a7d0efe1b8;hp=44db30ac6e99f8b6804452b89b69987fdf73bc27;hpb=503334ab44b3fe5e2eaa012170fcc05926f52d8a;p=oota-llvm.git

diff --git a/include/llvm/Support/YAMLTraits.h b/include/llvm/Support/YAMLTraits.h
index 44db30ac6e9..c04294a5e87 100644
--- a/include/llvm/Support/YAMLTraits.h
+++ b/include/llvm/Support/YAMLTraits.h
@@ -20,10 +20,11 @@
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Support/Compiler.h"
+#include "llvm/Support/Regex.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/YAMLParser.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/Support/system_error.h"
+#include <system_error>
 
 namespace llvm {
 namespace yaml {
@@ -45,6 +46,10 @@ struct MappingTraits {
   // static void mapping(IO &io, T &fields);
   // Optionally may provide:
   // static StringRef validate(IO &io, T &fields);
+  //
+  // The optional flow flag will cause generated YAML to use a flow mapping
+  // (e.g. { a: 0, b: 1 }):
+  // static const bool flow = true;
 };
 
 
@@ -98,6 +103,7 @@ struct ScalarBitSetTraits {
 ///        // return empty string on success, or error string
 ///        return StringRef();
 ///      }
+///      static bool mustQuote(StringRef) { return true; }
 ///    };
 template<typename T>
 struct ScalarTraits {
@@ -109,6 +115,38 @@ struct ScalarTraits {
   // Function to convert a string to a value.  Returns the empty
   // StringRef on success or an error string if string is malformed:
   //static StringRef input(StringRef scalar, void *ctxt, T &value);
+  //
+  // Function to determine if the value should be quoted.
+  //static bool mustQuote(StringRef);
+};
+
+
+/// This class should be specialized by type that requires custom conversion
+/// to/from a YAML literal block scalar. For example:
+///
+///    template <>
+///    struct BlockScalarTraits<MyType> {
+///      static void output(const MyType &Value, void*, llvm::raw_ostream &Out)
+///      {
+///        // stream out custom formatting
+///        Out << Val;
+///      }
+///      static StringRef input(StringRef Scalar, void*, MyType &Value) {
+///        // parse scalar and set `value`
+///        // return empty string on success, or error string
+///        return StringRef();
+///      }
+///    };
+template <typename T>
+struct BlockScalarTraits {
+  // Must provide:
+  //
+  // Function to write the value as a string:
+  // static void output(const T &Value, void *ctx, llvm::raw_ostream &Out);
+  //
+  // Function to convert a string to a value.  Returns the empty
+  // StringRef on success or an error string if string is malformed:
+  // static StringRef input(StringRef Scalar, void *ctxt, T &Value);
 };
 
 
@@ -171,7 +209,8 @@ struct has_ScalarEnumerationTraits
   static double test(...);
 
 public:
-  static bool const value = (sizeof(test<ScalarEnumerationTraits<T> >(0)) == 1);
+  static bool const value =
+    (sizeof(test<ScalarEnumerationTraits<T> >(nullptr)) == 1);
 };
 
 
@@ -188,7 +227,7 @@ struct has_ScalarBitSetTraits
   static double test(...);
 
 public:
-  static bool const value = (sizeof(test<ScalarBitSetTraits<T> >(0)) == 1);
+  static bool const value = (sizeof(test<ScalarBitSetTraits<T> >(nullptr)) == 1);
 };
 
 
@@ -198,17 +237,39 @@ struct has_ScalarTraits
 {
   typedef StringRef (*Signature_input)(StringRef, void*, T&);
   typedef void (*Signature_output)(const T&, void*, llvm::raw_ostream&);
+  typedef bool (*Signature_mustQuote)(StringRef);
 
   template <typename U>
-  static char test(SameType<Signature_input, &U::input>*,
-                   SameType<Signature_output, &U::output>*);
+  static char test(SameType<Signature_input, &U::input> *,
+                   SameType<Signature_output, &U::output> *,
+                   SameType<Signature_mustQuote, &U::mustQuote> *);
 
   template <typename U>
   static double test(...);
 
 public:
   static bool const value =
-    (sizeof(test<ScalarTraits<T> >(nullptr,nullptr)) == 1);
+      (sizeof(test<ScalarTraits<T>>(nullptr, nullptr, nullptr)) == 1);
+};
+
+
+// Test if BlockScalarTraits<T> is defined on type T.
+template <class T>
+struct has_BlockScalarTraits
+{
+  typedef StringRef (*Signature_input)(StringRef, void *, T &);
+  typedef void (*Signature_output)(const T &, void *, llvm::raw_ostream &);
+
+  template <typename U>
+  static char test(SameType<Signature_input, &U::input> *,
+                   SameType<Signature_output, &U::output> *);
+
+  template <typename U>
+  static double test(...);
+
+public:
+  static bool const value =
+      (sizeof(test<BlockScalarTraits<T>>(nullptr, nullptr)) == 1);
 };
 
 
@@ -225,7 +286,7 @@ struct has_MappingTraits
   static double test(...);
 
 public:
-  static bool const value = (sizeof(test<MappingTraits<T> >(0)) == 1);
+  static bool const value = (sizeof(test<MappingTraits<T> >(nullptr)) == 1);
 };
 
 // Test if MappingTraits<T>::validate() is defined on type T.
@@ -241,7 +302,7 @@ struct has_MappingValidateTraits
   static double test(...);
 
 public:
-  static bool const value = (sizeof(test<MappingTraits<T> >(0)) == 1);
+  static bool const value = (sizeof(test<MappingTraits<T> >(nullptr)) == 1);
 };
 
 
@@ -259,7 +320,7 @@ struct has_SequenceMethodTraits
   static double test(...);
 
 public:
-  static bool const value =  (sizeof(test<SequenceTraits<T> >(0)) == 1);
+  static bool const value =  (sizeof(test<SequenceTraits<T> >(nullptr)) == 1);
 };
 
 
@@ -289,7 +350,7 @@ struct has_FlowTraits<T, true>
   static char (&f(...))[2];
 
 public:
-  static bool const value = sizeof(f<Derived>(0)) == 2;
+  static bool const value = sizeof(f<Derived>(nullptr)) == 2;
 };
 
 
@@ -313,10 +374,84 @@ struct has_DocumentListTraits
   static double test(...);
 
 public:
-  static bool const value =  (sizeof(test<DocumentListTraits<T> >(0)) == 1);
+  static bool const value = (sizeof(test<DocumentListTraits<T> >(nullptr))==1);
 };
 
+inline bool isNumber(StringRef S) {
+  static const char OctalChars[] = "01234567";
+  if (S.startswith("0") &&
+      S.drop_front().find_first_not_of(OctalChars) == StringRef::npos)
+    return true;
+
+  if (S.startswith("0o") &&
+      S.drop_front(2).find_first_not_of(OctalChars) == StringRef::npos)
+    return true;
+
+  static const char HexChars[] = "0123456789abcdefABCDEF";
+  if (S.startswith("0x") &&
+      S.drop_front(2).find_first_not_of(HexChars) == StringRef::npos)
+    return true;
+
+  static const char DecChars[] = "0123456789";
+  if (S.find_first_not_of(DecChars) == StringRef::npos)
+    return true;
+
+  if (S.equals(".inf") || S.equals(".Inf") || S.equals(".INF"))
+    return true;
+
+  Regex FloatMatcher("^(\\.[0-9]+|[0-9]+(\\.[0-9]*)?)([eE][-+]?[0-9]+)?$");
+  if (FloatMatcher.match(S))
+    return true;
+
+  return false;
+}
+
+inline bool isNumeric(StringRef S) {
+  if ((S.front() == '-' || S.front() == '+') && isNumber(S.drop_front()))
+    return true;
+
+  if (isNumber(S))
+    return true;
+
+  if (S.equals(".nan") || S.equals(".NaN") || S.equals(".NAN"))
+    return true;
 
+  return false;
+}
+
+inline bool isNull(StringRef S) {
+  return S.equals("null") || S.equals("Null") || S.equals("NULL") ||
+         S.equals("~");
+}
+
+inline bool isBool(StringRef S) {
+  return S.equals("true") || S.equals("True") || S.equals("TRUE") ||
+         S.equals("false") || S.equals("False") || S.equals("FALSE");
+}
+
+inline bool needsQuotes(StringRef S) {
+  if (S.empty())
+    return true;
+  if (isspace(S.front()) || isspace(S.back()))
+    return true;
+  if (S.front() == ',')
+    return true;
+
+  static const char ScalarSafeChars[] =
+      "abcdefghijklmnopqrstuvwxyz"
+      "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-/^., \t";
+  if (S.find_first_not_of(ScalarSafeChars) != StringRef::npos)
+    return true;
+
+  if (isNull(S))
+    return true;
+  if (isBool(S))
+    return true;
+  if (isNumeric(S))
+    return true;
+
+  return false;
+}
 
 
 template<typename T>
@@ -324,6 +459,7 @@ struct missingTraits : public std::integral_constant<bool,
                                          !has_ScalarEnumerationTraits<T>::value
                                       && !has_ScalarBitSetTraits<T>::value
                                       && !has_ScalarTraits<T>::value
+                                      && !has_BlockScalarTraits<T>::value
                                       && !has_MappingTraits<T>::value
                                       && !has_SequenceTraits<T>::value
                                       && !has_DocumentListTraits<T>::value >  {};
@@ -363,15 +499,20 @@ public:
   virtual bool preflightKey(const char*, bool, bool, bool &, void *&) = 0;
   virtual void postflightKey(void*) = 0;
 
+  virtual void beginFlowMapping() = 0;
+  virtual void endFlowMapping() = 0;
+
   virtual void beginEnumScalar() = 0;
   virtual bool matchEnumScalar(const char*, bool) = 0;
+  virtual bool matchEnumFallback() = 0;
   virtual void endEnumScalar() = 0;
 
   virtual bool beginBitSetScalar(bool &) = 0;
   virtual bool bitSetMatch(const char*, bool) = 0;
   virtual void endBitSetScalar() = 0;
 
-  virtual void scalarString(StringRef &) = 0;
+  virtual void scalarString(StringRef &, bool) = 0;
+  virtual void blockScalarString(StringRef &) = 0;
 
   virtual void setError(const Twine &) = 0;
 
@@ -390,6 +531,16 @@ public:
     }
   }
 
+  template <typename FBT, typename T>
+  void enumFallback(T &Val) {
+    if ( matchEnumFallback() ) {
+      // FIXME: Force integral conversion to allow strong typedefs to convert.
+      FBT Res = (uint64_t)Val;
+      yamlize(*this, Res, true);
+      Val = (uint64_t)Res;
+    }
+  }
+
   template <typename T>
   void bitSetCase(T &Val, const char* Str, const T ConstVal) {
     if ( bitSetMatch(Str, outputting() && (Val & ConstVal) == ConstVal) ) {
@@ -405,6 +556,19 @@ public:
     }
   }
 
+  template <typename T>
+  void maskedBitSetCase(T &Val, const char *Str, T ConstVal, T Mask) {
+    if (bitSetMatch(Str, outputting() && (Val & Mask) == ConstVal))
+      Val = Val | ConstVal;
+  }
+
+  template <typename T>
+  void maskedBitSetCase(T &Val, const char *Str, uint32_t ConstVal,
+                        uint32_t Mask) {
+    if (bitSetMatch(Str, outputting() && (Val & Mask) == ConstVal))
+      Val = Val | ConstVal;
+  }
+
   void *getContext();
   void setContext(void *);
 
@@ -437,7 +601,7 @@ public:
   void mapOptional(const char* Key, T& Val, const T& Default) {
     this->processKeyWithDefault(Key, Val, Default, false);
   }
-  
+
 private:
   template <typename T>
   void processKeyWithDefault(const char *Key, Optional<T> &Val,
@@ -521,11 +685,11 @@ yamlize(IO &io, T &Val, bool) {
     llvm::raw_string_ostream Buffer(Storage);
     ScalarTraits<T>::output(Val, io.getContext(), Buffer);
     StringRef Str = Buffer.str();
-    io.scalarString(Str);
+    io.scalarString(Str, ScalarTraits<T>::mustQuote(Str));
   }
   else {
     StringRef Str;
-    io.scalarString(Str);
+    io.scalarString(Str, ScalarTraits<T>::mustQuote(Str));
     StringRef Result = ScalarTraits<T>::input(Str, io.getContext(), Val);
     if ( !Result.empty() ) {
       io.setError(llvm::Twine(Result));
@@ -533,11 +697,32 @@ yamlize(IO &io, T &Val, bool) {
   }
 }
 
+template <typename T>
+typename std::enable_if<has_BlockScalarTraits<T>::value, void>::type
+yamlize(IO &YamlIO, T &Val, bool) {
+  if (YamlIO.outputting()) {
+    std::string Storage;
+    llvm::raw_string_ostream Buffer(Storage);
+    BlockScalarTraits<T>::output(Val, YamlIO.getContext(), Buffer);
+    StringRef Str = Buffer.str();
+    YamlIO.blockScalarString(Str);
+  } else {
+    StringRef Str;
+    YamlIO.blockScalarString(Str);
+    StringRef Result =
+        BlockScalarTraits<T>::input(Str, YamlIO.getContext(), Val);
+    if (!Result.empty())
+      YamlIO.setError(llvm::Twine(Result));
+  }
+}
 
 template<typename T>
 typename std::enable_if<validatedMappingTraits<T>::value, void>::type
 yamlize(IO &io, T &Val, bool) {
-  io.beginMapping();
+  if (has_FlowTraits<MappingTraits<T>>::value)
+    io.beginFlowMapping();
+  else
+    io.beginMapping();
   if (io.outputting()) {
     StringRef Err = MappingTraits<T>::validate(io, Val);
     if (!Err.empty()) {
@@ -551,15 +736,24 @@ yamlize(IO &io, T &Val, bool) {
     if (!Err.empty())
       io.setError(Err);
   }
-  io.endMapping();
+  if (has_FlowTraits<MappingTraits<T>>::value)
+    io.endFlowMapping();
+  else
+    io.endMapping();
 }
 
 template<typename T>
 typename std::enable_if<unvalidatedMappingTraits<T>::value, void>::type
 yamlize(IO &io, T &Val, bool) {
-  io.beginMapping();
-  MappingTraits<T>::mapping(io, Val);
-  io.endMapping();
+  if (has_FlowTraits<MappingTraits<T>>::value) {
+    io.beginFlowMapping();
+    MappingTraits<T>::mapping(io, Val);
+    io.endFlowMapping();
+  } else {
+    io.beginMapping();
+    MappingTraits<T>::mapping(io, Val);
+    io.endMapping();
+  }
 }
 
 template<typename T>
@@ -602,78 +796,91 @@ template<>
 struct ScalarTraits<bool> {
   static void output(const bool &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, bool &);
+  static bool mustQuote(StringRef) { return false; }
 };
 
 template<>
 struct ScalarTraits<StringRef> {
   static void output(const StringRef &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, StringRef &);
+  static bool mustQuote(StringRef S) { return needsQuotes(S); }
 };
- 
+
 template<>
 struct ScalarTraits<std::string> {
   static void output(const std::string &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, std::string &);
+  static bool mustQuote(StringRef S) { return needsQuotes(S); }
 };
 
 template<>
 struct ScalarTraits<uint8_t> {
   static void output(const uint8_t &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, uint8_t &);
+  static bool mustQuote(StringRef) { return false; }
 };
 
 template<>
 struct ScalarTraits<uint16_t> {
   static void output(const uint16_t &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, uint16_t &);
+  static bool mustQuote(StringRef) { return false; }
 };
 
 template<>
 struct ScalarTraits<uint32_t> {
   static void output(const uint32_t &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, uint32_t &);
+  static bool mustQuote(StringRef) { return false; }
 };
 
 template<>
 struct ScalarTraits<uint64_t> {
   static void output(const uint64_t &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, uint64_t &);
+  static bool mustQuote(StringRef) { return false; }
 };
 
 template<>
 struct ScalarTraits<int8_t> {
   static void output(const int8_t &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, int8_t &);
+  static bool mustQuote(StringRef) { return false; }
 };
 
 template<>
 struct ScalarTraits<int16_t> {
   static void output(const int16_t &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, int16_t &);
+  static bool mustQuote(StringRef) { return false; }
 };
 
 template<>
 struct ScalarTraits<int32_t> {
   static void output(const int32_t &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, int32_t &);
+  static bool mustQuote(StringRef) { return false; }
 };
 
 template<>
 struct ScalarTraits<int64_t> {
   static void output(const int64_t &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, int64_t &);
+  static bool mustQuote(StringRef) { return false; }
 };
 
 template<>
 struct ScalarTraits<float> {
   static void output(const float &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, float &);
+  static bool mustQuote(StringRef) { return false; }
 };
 
 template<>
 struct ScalarTraits<double> {
   static void output(const double &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, double &);
+  static bool mustQuote(StringRef) { return false; }
 };
 
 
@@ -683,7 +890,7 @@ struct ScalarTraits<double> {
 template <typename TNorm, typename TFinal>
 struct MappingNormalization {
   MappingNormalization(IO &i_o, TFinal &Obj)
-      : io(i_o), BufPtr(NULL), Result(Obj) {
+      : io(i_o), BufPtr(nullptr), Result(Obj) {
     if ( io.outputting() ) {
       BufPtr = new (&Buffer) TNorm(io, Obj);
     }
@@ -769,10 +976,10 @@ public:
         void *Ctxt = nullptr,
         SourceMgr::DiagHandlerTy DiagHandler = nullptr,
         void *DiagHandlerCtxt = nullptr);
-  ~Input();
+  ~Input() override;
 
   // Check if there was an syntax or semantic error during parsing.
-  llvm::error_code error();
+  std::error_code error();
 
 private:
   bool outputting() override;
@@ -781,6 +988,8 @@ private:
   void endMapping() override;
   bool preflightKey(const char *, bool, bool, bool &, void *&) override;
   void postflightKey(void *) override;
+  void beginFlowMapping() override;
+  void endFlowMapping() override;
   unsigned beginSequence() override;
   void endSequence() override;
   bool preflightElement(unsigned index, void *&) override;
@@ -791,11 +1000,13 @@ private:
   void endFlowSequence() override;
   void beginEnumScalar() override;
   bool matchEnumScalar(const char*, bool) override;
+  bool matchEnumFallback() override;
   void endEnumScalar() override;
   bool beginBitSetScalar(bool &) override;
   bool bitSetMatch(const char *, bool ) override;
   void endBitSetScalar() override;
-  void scalarString(StringRef &) override;
+  void scalarString(StringRef &, bool) override;
+  void blockScalarString(StringRef &) override;
   void setError(const Twine &message) override;
   bool canElideEmptySequence() override;
 
@@ -827,7 +1038,8 @@ private:
     StringRef value() const { return _value; }
 
     static inline bool classof(const HNode *n) {
-      return ScalarNode::classof(n->_node);
+      return ScalarNode::classof(n->_node) ||
+             BlockScalarNode::classof(n->_node);
     }
     static inline bool classof(const ScalarHNode *) { return true; }
   protected:
@@ -835,16 +1047,17 @@ private:
   };
 
   class MapHNode : public HNode {
+    void anchor() override;
+
   public:
     MapHNode(Node *n) : HNode(n) { }
-    virtual ~MapHNode();
 
     static inline bool classof(const HNode *n) {
       return MappingNode::classof(n->_node);
     }
     static inline bool classof(const MapHNode *) { return true; }
 
-    typedef llvm::StringMap<HNode*> NameToNode;
+    typedef llvm::StringMap<std::unique_ptr<HNode>> NameToNode;
 
     bool isValidKey(StringRef key);
 
@@ -853,19 +1066,20 @@ private:
   };
 
   class SequenceHNode : public HNode {
+    void anchor() override;
+
   public:
     SequenceHNode(Node *n) : HNode(n) { }
-    virtual ~SequenceHNode();
 
     static inline bool classof(const HNode *n) {
       return SequenceNode::classof(n->_node);
     }
     static inline bool classof(const SequenceHNode *) { return true; }
 
-    std::vector<HNode*> Entries;
+    std::vector<std::unique_ptr<HNode>> Entries;
   };
 
-  Input::HNode *createHNodes(Node *node);
+  std::unique_ptr<Input::HNode> createHNodes(Node *node);
   void setError(HNode *hnode, const Twine &message);
   void setError(Node *node, const Twine &message);
 
@@ -874,13 +1088,16 @@ public:
   // These are only used by operator>>. They could be private
   // if those templated things could be made friends.
   bool setCurrentDocument();
-  void nextDocument();
+  bool nextDocument();
+
+  /// Returns the current node that's being parsed by the YAML Parser.
+  const Node *getCurrentNode() const;
 
 private:
   llvm::SourceMgr                     SrcMgr; // must be before Strm
   std::unique_ptr<llvm::yaml::Stream> Strm;
   std::unique_ptr<HNode>              TopNode;
-  llvm::error_code                    EC;
+  std::error_code                     EC;
   llvm::BumpPtrAllocator              StringAllocator;
   llvm::yaml::document_iterator       DocIterator;
   std::vector<bool>                   BitValuesUsed;
@@ -897,8 +1114,8 @@ private:
 ///
 class Output : public IO {
 public:
-  Output(llvm::raw_ostream &, void *Ctxt=nullptr);
-  virtual ~Output();
+  Output(llvm::raw_ostream &, void *Ctxt = nullptr, int WrapColumn = 70);
+  ~Output() override;
 
   bool outputting() override;
   bool mapTag(StringRef, bool) override;
@@ -906,6 +1123,8 @@ public:
   void endMapping() override;
   bool preflightKey(const char *key, bool, bool, bool &, void *&) override;
   void postflightKey(void *) override;
+  void beginFlowMapping() override;
+  void endFlowMapping() override;
   unsigned beginSequence() override;
   void endSequence() override;
   bool preflightElement(unsigned, void *&) override;
@@ -916,11 +1135,13 @@ public:
   void endFlowSequence() override;
   void beginEnumScalar() override;
   bool matchEnumScalar(const char*, bool) override;
+  bool matchEnumFallback() override;
   void endEnumScalar() override;
   bool beginBitSetScalar(bool &) override;
   bool bitSetMatch(const char *, bool ) override;
   void endBitSetScalar() override;
-  void scalarString(StringRef &) override;
+  void scalarString(StringRef &, bool) override;
+  void blockScalarString(StringRef &) override;
   void setError(const Twine &message) override;
   bool canElideEmptySequence() override;
 public:
@@ -937,13 +1158,23 @@ private:
   void newLineCheck();
   void outputNewLine();
   void paddedKey(StringRef key);
-
-  enum InState { inSeq, inFlowSeq, inMapFirstKey, inMapOtherKey };
+  void flowKey(StringRef Key);
+
+  enum InState {
+    inSeq,
+    inFlowSeq,
+    inMapFirstKey,
+    inMapOtherKey,
+    inFlowMapFirstKey,
+    inFlowMapOtherKey
+  };
 
   llvm::raw_ostream       &Out;
+  int                      WrapColumn;
   SmallVector<InState, 8>  StateStack;
   int                      Column;
   int                      ColumnAtFlowStart;
+  int                      ColumnAtMapFlowStart;
   bool                     NeedBitValueComma;
   bool                     NeedFlowSequenceComma;
   bool                     EnumerationMatchFound;
@@ -991,24 +1222,28 @@ template<>
 struct ScalarTraits<Hex8> {
   static void output(const Hex8 &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, Hex8 &);
+  static bool mustQuote(StringRef) { return false; }
 };
 
 template<>
 struct ScalarTraits<Hex16> {
   static void output(const Hex16 &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, Hex16 &);
+  static bool mustQuote(StringRef) { return false; }
 };
 
 template<>
 struct ScalarTraits<Hex32> {
   static void output(const Hex32 &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, Hex32 &);
+  static bool mustQuote(StringRef) { return false; }
 };
 
 template<>
 struct ScalarTraits<Hex64> {
   static void output(const Hex64 &, void*, llvm::raw_ostream &);
   static StringRef input(StringRef, void*, Hex64 &);
+  static bool mustQuote(StringRef) { return false; }
 };
 
 
@@ -1049,6 +1284,16 @@ operator>>(Input &yin, T &docSeq) {
   return yin;
 }
 
+// Define non-member operator>> so that Input can stream in a block scalar.
+template <typename T>
+inline
+typename std::enable_if<has_BlockScalarTraits<T>::value, Input &>::type
+operator>>(Input &In, T &Val) {
+  if (In.setCurrentDocument())
+    yamlize(In, Val, true);
+  return In;
+}
+
 // Provide better error message about types missing a trait specialization
 template <typename T>
 inline
@@ -1104,6 +1349,20 @@ operator<<(Output &yout, T &seq) {
   return yout;
 }
 
+// Define non-member operator<< so that Output can stream out a block scalar.
+template <typename T>
+inline
+typename std::enable_if<has_BlockScalarTraits<T>::value, Output &>::type
+operator<<(Output &Out, T &Val) {
+  Out.beginDocuments();
+  if (Out.preflightDocument(0)) {
+    yamlize(Out, Val, true);
+    Out.postflightDocument();
+  }
+  Out.endDocuments();
+  return Out;
+}
+
 // Provide better error message about types missing a trait specialization
 template <typename T>
 inline