+ return V->getValueID() == UndefValueVal;
+ }
+};
+
+//===----------------------------------------------------------------------===//
+/// MDString - a single uniqued string.
+/// These are used to efficiently contain a byte sequence for metadata.
+///
+class MDString : public Constant {
+ MDString(const MDString &); // DO NOT IMPLEMENT
+ void *operator new(size_t, unsigned); // DO NOT IMPLEMENT
+ MDString(const char *begin, const char *end);
+
+ const char *StrBegin, *StrEnd;
+ friend class LLVMContextImpl;
+protected:
+ // allocate space for exactly zero operands
+ void *operator new(size_t s) {
+ return User::operator new(s, 0);
+ }
+public:
+ /// size() - The length of this string.
+ ///
+ intptr_t size() const { return StrEnd - StrBegin; }
+
+ /// begin() - Pointer to the first byte of the string.
+ ///
+ const char *begin() const { return StrBegin; }
+
+ /// end() - Pointer to one byte past the end of the string.
+ ///
+ const char *end() const { return StrEnd; }
+
+ /// getType() specialization - Type is always MetadataTy.
+ ///
+ inline const Type *getType() const {
+ return Type::MetadataTy;
+ }
+
+ /// isNullValue - Return true if this is the value that would be returned by
+ /// getNullValue. This always returns false because getNullValue will never
+ /// produce metadata.
+ virtual bool isNullValue() const {
+ return false;
+ }
+
+ virtual void destroyConstant();
+
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const MDString *) { return true; }
+ static bool classof(const Value *V) {
+ return V->getValueID() == MDStringVal;