using namespace llvm;
//===----------------------------------------------------------------------===//
+// std::string wrapper for DenseMap purposes
+//===----------------------------------------------------------------------===//
+
+/// TableGenStringKey - This is a wrapper for std::string suitable for
+/// using as a key to a DenseMap. Because there isn't a particularly
+/// good way to indicate tombstone or empty keys for strings, we want
+/// to wrap std::string to indicate that this is a "special" string
+/// not expected to take on certain values (those of the tombstone and
+/// empty keys). This makes things a little safer as it clarifies
+/// that DenseMap is really not appropriate for general strings.
+
+class TableGenStringKey {
+public:
+ TableGenStringKey(const std::string &str) : data(str) {}
+ TableGenStringKey(const char *str) : data(str) {}
+
+ const std::string &str() const { return data; }
+
+private:
+ std::string data;
+};
+
+/// Specialize DenseMapInfo for TableGenStringKey.
+namespace llvm {
+
+template<> struct DenseMapInfo<TableGenStringKey> {
+ static inline TableGenStringKey getEmptyKey() {
+ TableGenStringKey Empty("<<<EMPTY KEY>>>");
+ return Empty;
+ }
+ static inline TableGenStringKey getTombstoneKey() {
+ TableGenStringKey Tombstone("<<<TOMBSTONE KEY>>>");
+ return Tombstone;
+ }
+ static unsigned getHashValue(const TableGenStringKey& Val) {
+ return HashString(Val.str());
+ }
+ static bool isEqual(const TableGenStringKey& LHS,
+ const TableGenStringKey& RHS) {
+ return LHS.str() == RHS.str();
+ }
+};
+
+}
+
+//===----------------------------------------------------------------------===//
// Type implementations
//===----------------------------------------------------------------------===//