+/// Given a vector of strings (function PGO names) \c NameStrs, the
+/// method generates a combined string \c Result thatis ready to be
+/// serialized. The \c Result string is comprised of three fields:
+/// The first field is the legnth of the uncompressed strings, and the
+/// the second field is the length of the zlib-compressed string.
+/// Both fields are encoded in ULEB128. If \c doCompress is false, the
+/// third field is the uncompressed strings; otherwise it is the
+/// compressed string. When the string compression is off, the
+/// second field will have value zero.
+int collectPGOFuncNameStrings(const std::vector<std::string> &NameStrs,
+ bool doCompression, std::string &Result);
+/// Produce \c Result string with the same format described above. The input
+/// is vector of PGO function name variables that are referenced.
+int collectPGOFuncNameStrings(const std::vector<GlobalVariable *> &NameVars,
+ std::string &Result);
+class InstrProfSymtab;
+/// \c NameStrings is a string composed of one of more sub-strings encoded in
+/// the
+/// format described above. The substrings are seperated by 0 or more zero
+/// bytes.
+/// This method decodes the string and populates the \c Symtab.
+int readPGOFuncNameStrings(StringRef NameStrings, InstrProfSymtab &Symtab);
+