Remove function local statics that interfere with memory pooling (#1392)

util/options_helper.cc

@@ -26,6 +26,8 @@
 
 namespace rocksdb {
 
+const std::string kNullptrString = "nullptr";
+
 DBOptions BuildDBOptions(const ImmutableDBOptions& immutable_db_options,
                          const MutableDBOptions& mutable_db_options) {
   DBOptions options;
@@ -451,7 +453,7 @@ bool ParseSliceTransformHelper(
     const std::string& kFixedPrefixName, const std::string& kCappedPrefixName,
     const std::string& value,
     std::shared_ptr<const SliceTransform>* slice_transform) {
-  static const std::string kNullptrString = "nullptr";
+
   auto& pe_value = value;
   if (pe_value.size() > kFixedPrefixName.size() &&
       pe_value.compare(0, kFixedPrefixName.size(), kFixedPrefixName) == 0) {
@@ -577,7 +579,7 @@ bool ParseOptionHelper(char* opt_address, const OptionType& opt_type,
 bool SerializeSingleOptionHelper(const char* opt_address,
                                  const OptionType opt_type,
                                  std::string* value) {
-  static const std::string kNullptrString = "nullptr";
+
   assert(value);
   switch (opt_type) {
     case OptionType::kBoolean:

util/options_helper.h

@@ -693,6 +693,7 @@ static std::unordered_map<std::string, InfoLogLevel> info_log_level_string_map =
      {"FATAL_LEVEL", InfoLogLevel::FATAL_LEVEL},
      {"HEADER_LEVEL", InfoLogLevel::HEADER_LEVEL}};
 
+extern const std::string kNullptrString;
 #endif  // !ROCKSDB_LITE
 
 }  // namespace rocksdb

util/options_parser.cc

@@ -510,7 +510,7 @@ bool AreEqualOptions(
     const std::unordered_map<std::string, std::string>* opt_map) {
   const char* offset1 = opt1 + type_info.offset;
   const char* offset2 = opt2 + type_info.offset;
-  static const std::string kNullptrString = "nullptr";
+
   switch (type_info.type) {
     case OptionType::kBoolean:
       return (*reinterpret_cast<const bool*>(offset1) ==