PS-8258 feature: Make Percona Server buildable on MacOS with RocksDB …

…enabled https://jira.percona.com/browse/PS-8258 In the top-level 'CMakeList.txt' file we now include 'extra/libkmip' subdirectory only when 'KMIP' keying component is configured to be built. RocksDB Storage Engine 'CMakeLists.txt' file now detects MacOS ('Darwin') platform and adds 'OS_MACOSX' preprocessor definition. 'rt' system library no longer added to 'ha_rocksdb.so' as a dependency on MacOS. 'rdb_buff.h' header from the RocksDB Storage Engine code extended with a set of macros for emulating big-endian / little-endian byte-manipulation functions for MacOS. Some RocksDB system variables declared with 'MYSQL_SYSVAR_ENUM' were using global variables of type 'uint64_t'. This was incompatible with the macro definition as it expected variables of type 'ulong'. On Linux platform it was not a problem as 'uint64_t' was defined as 'unsigned long' there. However, on MacOS 'uint64_t' is defined as 'unsigned long long'. Fixed by changing the type of underlying variables from 'uint64_t' to 'ulong'. The family of 'MYSQL_SYSVAR_XXX' macros extended with 'MYSQL_SYSVAR_UINT64_T' that is supposed to be used for 'uint64_t' variables. Because of the same reasons ('uint64_t' being defined differently on Linux and MacOS) we needed this new macro to be able bind system variables directly to RocksDB library variables that have 'uint64_t' type (the type of which we cannot change as this is RocksDB submodule code). A number of 'xxxprintf()' calls in the RocksDB Storage Engine code were incorrectly using '%lu' format specifier for 'uint64_t' types. Again, this was not a problem on Linux as 'uint64_t' was defined as 'unsigned long' there. For compatibility with MacOS, fixed by using proper 'PRIu64' format specifier instead. Fixed problem with passing an empty string to the 'std::regexp' constructor that used to work on Linux but is not allowed by the standard.
percona · Jun 1, 2022 · 8d28305 · 8d28305
1 parent bba0569
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diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -1894,7 +1894,10 @@ IF(WITH_PROTOBUF STREQUAL "bundled" OR WITH_FIDO STREQUAL "bundled")
   ENDIF()
 ENDIF()
 
-ADD_SUBDIRECTORY(extra/libkmip)
+IF(NOT DEFINED WITH_COMPONENT_KEYRING_KMIP AND NOT DEFINED WITHOUT_COMPONENT_KEYRING_KMIP
+   OR WITH_COMPONENT_KEYRING_KMIP)
+  ADD_SUBDIRECTORY(extra/libkmip)
+ENDIF()
 
 #
 # Setup maintainer mode options by the end. Platform checks are

diff --git a/include/mysql/plugin.h b/include/mysql/plugin.h
@@ -470,6 +470,20 @@ typedef void (*mysql_var_update_func)(MYSQL_THD thd, SYS_VAR *var,
       max,                                                                 \
       blk}
 
+#define MYSQL_SYSVAR_UINT64_T(name, varname, opt, comment, check, update, def, \
+                              min, max, blk)                                   \
+  DECLARE_MYSQL_SYSVAR_SIMPLE(name, uint64_t) = {                              \
+      PLUGIN_VAR_LONGLONG | PLUGIN_VAR_UNSIGNED | ((opt)&PLUGIN_VAR_MASK),     \
+      #name,                                                                   \
+      comment,                                                                 \
+      check,                                                                   \
+      update,                                                                  \
+      &varname,                                                                \
+      def,                                                                     \
+      min,                                                                     \
+      max,                                                                     \
+      blk}
+
 #define MYSQL_SYSVAR_ENUM(name, varname, opt, comment, check, update, def, \
                           typelib)                                         \
   DECLARE_MYSQL_SYSVAR_TYPELIB(name, unsigned long) = {                    \

diff --git a/storage/innobase/os/os0populate.cc b/storage/innobase/os/os0populate.cc
@@ -6,6 +6,8 @@
 #include <sys/utsname.h> /* uname() */
 #endif
 
+#if OS_MAP_POPULATE
+
 /** Retrieve and compare operating system release.
 @return	TRUE if the OS release is equal to, or later than release. */
 static bool os_compare_release(const char *release [[maybe_unused]]) {
@@ -17,6 +19,8 @@ static bool os_compare_release(const char *release [[maybe_unused]]) {
 #endif
 }
 
+#endif
+
 void prefault_if_not_map_populate(void *ptr [[maybe_unused]],
                                   size_t n_bytes [[maybe_unused]]) {
 #if OS_MAP_POPULATE

diff --git a/storage/rocksdb/CMakeLists.txt b/storage/rocksdb/CMakeLists.txt
@@ -189,6 +189,8 @@ ENDIF()
 
 IF(CMAKE_SYSTEM_NAME STREQUAL "Linux")
   add_definitions(-DOS_LINUX)
+ELSEIF(CMAKE_SYSTEM_NAME MATCHES "Darwin")
+  add_definitions(-DOS_MACOSX)
 ENDIF()
 
 ROCKSDB_SET_DEFINTIONS()
@@ -304,7 +306,10 @@ IF(HAVE_EXTERNAL_ROCKSDB)
   SET(rocksdb_static_libs ${rocksdb_static_libs} "${ROCKSDB_LIB_PATH}/${ROCKSDB_LIB_NAME}")
 ENDIF()
 
-SET(rocksdb_static_libs ${rocksdb_static_libs} ${ZLIB_LIBRARY} ${ZSTD_LIBRARY} ${LZ4_LIBRARY} "-lrt" "-ldl" ${PLUGIN_LD})
+SET(rocksdb_static_libs ${rocksdb_static_libs} ${ZLIB_LIBRARY} ${ZSTD_LIBRARY} ${LZ4_LIBRARY} "-ldl" ${PLUGIN_LD})
+IF(NOT CMAKE_SYSTEM_NAME MATCHES "Darwin")
+  SET(rocksdb_static_libs ${rocksdb_static_libs} "-lrt")
+ENDIF()
 
 MYSQL_ADD_PLUGIN(rocksdb ${ROCKSDB_SOURCES} STORAGE_ENGINE DEFAULT MODULE_ONLY
   LINK_LIBRARIES ${rocksdb_static_libs}

diff --git a/storage/rocksdb/ha_rocksdb.cc b/storage/rocksdb/ha_rocksdb.cc
@@ -660,11 +660,11 @@ static unsigned long long rocksdb_delayed_write_rate;
 static uint32_t rocksdb_max_latest_deadlocks = RDB_DEADLOCK_DETECT_DEPTH;
 static unsigned long  // NOLINT(runtime/int)
     rocksdb_persistent_cache_size_mb = 0;
-static uint64_t rocksdb_info_log_level = rocksdb::InfoLogLevel::ERROR_LEVEL;
+static ulong rocksdb_info_log_level = rocksdb::InfoLogLevel::ERROR_LEVEL;
 static char *rocksdb_wal_dir = nullptr;
 static char *rocksdb_persistent_cache_path = nullptr;
 static char *rocksdb_wsenv_path = nullptr;
-static uint64_t rocksdb_index_type =
+static ulong rocksdb_index_type =
     rocksdb::BlockBasedTableOptions::kBinarySearch;
 static uint32_t rocksdb_flush_log_at_trx_commit = 1;
 static uint32_t rocksdb_debug_optimizer_n_rows = 0;
@@ -725,8 +725,7 @@ static bool rpl_skip_tx_api_var = false;
 static bool rocksdb_print_snapshot_conflict_queries = false;
 static bool rocksdb_large_prefix = true;
 static bool rocksdb_allow_to_start_after_corruption = false;
-static uint64_t rocksdb_write_policy =
-    rocksdb::TxnDBWritePolicy::WRITE_COMMITTED;
+static ulong rocksdb_write_policy = rocksdb::TxnDBWritePolicy::WRITE_COMMITTED;
 char *rocksdb_read_free_rpl_tables;
 ulong rocksdb_max_row_locks;
 std::mutex rocksdb_read_free_rpl_tables_mutex;
@@ -736,7 +735,7 @@ Regex_list_handler rdb_read_free_regex_handler(key_rwlock_read_free_rpl_tables);
 Regex_list_handler rdb_read_free_regex_handler;
 #endif
 enum read_free_rpl_type { OFF = 0, PK_ONLY, PK_SK };
-static uint64_t rocksdb_read_free_rpl = read_free_rpl_type::OFF;
+static ulong rocksdb_read_free_rpl = read_free_rpl_type::OFF;
 static bool rocksdb_error_on_suboptimal_collation = false;
 static uint32_t rocksdb_stats_recalc_rate = 0;
 static bool rocksdb_no_create_column_family = false;
@@ -888,12 +887,13 @@ static int rocksdb_tracing(THD *const thd MY_ATTRIBUTE((__unused__)),
     return HA_EXIT_FAILURE;
   }
   // NO_LINT_DEBUG
-  LogPluginErrMsg(
-      INFORMATION_LEVEL, 0,
-      "Start tracing block cache accesses or queries. Sampling frequency: %lu, "
-      "Maximum trace file size: %lu, Trace file path %s.\n",
-      trace_opt.sampling_frequency, trace_opt.max_trace_file_size,
-      trace_file_path.c_str());
+  LogPluginErrMsg(INFORMATION_LEVEL, 0,
+                  "Start tracing block cache accesses or queries. Sampling "
+                  "frequency: %" PRIu64
+                  ", "
+                  "Maximum trace file size: %" PRIu64 ", Trace file path %s.\n",
+                  trace_opt.sampling_frequency, trace_opt.max_trace_file_size,
+                  trace_file_path.c_str());
   // Save the trace option.
   *static_cast<const char **>(save) = trace_opt_str_raw;
   return HA_EXIT_SUCCESS;
@@ -1500,12 +1500,13 @@ static MYSQL_SYSVAR_INT(max_open_files, rocksdb_db_options->max_open_files,
                         nullptr, rocksdb_db_options->max_open_files,
                         /* min */ -2, /* max */ INT_MAX, 0);
 
-static MYSQL_SYSVAR_ULONG(max_total_wal_size,
-                          rocksdb_db_options->max_total_wal_size,
-                          PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
-                          "DBOptions::max_total_wal_size for RocksDB", nullptr,
-                          nullptr, rocksdb_db_options->max_total_wal_size,
-                          /* min */ 0L, /* max */ LONG_MAX, 0);
+static MYSQL_SYSVAR_UINT64_T(max_total_wal_size,
+                             rocksdb_db_options->max_total_wal_size,
+                             PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
+                             "DBOptions::max_total_wal_size for RocksDB",
+                             nullptr, nullptr,
+                             rocksdb_db_options->max_total_wal_size,
+                             /* min */ 0L, /* max */ LONG_MAX, 0);
 
 static MYSQL_SYSVAR_BOOL(use_fsync,
                          *static_cast<bool *>(&rocksdb_db_options->use_fsync),
@@ -1542,7 +1543,7 @@ static MYSQL_SYSVAR_STR(fault_injection_options,
                         "Fault injection options for running rocksdb tests",
                         nullptr, nullptr, nullptr);
 
-static MYSQL_SYSVAR_ULONG(
+static MYSQL_SYSVAR_UINT64_T(
     delete_obsolete_files_period_micros,
     rocksdb_db_options->delete_obsolete_files_period_micros,
     PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
@@ -1623,13 +1624,13 @@ static MYSQL_SYSVAR_ULONG(keep_log_file_num,
                           nullptr, rocksdb_db_options->keep_log_file_num,
                           /* min */ 0L, /* max */ LONG_MAX, 0);
 
-static MYSQL_SYSVAR_ULONG(max_manifest_file_size,
-                          rocksdb_db_options->max_manifest_file_size,
-                          PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
-                          "DBOptions::max_manifest_file_size for RocksDB",
-                          nullptr, nullptr,
-                          rocksdb_db_options->max_manifest_file_size,
-                          /* min */ 0L, /* max */ ULONG_MAX, 0);
+static MYSQL_SYSVAR_UINT64_T(max_manifest_file_size,
+                             rocksdb_db_options->max_manifest_file_size,
+                             PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
+                             "DBOptions::max_manifest_file_size for RocksDB",
+                             nullptr, nullptr,
+                             rocksdb_db_options->max_manifest_file_size,
+                             /* min */ 0L, /* max */ ULONG_MAX, 0);
 
 static MYSQL_SYSVAR_INT(table_cache_numshardbits,
                         rocksdb_db_options->table_cache_numshardbits,
@@ -1639,18 +1640,20 @@ static MYSQL_SYSVAR_INT(table_cache_numshardbits,
                         rocksdb_db_options->table_cache_numshardbits,
                         /* min */ 0, /* max */ 19, 0);
 
-static MYSQL_SYSVAR_ULONG(wal_ttl_seconds, rocksdb_db_options->WAL_ttl_seconds,
-                          PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
-                          "DBOptions::WAL_ttl_seconds for RocksDB", nullptr,
-                          nullptr, rocksdb_db_options->WAL_ttl_seconds,
-                          /* min */ 0L, /* max */ LONG_MAX, 0);
+static MYSQL_SYSVAR_UINT64_T(wal_ttl_seconds,
+                             rocksdb_db_options->WAL_ttl_seconds,
+                             PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
+                             "DBOptions::WAL_ttl_seconds for RocksDB", nullptr,
+                             nullptr, rocksdb_db_options->WAL_ttl_seconds,
+                             /* min */ 0L, /* max */ LONG_MAX, 0);
 
-static MYSQL_SYSVAR_ULONG(wal_size_limit_mb,
-                          rocksdb_db_options->WAL_size_limit_MB,
-                          PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
-                          "DBOptions::WAL_size_limit_MB for RocksDB", nullptr,
-                          nullptr, rocksdb_db_options->WAL_size_limit_MB,
-                          /* min */ 0L, /* max */ LONG_MAX, 0);
+static MYSQL_SYSVAR_UINT64_T(wal_size_limit_mb,
+                             rocksdb_db_options->WAL_size_limit_MB,
+                             PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
+                             "DBOptions::WAL_size_limit_MB for RocksDB",
+                             nullptr, nullptr,
+                             rocksdb_db_options->WAL_size_limit_MB,
+                             /* min */ 0L, /* max */ LONG_MAX, 0);
 
 static MYSQL_SYSVAR_ULONG(manifest_preallocation_size,
                           rocksdb_db_options->manifest_preallocation_size,
@@ -1726,20 +1729,20 @@ static MYSQL_SYSVAR_BOOL(
     "DBOptions::use_adaptive_mutex for RocksDB", nullptr, nullptr,
     rocksdb_db_options->use_adaptive_mutex);
 
-static MYSQL_SYSVAR_ULONG(bytes_per_sync, rocksdb_db_options->bytes_per_sync,
-                          PLUGIN_VAR_RQCMDARG,
-                          "DBOptions::bytes_per_sync for RocksDB", nullptr,
-                          rocksdb_set_bytes_per_sync,
-                          rocksdb_db_options->bytes_per_sync,
-                          /* min */ 0L, /* max */ LONG_MAX, 0);
+static MYSQL_SYSVAR_UINT64_T(bytes_per_sync, rocksdb_db_options->bytes_per_sync,
+                             PLUGIN_VAR_RQCMDARG,
+                             "DBOptions::bytes_per_sync for RocksDB", nullptr,
+                             rocksdb_set_bytes_per_sync,
+                             rocksdb_db_options->bytes_per_sync,
+                             /* min */ 0L, /* max */ LONG_MAX, 0);
 
-static MYSQL_SYSVAR_ULONG(wal_bytes_per_sync,
-                          rocksdb_db_options->wal_bytes_per_sync,
-                          PLUGIN_VAR_RQCMDARG,
-                          "DBOptions::wal_bytes_per_sync for RocksDB", nullptr,
-                          rocksdb_set_wal_bytes_per_sync,
-                          rocksdb_db_options->wal_bytes_per_sync,
-                          /* min */ 0L, /* max */ LONG_MAX, 0);
+static MYSQL_SYSVAR_UINT64_T(wal_bytes_per_sync,
+                             rocksdb_db_options->wal_bytes_per_sync,
+                             PLUGIN_VAR_RQCMDARG,
+                             "DBOptions::wal_bytes_per_sync for RocksDB",
+                             nullptr, rocksdb_set_wal_bytes_per_sync,
+                             rocksdb_db_options->wal_bytes_per_sync,
+                             /* min */ 0L, /* max */ LONG_MAX, 0);
 
 static MYSQL_SYSVAR_BOOL(
     enable_thread_tracking,
@@ -1821,11 +1824,11 @@ static MYSQL_SYSVAR_BOOL(
     "BlockBasedTableOptions::no_block_cache for RocksDB", nullptr, nullptr,
     rocksdb_tbl_options->no_block_cache);
 
-static MYSQL_SYSVAR_ULONG(block_size, rocksdb_tbl_options->block_size,
-                          PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
-                          "BlockBasedTableOptions::block_size for RocksDB",
-                          nullptr, nullptr, rocksdb_tbl_options->block_size,
-                          /* min */ 1024L, /* max */ LONG_MAX, 0);
+static MYSQL_SYSVAR_UINT64_T(block_size, rocksdb_tbl_options->block_size,
+                             PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
+                             "BlockBasedTableOptions::block_size for RocksDB",
+                             nullptr, nullptr, rocksdb_tbl_options->block_size,
+                             /* min */ 1024L, /* max */ LONG_MAX, 0);
 
 static MYSQL_SYSVAR_INT(
     block_size_deviation, rocksdb_tbl_options->block_size_deviation,
@@ -5361,14 +5364,15 @@ static bool rocksdb_show_status(handlerton *const hton, THD *const thd,
       // NB! We're replacing hyphens with underscores in output to better match
       // the existing naming convention.
       if (rdb->GetIntProperty("rocksdb.is-write-stopped", &v)) {
-        snprintf(buf, sizeof(buf), "rocksdb.is_write_stopped COUNT : %lu\n", v);
+        snprintf(buf, sizeof(buf),
+                 "rocksdb.is_write_stopped COUNT : %" PRIu64 "\n", v);
         str.append(buf);
       }
 
       if (rdb->GetIntProperty("rocksdb.actual-delayed-write-rate", &v)) {
         snprintf(buf, sizeof(buf),
                  "rocksdb.actual_delayed_write_rate "
-                 "COUNT : %lu\n",
+                 "COUNT : %" PRIu64 "\n",
                  v);
         str.append(buf);
       }
@@ -5439,20 +5443,21 @@ static bool rocksdb_show_status(handlerton *const hton, THD *const thd,
     rocksdb::MemoryUtil::GetApproximateMemoryUsageByType(dbs, cache_set,
                                                          &temp_usage_by_type);
 
-    snprintf(buf, sizeof(buf), "\nMemTable Total: %lu",
+    snprintf(buf, sizeof(buf), "\nMemTable Total: %" PRIu64,
              temp_usage_by_type[rocksdb::MemoryUtil::kMemTableTotal]);
     str.append(buf);
-    snprintf(buf, sizeof(buf), "\nMemTable Unflushed: %lu",
+    snprintf(buf, sizeof(buf), "\nMemTable Unflushed: %" PRIu64,
              temp_usage_by_type[rocksdb::MemoryUtil::kMemTableUnFlushed]);
     str.append(buf);
-    snprintf(buf, sizeof(buf), "\nTable Readers Total: %lu",
+    snprintf(buf, sizeof(buf), "\nTable Readers Total: %" PRIu64,
              temp_usage_by_type[rocksdb::MemoryUtil::kTableReadersTotal]);
     str.append(buf);
-    snprintf(buf, sizeof(buf), "\nCache Total: %lu",
+    snprintf(buf, sizeof(buf), "\nCache Total: %" PRIu64,
              temp_usage_by_type[rocksdb::MemoryUtil::kCacheTotal]);
     str.append(buf);
-    snprintf(buf, sizeof(buf), "\nDefault Cache Capacity: %lu",
-             internal_cache_count * kDefaultInternalCacheSize);
+    snprintf(buf, sizeof(buf), "\nDefault Cache Capacity: %" PRIu64,
+             internal_cache_count *
+                 static_cast<uint64_t>(kDefaultInternalCacheSize));
     str.append(buf);
     res |= print_stats(thd, "MEMORY_STATS", "rocksdb", str, stat_print);
 

diff --git a/storage/rocksdb/ib_ut0counter.h b/storage/rocksdb/ib_ut0counter.h
@@ -84,7 +84,9 @@ struct thread_id_indexer_t : public generic_indexer_t<Type, N> {
   /* @return a random number, currently we use the thread id. Where
   thread id is represented as a pointer, it may not work as
   effectively. */
-  size_t get_rnd_index() const { return get_curr_thread_id(); }
+  size_t get_rnd_index() const {
+    return reinterpret_cast<std::uintptr_t>(get_curr_thread_id());
+  }
 };
 
 /** For counters wher N=1 */

diff --git a/storage/rocksdb/properties_collector.cc b/storage/rocksdb/properties_collector.cc
@@ -508,7 +508,8 @@ void Rdb_index_stats::merge(const Rdb_index_stats &s, const bool increment,
 
 void Rdb_index_stats::adjust_cardinality(double adjustment_factor) {
   for (int64_t &num_keys : m_distinct_keys_per_prefix) {
-    num_keys = std::max(1L, static_cast<int64_t>(num_keys * adjustment_factor));
+    num_keys = std::max(static_cast<int64_t>(1),
+                        static_cast<int64_t>(num_keys * adjustment_factor));
   }
 }
 

diff --git a/storage/rocksdb/rdb_buff.h b/storage/rocksdb/rdb_buff.h
@@ -31,6 +31,27 @@
 #include "rocksdb/slice.h"
 #include "rocksdb/status.h"
 
+#ifdef OS_MACOSX
+
+#include <libkern/OSByteOrder.h>
+
+#define htobe16(x) OSSwapHostToBigInt16(x)
+#define htole16(x) OSSwapHostToLittleInt16(x)
+#define be16toh(x) OSSwapBigToHostInt16(x)
+#define le16toh(x) OSSwapLittleToHostInt16(x)
+
+#define htobe32(x) OSSwapHostToBigInt32(x)
+#define htole32(x) OSSwapHostToLittleInt32(x)
+#define be32toh(x) OSSwapBigToHostInt32(x)
+#define le32toh(x) OSSwapLittleToHostInt32(x)
+
+#define htobe64(x) OSSwapHostToBigInt64(x)
+#define htole64(x) OSSwapHostToLittleInt64(x)
+#define be64toh(x) OSSwapBigToHostInt64(x)
+#define le64toh(x) OSSwapLittleToHostInt64(x)
+
+#endif
+
 namespace myrocks {
 
 /*

diff --git a/storage/rocksdb/rdb_sst_info.cc b/storage/rocksdb/rdb_sst_info.cc
@@ -141,7 +141,8 @@ rocksdb::Status Rdb_sst_file_ordered::Rdb_sst_file::commit() {
     if (m_tracing) {
       LogPluginErrMsg(INFORMATION_LEVEL, 0,
                       "SST Tracing: Adding file %s, smallest key: %s, "
-                      "largest key: %s, file size: %lu, num_entries: %lu",
+                      "largest key: %s, file size: %" PRIu64
+                      ", num_entries: %" PRIu64,
                       fileinfo.file_path.c_str(),
                       generateKey(fileinfo.smallest_key).c_str(),
                       generateKey(fileinfo.largest_key).c_str(),

diff --git a/storage/rocksdb/rdb_utils.cc b/storage/rocksdb/rdb_utils.cc
@@ -334,7 +334,13 @@ bool Regex_list_handler::set_patterns(
     // Note that this means the delimiter can not be part of a regular
     // expression.  This is currently not a problem as we are using the comma
     // character as a delimiter and commas are not valid in table names.
-    m_pattern.reset(new std::regex(norm_pattern, flags));
+
+    // std::regex implementation on MacOS X does not allow empty strings in
+    // constructors
+    if (norm_pattern.empty())
+      m_pattern.reset(new std::regex);
+    else
+      m_pattern.reset(new std::regex(norm_pattern, flags));
   } catch (const std::regex_error &e) {
     // This pattern is invalid.
     pattern_valid = false;