diff --git a/include/m_ctype.h b/include/m_ctype.h
index 5994816cbfc..641d0966f9e 100644
--- a/include/m_ctype.h
+++ b/include/m_ctype.h
@@ -516,7 +516,7 @@ extern struct charset_info_st my_charset_utf16le_general_ci;
 extern struct charset_info_st my_charset_utf32_bin;
 extern struct charset_info_st my_charset_utf32_general_ci;
 extern struct charset_info_st my_charset_utf32_unicode_ci;
-extern struct charset_info_st my_charset_utf8_bin;
+extern struct charset_info_st MYSQL_PLUGIN_IMPORT my_charset_utf8_bin;
 extern struct charset_info_st my_charset_utf8_general_mysql500_ci;
 extern struct charset_info_st my_charset_utf8_unicode_ci;
 extern struct charset_info_st my_charset_utf8mb4_bin;
diff --git a/include/my_default.h b/include/my_default.h
index 1d556de69ee..12392424939 100644
--- a/include/my_default.h
+++ b/include/my_default.h
@@ -20,9 +20,9 @@
 
 C_MODE_START
 
-extern const char *my_defaults_extra_file;
+extern MYSQL_PLUGIN_IMPORT const char *my_defaults_extra_file;
 extern const char *my_defaults_group_suffix;
-extern const char *my_defaults_file;
+extern MYSQL_PLUGIN_IMPORT const char *my_defaults_file;
 extern my_bool my_getopt_use_args_separator;
 extern my_bool my_getopt_is_args_separator(const char* arg);
 
diff --git a/sql/mysqld.h b/sql/mysqld.h
index dbc65cd2a43..02e3184404b 100644
--- a/sql/mysqld.h
+++ b/sql/mysqld.h
@@ -92,7 +92,7 @@ extern bool opt_disable_networking, opt_skip_show_db;
 extern bool opt_skip_name_resolve;
 extern bool opt_ignore_builtin_innodb;
 extern my_bool opt_character_set_client_handshake;
-extern bool volatile abort_loop;
+extern MYSQL_PLUGIN_IMPORT bool volatile abort_loop;
 extern bool in_bootstrap;
 extern uint connection_count;
 extern my_bool opt_safe_user_create;
@@ -155,7 +155,7 @@ extern char log_error_file[FN_REFLEN], *opt_tc_log_file;
 extern const double log_10[309];
 extern ulonglong keybuff_size;
 extern ulonglong thd_startup_options;
-extern ulong thread_id;
+extern MYSQL_PLUGIN_IMPORT ulong thread_id;
 extern ulong binlog_cache_use, binlog_cache_disk_use;
 extern ulong binlog_stmt_cache_use, binlog_stmt_cache_disk_use;
 extern ulong aborted_threads,aborted_connects;
@@ -226,7 +226,7 @@ extern MYSQL_FILE *bootstrap_file;
 extern my_bool old_mode;
 extern LEX_STRING opt_init_connect, opt_init_slave;
 extern int bootstrap_error;
-extern I_List<THD> threads;
+extern MYSQL_PLUGIN_IMPORT I_List<THD> threads;
 extern char err_shared_dir[];
 extern ulong connection_errors_select;
 extern ulong connection_errors_accept;
diff --git a/sql/slave.h b/sql/slave.h
index 5cc02c8a10b..946cc956c41 100644
--- a/sql/slave.h
+++ b/sql/slave.h
@@ -244,7 +244,7 @@ void slave_output_error_info(rpl_group_info *rgi, THD *thd);
 pthread_handler_t handle_slave_sql(void *arg);
 bool net_request_file(NET* net, const char* fname);
 
-extern bool volatile abort_loop;
+extern MYSQL_PLUGIN_IMPORT bool volatile abort_loop;
 extern Master_info *active_mi; /* active_mi for multi-master */
 extern Master_info *default_master_info; /* To replace active_mi */
 extern Master_info_index *master_info_index;
@@ -258,7 +258,7 @@ extern uint report_port;
 extern char *master_info_file, *report_user;
 extern char *report_host, *report_password;
 
-extern I_List<THD> threads;
+extern MYSQL_PLUGIN_IMPORT I_List<THD> threads;
 
 #else
 #define close_active_mi() /* no-op */
diff --git a/sql/sql_class.h b/sql/sql_class.h
index 46eeeceb112..799a6088d3f 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -1094,8 +1094,8 @@ typedef struct st_xid_state {
   uint rm_error;
 } XID_STATE;
 
-extern mysql_mutex_t LOCK_xid_cache;
-extern HASH xid_cache;
+extern MYSQL_PLUGIN_IMPORT mysql_mutex_t LOCK_xid_cache;
+extern MYSQL_PLUGIN_IMPORT HASH xid_cache;
 bool xid_cache_init(void);
 void xid_cache_free(void);
 XID_STATE *xid_cache_search(XID *xid);
diff --git a/sql/sql_plugin.h b/sql/sql_plugin.h
index a0225f4a071..e5f985aa082 100644
--- a/sql/sql_plugin.h
+++ b/sql/sql_plugin.h
@@ -153,7 +153,7 @@ typedef int (*plugin_type_init)(struct st_plugin_int *);
 
 extern I_List<i_string> *opt_plugin_load_list_ptr;
 extern char *opt_plugin_dir_ptr;
-extern char opt_plugin_dir[FN_REFLEN];
+extern MYSQL_PLUGIN_IMPORT char opt_plugin_dir[FN_REFLEN];
 extern const LEX_STRING plugin_type_names[];
 extern ulong plugin_maturity;
 extern TYPELIB plugin_maturity_values;
diff --git a/storage/connect/mycat.cc b/storage/connect/mycat.cc
index 97ad980dd6a..04cea59734e 100644
--- a/storage/connect/mycat.cc
+++ b/storage/connect/mycat.cc
@@ -105,19 +105,7 @@ PQRYRES OEMColumns(PGLOBAL g, PTOS topt, char *tab, char *db, bool info);
 /***********************************************************************/
 char *GetPluginDir(void)
 {
-  char *plugin_dir;
-
-#if defined(_WIN64)
-  plugin_dir = (char *)GetProcAddress(GetModuleHandle(NULL),
-    "?opt_plugin_dir@@3PADEA");
-#elif defined(_WIN32)
-  plugin_dir = (char*)GetProcAddress(GetModuleHandle(NULL),
-    "?opt_plugin_dir@@3PADA");
-#else
-  plugin_dir = opt_plugin_dir;
-#endif
-
-  return plugin_dir;
+  return opt_plugin_dir;
 } // end of GetPluginDir
 
 /***********************************************************************/
diff --git a/storage/spider/spd_table.cc b/storage/spider/spd_table.cc
index ead335c07ea..2448ee661c5 100644
--- a/storage/spider/spd_table.cc
+++ b/storage/spider/spd_table.cc
@@ -6325,43 +6325,6 @@ int spider_db_init(
   memset(&spider_alloc_mem_count, 0, sizeof(spider_alloc_mem_count));
   memset(&spider_free_mem_count, 0, sizeof(spider_free_mem_count));
 
-#ifdef _WIN32
-  HMODULE current_module = GetModuleHandle(NULL);
-  spd_db_att_thread_id = (ulong *)
-    GetProcAddress(current_module, "?thread_id@@3KA");
-#ifdef SPIDER_XID_USES_xid_cache_iterate
-#else
-#ifdef XID_CACHE_IS_SPLITTED
-  spd_db_att_xid_cache_split_num = (uint *)
-    GetProcAddress(current_module,
-      "?opt_xid_cache_split_num@@3IA");
-  spd_db_att_LOCK_xid_cache = *((pthread_mutex_t **)
-    GetProcAddress(current_module,
-      "?LOCK_xid_cache@@3PAUst_mysql_mutex@@A"));
-  spd_db_att_xid_cache = *((HASH **)
-    GetProcAddress(current_module, "?xid_cache@@3PAUst_hash@@A"));
-#else
-  spd_db_att_LOCK_xid_cache = (pthread_mutex_t *)
-#if MYSQL_VERSION_ID < 50500
-    GetProcAddress(current_module,
-      "?LOCK_xid_cache@@3U_RTL_CRITICAL_SECTION@@A");
-#else
-    GetProcAddress(current_module,
-      "?LOCK_xid_cache@@3Ust_mysql_mutex@@A");
-#endif
-  spd_db_att_xid_cache = (HASH *)
-    GetProcAddress(current_module, "?xid_cache@@3Ust_hash@@A");
-#endif
-#endif
-  spd_charset_utf8_bin = (struct charset_info_st *)
-    GetProcAddress(current_module, "my_charset_utf8_bin");
-  spd_defaults_extra_file = (const char **)
-    GetProcAddress(current_module, "my_defaults_extra_file");
-  spd_defaults_file = (const char **)
-    GetProcAddress(current_module, "my_defaults_file");
-  spd_abort_loop = (bool volatile *)
-    GetProcAddress(current_module, "?abort_loop@@3_NC");
-#else
   spd_db_att_thread_id = &thread_id;
 #ifdef SPIDER_XID_USES_xid_cache_iterate
 #else
@@ -6378,7 +6341,6 @@ int spider_db_init(
   spd_defaults_extra_file = &my_defaults_extra_file;
   spd_defaults_file = &my_defaults_file;
   spd_abort_loop = &abort_loop;
-#endif
 
 #ifdef HAVE_PSI_INTERFACE
   init_spider_psi_keys();