Debug xelabs tokudb builds do not work. mysqld hits an assert when ex…

…ecuting global constructors (before main gets called). the assert catches global mutex initialization which seems to be problematic. since tokudb has a global mutex (open_tables_mutex) and tokudb is statically linked into mysqld (plugin type mandatory), the assert fires.

we could:
1. remove the assert, or
2. rewrite tokudb to remove the open_tables_mutex, or
3. compile tokudb into a shared library.

this commit compiles tokudb into a shared library for debug builds.

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Reading symbols from bin/mysqld...done.
[New LWP 24606]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `bin/mysqld --initialize'.
Program terminated with signal SIGABRT, Aborted.
#0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
#0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
#1  0x00007f4498d8df5d in __GI_abort () at abort.c:90
#2  0x00007f4498d83f17 in __assert_fail_base (fmt=<optimized out>, assertion=assertion@entry=0x5581f567ed23 "safe_mutex_inited",
    file=file@entry=0x5581f567ecf0 "/home/rfp/projects/xelabs-server/mysys/thr_mutex.c", line=line@entry=39,
    function=function@entry=0x5581f567f040 <__PRETTY_FUNCTION__.6977> "safe_mutex_init") at assert.c:92
#3  0x00007f4498d83fc2 in __GI___assert_fail (assertion=0x5581f567ed23 "safe_mutex_inited", file=0x5581f567ecf0 "/home/rfp/projects/xelabs-server/mysys/thr_mutex.c", line=39,
    function=0x5581f567f040 <__PRETTY_FUNCTION__.6977> "safe_mutex_init") at assert.c:101
#4  0x00005581f4ab1a40 in safe_mutex_init (mp=0x5581f632b8e0 <TOKUDB_SHARE::_open_tables_mutex>, attr=0x5581f6336550 <my_fast_mutexattr>,
    file=0x5581f57ac188 "/home/rfp/projects/xelabs-server/storage/tokudb/tokudb_thread.h", line=207) at /home/rfp/projects/xelabs-server/mysys/thr_mutex.c:39
#5  0x00005581f500aa9f in my_mutex_init (mp=0x5581f632b8e0 <TOKUDB_SHARE::_open_tables_mutex>, attr=0x5581f6336550 <my_fast_mutexattr>,
    file=0x5581f57ac188 "/home/rfp/projects/xelabs-server/storage/tokudb/tokudb_thread.h", line=207) at /home/rfp/projects/xelabs-server/include/thr_mutex.h:167
#6  0x00005581f500ac25 in inline_mysql_mutex_init (key=4294967295, that=0x5581f632b8e0 <TOKUDB_SHARE::_open_tables_mutex>, attr=0x5581f6336550 <my_fast_mutexattr>,
    src_file=0x5581f57ac188 "/home/rfp/projects/xelabs-server/storage/tokudb/tokudb_thread.h", src_line=207)
    at /home/rfp/projects/xelabs-server/include/mysql/psi/mysql_thread.h:668
#7  0x00005581f5043ee5 in tokudb::thread::mutex_t::mutex_t (this=0x5581f632b8e0 <TOKUDB_SHARE::_open_tables_mutex>, key=4294967295)
    at /home/rfp/projects/xelabs-server/storage/tokudb/tokudb_thread.h:207
#8  0x00005581f5043e68 in tokudb::thread::mutex_t::mutex_t (this=0x5581f632b8e0 <TOKUDB_SHARE::_open_tables_mutex>)
    at /home/rfp/projects/xelabs-server/storage/tokudb/tokudb_thread.h:45
#9  0x00005581f50433a4 in __static_initialization_and_destruction_0 (__initialize_p=1, __priority=65535) at /home/rfp/projects/xelabs-server/storage/tokudb/ha_tokudb.cc:38
#10 0x00005581f5043936 in _GLOBAL__sub_I__ZN6tokudb8metadata4readEP9__toku_dbP13__toku_db_txnyPvmPm () at /home/rfp/projects/xelabs-server/storage/tokudb/ha_tokudb.cc:9061
#11 0x00005581f529aefd in __libc_csu_init ()
#12 0x00007f4498d76150 in __libc_start_main (main=0x5581f4025aea <main(int, char**)>, argc=2, argv=0x7ffe9dcd7118, init=0x5581f529aeb0 <__libc_csu_init>,
    fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffe9dcd7108) at ../csu/libc-start.c:264
#13 0x00005581f4025a0a in _start ()
(gdb) q

storage/tokudb/CMakeLists.txt

@@ -125,7 +125,6 @@ INCLUDE_DIRECTORIES(${CMAKE_CURRENT_BINARY_DIR}/${TOKU_FT_DIR_NAME})
 INCLUDE_DIRECTORIES(${CMAKE_CURRENT_BINARY_DIR}/${TOKU_FT_DIR_NAME}/buildheader)
 INCLUDE_DIRECTORIES(${CMAKE_CURRENT_BINARY_DIR}/${TOKU_FT_DIR_NAME}/portability)
 
-
 SET(TOKUDB_PLUGIN_DYNAMIC "ha_tokudb")
 SET(TOKUDB_SOURCES
     ha_tokudb.cc
@@ -134,7 +133,14 @@ SET(TOKUDB_SOURCES
     tokudb_sysvars.cc
     tokudb_thread.cc
     tokudb_dir_cmd.cc)
-MYSQL_ADD_PLUGIN(tokudb ${TOKUDB_SOURCES} STORAGE_ENGINE MANDATORY
+IF (NOT DEFINED TOKUDB_PLUGIN_TYPE)
+    IF (CMAKE_BUILD_TYPE MATCHES "Debug")
+      SET (TOKUDB_PLUGIN_TYPE MODULE_ONLY)
+    ELSE ()
+      SET (TOKUDB_PLUGIN_TYPE MANDATORY)
+  ENDIF ()
+ENDIF()
+MYSQL_ADD_PLUGIN(tokudb ${TOKUDB_SOURCES} STORAGE_ENGINE ${TOKUDB_PLUGIN_TYPE}
     LINK_LIBRARIES tokufractaltree_static tokuportability_static ${ZLIB_LIBRARY} stdc++)
 SET(CMAKE_MODULE_LINKER_FLAGS_RELEASE "${CMAKE_MODULE_LINKER_FLAGS_RELEASE} -flto -fuse-linker-plugin")
 SET(CMAKE_MODULE_LINKER_FLAGS_RELWITHDEBINFO "${CMAKE_MODULE_LINKER_FLAGS_RELWITHDEBINFO} -flto -fuse-linker-plugin")