Visual Studio Name Mangling "YAPEAV" and Mysql connector

Question

I'm getting unresolved external symbol error when linking my code with MySQL Connector C++ 1.1.0.
Here's the error message:

6>database.lib(db_manager.obj) : error LNK2019: unresolved external symbol
"class sql::mysql::MySQL_Driver * __cdecl sql::mysql::get_driver_instance(void)" (?get_driver_instance@mysql@sql@@YAPAVMySQL_Driver@12@XZ)
referenced in function "class sql::mysql::MySQL_Driver * __cdecl sql::mysql::get_mysql_driver_instance(void)" (?get_mysql_driver_instance@mysql@sql@@YAPAVMySQL_Driver@12@XZ)

I used dumpbin to get a list of symbols in the mysqlconn-static.lib and found a similar symbol:

COMDAT; sym= "class sql::mysql::MySQL_Driver * __cdecl sql::mysql::get_driver_instance(void)" (?get_driver_instance@mysql@sql@@YAPEAVMySQL_Driver@12@XZ)

When these two lines are lined up, the difference looks like:

(?get_driver_instance@mysql@sql@@YAPEAVMySQL_Driver@12@XZ)  
(?get_driver_instance@mysql@sql@@YAPAVMySQL_Driver@12@XZ)  

What is the difference in Name Managling between YAPEAV AND YAPAV?

I have an idea that my issue is related to incompatiblities between the MySQL Connector library and how I'm building my code.

I searched the web and found a bug against MySQL Connector 1.1.0, but it was changed to "not a bug".

I am using Visual Studio 2010 compiling to a 32-bit target using a 64-bit platform.
The MySQL Connector C++ is version 1.1.0.

Answer 1

The MSVC tool undname is your friend. Using it, you find that

• ?get_driver_instance@mysql@sql@@YAPEAVMySQL_Driver@12@XZ corresponds to:

  class sql::mysql::MySQL_Driver * __ptr64 __cdecl sql::mysql::get_driver_instance(void)
  

• ?get_driver_instance@mysql@sql@@YAPAVMySQL_Driver@12@XZ corresponds to:

  class sql::mysql::MySQL_Driver * __cdecl sql::mysql::get_driver_instance(void)
  

The difference being a __ptr64 decoration. It seems like you're building a 32-bit program but linking against a library built for a 64-bit target.