Can't build DLL on windows

[tan-tan-kanarek]

I try to use sqlpp11 on my development Windows machine, where I use Visual Studio to create C# .net core that use C++ DLL that use sqlpp11.
I managed to create Visual Studio project using:

cmake -G "Visual Studio 16 2019"

After few tweaks I managed to configure VS to produce a DLL for tests and windows dev, however I would like to make it easily (CLI) reproducible by other developers.
The command I was trying to use are:

cmake -G "NMake Makefiles" -DCMAKE_BUILD_TYPE=Debug -DBUILD_SHARED_LIBS=True -DCMAKE_INSTALL_PREFIX=C:\DataLayer\sqlpp11-connector-mysql\build\x64_Debug\lib -DDATE_INCLUDE_DIR=c:\DataLayer\date\include -DSQLPP11_INCLUDE_DIR=c:\DataLayer\sqlpp11\include "-DMYSQL_LIBRARY=C:\dev\mysql-connector-debug-x64\lib\libmysql.lib" "-DMYSQL_INCLUDE_DIR=C:\dev\mysql\include" ....

nmake /f Makefile MACHINE=x64 VC=19 install

The unfortunate outcome of this build is as followed:

connection_handle.cpp.obj : error LNK2019: unresolved external symbol mysql_init referenced in function "public: __cdecl sqlpp::mysql::detail::connection_handle_t::connection_handle_t(class std::shared_ptr<struct sqlpp::mysql::connection_config> const &)" (??0connection_handle_t@detail@mysql@sqlpp@@QEAA@AEBV?$shared_ptr@Uconnection_config@mysql@sqlpp@@@std@@@Z)
connection_handle.cpp.obj : error LNK2019: unresolved external symbol mysql_real_connect referenced in function "public: __cdecl sqlpp::mysql::detail::connection_handle_t::connection_handle_t(class std::shared_ptr<struct sqlpp::mysql::connection_config> const &)" (??0connection_handle_t@detail@mysql@sqlpp@@QEAA@AEBV?$shared_ptr@Uconnection_config@mysql@sqlpp@@@std@@@Z)
connection_handle.cpp.obj : error LNK2019: unresolved external symbol mysql_ping referenced in function "public: bool __cdecl sqlpp::mysql::detail::connection_handle_t::is_valid(void)" (?is_valid@connection_handle_t@detail@mysql@sqlpp@@QEAA_NXZ)
connection_handle.cpp.obj : error LNK2019: unresolved external symbol mysql_options referenced in function "public: __cdecl sqlpp::mysql::detail::connection_handle_t::connection_handle_t(class std::shared_ptr<struct sqlpp::mysql::connection_config> const &)" (??0connection_handle_t@detail@mysql@sqlpp@@QEAA@AEBV?$shared_ptr@Uconnection_config@mysql@sqlpp@@@std@@@Z)
connection_handle.cpp.obj : error LNK2019: unresolved external symbol mysql_close referenced in function "void __cdecl sqlpp::mysql::detail::handle_cleanup(struct MYSQL *)" (?handle_cleanup@detail@mysql@sqlpp@@YAXPEAUMYSQL@@@Z)
sqlpp-mysql.dll : fatal error LNK1120: 34 unresolved externals
NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe"' : return code '0xffffffff'
Stop.
NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.22.27905\bin\HostX86\x64\nmake.exe"' : return code '0x2'
Stop.
NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.22.27905\bin\HostX86\x64\nmake.exe"' : return code '0x2'
Stop.

It's worth mentioning that when BUILD_SHARED_LIBS=False everything built smoothly.

BTW, very cool project.

[rbock]

Hi,
Thanks for the report!

Seems like an issue with one of the CMakeLists.txt. However, I have no good way of testing and fixing this, as I do not have a Windows machine available. Can you try to figure it out and create a pull request?

Thanks,

Roland

[Toxe]

Hello @tan-tan-kanarek, in case this is still an issue: I made a small test project that builds and works on Windows (and Linux, macOS), maybe that can help you out.

It is sqlpp11_mysql.cpp from: https://github.com/Toxe/cpp-sql

Configuring and building this on Windows was actually fairly straightforward, compared to macOS and Linux. Oh and I am using Vcpkg.