dll example won't compile

[s9w]

Description

I'm having quite some trouble getting doctest to work with a dll. My dll consists only of the code from executable_dll_and_plugin/dll.cpp with the latest doctest.h file. Compiling this with VS2019 yields:

1>------ Build started: Project: sandbox_lib, Configuration: Debug x64 ------
1>math.cpp
1>   Creating library C:\...\vs_solution\x64\Debug\sandbox_lib.lib and object C:\...\vs_solution\x64\Debug\sandbox_lib.exp
1>math.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: struct doctest::detail::TestSuite & __cdecl doctest::detail::TestSuite::operator*(char const *)" (__imp_??DTestSuite@detail@doctest@@QEAAAEAU012@PEBD@Z) referenced in function "void __cdecl `dynamic initializer for '_DOCTEST_ANON_VAR_0''(void)" (??__E_DOCTEST_ANON_VAR_0@@YAXXZ)
1>math.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __cdecl doctest::detail::TestCase::TestCase(void (__cdecl*)(void),char const *,unsigned int,struct doctest::detail::TestSuite const &,char const *,int)" (__imp_??0TestCase@detail@doctest@@QEAA@P6AXXZPEBDIAEBUTestSuite@12@1H@Z) referenced in function "void __cdecl `dynamic initializer for '_DOCTEST_ANON_VAR_3''(void)" (??__E_DOCTEST_ANON_VAR_3@@YAXXZ)
1>math.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: struct doctest::detail::TestCase & __cdecl doctest::detail::TestCase::operator*(char const *)" (__imp_??DTestCase@detail@doctest@@QEAAAEAU012@PEBD@Z) referenced in function "void __cdecl `dynamic initializer for '_DOCTEST_ANON_VAR_3''(void)" (??__E_DOCTEST_ANON_VAR_3@@YAXXZ)
1>math.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __cdecl doctest::detail::TestCase::~TestCase(void)" (__imp_??1TestCase@detail@doctest@@QEAA@XZ) referenced in function "void __cdecl `dynamic initializer for '_DOCTEST_ANON_VAR_3''(void)" (??__E_DOCTEST_ANON_VAR_3@@YAXXZ)
1>math.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) int __cdecl doctest::detail::regTest(struct doctest::detail::TestCase const &)" (__imp_?regTest@detail@doctest@@YAHAEBUTestCase@12@@Z) referenced in function "void __cdecl `dynamic initializer for '_DOCTEST_ANON_VAR_3''(void)" (??__E_DOCTEST_ANON_VAR_3@@YAXXZ)
1>math.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) int __cdecl doctest::detail::setTestSuite(struct doctest::detail::TestSuite const &)" (__imp_?setTestSuite@detail@doctest@@YAHAEBUTestSuite@12@@Z) referenced in function "void __cdecl `dynamic initializer for '_DOCTEST_ANON_VAR_0''(void)" (??__E_DOCTEST_ANON_VAR_0@@YAXXZ)
1>math.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) struct doctest::detail::TestSuite & __cdecl doctest_detail_test_suite_ns::getCurrentTestSuite(void)" (__imp_?getCurrentTestSuite@doctest_detail_test_suite_ns@@YAAEAUTestSuite@detail@doctest@@XZ) referenced in function "void __cdecl `dynamic initializer for '_DOCTEST_ANON_VAR_3''(void)" (??__E_DOCTEST_ANON_VAR_3@@YAXXZ)
1>C:\...\vs_solution\x64\Debug\sandbox_lib.dll : fatal error LNK1120: 7 unresolved externals
1>Done building project "sandbox_lib.vcxproj" -- FAILED.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

Which seems apparently to be the case because the definitions are hidden by macro magic.

Extra information

• latest doctest.h
• VS2019 16.4 or so
• Win10

edit: seems to work if I chose static lib instead of dynamic in VS.

[onqtam]

The reason is that the dll project links to the implementation where the test runner of doctest resides - have a look at the accompanying CMakeLists.txt file - every binary which uses doctest links to it - even the plugin which is loaded at runtime.

[s9w]

Oh, I had the feeling the example was somewhat more complex than it seems. Thanks!