Jonathan Turkanis wrote:
Edward Diener wrote:
Gennadiy Rozental wrote:
3. init_unit_test_suite
I need to call external function from inside of DLLs. How it should be declared? Cause I am getting unresolved symbols error
Most Windows compilers support __declspec(dllexport) or __declspec(dllimport) in front of a function or class name and it is used like:
#if defined(BUILD_MY_DLL) #define MY_DLL_IMPORT_EXPORT_MACRO __declspec(dllexport) #elif defined(USE_MY_DLL) #define MY_DLL_IMPORT_EXPORT_MACRO __declspec(dllimport) #else #define MY_DLL_IMPORT_EXPORT_MACRO __declspec(dllimport) #endif
and then for some function or class you want to export/import you write:
MY_DLL_IMPORT_EXPORT_MACRO void SomeFunction();
I think Gennadiy wants the dll code to call a user-defined function, and the problem is that if you declare the function and then leave it undefined the linker complains, even though this works fine with static linking, since the user supplies the definition and the linker sees everything at once.
OK, but would it not be better just to use boost::function<> to allow the user to pass in a user-defined function at run-time from wherever he chooses ? This is much more flexible than attempting to declare a user-defined function in a Dll which the end-user is supposed to define and depend on compile/link to resolve it..