In C/C++,how to link dynamic link lib which compiled in GCC/G++ in MS VStudio?

Question

These days, I use Flex & Bison generated some codes to develop a SQL-parser alike tools, these code can't compiled silently(may be this another topic) in VS2005,but GCC/G++ works well, then I compiled these code with mingw in dll(in windows xp), and then linked these function facades in VS2005, but it seems can't link the dll during linking.

Does MS VS2005 recognize the dll which compiled using mingw on windows? Is there anything I need to do additional? For example, adding something in the include-file that declare the exported APIs?

Does any one can give some advices?

The condition is, as in VS2005, if you want to export some APIs, you may show a *.def file to tell nmake which API you want to export, and then you may create a(or some) *.h file to declare somthing about these APIs(adding some stdcall alike prefix as a call protocal) and some data-type definition. But with GCC/G++, you do not need to do such boring things, just use [ar], you can get these APIs, so my *.h file do not add call protocol and no *.def, just like common function declaration. After *.dll generated, add the *.h file and [mv] generated *.dll in VS2005 project directory, then set the linking *.dll in project setting. Does these steps generated my Question?

BTW, I found and tested VC6-compiled dll can be linked with mingw in Windows XP, but the reverse can't work.

Anyway, forgive my poor English, and thanks for your concern.

Answer 1

VS2005 does not recognize any DLL to compile anything, and I doubt mingw does.

When your application shall use a DLL, you need to tell VS2005 what functions are provided by the DLL.

Load Time Binding

The entry points are defined in the EXPORT directory of the DLL. The content of the EXPORT directory can be defined with the DEF file, while compiling the DLL. Theses exports can also defined using the #pragma __declspec(dllexport) directive. When you compile the DLL the linker will also generate a *.LIB file for the consuming application. This LIB is called import library.

The signatures of the exported functions must be provided by function prototypes, usually in a *.h file.

When you compile your application with load time binding, you include the *.h file in your source code and add the import library to the project settings. (not the *.DLL) When the O/S loads your application, the static code in the import library will load the DLL, read the EXPORT directory and fix all stubs to access the exported functions (and other symbols).

Dynamic Binding

You can omit the import library and load the DLL with your code using LoadLibrayy at the time that's appropriate. You need to define the pointers to the DLL entrypoints by yourself and must intialize theses pointers before calling GetProcAddress the actual functions.