[RESOLVED] using a dll without the .lib file

[Dave C]

I have a dll that I want to use in Visual C++ but I don't have the library file for it (.lib). When I try to compile I get "Error 2 error LNK1120: 1 unresolved externals"
Is there any way to use dllimport for this, like I can with C#? Or some other workaround? I have the header with the function prototypes.

TIA

[VictorN]

Did you try using GetProcAddress?

[2kaud]

Just generate the .lib file from the .dll. See https://stackoverflow.com/questions/...ile-from-a-dll See the .bat file(s) that automate this process.

[Dave C]

Just generate the .lib file from the .dll. See https://stackoverflow.com/questions/...ile-from-a-dll See the .bat file(s) that automate this process.

Thanks for that. So I used the batch file scripts from there and created a .lib file. I added that to my project under the linker's additional dependencies. But when I try to build the project I get unresolved external symbol errors for the DLL functions that I'm calling. Doesn't the lib file tell the compiler to use the DLL? Or do I need to do something else?

[VictorN]

Well, did you try LoadLibrary/GetProcAddress?
And there is another interesting resource: https://www.xspdf.com/resolution/2263630.html

[2kaud]

Are you compiling as C or C++? If as C++, are the function declarations for the dll functions specified as extern "C" (capital C) to avoid name 'mangling'? See https://stackoverflow.com/questions/...-extern-c-in-c

Are you linking dynamically or statically?

[Dave C]

Well, did you try LoadLibrary/GetProcAddress?
And there is another interesting resource: https://www.xspdf.com/resolution/2263630.html

I haven't tried that yet. If I can't get the .lib to work, I'll go that route. Thanks for the reference.

[Dave C]

Are you compiling as C or C++? If as C++, are the function declarations for the dll functions specified as extern "C" (capital C) to avoid name 'mangling'? See https://stackoverflow.com/questions/...-extern-c-in-c

Are you linking dynamically or statically?

Dynamic linking. The DLL is in the same directory as the .exe (debug). The header file for the dll definitions has the extern "C" -

#ifdef __cplusplus
extern "C" {
#endif

A typical function prototype looks like this:

void __cdecl C_2p_nominal(double z[], double theta[], double cc[],
int32_t C_fpp, int32_t C_out_hex[], double C_out[], int32_t n_samples,
int32_t n_cc);

[Are there CODE tags in this forum?]

Thanks for the help

[VictorN]

[Are there CODE tags in this forum?]

Yes, of course! See https://forums.codeguru.com/misc.php?do=bbcode#code

[2kaud]

I get unresolved external symbol errors for the DLL functions that I'm calling.

What's an example of the external symbol that can't be found - and what is called in the .dll?

[Dave C]

Well, did you try LoadLibrary/GetProcAddress?
And there is another interesting resource: https://www.xspdf.com/resolution/2263630.html

OK, I did that and it worked. Thank you.

[VictorN]

OK, I did that and it worked. Thank you.

You are welcome!