Re: "undefined reference" error message when using mkoctfile to create oct file

[Mike Miller]

On Thu, Feb 16, 2017 at 10:45:03 -0800, Yan Zhang wrote:
> Hi Folks,
> 
> I'm a new user of Octave and trying to make a oct file so that I can
> control a Newport Power Meter in my octave program. I have a c++ code
> file "PowerMeter.cc", and I also have a header file "NewpDll.h" and a
> dll file "usbdll.dll" which are obtained from Newport driver examples.
> When I tried to create the OCT file, I got the following messages:
> 
> ----------------------------------------------------------------
> >> mkoctfile PowerMeter.cc -usbdll.dll
> PowerMeter.o: In function `Z12CloseDevicesv':
> C:\Users\yan.zhang\Desktop\TestCam_Project\Oct_Src\cc/PowerMeter.cc:19: 
> undefined reference to address@hidden'
> PowerMeter.o: In function `Z11OpenDevicesi':
> C:\Users\yan.zhang\Desktop\TestCam_Project\Oct_Src\cc/PowerMeter.cc:29: 
> undefined reference to address@hidden'
> C:\Users\yan.zhang\Desktop\TestCam_Project\Oct_Src\cc/PowerMeter.cc:30: 
> undefined reference to address@hidden'
> PowerMeter.o: In function `Z4ReadiPciPm':
> C:\Users\yan.zhang\Desktop\TestCam_Project\Oct_Src\cc/PowerMeter.cc:40: 
> undefined reference to address@hidden'
> PowerMeter.o: In function `Z5WriteiPc':
> C:\Users\yan.zhang\Desktop\TestCam_Project\Oct_Src\cc/PowerMeter.cc:66: 
> undefined reference to address@hidden'
> collect2.exe: error: ld returned 1 exit status
> warning: mkoctfile exited with failure status
> warning: called from
>     mkoctfile at line 171 column 5
> ----------------------------------------------------------------
> 
> The functions "newp_usb_uninit_system", "newp_usb_init_product", etc
> are already declared in the "NewpDll.h", and they should be
> implemented in the usbdll.dll (I checked the dll file using "depends",
> a program that can look into dll files). I don't understand why I
> still got the above error messages.

I know very little about Windows programming, but isn't an import
library required as well as a dll? From what I do understand, the dll is
used at runtime, but an import library is required at build time to
resolve the symbols above. I think this library would typically be
called "usbdll.lib".

-- 
mike