C++ CMake: Undefine reference. libusb

Question

I have following directory structure:

   ├── CMakeLists.txt
   ├── main.cpp
   ├── libusb
   │   ├── lubusb.h
   │   ├── libusb-1.0.def
   │   └── libusb-1.0.a

Dumpbin of the libusb/libusb-1.0.a:

File Type: LIBRARY

Summary

     DB0 .bss
     350 .data
      40 .drectve
     CFC .pdata
    7060 .rdata
      20 .rdata$.refptr.INVALID_WINFD
      20 .rdata$.refptr.pCancelIoEx
      10 .rdata$.refptr.usbdk_backend
      30 .rdata$.refptr.usbi_backend
      20 .rdata$.refptr.usbi_default_context
      10 .rdata$.refptr.windows_version
      10 .rdata$.refptr.winusb_backend
     160 .rdata$zzz
     488 .rsrc
   132F0 .text
       0 .text.unlikely
    1090 .xdata

And write following to CMakeLists.txt:

cmake_minimum_required(VERSION 2.8)
project(untitled1)

set(CMAKE_CXX_STANDARD 11)

set(SOURCE_FILES ${CMAKE_CURRENT_SOURCE_DIR}/main.cpp)
add_executable(untitled1 ${SOURCE_FILES})
target_link_libraries(untitled1 ${CMAKE_CURRENT_SOURCE_DIR}/libusb/libusb-1.0.a)

Code of main.cpp:

#include <iostream>
#include "libusb/libusb.h"

int main() {
    libusb_init(NULL);

    std::cout << "Hello, World!" << std::endl;

    return 0;
}

In result, I am getting undefined reference:

CMakeFiles\untitled1.dir/objects.a(main.cpp.obj): In function `main':
C:/.../untitled1/main.cpp:5: undefined reference to `libusb_init@4'
collect2.exe: error: ld returned 1 exit status
mingw32-make.exe[3]: *** [untitled1.exe] Error 1
mingw32-make.exe[2]: *** [CMakeFiles/untitled1.dir/all] Error 2
mingw32-make.exe[1]: *** [CMakeFiles/untitled1.dir/rule] Error 2
mingw32-make.exe: *** [untitled1] Error 2

Did I do something wrong in Could someone please help?

Are you mixing c and c++? It seems libusb is C. Can you show how you include its header? Maybe a extern "C" is missing? — Olivier Sohn, Jul 16 '18 at 05:19
@OlivierSohn I include like this: #include "libusb/libusb.h" — Theder, Jul 16 '18 at 05:22
You can edit you question to include the code, it will be more readable (I cant' see anything :) ) — Olivier Sohn, Jul 16 '18 at 05:23
Then I think the 2nd answer of https://stackoverflow.com/questions/2403391/how-does-an-extern-c-declaration-work/2403409 will fix your issue. — Olivier Sohn, Jul 16 '18 at 05:59
Do you see this symbol in the output of `nm libusb/libusb-1.0.a` ? — pptaszni, Jul 16 '18 at 07:10
@Ptaq666, I use dumpbin on Windows, and output is in text of question — Theder, Jul 16 '18 at 12:36
@Theder yes, sorry, it seems extern "C" is in fact already handled in the header https://github.com/tenderlove/libusb/blob/master/libusb/libusb.h — Olivier Sohn, Jul 16 '18 at 19:14

C++ CMake: Undefine reference. libusb

0 Answers0