How do you add a library in QT

dolphonebubleine

All I am trying to do is add OpenCL to a QT project. My OpenCL files are in

@
c:/opencl

c:/opencl/include/CL/cl.h
c:/opencl/lib/x86/OpenCL.lib@

According to what I read "here":http://qt-project.org/forums/viewthread/6960 if you have a .lib and a .dll you should link dynamically and I do have a .dll.

@c:/opencl/bin/x86/OpenCL.dll@

I setup my .pro file:

@LIBS += -lOpenCL
LIBS += -LC:/opencl/lib/x86
INCLUDEPATH += C:/opencl/include@

I include the header file:

@#include <CL/cl.h>@

QT intellisense incorporates the header file

The application builds and runs fine. However, as soon as I try to call any of the functions in the library I get linker errors:

@LNK2019: unresolved external symbol clGetPlatformIDs referenced in function main
LNK1120: 1 unresolved externals@

sierdzio

2 potential solutions I see here:

linkers are sequential - they include the libraries in the order you specify. In your case, you are including the libfile (small 'L') before you specify the folder that contains it (big 'L'). Swap those 2 lines and it could work
on Windows, you can actually specify the path to your .lib file without any '-l' or '-L': LIBS += C:/opencl/lib/x86/OpenCL.lib

dolphonebubleine

Good guess but it's a nogo. Neither attempt worked.

@LIBS += "C:/opencl/lib/x86/OpenCL.lib"
INCLUDEPATH += C:/opencl/include@

@LIBS += -LC:/opencl/lib/x86
LIBS += -lOpenCL
INCLUDEPATH += C:/opencl/include@

dolphonebubleine

I finally figured this out (with some help).

I installed QT 64-bit. Then I linked to OpenCL 64 bit (did not realize it but I was linked to 32 bit OpenCL before).

sierdzio

Uh, very good find. 64/32 bit mismatches are sometimes hard to notice.