Linking globals named ... : symbol multiply defined

OpenCL
1

Hello!
I’m new to the forum and i really hope that i picked the right to post my question. I am currently in the process of learning OpenCL with a book called “OpenCL Programming by Example”. Now i came across a problem that i cannot solve. And although i have some programming background and in general get the idea what is wrong i don’t understand why the error exists. As mentioned in the title a “Linking globals named ‘MatrixMul_kernel_basic’: symbol multiply defined!” is thrown during “clBuildProgram”. I am unable to find any multiple declaration for the kerne/kernelname and therefore i’m a little bit stuck. I’ve already tried google and other search engines without luck, any help is greatly appreciated.

Kernelcode:

__kernel
void MatrixMul_kernel_basic(int dim,
                            __global float* A,
                            __global float* B,
                            __global float* C)
{
    //Get index of work item
    int col = get_global_id(0);
    int row = get_global_id(1);
    float result = 0.f;
    
    //Calculate row * col for one element
    for(int i = 0; i < dim; ++i)
    {
        result += A[row * dim + i] * B[i * dim + col];
    }
    C[row * dim + col] = result;
}

Hostcode:

char* firstKernel;
    ReadKernelFile("MatrixMul_kernel_basic.cl", firstKernel);
    
    cl_program program = clCreateProgramWithSource(
                                                   context,
                                                   1,
                                                   (const char**)&firstKernel,
                                                   NULL,
                                                   &clStatus);
    LOG_OCL_ERROR(clStatus, "clCreateProgramWithSource failed.");
    
    clStatus = clBuildProgram(
                              program,
                              1,
                              devices,
                              NULL,
                              NULL,
                              NULL
                              );

If you want to see the code to query platforms, devices, etc i will provide it later. After clBuildProgram() i am getting the build log which shows the error mentioned above.

Thank you in advance for your help!