make fails for assignment 1

$ make
[ 42%] Building CXX object Common/CMakeFiles/GPUCommon.dir/CAssignmentBase.cpp.o
[ 42%] Building CXX object Common/CMakeFiles/GPUCommon.dir/CLUtil.cpp.o
[ 42%] Building CXX object Common/CMakeFiles/GPUCommon.dir/CTimer.cpp.o
Linking CXX static library libGPUCommon.a
[ 42%] Built target GPUCommon
[ 42%] Building CXX object CMakeFiles/Assignment.dir/CAssignment1.cpp.o
[ 42%] Building CXX object CMakeFiles/Assignment.dir/main.cpp.o
[ 42%] Building CXX object CMakeFiles/Assignment.dir/CMatrixRotateTask.cpp.o
[ 42%] Building CXX object CMakeFiles/Assignment.dir/CSimpleArraysTask.cpp.o
Linking CXX executable Assignment
Common/libGPUCommon.a(CAssignmentBase.cpp.o): In function `CAssignmentBase::InitCLContext()':
CAssignmentBase.cpp:(.text+0x189): undefined reference to `clGetPlatformIDs'
CAssignmentBase.cpp:(.text+0x2c4): undefined reference to `clGetDeviceIDs'
CAssignmentBase.cpp:(.text+0x391): undefined reference to `clGetDeviceInfo'
CAssignmentBase.cpp:(.text+0x3f5): undefined reference to `clGetPlatformInfo'
CAssignmentBase.cpp:(.text+0x470): undefined reference to `clGetPlatformInfo'
CAssignmentBase.cpp:(.text+0x4eb): undefined reference to `clGetPlatformInfo'
CAssignmentBase.cpp:(.text+0x566): undefined reference to `clGetPlatformInfo'
CAssignmentBase.cpp:(.text+0x617): undefined reference to `clGetDeviceInfo'
CAssignmentBase.cpp:(.text+0x692): undefined reference to `clGetDeviceInfo'
CAssignmentBase.cpp:(.text+0x70d): undefined reference to `clGetDeviceInfo'
CAssignmentBase.cpp:(.text+0x788): undefined reference to `clGetDeviceInfo'
Common/libGPUCommon.a(CLUtil.cpp.o): In function `CLUtil::PrintBuildLog(_cl_program*, _cl_device_id*)':
CLUtil.cpp:(.text+0x23a): undefined reference to `clGetProgramBuildInfo'
CLUtil.cpp:(.text+0x261): undefined reference to `clGetProgramBuildInfo'
CLUtil.cpp:(.text+0x2ce): undefined reference to `clGetProgramBuildInfo'
collect2: error: ld returned 1 exit status
make[2]: *** [Assignment] Error 1
make[1]: *** [CMakeFiles/Assignment.dir/all] Error 2
make: *** [all] Error 2