CodeXL 2.4, Visual Studio 2012
OpenCL.pdb NOT found !
Please check "CodeXL User Guide" which clearly explains about the gpu kernel debugging steps. This guide can be accessible via CodeXL Application->Help->View Help or directly from CodeXL installation directory (under "Help" sub-folder).
If you've any other query or issue related to CodeXL, please ask/report to their support team here: Issues · GPUOpen-Tools/CodeXL · GitHub