After installing gDEBugger, double-click the application icon to start gDEBugger.
You will be greeted with the gDEBugger Home Page. Select “Create a New Project” to bring up the New Project Wizard. Select the application to be debugged and press the “Go” button (F5) to start debugging.
To start kernel debugging, you can choose one of a few options, the easiest of which is Stepping Into (F11) the clEnqueueNDRangeKernel function call. Once the kernel starts executing, you can debug it like C/C++ code, stepping into, out of, or over function calls in the kernel, setting source breakpoints, and inspecting the locals, autos, watch, and call stack views.
Use the other views described in this guide for more detailed and advanced information on the OpenCL and OpenGL runtimes, their states, and the objects created within them.