Making Simple Use of the Debugger. Overview

The Intel® IDB supports DBX and GDB modes. By default, IDB operates like the DBX debugger. In the GDB mode, Intel IDB operates like the GNU* Debugger, GDB*. See the Starting the Debugger section to get to know how to launch the debugger in the required mode.

You look for a bug by doing the following:

1. Find a repeatable reproducer of the bug (the simpler the reproducer is, the easier the next steps will be).
2. Prepare your program for debugging.
3. Start the debugger.

• Command the debugger to either
• Prepare to create a process running the program, or
• Attach to and interrupt a process that you created using normal operating system specific methods.
• Command the debugger to create breakpoints that will pause the process as close as possible to where the bug happened.
• If you are using the debugger to create the process, tell it to create the process now.

1. Do whatever it takes to reproduce the bug, so that the breakpoints will stop the process close to where the bug has caused something detectably wrong to happen.
2. Look around to determine the location of the bug:
   • If the bug is in the code where the debugger has stopped the process, exit the debugger and fix the bug.
   • If the bug has not happened yet, remove any breakpoints that are triggering too often, create other breakpoints that work better at locating the problem, and continue the process.
   • If the bug has already occurred, take the same steps of creating breakpoints and so on, but set one or more breakpoints earlier in the program before the error occurs. Rerun from an earlier position (a snapshot if you made one, or else the beginning of the program), and step through the program to determine the exact line causing the error.