Debug mexFunction of matlab using gdb

original url:

http://www.mathworks.com/help/matlab/matlab_external/debugging-on-linux-platforms.html

Debugging on Linux Platforms

The GNU® Debugger gdb, available on Linux® systems, provides complete source code debugging, including the ability to set breakpoints, examine variables, and step through the source code line-by-line.

In this procedure, the MATLAB® command prompt >> is shown in front of MATLAB commands, and linux> represents a Linux prompt; your system might show a different prompt. The debugger prompt is <gdb>.

To debug with gdb:

1. Compile the source MEX file with the -g option, which builds the file with debugging symbols included. For this example, at the Linux prompt, type:

   linux> mex -g yprime.c

2. At the Linux prompt, start the gdb debugger using the matlab function -D option.

   linux> matlab -Dgdb
   

3. Tell gdb to stop for debugging.

   <gdb> handle SIGSEGV SIGBUS nostop noprint
   

4. Start MATLAB without the Java® Virtual Machine (JVM™) by using the -nojvm startup flag.

   <gdb> run -nojvm

5. In MATLAB, enable debugging with the dbmex function and run your binary MEX file.

   >> dbmex on
   >> yprime(1,1:4)

6. You are ready to start debugging.

   It is often convenient to set a breakpoint at mexFunction so you stop at the beginning of the gateway routine.

   <gdb> break mexFunction
   <gdb> r

7. Once you hit one of your breakpoints, you can make full use of any commands the debugger provides to examine variables, display memory, or inspect registers.

   To proceed from a breakpoint, type:

   <gdb> continue

8. After stopping at the last breakpoint, type:

   <gdb> continue

   yprime finishes and MATLAB displays:

   ans =
   
       2.0000    8.9685    4.0000   -1.0947
   

9. From the MATLAB prompt you can return control to the debugger by typing:

   >> dbmex stop

   Or, if you are finished running MATLAB, type:

   >> quit

10. When you are finished with the debugger, type:

    <gdb> quit

    You return to the Linux prompt.

Refer to the documentation provided with your debugger for more information on its use.