How can I set breakpoints in multiple MEX files using DDD or GDB when debugging MEX files in MATLAB 7.8 (R2009a)?

I have a complex MATLAB program that I'm trying to interface and debug with some fairly complex C/C++ code. So I have multiple mex-files created to call different C/C++ functions from an external library. I need some help in setting the breakpoints when I run MATLAB within a debuggger.

I'm currently using ddd which is just a frontend to gdb. The examples in the MATLAB documentation only deal with the simple example of debugging a single mex-file. How do I specify a breakpoint for a specific mex-file?

If I type 'break mexFunction' as specified in the simple example in the documentation. I just get a breakpoint for the very first mexFunction that is called. And if I type break foo.c:mexFunction to stop at the entry point for a specific mex-file, I get the response "No source file named foo.c"

Are there any suggestions or methods to debug mex-files in this situation?

Answer 1

[MathWorks Support Team]

Here is an example of setting breakpoints in two MEX files. The example uses the following files:

1) timestwo.mexw32 % Refer to MATLAB documentation for code sample

2) yprime.mexw32 % Refer to MATLAB documentation for code sample

3) debugMexGDB.m: A MATLAB function that calls the above two MEX files as follows:

yprime(1:1,4)

disp('Hello world')

timestwo

Run the following commands in a Unix shell for debugging:

 matlab -Dgdb    # Launch MATLAB in gdb

 run -nojvm

 >> dbstop in debugMexGDB  # You are currently inside MATLAB

 >> dbmex on

 >> debugMexGDB

 K>> dbstep  # You are currently inside debugMexGDB

 (gdb) break yprime.c:mexFunction   # You are currently inside yprime

 (gdb) break timestwo.c:10

 (gdb) continue

 K>> dbstep   # You are currently inside debugMexGDB

 Hello world

 K>> dbstep

 (gdb) continue        # You are currently inside timestwo

 (gdb) quit