Re: How to debug GNU Radio's C++ program from source code?

Hello!

Even though GNU Radio has python bindings with swig or pybind11, the underlying code c++ symbols are still accessible with GDB. Using Visual Studio Code and GNU Radio compiled from source with Debug Symbols this is pretty straightforward:

1) Open up the source tree of gnuradio in visual studio code

2) edit the launch.json and add a C++/GDB configuration where program is python and args is the output of the GRC rendering

        {
            "name": "(gdb) Launch",
            "type": "cppdbg",
            "request": "launch",
            "program": "/usr/bin/python3",
            "args": ["/path/to/grc_output.py"],
            "stopAtEntry": false,
            "cwd": "${workspaceFolder}",
            "environment": [],
            "externalConsole": false,
            "MIMode": "gdb",
            "setupCommands": [
                {
                    "description": "Enable pretty-printing for gdb",
                    "text": "-enable-pretty-printing",
                    "ignoreFailures": true
                }
            ]
        },

3) put the breakpoint where you want to hit - note that GR will have been compiled with optimizations, so the breakpoints might be a bit funky

4) F5 to run the application

If you are debugging your own OOT, this makes it even simpler because you can compile as "-DCMAKE_BUILD_TYPE=Debug" and then your breakpoints will be very predictable - in this case you just open up VS code from the root of your project and follow the same steps.

Hope this helps.

Josh

On Tue, Aug 3, 2021 at 8:41 AM 能书能言 <2127629883@qq.com> wrote:

Hi guys!

I want to know how to debug c++ code in gnuradio. As far as I know, after we run GRC, a Python file will be generated. The Python file connects various blocks, but if I debug this Python file directly, I cannot observe the internal operations of the C++ block. I want to know if there is any way to let me Can I see the contents of the c++work function when I run the python file? It's like executing a pure Python or pure C++ program.

If this is not possible because of the swig connection method, how can I observe the work of a C++ block's work function? If I look at the code directly, it is definitely not accurate enough. Can I write a demo by myself? Or other ways.

In addition, how to edit an existing block? I just want to modify its function slightly. Do I have to use gr_modtool to create a new OOT module and rewrite it based on the contents of the original block? You must also use debugging methods when writing, but I don't know how to do it.

in addition. I have tried the tutorials on the official website, but none of them worked. I also checked the previous mailing list, but it was not very helpful. I think anyone has a better solution?

Sincerely