GDB 使用python

Please read the user spec Debugging with GDB (Tenth Edition, for GDB version 13.0.50.20221115-git)chapter 23.3 Extending GDB using Python.

Please notice that: if the GDB version which you are using is old (maybe version 6 or older), maybe it does not support python. Update your GDB.

1. Check PYTHONDIR

(gdb) python
> print(gdb.PYTHONDIR)
> end
/usr/bin/share/gdb/python

By the command print(gdb.PYTHONDIR) , we can get the directory of python that GDB are using.

2. Config ~/.gdbinit

python
import sys
sys.path.insert(0, "/usr/share/gcc-8/python")
from libstdcxx.v6 import register_libstdcxx_printers
register_libstdcxx_printers(None)
end

Insert python path and register the pretty printers for printing c++ containers.

3. Example

(gdb) python
>print(gdb.parse_and_eval("1+1"))
>end
2

You can parse and evalute the value of expression by using command gdb.parse_and_eval("expression")). The "expression" can be a pointer or an object in c++ context, and python wil evalute the value automatically. The feature is very useful, and you can wrap a function in ~/.gdbinit in order to impove debugging experience.

At the end, Suggest you oftern read GDB user spec.