I am using pdb to debug a python program, and the python program uses a module written by C. I want to use "step" command to enter the function in the module written by C, but I find this operation can't be successful. Is there any method to use pdb debug module written by C? Thanks in advance!
pdb won't allow you to debug modules written in C. You can however use gdb to debug errors you might be encountering in C code.
To launch a Python script using gdb you can use the following command:
gdb python
and then to execute your script:
(gdb) run <myscript>.py
Related
I'd like to be able to launch and attach a debugger at a specific point in some python 3.6 code without having to be attached to it from the program start. .NET has this via Debugger.Launch(), where when that statement is hit I am prompted to attach a debugger.
Is there something like this for Python 3.x?
import pdb;pdb.set_trace()
use above statement to debug command code,step in(s), step out(o),next(n), continue(c) and read official documentation python with pdb it will nice core dubugger of python 2 and python3
I have a core dump of a running CPython program and would like to execute Python code in the dumped process's context.
I have loaded the core and the interpreter into gdb with gdb python core-dump-file.
I know about python-interactive, but it isn't able to see the context (ex: import sys; sys.modules doesn't give me any of the process's modules)
How can I do this?
I don't mind calling CPython's C functions if that is the only possible way.
1) First check if your gdb has been built with python from source.
You can do this(in the gdb prompt) by:
(gdb) python print("Hi from python")
If you want to check the version of python in your system try:
(gdb) python import sys
(gdb) python print(sys.version)
If these commands fail. It probably means that your gdb was never built with python support in the first place.
You should build gdb from source, and in the configure step add --with-python="Path to python"
eg.
./configure --with-python=/usr/bin/python36
Hope this helps!!
I am debugging decode_raw_op_test from TensorFlow. The test file is written in python however it executes code from underlying C++ files.
Using pdb, I could debug python test file however it doesn't recognize c++ file. Is there a way in which we can debug underlying c++ code?
(I tried using gdb on decode_raw_op_test but it gives "File not in executable format: File format not recognized")
Debugging a mixed Python and C++ program is tricky. You can use gdb to debug the C++ parts of TensorFlow, however. There are two main ways to do this:
Run python under gdb, rather than the test script itself. Let's say that your test script is in bazel-bin/tensorflow/python/kernel_tests/decode_raw_op_test. You would run the following command:
$ gdb python bazel-bin/tensorflow/python/kernel_tests/decode_raw_op_test
(gdb) run
Note that gdb does not have great support for debugging the Python parts of the code. I'd recommend narrowing down the test case that you run to a single, simple test, and setting a breakpoint on a TensorFlow C API method, such as TF_Run, which is the main entry point from Python into C++ in TensorFlow.
Attach gdb to a running process. You can get the process ID of the Python test using ps and then run (where $PID is the process ID):
$ gdb -p $PID
You will probably need to arrange for your Python code to block so that there's time to attach. Calling the raw_input() function is an easy way to do this.
Could debug using below steps:
gdb python
then on gdb prompt, type
run bazel-bin/tensorflow/python/kernel_tests/decode_raw_op_test
Adding on mrry's answer, in today's TF2 environment, the main entry point would be TFE_Execute, this should be where you add the breakpoint.
I use Python with C (with SWIG), where the main module in Python processes data using C library. It crashes somewhere in the C library, so I want to analyse core dump and find the bug.
But, I do not have a regular executable to run with gdb, I have main.py, the library _library.so generated from my C code, and .o object files from C. How should feed gdb to see the core dump with this mixed code?
IIRC you can do this by running python through gdb, i.e.
gdb python
gdb> run -m main.py
When I have to deal with bugs in Python code, I often insert breakpoints so during execution I'm being dropped into the debuger when a breakpoint is reached. I've been mostly using pdb (command line) and pudb (ncurses interface).
Is it possible to launch winpdb instead in such situation? What's the breakpoint code I shall include in my python script so winpdb would get started?
Edit: I'm using a simple text editor (vim) for writing code. Please do not suggest me to use an IDE instead, which has winpdb integrated or has its own GUI debuger that is similar to winpdb.
Winpdb is normally used so that you run the script with winpdb:
winpdb myscript.py
If you want to start it from "inside" python instead, the documentation on how to do that is here: http://winpdb.org/docs/embedded-debugging/