I have a C++ project with a SWIG-generated Python front-end, which I build using CMake. I am now trying to find a convenient way to debug my mixed Python/C++ code. I am able to get a stack-trace of errors using gdb, but I would like to have some more fancy features such as the ability to step through the code and set breakpoints, for example using Eclipse.
Using the Eclipse generator for CMake I am able to generate a project that I am able to import into Eclipse. This works fine and I am also able to step through the pure C++ executables. But then the problem starts.
First of all, I am not able to build the Python front-end from inside Eclipse. From command line I just do "make python", but there is no target "python" in the Eclipse project.
Secondly, once I've compiled the Python front-end, I have no clue how to step through a Python script that contains calls to my wrapped C++ classes. Eclipse has debugging both for Python and for C++, but can they be combined?
some more fancy features such as the ability to step through the code and set breakpoints, for example using Eclipse
how are those features "fancy"? You can already do those in pdb for Python, or gdb for C++.
I'd suggest running the python code with pdb (or using pdb.set_trace() to interrupt execution at an interesting point), and attach gdb to the process in a separate terminal. Use pdb to set breakpoints in, and step through, your Python code. Use gdb to set breakpoints in, and step through, your C++ code. When pdb steps over a native call, gdb will take over. When gdb continue allows Python execution to resume, pdb will take over.
This should let you jump between C++ and Python breakpoints without needing to trace through the interpreter.
Disclaimer: I largely think IDEs are rubbish bloatware, so if Eclipse does have a good way to integrate this, I wouldn't know about it anyway.
Related
I'm working on a relatively old Centos system where I am restricted in the packages I can install. I needed a newer version of gdb, so I built that successfully from source in my home dir. This gdb steps through my code fine, but I am looking for trouble that is manifesting in the C++ allocator (mt_allocator.cc) and this new version of gdb can't step through that code. I can break successfully on a function there:
break '__gnu_cxx::__pool<true>::_M_initialize()'
but when that breakpoint hits and I try to step through the code, gdb tells me:
Single stepping until exit from function _ZN9__gnu_cxx6__poolILb1EE13_M_initializeEv,
which has no line number information.
I tried using the dir command within gdb to add the path to where mt_allocator.cc is, but that had no effect.
What do I need to tell gdb so it can find those files?
Ah, found it. The Centos package manager put the debug files for the STL code at /usr/lib/debug. So:
set debug-file-directory /usr/lib/debug
within gdb gets it done.
I have a C++ project that is called in Python (via boost-python) and I want to debug the C++ code from python process. How can I do that? In Windows with Visual Studio I can use the functionality attach to process. How to achieve the same in Eclipse?
Thanks
For me it works great just adding a debug configuration in C/C++ for the program /usr/bin/python (or whatever search path you have to the python interpreter) and then put the python program you want to run as the arguments. Put the breakpoints you want in the C-code and you should be all set for running the debug configuration and opening the debug perspective.
If it still does not work you may also check that you are using Legacy (or Standard) Process Launcher. For some reason the GDB process launcher does not seem to work here.
On Linux, I have some C++ programs built with my own makefiles, and I'm looking for some GUI debuggers to debug them at source level.
Previously I use KDbg(2.5.2) on openSUSE(12.3). It works but with some very annoying limitation, e.g., I cannot set a breakpoint when the debugged program is not trapped by Kdbg -- I mean, in order to set a new breakpoint, I have to set it before the program is launched or the program pauses on hitting an already set breakpoint.
Now I try to use Eclipse CDT. I got eclipse-cpp-juno-SR2-linux-gtk.tar.gz but find that I don't know how to load my executable so to start debugging.
I googled with words like 『eclipse debug pre-built C binary』, but few seems to care about this feature.
Can Eclipse CDT really do that? If Eclipse CDT can't, is there any better alternatives to KDbg? Please help.
According to hint from this answer, https://stackoverflow.com/a/248119/151453 , I finally figure out how to do it.
The key point is: In the Eclipse CDT project, create/edit a Launch Configuration so to tell the debugger what executable to load.
Now I have to admit, Eclipse CDT does quite well in C++ code debugging far better than KDbg.
Some screen shot below, on openSUSE 12.3 .
Now we can Run -> Debug (F11)
Debugger automatically pauses the program at main()'s first statement.
The Stand-alone Debugger is an Eclipse application which packages the Eclipse plug-ins from the CDT (C/C++ Development Tools) project into an application that can be started from a command-line script:
bash /path/scripts/cdtdebug.sh -e executable [args]
I'm just beginning to learn programming (on C++ and Python), and by beginning I mean total beginning ("hello world" beginning...). Not wanting to use multiple IDE's, I would like to be able to code and build–simple–programs with my text editor, Sublime Text 2. Could someone indicate me, with a step-by-step tutorial, how to implement C++ and Python compiling and executing capabilities in Sublime Text.
I've searched Sublime Text build systems on the site, but the answers are very specific and can't help a rookie like me (but they'll probably help me later).
Thanks
Sublime Text 2 already comes with scripts for building and running Python and C++ programs.
Simply press Cmd+B (or Ctrl+B on Windows & Linux) when a .py or .cpp file is open. The Python file will automatically execute and show the result in the built in console.
For C++, you need to press Cmd+Shift+B (Ctrl+Shift+B on Windows & Linux) to run it after building.
You need to have Python installed (get it here for Windows), and also a C++ compiler. The build system for C++ tries to call g++ by default (get it here for Windows. Remember to select the C++ compiler when installing!).
You will need to add the directories to path (c:\python32\ or similar for python, c:\mingw\bin or similar for the C++ compiler).
On windows, you may experience problems running the C++ programs (it tries to use bash). But Ctrl+B builds the program, and you can then use a command line to run it. Python works flawlessly on Windows.
windows(install minigw, python2.7 and added to the system path)
cpp:
build: ctrl+b
run: ctrl+shift+b
python:
build and run: ctrl+b
you may try to learn the the .sublime-build files in your Tools -> Build system -> New build system
So, you don't want to use an IDE but then you want IDE features from a text editor? :)
Most people who use a text editor for writing code use terminal to build and run the code.
So, for C++, the instructions are:
make (or gcc myprogram.c)
./myprogram
for a Python program, it's even simpler:
python ./myprogram.py
If you're not comfortable with terminal, then you probably need an IDE.
for c++ I actually made sublime to produce colorful error messages which are easier to read and you can also click on the errors which takes you to the file with the error.
You can look at how I modified the build to do what I wanted in here
Say I am in IPython (e.g. on the new QT console), and that I call a C++ library that I wrote from it (e.g. using SWIG or Boost.Python). I would like to set a breakpoint in my C++ code and have the ability to interact with my C++ workspace (i.e. my variables when I hit the breakpoint) with IPython (e.g. plot my C++ variables, etc.).
In other words I would like to debug my C++ code from IPython. Is this at all possible? What are some tools I can use for this?
(assuming you are on Linux)
You just need gdb. First set up configuration telling gdb where your source files are by adding this to $HOME/.gdbinit:
directory absolute-path-to-source
Now start gdb python and on the gdb prompt do:
set args /usr/bin/ipython
run
You can't directly do gdb ipython because ipython is a script. Please refer to the gdb documentation from here on.
In general, you won't be able to debug C++ code directly with IPython. What you can do, though, is use a C++ debugger to debug your C++ code.
Essentially, you tell your C++ debugger to execute whatever process you need to use to run your code (this could be IPython itself), and set a breakpoint in your C++ code (your debugger will know to wait for the appropriate DLL to be loaded if it's in a DLL). From there, you are debugging your part of the code that is running in the IPython process.