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.
Related
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 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.
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.
I'm trying to get Eclipse CDT (64 bit eclipse) working on Windows 7 with GCC. When I first got GDB working (that was a challenge in itself), running the program in debug mode was the only way I got output. Running it normally didn't give any console output. After hours of googling, I figured out that if I added C:/cygwin/bin to my environment path in eclipse, I could get output when running the program normally. Then I ran it in debug mode and there was no output. I tested this a couple of times to make sure it was the addition of the path causing the problem. This is the program I was running,
#include <iostream>
using namespace std;
int main() {
cout << "Hello World!" << endl;
return 0;
}
So how can I get both normal and debug modes working, and why did I have to include that path in the first place (it's already in my cygwin path and why does CDT need it?) ? Also, why is it that if I add a path to my Run configurations it will also be added to my Debug configurations?
From wiki eclipse:
In Eclipse CDT on Windows, standard output of the program being run or debugged is fully buffered, because it is not connected to a Windows console, but to a pipe. See bug 173732 for more details. Either add flush calls after every printf or add the following lines at the start of the main function:
setvbuf(stdout, NULL, _IONBF, 0);
setvbuf(stderr, NULL, _IONBF, 0);
I don't think I can answer everything but I use exactly the same set-up as you and I've had to deal with quite a few issues like this (I'm wondering if you had trouble how to juggle using the 32-bit/64-bit JVM and Internet browsing)!
The cygwin/bin path must be specified because that is where gcc, gdb and all the other cygwin tools and dlls are located (I'll assume you're using cygwin flavour of gcc rather than MinGW flavour). I believe you must specify it in the Windows environment (using a win32 file path) because Eclipse is running using the Windows JVM and therefore deals with win32 paths. Consequently, it doesn't matter that cygwin/bin is added to the PATH variable in the cygwin environment. CDT is looking for cygwin using Eclipse, and Eclipse needs to find cygwin1.dll from Windows.
I might be totally wrong, but if I had to guess I would say that you need to make absolutely sure you have properly set the PATH environment variable correctly for both configurations.
One thing to note is that in Eclipse there is no difference between a configuration shown in the Debug Configurations window and one with the same name in the Run Configurations window. The only difference between the two windows is that one will run the program without using a debugger and has tabs for setting debug settings. Therefore it's no surprise that changing settings in one will also affect the other.
As you may know, for many projects the build system is set up to produce two (sometimes more) sets of binaries: one with debugging info/symbols (DEBUG) and one without (RELEASE). In this case, you normally have two configurations in Eclipse: one to run the DEBUG binary and one to run the RELEASE binary. Both of these will show up in both the Debug Configurations window and in the Run Configurations window. The point is that you can run DEBUG either with or without gdb, but RELEASE cannot be used by gdb.
That said, I'm not sure why adding the correct path to the run configuration would stop the DEBUG binary from outputting to the console. I suspect something else is going on here, perhaps a mismatch of debug info and debugger.
To (hopefully) answer your question as to how to get both configurations working, go the whole-hog and just add C:\cygwin\bin; to the Windows PATH environment variable. I'm guessing that will allow both to work. I'll assume you know how to do that but please post a comment if not.
The other thing to try would be to compile and run the program from a cygwin shell. If it works there it's probably a safe bet that your PATH environment variable is not set correctly when using eclipse.
Hope that helps!
Adding the Path was correct before gdb 7.3. Now when I add the path I can no longer use breakpoints as it cannot find the dll files as they are no longer part of the path. To fix this you can easily add the entire path from the environment by following these instructions.
left click the project
enter the RUN/DEBUG settings for the project
select the executable
click edit
select Environment Tab
click Select...
scroll down to Path (Case sensitive)
check mark Path
press OK
press OK
press OK
You can see the dll problem as it appears in the gdb console
error,msg="During startup program exited with code 0xc00000be."
or
error,msg="During startup program exited with code 0x00000135."
and you may get an error window pop up saying it could not clear the breakpoint
You need to set up linker
I am using MinGW.
Follow below steps.
Goto Project > Properties > C/C++ Build > Settings > Tool Settings (Tab) > MinGW C++ Linker (Option) > Add Command (g++ -static-libgcc -static-libstdc++) (default command is only g++)
Don't debug or run C or C++ applications from inside Eclipse if they target Cygwin. TK link to "you're gonna have a bad time" meme.
There are problems with Cygwin stdout/stderr that don't show up if you run the programs from the normal Cygwin console (where you would be running bash), but they do show up in pretty much every other way you can run them.
The normal way that programs run other programs in Linux and other posix-supporting environments is to reroute the i/o to a pty. Cygwin can't support pty's 100% in Windows.
Some of the problems can be ameliorated by the setvbuf calls in #infoartenovo's answer.
A flip side of this problem is that applications written to use Windows' Console API don't work well in ptys.
We are all collateral damage in an unwinnable war.
http://cygwin.com/ml/cygwin/2011-12/msg00236.html
https://code.google.com/p/mintty/issues/detail?id=56