Debugging in VS Code

Visual Studio Code is a powerful text editor which can be expanded to a full featured integrated development environment (IDE) with plugins. To debug a program make sure to install the C/C++ Extension Pack which includes support for CMake and debugging with gdb.

Then in the editor:

1. Open e.g. ogs.cpp.
2. Set a breakpoint in the first line of the main()-function (around line 58) by clicking on the left gutter in the editor window (a red dot marks the enabled breakpoint).
3. Click on the CMake-sidebar.
4. Make sure that debug is the active configure and build preset.
5. Click the Build-button in the status bar.
6. Click the bug icon in the status bar.

After some seconds the debugger starts and halts at the specified breakpoint indicated y the yellow marker around the breakpoint and line. You can now step into or over statements with debugger controls at the top of the window:

To debug with specific arguments to ogs, e.g. for setting a .prj-file:

1. Click on the Debug-sidebar.
2. Click on create a launch.json file.
3. Click Add Configuration.
4. Select C/C++: (gdb) Launch

Edit the file e.g. like this:

"program": "${workspaceFolder}/../build/debug/bin/ogs",
"args": ["${workspaceFolder}/Tests/Data/Parabolic/ComponentTransport/ReactiveTransport/CO2Injection/cl.prj"],
"cwd": "${workspaceFolder}/../build/debug/_out",

This sets the program to debug to the ogs-binary in the debug build folder, sets a specific .prj-file to run and sets the working directory (output folder) to some _out-subfolder in the build directory.

You can also give the debug configuration some meaningful name, e.g. "name": "Debug cl.prj", which results in a new button in the status bar:

Click on it to start the debug session.