Using C++ And WSL In VS Code

Using C++ and WSL in VS Code

In this tutorial, you will configure Visual Studio Code to use the GCC C++ compiler (g++) and GDB debugger on Ubuntu in the Windows Subsystem for Linux (WSL). GCC stands for GNU Compiler Collection; GDB is the GNU debugger. WSL is a Linux environment within Windows that runs directly on the machine hardware, not in a virtual machine.

Note: Much of this tutorial is applicable to working with C++ and VS Code directly on a Linux machine.

Visual Studio Code has support for working directly in WSL with the WSL extension. We recommend this mode of WSL development, where all your source code files, in addition to the compiler, are hosted on the Linux distro. For more background, see VS Code Remote Development.

After completing this tutorial, you will be ready to create and configure your own C++ project, and to explore the VS Code documentation for further information about its many features. This tutorial does not teach you about GCC or Linux or the C++ language. For those subjects, there are many good resources available on the Web.

If you have any problems, feel free to file an issue for this tutorial in the VS Code documentation repository.

Prerequisites

To successfully complete this tutorial, you must do the following steps:

1. Install Visual Studio Code.

2. Install the WSL extension.

3. Install Windows Subsystem for Linux and then use the links on that same page to install your Linux distribution of choice. This tutorial uses Ubuntu. During installation, remember your Linux user password because you'll need it to install additional software.

Set up your Linux environment

1. Open the Bash shell for WSL. If you installed an Ubuntu distro, type "Ubuntu" in the Windows search box and then click on it in the result list. For Debian, type "Debian", and so on.

   

   The shell appears with a command prompt that by default consists of your user name and computer name, and puts you in your home directory. For Ubuntu it looks like this:

   

2. Make a directory called projects and then subdirectory under that called helloworld:

   sudo apt-get update

   If you like, you can run sudo apt-get update && sudo apt-get dist-upgrade to also download the latest versions of the system packages, but this can take significantly longer depending on your connection speed.

3. From the command prompt, install the GNU compiler tools and the GDB debugger by typing:

   whereis g++ whereis gdb

Note: The setup steps for installing the g++ compiler and GDB debugger apply if you are working directly on a Linux machine rather than in WSL. Running VS Code in your helloworld project, as well as the editing, building, and debugging steps are the same.

Run VS Code in WSL

Navigate to your helloworld project folder and launch VS Code from the WSL terminal with code .:

#include <iostream> #include <vector> #include <string> using namespace std; int main() { vector<string> msg {"Hello", "C++", "World", "from", "VS Code", "and the C++ extension!"}; for (const string& word : msg) { cout << word << " "; } cout << endl; }

Now press ⌘S (Windows, Linux Ctrl+S) to save the file. Notice how the file you just added appears in the File Explorer view (⇧⌘E (Windows, Linux Ctrl+Shift+E)) in the side bar of VS Code:

You can also enable Auto Save to automatically save your file changes, by checking Auto Save in the main File menu.

The Activity Bar on the far left lets you open different views such as Search, Source Control, and Run. You'll look at the Run view later in this tutorial. You can find out more about the other views in the VS Code User Interface documentation.

Explore IntelliSense

In your new helloworld.cpp file, hover over vector or string to see type information. After the declaration of the msg variable, start typing msg. as you would when calling a member function. You should immediately see a completion list that shows all the member functions, and a window that shows the type information for the msg object:

You can press the Tab key to insert the selected member; then, when you add the opening parenthesis, you will see information about any arguments that the function requires.

Run helloworld.cpp

Remember, the C++ extension uses the C++ compiler you have installed on your machine to build your program. Make sure you have a C++ compiler installed before attempting to run and debug helloworld.cpp in VS Code.

1. Open helloworld.cpp so that it is the active file.

2. Press the play button in the top right corner of the editor.

   

3. Choose g++ build and debug active file from the list of detected compilers on your system.

   

You'll only be asked to choose a compiler the first time you run helloworld.cpp. This compiler will be set as the "default" compiler in tasks.json file.

4. After the build succeeds, your program's output will appear in the integrated Terminal.

   

The first time you run your program, the C++ extension creates tasks.json, which you'll find in your project's .vscode folder. tasks.json stores build configurations.

Your new tasks.json file should look similar to the JSON below:

"group": { "kind": "build", "isDefault": true },

with this:

{ "version": "0.2.0", "configurations": [ { "name": "C/C++: g++ build and debug active file", "type": "cppdbg", "request": "launch", "program": "${fileDirname}/${fileBasenameNoExtension}", "args": [], "stopAtEntry": false, "cwd": "${workspaceFolder}", "environment": [], "externalConsole": false, "MIMode": "gdb", "miDebuggerPath": "/usr/bin/gdb", "setupCommands": [ { "description": "Enable pretty-printing for gdb", "text": "-enable-pretty-printing", "ignoreFailures": true } ], "preLaunchTask": "C/C++: g++ build active file" } ] }

In the JSON above, program specifies the program you want to debug. Here it is set to the active file folder ${fileDirname} and active filename without an extension ${fileBasenameNoExtension}, which if helloworld.cpp is the active file will be helloworld. The args property is an array of arguments to pass to the program at runtime.

By default, the C++ extension won't add any breakpoints to your source code and the stopAtEntry value is set to false.

Change the stopAtEntry value to true to cause the debugger to stop on the main method when you start debugging.

From now on, the play button and F5 will read from your launch.json file when launching your program for debugging.

C/C++ configurations

If you want more control over the C/C++ extension, you can create a c_cpp_properties.json file, which will allow you to change settings such as the path to the compiler, include paths, C++ standard (default is C++17), and more.

You can view the C/C++ configuration UI by running the command C/C++: Edit Configurations (UI) from the Command Palette (⇧⌘P (Windows, Linux Ctrl+Shift+P)).

This opens the C/C++ Configurations page. When you make changes here, VS Code writes them to a file called c_cpp_properties.json in the .vscode folder.

You only need to modify the Include path setting if your program includes header files that are not in your workspace or in the standard library path.

Visual Studio Code places these settings in .vscode/c_cpp_properties.json. If you open that file directly, it should look something like this: