Using GCC with MinGW

In this tutorial, you configure Visual Studio Code to use the GCC C++ compiler (g++) and GDB debugger frommingw-w64 to create programs that run on Windows. After configuring VS Code, you will compile, run, and debug a Hello World program.

This tutorial does not teach you about GCC, GDB, minGW-w64, 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 theVS Code documentation repository.

Prerequisites

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

1. InstallVisual Studio Code.

2. Install theC/C++ extension for VS Code. You can install the C/C++ extension by searching for 'C++' in the Extensions view (⇧⌘X (Windows, LinuxCtrl+Shift+X)).

   

Installing the MinGW-w64 toolchain

Get the latest version of MinGW-w64 viaMSYS2, which provides up-to-date native builds of GCC, MinGW-w64, and other helpful C++ tools and libraries. This will provide you with the necessary tools to compile your code, debug it, and configure it to work withIntelliSense.

To install the MinGW-w64 toolchain, check out this video or follow the steps below:

1. You can download the latest installer from the MSYS2 page or use thisdirect link to the installer.

2. Run the installer and follow the steps of the installation wizard. Note that MSYS2 requires 64 bit Windows 8.1 or newer.

3. In the wizard, choose your desired Installation Folder. Record this directory for later. In most cases, the recommended directory is acceptable. The same applies when you get to setting the start menu shortcuts step. When complete, ensure theRun MSYS2 now box is checked and selectFinish. This will open a MSYS2 terminal window for you.

4. In this terminal, install the MinGW-w64 toolchain by running the following command:

   pacman -S --needed base-devel mingw-w64-ucrt-x86_64-toolchain

5. Accept the default number of packages in thetoolchain group by pressingEnter.

   

6. EnterY when prompted whether to proceed with the installation.

7. Add the path of your MinGW-w64bin folder to the WindowsPATH environment variable by using the following steps:

   1. In the Windows search bar, typeSettings to open your Windows Settings.
   2. Search forEdit environment variables for your account.
   3. In yourUser variables, select thePath variable and then selectEdit.
   4. SelectNew and add the MinGW-w64 destination folder you recorded during the installation process to the list. If you used the default settings above, then this will be the path:C:\msys64\ucrt64\bin.
   5. SelectOK, and then selectOK again in theEnvironment Variables window to update thePATH environment variable.You have to reopen any console windows for the updatedPATH environment variable to be available.

Check your MinGW installation

To check that your MinGW-w64 tools are correctly installed and available, open anew Command Prompt and type:

gcc --versiong++ --versiongdb --version

You should see output that states which versions of GCC, g++ and GDB you have installed. If this is not the case:

1. Make sure your PATH variable entry matches the MinGW-w64 binary location where the toolchain was installed. If the compilers do not exist at that PATH entry, make sure you followed the previous instructions.
2. Ifgcc has the correct output but notgdb, then you need to install the packages you are missing from the MinGW-w64 toolset.
   • If on compilation you are getting the "The value of miDebuggerPath is invalid." message, one cause can be you are missing themingw-w64-gdb package.

Create a Hello World app

First, lets get a project set up.

1. Launch a Windows command prompt (EnterWindows command prompt in the Windows search bar).
2. Run the following commands. These will create an empty folder calledprojects where you can place all your VS Code projects. There, the next commands will create and navigate to a subfolder calledhelloworld. From there, you will openhelloworld directly in VS Code.

mkdir projectscd projectsmkdir helloworldcd helloworldcode .

The "code ." command opens VS Code in the current working folder, which becomes your "workspace". Accept theWorkspace Trust dialog by selectingYes, I trust the authors since this is a folder you created.

As you go through the tutorial, you will see three files created in a.vscode folder in the workspace:

• tasks.json (build instructions)
• launch.json (debugger settings)
• c_cpp_properties.json (compiler path and IntelliSense settings)

Add a Hello World source code file

In the File Explorer title bar, select theNew File button and name the filehelloworld.cpp.

Add hello world source code

Now paste in this source 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, LinuxCtrl+S) to save the file. Notice how the file you just added appears in theFile Explorer view (⇧⌘E (Windows, LinuxCtrl+Shift+E)) in the side bar of VS Code:

You can also enableAuto Save to automatically save your file changes, by selectingFile >Auto Save. You can find out more about the other views in the VS CodeUser Interface documentation.

Note: When you save or open a C++ file, you may see a notification from the C/C++ extension about the availability of an Insiders version, which lets you test new features and fixes. You can ignore this notification by selecting theX (Clear Notification).

Explore IntelliSense

IntelliSense is a tool to help you code faster and more efficiently by adding code editing features such as code completion, parameter info, quick info, and member lists.

To see IntelliSense in action,hover overvector orstring to see their type information. If you typemsg. in line 10, you can see a completion list of recommended member functions to call, all generated by IntelliSense:

You can press theTab key to insert a selected member. If you then add open parenthesis, IntelliSense will show information on which arguments are required.

If IntelliSense is not already configured, open the Command Palette (⇧⌘P (Windows, LinuxCtrl+Shift+P)) and enterSelect IntelliSense Configuration. From the dropdown of compilers, selectUse gcc.exe to configure. More information can be found in theIntelliSense configuration documentation.

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 completed the "Installing the MinGW-w64 toolchain" step before attempting to run and debughelloworld.cpp in VS Code.

1. Openhelloworld.cpp so that it is the active file.

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

   

3. ChooseC/C++: g++.exe 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 runhelloworld.cpp. This compiler will be set as the "default" compiler intasks.json file.

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

   

Congratulations! You've just run your first C++ program in VS Code!

Understanding tasks.json

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

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

{  "tasks": [    {      "type":"cppbuild",      "label":"C/C++: g++.exe build active file",      "command":"C:\\msys64\\ucrt64\\bin\\g++.exe",      "args": [        "-fdiagnostics-color=always",        "-g",        "${file}",        "-o",        "${fileDirname}\\${fileBasenameNoExtension}.exe"      ],      "options": {        "cwd":"${fileDirname}"      },      "problemMatcher": ["$gcc"],      "group": {        "kind":"build",        "isDefault":true      },      "detail":"Task generated by Debugger."    }  ],  "version":"2.0.0"}

Note: You can learn more abouttasks.json variables in thevariables reference.

Thecommand setting specifies the program to run; in this case that isg++.

Theargs array specifies the command-line arguments passed to g++. These arguments are listed in this file in the specific order expected by the compiler.

This task tells g++ to take the active file (${file}), compile it, and create an output file (-o switch) in the current directory (${fileDirname}) with the same name as the active file but with the.exe extension (${fileBasenameNoExtension}.exe). For us, this results inhelloworld.exe.

Thelabel value is what you will see in the tasks list; you can name this whatever you like.

Thedetail value is what you will see as the description of the task in the tasks list. It's highly recommended to rename this value to differentiate it from similar tasks.

TheproblemMatcher value selects the output parser to use for finding errors and warnings in the compiler output. For GCC, you'll get the best results if you use the$gcc problem matcher.

From now on, the play button will read fromtasks.json to figure out how to build and run your program. You can define multiple build tasks intasks.json, and whichever task is marked as the default will be used by the play button. In case you need to change the default compiler, you can runTasks: Configure Default Build Task in the Command Palette. Alternatively you can modify thetasks.json file and remove the default by replacing this segment:

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

with this:

    "group":"build",

Modifying tasks.json

Starting November 3, 2024, MSYS2 has disabled wildcard support formingw-w64 by default. This change impacts how wildcards like"*.cpp" are processed in build commands. To build multiple C++ files in yourtasks.json, you must explicitly list the files, use a build system likemake orcmake or implement the following workarounds: https://www.msys2.org/docs/c/#expanding-wildcard-arguments.

If you previously used"${workspaceFolder}/*.cpp" to compile all.cpp files in the current folder, this will no longer work directly. Instead, you can manually list the files or define a build script.

Debug helloworld.cpp

To debug your code,

1. Go back tohelloworld.cpp so that it is the active file.
2. Set a breakpoint by clicking on the editor margin or using F9 on the current line.
3. From the drop-down next to the play button, selectDebug C/C++ File.
4. ChooseC/C++: 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 or debughelloworld.cpp).

The play button has two modes:Run C/C++ File andDebug C/C++ File. It will default to the last-used mode. If you see the debug icon in the play button, you can just select the play button to debug, instead of using the drop-down.

Explore the debugger

Before you start stepping through the code, let's take a moment to notice several changes in the user interface:

• The Integrated Terminal appears at the bottom of the source code editor. In theDebug Console tab, you see output that indicates the debugger is up and running.

• The editor highlights the line where you set a breakpoint before starting the debugger:

  

• TheRun and Debug view on the left shows debugging information. You'll see an example later in the tutorial.

• At the top of the code editor, a debugging control panel appears. You can move this around the screen by grabbing the dots on the left side.

  

Step through the code

Now you're ready to start stepping through the code.

1. Select theStep over icon in the debugging control panel.

   

   This will advance program execution to the first line of the for loop, and skip over all the internal function calls within thevector andstring classes that are invoked when themsg variable is created and initialized. Notice the change in theVariables window on the left.

   

   In this case, the errors are expected because, although the variable names for the loop are now visible to the debugger, the statement has not executed yet, so there is nothing to read at this point. The contents ofmsg are visible, however, because that statement has completed.

2. PressStep over again to advance to the next statement in this program (skipping over all the internal code that is executed to initialize the loop). Now, theVariables window shows information about the loop variables.

3. PressStep over again to execute thecout statement. (Note that the C++ extension does not print any output to theDebug Console until the loop exits.)

4. If you like, you can keep pressingStep over until all the words in the vector have been printed to the console. But if you are curious, try pressing theStep Into button to step through source code in the C++ standard library!

   To return to your own code, one way is to keep pressingStep over. Another way is to set a breakpoint in your code by switching to thehelloworld.cpp tab in the code editor, putting the insertion point somewhere on thecout statement inside the loop, and pressingF9. A red dot appears in the gutter on the left to indicate that a breakpoint has been set on this line.

   

   Then pressF5 to start execution from the current line in the standard library header. Execution will break oncout. If you like, you can pressF9 again to toggle off the breakpoint.

   When the loop has completed, you can see the output in the Integrated Terminal, along with some other diagnostic information that is output by GDB.

   

Set a watch

Sometimes you might want to keep track of the value of a variable as your program executes. You can do this by setting awatch on the variable.

1. Place the insertion point inside the loop. In theWatch window, select the plus sign and in the text box, typeword, which is the name of the loop variable. Now view the Watch window as you step through the loop.

   

2. Add another watch by adding this statement before the loop:int i = 0;. Then, inside the loop, add this statement:++i;. Now add a watch fori as you did in the previous step.

3. To quickly view the value of any variable while execution is paused on a breakpoint, you can hover over it with the mouse pointer.

   

Customize debugging with launch.json

When you debug with the play button orF5, the C++ extension creates a dynamic debug configuration on the fly.

There are cases where you'd want to customize your debug configuration, such as specifying arguments to pass to the program at runtime. You can define custom debug configurations in alaunch.json file.

To createlaunch.json, chooseAdd Debug Configuration from the play button drop-down menu.

You'll then see a dropdown for various predefined debugging configurations. ChooseC/C++: g++.exe build and debug active file.

VS Code creates alaunch.json file in the.vscode folder`, which looks something like this:

{  "configurations": [    {      "name":"C/C++: g++.exe build and debug active file",      "type":"cppdbg",      "request":"launch",      "program":"${fileDirname}\\${fileBasenameNoExtension}.exe",      "args": [],      "stopAtEntry":false,      "cwd":"${fileDirname}",      "environment": [],      "externalConsole":false,      "MIMode":"gdb",      "miDebuggerPath":"C:\\msys64\\ucrt64\\bin\\gdb.exe",      "setupCommands": [        {          "description":"Enable pretty-printing for gdb",          "text":"-enable-pretty-printing",          "ignoreFailures":true        },        {          "description":"Set Disassembly Flavor to Intel",          "text":"-gdb-set disassembly-flavor intel",          "ignoreFailures":true        }      ],      "preLaunchTask":"C/C++: g++.exe build active file"    }  ],  "version":"2.0.0"}

In the JSON above,program specifies the program you want to debug. Here it is set to the active file folder (${fileDirname}) and active filename with the.exe extension (${fileBasenameNoExtension}.exe), which ifhelloworld.cpp is the active file will behelloworld.exe. Theargs 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 thestopAtEntry value is set tofalse.

Change thestopAtEntry value totrue to cause the debugger to stop on themain method when you start debugging.

From now on, the play button andF5 will read from yourlaunch.json file when launching your program for debugging.

Adding additional C/C++ settings

If you want more control over the C/C++ extension, you can create ac_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 commandC/C++: Edit Configurations (UI) from the Command Palette (⇧⌘P (Windows, LinuxCtrl+Shift+P)).

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

Here, we've changed theConfiguration name toGCC, set theCompiler path dropdown to the g++ compiler, and theIntelliSense mode to match the compiler (gcc-x64).

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

{  "configurations": [    {      "name":"GCC",      "includePath": ["${workspaceFolder}/**"],      "defines": ["_DEBUG","UNICODE","_UNICODE"],      "windowsSdkVersion":"10.0.22000.0",      "compilerPath":"C:/msys64/mingw64/bin/g++.exe",      "cStandard":"c17",      "cppStandard":"c++17",      "intelliSenseMode":"windows-gcc-x64"    }  ],  "version":4}

You only need to add to theInclude path array setting if your program includes header files that are not in your workspace or in the standard library path. It is strongly recommended not to add the system include path to theincludePath setting for compilers that we support.

Compiler path

The extension uses thecompilerPath setting to infer the path to the C++ standard library header files. When the extension knows where to find those files, it can provide features like smart completions andGo to Definition navigation.

The C/C++ extension attempts to populatecompilerPath with a default compiler based on what it finds on your system. The extension looks in several common compiler locations but will only automatically select one that is in either one of the "Program Files" folders or whose path is listed in the PATH environment variable. If the Microsoft Visual C++ compiler can be found it will be selected, otherwise it will select a version of gcc, g++, or clang.

If you have more than one compiler installed, you might need to changecompilerPath to match the preferred compiler for your project. You may also use theC/C++: Select IntelliSense Configuration... command in the Command Palette to select one of the compilers that the extension detected.

Troubleshooting

MSYS2 is installed, but g++ and gdb are still not found

You must follow the steps on theMSYS2 website to use the MSYS CLI to install the full MinGW-w64 toolchain(pacman -S --needed base-devel mingw-w64-ucrt-x86_64-toolchain), as well as all required prerequisites. The toolchain includes g++ and gdb.

As a Windows user, running the pacman command gives me an error

UCRT on Windows machines is only included in Windows 10 or later. If you are using another version of Windows, run the following command that does not use UCRT:

pacman -S --needed base-devel mingw-w64-x86_64-toolchain

When adding the MinGW-w64 destination folder to your list of environment variables, the default path will then be:C:\msys64\mingw64\bin.

MinGW 32-bit

If you need a 32-bit version of the MinGW toolset, consult theDownloading section on the MSYS2 wiki. It includes links to both 32-bit and 64-bit installation options.

Next steps

• Explore theVS Code User Guide.
• Review theOverview of the C++ extension.
• Create a new workspace, copy your.vscode JSON files to it, adjust the necessary settings for the new workspace path, program name, etc. and start coding!