The **C++ CMake tools for Windows** component uses the [Open Folder](open-folder-projects-cpp.md) feature to consume CMake project files (such as CMakeLists.txt) directly for the purposes of IntelliSense and browsing. Both Ninja and Visual Studio generators are supported. If you use a Visual Studio generator, it generates a temporary project file and passes it to msbuild.exe. However, the project is never loaded for IntelliSense or browsing purposes. You can also import an existing CMake cache.

When you choose **File > Open > Folder** to open a folder containing a CMakeLists.txt file, the following things happen:

You can open folders containing any number of CMake projects. Visual Studio detects and configures all the "root" CMakeLists.txt files in your workspace. CMake operations (configure, build, debug), C++ IntelliSense, and browsing are available to all CMake projects in your workspace.

1. Right click on the CMakeLists.txt and select **Build** from the context menu. If you have multiple targets in your folder structure, you can choose to build all or only one specific target.

To edit a CMakeLists.txt file, right-click on the file in **Solution Explorer** and choose **Open**. If you make changes to the file, a yellow status bar appears and informs you that IntelliSense will update. It gives you a chance to cancel the update operation. For information about CMakeLists.txt, see the [CMake documentation](https://cmake.org/documentation/).

As soon as you save the file, the configuration step automatically runs again and displays information in the **Output** window. Errors and warnings are shown in the **Error List** or **Output** window. Double-click on an error in the **Error List** to navigate to the offending line in CMakeLists.txt.

Visual Studio 2017 has rich support for CMake, including [cross-platform CMake projects](../linux/cmake-linux-project.md). The **Visual C++ Tools for CMake** component uses the **Open Folder** feature to enable the IDE to consume CMake project files (such as CMakeLists.txt) directly for the purposes of IntelliSense and browsing. Both Ninja and Visual Studio generators are supported. If you use a Visual Studio generator, it generates a temporary project file and passes it to msbuild.exe. However, the project is never loaded for IntelliSense or browsing purposes. You also can import an existing CMake cache.

When you choose **File > Open > Folder** to open a folder containing a CMakeLists.txt file, the following things happen:

You can open folders containing any number of CMake projects. Visual Studio detects and configures all the "root" CMakeLists.txt files in your workspace. CMake operations (configure, build, debug), C++ IntelliSense, and browsing are available to all CMake projects in your workspace.

When you import an existing *CMakeCache.txt* file, Visual Studio automatically extracts customized variables and creates a pre-populated *CMakeSettings.json* file based on them. The original cache isn't modified in any way. It can still be used from the command line, or with whatever tool or IDE used to generate it. The new *CMakeSettings.json* file is placed alongside the project's root CMakeLists.txt. Visual Studio generates a new cache based the settings file. You can override automatic cache generation in the **Tools > Options > CMake > General** dialog.

To edit a CMakeLists.txt file, right-click on the file in **Solution Explorer** and choose **Open**. If you make changes to the file, a yellow status bar appears and informs you that IntelliSense will update. It gives you a chance to cancel the update operation. For information about CMakeLists.txt, see the [CMake documentation](https://cmake.org/documentation/).

As soon as you save the file, the configuration step automatically runs again and displays information in the **Output** window. Errors and warnings are shown in the **Error List** or **Output** window. Double-click on an error in the **Error List** to navigate to the offending line in CMakeLists.txt.

When significant changes are made to the *CMakeSettings.json* or to CMakeLists.txt files, Visual Studio automatically reruns the CMake configure step. If the configure step finishes without errors, the information that's collected is available in C++ IntelliSense and language services. It's also used in build and debug operations.

- **View Cache** opens the CMakeCache.txt file from the build root folder in the editor. (Any edits you make here to CMakeCache.txt are wiped out if you clean the cache. To make changes that persist after the cache is cleaned, see [Customize CMake settings](customize-cmake-settings.md).)