This page describes how to configure include paths for folders containing C or C++ files to get the full IntelliSense experience. If you're seeing the following message when opening a folder in VS Code, it means the C++ IntelliSense engine needs additional information about the paths in which your include files are located.
The include paths are defined in the "includePath" setting in a file called c_cpp_properties.json located in the .vscode directory in the opened folder.
You can create or open this file by either using the "C/Cpp: Edit Configurations" command in the command palette or by selecting "Edit "includePath" setting" in the lightbulb menu (see the screenshot below). The quickest way to locate a lightbulb is to scroll to the top of the source file and click on any green squiggle that shows up under a #include statement.
When a folder is opened, the extension attempts to locate your system headers based on your operating system, but it does not know about any other libraries that your project depends on. You can hover over the green squiggles or open the Problems window to understand which headers the IntelliSense engine is unable to open - sometimes it's the dependent headers that can't be located.
You can specify the remaining paths using one of the techniques described below.
The extension can get the information for "includePath" and "defines" from a compile_commands.json file, which can be auto-generated by many build systems such as CMake and Ninja. Look for the section where your current configuration is defined (by default there's one configuration per OS, such as "Win32 or "Mac"), and set the "compileCommands" property in c_cpp_properties.json to the full path to your compile_commands.json file and the extension will use that instead of the "includes" and "defines" properties for IntelliSense.
The first thing to try is to leverage the lightbulb path suggestions to auto-resolve the include paths. When you open a folder, the extension will recursively search for potential include paths that match the header files your code is using based on the paths set by the "browse.path" setting in c_cpp_properties.json. Click on the green squiggles under #include statements and you'll see a lightbulb offering suggestions of paths that will allow IntelliSense to resolve the included file.
If you don't see path suggestions in the lightbulb, try adding the root folder where the headers are likely located in to the "browse.path" setting in c_cpp_properties.json. This allows the extension to recursively search in these folders and offer more suggestions in the lightbulb as the search process goes on.
If none of the above fully resolves the paths, you could manually specify the paths to the headers that your project depends on in the c_cpp_properties.json file. Look for the section where your current configuration is defined (by default there's one configuration per OS, such as "Win32 or "Mac"), and add your paths in the "includePath" setting and defines in the "defines" setting. For example, the following screenshot shows a snippet of the file specifying path for the Mac configuration.
There are two ways to verify that the include paths are correctly resolved:
- The green squiggles in the source file are no longer showing
- Error messages are cleared in the Problems window
This indicates that the IntelliSense engine has got the include paths resolved so you can start enjoying the full IntelliSense for your C or C++ code for the current translation unit. Note that you may still see errors on other files if they belong to a different translation unit that requires additional include paths to be configured.