CLion 2021.3 Help

Custom compilers

If the compiler you are working with is not supported by default in CLion, switch to the custom compiler option. You can define any compiler not yet known to the IDE, even a rare compiler which may not be available publicly. This option is especially useful for embedded development.

Prepare the compiler description

In order to work with a custom compiler in CLion, you need to create a configuration file with its description in YAML format.

  • We prepared a few examples to help you start. You can use them as-is or as a template for creating your own configs.

  • The custom compiler config format includes a mandatory compilers section with a list of records. Every record has a description of a compiler and several tags to identify compiler invocation.

    The first matching record is used to provide compiler information for CLion language engine, including a list of system-defined macros, target platform name for Clangd, and a list of system header paths.

    Custom compiler config example


    compiler name (mandatory parameter)


    regular expression for source file names


    regular expression for the compiler executable name, required to use a compiler with such name from any location (mandatory parameter)


    compiler command line keys


    detected language, C or CPP (required for CMake only)


    target platform name for Clangd


    compiler-specific header search paths; the variables allowed in this setting are ${compiler-exe}, ${compiler-exe-dir}, ${user-home}, and ${project-path}.


    compiler-specific macros in the 'name: value' YAML format (the value part can be empty)


    compiler-specific macros in the '#define name value' C format (the value part can be empty)

Specify the .yaml config in toolchain settings

  1. Go to Preferences/Settings | Build, Execution, Deployment | Toolchains | Custom Compiler.

  2. Set the Use custom compiler config (*.yaml) checkbox and provide the path:

    Custom compiler config setting
  3. Switch to the Toolchains dialog and select the toolchain to be edited or create a new one.

  4. Change the paths in the C Compiler and C++ Compiler fields to your custom compiler:

    Specifying a custom compiler in toolchain settings

    Alternatively, you can pass the custom compiler manually in your Makefile or via the CMake profile settings. In this case, the custom compiler will be used for the current project only.

Check the custom compiler

When a custom compiler is configured successfully, your code is resolved correctly and all code assistance actions work as expected. To double-check that your custom compiler is set up properly, do the following:

  1. Load your CMake, Makefile, or compilation database project.

  2. Open any of the C/C++ project files in the editor.

  3. Call Help | Diagnostics Tool | Show Compiler Info from the main menu.

  4. If everything is okay, you will see the compiler type and name as defined in your config file, as well as the list of compiler predefined macros:

    Compiler info view

Edit the .yaml config in CLion

  • CLion supports the YAML language by default (see CLion features in different languages). To get schema-specific verification, code completion, quick documentation, and other actions, switch to the Custom Compiler Definition schema.

    Open the .yaml config, click the schema switcher on the IDE's status bar at the bottom, and select Custom Compiler Definition:

    YAML custom compiler config schema
Last modified: 25 October 2021