IDE Integration

Visual Studio Code

Visual Studio Code needs to know some things about the project such as include paths and compiler paths before features such as code completion, go to definition, and graying out disabled code blocks will work. Fortunately, CMake can generate that configuration for us automatically.

Create a Compilation Database

To configure west to tell CMake to generate a compilation database, open a terminal to the ZMK repository and run the following command:

west config build.cmake-args -- -DCMAKE_EXPORT_COMPILE_COMMANDS=ON

Every build will now update the database. You will need to build once to create the database before code completion will work. We'll tell Visual Studio Code where to find the database in the next step.

note

If you have set any other CMake arguments such as the path to your zmk-config, the above command will overwrite them. You should instead provide the flag to export compile commands and all other arguments surrounded by quotes. For example:

west config build.cmake-args -- "-DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DZMK_CONFIG=/path/to/zmk-config/config"

Create a C/C++ Configuration

Install the C/C++ extension, then run F1 > C/C++: Edit Configurations (UI). It should automatically create a new configuration for you, but if the text box under Configuration name is empty, click Add Configuration, enter a name, and click OK.

Change these options:

Option	Value
Compiler path	Path to your toolchain's GCC binary (see below)
IntelliSense mode	linux-gcc-arm, windows-gcc-arm, or macos-gcc-arm
Advanced Settings > Compiler commands	${workspaceFolder}/app/build/compile_commands.json

If you are developing inside a Docker container, set the IntelliSense mode to linux-gcc-arm regardless of the host operating system.

Compiler path

Open VS Code's integrated terminal and run the following command:

cmake -P zephyr/cmake/verify-toolchain.cmake

This should print something like

-- ZEPHYR_TOOLCHAIN_VARIANT: zephyr
-- SDK_VERSION: 0.15.2
-- ZEPHYR_SDK_INSTALL_DIR  : /home/marvin/.local/zephyr-sdk-0.15.2

Your compiler path is the value of ZEPHYR_SDK_INSTALL_DIR plus /arm-zephyr-eabi/bin/arm-zephyr-eabi-gcc, for example:

/home/marvin/.local/zephyr-sdk-0.15.2/arm-zephyr-eabi/bin/arm-zephyr-eabi-gcc

If you are building for an platform other than ARM, replace /arm-zephyr-eabi/bin/arm-zephyr-eabi-gcc with the path to the compiler for the appropriate architecture, for example:

/home/marvin/.local/zephyr-sdk-0.15.2/riscv64-zephyr-elf/bin/riscv64-zephyr-elf-gcc

Compiler commands path

When building with all default options, the path to the compilation database file is ${workspaceFolder}/app/build/compile_commands.json as shown in the table above, however some arguments to west build can change this path.

The -d or --build-dir option lets you change the build directory to something other than build. Replace build in the above path with what you set this to. For example, if you build with -d build/my_shield, the path is ${workspaceFolder}/app/build/my_shield/compile_commands.json. If you use this to keep builds for multiple keyboards separate, you may want to create a separate C/C++ configuration for each one in VS Code.

You can also build from the root folder of the project instead of the app folder by adding -S app to your CMake arguments. In this case, simply remove app from the path to compile_commands.json, for example, ${workspaceFolder}/build/compile_commands.json.