--- title: C++ description: "Configure C++ language support in Zed, including language servers, formatting, and debugging." --- # C++ C++ support is available natively in Zed. - Tree-sitter: [tree-sitter/tree-sitter-cpp](https://github.com/tree-sitter/tree-sitter-cpp) - Language Server: [clangd/clangd](https://github.com/clangd/clangd) ## Binary You can configure which `clangd` binary Zed should use. By default, Zed will try to find a `clangd` in your `$PATH` and try to use that. If that binary successfully executes, it's used. Otherwise, Zed will fall back to installing its own `clangd` version and use that. If you want to install a pre-release `clangd` version instead you can instruct Zed to do so by setting `pre_release` to `true` in your `settings.json`: ```json [settings] { "lsp": { "clangd": { "fetch": { "pre_release": true } } } } ``` If you want to disable Zed looking for a `clangd` binary, you can set `ignore_system_version` to `true` in your `settings.json`: ```json [settings] { "lsp": { "clangd": { "binary": { "ignore_system_version": true } } } } ``` If you want to use a binary in a custom location, you can specify a `path` and optional `arguments`: ```json [settings] { "lsp": { "clangd": { "binary": { "path": "/path/to/clangd", "arguments": [] } } } } ``` This `"path"` has to be an absolute path. ## Arguments You can pass any number of arguments to clangd. To see a full set of available options, run `clangd --help` from the command line. For example with `--function-arg-placeholders=0` completions contain only parentheses for function calls, while the default (`--function-arg-placeholders=1`) completions also contain placeholders for method parameters. ```json [settings] { "lsp": { "clangd": { "binary": { "path": "/path/to/clangd", "arguments": ["--function-arg-placeholders=0"] } } } } ``` ## Formatting By default Zed will use the `clangd` language server for formatting C++ code. The Clangd is the same as the `clang-format` CLI tool. To configure this you can add a `.clang-format` file. For example: ```yaml # yaml-language-server: $schema=https://json.schemastore.org/clang-format-21.x.json --- BasedOnStyle: LLVM IndentWidth: 4 --- Language: Cpp # Force pointers to the type for C++. DerivePointerAlignment: false PointerAlignment: Left --- ``` See [Clang-Format Style Options](https://clang.llvm.org/docs/ClangFormatStyleOptions.html) for a complete list of options. You can trigger formatting via {#kb editor::Format} or the {#action editor::Format} action from the command palette or by enabling format on save. Configure formatting in Settings ({#kb zed::OpenSettings}) under Languages > C++, or add to your settings file: ```json [settings] "languages": { "C++": { "format_on_save": "on", "tab_size": 2 } } ``` ## More server configuration In the root of your project, it is generally common to create a `.clangd` file to set extra configuration. ```yaml # yaml-language-server: $schema=https://json.schemastore.org/clangd.json CompileFlags: Add: - "--include-directory=/path/to/include" Diagnostics: MissingIncludes: Strict UnusedIncludes: Strict ``` For more advanced usage of clangd configuration file, take a look into their [official page](https://clangd.llvm.org/config.html). ## Compile Commands For some projects Clangd requires a `compile_commands.json` file to properly analyze your project. This file contains the compilation database that tells clangd how your project should be built. ### CMake Compile Commands With CMake, you can generate `compile_commands.json` automatically by adding the following line to your `CMakeLists.txt`: ```cmake set(CMAKE_EXPORT_COMPILE_COMMANDS ON) ``` After building your project, CMake will generate the `compile_commands.json` file in the build directory and clangd will automatically pick it up. ## Debugging You can use CodeLLDB or GDB to debug native binaries. (Make sure that your build process passes `-g` to the C++ compiler, so that debug information is included in the resulting binary.) See below for examples of debug configurations that you can add to `.zed/debug.json`. - [CodeLLDB configuration documentation](https://github.com/vadimcn/codelldb/blob/master/MANUAL.md#starting-a-new-debug-session) - [GDB configuration documentation](https://sourceware.org/gdb/current/onlinedocs/gdb.html/Debugger-Adapter-Protocol.html) - GDB needs to be at least v14.1 ### Build and Debug Binary ```json [debug] [ { "label": "Debug native binary", "build": { "command": "make", "args": ["-j8"], "cwd": "$ZED_WORKTREE_ROOT" }, "program": "$ZED_WORKTREE_ROOT/build/prog", "request": "launch", "adapter": "CodeLLDB" } ] ``` ## Protocol Extensions Zed currently implements the following `clangd` [extensions](https://clangd.llvm.org/extensions): ### Inactive Regions Automatically dims inactive sections of code due to preprocessor directives, such as `#if`, `#ifdef`, or `#ifndef` blocks that evaluate to false. ### Switch Between Source and Header Files Allows switching between corresponding C++ source files (e.g., `.cpp`) and header files (e.g., `.h`). by running the command {#action editor::SwitchSourceHeader} from the command palette or by setting a keybinding for the `editor::SwitchSourceHeader` action. ```json [keymap] { "context": "Editor", "bindings": { "alt-enter": "editor::SwitchSourceHeader" } } ```