1---
 2title: C
 3description: "Configure C language support in Zed, including language servers, formatting, and debugging."
 4---
 5
 6# C
 7
 8C support is available natively in Zed.
 9
10- Tree-sitter: [tree-sitter/tree-sitter-c](https://github.com/tree-sitter/tree-sitter-c)
11- Language Server: [clangd/clangd](https://github.com/clangd/clangd)
12- Debug Adapter: [CodeLLDB](https://github.com/vadimcn) (primary), [GDB](https://sourceware.org/gdb/) (secondary, not available on Apple silicon)
13
14## Clangd: Force detect as C
15
16Clangd out of the box assumes mixed C++/C projects. If you have a C-only project you may wish to instruct clangd to treat all files as C using the `-xc` flag. To do this, create a `.clangd` file in the root of your project with the following:
17
18```yaml
19# yaml-language-server: $schema=https://json.schemastore.org/clangd.json
20CompileFlags:
21  Add: [-xc]
22```
23
24By default clang and gcc will recognize `*.C` and `*.H` (uppercase extensions) as C++ and not C and so Zed too follows this convention. If you are working with a C-only project (perhaps one with legacy uppercase pathing like `FILENAME.C`) you can override this behavior by adding this to your settings:
25
26```json [settings]
27{
28  "file_types": {
29    "C": ["C", "H"]
30  }
31}
32```
33
34## Formatting
35
36By default Zed will use the `clangd` language server for formatting C code like the `clang-format` CLI tool. To configure this you can add a `.clang-format` file. For example:
37
38```yaml
39# yaml-language-server: $schema=https://json.schemastore.org/clang-format-21.x.json
40---
41BasedOnStyle: GNU
42IndentWidth: 2
43---
44```
45
46See [Clang-Format Style Options](https://clang.llvm.org/docs/ClangFormatStyleOptions.html) for a complete list of options.
47
48You can trigger formatting via {#kb editor::Format} or the `editor: format` action from the command palette or by enabling format on save.
49
50Configure formatting in Settings ({#kb zed::OpenSettings}) under Languages > C, or add to your settings file:
51
52```json [settings]
53  "languages": {
54    "C": {
55      "format_on_save": "on",
56      "tab_size": 2
57    }
58  }
59```
60
61## Compile Commands
62
63For some projects Clangd requires a `compile_commands.json` file to properly analyze your project. This file contains the compilation database that tells clangd how your project should be built.
64
65### CMake Compile Commands
66
67With CMake, you can generate `compile_commands.json` automatically by adding the following line to your `CMakeLists.txt`:
68
69```cmake
70set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
71```
72
73After building your project, CMake will generate the `compile_commands.json` file in the build directory and clangd will automatically pick it up.
74
75## Debugging
76
77You can use CodeLLDB or GDB to debug native binaries. (Make sure that your build process passes `-g` to the C compiler, so that debug information is included in the resulting binary.) See below for examples of debug configurations that you can add to `.zed/debug.json`.
78
79- [CodeLLDB configuration documentation](https://github.com/vadimcn/codelldb/blob/master/MANUAL.md#starting-a-new-debug-session)
80- [GDB configuration documentation](https://sourceware.org/gdb/current/onlinedocs/gdb.html/Debugger-Adapter-Protocol.html)
81
82### Build and Debug Binary
83
84```json [debug]
85[
86  {
87    "label": "Debug native binary",
88    "build": {
89      "command": "make",
90      "args": ["-j8"],
91      "cwd": "$ZED_WORKTREE_ROOT"
92    },
93    "program": "$ZED_WORKTREE_ROOT/build/prog",
94    "request": "launch",
95    "adapter": "CodeLLDB"
96  }
97]
98```