How to export `compile_commands.json`?

Verafahn · August 9, 2026, 4:11am

When I use Zig to build a C++ project, I want better code hints in my editor. For CMake-based projects, I can generate a compile_commands.json file by adding the following code to the build configuration:

set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

I would like to know if Zig provides a similar mechanism.

Fitti · August 9, 2026, 7:57am

I have very recently started looking at C++, so I’m still deeply unfamiliar with the ecosystem, but I use the Zig build system for my experimentation repo. I have a config.zig file, as a single source of truth for everything, and then my build.zig pulls that in and creates or updates .clang-tidy and compile_flags.txt for me. I don’t know the compile_commands.json format, so maybe that requires a lot more machinery or something, but perhaps looking at my example helps.

github.com/Fittiboy/moderncpp_learning

build.zig

93215d17c


      
          const std = @import("std");
          
          const config = @import("config.zig");
          const include_dir = config.include_dir;
          const compile_flags = config.compile_flags;
          const clang_tidy = config.clang_tidy;
          
          pub fn build(b: *std.Build) void {
              // When compiling for Valgrind, the CPU model is changed
              // to `.baseline`, to avoid emitting illegal instructions.
              // Hence a query here, which can be modified before it is
              // resolved.
              var target_query = b.standardTargetOptionsQueryOnly(.{});

github.com/Fittiboy/moderncpp_learning

build.zig

93215d17c


      
              .target = target,
              .optimize = optimize,
              .link_libcpp = true,
          
              // Valgrind-specific settings.
              .valgrind = if (valgrind) true else null,
              .omit_frame_pointer = if (valgrind) false else null,
              .strip = if (valgrind) false else null,
          });
          
          // Generating and writing files for our language server and
          // formatter to use.
          const write = b.addWriteFiles();
          const clang_tidy_file = write.add(".clang-tidy", clang_tidy);
          const compile_flags_file = write.add(
              "compile_flags.txt",
              std.mem.join(b.allocator, "\n", compile_flags) catch @panic("OOM"),
          );
          const update = b.addUpdateSourceFiles();
          update.addCopyFileToSource(clang_tidy_file, ".clang-tidy");
          update.addCopyFileToSource(compile_flags_file, "compile_flags.txt");

Fitti · August 9, 2026, 8:03am

I vaguely remembered there being a project that does that exactly, and I found it:

Sazerac · August 9, 2026, 8:21am

FYI, A proposal is currently under development:
https://codeberg.org/ziglang/zig/pulls/35462