compile_commands.json generator for Bazel

This repository contains two tools to generate a compile_commands.json file from a Bazel workspace without the need to modify any of the Bazel configuration files. This is the equivalent of CMAKE_EXPORT_COMPILE_COMMANDS from CMake for Bazel.

The Microsoft C/C++ Extension for Visual Studio Code struggles sometimes with Bazel workspaces since not all include paths are at the default locations. The compile_commands.json file can be used with clangd to have a significant better LSP experience. For Visual Studio Code (VS Code), the clangd extension can be used to utilize the project compile information via the compile_commands.json file.

Invoke bazel-compile-commands //... to generate a compile_commands.json file for the Bazel label //.... For more information, see man 1 bazel-compile-commands.

The bazel-compile-commands command is ideal when you need a compile_commands.json file instantly and don't require automatic updates of the compile_commands.json file. For example in CI use cases when you when static analysis tools use a compile_commands.json file as input.

Usage of bazel-compile-commands

Inside a Bazel workspace run:

bazel-compile-commands

This will generate a compile_commands.json file in the current directory.

• Documentation or man 1 bazel-compile-commands
• Download latest release

VS Code integration

See the .vscode/tasks.json file as an example on how to integratebazel-compile-commands into VS Code.

Mentions

• Bartek Kryza mentions bazel-compile-commands in the blog post "compile_commands.json gallery", Dec. 2, 2024.
• Blog post in System/5: BazelCon 2024 recap, section IDE support, bullet point "Compilation database", Oct. 22, 2024.
• BazelCon 2024: The State of Compilation Database in Bazel (Video)

Build

Linux and macOS

bazel build --config=gnu //bcc:bazel-compile-commands

To cross-compiling for a Linux aarch64 platform, run:

bazel build --platforms=//:linux_aarch64 --config=gnu //bcc:bazel-compile-commands

Windows

bazel build --config=cl //bcc:bazel-compile-commands

Alternative tools

• Bear - Can work when used with the --spawn_strategy=local Bazel flag.
• hedronvision/bazel-compile-commands-extractor - Can be integrated into Bazel files.

Links

• Format of the compile_commands.json format
• clangd
• analysis_v2.proto
• Build Event Protocol

Issues

• https://github.com/bazelbuild/bazel/issues/12852

License

This source code is under the MIT license with the exceptions mentioned in "Third party source code in this repository".