bear

Generate compilation database for clang tooling

TLDR

Generate compilation database

$ bear -- make

Append to existing database

$ bear --append -- make clean all

Custom output file

$ bear --output [compile_commands.json] -- ninja

bear (Build EAR) generates a compilation database (compile_commands.json) by intercepting compiler calls during a build. This database enables tools like clangd, clang-tidy, and IDEs to understand the project structure without custom configuration.
The tool works with any build system by recording actual compiler invocations.

PARAMETERS

--append, -a

Append to existing compilation database

--output file, -o file

Output file (default: compile_commands.json)

--force-preload

Force library preload method

--force-wrapper

Force compiler wrapper method

--verbose, -v

Verbose output

WORKFLOW

$ # With Make
bear -- make

# With CMake/Ninja
bear -- ninja

# Clean build
bear -- make clean all

# Append incremental build
bear --append -- make module

FEATURES

- Build system agnostic
- Intercepts compiler calls
- Supports parallel builds
- Works with make, ninja, etc.
- No build system modification needed

COMPILATION DATABASE

Generated compile_commands.json format:

$ [
  {
    "directory": "/path/to/project",
    "command": "gcc -c file.c -o file.o",
    "file": "file.c"
  }
]

CAVEATS

Requires running full build. May not capture all compilation units if cached. Some build systems have native support (CMake: -DCMAKEEXPORTCOMPILE_COMMANDS=ON). Different interception methods on different platforms.

HISTORY

bear was created by László Nagy around 2012 to generate compilation databases for C/C++ projects using any build system.