Important
This project is currently under active development.
A significant challenge in the C++ ecosystem is that many build tools do not natively support the generation of a Compilation Database (CDB), which is essential for modern C++ language tooling. Examples include traditional Makefiles, CMake when using the MSBuild generator, and other complex build systems like Bazel or MSBuild itself.
While solutions like bear exist, they often require installing a different, specialized tool for each build system, which is inconvenient and limits cross-platform usability.
We are developing a new C++ language server that relies on a CDB to locate files and provide accurate language features. To ensure a seamless experience for our users, we aim to create catter, a single, unified, cross-platform tool to capture compilation commands from any build process.
catter is engineered to be fully operational on all major desktop operating systems:
- Windows
- macOS
- Linux
And it actually applies to any scenario where a series of tree-like commands need to be invoked in sequence. You can use catter's JavaScript script to capture, analyze and replace them in real time.
catter captures compilation commands without requiring modifications to the user's existing build scripts. This is achieved by:
- Process Monitoring/Interception: On each platform,
cattermonitors the build process tree to capture invocations of all commands invoked more than command of known C/C++ compilers (g++,clang,cl.exe, etc.) and their full command-line arguments.
To provide ultimate flexibility, catter includes a full JavaScript runtime environment for advanced control over the compilation command capture process.
- Full Scripting Support: Users can write custom JavaScript scripts to intercept, modify, and replace all commands executed during the compilation period.
- Dynamic Profiling: The tool supports real-time command sensing, enabling users to write dynamic JavaScript scripts for advanced build profiling and analysis.
- Custom CDB Generation: Users can leverage the scripting engine to implement their own custom logic for transforming captured commands, or even generating the Compilation Database entirely via script, giving unprecedented control over the final
compile_commands.json. - Avoid Full Compilation (If Possible): We can just writes scripts to easily intercept the compiler call and redirecting it to a "fake" compiler that simply records the command and creates an empty object file (
.o,.obj), enabling dry run and fake run scenarios without a time-consuming full build.
User run catter in command line, catter will call catter-proxy responsible to invoke commands. Every system call for real command will be replaced with catter-proxy in hooked program, therefore we can log the command instantly.
