Fil-C

Welcome to Fil-C, a memory safe implementation of the C and C++ programming languages you already know and love.

What is Fil-C?

Fil-C is a fanatically compatible memory-safe implementation of C and C++. Lots of software compiles and runs with Fil-C with zero or minimal changes. All memory safety errors are caught as Fil-C panics. Fil-C achieves this using a combination of concurrent garbage collection and invisible capabilities (InvisiCaps). Every possibly-unsafe C and C++ operation is checked. Fil-C has no unsafe statement and only limited FFI to unsafe code.

Key Features

Memory Safety: Advanced runtime checks to prevent exploitable memory safety errors. Unlike other approaches to increasing the safety of C, Fil-C achieves complete memory safety with zero escape hatches.
C and C++ Compatibility: Your C or C++ software most likely compiles and runs in Fil-C with zero changes. Many open source programs, including CPython, OpenSSH, GNU Emacs, and Wayland work great in Fil-C. Even advanced features like threads, atomics, exceptions, signal handling, longjmp/setjmp, and shared memory (mmap style or Sys-V style) work. It's possible to run a totally memory safe Linux userland, including GUI, with Fil-C.
Modern Tooling: Compiler is based on a recent version of clang (20.1.8), supports all clang extensions, most GCC extensions, and works with existing C/C++ build systems (make, autotools, cmake, meson, etc).

Quick Links

License

Fil-C's compiler is licensed under Apache 2. Fil-C's runtime is licensed under BSD 2-clause. Fil-C has two standard libraries; musl is used in the pizfix slice binary distributions and is licensed under MIT, while glibc is available in the /opt/fil binary distributions and in Pizlix and is licensed under LGPL 2.1.

Community

Join the Fil-C Discord community to discuss the language implementation, share projects, and contribute to its development.