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 binary distributions and is licensed under MIT, while glibc is available for source builds 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.