cbindgen demo project
If you're new to Rust FFI, or if you're using cbindgen for the first time, it may take a few attempts to get things right.
If you're lazy like me, you might want to start with a sample project, already set up for staticlib, panic="abort", and a working build.rs.
This is a simple Rust library, with a few constants and data structures that can be used from C code. It also includes a C program that calls some of that library's functions.
This version includes Rust std library support. If you want a no_std library, check out cbindgen-demo. There is also a version that adds alloc support without the full std library: cbindgen-alloc-demo.
How to build it:
> cargo build --release
> gcc -O2 -Wl,--gc-sections -pthread main.c target/release/libdemo.a -ldl -o demo
> strip demo
> ./demo