Mastering Rust - Second Edition

Calling Rust code from C

As we stated in the previous section, when Rust libraries expose their functions to other languages using the extern block, they expose the C ABI (cdecl) by default. As such, it becomes a very seamless experience of calling Rust code from C. To C, they appear just like regular C functions. We'll take a look at an example of calling Rust code from a C program. Let's create a cargo project for this by running cargo new rust_from_c --lib.

In our Cargo.toml file, we have the following items:

# rust_from_c/Cargo.toml[package]name = "rust_from_c"version = "0.1.0"authors = ["Rahul Sharma <[e-mail]>"]edition = "2018"[lib]name = "stringutils"crate-type = ["cdylib"]

Under the [lib] section, we specified the crate ...