lib.rs

//! This crate is used to statically assert that no panics whatsoever are present in the final program.
//! If any panics are present and are not optimized out, compiling will produce the following error:
//! ```sh
//! error: the static assertion that no panics are present has failed
//! ```
//!
//! Note: this crate will only work when compiling with `no_std`.
//!
//! ## Example:
//! ```rust
//! #![no_std]
//! #![no_main]
//! #![feature(lang_items, test)]
//!
//! extern crate libc;
//! extern crate no_panics_whatsoever;
//!
//! #[lang = "eh_personality"]
//! extern "C" fn eh_personality() {}
//!
//! fn foo(a: &[i32]) -> i32 {
//!     // a.get(0).copied().unwrap_or(1) // Compiles fine!
//!     a[0] // Fails to compile!
//! }
//!
//! #[no_mangle] // ensure that this symbol is called `main` in the output
//! pub extern fn main(_argc: i32, _argv: *const *const u8) -> i32 {
//!     foo(core::hint::black_box(&[42]))
//! }
//! ```

#![no_std]

use core::panic::PanicInfo;

#[panic_handler]
fn panic(_: &PanicInfo) -> ! {
    extern "C" {
        #[cfg_attr(
            target_family = "unix", link_name = "\n\n\x1b[s\x1b[1000D\x1b[0;31m\x1b[1merror\x1b[0m\x1b[1m: the static assertion that no panics are present has failed\x1b[0m\x1b[u\n\n"
        )]
        #[cfg_attr(not(target_family = "unix"), link_name = "\n\nerror: the static assertion that no panics are present has failed\n\n")]
        fn never_panic() -> !;
    }
    
    unsafe { never_panic() }
}