//! Defining the panic handler
//!
//! The panic handler can be defined through the `panic_fmt` [language item][1].
//! Make sure that the "abort-on-panic" feature of the cortex-m-rt crate is
//! disabled to avoid redefining the language item.
//!
//! [1]: https://doc.rust-lang.org/unstable-book/language-features/lang-items.html
//!
//! ---

#![feature(core_intrinsics)]
#![feature(lang_items)]
#![feature(used)]
#![no_std]

extern crate cortex_m;
extern crate cortex_m_rt;
extern crate cortex_m_semihosting;

use core::fmt::Write;
use core::intrinsics;

use cortex_m::asm;
use cortex_m_semihosting::hio;

fn main() {
    panic!("Oops");
}

#[lang = "panic_fmt"]
#[no_mangle]
pub unsafe extern "C" fn rust_begin_unwind(
    args: core::fmt::Arguments,
    file: &'static str,
    line: u32,
    col: u32,
) -> ! {
    if let Ok(mut stdout) = hio::hstdout() {
        write!(stdout, "panicked at '")
            .and_then(|_| {
                stdout
                    .write_fmt(args)
                    .and_then(|_| writeln!(stdout, "', {}:{}:{}", file, line, col))
            })
            .ok();
    }

    intrinsics::abort()
}

// As we are not using interrupts, we just register a dummy catch all handler
#[link_section = ".vector_table.interrupts"]
#[used]
static INTERRUPTS: [extern "C" fn(); 240] = [default_handler; 240];

extern "C" fn default_handler() {
    asm::bkpt();
}