#![no_main] #![no_std] extern crate cortex_m_rt; extern crate panic_halt; use cortex_m_rt::{entry, exception}; #[entry] fn foo() -> ! { loop {} } #[exception] unsafe fn DefaultHandler(_irqn: i16, undef: u32) {} //~^ ERROR `DefaultHandler` must have signature `unsafe fn(i16) [-> !]`