v0.2.0

src/examples/_2_panic.rs

@@ -1,35 +1,58 @@
-//! Redirecting `panic!` messages
+//! Defining the panic handler
 //!
-//! The `cortex-m-rt` crate provides two options to redirect `panic!` messages
-//! through these two Cargo features:
+//! 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.
 //!
-//! - `panic-over-semihosting`. `panic!` messages will be printed to the OpenOCD
-//!    console using semihosting. This is slow.
+//! [1]: https://doc.rust-lang.org/unstable-book/language-features/lang-items.html
 //!
-//! - `panic-over-itm`. `panic!` messages will be send through the ITM port 0.
-//!   This is much faster but requires ITM support on the device.
-//!
-//! If neither of these options is specified then the `panic!` message will be
-//! lost. Note that all `panic!`s will trigger a debugger breakpoint.
+//! ---
 //!
 //! ```
 //! 
+//! #![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]
+//! 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))
+//!             })
+//!             .ok();
+//!     }
+//! 
+//!     intrinsics::abort()
+//! }
+//! 
 //! // As we are not using interrupts, we just register a dummy catch all handler
-//! #[allow(dead_code)]
+//! #[link_section = ".vector_table.interrupts"]
 //! #[used]
-//! #[link_section = ".rodata.interrupts"]
 //! static INTERRUPTS: [extern "C" fn(); 240] = [default_handler; 240];
 //! 
 //! extern "C" fn default_handler() {