2 files changed, 26 insertions, 18 deletions
diff --git a/cortex-m-rt/src/lang_items.rs b/cortex-m-rt/src/lang_items.rs
index 9ff95b5..6b15f99 100644
--- a/cortex-m-rt/src/lang_items.rs
+++ b/cortex-m-rt/src/lang_items.rs
@@ -1,12 +1,7 @@
 /// Default panic handler
 #[cfg(feature = "abort-on-panic")]
 #[lang = "panic_fmt"]
-unsafe extern "C" fn panic_fmt(
-    _: ::core::fmt::Arguments,
-    _: &'static str,
-    _: u32,
-    _: u32,
-) -> ! {
+unsafe extern "C" fn panic_fmt(_: ::core::fmt::Arguments, _: &'static str, _: u32, _: u32) -> ! {
     ::core::intrinsics::abort()
 }
 
@@ -29,12 +24,22 @@ unsafe extern "C" fn panic_fmt(
 // has to call `rustc_main`. That's covered by the `reset_handler` function in
 // root of this crate.
 #[lang = "start"]
-extern "C" fn start(
-    main: fn(),
-    _argc: isize,
-    _argv: *const *const u8,
-) -> isize {
+extern "C" fn start<T>(main: fn() -> T, _argc: isize, _argv: *const *const u8) -> isize
+where
+    T: Termination,
+{
     main();
 
     0
 }
+
+#[lang = "termination"]
+pub trait Termination {
+    fn report(self) -> i32;
+}
+
+impl Termination for () {
+    fn report(self) -> i32 {
+        0
+    }
+}
diff --git a/cortex-m-rt/src/lib.rs b/cortex-m-rt/src/lib.rs
index df6640f..9c5e7bf 100644
--- a/cortex-m-rt/src/lib.rs
+++ b/cortex-m-rt/src/lib.rs
@@ -278,8 +278,7 @@
 //! }
 //! ```
 
-#![cfg_attr(any(target_arch = "arm", feature = "abort-on-panic"),
-            feature(core_intrinsics))]
+#![cfg_attr(any(target_arch = "arm", feature = "abort-on-panic"), feature(core_intrinsics))]
 #![deny(missing_docs)]
 #![deny(warnings)]
 #![feature(asm)]
@@ -291,8 +290,8 @@
 #![feature(used)]
 #![no_std]
 
-extern crate cortex_m;
 extern crate compiler_builtins;
+extern crate cortex_m;
 extern crate r0;
 
 #[cfg(not(test))]
@@ -374,7 +373,8 @@ unsafe extern "C" fn reset_handler() -> ! {
 }
 
 #[cfg(target_arch = "arm")]
-global_asm!(r#"
+global_asm!(
+    r#"
 .weak NMI
 NMI = DEFAULT_HANDLER
 
@@ -398,13 +398,16 @@ PENDSV = DEFAULT_HANDLER
 
 .weak SYS_TICK
 SYS_TICK = DEFAULT_HANDLER
-"#);
+"#
+);
 
 #[cfg(not(armv6m))]
-global_asm!(r#"
+global_asm!(
+    r#"
 .weak DEBUG_MONITOR
 DEBUG_MONITOR = DEFAULT_HANDLER
-"#);
+"#
+);
 
 #[cfg(target_arch = "arm")]
 extern "C" {