add binds example and make it work

ci/expected/binds.run

@@ -0,0 +1,4 @@
+init
+foo called 1 time
+idle
+foo called 2 times

ci/script.sh

@@ -93,6 +93,7 @@ main() {
                 idle
                 init
                 interrupt
+                binds
 
                 resource
                 lock

examples/binds.rs

@@ -0,0 +1,48 @@
+//! examples/binds.rs
+
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate panic_semihosting;
+
+use cortex_m_semihosting::{debug, hprintln};
+use lm3s6965::Interrupt;
+use rtfm::app;
+
+// `examples/interrupt.rs` rewritten to use `binds`
+#[app(device = lm3s6965)]
+const APP: () = {
+    #[init]
+    fn init() {
+        rtfm::pend(Interrupt::UART0);
+
+        hprintln!("init").unwrap();
+    }
+
+    #[idle]
+    fn idle() -> ! {
+        hprintln!("idle").unwrap();
+
+        rtfm::pend(Interrupt::UART0);
+
+        debug::exit(debug::EXIT_SUCCESS);
+
+        loop {}
+    }
+
+    #[interrupt(binds = UART0)]
+    fn foo() {
+        static mut TIMES: u32 = 0;
+
+        *TIMES += 1;
+
+        hprintln!(
+            "foo called {} time{}",
+            *TIMES,
+            if *TIMES > 1 { "s" } else { "" }
+        )
+        .unwrap();
+    }
+};

macros/src/codegen.rs

@@ -1128,7 +1128,7 @@ fn exceptions(ctxt: &mut Context, app: &App, analysis: &Analysis) -> Vec<proc_ma
             };
 
             let locals = mk_locals(&exception.statics, false);
-            let symbol = ident.to_string();
+            let symbol = exception.args.binds.as_ref().unwrap_or(ident).to_string();
             let alias = ctxt.ident_gen.mk_ident(None, false);
             let unsafety = &exception.unsafety;
             quote!(
@@ -1214,7 +1214,7 @@ fn interrupts(
 
         let locals = mk_locals(&interrupt.statics, false);
         let alias = ctxt.ident_gen.mk_ident(None, false);
-        let symbol = ident.to_string();
+        let symbol = interrupt.args.binds.as_ref().unwrap_or(ident).to_string();
         let unsafety = &interrupt.unsafety;
         scoped.push(quote!(
             // unsafe trampoline to deter end-users from calling this non-reentrant function