move dispatchers to app argument

CHANGELOG.md

@@ -5,6 +5,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+- Move dispatchers from extern block to app argument.
+
 ## [v0.5.5] - 2020-08-27
 
 - Includes the previous soundness fix.

book/en/src/migration/migration_v5.md

@@ -6,6 +6,37 @@ This section describes how to upgrade from v0.5.x to v0.6.0 of the RTIC framewor
 
 Change the version of `cortex-m-rtic` to `"0.6.0"`.
 
+## Move Dispatchers from `extern "C"` to app arguments.
+
+Change
+
+``` rust
+#[rtic::app(/* .. */)]
+const APP: () = {
+    [code here]
+
+    // RTIC requires that unused interrupts are declared in an extern block when
+    // using software tasks; these free interrupts will be used to dispatch the
+    // software tasks.
+    extern "C" {
+        fn SSI0();
+        fn QEI0();
+    }
+};
+```
+
+into
+
+``` rust
+#[rtic::app(/* .. */, dispatchers = [SSI0, QEI0])]
+mod app {
+  [code here]
+}
+```
+
+This works also for ram functions, see examples/ramfunc.rs
+
+
 ## Module instead of Const
 
 With the support of attributes on modules the `const APP` workaround is not needed.

examples/baseline.rs

@@ -8,7 +8,7 @@
 use panic_semihosting as _;
 
 // NOTE: does NOT properly work on QEMU
-#[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT)]
+#[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT, dispatchers = [SSI0])]
 mod app {
     use cortex_m_semihosting::{debug, hprintln};
     use lm3s6965::Interrupt;
@@ -47,11 +47,4 @@ mod app {
         // `foo` inherits the baseline of `UART0`: its `start` time
         foo::spawn().unwrap();
     }
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-    }
 }

examples/capacity.rs

@@ -7,7 +7,7 @@
 
 use panic_semihosting as _;
 
-#[rtic::app(device = lm3s6965)]
+#[rtic::app(device = lm3s6965, dispatchers = [SSI0])]
 mod app {
     use cortex_m_semihosting::{debug, hprintln};
     use lm3s6965::Interrupt;
@@ -40,11 +40,4 @@ mod app {
 
         debug::exit(debug::EXIT_SUCCESS);
     }
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-    }
 }

examples/cfg-whole-task.rs

@@ -7,7 +7,7 @@
 
 use panic_semihosting as _;
 
-#[rtic::app(device = lm3s6965)]
+#[rtic::app(device = lm3s6965,  dispatchers = [SSI0, QEI0])]
 mod app {
     use cortex_m_semihosting::debug;
     #[cfg(debug_assertions)]
@@ -83,12 +83,4 @@ mod app {
         )
         .ok();
     }
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-        fn QEI0();
-    }
 }

examples/cfg.rs

@@ -7,7 +7,7 @@
 
 use panic_semihosting as _;
 
-#[rtic::app(device = lm3s6965)]
+#[rtic::app(device = lm3s6965, dispatchers = [SSI0, QEI0])]
 mod app {
     use cortex_m_semihosting::debug;
     #[cfg(debug_assertions)]
@@ -62,12 +62,4 @@ mod app {
         )
         .ok();
     }
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-        fn QEI0();
-    }
 }

examples/double_schedule.rs

@@ -7,7 +7,7 @@
 
 use panic_semihosting as _;
 
-#[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT)]
+#[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT, dispatchers = [SSI0])]
 mod app {
     use rtic::cyccnt::U32Ext;
 
@@ -32,8 +32,4 @@ mod app {
     fn task2(_cx: task2::Context) {
         task1::schedule(_cx.scheduled + 100.cycles()).ok();
     }
-
-    extern "C" {
-        fn SSI0();
-    }
 }

examples/message.rs

@@ -7,7 +7,7 @@
 
 use panic_semihosting as _;
 
-#[rtic::app(device = lm3s6965)]
+#[rtic::app(device = lm3s6965, dispatchers = [SSI0])]
 mod app {
     use cortex_m_semihosting::{debug, hprintln};
 
@@ -45,11 +45,4 @@ mod app {
 
         foo::spawn().unwrap();
     }
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-    }
 }

examples/not-sync.rs

@@ -12,7 +12,7 @@ pub struct NotSync {
     _0: PhantomData<*const ()>,
 }
 
-#[rtic::app(device = lm3s6965)]
+#[rtic::app(device = lm3s6965, dispatchers = [SSI0])]
 mod app {
     use super::NotSync;
     use core::marker::PhantomData;
@@ -40,11 +40,4 @@ mod app {
     fn bar(c: bar::Context) {
         let _: &NotSync = c.resources.shared;
     }
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-    }
 }

examples/periodic.rs

@@ -8,7 +8,7 @@
 use panic_semihosting as _;
 
 // NOTE: does NOT work on QEMU!
-#[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT)]
+#[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT, dispatchers = [SSI0])]
 mod app {
     use cortex_m_semihosting::hprintln;
     use rtic::cyccnt::{Instant, U32Ext};
@@ -31,11 +31,4 @@ mod app {
 
         foo::schedule(cx.scheduled + PERIOD.cycles()).unwrap();
     }
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-    }
 }

examples/pool.rs

@@ -15,7 +15,7 @@ use rtic::app;
 // Declare a pool of 128-byte memory blocks
 pool!(P: [u8; 128]);
 
-#[app(device = lm3s6965)]
+#[app(device = lm3s6965, dispatchers = [SSI0, QEI0])]
 mod app {
     use crate::{Box, Pool};
     use cortex_m_semihosting::{debug, hprintln};
@@ -65,12 +65,4 @@ mod app {
         // this is done automatically so we can omit the call to `drop`
         // drop(x);
     }
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-        fn QEI0();
-    }
 }

examples/ramfunc.rs

@@ -7,7 +7,14 @@
 
 use panic_semihosting as _;
 
-#[rtic::app(device = lm3s6965)]
+#[rtic::app(
+    device = lm3s6965,
+    dispatchers = [
+        UART0,
+        #[link_section = ".data.UART1"]
+        UART1
+    ])
+]
 mod app {
     use cortex_m_semihosting::{debug, hprintln};
 
@@ -33,12 +40,4 @@ mod app {
     fn bar(_: bar::Context) {
         foo::spawn().unwrap();
     }
-
-    extern "C" {
-        fn UART0();
-
-        // run the task dispatcher from RAM
-        #[link_section = ".data.UART1"]
-        fn UART1();
-    }
 }

examples/schedule.rs

@@ -8,7 +8,7 @@
 use panic_halt as _;
 
 // NOTE: does NOT work on QEMU!
-#[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT)]
+#[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT, dispatchers = [SSI0])]
 mod app {
     use cortex_m::peripheral::DWT;
     use cortex_m_semihosting::hprintln;
@@ -46,11 +46,4 @@ mod app {
     fn bar(_: bar::Context) {
         hprintln!("bar  @ {:?}", Instant::now()).unwrap();
     }
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-    }
 }

examples/spawn.rs

@@ -7,7 +7,7 @@
 
 use panic_semihosting as _;
 
-#[rtic::app(device = lm3s6965)]
+#[rtic::app(device = lm3s6965, dispatchers = [SSI0])]
 mod app {
     use cortex_m_semihosting::{debug, hprintln};
 
@@ -26,11 +26,4 @@ mod app {
         }
         foo::spawn(2, 3).unwrap();
     }
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-    }
 }

examples/spawn2.rs

@@ -7,7 +7,7 @@
 
 use panic_semihosting as _;
 
-#[rtic::app(device = lm3s6965)]
+#[rtic::app(device = lm3s6965, dispatchers = [SSI0])]
 mod app {
     use cortex_m_semihosting::{debug, hprintln};
 
@@ -32,11 +32,4 @@ mod app {
         hprintln!("foo2 {}", x).unwrap();
         foo::spawn(x, 0).unwrap();
     }
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-    }
 }

examples/t-cfg.rs

@@ -5,7 +5,7 @@
 
 use panic_halt as _;
 
-#[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT)]
+#[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT, dispatchers = [SSI0, QEI0])]
 mod app {
     #[resources]
     struct Resources {
@@ -47,12 +47,4 @@ mod app {
     #[cfg(never)]
     #[task]
     fn quux(_: quux::Context) {}
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-        fn QEI0();
-    }
 }

examples/t-schedule-core-stable.rs

@@ -7,7 +7,7 @@
 
 use panic_halt as _;
 
-#[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT)]
+#[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT, dispatchers = [SSI0])]
 mod app {
     #[init]
     fn init(c: init::Context) -> init::LateResources {
@@ -18,11 +18,4 @@ mod app {
 
     #[task]
     fn some_task(_: some_task::Context) {}
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-    }
 }

examples/t-schedule.rs

@@ -7,7 +7,7 @@
 
 use panic_halt as _;
 
-#[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT)]
+#[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT, dispatchers = [SSI0])]
 mod app {
     use rtic::cyccnt::{Instant, U32Ext as _};
 
@@ -57,11 +57,4 @@ mod app {
 
     #[task]
     fn baz(_: baz::Context, _x: u32, _y: u32) {}
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-    }
 }

examples/t-spawn.rs

@@ -7,7 +7,7 @@
 
 use panic_halt as _;
 
-#[rtic::app(device = lm3s6965)]
+#[rtic::app(device = lm3s6965, dispatchers = [SSI0])]
 mod app {
     #[init]
     fn init(_: init::Context) -> init::LateResources {
@@ -55,11 +55,4 @@ mod app {
 
     #[task]
     fn baz(_: baz::Context, _x: u32, _y: u32) {}
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-    }
 }

examples/t-stask-main.rs

@@ -5,7 +5,7 @@
 
 use panic_semihosting as _;
 
-#[rtic::app(device = lm3s6965)]
+#[rtic::app(device = lm3s6965, dispatchers = [SSI0])]
 mod app {
     use cortex_m_semihosting::debug;
 
@@ -20,11 +20,4 @@ mod app {
     fn taskmain(_: taskmain::Context) {
         debug::exit(debug::EXIT_SUCCESS);
     }
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-    }
 }

examples/task.rs

@@ -7,7 +7,7 @@
 
 use panic_semihosting as _;
 
-#[rtic::app(device = lm3s6965)]
+#[rtic::app(device = lm3s6965, dispatchers = [SSI0, QEI0])]
 mod app {
     use cortex_m_semihosting::{debug, hprintln};
 
@@ -47,12 +47,4 @@ mod app {
     fn baz(_: baz::Context) {
         hprintln!("baz").unwrap();
     }
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-        fn QEI0();
-    }
 }

examples/types.rs

@@ -7,7 +7,7 @@
 
 use panic_semihosting as _;
 
-#[rtic::app(device = lm3s6965, peripherals = true, monotonic = rtic::cyccnt::CYCCNT)]
+#[rtic::app(device = lm3s6965, peripherals = true, monotonic = rtic::cyccnt::CYCCNT, dispatchers = [SSI0])]
 mod app {
     use cortex_m_semihosting::debug;
     use rtic::cyccnt;
@@ -48,11 +48,4 @@ mod app {
         let _: &mut u32 = cx.resources.shared;
         let _: foo::Resources = cx.resources;
     }
-
-    // RTIC requires that unused interrupts are declared in an extern block when
-    // using software tasks; these free interrupts will be used to dispatch the
-    // software tasks.
-    extern "C" {
-        fn SSI0();
-    }
 }

macros/src/analyze.rs

@@ -3,7 +3,7 @@ use std::collections::{BTreeMap, BTreeSet};
 
 use rtic_syntax::{
     analyze::{self, Priority},
-    ast::App,
+    ast::{App, ExternInterrupt},
     P,
 };
 use syn::Ident;
@@ -11,7 +11,7 @@ use syn::Ident;
 /// Extend the upstream `Analysis` struct with our field
 pub struct Analysis {
     parent: P<analyze::Analysis>,
-    pub interrupts: BTreeMap<Priority, Ident>,
+    pub interrupts: BTreeMap<Priority, (Ident, ExternInterrupt)>,
 }
 
 impl ops::Deref for Analysis {
@@ -22,23 +22,23 @@ impl ops::Deref for Analysis {
     }
 }
 
-// Assign an `extern` interrupt to each priority level
+// Assign an interrupt to each priority level
 pub fn app(analysis: P<analyze::Analysis>, app: &App) -> P<Analysis> {
-    let mut interrupts = BTreeMap::new();
+    // the set of priorities (each priority only once)
     let priorities = app
         .software_tasks
         .values()
         .map(|task| task.args.priority)
         .collect::<BTreeSet<_>>();
 
-    if !priorities.is_empty() {
-        interrupts = priorities
-            .iter()
-            .cloned()
-            .rev()
-            .zip(app.extern_interrupts.keys().cloned())
-            .collect();
-    }
+    // map from priorities to interrupts (holding name and attributes)
+    let interrupts: BTreeMap<Priority, _> = priorities
+        .iter()
+        .cloned()
+        .rev()
+        .zip(&app.args.extern_interrupts)
+        .map(|(p, (id, ext))| (p, (id.clone(), ext.clone())))
+        .collect();
 
     P::new(Analysis {
         parent: analysis,

macros/src/check.rs

@@ -1,28 +1,19 @@
 use std::collections::HashSet;
 
 use proc_macro2::Span;
-use rtic_syntax::{
-    analyze::Analysis,
-    ast::{App, CustomArg},
-};
+use rtic_syntax::{analyze::Analysis, ast::App};
 use syn::{parse, Path};
 
-pub struct Extra<'a> {
-    pub device: &'a Path,
-    pub monotonic: Option<&'a Path>,
+pub struct Extra {
+    pub device: Path,
+    pub monotonic: Option<Path>,
     pub peripherals: bool,
 }
 
-impl<'a> Extra<'a> {
-    pub fn monotonic(&self) -> &'a Path {
-        self.monotonic.expect("UNREACHABLE")
-    }
-}
-
-pub fn app<'a>(app: &'a App, _analysis: &Analysis) -> parse::Result<Extra<'a>> {
+pub fn app(app: &App, _analysis: &Analysis) -> parse::Result<Extra> {
     // Check that external (device-specific) interrupts are not named after known (Cortex-M)
     // exceptions
-    for name in app.extern_interrupts.keys() {
+    for name in app.args.extern_interrupts.keys() {
         let name_s = name.to_string();
 
         match &*name_s {
@@ -51,11 +42,11 @@ pub fn app<'a>(app: &'a App, _analysis: &Analysis) -> parse::Result<Extra<'a>> {
         .collect::<HashSet<_>>();
 
     let need = priorities.len();
-    let given = app.extern_interrupts.len();
+    let given = app.args.extern_interrupts.len();
     if need > given {
         let s = {
             format!(
-                "not enough `extern` interrupts to dispatch \
+                "not enough interrupts to dispatch \
                     all software tasks (need: {}; given: {})",
                 need, given
             )
@@ -66,52 +57,6 @@ pub fn app<'a>(app: &'a App, _analysis: &Analysis) -> parse::Result<Extra<'a>> {
         return Err(parse::Error::new(first.unwrap().span(), &s));
     }
 
-    let mut device = None;
-    let mut monotonic = None;
-    let mut peripherals = false;
-
-    for (k, v) in &app.args.custom {
-        let ks = k.to_string();
-
-        match &*ks {
-            "device" => match v {
-                CustomArg::Path(p) => device = Some(p),
-
-                _ => {
-                    return Err(parse::Error::new(
-                        k.span(),
-                        "unexpected argument value; this should be a path",
-                    ));
-                }
-            },
-
-            "monotonic" => match v {
-                CustomArg::Path(p) => monotonic = Some(p),
-
-                _ => {
-                    return Err(parse::Error::new(
-                        k.span(),
-                        "unexpected argument value; this should be a path",
-                    ));
-                }
-            },
-
-            "peripherals" => match v {
-                CustomArg::Bool(x) => peripherals = *x,
-                _ => {
-                    return Err(parse::Error::new(
-                        k.span(),
-                        "unexpected argument value; this should be a boolean",
-                    ));
-                }
-            },
-
-            _ => {
-                return Err(parse::Error::new(k.span(), "unexpected argument"));
-            }
-        }
-    }
-
     // Check that all exceptions are valid; only exceptions with configurable priorities are
     // accepted
     for (name, task) in &app.hardware_tasks {
@@ -119,7 +64,7 @@ pub fn app<'a>(app: &'a App, _analysis: &Analysis) -> parse::Result<Extra<'a>> {
         match &*name_s {
             "SysTick" => {
                 // If the timer queue is used, then SysTick is unavailable
-                if monotonic.is_some() {
+                if app.args.monotonic.is_some() {
                     return Err(parse::Error::new(
                         name.span(),
                         "this exception can't be used because it's being used by the runtime",
@@ -140,11 +85,11 @@ pub fn app<'a>(app: &'a App, _analysis: &Analysis) -> parse::Result<Extra<'a>> {
         }
     }
 
-    if let Some(device) = device {
+    if let Some(device) = app.args.device.clone() {
         Ok(Extra {
             device,
-            monotonic,
-            peripherals,
+            monotonic: app.args.monotonic.clone(),
+            peripherals: app.args.peripherals,
         })
     } else {
         Err(parse::Error::new(

macros/src/codegen.rs

@@ -86,7 +86,7 @@ pub fn app(app: &App, analysis: &Analysis, extra: &Extra) -> TokenStream2 {
     let user_imports = &app.user_imports;
     let user_code = &app.user_code;
     let name = &app.name;
-    let device = extra.device;
+    let device = &extra.device;
 
     // Get the list of all tasks
     // Currently unused, might be useful

macros/src/codegen/dispatchers.rs

@@ -119,11 +119,13 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
         ));
 
         let doc = format!("Interrupt handler to dispatch tasks at priority {}", level);
-        let interrupt = util::suffixed(&interrupts[&level].to_string());
+        let interrupt = util::suffixed(&interrupts[&level].0.to_string());
+        let attribute = &interrupts[&level].1.attrs;
         items.push(quote!(
             #[allow(non_snake_case)]
             #[doc = #doc]
             #[no_mangle]
+            #(#attribute)*
             unsafe fn #interrupt() {
                 /// The priority of this interrupt handler
                 const PRIORITY: u8 = #level;

macros/src/codegen/hardware_tasks.rs

@@ -29,7 +29,7 @@ pub fn codegen(
     let mut user_tasks = vec![];
 
     for (name, task) in &app.hardware_tasks {
-        let (let_instant, instant) = if let Some(m) = extra.monotonic {
+        let (let_instant, instant) = if let Some(ref m) = extra.monotonic {
             (
                 Some(quote!(let instant = <#m as rtic::Monotonic>::now();)),
                 Some(quote!(, instant)),

macros/src/codegen/module.rs

@@ -23,7 +23,7 @@ pub fn codegen(
     let mut lt = None;
     match ctxt {
         Context::Init => {
-            if let Some(m) = extra.monotonic {
+            if let Some(m) = &extra.monotonic {
                 fields.push(quote!(
                     /// System start time = `Instant(0 /* cycles */)`
                     pub start: <#m as rtic::Monotonic>::Instant
@@ -43,7 +43,7 @@ pub fn codegen(
             }
 
             if extra.peripherals {
-                let device = extra.device;
+                let device = &extra.device;
 
                 fields.push(quote!(
                     /// Device peripherals
@@ -67,7 +67,7 @@ pub fn codegen(
         Context::Idle => {}
 
         Context::HardwareTask(..) => {
-            if let Some(m) = extra.monotonic {
+            if let Some(m) = &extra.monotonic {
                 fields.push(quote!(
                     /// Time at which this handler started executing
                     pub start: <#m as rtic::Monotonic>::Instant
@@ -80,7 +80,7 @@ pub fn codegen(
         }
 
         Context::SoftwareTask(..) => {
-            if let Some(m) = extra.monotonic {
+            if let Some(m) = &extra.monotonic {
                 fields.push(quote!(
                     /// The time at which this task was scheduled to run
                     pub scheduled: <#m as rtic::Monotonic>::Instant
@@ -162,7 +162,7 @@ pub fn codegen(
     };
 
     let instant = if needs_instant {
-        let m = extra.monotonic();
+        let m = extra.monotonic.clone().expect("RTIC-ICE: UNREACHABLE");
 
         Some(quote!(, instant: <#m as rtic::Monotonic>::Instant))
     } else {
@@ -205,9 +205,13 @@ pub fn codegen(
         let app_name = &app.name;
         let app_path = quote! {crate::#app_name};
 
-        let device = extra.device;
+        let device = &extra.device;
         let enum_ = util::interrupt_ident();
-        let interrupt = &analysis.interrupts.get(&priority);
+        let interrupt = &analysis
+            .interrupts
+            .get(&priority)
+            .expect("RTIC-ICE: interrupt identifer not found")
+            .0;
 
         // Spawn caller
         items.push(quote!(
@@ -240,7 +244,7 @@ pub fn codegen(
         }));
 
         // Schedule caller
-        if let Some(m) = extra.monotonic {
+        if let Some(m) = &extra.monotonic {
             let instants = util::instants_ident(name);
 
             let tq = util::tq_ident();

macros/src/codegen/pre_init.rs

@@ -26,22 +26,20 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
         let mut core: rtic::export::Peripherals = rtic::export::Peripherals::steal().into();
     ));
 
-    let device = extra.device;
+    let device = &extra.device;
     let nvic_prio_bits = quote!(#device::NVIC_PRIO_BITS);
 
+    let interrupt_ids = analysis.interrupts.iter().map(|(p, (id, _))| (p, id));
+
     // Unmask interrupts and set their priorities
-    for (&priority, name) in analysis
-        .interrupts
-        .iter()
-        .chain(app.hardware_tasks.values().flat_map(|task| {
-            if !util::is_exception(&task.args.binds) {
-                Some((&task.args.priority, &task.args.binds))
-            } else {
-                // We do exceptions in another pass
-                None
-            }
-        }))
-    {
+    for (&priority, name) in interrupt_ids.chain(app.hardware_tasks.values().flat_map(|task| {
+        if !util::is_exception(&task.args.binds) {
+            Some((&task.args.priority, &task.args.binds))
+        } else {
+            // We do exceptions in another pass
+            None
+        }
+    })) {
         // Compile time assert that this priority is supported by the device
         stmts.push(quote!(let _ = [(); ((1 << #nvic_prio_bits) - #priority as usize)];));
 

macros/src/codegen/software_tasks.rs

@@ -57,7 +57,7 @@ pub fn codegen(
             .map(|_| quote!(core::mem::MaybeUninit::uninit()))
             .collect::<Vec<_>>();
 
-        if let Some(m) = extra.monotonic {
+        if let Some(m) = &extra.monotonic {
             let instants = util::instants_ident(name);
 
             let uninit = mk_uninit();

macros/src/codegen/timer_queue.rs

@@ -8,7 +8,7 @@ use crate::{analyze::Analysis, check::Extra, codegen::util};
 pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream2> {
     let mut items = vec![];
 
-    if let Some(m) = extra.monotonic {
+    if let Some(m) = &extra.monotonic {
         let t = util::schedule_t_ident();
 
         // Enumeration of `schedule`-able tasks
@@ -71,7 +71,7 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
                     let rq = util::rq_ident(priority);
                     let rqt = util::spawn_t_ident(priority);
                     let enum_ = util::interrupt_ident();
-                    let interrupt = &analysis.interrupts.get(&priority);
+                    let interrupt = &analysis.interrupts.get(&priority).expect("RTIC-ICE: interrupt not found").0;
 
                     let pend = {
                         quote!(

macros/src/codegen/util.rs

@@ -46,7 +46,7 @@ pub fn impl_mutex(
         (quote!(#name), quote!(self.priority))
     };
 
-    let device = extra.device;
+    let device = &extra.device;
     quote!(
         #(#cfgs)*
         impl<'a> rtic::Mutex for #path<'a> {

macros/src/tests/single.rs

@@ -6,7 +6,8 @@ fn analyze() {
     let mut settings = Settings::default();
     settings.parse_extern_interrupt = true;
     let (app, analysis) = rtic_syntax::parse2(
-        quote!(device = pac),
+        // First interrupt is assigned to the highest priority dispatcher
+        quote!(device = pac, dispatchers = [B, A]),
         quote!(
             mod app {
                 #[task(priority = 1)]
@@ -14,12 +15,6 @@ fn analyze() {
 
                 #[task(priority = 2)]
                 fn b(_: b::Context) {}
-
-                // First interrupt is assigned to the highest priority dispatcher
-                extern "C" {
-                    fn B();
-                    fn A();
-                }
             }
         ),
         settings,
@@ -29,6 +24,6 @@ fn analyze() {
     let analysis = crate::analyze::app(analysis, &app);
     let interrupts = &analysis.interrupts;
     assert_eq!(interrupts.len(), 2);
-    assert_eq!(interrupts[&2].to_string(), "B");
-    assert_eq!(interrupts[&1].to_string(), "A");
+    assert_eq!(interrupts[&2].0.to_string(), "B");
+    assert_eq!(interrupts[&1].0.to_string(), "A");
 }

ui/single/extern-interrupt-not-enough.stderr

@@ -1,4 +1,4 @@
-error: not enough `extern` interrupts to dispatch all software tasks (need: 1; given: 0)
+error: not enough interrupts to dispatch all software tasks (need: 1; given: 0)
  --> $DIR/extern-interrupt-not-enough.rs:6:8
   |
 6 |     fn a(_: a::Context) {}

ui/single/extern-interrupt-used.rs

@@ -1,6 +1,6 @@
 #![no_main]
 
-#[rtic::app(device = lm3s6965)]
+#[rtic::app(device = lm3s6965, dispatchers = [UART0])]
 mod app {
     #[task(binds = UART0)]
     fn a(_: a::Context) {}

ui/single/extern-interrupt-used.stderr

@@ -1,4 +1,4 @@
-error: `extern` interrupts can't be used as hardware tasks
+error: dispatcher interrupts can't be used as hardware tasks
  --> $DIR/extern-interrupt-used.rs:5:20
   |
 5 |     #[task(binds = UART0)]

ui/single/locals-cfg.rs

@@ -1,7 +1,7 @@
 #![no_main]
 use panic_halt as _;
 
-#[rtic::app(device = lm3s6965)]
+#[rtic::app(device = lm3s6965, dispatchers = [SSI0])]
 mod app {
     #[init]
     fn init(_: init::Context) -> init::LateResources {
@@ -46,8 +46,4 @@ mod app {
 
         FOO;
     }
-
-    extern "C" {
-        fn UART1();
-    }
 }