Merge #372

372: Now late resources are always used r=AfoHT a=korken89

Awaits the PR in `rtic-syntax`: https://github.com/rtic-rs/rtic-syntax/pull/32

Co-authored-by: Emil Fresk <emil.fresk@gmail.com>

examples/baseline.rs

@@ -13,13 +13,15 @@ use panic_semihosting as _;
 #[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT)]
 mod app {
     #[init(spawn = [foo])]
-    fn init(cx: init::Context) {
+    fn init(cx: init::Context) -> init::LateResources {
         // omitted: initialization of `CYCCNT`
 
         hprintln!("init(baseline = {:?})", cx.start).unwrap();
 
         // `foo` inherits the baseline of `init`: `Instant(0)`
         cx.spawn.foo().unwrap();
+
+        init::LateResources {}
     }
 
     #[task(schedule = [foo])]

examples/binds.rs

@@ -13,10 +13,12 @@ use panic_semihosting as _;
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init]
-    fn init(_: init::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         rtic::pend(Interrupt::UART0);
 
         hprintln!("init").unwrap();
+
+        init::LateResources {}
     }
 
     #[idle]

examples/capacity.rs

@@ -12,8 +12,10 @@ use panic_semihosting as _;
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init]
-    fn init(_: init::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         rtic::pend(Interrupt::UART0);
+
+        init::LateResources {}
     }
 
     #[task(binds = UART0, spawn = [foo, bar])]

examples/cfg.rs

@@ -20,9 +20,11 @@ mod app {
     }
 
     #[init(spawn = [foo])]
-    fn init(cx: init::Context) {
+    fn init(cx: init::Context) -> init::LateResources {
         cx.spawn.foo().unwrap();
         cx.spawn.foo().unwrap();
+
+        init::LateResources {}
     }
 
     #[idle]

examples/destructure.rs

@@ -23,9 +23,11 @@ mod app {
     }
 
     #[init]
-    fn init(_: init::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         rtic::pend(Interrupt::UART0);
         rtic::pend(Interrupt::UART1);
+
+        init::LateResources {}
     }
 
     // Direct destructure

examples/generics.rs

@@ -19,9 +19,11 @@ mod app {
     }
 
     #[init]
-    fn init(_: init::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         rtic::pend(Interrupt::UART0);
         rtic::pend(Interrupt::UART1);
+
+        init::LateResources {}
     }
 
     #[task(binds = UART0, resources = [shared])]

examples/hardware.rs

@@ -12,12 +12,14 @@ use panic_semihosting as _;
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init]
-    fn init(_: init::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         // Pends the UART0 interrupt but its handler won't run until *after*
         // `init` returns because interrupts are disabled
         rtic::pend(Interrupt::UART0); // equivalent to NVIC::pend
 
         hprintln!("init").unwrap();
+
+        init::LateResources {}
     }
 
     #[idle]

examples/idle.rs

@@ -11,8 +11,10 @@ use panic_semihosting as _;
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init]
-    fn init(_: init::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         hprintln!("init").unwrap();
+
+        init::LateResources {}
     }
 
     #[idle]

examples/init.rs

@@ -11,7 +11,7 @@ use panic_semihosting as _;
 #[rtic::app(device = lm3s6965, peripherals = true)]
 mod app {
     #[init]
-    fn init(cx: init::Context) {
+    fn init(cx: init::Context) -> init::LateResources {
         static mut X: u32 = 0;
 
         // Cortex-M peripherals
@@ -30,5 +30,7 @@ mod app {
         hprintln!("init").unwrap();
 
         debug::exit(debug::EXIT_SUCCESS);
+
+        init::LateResources {}
     }
 }

examples/lock.rs

@@ -18,8 +18,10 @@ mod app {
     }
 
     #[init]
-    fn init(_: init::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         rtic::pend(Interrupt::GPIOA);
+
+        init::LateResources {}
     }
 
     // when omitted priority is assumed to be `1`

examples/message.rs

@@ -11,8 +11,10 @@ use panic_semihosting as _;
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init(spawn = [foo])]
-    fn init(c: init::Context) {
+    fn init(c: init::Context) -> init::LateResources {
         c.spawn.foo(/* no message */).unwrap();
+
+        init::LateResources {}
     }
 
     #[task(spawn = [bar])]

examples/not-send.rs

@@ -26,9 +26,11 @@ mod app {
     }
 
     #[init(spawn = [baz, quux])]
-    fn init(c: init::Context) {
+    fn init(c: init::Context) -> init::LateResources {
         c.spawn.baz().unwrap();
         c.spawn.quux().unwrap();
+
+        init::LateResources {}
     }
 
     #[task(spawn = [bar])]

examples/not-sync.rs

@@ -26,8 +26,10 @@ mod app {
     }
 
     #[init]
-    fn init(_: init::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         debug::exit(debug::EXIT_SUCCESS);
+
+        init::LateResources {}
     }
 
     #[task(resources = [&shared])]

examples/periodic.rs

@@ -16,10 +16,12 @@ const PERIOD: u32 = 8_000_000;
 mod app {
 
     #[init(schedule = [foo])]
-    fn init(cx: init::Context) {
+    fn init(cx: init::Context) -> init::LateResources {
         // omitted: initialization of `CYCCNT`
 
         cx.schedule.foo(cx.start + PERIOD.cycles()).unwrap();
+
+        init::LateResources {}
     }
 
     #[task(schedule = [foo])]

examples/peripherals-taken.rs

@@ -9,8 +9,10 @@ use panic_semihosting as _;
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init]
-    fn taskmain(_: taskmain::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         assert!(cortex_m::Peripherals::take().is_none());
         debug::exit(debug::EXIT_SUCCESS);
+
+        init::LateResources {}
     }
 }

examples/pool.rs

@@ -25,13 +25,15 @@ mod app {
     use super::P;
 
     #[init]
-    fn init(_: init::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         static mut MEMORY: [u8; 512] = [0; 512];
 
         // Increase the capacity of the memory pool by ~4
         P::grow(MEMORY);
 
         rtic::pend(Interrupt::I2C0);
+
+        init::LateResources {}
     }
 
     #[task(binds = I2C0, priority = 2, spawn = [foo, bar])]

examples/preempt.rs

@@ -11,8 +11,10 @@ use rtic::app;
 #[app(device = lm3s6965)]
 mod app {
     #[init]
-    fn init(_: init::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         rtic::pend(Interrupt::GPIOA);
+
+        init::LateResources {}
     }
 
     #[task(binds = GPIOA, priority = 1)]

examples/ramfunc.rs

@@ -11,8 +11,10 @@ use panic_semihosting as _;
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init(spawn = [bar])]
-    fn init(c: init::Context) {
+    fn init(c: init::Context) -> init::LateResources {
         c.spawn.bar().unwrap();
+
+        init::LateResources {}
     }
 
     #[inline(never)]

examples/resource-user-struct.rs

@@ -26,9 +26,11 @@ mod app {
     }
 
     #[init]
-    fn init(_: init::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         rtic::pend(Interrupt::UART0);
         rtic::pend(Interrupt::UART1);
+
+        init::LateResources {}
     }
 
     // `shared` cannot be accessed from this context

examples/resource.rs

@@ -19,9 +19,11 @@ mod app {
     }
 
     #[init]
-    fn init(_: init::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         rtic::pend(Interrupt::UART0);
         rtic::pend(Interrupt::UART1);
+
+        init::LateResources {}
     }
 
     // `shared` cannot be accessed from this context

examples/schedule.rs

@@ -14,7 +14,7 @@ use rtic::cyccnt::{Instant, U32Ext as _};
 #[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT)]
 mod app {
     #[init(schedule = [foo, bar])]
-    fn init(mut cx: init::Context) {
+    fn init(mut cx: init::Context) -> init::LateResources {
         // Initialize (enable) the monotonic timer (CYCCNT)
         cx.core.DCB.enable_trace();
         // required on Cortex-M7 devices that software lock the DWT (e.g. STM32F7)
@@ -32,6 +32,8 @@ mod app {
 
         // Schedule `bar` to run 4e6 cycles in the future
         cx.schedule.bar(now + 4_000_000.cycles()).unwrap();
+
+        init::LateResources {}
     }
 
     #[task]

examples/shared-with-init.rs

@@ -23,12 +23,14 @@ mod app {
     }
 
     #[init(resources = [shared])]
-    fn init(c: init::Context) {
+    fn init(c: init::Context) -> init::LateResources {
         // this `message` will be sent to task `UART0`
         let message = MustBeSend;
         *c.resources.shared = Some(message);
 
         rtic::pend(Interrupt::UART0);
+
+        init::LateResources {}
     }
 
     #[task(binds = UART0, resources = [shared])]

examples/t-binds.rs

@@ -10,7 +10,9 @@ use panic_halt as _;
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init]
-    fn init(_: init::Context) {}
+    fn init(_: init::Context) -> init::LateResources {
+        init::LateResources {}
+    }
 
     // Cortex-M exception
     #[task(binds = SVCall)]

examples/t-cfg.rs

@@ -15,9 +15,11 @@ mod app {
     }
 
     #[init]
-    fn init(_: init::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         #[cfg(never)]
         static mut BAR: u32 = 0;
+
+        init::LateResources {}
     }
 
     #[idle]

examples/t-htask-main.rs

@@ -9,8 +9,10 @@ use panic_semihosting as _;
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init]
-    fn init(_: init::Context) {
+    fn init(_: init::Context) -> init::LateResources {
-        rtic::pend(lm3s6965::Interrupt::UART0)
+        rtic::pend(lm3s6965::Interrupt::UART0);
+
+        init::LateResources {}
     }
 
     #[task(binds = UART0)]

examples/t-idle-main.rs

@@ -9,7 +9,9 @@ use panic_semihosting as _;
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init]
-    fn init(_: init::Context) {}
+    fn init(_: init::Context) -> init::LateResources {
+        init::LateResources {}
+    }
 
     #[idle]
     fn taskmain(_: taskmain::Context) -> ! {

examples/t-init-main.rs

@@ -9,7 +9,9 @@ use panic_semihosting as _;
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init]
-    fn taskmain(_: taskmain::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         debug::exit(debug::EXIT_SUCCESS);
+
+        init::LateResources {}
     }
 }

examples/t-resource.rs

@@ -32,7 +32,7 @@ mod app {
     }
 
     #[init(resources = [o1, o4, o5, o6, s3])]
-    fn init(c: init::Context) {
+    fn init(c: init::Context) -> init::LateResources {
         // owned by `init` == `&'static mut`
         let _: &'static mut u32 = c.resources.o1;
 
@@ -43,6 +43,8 @@ mod app {
         let _: &mut u32 = c.resources.o4;
         let _: &mut u32 = c.resources.o5;
         let _: &mut u32 = c.resources.s3;
+
+        init::LateResources {}
     }
 
     #[idle(resources = [o2, &o4, s1, &s3])]

examples/t-schedule.rs

@@ -11,10 +11,12 @@ use rtic::cyccnt::{Instant, U32Ext as _};
 #[rtic::app(device = lm3s6965, monotonic = rtic::cyccnt::CYCCNT)]
 mod app {
     #[init(schedule = [foo, bar, baz])]
-    fn init(c: init::Context) {
+    fn init(c: init::Context) -> init::LateResources {
         let _: Result<(), ()> = c.schedule.foo(c.start + 10.cycles());
         let _: Result<(), u32> = c.schedule.bar(c.start + 20.cycles(), 0);
         let _: Result<(), (u32, u32)> = c.schedule.baz(c.start + 30.cycles(), 0, 1);
+
+        init::LateResources {}
     }
 
     #[idle(schedule = [foo, bar, baz])]

examples/t-spawn.rs

@@ -10,10 +10,12 @@ use panic_halt as _;
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init(spawn = [foo, bar, baz])]
-    fn init(c: init::Context) {
+    fn init(c: init::Context) -> init::LateResources {
         let _: Result<(), ()> = c.spawn.foo();
         let _: Result<(), u32> = c.spawn.bar(0);
         let _: Result<(), (u32, u32)> = c.spawn.baz(0, 1);
+
+        init::LateResources {}
     }
 
     #[idle(spawn = [foo, bar, baz])]

examples/t-stask-main.rs

@@ -9,8 +9,10 @@ use panic_semihosting as _;
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init(spawn = [taskmain])]
-    fn init(cx: init::Context) {
+    fn init(cx: init::Context) -> init::LateResources {
         cx.spawn.taskmain().ok();
+
+        init::LateResources {}
     }
 
     #[task]

examples/task.rs

@@ -11,8 +11,10 @@ use panic_semihosting as _;
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init(spawn = [foo])]
-    fn init(c: init::Context) {
+    fn init(c: init::Context) -> init::LateResources {
         c.spawn.foo().unwrap();
+
+        init::LateResources {}
     }
 
     #[task(spawn = [bar, baz])]

examples/types.rs

@@ -18,7 +18,7 @@ mod app {
     }
 
     #[init(schedule = [foo], spawn = [foo])]
-    fn init(cx: init::Context) {
+    fn init(cx: init::Context) -> init::LateResources {
         let _: cyccnt::Instant = cx.start;
         let _: rtic::Peripherals = cx.core;
         let _: lm3s6965::Peripherals = cx.device;
@@ -26,6 +26,8 @@ mod app {
         let _: init::Spawn = cx.spawn;
 
         debug::exit(debug::EXIT_SUCCESS);
+
+        init::LateResources {}
     }
 
     #[idle(schedule = [foo], spawn = [foo])]

macros/src/codegen/init.rs

@@ -36,9 +36,6 @@ pub fn codegen(
 
         let mut root_init = vec![];
 
-        let mut user_init_imports = vec![];
-
-        let ret = {
         let late_fields = analysis
             .late_resources
             .iter()
@@ -55,7 +52,7 @@ pub fn codegen(
             })
             .collect::<Vec<_>>();
 
-            if !late_fields.is_empty() {
+        let mut user_init_imports = vec![];
         let late_resources = util::late_resources_ident(&name);
 
         root_init.push(quote!(
@@ -72,12 +69,6 @@ pub fn codegen(
                 use super::#name_late;
         ));
 
-                Some(quote!(-> #name::LateResources))
-            } else {
-                None
-            }
-        };
-
         let mut locals_pat = None;
         let mut locals_new = None;
         if !init.locals.is_empty() {
@@ -95,7 +86,7 @@ pub fn codegen(
         let user_init = Some(quote!(
             #(#attrs)*
             #[allow(non_snake_case)]
-            fn #name(#(#locals_pat,)* #context: #name::Context) #ret {
+            fn #name(#(#locals_pat,)* #context: #name::Context) -> #name::LateResources {
                 #(#stmts)*
             }
         ));

macros/src/codegen/module.rs

@@ -261,7 +261,6 @@ pub fn codegen(ctxt: Context, resources_tick: bool, app: &App, extra: &Extra) ->
 
     if let Context::Init = ctxt {
         let init = &app.inits.first().unwrap();
-        if init.returns_late_resources {
         let late_resources = util::late_resources_ident(&init.name);
 
         items.push(quote!(
@@ -269,7 +268,6 @@ pub fn codegen(ctxt: Context, resources_tick: bool, app: &App, extra: &Extra) ->
             pub use super::#late_resources as LateResources;
         ));
     }
-    }
 
     let doc = match ctxt {
         Context::Idle => "Idle loop",

macros/src/lib.rs

@@ -35,8 +35,7 @@ mod tests;
 ///
 /// The items allowed in the module block are specified below:
 ///
-/// # 1. `#[resources]
+/// # 1. `#[resources] struct <resource-name>`
-///       struct <resource-name>`
 ///
 /// This structure contains the declaration of all the resources used by the application. Each field
 /// in this structure corresponds to a different resource. Each resource may optionally be given an

ui/single/locals-cfg.rs

@@ -4,11 +4,13 @@ use panic_halt as _;
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init]
-    fn init(_: init::Context) {
+    fn init(_: init::Context) -> init::LateResources {
         #[cfg(never)]
         static mut FOO: u32 = 0;
 
         FOO;
+
+        init::LateResources {}
     }
 
     #[idle]

ui/single/locals-cfg.stderr

@@ -5,27 +5,27 @@ error[E0425]: cannot find value `FOO` in this scope
    |         ^^^ not found in this scope
 
 error[E0425]: cannot find value `FOO` in this scope
-  --> $DIR/locals-cfg.rs:19:9
+  --> $DIR/locals-cfg.rs:21:9
    |
-19 |         FOO;
+21 |         FOO;
    |         ^^^ not found in this scope
 
 error[E0425]: cannot find value `FOO` in this scope
-  --> $DIR/locals-cfg.rs:29:9
+  --> $DIR/locals-cfg.rs:31:9
    |
-29 |         FOO;
+31 |         FOO;
    |         ^^^ not found in this scope
 
 error[E0425]: cannot find value `FOO` in this scope
-  --> $DIR/locals-cfg.rs:37:9
+  --> $DIR/locals-cfg.rs:39:9
    |
-37 |         FOO;
+39 |         FOO;
    |         ^^^ not found in this scope
 
 error[E0425]: cannot find value `FOO` in this scope
-  --> $DIR/locals-cfg.rs:45:9
+  --> $DIR/locals-cfg.rs:47:9
    |
-45 |         FOO;
+47 |         FOO;
    |         ^^^ not found in this scope
 
 error: duplicate lang item in crate `panic_halt` (which `$CRATE` depends on): `panic_impl`.

ui/single/resources-cfg.rs

@@ -43,12 +43,14 @@ mod app {
     }
 
     #[init(resources = [o1, o4, o5, o6, s3])]
-    fn init(c: init::Context) {
+    fn init(c: init::Context) -> init::LateResources {
         c.resources.o1;
         c.resources.o4;
         c.resources.o5;
         c.resources.o6;
         c.resources.s3;
+
+        init::LateResources {}
     }
 
     #[idle(resources = [o2, &o4, s1, &s3])]

ui/single/resources-cfg.stderr

@@ -45,81 +45,81 @@ error[E0609]: no field `s3` on type `initResources<'_>`
    = note: available fields are: `__marker__`
 
 error[E0609]: no field `o2` on type `idleResources<'_>`
-  --> $DIR/resources-cfg.rs:56:21
+  --> $DIR/resources-cfg.rs:58:21
    |
-56 |         c.resources.o2;
+58 |         c.resources.o2;
    |                     ^^ unknown field
    |
    = note: available fields are: `__marker__`
 
 error[E0609]: no field `o4` on type `idleResources<'_>`
-  --> $DIR/resources-cfg.rs:57:21
+  --> $DIR/resources-cfg.rs:59:21
    |
-57 |         c.resources.o4;
+59 |         c.resources.o4;
    |                     ^^ unknown field
    |
    = note: available fields are: `__marker__`
 
 error[E0609]: no field `s1` on type `idleResources<'_>`
-  --> $DIR/resources-cfg.rs:58:21
+  --> $DIR/resources-cfg.rs:60:21
    |
-58 |         c.resources.s1;
+60 |         c.resources.s1;
    |                     ^^ unknown field
    |
    = note: available fields are: `__marker__`
 
 error[E0609]: no field `s3` on type `idleResources<'_>`
-  --> $DIR/resources-cfg.rs:59:21
+  --> $DIR/resources-cfg.rs:61:21
    |
-59 |         c.resources.s3;
+61 |         c.resources.s3;
    |                     ^^ unknown field
    |
    = note: available fields are: `__marker__`
 
 error[E0609]: no field `o3` on type `uart0Resources<'_>`
-  --> $DIR/resources-cfg.rs:66:21
+  --> $DIR/resources-cfg.rs:68:21
    |
-66 |         c.resources.o3;
+68 |         c.resources.o3;
    |                     ^^ unknown field
    |
    = note: available fields are: `__marker__`
 
 error[E0609]: no field `s1` on type `uart0Resources<'_>`
-  --> $DIR/resources-cfg.rs:67:21
+  --> $DIR/resources-cfg.rs:69:21
    |
-67 |         c.resources.s1;
+69 |         c.resources.s1;
    |                     ^^ unknown field
    |
    = note: available fields are: `__marker__`
 
 error[E0609]: no field `s2` on type `uart0Resources<'_>`
-  --> $DIR/resources-cfg.rs:68:21
+  --> $DIR/resources-cfg.rs:70:21
    |
-68 |         c.resources.s2;
+70 |         c.resources.s2;
    |                     ^^ unknown field
    |
    = note: available fields are: `__marker__`
 
 error[E0609]: no field `s3` on type `uart0Resources<'_>`
-  --> $DIR/resources-cfg.rs:69:21
+  --> $DIR/resources-cfg.rs:71:21
    |
-69 |         c.resources.s3;
+71 |         c.resources.s3;
    |                     ^^ unknown field
    |
    = note: available fields are: `__marker__`
 
 error[E0609]: no field `s2` on type `uart1Resources<'_>`
-  --> $DIR/resources-cfg.rs:74:21
+  --> $DIR/resources-cfg.rs:76:21
    |
-74 |         c.resources.s2;
+76 |         c.resources.s2;
    |                     ^^ unknown field
    |
    = note: available fields are: `__marker__`
 
 error[E0609]: no field `o5` on type `uart1Resources<'_>`
-  --> $DIR/resources-cfg.rs:75:21
+  --> $DIR/resources-cfg.rs:77:21
    |
-75 |         c.resources.o5;
+77 |         c.resources.o5;
    |                     ^^ unknown field
    |
    = note: available fields are: `__marker__`

ui/single/task-priority-too-high.rs

@@ -3,7 +3,9 @@
 #[rtic::app(device = lm3s6965)]
 mod app {
     #[init]
-    fn init(_: init::Context) {}
+    fn init(_: init::Context) -> init::LateResources {
+        init::LateResources {}
+    }
 
     #[task(binds = GPIOA, priority = 1)]
     fn gpioa(_: gpioa::Context) {}