make resource proxies !Send

macros/src/trans.rs

@@ -438,12 +438,14 @@ fn resources(app: &App, ownerships: &Ownerships, root: &mut Vec<Tokens>) {
 
                 items.push(quote! {
                     #[allow(non_camel_case_types)]
-                    pub struct #name { _0: () }
+                    pub struct #name { _0: PhantomData<*const ()> }
+
+                    unsafe impl Sync for #name {}
 
                     #[allow(unsafe_code)]
                     impl #name {
                         pub unsafe fn new() -> Self {
-                            #name { _0: () }
+                            #name { _0: PhantomData }
                         }
                     }
                 });
@@ -455,6 +457,8 @@ fn resources(app: &App, ownerships: &Ownerships, root: &mut Vec<Tokens>) {
         root.push(quote! {
             #[allow(unsafe_code)]
             mod _resource {
+                use core::marker::PhantomData;
+
                 #(#items)*
             }
         })

tests/cfail/resource-not-send.rs

@@ -0,0 +1,52 @@
+#![deny(warnings)]
+#![feature(const_fn)]
+#![feature(proc_macro)]
+#![no_std]
+
+extern crate cortex_m_rtfm as rtfm;
+extern crate stm32f103xx;
+
+use rtfm::{app, Resource, Threshold};
+
+app! {
+    device: stm32f103xx,
+
+    resources: {
+        static SHARED: bool = false;
+    },
+
+    tasks: {
+        EXTI0: {
+            path: exti0,
+            priority: 1,
+            resources: [SHARED],
+        },
+
+        EXTI1: {
+            path: exti1,
+            priority: 2,
+            resources: [SHARED],
+        },
+    },
+}
+
+fn init(_p: init::Peripherals, _r: init::Resources) {}
+
+fn idle() -> ! {
+    loop {}
+}
+
+fn is_send<T>(_: &T) where T: Send {}
+fn is_sync<T>(_: &T) where T: Sync {}
+
+fn exti0(_t: &mut Threshold, r: EXTI0::Resources) {
+    // OK
+    is_sync(&r.SHARED);
+
+    // ERROR resource proxies are not `Send`able across tasks
+    is_send(&r.SHARED);
+    //~^ error the trait bound `*const (): core::marker::Send` is not satisfied
+}
+
+fn exti1(_t: &mut Threshold, _r: EXTI1::Resources) {
+}