syntax tweaks, relax check, add set_pending(), deal with imported types

- allow trailing commas in list of resources

- make task.resources optional

- add rtfm::set_pending function which can be used to force an interrupt into
  the pending state. This is a replacement of the old rtfm::request.
  rtfm::set_pending takes the Interrupt enum provided by the device crate as
  argument. (The old rtfm::request took a task function as argument)

- the user may want to use types they imported into the root of the crate. These
  types are not available in e.g. `mod idle` so `idle::Resources` *can't* be
  defined in that module. To workaround this problem `idle::Resources` will be
  defined in the root, with some other name, and then be re-exported in the
  `idle` module.

- remove the "a resource only used by one task should be local data" check. In
  some cases you do want a resource owned by a single task instead of local
  data since `init` can access resources but not a task local data.

macros/src/check.rs

@@ -1,17 +1,12 @@
-use syntax::Resources;
-use util::{Ceiling, Ceilings};
+use syntax::Statics;
+use util::Ceilings;
 
-pub fn resources(resources: &Resources, ceilings: &Ceilings) {
+pub fn resources(resources: &Statics, ceilings: &Ceilings) {
     for resource in resources.keys() {
-        if let Some(ceiling) = ceilings.get(&resource) {
-            assert_ne!(
-                *ceiling,
-                Ceiling::Owned,
-                "{} should be local data",
-                resource
-            );
-        } else {
-            panic!("resource {} is unused", resource)
-        }
+        assert!(
+            ceilings.get(&resource).is_some(),
+            "resource {} is unused",
+            resource
+        );
     }
 }

macros/src/lib.rs

@@ -1,3 +1,4 @@
+#![deny(warnings)]
 #![feature(plugin_registrar)]
 #![feature(proc_macro_internals)]
 #![feature(rustc_private)]

macros/src/syntax/mod.rs

@@ -10,7 +10,7 @@ pub struct App {
     pub device: Tokens,
     pub idle: Idle,
     pub init: Init,
-    pub resources: Resources,
+    pub resources: Statics,
     pub tasks: Tasks,
 }
 
@@ -21,7 +21,7 @@ pub struct Init {
 
 #[derive(Debug)]
 pub struct Idle {
-    pub local: Resources,
+    pub local: Statics,
     pub path: Tokens,
     pub resources: HashSet<Ident>,
 }
@@ -46,6 +46,6 @@ pub struct Resource {
     pub ty: Tokens,
 }
 
-pub type Resources = HashMap<Ident, Resource>;
+pub type Statics = HashMap<Ident, Resource>;
 
 pub type Tasks = HashMap<Ident, Task>;

macros/src/syntax/parse.rs

@@ -2,7 +2,7 @@ use std::collections::{HashMap, HashSet};
 
 use syn::{self, DelimToken, Ident, IntTy, Lit, Token, TokenTree};
 
-use syntax::{App, Idle, Init, Kind, Resource, Resources, Task, Tasks};
+use syntax::{App, Idle, Init, Kind, Resource, Statics, Task, Tasks};
 
 pub fn app(input: &str) -> App {
     let tts = syn::parse_token_trees(input).unwrap();
@@ -96,7 +96,7 @@ pub fn app(input: &str) -> App {
                         block.delim
                     );
 
-                    resources = Some(super::parse::resources(block.tts));
+                    resources = Some(super::parse::statics(block.tts));
                 }
             }
             "tasks" => {
@@ -169,7 +169,7 @@ pub fn idle(tts: Vec<TokenTree>) -> Idle {
                         block.delim
                     );
 
-                    local = Some(super::parse::resources(block.tts));
+                    local = Some(super::parse::statics(block.tts));
                 } else {
                     panic!("expected block, found {:?}", tt);
                 }
@@ -273,7 +273,7 @@ pub fn init(tts: Vec<TokenTree>) -> Init {
 fn idents(tts: Vec<TokenTree>) -> HashSet<Ident> {
     let mut idents = HashSet::new();
 
-    let mut tts = tts.into_iter();
+    let mut tts = tts.into_iter().peekable();
     while let Some(tt) = tts.next() {
         if let TokenTree::Token(Token::Ident(id)) = tt {
             assert!(!idents.contains(&id), "ident {} already listed", id);
@@ -281,6 +281,10 @@ fn idents(tts: Vec<TokenTree>) -> HashSet<Ident> {
 
             if let Some(tt) = tts.next() {
                 assert_eq!(tt, TokenTree::Token(Token::Comma));
+
+                if tts.peek().is_none() {
+                    break;
+                }
             } else {
                 break;
             }
@@ -292,7 +296,7 @@ fn idents(tts: Vec<TokenTree>) -> HashSet<Ident> {
     idents
 }
 
-pub fn resources(tts: Vec<TokenTree>) -> Resources {
+pub fn statics(tts: Vec<TokenTree>) -> Statics {
     let mut resources = HashMap::new();
 
     let mut tts = tts.into_iter();
@@ -502,7 +506,7 @@ fn task(tts: Vec<TokenTree>) -> Task {
         );
     }
 
-    let resources = resources.expect("resources field is missing");
+    let resources = resources.unwrap_or(HashSet::new());
     let priority = priority.expect("priority field is missing");
     let kind = if let Some(enabled) = enabled {
         Kind::Interrupt { enabled }

macros/src/trans.rs

@@ -39,22 +39,24 @@ fn init(app: &App, main: &mut Vec<Tokens>, root: &mut Vec<Tokens>) {
         let ty = &resource.ty;
 
         fields.push(quote! {
-            pub #name: &'a mut #ty,
+            pub #name: &'a mut #krate::Static<#ty>,
         });
 
         exprs.push(quote! {
-            #name: &mut *super::#name.get(),
+            #name: ::#krate::Static::ref_mut(&mut *super::#name.get()),
         });
     }
 
     root.push(quote! {
+        #[allow(non_camel_case_types)]
+        #[allow(non_snake_case)]
+        pub struct _initResources<#lifetime> {
+            #(#fields)*
+        }
+
         mod init {
             pub use ::#device::Peripherals;
-
-            #[allow(non_snake_case)]
-            pub struct Resources<#lifetime> {
-                #(#fields)*
-            }
+            pub use ::_initResources as Resources;
 
             impl<#lifetime> Resources<#lifetime> {
                 pub unsafe fn new() -> Self {
@@ -184,36 +186,80 @@ fn idle(
         let device = &app.device;
         let mut lifetime = None;
 
+        let mut needs_reexport = false;
+        for name in &app.idle.resources {
+            if ceilings[name].is_owned() {
+                if app.resources.get(name).is_some() {
+                    needs_reexport = true;
+                    break
+                }
+            }
+        }
+
+        let super_ = if needs_reexport {
+            None
+        } else {
+            Some(Ident::new("super"))
+        };
         let mut rexprs = vec![];
         let mut rfields = vec![];
         for name in &app.idle.resources {
             if ceilings[name].is_owned() {
                 lifetime = Some(quote!('a));
+                if let Some(resource) = app.resources.get(name) {
+                    let ty = &resource.ty;
 
-                rfields.push(quote! {
-                    pub #name: &'a mut ::#device::#name,
-                });
+                    rfields.push(quote! {
+                        pub #name: &'a mut ::#krate::Static<#ty>,
+                    });
 
-                rexprs.push(quote! {
-                    #name: &mut *::#device::#name.get(),
-                });
+                    rexprs.push(quote! {
+                        #name: ::#krate::Static::ref_mut(
+                            &mut *#super_::#name.get(),
+                        ),
+                    });
+                } else {
+                    rfields.push(quote! {
+                        pub #name: &'a mut ::#device::#name,
+                    });
+
+                    rexprs.push(quote! {
+                        #name: &mut *::#device::#name.get(),
+                    });
+                }
             } else {
                 rfields.push(quote! {
-                    pub #name: super::_resource::#name,
+                    pub #name: #super_::_resource::#name,
                 });
 
                 rexprs.push(quote! {
-                    #name: super::_resource::#name::new(),
+                    #name: #super_::_resource::#name::new(),
                 });
             }
         }
 
-        mod_items.push(quote! {
-            #[allow(non_snake_case)]
-            pub struct Resources<#lifetime> {
-                #(#rfields)*
-            }
+        if needs_reexport {
+            root.push(quote! {
+                #[allow(non_camel_case_types)]
+                #[allow(non_snake_case)]
+                pub struct _idleResources<#lifetime> {
+                    #(#rfields)*
+                }
+            });
 
+            mod_items.push(quote! {
+                pub use ::_idleResources as Resources;
+            });
+        } else {
+            mod_items.push(quote! {
+                #[allow(non_snake_case)]
+                pub struct Resources<#lifetime> {
+                    #(#rfields)*
+                }
+            });
+        }
+
+        mod_items.push(quote! {
             impl<#lifetime> Resources<#lifetime> {
                 pub unsafe fn new() -> Self {
                     Resources {
@@ -252,6 +298,7 @@ fn tasks(app: &App, ceilings: &Ceilings, root: &mut Vec<Tokens>) {
 
         let device = &app.device;
         let mut lifetime = None;
+        let mut needs_reexport = false;
         for name in &task.resources {
             match ceilings[name] {
                 Ceiling::Shared(ceiling) if ceiling > task.priority => {
@@ -268,6 +315,7 @@ fn tasks(app: &App, ceilings: &Ceilings, root: &mut Vec<Tokens>) {
                 _ => {
                     lifetime = Some(quote!('a));
                     if let Some(resource) = app.resources.get(name) {
+                        needs_reexport = true;
                         let ty = &resource.ty;
 
                         fields.push(quote! {
@@ -292,12 +340,27 @@ fn tasks(app: &App, ceilings: &Ceilings, root: &mut Vec<Tokens>) {
             }
         }
 
-        items.push(quote! {
-            #[allow(non_snake_case)]
-            pub struct Resources<#lifetime> {
-                #(#fields)*
-            }
-        });
+        if needs_reexport {
+            let rname = Ident::new(format!("_{}Resources", name));
+            root.push(quote! {
+                #[allow(non_camel_case_types)]
+                #[allow(non_snake_case)]
+                pub struct #rname<#lifetime> {
+                    #(#fields)*
+                }
+            });
+
+            items.push(quote! {
+                pub use ::#rname as Resources;
+            });
+        } else {
+            items.push(quote! {
+                #[allow(non_snake_case)]
+                pub struct Resources<#lifetime> {
+                    #(#fields)*
+                }
+            });
+        }
 
         items.push(quote! {
             impl<#lifetime> Resources<#lifetime> {
@@ -339,7 +402,22 @@ fn resources(app: &App, ceilings: &Ceilings, root: &mut Vec<Tokens>) {
         let mut impl_items = vec![];
 
         match *ceiling {
-            Ceiling::Owned => continue,
+            Ceiling::Owned(_) => {
+                if let Some(resource) = app.resources.get(name) {
+                    // For owned resources we don't need claim() or borrow(),
+                    // just get()
+                    let expr = &resource.expr;
+                    let ty = &resource.ty;
+
+                    root.push(quote! {
+                        static #name: #krate::Resource<#ty> =
+                            #krate::Resource::new(#expr);
+                    });
+                } else {
+                    // Peripheral
+                    continue
+                }
+            },
             Ceiling::Shared(ceiling) => {
                 if let Some(resource) = app.resources.get(name) {
                     let expr = &resource.expr;

macros/src/util.rs

@@ -1,3 +1,4 @@
+use std::cmp;
 use std::collections::HashMap;
 
 use syn::Ident;
@@ -8,13 +9,18 @@ pub type Ceilings = HashMap<Ident, Ceiling>;
 
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub enum Ceiling {
-    Owned,
+    // Owned by one or more tasks that have the same priority
+    Owned(u8),
+    // Shared by tasks with different priorities
     Shared(u8),
 }
 
 impl Ceiling {
     pub fn is_owned(&self) -> bool {
-        *self == Ceiling::Owned
+        match *self {
+            Ceiling::Owned(_) => true,
+            _ => false,
+        }
     }
 }
 
@@ -22,14 +28,22 @@ pub fn compute_ceilings(app: &App) -> Ceilings {
     let mut ceilings = HashMap::new();
 
     for resource in &app.idle.resources {
-        ceilings.insert(resource.clone(), Ceiling::Owned);
+        ceilings.insert(resource.clone(), Ceiling::Owned(0));
     }
 
     for task in app.tasks.values() {
         for resource in &task.resources {
             if let Some(ceiling) = ceilings.get_mut(resource) {
                 match *ceiling {
-                    Ceiling::Owned => *ceiling = Ceiling::Shared(task.priority),
+                    Ceiling::Owned(current) => {
+                        if current == task.priority {
+                            *ceiling = Ceiling::Owned(current);
+                        } else {
+                            *ceiling = Ceiling::Shared(
+                                cmp::max(current, task.priority),
+                            );
+                        }
+                    }
                     Ceiling::Shared(old) => {
                         if task.priority > old {
                             *ceiling = Ceiling::Shared(task.priority);
@@ -40,7 +54,7 @@ pub fn compute_ceilings(app: &App) -> Ceilings {
                 continue;
             }
 
-            ceilings.insert(resource.clone(), Ceiling::Owned);
+            ceilings.insert(resource.clone(), Ceiling::Owned(task.priority));
         }
     }
 

src/lib.rs

@@ -12,6 +12,7 @@ pub use cortex_m::asm::{bkpt, wfi};
 pub use cortex_m::interrupt::CriticalSection;
 pub use cortex_m::interrupt::free as atomic;
 pub use static_ref::Static;
+use cortex_m::interrupt::Nr;
 #[cfg(not(armv6m))]
 use cortex_m::register::{basepri_max, basepri};
 
@@ -175,6 +176,16 @@ impl Threshold {
 
 impl !Send for Threshold {}
 
+/// Sets an interrupt as pending
+pub fn set_pending<I>(interrupt: I)
+where
+    I: Nr,
+{
+    // NOTE(safe) atomic write
+    let nvic = unsafe { &*cortex_m::peripheral::NVIC.get() };
+    nvic.set_pending(interrupt);
+}
+
 #[macro_export]
 macro_rules! task {
     ($NAME:ident, $body:path) => {