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.

2 files changed, 13 insertions, 9 deletions

diff --git a/macros/src/syntax/mod.rs b/macros/src/syntax/mod.rs
index 53c17a82..757e05ed 100644
--- a/macros/src/syntax/mod.rs
+++ b/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>;
diff --git a/macros/src/syntax/parse.rs b/macros/src/syntax/parse.rs
index 9cfbd78b..056e804a 100644
--- a/macros/src/syntax/parse.rs
+++ b/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 }