Auto merge of #50 - japaric:singletons, r=japaric

Peripherals as scoped singletons

See this RFC for details: japaric/svd2rust#157

- The first commit adapts this crate to the changes in japaric/cortex-m#65 and japaric/svd2rust#158
- ~~The second commit is an alternative implementation of RFC #47 (there's another implementation in #49. This second commit is not required for RFC157 but let us experiment with safe DMA abstractions.~~ postponed

### TODO

- [x] un-bless peripherals as resources. Peripherals as resources were special cased: if resource listed in e.g. `app.tasks.FOO.resources` didn't appear in `app.resources` then it was assumed to be a peripheral and special code was generated for it. This is no longer required under RFC157.

~~This depends on PR japaric/rtfm-syntax#2~~ postponed

1 files changed, 14 insertions, 4 deletions

diff --git a/macros/src/check.rs b/macros/src/check.rs
index 3cd112a..63cac1f 100644
--- a/macros/src/check.rs
+++ b/macros/src/check.rs
@@ -63,16 +63,15 @@ pub fn app(app: check::App) -> Result<App> {
         tasks: app.tasks
             .into_iter()
             .map(|(k, v)| {
-                let v = ::check::task(k.as_ref(), v)
-                    .chain_err(|| format!("checking task `{}`", k))?;
+                let v =
+                    ::check::task(k.as_ref(), v).chain_err(|| format!("checking task `{}`", k))?;
 
                 Ok((k, v))
             })
             .collect::<Result<_>>()?,
     };
 
-    ::check::resources(&app)
-        .chain_err(|| "checking `resources`")?;
+    ::check::resources(&app).chain_err(|| "checking `resources`")?;
 
     Ok(app)
 }
@@ -93,6 +92,17 @@ fn resources(app: &App) -> Result<()> {
         bail!("resource `{}` is unused", resource);
     }
 
+    for (name, task) in &app.tasks {
+        for resource in &task.resources {
+            ensure!(
+                app.resources.contains_key(&resource),
+                "task {} contains an undeclared resource with name {}",
+                name,
+                resource
+            );
+        }
+    }
+
     Ok(())
 }