Merge #368

368: Mod over const r=korken89 a=AfoHT

Related [RFC](https://github.com/rtic-rs/rfcs/pull/34)

Dependent on [rtic-syntax-PR30](https://github.com/rtic-rs/rtic-syntax/pull/30)

~~Currently using my own dev-branch~~

Co-authored-by: Henrik Tjäder <henrik@tjaders.com>

book/en/src/by-example/app.md

@@ -7,7 +7,7 @@ This is the smallest possible RTIC application:
 ```
 
 All RTIC applications use the [`app`] attribute (`#[app(..)]`). This attribute
-must be applied to a `const` item that contains items. The `app` attribute has
+must be applied to a `mod`-item. The `app` attribute has
 a mandatory `device` argument that takes a *path* as a value. This path must
 point to a *peripheral access crate* (PAC) generated using [`svd2rust`]
 **v0.14.x** or newer. The `app` attribute will expand into a suitable entry
@@ -17,16 +17,9 @@ point so it's not required to use the [`cortex_m_rt::entry`] attribute.
 [`svd2rust`]: https://crates.io/crates/svd2rust
 [`cortex_m_rt::entry`]: ../../../api/cortex_m_rt_macros/attr.entry.html
 
-> **ASIDE**: Some of you may be wondering why we are using a `const` item as a
-> module and not a proper `mod` item. The reason is that using attributes on
-> modules requires a feature gate, which requires a nightly toolchain. To make
-> RTIC work on stable we use the `const` item instead. When more parts of macros
-> 1.2 are stabilized we'll move from a `const` item to a `mod` item and
-> eventually to a crate level attribute (`#![app]`).
-
 ## `init`
 
-Within the pseudo-module the `app` attribute expects to find an initialization
+Within the `app` module the attribute expects to find an initialization
 function marked with the `init` attribute. This function must have signature
 `fn(init::Context) [-> init::LateResources]` (the return type is not always
 required).
@@ -62,7 +55,7 @@ $ cargo run --example init
 ## `idle`
 
 A function marked with the `idle` attribute can optionally appear in the
-pseudo-module. This function is used as the special *idle task* and must have
+module. This function is used as the special *idle task* and must have
 signature `fn(idle::Context) - > !`.
 
 When present, the runtime will execute the `idle` task after `init`. Unlike

book/en/src/by-example/resources.md

@@ -4,11 +4,13 @@ The framework provides an abstraction to share data between any of the contexts
 we saw in the previous section (task handlers, `init` and `idle`): resources.
 
 Resources are data visible only to functions declared within the `#[app]`
-pseudo-module. The framework gives the user complete control over which context
+module. The framework gives the user complete control over which context
 can access which resource.
 
 All resources are declared as a single `struct` within the `#[app]`
-pseudo-module. Each field in the structure corresponds to a different resource.
+module. Each field in the structure corresponds to a different resource.
+The `struct` must be annotated with the following attribute: `#[resources]`.
+
 Resources can optionally be given an initial value using the `#[init]`
 attribute. Resources that are not given an initial value are referred to as
 *late* resources and are covered in more detail in a follow-up section in this

book/en/src/by-example/tasks.md

@@ -95,7 +95,7 @@ following snippet:
 
 ``` rust
 #[rtic::app(..)]
-const APP: () = {
+mod app {
     #[init(spawn = [foo, bar])]
     fn init(cx: init::Context) {
         cx.spawn.foo().unwrap();
@@ -116,5 +116,5 @@ const APP: () = {
     fn bar(cx: bar::Context, payload: i32) {
         // ..
     }
-};
+}
 ```

book/en/src/by-example/tips.md

@@ -143,7 +143,7 @@ $ tail target/rtic-expansion.rs
 
 ``` rust
 #[doc = r" Implementation details"]
-const APP: () = {
+mod app {
     #[doc = r" Always include the device crate which contains the vector table"]
     use lm3s6965 as _;
     #[no_mangle]
@@ -156,7 +156,7 @@ const APP: () = {
             rtic::export::wfi()
         }
     }
-};
+}
 ```
 
 Or, you can use the [`cargo-expand`] sub-command. This sub-command will expand

book/en/src/by-example/types-send-sync.md

@@ -1,6 +1,6 @@
 # Types, Send and Sync
 
-Every function within the `APP` pseudo-module has a `Context` structure as its
+Every function within the `app` module has a `Context` structure as its
 first parameter. All the fields of these structures have predictable,
 non-anonymous types so you can write plain functions that take them as arguments.