Move rtic macros to repo root, tune xtask

rtic-macros/src/syntax/optimize.rs

@@ -0,0 +1,36 @@
+use std::collections::{BTreeSet, HashMap};
+
+use crate::syntax::ast::App;
+
+pub fn app(app: &mut App, settings: &Settings) {
+    // "compress" priorities
+    // If the user specified, for example, task priorities of "1, 3, 6",
+    // compress them into "1, 2, 3" as to leave no gaps
+    if settings.optimize_priorities {
+        // all task priorities ordered in ascending order
+        let priorities = app
+            .hardware_tasks
+            .values()
+            .map(|task| Some(task.args.priority))
+            .chain(
+                app.software_tasks
+                    .values()
+                    .map(|task| Some(task.args.priority)),
+            )
+            .collect::<BTreeSet<_>>();
+
+        let map = priorities
+            .iter()
+            .cloned()
+            .zip(1..)
+            .collect::<HashMap<_, _>>();
+
+        for task in app.hardware_tasks.values_mut() {
+            task.args.priority = map[&Some(task.args.priority)];
+        }
+
+        for task in app.software_tasks.values_mut() {
+            task.args.priority = map[&Some(task.args.priority)];
+        }
+    }
+}