Move entry-point main into a separate module

Prevents conflict with user provided tasks named main

examples/task_named_main.rs

@@ -0,0 +1,26 @@
+//! examples/task_named_main.rs
+
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+use panic_semihosting as _;
+
+#[rtic::app(device = lm3s6965, dispatchers = [SSI0])]
+mod app {
+    use cortex_m_semihosting::{debug, hprintln};
+
+    #[init]
+    fn init(_: init::Context) -> init::LateResources {
+        main::spawn().unwrap();
+
+        init::LateResources {}
+    }
+
+    #[task]
+    fn main(_: main::Context) {
+        hprintln!("This task is named main, useful for rust-analyzer").unwrap();
+        debug::exit(debug::EXIT_SUCCESS);
+    }
+}

macros/src/codegen.rs

@@ -57,19 +57,22 @@ pub fn app(app: &App, analysis: &Analysis, extra: &Extra) -> TokenStream2 {
 
     let main = util::suffixed("main");
     mains.push(quote!(
-        #[no_mangle]
-        unsafe extern "C" fn #main() -> ! {
-            let _TODO: () = ();
+        pub mod rtic_ext {
+            use super::*;
+            #[no_mangle]
+            unsafe extern "C" fn #main() -> ! {
+                let _TODO: () = ();
 
-            #(#assertion_stmts)*
+                #(#assertion_stmts)*
 
-            #(#pre_init_stmts)*
+                #(#pre_init_stmts)*
 
-            #call_init
+                #call_init
 
-            #(#post_init_stmts)*
+                #(#post_init_stmts)*
 
-            #call_idle
+                #call_idle
+            }
         }
     ));