Merge #338

338: Fixes an issue where one could double take the cortex_m Peripheral r=japaric a=korken89

Closes #321 

Co-authored-by: Emil Fresk <emil.fresk@gmail.com>

.github/workflows/build.yml

@@ -174,6 +174,8 @@ jobs:
               cfg
               pool
               ramfunc
+
+              peripherals-taken
           )
 
           for ex in ${exs[@]}; do

examples/peripherals-taken.rs

@@ -0,0 +1,16 @@
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+use cortex_m_semihosting::debug;
+use panic_semihosting as _;
+
+#[rtic::app(device = lm3s6965)]
+const APP: () = {
+    #[init]
+    fn main(_: main::Context) {
+        assert!(cortex_m::Peripherals::take().is_none());
+        debug::exit(debug::EXIT_SUCCESS);
+    }
+};

macros/src/codegen/pre_init.rs

@@ -43,6 +43,13 @@ pub fn codegen(
         let mut core: rtic::export::Peripherals = core::mem::transmute(());
     ));
 
+    if app.args.cores == 1 {
+        stmts.push(quote!(
+            // To set the variable in cortex_m so the peripherals cannot be taken multiple times
+            let _ = cortex_m::Peripherals::steal();
+        ));
+    }
+
     let device = extra.device;
     let nvic_prio_bits = quote!(#device::NVIC_PRIO_BITS);