From df4a7fd3e5df370a83fcdc24aa628bed3fa9f543 Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Mon, 24 Jun 2019 14:15:00 +0200
Subject: [PATCH] check that the app is not compiled for more cores than were
 specified

---
 macros/src/codegen.rs | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/macros/src/codegen.rs b/macros/src/codegen.rs
index a3515994bf..8a5483237b 100644
--- a/macros/src/codegen.rs
+++ b/macros/src/codegen.rs
@@ -101,6 +101,18 @@ pub fn app(app: &App, analysis: &Analysis, extra: &Extra) -> TokenStream2 {
 
     let const_app_schedule = schedule::codegen(app, extra);
 
+    let cores = app.args.cores.to_string();
+    let cfg_core = quote!(#[cfg(core = #cores)]);
+    let msg = format!(
+        "specified {} core{} but tried to compile for more than {0} core{1}",
+        app.args.cores,
+        if app.args.cores > 1 { "s" } else { "" }
+    );
+    let check_excess_cores = quote!(
+        #cfg_core
+        compile_error!(#msg);
+    );
+
     let name = &app.name;
     let device = extra.device;
     quote!(
@@ -124,6 +136,8 @@ pub fn app(app: &App, analysis: &Analysis, extra: &Extra) -> TokenStream2 {
             /// Always include the device crate which contains the vector table
             use #device as _;
 
+            #check_excess_cores
+
             #(#const_app)*
 
             #(#const_app_resources)*