Merge #306

306: Retain cfg-attributes on resources r=korken89 a=AfoHT

When rust 1.43 lands as stable this will resolve #301 and allow for the kind of conditional compilation exemplified in the issue.

Tested on beta and nightly.

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

1 files changed, 40 insertions, 0 deletions

diff --git a/examples/t-cfg-resources.rs b/examples/t-cfg-resources.rs
new file mode 100644
index 00000000..86b5ea20
--- /dev/null
+++ b/examples/t-cfg-resources.rs
@@ -0,0 +1,40 @@
+//! [compile-pass] check that `#[cfg]` attributes applied on resources work
+//!
+#![no_main]
+#![no_std]
+
+use panic_halt as _;
+
+#[cfg(rustc_is_nightly)]
+mod example {
+
+    #[rtfm::app(device = lm3s6965)]
+    const APP: () = {
+        struct Resources {
+            // A resource
+            #[init(0)]
+            shared: u32,
+
+            // A conditionally compiled resource behind feature_x
+            #[cfg(feature = "feature_x")]
+            x: u32,
+
+            dummy: (),
+        }
+
+        #[init]
+        fn init(_: init::Context) -> init::LateResources {
+            init::LateResources {
+                // The feature needs to be applied everywhere x is defined or used
+                #[cfg(feature = "feature_x")]
+                x: 0,
+                dummy: () // dummy such that we have at least one late resource
+            }
+        }
+
+        #[idle]
+        fn idle(_cx: idle::Context) -> ! {
+            loop {}
+        }
+    };
+}