Merge #90

90: turn macros into attributes r=adamgreig a=japaric

This is a PoC implementation of RFC #82. Assuming that we are OK with this implementation we should
add some compile fail tests (e.g. using a function with the wrong signature as the entry point)
before landing this.

Look at the diff of the examples to get an overview of the changes.

cc @rust-embedded/cortex-m

Co-authored-by: Jorge Aparicio <jorge@japaric.io>

1 files changed, 16 insertions, 0 deletions

diff --git a/cortex-m-rt/tests/compile-fail/exception-bad-signature-1.rs b/cortex-m-rt/tests/compile-fail/exception-bad-signature-1.rs
new file mode 100644
index 0000000..966493e
--- /dev/null
+++ b/cortex-m-rt/tests/compile-fail/exception-bad-signature-1.rs
@@ -0,0 +1,16 @@
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt;
+extern crate panic_semihosting;
+
+use cortex_m_rt::{entry, exception};
+
+#[entry]
+fn foo() -> ! {
+    loop {}
+}
+
+#[exception] //~ ERROR custom attribute panicked
+//~^ HELP `#[exception]` functions other than `DefaultHandler` and `HardFault` must have signature `[unsafe] fn() [-> !]`
+fn SysTick(undef: u32) {}