Merge #122

122: [RFC] `#[interrupt]` r=therealprof a=japaric

this PR adds an `interrupt` attribute that's similar to the existing `exception`
except that it's used to override device-specific interrupt handlers.

The other big difference is that `cortex_m_rt::interrupt` can't be directly
used; it must first be imported from a device crate, which re-exports
`cortex_m_rt::interrupt`. This is required to check at compile time that the
interrupt is valid for the target device.

Safe `static mut` variables can be used with `#[interrupt]` handlers. The syntax
is the same as `#[exception]`s.

More background information can be found in #109.

The companion svd2rust PR is rust-embedded/svd2rust#235

r? @rust-embedded/cortex-m

Co-authored-by: Jorge Aparicio <jorge@japaric.io>
Co-authored-by: Adam Greig <adam@adamgreig.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/cortex-m-rt/tests/compile-fail/interrupt-invalid.rs b/cortex-m-rt/tests/compile-fail/interrupt-invalid.rs
new file mode 100644
index 0000000..4e79e7d
--- /dev/null
+++ b/cortex-m-rt/tests/compile-fail/interrupt-invalid.rs
@@ -0,0 +1,21 @@
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt;
+extern crate panic_halt;
+
+use cortex_m_rt::{entry, interrupt};
+
+#[entry]
+fn foo() -> ! {
+    loop {}
+}
+
+enum interrupt {
+    USART1,
+}
+
+// NOTE this looks a bit better when using a device crate:
+// "no variant named `foo` found for type `stm32f30x::Interrupt` in the current scope"
+#[interrupt] //~ ERROR no variant named `foo` found for type `interrupt` in the current scope
+fn foo() {}