diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/lib.rs | 2 | ||||
| -rw-r--r-- | src/macros.rs | 52 |
2 files changed, 49 insertions, 5 deletions
@@ -15,6 +15,7 @@ extern crate aligned; extern crate bare_metal; +extern crate untagged_option; extern crate volatile_register; #[macro_use] @@ -31,3 +32,4 @@ pub mod peripheral; pub mod register; pub use peripheral::Peripherals; +pub use untagged_option::UntaggedOption; diff --git a/src/macros.rs b/src/macros.rs index c9a32c2..7d2cf6a 100644 --- a/src/macros.rs +++ b/src/macros.rs @@ -52,17 +52,59 @@ macro_rules! iprintln { #[macro_export] macro_rules! singleton { (: $ty:ty = $expr:expr) => { - $crate::interrupt::free(|_| unsafe { + $crate::interrupt::free(|_| { static mut USED: bool = false; - static mut VAR: $ty = $expr; + static mut VAR: $crate::UntaggedOption<$ty> = $crate::UntaggedOption { none: () }; - if USED { + + #[allow(unsafe_code)] + let used = unsafe { USED }; + if used { None } else { - USED = true; - let var: &'static mut _ = &mut VAR; + #[allow(unsafe_code)] + unsafe { USED = true } + + let expr = $expr; + + #[allow(unsafe_code)] + unsafe { VAR.some = expr } + + #[allow(unsafe_code)] + let var: &'static mut _ = unsafe { &mut VAR.some }; + Some(var) } }) } } + + +/// ``` compile_fail +/// #[macro_use(singleton)] +/// extern crate cortex_m; +/// +/// fn main() {} +/// +/// fn foo() { +/// // check that the call to `uninitialized` requires unsafe +/// singleton!(: u8 = std::mem::uninitialized()); +/// } +/// ``` +#[allow(dead_code)] +const CFAIL: () = (); + +/// ``` +/// #![deny(unsafe_code)] +/// #[macro_use(singleton)] +/// extern crate cortex_m; +/// +/// fn main() {} +/// +/// fn foo() { +/// // check that calls to `singleton!` don't trip the `unsafe_code` lint +/// singleton!(: u8 = 0); +/// } +/// ``` +#[allow(dead_code)] +const CPASS: () = (); |