| 1 | //! Macros useful when writing procedural syntax extensions. |
|---|---|
| 2 | //! |
| 3 | //! The macros themselves are ordinary `macro_rules!` macros. |
| 4 | |
| 5 | /// Call `span_err` on an `ExtCtxt` and return `DummyResult::any`. |
| 6 | #[macro_export] |
| 7 | macro_rules! ext_bail { |
| 8 | ($cx:expr, $sp:expr, $msg:expr) => {{ |
| 9 | $cx.span_err($sp, $msg); |
| 10 | return ::syntax::ext::base::DummyResult::any($sp); |
| 11 | }} |
| 12 | } |
| 13 | |
| 14 | /// `ext_bail!` if the condition `$e` is true. |
| 15 | #[macro_export] |
| 16 | macro_rules! ext_bail_if { |
| 17 | ($e:expr, $cx:expr, $sp:expr, $msg:expr) => {{ |
| 18 | if $e { ext_bail!($cx, $sp, $msg) } |
| 19 | }} |
| 20 | } |
| 21 | |
| 22 | /// Unwrap the `Option` `$e`, or `ext_bail!`. |
| 23 | #[macro_export] |
| 24 | macro_rules! ext_expect { |
| 25 | ($cx:expr, $sp:expr, $e:expr, $msg:expr) => {{ |
| 26 | match $e { |
| 27 | Some(x) => x, |
| 28 | None => ext_bail!($cx, $sp, $msg), |
| 29 | } |
| 30 | }} |
| 31 | } |
| 32 |