src/vendor/mac/src/syntax_ext.rs

   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 }