librustc: Always parse `macro!()`/`macro![]` as expressions if not

followed by a semicolon.

This allows code like `vec![1i, 2, 3].len();` to work.

This breaks code that uses macros as statements without putting
semicolons after them, such as:

    fn main() {
        ...
        assert!(a == b)
        assert!(c == d)
        println(...);
    }

It also breaks code that uses macros as items without semicolons:

    local_data_key!(foo)

    fn main() {
        println("hello world")
    }

Add semicolons to fix this code. Those two examples can be fixed as
follows:

    fn main() {
        ...
        assert!(a == b);
        assert!(c == d);
        println(...);
    }

    local_data_key!(foo);

    fn main() {
        println("hello world")
    }

RFC #378.

Closes #18635.

[breaking-change]

1 files changed, 2 insertions, 2 deletions

diff --git a/src/libstd/sys/windows/mod.rs b/src/libstd/sys/windows/mod.rs
index 41361a0cde6..d22d4e0f534 100644
--- a/src/libstd/sys/windows/mod.rs
+++ b/src/libstd/sys/windows/mod.rs
@@ -24,7 +24,7 @@ use prelude::*;
 use io::{mod, IoResult, IoError};
 use sync::{Once, ONCE_INIT};
 
-macro_rules! helper_init( (static $name:ident: Helper<$m:ty>) => (
+macro_rules! helper_init { (static $name:ident: Helper<$m:ty>) => (
     static $name: Helper<$m> = Helper {
         lock: ::sync::MUTEX_INIT,
         cond: ::sync::CONDVAR_INIT,
@@ -33,7 +33,7 @@ macro_rules! helper_init( (static $name:ident: Helper<$m:ty>) => (
         initialized: ::cell::UnsafeCell { value: false },
         shutdown: ::cell::UnsafeCell { value: false },
     };
-) )
+) }
 
 pub mod c;
 pub mod ext;