auto merge of #19984 : japaric/rust/macro-expressions, r=alexcrichton

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]

---

Rebased version of #18958
r? @alexcrichton 
cc @pcwalton

Author: bors

src/doc/guide-macros.md

@@ -58,7 +58,7 @@ macro_rules! early_return(
             _ => {}
         }
     );
-)
+);
 // ...
 early_return!(input_1 T::SpecialA);
 // ...
@@ -179,8 +179,8 @@ macro_rules! early_return(
             )+
             _ => {}
         }
-    );
-)
+    )
+);
 // ...
 early_return!(input_1, [T::SpecialA|T::SpecialC|T::SpecialD]);
 // ...
@@ -275,17 +275,17 @@ macro_rules! biased_match (
             _ => { $err }
         };
     )
-)
+);
 
 # enum T1 { Good1(T2, uint), Bad1}
 # struct T2 { body: T3 }
 # enum T3 { Good2(uint), Bad2}
 # fn f(x: T1) -> uint {
 biased_match!((x)       ~ (T1::Good1(g1, val)) else { return 0 };
-              binds g1, val )
+              binds g1, val );
 biased_match!((g1.body) ~ (T3::Good2(result) )
                   else { panic!("Didn't get good_2") };
-              binds result )
+              binds result );
 // complicated stuff goes here
 return result + val;
 # }
@@ -303,7 +303,7 @@ pattern we want is clear:
     ( $( ($e:expr) ~ ($p:pat) else $err:stmt ; )*
       binds $( $bind_res:ident ),*
     )
-# => (0))
+# => (0));
 ~~~~
 
 However, it's not possible to directly expand to nested match statements. But
@@ -323,7 +323,7 @@ input patterns:
 # #![feature(macro_rules)]
 # macro_rules! b(
     ( binds $( $bind_res:ident ),* )
-# => (0))
+# => (0));
 # fn main() {}
 ~~~~
 
@@ -337,7 +337,7 @@ input patterns:
       $( ($e_rest:expr) ~ ($p_rest:pat) else $err_rest:stmt ; )*
       binds  $( $bind_res:ident ),*
     )
-# => (0))
+# => (0));
 ~~~~
 
 The resulting macro looks like this. Note that the separation into
@@ -366,7 +366,7 @@ macro_rules! biased_match_rec (
     );
     // Produce the requested values
     ( binds $( $bind_res:ident ),* ) => ( ($( $bind_res ),*) )
-)
+);
 
 // Wrap the whole thing in a `let`.
 macro_rules! biased_match (
@@ -388,7 +388,7 @@ macro_rules! biased_match (
             binds $( $bind_res ),*
         );
     )
-)
+);
 
 
 # enum T1 { Good1(T2, uint), Bad1}
@@ -398,7 +398,7 @@ macro_rules! biased_match (
 biased_match!(
     (x)       ~ (T1::Good1(g1, val)) else { return 0 };
     (g1.body) ~ (T3::Good2(result) ) else { panic!("Didn't get Good2") };
-    binds val, result )
+    binds val, result );
 // complicated stuff goes here
 return result + val;
 # }
@@ -444,7 +444,7 @@ macro_rules! loop_x (
             $e
         }
     );
-)
+);
 
 fn main() {
     'x: loop {
@@ -482,30 +482,30 @@ An example:
 
 ```rust
 # #![feature(macro_rules)]
-macro_rules! m1 (() => (()))
+macro_rules! m1 (() => (()));
 
 // visible here: m1
 
 mod foo {
     // visible here: m1
 
     #[macro_export]
-    macro_rules! m2 (() => (()))
+    macro_rules! m2 (() => (()));
 
     // visible here: m1, m2
 }
 
 // visible here: m1
 
-macro_rules! m3 (() => (()))
+macro_rules! m3 (() => (()));
 
 // visible here: m1, m3
 
 #[macro_escape]
 mod bar {
     // visible here: m1, m3
 
-    macro_rules! m4 (() => (()))
+    macro_rules! m4 (() => (()));
 
     // visible here: m1, m3, m4
 }

src/etc/regex-match-tests.py

@@ -63,7 +63,7 @@ def read_tests(f):
 def test_tostr(t):
     lineno, pat, text, groups = t
     options = map(group_tostr, groups)
-    return 'mat!(match_%s, r"%s", r"%s", %s)' \
+    return 'mat!{match_%s, r"%s", r"%s", %s}' \
            % (lineno, pat, '' if text == "NULL" else text, ', '.join(options))
 
 

src/libcollections/bit.rs

@@ -2083,7 +2083,7 @@ mod tests {
         let bools = vec![true, false, true, true];
         let bitv: Bitv = bools.iter().map(|n| *n).collect();
 
-        assert_eq!(bitv.iter().collect::<Vec<bool>>(), bools)
+        assert_eq!(bitv.iter().collect::<Vec<bool>>(), bools);
 
         let long = Vec::from_fn(10000, |i| i % 2 == 0);
         let bitv: Bitv = long.iter().map(|n| *n).collect();
@@ -2112,8 +2112,8 @@ mod tests {
         for &b in bools.iter() {
             for &l in lengths.iter() {
                 let bitset = BitvSet::from_bitv(Bitv::with_capacity(l, b));
-                assert_eq!(bitset.contains(&1u), b)
-                assert_eq!(bitset.contains(&(l-1u)), b)
+                assert_eq!(bitset.contains(&1u), b);
+                assert_eq!(bitset.contains(&(l-1u)), b);
                 assert!(!bitset.contains(&l))
             }
         }
@@ -2321,12 +2321,12 @@ mod tests {
         assert!(!a.is_disjoint(&d));
         assert!(!d.is_disjoint(&a));
 
-        assert!(a.is_disjoint(&b))
-        assert!(a.is_disjoint(&c))
-        assert!(b.is_disjoint(&a))
-        assert!(b.is_disjoint(&c))
-        assert!(c.is_disjoint(&a))
-        assert!(c.is_disjoint(&b))
+        assert!(a.is_disjoint(&b));
+        assert!(a.is_disjoint(&c));
+        assert!(b.is_disjoint(&a));
+        assert!(b.is_disjoint(&c));
+        assert!(c.is_disjoint(&a));
+        assert!(c.is_disjoint(&b));
     }
 
     #[test]

src/libcollections/enum_set.rs

@@ -411,7 +411,7 @@ mod test {
 
         assert!(e1.is_subset(&e2));
         assert!(e2.is_superset(&e1));
-        assert!(!e3.is_superset(&e2))
+        assert!(!e3.is_superset(&e2));
         assert!(!e2.is_superset(&e3))
     }
 
@@ -438,23 +438,23 @@ mod test {
         let mut e1: EnumSet<Foo> = EnumSet::new();
 
         let elems: ::vec::Vec<Foo> = e1.iter().collect();
-        assert!(elems.is_empty())
+        assert!(elems.is_empty());
 
         e1.insert(A);
         let elems: ::vec::Vec<_> = e1.iter().collect();
-        assert_eq!(vec![A], elems)
+        assert_eq!(vec![A], elems);
 
         e1.insert(C);
         let elems: ::vec::Vec<_> = e1.iter().collect();
-        assert_eq!(vec![A,C], elems)
+        assert_eq!(vec![A,C], elems);
 
         e1.insert(C);
         let elems: ::vec::Vec<_> = e1.iter().collect();
-        assert_eq!(vec![A,C], elems)
+        assert_eq!(vec![A,C], elems);
 
         e1.insert(B);
         let elems: ::vec::Vec<_> = e1.iter().collect();
-        assert_eq!(vec![A,B,C], elems)
+        assert_eq!(vec![A,B,C], elems);
     }
 
     ///////////////////////////////////////////////////////////////////////////
@@ -472,35 +472,35 @@ mod test {
 
         let e_union = e1 | e2;
         let elems: ::vec::Vec<_> = e_union.iter().collect();
-        assert_eq!(vec![A,B,C], elems)
+        assert_eq!(vec![A,B,C], elems);
 
         let e_intersection = e1 & e2;
         let elems: ::vec::Vec<_> = e_intersection.iter().collect();
-        assert_eq!(vec![C], elems)
+        assert_eq!(vec![C], elems);
 
         // Another way to express intersection
         let e_intersection = e1 - (e1 - e2);
         let elems: ::vec::Vec<_> = e_intersection.iter().collect();
-        assert_eq!(vec![C], elems)
+        assert_eq!(vec![C], elems);
 
         let e_subtract = e1 - e2;
         let elems: ::vec::Vec<_> = e_subtract.iter().collect();
-        assert_eq!(vec![A], elems)
+        assert_eq!(vec![A], elems);
 
         // Bitwise XOR of two sets, aka symmetric difference
         let e_symmetric_diff = e1 ^ e2;
         let elems: ::vec::Vec<_> = e_symmetric_diff.iter().collect();
-        assert_eq!(vec![A,B], elems)
+        assert_eq!(vec![A,B], elems);
 
         // Another way to express symmetric difference
         let e_symmetric_diff = (e1 - e2) | (e2 - e1);
         let elems: ::vec::Vec<_> = e_symmetric_diff.iter().collect();
-        assert_eq!(vec![A,B], elems)
+        assert_eq!(vec![A,B], elems);
 
         // Yet another way to express symmetric difference
         let e_symmetric_diff = (e1 | e2) - (e1 & e2);
         let elems: ::vec::Vec<_> = e_symmetric_diff.iter().collect();
-        assert_eq!(vec![A,B], elems)
+        assert_eq!(vec![A,B], elems);
     }
 
     #[test]

src/libcollections/macros.rs

@@ -11,12 +11,13 @@
 #![macro_escape]
 
 /// Creates a `std::vec::Vec` containing the arguments.
-macro_rules! vec(
+macro_rules! vec {
     ($($e:expr),*) => ({
         // leading _ to allow empty construction without a warning.
         let mut _temp = ::vec::Vec::new();
         $(_temp.push($e);)*
         _temp
     });
     ($($e:expr),+,) => (vec!($($e),+))
-)
+}
+

src/libcollections/slice.rs

@@ -2515,7 +2515,7 @@ mod tests {
                 assert_eq!(format!("{}", x), x_str);
                 assert_eq!(format!("{}", x.as_slice()), x_str);
             })
-        )
+        );
         let empty: Vec<int> = vec![];
         test_show_vec!(empty, "[]");
         test_show_vec!(vec![1i], "[1]");

src/libcollections/str.rs

@@ -415,14 +415,14 @@ Section: Misc
 // Return the initial codepoint accumulator for the first byte.
 // The first byte is special, only want bottom 5 bits for width 2, 4 bits
 // for width 3, and 3 bits for width 4
-macro_rules! utf8_first_byte(
+macro_rules! utf8_first_byte {
     ($byte:expr, $width:expr) => (($byte & (0x7F >> $width)) as u32)
-)
+}
 
 // return the value of $ch updated with continuation byte $byte
-macro_rules! utf8_acc_cont_byte(
+macro_rules! utf8_acc_cont_byte {
     ($ch:expr, $byte:expr) => (($ch << 6) | ($byte & 63u8) as u32)
-)
+}
 
 /*
 Section: MaybeOwned

src/libcollections/string.rs

@@ -167,7 +167,7 @@ impl String {
                     subseqidx = i;
                     res.as_mut_vec().push_all(REPLACEMENT);
                 }
-            }))
+            }));
 
             if byte < 128u8 {
                 // subseqidx handles this
@@ -788,8 +788,8 @@ macro_rules! impl_eq {
     }
 }
 
-impl_eq!(String, &'a str)
-impl_eq!(CowString<'a>, String)
+impl_eq! { String, &'a str }
+impl_eq! { CowString<'a>, String }
 
 impl<'a, 'b> PartialEq<&'b str> for CowString<'a> {
     #[inline]

src/libcollections/tree/map.rs

@@ -900,7 +900,7 @@ macro_rules! define_iterator {
      ) => {
         // private methods on the forward iterator (item!() for the
         // addr_mut in the next_ return value)
-        item!(impl<'a, K, V> $name<'a, K, V> {
+        item! { impl<'a, K, V> $name<'a, K, V> {
             #[inline(always)]
             fn next_(&mut self, forward: bool) -> Option<(&'a K, &'a $($addr_mut)* V)> {
                 while !self.stack.is_empty() || !self.node.is_null() {
@@ -968,10 +968,10 @@ macro_rules! define_iterator {
                     self.node = ptr::RawPtr::null();
                 }
             }
-        })
+        } }
 
         // the forward Iterator impl.
-        item!(impl<'a, K, V> Iterator<(&'a K, &'a $($addr_mut)* V)> for $name<'a, K, V> {
+        item! { impl<'a, K, V> Iterator<(&'a K, &'a $($addr_mut)* V)> for $name<'a, K, V> {
             /// Advances the iterator to the next node (in order) and return a
             /// tuple with a reference to the key and value. If there are no
             /// more nodes, return `None`.
@@ -983,10 +983,10 @@ macro_rules! define_iterator {
             fn size_hint(&self) -> (uint, Option<uint>) {
                 (self.remaining_min, Some(self.remaining_max))
             }
-        })
+        } }
 
         // the reverse Iterator impl.
-        item!(impl<'a, K, V> Iterator<(&'a K, &'a $($addr_mut)* V)> for $rev_name<'a, K, V> {
+        item! { impl<'a, K, V> Iterator<(&'a K, &'a $($addr_mut)* V)> for $rev_name<'a, K, V> {
             fn next(&mut self) -> Option<(&'a K, &'a $($addr_mut)* V)> {
                 self.iter.next_(false)
             }
@@ -995,7 +995,7 @@ macro_rules! define_iterator {
             fn size_hint(&self) -> (uint, Option<uint>) {
                 self.iter.size_hint()
             }
-        })
+        } }
     }
 } // end of define_iterator
 

src/libcollections/trie/map.rs

@@ -1141,7 +1141,7 @@ macro_rules! iterator_impl {
             }
         }
 
-        item!(impl<'a, T> Iterator<(uint, &'a $($mut_)* T)> for $name<'a, T> {
+        item! { impl<'a, T> Iterator<(uint, &'a $($mut_)* T)> for $name<'a, T> {
                 // you might wonder why we're not even trying to act within the
                 // rules, and are just manipulating raw pointers like there's no
                 // such thing as invalid pointers and memory unsafety. The
@@ -1213,7 +1213,7 @@ macro_rules! iterator_impl {
                 fn size_hint(&self) -> (uint, Option<uint>) {
                     (self.remaining_min, Some(self.remaining_max))
                 }
-            })
+            } }
     }
 }