---

yaml
---
r: 218855
b: refs/heads/snap-stage3
c: baf508b
h: refs/heads/master
i:
  218853: 5e6fed9
  218851: be9d551
  218847: e2cc3d6
v: v3

Author: bors

[refs]

@@ -1,6 +1,6 @@
 ---
 refs/heads/master: c044791d80ea0dc5c4b57b6030a67b69f8510239
-refs/heads/snap-stage3: bdef7faaba1f0e253115b222827b02e8b2ef97c7
+refs/heads/snap-stage3: baf508ba20d483513b4b5633ff1861d9fc0c92da
 refs/heads/try: b53c0f93eedcdedd4fd89bccc5a3a09d1c5cd23e
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596

branches/snap-stage3/src/doc/trpl/iterators.md

@@ -213,7 +213,7 @@ As we've said before, an iterator is something that we can call the
 `.next()` method on repeatedly, and it gives us a sequence of things.
 Because you need to call the method, this means that iterators
 can be *lazy* and not generate all of the values upfront. This code,
-for example, does not actually generate the numbers `1-100`, instead
+for example, does not actually generate the numbers `1-99`, instead
 creating a value that merely represents the sequence:
 
 ```rust

branches/snap-stage3/src/doc/trpl/mutability.md

@@ -89,7 +89,7 @@ philosophy, memory safety, and the mechanism by which Rust guarantees it, the
 > * exactly one mutable reference (`&mut T`)
 
 [ownership]: ownership.html
-[borrowing]: borrowing.html#The-Rules
+[borrowing]: references-and-borrowing.html#borrowing
 
 So, that’s the real definition of ‘immutability’: is this safe to have two
 pointers to? In `Arc<T>`’s case, yes: the mutation is entirely contained inside

branches/snap-stage3/src/liballoc/arc.rs

@@ -250,6 +250,9 @@ pub fn strong_count<T: ?Sized>(this: &Arc<T>) -> usize { this.inner().strong.loa
 ///
 /// Returns `None` if the `Arc<T>` is not unique.
 ///
+/// This function is marked **unsafe** because it is racy if weak pointers
+/// are active.
+///
 /// # Examples
 ///
 /// ```
@@ -258,24 +261,27 @@ pub fn strong_count<T: ?Sized>(this: &Arc<T>) -> usize { this.inner().strong.loa
 /// # fn main() {
 /// use alloc::arc::{Arc, get_mut};
 ///
+/// # unsafe {
 /// let mut x = Arc::new(3);
 /// *get_mut(&mut x).unwrap() = 4;
 /// assert_eq!(*x, 4);
 ///
 /// let _y = x.clone();
 /// assert!(get_mut(&mut x).is_none());
 /// # }
+/// # }
 /// ```
 #[inline]
 #[unstable(feature = "alloc")]
-pub fn get_mut<T: ?Sized>(this: &mut Arc<T>) -> Option<&mut T> {
+pub unsafe fn get_mut<T: ?Sized>(this: &mut Arc<T>) -> Option<&mut T> {
+    // FIXME(#24880) potential race with upgraded weak pointers here
     if strong_count(this) == 1 && weak_count(this) == 0 {
         // This unsafety is ok because we're guaranteed that the pointer
         // returned is the *only* pointer that will ever be returned to T. Our
         // reference count is guaranteed to be 1 at this point, and we required
         // the Arc itself to be `mut`, so we're returning the only possible
         // reference to the inner data.
-        let inner = unsafe { &mut **this._ptr };
+        let inner = &mut **this._ptr;
         Some(&mut inner.data)
     } else {
         None
@@ -332,19 +338,26 @@ impl<T: Clone> Arc<T> {
     /// This is also referred to as a copy-on-write operation because the inner
     /// data is cloned if the reference count is greater than one.
     ///
+    /// This method is marked **unsafe** because it is racy if weak pointers
+    /// are active.
+    ///
     /// # Examples
     ///
     /// ```
     /// # #![feature(alloc)]
     /// use std::sync::Arc;
     ///
+    /// # unsafe {
     /// let mut five = Arc::new(5);
     ///
     /// let mut_five = five.make_unique();
+    /// # }
     /// ```
     #[inline]
     #[unstable(feature = "alloc")]
-    pub fn make_unique(&mut self) -> &mut T {
+    pub unsafe fn make_unique(&mut self) -> &mut T {
+        // FIXME(#24880) potential race with upgraded weak pointers here
+        //
         // Note that we hold a strong reference, which also counts as a weak
         // reference, so we only clone if there is an additional reference of
         // either kind.
@@ -354,7 +367,7 @@ impl<T: Clone> Arc<T> {
         }
         // As with `get_mut()`, the unsafety is ok because our reference was
         // either unique to begin with, or became one upon cloning the contents.
-        let inner = unsafe { &mut **self._ptr };
+        let inner = &mut **self._ptr;
         &mut inner.data
     }
 }
@@ -744,39 +757,43 @@ mod tests {
 
     #[test]
     fn test_arc_get_mut() {
-        let mut x = Arc::new(3);
-        *get_mut(&mut x).unwrap() = 4;
-        assert_eq!(*x, 4);
-        let y = x.clone();
-        assert!(get_mut(&mut x).is_none());
-        drop(y);
-        assert!(get_mut(&mut x).is_some());
-        let _w = x.downgrade();
-        assert!(get_mut(&mut x).is_none());
+        unsafe {
+            let mut x = Arc::new(3);
+            *get_mut(&mut x).unwrap() = 4;
+            assert_eq!(*x, 4);
+            let y = x.clone();
+            assert!(get_mut(&mut x).is_none());
+            drop(y);
+            assert!(get_mut(&mut x).is_some());
+            let _w = x.downgrade();
+            assert!(get_mut(&mut x).is_none());
+        }
     }
 
     #[test]
     fn test_cowarc_clone_make_unique() {
-        let mut cow0 = Arc::new(75);
-        let mut cow1 = cow0.clone();
-        let mut cow2 = cow1.clone();
-
-        assert!(75 == *cow0.make_unique());
-        assert!(75 == *cow1.make_unique());
-        assert!(75 == *cow2.make_unique());
-
-        *cow0.make_unique() += 1;
-        *cow1.make_unique() += 2;
-        *cow2.make_unique() += 3;
-
-        assert!(76 == *cow0);
-        assert!(77 == *cow1);
-        assert!(78 == *cow2);
-
-        // none should point to the same backing memory
-        assert!(*cow0 != *cow1);
-        assert!(*cow0 != *cow2);
-        assert!(*cow1 != *cow2);
+        unsafe {
+            let mut cow0 = Arc::new(75);
+            let mut cow1 = cow0.clone();
+            let mut cow2 = cow1.clone();
+
+            assert!(75 == *cow0.make_unique());
+            assert!(75 == *cow1.make_unique());
+            assert!(75 == *cow2.make_unique());
+
+            *cow0.make_unique() += 1;
+            *cow1.make_unique() += 2;
+            *cow2.make_unique() += 3;
+
+            assert!(76 == *cow0);
+            assert!(77 == *cow1);
+            assert!(78 == *cow2);
+
+            // none should point to the same backing memory
+            assert!(*cow0 != *cow1);
+            assert!(*cow0 != *cow2);
+            assert!(*cow1 != *cow2);
+        }
     }
 
     #[test]
@@ -789,7 +806,9 @@ mod tests {
         assert!(75 == *cow1);
         assert!(75 == *cow2);
 
-        *cow0.make_unique() += 1;
+        unsafe {
+            *cow0.make_unique() += 1;
+        }
 
         assert!(76 == *cow0);
         assert!(75 == *cow1);
@@ -810,7 +829,9 @@ mod tests {
         assert!(75 == *cow0);
         assert!(75 == *cow1_weak.upgrade().unwrap());
 
-        *cow0.make_unique() += 1;
+        unsafe {
+            *cow0.make_unique() += 1;
+        }
 
         assert!(76 == *cow0);
         assert!(cow1_weak.upgrade().is_none());

branches/snap-stage3/src/libcollections/str.rs

@@ -30,7 +30,7 @@
 //! You can get a non-`'static` `&str` by taking a slice of a `String`:
 //!
 //! ```
-//! # let some_string = "Hello, world.".to_string();
+//! let some_string = "Hello, world.".to_string();
 //! let s = &some_string;
 //! ```
 //!

branches/snap-stage3/src/libcore/option.rs

@@ -320,7 +320,7 @@ impl<T> Option<T> {
     ///
     /// ```{.should_panic}
     /// let x: Option<&str> = None;
-    /// x.expect("the world is ending"); // panics with `world is ending`
+    /// x.expect("the world is ending"); // panics with `the world is ending`
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -422,7 +422,8 @@ impl<T> Option<T> {
         }
     }
 
-    /// Applies a function to the contained value or returns a default.
+    /// Applies a function to the contained value (if any),
+    /// or returns a `default` (if not).
     ///
     /// # Examples
     ///
@@ -435,14 +436,15 @@ impl<T> Option<T> {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn map_or<U, F: FnOnce(T) -> U>(self, def: U, f: F) -> U {
+    pub fn map_or<U, F: FnOnce(T) -> U>(self, default: U, f: F) -> U {
         match self {
             Some(t) => f(t),
-            None => def
+            None => default,
         }
     }
 
-    /// Applies a function to the contained value or computes a default.
+    /// Applies a function to the contained value (if any),
+    /// or computes a `default` (if not).
     ///
     /// # Examples
     ///
@@ -457,10 +459,10 @@ impl<T> Option<T> {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn map_or_else<U, D: FnOnce() -> U, F: FnOnce(T) -> U>(self, def: D, f: F) -> U {
+    pub fn map_or_else<U, D: FnOnce() -> U, F: FnOnce(T) -> U>(self, default: D, f: F) -> U {
         match self {
             Some(t) => f(t),
-            None => def()
+            None => default()
         }
     }
 

branches/snap-stage3/src/libstd/collections/hash/table.rs

@@ -528,6 +528,7 @@ fn test_rounding() {
 
 // Returns a tuple of (key_offset, val_offset),
 // from the start of a mallocated array.
+#[inline]
 fn calculate_offsets(hashes_size: usize,
                      keys_size: usize, keys_align: usize,
                      vals_align: usize)