Auto merge of #33658 - Manishearth:rollup, r=Manishearth

Rollup of 14 pull requests

- Successful merges: #33342, #33393, #33415, #33475, #33517, #33533, #33534, #33565, #33580, #33584, #33585, #33590, #33591, #33598
- Failed merges: #33578

src/liballoc/boxed.rs

@@ -525,14 +525,16 @@ impl<I: ExactSizeIterator + ?Sized> ExactSizeIterator for Box<I> {}
 /// }
 /// ```
 #[rustc_paren_sugar]
-#[unstable(feature = "fnbox", reason = "Newly introduced", issue = "28796")]
+#[unstable(feature = "fnbox",
+           reason = "will be deprecated if and when Box<FnOnce> becomes usable", issue = "28796")]
 pub trait FnBox<A> {
     type Output;
 
     fn call_box(self: Box<Self>, args: A) -> Self::Output;
 }
 
-#[unstable(feature = "fnbox", reason = "Newly introduced", issue = "28796")]
+#[unstable(feature = "fnbox",
+           reason = "will be deprecated if and when Box<FnOnce> becomes usable", issue = "28796")]
 impl<A, F> FnBox<A> for F where F: FnOnce<A>
 {
     type Output = F::Output;
@@ -542,7 +544,8 @@ impl<A, F> FnBox<A> for F where F: FnOnce<A>
     }
 }
 
-#[unstable(feature = "fnbox", reason = "Newly introduced", issue = "28796")]
+#[unstable(feature = "fnbox",
+           reason = "will be deprecated if and when Box<FnOnce> becomes usable", issue = "28796")]
 impl<'a, A, R> FnOnce<A> for Box<FnBox<A, Output = R> + 'a> {
     type Output = R;
 
@@ -551,7 +554,8 @@ impl<'a, A, R> FnOnce<A> for Box<FnBox<A, Output = R> + 'a> {
     }
 }
 
-#[unstable(feature = "fnbox", reason = "Newly introduced", issue = "28796")]
+#[unstable(feature = "fnbox",
+           reason = "will be deprecated if and when Box<FnOnce> becomes usable", issue = "28796")]
 impl<'a, A, R> FnOnce<A> for Box<FnBox<A, Output = R> + Send + 'a> {
     type Output = R;
 

src/libcollections/string.rs

@@ -184,7 +184,7 @@ use boxed::Box;
 /// let len = story.len();
 /// let capacity = story.capacity();
 ///
-/// // story has thirteen bytes
+/// // story has nineteen bytes
 /// assert_eq!(19, len);
 ///
 /// // Now that we have our parts, we throw the story away.

src/libcore/sync/atomic.rs

@@ -142,13 +142,13 @@ pub enum Ordering {
     #[stable(feature = "rust1", since = "1.0.0")]
     Relaxed,
     /// When coupled with a store, all previous writes become visible
-    /// to another thread that performs a load with `Acquire` ordering
+    /// to the other threads that perform a load with `Acquire` ordering
     /// on the same value.
     #[stable(feature = "rust1", since = "1.0.0")]
     Release,
     /// When coupled with a load, all subsequent loads will see data
     /// written before a store with `Release` ordering on the same value
-    /// in another thread.
+    /// in other threads.
     #[stable(feature = "rust1", since = "1.0.0")]
     Acquire,
     /// When coupled with a load, uses `Acquire` ordering, and with a store

src/librustc_borrowck/diagnostics.rs

@@ -378,6 +378,53 @@ let c = &i; // still ok!
 ```
 "##,
 
+E0500: r##"
+A borrowed variable was used in another closure. Example of erroneous code:
+
+```compile_fail
+fn you_know_nothing(jon_snow: &mut i32) {
+    let nights_watch = || {
+        *jon_snow = 2;
+    };
+    let starks = || {
+        *jon_snow = 3; // error: closure requires unique access to `jon_snow`
+                       //        but it is already borrowed
+    };
+}
+
+In here, `jon_snow` is already borrowed by the `nights_watch` closure, so it
+cannot be borrowed by the `starks` closure at the same time. To fix this issue,
+you can put the closure in its own scope:
+
+```
+fn you_know_nothing(jon_snow: &mut i32) {
+    {
+        let nights_watch = || {
+            *jon_snow = 2;
+        };
+    } // At this point, `jon_snow` is free.
+    let starks = || {
+        *jon_snow = 3;
+    };
+}
+```
+
+Or, if the type implements the `Clone` trait, you can clone it between
+closures:
+
+```
+fn you_know_nothing(jon_snow: &mut i32) {
+    let mut jon_copy = jon_snow.clone();
+    let nights_watch = || {
+        jon_copy = 2;
+    };
+    let starks = || {
+        *jon_snow = 3;
+    };
+}
+```
+"##,
+
 E0501: r##"
 This error indicates that a mutable variable is being used while it is still
 captured by a closure. Because the closure has borrowed the variable, it is not
@@ -642,6 +689,85 @@ fn print_fancy_ref(fancy_ref: &FancyNum){
 ```
 "##,
 
+E0505: r##"
+A value was moved out while it was still borrowed.
+Erroneous code example:
+
+```compile_fail
+struct Value {}
+
+fn eat(val: Value) {}
+
+fn main() {
+    let x = Value{};
+    {
+        let _ref_to_val: &Value = &x;
+        eat(x);
+    }
+}
+```
+
+Here, the function `eat` takes the ownership of `x`. However,
+`x` cannot be moved because it was borrowed to `_ref_to_val`.
+To fix that you can do few different things:
+
+* Try to avoid moving the variable.
+* Release borrow before move.
+* Implement the `Copy` trait on the type.
+
+Examples:
+
+```
+struct Value {}
+
+fn eat(val: &Value) {}
+
+fn main() {
+    let x = Value{};
+    {
+        let _ref_to_val: &Value = &x;
+        eat(&x); // pass by reference, if it's possible
+    }
+}
+```
+
+Or:
+
+```
+struct Value {}
+
+fn eat(val: Value) {}
+
+fn main() {
+    let x = Value{};
+    {
+        let _ref_to_val: &Value = &x;
+    }
+    eat(x); // release borrow and then move it.
+}
+```
+
+Or:
+
+```
+#[derive(Clone, Copy)] // implement Copy trait
+struct Value {}
+
+fn eat(val: Value) {}
+
+fn main() {
+    let x = Value{};
+    {
+        let _ref_to_val: &Value = &x;
+        eat(x); // it will be copied here.
+    }
+}
+```
+
+You can find more information about borrowing in the rust-book:
+http://doc.rust-lang.org/stable/book/references-and-borrowing.html
+"##,
+
 E0507: r##"
 You tried to move out of a value which was borrowed. Erroneous code example:
 
@@ -857,10 +983,8 @@ fn main() {
 register_diagnostics! {
     E0385, // {} in an aliasable location
     E0388, // {} in a static location
-    E0500, // closure requires unique access to `..` but .. is already borrowed
     E0502, // cannot borrow `..`.. as .. because .. is also borrowed as ...
     E0503, // cannot use `..` because it was mutably borrowed
-    E0505, // cannot move out of `..` because it is borrowed
     E0508, // cannot move out of type `..`, a non-copy fixed-size array
     E0524, // two closures require unique access to `..` at the same time
 }

src/librustc_const_eval/diagnostics.rs

@@ -62,8 +62,6 @@ fn foo(x: Empty) {
 However, this won't:
 
 ```compile_fail
-enum Empty {}
-
 fn foo(x: Option<String>) {
     match x {
         // empty
@@ -191,7 +189,7 @@ inner `String` to be moved into a variable called `s`.
 let x = Some("s".to_string());
 
 match x {
-    op_string @ Some(s) => {},
+    op_string @ Some(s) => {}, // error: cannot bind by-move with sub-bindings
     None => {},
 }
 ```
@@ -288,7 +286,8 @@ struct X { x: (), }
 
 let x = Some((X { x: () }, X { x: () }));
 match x {
-    Some((y, ref z)) => {},
+    Some((y, ref z)) => {}, // error: cannot bind by-move and by-ref in the
+                            //        same pattern
     None => panic!()
 }
 ```
@@ -574,6 +573,12 @@ be a compile-time constant. Erroneous code example:
     let x = [0i32; len]; // error: expected constant integer for repeat count,
                          //        found variable
 ```
+
+Working example:
+
+```
+let x = [0i32; 10];
+```
 "##,
 
 }

src/librustc_metadata/diagnostics.rs

@@ -26,6 +26,27 @@ name. Example:
 ```
 "##,
 
+E0455: r##"
+Linking with `kind=framework` is only supported when targeting OS X,
+as frameworks are specific to that operating system.
+
+Erroneous code example:
+
+```compile_fail"
+#[link(name = "FooCoreServices",  kind = "framework")] extern {}
+// OS used to compile is Linux for example
+```
+
+To solve this error you can use conditional compilation:
+
+```
+#[cfg_attr(target="macos", link(name = "FooCoreServices", kind = "framework"))]
+extern {}
+```
+
+See more: https://doc.rust-lang.org/book/conditional-compilation.html
+"##,
+
 E0458: r##"
 An unknown "kind" was specified for a link attribute. Erroneous code example:
 
@@ -73,7 +94,6 @@ well, and you link to them the same way.
 }
 
 register_diagnostics! {
-    E0455, // native frameworks are only available on OSX targets
     E0456, // plugin `..` is not available for triple `..`
     E0457, // plugin `..` only found in rlib format, but must be available...
     E0514, // metadata version mismatch

src/librustc_typeck/check/method/mod.rs

@@ -84,7 +84,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                          span: Span,
                          method_name: ast::Name,
                          self_ty: ty::Ty<'tcx>,
-                         call_expr_id: ast::NodeId)
+                         call_expr_id: ast::NodeId,
+                         allow_private: bool)
                          -> bool
     {
         let mode = probe::Mode::MethodCall;
@@ -93,7 +94,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
             Err(NoMatch(..)) => false,
             Err(Ambiguity(..)) => true,
             Err(ClosureAmbiguity(..)) => true,
-            Err(PrivateMatch(..)) => true,
+            Err(PrivateMatch(..)) => allow_private,
         }
     }
 

src/librustc_typeck/check/mod.rs

@@ -3053,12 +3053,18 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
 
         if let Some((did, field_ty)) = private_candidate {
             let struct_path = self.tcx().item_path_str(did);
-            let msg = format!("field `{}` of struct `{}` is private", field.node, struct_path);
-            self.tcx().sess.span_err(expr.span, &msg);
             self.write_ty(expr.id, field_ty);
+            let msg = format!("field `{}` of struct `{}` is private", field.node, struct_path);
+            let mut err = self.tcx().sess.struct_span_err(expr.span, &msg);
+            // Also check if an accessible method exists, which is often what is meant.
+            if self.method_exists(field.span, field.node, expr_t, expr.id, false) {
+                err.note(&format!("a method `{}` also exists, perhaps you wish to call it",
+                                  field.node));
+            }
+            err.emit();
         } else if field.node == keywords::Invalid.name() {
             self.write_error(expr.id);
-        } else if self.method_exists(field.span, field.node, expr_t, expr.id) {
+        } else if self.method_exists(field.span, field.node, expr_t, expr.id, true) {
             self.type_error_struct(field.span, |actual| {
                 format!("attempted to take value of method `{}` on type \
                          `{}`", field.node, actual)
@@ -3307,7 +3313,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
         let expr_ty = self.instantiate_type(def.def_id(), path);
         self.write_ty(expr.id, expr_ty);
 
-        self.check_expr_struct_fields(expr_ty, expr.span, variant, fields,
+        self.check_expr_struct_fields(expr_ty, path.span, variant, fields,
                                       base_expr.is_none());
         if let &Some(ref base_expr) = base_expr {
             self.check_expr_has_type(base_expr, expr_ty);