Auto merge of #35971 - jonathandturner:rollup, r=jonathandturner

Rollup of 4 pull requests

- Successful merges: #35876, #35920, #35948, #35961
- Failed merges: #35395

Author: bors

src/doc/reference.md

@@ -2283,7 +2283,7 @@ the `PartialEq` or `Clone` constraints for the appropriate `impl`:
 #[derive(PartialEq, Clone)]
 struct Foo<T> {
     a: i32,
-    b: T
+    b: T,
 }
 ```
 
@@ -3896,7 +3896,7 @@ Coercion is allowed between the following types:
   use std::ops::Deref;
 
   struct CharContainer {
-      value: char
+      value: char,
   }
 
   impl Deref for CharContainer {

src/libcore/ops.rs

@@ -245,25 +245,38 @@ add_impl! { usize u8 u16 u32 u64 isize i8 i16 i32 i64 f32 f64 }
 ///
 /// # Examples
 ///
-/// A trivial implementation of `Sub`. When `Foo - Foo` happens, it ends up
-/// calling `sub`, and therefore, `main` prints `Subtracting!`.
+/// This example creates a `Point` struct that implements the `Sub` trait, and
+/// then demonstrates subtracting two `Point`s.
 ///
 /// ```
 /// use std::ops::Sub;
 ///
-/// struct Foo;
+/// #[derive(Debug)]
+/// struct Point {
+///     x: i32,
+///     y: i32,
+/// }
 ///
-/// impl Sub for Foo {
-///     type Output = Foo;
+/// impl Sub for Point {
+///     type Output = Point;
 ///
-///     fn sub(self, _rhs: Foo) -> Foo {
-///         println!("Subtracting!");
-///         self
+///     fn sub(self, other: Point) -> Point {
+///         Point {
+///             x: self.x - other.x,
+///             y: self.y - other.y,
+///         }
+///     }
+/// }
+///
+/// impl PartialEq for Point {
+///     fn eq(&self, other: &Self) -> bool {
+///         self.x == other.x && self.y == other.y
 ///     }
 /// }
 ///
 /// fn main() {
-///     Foo - Foo;
+///     assert_eq!(Point { x: 3, y: 3 } - Point { x: 2, y: 3 },
+///                Point { x: 1, y: 0 });
 /// }
 /// ```
 #[lang = "sub"]
@@ -1156,25 +1169,36 @@ add_assign_impl! { usize u8 u16 u32 u64 isize i8 i16 i32 i64 f32 f64 }
 ///
 /// # Examples
 ///
-/// A trivial implementation of `SubAssign`. When `Foo -= Foo` happens, it ends up
-/// calling `sub_assign`, and therefore, `main` prints `Subtracting!`.
+/// This example creates a `Point` struct that implements the `SubAssign`
+/// trait, and then demonstrates sub-assigning to a mutable `Point`.
 ///
 /// ```
 /// use std::ops::SubAssign;
 ///
-/// struct Foo;
+/// #[derive(Debug)]
+/// struct Point {
+///     x: i32,
+///     y: i32,
+/// }
 ///
-/// impl SubAssign for Foo {
-///     fn sub_assign(&mut self, _rhs: Foo) {
-///         println!("Subtracting!");
+/// impl SubAssign for Point {
+///     fn sub_assign(&mut self, other: Point) {
+///         *self = Point {
+///             x: self.x - other.x,
+///             y: self.y - other.y,
+///         };
 ///     }
 /// }
 ///
-/// # #[allow(unused_assignments)]
-/// fn main() {
-///     let mut foo = Foo;
-///     foo -= Foo;
+/// impl PartialEq for Point {
+///     fn eq(&self, other: &Self) -> bool {
+///         self.x == other.x && self.y == other.y
+///     }
 /// }
+///
+/// let mut point = Point { x: 3, y: 3 };
+/// point -= Point { x: 2, y: 3 };
+/// assert_eq!(point, Point {x: 1, y: 0});
 /// ```
 #[lang = "sub_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]

src/librustc/diagnostics.rs

@@ -1527,6 +1527,37 @@ fn main() {
 ```
 "##,
 
+E0478: r##"
+A lifetime bound was not satisfied.
+
+Erroneous code example:
+
+```compile_fail,E0478
+// Check that the explicit lifetime bound (`'SnowWhite`, in this example) must
+// outlive all the superbounds from the trait (`'kiss`, in this example).
+
+trait Wedding<'t>: 't { }
+
+struct Prince<'kiss, 'SnowWhite> {
+    child: Box<Wedding<'kiss> + 'SnowWhite>,
+    // error: lifetime bound not satisfied
+}
+```
+
+In this example, the `'SnowWhite` lifetime is supposed to outlive the `'kiss`
+lifetime but the declaration of the `Prince` struct doesn't enforce it. To fix
+this issue, you need to specify it:
+
+```
+trait Wedding<'t>: 't { }
+
+struct Prince<'kiss, 'SnowWhite: 'kiss> { // You say here that 'kiss must live
+                                          // longer than 'SnowWhite.
+    child: Box<Wedding<'kiss> + 'SnowWhite>, // And now it's all good!
+}
+```
+"##,
+
 E0496: r##"
 A lifetime name is shadowing another lifetime name. Erroneous code example:
 
@@ -1715,7 +1746,6 @@ register_diagnostics! {
     E0475, // index of slice outside its lifetime
     E0476, // lifetime of the source pointer does not outlive lifetime bound...
     E0477, // the type `..` does not fulfill the required lifetime...
-    E0478, // lifetime bound not satisfied
     E0479, // the type `..` (provided as the value of a type parameter) is...
     E0480, // lifetime of method receiver does not outlive the method call
     E0481, // lifetime of function argument does not outlive the function call

src/librustc_metadata/creader.rs

@@ -101,8 +101,10 @@ fn register_native_lib(sess: &Session,
     if name.is_empty() {
         match span {
             Some(span) => {
-                span_err!(sess, span, E0454,
-                          "#[link(name = \"\")] given with empty name");
+                struct_span_err!(sess, span, E0454,
+                                 "#[link(name = \"\")] given with empty name")
+                    .span_label(span, &format!("empty name given"))
+                    .emit();
             }
             None => {
                 sess.err("empty library name given via `-l`");

src/librustc_mir/diagnostics.rs

@@ -18,7 +18,7 @@ for the entire lifetime of a program. Creating a boxed value allocates memory on
 the heap at runtime, and therefore cannot be done at compile time. Erroneous
 code example:
 
-```compile_fail
+```compile_fail,E0010
 #![feature(box_syntax)]
 
 const CON : Box<i32> = box 0;
@@ -30,7 +30,7 @@ Static and const variables can refer to other const variables. But a const
 variable cannot refer to a static variable. For example, `Y` cannot refer to
 `X` here:
 
-```compile_fail
+```compile_fail,E0013
 static X: i32 = 42;
 const Y: i32 = X;
 ```
@@ -66,7 +66,7 @@ E0016: r##"
 Blocks in constants may only contain items (such as constant, function
 definition, etc...) and a tail expression. Erroneous code example:
 
-```compile_fail
+```compile_fail,E0016
 const FOO: i32 = { let x = 0; x }; // 'x' isn't an item!
 ```
 
@@ -81,7 +81,7 @@ E0017: r##"
 References in statics and constants may only refer to immutable values.
 Erroneous code example:
 
-```compile_fail
+```compile_fail,E0017
 static X: i32 = 1;
 const C: i32 = 2;
 
@@ -107,7 +107,7 @@ vary.
 
 For example, if you write:
 
-```compile_fail
+```compile_fail,E0018
 static MY_STATIC: u32 = 42;
 static MY_STATIC_ADDR: usize = &MY_STATIC as *const _ as usize;
 static WHAT: usize = (MY_STATIC_ADDR^17) + MY_STATIC_ADDR;
@@ -152,7 +152,7 @@ impl Test {
 fn main() {
     const FOO: Test = Test::V1;
 
-    const A: i32 = FOO.test(); // You can't call Test::func() here !
+    const A: i32 = FOO.test(); // You can't call Test::func() here!
 }
 ```
 
@@ -214,14 +214,13 @@ static B: &'static u32 = &A; // ok!
 ```
 "##,
 
-
 E0395: r##"
 The value assigned to a constant scalar must be known at compile time,
 which is not the case when comparing raw pointers.
 
 Erroneous code example:
 
-```compile_fail
+```compile_fail,E0395
 static FOO: i32 = 42;
 static BAR: i32 = 42;
 
@@ -250,7 +249,7 @@ The value behind a raw pointer can't be determined at compile-time
 (or even link-time), which means it can't be used in a constant
 expression. Erroneous code example:
 
-```compile_fail
+```compile_fail,E0396
 const REG_ADDR: *const u8 = 0x5f3759df as *const u8;
 
 const VALUE: u8 = unsafe { *REG_ADDR };
@@ -272,7 +271,7 @@ E0492: r##"
 A borrow of a constant containing interior mutability was attempted. Erroneous
 code example:
 
-```compile_fail
+```compile_fail,E0492
 use std::sync::atomic::{AtomicUsize, ATOMIC_USIZE_INIT};
 
 const A: AtomicUsize = ATOMIC_USIZE_INIT;
@@ -299,7 +298,7 @@ static B: &'static AtomicUsize = &A; // ok!
 
 You can also have this error while using a cell type:
 
-```compile_fail
+```compile_fail,E0492
 #![feature(const_fn)]
 
 use std::cell::Cell;
@@ -351,7 +350,7 @@ E0493: r##"
 A type with a destructor was assigned to an invalid type of variable. Erroneous
 code example:
 
-```compile_fail
+```compile_fail,E0493
 struct Foo {
     a: u32
 }
@@ -374,7 +373,7 @@ E0494: r##"
 A reference of an interior static was assigned to another const/static.
 Erroneous code example:
 
-```compile_fail
+```compile_fail,E0494
 struct Foo {
     a: u32
 }

src/librustc_privacy/lib.rs

@@ -964,8 +964,11 @@ impl<'a, 'tcx: 'a, 'v> Visitor<'v> for SearchInterfaceForPrivateItemsVisitor<'a,
             if !vis.is_at_least(self.required_visibility, &self.tcx.map) {
                 if self.tcx.sess.features.borrow().pub_restricted ||
                    self.old_error_set.contains(&trait_ref.ref_id) {
-                    span_err!(self.tcx.sess, trait_ref.path.span, E0445,
-                              "private trait in public interface");
+                    struct_span_err!(self.tcx.sess, trait_ref.path.span, E0445,
+                                     "private trait in public interface")
+                        .span_label(trait_ref.path.span, &format!(
+                                    "private trait can't be public"))
+                        .emit();
                 } else {
                     self.tcx.sess.add_lint(lint::builtin::PRIVATE_IN_PUBLIC,
                                            node_id,

src/test/compile-fail/E0445.rs

@@ -12,8 +12,14 @@ trait Foo {
     fn dummy(&self) { }
 }
 
-pub trait Bar : Foo {} //~ ERROR E0445
-pub struct Bar2<T: Foo>(pub T); //~ ERROR E0445
-pub fn foo<T: Foo> (t: T) {} //~ ERROR E0445
+pub trait Bar : Foo {}
+//~^ ERROR private trait in public interface [E0445]
+//~| NOTE private trait can't be public
+pub struct Bar2<T: Foo>(pub T);
+//~^ ERROR private trait in public interface [E0445]
+//~| NOTE private trait can't be public
+pub fn foo<T: Foo> (t: T) {}
+//~^ ERROR private trait in public interface [E0445]
+//~| NOTE private trait can't be public
 
 fn main() {}

src/test/compile-fail/E0454.rs

@@ -8,7 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#[link(name = "")] extern {} //~ ERROR E0454
+#[link(name = "")] extern {}
+//~^ ERROR E0454
+//~| NOTE empty name given
 
 fn main() {
 }

src/test/compile-fail/E0478.rs

@@ -0,0 +1,18 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+trait Wedding<'t>: 't { }
+
+struct Prince<'kiss, 'SnowWhite> {
+    child: Box<Wedding<'kiss> + 'SnowWhite>, //~ ERROR E0478
+}
+
+fn main() {
+}

src/test/compile-fail/E0492.rs

@@ -0,0 +1,17 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::sync::atomic::{AtomicUsize, ATOMIC_USIZE_INIT};
+
+const A: AtomicUsize = ATOMIC_USIZE_INIT;
+static B: &'static AtomicUsize = &A; //~ ERROR E0492
+
+fn main() {
+}

src/test/compile-fail/E0493.rs

@@ -0,0 +1,22 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+struct Foo {
+    a: u32
+}
+
+impl Drop for Foo {
+    fn drop(&mut self) {}
+}
+
+const F : Foo = Foo { a : 0 }; //~ ERROR E0493
+
+fn main() {
+}