Auto merge of #26844 - steveklabnik:rollup, r=steveklabnik

- Successful merges: #26599, #26761, #26807, #26809, #26825, #26827, #26828, #26832, #26834, #26835
- Failed merges: #26796

CONTRIBUTING.md

@@ -83,6 +83,21 @@ feature. We use the 'fork and pull' model described there.
 
 Please make pull requests against the `master` branch.
 
+Compiling all of `make check` can take a while. When testing your pull request,
+consider using one of the more specialized `make` targets to cut down on the
+amount of time you have to wait. You need to have built the compiler at least
+once before running these will work, but that’s only one full build rather than
+one each time.
+
+    $ make -j8 rustc-stage1 && make check-stage1
+
+is one such example, which builds just `rustc`, and then runs the tests. If
+you’re adding something to the standard library, try
+
+    $ make -j8 check-stage1-std NO_REBUILD=1
+
+This will not rebuild the compiler, but will run the tests.
+
 All pull requests are reviewed by another person. We have a bot,
 @rust-highfive, that will automatically assign a random person to review your
 request.
@@ -108,6 +123,10 @@ will run all the tests on every platform we support. If it all works out,
 
 [merge-queue]: http://buildbot.rust-lang.org/homu/queue/rust
 
+Speaking of tests, Rust has a comprehensive test suite. More information about
+it can be found
+[here](https://github.com/rust-lang/rust-wiki-backup/blob/master/Note-testsuite.md).
+
 ## Writing Documentation
 
 Documentation improvements are very welcome. The source of `doc.rust-lang.org`

src/doc/reference.md

@@ -2515,9 +2515,8 @@ Here are some examples:
 #### Moved and copied types
 
 When a [local variable](#variables) is used as an
-[rvalue](#lvalues,-rvalues-and-temporaries) the variable will either be moved
+[rvalue](#lvalues,-rvalues-and-temporaries), the variable will be copied
-or copied, depending on its type. All values whose type implements `Copy` are
+if its type implements `Copy`. All others are moved.
-copied, all others are moved.
 
 ### Literal expressions
 
@@ -2882,7 +2881,6 @@ operand.
 ```
 # let mut x = 0;
 # let y = 0;
-
 x = y;
 ```
 

src/doc/trpl/ffi.md

@@ -533,19 +533,10 @@ attribute turns off Rust's name mangling, so that it is easier to link to.
 
 # FFI and panics
 
-It’s important to be mindful of `panic!`s when working with FFI. This code,
+It’s important to be mindful of `panic!`s when working with FFI. A `panic!`
-when called from C, will `abort`:
+across an FFI boundary is undefined behavior. If you’re writing code that may
-
+panic, you should run it in another thread, so that the panic doesn’t bubble up
-```rust
+to C:
-#[no_mangle]
-pub extern fn oh_no() -> ! {
-    panic!("Oops!");
-}
-# fn main() {}
-```
-
-If you’re writing code that may panic, you should run it in another thread,
-so that the panic doesn’t bubble up to C:
 
 ```rust
 use std::thread;

src/doc/trpl/patterns.md

@@ -282,6 +282,38 @@ This ‘destructuring’ behavior works on any compound data type, like
 [tuples]: primitive-types.html#tuples
 [enums]: enums.html
 
+# Ignoring bindings
+
+You can use `_` in a pattern to disregard the value. For example, here’s a
+`match` against a `Result<T, E>`:
+
+```rust
+# let some_value: Result<i32, &'static str> = Err("There was an error");
+match some_value {
+    Ok(value) => println!("got a value: {}", value),
+    Err(_) => println!("an error occurred"),
+}
+```
+
+In the first arm, we bind the value inside the `Ok` variant to `value`. But
+in the `Err` arm, we use `_` to disregard the specific error, and just print
+a general error message.
+
+`_` is valid in any pattern that creates a binding. This can be useful to
+ignore parts of a larger structure:
+
+```rust
+fn coordinate() -> (i32, i32, i32) {
+    // generate and return some sort of triple tuple
+# (1, 2, 3)
+}
+
+let (x, _, z) = coordinate();
+```
+
+Here, we bind the first and last element of the tuple to `x` and `z`, but
+ignore the middle element.
+
 # Mix and Match
 
 Whew! That’s a lot of different ways to match things, and they can all be

src/libcore/fmt/mod.rs

@@ -267,11 +267,16 @@ impl<'a> Display for Arguments<'a> {
     }
 }
 
-/// Format trait for the `?` character. Useful for debugging, all types
+/// Format trait for the `?` character.
-/// should implement this.
+///
+/// `Debug` should format the output in a programmer-facing, debugging context.
 ///
 /// Generally speaking, you should just `derive` a `Debug` implementation.
 ///
+/// For more information on formatters, see [the module-level documentation][module].
+///
+/// [module]: ../index.html
+///
 /// # Examples
 ///
 /// Deriving an implementation:
@@ -327,8 +332,39 @@ pub trait Debug {
     fn fmt(&self, &mut Formatter) -> Result;
 }
 
-/// When a value can be semantically expressed as a String, this trait may be
+/// Format trait for an empty format, `{}`.
-/// used. It corresponds to the default format, `{}`.
+///
+/// `Display` is similar to [`Debug`][debug], but `Display` is for user-facing
+/// output, and so cannot be derived.
+///
+/// [debug]: trait.Debug.html
+///
+/// For more information on formatters, see [the module-level documentation][module].
+///
+/// [module]: ../index.html
+///
+/// # Examples
+///
+/// Implementing `Display` on a type:
+///
+/// ```
+/// use std::fmt;
+///
+/// struct Point {
+///     x: i32,
+///     y: i32,
+/// }
+///
+/// impl fmt::Display for Point {
+///     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+///         write!(f, "({}, {})", self.x, self.y)
+///     }
+/// }
+///
+/// let origin = Point { x: 0, y: 0 };
+///
+/// println!("The origin is: {}", origin);
+/// ```
 #[rustc_on_unimplemented = "`{Self}` cannot be formatted with the default \
                             formatter; try using `:?` instead if you are using \
                             a format string"]
@@ -339,7 +375,43 @@ pub trait Display {
     fn fmt(&self, &mut Formatter) -> Result;
 }
 
-/// Format trait for the `o` character
+/// Format trait for the `o` character.
+///
+/// The `Octal` trait should format its output as a number in base-8.
+///
+/// For more information on formatters, see [the module-level documentation][module].
+///
+/// [module]: ../index.html
+///
+/// # Examples
+///
+/// Basic usage with `i32`:
+///
+/// ```
+/// let x = 42; // 42 is '52' in octal
+///
+/// assert_eq!(format!("{:o}", x), "52");
+/// ```
+///
+/// Implementing `Octal` on a type:
+///
+/// ```
+/// use std::fmt;
+///
+/// struct Length(i32);
+///
+/// impl fmt::Octal for Length {
+///     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+///         let val = self.0;
+///
+///         write!(f, "{:o}", val) // delegate to i32's implementation
+///     }
+/// }
+///
+/// let l = Length(9);
+///
+/// println!("l as octal is: {:o}", l);
+/// ```
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait Octal {
     /// Formats the value using the given formatter.
@@ -347,7 +419,43 @@ pub trait Octal {
     fn fmt(&self, &mut Formatter) -> Result;
 }
 
-/// Format trait for the `b` character
+/// Format trait for the `b` character.
+///
+/// The `Binary` trait should format its output as a number in binary.
+///
+/// For more information on formatters, see [the module-level documentation][module].
+///
+/// [module]: ../index.html
+///
+/// # Examples
+///
+/// Basic usage with `i32`:
+///
+/// ```
+/// let x = 42; // 42 is '101010' in binary
+///
+/// assert_eq!(format!("{:b}", x), "101010");
+/// ```
+///
+/// Implementing `Binary` on a type:
+///
+/// ```
+/// use std::fmt;
+///
+/// struct Length(i32);
+///
+/// impl fmt::Binary for Length {
+///     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+///         let val = self.0;
+///
+///         write!(f, "{:b}", val) // delegate to i32's implementation
+///     }
+/// }
+///
+/// let l = Length(107);
+///
+/// println!("l as binary is: {:b}", l);
+/// ```
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait Binary {
     /// Formats the value using the given formatter.
@@ -355,7 +463,44 @@ pub trait Binary {
     fn fmt(&self, &mut Formatter) -> Result;
 }
 
-/// Format trait for the `x` character
+/// Format trait for the `x` character.
+///
+/// The `LowerHex` trait should format its output as a number in hexidecimal, with `a` through `f`
+/// in lower case.
+///
+/// For more information on formatters, see [the module-level documentation][module].
+///
+/// [module]: ../index.html
+///
+/// # Examples
+///
+/// Basic usage with `i32`:
+///
+/// ```
+/// let x = 42; // 42 is '2a' in hex
+///
+/// assert_eq!(format!("{:x}", x), "2a");
+/// ```
+///
+/// Implementing `LowerHex` on a type:
+///
+/// ```
+/// use std::fmt;
+///
+/// struct Length(i32);
+///
+/// impl fmt::LowerHex for Length {
+///     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+///         let val = self.0;
+///
+///         write!(f, "{:x}", val) // delegate to i32's implementation
+///     }
+/// }
+///
+/// let l = Length(9);
+///
+/// println!("l as hex is: {:x}", l);
+/// ```
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait LowerHex {
     /// Formats the value using the given formatter.
@@ -363,7 +508,44 @@ pub trait LowerHex {
     fn fmt(&self, &mut Formatter) -> Result;
 }
 
-/// Format trait for the `X` character
+/// Format trait for the `X` character.
+///
+/// The `UpperHex` trait should format its output as a number in hexidecimal, with `A` through `F`
+/// in upper case.
+///
+/// For more information on formatters, see [the module-level documentation][module].
+///
+/// [module]: ../index.html
+///
+/// # Examples
+///
+/// Basic usage with `i32`:
+///
+/// ```
+/// let x = 42; // 42 is '2A' in hex
+///
+/// assert_eq!(format!("{:X}", x), "2A");
+/// ```
+///
+/// Implementing `UpperHex` on a type:
+///
+/// ```
+/// use std::fmt;
+///
+/// struct Length(i32);
+///
+/// impl fmt::UpperHex for Length {
+///     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+///         let val = self.0;
+///
+///         write!(f, "{:X}", val) // delegate to i32's implementation
+///     }
+/// }
+///
+/// let l = Length(9);
+///
+/// println!("l as hex is: {:X}", l);
+/// ```
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait UpperHex {
     /// Formats the value using the given formatter.
@@ -371,7 +553,44 @@ pub trait UpperHex {
     fn fmt(&self, &mut Formatter) -> Result;
 }
 
-/// Format trait for the `p` character
+/// Format trait for the `p` character.
+///
+/// The `Pointer` trait should format its output as a memory location. This is commonly presented
+/// as hexidecimal.
+///
+/// For more information on formatters, see [the module-level documentation][module].
+///
+/// [module]: ../index.html
+///
+/// # Examples
+///
+/// Basic usage with `&i32`:
+///
+/// ```
+/// let x = &42;
+///
+/// let address = format!("{:p}", x); // this produces something like '0x7f06092ac6d0'
+/// ```
+///
+/// Implementing `Pointer` on a type:
+///
+/// ```
+/// use std::fmt;
+///
+/// struct Length(i32);
+///
+/// impl fmt::Pointer for Length {
+///     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+///         // use `as` to convert to a `*const T`, which implements Pointer, which we can use
+///
+///         write!(f, "{:p}", self as *const Length)
+///     }
+/// }
+///
+/// let l = Length(42);
+///
+/// println!("l is in memory here: {:p}", l);
+/// ```
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait Pointer {
     /// Formats the value using the given formatter.
@@ -379,7 +598,42 @@ pub trait Pointer {
     fn fmt(&self, &mut Formatter) -> Result;
 }
 
-/// Format trait for the `e` character
+/// Format trait for the `e` character.
+///
+/// The `LowerExp` trait should format its output in scientific notation with a lower-case `e`.
+///
+/// For more information on formatters, see [the module-level documentation][module].
+///
+/// [module]: ../index.html
+///
+/// # Examples
+///
+/// Basic usage with `i32`:
+///
+/// ```
+/// let x = 42.0; // 42.0 is '4.2e1' in scientific notation
+///
+/// assert_eq!(format!("{:e}", x), "4.2e1");
+/// ```
+///
+/// Implementing `LowerExp` on a type:
+///
+/// ```
+/// use std::fmt;
+///
+/// struct Length(i32);
+///
+/// impl fmt::LowerExp for Length {
+///     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+///         let val = self.0;
+///         write!(f, "{}e1", val / 10)
+///     }
+/// }
+///
+/// let l = Length(100);
+///
+/// println!("l in scientific notation is: {:e}", l);
+/// ```
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait LowerExp {
     /// Formats the value using the given formatter.
@@ -387,7 +641,42 @@ pub trait LowerExp {
     fn fmt(&self, &mut Formatter) -> Result;
 }
 
-/// Format trait for the `E` character
+/// Format trait for the `E` character.
+///
+/// The `UpperExp` trait should format its output in scientific notation with an upper-case `E`.
+///
+/// For more information on formatters, see [the module-level documentation][module].
+///
+/// [module]: ../index.html
+///
+/// # Examples
+///
+/// Basic usage with `f32`:
+///
+/// ```
+/// let x = 42.0; // 42.0 is '4.2E1' in scientific notation
+///
+/// assert_eq!(format!("{:E}", x), "4.2E1");
+/// ```
+///
+/// Implementing `UpperExp` on a type:
+///
+/// ```
+/// use std::fmt;
+///
+/// struct Length(i32);
+///
+/// impl fmt::UpperExp for Length {
+///     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+///         let val = self.0;
+///         write!(f, "{}E1", val / 10)
+///     }
+/// }
+///
+/// let l = Length(100);
+///
+/// println!("l in scientific notation is: {:E}", l);
+/// ```
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait UpperExp {
     /// Formats the value using the given formatter.

src/liblibc/lib.rs

@@ -6128,7 +6128,7 @@ pub mod funcs {
         use types::os::arch::c95::{c_char, c_uchar, c_int, c_uint, c_ulong, size_t};
 
         extern {
-            pub fn ioctl(d: c_int, request: c_ulong, ...) -> c_int;
+            pub fn ioctl(fd: c_int, request: c_ulong, ...) -> c_int;
             pub fn sysctl(name: *mut c_int,
                           namelen: c_uint,
                           oldp: *mut c_void,
@@ -6160,12 +6160,12 @@ pub mod funcs {
     #[cfg(any(target_os = "linux", target_os = "android"))]
     pub mod bsd44 {
         use types::common::c95::{c_void};
-        use types::os::arch::c95::{c_uchar, c_int, size_t};
+        use types::os::arch::c95::{c_uchar, c_int, c_ulong, size_t};
 
         extern {
             #[cfg(not(all(target_os = "android", target_arch = "aarch64")))]
             pub fn getdtablesize() -> c_int;
-            pub fn ioctl(d: c_int, request: c_int, ...) -> c_int;
+            pub fn ioctl(fd: c_int, request: c_ulong, ...) -> c_int;
             pub fn madvise(addr: *mut c_void, len: size_t, advice: c_int)
                            -> c_int;
             pub fn mincore(addr: *mut c_void, len: size_t, vec: *mut c_uchar)

src/librustc_trans/trans/_match.rs

@@ -1351,7 +1351,7 @@ fn is_discr_reassigned(bcx: Block, discr: &ast::Expr, body: &ast::Expr) -> bool
         reassigned: false
     };
     {
-        let infcx = infer::new_infer_ctxt(bcx.tcx(), &bcx.tcx().tables, None, false);
+        let infcx = infer::normalizing_infer_ctxt(bcx.tcx(), &bcx.tcx().tables);
         let mut visitor = euv::ExprUseVisitor::new(&mut rc, &infcx);
         visitor.walk_expr(body);
     }

src/librustc_trans/trans/common.rs

@@ -936,7 +936,7 @@ pub fn normalize_and_test_predicates<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
            predicates);
 
     let tcx = ccx.tcx();
-    let infcx = infer::new_infer_ctxt(tcx, &tcx.tables, None, true);
+    let infcx = infer::normalizing_infer_ctxt(tcx, &tcx.tables);
     let mut selcx = traits::SelectionContext::new(&infcx);
     let mut fulfill_cx = infcx.fulfillment_cx.borrow_mut();
     let cause = traits::ObligationCause::dummy();

src/test/run-pass/issue-26805.rs

@@ -0,0 +1,15 @@
+// Copyright 2015 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 NonOrd;
+
+fn main() {
+    let _: Box<Iterator<Item = _>> = Box::new(vec![NonOrd].into_iter());
+}