Merge branch 'master' into redox_builder

Author: newpavlov

Cargo.lock

@@ -70,7 +70,7 @@ for details on how to format and write long error codes.
   [librustc_privacy](https://github.com/rust-lang/rust/blob/master/src/librustc_privacy/error_codes.rs),
   [librustc_resolve](https://github.com/rust-lang/rust/blob/master/src/librustc_resolve/error_codes.rs),
   [librustc_codegen_llvm](https://github.com/rust-lang/rust/blob/master/src/librustc_codegen_llvm/error_codes.rs),
-  [librustc_plugin](https://github.com/rust-lang/rust/blob/master/src/librustc_plugin/error_codes.rs),
+  [librustc_plugin_impl](https://github.com/rust-lang/rust/blob/master/src/librustc_plugin/error_codes.rs),
   [librustc_typeck](https://github.com/rust-lang/rust/blob/master/src/librustc_typeck/error_codes.rs).
 * Explanations have full markdown support. Use it, especially to highlight
 code with backticks.

src/doc/rustc-ux-guidelines.md

@@ -0,0 +1,36 @@
+# `or_patterns`
+
+The tracking issue for this feature is: [#54883]
+
+[#54883]: https://github.com/rust-lang/rust/issues/54883
+
+------------------------
+
+The `or_pattern` language feature allows `|` to be arbitrarily nested within
+a pattern, for example, `Some(A(0) | B(1 | 2))` becomes a valid pattern.
+
+## Examples
+
+```rust,ignore
+#![feature(or_patterns)]
+
+pub enum Foo {
+    Bar,
+    Baz,
+    Quux,
+}
+
+pub fn example(maybe_foo: Option<Foo>) {
+    match maybe_foo {
+        Some(Foo::Bar | Foo::Baz) => {
+            println!("The value contained `Bar` or `Baz`");
+        }
+        Some(_) => {
+            println!("The value did not contain `Bar` or `Baz`");
+        }
+        None => {
+            println!("The value was `None`");
+        }
+    }
+}
+```

src/doc/unstable-book/src/language-features/or-patterns.md

@@ -18,7 +18,7 @@ extend the compiler's behavior with new syntax extensions, lint checks, etc.
 A plugin is a dynamic library crate with a designated *registrar* function that
 registers extensions with `rustc`. Other crates can load these extensions using
 the crate attribute `#![plugin(...)]`.  See the
-`rustc_plugin` documentation for more about the
+`rustc_driver::plugin` documentation for more about the
 mechanics of defining and loading a plugin.
 
 If present, arguments passed as `#![plugin(foo(... args ...))]` are not
@@ -54,13 +54,13 @@ that implements Roman numeral integer literals.
 extern crate syntax;
 extern crate syntax_pos;
 extern crate rustc;
-extern crate rustc_plugin;
+extern crate rustc_driver;
 
 use syntax::parse::token::{self, Token};
 use syntax::tokenstream::TokenTree;
 use syntax::ext::base::{ExtCtxt, MacResult, DummyResult, MacEager};
 use syntax_pos::Span;
-use rustc_plugin::Registry;
+use rustc_driver::plugin::Registry;
 
 fn expand_rn(cx: &mut ExtCtxt, sp: Span, args: &[TokenTree])
         -> Box<dyn MacResult + 'static> {
@@ -180,11 +180,11 @@ extern crate syntax;
 // Load rustc as a plugin to get macros
 #[macro_use]
 extern crate rustc;
-extern crate rustc_plugin;
+extern crate rustc_driver;
 
 use rustc::lint::{EarlyContext, LintContext, LintPass, EarlyLintPass,
                   EarlyLintPassObject, LintArray};
-use rustc_plugin::Registry;
+use rustc_driver::plugin::Registry;
 use syntax::ast;
 
 declare_lint!(TEST_LINT, Warn, "Warn about items named 'lintme'");

src/doc/unstable-book/src/language-features/plugin.md

@@ -91,8 +91,10 @@ use core::ops::{
     CoerceUnsized, DispatchFromDyn, Deref, DerefMut, Receiver, Generator, GeneratorState
 };
 use core::ptr::{self, NonNull, Unique};
+use core::slice;
 use core::task::{Context, Poll};
 
+use crate::alloc::{self, Global, Alloc};
 use crate::vec::Vec;
 use crate::raw_vec::RawVec;
 use crate::str::from_boxed_utf8_unchecked;
@@ -121,6 +123,34 @@ impl<T> Box<T> {
         box x
     }
 
+    /// Constructs a new box with uninitialized contents.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(new_uninit)]
+    ///
+    /// let mut five = Box::<u32>::new_uninit();
+    ///
+    /// let five = unsafe {
+    ///     // Deferred initialization:
+    ///     five.as_mut_ptr().write(5);
+    ///
+    ///     five.assume_init()
+    /// };
+    ///
+    /// assert_eq!(*five, 5)
+    /// ```
+    #[unstable(feature = "new_uninit", issue = "63291")]
+    pub fn new_uninit() -> Box<mem::MaybeUninit<T>> {
+        let layout = alloc::Layout::new::<mem::MaybeUninit<T>>();
+        let ptr = unsafe {
+            Global.alloc(layout)
+                .unwrap_or_else(|_| alloc::handle_alloc_error(layout))
+        };
+        Box(ptr.cast().into())
+    }
+
     /// Constructs a new `Pin<Box<T>>`. If `T` does not implement `Unpin`, then
     /// `x` will be pinned in memory and unable to be moved.
     #[stable(feature = "pin", since = "1.33.0")]
@@ -130,6 +160,111 @@ impl<T> Box<T> {
     }
 }
 
+impl<T> Box<[T]> {
+    /// Constructs a new boxed slice with uninitialized contents.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(new_uninit)]
+    ///
+    /// let mut values = Box::<[u32]>::new_uninit_slice(3);
+    ///
+    /// let values = unsafe {
+    ///     // Deferred initialization:
+    ///     values[0].as_mut_ptr().write(1);
+    ///     values[1].as_mut_ptr().write(2);
+    ///     values[2].as_mut_ptr().write(3);
+    ///
+    ///     values.assume_init()
+    /// };
+    ///
+    /// assert_eq!(*values, [1, 2, 3])
+    /// ```
+    #[unstable(feature = "new_uninit", issue = "63291")]
+    pub fn new_uninit_slice(len: usize) -> Box<[mem::MaybeUninit<T>]> {
+        let layout = alloc::Layout::array::<mem::MaybeUninit<T>>(len).unwrap();
+        let ptr = unsafe { alloc::alloc(layout) };
+        let unique = Unique::new(ptr).unwrap_or_else(|| alloc::handle_alloc_error(layout));
+        let slice = unsafe { slice::from_raw_parts_mut(unique.cast().as_ptr(), len) };
+        Box(Unique::from(slice))
+    }
+}
+
+impl<T> Box<mem::MaybeUninit<T>> {
+    /// Converts to `Box<T>`.
+    ///
+    /// # Safety
+    ///
+    /// As with [`MaybeUninit::assume_init`],
+    /// it is up to the caller to guarantee that the value
+    /// really is in an initialized state.
+    /// Calling this when the content is not yet fully initialized
+    /// causes immediate undefined behavior.
+    ///
+    /// [`MaybeUninit::assume_init`]: ../../std/mem/union.MaybeUninit.html#method.assume_init
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(new_uninit)]
+    ///
+    /// let mut five = Box::<u32>::new_uninit();
+    ///
+    /// let five: Box<u32> = unsafe {
+    ///     // Deferred initialization:
+    ///     five.as_mut_ptr().write(5);
+    ///
+    ///     five.assume_init()
+    /// };
+    ///
+    /// assert_eq!(*five, 5)
+    /// ```
+    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[inline]
+    pub unsafe fn assume_init(self) -> Box<T> {
+        Box(Box::into_unique(self).cast())
+    }
+}
+
+impl<T> Box<[mem::MaybeUninit<T>]> {
+    /// Converts to `Box<[T]>`.
+    ///
+    /// # Safety
+    ///
+    /// As with [`MaybeUninit::assume_init`],
+    /// it is up to the caller to guarantee that the values
+    /// really are in an initialized state.
+    /// Calling this when the content is not yet fully initialized
+    /// causes immediate undefined behavior.
+    ///
+    /// [`MaybeUninit::assume_init`]: ../../std/mem/union.MaybeUninit.html#method.assume_init
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(new_uninit)]
+    ///
+    /// let mut values = Box::<[u32]>::new_uninit_slice(3);
+    ///
+    /// let values = unsafe {
+    ///     // Deferred initialization:
+    ///     values[0].as_mut_ptr().write(1);
+    ///     values[1].as_mut_ptr().write(2);
+    ///     values[2].as_mut_ptr().write(3);
+    ///
+    ///     values.assume_init()
+    /// };
+    ///
+    /// assert_eq!(*values, [1, 2, 3])
+    /// ```
+    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[inline]
+    pub unsafe fn assume_init(self) -> Box<[T]> {
+        Box(Unique::new_unchecked(Box::into_raw(self) as _))
+    }
+}
+
 impl<T: ?Sized> Box<T> {
     /// Constructs a box from a raw pointer.
     ///

src/liballoc/boxed.rs

@@ -1199,6 +1199,31 @@ impl<T> VecDeque<T> {
         }
     }
 
+    /// Removes the last element from the `VecDeque` and returns it, or `None` if
+    /// it is empty.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::collections::VecDeque;
+    ///
+    /// let mut buf = VecDeque::new();
+    /// assert_eq!(buf.pop_back(), None);
+    /// buf.push_back(1);
+    /// buf.push_back(3);
+    /// assert_eq!(buf.pop_back(), Some(3));
+    /// ```
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn pop_back(&mut self) -> Option<T> {
+        if self.is_empty() {
+            None
+        } else {
+            self.head = self.wrap_sub(self.head, 1);
+            let head = self.head;
+            unsafe { Some(self.buffer_read(head)) }
+        }
+    }
+
     /// Prepends an element to the `VecDeque`.
     ///
     /// # Examples
@@ -1243,38 +1268,13 @@ impl<T> VecDeque<T> {
         unsafe { self.buffer_write(head, value) }
     }
 
-    /// Removes the last element from the `VecDeque` and returns it, or `None` if
-    /// it is empty.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::collections::VecDeque;
-    ///
-    /// let mut buf = VecDeque::new();
-    /// assert_eq!(buf.pop_back(), None);
-    /// buf.push_back(1);
-    /// buf.push_back(3);
-    /// assert_eq!(buf.pop_back(), Some(3));
-    /// ```
-    #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn pop_back(&mut self) -> Option<T> {
-        if self.is_empty() {
-            None
-        } else {
-            self.head = self.wrap_sub(self.head, 1);
-            let head = self.head;
-            unsafe { Some(self.buffer_read(head)) }
-        }
-    }
-
     #[inline]
     fn is_contiguous(&self) -> bool {
         self.tail <= self.head
     }
 
-    /// Removes an element from anywhere in the `VecDeque` and returns it, replacing it with the
-    /// last element.
+    /// Removes an element from anywhere in the `VecDeque` and returns it,
+    /// replacing it with the first element.
     ///
     /// This does not preserve ordering, but is O(1).
     ///
@@ -1288,28 +1288,28 @@ impl<T> VecDeque<T> {
     /// use std::collections::VecDeque;
     ///
     /// let mut buf = VecDeque::new();
-    /// assert_eq!(buf.swap_remove_back(0), None);
+    /// assert_eq!(buf.swap_remove_front(0), None);
     /// buf.push_back(1);
     /// buf.push_back(2);
     /// buf.push_back(3);
     /// assert_eq!(buf, [1, 2, 3]);
     ///
-    /// assert_eq!(buf.swap_remove_back(0), Some(1));
-    /// assert_eq!(buf, [3, 2]);
+    /// assert_eq!(buf.swap_remove_front(2), Some(3));
+    /// assert_eq!(buf, [2, 1]);
     /// ```
     #[stable(feature = "deque_extras_15", since = "1.5.0")]
-    pub fn swap_remove_back(&mut self, index: usize) -> Option<T> {
+    pub fn swap_remove_front(&mut self, index: usize) -> Option<T> {
         let length = self.len();
-        if length > 0 && index < length - 1 {
-            self.swap(index, length - 1);
+        if length > 0 && index < length && index != 0 {
+            self.swap(index, 0);
         } else if index >= length {
             return None;
         }
-        self.pop_back()
+        self.pop_front()
     }
 
-    /// Removes an element from anywhere in the `VecDeque` and returns it,
-    /// replacing it with the first element.
+    /// Removes an element from anywhere in the `VecDeque` and returns it, replacing it with the
+    /// last element.
     ///
     /// This does not preserve ordering, but is O(1).
     ///
@@ -1323,24 +1323,24 @@ impl<T> VecDeque<T> {
     /// use std::collections::VecDeque;
     ///
     /// let mut buf = VecDeque::new();
-    /// assert_eq!(buf.swap_remove_front(0), None);
+    /// assert_eq!(buf.swap_remove_back(0), None);
     /// buf.push_back(1);
     /// buf.push_back(2);
     /// buf.push_back(3);
     /// assert_eq!(buf, [1, 2, 3]);
     ///
-    /// assert_eq!(buf.swap_remove_front(2), Some(3));
-    /// assert_eq!(buf, [2, 1]);
+    /// assert_eq!(buf.swap_remove_back(0), Some(1));
+    /// assert_eq!(buf, [3, 2]);
     /// ```
     #[stable(feature = "deque_extras_15", since = "1.5.0")]
-    pub fn swap_remove_front(&mut self, index: usize) -> Option<T> {
+    pub fn swap_remove_back(&mut self, index: usize) -> Option<T> {
         let length = self.len();
-        if length > 0 && index < length && index != 0 {
-            self.swap(index, 0);
+        if length > 0 && index < length - 1 {
+            self.swap(index, length - 1);
         } else if index >= length {
             return None;
         }
-        self.pop_front()
+        self.pop_back()
     }
 
     /// Inserts an element at `index` within the `VecDeque`, shifting all elements with indices