Auto merge of #55974 - pietroalbini:rollup, r=pietroalbini

Rollup of 17 pull requests

Successful merges:

 - #55182 (Redox: Update to new changes)
 - #55211 (Add BufWriter::buffer method)
 - #55507 (Add link to std::mem::size_of to size_of intrinsic documentation)
 - #55530 (Speed up String::from_utf16)
 - #55556 (Use `Mmap` to open the rmeta file.)
 - #55622 (NetBSD: link libstd with librt in addition to libpthread)
 - #55750 (Make `NodeId` and `HirLocalId` `newtype_index`)
 - #55778 (Wrap some query results in `Lrc`.)
 - #55781 (More precise spans for temps and their drops)
 - #55785 (Add mem::forget_unsized() for forgetting unsized values)
 - #55852 (Rewrite `...` as `..=` as a `MachineApplicable` 2018 idiom lint)
 - #55865 (Unix RwLock: avoid racy access to write_locked)
 - #55901 (fix various typos in doc comments)
 - #55926 (Change sidebar selector to fix compatibility with docs.rs)
 - #55930 (A handful of hir tweaks)
 - #55932 (core/char: Speed up `to_digit()` for `radix <= 10`)
 - #55956 (add tests for some fixed ICEs)

Failed merges:

r? @ghost

Author: bors

Diff for: src/Cargo.lock

@@ -2278,12 +2278,14 @@ version = "0.0.0"
 dependencies = [
  "flate2 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memmap 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc_macro 0.0.0",
  "rustc 0.0.0",
  "rustc_data_structures 0.0.0",
  "rustc_errors 0.0.0",
  "rustc_target 0.0.0",
  "serialize 0.0.0",
+ "stable_deref_trait 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "syntax 0.0.0",
  "syntax_ext 0.0.0",
  "syntax_pos 0.0.0",

Diff for: src/liballoc/collections/btree/node.rs

@@ -69,7 +69,7 @@ struct LeafNode<K, V> {
 
     /// This node's index into the parent node's `edges` array.
     /// `*node.parent.edges[node.parent_idx]` should be the same thing as `node`.
-    /// This is only guaranteed to be initialized when `parent` is nonnull.
+    /// This is only guaranteed to be initialized when `parent` is non-null.
     parent_idx: MaybeUninit<u16>,
 
     /// The number of keys and values this node stores.

Diff for: src/liballoc/raw_vec.rs

@@ -44,7 +44,7 @@ use boxed::Box;
 /// This enables you to use capacity growing logic catch the overflows in your length
 /// that might occur with zero-sized types.
 ///
-/// However this means that you need to be careful when roundtripping this type
+/// However this means that you need to be careful when round-tripping this type
 /// with a `Box<[T]>`: `cap()` won't yield the len. However `with_capacity`,
 /// `shrink_to_fit`, and `from_box` will actually set RawVec's private capacity
 /// field. This allows zero-sized types to not be special-cased by consumers of

Diff for: src/liballoc/string.rs

@@ -618,7 +618,15 @@ impl String {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn from_utf16(v: &[u16]) -> Result<String, FromUtf16Error> {
-        decode_utf16(v.iter().cloned()).collect::<Result<_, _>>().map_err(|_| FromUtf16Error(()))
+        let mut ret = String::with_capacity(v.len());
+        for c in decode_utf16(v.iter().cloned()) {
+            if let Ok(c) = c {
+                ret.push(c);
+            } else {
+                return Err(FromUtf16Error(()));
+            }
+        }
+        Ok(ret)
     }
 
     /// Decode a UTF-16 encoded slice `v` into a `String`, replacing

Diff for: src/libcore/benches/char/methods.rs

@@ -0,0 +1,42 @@
+// Copyright 2017 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 test::Bencher;
+
+const CHARS: [char; 9] = ['0', 'x', '2', '5', 'A', 'f', '7', '8', '9'];
+const RADIX: [u32; 5] = [2, 8, 10, 16, 32];
+
+#[bench]
+fn bench_to_digit_radix_2(b: &mut Bencher) {
+    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| c.to_digit(2)).min())
+}
+
+#[bench]
+fn bench_to_digit_radix_10(b: &mut Bencher) {
+    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| c.to_digit(10)).min())
+}
+
+#[bench]
+fn bench_to_digit_radix_16(b: &mut Bencher) {
+    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| c.to_digit(16)).min())
+}
+
+#[bench]
+fn bench_to_digit_radix_36(b: &mut Bencher) {
+    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| c.to_digit(36)).min())
+}
+
+#[bench]
+fn bench_to_digit_radix_var(b: &mut Bencher) {
+    b.iter(|| CHARS.iter().cycle()
+        .zip(RADIX.iter().cycle())
+        .take(10_000)
+        .map(|(c, radix)| c.to_digit(*radix)).min())
+}

Diff for: src/libcore/benches/char/mod.rs

@@ -0,0 +1,11 @@
+// Copyright 2017 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.
+
+mod methods;

Diff for: src/libcore/benches/lib.rs

@@ -15,6 +15,7 @@ extern crate core;
 extern crate test;
 
 mod any;
+mod char;
 mod hash;
 mod iter;
 mod num;

Diff for: src/libcore/char/methods.rs

@@ -121,15 +121,24 @@ impl char {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
     pub fn to_digit(self, radix: u32) -> Option<u32> {
-        if radix > 36 {
-            panic!("to_digit: radix is too high (maximum 36)");
-        }
-        let val = match self {
-          '0' ..= '9' => self as u32 - '0' as u32,
-          'a' ..= 'z' => self as u32 - 'a' as u32 + 10,
-          'A' ..= 'Z' => self as u32 - 'A' as u32 + 10,
-          _ => return None,
+        assert!(radix <= 36, "to_digit: radix is too high (maximum 36)");
+
+        // the code is split up here to improve execution speed for cases where
+        // the `radix` is constant and 10 or smaller
+        let val = if radix <= 10  {
+            match self {
+                '0' ..= '9' => self as u32 - '0' as u32,
+                _ => return None,
+            }
+        } else {
+            match self {
+                '0'..='9' => self as u32 - '0' as u32,
+                'a'..='z' => self as u32 - 'a' as u32 + 10,
+                'A'..='Z' => self as u32 - 'A' as u32 + 10,
+                _ => return None,
+            }
         };
+
         if val < radix { Some(val) }
         else { None }
     }

Diff for: src/libcore/intrinsics.rs

@@ -672,6 +672,9 @@ extern "rust-intrinsic" {
     ///
     /// More specifically, this is the offset in bytes between successive
     /// items of the same type, including alignment padding.
+    ///
+    /// The stabilized version of this intrinsic is
+    /// [`std::mem::size_of`](../../std/mem/fn.size_of.html).
     pub fn size_of<T>() -> usize;
 
     /// Moves a value to an uninitialized memory location.
@@ -714,6 +717,10 @@ extern "rust-intrinsic" {
     /// initialize memory previous set to the result of `uninit`.
     pub fn uninit<T>() -> T;
 
+    /// Moves a value out of scope without running drop glue.
+    #[cfg(not(stage0))]
+    pub fn forget<T: ?Sized>(_: T);
+
     /// Reinterprets the bits of a value of one type as another type.
     ///
     /// Both types must have the same size. Neither the original, nor the result,

Diff for: src/libcore/lib.rs

@@ -106,6 +106,7 @@
 #![feature(staged_api)]
 #![feature(stmt_expr_attributes)]
 #![feature(unboxed_closures)]
+#![feature(unsized_locals)]
 #![feature(untagged_unions)]
 #![feature(unwind_attributes)]
 #![feature(doc_alias)]

Diff for: src/libcore/mem.rs

@@ -143,6 +143,19 @@ pub fn forget<T>(t: T) {
     ManuallyDrop::new(t);
 }
 
+/// Like [`forget`], but also accepts unsized values.
+///
+/// This function is just a shim intended to be removed when the `unsized_locals` feature gets
+/// stabilized.
+///
+/// [`forget`]: fn.forget.html
+#[inline]
+#[cfg(not(stage0))]
+#[unstable(feature = "forget_unsized", issue = "0")]
+pub fn forget_unsized<T: ?Sized>(t: T) {
+    unsafe { intrinsics::forget(t) }
+}
+
 /// Returns the size of a type in bytes.
 ///
 /// More specifically, this is the offset in bytes between successive elements

Diff for: src/libcore/num/f32.rs

@@ -445,7 +445,7 @@ impl f32 {
     /// signaling NaNs on MIPS are quiet NaNs on x86, and vice-versa.
     ///
     /// Rather than trying to preserve signaling-ness cross-platform, this
-    /// implementation favours preserving the exact bits. This means that
+    /// implementation favors preserving the exact bits. This means that
     /// any payloads encoded in NaNs will be preserved even if the result of
     /// this method is sent over the network from an x86 machine to a MIPS one.
     ///

Diff for: src/libcore/task/wake.rs

@@ -108,7 +108,7 @@ impl Drop for Waker {
 /// is ready to be run.
 ///
 /// This is similar to the `Waker` type, but cannot be sent across threads.
-/// Task executors can use this type to implement more optimized singlethreaded wakeup
+/// Task executors can use this type to implement more optimized single-threaded wakeup
 /// behavior.
 #[repr(transparent)]
 #[derive(Clone)]

Diff for: src/liblibc

@@ -535,7 +535,7 @@ impl TokenTree {
     }
 }
 
-/// Prints token treee in a form convenient for debugging.
+/// Prints token tree in a form convenient for debugging.
 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
 impl fmt::Debug for TokenTree {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
@@ -730,7 +730,7 @@ impl fmt::Debug for Group {
 
 /// An `Punct` is an single punctuation character like `+`, `-` or `#`.
 ///
-/// Multicharacter operators like `+=` are represented as two instances of `Punct` with different
+/// Multi-character operators like `+=` are represented as two instances of `Punct` with different
 /// forms of `Spacing` returned.
 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
 #[derive(Clone)]
@@ -788,7 +788,7 @@ impl Punct {
 
     /// Returns the spacing of this punctuation character, indicating whether it's immediately
     /// followed by another `Punct` in the token stream, so they can potentially be combined into
-    /// a multicharacter operator (`Joint`), or it's followed by some other token or whitespace
+    /// a multi-character operator (`Joint`), or it's followed by some other token or whitespace
     /// (`Alone`) so the operator has certainly ended.
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     pub fn spacing(&self) -> Spacing {
@@ -947,7 +947,7 @@ macro_rules! suffixed_int_literals {
         /// This function will create an integer like `1u32` where the integer
         /// value specified is the first part of the token and the integral is
         /// also suffixed at the end.
-        /// Literals created from negative numbers may not survive rountrips through
+        /// Literals created from negative numbers may not survive round-trips through
         /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal).
         ///
         /// Literals created through this method have the `Span::call_site()`
@@ -1047,7 +1047,7 @@ impl Literal {
 
     /// Creates a new suffixed floating-point literal.
     ///
-    /// This consturctor will create a literal like `1.0f32` where the value
+    /// This constructor will create a literal like `1.0f32` where the value
     /// specified is the preceding part of the token and `f32` is the suffix of
     /// the token. This token will always be inferred to be an `f32` in the
     /// compiler.
@@ -1096,7 +1096,7 @@ impl Literal {
 
     /// Creates a new suffixed floating-point literal.
     ///
-    /// This consturctor will create a literal like `1.0f64` where the value
+    /// This constructor will create a literal like `1.0f64` where the value
     /// specified is the preceding part of the token and `f64` is the suffix of
     /// the token. This token will always be inferred to be an `f64` in the
     /// compiler.

Diff for: src/libproc_macro/lib.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 //! Some facilities for tracking how codegen-units are reused during incremental
-//! compilition. This is used for incremental compiliation tests and debug
+//! compilation. This is used for incremental compilation tests and debug
 //! output.
 
 use session::Session;

Diff for: src/librustc/dep_graph/cgu_reuse_tracker.rs

@@ -63,7 +63,7 @@
 use mir::interpret::GlobalId;
 use hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX};
 use hir::map::DefPathHash;
-use hir::{HirId, ItemLocalId};
+use hir::HirId;
 
 use ich::{Fingerprint, StableHashingContext};
 use rustc_data_structures::stable_hasher::{StableHasher, HashStable};
@@ -790,11 +790,11 @@ impl<'a, 'gcx: 'tcx + 'a, 'tcx: 'a> DepNodeParams<'a, 'gcx, 'tcx> for HirId {
     fn to_fingerprint(&self, tcx: TyCtxt<'_, '_, '_>) -> Fingerprint {
         let HirId {
             owner,
-            local_id: ItemLocalId(local_id),
+            local_id,
         } = *self;
 
         let def_path_hash = tcx.def_path_hash(DefId::local(owner));
-        let local_id = Fingerprint::from_smaller_hash(local_id as u64);
+        let local_id = Fingerprint::from_smaller_hash(local_id.as_u32().into());
 
         def_path_hash.0.combine(local_id)
     }

Diff for: src/librustc/dep_graph/dep_node.rs

@@ -36,7 +36,7 @@ pub enum NonMacroAttrKind {
     Tool,
     /// Single-segment custom attribute registered by a derive macro (`#[serde(default)]`).
     DeriveHelper,
-    /// Single-segment custom attriubte registered by a legacy plugin (`register_attribute`).
+    /// Single-segment custom attribute registered by a legacy plugin (`register_attribute`).
     LegacyPluginHelper,
     /// Single-segment custom attribute not registered in any way (`#[my_attr]`).
     Custom,

Diff for: src/librustc/hir/def.rs

@@ -49,7 +49,6 @@ use hir::map::{self, Map};
 use super::itemlikevisit::DeepVisitor;
 
 use std::cmp;
-use std::u32;
 
 #[derive(Copy, Clone)]
 pub enum FnKind<'a> {
@@ -1152,8 +1151,8 @@ pub struct IdRange {
 impl IdRange {
     pub fn max() -> IdRange {
         IdRange {
-            min: NodeId::from_u32(u32::MAX),
-            max: NodeId::from_u32(u32::MIN),
+            min: NodeId::MAX,
+            max: NodeId::from_u32(0),
         }
     }
 

Diff for: src/librustc/hir/intravisit.rs

@@ -588,7 +588,7 @@ impl<'a> LoweringContext<'a> {
             *local_id_counter += 1;
             hir::HirId {
                 owner: def_index,
-                local_id: hir::ItemLocalId(local_id),
+                local_id: hir::ItemLocalId::from_u32(local_id),
             }
         })
     }
@@ -616,7 +616,7 @@ impl<'a> LoweringContext<'a> {
 
             hir::HirId {
                 owner: def_index,
-                local_id: hir::ItemLocalId(local_id),
+                local_id: hir::ItemLocalId::from_u32(local_id),
             }
         })
     }

Diff for: src/librustc/hir/lowering.rs

@@ -101,7 +101,7 @@ impl<'a, 'hir: 'a> HirIdValidator<'a, 'hir> {
         if max != self.hir_ids_seen.len() - 1 {
             // Collect the missing ItemLocalIds
             let missing: Vec<_> = (0 .. max as u32 + 1)
-              .filter(|&i| !self.hir_ids_seen.contains_key(&ItemLocalId(i)))
+              .filter(|&i| !self.hir_ids_seen.contains_key(&ItemLocalId::from_u32(i)))
               .collect();
 
             // Try to map those to something more useful
@@ -110,7 +110,7 @@ impl<'a, 'hir: 'a> HirIdValidator<'a, 'hir> {
             for local_id in missing {
                 let hir_id = HirId {
                     owner: owner_def_index,
-                    local_id: ItemLocalId(local_id as u32),
+                    local_id: ItemLocalId::from_u32(local_id),
                 };
 
                 trace!("missing hir id {:#?}", hir_id);
@@ -124,7 +124,7 @@ impl<'a, 'hir: 'a> HirIdValidator<'a, 'hir> {
                                        .enumerate()
                                        .find(|&(_, &entry)| hir_id == entry)
                                        .expect("no node_to_hir_id entry");
-                let node_id = NodeId::new(node_id);
+                let node_id = NodeId::from_usize(node_id);
                 missing_items.push(format!("[local_id: {}, node:{}]",
                                            local_id,
                                            self.hir_map.node_to_string(node_id)));