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

3 files changed, 21 insertions, 39 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 808e19d6f12..227017a9073 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -18,7 +18,6 @@ pub use util::parser::ExprPrecedence;
 use ext::hygiene::{Mark, SyntaxContext};
 use print::pprust;
 use ptr::P;
-use rustc_data_structures::indexed_vec;
 use rustc_data_structures::indexed_vec::Idx;
 #[cfg(target_arch = "x86_64")]
 use rustc_data_structures::static_assert;
@@ -33,7 +32,6 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::sync::Lrc;
 use serialize::{self, Decoder, Encoder};
 use std::fmt;
-use std::u32;
 
 pub use rustc_target::abi::FloatTy;
 
@@ -215,71 +213,54 @@ pub struct ParenthesisedArgs {
     pub output: Option<P<Ty>>,
 }
 
-#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
-pub struct NodeId(u32);
-
-impl NodeId {
-    pub fn new(x: usize) -> NodeId {
-        assert!(x < (u32::MAX as usize));
-        NodeId(x as u32)
-    }
-
-    pub fn from_u32(x: u32) -> NodeId {
-        NodeId(x)
-    }
-
-    pub fn as_usize(&self) -> usize {
-        self.0 as usize
+// hack to ensure that we don't try to access the private parts of `NodeId` in this module
+mod node_id_inner {
+    use rustc_data_structures::indexed_vec::Idx;
+    newtype_index! {
+        pub struct NodeId {
+            ENCODABLE = custom
+            DEBUG_FORMAT = "NodeId({})"
+        }
     }
+}
 
-    pub fn as_u32(&self) -> u32 {
-        self.0
-    }
+pub use self::node_id_inner::NodeId;
 
+impl NodeId {
     pub fn placeholder_from_mark(mark: Mark) -> Self {
-        NodeId(mark.as_u32())
+        NodeId::from_u32(mark.as_u32())
     }
 
     pub fn placeholder_to_mark(self) -> Mark {
-        Mark::from_u32(self.0)
+        Mark::from_u32(self.as_u32())
     }
 }
 
 impl fmt::Display for NodeId {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Display::fmt(&self.0, f)
+        fmt::Display::fmt(&self.as_u32(), f)
     }
 }
 
 impl serialize::UseSpecializedEncodable for NodeId {
     fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
-        s.emit_u32(self.0)
+        s.emit_u32(self.as_u32())
     }
 }
 
 impl serialize::UseSpecializedDecodable for NodeId {
     fn default_decode<D: Decoder>(d: &mut D) -> Result<NodeId, D::Error> {
-        d.read_u32().map(NodeId)
-    }
-}
-
-impl indexed_vec::Idx for NodeId {
-    fn new(idx: usize) -> Self {
-        NodeId::new(idx)
-    }
-
-    fn index(self) -> usize {
-        self.as_usize()
+        d.read_u32().map(NodeId::from_u32)
     }
 }
 
 /// Node id used to represent the root of the crate.
-pub const CRATE_NODE_ID: NodeId = NodeId(0);
+pub const CRATE_NODE_ID: NodeId = NodeId::from_u32_const(0);
 
 /// When parsing and doing expansions, we initially give all AST nodes this AST
 /// node value. Then later, in the renumber pass, we renumber them to have
 /// small, positive ids.
-pub const DUMMY_NODE_ID: NodeId = NodeId(!0);
+pub const DUMMY_NODE_ID: NodeId = NodeId::MAX;
 
 /// A modifier on a bound, currently this is only used for `?Sized`, where the
 /// modifier is `Maybe`. Negative bounds should also be handled here.
diff --git a/src/libsyntax/lib.rs b/src/libsyntax/lib.rs
index e9a6535cba1..9bbd59e09be 100644
--- a/src/libsyntax/lib.rs
+++ b/src/libsyntax/lib.rs
@@ -26,6 +26,7 @@
 #![feature(rustc_diagnostic_macros)]
 #![feature(slice_sort_by_cached_key)]
 #![feature(str_escape)]
+#![feature(step_trait)]
 #![feature(try_trait)]
 #![feature(unicode_internals)]
 
@@ -37,7 +38,7 @@ extern crate serialize;
 #[macro_use] extern crate log;
 pub extern crate rustc_errors as errors;
 extern crate syntax_pos;
-extern crate rustc_data_structures;
+#[macro_use] extern crate rustc_data_structures;
 extern crate rustc_target;
 #[macro_use] extern crate scoped_tls;
 #[macro_use]
diff --git a/src/libsyntax/tokenstream.rs b/src/libsyntax/tokenstream.rs
index 29bd63d28c5..cfdd4340a19 100644
--- a/src/libsyntax/tokenstream.rs
+++ b/src/libsyntax/tokenstream.rs
@@ -150,7 +150,7 @@ impl TokenTree {
         }
     }
 
-    /// Modify the `TokenTree`'s span inplace.
+    /// Modify the `TokenTree`'s span in-place.
     pub fn set_span(&mut self, span: Span) {
         match *self {
             TokenTree::Token(ref mut sp, _) => *sp = span,