Fix merge issues

.azure-pipelines/steps/run.yml

@@ -37,7 +37,8 @@ steps:
     set -e
     brew update
     brew install xz
-    brew install swig
+    brew install swig@3
+    brew link --force swig@3
   displayName: Install build dependencies (OSX)
   condition: and(succeeded(), eq(variables['Agent.OS'], 'Darwin'), eq(variables['SCRIPT'],'./x.py dist'))
 

.travis.yml

@@ -263,7 +263,8 @@ install:
           if [[ "$SCRIPT" == "./x.py dist" ]]; then
             travis_retry brew update &&
             travis_retry brew install xz &&
-            travis_retry brew install swig;
+            travis_retry brew install swig@3 &&
+            brew link --force swig@3;
           fi &&
           travis_retry curl -fo /usr/local/bin/sccache https://s3-us-west-1.amazonaws.com/rust-lang-ci2/rust-ci-mirror/2018-04-02-sccache-x86_64-apple-darwin &&
             chmod +x /usr/local/bin/sccache &&

src/bootstrap/job.rs

@@ -32,6 +32,7 @@
 use std::env;
 use std::io;
 use std::mem;
+use std::ptr;
 use crate::Build;
 
 type HANDLE = *mut u8;
@@ -118,8 +119,8 @@ pub unsafe fn setup(build: &mut Build) {
     SetErrorMode(mode & !SEM_NOGPFAULTERRORBOX);
 
     // Create a new job object for us to use
-    let job = CreateJobObjectW(0 as *mut _, 0 as *const _);
-    assert!(job != 0 as *mut _, "{}", io::Error::last_os_error());
+    let job = CreateJobObjectW(ptr::null_mut(), ptr::null());
+    assert!(!job.is_null(), "{}", io::Error::last_os_error());
 
     // Indicate that when all handles to the job object are gone that all
     // process in the object should be killed. Note that this includes our
@@ -166,8 +167,8 @@ pub unsafe fn setup(build: &mut Build) {
     };
 
     let parent = OpenProcess(PROCESS_DUP_HANDLE, FALSE, pid.parse().unwrap());
-    assert!(parent != 0 as *mut _, "{}", io::Error::last_os_error());
-    let mut parent_handle = 0 as *mut _;
+    assert!(!parent.is_null(), "{}", io::Error::last_os_error());
+    let mut parent_handle = ptr::null_mut();
     let r = DuplicateHandle(GetCurrentProcess(), job,
                             parent, &mut parent_handle,
                             0, FALSE, DUPLICATE_SAME_ACCESS);

src/bootstrap/util.rs

@@ -209,7 +209,7 @@ pub fn symlink_dir(config: &Config, src: &Path, dest: &Path) -> io::Result<()> {
             let h = CreateFileW(path.as_ptr(),
                                 GENERIC_WRITE,
                                 FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
-                                0 as *mut _,
+                                ptr::null_mut(),
                                 OPEN_EXISTING,
                                 FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS,
                                 ptr::null_mut());

src/ci/cpu-usage-over-time.py

@@ -30,23 +30,8 @@
 # the second column is always zero.
 #
 # Once you've downloaded a file there's various ways to plot it and visualize
-# it. For command line usage you can use a script like so:
-#
-#      set timefmt '%Y-%m-%dT%H:%M:%S'
-#      set xdata time
-#      set ylabel "Idle CPU %"
-#      set xlabel "Time"
-#      set datafile sep ','
-#      set term png
-#      set output "printme.png"
-#      set grid
-#      builder = "i686-apple"
-#      plot "cpu-".builder.".csv" using 1:2 with lines title builder
-#
-# Executed as `gnuplot < ./foo.plot` it will generate a graph called
-# `printme.png` which you can then open up. If you know how to improve this
-# script or the viewing process that would be much appreciated :) (or even if
-# you know how to automate it!)
+# it. For command line usage you use the `src/etc/cpu-usage-over-time-plot.sh`
+# script in this repository.
 
 import datetime
 import sys

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

@@ -132,7 +132,7 @@ The advantages over a simple `fn(&str) -> u32` are:
 In addition to procedural macros, you can define new
 [`derive`](../../reference/attributes/derive.md)-like attributes and other kinds
 of extensions.  See `Registry::register_syntax_extension` and the
-`SyntaxExtension` enum.  For a more involved macro example, see
+`SyntaxExtension` struct.  For a more involved macro example, see
 [`regex_macros`](https://github.com/rust-lang/regex/blob/master/regex_macros/src/lib.rs).
 
 

src/etc/cpu-usage-over-time-plot.sh

@@ -0,0 +1,49 @@
+#!/bin/bash
+
+# A small script to help visualizing CPU usage over time data collected on CI
+# using `gnuplot`.
+#
+# This script is expected to be called with two arguments. The first is the full
+# commit SHA of the build you're interested in, and the second is the name of
+# the builder. For example:
+#
+#  ./src/etc/cpu-usage-over-time-plot.sh e699ea096fcc2fc9ce8e8bcf884e11496a31cc9f i686-mingw-1
+#
+# That will generate `$builder.png` in the current directory which you can open
+# up to see a hopefully pretty graph.
+#
+# Improvements to this script are greatly appreciated!
+
+set -ex
+
+bucket=rust-lang-ci-evalazure
+commit=$1
+builder=$2
+
+curl -O https://$bucket.s3.amazonaws.com/rustc-builds/$commit/cpu-$builder.csv
+
+gnuplot <<-EOF
+reset
+set timefmt '%Y-%m-%dT%H:%M:%S'
+set xdata time
+set ylabel "CPU Usage %"
+set xlabel "Time"
+set datafile sep ','
+set term png size 3000,1000
+set output "$builder.png"
+set grid
+
+f(x) = mean_y
+fit f(x) 'cpu-$builder.csv' using 1:(100-\$2) via mean_y
+
+set label 1 gprintf("Average = %g%%", mean_y) center font ",18"
+set label 1 at graph 0.50, 0.25
+set xtics rotate by 45 offset -2,-2.4 300
+set ytics 10
+set boxwidth 0.5
+
+plot \\
+   mean_y with lines linetype 1 linecolor rgb "#ff0000" title "average", \\
+   "cpu-$builder.csv" using 1:(100-\$2) with points pointtype 7 pointsize 0.4 title "$builder", \\
+   "" using 1:(100-\$2) smooth bezier linewidth 3 title "bezier"
+EOF

src/etc/rust-lldb

@@ -31,7 +31,7 @@ category_definition="type summary add --no-value --python-function lldb_rust_for
 category_enable="type category enable Rust"
 
 # Call LLDB with the commands added to the argument list
-exec "$lldb" --one-line-before-file="$script_import" \
-    --one-line-before-file="$category_definition" \
-    --one-line-before-file="$category_enable" \
+exec "$lldb" --one-line-before-file "$script_import" \
+    --one-line-before-file "$category_definition" \
+    --one-line-before-file "$category_enable" \
     "$@"

src/liballoc/rc.rs

@@ -1515,18 +1515,18 @@ impl<T: ?Sized> Weak<T> {
     ///
     /// ```
     /// #![feature(weak_ptr_eq)]
-    /// use std::rc::{Rc, Weak};
+    /// use std::rc::Rc;
     ///
     /// let first_rc = Rc::new(5);
     /// let first = Rc::downgrade(&first_rc);
     /// let second = Rc::downgrade(&first_rc);
     ///
-    /// assert!(Weak::ptr_eq(&first, &second));
+    /// assert!(first.ptr_eq(&second));
     ///
     /// let third_rc = Rc::new(5);
     /// let third = Rc::downgrade(&third_rc);
     ///
-    /// assert!(!Weak::ptr_eq(&first, &third));
+    /// assert!(!first.ptr_eq(&third));
     /// ```
     ///
     /// Comparing `Weak::new`.
@@ -1537,16 +1537,16 @@ impl<T: ?Sized> Weak<T> {
     ///
     /// let first = Weak::new();
     /// let second = Weak::new();
-    /// assert!(Weak::ptr_eq(&first, &second));
+    /// assert!(first.ptr_eq(&second));
     ///
     /// let third_rc = Rc::new(());
     /// let third = Rc::downgrade(&third_rc);
-    /// assert!(!Weak::ptr_eq(&first, &third));
+    /// assert!(!first.ptr_eq(&third));
     /// ```
     #[inline]
     #[unstable(feature = "weak_ptr_eq", issue = "55981")]
-    pub fn ptr_eq(this: &Self, other: &Self) -> bool {
-        this.ptr.as_ptr() == other.ptr.as_ptr()
+    pub fn ptr_eq(&self, other: &Self) -> bool {
+        self.ptr.as_ptr() == other.ptr.as_ptr()
     }
 }
 

src/liballoc/sync.rs

@@ -1349,18 +1349,18 @@ impl<T: ?Sized> Weak<T> {
     ///
     /// ```
     /// #![feature(weak_ptr_eq)]
-    /// use std::sync::{Arc, Weak};
+    /// use std::sync::Arc;
     ///
     /// let first_rc = Arc::new(5);
     /// let first = Arc::downgrade(&first_rc);
     /// let second = Arc::downgrade(&first_rc);
     ///
-    /// assert!(Weak::ptr_eq(&first, &second));
+    /// assert!(first.ptr_eq(&second));
     ///
     /// let third_rc = Arc::new(5);
     /// let third = Arc::downgrade(&third_rc);
     ///
-    /// assert!(!Weak::ptr_eq(&first, &third));
+    /// assert!(!first.ptr_eq(&third));
     /// ```
     ///
     /// Comparing `Weak::new`.
@@ -1371,16 +1371,16 @@ impl<T: ?Sized> Weak<T> {
     ///
     /// let first = Weak::new();
     /// let second = Weak::new();
-    /// assert!(Weak::ptr_eq(&first, &second));
+    /// assert!(first.ptr_eq(&second));
     ///
     /// let third_rc = Arc::new(());
     /// let third = Arc::downgrade(&third_rc);
-    /// assert!(!Weak::ptr_eq(&first, &third));
+    /// assert!(!first.ptr_eq(&third));
     /// ```
     #[inline]
     #[unstable(feature = "weak_ptr_eq", issue = "55981")]
-    pub fn ptr_eq(this: &Self, other: &Self) -> bool {
-        this.ptr.as_ptr() == other.ptr.as_ptr()
+    pub fn ptr_eq(&self, other: &Self) -> bool {
+        self.ptr.as_ptr() == other.ptr.as_ptr()
     }
 }
 

src/libarena/lib.rs

@@ -114,8 +114,8 @@ impl<T> Default for TypedArena<T> {
         TypedArena {
             // We set both `ptr` and `end` to 0 so that the first call to
             // alloc() will trigger a grow().
-            ptr: Cell::new(0 as *mut T),
-            end: Cell::new(0 as *mut T),
+            ptr: Cell::new(ptr::null_mut()),
+            end: Cell::new(ptr::null_mut()),
             chunks: RefCell::new(vec![]),
             _own: PhantomData,
         }
@@ -370,8 +370,8 @@ impl Default for DroplessArena {
     #[inline]
     fn default() -> DroplessArena {
         DroplessArena {
-            ptr: Cell::new(0 as *mut u8),
-            end: Cell::new(0 as *mut u8),
+            ptr: Cell::new(ptr::null_mut()),
+            end: Cell::new(ptr::null_mut()),
             chunks: Default::default(),
         }
     }

src/libcore/convert.rs

@@ -202,9 +202,9 @@ pub trait AsMut<T: ?Sized> {
 /// A value-to-value conversion that consumes the input value. The
 /// opposite of [`From`].
 ///
-/// One should only implement `Into` if a conversion to a type outside the current crate is
-/// required. Otherwise one should always prefer implementing [`From`] over `Into` because
-/// implementing [`From`] automatically provides one with a implementation of `Into` thanks to
+/// One should only implement [`Into`] if a conversion to a type outside the current crate is
+/// required. Otherwise one should always prefer implementing [`From`] over [`Into`] because
+/// implementing [`From`] automatically provides one with a implementation of [`Into`] thanks to
 /// the blanket implementation in the standard library. [`From`] cannot do these type of
 /// conversions because of Rust's orphaning rules.
 ///
@@ -213,9 +213,9 @@ pub trait AsMut<T: ?Sized> {
 /// # Generic Implementations
 ///
 /// - [`From`]`<T> for U` implies `Into<U> for T`
-/// - `Into` is reflexive, which means that `Into<T> for T` is implemented
+/// - [`Into`] is reflexive, which means that `Into<T> for T` is implemented
 ///
-/// # Implementing `Into` for conversions to external types
+/// # Implementing [`Into`] for conversions to external types
 ///
 /// If the destination type is not part of the current crate
 /// then you can't implement [`From`] directly.
@@ -231,7 +231,7 @@ pub trait AsMut<T: ?Sized> {
 /// ```
 /// This will fail to compile because we cannot implement a trait for a type
 /// if both the trait and the type are not defined by the current crate.
-/// This is due to Rust's orphaning rules. To bypass this, you can implement `Into` directly:
+/// This is due to Rust's orphaning rules. To bypass this, you can implement [`Into`] directly:
 ///
 /// ```
 /// struct Wrapper<T>(Vec<T>);
@@ -242,19 +242,19 @@ pub trait AsMut<T: ?Sized> {
 /// }
 /// ```
 ///
-/// It is important to understand that `Into` does not provide a [`From`] implementation
-/// (as [`From`] does with `Into`). Therefore, you should always try to implement [`From`]
-/// and then fall back to `Into` if [`From`] can't be implemented.
+/// It is important to understand that [`Into`] does not provide a [`From`] implementation
+/// (as [`From`] does with [`Into`]). Therefore, you should always try to implement [`From`]
+/// and then fall back to [`Into`] if [`From`] can't be implemented.
 ///
-/// Prefer using `Into` over [`From`] when specifying trait bounds on a generic function
-/// to ensure that types that only implement `Into` can be used as well.
+/// Prefer using [`Into`] over [`From`] when specifying trait bounds on a generic function
+/// to ensure that types that only implement [`Into`] can be used as well.
 ///
 /// # Examples
 ///
 /// [`String`] implements `Into<Vec<u8>>`:
 ///
 /// In order to express that we want a generic function to take all arguments that can be
-/// converted to a specified type `T`, we can use a trait bound of `Into<T>`.
+/// converted to a specified type `T`, we can use a trait bound of [`Into`]`<T>`.
 /// For example: The function `is_hello` takes all arguments that can be converted into a
 /// `Vec<u8>`.
 ///
@@ -273,7 +273,7 @@ pub trait AsMut<T: ?Sized> {
 /// [`Result<T, E>`]: ../../std/result/enum.Result.html
 /// [`String`]: ../../std/string/struct.String.html
 /// [`From`]: trait.From.html
-/// [`into`]: trait.Into.html#tymethod.into
+/// [`Into`]: trait.Into.html
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait Into<T>: Sized {
     /// Performs the conversion.

src/libcore/ffi.rs

@@ -5,6 +5,8 @@
 //! Utilities related to FFI bindings.
 
 use crate::fmt;
+use crate::marker::PhantomData;
+use crate::ops::{Deref, DerefMut};
 
 /// Equivalent to C's `void` type when used as a [pointer].
 ///
@@ -45,25 +47,33 @@ impl fmt::Debug for c_void {
 }
 
 /// Basic implementation of a `va_list`.
+// The name is WIP, using `VaListImpl` for now.
 #[cfg(any(all(not(target_arch = "aarch64"), not(target_arch = "powerpc"),
-              not(target_arch = "x86_64")),
+              not(target_arch = "x86_64"), not(target_arch = "asmjs")),
+          all(target_arch = "aarch64", target_os = "ios"),
+          windows))]
+#[repr(transparent)]
+#[unstable(feature = "c_variadic",
+           reason = "the `c_variadic` feature has not been properly tested on \
+                     all supported platforms",
+           issue = "44930")]
+#[lang = "va_list"]
+pub struct VaListImpl<'f> {
+    ptr: *mut c_void,
+    _marker: PhantomData<&'f c_void>,
+}
+
+#[cfg(any(all(not(target_arch = "aarch64"), not(target_arch = "powerpc"),
+              not(target_arch = "x86_64"), not(target_arch = "asmjs")),
           all(target_arch = "aarch64", target_os = "ios"),
           windows))]
 #[unstable(feature = "c_variadic",
            reason = "the `c_variadic` feature has not been properly tested on \
                      all supported platforms",
            issue = "44930")]
-extern {
-    type VaListImpl;
-}
-
-#[cfg(any(all(not(target_arch = "aarch64"), not(target_arch = "powerpc"),
-              not(target_arch = "x86_64")),
-          all(target_arch = "aarch64", target_os = "ios"),
-          windows))]
-impl fmt::Debug for VaListImpl {
+impl<'f> fmt::Debug for VaListImpl<'f> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "va_list* {:p}", self)
+        write!(f, "va_list* {:p}", self.ptr)
     }
 }
 
@@ -79,12 +89,14 @@ impl fmt::Debug for VaListImpl {
            reason = "the `c_variadic` feature has not been properly tested on \
                      all supported platforms",
            issue = "44930")]
-struct VaListImpl {
+#[lang = "va_list"]
+pub struct VaListImpl<'f> {
     stack: *mut c_void,
     gr_top: *mut c_void,
     vr_top: *mut c_void,
     gr_offs: i32,
     vr_offs: i32,
+    _marker: PhantomData<&'f c_void>,
 }
 
 /// PowerPC ABI implementation of a `va_list`.
@@ -95,12 +107,14 @@ struct VaListImpl {
            reason = "the `c_variadic` feature has not been properly tested on \
                      all supported platforms",
            issue = "44930")]
-struct VaListImpl {
+#[lang = "va_list"]
+pub struct VaListImpl<'f> {
     gpr: u8,
     fpr: u8,
     reserved: u16,
     overflow_arg_area: *mut c_void,
     reg_save_area: *mut c_void,
+    _marker: PhantomData<&'f c_void>,
 }
 
 /// x86_64 ABI implementation of a `va_list`.
@@ -111,22 +125,131 @@ struct VaListImpl {
            reason = "the `c_variadic` feature has not been properly tested on \
                      all supported platforms",
            issue = "44930")]
-struct VaListImpl {
+#[lang = "va_list"]
+pub struct VaListImpl<'f> {
     gp_offset: i32,
     fp_offset: i32,
     overflow_arg_area: *mut c_void,
     reg_save_area: *mut c_void,
+    _marker: PhantomData<&'f c_void>,
+}
+
+/// asm.js ABI implementation of a `va_list`.
+// asm.js uses the PNaCl ABI, which specifies that a `va_list` is
+// an array of 4 32-bit integers, according to the old PNaCl docs at
+// https://web.archive.org/web/20130518054430/https://www.chromium.org/nativeclient/pnacl/bitcode-abi#TOC-Derived-Types
+// and clang does the same in `CreatePNaClABIBuiltinVaListDecl` from `lib/AST/ASTContext.cpp`
+#[cfg(all(target_arch = "asmjs", not(windows)))]
+#[repr(C)]
+#[unstable(feature = "c_variadic",
+           reason = "the `c_variadic` feature has not been properly tested on \
+                     all supported platforms",
+           issue = "44930")]
+#[lang = "va_list"]
+pub struct VaListImpl<'f> {
+    inner: [crate::mem::MaybeUninit<i32>; 4],
+    _marker: PhantomData<&'f c_void>,
+}
+
+#[cfg(all(target_arch = "asmjs", not(windows)))]
+#[unstable(feature = "c_variadic",
+           reason = "the `c_variadic` feature has not been properly tested on \
+                     all supported platforms",
+           issue = "44930")]
+impl<'f> fmt::Debug for VaListImpl<'f> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        unsafe {
+            write!(f, "va_list* [{:#x}, {:#x}, {:#x}, {:#x}]",
+                   self.inner[0].read(), self.inner[1].read(),
+                   self.inner[2].read(), self.inner[3].read())
+        }
+    }
 }
 
 /// A wrapper for a `va_list`
-#[lang = "va_list"]
+#[repr(transparent)]
 #[derive(Debug)]
 #[unstable(feature = "c_variadic",
            reason = "the `c_variadic` feature has not been properly tested on \
                      all supported platforms",
            issue = "44930")]
-#[repr(transparent)]
-pub struct VaList<'a>(&'a mut VaListImpl);
+pub struct VaList<'a, 'f: 'a> {
+    #[cfg(any(all(not(target_arch = "aarch64"), not(target_arch = "powerpc"),
+                  not(target_arch = "x86_64"), not(target_arch = "asmjs")),
+              all(target_arch = "aarch64", target_os = "ios"),
+              windows))]
+    inner: VaListImpl<'f>,
+
+    #[cfg(all(any(target_arch = "aarch64", target_arch = "powerpc",
+                  target_arch = "x86_64", target_arch = "asmjs"),
+              any(not(target_arch = "aarch64"), not(target_os = "ios")),
+              not(windows)))]
+    inner: &'a mut VaListImpl<'f>,
+
+    _marker: PhantomData<&'a mut VaListImpl<'f>>,
+}
+
+#[cfg(any(all(not(target_arch = "aarch64"), not(target_arch = "powerpc"),
+              not(target_arch = "x86_64"), not(target_arch = "asmjs")),
+          all(target_arch = "aarch64", target_os = "ios"),
+          windows))]
+#[unstable(feature = "c_variadic",
+           reason = "the `c_variadic` feature has not been properly tested on \
+                     all supported platforms",
+           issue = "44930")]
+impl<'f> VaListImpl<'f> {
+    /// Convert a `VaListImpl` into a `VaList` that is binary-compatible with C's `va_list`.
+    #[inline]
+    pub fn as_va_list<'a>(&'a mut self) -> VaList<'a, 'f> {
+        VaList {
+            inner: VaListImpl { ..*self },
+            _marker: PhantomData,
+        }
+    }
+}
+
+#[cfg(all(any(target_arch = "aarch64", target_arch = "powerpc",
+              target_arch = "x86_64", target_arch = "asmjs"),
+          any(not(target_arch = "aarch64"), not(target_os = "ios")),
+          not(windows)))]
+#[unstable(feature = "c_variadic",
+           reason = "the `c_variadic` feature has not been properly tested on \
+                     all supported platforms",
+           issue = "44930")]
+impl<'f> VaListImpl<'f> {
+    /// Convert a `VaListImpl` into a `VaList` that is binary-compatible with C's `va_list`.
+    #[inline]
+    pub fn as_va_list<'a>(&'a mut self) -> VaList<'a, 'f> {
+        VaList {
+            inner: self,
+            _marker: PhantomData,
+        }
+    }
+}
+
+#[unstable(feature = "c_variadic",
+           reason = "the `c_variadic` feature has not been properly tested on \
+                     all supported platforms",
+           issue = "44930")]
+impl<'a, 'f: 'a> Deref for VaList<'a, 'f> {
+    type Target = VaListImpl<'f>;
+
+    #[inline]
+    fn deref(&self) -> &VaListImpl<'f> {
+        &self.inner
+    }
+}
+
+#[unstable(feature = "c_variadic",
+           reason = "the `c_variadic` feature has not been properly tested on \
+                     all supported platforms",
+           issue = "44930")]
+impl<'a, 'f: 'a> DerefMut for VaList<'a, 'f> {
+    #[inline]
+    fn deref_mut(&mut self) -> &mut VaListImpl<'f> {
+        &mut self.inner
+    }
+}
 
 // The VaArgSafe trait needs to be used in public interfaces, however, the trait
 // itself must not be allowed to be used outside this module. Allowing users to
@@ -175,56 +298,76 @@ impl<T> sealed_trait::VaArgSafe for *mut T {}
            issue = "44930")]
 impl<T> sealed_trait::VaArgSafe for *const T {}
 
-impl<'a> VaList<'a> {
+#[unstable(feature = "c_variadic",
+           reason = "the `c_variadic` feature has not been properly tested on \
+                     all supported platforms",
+           issue = "44930")]
+#[cfg(not(bootstrap))]
+impl<'f> VaListImpl<'f> {
     /// Advance to the next arg.
-    #[unstable(feature = "c_variadic",
-               reason = "the `c_variadic` feature has not been properly tested on \
-                         all supported platforms",
-               issue = "44930")]
+    #[inline]
     pub unsafe fn arg<T: sealed_trait::VaArgSafe>(&mut self) -> T {
         va_arg(self)
     }
 
     /// Copies the `va_list` at the current location.
-    #[unstable(feature = "c_variadic",
-               reason = "the `c_variadic` feature has not been properly tested on \
-                         all supported platforms",
-               issue = "44930")]
     pub unsafe fn with_copy<F, R>(&self, f: F) -> R
-            where F: for<'copy> FnOnce(VaList<'copy>) -> R {
-        #[cfg(any(all(not(target_arch = "aarch64"), not(target_arch = "powerpc"),
-                      not(target_arch = "x86_64")),
-                  all(target_arch = "aarch64", target_os = "ios"),
-                  windows))]
-        let mut ap = va_copy(self);
-        #[cfg(all(any(target_arch = "aarch64", target_arch = "powerpc", target_arch = "x86_64"),
-                  not(windows), not(all(target_arch = "aarch64", target_os = "ios"))))]
-        let mut ap_inner = va_copy(self);
-        #[cfg(all(any(target_arch = "aarch64", target_arch = "powerpc", target_arch = "x86_64"),
-                  not(windows), not(all(target_arch = "aarch64", target_os = "ios"))))]
-        let mut ap = VaList(&mut ap_inner);
-        let ret = f(VaList(ap.0));
+            where F: for<'copy> FnOnce(VaList<'copy, 'f>) -> R {
+        let mut ap = self.clone();
+        let ret = f(ap.as_va_list());
         va_end(&mut ap);
         ret
     }
 }
 
+#[unstable(feature = "c_variadic",
+           reason = "the `c_variadic` feature has not been properly tested on \
+                     all supported platforms",
+           issue = "44930")]
+#[cfg(not(bootstrap))]
+impl<'f> Clone for VaListImpl<'f> {
+    #[inline]
+    fn clone(&self) -> Self {
+        let mut dest = crate::mem::MaybeUninit::uninit();
+        unsafe {
+            va_copy(dest.as_mut_ptr(), self);
+            dest.assume_init()
+        }
+    }
+}
+
+#[unstable(feature = "c_variadic",
+           reason = "the `c_variadic` feature has not been properly tested on \
+                     all supported platforms",
+           issue = "44930")]
+#[cfg(not(bootstrap))]
+impl<'f> Drop for VaListImpl<'f> {
+    fn drop(&mut self) {
+        // FIXME: this should call `va_end`, but there's no clean way to
+        // guarantee that `drop` always gets inlined into its caller,
+        // so the `va_end` would get directly called from the same function as
+        // the corresponding `va_copy`. `man va_end` states that C requires this,
+        // and LLVM basically follows the C semantics, so we need to make sure
+        // that `va_end` is always called from the same function as `va_copy`.
+        // For more details, see https://github.com/rust-lang/rust/pull/59625
+        // and https://llvm.org/docs/LangRef.html#llvm-va-end-intrinsic.
+        //
+        // This works for now, since `va_end` is a no-op on all current LLVM targets.
+    }
+}
+
 extern "rust-intrinsic" {
     /// Destroy the arglist `ap` after initialization with `va_start` or
     /// `va_copy`.
-    fn va_end(ap: &mut VaList<'_>);
+    #[cfg(not(bootstrap))]
+    fn va_end(ap: &mut VaListImpl<'_>);
 
     /// Copies the current location of arglist `src` to the arglist `dst`.
-    #[cfg(any(all(not(target_arch = "aarch64"), not(target_arch = "powerpc"),
-                  not(target_arch = "x86_64")),
-              all(target_arch = "aarch64", target_os = "ios"),
-              windows))]
-    fn va_copy<'a>(src: &VaList<'a>) -> VaList<'a>;
-    #[cfg(all(any(target_arch = "aarch64", target_arch = "powerpc", target_arch = "x86_64"),
-              not(windows), not(all(target_arch = "aarch64", target_os = "ios"))))]
-    fn va_copy(src: &VaList<'_>) -> VaListImpl;
+    #[cfg(not(bootstrap))]
+    fn va_copy<'f>(dest: *mut VaListImpl<'f>, src: &VaListImpl<'f>);
 
     /// Loads an argument of type `T` from the `va_list` `ap` and increment the
     /// argument `ap` points to.
-    fn va_arg<T: sealed_trait::VaArgSafe>(ap: &mut VaList<'_>) -> T;
+    #[cfg(not(bootstrap))]
+    fn va_arg<T: sealed_trait::VaArgSafe>(ap: &mut VaListImpl<'_>) -> T;
 }

src/libcore/intrinsics.rs

@@ -1607,3 +1607,9 @@ pub fn maxnumf64(x: f64, y: f64) -> f64 {
     // Identical to the `f32` case.
     (if x < y || x != x { y } else { x }) * 1.0
 }
+
+/// For bootstrapping, implement unchecked_sub as just wrapping_sub.
+#[cfg(bootstrap)]
+pub unsafe fn unchecked_sub<T>(x: T, y: T) -> T {
+    sub_with_overflow(x, y).0
+}

src/libcore/iter/adapters/mod.rs

@@ -1509,6 +1509,20 @@ impl<I> DoubleEndedIterator for Skip<I> where I: DoubleEndedIterator + ExactSize
         }
     }
 
+    #[inline]
+    fn nth_back(&mut self, n: usize) -> Option<I::Item> {
+        let len = self.len();
+        if n < len {
+            self.iter.nth_back(n)
+        } else {
+            if len > 0 {
+                // consume the original iterator
+                self.iter.nth_back(len-1);
+            }
+            None
+        }
+    }
+
     fn try_rfold<Acc, Fold, R>(&mut self, init: Acc, mut fold: Fold) -> R where
         Self: Sized, Fold: FnMut(Acc, Self::Item) -> R, R: Try<Ok=Acc>
     {

src/libcore/lib.rs

@@ -100,6 +100,7 @@
 #![feature(staged_api)]
 #![feature(std_internals)]
 #![feature(stmt_expr_attributes)]
+#![cfg_attr(not(bootstrap), feature(transparent_unions))]
 #![feature(unboxed_closures)]
 #![feature(unsized_locals)]
 #![feature(untagged_unions)]

src/libcore/mem/maybe_uninit.rs

@@ -172,7 +172,7 @@ use crate::mem::ManuallyDrop;
 ///
 /// # Layout
 ///
-/// `MaybeUninit<T>` is guaranteed to have the same size and alignment as `T`:
+/// `MaybeUninit<T>` is guaranteed to have the same size, alignment, and ABI as `T`:
 ///
 /// ```rust
 /// use std::mem::{MaybeUninit, size_of, align_of};
@@ -191,9 +191,23 @@ use crate::mem::ManuallyDrop;
 /// assert_eq!(size_of::<Option<bool>>(), 1);
 /// assert_eq!(size_of::<Option<MaybeUninit<bool>>>(), 2);
 /// ```
+///
+/// If `T` is FFI-safe, then so is `MaybeUninit<T>`.
+///
+/// While `MaybeUninit` is `#[repr(transparent)]` (indicating it guarantees the same size,
+/// alignment, and ABI as `T`), this does *not* change any of the previous caveats. `Option<T>` and
+/// `Option<MaybeUninit<T>>` may still have different sizes, and types containing a field of type
+/// `T` may be laid out (and sized) differently than if that field were `MaybeUninit<T>`.
+/// `MaybeUninit` is a union type, and `#[repr(transparent)]` on unions is unstable (see [the
+/// tracking issue](https://github.com/rust-lang/rust/issues/60405)). Over time, the exact
+/// guarantees of `#[repr(transparent)]` on unions may evolve, and `MaybeUninit` may or may not
+/// remain `#[repr(transparent)]`. That said, `MaybeUninit<T>` will *always* guarantee that it has
+/// the same size, alignment, and ABI as `T`; it's just that the way `MaybeUninit` implements that
+/// guarantee may evolve.
 #[allow(missing_debug_implementations)]
 #[stable(feature = "maybe_uninit", since = "1.36.0")]
 #[derive(Copy)]
+#[cfg_attr(not(bootstrap), repr(transparent))]
 pub union MaybeUninit<T> {
     uninit: (),
     value: ManuallyDrop<T>,

src/libcore/ptr/mod.rs

@@ -230,6 +230,53 @@ pub const fn null<T>() -> *const T { 0 as *const T }
 #[rustc_promotable]
 pub const fn null_mut<T>() -> *mut T { 0 as *mut T }
 
+#[repr(C)]
+pub(crate) union Repr<T> {
+    pub(crate) rust: *const [T],
+    rust_mut: *mut [T],
+    pub(crate) raw: FatPtr<T>,
+}
+
+#[repr(C)]
+pub(crate) struct FatPtr<T> {
+    data: *const T,
+    pub(crate) len: usize,
+}
+
+/// Forms a slice from a pointer and a length.
+///
+/// The `len` argument is the number of **elements**, not the number of bytes.
+///
+/// # Examples
+///
+/// ```rust
+/// #![feature(slice_from_raw_parts)]
+/// use std::ptr;
+///
+/// // create a slice pointer when starting out with a pointer to the first element
+/// let mut x = [5, 6, 7];
+/// let ptr = &mut x[0] as *mut _;
+/// let slice = ptr::slice_from_raw_parts_mut(ptr, 3);
+/// assert_eq!(unsafe { &*slice }[2], 7);
+/// ```
+#[inline]
+#[unstable(feature = "slice_from_raw_parts", reason = "recently added", issue = "36925")]
+pub fn slice_from_raw_parts<T>(data: *const T, len: usize) -> *const [T] {
+    unsafe { Repr { raw: FatPtr { data, len } }.rust }
+}
+
+/// Performs the same functionality as [`from_raw_parts`], except that a
+/// mutable slice is returned.
+///
+/// See the documentation of [`from_raw_parts`] for more details.
+///
+/// [`from_raw_parts`]: ../../std/slice/fn.from_raw_parts.html
+#[inline]
+#[unstable(feature = "slice_from_raw_parts", reason = "recently added", issue = "36925")]
+pub fn slice_from_raw_parts_mut<T>(data: *mut T, len: usize) -> *mut [T] {
+    unsafe { Repr { raw: FatPtr { data, len } }.rust_mut }
+}
+
 /// Swaps the values at two mutable locations of the same type, without
 /// deinitializing either.
 ///

src/libcore/slice/mod.rs

@@ -25,7 +25,7 @@
 use crate::cmp::Ordering::{self, Less, Equal, Greater};
 use crate::cmp;
 use crate::fmt;
-use crate::intrinsics::assume;
+use crate::intrinsics::{assume, exact_div, unchecked_sub};
 use crate::isize;
 use crate::iter::*;
 use crate::ops::{FnMut, Try, self};
@@ -45,19 +45,6 @@ pub mod memchr;
 mod rotate;
 mod sort;
 
-#[repr(C)]
-union Repr<'a, T: 'a> {
-    rust: &'a [T],
-    rust_mut: &'a mut [T],
-    raw: FatPtr<T>,
-}
-
-#[repr(C)]
-struct FatPtr<T> {
-    data: *const T,
-    len: usize,
-}
-
 //
 // Extension traits
 //
@@ -78,7 +65,7 @@ impl<T> [T] {
     #[rustc_const_unstable(feature = "const_slice_len")]
     pub const fn len(&self) -> usize {
         unsafe {
-            Repr { rust: self }.raw.len
+            crate::ptr::Repr { rust: self }.raw.len
         }
     }
 
@@ -2998,14 +2985,27 @@ macro_rules! is_empty {
 // unexpected way. (Tested by `codegen/slice-position-bounds-check`.)
 macro_rules! len {
     ($self: ident) => {{
+        #![allow(unused_unsafe)] // we're sometimes used within an unsafe block
+
         let start = $self.ptr;
-        let diff = ($self.end as usize).wrapping_sub(start as usize);
         let size = size_from_ptr(start);
         if size == 0 {
+            // This _cannot_ use `unchecked_sub` because we depend on wrapping
+            // to represent the length of long ZST slice iterators.
+            let diff = ($self.end as usize).wrapping_sub(start as usize);
             diff
         } else {
-            // Using division instead of `offset_from` helps LLVM remove bounds checks
-            diff / size
+            // We know that `start <= end`, so can do better than `offset_from`,
+            // which needs to deal in signed.  By setting appropriate flags here
+            // we can tell LLVM this, which helps it remove bounds checks.
+            // SAFETY: By the type invariant, `start <= end`
+            let diff = unsafe { unchecked_sub($self.end as usize, start as usize) };
+            // By also telling LLVM that the pointers are apart by an exact
+            // multiple of the type size, it can optimize `len() == 0` down to
+            // `start == end` instead of `(end - start) < size`.
+            // SAFETY: By the type invariant, the pointers are aligned so the
+            //         distance between them must be a multiple of pointee size
+            unsafe { exact_div(diff, size) }
         }
     }}
 }
@@ -3019,6 +3019,28 @@ macro_rules! iterator {
         {$( $mut_:tt )*},
         {$($extra:tt)*}
     ) => {
+        // Returns the first element and moves the start of the iterator forwards by 1.
+        // Greatly improves performance compared to an inlined function. The iterator
+        // must not be empty.
+        macro_rules! next_unchecked {
+            ($self: ident) => {& $( $mut_ )* *$self.post_inc_start(1)}
+        }
+
+        // Returns the last element and moves the end of the iterator backwards by 1.
+        // Greatly improves performance compared to an inlined function. The iterator
+        // must not be empty.
+        macro_rules! next_back_unchecked {
+            ($self: ident) => {& $( $mut_ )* *$self.pre_dec_end(1)}
+        }
+
+        // Shrinks the iterator when T is a ZST, by moving the end of the iterator
+        // backwards by `n`. `n` must not exceed `self.len()`.
+        macro_rules! zst_shrink {
+            ($self: ident, $n: ident) => {
+                $self.end = ($self.end as * $raw_mut u8).wrapping_offset(-$n) as * $raw_mut T;
+            }
+        }
+
         impl<'a, T> $name<'a, T> {
             // Helper function for creating a slice from the iterator.
             #[inline(always)]
@@ -3028,12 +3050,11 @@ macro_rules! iterator {
 
             // Helper function for moving the start of the iterator forwards by `offset` elements,
             // returning the old start.
-            // Unsafe because the offset must be in-bounds or one-past-the-end.
+            // Unsafe because the offset must not exceed `self.len()`.
             #[inline(always)]
             unsafe fn post_inc_start(&mut self, offset: isize) -> * $raw_mut T {
                 if mem::size_of::<T>() == 0 {
-                    // This is *reducing* the length.  `ptr` never changes with ZST.
-                    self.end = (self.end as * $raw_mut u8).wrapping_offset(-offset) as * $raw_mut T;
+                    zst_shrink!(self, offset);
                     self.ptr
                 } else {
                     let old = self.ptr;
@@ -3044,11 +3065,11 @@ macro_rules! iterator {
 
             // Helper function for moving the end of the iterator backwards by `offset` elements,
             // returning the new end.
-            // Unsafe because the offset must be in-bounds or one-past-the-end.
+            // Unsafe because the offset must not exceed `self.len()`.
             #[inline(always)]
             unsafe fn pre_dec_end(&mut self, offset: isize) -> * $raw_mut T {
                 if mem::size_of::<T>() == 0 {
-                    self.end = (self.end as * $raw_mut u8).wrapping_offset(-offset) as * $raw_mut T;
+                    zst_shrink!(self, offset);
                     self.ptr
                 } else {
                     self.end = self.end.offset(-offset);
@@ -3085,7 +3106,7 @@ macro_rules! iterator {
                     if is_empty!(self) {
                         None
                     } else {
-                        Some(& $( $mut_ )* *self.post_inc_start(1))
+                        Some(next_unchecked!(self))
                     }
                 }
             }
@@ -3114,11 +3135,10 @@ macro_rules! iterator {
                     }
                     return None;
                 }
-                // We are in bounds. `offset` does the right thing even for ZSTs.
+                // We are in bounds. `post_inc_start` does the right thing even for ZSTs.
                 unsafe {
-                    let elem = Some(& $( $mut_ )* *self.ptr.add(n));
-                    self.post_inc_start((n as isize).wrapping_add(1));
-                    elem
+                    self.post_inc_start(n as isize);
+                    Some(next_unchecked!(self))
                 }
             }
 
@@ -3135,13 +3155,13 @@ macro_rules! iterator {
                 let mut accum = init;
                 unsafe {
                     while len!(self) >= 4 {
-                        accum = f(accum, & $( $mut_ )* *self.post_inc_start(1))?;
-                        accum = f(accum, & $( $mut_ )* *self.post_inc_start(1))?;
-                        accum = f(accum, & $( $mut_ )* *self.post_inc_start(1))?;
-                        accum = f(accum, & $( $mut_ )* *self.post_inc_start(1))?;
+                        accum = f(accum, next_unchecked!(self))?;
+                        accum = f(accum, next_unchecked!(self))?;
+                        accum = f(accum, next_unchecked!(self))?;
+                        accum = f(accum, next_unchecked!(self))?;
                     }
                     while !is_empty!(self) {
-                        accum = f(accum, & $( $mut_ )* *self.post_inc_start(1))?;
+                        accum = f(accum, next_unchecked!(self))?;
                     }
                 }
                 Try::from_ok(accum)
@@ -3212,11 +3232,25 @@ macro_rules! iterator {
                     if is_empty!(self) {
                         None
                     } else {
-                        Some(& $( $mut_ )* *self.pre_dec_end(1))
+                        Some(next_back_unchecked!(self))
                     }
                 }
             }
 
+            #[inline]
+            fn nth_back(&mut self, n: usize) -> Option<$elem> {
+                if n >= len!(self) {
+                    // This iterator is now empty.
+                    self.end = self.ptr;
+                    return None;
+                }
+                // We are in bounds. `pre_dec_end` does the right thing even for ZSTs.
+                unsafe {
+                    self.pre_dec_end(n as isize);
+                    Some(next_back_unchecked!(self))
+                }
+            }
+
             #[inline]
             fn try_rfold<B, F, R>(&mut self, init: B, mut f: F) -> R where
                 Self: Sized, F: FnMut(B, Self::Item) -> R, R: Try<Ok=B>
@@ -3225,14 +3259,14 @@ macro_rules! iterator {
                 let mut accum = init;
                 unsafe {
                     while len!(self) >= 4 {
-                        accum = f(accum, & $( $mut_ )* *self.pre_dec_end(1))?;
-                        accum = f(accum, & $( $mut_ )* *self.pre_dec_end(1))?;
-                        accum = f(accum, & $( $mut_ )* *self.pre_dec_end(1))?;
-                        accum = f(accum, & $( $mut_ )* *self.pre_dec_end(1))?;
+                        accum = f(accum, next_back_unchecked!(self))?;
+                        accum = f(accum, next_back_unchecked!(self))?;
+                        accum = f(accum, next_back_unchecked!(self))?;
+                        accum = f(accum, next_back_unchecked!(self))?;
                     }
                     // inlining is_empty everywhere makes a huge performance difference
                     while !is_empty!(self) {
-                        accum = f(accum, & $( $mut_ )* *self.pre_dec_end(1))?;
+                        accum = f(accum, next_back_unchecked!(self))?;
                     }
                 }
                 Try::from_ok(accum)
@@ -5182,7 +5216,7 @@ pub unsafe fn from_raw_parts<'a, T>(data: *const T, len: usize) -> &'a [T] {
     debug_assert!(data as usize % mem::align_of::<T>() == 0, "attempt to create unaligned slice");
     debug_assert!(mem::size_of::<T>().saturating_mul(len) <= isize::MAX as usize,
                   "attempt to create slice covering half the address space");
-    Repr { raw: FatPtr { data, len } }.rust
+    &*ptr::slice_from_raw_parts(data, len)
 }
 
 /// Performs the same functionality as [`from_raw_parts`], except that a
@@ -5203,7 +5237,7 @@ pub unsafe fn from_raw_parts_mut<'a, T>(data: *mut T, len: usize) -> &'a mut [T]
     debug_assert!(data as usize % mem::align_of::<T>() == 0, "attempt to create unaligned slice");
     debug_assert!(mem::size_of::<T>().saturating_mul(len) <= isize::MAX as usize,
                   "attempt to create slice covering half the address space");
-    Repr { raw: FatPtr { data, len } }.rust_mut
+    &mut *ptr::slice_from_raw_parts_mut(data, len)
 }
 
 /// Converts a reference to T into a slice of length 1 (without copying).

src/libcore/tests/iter.rs

@@ -2333,6 +2333,40 @@ fn test_skip_try_folds() {
     assert_eq!(iter.next_back(), Some(24));
 }
 
+#[test]
+fn test_skip_nth_back() {
+    let xs = [0, 1, 2, 3, 4, 5];
+    let mut it = xs.iter().skip(2);
+    assert_eq!(it.nth_back(0), Some(&5));
+    assert_eq!(it.nth_back(1), Some(&3));
+    assert_eq!(it.nth_back(0), Some(&2));
+    assert_eq!(it.nth_back(0), None);
+
+    let ys = [2, 3, 4, 5];
+    let mut ity = ys.iter();
+    let mut it = xs.iter().skip(2);
+    assert_eq!(it.nth_back(1), ity.nth_back(1));
+    assert_eq!(it.clone().nth(0), ity.clone().nth(0));
+    assert_eq!(it.nth_back(0), ity.nth_back(0));
+    assert_eq!(it.clone().nth(0), ity.clone().nth(0));
+    assert_eq!(it.nth_back(0), ity.nth_back(0));
+    assert_eq!(it.clone().nth(0), ity.clone().nth(0));
+    assert_eq!(it.nth_back(0), ity.nth_back(0));
+    assert_eq!(it.clone().nth(0), ity.clone().nth(0));
+
+    let mut it = xs.iter().skip(2);
+    assert_eq!(it.nth_back(4), None);
+    assert_eq!(it.nth_back(0), None);
+
+    let mut it = xs.iter();
+    it.by_ref().skip(2).nth_back(3);
+    assert_eq!(it.next_back(), Some(&1));
+
+    let mut it = xs.iter();
+    it.by_ref().skip(2).nth_back(10);
+    assert_eq!(it.next_back(), Some(&1));
+}
+
 #[test]
 fn test_take_try_folds() {
     let f = &|acc, x| i32::checked_add(2*acc, x);

src/libcore/tests/slice.rs

@@ -88,6 +88,19 @@ fn test_iterator_nth() {
     assert_eq!(iter.nth(1).unwrap(), &v[4]);
 }
 
+#[test]
+fn test_iterator_nth_back() {
+    let v: &[_] = &[0, 1, 2, 3, 4];
+    for i in 0..v.len() {
+        assert_eq!(v.iter().nth_back(i).unwrap(), &v[v.len() - i - 1]);
+    }
+    assert_eq!(v.iter().nth_back(v.len()), None);
+
+    let mut iter = v.iter();
+    assert_eq!(iter.nth_back(2).unwrap(), &v[2]);
+    assert_eq!(iter.nth_back(1).unwrap(), &v[0]);
+}
+
 #[test]
 fn test_iterator_last() {
     let v: &[_] = &[0, 1, 2, 3, 4];

src/libpanic_unwind/dummy.rs

@@ -7,7 +7,7 @@ use core::any::Any;
 use core::intrinsics;
 
 pub fn payload() -> *mut u8 {
-    0 as *mut u8
+    core::ptr::null_mut()
 }
 
 pub unsafe fn cleanup(_ptr: *mut u8) -> Box<dyn Any + Send> {

src/libpanic_unwind/seh.rs

@@ -104,7 +104,7 @@ mod imp {
     pub const NAME2: [u8; 7] = [b'.', b'P', b'A', b'X', 0, 0, 0];
 
     macro_rules! ptr {
-        (0) => (0 as *mut u8);
+        (0) => (core::ptr::null_mut());
         ($e:expr) => ($e as *mut u8);
     }
 }
@@ -223,13 +223,13 @@ extern "C" {
 #[cfg_attr(not(test), lang = "msvc_try_filter")]
 static mut TYPE_DESCRIPTOR1: _TypeDescriptor = _TypeDescriptor {
     pVFTable: unsafe { &TYPE_INFO_VTABLE } as *const _ as *const _,
-    spare: 0 as *mut _,
+    spare: core::ptr::null_mut(),
     name: imp::NAME1,
 };
 
 static mut TYPE_DESCRIPTOR2: _TypeDescriptor = _TypeDescriptor {
     pVFTable: unsafe { &TYPE_INFO_VTABLE } as *const _ as *const _,
-    spare: 0 as *mut _,
+    spare: core::ptr::null_mut(),
     name: imp::NAME2,
 };
 

src/librustc/cfg/construct.rs

@@ -7,7 +7,7 @@ use crate::ty::{self, TyCtxt};
 use crate::hir::{self, PatKind};
 use crate::hir::def_id::DefId;
 
-struct CFGBuilder<'a, 'tcx: 'a> {
+struct CFGBuilder<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
     owner_def_id: DefId,
     tables: &'a ty::TypeckTables<'tcx>,
@@ -42,7 +42,7 @@ pub fn construct<'tcx>(tcx: TyCtxt<'tcx>, body: &hir::Body) -> CFG {
     let body_exit;
 
     // Find the tables for this body.
-    let owner_def_id = tcx.hir().local_def_id(tcx.hir().body_owner(body.id()));
+    let owner_def_id = tcx.hir().body_owner_def_id(body.id());
     let tables = tcx.typeck_tables_of(owner_def_id);
 
     let mut cfg_builder = CFGBuilder {
@@ -330,7 +330,7 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> {
             hir::ExprKind::DropTemps(ref e) |
             hir::ExprKind::Unary(_, ref e) |
             hir::ExprKind::Field(ref e, _) |
-            hir::ExprKind::Yield(ref e) |
+            hir::ExprKind::Yield(ref e, _) |
             hir::ExprKind::Repeat(ref e, _) => {
                 self.straightline(expr, pred, Some(&**e).into_iter())
             }
@@ -357,7 +357,7 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> {
             args: I) -> CFGIndex {
         let func_or_rcvr_exit = self.expr(func_or_rcvr, pred);
         let ret = self.straightline(call_expr, func_or_rcvr_exit, args);
-        let m = self.tcx.hir().get_module_parent_by_hir_id(call_expr.hir_id);
+        let m = self.tcx.hir().get_module_parent(call_expr.hir_id);
         if self.tcx.is_ty_uninhabited_from(m, self.tables.expr_ty(call_expr)) {
             self.add_unreachable_node()
         } else {

src/librustc/cfg/graphviz.rs

@@ -11,7 +11,7 @@ use crate::ty::TyCtxt;
 pub type Node<'a> = (cfg::CFGIndex, &'a cfg::CFGNode);
 pub type Edge<'a> = &'a cfg::CFGEdge;
 
-pub struct LabelledCFG<'a, 'tcx: 'a> {
+pub struct LabelledCFG<'a, 'tcx> {
     pub tcx: TyCtxt<'tcx>,
     pub cfg: &'a cfg::CFG,
     pub name: String,
@@ -22,11 +22,11 @@ pub struct LabelledCFG<'a, 'tcx: 'a> {
 impl<'a, 'tcx> LabelledCFG<'a, 'tcx> {
     fn local_id_to_string(&self, local_id: hir::ItemLocalId) -> String {
         assert!(self.cfg.owner_def_id.is_local());
-        let node_id = self.tcx.hir().hir_to_node_id(hir::HirId {
+        let hir_id = hir::HirId {
             owner: self.tcx.hir().def_index_to_hir_id(self.cfg.owner_def_id.index).owner,
             local_id
-        });
-        let s = self.tcx.hir().node_to_string(node_id);
+        };
+        let s = self.tcx.hir().node_to_string(hir_id);
 
         // Replacing newlines with \\l causes each line to be left-aligned,
         // improving presentation of (long) pretty-printed expressions.

src/librustc/dep_graph/dep_node.rs

@@ -204,11 +204,9 @@ macro_rules! define_dep_nodes {
         impl DepNode {
             #[allow(unreachable_code, non_snake_case)]
             #[inline(always)]
-            pub fn new<'a, 'tcx>(tcx: TyCtxt<'tcx>,
+            pub fn new<'tcx>(tcx: TyCtxt<'tcx>,
                                        dep: DepConstructor<'tcx>)
                                        -> DepNode
-                where 'tcx: 'a,
-                      'tcx: 'a
             {
                 match dep {
                     $(

src/librustc/hir/intravisit.rs

@@ -74,7 +74,7 @@ impl<'a> FnKind<'a> {
 ///
 /// See the comments on `ItemLikeVisitor` for more details on the overall
 /// visit strategy.
-pub enum NestedVisitorMap<'this, 'tcx: 'this> {
+pub enum NestedVisitorMap<'this, 'tcx> {
     /// Do not visit any nested things. When you add a new
     /// "non-nested" thing, you will want to audit such uses to see if
     /// they remain valid.
@@ -171,7 +171,7 @@ pub trait Visitor<'v> : Sized {
     /// but cannot supply a `Map`; see `nested_visit_map` for advice.
     #[allow(unused_variables)]
     fn visit_nested_item(&mut self, id: ItemId) {
-        let opt_item = self.nested_visit_map().inter().map(|map| map.expect_item_by_hir_id(id.id));
+        let opt_item = self.nested_visit_map().inter().map(|map| map.expect_item(id.id));
         if let Some(item) = opt_item {
             self.visit_item(item);
         }
@@ -773,7 +773,6 @@ pub fn walk_generic_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v Generi
 
 pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics) {
     walk_list!(visitor, visit_generic_param, &generics.params);
-    visitor.visit_id(generics.where_clause.hir_id);
     walk_list!(visitor, visit_where_predicate, &generics.where_clause.predicates);
 }
 
@@ -1089,7 +1088,7 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
                 visitor.visit_expr(expr)
             }
         }
-        ExprKind::Yield(ref subexpression) => {
+        ExprKind::Yield(ref subexpression, _) => {
             visitor.visit_expr(subexpression);
         }
         ExprKind::Lit(_) | ExprKind::Err => {}

src/librustc/hir/lowering.rs

@@ -62,14 +62,14 @@ use syntax::errors;
 use syntax::ext::hygiene::{Mark, SyntaxContext};
 use syntax::print::pprust;
 use syntax::ptr::P;
-use syntax::source_map::{self, respan, CompilerDesugaringKind, Spanned};
+use syntax::source_map::{self, respan, ExpnInfo, CompilerDesugaringKind, Spanned};
 use syntax::source_map::CompilerDesugaringKind::IfTemporary;
 use syntax::std_inject;
 use syntax::symbol::{kw, sym, Symbol};
 use syntax::tokenstream::{TokenStream, TokenTree};
 use syntax::parse::token::{self, Token};
 use syntax::visit::{self, Visitor};
-use syntax_pos::{DUMMY_SP, edition, Span};
+use syntax_pos::{DUMMY_SP, Span};
 
 const HIR_ID_COUNTER_LOCKED: u32 = 0xFFFFFFFF;
 
@@ -95,8 +95,7 @@ pub struct LoweringContext<'a> {
 
     modules: BTreeMap<NodeId, hir::ModuleItems>,
 
-    is_generator: bool,
-    is_async_body: bool,
+    generator_kind: Option<hir::GeneratorKind>,
 
     /// Used to get the current `fn`'s def span to point to when using `await`
     /// outside of an `async fn`.
@@ -142,6 +141,9 @@ pub struct LoweringContext<'a> {
     current_hir_id_owner: Vec<(DefIndex, u32)>,
     item_local_id_counters: NodeMap<u32>,
     node_id_to_hir_id: IndexVec<NodeId, hir::HirId>,
+
+    allow_try_trait: Option<Lrc<[Symbol]>>,
+    allow_gen_future: Option<Lrc<[Symbol]>>,
 }
 
 pub trait Resolver {
@@ -261,12 +263,13 @@ pub fn lower_crate(
         current_hir_id_owner: vec![(CRATE_DEF_INDEX, 0)],
         item_local_id_counters: Default::default(),
         node_id_to_hir_id: IndexVec::new(),
-        is_generator: false,
-        is_async_body: false,
+        generator_kind: None,
         current_item: None,
         lifetimes_to_define: Vec::new(),
         is_collecting_in_band_lifetimes: false,
         in_scope_lifetimes: Vec::new(),
+        allow_try_trait: Some([sym::try_trait][..].into()),
+        allow_gen_future: Some([sym::gen_future][..].into()),
     }.lower_crate(krate)
 }
 
@@ -415,7 +418,7 @@ impl<'a> LoweringContext<'a> {
         /// needed from arbitrary locations in the crate,
         /// e.g., the number of lifetime generic parameters
         /// declared for every type and trait definition.
-        struct MiscCollector<'tcx, 'interner: 'tcx> {
+        struct MiscCollector<'tcx, 'interner> {
             lctx: &'tcx mut LoweringContext<'interner>,
             hir_id_owner: Option<NodeId>,
         }
@@ -561,7 +564,7 @@ impl<'a> LoweringContext<'a> {
             }
         }
 
-        struct ItemLowerer<'tcx, 'interner: 'tcx> {
+        struct ItemLowerer<'tcx, 'interner> {
             lctx: &'tcx mut LoweringContext<'interner>,
         }
 
@@ -605,15 +608,7 @@ impl<'a> LoweringContext<'a> {
                 });
 
                 if let Some(hir_id) = item_hir_id {
-                    let item_generics = match self.lctx.items.get(&hir_id).unwrap().node {
-                        hir::ItemKind::Impl(_, _, _, ref generics, ..)
-                        | hir::ItemKind::Trait(_, _, ref generics, ..) => {
-                            generics.params.clone()
-                        }
-                        _ => HirVec::new(),
-                    };
-
-                    self.lctx.with_parent_impl_lifetime_defs(&item_generics, |this| {
+                    self.lctx.with_parent_item_lifetime_defs(hir_id, |this| {
                         let this = &mut ItemLowerer { lctx: this };
                         if let ItemKind::Impl(.., ref opt_trait_ref, _, _) = item.node {
                             this.with_trait_impl_ref(opt_trait_ref, |this| {
@@ -790,18 +785,49 @@ impl<'a> LoweringContext<'a> {
         })
     }
 
-    fn record_body(&mut self, arguments: HirVec<hir::Arg>, value: hir::Expr) -> hir::BodyId {
-        if self.is_generator && self.is_async_body {
-            span_err!(
-                self.sess,
-                value.span,
-                E0727,
-                "`async` generators are not yet supported",
-            );
-            self.sess.abort_if_errors();
+    fn generator_movability_for_fn(
+        &mut self,
+        decl: &ast::FnDecl,
+        fn_decl_span: Span,
+        generator_kind: Option<hir::GeneratorKind>,
+        movability: Movability,
+    ) -> Option<hir::GeneratorMovability> {
+        match generator_kind {
+            Some(hir::GeneratorKind::Gen) =>  {
+                if !decl.inputs.is_empty() {
+                    span_err!(
+                        self.sess,
+                        fn_decl_span,
+                        E0628,
+                        "generators cannot have explicit arguments"
+                    );
+                    self.sess.abort_if_errors();
+                }
+                Some(match movability {
+                    Movability::Movable => hir::GeneratorMovability::Movable,
+                    Movability::Static => hir::GeneratorMovability::Static,
+                })
+            },
+            Some(hir::GeneratorKind::Async) => {
+                bug!("non-`async` closure body turned `async` during lowering");
+            },
+            None => {
+                if movability == Movability::Static {
+                    span_err!(
+                        self.sess,
+                        fn_decl_span,
+                        E0697,
+                        "closures cannot be static"
+                    );
+                }
+                None
+            },
         }
+    }
+
+    fn record_body(&mut self, arguments: HirVec<hir::Arg>, value: hir::Expr) -> hir::BodyId {
         let body = hir::Body {
-            is_generator: self.is_generator || self.is_async_body,
+            generator_kind: self.generator_kind,
             arguments,
             value,
         };
@@ -848,14 +874,10 @@ impl<'a> LoweringContext<'a> {
         allow_internal_unstable: Option<Lrc<[Symbol]>>,
     ) -> Span {
         let mark = Mark::fresh(Mark::root());
-        mark.set_expn_info(source_map::ExpnInfo {
-            call_site: span,
+        mark.set_expn_info(ExpnInfo {
             def_site: Some(span),
-            format: source_map::CompilerDesugaring(reason),
             allow_internal_unstable,
-            allow_internal_unsafe: false,
-            local_inner_macros: false,
-            edition: edition::Edition::from_session(),
+            ..ExpnInfo::default(source_map::CompilerDesugaring(reason), span, self.sess.edition())
         });
         span.with_ctxt(SyntaxContext::empty().apply_mark(mark))
     }
@@ -1024,14 +1046,22 @@ impl<'a> LoweringContext<'a> {
     // This should only be used with generics that have already had their
     // in-band lifetimes added. In practice, this means that this function is
     // only used when lowering a child item of a trait or impl.
-    fn with_parent_impl_lifetime_defs<T, F>(&mut self,
-        params: &HirVec<hir::GenericParam>,
+    fn with_parent_item_lifetime_defs<T, F>(&mut self,
+        parent_hir_id: hir::HirId,
         f: F
     ) -> T where
         F: FnOnce(&mut LoweringContext<'_>) -> T,
     {
         let old_len = self.in_scope_lifetimes.len();
-        let lt_def_names = params.iter().filter_map(|param| match param.kind {
+
+        let parent_generics = match self.items.get(&parent_hir_id).unwrap().node {
+            hir::ItemKind::Impl(_, _, _, ref generics, ..)
+            | hir::ItemKind::Trait(_, _, ref generics, ..) => {
+                &generics.params[..]
+            }
+            _ => &[],
+        };
+        let lt_def_names = parent_generics.iter().filter_map(|param| match param.kind {
             hir::GenericParamKind::Lifetime { .. } => Some(param.name.ident().modern()),
             _ => None,
         });
@@ -1083,8 +1113,7 @@ impl<'a> LoweringContext<'a> {
 
         lowered_generics.params = lowered_generics
             .params
-            .iter()
-            .cloned()
+            .into_iter()
             .chain(in_band_defs)
             .collect();
 
@@ -1142,7 +1171,7 @@ impl<'a> LoweringContext<'a> {
         };
         let decl = self.lower_fn_decl(&ast_decl, None, /* impl trait allowed */ false, None);
         let body_id = self.lower_fn_body(&ast_decl, |this| {
-            this.is_async_body = true;
+            this.generator_kind = Some(hir::GeneratorKind::Async);
             body(this)
         });
         let generator = hir::Expr {
@@ -1156,7 +1185,7 @@ impl<'a> LoweringContext<'a> {
         let unstable_span = self.mark_span_with_reason(
             CompilerDesugaringKind::Async,
             span,
-            Some(vec![sym::gen_future].into()),
+            self.allow_gen_future.clone(),
         );
         let gen_future = self.expr_std_path(
             unstable_span, &[sym::future, sym::from_generator], None, ThinVec::new());
@@ -1167,12 +1196,10 @@ impl<'a> LoweringContext<'a> {
         &mut self,
         f: impl FnOnce(&mut LoweringContext<'_>) -> (HirVec<hir::Arg>, hir::Expr),
     ) -> hir::BodyId {
-        let prev_is_generator = mem::replace(&mut self.is_generator, false);
-        let prev_is_async_body = mem::replace(&mut self.is_async_body, false);
+        let prev_gen_kind = self.generator_kind.take();
         let (arguments, result) = f(self);
         let body_id = self.record_body(arguments, result);
-        self.is_generator = prev_is_generator;
-        self.is_async_body = prev_is_async_body;
+        self.generator_kind = prev_gen_kind;
         body_id
     }
 
@@ -1674,7 +1701,7 @@ impl<'a> LoweringContext<'a> {
             }
             TyKind::Mac(_) => bug!("`TyMac` should have been expanded by now."),
             TyKind::CVarArgs => {
-                // Create the implicit lifetime of the "spoofed" `VaList`.
+                // Create the implicit lifetime of the "spoofed" `VaListImpl`.
                 let span = self.sess.source_map().next_point(t.span.shrink_to_lo());
                 let lt = self.new_implicit_lifetime(span);
                 hir::TyKind::CVarArgs(lt)
@@ -1727,8 +1754,8 @@ impl<'a> LoweringContext<'a> {
                 generics: hir::Generics {
                     params: lifetime_defs,
                     where_clause: hir::WhereClause {
-                        hir_id: lctx.next_id(),
                         predicates: hir_vec![],
+                        span,
                     },
                     span,
                 },
@@ -1788,7 +1815,7 @@ impl<'a> LoweringContext<'a> {
         // This visitor walks over `impl Trait` bounds and creates defs for all lifetimes that
         // appear in the bounds, excluding lifetimes that are created within the bounds.
         // E.g., `'a`, `'b`, but not `'c` in `impl for<'c> SomeTrait<'a, 'b, 'c>`.
-        struct ImplTraitLifetimeCollector<'r, 'a: 'r> {
+        struct ImplTraitLifetimeCollector<'r, 'a> {
             context: &'r mut LoweringContext<'a>,
             parent: DefIndex,
             exist_ty_id: NodeId,
@@ -1799,7 +1826,7 @@ impl<'a> LoweringContext<'a> {
             output_lifetime_params: Vec<hir::GenericParam>,
         }
 
-        impl<'r, 'a: 'r, 'v> hir::intravisit::Visitor<'v> for ImplTraitLifetimeCollector<'r, 'a> {
+        impl<'r, 'a, 'v> hir::intravisit::Visitor<'v> for ImplTraitLifetimeCollector<'r, 'a> {
             fn nested_visit_map<'this>(
                 &'this mut self,
             ) -> hir::intravisit::NestedVisitorMap<'this, 'v> {
@@ -2619,8 +2646,8 @@ impl<'a> LoweringContext<'a> {
                 generics: hir::Generics {
                     params: generic_params,
                     where_clause: hir::WhereClause {
-                        hir_id: this.next_id(),
                         predicates: hir_vec![],
+                        span,
                     },
                     span,
                 },
@@ -2973,11 +3000,11 @@ impl<'a> LoweringContext<'a> {
             AnonymousLifetimeMode::ReportError,
             |this| {
                 hir::WhereClause {
-                    hir_id: this.lower_node_id(wc.id),
                     predicates: wc.predicates
                         .iter()
                         .map(|predicate| this.lower_where_predicate(predicate))
                         .collect(),
+                    span: wc.span,
                 }
             },
         )
@@ -3086,8 +3113,8 @@ impl<'a> LoweringContext<'a> {
             &NodeMap::default(),
             itctx.reborrow(),
         );
-        let trait_ref = self.with_parent_impl_lifetime_defs(
-            &bound_generic_params,
+        let trait_ref = self.with_in_scope_lifetime_defs(
+            &p.bound_generic_params,
             |this| this.lower_trait_ref(&p.trait_ref, itctx),
         );
 
@@ -3574,8 +3601,7 @@ impl<'a> LoweringContext<'a> {
                 // Essentially a single `use` which imports two names is desugared into
                 // two imports.
                 for (res, &new_node_id) in resolutions.zip([id1, id2].iter()) {
-                    let vis = vis.clone();
-                    let ident = ident.clone();
+                    let ident = *ident;
                     let mut path = path.clone();
                     for seg in &mut path.segments {
                         seg.id = self.sess.next_node_id();
@@ -3588,19 +3614,7 @@ impl<'a> LoweringContext<'a> {
                         let path =
                             this.lower_path_extra(res, &path, ParamMode::Explicit, None);
                         let item = hir::ItemKind::Use(P(path), hir::UseKind::Single);
-                        let vis_kind = match vis.node {
-                            hir::VisibilityKind::Public => hir::VisibilityKind::Public,
-                            hir::VisibilityKind::Crate(sugar) => hir::VisibilityKind::Crate(sugar),
-                            hir::VisibilityKind::Inherited => hir::VisibilityKind::Inherited,
-                            hir::VisibilityKind::Restricted { ref path, hir_id: _ } => {
-                                let path = this.renumber_segment_ids(path);
-                                hir::VisibilityKind::Restricted {
-                                    path,
-                                    hir_id: this.next_id(),
-                                }
-                            }
-                        };
-                        let vis = respan(vis.span, vis_kind);
+                        let vis = this.rebuild_vis(&vis);
 
                         this.insert_item(
                             hir::Item {
@@ -3664,8 +3678,6 @@ impl<'a> LoweringContext<'a> {
                 for &(ref use_tree, id) in trees {
                     let new_hir_id = self.lower_node_id(id);
 
-                    let mut vis = vis.clone();
-                    let mut ident = ident.clone();
                     let mut prefix = prefix.clone();
 
                     // Give the segments new node-ids since they are being cloned.
@@ -3679,6 +3691,9 @@ impl<'a> LoweringContext<'a> {
                     // own its own names, we have to adjust the owner before
                     // lowering the rest of the import.
                     self.with_hir_id_owner(id, |this| {
+                        let mut vis = this.rebuild_vis(&vis);
+                        let mut ident = *ident;
+
                         let item = this.lower_use_tree(use_tree,
                                                        &prefix,
                                                        id,
@@ -3686,20 +3701,6 @@ impl<'a> LoweringContext<'a> {
                                                        &mut ident,
                                                        attrs);
 
-                        let vis_kind = match vis.node {
-                            hir::VisibilityKind::Public => hir::VisibilityKind::Public,
-                            hir::VisibilityKind::Crate(sugar) => hir::VisibilityKind::Crate(sugar),
-                            hir::VisibilityKind::Inherited => hir::VisibilityKind::Inherited,
-                            hir::VisibilityKind::Restricted { ref path, hir_id: _ } => {
-                                let path = this.renumber_segment_ids(path);
-                                hir::VisibilityKind::Restricted {
-                                    path: path,
-                                    hir_id: this.next_id(),
-                                }
-                            }
-                        };
-                        let vis = respan(vis.span, vis_kind);
-
                         this.insert_item(
                             hir::Item {
                                 hir_id: new_hir_id,
@@ -3745,15 +3746,35 @@ impl<'a> LoweringContext<'a> {
     /// Paths like the visibility path in `pub(super) use foo::{bar, baz}` are repeated
     /// many times in the HIR tree; for each occurrence, we need to assign distinct
     /// `NodeId`s. (See, e.g., #56128.)
-    fn renumber_segment_ids(&mut self, path: &P<hir::Path>) -> P<hir::Path> {
-        debug!("renumber_segment_ids(path = {:?})", path);
-        let mut path = path.clone();
-        for seg in path.segments.iter_mut() {
-            if seg.hir_id.is_some() {
-                seg.hir_id = Some(self.next_id());
-            }
+    fn rebuild_use_path(&mut self, path: &hir::Path) -> hir::Path {
+        debug!("rebuild_use_path(path = {:?})", path);
+        let segments = path.segments.iter().map(|seg| hir::PathSegment {
+            ident: seg.ident,
+            hir_id: seg.hir_id.map(|_| self.next_id()),
+            res: seg.res,
+            args: None,
+            infer_args: seg.infer_args,
+        }).collect();
+        hir::Path {
+            span: path.span,
+            res: path.res,
+            segments,
         }
-        path
+    }
+
+    fn rebuild_vis(&mut self, vis: &hir::Visibility) -> hir::Visibility {
+        let vis_kind = match vis.node {
+            hir::VisibilityKind::Public => hir::VisibilityKind::Public,
+            hir::VisibilityKind::Crate(sugar) => hir::VisibilityKind::Crate(sugar),
+            hir::VisibilityKind::Inherited => hir::VisibilityKind::Inherited,
+            hir::VisibilityKind::Restricted { ref path, hir_id: _ } => {
+                hir::VisibilityKind::Restricted {
+                    path: P(self.rebuild_use_path(path)),
+                    hir_id: self.next_id(),
+                }
+            }
+        };
+        respan(vis.span, vis_kind)
     }
 
     fn lower_trait_item(&mut self, i: &TraitItem) -> hir::TraitItem {
@@ -4382,7 +4403,7 @@ impl<'a> LoweringContext<'a> {
                     let unstable_span = this.mark_span_with_reason(
                         CompilerDesugaringKind::TryBlock,
                         body.span,
-                        Some(vec![sym::try_trait].into()),
+                        this.allow_try_trait.clone(),
                     );
                     let mut block = this.lower_block(body, true).into_inner();
                     let tail = block.expr.take().map_or_else(
@@ -4475,37 +4496,18 @@ impl<'a> LoweringContext<'a> {
 
                     self.with_new_scopes(|this| {
                         this.current_item = Some(fn_decl_span);
-                        let mut is_generator = false;
+                        let mut generator_kind = None;
                         let body_id = this.lower_fn_body(decl, |this| {
                             let e = this.lower_expr(body);
-                            is_generator = this.is_generator;
+                            generator_kind = this.generator_kind;
                             e
                         });
-                        let generator_option = if is_generator {
-                            if !decl.inputs.is_empty() {
-                                span_err!(
-                                    this.sess,
-                                    fn_decl_span,
-                                    E0628,
-                                    "generators cannot have explicit arguments"
-                                );
-                                this.sess.abort_if_errors();
-                            }
-                            Some(match movability {
-                                Movability::Movable => hir::GeneratorMovability::Movable,
-                                Movability::Static => hir::GeneratorMovability::Static,
-                            })
-                        } else {
-                            if movability == Movability::Static {
-                                span_err!(
-                                    this.sess,
-                                    fn_decl_span,
-                                    E0697,
-                                    "closures cannot be static"
-                                );
-                            }
-                            None
-                        };
+                        let generator_option = this.generator_movability_for_fn(
+                            &decl,
+                            fn_decl_span,
+                            generator_kind,
+                            movability,
+                        );
                         hir::ExprKind::Closure(
                             this.lower_capture_clause(capture_clause),
                             fn_decl,
@@ -4677,12 +4679,26 @@ impl<'a> LoweringContext<'a> {
             }
 
             ExprKind::Yield(ref opt_expr) => {
-                self.is_generator = true;
+                match self.generator_kind {
+                    Some(hir::GeneratorKind::Gen) => {},
+                    Some(hir::GeneratorKind::Async) => {
+                        span_err!(
+                            self.sess,
+                            e.span,
+                            E0727,
+                            "`async` generators are not yet supported",
+                        );
+                        self.sess.abort_if_errors();
+                    },
+                    None => {
+                        self.generator_kind = Some(hir::GeneratorKind::Gen);
+                    }
+                }
                 let expr = opt_expr
                     .as_ref()
                     .map(|x| self.lower_expr(x))
                     .unwrap_or_else(|| self.expr_unit(e.span));
-                hir::ExprKind::Yield(P(expr))
+                hir::ExprKind::Yield(P(expr), hir::YieldSource::Yield)
             }
 
             ExprKind::Err => hir::ExprKind::Err,
@@ -4968,13 +4984,13 @@ impl<'a> LoweringContext<'a> {
                 let unstable_span = self.mark_span_with_reason(
                     CompilerDesugaringKind::QuestionMark,
                     e.span,
-                    Some(vec![sym::try_trait].into()),
+                    self.allow_try_trait.clone(),
                 );
                 let try_span = self.sess.source_map().end_point(e.span);
                 let try_span = self.mark_span_with_reason(
                     CompilerDesugaringKind::QuestionMark,
                     try_span,
-                    Some(vec![sym::try_trait].into()),
+                    self.allow_try_trait.clone(),
                 );
 
                 // `Try::into_result(<expr>)`
@@ -5754,19 +5770,23 @@ impl<'a> LoweringContext<'a> {
         //         yield ();
         //     }
         // }
-        if !self.is_async_body {
-            let mut err = struct_span_err!(
-                self.sess,
-                await_span,
-                E0728,
-                "`await` is only allowed inside `async` functions and blocks"
-            );
-            err.span_label(await_span, "only allowed inside `async` functions and blocks");
-            if let Some(item_sp) = self.current_item {
-                err.span_label(item_sp, "this is not `async`");
+        match self.generator_kind {
+            Some(hir::GeneratorKind::Async) => {},
+            Some(hir::GeneratorKind::Gen) |
+            None => {
+                let mut err = struct_span_err!(
+                    self.sess,
+                    await_span,
+                    E0728,
+                    "`await` is only allowed inside `async` functions and blocks"
+                );
+                err.span_label(await_span, "only allowed inside `async` functions and blocks");
+                if let Some(item_sp) = self.current_item {
+                    err.span_label(item_sp, "this is not `async`");
+                }
+                err.emit();
+                return hir::ExprKind::Err;
             }
-            err.emit();
-            return hir::ExprKind::Err;
         }
         let span = self.mark_span_with_reason(
             CompilerDesugaringKind::Await,
@@ -5776,7 +5796,7 @@ impl<'a> LoweringContext<'a> {
         let gen_future_span = self.mark_span_with_reason(
             CompilerDesugaringKind::Await,
             await_span,
-            Some(vec![sym::gen_future].into()),
+            self.allow_gen_future.clone(),
         );
 
         // let mut pinned = <expr>;
@@ -5864,7 +5884,7 @@ impl<'a> LoweringContext<'a> {
             let unit = self.expr_unit(span);
             let yield_expr = P(self.expr(
                 span,
-                hir::ExprKind::Yield(P(unit)),
+                hir::ExprKind::Yield(P(unit), hir::YieldSource::Await),
                 ThinVec::new(),
             ));
             self.stmt(span, hir::StmtKind::Expr(yield_expr))

src/librustc/hir/map/hir_id_validator.rs

@@ -1,6 +1,5 @@
 use crate::hir::def_id::{DefId, DefIndex, CRATE_DEF_INDEX};
 use crate::hir::{self, intravisit, HirId, ItemLocalId};
-use syntax::ast::NodeId;
 use crate::hir::itemlikevisit::ItemLikeVisitor;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::sync::{Lock, ParallelIterator, par_iter};
@@ -27,19 +26,19 @@ pub fn check_crate<'hir>(hir_map: &hir::map::Map<'hir>) {
     }
 }
 
-struct HirIdValidator<'a, 'hir: 'a> {
+struct HirIdValidator<'a, 'hir> {
     hir_map: &'a hir::map::Map<'hir>,
     owner_def_index: Option<DefIndex>,
     hir_ids_seen: FxHashSet<ItemLocalId>,
     errors: &'a Lock<Vec<String>>,
 }
 
-struct OuterVisitor<'a, 'hir: 'a> {
+struct OuterVisitor<'a, 'hir> {
     hir_map: &'a hir::map::Map<'hir>,
     errors: &'a Lock<Vec<String>>,
 }
 
-impl<'a, 'hir: 'a> OuterVisitor<'a, 'hir> {
+impl<'a, 'hir> OuterVisitor<'a, 'hir> {
     fn new_inner_visitor(&self,
                          hir_map: &'a hir::map::Map<'hir>)
                          -> HirIdValidator<'a, 'hir> {
@@ -52,7 +51,7 @@ impl<'a, 'hir: 'a> OuterVisitor<'a, 'hir> {
     }
 }
 
-impl<'a, 'hir: 'a> ItemLikeVisitor<'hir> for OuterVisitor<'a, 'hir> {
+impl<'a, 'hir> ItemLikeVisitor<'hir> for OuterVisitor<'a, 'hir> {
     fn visit_item(&mut self, i: &'hir hir::Item) {
         let mut inner_visitor = self.new_inner_visitor(self.hir_map);
         inner_visitor.check(i.hir_id, |this| intravisit::walk_item(this, i));
@@ -69,7 +68,7 @@ impl<'a, 'hir: 'a> ItemLikeVisitor<'hir> for OuterVisitor<'a, 'hir> {
     }
 }
 
-impl<'a, 'hir: 'a> HirIdValidator<'a, 'hir> {
+impl<'a, 'hir> HirIdValidator<'a, 'hir> {
     #[cold]
     #[inline(never)]
     fn error(&self, f: impl FnOnce() -> String) {
@@ -112,19 +111,9 @@ impl<'a, 'hir: 'a> HirIdValidator<'a, 'hir> {
 
                 trace!("missing hir id {:#?}", hir_id);
 
-                // We are already in ICE mode here, so doing a linear search
-                // should be fine.
-                let (node_id, _) = self.hir_map
-                                       .definitions()
-                                       .node_to_hir_id
-                                       .iter()
-                                       .enumerate()
-                                       .find(|&(_, &entry)| hir_id == entry)
-                                       .expect("no node_to_hir_id entry");
-                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)));
+                                           self.hir_map.node_to_string(hir_id)));
             }
             self.error(|| format!(
                 "ItemLocalIds not assigned densely in {}. \
@@ -138,13 +127,13 @@ impl<'a, 'hir: 'a> HirIdValidator<'a, 'hir> {
                         owner: owner_def_index,
                         local_id,
                     })
-                    .map(|h| format!("({:?} {})", h, self.hir_map.hir_to_string(h)))
+                    .map(|h| format!("({:?} {})", h, self.hir_map.node_to_string(h)))
                     .collect::<Vec<_>>()));
         }
     }
 }
 
-impl<'a, 'hir: 'a> intravisit::Visitor<'hir> for HirIdValidator<'a, 'hir> {
+impl<'a, 'hir> intravisit::Visitor<'hir> for HirIdValidator<'a, 'hir> {
 
     fn nested_visit_map<'this>(&'this mut self)
                                -> intravisit::NestedVisitorMap<'this, 'hir> {
@@ -156,14 +145,14 @@ impl<'a, 'hir: 'a> intravisit::Visitor<'hir> for HirIdValidator<'a, 'hir> {
 
         if hir_id == hir::DUMMY_HIR_ID {
             self.error(|| format!("HirIdValidator: HirId {:?} is invalid",
-                                  self.hir_map.hir_to_string(hir_id)));
+                                  self.hir_map.node_to_string(hir_id)));
             return;
         }
 
         if owner != hir_id.owner {
             self.error(|| format!(
                 "HirIdValidator: The recorded owner of {} is {} instead of {}",
-                self.hir_map.hir_to_string(hir_id),
+                self.hir_map.node_to_string(hir_id),
                 self.hir_map.def_path(DefId::local(hir_id.owner)).to_string_no_crate(),
                 self.hir_map.def_path(DefId::local(owner)).to_string_no_crate()));
         }

src/librustc/hir/map/mod.rs

@@ -35,7 +35,7 @@ mod def_collector;
 pub mod definitions;
 mod hir_id_validator;
 
-/// Represents an entry and its parent `NodeId`.
+/// Represents an entry and its parent `HirId`.
 #[derive(Copy, Clone, Debug)]
 pub struct Entry<'hir> {
     parent: HirId,
@@ -51,11 +51,11 @@ impl<'hir> Entry<'hir> {
         }
     }
 
-    fn fn_decl(&self) -> Option<&FnDecl> {
+    fn fn_decl(&self) -> Option<&'hir FnDecl> {
         match self.node {
             Node::Item(ref item) => {
                 match item.node {
-                    ItemKind::Fn(ref fn_decl, _, _, _) => Some(&fn_decl),
+                    ItemKind::Fn(ref fn_decl, _, _, _) => Some(fn_decl),
                     _ => None,
                 }
             }
@@ -76,7 +76,7 @@ impl<'hir> Entry<'hir> {
 
             Node::Expr(ref expr) => {
                 match expr.node {
-                    ExprKind::Closure(_, ref fn_decl, ..) => Some(&fn_decl),
+                    ExprKind::Closure(_, ref fn_decl, ..) => Some(fn_decl),
                     _ => None,
                 }
             }
@@ -200,7 +200,7 @@ impl<'hir> Map<'hir> {
     /// "reveals" the content of a node to the caller (who might not
     /// otherwise have had access to those contents, and hence needs a
     /// read recorded). If the function just returns a DefId or
-    /// NodeId, no actual content was returned, so no read is needed.
+    /// HirId, no actual content was returned, so no read is needed.
     pub fn read(&self, hir_id: HirId) {
         if let Some(entry) = self.lookup(hir_id) {
             self.dep_graph.read_index(entry.dep_node);
@@ -286,21 +286,11 @@ impl<'hir> Map<'hir> {
         self.definitions.def_index_to_hir_id(def_index)
     }
 
-    #[inline]
-    pub fn def_index_to_node_id(&self, def_index: DefIndex) -> NodeId {
-        self.definitions.def_index_to_node_id(def_index)
-    }
-
     #[inline]
     pub fn local_def_id_to_hir_id(&self, def_id: LocalDefId) -> HirId {
         self.definitions.def_index_to_hir_id(def_id.to_def_id().index)
     }
 
-    #[inline]
-    pub fn local_def_id_to_node_id(&self, def_id: LocalDefId) -> NodeId {
-        self.definitions.as_local_node_id(def_id.to_def_id()).unwrap()
-    }
-
     fn def_kind(&self, node_id: NodeId) -> Option<DefKind> {
         let node = if let Some(node) = self.find(node_id) {
             node
@@ -422,42 +412,30 @@ impl<'hir> Map<'hir> {
         self.forest.krate.body(id)
     }
 
-    pub fn fn_decl(&self, node_id: ast::NodeId) -> Option<FnDecl> {
-        let hir_id = self.node_to_hir_id(node_id);
-        self.fn_decl_by_hir_id(hir_id)
-    }
-
-    // FIXME(@ljedrz): replace the `NodeId` variant.
-    pub fn fn_decl_by_hir_id(&self, hir_id: HirId) -> Option<FnDecl> {
+    pub fn fn_decl_by_hir_id(&self, hir_id: HirId) -> Option<&'hir FnDecl> {
         if let Some(entry) = self.find_entry(hir_id) {
-            entry.fn_decl().cloned()
+            entry.fn_decl()
         } else {
             bug!("no entry for hir_id `{}`", hir_id)
         }
     }
 
-    /// Returns the `NodeId` that corresponds to the definition of
+    /// Returns the `HirId` that corresponds to the definition of
     /// which this is the body of, i.e., a `fn`, `const` or `static`
     /// item (possibly associated), a closure, or a `hir::AnonConst`.
-    pub fn body_owner(&self, BodyId { hir_id }: BodyId) -> NodeId {
+    pub fn body_owner(&self, BodyId { hir_id }: BodyId) -> HirId {
         let parent = self.get_parent_node_by_hir_id(hir_id);
         assert!(self.lookup(parent).map_or(false, |e| e.is_body_owner(hir_id)));
-        self.hir_to_node_id(parent)
+        parent
     }
 
     pub fn body_owner_def_id(&self, id: BodyId) -> DefId {
-        self.local_def_id(self.body_owner(id))
+        self.local_def_id_from_hir_id(self.body_owner(id))
     }
 
-    /// Given a `NodeId`, returns the `BodyId` associated with it,
+    /// Given a `HirId`, returns the `BodyId` associated with it,
     /// if the node is a body owner, otherwise returns `None`.
-    pub fn maybe_body_owned_by(&self, id: NodeId) -> Option<BodyId> {
-        let hir_id = self.node_to_hir_id(id);
-        self.maybe_body_owned_by_by_hir_id(hir_id)
-    }
-
-    // FIXME(@ljedrz): replace the `NodeId` variant.
-    pub fn maybe_body_owned_by_by_hir_id(&self, hir_id: HirId) -> Option<BodyId> {
+    pub fn maybe_body_owned_by(&self, hir_id: HirId) -> Option<BodyId> {
         if let Some(entry) = self.find_entry(hir_id) {
             if self.dep_graph.is_fully_enabled() {
                 let hir_id_owner = hir_id.owner;
@@ -473,19 +451,13 @@ impl<'hir> Map<'hir> {
 
     /// Given a body owner's id, returns the `BodyId` associated with it.
     pub fn body_owned_by(&self, id: HirId) -> BodyId {
-        self.maybe_body_owned_by_by_hir_id(id).unwrap_or_else(|| {
-            span_bug!(self.span_by_hir_id(id), "body_owned_by: {} has no associated body",
-                      self.hir_to_string(id));
+        self.maybe_body_owned_by(id).unwrap_or_else(|| {
+            span_bug!(self.span(id), "body_owned_by: {} has no associated body",
+                      self.node_to_string(id));
         })
     }
 
-    pub fn body_owner_kind(&self, id: NodeId) -> BodyOwnerKind {
-        let hir_id = self.node_to_hir_id(id);
-        self.body_owner_kind_by_hir_id(hir_id)
-    }
-
-    // FIXME(@ljedrz): replace the `NodeId` variant.
-    pub fn body_owner_kind_by_hir_id(&self, id: HirId) -> BodyOwnerKind {
+    pub fn body_owner_kind(&self, id: HirId) -> BodyOwnerKind {
         match self.get_by_hir_id(id) {
             Node::Item(&Item { node: ItemKind::Const(..), .. }) |
             Node::TraitItem(&TraitItem { node: TraitItemKind::Const(..), .. }) |
@@ -514,7 +486,7 @@ impl<'hir> Map<'hir> {
             Node::Item(&Item { node: ItemKind::Trait(..), .. }) |
             Node::Item(&Item { node: ItemKind::TraitAlias(..), .. }) => id,
             Node::GenericParam(_) => self.get_parent_node_by_hir_id(id),
-            _ => bug!("ty_param_owner: {} not a type parameter", self.hir_to_string(id))
+            _ => bug!("ty_param_owner: {} not a type parameter", self.node_to_string(id))
         }
     }
 
@@ -523,7 +495,7 @@ impl<'hir> Map<'hir> {
             Node::Item(&Item { node: ItemKind::Trait(..), .. }) |
             Node::Item(&Item { node: ItemKind::TraitAlias(..), .. }) => kw::SelfUpper,
             Node::GenericParam(param) => param.name.ident().name,
-            _ => bug!("ty_param_name: {} not a type parameter", self.hir_to_string(id)),
+            _ => bug!("ty_param_name: {} not a type parameter", self.node_to_string(id)),
         }
     }
 
@@ -576,7 +548,7 @@ impl<'hir> Map<'hir> {
         let module = &self.forest.krate.modules[&node_id];
 
         for id in &module.items {
-            visitor.visit_item(self.expect_item_by_hir_id(*id));
+            visitor.visit_item(self.expect_item(*id));
         }
 
         for id in &module.trait_items {
@@ -709,7 +681,7 @@ impl<'hir> Map<'hir> {
 
     /// If there is some error when walking the parents (e.g., a node does not
     /// have a parent in the map or a node can't be found), then we return the
-    /// last good `NodeId` we found. Note that reaching the crate root (`id == 0`),
+    /// last good `HirId` we found. Note that reaching the crate root (`id == 0`),
     /// is not an error, since items in the crate module have the crate root as
     /// parent.
     fn walk_parent_nodes<F, F2>(&self,
@@ -745,7 +717,7 @@ impl<'hir> Map<'hir> {
         }
     }
 
-    /// Retrieves the `NodeId` for `id`'s enclosing method, unless there's a
+    /// Retrieves the `HirId` for `id`'s enclosing method, unless there's a
     /// `while` or `loop` before reaching it, as block tail returns are not
     /// available in them.
     ///
@@ -753,7 +725,7 @@ impl<'hir> Map<'hir> {
     /// fn foo(x: usize) -> bool {
     ///     if x == 1 {
     ///         true  // `get_return_block` gets passed the `id` corresponding
-    ///     } else {  // to this, it will return `foo`'s `NodeId`.
+    ///     } else {  // to this, it will return `foo`'s `HirId`.
     ///         false
     ///     }
     /// }
@@ -793,17 +765,10 @@ impl<'hir> Map<'hir> {
         self.walk_parent_nodes(id, match_fn, match_non_returning_block).ok()
     }
 
-    /// Retrieves the `NodeId` for `id`'s parent item, or `id` itself if no
+    /// Retrieves the `HirId` for `id`'s parent item, or `id` itself if no
     /// parent item is in this map. The "parent item" is the closest parent node
     /// in the HIR which is recorded by the map and is an item, either an item
     /// in a module, trait, or impl.
-    pub fn get_parent(&self, id: NodeId) -> NodeId {
-        let hir_id = self.node_to_hir_id(id);
-        let parent_hir_id = self.get_parent_item(hir_id);
-        self.hir_to_node_id(parent_hir_id)
-    }
-
-    // FIXME(@ljedrz): replace the `NodeId` variant.
     pub fn get_parent_item(&self, hir_id: HirId) -> HirId {
         match self.walk_parent_nodes(hir_id, |node| match *node {
             Node::Item(_) |
@@ -819,13 +784,7 @@ impl<'hir> Map<'hir> {
 
     /// Returns the `DefId` of `id`'s nearest module parent, or `id` itself if no
     /// module parent is in this map.
-    pub fn get_module_parent(&self, id: NodeId) -> DefId {
-        let hir_id = self.node_to_hir_id(id);
-        self.get_module_parent_by_hir_id(hir_id)
-    }
-
-    // FIXME(@ljedrz): replace the `NodeId` variant.
-    pub fn get_module_parent_by_hir_id(&self, id: HirId) -> DefId {
+    pub fn get_module_parent(&self, id: HirId) -> DefId {
         self.local_def_id_from_hir_id(self.get_module_parent_node(id))
     }
 
@@ -901,23 +860,11 @@ impl<'hir> Map<'hir> {
         Some(scope)
     }
 
-    pub fn get_parent_did(&self, id: NodeId) -> DefId {
-        let hir_id = self.node_to_hir_id(id);
-        self.get_parent_did_by_hir_id(hir_id)
-    }
-
-    // FIXME(@ljedrz): replace the `NodeId` variant.
-    pub fn get_parent_did_by_hir_id(&self, id: HirId) -> DefId {
+    pub fn get_parent_did(&self, id: HirId) -> DefId {
         self.local_def_id_from_hir_id(self.get_parent_item(id))
     }
 
-    pub fn get_foreign_abi(&self, id: NodeId) -> Abi {
-        let hir_id = self.node_to_hir_id(id);
-        self.get_foreign_abi_by_hir_id(hir_id)
-    }
-
-    // FIXME(@ljedrz): replace the `NodeId` variant.
-    pub fn get_foreign_abi_by_hir_id(&self, hir_id: HirId) -> Abi {
+    pub fn get_foreign_abi(&self, hir_id: HirId) -> Abi {
         let parent = self.get_parent_item(hir_id);
         if let Some(entry) = self.find_entry(parent) {
             if let Entry {
@@ -927,33 +874,27 @@ impl<'hir> Map<'hir> {
                 return nm.abi;
             }
         }
-        bug!("expected foreign mod or inlined parent, found {}", self.hir_to_string(parent))
+        bug!("expected foreign mod or inlined parent, found {}", self.node_to_string(parent))
     }
 
-    pub fn expect_item(&self, id: NodeId) -> &'hir Item {
-        let hir_id = self.node_to_hir_id(id);
-        self.expect_item_by_hir_id(hir_id)
-    }
-
-    // FIXME(@ljedrz): replace the `NodeId` variant.
-    pub fn expect_item_by_hir_id(&self, id: HirId) -> &'hir Item {
+    pub fn expect_item(&self, id: HirId) -> &'hir Item {
         match self.find_by_hir_id(id) { // read recorded by `find`
             Some(Node::Item(item)) => item,
-            _ => bug!("expected item, found {}", self.hir_to_string(id))
+            _ => bug!("expected item, found {}", self.node_to_string(id))
         }
     }
 
     pub fn expect_impl_item(&self, id: HirId) -> &'hir ImplItem {
         match self.find_by_hir_id(id) {
             Some(Node::ImplItem(item)) => item,
-            _ => bug!("expected impl item, found {}", self.hir_to_string(id))
+            _ => bug!("expected impl item, found {}", self.node_to_string(id))
         }
     }
 
     pub fn expect_trait_item(&self, id: HirId) -> &'hir TraitItem {
         match self.find_by_hir_id(id) {
             Some(Node::TraitItem(item)) => item,
-            _ => bug!("expected trait item, found {}", self.hir_to_string(id))
+            _ => bug!("expected trait item, found {}", self.node_to_string(id))
         }
     }
 
@@ -963,26 +904,26 @@ impl<'hir> Map<'hir> {
                 match i.node {
                     ItemKind::Struct(ref struct_def, _) |
                     ItemKind::Union(ref struct_def, _) => struct_def,
-                    _ => bug!("struct ID bound to non-struct {}", self.hir_to_string(id))
+                    _ => bug!("struct ID bound to non-struct {}", self.node_to_string(id))
                 }
             }
             Some(Node::Variant(variant)) => &variant.node.data,
             Some(Node::Ctor(data)) => data,
-            _ => bug!("expected struct or variant, found {}", self.hir_to_string(id))
+            _ => bug!("expected struct or variant, found {}", self.node_to_string(id))
         }
     }
 
     pub fn expect_variant(&self, id: HirId) -> &'hir Variant {
         match self.find_by_hir_id(id) {
             Some(Node::Variant(variant)) => variant,
-            _ => bug!("expected variant, found {}", self.hir_to_string(id)),
+            _ => bug!("expected variant, found {}", self.node_to_string(id)),
         }
     }
 
     pub fn expect_foreign_item(&self, id: HirId) -> &'hir ForeignItem {
         match self.find_by_hir_id(id) {
             Some(Node::ForeignItem(item)) => item,
-            _ => bug!("expected foreign item, found {}", self.hir_to_string(id))
+            _ => bug!("expected foreign item, found {}", self.node_to_string(id))
         }
     }
 
@@ -995,7 +936,7 @@ impl<'hir> Map<'hir> {
     pub fn expect_expr_by_hir_id(&self, id: HirId) -> &'hir Expr {
         match self.find_by_hir_id(id) { // read recorded by find
             Some(Node::Expr(expr)) => expr,
-            _ => bug!("expected expr, found {}", self.hir_to_string(id))
+            _ => bug!("expected expr, found {}", self.node_to_string(id))
         }
     }
 
@@ -1018,19 +959,13 @@ impl<'hir> Map<'hir> {
             Node::GenericParam(param) => param.name.ident().name,
             Node::Binding(&Pat { node: PatKind::Binding(_, _, l, _), .. }) => l.name,
             Node::Ctor(..) => self.name_by_hir_id(self.get_parent_item(id)),
-            _ => bug!("no name for {}", self.hir_to_string(id))
+            _ => bug!("no name for {}", self.node_to_string(id))
         }
     }
 
     /// Given a node ID, gets a list of attributes associated with the AST
     /// corresponding to the node-ID.
-    pub fn attrs(&self, id: NodeId) -> &'hir [ast::Attribute] {
-        let hir_id = self.node_to_hir_id(id);
-        self.attrs_by_hir_id(hir_id)
-    }
-
-    // FIXME(@ljedrz): replace the `NodeId` variant.
-    pub fn attrs_by_hir_id(&self, id: HirId) -> &'hir [ast::Attribute] {
+    pub fn attrs(&self, id: HirId) -> &'hir [ast::Attribute] {
         self.read(id); // reveals attributes on the node
         let attrs = match self.find_entry(id).map(|entry| entry.node) {
             Some(Node::Local(l)) => Some(&l.attrs[..]),
@@ -1046,7 +981,7 @@ impl<'hir> Map<'hir> {
             Some(Node::GenericParam(param)) => Some(&param.attrs[..]),
             // Unit/tuple structs/variants take the attributes straight from
             // the struct/variant definition.
-            Some(Node::Ctor(..)) => return self.attrs_by_hir_id(self.get_parent_item(id)),
+            Some(Node::Ctor(..)) => return self.attrs(self.get_parent_item(id)),
             Some(Node::Crate) => Some(&self.forest.krate.attrs[..]),
             _ => None
         };
@@ -1093,13 +1028,7 @@ impl<'hir> Map<'hir> {
         })
     }
 
-    pub fn span(&self, id: NodeId) -> Span {
-        let hir_id = self.node_to_hir_id(id);
-        self.span_by_hir_id(hir_id)
-    }
-
-    // FIXME(@ljedrz): replace the `NodeId` variant.
-    pub fn span_by_hir_id(&self, hir_id: HirId) -> Span {
+    pub fn span(&self, hir_id: HirId) -> Span {
         self.read(hir_id); // reveals span from node
         match self.find_entry(hir_id).map(|entry| entry.node) {
             Some(Node::Item(item)) => item.span,
@@ -1139,32 +1068,17 @@ impl<'hir> Map<'hir> {
     }
 
     pub fn span_if_local(&self, id: DefId) -> Option<Span> {
-        self.as_local_node_id(id).map(|id| self.span(id))
+        self.as_local_hir_id(id).map(|id| self.span(id))
     }
 
-    pub fn node_to_string(&self, id: NodeId) -> String {
-        hir_id_to_string(self, self.node_to_hir_id(id), true)
-    }
-
-    // FIXME(@ljedrz): replace the `NodeId` variant.
-    pub fn hir_to_string(&self, id: HirId) -> String {
+    pub fn node_to_string(&self, id: HirId) -> String {
         hir_id_to_string(self, id, true)
     }
 
-    pub fn node_to_user_string(&self, id: NodeId) -> String {
-        hir_id_to_string(self, self.node_to_hir_id(id), false)
-    }
-
-    // FIXME(@ljedrz): replace the `NodeId` variant.
     pub fn hir_to_user_string(&self, id: HirId) -> String {
         hir_id_to_string(self, id, false)
     }
 
-    pub fn node_to_pretty_string(&self, id: NodeId) -> String {
-        print::to_string(self, |s| s.print_node(self.get(id)))
-    }
-
-    // FIXME(@ljedrz): replace the `NodeId` variant.
     pub fn hir_to_pretty_string(&self, id: HirId) -> String {
         print::to_string(self, |s| s.print_node(self.get_by_hir_id(id)))
     }
@@ -1307,7 +1221,7 @@ pub fn map_crate<'hir>(sess: &crate::session::Session,
 impl<'hir> print::PpAnn for Map<'hir> {
     fn nested(&self, state: &mut print::State<'_>, nested: print::Nested) -> io::Result<()> {
         match nested {
-            Nested::Item(id) => state.print_item(self.expect_item_by_hir_id(id.id)),
+            Nested::Item(id) => state.print_item(self.expect_item(id.id)),
             Nested::TraitItem(id) => state.print_trait_item(self.trait_item(id)),
             Nested::ImplItem(id) => state.print_impl_item(self.impl_item(id)),
             Nested::Body(id) => state.print_expr(&self.body(id).value),

src/librustc/hir/mod.rs

@@ -155,7 +155,7 @@ pub const DUMMY_HIR_ID: HirId = HirId {
 
 pub const DUMMY_ITEM_LOCAL_ID: ItemLocalId = ItemLocalId::MAX;
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Copy, HashStable)]
+#[derive(Copy, Clone, RustcEncodable, RustcDecodable, HashStable)]
 pub struct Lifetime {
     pub hir_id: HirId,
     pub span: Span,
@@ -295,7 +295,7 @@ impl Lifetime {
 /// A `Path` is essentially Rust's notion of a name; for instance,
 /// `std::cmp::PartialEq`. It's represented as a sequence of identifiers,
 /// along with a bunch of supporting information.
-#[derive(Clone, RustcEncodable, RustcDecodable, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, HashStable)]
 pub struct Path {
     pub span: Span,
     /// The resolution for the path.
@@ -324,7 +324,7 @@ impl fmt::Display for Path {
 
 /// A segment of a path: an identifier, an optional lifetime, and a set of
 /// types.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct PathSegment {
     /// The identifier portion of this path segment.
     #[stable_hasher(project(name))]
@@ -383,27 +383,23 @@ impl PathSegment {
         }
     }
 
-    // FIXME: hack required because you can't create a static
-    // `GenericArgs`, so you can't just return a `&GenericArgs`.
-    pub fn with_generic_args<F, R>(&self, f: F) -> R
-        where F: FnOnce(&GenericArgs) -> R
-    {
-        let dummy = GenericArgs::none();
-        f(if let Some(ref args) = self.args {
-            &args
+    pub fn generic_args(&self) -> &GenericArgs {
+        if let Some(ref args) = self.args {
+            args
         } else {
-            &dummy
-        })
+            const DUMMY: &GenericArgs = &GenericArgs::none();
+            DUMMY
+        }
     }
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct ConstArg {
     pub value: AnonConst,
     pub span: Span,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum GenericArg {
     Lifetime(Lifetime),
     Type(Ty),
@@ -435,7 +431,7 @@ impl GenericArg {
     }
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct GenericArgs {
     /// The generic arguments for this path segment.
     pub args: HirVec<GenericArg>,
@@ -449,7 +445,7 @@ pub struct GenericArgs {
 }
 
 impl GenericArgs {
-    pub fn none() -> Self {
+    pub const fn none() -> Self {
         Self {
             args: HirVec::new(),
             bindings: HirVec::new(),
@@ -509,7 +505,7 @@ pub enum TraitBoundModifier {
 /// `typeck::collect::compute_bounds` matches these against
 /// the "special" built-in traits (see `middle::lang_items`) and
 /// detects `Copy`, `Send` and `Sync`.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum GenericBound {
     Trait(PolyTraitRef, TraitBoundModifier),
     Outlives(Lifetime),
@@ -545,7 +541,7 @@ pub enum LifetimeParamKind {
     Error,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum GenericParamKind {
     /// A lifetime definition (e.g., `'a: 'b + 'c + 'd`).
     Lifetime {
@@ -560,7 +556,7 @@ pub enum GenericParamKind {
     }
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct GenericParam {
     pub hir_id: HirId,
     pub name: ParamName,
@@ -580,7 +576,7 @@ pub struct GenericParamCount {
 
 /// Represents lifetimes and type parameters attached to a declaration
 /// of a function, enum, trait, etc.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct Generics {
     pub params: HirVec<GenericParam>,
     pub where_clause: WhereClause,
@@ -588,12 +584,12 @@ pub struct Generics {
 }
 
 impl Generics {
-    pub fn empty() -> Generics {
+    pub const fn empty() -> Generics {
         Generics {
             params: HirVec::new(),
             where_clause: WhereClause {
-                hir_id: DUMMY_HIR_ID,
                 predicates: HirVec::new(),
+                span: DUMMY_SP,
             },
             span: DUMMY_SP,
         }
@@ -642,26 +638,25 @@ pub enum SyntheticTyParamKind {
 }
 
 /// A where-clause in a definition.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct WhereClause {
-    pub hir_id: HirId,
     pub predicates: HirVec<WherePredicate>,
+    // Only valid if predicates isn't empty.
+    span: Span,
 }
 
 impl WhereClause {
     pub fn span(&self) -> Option<Span> {
-        self.predicates.iter().map(|predicate| predicate.span())
-            .fold(None, |acc, i| match (acc, i) {
-                (None, i) => Some(i),
-                (Some(acc), i) => {
-                    Some(acc.to(i))
-                }
-            })
+        if self.predicates.is_empty() {
+            None
+        } else {
+            Some(self.span)
+        }
     }
 }
 
 /// A single predicate in a where-clause.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum WherePredicate {
     /// A type binding (e.g., `for<'c> Foo: Send + Clone + 'c`).
     BoundPredicate(WhereBoundPredicate),
@@ -682,7 +677,7 @@ impl WherePredicate {
 }
 
 /// A type bound (e.g., `for<'c> Foo: Send + Clone + 'c`).
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct WhereBoundPredicate {
     pub span: Span,
     /// Any generics from a `for` binding.
@@ -694,7 +689,7 @@ pub struct WhereBoundPredicate {
 }
 
 /// A lifetime predicate (e.g., `'a: 'b + 'c`).
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct WhereRegionPredicate {
     pub span: Span,
     pub lifetime: Lifetime,
@@ -702,7 +697,7 @@ pub struct WhereRegionPredicate {
 }
 
 /// An equality predicate (e.g., `T = int`); currently unsupported.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct WhereEqPredicate {
     pub hir_id: HirId,
     pub span: Span,
@@ -710,7 +705,7 @@ pub struct WhereEqPredicate {
     pub rhs_ty: P<Ty>,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
+#[derive(RustcEncodable, RustcDecodable, Debug)]
 pub struct ModuleItems {
     // Use BTreeSets here so items are in the same order as in the
     // list of all items in Crate
@@ -725,7 +720,7 @@ pub struct ModuleItems {
 /// For more details, see the [rustc guide].
 ///
 /// [rustc guide]: https://rust-lang.github.io/rustc-guide/hir.html
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
+#[derive(RustcEncodable, RustcDecodable, Debug)]
 pub struct Crate {
     pub module: Mod,
     pub attrs: HirVec<Attribute>,
@@ -820,7 +815,7 @@ impl Crate {
 /// A macro definition, in this crate or imported from another.
 ///
 /// Not parsed directly, but created on macro import or `macro_rules!` expansion.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct MacroDef {
     pub name: Name,
     pub vis: Visibility,
@@ -834,7 +829,7 @@ pub struct MacroDef {
 /// A block of statements `{ .. }`, which may have a label (in this case the
 /// `targeted_by_break` field will be `true`) and may be `unsafe` by means of
 /// the `rules` being anything but `DefaultBlock`.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct Block {
     /// Statements in a block.
     pub stmts: HirVec<Stmt>,
@@ -852,7 +847,7 @@ pub struct Block {
     pub targeted_by_break: bool,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, HashStable)]
 pub struct Pat {
     #[stable_hasher(ignore)]
     pub hir_id: HirId,
@@ -915,7 +910,7 @@ impl Pat {
 /// Patterns like the fields of Foo `{ x, ref y, ref mut z }`
 /// are treated the same as` x: x, y: ref y, z: ref mut z`,
 /// except `is_shorthand` is true.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct FieldPat {
     #[stable_hasher(ignore)]
     pub hir_id: HirId,
@@ -930,7 +925,7 @@ pub struct FieldPat {
 /// Explicit binding annotations given in the HIR for a binding. Note
 /// that this is not the final binding *mode* that we infer after type
 /// inference.
-#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy, HashStable)]
+#[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum BindingAnnotation {
     /// No binding annotation given: this means that the final binding mode
     /// will depend on whether we have skipped through a `&` reference
@@ -957,7 +952,7 @@ pub enum RangeEnd {
     Excluded,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum PatKind {
     /// Represents a wildcard pattern (i.e., `_`).
     Wild,
@@ -1002,8 +997,8 @@ pub enum PatKind {
     Slice(HirVec<P<Pat>>, Option<P<Pat>>, HirVec<P<Pat>>),
 }
 
-#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, HashStable,
-         RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, HashStable,
+         RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum Mutability {
     MutMutable,
     MutImmutable,
@@ -1019,7 +1014,7 @@ impl Mutability {
     }
 }
 
-#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy, Hash, HashStable)]
+#[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Hash, HashStable)]
 pub enum BinOpKind {
     /// The `+` operator (addition).
     Add,
@@ -1153,7 +1148,7 @@ impl Into<ast::BinOpKind> for BinOpKind {
 
 pub type BinOp = Spanned<BinOpKind>;
 
-#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy, Hash, HashStable)]
+#[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Hash, HashStable)]
 pub enum UnOp {
     /// The `*` operator (deferencing).
     UnDeref,
@@ -1182,7 +1177,7 @@ impl UnOp {
 }
 
 /// A statement.
-#[derive(Clone, RustcEncodable, RustcDecodable)]
+#[derive(RustcEncodable, RustcDecodable)]
 pub struct Stmt {
     pub hir_id: HirId,
     pub node: StmtKind,
@@ -1197,7 +1192,7 @@ impl fmt::Debug for Stmt {
 }
 
 /// The contents of a statement.
-#[derive(Clone, RustcEncodable, RustcDecodable, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, HashStable)]
 pub enum StmtKind {
     /// A local (`let`) binding.
     Local(P<Local>),
@@ -1224,7 +1219,7 @@ impl StmtKind {
 }
 
 /// Represents a `let` statement (i.e., `let <pat>:<ty> = <expr>;`).
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct Local {
     pub pat: P<Pat>,
     /// Type annotation, if any (otherwise the type will be inferred).
@@ -1241,7 +1236,7 @@ pub struct Local {
 
 /// Represents a single arm of a `match` expression, e.g.
 /// `<pats> (if <guard>) => <body>`.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct Arm {
     #[stable_hasher(ignore)]
     pub hir_id: HirId,
@@ -1255,12 +1250,12 @@ pub struct Arm {
     pub body: P<Expr>,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum Guard {
     If(P<Expr>),
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct Field {
     #[stable_hasher(ignore)]
     pub hir_id: HirId,
@@ -1270,7 +1265,7 @@ pub struct Field {
     pub is_shorthand: bool,
 }
 
-#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy, HashStable)]
+#[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum BlockCheckMode {
     DefaultBlock,
     UnsafeBlock(UnsafeSource),
@@ -1278,7 +1273,7 @@ pub enum BlockCheckMode {
     PopUnsafeBlock(UnsafeSource),
 }
 
-#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy, HashStable)]
+#[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum UnsafeSource {
     CompilerGenerated,
     UserProvided,
@@ -1306,15 +1301,15 @@ pub struct BodyId {
 ///
 /// - an `arguments` array containing the `(x, y)` pattern
 /// - a `value` containing the `x + y` expression (maybe wrapped in a block)
-/// - `is_generator` would be false
+/// - `generator_kind` would be `None`
 ///
 /// All bodies have an **owner**, which can be accessed via the HIR
 /// map using `body_owner_def_id()`.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
+#[derive(RustcEncodable, RustcDecodable, Debug)]
 pub struct Body {
     pub arguments: HirVec<Arg>,
     pub value: Expr,
-    pub is_generator: bool,
+    pub generator_kind: Option<GeneratorKind>,
 }
 
 impl Body {
@@ -1325,6 +1320,26 @@ impl Body {
     }
 }
 
+/// The type of source expression that caused this generator to be created.
+// Not `IsAsync` because we want to eventually add support for `AsyncGen`
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, HashStable,
+         RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
+pub enum GeneratorKind {
+    /// An `async` block or function.
+    Async,
+    /// A generator literal created via a `yield` inside a closure.
+    Gen,
+}
+
+impl fmt::Display for GeneratorKind {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str(match self {
+            GeneratorKind::Async => "`async` object",
+            GeneratorKind::Gen => "generator",
+        })
+    }
+}
+
 #[derive(Copy, Clone, Debug)]
 pub enum BodyOwnerKind {
     /// Functions and methods.
@@ -1364,7 +1379,7 @@ pub struct AnonConst {
 }
 
 /// An expression
-#[derive(Clone, RustcEncodable, RustcDecodable)]
+#[derive(RustcEncodable, RustcDecodable)]
 pub struct Expr {
     pub span: Span,
     pub node: ExprKind,
@@ -1475,7 +1490,7 @@ impl fmt::Debug for Expr {
     }
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum ExprKind {
     /// A `box x` expression.
     Box(P<Expr>),
@@ -1531,8 +1546,8 @@ pub enum ExprKind {
     ///
     /// The final span is the span of the argument block `|...|`.
     ///
-    /// This may also be a generator literal, indicated by the final boolean,
-    /// in that case there is an `GeneratorClause`.
+    /// This may also be a generator literal or an `async block` as indicated by the
+    /// `Option<GeneratorMovability>`.
     Closure(CaptureClause, P<FnDecl>, BodyId, Span, Option<GeneratorMovability>),
     /// A block (e.g., `'label: { ... }`).
     Block(P<Block>, Option<Label>),
@@ -1576,14 +1591,14 @@ pub enum ExprKind {
     Repeat(P<Expr>, AnonConst),
 
     /// A suspension point for generators (i.e., `yield <expr>`).
-    Yield(P<Expr>),
+    Yield(P<Expr>, YieldSource),
 
     /// A placeholder for an expression that wasn't syntactically well formed in some way.
     Err,
 }
 
 /// Represents an optionally `Self`-qualified value/type path or associated extension.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum QPath {
     /// Path to a definition, optionally "fully-qualified" with a `Self`
     /// type, if the path points to an associated item in a trait.
@@ -1603,7 +1618,7 @@ pub enum QPath {
 }
 
 /// Hints at the original code for a let statement.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy, HashStable)]
+#[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum LocalSource {
     /// A `match _ { .. }`.
     Normal,
@@ -1625,7 +1640,7 @@ pub enum LocalSource {
 }
 
 /// Hints at the original code for a `match _ { .. }`.
-#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy, HashStable)]
+#[derive(Copy, Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, HashStable)]
 pub enum MatchSource {
     /// A `match _ { .. }`.
     Normal,
@@ -1649,7 +1664,7 @@ pub enum MatchSource {
 }
 
 /// The loop type that yielded an `ExprKind::Loop`.
-#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy, HashStable)]
+#[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum LoopSource {
     /// A `loop { .. }` loop.
     Loop,
@@ -1659,7 +1674,7 @@ pub enum LoopSource {
     ForLoop,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy, HashStable)]
+#[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum LoopIdError {
     OutsideLoopScope,
     UnlabeledCfInWhileCondition,
@@ -1668,16 +1683,16 @@ pub enum LoopIdError {
 
 impl fmt::Display for LoopIdError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Display::fmt(match *self {
+        f.write_str(match self {
             LoopIdError::OutsideLoopScope => "not inside loop scope",
             LoopIdError::UnlabeledCfInWhileCondition =>
                 "unlabeled control flow (break or continue) in while condition",
             LoopIdError::UnresolvedLabel => "label not found",
-        }, f)
+        })
     }
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy, HashStable)]
+#[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct Destination {
     // This is `Some(_)` iff there is an explicit user-specified `label
     pub label: Option<Label>,
@@ -1687,14 +1702,35 @@ pub struct Destination {
     pub target_id: Result<HirId, LoopIdError>,
 }
 
-#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, HashStable,
-         RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
+/// Whether a generator contains self-references, causing it to be `!Unpin`.
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, HashStable,
+         RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum GeneratorMovability {
+    /// May contain self-references, `!Unpin`.
     Static,
+    /// Must not contain self-references, `Unpin`.
     Movable,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy, HashStable)]
+/// The yield kind that caused an `ExprKind::Yield`.
+#[derive(Copy, Clone, Debug, RustcEncodable, RustcDecodable, HashStable)]
+pub enum YieldSource {
+    /// An `<expr>.await`.
+    Await,
+    /// A plain `yield`.
+    Yield,
+}
+
+impl fmt::Display for YieldSource {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str(match self {
+            YieldSource::Await => "`await`",
+            YieldSource::Yield => "`yield`",
+        })
+    }
+}
+
+#[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum CaptureClause {
     CaptureByValue,
     CaptureByRef,
@@ -1702,14 +1738,14 @@ pub enum CaptureClause {
 
 // N.B., if you change this, you'll probably want to change the corresponding
 // type structure in middle/ty.rs as well.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct MutTy {
     pub ty: P<Ty>,
     pub mutbl: Mutability,
 }
 
 /// Represents a method's signature in a trait declaration or implementation.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct MethodSig {
     pub header: FnHeader,
     pub decl: P<FnDecl>,
@@ -1727,7 +1763,7 @@ pub struct TraitItemId {
 /// possibly including a default implementation. A trait item is
 /// either required (meaning it doesn't have an implementation, just a
 /// signature) or provided (meaning it has a default implementation).
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
+#[derive(RustcEncodable, RustcDecodable, Debug)]
 pub struct TraitItem {
     pub ident: Ident,
     pub hir_id: HirId,
@@ -1738,7 +1774,7 @@ pub struct TraitItem {
 }
 
 /// Represents a trait method's body (or just argument names).
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum TraitMethod {
     /// No default body in the trait, just a signature.
     Required(HirVec<Ident>),
@@ -1748,7 +1784,7 @@ pub enum TraitMethod {
 }
 
 /// Represents a trait method or associated constant or type
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum TraitItemKind {
     /// An associated constant with an optional value (otherwise `impl`s must contain a value).
     Const(P<Ty>, Option<BodyId>),
@@ -1768,7 +1804,7 @@ pub struct ImplItemId {
 }
 
 /// Represents anything within an `impl` block
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
+#[derive(RustcEncodable, RustcDecodable, Debug)]
 pub struct ImplItem {
     pub ident: Ident,
     pub hir_id: HirId,
@@ -1781,7 +1817,7 @@ pub struct ImplItem {
 }
 
 /// Represents various kinds of content within an `impl`.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum ImplItemKind {
     /// An associated constant of the given type, set to the constant result
     /// of the expression
@@ -1808,7 +1844,7 @@ pub enum ImplItemKind {
 ///    Binding(...),
 /// }
 /// ```
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct TypeBinding {
     pub hir_id: HirId,
     #[stable_hasher(project(name))]
@@ -1818,7 +1854,7 @@ pub struct TypeBinding {
 }
 
 // Represents the two kinds of type bindings.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum TypeBindingKind {
     /// E.g., `Foo<Bar: Send>`.
     Constraint {
@@ -1839,7 +1875,7 @@ impl TypeBinding {
     }
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable)]
+#[derive(RustcEncodable, RustcDecodable)]
 pub struct Ty {
     pub hir_id: HirId,
     pub node: TyKind,
@@ -1854,7 +1890,7 @@ impl fmt::Debug for Ty {
 }
 
 /// Not represented directly in the AST; referred to by name through a `ty_path`.
-#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy, HashStable)]
+#[derive(Copy, Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, HashStable)]
 pub enum PrimTy {
     Int(IntTy),
     Uint(UintTy),
@@ -1864,7 +1900,7 @@ pub enum PrimTy {
     Char,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct BareFnTy {
     pub unsafety: Unsafety,
     pub abi: Abi,
@@ -1873,7 +1909,7 @@ pub struct BareFnTy {
     pub arg_names: HirVec<Ident>,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct ExistTy {
     pub generics: Generics,
     pub bounds: GenericBounds,
@@ -1893,7 +1929,7 @@ pub enum ExistTyOrigin {
 }
 
 /// The various kinds of types recognized by the compiler.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum TyKind {
     /// A variable length slice (i.e., `[T]`).
     Slice(P<Ty>),
@@ -1930,12 +1966,12 @@ pub enum TyKind {
     Infer,
     /// Placeholder for a type that has failed to be defined.
     Err,
-    /// Placeholder for C-variadic arguments. We "spoof" the `VaList` created
+    /// Placeholder for C-variadic arguments. We "spoof" the `VaListImpl` created
     /// from the variadic arguments. This type is only valid up to typeck.
     CVarArgs(Lifetime),
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct InlineAsmOutput {
     pub constraint: Symbol,
     pub is_rw: bool,
@@ -1958,14 +1994,14 @@ pub struct InlineAsm {
 }
 
 /// Represents an argument in a function header.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct Arg {
     pub pat: P<Pat>,
     pub hir_id: HirId,
 }
 
 /// Represents the header (not the body) of a function declaration.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct FnDecl {
     /// The types of the function's arguments.
     ///
@@ -1978,7 +2014,7 @@ pub struct FnDecl {
 }
 
 /// Represents what type of implicit self a function has, if any.
-#[derive(Clone, Copy, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum ImplicitSelfKind {
     /// Represents a `fn x(self);`.
     Imm,
@@ -2058,11 +2094,10 @@ impl Defaultness {
 
 impl fmt::Display for Unsafety {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Display::fmt(match *self {
-                              Unsafety::Normal => "normal",
-                              Unsafety::Unsafe => "unsafe",
-                          },
-                          f)
+        f.write_str(match self {
+            Unsafety::Normal => "normal",
+            Unsafety::Unsafe => "unsafe",
+        })
     }
 }
 
@@ -2076,15 +2111,15 @@ pub enum ImplPolarity {
 
 impl fmt::Debug for ImplPolarity {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match *self {
-            ImplPolarity::Positive => "positive".fmt(f),
-            ImplPolarity::Negative => "negative".fmt(f),
-        }
+        f.write_str(match self {
+            ImplPolarity::Positive => "positive",
+            ImplPolarity::Negative => "negative",
+        })
     }
 }
 
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum FunctionRetTy {
     /// Return type is not specified.
     ///
@@ -2114,7 +2149,7 @@ impl FunctionRetTy {
     }
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
+#[derive(RustcEncodable, RustcDecodable, Debug)]
 pub struct Mod {
     /// A span from the first token past `{` to the last token until `}`.
     /// For `mod foo;`, the inner span ranges from the first token
@@ -2123,25 +2158,25 @@ pub struct Mod {
     pub item_ids: HirVec<ItemId>,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct ForeignMod {
     pub abi: Abi,
     pub items: HirVec<ForeignItem>,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct GlobalAsm {
     pub asm: Symbol,
     #[stable_hasher(ignore)] // This is used for error reporting
     pub ctxt: SyntaxContext,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct EnumDef {
     pub variants: HirVec<Variant>,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct VariantKind {
     /// Name of the variant.
     #[stable_hasher(project(name))]
@@ -2177,10 +2212,10 @@ pub enum UseKind {
 /// References to traits in impls.
 ///
 /// `resolve` maps each `TraitRef`'s `ref_id` to its defining trait; that's all
-/// that the `ref_id` is for. Note that `ref_id`'s value is not the `NodeId` of the
-/// trait being referred to but just a unique `NodeId` that serves as a key
+/// that the `ref_id` is for. Note that `ref_id`'s value is not the `HirId` of the
+/// trait being referred to but just a unique `HirId` that serves as a key
 /// within the resolution map.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct TraitRef {
     pub path: Path,
     // Don't hash the ref_id. It is tracked via the thing it is used to access
@@ -2202,7 +2237,7 @@ impl TraitRef {
     }
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct PolyTraitRef {
     /// The `'a` in `<'a> Foo<&'a T>`.
     pub bound_generic_params: HirVec<GenericParam>,
@@ -2215,7 +2250,7 @@ pub struct PolyTraitRef {
 
 pub type Visibility = Spanned<VisibilityKind>;
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
+#[derive(RustcEncodable, RustcDecodable, Debug)]
 pub enum VisibilityKind {
     Public,
     Crate(CrateSugar),
@@ -2250,7 +2285,7 @@ impl VisibilityKind {
     }
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct StructField {
     pub span: Span,
     #[stable_hasher(project(name))]
@@ -2270,7 +2305,7 @@ impl StructField {
 }
 
 /// Fields and constructor IDs of enum variants and structs.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum VariantData {
     /// A struct variant.
     ///
@@ -2315,7 +2350,7 @@ pub struct ItemId {
 /// An item
 ///
 /// The name might be a dummy name in case of anonymous items
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
+#[derive(RustcEncodable, RustcDecodable, Debug)]
 pub struct Item {
     pub ident: Ident,
     pub hir_id: HirId,
@@ -2325,7 +2360,7 @@ pub struct Item {
     pub span: Span,
 }
 
-#[derive(Clone, Copy, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct FnHeader {
     pub unsafety: Unsafety,
     pub constness: Constness,
@@ -2342,7 +2377,7 @@ impl FnHeader {
     }
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum ItemKind {
     /// An `extern crate` item, with optional *original* crate name if the crate was renamed.
     ///
@@ -2445,7 +2480,7 @@ impl ItemKind {
 /// type or method, and whether it is public). This allows other
 /// passes to find the impl they want without loading the ID (which
 /// means fewer edges in the incremental compilation graph).
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct TraitItemRef {
     pub id: TraitItemId,
     #[stable_hasher(project(name))]
@@ -2461,7 +2496,7 @@ pub struct TraitItemRef {
 /// type or method, and whether it is public). This allows other
 /// passes to find the impl they want without loading the ID (which
 /// means fewer edges in the incremental compilation graph).
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct ImplItemRef {
     pub id: ImplItemId,
     #[stable_hasher(project(name))]
@@ -2480,7 +2515,7 @@ pub enum AssocItemKind {
     Existential,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct ForeignItem {
     #[stable_hasher(project(name))]
     pub ident: Ident,
@@ -2492,7 +2527,7 @@ pub struct ForeignItem {
 }
 
 /// An item within an `extern` block.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]
+#[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub enum ForeignItemKind {
     /// A foreign function.
     Fn(P<FnDecl>, HirVec<Ident>, Generics),

src/librustc/hir/print.rs

@@ -625,10 +625,10 @@ impl<'a> State<'a> {
                         self.word_space("for ?")?;
                         self.print_trait_ref(&ptr.trait_ref)?;
                     } else {
-                        real_bounds.push(b.clone());
+                        real_bounds.push(b);
                     }
                 }
-                self.print_bounds(":", &real_bounds[..])?;
+                self.print_bounds(":", real_bounds)?;
                 self.s.word(";")?;
                 self.end()?; // end the outer ibox
             }
@@ -698,10 +698,10 @@ impl<'a> State<'a> {
                         self.word_space("for ?")?;
                         self.print_trait_ref(&ptr.trait_ref)?;
                     } else {
-                        real_bounds.push(b.clone());
+                        real_bounds.push(b);
                     }
                 }
-                self.print_bounds(":", &real_bounds[..])?;
+                self.print_bounds(":", real_bounds)?;
                 self.print_where_clause(&generics.where_clause)?;
                 self.s.word(" ")?;
                 self.bopen()?;
@@ -724,11 +724,11 @@ impl<'a> State<'a> {
                         self.word_space("for ?")?;
                         self.print_trait_ref(&ptr.trait_ref)?;
                     } else {
-                        real_bounds.push(b.clone());
+                        real_bounds.push(b);
                     }
                 }
                 self.nbsp()?;
-                self.print_bounds("=", &real_bounds[..])?;
+                self.print_bounds("=", real_bounds)?;
                 self.print_where_clause(&generics.where_clause)?;
                 self.s.word(";")?;
             }
@@ -1194,12 +1194,11 @@ impl<'a> State<'a> {
         self.s.word(".")?;
         self.print_ident(segment.ident)?;
 
-        segment.with_generic_args(|generic_args| {
-            if !generic_args.args.is_empty() || !generic_args.bindings.is_empty() {
-                return self.print_generic_args(&generic_args, segment.infer_args, true);
-            }
-            Ok(())
-        })?;
+        let generic_args = segment.generic_args();
+        if !generic_args.args.is_empty() || !generic_args.bindings.is_empty() {
+            self.print_generic_args(generic_args, segment.infer_args, true)?;
+        }
+
         self.print_call_post(base_args)
     }
 
@@ -1501,7 +1500,7 @@ impl<'a> State<'a> {
 
                 self.pclose()?;
             }
-            hir::ExprKind::Yield(ref expr) => {
+            hir::ExprKind::Yield(ref expr, _) => {
                 self.word_space("yield")?;
                 self.print_expr_maybe_paren(&expr, parser::PREC_JUMP)?;
             }
@@ -1559,11 +1558,9 @@ impl<'a> State<'a> {
                 self.s.word("::")?
             }
             if segment.ident.name != kw::PathRoot {
-               self.print_ident(segment.ident)?;
-               segment.with_generic_args(|generic_args| {
-                   self.print_generic_args(generic_args, segment.infer_args,
-                                           colons_before_params)
-               })?;
+                self.print_ident(segment.ident)?;
+                self.print_generic_args(segment.generic_args(), segment.infer_args,
+                                        colons_before_params)?;
             }
         }
 
@@ -1572,10 +1569,8 @@ impl<'a> State<'a> {
 
     pub fn print_path_segment(&mut self, segment: &hir::PathSegment) -> io::Result<()> {
         if segment.ident.name != kw::PathRoot {
-           self.print_ident(segment.ident)?;
-           segment.with_generic_args(|generic_args| {
-               self.print_generic_args(generic_args, segment.infer_args, false)
-           })?;
+            self.print_ident(segment.ident)?;
+            self.print_generic_args(segment.generic_args(), segment.infer_args, false)?;
         }
         Ok(())
     }
@@ -1600,11 +1595,9 @@ impl<'a> State<'a> {
                     }
                     if segment.ident.name != kw::PathRoot {
                         self.print_ident(segment.ident)?;
-                        segment.with_generic_args(|generic_args| {
-                            self.print_generic_args(generic_args,
-                                                    segment.infer_args,
-                                                    colons_before_params)
-                        })?;
+                        self.print_generic_args(segment.generic_args(),
+                                                segment.infer_args,
+                                                colons_before_params)?;
                     }
                 }
 
@@ -1612,11 +1605,9 @@ impl<'a> State<'a> {
                 self.s.word("::")?;
                 let item_segment = path.segments.last().unwrap();
                 self.print_ident(item_segment.ident)?;
-                item_segment.with_generic_args(|generic_args| {
-                    self.print_generic_args(generic_args,
-                                            item_segment.infer_args,
-                                            colons_before_params)
-                })
+                self.print_generic_args(item_segment.generic_args(),
+                                        item_segment.infer_args,
+                                        colons_before_params)
             }
             hir::QPath::TypeRelative(ref qself, ref item_segment) => {
                 self.s.word("<")?;
@@ -1624,11 +1615,9 @@ impl<'a> State<'a> {
                 self.s.word(">")?;
                 self.s.word("::")?;
                 self.print_ident(item_segment.ident)?;
-                item_segment.with_generic_args(|generic_args| {
-                    self.print_generic_args(generic_args,
-                                            item_segment.infer_args,
-                                            colons_before_params)
-                })
+                self.print_generic_args(item_segment.generic_args(),
+                                        item_segment.infer_args,
+                                        colons_before_params)
             }
         }
     }
@@ -2009,31 +1998,34 @@ impl<'a> State<'a> {
         }
     }
 
-    pub fn print_bounds(&mut self, prefix: &'static str, bounds: &[hir::GenericBound])
-                        -> io::Result<()> {
-        if !bounds.is_empty() {
-            self.s.word(prefix)?;
-            let mut first = true;
-            for bound in bounds {
-                if !(first && prefix.is_empty()) {
-                    self.nbsp()?;
-                }
-                if first {
-                    first = false;
-                } else {
-                    self.word_space("+")?;
-                }
+    pub fn print_bounds<'b>(
+        &mut self,
+        prefix: &'static str,
+        bounds: impl IntoIterator<Item = &'b hir::GenericBound>,
+    ) -> io::Result<()> {
+        let mut first = true;
+        for bound in bounds {
+            if first {
+                self.s.word(prefix)?;
+            }
+            if !(first && prefix.is_empty()) {
+                self.nbsp()?;
+            }
+            if first {
+                first = false;
+            } else {
+                self.word_space("+")?;
+            }
 
-                match bound {
-                    GenericBound::Trait(tref, modifier) => {
-                        if modifier == &TraitBoundModifier::Maybe {
-                            self.s.word("?")?;
-                        }
-                        self.print_poly_trait_ref(tref)?;
-                    }
-                    GenericBound::Outlives(lt) => {
-                        self.print_lifetime(lt)?;
+            match bound {
+                GenericBound::Trait(tref, modifier) => {
+                    if modifier == &TraitBoundModifier::Maybe {
+                        self.s.word("?")?;
                     }
+                    self.print_poly_trait_ref(tref)?;
+                }
+                GenericBound::Outlives(lt) => {
+                    self.print_lifetime(lt)?;
                 }
             }
         }
@@ -2202,8 +2194,8 @@ impl<'a> State<'a> {
         let generics = hir::Generics {
             params: hir::HirVec::new(),
             where_clause: hir::WhereClause {
-                hir_id: hir::DUMMY_HIR_ID,
                 predicates: hir::HirVec::new(),
+                span: syntax_pos::DUMMY_SP,
             },
             span: syntax_pos::DUMMY_SP,
         };

src/librustc/hir/upvars.rs

@@ -14,8 +14,8 @@ pub fn provide(providers: &mut Providers<'_>) {
             return None;
         }
 
-        let node_id = tcx.hir().as_local_node_id(def_id).unwrap();
-        let body = tcx.hir().body(tcx.hir().maybe_body_owned_by(node_id)?);
+        let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap();
+        let body = tcx.hir().body(tcx.hir().maybe_body_owned_by(hir_id)?);
 
         let mut local_collector = LocalCollector::default();
         local_collector.visit_body(body);

src/librustc/ich/impls_hir.rs

@@ -335,15 +335,15 @@ impl<'a> HashStable<StableHashingContext<'a>> for hir::Body {
                                           hcx: &mut StableHashingContext<'a>,
                                           hasher: &mut StableHasher<W>) {
         let hir::Body {
-            ref arguments,
-            ref value,
-            is_generator,
-        } = *self;
+            arguments,
+            value,
+            generator_kind,
+        } = self;
 
         hcx.with_node_id_hashing_mode(NodeIdHashingMode::Ignore, |hcx| {
             arguments.hash_stable(hcx, hasher);
             value.hash_stable(hcx, hasher);
-            is_generator.hash_stable(hcx, hasher);
+            generator_kind.hash_stable(hcx, hasher);
         });
     }
 }

src/librustc/ich/impls_syntax.rs

@@ -391,10 +391,17 @@ impl_stable_hash_for!(enum ::syntax::ast::MetaItemKind {
     NameValue(lit)
 });
 
+impl_stable_hash_for!(enum ::syntax_pos::hygiene::Transparency {
+    Transparent,
+    SemiTransparent,
+    Opaque,
+});
+
 impl_stable_hash_for!(struct ::syntax_pos::hygiene::ExpnInfo {
     call_site,
-    def_site,
     format,
+    def_site,
+    default_transparency,
     allow_internal_unstable,
     allow_internal_unsafe,
     local_inner_macros,

src/librustc/infer/at.rs

@@ -30,13 +30,13 @@ use super::*;
 use crate::ty::Const;
 use crate::ty::relate::{Relate, TypeRelation};
 
-pub struct At<'a, 'tcx: 'a> {
+pub struct At<'a, 'tcx> {
     pub infcx: &'a InferCtxt<'a, 'tcx>,
     pub cause: &'a ObligationCause<'tcx>,
     pub param_env: ty::ParamEnv<'tcx>,
 }
 
-pub struct Trace<'a, 'tcx: 'a> {
+pub struct Trace<'a, 'tcx> {
     at: At<'a, 'tcx>,
     a_is_expected: bool,
     trace: TypeTrace<'tcx>,

src/librustc/infer/canonical/canonicalizer.rs

@@ -14,7 +14,7 @@ use crate::mir::interpret::ConstValue;
 use std::sync::atomic::Ordering;
 use crate::ty::fold::{TypeFoldable, TypeFolder};
 use crate::ty::subst::Kind;
-use crate::ty::{self, BoundVar, InferConst, Lift, List, Ty, TyCtxt, TypeFlags};
+use crate::ty::{self, BoundVar, InferConst, List, Ty, TyCtxt, TypeFlags};
 use crate::ty::flags::FlagComputation;
 
 use rustc_data_structures::fx::FxHashMap;
@@ -43,7 +43,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
         query_state: &mut OriginalQueryValues<'tcx>,
     ) -> Canonicalized<'tcx, V>
     where
-        V: TypeFoldable<'tcx> + Lift<'tcx>,
+        V: TypeFoldable<'tcx>,
     {
         self.tcx
             .sess
@@ -87,7 +87,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
     /// [c]: https://rust-lang.github.io/rustc-guide/traits/canonicalization.html#canonicalizing-the-query-result
     pub fn canonicalize_response<V>(&self, value: &V) -> Canonicalized<'tcx, V>
     where
-        V: TypeFoldable<'tcx> + Lift<'tcx>,
+        V: TypeFoldable<'tcx>,
     {
         let mut query_state = OriginalQueryValues::default();
         Canonicalizer::canonicalize(
@@ -101,7 +101,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
 
     pub fn canonicalize_user_type_annotation<V>(&self, value: &V) -> Canonicalized<'tcx, V>
     where
-        V: TypeFoldable<'tcx> + Lift<'tcx>,
+        V: TypeFoldable<'tcx>,
     {
         let mut query_state = OriginalQueryValues::default();
         Canonicalizer::canonicalize(
@@ -132,7 +132,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
         query_state: &mut OriginalQueryValues<'tcx>,
     ) -> Canonicalized<'tcx, V>
     where
-        V: TypeFoldable<'tcx> + Lift<'tcx>,
+        V: TypeFoldable<'tcx>,
     {
         self.tcx
             .sess
@@ -275,7 +275,7 @@ impl CanonicalizeRegionMode for CanonicalizeFreeRegionsOtherThanStatic {
     }
 }
 
-struct Canonicalizer<'cx, 'tcx: 'cx> {
+struct Canonicalizer<'cx, 'tcx> {
     infcx: Option<&'cx InferCtxt<'cx, 'tcx>>,
     tcx: TyCtxt<'tcx>,
     variables: SmallVec<[CanonicalVarInfo; 8]>,
@@ -506,7 +506,7 @@ impl<'cx, 'tcx> Canonicalizer<'cx, 'tcx> {
         query_state: &mut OriginalQueryValues<'tcx>,
     ) -> Canonicalized<'tcx, V>
     where
-        V: TypeFoldable<'tcx> + Lift<'tcx>,
+        V: TypeFoldable<'tcx>,
     {
         let needs_canonical_flags = if canonicalize_region_mode.any() {
             TypeFlags::KEEP_IN_LOCAL_TCX |
@@ -520,20 +520,12 @@ impl<'cx, 'tcx> Canonicalizer<'cx, 'tcx> {
             TypeFlags::HAS_CT_PLACEHOLDER
         };
 
-        let gcx = tcx.global_tcx();
-
         // Fast path: nothing that needs to be canonicalized.
         if !value.has_type_flags(needs_canonical_flags) {
-            let out_value = gcx.lift(value).unwrap_or_else(|| {
-                bug!(
-                    "failed to lift `{:?}` (nothing to canonicalize)",
-                    value
-                )
-            });
             let canon_value = Canonical {
                 max_universe: ty::UniverseIndex::ROOT,
                 variables: List::empty(),
-                value: out_value,
+                value: value.clone(),
             };
             return canon_value;
         }
@@ -553,13 +545,7 @@ impl<'cx, 'tcx> Canonicalizer<'cx, 'tcx> {
         // Once we have canonicalized `out_value`, it should not
         // contain anything that ties it to this inference context
         // anymore, so it should live in the global arena.
-        let out_value = gcx.lift(&out_value).unwrap_or_else(|| {
-            bug!(
-                "failed to lift `{:?}`, canonicalized from `{:?}`",
-                out_value,
-                value
-            )
-        });
+        debug_assert!(!out_value.has_type_flags(TypeFlags::KEEP_IN_LOCAL_TCX));
 
         let canonical_variables = tcx.intern_canonical_var_infos(&canonicalizer.variables);
 

src/librustc/infer/canonical/mod.rs

@@ -194,10 +194,10 @@ pub struct QueryResponse<'tcx, R> {
     pub value: R,
 }
 
-pub type Canonicalized<'tcx, V> = Canonical<'tcx, <V as Lift<'tcx>>::Lifted>;
+pub type Canonicalized<'tcx, V> = Canonical<'tcx, V>;
 
 pub type CanonicalizedQueryResponse<'tcx, T> =
-    &'tcx Canonical<'tcx, QueryResponse<'tcx, <T as Lift<'tcx>>::Lifted>>;
+    &'tcx Canonical<'tcx, QueryResponse<'tcx, T>>;
 
 /// Indicates whether or not we were able to prove the query to be
 /// true.

src/librustc/infer/canonical/query_response.rs

@@ -26,7 +26,7 @@ use crate::traits::TraitEngine;
 use crate::traits::{Obligation, ObligationCause, PredicateObligation};
 use crate::ty::fold::TypeFoldable;
 use crate::ty::subst::{Kind, UnpackedKind};
-use crate::ty::{self, BoundVar, InferConst, Lift, Ty, TyCtxt};
+use crate::ty::{self, BoundVar, InferConst, Ty, TyCtxt};
 use crate::util::captures::Captures;
 
 impl<'tcx> InferCtxtBuilder<'tcx> {
@@ -53,8 +53,8 @@ impl<'tcx> InferCtxtBuilder<'tcx> {
     ) -> Fallible<CanonicalizedQueryResponse<'tcx, R>>
     where
         K: TypeFoldable<'tcx>,
-        R: Debug + Lift<'tcx> + TypeFoldable<'tcx>,
-        Canonical<'tcx, <QueryResponse<'tcx, R> as Lift<'tcx>>::Lifted>: ArenaAllocatable,
+        R: Debug + TypeFoldable<'tcx>,
+        Canonical<'tcx, QueryResponse<'tcx, R>>: ArenaAllocatable,
     {
         self.enter_with_canonical(
             DUMMY_SP,
@@ -99,8 +99,8 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
         fulfill_cx: &mut dyn TraitEngine<'tcx>,
     ) -> Fallible<CanonicalizedQueryResponse<'tcx, T>>
     where
-        T: Debug + Lift<'tcx> + TypeFoldable<'tcx>,
-        Canonical<'tcx, <QueryResponse<'tcx, T> as Lift<'tcx>>::Lifted>: ArenaAllocatable,
+        T: Debug + TypeFoldable<'tcx>,
+        Canonical<'tcx, QueryResponse<'tcx, T>>: ArenaAllocatable,
     {
         let query_response = self.make_query_response(inference_vars, answer, fulfill_cx)?;
         let canonical_result = self.canonicalize_response(&query_response);
@@ -126,9 +126,9 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
         &self,
         inference_vars: CanonicalVarValues<'tcx>,
         answer: T,
-    ) -> Canonical<'tcx, QueryResponse<'tcx, <T as Lift<'tcx>>::Lifted>>
+    ) -> Canonical<'tcx, QueryResponse<'tcx, T>>
     where
-        T: Debug + Lift<'tcx> + TypeFoldable<'tcx>,
+        T: Debug + TypeFoldable<'tcx>,
     {
         self.canonicalize_response(&QueryResponse {
             var_values: inference_vars,
@@ -147,7 +147,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
         fulfill_cx: &mut dyn TraitEngine<'tcx>,
     ) -> Result<QueryResponse<'tcx, T>, NoSolution>
     where
-        T: Debug + TypeFoldable<'tcx> + Lift<'tcx>,
+        T: Debug + TypeFoldable<'tcx>,
     {
         let tcx = self.tcx;
 

src/librustc/infer/combine.rs

@@ -44,7 +44,7 @@ use syntax::ast;
 use syntax_pos::{Span, DUMMY_SP};
 
 #[derive(Clone)]
-pub struct CombineFields<'infcx, 'tcx: 'infcx> {
+pub struct CombineFields<'infcx, 'tcx> {
     pub infcx: &'infcx InferCtxt<'infcx, 'tcx>,
     pub trace: TypeTrace<'tcx>,
     pub cause: Option<ty::relate::Cause>,
@@ -355,7 +355,7 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> {
     }
 }
 
-struct Generalizer<'cx, 'tcx: 'cx> {
+struct Generalizer<'cx, 'tcx> {
     infcx: &'cx InferCtxt<'cx, 'tcx>,
 
     /// The span, used when creating new type variables and things.

src/librustc/infer/equate.rs

@@ -11,7 +11,7 @@ use crate::mir::interpret::ConstValue;
 use crate::infer::unify_key::replace_if_possible;
 
 /// Ensures `a` is made equal to `b`. Returns `a` on success.
-pub struct Equate<'combine, 'infcx: 'combine, 'tcx: 'infcx> {
+pub struct Equate<'combine, 'infcx, 'tcx> {
     fields: &'combine mut CombineFields<'infcx, 'tcx>,
     a_is_expected: bool,
 }

src/librustc/infer/error_reporting/mod.rs

@@ -86,7 +86,7 @@ impl<'tcx> TyCtxt<'tcx> {
                     )
                 };
                 let span = scope.span(self, region_scope_tree);
-                let tag = match self.hir().find(scope.node_id(self, region_scope_tree)) {
+                let tag = match self.hir().find_by_hir_id(scope.hir_id(region_scope_tree)) {
                     Some(Node::Block(_)) => "block",
                     Some(Node::Expr(expr)) => match expr.node {
                         hir::ExprKind::Call(..) => "call",
@@ -191,7 +191,7 @@ impl<'tcx> TyCtxt<'tcx> {
         };
         let (prefix, span) = match *region {
             ty::ReEarlyBound(ref br) => {
-                let mut sp = cm.def_span(self.hir().span_by_hir_id(node));
+                let mut sp = cm.def_span(self.hir().span(node));
                 if let Some(param) = self.hir()
                     .get_generics(scope)
                     .and_then(|generics| generics.get_named(br.name))
@@ -204,7 +204,7 @@ impl<'tcx> TyCtxt<'tcx> {
                 bound_region: ty::BoundRegion::BrNamed(_, name),
                 ..
             }) => {
-                let mut sp = cm.def_span(self.hir().span_by_hir_id(node));
+                let mut sp = cm.def_span(self.hir().span(node));
                 if let Some(param) = self.hir()
                     .get_generics(scope)
                     .and_then(|generics| generics.get_named(name))
@@ -216,11 +216,11 @@ impl<'tcx> TyCtxt<'tcx> {
             ty::ReFree(ref fr) => match fr.bound_region {
                 ty::BrAnon(idx) => (
                     format!("the anonymous lifetime #{} defined on", idx + 1),
-                    self.hir().span_by_hir_id(node),
+                    self.hir().span(node),
                 ),
                 _ => (
                     format!("the lifetime {} as defined on", region),
-                    cm.def_span(self.hir().span_by_hir_id(node)),
+                    cm.def_span(self.hir().span(node)),
                 ),
             },
             _ => bug!(),
@@ -1330,12 +1330,12 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                     if !param.is_self() {
                         let type_param = generics.type_param(param, self.tcx);
                         let hir = &self.tcx.hir();
-                        hir.as_local_node_id(type_param.def_id).map(|id| {
+                        hir.as_local_hir_id(type_param.def_id).map(|id| {
                             // Get the `hir::Param` to verify whether it already has any bounds.
                             // We do this to avoid suggesting code that ends up as `T: 'a'b`,
                             // instead we suggest `T: 'a + 'b` in that case.
                             let mut has_bounds = false;
-                            if let Node::GenericParam(ref param) = hir.get(id) {
+                            if let Node::GenericParam(ref param) = hir.get_by_hir_id(id) {
                                 has_bounds = !param.bounds.is_empty();
                             }
                             let sp = hir.span(id);

src/librustc/infer/error_reporting/need_type_info.rs

@@ -227,16 +227,15 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
 
     pub fn need_type_info_err_in_generator(
         &self,
+        kind: hir::GeneratorKind,
         span: Span,
         ty: Ty<'tcx>,
     ) -> DiagnosticBuilder<'tcx> {
         let ty = self.resolve_vars_if_possible(&ty);
         let name = self.extract_type_name(&ty, None);
-
-        let mut err = struct_span_err!(self.tcx.sess,
-                       span,
-                       E0698,
-                       "type inside generator must be known in this context");
+        let mut err = struct_span_err!(
+            self.tcx.sess, span, E0698, "type inside {} must be known in this context", kind,
+        );
         err.span_label(span, InferCtxt::missing_type_msg(&name));
         err
     }

src/librustc/infer/error_reporting/nice_region_error/find_anon_type.rs

@@ -28,8 +28,8 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
     ) -> Option<(&hir::Ty, &hir::FnDecl)> {
         if let Some(anon_reg) = self.tcx().is_suitable_region(region) {
             let def_id = anon_reg.def_id;
-            if let Some(node_id) = self.tcx().hir().as_local_node_id(def_id) {
-                let fndecl = match self.tcx().hir().get(node_id) {
+            if let Some(hir_id) = self.tcx().hir().as_local_hir_id(def_id) {
+                let fndecl = match self.tcx().hir().get_by_hir_id(hir_id) {
                     Node::Item(&hir::Item {
                         node: hir::ItemKind::Fn(ref fndecl, ..),
                         ..

src/librustc/infer/error_reporting/nice_region_error/mod.rs

@@ -30,7 +30,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
     }
 }
 
-pub struct NiceRegionError<'cx, 'tcx: 'cx> {
+pub struct NiceRegionError<'cx, 'tcx> {
     infcx: &'cx InferCtxt<'cx, 'tcx>,
     error: Option<RegionResolutionError<'tcx>>,
     regions: Option<(Span, ty::Region<'tcx>, ty::Region<'tcx>)>,

src/librustc/infer/error_reporting/nice_region_error/outlives_closure.rs

@@ -48,11 +48,11 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
             if let (&SubregionOrigin::BindingTypeIsNotValidAtDecl(ref external_span),
                     &RegionKind::ReFree(ref free_region)) = (&sub_origin, sup_region) {
                 let hir = &self.tcx().hir();
-                if let Some(node_id) = hir.as_local_node_id(free_region.scope) {
+                if let Some(hir_id) = hir.as_local_hir_id(free_region.scope) {
                     if let Node::Expr(Expr {
                         node: Closure(_, _, _, closure_span, None),
                         ..
-                    }) = hir.get(node_id) {
+                    }) = hir.get_by_hir_id(hir_id) {
                         let sup_sp = sup_origin.span();
                         let origin_sp = origin.span();
                         let mut err = self.tcx().sess.struct_span_err(

src/librustc/infer/error_reporting/nice_region_error/util.rs

@@ -51,11 +51,11 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
         };
 
         let hir = &self.tcx().hir();
-        if let Some(node_id) = hir.as_local_node_id(id) {
-            if let Some(body_id) = hir.maybe_body_owned_by(node_id) {
+        if let Some(hir_id) = hir.as_local_hir_id(id) {
+            if let Some(body_id) = hir.maybe_body_owned_by(hir_id) {
                 let body = hir.body(body_id);
                 let owner_id = hir.body_owner(body_id);
-                let fn_decl = hir.fn_decl(owner_id).unwrap();
+                let fn_decl = hir.fn_decl_by_hir_id(owner_id).unwrap();
                 if let Some(tables) = self.tables {
                     body.arguments
                         .iter()
@@ -63,7 +63,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
                         .filter_map(|(index, arg)| {
                             // May return None; sometimes the tables are not yet populated.
                             let ty_hir_id = fn_decl.inputs[index].hir_id;
-                            let arg_ty_span = hir.span(hir.hir_to_node_id(ty_hir_id));
+                            let arg_ty_span = hir.span(ty_hir_id);
                             let ty = tables.node_type_opt(arg.hir_id)?;
                             let mut found_anon_region = false;
                             let new_arg_ty = self.tcx().fold_regions(&ty, &mut false, |r, _| {

src/librustc/infer/freshen.rs

@@ -41,7 +41,7 @@ use std::collections::hash_map::Entry;
 use super::InferCtxt;
 use super::unify_key::ToType;
 
-pub struct TypeFreshener<'a, 'tcx: 'a> {
+pub struct TypeFreshener<'a, 'tcx> {
     infcx: &'a InferCtxt<'a, 'tcx>,
     ty_freshen_count: u32,
     const_freshen_count: u32,

src/librustc/infer/fudge.rs

@@ -133,7 +133,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     }
 }
 
-pub struct InferenceFudger<'a, 'tcx: 'a> {
+pub struct InferenceFudger<'a, 'tcx> {
     infcx: &'a InferCtxt<'a, 'tcx>,
     type_vars: (Range<TyVid>, Vec<TypeVariableOrigin>),
     int_vars: Range<IntVid>,

src/librustc/infer/glb.rs

@@ -8,7 +8,7 @@ use crate::ty::{self, Ty, TyCtxt};
 use crate::ty::relate::{Relate, RelateResult, TypeRelation};
 
 /// "Greatest lower bound" (common subtype)
-pub struct Glb<'combine, 'infcx: 'combine, 'tcx: 'infcx> {
+pub struct Glb<'combine, 'infcx, 'tcx> {
     fields: &'combine mut CombineFields<'infcx, 'tcx>,
     a_is_expected: bool,
 }

src/librustc/infer/lattice.rs

@@ -27,7 +27,7 @@ use crate::ty::TyVar;
 use crate::ty::{self, Ty};
 use crate::ty::relate::{RelateResult, TypeRelation};
 
-pub trait LatticeDir<'f, 'tcx: 'f>: TypeRelation<'tcx> {
+pub trait LatticeDir<'f, 'tcx>: TypeRelation<'tcx> {
     fn infcx(&self) -> &'f InferCtxt<'f, 'tcx>;
 
     fn cause(&self) -> &ObligationCause<'tcx>;
@@ -41,14 +41,13 @@ pub trait LatticeDir<'f, 'tcx: 'f>: TypeRelation<'tcx> {
     fn relate_bound(&mut self, v: Ty<'tcx>, a: Ty<'tcx>, b: Ty<'tcx>) -> RelateResult<'tcx, ()>;
 }
 
-pub fn super_lattice_tys<'a, 'tcx, L>(
+pub fn super_lattice_tys<'a, 'tcx: 'a, L>(
     this: &mut L,
     a: Ty<'tcx>,
     b: Ty<'tcx>,
 ) -> RelateResult<'tcx, Ty<'tcx>>
 where
     L: LatticeDir<'a, 'tcx>,
-    'tcx: 'a,
 {
     debug!("{}.lattice_tys({:?}, {:?})",
            this.tag(),

src/librustc/infer/lexical_region_resolve/graphviz.rs

@@ -107,7 +107,7 @@ pub fn maybe_print_constraints_for<'a, 'tcx>(
     }
 }
 
-struct ConstraintGraph<'a, 'tcx: 'a> {
+struct ConstraintGraph<'a, 'tcx> {
     graph_name: String,
     region_rels: &'a RegionRelations<'a, 'tcx>,
     map: &'a BTreeMap<Constraint<'tcx>, SubregionOrigin<'tcx>>,

src/librustc/infer/lexical_region_resolve/mod.rs

@@ -93,7 +93,7 @@ struct RegionAndOrigin<'tcx> {
 
 type RegionGraph<'tcx> = Graph<(), Constraint<'tcx>>;
 
-struct LexicalResolver<'cx, 'tcx: 'cx> {
+struct LexicalResolver<'cx, 'tcx> {
     region_rels: &'cx RegionRelations<'cx, 'tcx>,
     var_infos: VarInfos,
     data: RegionConstraintData<'tcx>,

src/librustc/infer/lub.rs

@@ -8,7 +8,7 @@ use crate::ty::{self, Ty, TyCtxt};
 use crate::ty::relate::{Relate, RelateResult, TypeRelation};
 
 /// "Least upper bound" (common supertype)
-pub struct Lub<'combine, 'infcx: 'combine, 'tcx: 'infcx> {
+pub struct Lub<'combine, 'infcx, 'tcx> {
     fields: &'combine mut CombineFields<'infcx, 'tcx>,
     a_is_expected: bool,
 }

src/librustc/infer/mod.rs

@@ -585,7 +585,7 @@ impl<'tcx> InferOk<'tcx, ()> {
 }
 
 #[must_use = "once you start a snapshot, you should always consume it"]
-pub struct CombinedSnapshot<'a, 'tcx: 'a> {
+pub struct CombinedSnapshot<'a, 'tcx> {
     projection_cache_snapshot: traits::ProjectionCacheSnapshot,
     type_snapshot: type_variable::Snapshot<'tcx>,
     const_snapshot: ut::Snapshot<ut::InPlace<ty::ConstVid<'tcx>>>,

src/librustc/infer/nll_relate/mod.rs

@@ -38,7 +38,7 @@ pub enum NormalizationStrategy {
     Eager,
 }
 
-pub struct TypeRelating<'me, 'tcx: 'me, D>
+pub struct TypeRelating<'me, 'tcx, D>
 where
     D: TypeRelatingDelegate<'tcx>,
 {
@@ -741,7 +741,7 @@ where
 /// binder depth, and finds late-bound regions targeting the
 /// `for<..`>.  For each of those, it creates an entry in
 /// `bound_region_scope`.
-struct ScopeInstantiator<'me, 'tcx: 'me> {
+struct ScopeInstantiator<'me, 'tcx> {
     next_region: &'me mut dyn FnMut(ty::BoundRegion) -> ty::Region<'tcx>,
     // The debruijn index of the scope we are instantiating.
     target_index: ty::DebruijnIndex,
@@ -798,7 +798,7 @@ impl<'me, 'tcx> TypeVisitor<'tcx> for ScopeInstantiator<'me, 'tcx> {
 /// scopes.
 ///
 /// [blog post]: https://is.gd/0hKvIr
-struct TypeGeneralizer<'me, 'tcx: 'me, D>
+struct TypeGeneralizer<'me, 'tcx, D>
 where
     D: TypeRelatingDelegate<'tcx> + 'me,
 {

src/librustc/infer/opaque_types/mod.rs

@@ -469,11 +469,6 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
             definition_ty
         );
 
-        // We can unwrap here because our reverse mapper always
-        // produces things with 'tcx lifetime, though the type folder
-        // obscures that.
-        let definition_ty = gcx.lift(&definition_ty).unwrap();
-
         definition_ty
     }
 }
@@ -723,7 +718,7 @@ impl TypeFolder<'tcx> for ReverseMapper<'tcx> {
     }
 }
 
-struct Instantiator<'a, 'tcx: 'a> {
+struct Instantiator<'a, 'tcx> {
     infcx: &'a InferCtxt<'a, 'tcx>,
     parent_def_id: DefId,
     body_id: hir::HirId,
@@ -819,7 +814,7 @@ impl<'a, 'tcx> Instantiator<'a, 'tcx> {
                             },
                             _ => bug!(
                                 "expected (impl) item, found {}",
-                                tcx.hir().hir_to_string(opaque_hir_id),
+                                tcx.hir().node_to_string(opaque_hir_id),
                             ),
                         };
                         if in_definition_scope {

src/librustc/infer/outlives/env.rs

@@ -67,7 +67,7 @@ pub struct OutlivesEnvironment<'tcx> {
 /// because of implied bounds.
 pub type RegionBoundPairs<'tcx> = Vec<(ty::Region<'tcx>, GenericKind<'tcx>)>;
 
-impl<'a, 'tcx: 'a> OutlivesEnvironment<'tcx> {
+impl<'a, 'tcx> OutlivesEnvironment<'tcx> {
     pub fn new(param_env: ty::ParamEnv<'tcx>) -> Self {
         let mut env = OutlivesEnvironment {
             param_env,

src/librustc/infer/outlives/obligations.rs

@@ -226,7 +226,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
 /// via a "delegate" of type `D` -- this is usually the `infcx`, which
 /// accrues them into the `region_obligations` code, but for NLL we
 /// use something else.
-pub struct TypeOutlives<'cx, 'tcx: 'cx, D>
+pub struct TypeOutlives<'cx, 'tcx, D>
 where
     D: TypeOutlivesDelegate<'tcx>,
 {

src/librustc/infer/outlives/verify.rs

@@ -12,7 +12,7 @@ use crate::util::captures::Captures;
 /// via a "delegate" of type `D` -- this is usually the `infcx`, which
 /// accrues them into the `region_obligations` code, but for NLL we
 /// use something else.
-pub struct VerifyBoundCx<'cx, 'tcx: 'cx> {
+pub struct VerifyBoundCx<'cx, 'tcx> {
     tcx: TyCtxt<'tcx>,
     region_bound_pairs: &'cx RegionBoundPairs<'tcx>,
     implicit_region_bound: Option<ty::Region<'tcx>>,

src/librustc/infer/resolve.rs

@@ -12,7 +12,7 @@ use crate::ty::fold::{TypeFolder, TypeVisitor};
 /// been unified with (similar to `shallow_resolve`, but deep). This is
 /// useful for printing messages etc but also required at various
 /// points for correctness.
-pub struct OpportunisticVarResolver<'a, 'tcx: 'a> {
+pub struct OpportunisticVarResolver<'a, 'tcx> {
     infcx: &'a InferCtxt<'a, 'tcx>,
 }
 
@@ -50,7 +50,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for OpportunisticVarResolver<'a, 'tcx> {
 /// The opportunistic type and region resolver is similar to the
 /// opportunistic type resolver, but also opportunistically resolves
 /// regions. It is useful for canonicalization.
-pub struct OpportunisticTypeAndRegionResolver<'a, 'tcx: 'a> {
+pub struct OpportunisticTypeAndRegionResolver<'a, 'tcx> {
     infcx: &'a InferCtxt<'a, 'tcx>,
 }
 
@@ -101,7 +101,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for OpportunisticTypeAndRegionResolver<'a, 'tcx>
 /// type variables that don't yet have a value. The first unresolved type is stored.
 /// It does not construct the fully resolved type (which might
 /// involve some hashing and so forth).
-pub struct UnresolvedTypeFinder<'a, 'tcx: 'a> {
+pub struct UnresolvedTypeFinder<'a, 'tcx> {
     infcx: &'a InferCtxt<'a, 'tcx>,
 
     /// Used to find the type parameter name and location for error reporting.
@@ -171,7 +171,7 @@ where
 
 // N.B. This type is not public because the protocol around checking the
 // `err` field is not enforcable otherwise.
-struct FullTypeResolver<'a, 'tcx: 'a> {
+struct FullTypeResolver<'a, 'tcx> {
     infcx: &'a InferCtxt<'a, 'tcx>,
     err: Option<FixupError<'tcx>>,
 }

src/librustc/infer/sub.rs

@@ -11,7 +11,7 @@ use crate::mir::interpret::ConstValue;
 use std::mem;
 
 /// Ensures `a` is made a subtype of `b`. Returns `a` on success.
-pub struct Sub<'combine, 'infcx: 'combine, 'tcx: 'infcx> {
+pub struct Sub<'combine, 'infcx, 'tcx> {
     fields: &'combine mut CombineFields<'infcx, 'tcx>,
     a_is_expected: bool,
 }

src/librustc/lint/context.rs

@@ -507,7 +507,7 @@ impl LintStore {
 }
 
 /// Context for lint checking after type checking.
-pub struct LateContext<'a, 'tcx: 'a> {
+pub struct LateContext<'a, 'tcx> {
     /// Type context we're checking in.
     pub tcx: TyCtxt<'tcx>,
 
@@ -533,7 +533,7 @@ pub struct LateContext<'a, 'tcx: 'a> {
     only_module: bool,
 }
 
-pub struct LateContextAndPass<'a, 'tcx: 'a, T: LateLintPass<'a, 'tcx>> {
+pub struct LateContextAndPass<'a, 'tcx, T: LateLintPass<'a, 'tcx>> {
     context: LateContext<'a, 'tcx>,
     pass: T,
 }
@@ -1399,7 +1399,7 @@ fn late_lint_mod_pass<'tcx, T: for<'a> LateLintPass<'a, 'tcx>>(
 
     // Visit the crate attributes
     if hir_id == hir::CRATE_HIR_ID {
-        walk_list!(cx, visit_attribute, tcx.hir().attrs_by_hir_id(hir::CRATE_HIR_ID));
+        walk_list!(cx, visit_attribute, tcx.hir().attrs(hir::CRATE_HIR_ID));
     }
 }
 

src/librustc/lint/mod.rs

@@ -762,7 +762,7 @@ pub fn struct_lint_level<'a>(sess: &'a Session,
 }
 
 pub fn maybe_lint_level_root(tcx: TyCtxt<'_>, id: hir::HirId) -> bool {
-    let attrs = tcx.hir().attrs_by_hir_id(id);
+    let attrs = tcx.hir().attrs(id);
     attrs.iter().any(|attr| Level::from_symbol(attr.name_or_empty()).is_some())
 }
 

src/librustc/middle/dead.rs

@@ -38,7 +38,7 @@ fn should_explore<'tcx>(tcx: TyCtxt<'tcx>, hir_id: hir::HirId) -> bool {
     }
 }
 
-struct MarkSymbolVisitor<'a, 'tcx: 'a> {
+struct MarkSymbolVisitor<'a, 'tcx> {
     worklist: Vec<hir::HirId>,
     tcx: TyCtxt<'tcx>,
     tables: &'a ty::TypeckTables<'tcx>,
@@ -292,7 +292,7 @@ impl<'a, 'tcx> Visitor<'tcx> for MarkSymbolVisitor<'a, 'tcx> {
     fn visit_ty(&mut self, ty: &'tcx hir::Ty) {
         match ty.node {
             TyKind::Def(item_id, _) => {
-                let item = self.tcx.hir().expect_item_by_hir_id(item_id.id);
+                let item = self.tcx.hir().expect_item(item_id.id);
                 intravisit::walk_item(self, item);
             }
             _ => ()
@@ -351,7 +351,7 @@ fn has_allow_dead_code_or_lang_attr(
 //   or
 //   2) We are not sure to be live or not
 //     * Implementation of a trait method
-struct LifeSeeder<'k, 'tcx: 'k> {
+struct LifeSeeder<'k, 'tcx> {
     worklist: Vec<hir::HirId>,
     krate: &'k hir::Crate,
     tcx: TyCtxt<'tcx>,

src/librustc/middle/entry.rs

@@ -11,7 +11,7 @@ use crate::hir::itemlikevisit::ItemLikeVisitor;
 use crate::ty::TyCtxt;
 use crate::ty::query::Providers;
 
-struct EntryContext<'a, 'tcx: 'a> {
+struct EntryContext<'a, 'tcx> {
     session: &'a Session,
 
     map: &'a hir_map::Map<'tcx>,

src/librustc/middle/expr_use_visitor.rs

@@ -229,7 +229,7 @@ impl OverloadedCallType {
 // The ExprUseVisitor type
 //
 // This is the code that actually walks the tree.
-pub struct ExprUseVisitor<'a, 'tcx: 'a> {
+pub struct ExprUseVisitor<'a, 'tcx> {
     mc: mc::MemCategorizationContext<'a, 'tcx>,
     delegate: &'a mut dyn Delegate<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
@@ -546,7 +546,7 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx> {
                 self.consume_expr(&base);
             }
 
-            hir::ExprKind::Yield(ref value) => {
+            hir::ExprKind::Yield(ref value, _) => {
                 self.consume_expr(&value);
             }
         }

src/librustc/middle/free_region.rs

@@ -15,7 +15,7 @@ use crate::ty::{self, TyCtxt, Region};
 ///
 /// This stuff is a bit convoluted and should be refactored, but as we
 /// transition to NLL, it'll all go away anyhow.
-pub struct RegionRelations<'a, 'tcx: 'a> {
+pub struct RegionRelations<'a, 'tcx> {
     pub tcx: TyCtxt<'tcx>,
 
     /// The context used to fetch the region maps.

src/librustc/middle/liveness.rs

@@ -352,7 +352,7 @@ impl IrMaps<'tcx> {
     }
 }
 
-fn visit_fn<'a, 'tcx: 'a>(
+fn visit_fn<'tcx>(
     ir: &mut IrMaps<'tcx>,
     fk: FnKind<'tcx>,
     decl: &'tcx hir::FnDecl,
@@ -682,7 +682,7 @@ const ACC_READ: u32 = 1;
 const ACC_WRITE: u32 = 2;
 const ACC_USE: u32 = 4;
 
-struct Liveness<'a, 'tcx: 'a> {
+struct Liveness<'a, 'tcx> {
     ir: &'a mut IrMaps<'tcx>,
     tables: &'a ty::TypeckTables<'tcx>,
     s: Specials,
@@ -1171,7 +1171,7 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
             }
 
             hir::ExprKind::Call(ref f, ref args) => {
-                let m = self.ir.tcx.hir().get_module_parent_by_hir_id(expr.hir_id);
+                let m = self.ir.tcx.hir().get_module_parent(expr.hir_id);
                 let succ = if self.ir.tcx.is_ty_uninhabited_from(m, self.tables.expr_ty(expr)) {
                     self.s.exit_ln
                 } else {
@@ -1182,7 +1182,7 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
             }
 
             hir::ExprKind::MethodCall(.., ref args) => {
-                let m = self.ir.tcx.hir().get_module_parent_by_hir_id(expr.hir_id);
+                let m = self.ir.tcx.hir().get_module_parent(expr.hir_id);
                 let succ = if self.ir.tcx.is_ty_uninhabited_from(m, self.tables.expr_ty(expr)) {
                     self.s.exit_ln
                 } else {
@@ -1218,7 +1218,7 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
             hir::ExprKind::Type(ref e, _) |
             hir::ExprKind::DropTemps(ref e) |
             hir::ExprKind::Unary(_, ref e) |
-            hir::ExprKind::Yield(ref e) |
+            hir::ExprKind::Yield(ref e, _) |
             hir::ExprKind::Repeat(ref e, _) => {
                 self.propagate_through_expr(&e, succ)
             }

src/librustc/middle/mem_categorization.rs

@@ -342,9 +342,9 @@ impl MutabilityCategory {
     fn from_local(
         tcx: TyCtxt<'_>,
         tables: &ty::TypeckTables<'_>,
-        id: ast::NodeId,
+        id: hir::HirId,
     ) -> MutabilityCategory {
-        let ret = match tcx.hir().get(id) {
+        let ret = match tcx.hir().get_by_hir_id(id) {
             Node::Binding(p) => match p.node {
                 PatKind::Binding(..) => {
                     let bm = *tables.pat_binding_modes()
@@ -500,7 +500,6 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> {
             // FIXME
             None if self.is_tainted_by_errors() => Err(()),
             None => {
-                let id = self.tcx.hir().hir_to_node_id(id);
                 bug!("no type for node {}: {} in mem_categorization",
                      id, self.tcx.hir().node_to_string(id));
             }
@@ -753,15 +752,14 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> {
             }
 
             Res::Local(var_id) => {
-                let var_nid = self.tcx.hir().hir_to_node_id(var_id);
                 if self.upvars.map_or(false, |upvars| upvars.contains_key(&var_id)) {
-                    self.cat_upvar(hir_id, span, var_nid)
+                    self.cat_upvar(hir_id, span, var_id)
                 } else {
                     Ok(cmt_ {
                         hir_id,
                         span,
                         cat: Categorization::Local(var_id),
-                        mutbl: MutabilityCategory::from_local(self.tcx, self.tables, var_nid),
+                        mutbl: MutabilityCategory::from_local(self.tcx, self.tables, var_id),
                         ty: expr_ty,
                         note: NoteNone
                     })
@@ -778,7 +776,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> {
         &self,
         hir_id: hir::HirId,
         span: Span,
-        var_id: ast::NodeId,
+        var_id: hir::HirId,
     ) -> McResult<cmt_<'tcx>> {
         // An upvar can have up to 3 components. We translate first to a
         // `Categorization::Upvar`, which is itself a fiction -- it represents the reference to the
@@ -819,22 +817,18 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> {
                              .unwrap_or(ty::ClosureKind::LATTICE_BOTTOM),
 
                     None =>
-                        self.tcx.global_tcx()
-                                .lift(&closure_substs)
-                                .expect("no inference cx, but inference variables in closure ty")
-                                .closure_kind(closure_def_id, self.tcx.global_tcx()),
+                        closure_substs.closure_kind(closure_def_id, self.tcx.global_tcx()),
                 }
             }
             _ => span_bug!(span, "unexpected type for fn in mem_categorization: {:?}", ty),
         };
 
-        let var_hir_id = self.tcx.hir().node_to_hir_id(var_id);
         let upvar_id = ty::UpvarId {
-            var_path: ty::UpvarPath { hir_id: var_hir_id },
+            var_path: ty::UpvarPath { hir_id: var_id },
             closure_expr_id: closure_expr_def_id.to_local(),
         };
 
-        let var_ty = self.node_ty(var_hir_id)?;
+        let var_ty = self.node_ty(var_id)?;
 
         // Mutability of original variable itself
         let var_mutbl = MutabilityCategory::from_local(self.tcx, self.tables, var_id);

src/librustc/middle/reachable.rs

@@ -65,7 +65,7 @@ fn method_might_be_inlined<'tcx>(
 }
 
 // Information needed while computing reachability.
-struct ReachableContext<'a, 'tcx: 'a> {
+struct ReachableContext<'a, 'tcx> {
     // The type context.
     tcx: TyCtxt<'tcx>,
     tables: &'a ty::TypeckTables<'tcx>,
@@ -174,12 +174,12 @@ impl<'a, 'tcx> ReachableContext<'a, 'tcx> {
                         } else {
                             let impl_did = self.tcx
                                                .hir()
-                                               .get_parent_did_by_hir_id(hir_id);
+                                               .get_parent_did(hir_id);
                             // Check the impl. If the generics on the self
                             // type of the impl require inlining, this method
                             // does too.
                             let impl_hir_id = self.tcx.hir().as_local_hir_id(impl_did).unwrap();
-                            match self.tcx.hir().expect_item_by_hir_id(impl_hir_id).node {
+                            match self.tcx.hir().expect_item(impl_hir_id).node {
                                 hir::ItemKind::Impl(..) => {
                                     let generics = self.tcx.generics_of(impl_did);
                                     generics.requires_monomorphization(self.tcx)
@@ -296,7 +296,7 @@ impl<'a, 'tcx> ReachableContext<'a, 'tcx> {
                         self.visit_nested_body(body);
                     }
                     hir::ImplItemKind::Method(_, body) => {
-                        let did = self.tcx.hir().get_parent_did_by_hir_id(search_item);
+                        let did = self.tcx.hir().get_parent_did(search_item);
                         if method_might_be_inlined(self.tcx, impl_item, did) {
                             self.visit_nested_body(body)
                         }
@@ -318,7 +318,7 @@ impl<'a, 'tcx> ReachableContext<'a, 'tcx> {
             _ => {
                 bug!(
                     "found unexpected node kind in worklist: {} ({:?})",
-                    self.tcx.hir().hir_to_string(search_item),
+                    self.tcx.hir().node_to_string(search_item),
                     node,
                 );
             }
@@ -334,13 +334,13 @@ impl<'a, 'tcx> ReachableContext<'a, 'tcx> {
 // items of non-exported traits (or maybe all local traits?) unless their respective
 // trait items are used from inlinable code through method call syntax or UFCS, or their
 // trait is a lang item.
-struct CollectPrivateImplItemsVisitor<'a, 'tcx: 'a> {
+struct CollectPrivateImplItemsVisitor<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
     access_levels: &'a privacy::AccessLevels,
     worklist: &'a mut Vec<hir::HirId>,
 }
 
-impl<'a, 'tcx: 'a> ItemLikeVisitor<'tcx> for CollectPrivateImplItemsVisitor<'a, 'tcx> {
+impl<'a, 'tcx> ItemLikeVisitor<'tcx> for CollectPrivateImplItemsVisitor<'a, 'tcx> {
     fn visit_item(&mut self, item: &hir::Item) {
         // Anything which has custom linkage gets thrown on the worklist no
         // matter where it is in the crate, along with "special std symbols"

src/librustc/middle/region.rs

@@ -14,7 +14,6 @@ use std::mem;
 use std::fmt;
 use rustc_macros::HashStable;
 use syntax::source_map;
-use syntax::ast;
 use syntax_pos::{Span, DUMMY_SP};
 use crate::ty::{DefIdTree, TyCtxt};
 use crate::ty::query::Providers;
@@ -169,15 +168,15 @@ impl Scope {
         self.id
     }
 
-    pub fn node_id(&self, tcx: TyCtxt<'_>, scope_tree: &ScopeTree) -> ast::NodeId {
+    pub fn hir_id(&self, scope_tree: &ScopeTree) -> hir::HirId {
         match scope_tree.root_body {
             Some(hir_id) => {
-                tcx.hir().hir_to_node_id(hir::HirId {
+                hir::HirId {
                     owner: hir_id.owner,
                     local_id: self.item_local_id()
-                })
+                }
             }
-            None => ast::DUMMY_NODE_ID
+            None => hir::DUMMY_HIR_ID
         }
     }
 
@@ -185,13 +184,13 @@ impl Scope {
     /// returned span may not correspond to the span of any `NodeId` in
     /// the AST.
     pub fn span(&self, tcx: TyCtxt<'_>, scope_tree: &ScopeTree) -> Span {
-        let node_id = self.node_id(tcx, scope_tree);
-        if node_id == ast::DUMMY_NODE_ID {
+        let hir_id = self.hir_id(scope_tree);
+        if hir_id == hir::DUMMY_HIR_ID {
             return DUMMY_SP;
         }
-        let span = tcx.hir().span(node_id);
+        let span = tcx.hir().span(hir_id);
         if let ScopeData::Remainder(first_statement_index) = self.data {
-            if let Node::Block(ref blk) = tcx.hir().get(node_id) {
+            if let Node::Block(ref blk) = tcx.hir().get_by_hir_id(hir_id) {
                 // Want span for scope starting after the
                 // indexed statement and ending at end of
                 // `blk`; reuse span of `blk` and shift `lo`
@@ -332,7 +331,7 @@ pub struct ScopeTree {
     /// The reason is that semantically, until the `box` expression returns,
     /// the values are still owned by their containing expressions. So
     /// we'll see that `&x`.
-    yield_in_scope: FxHashMap<Scope, (Span, usize)>,
+    yield_in_scope: FxHashMap<Scope, YieldData>,
 
     /// The number of visit_expr and visit_pat calls done in the body.
     /// Used to sanity check visit_expr/visit_pat call count when
@@ -340,6 +339,15 @@ pub struct ScopeTree {
     body_expr_count: FxHashMap<hir::BodyId, usize>,
 }
 
+#[derive(Debug, Copy, Clone, RustcEncodable, RustcDecodable, HashStable)]
+pub struct YieldData {
+    /// `Span` of the yield.
+    pub span: Span,
+    /// The number of expressions and patterns appearing before the `yield` in the body + 1.
+    pub expr_and_pat_count: usize,
+    pub source: hir::YieldSource,
+}
+
 #[derive(Debug, Copy, Clone)]
 pub struct Context {
     /// the root of the current region tree. This is typically the id
@@ -650,7 +658,7 @@ impl<'tcx> ScopeTree {
         let param_owner = tcx.parent(br.def_id).unwrap();
 
         let param_owner_id = tcx.hir().as_local_hir_id(param_owner).unwrap();
-        let scope = tcx.hir().maybe_body_owned_by_by_hir_id(param_owner_id).map(|body_id| {
+        let scope = tcx.hir().maybe_body_owned_by(param_owner_id).map(|body_id| {
             tcx.hir().body(body_id).value.hir_id.local_id
         }).unwrap_or_else(|| {
             // The lifetime was defined on node that doesn't own a body,
@@ -696,7 +704,7 @@ impl<'tcx> ScopeTree {
     /// returns `Some((span, expr_count))` with the span of a yield we found and
     /// the number of expressions and patterns appearing before the `yield` in the body + 1.
     /// If there a are multiple yields in a scope, the one with the highest number is returned.
-    pub fn yield_in_scope(&self, scope: Scope) -> Option<(Span, usize)> {
+    pub fn yield_in_scope(&self, scope: Scope) -> Option<YieldData> {
         self.yield_in_scope.get(&scope).cloned()
     }
 
@@ -707,14 +715,14 @@ impl<'tcx> ScopeTree {
                                    scope: Scope,
                                    expr_hir_id: hir::HirId,
                                    body: &'tcx hir::Body) -> Option<Span> {
-        self.yield_in_scope(scope).and_then(|(span, count)| {
+        self.yield_in_scope(scope).and_then(|YieldData { span, expr_and_pat_count, .. }| {
             let mut visitor = ExprLocatorVisitor {
                 hir_id: expr_hir_id,
                 result: None,
                 expr_and_pat_count: 0,
             };
             visitor.visit_body(body);
-            if count >= visitor.result.unwrap() {
+            if expr_and_pat_count >= visitor.result.unwrap() {
                 Some(span)
             } else {
                 None
@@ -954,12 +962,16 @@ fn resolve_expr<'tcx>(visitor: &mut RegionResolutionVisitor<'tcx>, expr: &'tcx h
 
     debug!("resolve_expr post-increment {}, expr = {:?}", visitor.expr_and_pat_count, expr);
 
-    if let hir::ExprKind::Yield(..) = expr.node {
+    if let hir::ExprKind::Yield(_, source) = &expr.node {
         // Mark this expr's scope and all parent scopes as containing `yield`.
         let mut scope = Scope { id: expr.hir_id.local_id, data: ScopeData::Node };
         loop {
-            visitor.scope_tree.yield_in_scope.insert(scope,
-                (expr.span, visitor.expr_and_pat_count));
+            let data = YieldData {
+                span: expr.span,
+                expr_and_pat_count: visitor.expr_and_pat_count,
+                source: *source,
+            };
+            visitor.scope_tree.yield_in_scope.insert(scope, data);
 
             // Keep traversing up while we can.
             match visitor.scope_tree.parent_map.get(&scope) {
@@ -1303,7 +1315,7 @@ impl<'tcx> Visitor<'tcx> for RegionResolutionVisitor<'tcx> {
             resolve_local(self, None, Some(&body.value));
         }
 
-        if body.is_generator {
+        if body.generator_kind.is_some() {
             self.scope_tree.body_expr_count.insert(body_id, self.expr_and_pat_count);
         }
 
@@ -1337,7 +1349,7 @@ fn region_scope_tree<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ScopeTree
     }
 
     let id = tcx.hir().as_local_hir_id(def_id).unwrap();
-    let scope_tree = if let Some(body_id) = tcx.hir().maybe_body_owned_by_by_hir_id(id) {
+    let scope_tree = if let Some(body_id) = tcx.hir().maybe_body_owned_by(id) {
         let mut visitor = RegionResolutionVisitor {
             tcx,
             scope_tree: ScopeTree::default(),

src/librustc/middle/resolve_lifetime.rs

@@ -217,7 +217,7 @@ impl_stable_hash_for!(struct crate::middle::resolve_lifetime::ResolveLifetimes {
     object_lifetime_defaults
 });
 
-struct LifetimeContext<'a, 'tcx: 'a> {
+struct LifetimeContext<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
     map: &'a mut NamedRegionMap,
     scope: ScopeRef<'a>,
@@ -625,7 +625,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
                 // `abstract type MyAnonTy<'b>: MyTrait<'b>;`
                 //                          ^            ^ this gets resolved in the scope of
                 //                                         the exist_ty generics
-                let (generics, bounds) = match self.tcx.hir().expect_item_by_hir_id(item_id.id).node
+                let (generics, bounds) = match self.tcx.hir().expect_item(item_id.id).node
                 {
                     // named existential types are reached via TyKind::Path
                     // this arm is for `impl Trait` in the types of statics, constants and locals
@@ -1160,7 +1160,7 @@ fn signal_shadowing_problem(tcx: TyCtxt<'_>, name: ast::Name, orig: Original, sh
 // Adds all labels in `b` to `ctxt.labels_in_fn`, signalling a warning
 // if one of the label shadows a lifetime or another label.
 fn extract_labels(ctxt: &mut LifetimeContext<'_, '_>, body: &hir::Body) {
-    struct GatherLabels<'a, 'tcx: 'a> {
+    struct GatherLabels<'a, 'tcx> {
         tcx: TyCtxt<'tcx>,
         scope: ScopeRef<'a>,
         labels_in_fn: &'a mut Vec<ast::Ident>,
@@ -1236,7 +1236,7 @@ fn extract_labels(ctxt: &mut LifetimeContext<'_, '_>, body: &hir::Body) {
                         signal_shadowing_problem(
                             tcx,
                             label.name,
-                            original_lifetime(tcx.hir().span_by_hir_id(hir_id)),
+                            original_lifetime(tcx.hir().span(hir_id)),
                             shadower_label(label.span),
                         );
                         return;
@@ -1590,7 +1590,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                             if let Some(parent_hir_id) = self.tcx.hir()
                                 .as_local_hir_id(parent_def_id) {
                                     // lifetimes in `derive` expansions don't count (Issue #53738)
-                                    if self.tcx.hir().attrs_by_hir_id(parent_hir_id).iter()
+                                    if self.tcx.hir().attrs(parent_hir_id).iter()
                                         .any(|attr| attr.check_name(sym::automatically_derived)) {
                                             continue;
                                         }
@@ -1690,7 +1690,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
         // Find the start of nested early scopes, e.g., in methods.
         let mut index = 0;
         if let Some(parent_id) = parent_id {
-            let parent = self.tcx.hir().expect_item_by_hir_id(parent_id);
+            let parent = self.tcx.hir().expect_item(parent_id);
             if sub_items_have_self_param(&parent.node) {
                 index += 1; // Self comes before lifetimes
             }
@@ -1823,7 +1823,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                 // Do not free early-bound regions, only late-bound ones.
             } else if let Some(body_id) = outermost_body {
                 let fn_id = self.tcx.hir().body_owner(body_id);
-                match self.tcx.hir().get(fn_id) {
+                match self.tcx.hir().get_by_hir_id(fn_id) {
                     Node::Item(&hir::Item {
                         node: hir::ItemKind::Fn(..),
                         ..
@@ -1836,7 +1836,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                         node: hir::ImplItemKind::Method(..),
                         ..
                     }) => {
-                        let scope = self.tcx.hir().local_def_id(fn_id);
+                        let scope = self.tcx.hir().local_def_id_from_hir_id(fn_id);
                         def = Region::Free(scope, def.id().unwrap());
                     }
                     _ => {}
@@ -2065,7 +2065,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
             }) => {
                 if let hir::ItemKind::Trait(.., ref trait_items) = self.tcx
                     .hir()
-                    .expect_item_by_hir_id(self.tcx.hir().get_parent_item(parent))
+                    .expect_item(self.tcx.hir().get_parent_item(parent))
                     .node
                 {
                     assoc_item_kind = trait_items
@@ -2085,7 +2085,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
             }) => {
                 if let hir::ItemKind::Impl(.., ref self_ty, ref impl_items) = self.tcx
                     .hir()
-                    .expect_item_by_hir_id(self.tcx.hir().get_parent_item(parent))
+                    .expect_item(self.tcx.hir().get_parent_item(parent))
                     .node
                 {
                     impl_self = Some(self_ty);
@@ -2629,7 +2629,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                         signal_shadowing_problem(
                             self.tcx,
                             param.name.ident().name,
-                            original_lifetime(self.tcx.hir().span_by_hir_id(hir_id)),
+                            original_lifetime(self.tcx.hir().span(hir_id)),
                             shadower_lifetime(&param),
                         );
                         return;
@@ -2696,7 +2696,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
 
         debug!(
             "insert_lifetime: {} resolved to {:?} span={:?}",
-            self.tcx.hir().hir_to_string(lifetime_ref.hir_id),
+            self.tcx.hir().node_to_string(lifetime_ref.hir_id),
             def,
             self.tcx.sess.source_map().span_to_string(lifetime_ref.span)
         );

src/librustc/middle/stability.rs

@@ -105,7 +105,7 @@ impl_stable_hash_for!(struct self::Index<'tcx> {
 });
 
 // A private tree-walker for producing an Index.
-struct Annotator<'a, 'tcx: 'a> {
+struct Annotator<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
     index: &'a mut Index<'tcx>,
     parent_stab: Option<&'tcx Stability>,
@@ -113,7 +113,7 @@ struct Annotator<'a, 'tcx: 'a> {
     in_trait_impl: bool,
 }
 
-impl<'a, 'tcx: 'a> Annotator<'a, 'tcx> {
+impl<'a, 'tcx> Annotator<'a, 'tcx> {
     // Determine the stability for a node based on its attributes and inherited
     // stability. The stability is recorded in the index and used as the parent.
     fn annotate<F>(&mut self, hir_id: HirId, attrs: &[Attribute],
@@ -316,12 +316,12 @@ impl<'a, 'tcx> Visitor<'tcx> for Annotator<'a, 'tcx> {
     }
 }
 
-struct MissingStabilityAnnotations<'a, 'tcx: 'a> {
+struct MissingStabilityAnnotations<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
     access_levels: &'a AccessLevels,
 }
 
-impl<'a, 'tcx: 'a> MissingStabilityAnnotations<'a, 'tcx> {
+impl<'a, 'tcx> MissingStabilityAnnotations<'a, 'tcx> {
     fn check_missing_stability(&self, hir_id: HirId, span: Span, name: &str) {
         let stab = self.tcx.stability().local_stability(hir_id);
         let is_error = !self.tcx.sess.opts.test &&

src/librustc/middle/weak_lang_items.rs

@@ -17,7 +17,7 @@ use crate::ty::TyCtxt;
 macro_rules! weak_lang_items {
     ($($name:ident, $item:ident, $sym:ident;)*) => (
 
-struct Context<'a, 'tcx: 'a> {
+struct Context<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
     items: &'a mut lang_items::LanguageItems,
 }

src/librustc/mir/interpret/value.rs

@@ -2,7 +2,7 @@ use std::fmt;
 use rustc_macros::HashStable;
 use rustc_apfloat::{Float, ieee::{Double, Single}};
 
-use crate::ty::{Ty, InferConst, ParamConst, layout::{HasDataLayout, Size}, subst::SubstsRef};
+use crate::ty::{Ty, InferConst, ParamConst, layout::{HasDataLayout, Size, Align}, subst::SubstsRef};
 use crate::ty::PlaceholderConst;
 use crate::hir::def_id::DefId;
 
@@ -45,7 +45,12 @@ pub enum ConstValue<'tcx> {
 
     /// An allocation together with a pointer into the allocation.
     /// Invariant: the pointer's `AllocId` resolves to the allocation.
-    ByRef(Pointer, &'tcx Allocation),
+    /// The alignment exists to allow `const_field` to have `ByRef` access to nonprimitive fields
+    /// of `repr(packed)` structs. The alignment may be lower than the type of this constant.
+    /// This permits reads with lower alignment than what the type would normally require.
+    /// FIXME(RalfJ,oli-obk): The alignment checks are part of miri, but const eval doesn't really
+    /// need them. Disabling them may be too hard though.
+    ByRef(Pointer, Align, &'tcx Allocation),
 
     /// Used in the HIR by using `Unevaluated` everywhere and later normalizing to one of the other
     /// variants when the code is monomorphic enough for that.

src/librustc/mir/mod.rs

@@ -2104,7 +2104,7 @@ impl<'tcx> Place<'tcx> {
 /// N.B., this particular impl strategy is not the most obvious. It was
 /// chosen because it makes a measurable difference to NLL
 /// performance, as this code (`borrow_conflicts_with_place`) is somewhat hot.
-pub enum Projections<'p, 'tcx: 'p> {
+pub enum Projections<'p, 'tcx> {
     Empty,
 
     List {
@@ -2143,7 +2143,7 @@ impl<'p, 'tcx> IntoIterator for &'p Projections<'p, 'tcx> {
 /// N.B., this is not a *true* Rust iterator -- the code above just
 /// manually invokes `next`. This is because we (sometimes) want to
 /// keep executing even after `None` has been returned.
-pub struct ProjectionsIter<'p, 'tcx: 'p> {
+pub struct ProjectionsIter<'p, 'tcx> {
     pub value: &'p Projections<'p, 'tcx>,
 }
 
@@ -2565,7 +2565,7 @@ impl<'tcx> Debug for Rvalue<'tcx> {
                             let name = if tcx.sess.opts.debugging_opts.span_free_formats {
                                 format!("[closure@{:?}]", hir_id)
                             } else {
-                                format!("[closure@{:?}]", tcx.hir().span_by_hir_id(hir_id))
+                                format!("[closure@{:?}]", tcx.hir().span(hir_id))
                             };
                             let mut struct_fmt = fmt.debug_struct(&name);
 
@@ -2585,7 +2585,7 @@ impl<'tcx> Debug for Rvalue<'tcx> {
                     AggregateKind::Generator(def_id, _, _) => ty::tls::with(|tcx| {
                         if let Some(hir_id) = tcx.hir().as_local_hir_id(def_id) {
                             let name = format!("[generator@{:?}]",
-                                               tcx.hir().span_by_hir_id(hir_id));
+                                               tcx.hir().span(hir_id));
                             let mut struct_fmt = fmt.debug_struct(&name);
 
                             if let Some(upvars) = tcx.upvars(def_id) {

src/librustc/mir/mono.rs

@@ -218,7 +218,7 @@ impl<'tcx> MonoItem<'tcx> {
             MonoItem::GlobalAsm(hir_id) => {
                 Some(hir_id)
             }
-        }.map(|hir_id| tcx.hir().span_by_hir_id(hir_id))
+        }.map(|hir_id| tcx.hir().span(hir_id))
     }
 }
 

src/librustc/mir/tcx.rs

@@ -122,13 +122,25 @@ impl<'tcx> Place<'tcx> {
     where
         D: HasLocalDecls<'tcx>,
     {
-        match *self {
-            Place::Base(PlaceBase::Local(index)) =>
-                PlaceTy::from_ty(local_decls.local_decls()[index].ty),
-            Place::Base(PlaceBase::Static(ref data)) =>
-                PlaceTy::from_ty(data.ty),
-            Place::Projection(ref proj) =>
-                proj.base.ty(local_decls, tcx).projection_ty(tcx, &proj.elem),
+        self.iterate(|place_base, place_projections| {
+            let mut place_ty = place_base.ty(local_decls);
+
+            for proj in place_projections {
+                place_ty = place_ty.projection_ty(tcx, &proj.elem);
+            }
+
+            place_ty
+        })
+    }
+}
+
+impl<'tcx> PlaceBase<'tcx> {
+    pub fn ty<D>(&self, local_decls: &D) -> PlaceTy<'tcx>
+        where D: HasLocalDecls<'tcx>
+    {
+        match self {
+            PlaceBase::Local(index) => PlaceTy::from_ty(local_decls.local_decls()[*index].ty),
+            PlaceBase::Static(data) => PlaceTy::from_ty(data.ty),
         }
     }
 }

src/librustc/mir/traversal.rs

@@ -20,7 +20,7 @@ use super::*;
 ///
 /// A preorder traversal of this graph is either `A B D C` or `A C D B`
 #[derive(Clone)]
-pub struct Preorder<'a, 'tcx: 'a> {
+pub struct Preorder<'a, 'tcx> {
     body: &'a Body<'tcx>,
     visited: BitSet<BasicBlock>,
     worklist: Vec<BasicBlock>,
@@ -98,7 +98,7 @@ impl<'a, 'tcx> Iterator for Preorder<'a, 'tcx> {
 /// ```
 ///
 /// A Postorder traversal of this graph is `D B C A` or `D C B A`
-pub struct Postorder<'a, 'tcx: 'a> {
+pub struct Postorder<'a, 'tcx> {
     body: &'a Body<'tcx>,
     visited: BitSet<BasicBlock>,
     visit_stack: Vec<(BasicBlock, Successors<'a>)>,
@@ -251,7 +251,7 @@ impl<'a, 'tcx> Iterator for Postorder<'a, 'tcx> {
 /// constructed as few times as possible. Use the `reset` method to be able
 /// to re-use the traversal
 #[derive(Clone)]
-pub struct ReversePostorder<'a, 'tcx: 'a> {
+pub struct ReversePostorder<'a, 'tcx> {
     body: &'a Body<'tcx>,
     blocks: Vec<BasicBlock>,
     idx: usize

src/librustc/traits/codegen/mod.rs

@@ -141,9 +141,9 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         &self,
         fulfill_cx: &mut FulfillmentContext<'tcx>,
         result: &T,
-    ) -> T::Lifted
+    ) -> T
     where
-        T: TypeFoldable<'tcx> + ty::Lift<'tcx>,
+        T: TypeFoldable<'tcx>,
     {
         debug!("drain_fulfillment_cx_or_panic()");
 
@@ -155,10 +155,6 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         }
 
         let result = self.resolve_vars_if_possible(result);
-        let result = self.tcx.erase_regions(&result);
-
-        self.tcx.lift_to_global(&result).unwrap_or_else(||
-            bug!("Uninferred types/regions/consts in `{:?}`", result)
-        )
+        self.tcx.erase_regions(&result)
     }
 }

src/librustc/traits/error_reporting.rs

@@ -1013,10 +1013,8 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         trait_ref: &ty::Binder<ty::TraitRef<'tcx>>,
     ) {
         let hir = self.tcx.hir();
-        let parent_node = hir.get_parent_node(
-            hir.hir_to_node_id(obligation.cause.body_id),
-        );
-        let node = hir.find(parent_node);
+        let parent_node = hir.get_parent_node_by_hir_id(obligation.cause.body_id);
+        let node = hir.find_by_hir_id(parent_node);
         if let Some(hir::Node::Item(hir::Item {
             node: hir::ItemKind::Fn(decl, _, _, body_id),
             ..
@@ -1052,10 +1050,10 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 (self.tcx.sess.source_map().def_span(span), self.tcx.hir().body(id).arguments.iter()
                     .map(|arg| {
                         if let hir::Pat {
-                            node: hir::PatKind::Tuple(args, _),
+                            node: hir::PatKind::Tuple(ref args, _),
                             span,
                             ..
-                        } = arg.pat.clone().into_inner() {
+                        } = *arg.pat {
                             ArgKind::Tuple(
                                 Some(span),
                                 args.iter().map(|pat| {
@@ -1098,7 +1096,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
             }
             Node::Ctor(ref variant_data) => {
                 let span = variant_data.ctor_hir_id()
-                    .map(|hir_id| self.tcx.hir().span_by_hir_id(hir_id))
+                    .map(|hir_id| self.tcx.hir().span(hir_id))
                     .unwrap_or(DUMMY_SP);
                 let span = self.tcx.sess.source_map().def_span(span);
 
@@ -1451,7 +1449,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         param_env: ty::ParamEnv<'tcx>,
         pred: ty::PolyTraitRef<'tcx>,
     ) -> bool {
-        struct ParamToVarFolder<'a, 'tcx: 'a> {
+        struct ParamToVarFolder<'a, 'tcx> {
             infcx: &'a InferCtxt<'a, 'tcx>,
             var_map: FxHashMap<Ty<'tcx>, Ty<'tcx>>,
         }

src/librustc/traits/fulfill.rs

@@ -224,7 +224,7 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
     }
 }
 
-struct FulfillProcessor<'a, 'b: 'a, 'tcx: 'b> {
+struct FulfillProcessor<'a, 'b, 'tcx> {
     selcx: &'a mut SelectionContext<'b, 'tcx>,
     register_region_obligations: bool,
 }

src/librustc/traits/project.rs

@@ -285,7 +285,7 @@ where
     }
 }
 
-struct AssocTypeNormalizer<'a, 'b: 'a, 'tcx: 'b> {
+struct AssocTypeNormalizer<'a, 'b, 'tcx> {
     selcx: &'a mut SelectionContext<'b, 'tcx>,
     param_env: ty::ParamEnv<'tcx>,
     cause: ObligationCause<'tcx>,
@@ -409,7 +409,6 @@ impl<'a, 'b, 'tcx> TypeFolder<'tcx> for AssocTypeNormalizer<'a, 'b, 'tcx> {
                             promoted: None
                         };
                         if let Ok(evaluated) = tcx.const_eval(param_env.and(cid)) {
-                            let substs = tcx.lift_to_global(&substs).unwrap();
                             let evaluated = evaluated.subst(tcx, substs);
                             return evaluated;
                         }

src/librustc/traits/query/normalize.rs

@@ -73,7 +73,7 @@ pub struct NormalizationResult<'tcx> {
     pub normalized_ty: Ty<'tcx>,
 }
 
-struct QueryNormalizer<'cx, 'tcx: 'cx> {
+struct QueryNormalizer<'cx, 'tcx> {
     infcx: &'cx InferCtxt<'cx, 'tcx>,
     cause: &'cx ObligationCause<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
@@ -203,7 +203,6 @@ impl<'cx, 'tcx> TypeFolder<'tcx> for QueryNormalizer<'cx, 'tcx> {
                             promoted: None,
                         };
                         if let Ok(evaluated) = tcx.const_eval(param_env.and(cid)) {
-                            let substs = tcx.lift_to_global(&substs).unwrap();
                             let evaluated = evaluated.subst(tcx, substs);
                             return evaluated;
                         }

src/librustc/traits/query/type_op/mod.rs

@@ -8,7 +8,7 @@ use std::rc::Rc;
 use crate::traits::query::Fallible;
 use crate::traits::ObligationCause;
 use crate::ty::fold::TypeFoldable;
-use crate::ty::{Lift, ParamEnvAnd, TyCtxt};
+use crate::ty::{ParamEnvAnd, TyCtxt};
 
 pub mod ascribe_user_type;
 pub mod custom;
@@ -44,8 +44,8 @@ pub trait TypeOp<'tcx>: Sized + fmt::Debug {
 /// which produces the resulting query region constraints.
 ///
 /// [c]: https://rust-lang.github.io/rustc-guide/traits/canonicalization.html
-pub trait QueryTypeOp<'tcx>: fmt::Debug + Sized + TypeFoldable<'tcx> + Lift<'tcx> {
-    type QueryResponse: TypeFoldable<'tcx> + Lift<'tcx>;
+pub trait QueryTypeOp<'tcx>: fmt::Debug + Sized + TypeFoldable<'tcx> + 'tcx {
+    type QueryResponse: TypeFoldable<'tcx>;
 
     /// Give query the option for a simple fast path that never
     /// actually hits the tcx cache lookup etc. Return `Some(r)` with

src/librustc/traits/query/type_op/normalize.rs

@@ -20,7 +20,7 @@ where
 
 impl<'tcx, T> super::QueryTypeOp<'tcx> for Normalize<T>
 where
-    T: Normalizable<'tcx>,
+    T: Normalizable<'tcx> + 'tcx,
 {
     type QueryResponse = T;
 

src/librustc/traits/select.rs

@@ -50,7 +50,7 @@ use std::iter;
 use std::rc::Rc;
 use crate::util::nodemap::{FxHashMap, FxHashSet};
 
-pub struct SelectionContext<'cx, 'tcx: 'cx> {
+pub struct SelectionContext<'cx, 'tcx> {
     infcx: &'cx InferCtxt<'cx, 'tcx>,
 
     /// Freshener used specifically for entries on the obligation
@@ -144,7 +144,7 @@ impl IntercrateAmbiguityCause {
 }
 
 // A stack that walks back up the stack frame.
-struct TraitObligationStack<'prev, 'tcx: 'prev> {
+struct TraitObligationStack<'prev, 'tcx> {
     obligation: &'prev TraitObligation<'tcx>,
 
     /// Trait ref from `obligation` but "freshened" with the
@@ -690,14 +690,13 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
     /// Evaluates the predicates in `predicates` recursively. Note that
     /// this applies projections in the predicates, and therefore
     /// is run within an inference probe.
-    fn evaluate_predicates_recursively<'a, 'o, I>(
+    fn evaluate_predicates_recursively<'o, I>(
         &mut self,
         stack: TraitObligationStackList<'o, 'tcx>,
         predicates: I,
     ) -> Result<EvaluationResult, OverflowError>
     where
         I: IntoIterator<Item = PredicateObligation<'tcx>>,
-        'tcx: 'a,
     {
         let mut result = EvaluatedToOk;
         for obligation in predicates {
@@ -3789,9 +3788,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         matcher.relate(previous, current).is_ok()
     }
 
-    fn push_stack<'o, 's: 'o>(
+    fn push_stack<'o>(
         &mut self,
-        previous_stack: TraitObligationStackList<'s, 'tcx>,
+        previous_stack: TraitObligationStackList<'o, 'tcx>,
         obligation: &'o TraitObligation<'tcx>,
     ) -> TraitObligationStack<'o, 'tcx> {
         let fresh_trait_ref = obligation
@@ -4252,7 +4251,7 @@ impl<'tcx> ProvisionalEvaluationCache<'tcx> {
 }
 
 #[derive(Copy, Clone)]
-struct TraitObligationStackList<'o, 'tcx: 'o> {
+struct TraitObligationStackList<'o, 'tcx> {
     cache: &'o ProvisionalEvaluationCache<'tcx>,
     head: Option<&'o TraitObligationStack<'o, 'tcx>>,
 }

src/librustc/traits/specialize/mod.rs

@@ -132,12 +132,7 @@ pub fn find_associated_item<'tcx>(
                 let substs = substs.rebase_onto(tcx, trait_def_id, impl_data.substs);
                 let substs = translate_substs(&infcx, param_env, impl_data.impl_def_id,
                                               substs, node_item.node);
-                let substs = infcx.tcx.erase_regions(&substs);
-                tcx.lift(&substs).unwrap_or_else(||
-                    bug!("find_method: translate_substs \
-                          returned {:?} which contains inference types/regions",
-                         substs)
-                )
+                infcx.tcx.erase_regions(&substs)
             });
             (node_item.item.def_id, substs)
         }

src/librustc/traits/util.rs

@@ -654,7 +654,7 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn impl_is_default(self, node_item_def_id: DefId) -> bool {
         match self.hir().as_local_hir_id(node_item_def_id) {
             Some(hir_id) => {
-                let item = self.hir().expect_item_by_hir_id(hir_id);
+                let item = self.hir().expect_item(hir_id);
                 if let hir::ItemKind::Impl(_, _, defaultness, ..) = item.node {
                     defaultness.is_default()
                 } else {

src/librustc/ty/context.rs

@@ -250,11 +250,9 @@ fn validate_hir_id_for_typeck_tables(local_id_root: Option<DefId>,
         if let Some(local_id_root) = local_id_root {
             if hir_id.owner != local_id_root.index {
                 ty::tls::with(|tcx| {
-                    let node_id = tcx.hir().hir_to_node_id(hir_id);
-
                     bug!("node {} with HirId::owner {:?} cannot be placed in \
                           TypeckTables with local_id_root {:?}",
-                         tcx.hir().node_to_string(node_id),
+                         tcx.hir().node_to_string(hir_id),
                          DefId::local(hir_id.owner),
                          local_id_root)
                 });
@@ -556,7 +554,7 @@ impl<'tcx> TypeckTables<'tcx> {
     pub fn node_type(&self, id: hir::HirId) -> Ty<'tcx> {
         self.node_type_opt(id).unwrap_or_else(||
             bug!("node_type: no type for node `{}`",
-                 tls::with(|tcx| tcx.hir().hir_to_string(id)))
+                 tls::with(|tcx| tcx.hir().node_to_string(id)))
         )
     }
 

src/librustc/ty/error.rs

@@ -192,9 +192,12 @@ impl<'tcx> ty::TyS<'tcx> {
 
             ty::Adt(def, _) => format!("{} `{}`", def.descr(), tcx.def_path_str(def.did)).into(),
             ty::Foreign(def_id) => format!("extern type `{}`", tcx.def_path_str(def_id)).into(),
-            ty::Array(_, n) => match n.assert_usize(tcx) {
-                Some(n) => format!("array of {} elements", n).into(),
-                None => "array".into(),
+            ty::Array(_, n) => {
+                let n = tcx.lift_to_global(&n).unwrap();
+                match n.assert_usize(tcx) {
+                    Some(n) => format!("array of {} elements", n).into(),
+                    None => "array".into(),
+                }
             }
             ty::Slice(_) => "slice".into(),
             ty::RawPtr(_) => "*-ptr".into(),

src/librustc/ty/layout.rs

@@ -2711,7 +2711,7 @@ where
             }
 
             // If this is a C-variadic function, this is not the return value,
-            // and there is one or more fixed arguments; ensure that the `VaList`
+            // and there is one or more fixed arguments; ensure that the `VaListImpl`
             // is ignored as an argument.
             if sig.c_variadic {
                 match (last_arg_idx, arg_idx) {
@@ -2722,7 +2722,7 @@ where
                         };
                         match ty.sty {
                             ty::Adt(def, _) if def.did == va_list_did => {
-                                // This is the "spoofed" `VaList`. Set the arguments mode
+                                // This is the "spoofed" `VaListImpl`. Set the arguments mode
                                 // so that it will be ignored.
                                 arg.mode = PassMode::Ignore(IgnoreMode::CVarArgs);
                             }

src/librustc/ty/mod.rs

@@ -277,7 +277,7 @@ impl Visibility {
                 def => Visibility::Restricted(def.def_id()),
             },
             hir::VisibilityKind::Inherited => {
-                Visibility::Restricted(tcx.hir().get_module_parent_by_hir_id(id))
+                Visibility::Restricted(tcx.hir().get_module_parent(id))
             }
         }
     }
@@ -3016,7 +3016,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Gets the attributes of a definition.
     pub fn get_attrs(self, did: DefId) -> Attributes<'tcx> {
         if let Some(id) = self.hir().as_local_hir_id(did) {
-            Attributes::Borrowed(self.hir().attrs_by_hir_id(id))
+            Attributes::Borrowed(self.hir().attrs(id))
         } else {
             Attributes::Owned(self.item_attrs(did))
         }
@@ -3068,7 +3068,7 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn span_of_impl(self, impl_did: DefId) -> Result<Span, Symbol> {
         if impl_did.is_local() {
             let hir_id = self.hir().as_local_hir_id(impl_did).unwrap();
-            Ok(self.hir().span_by_hir_id(hir_id))
+            Ok(self.hir().span(hir_id))
         } else {
             Err(self.crate_name(impl_did.krate))
         }
@@ -3103,7 +3103,7 @@ impl<'tcx> TyCtxt<'tcx> {
         let scope = match ident.span.modernize_and_adjust(self.expansion_that_defined(scope)) {
             Some(actual_expansion) =>
                 self.hir().definitions().parent_module_of_macro_def(actual_expansion),
-            None => self.hir().get_module_parent_by_hir_id(block),
+            None => self.hir().get_module_parent(block),
         };
         (ident, scope)
     }
@@ -3129,7 +3129,7 @@ fn associated_item<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> AssocItem {
     let id = tcx.hir().as_local_hir_id(def_id).unwrap();
     let parent_id = tcx.hir().get_parent_item(id);
     let parent_def_id = tcx.hir().local_def_id_from_hir_id(parent_id);
-    let parent_item = tcx.hir().expect_item_by_hir_id(parent_id);
+    let parent_item = tcx.hir().expect_item(parent_id);
     match parent_item.node {
         hir::ItemKind::Impl(.., ref impl_item_refs) => {
             if let Some(impl_item_ref) = impl_item_refs.iter().find(|i| i.id.hir_id == id) {
@@ -3186,7 +3186,7 @@ fn adt_sized_constraint<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> AdtSizedConst
 
 fn associated_item_def_ids<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx [DefId] {
     let id = tcx.hir().as_local_hir_id(def_id).unwrap();
-    let item = tcx.hir().expect_item_by_hir_id(id);
+    let item = tcx.hir().expect_item(id);
     match item.node {
         hir::ItemKind::Trait(.., ref trait_item_refs) => {
             tcx.arena.alloc_from_iter(
@@ -3266,7 +3266,7 @@ fn param_env<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> ParamEnv<'tcx> {
     );
 
     let body_id = tcx.hir().as_local_hir_id(def_id).map_or(hir::DUMMY_HIR_ID, |id| {
-        tcx.hir().maybe_body_owned_by_by_hir_id(id).map_or(id, |body| body.hir_id)
+        tcx.hir().maybe_body_owned_by(id).map_or(id, |body| body.hir_id)
     });
     let cause = traits::ObligationCause::misc(tcx.def_span(def_id), body_id);
     traits::normalize_param_env_or_error(tcx, def_id, unnormalized_env, cause)

src/librustc/ty/print/pretty.rs

@@ -589,7 +589,7 @@ pub trait PrettyPrinter<'tcx>:
 
                 // FIXME(eddyb) should use `def_span`.
                 if let Some(hir_id) = self.tcx().hir().as_local_hir_id(did) {
-                    p!(write("@{:?}", self.tcx().hir().span_by_hir_id(hir_id)));
+                    p!(write("@{:?}", self.tcx().hir().span(hir_id)));
                     let mut sep = " ";
                     for (&var_id, upvar_ty) in self.tcx().upvars(did)
                         .as_ref()
@@ -631,7 +631,7 @@ pub trait PrettyPrinter<'tcx>:
                     if self.tcx().sess.opts.debugging_opts.span_free_formats {
                         p!(write("@{:?}", hir_id));
                     } else {
-                        p!(write("@{:?}", self.tcx().hir().span_by_hir_id(hir_id)));
+                        p!(write("@{:?}", self.tcx().hir().span(hir_id)));
                     }
                     let mut sep = " ";
                     for (&var_id, upvar_ty) in self.tcx().upvars(did)

src/librustc/ty/query/on_disk_cache.rs

@@ -505,13 +505,11 @@ impl<'a, 'tcx> DecoderWithPosition for CacheDecoder<'a, 'tcx> {
 
 // Decode something that was encoded with encode_tagged() and verify that the
 // tag matches and the correct amount of bytes was read.
-fn decode_tagged<'a, 'tcx, D, T, V>(decoder: &mut D,
-                                    expected_tag: T)
-                                    -> Result<V, D::Error>
-    where T: Decodable + Eq + ::std::fmt::Debug,
-          V: Decodable,
-          D: DecoderWithPosition,
-          'tcx: 'a,
+fn decode_tagged<D, T, V>(decoder: &mut D, expected_tag: T) -> Result<V, D::Error>
+where
+    T: Decodable + Eq + ::std::fmt::Debug,
+    V: Decodable,
+    D: DecoderWithPosition,
 {
     let start_pos = decoder.position();
 

src/librustc/ty/query/plumbing.rs

@@ -89,7 +89,7 @@ macro_rules! profq_query_msg {
 
 /// A type representing the responsibility to execute the job in the `job` field.
 /// This will poison the relevant query if dropped.
-pub(super) struct JobOwner<'a, 'tcx: 'a, Q: QueryDescription<'tcx> + 'a> {
+pub(super) struct JobOwner<'a, 'tcx, Q: QueryDescription<'tcx> + 'a> {
     cache: &'a Lock<QueryCache<'tcx, Q>>,
     key: Q::Key,
     job: Lrc<QueryJob<'tcx>>,
@@ -230,7 +230,7 @@ pub struct CycleError<'tcx> {
 }
 
 /// The result of `try_get_lock`
-pub(super) enum TryGetJob<'a, 'tcx: 'a, D: QueryDescription<'tcx> + 'a> {
+pub(super) enum TryGetJob<'a, 'tcx, D: QueryDescription<'tcx> + 'a> {
     /// The query is not yet started. Contains a guard to the cache eventually used to start it.
     NotYetStarted(JobOwner<'a, 'tcx, D>),
 

src/librustc/ty/structural_impls.rs

@@ -1335,7 +1335,7 @@ impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::Const<'tcx> {
 impl<'tcx> TypeFoldable<'tcx> for ConstValue<'tcx> {
     fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
         match *self {
-            ConstValue::ByRef(ptr, alloc) => ConstValue::ByRef(ptr, alloc),
+            ConstValue::ByRef(ptr, align, alloc) => ConstValue::ByRef(ptr, align, alloc),
             ConstValue::Infer(ic) => ConstValue::Infer(ic.fold_with(folder)),
             ConstValue::Param(p) => ConstValue::Param(p.fold_with(folder)),
             ConstValue::Placeholder(p) => ConstValue::Placeholder(p),

src/librustc/ty/sty.rs

@@ -2262,7 +2262,6 @@ impl<'tcx> Const<'tcx> {
 
     #[inline]
     pub fn from_bits(tcx: TyCtxt<'tcx>, bits: u128, ty: ParamEnvAnd<'tcx, Ty<'tcx>>) -> &'tcx Self {
-        let ty = tcx.lift_to_global(&ty).unwrap();
         let size = tcx.layout_of(ty).unwrap_or_else(|e| {
             panic!("could not compute layout for {:?}: {:?}", ty, e)
         }).size;
@@ -2289,7 +2288,6 @@ impl<'tcx> Const<'tcx> {
         if self.ty != ty.value {
             return None;
         }
-        let ty = tcx.lift_to_global(&ty).unwrap();
         let size = tcx.layout_of(ty).ok()?.size;
         self.val.try_to_bits(size)
     }
@@ -2300,15 +2298,14 @@ impl<'tcx> Const<'tcx> {
     }
 
     #[inline]
-    pub fn assert_bits(&self, tcx: TyCtxt<'_>, ty: ParamEnvAnd<'tcx, Ty<'tcx>>) -> Option<u128> {
+    pub fn assert_bits(&self, tcx: TyCtxt<'tcx>, ty: ParamEnvAnd<'tcx, Ty<'tcx>>) -> Option<u128> {
         assert_eq!(self.ty, ty.value);
-        let ty = tcx.lift_to_global(&ty).unwrap();
         let size = tcx.layout_of(ty).ok()?.size;
         self.val.try_to_bits(size)
     }
 
     #[inline]
-    pub fn assert_bool(&self, tcx: TyCtxt<'_>) -> Option<bool> {
+    pub fn assert_bool(&self, tcx: TyCtxt<'tcx>) -> Option<bool> {
         self.assert_bits(tcx, ParamEnv::empty().and(tcx.types.bool)).and_then(|v| match v {
             0 => Some(false),
             1 => Some(true),
@@ -2317,18 +2314,18 @@ impl<'tcx> Const<'tcx> {
     }
 
     #[inline]
-    pub fn assert_usize(&self, tcx: TyCtxt<'_>) -> Option<u64> {
+    pub fn assert_usize(&self, tcx: TyCtxt<'tcx>) -> Option<u64> {
         self.assert_bits(tcx, ParamEnv::empty().and(tcx.types.usize)).map(|v| v as u64)
     }
 
     #[inline]
-    pub fn unwrap_bits(&self, tcx: TyCtxt<'_>, ty: ParamEnvAnd<'tcx, Ty<'tcx>>) -> u128 {
+    pub fn unwrap_bits(&self, tcx: TyCtxt<'tcx>, ty: ParamEnvAnd<'tcx, Ty<'tcx>>) -> u128 {
         self.assert_bits(tcx, ty).unwrap_or_else(||
             bug!("expected bits of {}, got {:#?}", ty.value, self))
     }
 
     #[inline]
-    pub fn unwrap_usize(&self, tcx: TyCtxt<'_>) -> u64 {
+    pub fn unwrap_usize(&self, tcx: TyCtxt<'tcx>) -> u64 {
         self.assert_usize(tcx).unwrap_or_else(||
             bug!("expected constant usize, got {:#?}", self))
     }