Auto merge of #56437 - Centril:rollup, r=Centril

Rollup of 14 pull requests

Successful merges:

 - #56110 (Consider references and unions potentially inhabited during privacy-respecting inhabitedness checks)
 - #56305 (update miri)
 - #56366 (Stabilize self_in_typedefs feature)
 - #56372 (Refer to the second borrow as the "second borrow" in E0501.rs)
 - #56394 (Deal with EINTR in net timeout tests)
 - #56395 (Stabilize dbg!(...))
 - #56401 (Move VecDeque::resize_with out of the impl<T:Clone> block)
 - #56402 (Improve the unstable book example for #[marker] trait)
 - #56412 (Update tracking issue for `extern_crate_self`)
 - #56416 (Remove unneeded body class selector)
 - #56418 (Fix failing tidy (line endings on Windows))
 - #56419 (Remove some uses of try!)
 - #56424 (Mention raw-ident syntax)
 - #56432 (Update issue number of `shrink_to` methods to point the tracking issue)

Failed merges:

r? @ghost

Cargo.lock

@@ -624,6 +624,15 @@ name = "difference"
 version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "directories"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "dlmalloc"
 version = "0.0.0"
@@ -1316,6 +1325,7 @@ dependencies = [
  "cargo_metadata 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "colored 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "compiletest_rs 0.3.17 (registry+https://github.com/rust-lang/crates.io-index)",
+ "directories 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.5.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "vergen 3.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3288,6 +3298,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum derive_more 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3f57d78cf3bd45270dad4e70c21ec77a960b36c7a841ff9db76aaa775a8fb871"
 "checksum diff 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)" = "3c2b69f912779fbb121ceb775d74d51e915af17aaebc38d28a592843a2dd0a3a"
 "checksum difference 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "524cbf6897b527295dff137cec09ecf3a05f4fddffd7dfcd1585403449e74198"
+"checksum directories 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "72d337a64190607d4fcca2cb78982c5dd57f4916e19696b48a575fa746b6cb0f"
 "checksum either 1.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3be565ca5c557d7f59e7cfcf1844f9e3033650c929c6566f511e8005f205c1d0"
 "checksum elasticlunr-rs 2.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "4837d77a1e157489a3933b743fd774ae75074e0e390b2b7f071530048a0d87ee"
 "checksum ena 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f56c93cc076508c549d9bb747f79aa9b4eb098be7b8cad8830c3137ef52d1e00"

src/bootstrap/doc.rs

@@ -915,13 +915,13 @@ fn symlink_dir_force(config: &Config, src: &Path, dst: &Path) -> io::Result<()>
     }
     if let Ok(m) = fs::symlink_metadata(dst) {
         if m.file_type().is_dir() {
-            try!(fs::remove_dir_all(dst));
+            fs::remove_dir_all(dst)?;
         } else {
             // handle directory junctions on windows by falling back to
             // `remove_dir`.
-            try!(fs::remove_file(dst).or_else(|_| {
+            fs::remove_file(dst).or_else(|_| {
                 fs::remove_dir(dst)
-            }));
+            })?;
         }
     }
 

src/bootstrap/util.rs

@@ -203,11 +203,11 @@ pub fn symlink_dir(config: &Config, src: &Path, dest: &Path) -> io::Result<()> {
         // We're using low-level APIs to create the junction, and these are more
         // picky about paths. For example, forward slashes cannot be used as a
         // path separator, so we should try to canonicalize the path first.
-        let target = try!(fs::canonicalize(target));
+        let target = fs::canonicalize(target)?;
 
-        try!(fs::create_dir(junction));
+        fs::create_dir(junction)?;
 
-        let path = try!(to_u16s(junction));
+        let path = to_u16s(junction)?;
 
         unsafe {
             let h = CreateFileW(path.as_ptr(),

src/doc/unstable-book/src/language-features/marker-trait-attr.md

@@ -17,15 +17,17 @@ when they'd need to do the same thing for every type anyway).
 ```rust
 #![feature(marker_trait_attr)]
 
-use std::fmt::{Debug, Display};
+#[marker] trait CheapToClone: Clone {}
 
-#[marker] trait MyMarker {}
+impl<T: Copy> CheapToClone for T {}
 
-impl<T: Debug> MyMarker for T {}
-impl<T: Display> MyMarker for T {}
+// These could potentally overlap with the blanket implementation above,
+// so are only allowed because CheapToClone is a marker trait.
+impl<T: CheapToClone, U: CheapToClone> CheapToClone for (T, U) {}
+impl<T: CheapToClone> CheapToClone for std::ops::Range<T> {}
 
-fn foo<T: MyMarker>(t: T) -> T {
-    t
+fn cheap_clone<T: CheapToClone>(t: T) -> T {
+    t.clone()
 }
 ```
 

src/liballoc/collections/binary_heap.rs

@@ -529,7 +529,7 @@ impl<T: Ord> BinaryHeap<T> {
     /// assert!(heap.capacity() >= 10);
     /// ```
     #[inline]
-    #[unstable(feature = "shrink_to", reason = "new API", issue="0")]
+    #[unstable(feature = "shrink_to", reason = "new API", issue="56431")]
     pub fn shrink_to(&mut self, min_capacity: usize) {
         self.data.shrink_to(min_capacity)
     }

src/liballoc/collections/vec_deque.rs

@@ -19,7 +19,7 @@
 
 use core::cmp::Ordering;
 use core::fmt;
-use core::iter::{repeat, repeat_with, FromIterator, FusedIterator};
+use core::iter::{repeat_with, FromIterator, FusedIterator};
 use core::mem;
 use core::ops::Bound::{Excluded, Included, Unbounded};
 use core::ops::{Index, IndexMut, RangeBounds};
@@ -701,7 +701,7 @@ impl<T> VecDeque<T> {
     /// buf.shrink_to(0);
     /// assert!(buf.capacity() >= 4);
     /// ```
-    #[unstable(feature = "shrink_to", reason = "new API", issue="0")]
+    #[unstable(feature = "shrink_to", reason = "new API", issue="56431")]
     pub fn shrink_to(&mut self, min_capacity: usize) {
         assert!(self.capacity() >= min_capacity, "Tried to shrink to a larger capacity");
 
@@ -1886,16 +1886,16 @@ impl<T> VecDeque<T> {
             debug_assert!(!self.is_full());
         }
     }
-}
 
-impl<T: Clone> VecDeque<T> {
-    /// Modifies the `VecDeque` in-place so that `len()` is equal to new_len,
-    /// either by removing excess elements from the back or by appending clones of `value`
-    /// to the back.
+    /// Modifies the `VecDeque` in-place so that `len()` is equal to `new_len`,
+    /// either by removing excess elements from the back or by appending
+    /// elements generated by calling `generator` to the back.
     ///
     /// # Examples
     ///
     /// ```
+    /// #![feature(vec_resize_with)]
+    ///
     /// use std::collections::VecDeque;
     ///
     /// let mut buf = VecDeque::new();
@@ -1904,32 +1904,36 @@ impl<T: Clone> VecDeque<T> {
     /// buf.push_back(15);
     /// assert_eq!(buf, [5, 10, 15]);
     ///
-    /// buf.resize(2, 0);
+    /// buf.resize_with(5, Default::default);
+    /// assert_eq!(buf, [5, 10, 15, 0, 0]);
+    ///
+    /// buf.resize_with(2, || unreachable!());
     /// assert_eq!(buf, [5, 10]);
     ///
-    /// buf.resize(5, 20);
-    /// assert_eq!(buf, [5, 10, 20, 20, 20]);
+    /// let mut state = 100;
+    /// buf.resize_with(5, || { state += 1; state });
+    /// assert_eq!(buf, [5, 10, 101, 102, 103]);
     /// ```
-    #[stable(feature = "deque_extras", since = "1.16.0")]
-    pub fn resize(&mut self, new_len: usize, value: T) {
+    #[unstable(feature = "vec_resize_with", issue = "41758")]
+    pub fn resize_with(&mut self, new_len: usize, generator: impl FnMut()->T) {
         let len = self.len();
 
         if new_len > len {
-            self.extend(repeat(value).take(new_len - len))
+            self.extend(repeat_with(generator).take(new_len - len))
         } else {
             self.truncate(new_len);
         }
     }
+}
 
-    /// Modifies the `VecDeque` in-place so that `len()` is equal to `new_len`,
-    /// either by removing excess elements from the back or by appending
-    /// elements generated by calling `generator` to the back.
+impl<T: Clone> VecDeque<T> {
+    /// Modifies the `VecDeque` in-place so that `len()` is equal to new_len,
+    /// either by removing excess elements from the back or by appending clones of `value`
+    /// to the back.
     ///
     /// # Examples
     ///
     /// ```
-    /// #![feature(vec_resize_with)]
-    ///
     /// use std::collections::VecDeque;
     ///
     /// let mut buf = VecDeque::new();
@@ -1938,25 +1942,15 @@ impl<T: Clone> VecDeque<T> {
     /// buf.push_back(15);
     /// assert_eq!(buf, [5, 10, 15]);
     ///
-    /// buf.resize_with(5, Default::default);
-    /// assert_eq!(buf, [5, 10, 15, 0, 0]);
-    ///
-    /// buf.resize_with(2, || unreachable!());
+    /// buf.resize(2, 0);
     /// assert_eq!(buf, [5, 10]);
     ///
-    /// let mut state = 100;
-    /// buf.resize_with(5, || { state += 1; state });
-    /// assert_eq!(buf, [5, 10, 101, 102, 103]);
+    /// buf.resize(5, 20);
+    /// assert_eq!(buf, [5, 10, 20, 20, 20]);
     /// ```
-    #[unstable(feature = "vec_resize_with", issue = "41758")]
-    pub fn resize_with(&mut self, new_len: usize, generator: impl FnMut()->T) {
-        let len = self.len();
-
-        if new_len > len {
-            self.extend(repeat_with(generator).take(new_len - len))
-        } else {
-            self.truncate(new_len);
-        }
+    #[stable(feature = "deque_extras", since = "1.16.0")]
+    pub fn resize(&mut self, new_len: usize, value: T) {
+        self.resize_with(new_len, || value.clone());
     }
 }
 

src/liballoc/string.rs

@@ -1050,7 +1050,7 @@ impl String {
     /// assert!(s.capacity() >= 3);
     /// ```
     #[inline]
-    #[unstable(feature = "shrink_to", reason = "new API", issue="0")]
+    #[unstable(feature = "shrink_to", reason = "new API", issue="56431")]
     pub fn shrink_to(&mut self, min_capacity: usize) {
         self.vec.shrink_to(min_capacity)
     }

src/liballoc/vec.rs

@@ -613,7 +613,7 @@ impl<T> Vec<T> {
     /// vec.shrink_to(0);
     /// assert!(vec.capacity() >= 3);
     /// ```
-    #[unstable(feature = "shrink_to", reason = "new API", issue="0")]
+    #[unstable(feature = "shrink_to", reason = "new API", issue="56431")]
     pub fn shrink_to(&mut self, min_capacity: usize) {
         self.buf.shrink_to_fit(cmp::max(self.len, min_capacity));
     }

src/libcore/macros.rs

@@ -238,6 +238,10 @@ macro_rules! debug_assert_ne {
 /// with converting downstream errors.
 ///
 /// The `?` operator was added to replace `try!` and should be used instead.
+/// Furthermore, `try` is a reserved word in Rust 2018, so if you must use
+/// it, you will need to use the [raw-identifier syntax][ris]: `r#try`.
+///
+/// [ris]: https://doc.rust-lang.org/nightly/rust-by-example/compatibility/raw_identifiers.html
 ///
 /// `try!` matches the given [`Result`]. In case of the `Ok` variant, the
 /// expression has the value of the wrapped value.
@@ -278,14 +282,14 @@ macro_rules! debug_assert_ne {
 ///
 /// // The previous method of quick returning Errors
 /// fn write_to_file_using_try() -> Result<(), MyError> {
-///     let mut file = try!(File::create("my_best_friends.txt"));
-///     try!(file.write_all(b"This is a list of my best friends."));
+///     let mut file = r#try!(File::create("my_best_friends.txt"));
+///     r#try!(file.write_all(b"This is a list of my best friends."));
 ///     Ok(())
 /// }
 ///
 /// // This is equivalent to:
 /// fn write_to_file_using_match() -> Result<(), MyError> {
-///     let mut file = try!(File::create("my_best_friends.txt"));
+///     let mut file = r#try!(File::create("my_best_friends.txt"));
 ///     match file.write_all(b"This is a list of my best friends.") {
 ///         Ok(v) => v,
 ///         Err(e) => return Err(From::from(e)),
@@ -296,14 +300,14 @@ macro_rules! debug_assert_ne {
 #[macro_export]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(alias = "?")]
-macro_rules! try {
+macro_rules! r#try {
     ($expr:expr) => (match $expr {
         $crate::result::Result::Ok(val) => val,
         $crate::result::Result::Err(err) => {
             return $crate::result::Result::Err($crate::convert::From::from(err))
         }
     });
-    ($expr:expr,) => (try!($expr));
+    ($expr:expr,) => (r#try!($expr));
 }
 
 /// Write formatted data into a buffer.

src/librustc/ty/inhabitedness/mod.rs

@@ -167,23 +167,16 @@ impl<'a, 'gcx, 'tcx> VariantDef {
         substs: &'tcx Substs<'tcx>,
         adt_kind: AdtKind) -> DefIdForest
     {
-        match adt_kind {
-            AdtKind::Union => {
-                DefIdForest::intersection(tcx, self.fields.iter().map(|f| {
-                    f.uninhabited_from(visited, tcx, substs, false)
-                }))
-            },
-            AdtKind::Struct => {
-                DefIdForest::union(tcx, self.fields.iter().map(|f| {
-                    f.uninhabited_from(visited, tcx, substs, false)
-                }))
-            },
-            AdtKind::Enum => {
-                DefIdForest::union(tcx, self.fields.iter().map(|f| {
-                    f.uninhabited_from(visited, tcx, substs, true)
-                }))
-            },
-        }
+        let is_enum = match adt_kind {
+            // For now, `union`s are never considered uninhabited.
+            // The precise semantics of inhabitedness with respect to unions is currently undecided.
+            AdtKind::Union => return DefIdForest::empty(),
+            AdtKind::Enum => true,
+            AdtKind::Struct => false,
+        };
+        DefIdForest::union(tcx, self.fields.iter().map(|f| {
+            f.uninhabited_from(visited, tcx, substs, is_enum)
+        }))
     }
 }
 
@@ -194,8 +187,8 @@ impl<'a, 'gcx, 'tcx> FieldDef {
         visited: &mut FxHashMap<DefId, FxHashSet<&'tcx Substs<'tcx>>>,
         tcx: TyCtxt<'a, 'gcx, 'tcx>,
         substs: &'tcx Substs<'tcx>,
-        is_enum: bool) -> DefIdForest
-    {
+        is_enum: bool,
+    ) -> DefIdForest {
         let mut data_uninhabitedness = move || {
             self.ty(tcx, substs).uninhabited_from(visited, tcx)
         };
@@ -253,14 +246,16 @@ impl<'a, 'gcx, 'tcx> TyS<'tcx> {
                 let substs_set = visited.get_mut(&def.did).unwrap();
                 substs_set.remove(substs);
                 ret
-            },
+            }
 
             Never => DefIdForest::full(tcx),
+
             Tuple(ref tys) => {
                 DefIdForest::union(tcx, tys.iter().map(|ty| {
                     ty.uninhabited_from(visited, tcx)
                 }))
-            },
+            }
+
             Array(ty, len) => {
                 match len.assert_usize(tcx) {
                     // If the array is definitely non-empty, it's uninhabited if
@@ -269,9 +264,13 @@ impl<'a, 'gcx, 'tcx> TyS<'tcx> {
                     _ => DefIdForest::empty()
                 }
             }
-            Ref(_, ty, _) => {
-                ty.uninhabited_from(visited, tcx)
-            }
+
+            // References to uninitialised memory is valid for any type, including
+            // uninhabited types, in unsafe code, so we treat all references as
+            // inhabited.
+            // The precise semantics of inhabitedness with respect to references is currently
+            // undecided.
+            Ref(..) => DefIdForest::empty(),
 
             _ => DefIdForest::empty(),
         }