Auto merge of #57737 - Centril:rollup, r=Centril

Rollup of 10 pull requests

Successful merges:

 - #56594 (Remove confusing comment about ideally using `!` for `c_void`)
 - #57340 (Use correct tracking issue for c_variadic)
 - #57357 (Cleanup PartialEq docs.)
 - #57551 (resolve: Add a test for issue #57539)
 - #57636 (Fix sources sidebar not showing up)
 - #57646 (Fixes text becoming invisible when element targetted)
 - #57654 (Add some links in std::fs.)
 - #57683 (Document Unpin in std::prelude documentation)
 - #57685 (Enhance `Pin` impl applicability for `PartialEq` and `PartialOrd`.)
 - #57710 (Fix non-clickable urls)

Failed merges:

r? @ghost

13 files changed, 138 insertions, 66 deletions

diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
index 86f28a957cd..d43a5c1032c 100644
--- a/src/libcore/cmp.rs
+++ b/src/libcore/cmp.rs
@@ -91,6 +91,8 @@ use self::Ordering::*;
 /// For example, let's tweak our previous code a bit:
 ///
 /// ```
+/// // The derive implements <BookFormat> == <BookFormat> comparisons
+/// #[derive(PartialEq)]
 /// enum BookFormat {
 ///     Paperback,
 ///     Hardback,
@@ -102,31 +104,34 @@ use self::Ordering::*;
 ///     format: BookFormat,
 /// }
 ///
+/// // Implement <Book> == <BookFormat> comparisons
 /// impl PartialEq<BookFormat> for Book {
 ///     fn eq(&self, other: &BookFormat) -> bool {
-///         match (&self.format, other) {
-///            (BookFormat::Paperback, BookFormat::Paperback) => true,
-///            (BookFormat::Hardback,  BookFormat::Hardback)  => true,
-///            (BookFormat::Ebook,     BookFormat::Ebook)     => true,
-///            (_, _) => false,
-///         }
+///         self.format == *other
+///     }
+/// }
+///
+/// // Implement <BookFormat> == <Book> comparisons
+/// impl PartialEq<Book> for BookFormat {
+///     fn eq(&self, other: &Book) -> bool {
+///         *self == other.format
 ///     }
 /// }
 ///
 /// let b1 = Book { isbn: 3, format: BookFormat::Paperback };
 ///
 /// assert!(b1 == BookFormat::Paperback);
-/// assert!(b1 != BookFormat::Ebook);
+/// assert!(BookFormat::Ebook != b1);
 /// ```
 ///
 /// By changing `impl PartialEq for Book` to `impl PartialEq<BookFormat> for Book`,
-/// we've changed what type we can use on the right side of the `==` operator.
-/// This lets us use it in the `assert!` statements at the bottom.
+/// we allow `BookFormat`s to be compared with `Book`s.
 ///
 /// You can also combine these implementations to let the `==` operator work with
 /// two different types:
 ///
 /// ```
+/// #[derive(PartialEq)]
 /// enum BookFormat {
 ///     Paperback,
 ///     Hardback,
@@ -140,12 +145,13 @@ use self::Ordering::*;
 ///
 /// impl PartialEq<BookFormat> for Book {
 ///     fn eq(&self, other: &BookFormat) -> bool {
-///         match (&self.format, other) {
-///            (&BookFormat::Paperback, &BookFormat::Paperback) => true,
-///            (&BookFormat::Hardback,  &BookFormat::Hardback)  => true,
-///            (&BookFormat::Ebook,     &BookFormat::Ebook)     => true,
-///            (_, _) => false,
-///         }
+///         self.format == *other
+///     }
+/// }
+///
+/// impl PartialEq<Book> for BookFormat {
+///     fn eq(&self, other: &Book) -> bool {
+///         *self == other.format
 ///     }
 /// }
 ///
@@ -159,7 +165,7 @@ use self::Ordering::*;
 /// let b2 = Book { isbn: 3, format: BookFormat::Ebook };
 ///
 /// assert!(b1 == BookFormat::Paperback);
-/// assert!(b1 != BookFormat::Ebook);
+/// assert!(BookFormat::Ebook != b1);
 /// assert!(b1 == b2);
 /// ```
 ///
diff --git a/src/libcore/ffi.rs b/src/libcore/ffi.rs
index 0717a88b6b8..644380c69f2 100644
--- a/src/libcore/ffi.rs
+++ b/src/libcore/ffi.rs
@@ -12,24 +12,27 @@ use ::fmt;
 /// and `*mut c_void` is equivalent to C's `void*`. That said, this is
 /// *not* the same as C's `void` return type, which is Rust's `()` type.
 ///
-/// Ideally, this type would be equivalent to [`!`], but currently it may
-/// be more ideal to use `c_void` for FFI purposes.
+/// To model pointers to opaque types in FFI, until `extern type` is
+/// stabilized, it is recommended to use a newtype wrapper around an empty
+/// byte array. See the [Nomicon] for details.
 ///
-/// [`!`]: ../../std/primitive.never.html
 /// [pointer]: ../../std/primitive.pointer.html
+/// [Nomicon]: https://doc.rust-lang.org/nomicon/ffi.html#representing-opaque-structs
 // N.B., for LLVM to recognize the void pointer type and by extension
 //     functions like malloc(), we need to have it represented as i8* in
 //     LLVM bitcode. The enum used here ensures this and prevents misuse
-//     of the "raw" type by only having private variants.. We need two
+//     of the "raw" type by only having private variants. We need two
 //     variants, because the compiler complains about the repr attribute
-//     otherwise.
+//     otherwise and we need at least one variant as otherwise the enum
+//     would be uninhabited and at least dereferencing such pointers would
+//     be UB.
 #[repr(u8)]
 #[stable(feature = "raw_os", since = "1.1.0")]
 pub enum c_void {
-    #[unstable(feature = "c_void_variant", reason = "should not have to exist",
+    #[unstable(feature = "c_void_variant", reason = "temporary implementation detail",
                issue = "0")]
     #[doc(hidden)] __variant1,
-    #[unstable(feature = "c_void_variant", reason = "should not have to exist",
+    #[unstable(feature = "c_void_variant", reason = "temporary implementation detail",
                issue = "0")]
     #[doc(hidden)] __variant2,
 }
@@ -49,7 +52,7 @@ impl fmt::Debug for c_void {
 #[unstable(feature = "c_variadic",
            reason = "the `c_variadic` feature has not been properly tested on \
                      all supported platforms",
-           issue = "27745")]
+           issue = "44930")]
 extern {
     type VaListImpl;
 }
@@ -74,7 +77,7 @@ impl fmt::Debug for VaListImpl {
 #[unstable(feature = "c_variadic",
            reason = "the `c_variadic` feature has not been properly tested on \
                      all supported platforms",
-           issue = "27745")]
+           issue = "44930")]
 struct VaListImpl {
     stack: *mut (),
     gr_top: *mut (),
@@ -90,7 +93,7 @@ struct VaListImpl {
 #[unstable(feature = "c_variadic",
            reason = "the `c_variadic` feature has not been properly tested on \
                      all supported platforms",
-           issue = "27745")]
+           issue = "44930")]
 struct VaListImpl {
     gpr: u8,
     fpr: u8,
@@ -106,7 +109,7 @@ struct VaListImpl {
 #[unstable(feature = "c_variadic",
            reason = "the `c_variadic` feature has not been properly tested on \
                      all supported platforms",
-           issue = "27745")]
+           issue = "44930")]
 struct VaListImpl {
     gp_offset: i32,
     fp_offset: i32,
@@ -120,7 +123,7 @@ struct VaListImpl {
 #[unstable(feature = "c_variadic",
            reason = "the `c_variadic` feature has not been properly tested on \
                      all supported platforms",
-           issue = "27745")]
+           issue = "44930")]
 #[repr(transparent)]
 pub struct VaList<'a>(&'a mut VaListImpl);
 
@@ -140,7 +143,7 @@ mod sealed_trait {
     #[unstable(feature = "c_variadic",
                reason = "the `c_variadic` feature has not been properly tested on \
                          all supported platforms",
-               issue = "27745")]
+               issue = "44930")]
     pub trait VaArgSafe {}
 }
 
@@ -150,7 +153,7 @@ macro_rules! impl_va_arg_safe {
             #[unstable(feature = "c_variadic",
                        reason = "the `c_variadic` feature has not been properly tested on \
                                  all supported platforms",
-                       issue = "27745")]
+                       issue = "44930")]
             impl sealed_trait::VaArgSafe for $t {}
         )+
     }
@@ -163,12 +166,12 @@ impl_va_arg_safe!{f64}
 #[unstable(feature = "c_variadic",
            reason = "the `c_variadic` feature has not been properly tested on \
                      all supported platforms",
-           issue = "27745")]
+           issue = "44930")]
 impl<T> sealed_trait::VaArgSafe for *mut T {}
 #[unstable(feature = "c_variadic",
            reason = "the `c_variadic` feature has not been properly tested on \
                      all supported platforms",
-           issue = "27745")]
+           issue = "44930")]
 impl<T> sealed_trait::VaArgSafe for *const T {}
 
 impl<'a> VaList<'a> {
@@ -176,7 +179,7 @@ impl<'a> VaList<'a> {
     #[unstable(feature = "c_variadic",
                reason = "the `c_variadic` feature has not been properly tested on \
                          all supported platforms",
-               issue = "27745")]
+               issue = "44930")]
     pub unsafe fn arg<T: sealed_trait::VaArgSafe>(&mut self) -> T {
         va_arg(self)
     }
@@ -185,7 +188,7 @@ impl<'a> VaList<'a> {
     #[unstable(feature = "c_variadic",
                reason = "the `c_variadic` feature has not been properly tested on \
                          all supported platforms",
-               issue = "27745")]
+               issue = "44930")]
     pub unsafe fn 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"),
diff --git a/src/libcore/pin.rs b/src/libcore/pin.rs
index 762e07549a5..7c09a36d898 100644
--- a/src/libcore/pin.rs
+++ b/src/libcore/pin.rs
@@ -99,6 +99,7 @@
 
 use fmt;
 use marker::{Sized, Unpin};
+use cmp::{self, PartialEq, PartialOrd};
 use ops::{Deref, DerefMut, Receiver, CoerceUnsized, DispatchFromDyn};
 
 /// A pinned pointer.
@@ -112,16 +113,57 @@ use ops::{Deref, DerefMut, Receiver, CoerceUnsized, DispatchFromDyn};
 /// [`Unpin`]: ../../std/marker/trait.Unpin.html
 /// [`pin` module]: ../../std/pin/index.html
 //
-// Note: the derives below are allowed because they all only use `&P`, so they
-// cannot move the value behind `pointer`.
+// Note: the derives below, and the explicit `PartialEq` and `PartialOrd`
+// implementations, are allowed because they all only use `&P`, so they cannot move
+// the value behind `pointer`.
 #[stable(feature = "pin", since = "1.33.0")]
 #[fundamental]
 #[repr(transparent)]
-#[derive(Copy, Clone, Hash, Eq, PartialEq, Ord, PartialOrd)]
+#[derive(Copy, Clone, Hash, Eq, Ord)]
 pub struct Pin<P> {
     pointer: P,
 }
 
+#[stable(feature = "pin_partialeq_partialord_impl_applicability", since = "1.34.0")]
+impl<P, Q> PartialEq<Pin<Q>> for Pin<P>
+where
+    P: PartialEq<Q>,
+{
+    fn eq(&self, other: &Pin<Q>) -> bool {
+        self.pointer == other.pointer
+    }
+
+    fn ne(&self, other: &Pin<Q>) -> bool {
+        self.pointer != other.pointer
+    }
+}
+
+#[stable(feature = "pin_partialeq_partialord_impl_applicability", since = "1.34.0")]
+impl<P, Q> PartialOrd<Pin<Q>> for Pin<P>
+where
+    P: PartialOrd<Q>,
+{
+    fn partial_cmp(&self, other: &Pin<Q>) -> Option<cmp::Ordering> {
+        self.pointer.partial_cmp(&other.pointer)
+    }
+
+    fn lt(&self, other: &Pin<Q>) -> bool {
+        self.pointer < other.pointer
+    }
+
+    fn le(&self, other: &Pin<Q>) -> bool {
+        self.pointer <= other.pointer
+    }
+
+    fn gt(&self, other: &Pin<Q>) -> bool {
+        self.pointer > other.pointer
+    }
+
+    fn ge(&self, other: &Pin<Q>) -> bool {
+        self.pointer >= other.pointer
+    }
+}
+
 impl<P: Deref> Pin<P>
 where
     P::Target: Unpin,
diff --git a/src/librustdoc/html/render.rs b/src/librustdoc/html/render.rs
index 3a64c56fc8e..06846d4ed0c 100644
--- a/src/librustdoc/html/render.rs
+++ b/src/librustdoc/html/render.rs
@@ -1076,7 +1076,7 @@ themePicker.onblur = handleThemeButtonsBlur;
         all_sources.sort();
         let mut w = try_err!(File::create(&dst), &dst);
         try_err!(writeln!(&mut w,
-                          "var N = null;var sourcesIndex = {{}};\n{}",
+                          "var N = null;var sourcesIndex = {{}};\n{}\ncreateSourceSidebar();",
                           all_sources.join("\n")),
                  &dst);
     }
diff --git a/src/librustdoc/html/static/rustdoc.css b/src/librustdoc/html/static/rustdoc.css
index 8a8b7adcf7d..36765496ff4 100644
--- a/src/librustdoc/html/static/rustdoc.css
+++ b/src/librustdoc/html/static/rustdoc.css
@@ -391,10 +391,6 @@ h4 > code, h3 > code, .invisible > code {
 	display: block;
 }
 
-.in-band, code {
-	z-index: -5;
-}
-
 .invisible {
 	width: 100%;
 	display: inline-block;
diff --git a/src/librustdoc/html/static/source-script.js b/src/librustdoc/html/static/source-script.js
index 0affe1c6812..c5d6fa16f55 100644
--- a/src/librustdoc/html/static/source-script.js
+++ b/src/librustdoc/html/static/source-script.js
@@ -137,5 +137,3 @@ function createSourceSidebar() {
 
     main.insertBefore(sidebar, main.firstChild);
 }
-
-createSourceSidebar();
diff --git a/src/librustdoc/html/static/themes/dark.css b/src/librustdoc/html/static/themes/dark.css
index 1390be70063..52a30967a23 100644
--- a/src/librustdoc/html/static/themes/dark.css
+++ b/src/librustdoc/html/static/themes/dark.css
@@ -82,12 +82,6 @@ pre {
 	border-bottom-color: #ddd;
 }
 
-:target { background: #494a3d; }
-
-:target > .in-band {
-	background: #494a3d;
-}
-
 .content .method .where,
 .content .fn .where,
 .content .where.fmt-newline {
@@ -252,7 +246,7 @@ a.test-arrow:hover{
 	color: #999;
 }
 
-:target > code {
+:target > code, :target > .in-band {
 	background-color: #494a3d;
 }
 
diff --git a/src/librustdoc/html/static/themes/light.css b/src/librustdoc/html/static/themes/light.css
index 2b04dd2388d..d20fea666e6 100644
--- a/src/librustdoc/html/static/themes/light.css
+++ b/src/librustdoc/html/static/themes/light.css
@@ -84,12 +84,6 @@ pre {
 	border-bottom-color: #ddd;
 }
 
-:target { background: #FDFFD3; }
-
-:target > .in-band {
-	background: #FDFFD3;
-}
-
 .content .method .where,
 .content .fn .where,
 .content .where.fmt-newline {
@@ -247,7 +241,7 @@ a.test-arrow:hover{
 	color: #999;
 }
 
-:target > code {
+:target > code, :target > .in-band {
 	background: #FDFFD3;
 }
 
diff --git a/src/libstd/ffi/mod.rs b/src/libstd/ffi/mod.rs
index 62081e713f1..7a38f0ebd5a 100644
--- a/src/libstd/ffi/mod.rs
+++ b/src/libstd/ffi/mod.rs
@@ -169,7 +169,7 @@ pub use core::ffi::c_void;
 #[unstable(feature = "c_variadic",
            reason = "the `c_variadic` feature has not been properly tested on \
                      all supported platforms",
-           issue = "27745")]
+           issue = "44930")]
 pub use core::ffi::VaList;
 
 mod c_str;
diff --git a/src/libstd/fs.rs b/src/libstd/fs.rs
index 119b3f7f9f2..3538816c112 100644
--- a/src/libstd/fs.rs
+++ b/src/libstd/fs.rs
@@ -1121,7 +1121,9 @@ impl Permissions {
     /// writing.
     ///
     /// This operation does **not** modify the filesystem. To modify the
-    /// filesystem use the `fs::set_permissions` function.
+    /// filesystem use the [`fs::set_permissions`] function.
+    ///
+    /// [`fs::set_permissions`]: fn.set_permissions.html
     ///
     /// # Examples
     ///
@@ -1639,10 +1641,15 @@ pub fn hard_link<P: AsRef<Path>, Q: AsRef<Path>>(src: P, dst: Q) -> io::Result<(
 ///
 /// The `dst` path will be a symbolic link pointing to the `src` path.
 /// On Windows, this will be a file symlink, not a directory symlink;
-/// for this reason, the platform-specific `std::os::unix::fs::symlink`
-/// and `std::os::windows::fs::{symlink_file, symlink_dir}` should be
+/// for this reason, the platform-specific [`std::os::unix::fs::symlink`]
+/// and [`std::os::windows::fs::symlink_file`] or [`symlink_dir`] should be
 /// used instead to make the intent explicit.
 ///
+/// [`std::os::unix::fs::symlink`]: ../os/unix/fs/fn.symlink.html
+/// [`std::os::windows::fs::symlink_file`]: ../os/windows/fs/fn.symlink_file.html
+/// [`symlink_dir`]: ../os/windows/fs/fn.symlink_dir.html
+///
+///
 /// # Examples
 ///
 /// ```no_run
@@ -1795,7 +1802,7 @@ pub fn create_dir<P: AsRef<Path>>(path: P) -> io::Result<()> {
 /// * If any directory in the path specified by `path`
 /// does not already exist and it could not be created otherwise. The specific
 /// error conditions for when a directory is being created (after it is
-/// determined to not exist) are outlined by `fs::create_dir`.
+/// determined to not exist) are outlined by [`fs::create_dir`].
 ///
 /// Notable exception is made for situations where any of the directories
 /// specified in the `path` could not be created as it was being created concurrently.
@@ -1803,6 +1810,8 @@ pub fn create_dir<P: AsRef<Path>>(path: P) -> io::Result<()> {
 /// concurrently from multiple threads or processes is guaranteed not to fail
 /// due to a race condition with itself.
 ///
+/// [`fs::create_dir`]: fn.create_dir.html
+///
 /// # Examples
 ///
 /// ```no_run
@@ -1868,7 +1877,10 @@ pub fn remove_dir<P: AsRef<Path>>(path: P) -> io::Result<()> {
 ///
 /// # Errors
 ///
-/// See `file::remove_file` and `fs::remove_dir`.
+/// See [`fs::remove_file`] and [`fs::remove_dir`].
+///
+/// [`fs::remove_file`]:  fn.remove_file.html
+/// [`fs::remove_dir`]: fn.remove_dir.html
 ///
 /// # Examples
 ///
diff --git a/src/libstd/prelude/mod.rs b/src/libstd/prelude/mod.rs
index ec8318f3728..bf689bad559 100644
--- a/src/libstd/prelude/mod.rs
+++ b/src/libstd/prelude/mod.rs
@@ -44,8 +44,8 @@
 //! The current version of the prelude (version 1) lives in
 //! [`std::prelude::v1`], and re-exports the following.
 //!
-//! * [`std::marker`]::{[`Copy`], [`Send`], [`Sized`], [`Sync`]}. The marker
-//!   traits indicate fundamental properties of types.
+//! * [`std::marker`]::{[`Copy`], [`Send`], [`Sized`], [`Sync`], [`Unpin`]}. The
+//!   marker traits indicate fundamental properties of types.
 //! * [`std::ops`]::{[`Drop`], [`Fn`], [`FnMut`], [`FnOnce`]}. Various
 //!   operations for both destructors and overloading `()`.
 //! * [`std::mem`]::[`drop`][`mem::drop`], a convenience function for explicitly
@@ -108,6 +108,7 @@
 //! [`Sync`]: ../marker/trait.Sync.html
 //! [`ToOwned`]: ../borrow/trait.ToOwned.html
 //! [`ToString`]: ../string/trait.ToString.html
+//! [`Unpin`]: ../marker/trait.Unpin.html
 //! [`Vec`]: ../vec/struct.Vec.html
 //! [`Clone::clone`]: ../clone/trait.Clone.html#tymethod.clone
 //! [`mem::drop`]: ../mem/fn.drop.html
diff --git a/src/test/ui/imports/issue-57539.rs b/src/test/ui/imports/issue-57539.rs
new file mode 100644
index 00000000000..90b74eb4647
--- /dev/null
+++ b/src/test/ui/imports/issue-57539.rs
@@ -0,0 +1,8 @@
+// edition:2018
+
+mod core {
+    use core; //~ ERROR `core` is ambiguous
+    use crate::*;
+}
+
+fn main() {}
diff --git a/src/test/ui/imports/issue-57539.stderr b/src/test/ui/imports/issue-57539.stderr
new file mode 100644
index 00000000000..3f745fd8204
--- /dev/null
+++ b/src/test/ui/imports/issue-57539.stderr
@@ -0,0 +1,18 @@
+error[E0659]: `core` is ambiguous (name vs any other name during import resolution)
+  --> $DIR/issue-57539.rs:4:9
+   |
+LL |     use core; //~ ERROR `core` is ambiguous
+   |         ^^^^ ambiguous name
+   |
+   = note: `core` could refer to a built-in extern crate
+   = help: use `::core` to refer to this extern crate unambiguously
+note: `core` could also refer to the module imported here
+  --> $DIR/issue-57539.rs:5:9
+   |
+LL |     use crate::*;
+   |         ^^^^^^^^
+   = help: use `self::core` to refer to this module unambiguously
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0659`.