Rollup merge of #39344 - ollie27:links, r=steveklabnik

Fix a few links in the docs

r? @steveklabnik

src/doc/book/ffi.md

@@ -710,7 +710,7 @@ Please note that [`catch_unwind()`] will only catch unwinding panics, not
 those who abort the process. See the documentation of [`catch_unwind()`]
 for more information.
 
-[`catch_unwind()`]: https://doc.rust-lang.org/std/panic/fn.catch_unwind.html
+[`catch_unwind()`]: ../std/panic/fn.catch_unwind.html
 
 # Representing opaque structs
 

src/liballoc/arc.rs

@@ -59,7 +59,7 @@
 /// as long as `T` implements [`Send`] and [`Sync`][sync]. The disadvantage is
 /// that atomic operations are more expensive than ordinary memory accesses.
 /// If you are not sharing reference-counted values between threads, consider
-/// using [`rc::Rc`] for lower overhead. [`Rc`] is a safe default, because
+/// using [`rc::Rc`][`Rc`] for lower overhead. [`Rc`] is a safe default, because
 /// the compiler will catch any attempt to send an [`Rc`] between threads.
 /// However, a library might choose `Arc` in order to give library consumers
 /// more flexibility.

src/libcore/hash/mod.rs

@@ -307,6 +307,7 @@ pub trait BuildHasher {
 /// [`BuildHasher`]: trait.BuildHasher.html
 /// [`Default`]: ../default/trait.Default.html
 /// [`Hasher`]: trait.Hasher.html
+/// [`HashMap`]: ../../std/collections/struct.HashMap.html
 #[stable(since = "1.7.0", feature = "build_hasher")]
 pub struct BuildHasherDefault<H>(marker::PhantomData<H>);
 

src/libcore/iter/iterator.rs

@@ -1108,9 +1108,9 @@ fn by_ref(&mut self) -> &mut Self where Self: Sized { self }
     ///
     /// One of the keys to `collect()`'s power is that many things you might
     /// not think of as 'collections' actually are. For example, a [`String`]
-    /// is a collection of [`char`]s. And a collection of [`Result<T, E>`] can
-    /// be thought of as single [`Result`]`<Collection<T>, E>`. See the examples
-    /// below for more.
+    /// is a collection of [`char`]s. And a collection of
+    /// [`Result<T, E>`][`Result`] can be thought of as single
+    /// [`Result`]`<Collection<T>, E>`. See the examples below for more.
     ///
     /// Because `collect()` is so general, it can cause problems with type
     /// inference. As such, `collect()` is one of the few times you'll see

src/libcore/sync/atomic.rs

@@ -24,7 +24,7 @@
 //! same as [LLVM atomic orderings][1]. For more information see the [nomicon][2].
 //!
 //! [1]: http://llvm.org/docs/LangRef.html#memory-model-for-concurrent-operations
-//! [2]: https://doc.rust-lang.org/nomicon/atomics.html
+//! [2]: ../../../nomicon/atomics.html
 //!
 //! Atomic variables are safe to share between threads (they implement `Sync`)
 //! but they do not themselves provide the mechanism for sharing and follow the
@@ -144,7 +144,7 @@ unsafe impl<T> Sync for AtomicPtr<T> {}
 /// LLVM's](http://llvm.org/docs/LangRef.html#memory-model-for-concurrent-operations).
 ///
 /// For more information see the [nomicon][1].
-/// [1]: https://doc.rust-lang.org/nomicon/atomics.html
+/// [1]: ../../../nomicon/atomics.html
 #[stable(feature = "rust1", since = "1.0.0")]
 #[derive(Copy, Clone, Debug)]
 pub enum Ordering {

src/libstd/env.rs

@@ -222,7 +222,7 @@ fn _var_os(key: &OsStr) -> Option<OsString> {
 
 /// Possible errors from the [`env::var`] function.
 ///
-/// [env::var]: fn.var.html
+/// [`env::var`]: fn.var.html
 #[derive(Debug, PartialEq, Eq, Clone)]
 #[stable(feature = "env", since = "1.0.0")]
 pub enum VarError {

src/libstd/thread/mod.rs

@@ -391,7 +391,7 @@ pub fn spawn<F, T>(self, f: F) -> io::Result<JoinHandle<T>> where
 /// [`JoinHandle`]: ../../std/thread/struct.JoinHandle.html
 /// [`join`]: ../../std/thread/struct.JoinHandle.html#method.join
 /// [`Err`]: ../../std/result/enum.Result.html#variant.Err
-/// [`panic!`]: ../../std/macro.panic.html
+/// [`panic`]: ../../std/macro.panic.html
 /// [`Builder::spawn`]: ../../std/thread/struct.Builder.html#method.spawn
 ///
 /// # Examples
@@ -974,7 +974,7 @@ pub fn thread(&self) -> &Thread {
     /// to [`panic`].
     ///
     /// [`Err`]: ../../std/result/enum.Result.html#variant.Err
-    /// [`panic!`]: ../../std/macro.panic.html
+    /// [`panic`]: ../../std/macro.panic.html
     ///
     /// # Examples
     ///