Rollup merge of #49829 - ecstatic-morse:os-docs, r=steveklabnik

Add doc links to `std::os` extension traits

Addresses a small subset of #29367.

This adds documentation links to the original type for various OS-specific extension traits, and uses a common sentence for introducing such traits (which now consistently ends in a period).

3 files changed, 21 insertions, 11 deletions

diff --git a/src/libstd/sys/windows/ext/ffi.rs b/src/libstd/sys/windows/ext/ffi.rs
index d6b8896ac09..98d43552489 100644
--- a/src/libstd/sys/windows/ext/ffi.rs
+++ b/src/libstd/sys/windows/ext/ffi.rs
@@ -76,7 +76,9 @@ use sys_common::{FromInner, AsInner};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use sys_common::wtf8::EncodeWide;
 
-/// Windows-specific extensions to `OsString`.
+/// Windows-specific extensions to [`OsString`].
+///
+/// [`OsString`]: ../../../../std/ffi/struct.OsString.html
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait OsStringExt {
     /// Creates an `OsString` from a potentially ill-formed UTF-16 slice of
@@ -109,7 +111,9 @@ impl OsStringExt for OsString {
     }
 }
 
-/// Windows-specific extensions to `OsStr`.
+/// Windows-specific extensions to [`OsStr`].
+///
+/// [`OsStr`]: ../../../../std/ffi/struct.OsStr.html
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait OsStrExt {
     /// Re-encodes an `OsStr` as a wide character sequence, i.e. potentially
diff --git a/src/libstd/sys/windows/ext/fs.rs b/src/libstd/sys/windows/ext/fs.rs
index e5cd51b6550..78c9e95a055 100644
--- a/src/libstd/sys/windows/ext/fs.rs
+++ b/src/libstd/sys/windows/ext/fs.rs
@@ -103,9 +103,9 @@ impl FileExt for fs::File {
     }
 }
 
-/// Windows-specific extensions to [`OpenOptions`].
+/// Windows-specific extensions to [`fs::OpenOptions`].
 ///
-/// [`OpenOptions`]: ../../../fs/struct.OpenOptions.html
+/// [`fs::OpenOptions`]: ../../../../std/fs/struct.OpenOptions.html
 #[stable(feature = "open_options_ext", since = "1.10.0")]
 pub trait OpenOptionsExt {
     /// Overrides the `dwDesiredAccess` argument to the call to [`CreateFile`]
@@ -281,13 +281,12 @@ impl OpenOptionsExt for OpenOptions {
     }
 }
 
-/// Extension methods for [`fs::Metadata`] to access the raw fields contained
-/// within.
+/// Windows-specific extensions to [`fs::Metadata`].
 ///
 /// The data members that this trait exposes correspond to the members
 /// of the [`BY_HANDLE_FILE_INFORMATION`] structure.
 ///
-/// [`fs::Metadata`]: ../../../fs/struct.Metadata.html
+/// [`fs::Metadata`]: ../../../../std/fs/struct.Metadata.html
 /// [`BY_HANDLE_FILE_INFORMATION`]:
 ///     https://msdn.microsoft.com/en-us/library/windows/desktop/aa363788.aspx
 #[stable(feature = "metadata_ext", since = "1.1.0")]
@@ -445,8 +444,11 @@ impl MetadataExt for Metadata {
     fn file_size(&self) -> u64 { self.as_inner().size() }
 }
 
-/// Add support for the Windows specific fact that a symbolic link knows whether it is a file
-/// or directory.
+/// Windows-specific extensions to [`FileType`].
+///
+/// On Windows, a symbolic link knows whether it is a file or directory.
+///
+/// [`FileType`]: ../../../../std/fs/struct.FileType.html
 #[unstable(feature = "windows_file_type_ext", issue = "0")]
 pub trait FileTypeExt {
     /// Returns whether this file type is a symbolic link that is also a directory.
diff --git a/src/libstd/sys/windows/ext/process.rs b/src/libstd/sys/windows/ext/process.rs
index 759f055c4b1..a02bcbe0c87 100644
--- a/src/libstd/sys/windows/ext/process.rs
+++ b/src/libstd/sys/windows/ext/process.rs
@@ -82,7 +82,9 @@ impl IntoRawHandle for process::ChildStderr {
     }
 }
 
-/// Windows-specific extensions to `std::process::ExitStatus`
+/// Windows-specific extensions to [`process::ExitStatus`].
+///
+/// [`process::ExitStatus`]: ../../../../std/process/struct.ExitStatus.html
 #[stable(feature = "exit_status_from", since = "1.12.0")]
 pub trait ExitStatusExt {
     /// Creates a new `ExitStatus` from the raw underlying `u32` return value of
@@ -98,7 +100,9 @@ impl ExitStatusExt for process::ExitStatus {
     }
 }
 
-/// Windows-specific extensions to the `std::process::Command` builder
+/// Windows-specific extensions to the [`process::Command`] builder.
+///
+/// [`process::Command`]: ../../../../std/process/struct.Command.html
 #[stable(feature = "windows_process_extensions", since = "1.16.0")]
 pub trait CommandExt {
     /// Sets the [process creation flags][1] to be passed to `CreateProcess`.