Rollup of 7 pull requests

src/bootstrap/flags.rs

@@ -136,9 +136,12 @@ To learn more about a subcommand, run `./x.py <subcommand> -h`");
         let subcommand = match subcommand {
             Some(s) => s,
             None => {
-                // No subcommand -- show the general usage and subcommand help
+                // No or an invalid subcommand -- show the general usage and subcommand help
+                // An exit code will be 0 when no subcommand is given, and 1 in case of an invalid
+                // subcommand.
                 println!("{}\n", subcommand_help);
-                process::exit(1);
+                let exit_code = if args.is_empty() { 0 } else { 1 };
+                process::exit(exit_code);
             }
         };
 

src/doc/unstable-book/src/language-features/on-unimplemented.md

@@ -15,8 +15,8 @@ For example:
 ```rust,compile_fail
 #![feature(on_unimplemented)]
 
-#[rustc_on_unimplemented="a collection of type `{Self}` cannot be built from an \
-                          iterator over elements of type `{A}`"]
+#[rustc_on_unimplemented="an iterator over elements of type `{A}` \
+    cannot be built from a collection of type `{Self}`"]
 trait MyIterator<A> {
     fn next(&mut self) -> A;
 }
@@ -37,9 +37,9 @@ error[E0277]: the trait bound `&[{integer}]: MyIterator<char>` is not satisfied
   --> <anon>:14:5
    |
 14 |     iterate_chars(&[1, 2, 3][..]);
-   |     ^^^^^^^^^^^^^ the trait `MyIterator<char>` is not implemented for `&[{integer}]`
+   |     ^^^^^^^^^^^^^ an iterator over elements of type `char` cannot be built from a collection of type `&[{integer}]`
    |
-   = note: a collection of type `&[{integer}]` cannot be built from an iterator over elements of type `char`
+   = help: the trait `MyIterator<char>` is not implemented for `&[{integer}]`
    = note: required by `iterate_chars`
 
 error: aborting due to previous error

src/librustc/diagnostics.rs

@@ -1875,7 +1875,7 @@ fn main() {
 "##,
 
 E0601: r##"
-No `main` function was found in a binary crate. To fix this error, just add a
+No `main` function was found in a binary crate. To fix this error, add a
 `main` function. For example:
 
 ```

src/librustc/session/mod.rs

@@ -776,7 +776,12 @@ pub fn build_session_(sopts: config::Options,
     let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
     let print_fuel = Cell::new(0);
 
-    let working_dir = env::current_dir().unwrap().to_string_lossy().into_owned();
+    let working_dir = match env::current_dir() {
+        Ok(dir) => dir.to_string_lossy().into_owned(),
+        Err(e) => {
+            panic!(p_s.span_diagnostic.fatal(&format!("Current directory is invalid: {}", e)))
+        }
+    };
     let working_dir = file_path_mapping.map_prefix(working_dir);
 
     let sess = Session {

src/librustdoc/Cargo.toml

@@ -13,7 +13,7 @@ doctest = false
 [dependencies]
 env_logger = { version = "0.4", default-features = false }
 log = "0.3"
-pulldown-cmark = { version = "0.0.14", default-features = false }
+pulldown-cmark = { version = "0.1.0", default-features = false }
 html-diff = "0.0.4"
 
 [build-dependencies]

src/librustdoc/html/markdown.rs

@@ -371,7 +371,7 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for Footnotes<'a, I> {
             match self.inner.next() {
                 Some(Event::FootnoteReference(ref reference)) => {
                     let entry = self.get_entry(&reference);
-                    let reference = format!("<sup id=\"supref{0}\"><a href=\"#ref{0}\">{0}\
+                    let reference = format!("<sup id=\"fnref{0}\"><a href=\"#fn{0}\">{0}\
                                              </a></sup>",
                                             (*entry).1);
                     return Some(Event::Html(reference.into()));
@@ -394,15 +394,15 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for Footnotes<'a, I> {
                         v.sort_by(|a, b| a.1.cmp(&b.1));
                         let mut ret = String::from("<div class=\"footnotes\"><hr><ol>");
                         for (mut content, id) in v {
-                            write!(ret, "<li id=\"ref{}\">", id).unwrap();
+                            write!(ret, "<li id=\"fn{}\">", id).unwrap();
                             let mut is_paragraph = false;
                             if let Some(&Event::End(Tag::Paragraph)) = content.last() {
                                 content.pop();
                                 is_paragraph = true;
                             }
                             html::push_html(&mut ret, content.into_iter());
                             write!(ret,
-                                   "&nbsp;<a href=\"#supref{}\" rev=\"footnote\">↩</a>",
+                                   "&nbsp;<a href=\"#fnref{}\" rev=\"footnote\">↩</a>",
                                    id).unwrap();
                             if is_paragraph {
                                 ret.push_str("</p>");

src/libstd/net/udp.rs

@@ -721,16 +721,45 @@ impl UdpSocket {
 
     /// Moves this UDP socket into or out of nonblocking mode.
     ///
-    /// On Unix this corresponds to calling fcntl, and on Windows this
-    /// corresponds to calling ioctlsocket.
+    /// This will result in `recv`, `recv_from`, `send`, and `send_to`
+    /// operations becoming nonblocking, i.e. immediately returning from their
+    /// calls. If the IO operation is successful, `Ok` is returned and no
+    /// further action is required. If the IO operation could not be completed
+    /// and needs to be retried, an error with kind
+    /// [`io::ErrorKind::WouldBlock`] is returned.
+    ///
+    /// On Unix platforms, calling this method corresponds to calling `fcntl`
+    /// `FIONBIO`. On Windows calling this method corresponds to calling
+    /// `ioctlsocket` `FIONBIO`.
+    ///
+    /// [`io::ErrorKind::WouldBlock`]: ../io/enum.ErrorKind.html#variant.WouldBlock
     ///
     /// # Examples
     ///
+    /// Create a UDP socket bound to `127.0.0.1:7878` and read bytes in
+    /// nonblocking mode:
+    ///
     /// ```no_run
+    /// use std::io;
     /// use std::net::UdpSocket;
     ///
-    /// let socket = UdpSocket::bind("127.0.0.1:34254").expect("couldn't bind to address");
-    /// socket.set_nonblocking(true).expect("set_nonblocking call failed");
+    /// let socket = UdpSocket::bind("127.0.0.1:7878").unwrap();
+    /// socket.set_nonblocking(true).unwrap();
+    ///
+    /// # fn wait_for_fd() { unimplemented!() }
+    /// let mut buf = [0; 10];
+    /// let (num_bytes_read, _) = loop {
+    ///     match socket.recv_from(&mut buf) {
+    ///         Ok(n) => break n,
+    ///         Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
+    ///             // wait until network socket is ready, typically implemented
+    ///             // via platform-specific APIs such as epoll or IOCP
+    ///             wait_for_fd();
+    ///         }
+    ///         Err(e) => panic!("encountered IO error: {}", e),
+    ///     }
+    /// };
+    /// println!("bytes: {:?}", &buf[..num_bytes_read]);
     /// ```
     #[stable(feature = "net2_mutators", since = "1.9.0")]
     pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {

src/libstd/process.rs

@@ -10,27 +10,68 @@
 
 //! A module for working with processes.
 //!
-//! # Examples
+//! This module is mostly concerned with spawning and interacting with child
+//! processes, but it also provides [`abort`] and [`exit`] for terminating the
+//! current process.
 //!
-//! Basic usage where we try to execute the `cat` shell command:
+//! # Spawning a process
 //!
-//! ```should_panic
+//! The [`Command`] struct is used to configure and spawn processes:
+//!
+//! ```
 //! use std::process::Command;
 //!
-//! let mut child = Command::new("/bin/cat")
-//!                         .arg("file.txt")
-//!                         .spawn()
-//!                         .expect("failed to execute child");
+//! let output = Command::new("echo")
+//!                      .arg("Hello world")
+//!                      .output()
+//!                      .expect("Failed to execute command");
+//!
+//! assert_eq!(b"Hello world\n", output.stdout.as_slice());
+//! ```
+//!
+//! Several methods on [`Command`], such as [`spawn`] or [`output`], can be used
+//! to spawn a process. In particular, [`output`] spawns the child process and
+//! waits until the process terminates, while [`spawn`] will return a [`Child`]
+//! that represents the spawned child process.
 //!
-//! let ecode = child.wait()
-//!                  .expect("failed to wait on child");
+//! # Handling I/O
+//!
+//! The [`stdout`], [`stdin`], and [`stderr`] of a child process can be
+//! configured by passing an [`Stdio`] to the corresponding method on
+//! [`Command`]. Once spawned, they can be accessed from the [`Child`]. For
+//! example, piping output from one command into another command can be done
+//! like so:
 //!
-//! assert!(ecode.success());
 //! ```
+//! use std::process::{Command, Stdio};
+//!
+//! // stdout must be configured with `Stdio::piped` in order to use
+//! // `echo_child.stdout`
+//! let echo_child = Command::new("echo")
+//!     .arg("Oh no, a tpyo!")
+//!     .stdout(Stdio::piped())
+//!     .spawn()
+//!     .expect("Failed to start echo process");
 //!
-//! Calling a command with input and reading its output:
+//! // Note that `echo_child` is moved here, but we won't be needing
+//! // `echo_child` anymore
+//! let echo_out = echo_child.stdout.expect("Failed to open echo stdout");
 //!
-//! ```no_run
+//! let mut sed_child = Command::new("sed")
+//!     .arg("s/tpyo/typo/")
+//!     .stdin(Stdio::from(echo_out))
+//!     .stdout(Stdio::piped())
+//!     .spawn()
+//!     .expect("Failed to start sed process");
+//!
+//! let output = sed_child.wait_with_output().expect("Failed to wait on sed");
+//! assert_eq!(b"Oh no, a typo!\n", output.stdout.as_slice());
+//! ```
+//!
+//! Note that [`ChildStderr`] and [`ChildStdout`] implement [`Write`] and
+//! [`ChildStdin`] implements [`Read`]:
+//!
+//! ```
 //! use std::process::{Command, Stdio};
 //! use std::io::Write;
 //!
@@ -52,6 +93,26 @@
 //!
 //! assert_eq!(b"test", output.stdout.as_slice());
 //! ```
+//!
+//! [`abort`]: fn.abort.html
+//! [`exit`]: fn.exit.html
+//!
+//! [`Command`]: struct.Command.html
+//! [`spawn`]: struct.Command.html#method.spawn
+//! [`output`]: struct.Command.html#method.output
+//!
+//! [`Child`]: struct.Child.html
+//! [`ChildStdin`]: struct.ChildStdin.html
+//! [`ChildStdout`]: struct.ChildStdout.html
+//! [`ChildStderr`]: struct.ChildStderr.html
+//! [`Stdio`]: struct.Stdio.html
+//!
+//! [`stdout`]: struct.Command.html#method.stdout
+//! [`stdin`]: struct.Command.html#method.stdin
+//! [`stderr`]: struct.Command.html#method.stderr
+//!
+//! [`Write`]: ../io/trait.Write.html
+//! [`Read`]: ../io/trait.Read.html
 
 #![stable(feature = "process", since = "1.0.0")]