Auto merge of #34720 - Manishearth:rollup, r=Manishearth

Rollup of 9 pull requests

- Successful merges: #34097, #34456, #34610, #34612, #34659, #34688, #34691, #34699, #34700
- Failed merges:

src/doc/book/conditional-compilation.md

@@ -41,8 +41,9 @@ they get set in the [`[features]` section][features] of your `Cargo.toml`:
 # no features by default
 default = []
 
-# The “secure-password” feature depends on the bcrypt package.
-secure-password = ["bcrypt"]
+# Add feature "foo" here, then you can use it. 
+# Our "foo" feature depends on nothing else.
+foo = []
 ```
 
 When you do this, Cargo passes along a flag to `rustc`:

src/doc/book/getting-started.md

@@ -11,7 +11,7 @@ an Internet connection to run the commands in this section, as we’ll be
 downloading Rust from the Internet.
 
 We’ll be showing off a number of commands using a terminal, and those lines all
-start with `$`. We don't need to type in the `$`s, they are there to indicate
+start with `$`. You don't need to type in the `$`s, they are there to indicate
 the start of each command. We’ll see many tutorials and examples around the web
 that follow this convention: `$` for commands run as our regular user, and `#`
 for commands we should be running as an administrator.
@@ -159,9 +159,11 @@ You should see the version number, commit hash, and commit date.
 If you do, Rust has been installed successfully! Congrats!
 
 If you don't and you're on Windows, check that Rust is in your %PATH% system
-variable. If it isn't, run the installer again, select "Change" on the "Change,
-repair, or remove installation" page and ensure "Add to PATH" is installed on
-the local hard drive.
+variable: `$ echo %PATH%`. If it isn't, run the installer again, select "Change"
+on the "Change, repair, or remove installation" page and ensure "Add to PATH" is
+installed on the local hard drive.  If you need to configure your path manually,
+you can find the Rust executables in a directory like
+`"C:\Program Files\Rust stable GNU 1.x\bin"`.
 
 Rust does not do its own linking, and so you’ll need to have a linker
 installed. Doing so will depend on your specific system, consult its
@@ -339,15 +341,16 @@ On Windows, you'd enter:
 
 ```bash
 $ dir
-main.exe  main.rs
+main.exe
+main.rs
 ```
 
 This shows we have two files: the source code, with an `.rs` extension, and the
 executable (`main.exe` on Windows, `main` everywhere else). All that's left to
 do from here is run the `main` or `main.exe` file, like this:
 
 ```bash
-$ ./main  # or main.exe on Windows
+$ ./main  # or .\main.exe on Windows
 ```
 
 If *main.rs* were your "Hello, world!" program, this would print `Hello,

src/liballoc/rc.rs

@@ -10,7 +10,8 @@
 
 #![allow(deprecated)]
 
-//! Thread-local reference-counted boxes (the `Rc<T>` type).
+//! Unsynchronized reference-counted boxes (the `Rc<T>` type) which are usable
+//! only within a single thread.
 //!
 //! The `Rc<T>` type provides shared ownership of an immutable value.
 //! Destruction is deterministic, and will occur as soon as the last owner is

src/libcore/iter/traits.rs

@@ -371,13 +371,16 @@ pub trait Extend<A> {
 /// Basic usage:
 ///
 /// ```
-/// let numbers = vec![1, 2, 3];
+/// let numbers = vec![1, 2, 3, 4, 5, 6];
 ///
 /// let mut iter = numbers.iter();
 ///
 /// assert_eq!(Some(&1), iter.next());
-/// assert_eq!(Some(&3), iter.next_back());
-/// assert_eq!(Some(&2), iter.next_back());
+/// assert_eq!(Some(&6), iter.next_back());
+/// assert_eq!(Some(&5), iter.next_back());
+/// assert_eq!(Some(&2), iter.next());
+/// assert_eq!(Some(&3), iter.next());
+/// assert_eq!(Some(&4), iter.next());
 /// assert_eq!(None, iter.next());
 /// assert_eq!(None, iter.next_back());
 /// ```
@@ -395,13 +398,16 @@ pub trait DoubleEndedIterator: Iterator {
     /// Basic usage:
     ///
     /// ```
-    /// let numbers = vec![1, 2, 3];
+    /// let numbers = vec![1, 2, 3, 4, 5, 6];
     ///
     /// let mut iter = numbers.iter();
     ///
     /// assert_eq!(Some(&1), iter.next());
-    /// assert_eq!(Some(&3), iter.next_back());
-    /// assert_eq!(Some(&2), iter.next_back());
+    /// assert_eq!(Some(&6), iter.next_back());
+    /// assert_eq!(Some(&5), iter.next_back());
+    /// assert_eq!(Some(&2), iter.next());
+    /// assert_eq!(Some(&3), iter.next());
+    /// assert_eq!(Some(&4), iter.next());
     /// assert_eq!(None, iter.next());
     /// assert_eq!(None, iter.next_back());
     /// ```

src/libpanic_unwind/gcc.rs

@@ -57,6 +57,7 @@
 #![allow(private_no_mangle_fns)]
 
 use core::any::Any;
+use core::ptr;
 use alloc::boxed::Box;
 
 use unwind as uw;
@@ -88,7 +89,7 @@ pub unsafe fn panic(data: Box<Any + Send>) -> u32 {
 }
 
 pub fn payload() -> *mut u8 {
-    0 as *mut u8
+    ptr::null_mut()
 }
 
 pub unsafe fn cleanup(ptr: *mut u8) -> Box<Any + Send> {

src/libpanic_unwind/seh64_gnu.rs

@@ -18,6 +18,7 @@ use alloc::boxed::Box;
 
 use core::any::Any;
 use core::intrinsics;
+use core::ptr;
 use dwarf::eh;
 use windows as c;
 
@@ -50,7 +51,7 @@ pub unsafe fn panic(data: Box<Any + Send>) -> u32 {
 }
 
 pub fn payload() -> *mut u8 {
-    0 as *mut u8
+    ptr::null_mut();
 }
 
 pub unsafe fn cleanup(ptr: *mut u8) -> Box<Any + Send> {

src/librustc_trans/base.rs

@@ -98,6 +98,7 @@ use libc::c_uint;
 use std::ffi::{CStr, CString};
 use std::cell::{Cell, RefCell};
 use std::collections::{HashMap, HashSet};
+use std::ptr;
 use std::str;
 use std::{i8, i16, i32, i64};
 use syntax_pos::{Span, DUMMY_SP};
@@ -2420,7 +2421,7 @@ pub fn create_entry_wrapper(ccx: &CrateContext, sp: Span, main_llfn: ValueRef) {
                                                  start_fn,
                                                  args.as_ptr(),
                                                  args.len() as c_uint,
-                                                 0 as *mut _,
+                                                 ptr::null_mut(),
                                                  noname());
 
             llvm::LLVMBuildRet(bld, result);

src/librustc_trans/builder.rs

@@ -177,7 +177,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
 
         check_call("invoke", llfn, args);
 
-        let bundle = bundle.as_ref().map(|b| b.raw()).unwrap_or(0 as *mut _);
+        let bundle = bundle.as_ref().map(|b| b.raw()).unwrap_or(ptr::null_mut());
 
         unsafe {
             llvm::LLVMRustBuildInvoke(self.llbuilder,
@@ -859,7 +859,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
 
         check_call("call", llfn, args);
 
-        let bundle = bundle.as_ref().map(|b| b.raw()).unwrap_or(0 as *mut _);
+        let bundle = bundle.as_ref().map(|b| b.raw()).unwrap_or(ptr::null_mut());
 
         unsafe {
             llvm::LLVMRustBuildCall(self.llbuilder, llfn, args.as_ptr(),
@@ -961,7 +961,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             self.count_insn("trap");
             llvm::LLVMRustBuildCall(self.llbuilder, t,
                                     args.as_ptr(), args.len() as c_uint,
-                                    0 as *mut _,
+                                    ptr::null_mut(),
                                     noname());
         }
     }
@@ -1000,7 +1000,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                        parent: Option<ValueRef>,
                        args: &[ValueRef]) -> ValueRef {
         self.count_insn("cleanuppad");
-        let parent = parent.unwrap_or(0 as *mut _);
+        let parent = parent.unwrap_or(ptr::null_mut());
         let name = CString::new("cleanuppad").unwrap();
         let ret = unsafe {
             llvm::LLVMRustBuildCleanupPad(self.llbuilder,
@@ -1016,7 +1016,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     pub fn cleanup_ret(&self, cleanup: ValueRef,
                        unwind: Option<BasicBlockRef>) -> ValueRef {
         self.count_insn("cleanupret");
-        let unwind = unwind.unwrap_or(0 as *mut _);
+        let unwind = unwind.unwrap_or(ptr::null_mut());
         let ret = unsafe {
             llvm::LLVMRustBuildCleanupRet(self.llbuilder, cleanup, unwind)
         };
@@ -1052,8 +1052,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                         unwind: Option<BasicBlockRef>,
                         num_handlers: usize) -> ValueRef {
         self.count_insn("catchswitch");
-        let parent = parent.unwrap_or(0 as *mut _);
-        let unwind = unwind.unwrap_or(0 as *mut _);
+        let parent = parent.unwrap_or(ptr::null_mut());
+        let unwind = unwind.unwrap_or(ptr::null_mut());
         let name = CString::new("catchswitch").unwrap();
         let ret = unsafe {
             llvm::LLVMRustBuildCatchSwitch(self.llbuilder, parent, unwind,

src/libstd/io/error.rs

@@ -214,6 +214,30 @@ impl Error {
     }
 
     /// Creates a new instance of an `Error` from a particular OS error code.
+    ///
+    /// # Examples
+    ///
+    /// On Linux:
+    ///
+    /// ```
+    /// # if cfg!(target_os = "linux") {
+    /// use std::io;
+    ///
+    /// let error = io::Error::from_raw_os_error(98);
+    /// assert_eq!(error.kind(), io::ErrorKind::AddrInUse);
+    /// # }
+    /// ```
+    ///
+    /// On Windows:
+    ///
+    /// ```
+    /// # if cfg!(windows) {
+    /// use std::io;
+    ///
+    /// let error = io::Error::from_raw_os_error(10048);
+    /// assert_eq!(error.kind(), io::ErrorKind::AddrInUse);
+    /// # }
+    /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn from_raw_os_error(code: i32) -> Error {
         Error { repr: Repr::Os(code) }

src/libstd/path.rs

@@ -1529,8 +1529,7 @@ impl Path {
 
     /// The final component of the path, if it is a normal file.
     ///
-    /// If the path terminates in `.`, `..`, or consists solely of a root of
-    /// prefix, `file_name` will return `None`.
+    /// If the path terminates in `..`, `file_name` will return `None`.
     ///
     /// # Examples
     ///
@@ -1543,6 +1542,17 @@ impl Path {
     ///
     /// assert_eq!(Some(os_str), path.file_name());
     /// ```
+    ///
+    /// # Other examples
+    ///
+    /// ```
+    /// use std::path::Path;
+    /// use std::ffi::OsStr;
+    ///
+    /// assert_eq!(Some(OsStr::new("foo.txt")), Path::new("foo.txt/.").file_name());
+    /// assert_eq!(Some(OsStr::new("foo.txt")), Path::new("foo.txt/.//").file_name());
+    /// assert_eq!(None, Path::new("foo.txt/..").file_name());
+    /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn file_name(&self) -> Option<&OsStr> {
         self.components().next_back().and_then(|p| {

src/libstd/sync/once.rs

@@ -65,6 +65,7 @@
 // it!
 
 use marker;
+use ptr;
 use sync::atomic::{AtomicUsize, AtomicBool, Ordering};
 use thread::{self, Thread};
 
@@ -297,7 +298,7 @@ impl Once {
                     let mut node = Waiter {
                         thread: Some(thread::current()),
                         signaled: AtomicBool::new(false),
-                        next: 0 as *mut Waiter,
+                        next: ptr::null_mut(),
                     };
                     let me = &mut node as *mut Waiter as usize;
                     assert!(me & STATE_MASK == 0);

src/libstd/sys/common/net.rs

@@ -152,9 +152,19 @@ pub fn lookup_host(host: &str) -> io::Result<LookupHost> {
     init();
 
     let c_host = CString::new(host)?;
+    let hints = c::addrinfo {
+        ai_flags: 0,
+        ai_family: 0,
+        ai_socktype: c::SOCK_STREAM,
+        ai_protocol: 0,
+        ai_addrlen: 0,
+        ai_addr: ptr::null_mut(),
+        ai_canonname: ptr::null_mut(),
+        ai_next: ptr::null_mut()
+    };
     let mut res = ptr::null_mut();
     unsafe {
-        cvt_gai(c::getaddrinfo(c_host.as_ptr(), ptr::null(), ptr::null(),
+        cvt_gai(c::getaddrinfo(c_host.as_ptr(), ptr::null(), &hints,
                                &mut res))?;
         Ok(LookupHost { original: res, cur: res })
     }

src/libstd/sys/unix/os.rs

@@ -227,11 +227,11 @@ pub fn current_exe() -> io::Result<PathBuf> {
                        libc::KERN_PROC_ARGV];
         let mib = mib.as_mut_ptr();
         let mut argv_len = 0;
-        cvt(libc::sysctl(mib, 4, 0 as *mut _, &mut argv_len,
-                         0 as *mut _, 0))?;
+        cvt(libc::sysctl(mib, 4, ptr::null_mut(), &mut argv_len,
+                         ptr::null_mut(), 0))?;
         let mut argv = Vec::<*const libc::c_char>::with_capacity(argv_len as usize);
         cvt(libc::sysctl(mib, 4, argv.as_mut_ptr() as *mut _,
-                         &mut argv_len, 0 as *mut _, 0))?;
+                         &mut argv_len, ptr::null_mut(), 0))?;
         argv.set_len(argv_len as usize);
         if argv[0].is_null() {
             return Err(io::Error::new(io::ErrorKind::Other,

src/libstd/sys/unix/pipe.rs

@@ -14,6 +14,7 @@ use cmp;
 use io;
 use libc::{self, c_int};
 use mem;
+use ptr;
 use sys::cvt_r;
 use sys::fd::FileDesc;
 
@@ -92,8 +93,8 @@ pub fn read2(p1: AnonPipe,
             let mut read: libc::fd_set = mem::zeroed();
             libc::FD_SET(p1.raw(), &mut read);
             libc::FD_SET(p2.raw(), &mut read);
-            libc::select(max + 1, &mut read, 0 as *mut _, 0 as *mut _,
-                         0 as *mut _)
+            libc::select(max + 1, &mut read, ptr::null_mut(), ptr::null_mut(),
+                         ptr::null_mut())
         })?;
 
         // Read as much as we can from each pipe, ignoring EWOULDBLOCK or

src/libstd/sys/unix/process.rs

@@ -96,7 +96,7 @@ impl Command {
         let mut saw_nul = false;
         let program = os2c(program, &mut saw_nul);
         Command {
-            argv: vec![program.as_ptr(), 0 as *const _],
+            argv: vec![program.as_ptr(), ptr::null()],
             program: program,
             args: Vec::new(),
             env: None,
@@ -117,7 +117,7 @@ impl Command {
         // pointer.
         let arg = os2c(arg, &mut self.saw_nul);
         self.argv[self.args.len() + 1] = arg.as_ptr();
-        self.argv.push(0 as *const _);
+        self.argv.push(ptr::null());
 
         // Also make sure we keep track of the owned value to schedule a
         // destructor for this memory.
@@ -134,7 +134,7 @@ impl Command {
                 envp.push(s.as_ptr());
                 map.insert(k, (envp.len() - 1, s));
             }
-            envp.push(0 as *const _);
+            envp.push(ptr::null());
             self.env = Some(map);
             self.envp = Some(envp);
         }
@@ -158,7 +158,7 @@ impl Command {
             Entry::Vacant(e) => {
                 let len = envp.len();
                 envp[len - 1] = new_key.as_ptr();
-                envp.push(0 as *const _);
+                envp.push(ptr::null());
                 e.insert((len - 1, new_key));
             }
         }
@@ -183,7 +183,7 @@ impl Command {
 
     pub fn env_clear(&mut self) {
         self.env = Some(HashMap::new());
-        self.envp = Some(vec![0 as *const _]);
+        self.envp = Some(vec![ptr::null()]);
     }
 
     pub fn cwd(&mut self, dir: &OsStr) {