Rollup of 7 pull requests

README.md

@@ -129,6 +129,9 @@ CALL "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\amd64\vcvars64.
 python x.py build
 ```
 
+If you are seeing build failure when compiling `rustc_binaryen`, make sure the path
+length of the rust folder is not longer than 22 characters.
+
 #### Specifying an ABI
 [specifying-an-abi]: #specifying-an-abi
 

src/liballoc/fmt.rs

@@ -236,6 +236,8 @@
 //! writeln!     // same as write but appends a newline
 //! print!       // the format string is printed to the standard output
 //! println!     // same as print but appends a newline
+//! eprint!      // the format string is printed to the standard error
+//! eprintln!    // same as eprint but appends a newline
 //! format_args! // described below.
 //! ```
 //!
@@ -264,6 +266,11 @@
 //! print!("Hello {}!", "world");
 //! println!("I have a newline {}", "character at the end");
 //! ```
+//! ### `eprint!`
+//!
+//! The [`eprint!`] and [`eprintln!`] macros are identical to
+//! [`print!`] and [`println!`], respectively, except they emit their
+//! output to stderr.
 //!
 //! ### `format_args!`
 //!
@@ -490,7 +497,10 @@
 //! [`writeln!`]: ../../std/macro.writeln.html
 //! [`write_fmt`]: ../../std/io/trait.Write.html#method.write_fmt
 //! [`std::io::Write`]: ../../std/io/trait.Write.html
+//! [`print!`]: ../../std/macro.print.html
 //! [`println!`]: ../../std/macro.println.html
+//! [`eprint!`]: ../../std/macro.eprint.html
+//! [`eprintln!`]: ../../std/macro.eprintln.html
 //! [`write!`]: ../../std/macro.write.html
 //! [`format_args!`]: ../../std/macro.format_args.html
 //! [`fmt::Arguments`]: struct.Arguments.html

src/libcore/marker.rs

@@ -314,7 +314,7 @@ pub trait Copy : Clone {
 ///
 /// For cases when one does need thread-safe interior mutability,
 /// Rust provides [atomic data types], as well as explicit locking via
-/// [`sync::Mutex`][mutex] and [`sync::RWLock`][rwlock]. These types
+/// [`sync::Mutex`][mutex] and [`sync::RwLock`][rwlock]. These types
 /// ensure that any mutation cannot cause data races, hence the types
 /// are `Sync`. Likewise, [`sync::Arc`][arc] provides a thread-safe
 /// analogue of [`Rc`][rc].

src/librustc/middle/lang_items.rs

@@ -40,7 +40,7 @@ macro_rules! language_item_table {
 
 
 enum_from_u32! {
-    #[derive(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
+    #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
     pub enum LangItem {
         $($variant,)*
     }

src/librustc_mir/transform/instcombine.rs

@@ -10,10 +10,10 @@
 
 //! Performs various peephole optimizations.
 
-use rustc::mir::{Location, Lvalue, Mir, Operand, ProjectionElem, Rvalue, Local};
+use rustc::mir::{Constant, Literal, Location, Lvalue, Mir, Operand, ProjectionElem, Rvalue, Local};
 use rustc::mir::visit::{MutVisitor, Visitor};
-use rustc::ty::TyCtxt;
-use rustc::util::nodemap::FxHashSet;
+use rustc::ty::{TyCtxt, TypeVariants};
+use rustc::util::nodemap::{FxHashMap, FxHashSet};
 use rustc_data_structures::indexed_vec::Idx;
 use std::mem;
 use transform::{MirPass, MirSource};
@@ -44,11 +44,11 @@ impl MirPass for InstCombine {
     }
 }
 
-pub struct InstCombineVisitor {
-    optimizations: OptimizationList,
+pub struct InstCombineVisitor<'tcx> {
+    optimizations: OptimizationList<'tcx>,
 }
 
-impl<'tcx> MutVisitor<'tcx> for InstCombineVisitor {
+impl<'tcx> MutVisitor<'tcx> for InstCombineVisitor<'tcx> {
     fn visit_rvalue(&mut self, rvalue: &mut Rvalue<'tcx>, location: Location) {
         if self.optimizations.and_stars.remove(&location) {
             debug!("Replacing `&*`: {:?}", rvalue);
@@ -62,6 +62,11 @@ impl<'tcx> MutVisitor<'tcx> for InstCombineVisitor {
             *rvalue = Rvalue::Use(Operand::Consume(new_lvalue))
         }
 
+        if let Some(constant) = self.optimizations.arrays_lengths.remove(&location) {
+            debug!("Replacing `Len([_; N])`: {:?}", rvalue);
+            *rvalue = Rvalue::Use(Operand::Constant(box constant));
+        }
+
         self.super_rvalue(rvalue, location)
     }
 }
@@ -70,7 +75,7 @@ impl<'tcx> MutVisitor<'tcx> for InstCombineVisitor {
 struct OptimizationFinder<'b, 'a, 'tcx:'a+'b> {
     mir: &'b Mir<'tcx>,
     tcx: TyCtxt<'a, 'tcx, 'tcx>,
-    optimizations: OptimizationList,
+    optimizations: OptimizationList<'tcx>,
 }
 
 impl<'b, 'a, 'tcx:'b> OptimizationFinder<'b, 'a, 'tcx> {
@@ -93,11 +98,23 @@ impl<'b, 'a, 'tcx> Visitor<'tcx> for OptimizationFinder<'b, 'a, 'tcx> {
             }
         }
 
+        if let Rvalue::Len(ref lvalue) = *rvalue {
+            let lvalue_ty = lvalue.ty(&self.mir.local_decls, self.tcx).to_ty(self.tcx);
+            if let TypeVariants::TyArray(_, len) = lvalue_ty.sty {
+                let span = self.mir.source_info(location).span;
+                let ty = self.tcx.types.usize;
+                let literal = Literal::Value { value: len };
+                let constant = Constant { span, ty, literal };
+                self.optimizations.arrays_lengths.insert(location, constant);
+            }
+        }
+
         self.super_rvalue(rvalue, location)
     }
 }
 
 #[derive(Default)]
-struct OptimizationList {
+struct OptimizationList<'tcx> {
     and_stars: FxHashSet<Location>,
+    arrays_lengths: FxHashMap<Location, Constant<'tcx>>,
 }

src/libstd/ffi/c_str.rs

@@ -19,8 +19,10 @@ use memchr;
 use ops;
 use os::raw::c_char;
 use ptr;
+use rc::Rc;
 use slice;
 use str::{self, Utf8Error};
+use sync::Arc;
 use sys;
 
 /// A type representing an owned, C-compatible, nul-terminated string with no nul bytes in the
@@ -704,6 +706,42 @@ impl From<CString> for Box<CStr> {
     }
 }
 
+#[stable(feature = "shared_from_slice2", since = "1.23.0")]
+impl From<CString> for Arc<CStr> {
+    #[inline]
+    fn from(s: CString) -> Arc<CStr> {
+        let arc: Arc<[u8]> = Arc::from(s.into_inner());
+        unsafe { Arc::from_raw(Arc::into_raw(arc) as *const CStr) }
+    }
+}
+
+#[stable(feature = "shared_from_slice2", since = "1.23.0")]
+impl<'a> From<&'a CStr> for Arc<CStr> {
+    #[inline]
+    fn from(s: &CStr) -> Arc<CStr> {
+        let arc: Arc<[u8]> = Arc::from(s.to_bytes_with_nul());
+        unsafe { Arc::from_raw(Arc::into_raw(arc) as *const CStr) }
+    }
+}
+
+#[stable(feature = "shared_from_slice2", since = "1.23.0")]
+impl From<CString> for Rc<CStr> {
+    #[inline]
+    fn from(s: CString) -> Rc<CStr> {
+        let rc: Rc<[u8]> = Rc::from(s.into_inner());
+        unsafe { Rc::from_raw(Rc::into_raw(rc) as *const CStr) }
+    }
+}
+
+#[stable(feature = "shared_from_slice2", since = "1.23.0")]
+impl<'a> From<&'a CStr> for Rc<CStr> {
+    #[inline]
+    fn from(s: &CStr) -> Rc<CStr> {
+        let rc: Rc<[u8]> = Rc::from(s.to_bytes_with_nul());
+        unsafe { Rc::from_raw(Rc::into_raw(rc) as *const CStr) }
+    }
+}
+
 #[stable(feature = "default_box_extra", since = "1.17.0")]
 impl Default for Box<CStr> {
     fn default() -> Box<CStr> {
@@ -1201,6 +1239,8 @@ mod tests {
     use borrow::Cow::{Borrowed, Owned};
     use hash::{Hash, Hasher};
     use collections::hash_map::DefaultHasher;
+    use rc::Rc;
+    use sync::Arc;
 
     #[test]
     fn c_to_rust() {
@@ -1337,4 +1377,21 @@ mod tests {
         let boxed = <Box<CStr>>::default();
         assert_eq!(boxed.to_bytes_with_nul(), &[0]);
     }
+
+    #[test]
+    fn into_rc() {
+        let orig: &[u8] = b"Hello, world!\0";
+        let cstr = CStr::from_bytes_with_nul(orig).unwrap();
+        let rc: Rc<CStr> = Rc::from(cstr);
+        let arc: Arc<CStr> = Arc::from(cstr);
+
+        assert_eq!(&*rc, cstr);
+        assert_eq!(&*arc, cstr);
+
+        let rc2: Rc<CStr> = Rc::from(cstr.to_owned());
+        let arc2: Arc<CStr> = Arc::from(cstr.to_owned());
+
+        assert_eq!(&*rc2, cstr);
+        assert_eq!(&*arc2, cstr);
+    }
 }

src/libstd/ffi/os_str.rs

@@ -13,6 +13,8 @@ use fmt;
 use ops;
 use cmp;
 use hash::{Hash, Hasher};
+use rc::Rc;
+use sync::Arc;
 
 use sys::os_str::{Buf, Slice};
 use sys_common::{AsInner, IntoInner, FromInner};
@@ -592,6 +594,42 @@ impl From<OsString> for Box<OsStr> {
     }
 }
 
+#[stable(feature = "shared_from_slice2", since = "1.23.0")]
+impl From<OsString> for Arc<OsStr> {
+    #[inline]
+    fn from(s: OsString) -> Arc<OsStr> {
+        let arc = s.inner.into_arc();
+        unsafe { Arc::from_raw(Arc::into_raw(arc) as *const OsStr) }
+    }
+}
+
+#[stable(feature = "shared_from_slice2", since = "1.23.0")]
+impl<'a> From<&'a OsStr> for Arc<OsStr> {
+    #[inline]
+    fn from(s: &OsStr) -> Arc<OsStr> {
+        let arc = s.inner.into_arc();
+        unsafe { Arc::from_raw(Arc::into_raw(arc) as *const OsStr) }
+    }
+}
+
+#[stable(feature = "shared_from_slice2", since = "1.23.0")]
+impl From<OsString> for Rc<OsStr> {
+    #[inline]
+    fn from(s: OsString) -> Rc<OsStr> {
+        let rc = s.inner.into_rc();
+        unsafe { Rc::from_raw(Rc::into_raw(rc) as *const OsStr) }
+    }
+}
+
+#[stable(feature = "shared_from_slice2", since = "1.23.0")]
+impl<'a> From<&'a OsStr> for Rc<OsStr> {
+    #[inline]
+    fn from(s: &OsStr) -> Rc<OsStr> {
+        let rc = s.inner.into_rc();
+        unsafe { Rc::from_raw(Rc::into_raw(rc) as *const OsStr) }
+    }
+}
+
 #[stable(feature = "box_default_extra", since = "1.17.0")]
 impl Default for Box<OsStr> {
     fn default() -> Box<OsStr> {
@@ -793,6 +831,9 @@ mod tests {
     use super::*;
     use sys_common::{AsInner, IntoInner};
 
+    use rc::Rc;
+    use sync::Arc;
+
     #[test]
     fn test_os_string_with_capacity() {
         let os_string = OsString::with_capacity(0);
@@ -935,4 +976,21 @@ mod tests {
         assert_eq!(os_str, os_string);
         assert!(os_string.capacity() >= 123);
     }
+
+    #[test]
+    fn into_rc() {
+        let orig = "Hello, world!";
+        let os_str = OsStr::new(orig);
+        let rc: Rc<OsStr> = Rc::from(os_str);
+        let arc: Arc<OsStr> = Arc::from(os_str);
+
+        assert_eq!(&*rc, os_str);
+        assert_eq!(&*arc, os_str);
+
+        let rc2: Rc<OsStr> = Rc::from(os_str.to_owned());
+        let arc2: Arc<OsStr> = Arc::from(os_str.to_owned());
+
+        assert_eq!(&*rc2, os_str);
+        assert_eq!(&*arc2, os_str);
+    }
 }

src/libstd/io/mod.rs

@@ -441,7 +441,7 @@ fn read_to_end<R: Read + ?Sized>(r: &mut R, buf: &mut Vec<u8>) -> Result<usize>
 /// # }
 /// ```
 ///
-/// Read from `&str` because [`&[u8]`] implements [`Read`]:
+/// Read from `&str` because [`&[u8]`] implements `Read`:
 ///
 /// ```
 /// # use std::io;
@@ -465,7 +465,6 @@ fn read_to_end<R: Read + ?Sized>(r: &mut R, buf: &mut Vec<u8>) -> Result<usize>
 /// [`BufRead`]: trait.BufRead.html
 /// [`BufReader`]: struct.BufReader.html
 /// [`&[u8]`]: primitive.slice.html
-///
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(spotlight)]
 pub trait Read {