Rollup of 12 pull requests

src/bootstrap/dist.rs

@@ -23,7 +23,7 @@ use crate::builder::{Builder, RunConfig, ShouldRun, Step};
 use crate::compile;
 use crate::tool::{self, Tool};
 use crate::cache::{INTERNER, Interned};
-use time;
+use time::{self, Timespec};
 
 pub fn pkgname(builder: &Builder, component: &str) -> String {
     if component == "cargo" {
@@ -528,7 +528,19 @@ impl Step for Rustc {
             t!(fs::create_dir_all(image.join("share/man/man1")));
             let man_src = builder.src.join("src/doc/man");
             let man_dst = image.join("share/man/man1");
-            let month_year = t!(time::strftime("%B %Y", &time::now()));
+
+            // Reproducible builds: If SOURCE_DATE_EPOCH is set, use that as the time.
+            let time = env::var("SOURCE_DATE_EPOCH")
+                .map(|timestamp| {
+                    let epoch = timestamp.parse().map_err(|err| {
+                        format!("could not parse SOURCE_DATE_EPOCH: {}", err)
+                    }).unwrap();
+
+                    time::at(Timespec::new(epoch, 0))
+                })
+                .unwrap_or_else(|_| time::now());
+
+            let month_year = t!(time::strftime("%B %Y", &time));
             // don't use our `bootstrap::util::{copy, cp_r}`, because those try
             // to hardlink, and we don't want to edit the source templates
             for file_entry in builder.read_dir(&man_src) {

src/doc/index.md

@@ -71,6 +71,10 @@ accomplishing various tasks.
   </form>
 </div>
 
+## The Edition Guide
+
+[The Edition Guide](edition-guide/index.html) describes the Rust editions.
+
 ## The Rustc Book
 
 [The Rustc Book](rustc/index.html) describes the Rust compiler, `rustc`.

src/liballoc/rc.rs

@@ -433,6 +433,27 @@ impl<T: ?Sized> Rc<T> {
         }
     }
 
+    /// Consumes the `Rc`, returning the wrapped pointer as `NonNull<T>`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(rc_into_raw_non_null)]
+    ///
+    /// use std::rc::Rc;
+    ///
+    /// let x = Rc::new(10);
+    /// let ptr = Rc::into_raw_non_null(x);
+    /// let deref = unsafe { *ptr.as_ref() };
+    /// assert_eq!(deref, 10);
+    /// ```
+    #[unstable(feature = "rc_into_raw_non_null", issue = "47336")]
+    #[inline]
+    pub fn into_raw_non_null(this: Self) -> NonNull<T> {
+        // safe because Rc guarantees its pointer is non-null
+        unsafe { NonNull::new_unchecked(Rc::into_raw(this) as *mut _) }
+    }
+
     /// Creates a new [`Weak`][weak] pointer to this value.
     ///
     /// [weak]: struct.Weak.html

src/liballoc/sync.rs

@@ -413,6 +413,27 @@ impl<T: ?Sized> Arc<T> {
         }
     }
 
+    /// Consumes the `Arc`, returning the wrapped pointer as `NonNull<T>`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(rc_into_raw_non_null)]
+    ///
+    /// use std::sync::Arc;
+    ///
+    /// let x = Arc::new(10);
+    /// let ptr = Arc::into_raw_non_null(x);
+    /// let deref = unsafe { *ptr.as_ref() };
+    /// assert_eq!(deref, 10);
+    /// ```
+    #[unstable(feature = "rc_into_raw_non_null", issue = "47336")]
+    #[inline]
+    pub fn into_raw_non_null(this: Self) -> NonNull<T> {
+        // safe because Arc guarantees its pointer is non-null
+        unsafe { NonNull::new_unchecked(Arc::into_raw(this) as *mut _) }
+    }
+
     /// Creates a new [`Weak`][weak] pointer to this value.
     ///
     /// [weak]: struct.Weak.html

src/libcore/str/mod.rs

@@ -3489,6 +3489,8 @@ impl str {
     ///
     /// assert_eq!("Hello\tworld", s.trim());
     /// ```
+    #[must_use = "this returns the trimmed string as a slice, \
+                  without modifying the original"]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn trim(&self) -> &str {
         self.trim_matches(|c: char| c.is_whitespace())
@@ -3524,6 +3526,8 @@ impl str {
     /// let s = "  עברית  ";
     /// assert!(Some('ע') == s.trim_start().chars().next());
     /// ```
+    #[must_use = "this returns the trimmed string as a new slice, \
+                  without modifying the original"]
     #[stable(feature = "trim_direction", since = "1.30.0")]
     pub fn trim_start(&self) -> &str {
         self.trim_start_matches(|c: char| c.is_whitespace())
@@ -3559,6 +3563,8 @@ impl str {
     /// let s = "  עברית  ";
     /// assert!(Some('ת') == s.trim_end().chars().rev().next());
     /// ```
+    #[must_use = "this returns the trimmed string as a new slice, \
+                  without modifying the original"]
     #[stable(feature = "trim_direction", since = "1.30.0")]
     pub fn trim_end(&self) -> &str {
         self.trim_end_matches(|c: char| c.is_whitespace())
@@ -3661,6 +3667,8 @@ impl str {
     /// ```
     /// assert_eq!("1foo1barXX".trim_matches(|c| c == '1' || c == 'X'), "foo1bar");
     /// ```
+    #[must_use = "this returns the trimmed string as a new slice, \
+                  without modifying the original"]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn trim_matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> &'a str
         where P::Searcher: DoubleEndedSearcher<'a>
@@ -3706,6 +3714,8 @@ impl str {
     /// let x: &[_] = &['1', '2'];
     /// assert_eq!("12foo1bar12".trim_start_matches(x), "foo1bar12");
     /// ```
+    #[must_use = "this returns the trimmed string as a new slice, \
+                  without modifying the original"]
     #[stable(feature = "trim_direction", since = "1.30.0")]
     pub fn trim_start_matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> &'a str {
         let mut i = self.len();
@@ -3749,6 +3759,8 @@ impl str {
     /// ```
     /// assert_eq!("1fooX".trim_end_matches(|c| c == '1' || c == 'X'), "1foo");
     /// ```
+    #[must_use = "this returns the trimmed string as a new slice, \
+                  without modifying the original"]
     #[stable(feature = "trim_direction", since = "1.30.0")]
     pub fn trim_end_matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> &'a str
         where P::Searcher: ReverseSearcher<'a>
@@ -3774,10 +3786,10 @@ impl str {
     ///
     /// # Text directionality
     ///
-    /// A string is a sequence of bytes. 'Left' in this context means the first
-    /// position of that byte string; for a language like Arabic or Hebrew
-    /// which are 'right to left' rather than 'left to right', this will be
-    /// the _right_ side, not the left.
+    /// A string is a sequence of bytes. `start` in this context means the first
+    /// position of that byte string; for a left-to-right language like English or
+    /// Russian, this will be left side; and for right-to-left languages like
+    /// like Arabic or Hebrew, this will be the right side.
     ///
     /// # Examples
     ///
@@ -3806,10 +3818,10 @@ impl str {
     ///
     /// # Text directionality
     ///
-    /// A string is a sequence of bytes. 'Right' in this context means the last
-    /// position of that byte string; for a language like Arabic or Hebrew
-    /// which are 'right to left' rather than 'left to right', this will be
-    /// the _left_ side, not the right.
+    /// A string is a sequence of bytes. `end` in this context means the last
+    /// position of that byte string; for a left-to-right language like English or
+    /// Russian, this will be right side; and for right-to-left languages like
+    /// like Arabic or Hebrew, this will be the left side.
     ///
     /// # Examples
     ///

src/librustc/mir/interpret/value.rs

@@ -14,7 +14,7 @@ pub struct RawConst<'tcx> {
 }
 
 /// Represents a constant value in Rust. Scalar and ScalarPair are optimizations which
-/// matches the LocalValue optimizations for easy conversions between Value and ConstValue.
+/// matches the LocalState optimizations for easy conversions between Value and ConstValue.
 #[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord, RustcEncodable, RustcDecodable, Hash)]
 pub enum ConstValue<'tcx> {
     /// Used only for types with layout::abi::Scalar ABI and ZSTs

src/librustc_codegen_llvm/llvm_util.rs

@@ -147,6 +147,7 @@ const X86_WHITELIST: &[(&str, Option<&str>)] = &[
     ("fxsr", None),
     ("lzcnt", None),
     ("mmx", Some("mmx_target_feature")),
+    ("movbe", Some("movbe_target_feature")),
     ("pclmulqdq", None),
     ("popcnt", None),
     ("rdrand", None),

src/librustc_mir/dataflow/impls/borrows.rs

@@ -215,8 +215,8 @@ impl<'a, 'gcx, 'tcx> Borrows<'a, 'gcx, 'tcx> {
             if places_conflict::places_conflict(
                 self.tcx,
                 self.mir,
-                place,
                 &borrow_data.borrowed_place,
+                place,
                 places_conflict::PlaceConflictBias::NoOverlap,
             ) {
                 debug!(

src/librustc_mir/interpret/eval_context.rs

@@ -76,8 +76,7 @@ pub struct Frame<'mir, 'tcx: 'mir, Tag=(), Extra=()> {
     /// The locals are stored as `Option<Value>`s.
     /// `None` represents a local that is currently dead, while a live local
     /// can either directly contain `Scalar` or refer to some part of an `Allocation`.
-    pub locals: IndexVec<mir::Local, LocalValue<Tag>>,
-    pub local_layouts: IndexVec<mir::Local, Cell<Option<TyLayout<'tcx>>>>,
+    pub locals: IndexVec<mir::Local, LocalState<'tcx, Tag>>,
 
     ////////////////////////////////////////////////////////////////////////////////
     // Current position within the function
@@ -106,7 +105,15 @@ pub enum StackPopCleanup {
     None { cleanup: bool },
 }
 
-// State of a local variable
+/// State of a local variable including a memoized layout
+#[derive(Clone, PartialEq, Eq)]
+pub struct LocalState<'tcx, Tag=(), Id=AllocId> {
+    pub state: LocalValue<Tag, Id>,
+    /// Don't modify if `Some`, this is only used to prevent computing the layout twice
+    pub layout: Cell<Option<TyLayout<'tcx>>>,
+}
+
+/// State of a local variable
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub enum LocalValue<Tag=(), Id=AllocId> {
     Dead,
@@ -117,16 +124,16 @@ pub enum LocalValue<Tag=(), Id=AllocId> {
     Live(Operand<Tag, Id>),
 }
 
-impl<'tcx, Tag> LocalValue<Tag> {
+impl<'tcx, Tag> LocalState<'tcx, Tag> {
     pub fn access(&self) -> EvalResult<'tcx, &Operand<Tag>> {
-        match self {
+        match self.state {
             LocalValue::Dead => err!(DeadLocal),
             LocalValue::Live(ref val) => Ok(val),
         }
     }
 
     pub fn access_mut(&mut self) -> EvalResult<'tcx, &mut Operand<Tag>> {
-        match self {
+        match self.state {
             LocalValue::Dead => err!(DeadLocal),
             LocalValue::Live(ref mut val) => Ok(val),
         }
@@ -310,17 +317,21 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tc
     pub fn layout_of_local(
         &self,
         frame: &Frame<'mir, 'tcx, M::PointerTag, M::FrameExtra>,
-        local: mir::Local
+        local: mir::Local,
+        layout: Option<TyLayout<'tcx>>,
     ) -> EvalResult<'tcx, TyLayout<'tcx>> {
-        let cell = &frame.local_layouts[local];
-        if cell.get().is_none() {
-            let local_ty = frame.mir.local_decls[local].ty;
-            let local_ty = self.monomorphize_with_substs(local_ty, frame.instance.substs);
-            let layout = self.layout_of(local_ty)?;
-            cell.set(Some(layout));
+        match frame.locals[local].layout.get() {
+            None => {
+                let layout = ::interpret::operand::from_known_layout(layout, || {
+                    let local_ty = frame.mir.local_decls[local].ty;
+                    let local_ty = self.monomorphize_with_substs(local_ty, frame.instance.substs);
+                    self.layout_of(local_ty)
+                })?;
+                frame.locals[local].layout.set(Some(layout));
+                Ok(layout)
+            }
+            Some(layout) => Ok(layout),
         }
-
-        Ok(cell.get().unwrap())
     }
 
     pub fn str_to_immediate(&mut self, s: &str) -> EvalResult<'tcx, Immediate<M::PointerTag>> {
@@ -454,7 +465,6 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tc
             // empty local array, we fill it in below, after we are inside the stack frame and
             // all methods actually know about the frame
             locals: IndexVec::new(),
-            local_layouts: IndexVec::from_elem_n(Default::default(), mir.local_decls.len()),
             span,
             instance,
             stmt: 0,
@@ -466,12 +476,16 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tc
             // We put some marker immediate into the locals that we later want to initialize.
             // This can be anything except for LocalValue::Dead -- because *that* is the
             // value we use for things that we know are initially dead.
-            let dummy =
-                LocalValue::Live(Operand::Immediate(Immediate::Scalar(ScalarMaybeUndef::Undef)));
+            let dummy = LocalState {
+                state: LocalValue::Live(Operand::Immediate(Immediate::Scalar(
+                    ScalarMaybeUndef::Undef,
+                ))),
+                layout: Cell::new(None),
+            };
             let mut locals = IndexVec::from_elem(dummy, &mir.local_decls);
             // Return place is handled specially by the `eval_place` functions, and the
             // entry in `locals` should never be used. Make it dead, to be sure.
-            locals[mir::RETURN_PLACE] = LocalValue::Dead;
+            locals[mir::RETURN_PLACE].state = LocalValue::Dead;
             // Now mark those locals as dead that we do not want to initialize
             match self.tcx.describe_def(instance.def_id()) {
                 // statics and constants don't have `Storage*` statements, no need to look for them
@@ -484,7 +498,7 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tc
                             match stmt.kind {
                                 StorageLive(local) |
                                 StorageDead(local) => {
-                                    locals[local] = LocalValue::Dead;
+                                    locals[local].state = LocalValue::Dead;
                                 }
                                 _ => {}
                             }
@@ -494,11 +508,13 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tc
             }
             // Finally, properly initialize all those that still have the dummy value
             for (idx, local) in locals.iter_enumerated_mut() {
-                match *local {
+                match local.state {
                     LocalValue::Live(_) => {
-                        // This needs to be peoperly initialized.
-                        let layout = self.layout_of_local(self.frame(), idx)?;
-                        *local = LocalValue::Live(self.uninit_operand(layout)?);
+                        // This needs to be properly initialized.
+                        let ty = self.monomorphize(mir.local_decls[idx].ty)?;
+                        let layout = self.layout_of(ty)?;
+                        local.state = LocalValue::Live(self.uninit_operand(layout)?);
+                        local.layout = Cell::new(Some(layout));
                     }
                     LocalValue::Dead => {
                         // Nothing to do
@@ -543,7 +559,7 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tc
         }
         // Deallocate all locals that are backed by an allocation.
         for local in frame.locals {
-            self.deallocate_local(local)?;
+            self.deallocate_local(local.state)?;
         }
         // Validate the return value. Do this after deallocating so that we catch dangling
         // references.
@@ -591,10 +607,10 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tc
         assert!(local != mir::RETURN_PLACE, "Cannot make return place live");
         trace!("{:?} is now live", local);
 
-        let layout = self.layout_of_local(self.frame(), local)?;
+        let layout = self.layout_of_local(self.frame(), local, None)?;
         let init = LocalValue::Live(self.uninit_operand(layout)?);
         // StorageLive *always* kills the value that's currently stored
-        Ok(mem::replace(&mut self.frame_mut().locals[local], init))
+        Ok(mem::replace(&mut self.frame_mut().locals[local].state, init))
     }
 
     /// Returns the old value of the local.
@@ -603,7 +619,7 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tc
         assert!(local != mir::RETURN_PLACE, "Cannot make return place dead");
         trace!("{:?} is now dead", local);
 
-        mem::replace(&mut self.frame_mut().locals[local], LocalValue::Dead)
+        mem::replace(&mut self.frame_mut().locals[local].state, LocalValue::Dead)
     }
 
     pub(super) fn deallocate_local(

src/librustc_mir/interpret/mod.rs

@@ -18,7 +18,7 @@ mod visitor;
 pub use rustc::mir::interpret::*; // have all the `interpret` symbols in one place: here
 
 pub use self::eval_context::{
-    EvalContext, Frame, StackPopCleanup, LocalValue,
+    EvalContext, Frame, StackPopCleanup, LocalState, LocalValue,
 };
 
 pub use self::place::{Place, PlaceTy, MemPlace, MPlaceTy};