Merge pull request #38377 from brson/beta-next

[beta] backports and bump

Author: alexcrichton

mk/main.mk

@@ -18,7 +18,7 @@ CFG_RELEASE_NUM=1.14.0
 # An optional number to put after the label, e.g. '.2' -> '-beta.2'
 # NB Make sure it starts with a dot to conform to semver pre-release
 # versions (section 9)
-CFG_PRERELEASE_VERSION=.3
+CFG_PRERELEASE_VERSION=.4
 
 ifeq ($(CFG_RELEASE_CHANNEL),stable)
 # This is the normal semver version string, e.g. "0.12.0", "0.12.0-nightly"

src/doc/book/syntax-index.md

@@ -94,6 +94,7 @@
 * `|=` (`var |= expr`): bitwise or & assignment. Overloadable (`BitOrAssign`).
 * `||` (`expr || expr`): logical or.
 * `_`: "ignored" pattern binding (see [Patterns (Ignoring bindings)]). Also used to make integer-literals readable (see [Reference (Integer literals)]).
+* `?` (`expr?`): Error propagation. Returns early when `Err(_)` is encountered, unwraps otherwise. Similar to the [`try!` macro].
 
 ## Other Syntax
 
@@ -210,6 +211,7 @@
 [Functions]: functions.html
 [Generics]: generics.html
 [Iterators]: iterators.html
+[`try!` macro]: error-handling.html#the-try-macro
 [Lifetimes]: lifetimes.html
 [Loops (`for`)]: loops.html#for
 [Loops (`loop`)]: loops.html#loop

src/doc/reference.md

@@ -2858,8 +2858,8 @@ assert_eq!(x, y);
 
 ### Unary operator expressions
 
-Rust defines the following unary operators. They are all written as prefix operators,
-before the expression they apply to.
+Rust defines the following unary operators. With the exception of `?`, they are
+all written as prefix operators, before the expression they apply to.
 
 * `-`
   : Negation. Signed integer types and floating-point types support negation. It
@@ -2888,6 +2888,10 @@ before the expression they apply to.
     If the `&` or `&mut` operators are applied to an rvalue, a
     temporary value is created; the lifetime of this temporary value
     is defined by [syntactic rules](#temporary-lifetimes).
+* `?`
+  : Propagating errors if applied to `Err(_)` and unwrapping if
+    applied to `Ok(_)`. Only works on the `Result<T, E>` type,
+    and written in postfix notation.
 
 ### Binary operator expressions
 

src/libcore/macros.rs

@@ -520,15 +520,15 @@ macro_rules! unimplemented {
 /// into libsyntax itself.
 ///
 /// For more information, see documentation for `std`'s macros.
-#[cfg(dox)]
-pub mod builtin {
+mod builtin {
     /// The core macro for formatted string creation & output.
     ///
     /// For more information, see the documentation for [`std::format_args!`].
     ///
     /// [`std::format_args!`]: ../std/macro.format_args.html
     #[stable(feature = "rust1", since = "1.0.0")]
     #[macro_export]
+    #[cfg(dox)]
     macro_rules! format_args { ($fmt:expr, $($args:tt)*) => ({
         /* compiler built-in */
     }) }
@@ -540,6 +540,7 @@ pub mod builtin {
     /// [`std::env!`]: ../std/macro.env.html
     #[stable(feature = "rust1", since = "1.0.0")]
     #[macro_export]
+    #[cfg(dox)]
     macro_rules! env { ($name:expr) => ({ /* compiler built-in */ }) }
 
     /// Optionally inspect an environment variable at compile time.
@@ -549,6 +550,7 @@ pub mod builtin {
     /// [`std::option_env!`]: ../std/macro.option_env.html
     #[stable(feature = "rust1", since = "1.0.0")]
     #[macro_export]
+    #[cfg(dox)]
     macro_rules! option_env { ($name:expr) => ({ /* compiler built-in */ }) }
 
     /// Concatenate identifiers into one identifier.
@@ -558,6 +560,7 @@ pub mod builtin {
     /// [`std::concat_idents!`]: ../std/macro.concat_idents.html
     #[unstable(feature = "concat_idents_macro", issue = "29599")]
     #[macro_export]
+    #[cfg(dox)]
     macro_rules! concat_idents {
         ($($e:ident),*) => ({ /* compiler built-in */ })
     }
@@ -569,6 +572,7 @@ pub mod builtin {
     /// [`std::concat!`]: ../std/macro.concat.html
     #[stable(feature = "rust1", since = "1.0.0")]
     #[macro_export]
+    #[cfg(dox)]
     macro_rules! concat { ($($e:expr),*) => ({ /* compiler built-in */ }) }
 
     /// A macro which expands to the line number on which it was invoked.
@@ -578,6 +582,7 @@ pub mod builtin {
     /// [`std::line!`]: ../std/macro.line.html
     #[stable(feature = "rust1", since = "1.0.0")]
     #[macro_export]
+    #[cfg(dox)]
     macro_rules! line { () => ({ /* compiler built-in */ }) }
 
     /// A macro which expands to the column number on which it was invoked.
@@ -587,6 +592,7 @@ pub mod builtin {
     /// [`std::column!`]: ../std/macro.column.html
     #[stable(feature = "rust1", since = "1.0.0")]
     #[macro_export]
+    #[cfg(dox)]
     macro_rules! column { () => ({ /* compiler built-in */ }) }
 
     /// A macro which expands to the file name from which it was invoked.
@@ -596,6 +602,7 @@ pub mod builtin {
     /// [`std::file!`]: ../std/macro.file.html
     #[stable(feature = "rust1", since = "1.0.0")]
     #[macro_export]
+    #[cfg(dox)]
     macro_rules! file { () => ({ /* compiler built-in */ }) }
 
     /// A macro which stringifies its argument.
@@ -605,6 +612,7 @@ pub mod builtin {
     /// [`std::stringify!`]: ../std/macro.stringify.html
     #[stable(feature = "rust1", since = "1.0.0")]
     #[macro_export]
+    #[cfg(dox)]
     macro_rules! stringify { ($t:tt) => ({ /* compiler built-in */ }) }
 
     /// Includes a utf8-encoded file as a string.
@@ -614,6 +622,7 @@ pub mod builtin {
     /// [`std::include_str!`]: ../std/macro.include_str.html
     #[stable(feature = "rust1", since = "1.0.0")]
     #[macro_export]
+    #[cfg(dox)]
     macro_rules! include_str { ($file:expr) => ({ /* compiler built-in */ }) }
 
     /// Includes a file as a reference to a byte array.
@@ -623,6 +632,7 @@ pub mod builtin {
     /// [`std::include_bytes!`]: ../std/macro.include_bytes.html
     #[stable(feature = "rust1", since = "1.0.0")]
     #[macro_export]
+    #[cfg(dox)]
     macro_rules! include_bytes { ($file:expr) => ({ /* compiler built-in */ }) }
 
     /// Expands to a string that represents the current module path.
@@ -632,6 +642,7 @@ pub mod builtin {
     /// [`std::module_path!`]: ../std/macro.module_path.html
     #[stable(feature = "rust1", since = "1.0.0")]
     #[macro_export]
+    #[cfg(dox)]
     macro_rules! module_path { () => ({ /* compiler built-in */ }) }
 
     /// Boolean evaluation of configuration flags.
@@ -641,6 +652,7 @@ pub mod builtin {
     /// [`std::cfg!`]: ../std/macro.cfg.html
     #[stable(feature = "rust1", since = "1.0.0")]
     #[macro_export]
+    #[cfg(dox)]
     macro_rules! cfg { ($($cfg:tt)*) => ({ /* compiler built-in */ }) }
 
     /// Parse a file as an expression or an item according to the context.
@@ -650,5 +662,6 @@ pub mod builtin {
     /// [`std::include!`]: ../std/macro.include.html
     #[stable(feature = "rust1", since = "1.0.0")]
     #[macro_export]
+    #[cfg(dox)]
     macro_rules! include { ($file:expr) => ({ /* compiler built-in */ }) }
 }

src/librustc/traits/project.rs

@@ -1222,8 +1222,8 @@ fn confirm_closure_candidate<'cx, 'gcx, 'tcx>(
                                obligation,
                                &closure_type.sig,
                                util::TupleArgumentsFlag::No)
-        .with_addl_obligations(obligations)
         .with_addl_obligations(vtable.nested)
+        .with_addl_obligations(obligations)
 }
 
 fn confirm_callable_candidate<'cx, 'gcx, 'tcx>(

src/librustc_trans/adt.rs

@@ -689,9 +689,8 @@ pub fn trans_const<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, t: Ty<'tcx>, discr: D
             let lldiscr = C_integral(Type::from_integer(ccx, d), discr.0 as u64, true);
             let mut vals_with_discr = vec![lldiscr];
             vals_with_discr.extend_from_slice(vals);
-            let mut contents = build_const_struct(ccx, &variant,
-                &vals_with_discr[..]);
-            let needed_padding = l.size(dl).bytes() - variant.min_size.bytes();
+            let mut contents = build_const_struct(ccx, &variant, &vals_with_discr[..]);
+            let needed_padding = l.size(dl).bytes() - variant.stride().bytes();
             if needed_padding > 0 {
                 contents.push(padding(ccx, needed_padding));
             }
@@ -704,8 +703,7 @@ pub fn trans_const<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, t: Ty<'tcx>, discr: D
         }
         layout::Univariant { ref variant, .. } => {
             assert_eq!(discr, Disr(0));
-            let contents = build_const_struct(ccx,
-                &variant, vals);
+            let contents = build_const_struct(ccx, &variant, vals);
             C_struct(ccx, &contents[..], variant.packed)
         }
         layout::Vector { .. } => {
@@ -722,17 +720,15 @@ pub fn trans_const<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, t: Ty<'tcx>, discr: D
         }
         layout::StructWrappedNullablePointer { ref nonnull, nndiscr, .. } => {
             if discr.0 == nndiscr {
-                C_struct(ccx, &build_const_struct(ccx, &nonnull, vals),
-                         false)
+                C_struct(ccx, &build_const_struct(ccx, &nonnull, vals), false)
             } else {
                 let fields = compute_fields(ccx, t, nndiscr as usize, false);
                 let vals = fields.iter().map(|&ty| {
                     // Always use null even if it's not the `discrfield`th
                     // field; see #8506.
                     C_null(type_of::sizing_type_of(ccx, ty))
                 }).collect::<Vec<ValueRef>>();
-                C_struct(ccx, &build_const_struct(ccx, &nonnull, &vals[..]),
-                         false)
+                C_struct(ccx, &build_const_struct(ccx, &nonnull, &vals[..]), false)
             }
         }
         _ => bug!("trans_const: cannot handle type {} repreented as {:#?}", t, l)

src/test/run-pass/issue-38002.rs

@@ -0,0 +1,45 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Check that constant ADTs are translated OK, part k of N.
+
+#![feature(slice_patterns)]
+
+enum Bar {
+    C
+}
+
+enum Foo {
+    A {},
+    B {
+        y: usize,
+        z: Bar
+    },
+}
+
+const LIST: [(usize, Foo); 2] = [
+    (51, Foo::B { y: 42, z: Bar::C }),
+    (52, Foo::B { y: 45, z: Bar::C }),
+];
+
+pub fn main() {
+    match LIST {
+        [
+            (51, Foo::B { y: 42, z: Bar::C }),
+            (52, Foo::B { y: 45, z: Bar::C })
+        ] => {}
+        _ => {
+            // I would want to print the enum here, but if
+            // the discriminant is garbage this causes an
+            // `unreachable` and silent process exit.
+            panic!("trivial match failed")
+        }
+    }
+}

src/test/run-pass/issue-38033.rs

@@ -0,0 +1,88 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::marker;
+use std::mem;
+
+fn main() {
+    let workers = (0..0).map(|_| result::<u32, ()>());
+    drop(join_all(workers).poll());
+}
+
+trait Future {
+    type Item;
+    type Error;
+
+    fn poll(&mut self) -> Result<Self::Item, Self::Error>;
+}
+
+trait IntoFuture {
+    type Future: Future<Item=Self::Item, Error=Self::Error>;
+    type Item;
+    type Error;
+
+    fn into_future(self) -> Self::Future;
+}
+
+impl<F: Future> IntoFuture for F {
+    type Future = F;
+    type Item = F::Item;
+    type Error = F::Error;
+
+    fn into_future(self) -> F {
+        self
+    }
+}
+
+struct FutureResult<T, E> {
+    _inner: marker::PhantomData<(T, E)>,
+}
+
+fn result<T, E>() -> FutureResult<T, E> {
+    loop {}
+}
+
+impl<T, E> Future for FutureResult<T, E> {
+    type Item = T;
+    type Error = E;
+
+    fn poll(&mut self) -> Result<T, E> {
+        loop {}
+    }
+}
+
+struct JoinAll<I>
+    where I: IntoIterator,
+          I::Item: IntoFuture,
+{
+    elems: Vec<<I::Item as IntoFuture>::Item>,
+}
+
+fn join_all<I>(_: I) -> JoinAll<I>
+    where I: IntoIterator,
+          I::Item: IntoFuture,
+{
+    JoinAll { elems: vec![] }
+}
+
+impl<I> Future for JoinAll<I>
+    where I: IntoIterator,
+          I::Item: IntoFuture,
+{
+    type Item = Vec<<I::Item as IntoFuture>::Item>;
+    type Error = <I::Item as IntoFuture>::Error;
+
+    fn poll(&mut self) -> Result<Self::Item, Self::Error> {
+        let elems = mem::replace(&mut self.elems, Vec::new());
+        Ok(elems.into_iter().map(|e| {
+            e
+        }).collect::<Vec<_>>())
+    }
+}