Rollup of 9 pull requests

Cargo.lock

@@ -2751,20 +2751,6 @@ dependencies = [
  "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "rustc_allocator"
-version = "0.0.0"
-dependencies = [
- "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc 0.0.0",
- "rustc_data_structures 0.0.0",
- "rustc_errors 0.0.0",
- "rustc_target 0.0.0",
- "smallvec 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
- "syntax 0.0.0",
- "syntax_pos 0.0.0",
-]
-
 [[package]]
 name = "rustc_apfloat"
 version = "0.0.0"
@@ -2822,7 +2808,6 @@ dependencies = [
  "num_cpus 1.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc 0.0.0",
- "rustc_allocator 0.0.0",
  "rustc_apfloat 0.0.0",
  "rustc_codegen_utils 0.0.0",
  "rustc_data_structures 0.0.0",
@@ -2883,7 +2868,6 @@ dependencies = [
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc 0.0.0",
  "rustc-rayon 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc_allocator 0.0.0",
  "rustc_ast_borrowck 0.0.0",
  "rustc_codegen_utils 0.0.0",
  "rustc_data_structures 0.0.0",
@@ -2904,7 +2888,6 @@ dependencies = [
  "serialize 0.0.0",
  "smallvec 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "syntax 0.0.0",
- "syntax_ext 0.0.0",
  "syntax_pos 0.0.0",
 ]
 
@@ -2948,7 +2931,6 @@ dependencies = [
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc 0.0.0",
  "rustc-rayon 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc_allocator 0.0.0",
  "rustc_ast_borrowck 0.0.0",
  "rustc_codegen_ssa 0.0.0",
  "rustc_codegen_utils 0.0.0",

src/bootstrap/sanity.rs

@@ -78,8 +78,11 @@ pub fn check(build: &mut Build) {
 
     // We need cmake, but only if we're actually building LLVM or sanitizers.
     let building_llvm = build.hosts.iter()
-        .filter_map(|host| build.config.target_config.get(host))
-        .any(|config| config.llvm_config.is_none());
+        .map(|host| build.config.target_config
+            .get(host)
+            .map(|config| config.llvm_config.is_none())
+            .unwrap_or(true))
+        .any(|build_llvm_ourselves| build_llvm_ourselves);
     if building_llvm || build.config.sanitizers {
         cmd_finder.must_have("cmake");
     }
@@ -106,6 +109,14 @@ pub fn check(build: &mut Build) {
                 build.config.ninja = true;
             }
         }
+
+        if build.config.lldb_enabled {
+            cmd_finder.must_have("swig");
+            let out = output(Command::new("swig").arg("-version"));
+            if !out.contains("SWIG Version 3") && !out.contains("SWIG Version 4") {
+                panic!("Ensure that Swig 3.x.x or 4.x.x is installed.");
+            }
+        }
     }
 
     build.config.python = build.config.python.take().map(|p| cmd_finder.must_have(p))

src/doc/rustdoc/src/unstable-features.md

@@ -183,9 +183,8 @@ Book][unstable-masked] and [its tracking issue][issue-masked].
 
 As designed in [RFC 1990], Rustdoc can read an external file to use as a type's documentation. This
 is useful if certain documentation is so long that it would break the flow of reading the source.
-Instead of writing it all inline, writing `#[doc(include = "sometype.md")]` (where `sometype.md` is
-a file adjacent to the `lib.rs` for the crate) will ask Rustdoc to instead read that file and use it
-as if it were written inline.
+Instead of writing it all inline, writing `#[doc(include = "sometype.md")]` will ask Rustdoc to
+instead read that file and use it as if it were written inline.
 
 [RFC 1990]: https://github.com/rust-lang/rfcs/pull/1990
 

src/liballoc/slice.rs

@@ -494,10 +494,10 @@ impl<T> [T] {
     /// assert_eq!([[1, 2], [3, 4]].concat(), [1, 2, 3, 4]);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn concat<Separator: ?Sized>(&self) -> T::Output
-        where T: SliceConcat<Separator>
+    pub fn concat<Item: ?Sized>(&self) -> <Self as Concat<Item>>::Output
+        where Self: Concat<Item>
     {
-        SliceConcat::concat(self)
+        Concat::concat(self)
     }
 
     /// Flattens a slice of `T` into a single value `Self::Output`, placing a
@@ -508,12 +508,13 @@ impl<T> [T] {
     /// ```
     /// assert_eq!(["hello", "world"].join(" "), "hello world");
     /// assert_eq!([[1, 2], [3, 4]].join(&0), [1, 2, 0, 3, 4]);
+    /// assert_eq!([[1, 2], [3, 4]].join(&[0, 0][..]), [1, 2, 0, 0, 3, 4]);
     /// ```
     #[stable(feature = "rename_connect_to_join", since = "1.3.0")]
-    pub fn join<Separator: ?Sized>(&self, sep: &Separator) -> T::Output
-        where T: SliceConcat<Separator>
+    pub fn join<Separator>(&self, sep: Separator) -> <Self as Join<Separator>>::Output
+        where Self: Join<Separator>
     {
-        SliceConcat::join(self, sep)
+        Join::join(self, sep)
     }
 
     /// Flattens a slice of `T` into a single value `Self::Output`, placing a
@@ -528,10 +529,10 @@ impl<T> [T] {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_deprecated(since = "1.3.0", reason = "renamed to join")]
-    pub fn connect<Separator: ?Sized>(&self, sep: &Separator) -> T::Output
-        where T: SliceConcat<Separator>
+    pub fn connect<Separator>(&self, sep: Separator) -> <Self as Join<Separator>>::Output
+        where Self: Join<Separator>
     {
-        SliceConcat::join(self, sep)
+        Join::join(self, sep)
     }
 
 }
@@ -578,45 +579,83 @@ impl [u8] {
 // Extension traits for slices over specific kinds of data
 ////////////////////////////////////////////////////////////////////////////////
 
-/// Helper trait for [`[T]::concat`](../../std/primitive.slice.html#method.concat)
-/// and [`[T]::join`](../../std/primitive.slice.html#method.join)
+/// Helper trait for [`[T]::concat`](../../std/primitive.slice.html#method.concat).
+///
+/// Note: the `Item` type parameter is not used in this trait,
+/// but it allows impls to be more generic.
+/// Without it, we get this error:
+///
+/// ```error
+/// error[E0207]: the type parameter `T` is not constrained by the impl trait, self type, or predica
+///    --> src/liballoc/slice.rs:608:6
+///     |
+/// 608 | impl<T: Clone, V: Borrow<[T]>> Concat for [V] {
+///     |      ^ unconstrained type parameter
+/// ```
+///
+/// This is because there could exist `V` types with multiple `Borrow<[_]>` impls,
+/// such that multiple `T` types would apply:
+///
+/// ```
+/// # #[allow(dead_code)]
+/// pub struct Foo(Vec<u32>, Vec<String>);
+///
+/// impl std::borrow::Borrow<[u32]> for Foo {
+///     fn borrow(&self) -> &[u32] { &self.0 }
+/// }
+///
+/// impl std::borrow::Borrow<[String]> for Foo {
+///     fn borrow(&self) -> &[String] { &self.1 }
+/// }
+/// ```
 #[unstable(feature = "slice_concat_trait", issue = "27747")]
-pub trait SliceConcat<Separator: ?Sized>: Sized {
+pub trait Concat<Item: ?Sized> {
     #[unstable(feature = "slice_concat_trait", issue = "27747")]
     /// The resulting type after concatenation
     type Output;
 
     /// Implementation of [`[T]::concat`](../../std/primitive.slice.html#method.concat)
     #[unstable(feature = "slice_concat_trait", issue = "27747")]
-    fn concat(slice: &[Self]) -> Self::Output;
+    fn concat(slice: &Self) -> Self::Output;
+}
+
+/// Helper trait for [`[T]::join`](../../std/primitive.slice.html#method.join)
+#[unstable(feature = "slice_concat_trait", issue = "27747")]
+pub trait Join<Separator> {
+    #[unstable(feature = "slice_concat_trait", issue = "27747")]
+    /// The resulting type after concatenation
+    type Output;
 
     /// Implementation of [`[T]::join`](../../std/primitive.slice.html#method.join)
     #[unstable(feature = "slice_concat_trait", issue = "27747")]
-    fn join(slice: &[Self], sep: &Separator) -> Self::Output;
+    fn join(slice: &Self, sep: Separator) -> Self::Output;
 }
 
-#[unstable(feature = "slice_concat_ext",
-           reason = "trait should not have to exist",
-           issue = "27747")]
-impl<T: Clone, V: Borrow<[T]>> SliceConcat<T> for V {
+#[unstable(feature = "slice_concat_ext", issue = "27747")]
+impl<T: Clone, V: Borrow<[T]>> Concat<T> for [V] {
     type Output = Vec<T>;
 
-    fn concat(slice: &[Self]) -> Vec<T> {
+    fn concat(slice: &Self) -> Vec<T> {
         let size = slice.iter().map(|slice| slice.borrow().len()).sum();
         let mut result = Vec::with_capacity(size);
         for v in slice {
             result.extend_from_slice(v.borrow())
         }
         result
     }
+}
+
+#[unstable(feature = "slice_concat_ext", issue = "27747")]
+impl<T: Clone, V: Borrow<[T]>> Join<&T> for [V] {
+    type Output = Vec<T>;
 
-    fn join(slice: &[Self], sep: &T) -> Vec<T> {
+    fn join(slice: &Self, sep: &T) -> Vec<T> {
         let mut iter = slice.iter();
         let first = match iter.next() {
             Some(first) => first,
             None => return vec![],
         };
-        let size = slice.iter().map(|slice| slice.borrow().len()).sum::<usize>() + slice.len() - 1;
+        let size = slice.iter().map(|v| v.borrow().len()).sum::<usize>() + slice.len() - 1;
         let mut result = Vec::with_capacity(size);
         result.extend_from_slice(first.borrow());
 
@@ -628,6 +667,29 @@ impl<T: Clone, V: Borrow<[T]>> SliceConcat<T> for V {
     }
 }
 
+#[unstable(feature = "slice_concat_ext", issue = "27747")]
+impl<T: Clone, V: Borrow<[T]>> Join<&[T]> for [V] {
+    type Output = Vec<T>;
+
+    fn join(slice: &Self, sep: &[T]) -> Vec<T> {
+        let mut iter = slice.iter();
+        let first = match iter.next() {
+            Some(first) => first,
+            None => return vec![],
+        };
+        let size = slice.iter().map(|v| v.borrow().len()).sum::<usize>() +
+            sep.len() * (slice.len() - 1);
+        let mut result = Vec::with_capacity(size);
+        result.extend_from_slice(first.borrow());
+
+        for v in iter {
+            result.extend_from_slice(sep);
+            result.extend_from_slice(v.borrow())
+        }
+        result
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // Standard trait implementations for slices
 ////////////////////////////////////////////////////////////////////////////////

src/liballoc/str.rs

@@ -37,7 +37,7 @@ use core::unicode::conversions;
 
 use crate::borrow::ToOwned;
 use crate::boxed::Box;
-use crate::slice::{SliceConcat, SliceIndex};
+use crate::slice::{Concat, Join, SliceIndex};
 use crate::string::String;
 use crate::vec::Vec;
 
@@ -71,17 +71,22 @@ pub use core::str::SplitAsciiWhitespace;
 #[stable(feature = "str_escape", since = "1.34.0")]
 pub use core::str::{EscapeDebug, EscapeDefault, EscapeUnicode};
 
-#[unstable(feature = "slice_concat_ext",
-           reason = "trait should not have to exist",
-           issue = "27747")]
-impl<S: Borrow<str>> SliceConcat<str> for S {
+/// Note: `str` in `Concat<str>` is not meaningful here.
+/// This type parameter of the trait only exists to enable another impl.
+#[unstable(feature = "slice_concat_ext", issue = "27747")]
+impl<S: Borrow<str>> Concat<str> for [S] {
     type Output = String;
 
-    fn concat(slice: &[Self]) -> String {
-        Self::join(slice, "")
+    fn concat(slice: &Self) -> String {
+        Join::join(slice, "")
     }
+}
+
+#[unstable(feature = "slice_concat_ext", issue = "27747")]
+impl<S: Borrow<str>> Join<&str> for [S] {
+    type Output = String;
 
-    fn join(slice: &[Self], sep: &str) -> String {
+    fn join(slice: &Self, sep: &str) -> String {
         unsafe {
             String::from_utf8_unchecked( join_generic_copy(slice, sep.as_bytes()) )
         }

src/libcore/macros.rs

@@ -1281,6 +1281,13 @@ mod builtin {
     #[rustc_macro_transparency = "semitransparent"]
     pub macro test_case($item:item) { /* compiler built-in */ }
 
+    /// Attribute macro applied to a static to register it as a global allocator.
+    #[stable(feature = "global_allocator", since = "1.28.0")]
+    #[allow_internal_unstable(rustc_attrs)]
+    #[rustc_builtin_macro]
+    #[rustc_macro_transparency = "semitransparent"]
+    pub macro global_allocator($item:item) { /* compiler built-in */ }
+
     /// Derive macro generating an impl of the trait `Clone`.
     #[rustc_builtin_macro]
     #[rustc_macro_transparency = "semitransparent"]

src/librustc/lib.rs

@@ -104,7 +104,6 @@ pub mod infer;
 pub mod lint;
 
 pub mod middle {
-    pub mod allocator;
     pub mod borrowck;
     pub mod expr_use_visitor;
     pub mod cstore;

src/librustc/middle/dead.rs

@@ -320,11 +320,6 @@ fn has_allow_dead_code_or_lang_attr(
         return true;
     }
 
-    // Don't lint about global allocators
-    if attr::contains_name(attrs, sym::global_allocator) {
-        return true;
-    }
-
     let def_id = tcx.hir().local_def_id(id);
     let cg_attrs = tcx.codegen_fn_attrs(def_id);
 

src/librustc/session/mod.rs

@@ -7,7 +7,6 @@ use rustc_data_structures::fingerprint::Fingerprint;
 
 use crate::lint;
 use crate::lint::builtin::BuiltinLintDiagnostics;
-use crate::middle::allocator::AllocatorKind;
 use crate::middle::dependency_format;
 use crate::session::config::{OutputType, PrintRequest, SwitchWithOptPath};
 use crate::session::search_paths::{PathKind, SearchPath};
@@ -27,6 +26,7 @@ use errors::emitter::HumanReadableErrorType;
 use errors::annotate_snippet_emitter_writer::{AnnotateSnippetEmitterWriter};
 use syntax::ast::{self, NodeId};
 use syntax::edition::Edition;
+use syntax::ext::allocator::AllocatorKind;
 use syntax::feature_gate::{self, AttributeType};
 use syntax::json::JsonEmitter;
 use syntax::source_map;

src/librustc/ty/sty.rs

@@ -1703,22 +1703,21 @@ impl<'tcx> TyS<'tcx> {
     /// will be `Abi::Uninhabited`. (Note that uninhabited types may have nonzero
     /// size, to account for partial initialisation. See #49298 for details.)
     pub fn conservative_is_privately_uninhabited(&self, tcx: TyCtxt<'tcx>) -> bool {
-        // FIXME(varkor): we can make this less conversative by substituting concrete
-        // type arguments.
         match self.sty {
             ty::Never => true,
             ty::Adt(def, _) if def.is_union() => {
                 // For now, `union`s are never considered uninhabited.
                 false
             }
-            ty::Adt(def, _) => {
+            ty::Adt(def, substs) => {
                 // Any ADT is uninhabited if either:
                 // (a) It has no variants (i.e. an empty `enum`);
                 // (b) Each of its variants (a single one in the case of a `struct`) has at least
                 //     one uninhabited field.
                 def.variants.iter().all(|var| {
                     var.fields.iter().any(|field| {
-                        tcx.type_of(field.did).conservative_is_privately_uninhabited(tcx)
+                        tcx.type_of(field.did).subst(tcx, substs)
+                            .conservative_is_privately_uninhabited(tcx)
                     })
                 })
             }