Rollup of 5 pull requests

src/liballoc/Cargo.toml

@@ -25,6 +25,7 @@ path = "../liballoc/tests/lib.rs"
 [[bench]]
 name = "collectionsbenches"
 path = "../liballoc/benches/lib.rs"
+test = true
 
 [[bench]]
 name = "vec_deque_append_bench"

src/libcore/Cargo.toml

@@ -19,6 +19,7 @@ path = "../libcore/tests/lib.rs"
 [[bench]]
 name = "corebenches"
 path = "../libcore/benches/lib.rs"
+test = true
 
 [dev-dependencies]
 rand = "0.7"

src/libcore/tests/array.rs

@@ -241,3 +241,52 @@ fn iterator_drops() {
     }
     assert_eq!(i.get(), 5);
 }
+
+// This test does not work on targets without panic=unwind support.
+// To work around this problem, test is marked is should_panic, so it will
+// be automagically skipped on unsuitable targets, such as
+// wasm32-unknown-unkown.
+//
+// It means that we use panic for indicating success.
+#[test]
+#[should_panic(expected = "test succeeded")]
+fn array_default_impl_avoids_leaks_on_panic() {
+    use core::sync::atomic::{AtomicUsize, Ordering::Relaxed};
+    static COUNTER: AtomicUsize = AtomicUsize::new(0);
+    #[derive(Debug)]
+    struct Bomb(usize);
+
+    impl Default for Bomb {
+        fn default() -> Bomb {
+            if COUNTER.load(Relaxed) == 3 {
+                panic!("bomb limit exceeded");
+            }
+
+            COUNTER.fetch_add(1, Relaxed);
+            Bomb(COUNTER.load(Relaxed))
+        }
+    }
+
+    impl Drop for Bomb {
+        fn drop(&mut self) {
+            COUNTER.fetch_sub(1, Relaxed);
+        }
+    }
+
+    let res = std::panic::catch_unwind(|| <[Bomb; 5]>::default());
+    let panic_msg = match res {
+        Ok(_) => unreachable!(),
+        Err(p) => p.downcast::<&'static str>().unwrap(),
+    };
+    assert_eq!(*panic_msg, "bomb limit exceeded");
+    // check that all bombs are successfully dropped
+    assert_eq!(COUNTER.load(Relaxed), 0);
+    panic!("test succeeded")
+}
+
+#[test]
+fn empty_array_is_always_default() {
+    struct DoesNotImplDefault;
+
+    let _arr = <[DoesNotImplDefault; 0]>::default();
+}

src/librustc_lint/types.rs

@@ -927,22 +927,33 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
     fn check_for_opaque_ty(&mut self, sp: Span, ty: Ty<'tcx>) -> bool {
         use rustc_middle::ty::TypeFoldable;
 
-        struct ProhibitOpaqueTypes<'tcx> {
+        struct ProhibitOpaqueTypes<'a, 'tcx> {
+            cx: &'a LateContext<'a, 'tcx>,
             ty: Option<Ty<'tcx>>,
         };
 
-        impl<'tcx> ty::fold::TypeVisitor<'tcx> for ProhibitOpaqueTypes<'tcx> {
+        impl<'a, 'tcx> ty::fold::TypeVisitor<'tcx> for ProhibitOpaqueTypes<'a, 'tcx> {
             fn visit_ty(&mut self, ty: Ty<'tcx>) -> bool {
-                if let ty::Opaque(..) = ty.kind {
-                    self.ty = Some(ty);
-                    true
-                } else {
-                    ty.super_visit_with(self)
+                match ty.kind {
+                    ty::Opaque(..) => {
+                        self.ty = Some(ty);
+                        true
+                    }
+                    // Consider opaque types within projections FFI-safe if they do not normalize
+                    // to more opaque types.
+                    ty::Projection(..) => {
+                        let ty = self.cx.tcx.normalize_erasing_regions(self.cx.param_env, ty);
+
+                        // If `ty` is a opaque type directly then `super_visit_with` won't invoke
+                        // this function again.
+                        if ty.has_opaque_types() { self.visit_ty(ty) } else { false }
+                    }
+                    _ => ty.super_visit_with(self),
                 }
             }
         }
 
-        let mut visitor = ProhibitOpaqueTypes { ty: None };
+        let mut visitor = ProhibitOpaqueTypes { cx: self.cx, ty: None };
         ty.visit_with(&mut visitor);
         if let Some(ty) = visitor.ty {
             self.emit_ffi_unsafe_type_lint(ty, sp, "opaque types have no C equivalent", None);

src/librustc_mir/monomorphize/collector.rs

@@ -586,6 +586,14 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> {
                     self.output.push(create_fn_mono_item(instance));
                 }
             }
+            mir::Rvalue::ThreadLocalRef(def_id) => {
+                assert!(self.tcx.is_thread_local_static(def_id));
+                let instance = Instance::mono(self.tcx, def_id);
+                if should_monomorphize_locally(self.tcx, &instance) {
+                    trace!("collecting thread-local static {:?}", def_id);
+                    self.output.push(MonoItem::Static(def_id));
+                }
+            }
             _ => { /* not interesting */ }
         }
 

src/libstd/Cargo.toml

@@ -74,3 +74,8 @@ std_detect_dlsym_getauxval = []
 threads = 125
 # Maximum heap size
 heap_size = 0x8000000
+
+[[bench]]
+name = "stdbenches"
+path = "benches/lib.rs"
+test = true

src/libstd/time.rs

@@ -60,6 +60,21 @@ pub use core::time::Duration;
 /// }
 /// ```
 ///
+/// # OS-specific behaviors
+///
+/// An `Instant` is a wrapper around system-specific types and it may behave
+/// differently depending on the underlying operating system. For example,
+/// the following snippet is fine on Linux but panics on macOS:
+///
+/// ```no_run
+/// use std::time::{Instant, Duration};
+///
+/// let now = Instant::now();
+/// let max_nanoseconds = u64::MAX / 1_000_000_000;
+/// let duration = Duration::new(max_nanoseconds, 0);
+/// println!("{:?}", now + duration);
+/// ```
+///
 /// # Underlying System calls
 /// Currently, the following system calls are being used to get the current time using `now()`:
 ///

src/test/ui/lint/lint-ctypes-73251-1.rs

@@ -0,0 +1,24 @@
+#![feature(type_alias_impl_trait)]
+#![deny(improper_ctypes)]
+
+pub trait Baz { }
+
+impl Baz for u32 { }
+
+type Qux = impl Baz;
+
+pub trait Foo {
+    type Assoc;
+}
+
+impl Foo for u32 {
+    type Assoc = Qux;
+}
+
+fn assign() -> Qux { 1 }
+
+extern "C" {
+    pub fn lint_me() -> <u32 as Foo>::Assoc; //~ ERROR: uses type `Qux`
+}
+
+fn main() {}

src/test/ui/lint/lint-ctypes-73251-1.stderr

@@ -0,0 +1,15 @@
+error: `extern` block uses type `Qux`, which is not FFI-safe
+  --> $DIR/lint-ctypes-73251-1.rs:21:25
+   |
+LL |     pub fn lint_me() -> <u32 as Foo>::Assoc;
+   |                         ^^^^^^^^^^^^^^^^^^^ not FFI-safe
+   |
+note: the lint level is defined here
+  --> $DIR/lint-ctypes-73251-1.rs:2:9
+   |
+LL | #![deny(improper_ctypes)]
+   |         ^^^^^^^^^^^^^^^
+   = note: opaque types have no C equivalent
+
+error: aborting due to previous error
+

src/test/ui/lint/lint-ctypes-73251-2.rs

@@ -0,0 +1,32 @@
+#![feature(type_alias_impl_trait)]
+#![deny(improper_ctypes)]
+
+pub trait TraitA {
+    type Assoc;
+}
+
+impl TraitA for u32 {
+    type Assoc = u32;
+}
+
+pub trait TraitB {
+    type Assoc;
+}
+
+impl<T> TraitB for T where T: TraitA {
+    type Assoc = <T as TraitA>::Assoc;
+}
+
+type AliasA = impl TraitA<Assoc = u32>;
+
+type AliasB = impl TraitB<Assoc = AliasA>;
+
+fn use_of_a() -> AliasA { 3 }
+
+fn use_of_b() -> AliasB { 3 }
+
+extern "C" {
+    pub fn lint_me() -> <AliasB as TraitB>::Assoc; //~ ERROR: uses type `AliasA`
+}
+
+fn main() {}

src/test/ui/lint/lint-ctypes-73251-2.stderr

@@ -0,0 +1,15 @@
+error: `extern` block uses type `AliasA`, which is not FFI-safe
+  --> $DIR/lint-ctypes-73251-2.rs:29:25
+   |
+LL |     pub fn lint_me() -> <AliasB as TraitB>::Assoc;
+   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
+   |
+note: the lint level is defined here
+  --> $DIR/lint-ctypes-73251-2.rs:2:9
+   |
+LL | #![deny(improper_ctypes)]
+   |         ^^^^^^^^^^^^^^^
+   = note: opaque types have no C equivalent
+
+error: aborting due to previous error
+

src/test/ui/lint/lint-ctypes-73251.rs

@@ -0,0 +1,22 @@
+// check-pass
+
+#![feature(type_alias_impl_trait)]
+#![deny(improper_ctypes)]
+
+pub trait Foo {
+    type Assoc;
+}
+
+impl Foo for () {
+    type Assoc = u32;
+}
+
+type Bar = impl Foo<Assoc = u32>;
+
+fn assign() -> Bar {}
+
+extern "C" {
+    pub fn lint_me() -> <Bar as Foo>::Assoc;
+}
+
+fn main() {}

src/test/ui/tls.rs

@@ -0,0 +1,14 @@
+// run-pass
+// ignore-emscripten no threads support
+// compile-flags: -O
+
+#![feature(thread_local)]
+
+#[thread_local]
+static S: u32 = 222;
+
+fn main() {
+    let local = &S as *const u32 as usize;
+    let foreign = std::thread::spawn(|| &S as *const u32 as usize).join().unwrap();
+    assert_ne!(local, foreign);
+}