Rollup of 7 pull requests

src/liballoc/lib.rs

@@ -80,6 +80,7 @@
 #![feature(box_into_raw_non_null)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
+#![feature(cfg_sanitize)]
 #![feature(cfg_target_has_atomic)]
 #![feature(coerce_unsized)]
 #![feature(const_generic_impls_guard)]

src/liballoc/sync.rs

@@ -40,6 +40,23 @@ mod tests;
 /// necessarily) at _exactly_ `MAX_REFCOUNT + 1` references.
 const MAX_REFCOUNT: usize = (isize::MAX) as usize;
 
+#[cfg(not(sanitize = "thread"))]
+macro_rules! acquire {
+    ($x:expr) => {
+        atomic::fence(Acquire)
+    };
+}
+
+// ThreadSanitizer does not support memory fences. To avoid false positive
+// reports in Arc / Weak implementation use atomic loads for synchronization
+// instead.
+#[cfg(sanitize = "thread")]
+macro_rules! acquire {
+    ($x:expr) => {
+        $x.load(Acquire)
+    };
+}
+
 /// A thread-safe reference-counting pointer. 'Arc' stands for 'Atomically
 /// Reference Counted'.
 ///
@@ -402,7 +419,7 @@ impl<T> Arc<T> {
             return Err(this);
         }
 
-        atomic::fence(Acquire);
+        acquire!(this.inner().strong);
 
         unsafe {
             let elem = ptr::read(&this.ptr.as_ref().data);
@@ -739,7 +756,7 @@ impl<T: ?Sized> Arc<T> {
         ptr::drop_in_place(&mut self.ptr.as_mut().data);
 
         if self.inner().weak.fetch_sub(1, Release) == 1 {
-            atomic::fence(Acquire);
+            acquire!(self.inner().weak);
             Global.dealloc(self.ptr.cast(), Layout::for_value(self.ptr.as_ref()))
         }
     }
@@ -1243,7 +1260,7 @@ unsafe impl<#[may_dangle] T: ?Sized> Drop for Arc<T> {
         //
         // [1]: (www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html)
         // [2]: (https://github.com/rust-lang/rust/pull/41714)
-        atomic::fence(Acquire);
+        acquire!(self.inner().strong);
 
         unsafe {
             self.drop_slow();
@@ -1701,7 +1718,7 @@ impl<T: ?Sized> Drop for Weak<T> {
         let inner = if let Some(inner) = self.inner() { inner } else { return };
 
         if inner.weak.fetch_sub(1, Release) == 1 {
-            atomic::fence(Acquire);
+            acquire!(inner.weak);
             unsafe { Global.dealloc(self.ptr.cast(), Layout::for_value(self.ptr.as_ref())) }
         }
     }

src/libcore/ops/range.rs

@@ -1,5 +1,5 @@
 use crate::fmt;
-use crate::hash::{Hash, Hasher};
+use crate::hash::Hash;
 
 /// An unbounded range (`..`).
 ///
@@ -330,7 +330,7 @@ impl<Idx: PartialOrd<Idx>> RangeTo<Idx> {
 /// assert_eq!(arr[1..=3], [  1,2,3  ]);  // RangeInclusive
 /// ```
 #[doc(alias = "..=")]
-#[derive(Clone)] // not Copy -- see #27186
+#[derive(Clone, PartialEq, Eq, Hash)] // not Copy -- see #27186
 #[stable(feature = "inclusive_range", since = "1.26.0")]
 pub struct RangeInclusive<Idx> {
     // Note that the fields here are not public to allow changing the
@@ -350,26 +350,6 @@ pub struct RangeInclusive<Idx> {
     pub(crate) exhausted: bool,
 }
 
-#[stable(feature = "inclusive_range", since = "1.26.0")]
-impl<Idx: PartialEq> PartialEq for RangeInclusive<Idx> {
-    #[inline]
-    fn eq(&self, other: &Self) -> bool {
-        self.start == other.start && self.end == other.end && self.exhausted == other.exhausted
-    }
-}
-
-#[stable(feature = "inclusive_range", since = "1.26.0")]
-impl<Idx: Eq> Eq for RangeInclusive<Idx> {}
-
-#[stable(feature = "inclusive_range", since = "1.26.0")]
-impl<Idx: Hash> Hash for RangeInclusive<Idx> {
-    fn hash<H: Hasher>(&self, state: &mut H) {
-        self.start.hash(state);
-        self.end.hash(state);
-        self.exhausted.hash(state);
-    }
-}
-
 impl<Idx> RangeInclusive<Idx> {
     /// Creates a new inclusive range. Equivalent to writing `start..=end`.
     ///

src/libcore/tests/mem.rs

@@ -129,21 +129,3 @@ fn test_discriminant_send_sync() {
     is_send_sync::<Discriminant<Regular>>();
     is_send_sync::<Discriminant<NotSendSync>>();
 }
-
-#[test]
-fn test_const_forget() {
-    const _: () = forget(0i32);
-    const _: () = forget(Vec::<Vec<Box<i32>>>::new());
-
-    // Writing this function signature without const-forget
-    // triggers compiler errors:
-    // 1) That we use a non-const fn inside a const fn
-    // 2) without the forget, it complains about the destructor of Box
-    const fn const_forget_box<T>(x: Box<T>) {
-        forget(x);
-    }
-
-    // Call the forget_box at runtime,
-    // as we can't const-construct a box yet.
-    const_forget_box(Box::new(0i32));
-}

src/librustc/ty/query/caches.rs

@@ -1,82 +1,94 @@
 use crate::dep_graph::DepNodeIndex;
-use crate::ty::query::config::QueryAccessors;
 use crate::ty::query::plumbing::{QueryLookup, QueryState, QueryStateShard};
 use crate::ty::TyCtxt;
 
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sharded::Sharded;
 use std::default::Default;
 use std::hash::Hash;
+use std::marker::PhantomData;
 
 pub(crate) trait CacheSelector<K, V> {
-    type Cache: QueryCache<K, V>;
+    type Cache: QueryCache<Key = K, Value = V>;
 }
 
-pub(crate) trait QueryCache<K, V>: Default {
+pub(crate) trait QueryCache: Default {
+    type Key;
+    type Value;
     type Sharded: Default;
 
     /// Checks if the query is already computed and in the cache.
     /// It returns the shard index and a lock guard to the shard,
     /// which will be used if the query is not in the cache and we need
     /// to compute it.
-    fn lookup<'tcx, R, GetCache, OnHit, OnMiss, Q>(
+    fn lookup<'tcx, R, GetCache, OnHit, OnMiss>(
         &self,
-        state: &'tcx QueryState<'tcx, Q>,
+        state: &'tcx QueryState<'tcx, Self>,
         get_cache: GetCache,
-        key: K,
+        key: Self::Key,
         // `on_hit` can be called while holding a lock to the query state shard.
         on_hit: OnHit,
         on_miss: OnMiss,
     ) -> R
     where
-        Q: QueryAccessors<'tcx>,
-        GetCache: for<'a> Fn(&'a mut QueryStateShard<'tcx, Q>) -> &'a mut Self::Sharded,
-        OnHit: FnOnce(&V, DepNodeIndex) -> R,
-        OnMiss: FnOnce(K, QueryLookup<'tcx, Q>) -> R;
+        GetCache: for<'a> Fn(
+            &'a mut QueryStateShard<'tcx, Self::Key, Self::Sharded>,
+        ) -> &'a mut Self::Sharded,
+        OnHit: FnOnce(&Self::Value, DepNodeIndex) -> R,
+        OnMiss: FnOnce(Self::Key, QueryLookup<'tcx, Self::Key, Self::Sharded>) -> R;
 
     fn complete(
         &self,
         tcx: TyCtxt<'tcx>,
         lock_sharded_storage: &mut Self::Sharded,
-        key: K,
-        value: V,
+        key: Self::Key,
+        value: Self::Value,
         index: DepNodeIndex,
     );
 
     fn iter<R, L>(
         &self,
         shards: &Sharded<L>,
         get_shard: impl Fn(&mut L) -> &mut Self::Sharded,
-        f: impl for<'a> FnOnce(Box<dyn Iterator<Item = (&'a K, &'a V, DepNodeIndex)> + 'a>) -> R,
+        f: impl for<'a> FnOnce(
+            Box<dyn Iterator<Item = (&'a Self::Key, &'a Self::Value, DepNodeIndex)> + 'a>,
+        ) -> R,
     ) -> R;
 }
 
 pub struct DefaultCacheSelector;
 
 impl<K: Eq + Hash, V: Clone> CacheSelector<K, V> for DefaultCacheSelector {
-    type Cache = DefaultCache;
+    type Cache = DefaultCache<K, V>;
 }
 
-#[derive(Default)]
-pub struct DefaultCache;
+pub struct DefaultCache<K, V>(PhantomData<(K, V)>);
+
+impl<K, V> Default for DefaultCache<K, V> {
+    fn default() -> Self {
+        DefaultCache(PhantomData)
+    }
+}
 
-impl<K: Eq + Hash, V: Clone> QueryCache<K, V> for DefaultCache {
+impl<K: Eq + Hash, V: Clone> QueryCache for DefaultCache<K, V> {
+    type Key = K;
+    type Value = V;
     type Sharded = FxHashMap<K, (V, DepNodeIndex)>;
 
     #[inline(always)]
-    fn lookup<'tcx, R, GetCache, OnHit, OnMiss, Q>(
+    fn lookup<'tcx, R, GetCache, OnHit, OnMiss>(
         &self,
-        state: &'tcx QueryState<'tcx, Q>,
+        state: &'tcx QueryState<'tcx, Self>,
         get_cache: GetCache,
         key: K,
         on_hit: OnHit,
         on_miss: OnMiss,
     ) -> R
     where
-        Q: QueryAccessors<'tcx>,
-        GetCache: for<'a> Fn(&'a mut QueryStateShard<'tcx, Q>) -> &'a mut Self::Sharded,
+        GetCache:
+            for<'a> Fn(&'a mut QueryStateShard<'tcx, K, Self::Sharded>) -> &'a mut Self::Sharded,
         OnHit: FnOnce(&V, DepNodeIndex) -> R,
-        OnMiss: FnOnce(K, QueryLookup<'tcx, Q>) -> R,
+        OnMiss: FnOnce(K, QueryLookup<'tcx, K, Self::Sharded>) -> R,
     {
         let mut lookup = state.get_lookup(&key);
         let lock = &mut *lookup.lock;

src/librustc/ty/query/config.rs

@@ -2,7 +2,7 @@ use crate::dep_graph::SerializedDepNodeIndex;
 use crate::dep_graph::{DepKind, DepNode};
 use crate::ty::query::caches::QueryCache;
 use crate::ty::query::plumbing::CycleError;
-use crate::ty::query::{Query, QueryState};
+use crate::ty::query::QueryState;
 use crate::ty::TyCtxt;
 use rustc_data_structures::profiling::ProfileCategory;
 use rustc_hir::def_id::DefId;
@@ -28,18 +28,15 @@ pub trait QueryConfig<'tcx> {
 pub(crate) trait QueryAccessors<'tcx>: QueryConfig<'tcx> {
     const ANON: bool;
     const EVAL_ALWAYS: bool;
+    const DEP_KIND: DepKind;
 
-    type Cache: QueryCache<Self::Key, Self::Value>;
-
-    fn query(key: Self::Key) -> Query<'tcx>;
+    type Cache: QueryCache<Key = Self::Key, Value = Self::Value>;
 
     // Don't use this method to access query results, instead use the methods on TyCtxt
-    fn query_state<'a>(tcx: TyCtxt<'tcx>) -> &'a QueryState<'tcx, Self>;
+    fn query_state<'a>(tcx: TyCtxt<'tcx>) -> &'a QueryState<'tcx, Self::Cache>;
 
     fn to_dep_node(tcx: TyCtxt<'tcx>, key: &Self::Key) -> DepNode;
 
-    fn dep_kind() -> DepKind;
-
     // Don't use this method to compute query results, instead use the methods on TyCtxt
     fn compute(tcx: TyCtxt<'tcx>, key: Self::Key) -> Self::Value;
 
@@ -62,10 +59,7 @@ pub(crate) trait QueryDescription<'tcx>: QueryAccessors<'tcx> {
     }
 }
 
-impl<'tcx, M: QueryAccessors<'tcx, Key = DefId>> QueryDescription<'tcx> for M
-where
-    <M as QueryAccessors<'tcx>>::Cache: QueryCache<DefId, <M as QueryConfig<'tcx>>::Value>,
-{
+impl<'tcx, M: QueryAccessors<'tcx, Key = DefId>> QueryDescription<'tcx> for M {
     default fn describe(tcx: TyCtxt<'_>, def_id: DefId) -> Cow<'static, str> {
         if !tcx.sess.verbose() {
             format!("processing `{}`", tcx.def_path_str(def_id)).into()

src/librustc/ty/query/mod.rs

@@ -57,13 +57,12 @@ use rustc_span::symbol::Symbol;
 use rustc_span::{Span, DUMMY_SP};
 use std::borrow::Cow;
 use std::collections::BTreeMap;
-use std::convert::TryFrom;
 use std::ops::Deref;
 use std::sync::Arc;
 
 #[macro_use]
 mod plumbing;
-pub use self::plumbing::CycleError;
+pub(crate) use self::plumbing::CycleError;
 use self::plumbing::*;
 
 mod stats;