Auto merge of #55114 - oli-obk:fx#map, r=nikomatsakis

Deprecate the `FxHashMap()` and `FxHashSet()` constructor function hack

Author: bors

src/bootstrap/cache.rs

@@ -169,19 +169,21 @@ impl Ord for Interned<String> {
     }
 }
 
-struct TyIntern<T> {
+struct TyIntern<T: Hash + Clone + Eq> {
     items: Vec<T>,
     set: HashMap<T, Interned<T>>,
 }
 
-impl<T: Hash + Clone + Eq> TyIntern<T> {
-    fn new() -> TyIntern<T> {
+impl<T: Hash + Clone + Eq> Default for TyIntern<T> {
+    fn default() -> Self {
         TyIntern {
             items: Vec::new(),
-            set: HashMap::new(),
+            set: Default::default(),
         }
     }
+}
 
+impl<T: Hash + Clone + Eq> TyIntern<T> {
     fn intern_borrow<B>(&mut self, item: &B) -> Interned<T>
     where
         B: Eq + Hash + ToOwned<Owned=T> + ?Sized,
@@ -212,19 +214,13 @@ impl<T: Hash + Clone + Eq> TyIntern<T> {
     }
 }
 
+#[derive(Default)]
 pub struct Interner {
     strs: Mutex<TyIntern<String>>,
     paths: Mutex<TyIntern<PathBuf>>,
 }
 
 impl Interner {
-    fn new() -> Interner {
-        Interner {
-            strs: Mutex::new(TyIntern::new()),
-            paths: Mutex::new(TyIntern::new()),
-        }
-    }
-
     pub fn intern_str(&self, s: &str) -> Interned<String> {
         self.strs.lock().unwrap().intern_borrow(s)
     }
@@ -238,7 +234,7 @@ impl Interner {
 }
 
 lazy_static! {
-    pub static ref INTERNER: Interner = Interner::new();
+    pub static ref INTERNER: Interner = Interner::default();
 }
 
 /// This is essentially a HashMap which allows storing any type in its input and

src/libarena/lib.rs

@@ -114,10 +114,9 @@ impl<T> TypedArenaChunk<T> {
 
 const PAGE: usize = 4096;
 
-impl<T> TypedArena<T> {
+impl<T> Default for TypedArena<T> {
     /// Creates a new `TypedArena`.
-    #[inline]
-    pub fn new() -> TypedArena<T> {
+    fn default() -> TypedArena<T> {
         TypedArena {
             // We set both `ptr` and `end` to 0 so that the first call to
             // alloc() will trigger a grow().
@@ -127,7 +126,9 @@ impl<T> TypedArena<T> {
             _own: PhantomData,
         }
     }
+}
 
+impl<T> TypedArena<T> {
     /// Allocates an object in the `TypedArena`, returning a reference to it.
     #[inline]
     pub fn alloc(&self, object: T) -> &mut T {
@@ -296,15 +297,17 @@ pub struct DroplessArena {
 
 unsafe impl Send for DroplessArena {}
 
-impl DroplessArena {
-    pub fn new() -> DroplessArena {
+impl Default for DroplessArena {
+    fn default() -> DroplessArena {
         DroplessArena {
             ptr: Cell::new(0 as *mut u8),
             end: Cell::new(0 as *mut u8),
-            chunks: RefCell::new(vec![]),
+            chunks: Default::default(),
         }
     }
+}
 
+impl DroplessArena {
     pub fn in_arena<T: ?Sized>(&self, ptr: *const T) -> bool {
         let ptr = ptr as *const u8 as *mut u8;
         for chunk in &*self.chunks.borrow() {
@@ -419,18 +422,13 @@ impl DroplessArena {
     }
 }
 
+#[derive(Default)]
+// FIXME(@Zoxc): this type is entirely unused in rustc
 pub struct SyncTypedArena<T> {
     lock: MTLock<TypedArena<T>>,
 }
 
 impl<T> SyncTypedArena<T> {
-    #[inline(always)]
-    pub fn new() -> SyncTypedArena<T> {
-        SyncTypedArena {
-            lock: MTLock::new(TypedArena::new())
-        }
-    }
-
     #[inline(always)]
     pub fn alloc(&self, object: T) -> &mut T {
         // Extend the lifetime of the result since it's limited to the lock guard
@@ -452,18 +450,12 @@ impl<T> SyncTypedArena<T> {
     }
 }
 
+#[derive(Default)]
 pub struct SyncDroplessArena {
     lock: MTLock<DroplessArena>,
 }
 
 impl SyncDroplessArena {
-    #[inline(always)]
-    pub fn new() -> SyncDroplessArena {
-        SyncDroplessArena {
-            lock: MTLock::new(DroplessArena::new())
-        }
-    }
-
     #[inline(always)]
     pub fn in_arena<T: ?Sized>(&self, ptr: *const T) -> bool {
         self.lock.lock().in_arena(ptr)
@@ -508,7 +500,7 @@ mod tests {
 
     #[test]
     pub fn test_unused() {
-        let arena: TypedArena<Point> = TypedArena::new();
+        let arena: TypedArena<Point> = TypedArena::default();
         assert!(arena.chunks.borrow().is_empty());
     }
 
@@ -546,7 +538,7 @@ mod tests {
             }
         }
 
-        let arena = Wrap(TypedArena::new());
+        let arena = Wrap(TypedArena::default());
 
         let result = arena.alloc_outer(|| Outer {
             inner: arena.alloc_inner(|| Inner { value: 10 }),
@@ -557,15 +549,15 @@ mod tests {
 
     #[test]
     pub fn test_copy() {
-        let arena = TypedArena::new();
+        let arena = TypedArena::default();
         for _ in 0..100000 {
             arena.alloc(Point { x: 1, y: 2, z: 3 });
         }
     }
 
     #[bench]
     pub fn bench_copy(b: &mut Bencher) {
-        let arena = TypedArena::new();
+        let arena = TypedArena::default();
         b.iter(|| arena.alloc(Point { x: 1, y: 2, z: 3 }))
     }
 
@@ -584,7 +576,7 @@ mod tests {
 
     #[test]
     pub fn test_noncopy() {
-        let arena = TypedArena::new();
+        let arena = TypedArena::default();
         for _ in 0..100000 {
             arena.alloc(Noncopy {
                 string: "hello world".to_string(),
@@ -595,15 +587,15 @@ mod tests {
 
     #[test]
     pub fn test_typed_arena_zero_sized() {
-        let arena = TypedArena::new();
+        let arena = TypedArena::default();
         for _ in 0..100000 {
             arena.alloc(());
         }
     }
 
     #[test]
     pub fn test_typed_arena_clear() {
-        let mut arena = TypedArena::new();
+        let mut arena = TypedArena::default();
         for _ in 0..10 {
             arena.clear();
             for _ in 0..10000 {
@@ -628,7 +620,7 @@ mod tests {
     fn test_typed_arena_drop_count() {
         let counter = Cell::new(0);
         {
-            let arena: TypedArena<DropCounter> = TypedArena::new();
+            let arena: TypedArena<DropCounter> = TypedArena::default();
             for _ in 0..100 {
                 // Allocate something with drop glue to make sure it doesn't leak.
                 arena.alloc(DropCounter { count: &counter });
@@ -640,7 +632,7 @@ mod tests {
     #[test]
     fn test_typed_arena_drop_on_clear() {
         let counter = Cell::new(0);
-        let mut arena: TypedArena<DropCounter> = TypedArena::new();
+        let mut arena: TypedArena<DropCounter> = TypedArena::default();
         for i in 0..10 {
             for _ in 0..100 {
                 // Allocate something with drop glue to make sure it doesn't leak.
@@ -667,7 +659,7 @@ mod tests {
     fn test_typed_arena_drop_small_count() {
         DROP_COUNTER.with(|c| c.set(0));
         {
-            let arena: TypedArena<SmallDroppable> = TypedArena::new();
+            let arena: TypedArena<SmallDroppable> = TypedArena::default();
             for _ in 0..100 {
                 // Allocate something with drop glue to make sure it doesn't leak.
                 arena.alloc(SmallDroppable);
@@ -679,7 +671,7 @@ mod tests {
 
     #[bench]
     pub fn bench_noncopy(b: &mut Bencher) {
-        let arena = TypedArena::new();
+        let arena = TypedArena::default();
         b.iter(|| {
             arena.alloc(Noncopy {
                 string: "hello world".to_string(),

src/librustc/dep_graph/cgu_reuse_tracker.rs

@@ -51,8 +51,8 @@ pub struct CguReuseTracker {
 impl CguReuseTracker {
     pub fn new() -> CguReuseTracker {
         let data = TrackerData {
-            actual_reuse: FxHashMap(),
-            expected_reuse: FxHashMap(),
+            actual_reuse: Default::default(),
+            expected_reuse: Default::default(),
         };
 
         CguReuseTracker {

src/librustc/dep_graph/dep_tracking_map.rs

@@ -36,7 +36,7 @@ impl<M: DepTrackingMapConfig> DepTrackingMap<M> {
         DepTrackingMap {
             phantom: PhantomData,
             graph,
-            map: FxHashMap(),
+            map: Default::default(),
         }
     }
 }

src/librustc/dep_graph/graph.rs

@@ -101,11 +101,11 @@ impl DepGraph {
         DepGraph {
             data: Some(Lrc::new(DepGraphData {
                 previous_work_products: prev_work_products,
-                dep_node_debug: Lock::new(FxHashMap()),
+                dep_node_debug: Lock::new(Default::default()),
                 current: Lock::new(CurrentDepGraph::new()),
                 previous: prev_graph,
                 colors: Lock::new(DepNodeColorMap::new(prev_graph_node_count)),
-                loaded_from_cache: Lock::new(FxHashMap()),
+                loaded_from_cache: Lock::new(Default::default()),
             })),
             fingerprints: Lrc::new(Lock::new(fingerprints)),
         }
@@ -209,7 +209,7 @@ impl DepGraph {
             |key| OpenTask::Regular(Lock::new(RegularOpenTask {
                 node: key,
                 reads: SmallVec::new(),
-                read_set: FxHashSet(),
+                read_set: Default::default(),
             })),
             |data, key, task| data.borrow_mut().complete_task(key, task))
     }
@@ -353,7 +353,7 @@ impl DepGraph {
             let (result, open_task) = ty::tls::with_context(|icx| {
                 let task = OpenTask::Anon(Lock::new(AnonOpenTask {
                     reads: SmallVec::new(),
-                    read_set: FxHashSet(),
+                    read_set: Default::default(),
                 }));
 
                 let r = {
@@ -937,7 +937,7 @@ impl CurrentDepGraph {
         CurrentDepGraph {
             nodes: IndexVec::new(),
             edges: IndexVec::new(),
-            node_to_node_index: FxHashMap(),
+            node_to_node_index: Default::default(),
             anon_id_seed: stable_hasher.finish(),
             forbidden_edge,
             total_read_count: 0,

src/librustc/dep_graph/prev.rs

@@ -13,7 +13,7 @@ use rustc_data_structures::fx::FxHashMap;
 use super::dep_node::DepNode;
 use super::serialized::{SerializedDepGraph, SerializedDepNodeIndex};
 
-#[derive(Debug, RustcEncodable, RustcDecodable)]
+#[derive(Debug, RustcEncodable, RustcDecodable, Default)]
 pub struct PreviousDepGraph {
     data: SerializedDepGraph,
     index: FxHashMap<DepNode, SerializedDepNodeIndex>,

src/librustc/dep_graph/query.rs

@@ -25,7 +25,7 @@ impl DepGraphQuery {
                edges: &[(DepNode, DepNode)])
                -> DepGraphQuery {
         let mut graph = Graph::with_capacity(nodes.len(), edges.len());
-        let mut indices = FxHashMap();
+        let mut indices = FxHashMap::default();
         for node in nodes {
             indices.insert(node.clone(), graph.add_node(node.clone()));
         }

src/librustc/dep_graph/serialized.rs

@@ -19,7 +19,7 @@ newtype_index! {
 }
 
 /// Data for use when recompiling the **current crate**.
-#[derive(Debug, RustcEncodable, RustcDecodable)]
+#[derive(Debug, RustcEncodable, RustcDecodable, Default)]
 pub struct SerializedDepGraph {
     /// The set of all DepNodes in the graph
     pub nodes: IndexVec<SerializedDepNodeIndex, DepNode>,
@@ -36,16 +36,6 @@ pub struct SerializedDepGraph {
 }
 
 impl SerializedDepGraph {
-
-    pub fn new() -> SerializedDepGraph {
-        SerializedDepGraph {
-            nodes: IndexVec::new(),
-            fingerprints: IndexVec::new(),
-            edge_list_indices: IndexVec::new(),
-            edge_list_data: Vec::new(),
-        }
-    }
-
     #[inline]
     pub fn edge_targets_from(&self,
                              source: SerializedDepNodeIndex)

src/librustc/hir/map/definitions.rs

@@ -421,10 +421,10 @@ impl Definitions {
             node_to_def_index: NodeMap(),
             def_index_to_node: [vec![], vec![]],
             node_to_hir_id: IndexVec::new(),
-            parent_modules_of_macro_defs: FxHashMap(),
-            expansions_that_defined: FxHashMap(),
-            next_disambiguator: FxHashMap(),
-            def_index_to_span: FxHashMap(),
+            parent_modules_of_macro_defs: Default::default(),
+            expansions_that_defined: Default::default(),
+            next_disambiguator: Default::default(),
+            def_index_to_span: Default::default(),
         }
     }
 

src/librustc/hir/map/hir_id_validator.rs

@@ -51,7 +51,7 @@ impl<'a, 'hir: 'a> OuterVisitor<'a, 'hir> {
         HirIdValidator {
             hir_map,
             owner_def_index: None,
-            hir_ids_seen: FxHashMap(),
+            hir_ids_seen: Default::default(),
             errors: Vec::new(),
         }
     }

src/librustc/ich/hcx.rs

@@ -370,7 +370,7 @@ impl<'a> HashStable<StableHashingContext<'a>> for Span {
             // recursing every time.
             thread_local! {
                 static CACHE: RefCell<FxHashMap<hygiene::Mark, u64>> =
-                    RefCell::new(FxHashMap());
+                    RefCell::new(Default::default());
             }
 
             let sub_hash: u64 = CACHE.with(|cache| {

src/librustc/ich/impls_ty.rs

@@ -32,7 +32,7 @@ for &'gcx ty::List<T>
                                           hasher: &mut StableHasher<W>) {
         thread_local! {
             static CACHE: RefCell<FxHashMap<(usize, usize), Fingerprint>> =
-                RefCell::new(FxHashMap());
+                RefCell::new(Default::default());
         }
 
         let hash = CACHE.with(|cache| {

src/librustc/infer/freshen.rs

@@ -62,7 +62,7 @@ impl<'a, 'gcx, 'tcx> TypeFreshener<'a, 'gcx, 'tcx> {
         TypeFreshener {
             infcx,
             freshen_count: 0,
-            freshen_map: FxHashMap(),
+            freshen_map: Default::default(),
         }
     }