Rollup merge of rust-lang#64794 - Mark-Simulacrum:rm-dep-track-map, r…

…=estebank

Remove unused DepTrackingMap

Deletes some related code (MemoizationMap trait, etc.)

I believe this became unused with red/green incremental introduction, but am uncertain.

src/librustc/dep_graph/mod.rs

@@ -1,14 +1,12 @@
 pub mod debug;
 mod dep_node;
-mod dep_tracking_map;
 mod graph;
 mod prev;
 mod query;
 mod safe;
 mod serialized;
 pub mod cgu_reuse_tracker;
 
-pub use self::dep_tracking_map::{DepTrackingMap, DepTrackingMapConfig};
 pub use self::dep_node::{DepNode, DepKind, DepConstructor, WorkProductId, RecoverKey, label_strs};
 pub use self::graph::{DepGraph, WorkProduct, DepNodeIndex, DepNodeColor, TaskDeps, hash_result};
 pub use self::graph::WorkProductFileKind;

src/librustc/traits/codegen/mod.rs

@@ -3,12 +3,10 @@
 // seems likely that they should eventually be merged into more
 // general routines.
 
-use crate::dep_graph::{DepKind, DepTrackingMapConfig};
-use std::marker::PhantomData;
 use crate::infer::InferCtxt;
 use crate::traits::{FulfillmentContext, Obligation, ObligationCause, SelectionContext,
              TraitEngine, Vtable};
-use crate::ty::{self, Ty, TyCtxt};
+use crate::ty::{self, TyCtxt};
 use crate::ty::subst::{Subst, SubstsRef};
 use crate::ty::fold::TypeFoldable;
 
@@ -100,33 +98,8 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 }
 
-// Implement DepTrackingMapConfig for `trait_cache`
-pub struct TraitSelectionCache<'tcx> {
-    data: PhantomData<&'tcx ()>
-}
-
-impl<'tcx> DepTrackingMapConfig for TraitSelectionCache<'tcx> {
-    type Key = (ty::ParamEnv<'tcx>, ty::PolyTraitRef<'tcx>);
-    type Value = Vtable<'tcx, ()>;
-    fn to_dep_kind() -> DepKind {
-        DepKind::TraitSelect
-    }
-}
-
 // # Global Cache
 
-pub struct ProjectionCache<'tcx> {
-    data: PhantomData<&'tcx ()>,
-}
-
-impl<'tcx> DepTrackingMapConfig for ProjectionCache<'tcx> {
-    type Key = Ty<'tcx>;
-    type Value = Ty<'tcx>;
-    fn to_dep_kind() -> DepKind {
-        DepKind::TraitSelect
-    }
-}
-
 impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     /// Finishes processes any obligations that remain in the
     /// fulfillment context, and then returns the result with all type

src/librustc/util/common.rs

@@ -1,10 +1,9 @@
 #![allow(non_camel_case_types)]
 
-use rustc_data_structures::{fx::FxHashMap, sync::Lock};
+use rustc_data_structures::sync::Lock;
 
-use std::cell::{RefCell, Cell};
+use std::cell::Cell;
 use std::fmt::Debug;
-use std::hash::Hash;
 use std::time::{Duration, Instant};
 
 use std::sync::mpsc::{Sender};
@@ -279,39 +278,3 @@ pub fn indenter() -> Indenter {
     debug!(">>");
     Indenter { _cannot_construct_outside_of_this_module: () }
 }
-
-pub trait MemoizationMap {
-    type Key: Clone;
-    type Value: Clone;
-
-    /// If `key` is present in the map, return the value,
-    /// otherwise invoke `op` and store the value in the map.
-    ///
-    /// N.B., if the receiver is a `DepTrackingMap`, special care is
-    /// needed in the `op` to ensure that the correct edges are
-    /// added into the dep graph. See the `DepTrackingMap` impl for
-    /// more details!
-    fn memoize<OP>(&self, key: Self::Key, op: OP) -> Self::Value
-        where OP: FnOnce() -> Self::Value;
-}
-
-impl<K, V> MemoizationMap for RefCell<FxHashMap<K,V>>
-    where K: Hash+Eq+Clone, V: Clone
-{
-    type Key = K;
-    type Value = V;
-
-    fn memoize<OP>(&self, key: K, op: OP) -> V
-        where OP: FnOnce() -> V
-    {
-        let result = self.borrow().get(&key).cloned();
-        match result {
-            Some(result) => result,
-            None => {
-                let result = op();
-                self.borrow_mut().insert(key, result.clone());
-                result
-            }
-        }
-    }
-}