1 files changed, 0 insertions, 63 deletions
diff --git a/compiler/rustc_middle/src/mir/graph_cyclic_cache.rs b/compiler/rustc_middle/src/mir/graph_cyclic_cache.rs
deleted file mode 100644
index f97bf2883..000000000
--- a/compiler/rustc_middle/src/mir/graph_cyclic_cache.rs
+++ /dev/null
@@ -1,63 +0,0 @@
-use rustc_data_structures::graph::{
-    self, DirectedGraph, WithNumNodes, WithStartNode, WithSuccessors,
-};
-use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
-use rustc_data_structures::sync::OnceCell;
-use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
-
-/// Helper type to cache the result of `graph::is_cyclic`.
-#[derive(Clone, Debug)]
-pub(super) struct GraphIsCyclicCache {
-    cache: OnceCell<bool>,
-}
-
-impl GraphIsCyclicCache {
-    #[inline]
-    pub(super) fn new() -> Self {
-        GraphIsCyclicCache { cache: OnceCell::new() }
-    }
-
-    pub(super) fn is_cyclic<G>(&self, graph: &G) -> bool
-    where
-        G: ?Sized + DirectedGraph + WithStartNode + WithSuccessors + WithNumNodes,
-    {
-        *self.cache.get_or_init(|| graph::is_cyclic(graph))
-    }
-
-    /// Invalidates the cache.
-    #[inline]
-    pub(super) fn invalidate(&mut self) {
-        // Invalidating the cache requires mutating the MIR, which in turn requires a unique
-        // reference (`&mut`) to the `mir::Body`. Because of this, we can assume that all
-        // callers of `invalidate` have a unique reference to the MIR and thus to the
-        // cache. This means we never need to do synchronization when `invalidate` is called,
-        // we can simply reinitialize the `OnceCell`.
-        self.cache = OnceCell::new();
-    }
-}
-
-impl<S: Encoder> Encodable<S> for GraphIsCyclicCache {
-    #[inline]
-    fn encode(&self, s: &mut S) {
-        Encodable::encode(&(), s);
-    }
-}
-
-impl<D: Decoder> Decodable<D> for GraphIsCyclicCache {
-    #[inline]
-    fn decode(d: &mut D) -> Self {
-        let () = Decodable::decode(d);
-        Self::new()
-    }
-}
-
-impl<CTX> HashStable<CTX> for GraphIsCyclicCache {
-    #[inline]
-    fn hash_stable(&self, _: &mut CTX, _: &mut StableHasher) {
-        // do nothing
-    }
-}
-
-TrivialTypeTraversalAndLiftImpls! {
-    GraphIsCyclicCache,
-}