Move librustc_hir/def_id.rs to librustc_span/def_id.rs

[rust.git] / src / librustc_hir / stable_hash_impls.rs

diff --git a/src/librustc_hir/stable_hash_impls.rs b/src/librustc_hir/stable_hash_impls.rs
index 696a350ebdd15e7d97ba5ed1fe37850c9a51d307..e8407b537011bf64655ce230cca5c6161150749c 100644 (file)
--- a/src/librustc_hir/stable_hash_impls.rs
+++ b/src/librustc_hir/stable_hash_impls.rs
@@ -1,6 +1,5 @@
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 
-use crate::def_id::DefId;
 use crate::hir::{BodyId, Expr, ImplItemId, ItemId, Mod, TraitItemId, Ty, VisibilityKind};
 use crate::hir_id::HirId;
 
@@ -8,12 +7,9 @@
 /// This is a hack to allow using the `HashStable_Generic` derive macro
 /// instead of implementing everything in librustc.
 pub trait HashStableContext: syntax::HashStableContext + rustc_target::HashStableContext {
-    fn hash_def_id(&mut self, _: DefId, hasher: &mut StableHasher);
     fn hash_hir_id(&mut self, _: HirId, hasher: &mut StableHasher);
     fn hash_body_id(&mut self, _: BodyId, hasher: &mut StableHasher);
-    fn hash_item_id(&mut self, _: ItemId, hasher: &mut StableHasher);
-    fn hash_impl_item_id(&mut self, _: ImplItemId, hasher: &mut StableHasher);
-    fn hash_trait_item_id(&mut self, _: TraitItemId, hasher: &mut StableHasher);
+    fn hash_reference_to_item(&mut self, _: HirId, hasher: &mut StableHasher);
     fn hash_hir_mod(&mut self, _: &Mod<'_>, hasher: &mut StableHasher);
     fn hash_hir_expr(&mut self, _: &Expr<'_>, hasher: &mut StableHasher);
     fn hash_hir_ty(&mut self, _: &Ty<'_>, hasher: &mut StableHasher);
@@ -26,33 +22,34 @@ fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
     }
 }
 
-impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for DefId {
-    fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
-        hcx.hash_def_id(*self, hasher)
-    }
-}
-
 impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for BodyId {
     fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
         hcx.hash_body_id(*self, hasher)
     }
 }
 
+// The following implementations of HashStable for `ItemId`, `TraitItemId`, and
+// `ImplItemId` deserve special attention. Normally we do not hash `NodeId`s within
+// the HIR, since they just signify a HIR nodes own path. But `ItemId` et al
+// are used when another item in the HIR is *referenced* and we certainly
+// want to pick up on a reference changing its target, so we hash the NodeIds
+// in "DefPath Mode".
+
 impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for ItemId {
     fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
-        hcx.hash_item_id(*self, hasher)
+        hcx.hash_reference_to_item(self.id, hasher)
     }
 }
 
 impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for ImplItemId {
     fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
-        hcx.hash_impl_item_id(*self, hasher)
+        hcx.hash_reference_to_item(self.hir_id, hasher)
     }
 }
 
 impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for TraitItemId {
     fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
-        hcx.hash_trait_item_id(*self, hasher)
+        hcx.hash_reference_to_item(self.hir_id, hasher)
     }
 }