rustc_metadata: Encode list of all crate's traits into metadata

2 files changed, 11 insertions, 5 deletions

diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index ad3f61d0784..027c0c64924 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -1609,11 +1609,11 @@ rustc_queries! {
         desc { "fetching all foreign CrateNum instances" }
     }
 
-    /// A vector of every trait accessible in the whole crate
-    /// (i.e., including those from subcrates). This is used only for
-    /// error reporting.
-    query all_traits(_: ()) -> &'tcx [DefId] {
-        desc { "fetching all foreign and local traits" }
+    /// A list of all traits in a crate, used by rustdoc and error reporting.
+    /// NOTE: Not named just `traits` due to a naming conflict.
+    query traits_in_crate(_: CrateNum) -> &'tcx [DefId] {
+        desc { "fetching all traits in a crate" }
+        separate_provide_extern
     }
 
     /// The list of symbols exported from the given crate.
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index caa7008f108..dd571e29bf6 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -1577,6 +1577,12 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn const_eval_limit(self) -> Limit {
         self.limits(()).const_eval_limit
     }
+
+    pub fn all_traits(self) -> impl Iterator<Item = DefId> + 'tcx {
+        iter::once(LOCAL_CRATE)
+            .chain(self.crates(()).iter().copied())
+            .flat_map(move |cnum| self.traits_in_crate(cnum).iter().copied())
+    }
 }
 
 /// A trait implemented for all `X<'a>` types that can be safely and