Remove unnecessary TRY_LOAD_FROM_DISK constant

Author: jyn514

compiler/rustc_query_impl/src/lib.rs

@@ -34,7 +34,6 @@ pub use rustc_query_system::query::{deadlock, QueryContext};
 mod keys;
 use keys::Key;
 
-use rustc_query_system::dep_graph::SerializedDepNodeIndex;
 pub use rustc_query_system::query::QueryConfig;
 pub(crate) use rustc_query_system::query::{QueryDescription, QueryVTable};
 

compiler/rustc_query_impl/src/plumbing.rs

@@ -412,9 +412,6 @@ macro_rules! define_queries {
         impl<'tcx> QueryDescription<QueryCtxt<'tcx>> for queries::$name<'tcx> {
             rustc_query_description! { $name }
 
-            const TRY_LOAD_FROM_DISK: Option<fn(QueryCtxt<'tcx>, SerializedDepNodeIndex) -> Option<Self::Value>>
-                = should_ever_cache_on_disk!([$($modifiers)*]);
-
             type Cache = query_storage::$name<'tcx>;
 
             #[inline(always)]
@@ -445,7 +442,7 @@ macro_rules! define_queries {
                     hash_result: hash_result!([$($modifiers)*]),
                     handle_cycle_error: handle_cycle_error!([$($modifiers)*]),
                     compute,
-                    try_load_from_disk: if cache_on_disk { Self::TRY_LOAD_FROM_DISK } else { None },
+                    try_load_from_disk: if cache_on_disk { should_ever_cache_on_disk!([$($modifiers)*]) } else { None },
                 }
             }
 

compiler/rustc_query_system/src/query/config.rs

@@ -29,8 +29,7 @@ pub struct QueryVTable<CTX: QueryContext, K, V> {
     pub compute: fn(CTX::DepContext, K) -> V,
     pub hash_result: Option<fn(&mut StableHashingContext<'_>, &V) -> Fingerprint>,
     pub handle_cycle_error: HandleCycleError,
-    // NOTE: this is not quite the same as `Q::TRY_LOAD_FROM_DISK`; it can also be `None` if
-    // `cache_on_disk` returned false for this key.
+    // NOTE: this is also `None` if `cache_on_disk()` returns false, not just if it's unsupported by the query
     pub try_load_from_disk: Option<fn(CTX, SerializedDepNodeIndex) -> Option<V>>,
 }
 
@@ -48,8 +47,6 @@ impl<CTX: QueryContext, K, V> QueryVTable<CTX, K, V> {
 }
 
 pub trait QueryDescription<CTX: QueryContext>: QueryConfig {
-    const TRY_LOAD_FROM_DISK: Option<fn(CTX, SerializedDepNodeIndex) -> Option<Self::Value>>;
-
     type Cache: QueryCache<Key = Self::Key, Stored = Self::Stored, Value = Self::Value>;
 
     fn describe(tcx: CTX, key: Self::Key) -> String;