Type erase query results.

cjgillot · cjgillot · commit 28f391cb5efa · 2023-03-07T21:39:32.000Z
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
@@ -7,7 +7,7 @@
 use crate::ty::{self, print::describe_as_module, TyCtxt};
 use rustc_span::def_id::LOCAL_CRATE;
 
-mod erase;
+pub mod erase;
 mod keys;
 pub use keys::Key;
 
diff --git a/compiler/rustc_middle/src/ty/query.rs b/compiler/rustc_middle/src/ty/query.rs
@@ -69,6 +69,7 @@ use std::ops::Deref;
 use std::path::PathBuf;
 use std::sync::Arc;
 
+use crate::query::erase::{erase, restore, Erase};
 pub(crate) use rustc_query_system::query::QueryJobId;
 use rustc_query_system::query::*;
 
@@ -246,7 +247,30 @@ macro_rules! define_callbacks {
             use super::*;
 
             $(
-                pub type $name<'tcx> = <<$($K)* as Key>::CacheSelector as CacheSelector<'tcx, $V>>::Cache;
+                pub type $name<'tcx> = <<$($K)* as Key>::CacheSelector as CacheSelector<'tcx, Erase<$V>>>::Cache;
+            )*
+        }
+        #[allow(nonstandard_style, unused_lifetimes)]
+        pub mod query_cache {
+            $(
+                #[derive(Default)]
+                pub struct $name<'tcx> {
+                    _phantom_lt: std::marker::PhantomData<&'tcx ()>,
+                    _phantom_key: std::marker::PhantomData<super::query_keys::$name<'tcx>>,
+                    _phantom_value: std::marker::PhantomData<super::query_values::$name<'tcx>>,
+                    cache: super::query_storage::$name<'static>,
+                }
+
+                impl<'tcx> $name<'tcx> {
+                    pub fn cache(&'tcx self) -> &'tcx super::query_storage::$name<'tcx> {
+                        unsafe {
+                            std::mem::transmute::<
+                                &super::query_storage::$name<'_>,
+                                &super::query_storage::$name<'_>,
+                            >(&self.cache)
+                        }
+                    }
+                }
             )*
         }
 
@@ -270,7 +294,7 @@ macro_rules! define_callbacks {
 
         #[derive(Default)]
         pub struct QueryCaches<'tcx> {
-            $($(#[$attr])* pub $name: query_storage::$name<'tcx>,)*
+            $($(#[$attr])* pub $name: query_cache::$name<'tcx>,)*
         }
 
         impl<'tcx> TyCtxtEnsure<'tcx> {
@@ -280,7 +304,7 @@ macro_rules! define_callbacks {
                 let key = key.into_query_param();
                 opt_remap_env_constness!([$($modifiers)*][key]);
 
-                match try_get_cached(self.tcx, &self.tcx.query_system.caches.$name, &key) {
+                match try_get_cached(self.tcx, self.tcx.query_system.caches.$name.cache(), &key) {
                     Some(_) => return,
                     None => self.tcx.queries.$name(self.tcx, DUMMY_SP, key, QueryMode::Ensure),
                 };
@@ -305,10 +329,11 @@ macro_rules! define_callbacks {
                 let key = key.into_query_param();
                 opt_remap_env_constness!([$($modifiers)*][key]);
 
-                match try_get_cached(self.tcx, &self.tcx.query_system.caches.$name, &key) {
+                let value = match try_get_cached(self.tcx, self.tcx.query_system.caches.$name.cache(), &key) {
                     Some(value) => value,
                     None => self.tcx.queries.$name(self.tcx, self.span, key, QueryMode::Get).unwrap(),
-                }
+                };
+                restore(value)
             })*
         }
 
@@ -372,7 +397,7 @@ macro_rules! define_callbacks {
                 span: Span,
                 key: query_keys::$name<'tcx>,
                 mode: QueryMode,
-            ) -> Option<$V>;)*
+            ) -> Option<Erase<$V>>;)*
         }
     };
 }
@@ -400,10 +425,11 @@ macro_rules! define_feedable {
 
                 let tcx = self.tcx;
                 let value = query_provided_to_value::$name(tcx, value);
-                let cache = &tcx.query_system.caches.$name;
+                let cache = tcx.query_system.caches.$name.cache();
 
                 match try_get_cached(tcx, cache, &key) {
                     Some(old) => {
+                        let old = restore(old);
                         bug!(
                             "Trying to feed an already recorded value for query {} key={key:?}:\nold value: {old:?}\nnew value: {value:?}",
                             stringify!($name),
@@ -418,7 +444,7 @@ macro_rules! define_feedable {
                             &value,
                             hash_result!([$($modifiers)*]),
                         );
-                        cache.complete(key, value, dep_node_index);
+                        cache.complete(key, erase(value), dep_node_index);
                         value
                     }
                 }
diff --git a/compiler/rustc_query_impl/src/lib.rs b/compiler/rustc_query_impl/src/lib.rs
@@ -20,6 +20,7 @@ extern crate rustc_middle;
 use rustc_data_structures::sync::AtomicU64;
 use rustc_middle::arena::Arena;
 use rustc_middle::dep_graph::{self, DepKindStruct};
+use rustc_middle::query::erase::{erase, restore, Erase};
 use rustc_middle::query::Key;
 use rustc_middle::ty::query::{
     query_keys, query_provided, query_provided_to_value, query_storage, query_values,
diff --git a/compiler/rustc_query_impl/src/on_disk_cache.rs b/compiler/rustc_query_impl/src/on_disk_cache.rs
@@ -10,6 +10,7 @@ use rustc_index::vec::{Idx, IndexVec};
 use rustc_middle::dep_graph::{DepNodeIndex, SerializedDepNodeIndex};
 use rustc_middle::mir::interpret::{AllocDecodingSession, AllocDecodingState};
 use rustc_middle::mir::{self, interpret};
+use rustc_middle::query::erase::{restore_ref, Erase, EraseType};
 use rustc_middle::ty::codec::{RefDecodable, TyDecoder, TyEncoder};
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_query_system::dep_graph::DepContext;
@@ -1056,14 +1057,14 @@ impl<'a, 'tcx> Encodable<CacheEncoder<'a, 'tcx>> for [u8] {
     }
 }
 
-pub fn encode_query_results<'a, 'tcx, CTX, Q>(
+pub fn encode_query_results<'a, 'tcx, CTX, Q, V>(
     tcx: CTX,
     encoder: &mut CacheEncoder<'a, 'tcx>,
     query_result_index: &mut EncodedDepNodeIndex,
 ) where
     CTX: QueryContext + 'tcx,
-    Q: super::QueryConfig<CTX>,
-    Q::Value: Encodable<CacheEncoder<'a, 'tcx>>,
+    Q: super::QueryConfig<CTX, Value = Erase<V>>,
+    V: EraseType + std::fmt::Debug + Encodable<CacheEncoder<'a, 'tcx>>,
 {
     let _timer = tcx
         .dep_context()
@@ -1081,6 +1082,7 @@ pub fn encode_query_results<'a, 'tcx, CTX, Q>(
 
             // Encode the type check tables with the `SerializedDepNodeIndex`
             // as tag.
+            let value = restore_ref(value);
             encoder.encode_tagged(dep_node, value);
         }
     });
diff --git a/compiler/rustc_query_impl/src/plumbing.rs b/compiler/rustc_query_impl/src/plumbing.rs
@@ -264,7 +264,9 @@ macro_rules! feedable {
 
 macro_rules! hash_result {
     ([]) => {{
-        Some(dep_graph::hash_result)
+        Some(|hcx, result| {
+            dep_graph::hash_result(hcx, &restore(*result))
+        })
     }};
     ([(no_hash) $($rest:tt)*]) => {{
         None
@@ -469,7 +471,7 @@ macro_rules! define_queries {
 
         $(impl<'tcx> QueryConfig<QueryCtxt<'tcx>> for queries::$name<'tcx> {
             type Key = query_keys::$name<'tcx>;
-            type Value = query_values::$name<'tcx>;
+            type Value = Erase<query_values::$name<'tcx>>;
             const NAME: &'static str = stringify!($name);
 
             #[inline]
@@ -490,20 +492,20 @@ macro_rules! define_queries {
             fn query_cache<'a>(tcx: QueryCtxt<'tcx>) -> &'a Self::Cache
                 where 'tcx:'a
             {
-                &tcx.query_system.caches.$name
+                tcx.query_system.caches.$name.cache()
             }
 
             fn execute_query(tcx: TyCtxt<'tcx>, key: Self::Key) -> Self::Value {
-                tcx.$name(key)
+                erase(tcx.$name(key))
             }
 
             #[inline]
             #[allow(unused_variables)]
             fn compute(qcx: QueryCtxt<'tcx>, key: Self::Key) -> Self::Value {
-                query_provided_to_value::$name(
+                erase(query_provided_to_value::$name(
                     qcx.tcx,
                     get_provider!([$($modifiers)*][qcx, $name, key])(qcx.tcx, key)
-                )
+                ))
             }
 
             #[inline]
@@ -516,6 +518,7 @@ macro_rules! define_queries {
                                 dep_node
                             );
                             value.map(|value| query_provided_to_value::$name(qcx.tcx, value))
+                                .map(erase)
                         })
                     } else {
                         None
@@ -645,12 +648,12 @@ macro_rules! define_queries {
                     $crate::profiling_support::alloc_self_profile_query_strings_for_query_cache(
                         tcx,
                         stringify!($name),
-                        &tcx.query_system.caches.$name,
+                        tcx.query_system.caches.$name.cache(),
                         string_cache,
                     )
                 },
                 encode_query_results: expand_if_cached!([$($modifiers)*], |tcx, encoder, query_result_index|
-                    $crate::on_disk_cache::encode_query_results::<_, super::queries::$name<'_>>(tcx, encoder, query_result_index)
+                    $crate::on_disk_cache::encode_query_results::<_, super::queries::$name<'_>, _>(tcx, encoder, query_result_index)
                 ),
             }})*
         }
@@ -695,7 +698,7 @@ macro_rules! define_queries_struct {
             $(
                 $(#[$attr])*
                 $name: QueryState<
-                    <queries::$name<'tcx> as QueryConfig<QueryCtxt<'tcx>>>::Key,
+                    query_keys::$name<'tcx>,
                     rustc_middle::dep_graph::DepKind,
                 >,
             )*
@@ -737,7 +740,7 @@ macro_rules! define_queries_struct {
                 span: Span,
                 key: <queries::$name<'tcx> as QueryConfig<QueryCtxt<'tcx>>>::Key,
                 mode: QueryMode,
-            ) -> Option<query_values::$name<'tcx>> {
+            ) -> Option<Erase<query_values::$name<'tcx>>> {
                 let qcx = QueryCtxt { tcx, queries: self };
                 get_query::<queries::$name<'tcx>, _, rustc_middle::dep_graph::DepKind>(qcx, span, key, mode)
             })*
diff --git a/compiler/rustc_query_system/src/query/caches.rs b/compiler/rustc_query_system/src/query/caches.rs
@@ -55,14 +55,14 @@ impl<K, V> Default for DefaultCache<K, V> {
     }
 }
 
-impl<K: Eq + Hash, V: Copy + Debug> QueryStorage for DefaultCache<K, V> {
+impl<K: Eq + Hash, V: Copy> QueryStorage for DefaultCache<K, V> {
     type Value = V;
 }
 
 impl<K, V> QueryCache for DefaultCache<K, V>
 where
     K: Eq + Hash + Copy + Debug,
-    V: Copy + Debug,
+    V: Copy,
 {
     type Key = K;
 
@@ -127,13 +127,13 @@ impl<V> Default for SingleCache<V> {
     }
 }
 
-impl<V: Copy + Debug> QueryStorage for SingleCache<V> {
+impl<V: Copy> QueryStorage for SingleCache<V> {
     type Value = V;
 }
 
 impl<V> QueryCache for SingleCache<V>
 where
-    V: Copy + Debug,
+    V: Copy,
 {
     type Key = ();
 
@@ -173,14 +173,14 @@ impl<K: Idx, V> Default for VecCache<K, V> {
     }
 }
 
-impl<K: Eq + Idx, V: Copy + Debug> QueryStorage for VecCache<K, V> {
+impl<K: Eq + Idx, V: Copy> QueryStorage for VecCache<K, V> {
     type Value = V;
 }
 
 impl<K, V> QueryCache for VecCache<K, V>
 where
     K: Eq + Idx + Copy + Debug,
-    V: Copy + Debug,
+    V: Copy,
 {
     type Key = K;
 

Original file line number	Diff line number	Diff line change
`@@ -55,14 +55,14 @@ impl<K, V> Default for DefaultCache<K, V> {`
`55`	`55`	`}`
`56`	`56`	`}`
`57`	`57`
`58`		`-impl<K: Eq + Hash, V: Copy + Debug> QueryStorage for DefaultCache<K, V> {`
	`58`	`+impl<K: Eq + Hash, V: Copy> QueryStorage for DefaultCache<K, V> {`
`59`	`59`	`type Value = V;`
`60`	`60`	`}`
`61`	`61`
`62`	`62`	`impl<K, V> QueryCache for DefaultCache<K, V>`
`63`	`63`	`where`
`64`	`64`	`K: Eq + Hash + Copy + Debug,`
`65`		`- V: Copy + Debug,`
	`65`	`+ V: Copy,`
`66`	`66`	`{`
`67`	`67`	`type Key = K;`
`68`	`68`
`@@ -127,13 +127,13 @@ impl<V> Default for SingleCache<V> {`
`127`	`127`	`}`
`128`	`128`	`}`
`129`	`129`
`130`		`-impl<V: Copy + Debug> QueryStorage for SingleCache<V> {`
	`130`	`+impl<V: Copy> QueryStorage for SingleCache<V> {`
`131`	`131`	`type Value = V;`
`132`	`132`	`}`
`133`	`133`
`134`	`134`	`impl<V> QueryCache for SingleCache<V>`
`135`	`135`	`where`
`136`		`- V: Copy + Debug,`
	`136`	`+ V: Copy,`
`137`	`137`	`{`
`138`	`138`	`type Key = ();`
`139`	`139`
`@@ -173,14 +173,14 @@ impl<K: Idx, V> Default for VecCache<K, V> {`
`173`	`173`	`}`
`174`	`174`	`}`
`175`	`175`
`176`		`-impl<K: Eq + Idx, V: Copy + Debug> QueryStorage for VecCache<K, V> {`
	`176`	`+impl<K: Eq + Idx, V: Copy> QueryStorage for VecCache<K, V> {`
`177`	`177`	`type Value = V;`
`178`	`178`	`}`
`179`	`179`
`180`	`180`	`impl<K, V> QueryCache for VecCache<K, V>`
`181`	`181`	`where`
`182`	`182`	`K: Eq + Idx + Copy + Debug,`
`183`		`- V: Copy + Debug,`
	`183`	`+ V: Copy,`
`184`	`184`	`{`
`185`	`185`	`type Key = K;`
`186`	`186`