Auto merge of #108167 - Zoxc:query-config-instance-slim, r=cjgillot

Make `rustc_query_system` take `QueryConfig` by instance.

This allows for easy switching between virtual tables and specialized instances for queries. It also has the benefit of less turbofish. `QueryStorage` has also been merged with `QueryCache`.

Split out from https://github.com/rust-lang/rust/pull/107937.

r? `@cjgillot`

5 files changed, 96 insertions, 82 deletions

diff --git a/compiler/rustc_query_system/src/dep_graph/mod.rs b/compiler/rustc_query_system/src/dep_graph/mod.rs
index 6969f2dbef8..ba83b775631 100644
--- a/compiler/rustc_query_system/src/dep_graph/mod.rs
+++ b/compiler/rustc_query_system/src/dep_graph/mod.rs
@@ -88,6 +88,15 @@ impl<T: DepContext> HasDepContext for T {
     }
 }
 
+impl<T: HasDepContext, Q: Copy> HasDepContext for (T, Q) {
+    type DepKind = T::DepKind;
+    type DepContext = T::DepContext;
+
+    fn dep_context(&self) -> &Self::DepContext {
+        self.0.dep_context()
+    }
+}
+
 /// Describes the contents of the fingerprint generated by a given query.
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
 pub enum FingerprintStyle {
diff --git a/compiler/rustc_query_system/src/query/caches.rs b/compiler/rustc_query_system/src/query/caches.rs
index 4b3cd16c29f..5f554a54dea 100644
--- a/compiler/rustc_query_system/src/query/caches.rs
+++ b/compiler/rustc_query_system/src/query/caches.rs
@@ -16,12 +16,9 @@ pub trait CacheSelector<'tcx, V> {
         V: Copy;
 }
 
-pub trait QueryStorage {
-    type Value: Copy;
-}
-
-pub trait QueryCache: QueryStorage + Sized {
+pub trait QueryCache: Sized {
     type Key: Hash + Eq + Copy + Debug;
+    type Value: Copy + Debug;
 
     /// Checks if the query is already computed and in the cache.
     /// It returns the shard index and a lock guard to the shard,
@@ -55,16 +52,13 @@ impl<K, V> Default for DefaultCache<K, V> {
     }
 }
 
-impl<K: Eq + Hash, V: Copy + Debug> 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,
 {
     type Key = K;
+    type Value = V;
 
     #[inline(always)]
     fn lookup(&self, key: &K) -> Option<(V, DepNodeIndex)> {
@@ -127,15 +121,12 @@ impl<V> Default for SingleCache<V> {
     }
 }
 
-impl<V: Copy + Debug> QueryStorage for SingleCache<V> {
-    type Value = V;
-}
-
 impl<V> QueryCache for SingleCache<V>
 where
     V: Copy + Debug,
 {
     type Key = ();
+    type Value = V;
 
     #[inline(always)]
     fn lookup(&self, _key: &()) -> Option<(V, DepNodeIndex)> {
@@ -173,16 +164,13 @@ impl<K: Idx, V> Default for VecCache<K, V> {
     }
 }
 
-impl<K: Eq + Idx, V: Copy + Debug> 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,
 {
     type Key = K;
+    type Value = V;
 
     #[inline(always)]
     fn lookup(&self, key: &K) -> Option<(V, DepNodeIndex)> {
diff --git a/compiler/rustc_query_system/src/query/config.rs b/compiler/rustc_query_system/src/query/config.rs
index d5637387346..e44a00ca6cb 100644
--- a/compiler/rustc_query_system/src/query/config.rs
+++ b/compiler/rustc_query_system/src/query/config.rs
@@ -10,14 +10,12 @@ use rustc_data_structures::fingerprint::Fingerprint;
 use std::fmt::Debug;
 use std::hash::Hash;
 
-pub type HashResult<Qcx, Q> =
-    Option<fn(&mut StableHashingContext<'_>, &<Q as QueryConfig<Qcx>>::Value) -> Fingerprint>;
+pub type HashResult<V> = Option<fn(&mut StableHashingContext<'_>, &V) -> Fingerprint>;
 
-pub type TryLoadFromDisk<Qcx, Q> =
-    Option<fn(Qcx, SerializedDepNodeIndex) -> Option<<Q as QueryConfig<Qcx>>::Value>>;
+pub type TryLoadFromDisk<Qcx, V> = Option<fn(Qcx, SerializedDepNodeIndex) -> Option<V>>;
 
-pub trait QueryConfig<Qcx: QueryContext> {
-    const NAME: &'static str;
+pub trait QueryConfig<Qcx: QueryContext>: Copy {
+    fn name(self) -> &'static str;
 
     // `Key` and `Value` are `Copy` instead of `Clone` to ensure copying them stays cheap,
     // but it isn't necessary.
@@ -27,36 +25,35 @@ pub trait QueryConfig<Qcx: QueryContext> {
     type Cache: QueryCache<Key = Self::Key, Value = Self::Value>;
 
     // Don't use this method to access query results, instead use the methods on TyCtxt
-    fn query_state<'a>(tcx: Qcx) -> &'a QueryState<Self::Key, Qcx::DepKind>
+    fn query_state<'a>(self, tcx: Qcx) -> &'a QueryState<Self::Key, Qcx::DepKind>
     where
         Qcx: 'a;
 
     // Don't use this method to access query results, instead use the methods on TyCtxt
-    fn query_cache<'a>(tcx: Qcx) -> &'a Self::Cache
+    fn query_cache<'a>(self, tcx: Qcx) -> &'a Self::Cache
     where
         Qcx: 'a;
 
-    fn cache_on_disk(tcx: Qcx::DepContext, key: &Self::Key) -> bool;
+    fn cache_on_disk(self, tcx: Qcx::DepContext, key: &Self::Key) -> bool;
 
     // Don't use this method to compute query results, instead use the methods on TyCtxt
-    fn execute_query(tcx: Qcx::DepContext, k: Self::Key) -> Self::Value;
+    fn execute_query(self, tcx: Qcx::DepContext, k: Self::Key) -> Self::Value;
 
-    fn compute(tcx: Qcx, key: Self::Key) -> Self::Value;
+    fn compute(self, tcx: Qcx, key: Self::Key) -> Self::Value;
 
-    fn try_load_from_disk(qcx: Qcx, idx: &Self::Key) -> TryLoadFromDisk<Qcx, Self>;
+    fn try_load_from_disk(self, qcx: Qcx, idx: &Self::Key) -> TryLoadFromDisk<Qcx, Self::Value>;
 
-    const ANON: bool;
-    const EVAL_ALWAYS: bool;
-    const DEPTH_LIMIT: bool;
-    const FEEDABLE: bool;
+    fn anon(self) -> bool;
+    fn eval_always(self) -> bool;
+    fn depth_limit(self) -> bool;
+    fn feedable(self) -> bool;
 
-    const DEP_KIND: Qcx::DepKind;
-    const HANDLE_CYCLE_ERROR: HandleCycleError;
-
-    const HASH_RESULT: HashResult<Qcx, Self>;
+    fn dep_kind(self) -> Qcx::DepKind;
+    fn handle_cycle_error(self) -> HandleCycleError;
+    fn hash_result(self) -> HashResult<Self::Value>;
 
     // Just here for convernience and checking that the key matches the kind, don't override this.
-    fn construct_dep_node(tcx: Qcx::DepContext, key: &Self::Key) -> DepNode<Qcx::DepKind> {
-        DepNode::construct(tcx, Self::DEP_KIND, key)
+    fn construct_dep_node(self, tcx: Qcx::DepContext, key: &Self::Key) -> DepNode<Qcx::DepKind> {
+        DepNode::construct(tcx, self.dep_kind(), key)
     }
 }
diff --git a/compiler/rustc_query_system/src/query/mod.rs b/compiler/rustc_query_system/src/query/mod.rs
index 383c63cd2f8..312b0e1688d 100644
--- a/compiler/rustc_query_system/src/query/mod.rs
+++ b/compiler/rustc_query_system/src/query/mod.rs
@@ -8,8 +8,7 @@ pub use self::job::{print_query_stack, QueryInfo, QueryJob, QueryJobId, QueryJob
 
 mod caches;
 pub use self::caches::{
-    CacheSelector, DefaultCacheSelector, QueryCache, QueryStorage, SingleCacheSelector,
-    VecCacheSelector,
+    CacheSelector, DefaultCacheSelector, QueryCache, SingleCacheSelector, VecCacheSelector,
 };
 
 mod config;
diff --git a/compiler/rustc_query_system/src/query/plumbing.rs b/compiler/rustc_query_system/src/query/plumbing.rs
index 5f003fa70e1..005fcd8c4cc 100644
--- a/compiler/rustc_query_system/src/query/plumbing.rs
+++ b/compiler/rustc_query_system/src/query/plumbing.rs
@@ -2,6 +2,7 @@
 //! generate the actual methods on tcx which find and execute the provider,
 //! manage the caches, and so forth.
 
+use crate::dep_graph::HasDepContext;
 use crate::dep_graph::{DepContext, DepKind, DepNode, DepNodeIndex, DepNodeParams};
 use crate::ich::StableHashingContext;
 use crate::query::caches::QueryCache;
@@ -126,7 +127,7 @@ fn mk_cycle<Qcx, R, D: DepKind>(
     handler: HandleCycleError,
 ) -> R
 where
-    Qcx: QueryContext + crate::query::HasDepContext<DepKind = D>,
+    Qcx: QueryContext + HasDepContext<DepKind = D>,
     R: std::fmt::Debug + Value<Qcx::DepContext, Qcx::DepKind>,
 {
     let error = report_cycle(qcx.dep_context().sess(), &cycle_error);
@@ -181,7 +182,7 @@ where
         key: K,
     ) -> TryGetJob<'b, K, D>
     where
-        Qcx: QueryContext + crate::query::HasDepContext<DepKind = D>,
+        Qcx: QueryContext + HasDepContext<DepKind = D>,
     {
         #[cfg(parallel_compiler)]
         let mut state_lock = state.active.get_shard_by_value(&key).lock();
@@ -350,6 +351,7 @@ where
 
 #[inline(never)]
 fn try_execute_query<Q, Qcx>(
+    query: Q,
     qcx: Qcx,
     span: Span,
     key: Q::Key,
@@ -359,12 +361,12 @@ where
     Q: QueryConfig<Qcx>,
     Qcx: QueryContext,
 {
-    let state = Q::query_state(qcx);
+    let state = query.query_state(qcx);
     match JobOwner::<'_, Q::Key, Qcx::DepKind>::try_start(&qcx, state, span, key) {
         TryGetJob::NotYetStarted(job) => {
-            let (result, dep_node_index) = execute_job::<Q, Qcx>(qcx, key, dep_node, job.id);
-            let cache = Q::query_cache(qcx);
-            if Q::FEEDABLE {
+            let (result, dep_node_index) = execute_job(query, qcx, key.clone(), dep_node, job.id);
+            let cache = query.query_cache(qcx);
+            if query.feedable() {
                 // We should not compute queries that also got a value via feeding.
                 // This can't happen, as query feeding adds the very dependencies to the fed query
                 // as its feeding query had. So if the fed query is red, so is its feeder, which will
@@ -379,12 +381,12 @@ where
             (result, Some(dep_node_index))
         }
         TryGetJob::Cycle(error) => {
-            let result = mk_cycle(qcx, error, Q::HANDLE_CYCLE_ERROR);
+            let result = mk_cycle(qcx, error, query.handle_cycle_error());
             (result, None)
         }
         #[cfg(parallel_compiler)]
         TryGetJob::JobCompleted(query_blocked_prof_timer) => {
-            let Some((v, index)) = Q::query_cache(qcx).lookup(&key) else {
+            let Some((v, index)) = query.query_cache(qcx).lookup(&key) else {
                 panic!("value must be in cache after waiting")
             };
 
@@ -398,6 +400,7 @@ where
 
 #[inline(always)]
 fn execute_job<Q, Qcx>(
+    query: Q,
     qcx: Qcx,
     key: Q::Key,
     mut dep_node_opt: Option<DepNode<Qcx::DepKind>>,
@@ -418,14 +421,14 @@ where
         }
 
         let prof_timer = qcx.dep_context().profiler().query_provider();
-        let result = qcx.start_query(job_id, Q::DEPTH_LIMIT, None, || Q::compute(qcx, key));
+        let result = qcx.start_query(job_id, query.depth_limit(), None, || query.compute(qcx, key));
         let dep_node_index = dep_graph.next_virtual_depnode_index();
         prof_timer.finish_with_query_invocation_id(dep_node_index.into());
 
         // Similarly, fingerprint the result to assert that
         // it doesn't have anything not considered hashable.
         if cfg!(debug_assertions)
-            && let Some(hash_result) = Q::HASH_RESULT
+            && let Some(hash_result) = query.hash_result()
         {
             qcx.dep_context().with_stable_hashing_context(|mut hcx| {
                 hash_result(&mut hcx, &result);
@@ -435,15 +438,15 @@ where
         return (result, dep_node_index);
     }
 
-    if !Q::ANON && !Q::EVAL_ALWAYS {
+    if !query.anon() && !query.eval_always() {
         // `to_dep_node` is expensive for some `DepKind`s.
         let dep_node =
-            dep_node_opt.get_or_insert_with(|| Q::construct_dep_node(*qcx.dep_context(), &key));
+            dep_node_opt.get_or_insert_with(|| query.construct_dep_node(*qcx.dep_context(), &key));
 
         // The diagnostics for this query will be promoted to the current session during
         // `try_mark_green()`, so we can ignore them here.
         if let Some(ret) = qcx.start_query(job_id, false, None, || {
-            try_load_from_disk_and_cache_in_memory::<Q, Qcx>(qcx, &key, &dep_node)
+            try_load_from_disk_and_cache_in_memory(query, qcx, &key, &dep_node)
         }) {
             return ret;
         }
@@ -453,17 +456,24 @@ where
     let diagnostics = Lock::new(ThinVec::new());
 
     let (result, dep_node_index) =
-        qcx.start_query(job_id, Q::DEPTH_LIMIT, Some(&diagnostics), || {
-            if Q::ANON {
-                return dep_graph
-                    .with_anon_task(*qcx.dep_context(), Q::DEP_KIND, || Q::compute(qcx, key));
+        qcx.start_query(job_id, query.depth_limit(), Some(&diagnostics), || {
+            if query.anon() {
+                return dep_graph.with_anon_task(*qcx.dep_context(), query.dep_kind(), || {
+                    query.compute(qcx, key)
+                });
             }
 
             // `to_dep_node` is expensive for some `DepKind`s.
             let dep_node =
-                dep_node_opt.unwrap_or_else(|| Q::construct_dep_node(*qcx.dep_context(), &key));
-
-            dep_graph.with_task(dep_node, qcx, key, Q::compute, Q::HASH_RESULT)
+                dep_node_opt.unwrap_or_else(|| query.construct_dep_node(*qcx.dep_context(), &key));
+
+            dep_graph.with_task(
+                dep_node,
+                (qcx, query),
+                key,
+                |(qcx, query), key| query.compute(qcx, key),
+                query.hash_result(),
+            )
         });
 
     prof_timer.finish_with_query_invocation_id(dep_node_index.into());
@@ -472,7 +482,7 @@ where
     let side_effects = QuerySideEffects { diagnostics };
 
     if std::intrinsics::unlikely(!side_effects.is_empty()) {
-        if Q::ANON {
+        if query.anon() {
             qcx.store_side_effects_for_anon_node(dep_node_index, side_effects);
         } else {
             qcx.store_side_effects(dep_node_index, side_effects);
@@ -484,6 +494,7 @@ where
 
 #[inline(always)]
 fn try_load_from_disk_and_cache_in_memory<Q, Qcx>(
+    query: Q,
     qcx: Qcx,
     key: &Q::Key,
     dep_node: &DepNode<Qcx::DepKind>,
@@ -502,7 +513,7 @@ where
 
     // First we try to load the result from the on-disk cache.
     // Some things are never cached on disk.
-    if let Some(try_load_from_disk) = Q::try_load_from_disk(qcx, &key) {
+    if let Some(try_load_from_disk) = query.try_load_from_disk(qcx, &key) {
         let prof_timer = qcx.dep_context().profiler().incr_cache_loading();
 
         // The call to `with_query_deserialization` enforces that no new `DepNodes`
@@ -536,7 +547,7 @@ where
             if std::intrinsics::unlikely(
                 try_verify || qcx.dep_context().sess().opts.unstable_opts.incremental_verify_ich,
             ) {
-                incremental_verify_ich(*qcx.dep_context(), &result, dep_node, Q::HASH_RESULT);
+                incremental_verify_ich(*qcx.dep_context(), &result, dep_node, query.hash_result());
             }
 
             return Some((result, dep_node_index));
@@ -555,7 +566,7 @@ where
     let prof_timer = qcx.dep_context().profiler().query_provider();
 
     // The dep-graph for this computation is already in-place.
-    let result = dep_graph.with_ignore(|| Q::compute(qcx, *key));
+    let result = dep_graph.with_ignore(|| query.compute(qcx, *key));
 
     prof_timer.finish_with_query_invocation_id(dep_node_index.into());
 
@@ -568,7 +579,7 @@ where
     //
     // See issue #82920 for an example of a miscompilation that would get turned into
     // an ICE by this check
-    incremental_verify_ich(*qcx.dep_context(), &result, dep_node, Q::HASH_RESULT);
+    incremental_verify_ich(*qcx.dep_context(), &result, dep_node, query.hash_result());
 
     Some((result, dep_node_index))
 }
@@ -689,19 +700,23 @@ fn incremental_verify_ich_failed(sess: &Session, dep_node: DebugArg<'_>, result:
 ///
 /// Note: The optimization is only available during incr. comp.
 #[inline(never)]
-fn ensure_must_run<Q, Qcx>(qcx: Qcx, key: &Q::Key) -> (bool, Option<DepNode<Qcx::DepKind>>)
+fn ensure_must_run<Q, Qcx>(
+    query: Q,
+    qcx: Qcx,
+    key: &Q::Key,
+) -> (bool, Option<DepNode<Qcx::DepKind>>)
 where
     Q: QueryConfig<Qcx>,
     Qcx: QueryContext,
 {
-    if Q::EVAL_ALWAYS {
+    if query.eval_always() {
         return (true, None);
     }
 
     // Ensuring an anonymous query makes no sense
-    assert!(!Q::ANON);
+    assert!(!query.anon());
 
-    let dep_node = Q::construct_dep_node(*qcx.dep_context(), key);
+    let dep_node = query.construct_dep_node(*qcx.dep_context(), key);
 
     let dep_graph = qcx.dep_context().dep_graph();
     match dep_graph.try_mark_green(qcx, &dep_node) {
@@ -729,15 +744,19 @@ pub enum QueryMode {
 }
 
 #[inline(always)]
-pub fn get_query<Q, Qcx, D>(qcx: Qcx, span: Span, key: Q::Key, mode: QueryMode) -> Option<Q::Value>
+pub fn get_query<Q, Qcx>(
+    query: Q,
+    qcx: Qcx,
+    span: Span,
+    key: Q::Key,
+    mode: QueryMode,
+) -> Option<Q::Value>
 where
-    D: DepKind,
     Q: QueryConfig<Qcx>,
-    Q::Value: Value<Qcx::DepContext, D>,
     Qcx: QueryContext,
 {
     let dep_node = if let QueryMode::Ensure = mode {
-        let (must_run, dep_node) = ensure_must_run::<Q, _>(qcx, &key);
+        let (must_run, dep_node) = ensure_must_run(query, qcx, &key);
         if !must_run {
             return None;
         }
@@ -747,28 +766,30 @@ where
     };
 
     let (result, dep_node_index) =
-        ensure_sufficient_stack(|| try_execute_query::<Q, Qcx>(qcx, span, key, dep_node));
+        ensure_sufficient_stack(|| try_execute_query(query, qcx, span, key, dep_node));
     if let Some(dep_node_index) = dep_node_index {
         qcx.dep_context().dep_graph().read_index(dep_node_index)
     }
     Some(result)
 }
 
-pub fn force_query<Q, Qcx, D>(qcx: Qcx, key: Q::Key, dep_node: DepNode<Qcx::DepKind>)
-where
-    D: DepKind,
+pub fn force_query<Q, Qcx>(
+    query: Q,
+    qcx: Qcx,
+    key: Q::Key,
+    dep_node: DepNode<<Qcx as HasDepContext>::DepKind>,
+) where
     Q: QueryConfig<Qcx>,
-    Q::Value: Value<Qcx::DepContext, D>,
     Qcx: QueryContext,
 {
     // We may be concurrently trying both execute and force a query.
     // Ensure that only one of them runs the query.
-    if let Some((_, index)) = Q::query_cache(qcx).lookup(&key) {
+    if let Some((_, index)) = query.query_cache(qcx).lookup(&key) {
         qcx.dep_context().profiler().query_cache_hit(index.into());
         return;
     }
 
-    debug_assert!(!Q::ANON);
+    debug_assert!(!query.anon());
 
-    ensure_sufficient_stack(|| try_execute_query::<Q, _>(qcx, DUMMY_SP, key, Some(dep_node)));
+    ensure_sufficient_stack(|| try_execute_query(query, qcx, DUMMY_SP, key, Some(dep_node)));
 }