Auto merge of #90065 - cjgillot:novalcache, r=Mark-Simulacrum

Do not depend on the stored value when trying to cache on disk.

Having different criteria for loading and saving of query results can lead to saved results that may never be loaded.
Since the on-disk cache is discarded as soon as a compilation error is issued, there should not be any need for an exclusion mecanism based on errors.

As a result, the possibility to condition the storage on the value itself does not appear useful.

6 files changed, 12 insertions, 25 deletions

diff --git a/compiler/rustc_macros/src/query.rs b/compiler/rustc_macros/src/query.rs
index 005017185c1..443af50c5ff 100644
--- a/compiler/rustc_macros/src/query.rs
+++ b/compiler/rustc_macros/src/query.rs
@@ -36,7 +36,7 @@ enum QueryModifier {
     Storage(Type),
 
     /// Cache the query to disk if the `Expr` returns true.
-    Cache(Option<(IdentOrWild, IdentOrWild)>, Block),
+    Cache(Option<IdentOrWild>, Block),
 
     /// Custom code to load the query from disk.
     LoadCached(Ident, Ident, Block),
@@ -87,9 +87,7 @@ impl Parse for QueryModifier {
                 let args;
                 parenthesized!(args in input);
                 let tcx = args.parse()?;
-                args.parse::<Token![,]>()?;
-                let value = args.parse()?;
-                Some((tcx, value))
+                Some(tcx)
             } else {
                 None
             };
@@ -197,7 +195,7 @@ struct QueryModifiers {
     storage: Option<Type>,
 
     /// Cache the query to disk if the `Block` returns true.
-    cache: Option<(Option<(IdentOrWild, IdentOrWild)>, Block)>,
+    cache: Option<(Option<IdentOrWild>, Block)>,
 
     /// Custom code to load the query from disk.
     load_cached: Option<(Ident, Ident, Block)>,
@@ -375,14 +373,7 @@ fn add_query_description_impl(
         let tcx = args
             .as_ref()
             .map(|t| {
-                let t = &(t.0).0;
-                quote! { #t }
-            })
-            .unwrap_or_else(|| quote! { _ });
-        let value = args
-            .as_ref()
-            .map(|t| {
-                let t = &(t.1).0;
+                let t = &t.0;
                 quote! { #t }
             })
             .unwrap_or_else(|| quote! { _ });
@@ -394,7 +385,6 @@ fn add_query_description_impl(
             fn cache_on_disk(
                 #tcx: QueryCtxt<'tcx>,
                 #key: &Self::Key,
-                #value: Option<&Self::Value>
             ) -> bool {
                 #expr
             }
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 18be9817c5f..c6c0fdc8851 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -765,10 +765,7 @@ rustc_queries! {
     /// additional requirements that the closure's creator must verify.
     query mir_borrowck(key: LocalDefId) -> &'tcx mir::BorrowCheckResult<'tcx> {
         desc { |tcx| "borrow-checking `{}`", tcx.def_path_str(key.to_def_id()) }
-        cache_on_disk_if(tcx, opt_result) {
-            tcx.is_closure(key.to_def_id())
-                || opt_result.map_or(false, |r| !r.concrete_opaque_types.is_empty())
-        }
+        cache_on_disk_if(tcx) { tcx.is_closure(key.to_def_id()) }
     }
     query mir_borrowck_const_arg(key: (LocalDefId, DefId)) -> &'tcx mir::BorrowCheckResult<'tcx> {
         desc {
diff --git a/compiler/rustc_query_impl/src/on_disk_cache.rs b/compiler/rustc_query_impl/src/on_disk_cache.rs
index 86b12b3586a..7678c86596b 100644
--- a/compiler/rustc_query_impl/src/on_disk_cache.rs
+++ b/compiler/rustc_query_impl/src/on_disk_cache.rs
@@ -1033,7 +1033,7 @@ where
         if res.is_err() {
             return;
         }
-        if Q::cache_on_disk(tcx, &key, Some(value)) {
+        if Q::cache_on_disk(tcx, &key) {
             let dep_node = SerializedDepNodeIndex::new(dep_node.index());
 
             // Record position of the cache entry.
diff --git a/compiler/rustc_query_impl/src/plumbing.rs b/compiler/rustc_query_impl/src/plumbing.rs
index 8c3fbb2071c..a822ef14778 100644
--- a/compiler/rustc_query_impl/src/plumbing.rs
+++ b/compiler/rustc_query_impl/src/plumbing.rs
@@ -418,7 +418,7 @@ macro_rules! define_queries {
 
                     let key = recover(tcx, dep_node).unwrap_or_else(|| panic!("Failed to recover key for {:?} with hash {}", dep_node, dep_node.hash));
                     let tcx = QueryCtxt::from_tcx(tcx);
-                    if queries::$name::cache_on_disk(tcx, &key, None) {
+                    if queries::$name::cache_on_disk(tcx, &key) {
                         let _ = tcx.$name(key);
                     }
                 }
diff --git a/compiler/rustc_query_system/src/query/config.rs b/compiler/rustc_query_system/src/query/config.rs
index fc3b7980dfb..07b2e2b1080 100644
--- a/compiler/rustc_query_system/src/query/config.rs
+++ b/compiler/rustc_query_system/src/query/config.rs
@@ -27,7 +27,7 @@ pub(crate) 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: fn(CTX, DiagnosticBuilder<'_>) -> V,
-    pub cache_on_disk: fn(CTX, &K, Option<&V>) -> bool,
+    pub cache_on_disk: fn(CTX, &K) -> bool,
     pub try_load_from_disk: fn(CTX, SerializedDepNodeIndex) -> Option<V>,
 }
 
@@ -43,8 +43,8 @@ impl<CTX: QueryContext, K, V> QueryVtable<CTX, K, V> {
         (self.compute)(tcx, key)
     }
 
-    pub(crate) fn cache_on_disk(&self, tcx: CTX, key: &K, value: Option<&V>) -> bool {
-        (self.cache_on_disk)(tcx, key, value)
+    pub(crate) fn cache_on_disk(&self, tcx: CTX, key: &K) -> bool {
+        (self.cache_on_disk)(tcx, key)
     }
 
     pub(crate) fn try_load_from_disk(&self, tcx: CTX, index: SerializedDepNodeIndex) -> Option<V> {
@@ -82,7 +82,7 @@ pub trait QueryDescription<CTX: QueryContext>: QueryAccessors<CTX> {
     fn describe(tcx: CTX, key: Self::Key) -> String;
 
     #[inline]
-    fn cache_on_disk(_: CTX, _: &Self::Key, _: Option<&Self::Value>) -> bool {
+    fn cache_on_disk(_: CTX, _: &Self::Key) -> bool {
         false
     }
 
diff --git a/compiler/rustc_query_system/src/query/plumbing.rs b/compiler/rustc_query_system/src/query/plumbing.rs
index 056611317dc..5506666b6a1 100644
--- a/compiler/rustc_query_system/src/query/plumbing.rs
+++ b/compiler/rustc_query_system/src/query/plumbing.rs
@@ -512,7 +512,7 @@ where
 
     // First we try to load the result from the on-disk cache.
     // Some things are never cached on disk.
-    if query.cache_on_disk(tcx, key, None) {
+    if query.cache_on_disk(tcx, key) {
         let prof_timer = tcx.dep_context().profiler().incr_cache_loading();
         let result = query.try_load_from_disk(tcx, prev_dep_node_index);
         prof_timer.finish_with_query_invocation_id(dep_node_index.into());