Create QuerySideEffects and use it for diagnostics

compiler/rustc_query_system/src/query/mod.rs

@@ -62,6 +62,31 @@ impl QueryStackFrame {
     }
 }
 
+/// Tracks 'side effects' for a particular query.
+/// This struct is saved to disk along with the query result,
+/// and loaded from disk if we mark the query as green.
+/// This allows us to 'replay' changes to global state
+/// that would otherwise only occur if we actually
+/// executed the query method.
+#[derive(Debug, Clone, Default, Encodable, Decodable)]
+pub struct QuerySideEffects {
+    /// Stores any diagnostics emitted during query execution.
+    /// These diagnostics will be re-emitted if we mark
+    /// the query as green.
+    pub diagnostics: ThinVec<Diagnostic>,
+}
+
+impl QuerySideEffects {
+    pub fn is_empty(&self) -> bool {
+        let QuerySideEffects { diagnostics } = self;
+        diagnostics.is_empty()
+    }
+    pub fn append(&mut self, other: QuerySideEffects) {
+        let QuerySideEffects { diagnostics } = self;
+        diagnostics.extend(other.diagnostics);
+    }
+}
+
 pub trait QueryContext: HasDepContext {
     /// Get the query information from the TLS context.
     fn current_query_job(&self) -> Option<QueryJobId<Self::DepKind>>;
@@ -74,17 +99,17 @@ pub trait QueryContext: HasDepContext {
     /// Try to force a dep node to execute and see if it's green.
     fn try_force_from_dep_node(&self, dep_node: &DepNode<Self::DepKind>) -> bool;
 
-    /// Load diagnostics associated to the node in the previous session.
-    fn load_diagnostics(&self, prev_dep_node_index: SerializedDepNodeIndex) -> Vec<Diagnostic>;
+    /// Load side effects associated to the node in the previous session.
+    fn load_side_effects(&self, prev_dep_node_index: SerializedDepNodeIndex) -> QuerySideEffects;
 
     /// Register diagnostics for the given node, for use in next session.
-    fn store_diagnostics(&self, dep_node_index: DepNodeIndex, diagnostics: ThinVec<Diagnostic>);
+    fn store_side_effects(&self, dep_node_index: DepNodeIndex, side_effects: QuerySideEffects);
 
     /// Register diagnostics for the given node, for use in next session.
-    fn store_diagnostics_for_anon_node(
+    fn store_side_effects_for_anon_node(
         &self,
         dep_node_index: DepNodeIndex,
-        diagnostics: ThinVec<Diagnostic>,
+        side_effects: QuerySideEffects,
     );
 
     /// Executes a job by changing the `ImplicitCtxt` to point to the

compiler/rustc_query_system/src/query/plumbing.rs

@@ -9,7 +9,7 @@ use crate::query::config::{QueryDescription, QueryVtable, QueryVtableExt};
 use crate::query::job::{
     report_cycle, QueryInfo, QueryJob, QueryJobId, QueryJobInfo, QueryShardJobId,
 };
-use crate::query::{QueryContext, QueryMap, QueryStackFrame};
+use crate::query::{QueryContext, QueryMap, QuerySideEffects, QueryStackFrame};
 
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::{FxHashMap, FxHasher};
@@ -479,8 +479,10 @@ where
 
         dep_graph.read_index(dep_node_index);
 
-        if unlikely!(!diagnostics.is_empty()) {
-            tcx.store_diagnostics_for_anon_node(dep_node_index, diagnostics);
+        let side_effects = QuerySideEffects { diagnostics };
+
+        if unlikely!(!side_effects.is_empty()) {
+            tcx.store_side_effects_for_anon_node(dep_node_index, side_effects);
         }
 
         return job.complete(result, dep_node_index);
@@ -677,8 +679,10 @@ where
 
     prof_timer.finish_with_query_invocation_id(dep_node_index.into());
 
-    if unlikely!(!diagnostics.is_empty()) && dep_node.kind != DepKind::NULL {
-        tcx.store_diagnostics(dep_node_index, diagnostics);
+    let side_effects = QuerySideEffects { diagnostics };
+
+    if unlikely!(!side_effects.is_empty()) && dep_node.kind != DepKind::NULL {
+        tcx.store_side_effects(dep_node_index, side_effects);
     }
 
     let result = job.complete(result, dep_node_index);