Add docs to new methods

compiler/rustc_data_structures/src/profiling.rs

@@ -255,7 +255,7 @@ impl SelfProfilerRef {
     /// Start profiling with some event filter for a given event. Profiling continues until the
     /// TimingGuard returned from this call is dropped.
     #[inline(always)]
-    pub fn generic_activity_with_event(&self, event_id: EventId) -> TimingGuard<'_> {
+    pub fn generic_activity_with_event_id(&self, event_id: EventId) -> TimingGuard<'_> {
         self.exec(EventFilter::GENERIC_ACTIVITIES, |profiler| {
             TimingGuard::start(profiler, profiler.generic_activity_event_kind, event_id)
         })
@@ -390,7 +390,11 @@ impl SelfProfilerRef {
         }
     }
 
-    pub fn get_or_alloc_cached_string(&self, s: &'static str) -> Option<StringId> {
+    /// Gets a `StringId` for the given string. This method makes sure that
+    /// any strings going through it will only be allocated once in the
+    /// profiling data.
+    /// Returns `None` if the self-profiling is not enabled.
+    pub fn get_or_alloc_cached_string(&self, s: &str) -> Option<StringId> {
         self.profiler.as_ref().map(|p| p.get_or_alloc_cached_string(s))
     }
 

compiler/rustc_query_system/src/dep_graph/graph.rs

@@ -39,6 +39,7 @@ pub struct DepGraph<K: DepKind> {
     /// The cached event id for profiling node interning. This saves us
     /// from having to look up the event id every time we intern a node
     /// which may incur too much overhead.
+    /// This will be None if self-profiling is disabled.
     node_intern_event_id: Option<EventId>,
 }
 
@@ -265,7 +266,7 @@ impl<K: DepKind> DepGraph<K> {
             // Get timer for profiling `DepNode` interning
             let node_intern_timer = self
                 .node_intern_event_id
-                .map(|eid| dcx.profiler().generic_activity_with_event(eid));
+                .map(|eid| dcx.profiler().generic_activity_with_event_id(eid));
             // Intern the new `DepNode`.
             let (dep_node_index, prev_and_color) = data.current.intern_node(
                 dcx.profiler(),