Rollup merge of #110886 - nnethercote:dep-graph-cleanups, r=cjgillot

`DepGraph` cleanups

r? `@cjgillot`

Author: matthiaskrgr

compiler/rustc_query_system/src/dep_graph/graph.rs

@@ -354,24 +354,20 @@ impl<K: DepKind> DepGraphData<K> {
                  - dep-node: {key:?}"
         );
 
-        let task_deps = if cx.dep_context().is_eval_always(key.kind) {
-            None
+        let with_deps = |task_deps| K::with_deps(task_deps, || task(cx, arg));
+        let (result, edges) = if cx.dep_context().is_eval_always(key.kind) {
+            (with_deps(TaskDepsRef::EvalAlways), smallvec![])
         } else {
-            Some(Lock::new(TaskDeps {
+            let task_deps = Lock::new(TaskDeps {
                 #[cfg(debug_assertions)]
                 node: Some(key),
                 reads: SmallVec::new(),
                 read_set: Default::default(),
                 phantom_data: PhantomData,
-            }))
+            });
+            (with_deps(TaskDepsRef::Allow(&task_deps)), task_deps.into_inner().reads)
         };
 
-        let task_deps_ref =
-            task_deps.as_ref().map(TaskDepsRef::Allow).unwrap_or(TaskDepsRef::EvalAlways);
-
-        let result = K::with_deps(task_deps_ref, || task(cx, arg));
-        let edges = task_deps.map_or_else(|| smallvec![], |lock| lock.into_inner().reads);
-
         let dcx = cx.dep_context();
         let hashing_timer = dcx.profiler().incr_result_hashing();
         let current_fingerprint =
@@ -1236,76 +1232,48 @@ impl<K: DepKind> CurrentDepGraph<K> {
             self.node_intern_event_id.map(|eid| profiler.generic_activity_with_event_id(eid));
 
         if let Some(prev_index) = prev_graph.node_to_index_opt(&key) {
+            let get_dep_node_index = |color, fingerprint| {
+                if print_status {
+                    eprintln!("[task::{color:}] {key:?}");
+                }
+
+                let mut prev_index_to_index = self.prev_index_to_index.lock();
+
+                let dep_node_index = match prev_index_to_index[prev_index] {
+                    Some(dep_node_index) => dep_node_index,
+                    None => {
+                        let dep_node_index =
+                            self.encoder.borrow().send(profiler, key, fingerprint, edges);
+                        prev_index_to_index[prev_index] = Some(dep_node_index);
+                        dep_node_index
+                    }
+                };
+
+                #[cfg(debug_assertions)]
+                self.record_edge(dep_node_index, key, fingerprint);
+
+                dep_node_index
+            };
+
             // Determine the color and index of the new `DepNode`.
             if let Some(fingerprint) = fingerprint {
                 if fingerprint == prev_graph.fingerprint_by_index(prev_index) {
-                    if print_status {
-                        eprintln!("[task::green] {key:?}");
-                    }
-
                     // This is a green node: it existed in the previous compilation,
                     // its query was re-executed, and it has the same result as before.
-                    let mut prev_index_to_index = self.prev_index_to_index.lock();
-
-                    let dep_node_index = match prev_index_to_index[prev_index] {
-                        Some(dep_node_index) => dep_node_index,
-                        None => {
-                            let dep_node_index =
-                                self.encoder.borrow().send(profiler, key, fingerprint, edges);
-                            prev_index_to_index[prev_index] = Some(dep_node_index);
-                            dep_node_index
-                        }
-                    };
-
-                    #[cfg(debug_assertions)]
-                    self.record_edge(dep_node_index, key, fingerprint);
+                    let dep_node_index = get_dep_node_index("green", fingerprint);
                     (dep_node_index, Some((prev_index, DepNodeColor::Green(dep_node_index))))
                 } else {
-                    if print_status {
-                        eprintln!("[task::red] {key:?}");
-                    }
-
                     // This is a red node: it existed in the previous compilation, its query
                     // was re-executed, but it has a different result from before.
-                    let mut prev_index_to_index = self.prev_index_to_index.lock();
-
-                    let dep_node_index = match prev_index_to_index[prev_index] {
-                        Some(dep_node_index) => dep_node_index,
-                        None => {
-                            let dep_node_index =
-                                self.encoder.borrow().send(profiler, key, fingerprint, edges);
-                            prev_index_to_index[prev_index] = Some(dep_node_index);
-                            dep_node_index
-                        }
-                    };
-
-                    #[cfg(debug_assertions)]
-                    self.record_edge(dep_node_index, key, fingerprint);
+                    let dep_node_index = get_dep_node_index("red", fingerprint);
                     (dep_node_index, Some((prev_index, DepNodeColor::Red)))
                 }
             } else {
-                if print_status {
-                    eprintln!("[task::unknown] {key:?}");
-                }
-
                 // This is a red node, effectively: it existed in the previous compilation
                 // session, its query was re-executed, but it doesn't compute a result hash
                 // (i.e. it represents a `no_hash` query), so we have no way of determining
                 // whether or not the result was the same as before.
-                let mut prev_index_to_index = self.prev_index_to_index.lock();
-
-                let dep_node_index = match prev_index_to_index[prev_index] {
-                    Some(dep_node_index) => dep_node_index,
-                    None => {
-                        let dep_node_index =
-                            self.encoder.borrow().send(profiler, key, Fingerprint::ZERO, edges);
-                        prev_index_to_index[prev_index] = Some(dep_node_index);
-                        dep_node_index
-                    }
-                };
-
-                #[cfg(debug_assertions)]
-                self.record_edge(dep_node_index, key, Fingerprint::ZERO);
+                let dep_node_index = get_dep_node_index("unknown", Fingerprint::ZERO);
                 (dep_node_index, Some((prev_index, DepNodeColor::Red)))
             }
         } else {