diff options
| -rw-r--r-- | compiler/rustc_incremental/src/persist/save.rs | 1 | ||||
| -rw-r--r-- | compiler/rustc_query_system/src/dep_graph/graph.rs | 76 |
2 files changed, 50 insertions, 27 deletions
diff --git a/compiler/rustc_incremental/src/persist/save.rs b/compiler/rustc_incremental/src/persist/save.rs index 9603b102cbc..a8455854ebb 100644 --- a/compiler/rustc_incremental/src/persist/save.rs +++ b/compiler/rustc_incremental/src/persist/save.rs @@ -229,6 +229,7 @@ pub fn build_dep_graph( } Some(DepGraph::new( + &sess.prof, prev_graph, prev_work_products, encoder, diff --git a/compiler/rustc_query_system/src/dep_graph/graph.rs b/compiler/rustc_query_system/src/dep_graph/graph.rs index cfae65abe83..9481da70f42 100644 --- a/compiler/rustc_query_system/src/dep_graph/graph.rs +++ b/compiler/rustc_query_system/src/dep_graph/graph.rs @@ -44,6 +44,7 @@ rustc_index::newtype_index! { impl DepNodeIndex { pub const INVALID: DepNodeIndex = DepNodeIndex::MAX; + pub const DUMMY_ANON: DepNodeIndex = DepNodeIndex::from_u32(0); } impl std::convert::From<DepNodeIndex> for QueryInvocationId { @@ -108,6 +109,7 @@ where impl<K: DepKind> DepGraph<K> { pub fn new( + profiler: &SelfProfilerRef, prev_graph: SerializedDepGraph<K>, prev_work_products: FxHashMap<WorkProductId, WorkProduct>, encoder: FileEncoder, @@ -116,16 +118,23 @@ impl<K: DepKind> DepGraph<K> { ) -> DepGraph<K> { let prev_graph_node_count = prev_graph.node_count(); + let current = + CurrentDepGraph::new(prev_graph_node_count, encoder, record_graph, record_stats); + + // Instantiate an *always green* node for dependency-less anonymous queries. + let _green_node_index = current.intern_new_node( + profiler, + DepNode { kind: DepKind::NULL, hash: current.anon_id_seed.into() }, + smallvec![], + Fingerprint::ZERO, + ); + debug_assert_eq!(_green_node_index, DepNodeIndex::DUMMY_ANON); + DepGraph { data: Some(Lrc::new(DepGraphData { previous_work_products: prev_work_products, dep_node_debug: Default::default(), - current: CurrentDepGraph::new( - prev_graph_node_count, - encoder, - record_graph, - record_stats, - ), + current, emitting_diagnostics: Default::default(), emitting_diagnostics_cond_var: Condvar::new(), previous: prev_graph, @@ -287,29 +296,42 @@ impl<K: DepKind> DepGraph<K> { let task_deps = Lock::new(TaskDeps::default()); let result = K::with_deps(Some(&task_deps), op); let task_deps = task_deps.into_inner(); + let task_deps = task_deps.reads; - // The dep node indices are hashed here instead of hashing the dep nodes of the - // dependencies. These indices may refer to different nodes per session, but this isn't - // a problem here because we that ensure the final dep node hash is per session only by - // combining it with the per session random number `anon_id_seed`. This hash only need - // to map the dependencies to a single value on a per session basis. - let mut hasher = StableHasher::new(); - task_deps.reads.hash(&mut hasher); - - let target_dep_node = DepNode { - kind: dep_kind, - // Fingerprint::combine() is faster than sending Fingerprint - // through the StableHasher (at least as long as StableHasher - // is so slow). - hash: data.current.anon_id_seed.combine(hasher.finish()).into(), - }; + let dep_node_index = match task_deps.len() { + 0 => { + // Dependency-less anonymous nodes can safely be replaced by a dummy node. + DepNodeIndex::DUMMY_ANON + } + 1 => { + // When there is only one dependency, don't bother creating a node. + task_deps[0] + } + _ => { + // The dep node indices are hashed here instead of hashing the dep nodes of the + // dependencies. These indices may refer to different nodes per session, but this isn't + // a problem here because we that ensure the final dep node hash is per session only by + // combining it with the per session random number `anon_id_seed`. This hash only need + // to map the dependencies to a single value on a per session basis. + let mut hasher = StableHasher::new(); + task_deps.hash(&mut hasher); + + let target_dep_node = DepNode { + kind: dep_kind, + // Fingerprint::combine() is faster than sending Fingerprint + // through the StableHasher (at least as long as StableHasher + // is so slow). + hash: data.current.anon_id_seed.combine(hasher.finish()).into(), + }; - let dep_node_index = data.current.intern_new_node( - cx.profiler(), - target_dep_node, - task_deps.reads, - Fingerprint::ZERO, - ); + data.current.intern_new_node( + cx.profiler(), + target_dep_node, + task_deps, + Fingerprint::ZERO, + ) + } + }; (result, dep_node_index) } else { |