Create the previous dep graph index on a background thread

compiler/rustc_data_structures/src/marker.rs

@@ -70,6 +70,7 @@ macro_rules! impl_dyn_send {
 }
 
 impl_dyn_send!(
+    [std::thread::JoinHandle<T> where T]
     [std::sync::atomic::AtomicPtr<T> where T]
     [std::sync::Mutex<T> where T: ?Sized+ DynSend]
     [std::sync::mpsc::Sender<T> where T: DynSend]
@@ -152,6 +153,7 @@ macro_rules! impl_dyn_sync {
 }
 
 impl_dyn_sync!(
+    [std::thread::JoinHandle<T> where T]
     [std::sync::atomic::AtomicPtr<T> where T]
     [std::sync::OnceLock<T> where T: DynSend + DynSync]
     [std::sync::Mutex<T> where T: ?Sized + DynSend]

compiler/rustc_incremental/src/persist/load.rs

@@ -35,9 +35,9 @@ pub enum LoadResult<T> {
     LoadDepGraph(PathBuf, std::io::Error),
 }
 
-impl<T: Default> LoadResult<T> {
+impl<T> LoadResult<T> {
     /// Accesses the data returned in [`LoadResult::Ok`].
-    pub fn open(self, sess: &Session) -> T {
+    pub fn open(self, sess: &Session, fallback: impl FnOnce() -> T) -> T {
         // Check for errors when using `-Zassert-incremental-state`
         match (sess.opts.assert_incr_state, &self) {
             (Some(IncrementalStateAssertion::NotLoaded), LoadResult::Ok { .. }) => {
@@ -55,14 +55,14 @@ impl<T: Default> LoadResult<T> {
         match self {
             LoadResult::LoadDepGraph(path, err) => {
                 sess.dcx().emit_warn(errors::LoadDepGraph { path, err });
-                Default::default()
+                fallback()
             }
             LoadResult::DataOutOfDate => {
                 if let Err(err) = delete_all_session_dir_contents(sess) {
                     sess.dcx()
                         .emit_err(errors::DeleteIncompatible { path: dep_graph_path(sess), err });
                 }
-                Default::default()
+                fallback()
             }
             LoadResult::Ok { data } => data,
         }
@@ -93,13 +93,15 @@ fn delete_dirty_work_product(sess: &Session, swp: SerializedWorkProduct) {
 
 fn load_dep_graph(
     sess: &Session,
-    deps: &DepsType,
-) -> LoadResult<(Arc<SerializedDepGraph>, WorkProductMap)> {
+    deps: &Arc<DepsType>,
+) -> LoadResult<(Arc<SerializedDepGraph<DepsType>>, WorkProductMap)> {
     let prof = sess.prof.clone();
 
     if sess.opts.incremental.is_none() {
         // No incremental compilation.
-        return LoadResult::Ok { data: Default::default() };
+        return LoadResult::Ok {
+            data: (Arc::new(SerializedDepGraph::empty(deps, sess)), Default::default()),
+        };
     }
 
     let _timer = sess.prof.generic_activity("incr_comp_prepare_load_dep_graph");
@@ -174,7 +176,7 @@ fn load_dep_graph(
                 return LoadResult::DataOutOfDate;
             }
 
-            let dep_graph = SerializedDepGraph::decode::<DepsType>(&mut decoder, deps);
+            let dep_graph = SerializedDepGraph::decode(&mut decoder, deps, sess);
 
             LoadResult::Ok { data: (dep_graph, prev_work_products) }
         }
@@ -208,7 +210,7 @@ pub fn load_query_result_cache(sess: &Session) -> Option<OnDiskCache> {
 
 /// Setups the dependency graph by loading an existing graph from disk and set up streaming of a
 /// new graph to an incremental session directory.
-pub fn setup_dep_graph(sess: &Session, crate_name: Symbol, deps: &DepsType) -> DepGraph {
+pub fn setup_dep_graph(sess: &Session, crate_name: Symbol, deps: &Arc<DepsType>) -> DepGraph {
     // `load_dep_graph` can only be called after `prepare_session_directory`.
     prepare_session_directory(sess, crate_name);
 
@@ -227,7 +229,8 @@ pub fn setup_dep_graph(sess: &Session, crate_name: Symbol, deps: &DepsType) -> D
     }
 
     res.and_then(|result| {
-        let (prev_graph, prev_work_products) = result.open(sess);
+        let (prev_graph, prev_work_products) = result
+            .open(sess, || (Arc::new(SerializedDepGraph::empty(deps, sess)), Default::default()));
         build_dep_graph(sess, prev_graph, prev_work_products)
     })
     .unwrap_or_else(DepGraph::new_disabled)

compiler/rustc_incremental/src/persist/save.rs

@@ -4,7 +4,7 @@ use std::sync::Arc;
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::sync::join;
 use rustc_middle::dep_graph::{
-    DepGraph, SerializedDepGraph, WorkProduct, WorkProductId, WorkProductMap,
+    DepGraph, DepsType, SerializedDepGraph, WorkProduct, WorkProductId, WorkProductMap,
 };
 use rustc_middle::ty::TyCtxt;
 use rustc_serialize::Encodable as RustcEncodable;
@@ -144,7 +144,7 @@ fn encode_query_cache(tcx: TyCtxt<'_>, encoder: FileEncoder) -> FileEncodeResult
 /// and moves it to the permanent dep-graph path
 pub(crate) fn build_dep_graph(
     sess: &Session,
-    prev_graph: Arc<SerializedDepGraph>,
+    prev_graph: Arc<SerializedDepGraph<DepsType>>,
     prev_work_products: WorkProductMap,
 ) -> Option<DepGraph> {
     if sess.opts.incremental.is_none() {

compiler/rustc_interface/src/passes.rs

@@ -828,7 +828,7 @@ pub fn create_and_enter_global_ctxt<T, F: for<'tcx> FnOnce(TyCtxt<'tcx>) -> T>(
 
     let outputs = util::build_output_filenames(&pre_configured_attrs, sess);
 
-    let dep_type = DepsType { dep_names: rustc_query_impl::dep_kind_names() };
+    let dep_type = Arc::new(DepsType { dep_names: rustc_query_impl::dep_kind_names() });
     let dep_graph = setup_dep_graph(sess, crate_name, &dep_type);
 
     let cstore =

compiler/rustc_query_system/src/dep_graph/graph.rs

@@ -91,7 +91,7 @@ pub(crate) struct DepGraphData<D: Deps> {
 
     /// The dep-graph from the previous compilation session. It contains all
     /// nodes and edges as well as all fingerprints of nodes that have them.
-    previous: Arc<SerializedDepGraph>,
+    previous: Arc<SerializedDepGraph<D>>,
 
     colors: DepNodeColorMap,
 
@@ -121,7 +121,7 @@ where
 impl<D: Deps> DepGraph<D> {
     pub fn new(
         session: &Session,
-        prev_graph: Arc<SerializedDepGraph>,
+        prev_graph: Arc<SerializedDepGraph<D>>,
         prev_work_products: WorkProductMap,
         encoder: FileEncoder,
     ) -> DepGraph<D> {
@@ -1171,7 +1171,7 @@ impl<D: Deps> CurrentDepGraph<D> {
         session: &Session,
         prev_graph_node_count: usize,
         encoder: FileEncoder,
-        previous: Arc<SerializedDepGraph>,
+        previous: Arc<SerializedDepGraph<D>>,
     ) -> Self {
         let mut stable_hasher = StableHasher::new();
         previous.session_count().hash(&mut stable_hasher);
@@ -1260,7 +1260,7 @@ impl<D: Deps> CurrentDepGraph<D> {
     #[inline]
     fn debug_assert_not_in_new_nodes(
         &self,
-        prev_graph: &SerializedDepGraph,
+        prev_graph: &SerializedDepGraph<D>,
         prev_index: SerializedDepNodeIndex,
     ) {
         if let Some(ref nodes_in_current_session) = self.nodes_in_current_session {

compiler/rustc_query_system/src/dep_graph/mod.rs

@@ -12,7 +12,7 @@ pub(crate) use graph::DepGraphData;
 pub use graph::{DepGraph, DepNodeIndex, TaskDepsRef, WorkProduct, WorkProductMap, hash_result};
 pub use query::DepGraphQuery;
 use rustc_data_structures::profiling::SelfProfilerRef;
-use rustc_data_structures::sync::DynSync;
+use rustc_data_structures::sync::{DynSend, DynSync};
 use rustc_session::Session;
 pub use serialized::{SerializedDepGraph, SerializedDepNodeIndex};
 use tracing::instrument;
@@ -90,7 +90,7 @@ pub trait DepContext: Copy {
     }
 }
 
-pub trait Deps: DynSync {
+pub trait Deps: DynSend + DynSync + Send + Sync + 'static {
     /// Execute the operation with provided dependencies.
     fn with_deps<OP, R>(deps: TaskDepsRef<'_>, op: OP) -> R
     where