Move HIR traversal queries in rustc_ast_lowering.

Author: cjgillot

compiler/rustc_ast_lowering/src/lib.rs

@@ -84,6 +84,9 @@ mod index;
 mod item;
 mod pat;
 mod path;
+mod query;
+
+pub use query::provide;
 
 struct LoweringContext<'hir> {
     tcx: TyCtxt<'hir>,

compiler/rustc_ast_lowering/src/query.rs

@@ -0,0 +1,217 @@
+use rustc_data_structures::fingerprint::Fingerprint;
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_data_structures::svh::Svh;
+use rustc_hir::def_id::{CrateNum, LocalDefId, StableCrateId, LOCAL_CRATE};
+use rustc_hir::intravisit::{self, Visitor};
+use rustc_hir::{ForeignItem, ImplItem, Item, ItemKind, Mod, TraitItem};
+use rustc_hir::{ForeignItemId, HirId, ImplItemId, ItemId, ModuleItems, TraitItemId};
+use rustc_middle::hir::nested_filter;
+use rustc_middle::ty::query::Providers;
+use rustc_middle::ty::TyCtxt;
+use rustc_span::Span;
+
+pub fn provide(providers: &mut Providers) {
+    *providers = Providers { crate_hash, hir_module_items, hir_crate_items, ..*providers };
+}
+
+fn crate_hash(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Svh {
+    debug_assert_eq!(crate_num, LOCAL_CRATE);
+    let krate = tcx.hir_crate(());
+    let hir_body_hash = krate.hir_hash;
+
+    let upstream_crates = upstream_crates(tcx);
+
+    // We hash the final, remapped names of all local source files so we
+    // don't have to include the path prefix remapping commandline args.
+    // If we included the full mapping in the SVH, we could only have
+    // reproducible builds by compiling from the same directory. So we just
+    // hash the result of the mapping instead of the mapping itself.
+    let mut source_file_names: Vec<_> = tcx
+        .sess
+        .source_map()
+        .files()
+        .iter()
+        .filter(|source_file| source_file.cnum == LOCAL_CRATE)
+        .map(|source_file| source_file.name_hash)
+        .collect();
+
+    source_file_names.sort_unstable();
+
+    let crate_hash: Fingerprint = tcx.with_stable_hashing_context(|mut hcx| {
+        let mut stable_hasher = StableHasher::new();
+        hir_body_hash.hash_stable(&mut hcx, &mut stable_hasher);
+        upstream_crates.hash_stable(&mut hcx, &mut stable_hasher);
+        source_file_names.hash_stable(&mut hcx, &mut stable_hasher);
+        if tcx.sess.opts.debugging_opts.incremental_relative_spans {
+            let definitions = tcx.definitions_untracked();
+            let mut owner_spans: Vec<_> = krate
+                .owners
+                .iter_enumerated()
+                .filter_map(|(def_id, info)| {
+                    let _ = info.as_owner()?;
+                    let def_path_hash = definitions.def_path_hash(def_id);
+                    let span = definitions.def_span(def_id);
+                    debug_assert_eq!(span.parent(), None);
+                    Some((def_path_hash, span))
+                })
+                .collect();
+            owner_spans.sort_unstable_by_key(|bn| bn.0);
+            owner_spans.hash_stable(&mut hcx, &mut stable_hasher);
+        }
+        tcx.sess.opts.dep_tracking_hash(true).hash_stable(&mut hcx, &mut stable_hasher);
+        tcx.sess.local_stable_crate_id().hash_stable(&mut hcx, &mut stable_hasher);
+        // Hash visibility information since it does not appear in HIR.
+        let resolutions = tcx.resolutions(());
+        resolutions.visibilities.hash_stable(&mut hcx, &mut stable_hasher);
+        resolutions.has_pub_restricted.hash_stable(&mut hcx, &mut stable_hasher);
+        stable_hasher.finish()
+    });
+
+    Svh::new(crate_hash.to_smaller_hash())
+}
+
+fn upstream_crates(tcx: TyCtxt<'_>) -> Vec<(StableCrateId, Svh)> {
+    let mut upstream_crates: Vec<_> = tcx
+        .crates(())
+        .iter()
+        .map(|&cnum| {
+            let stable_crate_id = tcx.stable_crate_id(cnum);
+            let hash = tcx.crate_hash(cnum);
+            (stable_crate_id, hash)
+        })
+        .collect();
+    upstream_crates.sort_unstable_by_key(|&(stable_crate_id, _)| stable_crate_id);
+    upstream_crates
+}
+
+fn hir_module_items(tcx: TyCtxt<'_>, module_id: LocalDefId) -> ModuleItems {
+    let mut collector = ModuleCollector {
+        tcx,
+        submodules: Vec::default(),
+        items: Vec::default(),
+        trait_items: Vec::default(),
+        impl_items: Vec::default(),
+        foreign_items: Vec::default(),
+    };
+
+    let (hir_mod, span, hir_id) = tcx.hir().get_module(module_id);
+    collector.visit_mod(hir_mod, span, hir_id);
+
+    let ModuleCollector { submodules, items, trait_items, impl_items, foreign_items, .. } =
+        collector;
+    return ModuleItems {
+        submodules: submodules.into_boxed_slice(),
+        items: items.into_boxed_slice(),
+        trait_items: trait_items.into_boxed_slice(),
+        impl_items: impl_items.into_boxed_slice(),
+        foreign_items: foreign_items.into_boxed_slice(),
+    };
+
+    struct ModuleCollector<'tcx> {
+        tcx: TyCtxt<'tcx>,
+        submodules: Vec<LocalDefId>,
+        items: Vec<ItemId>,
+        trait_items: Vec<TraitItemId>,
+        impl_items: Vec<ImplItemId>,
+        foreign_items: Vec<ForeignItemId>,
+    }
+
+    impl<'hir> Visitor<'hir> for ModuleCollector<'hir> {
+        type NestedFilter = nested_filter::All;
+
+        fn nested_visit_map(&mut self) -> Self::Map {
+            self.tcx.hir()
+        }
+
+        fn visit_item(&mut self, item: &'hir Item<'hir>) {
+            self.items.push(item.item_id());
+            if let ItemKind::Mod(..) = item.kind {
+                // If this declares another module, do not recurse inside it.
+                self.submodules.push(item.def_id);
+            } else {
+                intravisit::walk_item(self, item)
+            }
+        }
+
+        fn visit_trait_item(&mut self, item: &'hir TraitItem<'hir>) {
+            self.trait_items.push(item.trait_item_id());
+            intravisit::walk_trait_item(self, item)
+        }
+
+        fn visit_impl_item(&mut self, item: &'hir ImplItem<'hir>) {
+            self.impl_items.push(item.impl_item_id());
+            intravisit::walk_impl_item(self, item)
+        }
+
+        fn visit_foreign_item(&mut self, item: &'hir ForeignItem<'hir>) {
+            self.foreign_items.push(item.foreign_item_id());
+            intravisit::walk_foreign_item(self, item)
+        }
+    }
+}
+
+fn hir_crate_items(tcx: TyCtxt<'_>, _: ()) -> ModuleItems {
+    let mut collector = CrateCollector {
+        tcx,
+        submodules: Vec::default(),
+        items: Vec::default(),
+        trait_items: Vec::default(),
+        impl_items: Vec::default(),
+        foreign_items: Vec::default(),
+    };
+
+    tcx.hir().walk_toplevel_module(&mut collector);
+
+    let CrateCollector { submodules, items, trait_items, impl_items, foreign_items, .. } =
+        collector;
+
+    return ModuleItems {
+        submodules: submodules.into_boxed_slice(),
+        items: items.into_boxed_slice(),
+        trait_items: trait_items.into_boxed_slice(),
+        impl_items: impl_items.into_boxed_slice(),
+        foreign_items: foreign_items.into_boxed_slice(),
+    };
+
+    struct CrateCollector<'tcx> {
+        tcx: TyCtxt<'tcx>,
+        submodules: Vec<LocalDefId>,
+        items: Vec<ItemId>,
+        trait_items: Vec<TraitItemId>,
+        impl_items: Vec<ImplItemId>,
+        foreign_items: Vec<ForeignItemId>,
+    }
+
+    impl<'hir> Visitor<'hir> for CrateCollector<'hir> {
+        type NestedFilter = nested_filter::All;
+
+        fn nested_visit_map(&mut self) -> Self::Map {
+            self.tcx.hir()
+        }
+
+        fn visit_item(&mut self, item: &'hir Item<'hir>) {
+            self.items.push(item.item_id());
+            intravisit::walk_item(self, item)
+        }
+
+        fn visit_mod(&mut self, m: &'hir Mod<'hir>, _s: Span, n: HirId) {
+            self.submodules.push(n.owner);
+            intravisit::walk_mod(self, m, n);
+        }
+
+        fn visit_foreign_item(&mut self, item: &'hir ForeignItem<'hir>) {
+            self.foreign_items.push(item.foreign_item_id());
+            intravisit::walk_foreign_item(self, item)
+        }
+
+        fn visit_trait_item(&mut self, item: &'hir TraitItem<'hir>) {
+            self.trait_items.push(item.trait_item_id());
+            intravisit::walk_trait_item(self, item)
+        }
+
+        fn visit_impl_item(&mut self, item: &'hir ImplItem<'hir>) {
+            self.impl_items.push(item.impl_item_id());
+            intravisit::walk_impl_item(self, item)
+        }
+    }
+}

compiler/rustc_hir/src/hir.rs

@@ -796,6 +796,35 @@ impl<T> MaybeOwner<T> {
     }
 }
 
+/// Gather the LocalDefId for each item-like within a module, including items contained within
+/// bodies.  The Ids are in visitor order.  This is used to partition a pass between modules.
+#[derive(Debug, HashStable_Generic)]
+pub struct ModuleItems {
+    pub submodules: Box<[LocalDefId]>,
+    pub items: Box<[ItemId]>,
+    pub trait_items: Box<[TraitItemId]>,
+    pub impl_items: Box<[ImplItemId]>,
+    pub foreign_items: Box<[ForeignItemId]>,
+}
+
+impl ModuleItems {
+    pub fn items(&self) -> impl Iterator<Item = ItemId> + '_ {
+        self.items.iter().copied()
+    }
+
+    pub fn trait_items(&self) -> impl Iterator<Item = TraitItemId> + '_ {
+        self.trait_items.iter().copied()
+    }
+
+    pub fn impl_items(&self) -> impl Iterator<Item = ImplItemId> + '_ {
+        self.impl_items.iter().copied()
+    }
+
+    pub fn foreign_items(&self) -> impl Iterator<Item = ForeignItemId> + '_ {
+        self.foreign_items.iter().copied()
+    }
+}
+
 /// The top-level data structure that stores the entire contents of
 /// the crate currently being compiled.
 ///

compiler/rustc_interface/src/passes.rs

@@ -15,7 +15,7 @@ use rustc_errors::{Applicability, ErrorGuaranteed, MultiSpan, PResult};
 use rustc_expand::base::{ExtCtxt, LintStoreExpand, ResolverExpand};
 use rustc_hir::def_id::{LocalDefId, StableCrateId, LOCAL_CRATE};
 use rustc_hir::definitions::Definitions;
-use rustc_hir::{Crate, MaybeOwner, OwnerInfo};
+use rustc_hir::Crate;
 use rustc_index::vec::{Idx, IndexVec};
 use rustc_lint::{EarlyCheckNode, LintStore};
 use rustc_metadata::creader::CStore;
@@ -525,11 +525,6 @@ fn hir_crate<'tcx>(tcx: TyCtxt<'tcx>, (): ()) -> Crate<'tcx> {
     hir_crate
 }
 
-/// Lower AST to HIR.
-fn lower_to_hir<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> MaybeOwner<&'tcx OwnerInfo<'tcx>> {
-    rustc_ast_lowering::lower_to_hir(tcx, def_id, rustc_parse::nt_to_tokenstream)
-}
-
 // Returns all the paths that correspond to generated files.
 fn generated_output_paths(
     sess: &Session,
@@ -795,7 +790,9 @@ pub static DEFAULT_QUERY_PROVIDERS: SyncLazy<Providers> = SyncLazy::new(|| {
     let providers = &mut Providers::default();
     providers.analysis = analysis;
     providers.hir_crate = hir_crate;
-    providers.lower_to_hir = lower_to_hir;
+    providers.lower_to_hir =
+        |tcx, def_id| rustc_ast_lowering::lower_to_hir(tcx, def_id, rustc_parse::nt_to_tokenstream);
+    rustc_ast_lowering::provide(providers);
     proc_macro_decls::provide(providers);
     rustc_const_eval::provide(providers);
     rustc_middle::hir::provide(providers);