[WIP] Use arenas to avoid Lrc in queries #3

Cargo.lock

@@ -2812,6 +2812,7 @@ dependencies = [
  "rustc_errors 0.0.0",
  "rustc_target 0.0.0",
  "serialize 0.0.0",
+ "smallvec 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "stable_deref_trait 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "syntax 0.0.0",
  "syntax_ext 0.0.0",

src/librustc/arena.rs

@@ -14,8 +14,61 @@ macro_rules! arena_types {
                 rustc::hir::def_id::DefId,
                 rustc::ty::subst::SubstsRef<$tcx>
             )>,
-            [few] mir_keys: rustc::util::nodemap::DefIdSet,
+            [few, decode] mir_keys: rustc::util::nodemap::DefIdSet,
             [decode] specialization_graph: rustc::traits::specialization_graph::Graph,
+            [few] crate_inherent_impls: rustc::ty::CrateInherentImpls,
+            [] generic_predicates: rustc::ty::GenericPredicates<'tcx>,
+            [] region_scope_tree: rustc::middle::region::ScopeTree,
+            [] item_local_set: rustc::util::nodemap::ItemLocalSet,
+            [decode] mir_const_qualif: rustc_data_structures::bit_set::BitSet<rustc::mir::Local>,
+            [decode] borrowck: rustc::middle::borrowck::BorrowCheckResult,
+            [] trait_impls_of: rustc::ty::trait_def::TraitImpls,
+            [few] upstream_monomorphizations:
+                rustc::util::nodemap::DefIdMap<
+                    rustc_data_structures::fx::FxHashMap<
+                        rustc::ty::subst::SubstsRef<'tcx>,
+                        rustc::hir::def_id::CrateNum
+                    >
+                >,
+            [few] resolve_lifetimes: rustc::middle::resolve_lifetime::ResolveLifetimes,
+            [] dropck_outlives:
+                rustc::infer::canonical::Canonical<'tcx,
+                    rustc::infer::canonical::QueryResponse<'tcx,
+                        rustc::traits::query::dropck_outlives::DropckOutlivesResult<'tcx>
+                    >
+                >,
+            [] normalize_projection_ty:
+                rustc::infer::canonical::Canonical<'tcx,
+                    rustc::infer::canonical::QueryResponse<'tcx,
+                        rustc::traits::query::normalize::NormalizationResult<'tcx>
+                    >
+                >,
+            [] implied_outlives_bounds:
+                rustc::infer::canonical::Canonical<'tcx,
+                    rustc::infer::canonical::QueryResponse<'tcx,
+                        Vec<rustc::traits::query::outlives_bounds::OutlivesBound<'tcx>>
+                    >
+                >,
+            [] type_op_subtype:
+                rustc::infer::canonical::Canonical<'tcx,
+                    rustc::infer::canonical::QueryResponse<'tcx, ()>
+                >,
+            [] type_op_normalize_poly_fn_sig:
+                rustc::infer::canonical::Canonical<'tcx,
+                    rustc::infer::canonical::QueryResponse<'tcx, rustc::ty::PolyFnSig<'tcx>>
+                >,
+            [] type_op_normalize_fn_sig:
+                rustc::infer::canonical::Canonical<'tcx,
+                    rustc::infer::canonical::QueryResponse<'tcx, rustc::ty::FnSig<'tcx>>
+                >,
+            [] type_op_normalize_predicate:
+                rustc::infer::canonical::Canonical<'tcx,
+                    rustc::infer::canonical::QueryResponse<'tcx, rustc::ty::Predicate<'tcx>>
+                >,
+            [] type_op_normalize_ty:
+                rustc::infer::canonical::Canonical<'tcx,
+                    rustc::infer::canonical::QueryResponse<'tcx, rustc::ty::Ty<'tcx>>
+                >,
         ], $tcx);
     )
 }

src/librustc/infer/canonical/mod.rs

@@ -23,7 +23,6 @@
 
 use crate::infer::{InferCtxt, RegionVariableOrigin, TypeVariableOrigin};
 use rustc_data_structures::indexed_vec::IndexVec;
-use rustc_data_structures::sync::Lrc;
 use rustc_macros::HashStable;
 use serialize::UseSpecializedDecodable;
 use smallvec::SmallVec;
@@ -186,7 +185,7 @@ pub struct QueryResponse<'tcx, R> {
 pub type Canonicalized<'gcx, V> = Canonical<'gcx, <V as Lift<'gcx>>::Lifted>;
 
 pub type CanonicalizedQueryResponse<'gcx, T> =
-    Lrc<Canonical<'gcx, QueryResponse<'gcx, <T as Lift<'gcx>>::Lifted>>>;
+    &'gcx Canonical<'gcx, QueryResponse<'gcx, <T as Lift<'gcx>>::Lifted>>;
 
 /// Indicates whether or not we were able to prove the query to be
 /// true.

src/librustc/infer/canonical/query_response.rs

@@ -7,6 +7,7 @@
 //!
 //! [c]: https://rust-lang.github.io/rustc-guide/traits/canonicalization.html
 
+use crate::arena::ArenaAllocatable;
 use crate::infer::canonical::substitute::substitute_value;
 use crate::infer::canonical::{
     Canonical, CanonicalVarValues, CanonicalizedQueryResponse, Certainty,
@@ -17,7 +18,6 @@ use crate::infer::InferCtxtBuilder;
 use crate::infer::{InferCtxt, InferOk, InferResult};
 use rustc_data_structures::indexed_vec::Idx;
 use rustc_data_structures::indexed_vec::IndexVec;
-use rustc_data_structures::sync::Lrc;
 use std::fmt::Debug;
 use syntax_pos::DUMMY_SP;
 use crate::traits::query::{Fallible, NoSolution};
@@ -54,6 +54,7 @@ impl<'cx, 'gcx, 'tcx> InferCtxtBuilder<'cx, 'gcx, 'tcx> {
     where
         K: TypeFoldable<'tcx>,
         R: Debug + Lift<'gcx> + TypeFoldable<'tcx>,
+        Canonical<'gcx, <QueryResponse<'gcx, R> as Lift<'gcx>>::Lifted>: ArenaAllocatable,
     {
         self.enter_with_canonical(
             DUMMY_SP,
@@ -99,6 +100,7 @@ impl<'cx, 'gcx, 'tcx> InferCtxt<'cx, 'gcx, 'tcx> {
     ) -> Fallible<CanonicalizedQueryResponse<'gcx, T>>
     where
         T: Debug + Lift<'gcx> + TypeFoldable<'tcx>,
+        Canonical<'gcx, <QueryResponse<'gcx, T> as Lift<'gcx>>::Lifted>: ArenaAllocatable,
     {
         let query_response = self.make_query_response(inference_vars, answer, fulfill_cx)?;
         let canonical_result = self.canonicalize_response(&query_response);
@@ -108,7 +110,7 @@ impl<'cx, 'gcx, 'tcx> InferCtxt<'cx, 'gcx, 'tcx> {
             canonical_result
         );
 
-        Ok(Lrc::new(canonical_result))
+        Ok(self.tcx.arena.alloc(canonical_result))
     }
 
     /// A version of `make_canonicalized_query_response` that does

src/librustc/middle/expr_use_visitor.rs

@@ -17,7 +17,6 @@ use crate::middle::region;
 use crate::ty::{self, DefIdTree, TyCtxt, adjustment};
 
 use crate::hir::{self, PatKind};
-use rustc_data_structures::sync::Lrc;
 use std::rc::Rc;
 use syntax::ptr::P;
 use syntax_pos::Span;
@@ -272,7 +271,7 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx, 'tcx> {
                param_env: ty::ParamEnv<'tcx>,
                region_scope_tree: &'a region::ScopeTree,
                tables: &'a ty::TypeckTables<'tcx>,
-               rvalue_promotable_map: Option<Lrc<ItemLocalSet>>)
+               rvalue_promotable_map: Option<&'tcx ItemLocalSet>)
                -> Self
     {
         ExprUseVisitor {

src/librustc/middle/mem_categorization.rs

@@ -77,7 +77,6 @@ use syntax_pos::Span;
 use std::borrow::Cow;
 use std::fmt;
 use std::hash::{Hash, Hasher};
-use rustc_data_structures::sync::Lrc;
 use rustc_data_structures::indexed_vec::Idx;
 use std::rc::Rc;
 use crate::util::nodemap::ItemLocalSet;
@@ -290,7 +289,7 @@ pub struct MemCategorizationContext<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
     pub tcx: TyCtxt<'a, 'gcx, 'tcx>,
     pub region_scope_tree: &'a region::ScopeTree,
     pub tables: &'a ty::TypeckTables<'tcx>,
-    rvalue_promotable_map: Option<Lrc<ItemLocalSet>>,
+    rvalue_promotable_map: Option<&'tcx ItemLocalSet>,
     infcx: Option<&'a InferCtxt<'a, 'gcx, 'tcx>>,
 }
 
@@ -400,7 +399,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx, 'tcx> {
     pub fn new(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                region_scope_tree: &'a region::ScopeTree,
                tables: &'a ty::TypeckTables<'tcx>,
-               rvalue_promotable_map: Option<Lrc<ItemLocalSet>>)
+               rvalue_promotable_map: Option<&'tcx ItemLocalSet>)
                -> MemCategorizationContext<'a, 'tcx, 'tcx> {
         MemCategorizationContext {
             tcx,

src/librustc/middle/region.rs

@@ -12,7 +12,6 @@ use crate::ty;
 
 use std::mem;
 use std::fmt;
-use rustc_data_structures::sync::Lrc;
 use rustc_macros::HashStable;
 use syntax::source_map;
 use syntax::ast;
@@ -1323,7 +1322,7 @@ impl<'a, 'tcx> Visitor<'tcx> for RegionResolutionVisitor<'a, 'tcx> {
 }
 
 fn region_scope_tree<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId)
-    -> Lrc<ScopeTree>
+    -> &'tcx ScopeTree
 {
     let closure_base_def_id = tcx.closure_base_def_id(def_id);
     if closure_base_def_id != def_id {
@@ -1365,7 +1364,7 @@ fn region_scope_tree<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId)
         ScopeTree::default()
     };
 
-    Lrc::new(scope_tree)
+    tcx.arena.alloc(scope_tree)
 }
 
 pub fn provide(providers: &mut Providers<'_>) {

src/librustc/middle/resolve_lifetime.rs

@@ -15,7 +15,6 @@ use crate::rustc::lint;
 use crate::session::Session;
 use crate::util::nodemap::{DefIdMap, FxHashMap, FxHashSet, HirIdMap, HirIdSet};
 use errors::{Applicability, DiagnosticBuilder};
-use rustc_data_structures::sync::Lrc;
 use rustc_macros::HashStable;
 use std::borrow::Cow;
 use std::cell::Cell;
@@ -211,10 +210,10 @@ struct NamedRegionMap {
 /// See [`NamedRegionMap`].
 #[derive(Default)]
 pub struct ResolveLifetimes {
-    defs: FxHashMap<LocalDefId, Lrc<FxHashMap<ItemLocalId, Region>>>,
-    late_bound: FxHashMap<LocalDefId, Lrc<FxHashSet<ItemLocalId>>>,
+    defs: FxHashMap<LocalDefId, FxHashMap<ItemLocalId, Region>>,
+    late_bound: FxHashMap<LocalDefId, FxHashSet<ItemLocalId>>,
     object_lifetime_defaults:
-        FxHashMap<LocalDefId, Lrc<FxHashMap<ItemLocalId, Lrc<Vec<ObjectLifetimeDefault>>>>>,
+        FxHashMap<LocalDefId, FxHashMap<ItemLocalId, Vec<ObjectLifetimeDefault>>>,
 }
 
 impl_stable_hash_for!(struct crate::middle::resolve_lifetime::ResolveLifetimes {
@@ -347,23 +346,21 @@ pub fn provide(providers: &mut ty::query::Providers<'_>) {
 
         named_region_map: |tcx, id| {
             let id = LocalDefId::from_def_id(DefId::local(id)); // (*)
-            tcx.resolve_lifetimes(LOCAL_CRATE).defs.get(&id).cloned()
+            tcx.resolve_lifetimes(LOCAL_CRATE).defs.get(&id)
         },
 
         is_late_bound_map: |tcx, id| {
             let id = LocalDefId::from_def_id(DefId::local(id)); // (*)
             tcx.resolve_lifetimes(LOCAL_CRATE)
                 .late_bound
                 .get(&id)
-                .cloned()
         },
 
         object_lifetime_defaults_map: |tcx, id| {
             let id = LocalDefId::from_def_id(DefId::local(id)); // (*)
             tcx.resolve_lifetimes(LOCAL_CRATE)
                 .object_lifetime_defaults
                 .get(&id)
-                .cloned()
         },
 
         ..*providers
@@ -379,7 +376,7 @@ pub fn provide(providers: &mut ty::query::Providers<'_>) {
 fn resolve_lifetimes<'tcx>(
     tcx: TyCtxt<'_, 'tcx, 'tcx>,
     for_krate: CrateNum,
-) -> Lrc<ResolveLifetimes> {
+) -> &'tcx ResolveLifetimes {
     assert_eq!(for_krate, LOCAL_CRATE);
 
     let named_region_map = krate(tcx);
@@ -388,24 +385,22 @@ fn resolve_lifetimes<'tcx>(
 
     for (hir_id, v) in named_region_map.defs {
         let map = rl.defs.entry(hir_id.owner_local_def_id()).or_default();
-        Lrc::get_mut(map).unwrap().insert(hir_id.local_id, v);
+        map.insert(hir_id.local_id, v);
     }
     for hir_id in named_region_map.late_bound {
         let map = rl.late_bound
             .entry(hir_id.owner_local_def_id())
             .or_default();
-        Lrc::get_mut(map).unwrap().insert(hir_id.local_id);
+        map.insert(hir_id.local_id);
     }
     for (hir_id, v) in named_region_map.object_lifetime_defaults {
         let map = rl.object_lifetime_defaults
             .entry(hir_id.owner_local_def_id())
             .or_default();
-        Lrc::get_mut(map)
-            .unwrap()
-            .insert(hir_id.local_id, Lrc::new(v));
+        map.insert(hir_id.local_id, v);
     }
 
-    Lrc::new(rl)
+    tcx.arena.alloc(rl)
 }
 
 fn krate<'tcx>(tcx: TyCtxt<'_, 'tcx, 'tcx>) -> NamedRegionMap {