separate out an arena for HIR

Author: Centril

Cargo.lock

@@ -3477,6 +3477,7 @@ dependencies = [
 name = "rustc_ast_lowering"
 version = "0.0.0"
 dependencies = [
+ "arena",
  "log",
  "rustc",
  "rustc_ast",

src/libarena/lib.rs

@@ -624,7 +624,8 @@ macro_rules! declare_arena {
         }
 
         $(
-            impl ArenaAllocatable for $ty {}
+            #[allow(unused_lifetimes)]
+            impl<$tcx> ArenaAllocatable for $ty {}
             unsafe impl<$tcx> ArenaField<$tcx> for $ty {
                 #[inline]
                 fn arena<'a>(_arena: &'a Arena<$tcx>) -> Option<&'a $crate::TypedArena<Self>> {
@@ -653,7 +654,7 @@ macro_rules! declare_arena {
                 self.dropless.alloc_slice(value)
             }
 
-            pub fn alloc_from_iter<T: ArenaAllocatable>(
+            pub fn alloc_from_iter<'a, T: ArenaAllocatable>(
                 &'a self,
                 iter: impl ::std::iter::IntoIterator<Item = T>,
             ) -> &'a mut [T] {

src/librustc/arena.rs

@@ -120,40 +120,6 @@ macro_rules! arena_types {
             // Interned types
             [] tys: rustc::ty::TyS<$tcx>,
 
-            // HIR types
-            [few] hir_krate: rustc_hir::Crate<$tcx>,
-            [] arm: rustc_hir::Arm<$tcx>,
-            [] attribute: rustc_ast::ast::Attribute,
-            [] block: rustc_hir::Block<$tcx>,
-            [] bare_fn_ty: rustc_hir::BareFnTy<$tcx>,
-            [few] global_asm: rustc_hir::GlobalAsm,
-            [] generic_arg: rustc_hir::GenericArg<$tcx>,
-            [] generic_args: rustc_hir::GenericArgs<$tcx>,
-            [] generic_bound: rustc_hir::GenericBound<$tcx>,
-            [] generic_param: rustc_hir::GenericParam<$tcx>,
-            [] expr: rustc_hir::Expr<$tcx>,
-            [] field: rustc_hir::Field<$tcx>,
-            [] field_pat: rustc_hir::FieldPat<$tcx>,
-            [] fn_decl: rustc_hir::FnDecl<$tcx>,
-            [] foreign_item: rustc_hir::ForeignItem<$tcx>,
-            [] impl_item_ref: rustc_hir::ImplItemRef<$tcx>,
-            [] inline_asm: rustc_hir::InlineAsm<$tcx>,
-            [] local: rustc_hir::Local<$tcx>,
-            [few] macro_def: rustc_hir::MacroDef<$tcx>,
-            [] param: rustc_hir::Param<$tcx>,
-            [] pat: rustc_hir::Pat<$tcx>,
-            [] path: rustc_hir::Path<$tcx>,
-            [] path_segment: rustc_hir::PathSegment<$tcx>,
-            [] poly_trait_ref: rustc_hir::PolyTraitRef<$tcx>,
-            [] qpath: rustc_hir::QPath<$tcx>,
-            [] stmt: rustc_hir::Stmt<$tcx>,
-            [] struct_field: rustc_hir::StructField<$tcx>,
-            [] trait_item_ref: rustc_hir::TraitItemRef,
-            [] ty: rustc_hir::Ty<$tcx>,
-            [] type_binding: rustc_hir::TypeBinding<$tcx>,
-            [] variant: rustc_hir::Variant<$tcx>,
-            [] where_predicate: rustc_hir::WherePredicate<$tcx>,
-
             // HIR query types
             [few] indexed_hir: rustc::hir::map::IndexedHir<$tcx>,
             [few] hir_definitions: rustc::hir::map::definitions::Definitions,

src/librustc/ty/codec.rs

@@ -396,6 +396,7 @@ macro_rules! implement_ty_decoder {
             // the caller to pick any lifetime for `'tcx`, including `'static`,
             // by using the unspecialized proxies to them.
 
+            rustc_hir::arena_types!(impl_arena_allocatable_decoders, [$DecoderName [$($typaram),*]], 'tcx);
             arena_types!(impl_arena_allocatable_decoders, [$DecoderName [$($typaram),*]], 'tcx);
 
             impl<$($typaram),*> SpecializedDecoder<CrateNum>

src/librustc_ast_lowering/Cargo.toml

@@ -10,6 +10,7 @@ path = "lib.rs"
 doctest = false
 
 [dependencies]
+arena = { path = "../libarena" }
 log = { version = "0.4", features = ["release_max_level_info", "std"] }
 rustc = { path = "../librustc" }
 rustc_ast_pretty = { path = "../librustc_ast_pretty" }

src/librustc_ast_lowering/item.rs

@@ -1,7 +1,7 @@
 use super::{AnonymousLifetimeMode, LoweringContext, ParamMode};
 use super::{ImplTraitContext, ImplTraitPosition, ImplTraitTypeIdVisitor};
+use crate::Arena;
 
-use rustc::arena::Arena;
 use rustc::bug;
 use rustc_ast::ast::*;
 use rustc_ast::attr;

src/librustc_ast_lowering/lib.rs

@@ -32,9 +32,10 @@
 
 #![feature(array_value_iter)]
 #![feature(crate_visibility_modifier)]
+#![feature(marker_trait_attr)]
+#![feature(specialization)]
 #![recursion_limit = "256"]
 
-use rustc::arena::Arena;
 use rustc::dep_graph::DepGraph;
 use rustc::hir::map::definitions::{DefKey, DefPathData, Definitions};
 use rustc::{bug, span_bug};
@@ -85,6 +86,8 @@ mod path;
 
 const HIR_ID_COUNTER_LOCKED: u32 = 0xFFFFFFFF;
 
+rustc_hir::arena_types!(::arena::declare_arena, [], 'tcx);
+
 struct LoweringContext<'a, 'hir: 'a> {
     crate_root: Option<Symbol>,
 

src/librustc_hir/arena.rs

@@ -0,0 +1,49 @@
+/// This declares a list of types which can be allocated by `Arena`.
+///
+/// The `few` modifier will cause allocation to use the shared arena and recording the destructor.
+/// This is faster and more memory efficient if there's only a few allocations of the type.
+/// Leaving `few` out will cause the type to get its own dedicated `TypedArena` which is
+/// faster and more memory efficient if there is lots of allocations.
+///
+/// Specifying the `decode` modifier will add decode impls for &T and &[T] where T is the type
+/// listed. These impls will appear in the implement_ty_decoder! macro.
+#[macro_export]
+macro_rules! arena_types {
+    ($macro:path, $args:tt, $tcx:lifetime) => (
+        $macro!($args, [
+            // HIR types
+            [few] hir_krate: rustc_hir::Crate<$tcx>,
+            [] arm: rustc_hir::Arm<$tcx>,
+            [] attribute: rustc_ast::ast::Attribute,
+            [] block: rustc_hir::Block<$tcx>,
+            [] bare_fn_ty: rustc_hir::BareFnTy<$tcx>,
+            [few] global_asm: rustc_hir::GlobalAsm,
+            [] generic_arg: rustc_hir::GenericArg<$tcx>,
+            [] generic_args: rustc_hir::GenericArgs<$tcx>,
+            [] generic_bound: rustc_hir::GenericBound<$tcx>,
+            [] generic_param: rustc_hir::GenericParam<$tcx>,
+            [] expr: rustc_hir::Expr<$tcx>,
+            [] field: rustc_hir::Field<$tcx>,
+            [] field_pat: rustc_hir::FieldPat<$tcx>,
+            [] fn_decl: rustc_hir::FnDecl<$tcx>,
+            [] foreign_item: rustc_hir::ForeignItem<$tcx>,
+            [] impl_item_ref: rustc_hir::ImplItemRef<$tcx>,
+            [] inline_asm: rustc_hir::InlineAsm<$tcx>,
+            [] local: rustc_hir::Local<$tcx>,
+            [few] macro_def: rustc_hir::MacroDef<$tcx>,
+            [] param: rustc_hir::Param<$tcx>,
+            [] pat: rustc_hir::Pat<$tcx>,
+            [] path: rustc_hir::Path<$tcx>,
+            [] path_segment: rustc_hir::PathSegment<$tcx>,
+            [] poly_trait_ref: rustc_hir::PolyTraitRef<$tcx>,
+            [] qpath: rustc_hir::QPath<$tcx>,
+            [] stmt: rustc_hir::Stmt<$tcx>,
+            [] struct_field: rustc_hir::StructField<$tcx>,
+            [] trait_item_ref: rustc_hir::TraitItemRef,
+            [] ty: rustc_hir::Ty<$tcx>,
+            [] type_binding: rustc_hir::TypeBinding<$tcx>,
+            [] variant: rustc_hir::Variant<$tcx>,
+            [] where_predicate: rustc_hir::WherePredicate<$tcx>,
+        ], $tcx);
+    )
+}

src/librustc_hir/lib.rs

@@ -13,6 +13,7 @@
 #[macro_use]
 extern crate rustc_data_structures;
 
+mod arena;
 pub mod def;
 pub use rustc_span::def_id;
 mod hir;

src/librustc_interface/passes.rs

@@ -437,7 +437,7 @@ pub fn lower_to_hir<'res, 'tcx>(
     resolver: &'res mut Resolver<'_>,
     dep_graph: &'res DepGraph,
     krate: &'res ast::Crate,
-    arena: &'tcx Arena<'tcx>,
+    arena: &'tcx rustc_ast_lowering::Arena<'tcx>,
 ) -> Crate<'tcx> {
     // Lower AST to HIR.
     let hir_crate = rustc_ast_lowering::lower_crate(