1 files changed, 52 insertions, 0 deletions
diff --git a/compiler/rustc_hir/src/arena.rs b/compiler/rustc_hir/src/arena.rs
new file mode 100644
index 00000000000..85ab7906d25
--- /dev/null
+++ b/compiler/rustc_hir/src/arena.rs
@@ -0,0 +1,52 @@
+/// 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>,
+            [] asm_operand: rustc_hir::InlineAsmOperand<$tcx>,
+            [] asm_template: rustc_ast::InlineAsmTemplatePiece,
+            [] attribute: rustc_ast::Attribute,
+            [] block: rustc_hir::Block<$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<$tcx>,
+            [few] inline_asm: rustc_hir::InlineAsm<$tcx>,
+            [few] llvm_inline_asm: rustc_hir::LlvmInlineAsm<$tcx>,
+            [] local: rustc_hir::Local<$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);
+    )
+}