Use Arena inside hir::Body.

src/librustc/arena.rs

@@ -130,6 +130,7 @@ macro_rules! arena_types {
             [] foreign_item: rustc::hir::ForeignItem<$tcx>,
             [] impl_item_ref: rustc::hir::ImplItemRef,
             [] macro_def: rustc::hir::MacroDef<$tcx>,
+            [] param: rustc::hir::Param,
             [] path: rustc::hir::Path,
             [] struct_field: rustc::hir::StructField<$tcx>,
             [] trait_item_ref: rustc::hir::TraitItemRef,

src/librustc/hir/intravisit.rs

@@ -222,7 +222,7 @@ pub trait Visitor<'v>: Sized {
         walk_item(self, i)
     }
 
-    fn visit_body(&mut self, b: &'v Body) {
+    fn visit_body(&mut self, b: &'v Body<'v>) {
         walk_body(self, b);
     }
 
@@ -401,8 +401,8 @@ pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod<'v>, mod_hi
     }
 }
 
-pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body) {
-    walk_list!(visitor, visit_param, &body.params);
+pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body<'v>) {
+    walk_list!(visitor, visit_param, body.params);
     visitor.visit_expr(&body.value);
 }
 

src/librustc/hir/lowering.rs

@@ -99,7 +99,7 @@ pub struct LoweringContext<'a, 'hir: 'a> {
 
     trait_items: BTreeMap<hir::TraitItemId, hir::TraitItem<'hir>>,
     impl_items: BTreeMap<hir::ImplItemId, hir::ImplItem<'hir>>,
-    bodies: BTreeMap<hir::BodyId, hir::Body>,
+    bodies: BTreeMap<hir::BodyId, hir::Body<'hir>>,
     exported_macros: Vec<hir::MacroDef<'hir>>,
     non_exported_macro_attrs: Vec<ast::Attribute>,
 
@@ -3428,7 +3428,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     }
 }
 
-fn body_ids(bodies: &BTreeMap<hir::BodyId, hir::Body>) -> Vec<hir::BodyId> {
+fn body_ids(bodies: &BTreeMap<hir::BodyId, hir::Body<'hir>>) -> Vec<hir::BodyId> {
     // Sorting by span ensures that we get things in order within a
     // file, and also puts the files in a sensible order.
     let mut body_ids: Vec<_> = bodies.keys().cloned().collect();

src/librustc/hir/lowering/item.rs

@@ -5,7 +5,7 @@ use super::ImplTraitTypeIdVisitor;
 use super::AnonymousLifetimeMode;
 use super::ParamMode;
 
-use crate::hir::{self, HirVec};
+use crate::hir;
 use crate::hir::ptr::P;
 use crate::hir::def_id::DefId;
 use crate::hir::def::{Res, DefKind};
@@ -107,7 +107,7 @@ impl<'a, 'lowering, 'hir> Visitor<'a> for ItemLowerer<'a, 'lowering, 'hir> {
     }
 }
 
-impl LoweringContext<'_, 'hir> {
+impl<'hir> LoweringContext<'_, 'hir> {
     // Same as the method above, but accepts `hir::GenericParam`s
     // instead of `ast::GenericParam`s.
     // This should only be used with generics that have already had their
@@ -1052,7 +1052,7 @@ impl LoweringContext<'_, 'hir> {
         }
     }
 
-    fn record_body(&mut self, params: HirVec<hir::Param>, value: hir::Expr) -> hir::BodyId {
+    fn record_body(&mut self, params: &'hir [hir::Param], value: hir::Expr) -> hir::BodyId {
         let body = hir::Body {
             generator_kind: self.generator_kind,
             params,
@@ -1065,7 +1065,7 @@ impl LoweringContext<'_, 'hir> {
 
     fn lower_body(
         &mut self,
-        f: impl FnOnce(&mut LoweringContext<'_, '_>) -> (HirVec<hir::Param>, hir::Expr),
+        f: impl FnOnce(&mut Self) -> (&'hir [hir::Param], hir::Expr),
     ) -> hir::BodyId {
         let prev_gen_kind = self.generator_kind.take();
         let (parameters, result) = f(self);
@@ -1089,7 +1089,9 @@ impl LoweringContext<'_, 'hir> {
         body: impl FnOnce(&mut LoweringContext<'_, '_>) -> hir::Expr,
     ) -> hir::BodyId {
         self.lower_body(|this| (
-            decl.inputs.iter().map(|x| this.lower_param(x)).collect(),
+            this.arena.alloc_from_iter(
+                decl.inputs.iter().map(|x| this.lower_param(x))
+            ),
             body(this),
         ))
     }
@@ -1111,7 +1113,7 @@ impl LoweringContext<'_, 'hir> {
     }
 
     pub(super) fn lower_const_body(&mut self, span: Span, expr: Option<&Expr>) -> hir::BodyId {
-        self.lower_body(|this| (hir_vec![], match expr {
+        self.lower_body(|this| (&[], match expr {
             Some(expr) => this.lower_expr(expr),
             None => this.expr_err(span),
         }))
@@ -1299,7 +1301,8 @@ impl LoweringContext<'_, 'hir> {
                     );
                     this.expr_block(P(body), AttrVec::new())
                 });
-            (HirVec::from(parameters), this.expr(body_span, async_expr, AttrVec::new()))
+
+            (this.arena.alloc_from_iter(parameters), this.expr(body_span, async_expr, AttrVec::new()))
         })
     }
 

src/librustc/hir/map/mod.rs

@@ -459,7 +459,7 @@ impl<'hir> Map<'hir> {
         self.forest.krate.impl_item(id)
     }
 
-    pub fn body(&self, id: BodyId) -> &'hir Body {
+    pub fn body(&self, id: BodyId) -> &'hir Body<'hir> {
         self.read(id.hir_id);
 
         // N.B., intentionally bypass `self.forest.krate()` so that we

src/librustc/hir/mod.rs

@@ -760,7 +760,7 @@ pub struct Crate<'hir> {
 
     pub trait_items: BTreeMap<TraitItemId, TraitItem<'hir>>,
     pub impl_items: BTreeMap<ImplItemId, ImplItem<'hir>>,
-    pub bodies: BTreeMap<BodyId, Body>,
+    pub bodies: BTreeMap<BodyId, Body<'hir>>,
     pub trait_impls: BTreeMap<DefId, Vec<HirId>>,
 
     /// A list of the body ids written out in the order in which they
@@ -787,7 +787,7 @@ impl Crate<'hir> {
         &self.impl_items[&id]
     }
 
-    pub fn body(&self, id: BodyId) -> &Body {
+    pub fn body(&self, id: BodyId) -> &Body<'hir> {
         &self.bodies[&id]
     }
 }
@@ -1353,13 +1353,13 @@ pub struct BodyId {
 /// All bodies have an **owner**, which can be accessed via the HIR
 /// map using `body_owner_def_id()`.
 #[derive(RustcEncodable, RustcDecodable, Debug)]
-pub struct Body {
-    pub params: HirVec<Param>,
+pub struct Body<'hir> {
+    pub params: &'hir [Param],
     pub value: Expr,
     pub generator_kind: Option<GeneratorKind>,
 }
 
-impl Body {
+impl Body<'hir> {
     pub fn id(&self) -> BodyId {
         BodyId {
             hir_id: self.value.hir_id,

src/librustc/ich/hcx.rs

@@ -61,7 +61,7 @@ struct BodyResolver<'tcx>(&'tcx hir::Crate<'tcx>);
 impl<'tcx> BodyResolver<'tcx> {
     /// Returns a reference to the `hir::Body` with the given `BodyId`.
     /// **Does not do any tracking**; use carefully.
-    fn body(self, id: hir::BodyId) -> &'tcx hir::Body {
+    fn body(self, id: hir::BodyId) -> &'tcx hir::Body<'tcx> {
         self.0.body(id)
     }
 }

src/librustc/ich/impls_hir.rs

@@ -266,7 +266,7 @@ impl<'a> HashStable<StableHashingContext<'a>> for hir::Item<'_> {
     }
 }
 
-impl<'a> HashStable<StableHashingContext<'a>> for hir::Body {
+impl<'a> HashStable<StableHashingContext<'a>> for hir::Body<'_> {
     fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
         let hir::Body {
             params,

src/librustc/infer/error_reporting/need_type_info.rs

@@ -83,8 +83,8 @@ impl<'a, 'tcx> Visitor<'tcx> for FindLocalByTypeVisitor<'a, 'tcx> {
         intravisit::walk_local(self, local);
     }
 
-    fn visit_body(&mut self, body: &'tcx Body) {
-        for param in &body.params {
+    fn visit_body(&mut self, body: &'tcx Body<'tcx>) {
+        for param in body.params {
             if let (None, Some(ty)) = (
                 self.found_arg_pattern,
                 self.node_matches_type(param.hir_id),
@@ -113,7 +113,7 @@ fn closure_return_type_suggestion(
     span: Span,
     err: &mut DiagnosticBuilder<'_>,
     output: &FunctionRetTy,
-    body: &Body,
+    body: &Body<'_>,
     descr: &str,
     name: &str,
     ret: &str,

src/librustc/lint/context.rs

@@ -924,7 +924,7 @@ for LateContextAndPass<'a, 'tcx, T> {
         });
     }
 
-    fn visit_body(&mut self, body: &'tcx hir::Body) {
+    fn visit_body(&mut self, body: &'tcx hir::Body<'tcx>) {
         lint_callback!(self, check_body, body);
         hir_visit::walk_body(self, body);
         lint_callback!(self, check_body_post, body);

src/librustc/lint/mod.rs

@@ -87,8 +87,8 @@ macro_rules! late_lint_methods {
     ($macro:path, $args:tt, [$hir:tt]) => (
         $macro!($args, [$hir], [
             fn check_param(a: &$hir hir::Param);
-            fn check_body(a: &$hir hir::Body);
-            fn check_body_post(a: &$hir hir::Body);
+            fn check_body(a: &$hir hir::Body<$hir>);
+            fn check_body_post(a: &$hir hir::Body<$hir>);
             fn check_name(a: Span, b: ast::Name);
             fn check_crate(a: &$hir hir::Crate<$hir>);
             fn check_crate_post(a: &$hir hir::Crate<$hir>);
@@ -114,13 +114,13 @@ macro_rules! late_lint_methods {
             fn check_fn(
                 a: hir::intravisit::FnKind<$hir>,
                 b: &$hir hir::FnDecl,
-                c: &$hir hir::Body,
+                c: &$hir hir::Body<$hir>,
                 d: Span,
                 e: hir::HirId);
             fn check_fn_post(
                 a: hir::intravisit::FnKind<$hir>,
                 b: &$hir hir::FnDecl,
-                c: &$hir hir::Body,
+                c: &$hir hir::Body<$hir>,
                 d: Span,
                 e: hir::HirId
             );

src/librustc/middle/region.rs

@@ -715,7 +715,7 @@ impl<'tcx> ScopeTree {
     pub fn yield_in_scope_for_expr(&self,
                                    scope: Scope,
                                    expr_hir_id: hir::HirId,
-                                   body: &'tcx hir::Body) -> Option<Span> {
+                                   body: &'tcx hir::Body<'tcx>) -> Option<Span> {
         self.yield_in_scope(scope).and_then(|YieldData { span, expr_and_pat_count, .. }| {
             let mut visitor = ExprLocatorVisitor {
                 hir_id: expr_hir_id,
@@ -1362,7 +1362,7 @@ impl<'tcx> Visitor<'tcx> for RegionResolutionVisitor<'tcx> {
         resolve_block(self, b);
     }
 
-    fn visit_body(&mut self, body: &'tcx hir::Body) {
+    fn visit_body(&mut self, body: &'tcx hir::Body<'tcx>) {
         let body_id = body.id();
         let owner_id = self.tcx.hir().body_owner(body_id);
 
@@ -1387,7 +1387,7 @@ impl<'tcx> Visitor<'tcx> for RegionResolutionVisitor<'tcx> {
 
         // The arguments and `self` are parented to the fn.
         self.cx.var_parent = self.cx.parent.take();
-        for param in &body.params {
+        for param in body.params {
             self.visit_pat(&param.pat);
         }
 

src/librustc/middle/resolve_lifetime.rs

@@ -1167,7 +1167,7 @@ fn signal_shadowing_problem(tcx: TyCtxt<'_>, name: ast::Name, orig: Original, sh
 
 // Adds all labels in `b` to `ctxt.labels_in_fn`, signalling a warning
 // if one of the label shadows a lifetime or another label.
-fn extract_labels(ctxt: &mut LifetimeContext<'_, '_>, body: &hir::Body) {
+fn extract_labels(ctxt: &mut LifetimeContext<'_, '_>, body: &hir::Body<'_>) {
     struct GatherLabels<'a, 'tcx> {
         tcx: TyCtxt<'tcx>,
         scope: ScopeRef<'a>,

src/librustc_lint/nonstandard_style.rs

@@ -298,7 +298,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NonSnakeCase {
         cx: &LateContext<'_, '_>,
         fk: FnKind<'_>,
         _: &hir::FnDecl,
-        _: &hir::Body,
+        _: &hir::Body<'_>,
         _: Span,
         id: hir::HirId,
     ) {

src/librustc_mir/build/mod.rs

@@ -552,7 +552,7 @@ fn construct_fn<'a, 'tcx, A>(
     abi: Abi,
     return_ty: Ty<'tcx>,
     return_ty_span: Span,
-    body: &'tcx hir::Body,
+    body: &'tcx hir::Body<'tcx>,
 ) -> Body<'tcx>
 where
     A: Iterator<Item=ArgInfo<'tcx>>

src/librustc_mir/hair/pattern/check_match.rs

@@ -76,10 +76,10 @@ impl<'tcx> Visitor<'tcx> for MatchVisitor<'_, 'tcx> {
         self.check_patterns(false, &loc.pat);
     }
 
-    fn visit_body(&mut self, body: &'tcx hir::Body) {
+    fn visit_body(&mut self, body: &'tcx hir::Body<'tcx>) {
         intravisit::walk_body(self, body);
 
-        for param in &body.params {
+        for param in body.params {
             self.check_irrefutable(&param.pat, "function argument", None);
             self.check_patterns(false, &param.pat);
         }

src/librustc_passes/check_const.rs

@@ -75,7 +75,7 @@ enum ConstKind {
 }
 
 impl ConstKind {
-    fn for_body(body: &hir::Body, hir_map: &Map<'_>) -> Option<Self> {
+    fn for_body(body: &hir::Body<'_>, hir_map: &Map<'_>) -> Option<Self> {
         let is_const_fn = |id| hir_map.fn_sig_by_hir_id(id).unwrap().header.is_const();
 
         let owner = hir_map.body_owner(body.id());
@@ -215,7 +215,7 @@ impl<'tcx> Visitor<'tcx> for CheckConstVisitor<'tcx> {
         self.recurse_into(kind, |this| hir::intravisit::walk_anon_const(this, anon));
     }
 
-    fn visit_body(&mut self, body: &'tcx hir::Body) {
+    fn visit_body(&mut self, body: &'tcx hir::Body<'tcx>) {
         let kind = ConstKind::for_body(body, self.tcx.hir());
         self.recurse_into(kind, |this| hir::intravisit::walk_body(this, body));
     }

src/librustc_passes/liveness.rs

@@ -371,7 +371,7 @@ fn visit_fn<'tcx>(
 
     let body = ir.tcx.hir().body(body_id);
 
-    for param in &body.params {
+    for param in body.params {
         let is_shorthand = match param.pat.kind {
             rustc::hir::PatKind::Struct(..) => true,
             _ => false,
@@ -1463,8 +1463,8 @@ impl<'tcx> Liveness<'_, 'tcx> {
         }
     }
 
-    fn warn_about_unused_args(&self, body: &hir::Body, entry_ln: LiveNode) {
-        for p in &body.params {
+    fn warn_about_unused_args(&self, body: &hir::Body<'_>, entry_ln: LiveNode) {
+        for p in body.params {
             self.check_unused_vars_in_pat(&p.pat, Some(entry_ln), |spans, hir_id, ln, var| {
                 if self.live_on_entry(ln, var).is_none() {
                     self.report_dead_assign(hir_id, spans, var, true);