Auto merge of #66936 - cjgillot:hirene-expr, r=Zoxc

Allocate HIR on an arena 2/4 -- Expr & Pat

This is the second PR in the series started by #66931

This time, commits don't really make sense on their own.
They are mostly split by type of compile error.

The additional diff is here: cjgillot/rust@hirene-preamble...hirene-expr

src/librustc/arena.rs

@@ -125,14 +125,25 @@ macro_rules! arena_types {
 
             // HIR types
             [few] hir_forest: rustc::hir::map::Forest<$tcx>,
+            [] arm: rustc::hir::Arm<$tcx>,
             [] attribute: syntax::ast::Attribute,
+            [] block: rustc::hir::Block<$tcx>,
             [few] global_asm: rustc::hir::GlobalAsm,
+            [] expr: rustc::hir::Expr<$tcx>,
+            [] field: rustc::hir::Field<$tcx>,
+            [] field_pat: rustc::hir::FieldPat<$tcx>,
             [] fn_decl: rustc::hir::FnDecl,
             [] foreign_item: rustc::hir::ForeignItem<$tcx>,
             [] impl_item_ref: rustc::hir::ImplItemRef,
+            [] inline_asm: rustc::hir::InlineAsm<$tcx>,
+            [] local: rustc::hir::Local<$tcx>,
             [few] macro_def: rustc::hir::MacroDef<$tcx>,
-            [] param: rustc::hir::Param,
+            [] param: rustc::hir::Param<$tcx>,
+            [] pat: rustc::hir::Pat<$tcx>,
             [] path: rustc::hir::Path,
+            [] path_segment: rustc::hir::PathSegment,
+            [] qpath: rustc::hir::QPath,
+            [] stmt: rustc::hir::Stmt<$tcx>,
             [] struct_field: rustc::hir::StructField<$tcx>,
             [] trait_item_ref: rustc::hir::TraitItemRef,
             [] ty: rustc::hir::Ty,

src/librustc/hir/check_attr.rs

@@ -458,7 +458,7 @@ impl CheckAttrVisitor<'tcx> {
             .emit();
     }
 
-    fn check_stmt_attributes(&self, stmt: &hir::Stmt) {
+    fn check_stmt_attributes(&self, stmt: &hir::Stmt<'_>) {
         // When checking statements ignore expressions, they will be checked later
         if let hir::StmtKind::Local(ref l) = stmt.kind {
             for attr in l.attrs.iter() {
@@ -477,7 +477,7 @@ impl CheckAttrVisitor<'tcx> {
         }
     }
 
-    fn check_expr_attributes(&self, expr: &hir::Expr) {
+    fn check_expr_attributes(&self, expr: &hir::Expr<'_>) {
         let target = match expr.kind {
             hir::ExprKind::Closure(..) => Target::Closure,
             _ => Target::Expression,
@@ -537,12 +537,12 @@ impl Visitor<'tcx> for CheckAttrVisitor<'tcx> {
         intravisit::walk_impl_item(self, impl_item)
     }
 
-    fn visit_stmt(&mut self, stmt: &'tcx hir::Stmt) {
+    fn visit_stmt(&mut self, stmt: &'tcx hir::Stmt<'tcx>) {
         self.check_stmt_attributes(stmt);
         intravisit::walk_stmt(self, stmt)
     }
 
-    fn visit_expr(&mut self, expr: &'tcx hir::Expr) {
+    fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
         self.check_expr_attributes(expr);
         intravisit::walk_expr(self, expr)
     }

src/librustc/hir/intravisit.rs

@@ -212,7 +212,7 @@ pub trait Visitor<'v>: Sized {
         }
     }
 
-    fn visit_param(&mut self, param: &'v Param) {
+    fn visit_param(&mut self, param: &'v Param<'v>) {
         walk_param(self, param)
     }
 
@@ -253,25 +253,25 @@ pub trait Visitor<'v>: Sized {
     fn visit_foreign_item(&mut self, i: &'v ForeignItem<'v>) {
         walk_foreign_item(self, i)
     }
-    fn visit_local(&mut self, l: &'v Local) {
+    fn visit_local(&mut self, l: &'v Local<'v>) {
         walk_local(self, l)
     }
-    fn visit_block(&mut self, b: &'v Block) {
+    fn visit_block(&mut self, b: &'v Block<'v>) {
         walk_block(self, b)
     }
-    fn visit_stmt(&mut self, s: &'v Stmt) {
+    fn visit_stmt(&mut self, s: &'v Stmt<'v>) {
         walk_stmt(self, s)
     }
-    fn visit_arm(&mut self, a: &'v Arm) {
+    fn visit_arm(&mut self, a: &'v Arm<'v>) {
         walk_arm(self, a)
     }
-    fn visit_pat(&mut self, p: &'v Pat) {
+    fn visit_pat(&mut self, p: &'v Pat<'v>) {
         walk_pat(self, p)
     }
     fn visit_anon_const(&mut self, c: &'v AnonConst) {
         walk_anon_const(self, c)
     }
-    fn visit_expr(&mut self, ex: &'v Expr) {
+    fn visit_expr(&mut self, ex: &'v Expr<'v>) {
         walk_expr(self, ex)
     }
     fn visit_ty(&mut self, t: &'v Ty) {
@@ -409,7 +409,7 @@ pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body<'v>) {
     visitor.visit_expr(&body.value);
 }
 
-pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local) {
+pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local<'v>) {
     // Intentionally visiting the expr first - the initialization expr
     // dominates the local's definition.
     walk_list!(visitor, visit_expr, &local.init);
@@ -462,10 +462,10 @@ where
     visitor.visit_path(&trait_ref.path, trait_ref.hir_ref_id)
 }
 
-pub fn walk_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v Param) {
+pub fn walk_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v Param<'v>) {
     visitor.visit_id(param.hir_id);
     visitor.visit_pat(&param.pat);
-    walk_list!(visitor, visit_attribute, &param.attrs);
+    walk_list!(visitor, visit_attribute, param.attrs);
 }
 
 pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) {
@@ -684,26 +684,26 @@ pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(visitor: &mut V, type_binding
     }
 }
 
-pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat) {
+pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat<'v>) {
     visitor.visit_id(pattern.hir_id);
     match pattern.kind {
-        PatKind::TupleStruct(ref qpath, ref children, _) => {
+        PatKind::TupleStruct(ref qpath, children, _) => {
             visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
             walk_list!(visitor, visit_pat, children);
         }
         PatKind::Path(ref qpath) => {
             visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
         }
-        PatKind::Struct(ref qpath, ref fields, _) => {
+        PatKind::Struct(ref qpath, fields, _) => {
             visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
             for field in fields {
                 visitor.visit_id(field.hir_id);
                 visitor.visit_ident(field.ident);
                 visitor.visit_pat(&field.pat)
             }
         }
-        PatKind::Or(ref pats) => walk_list!(visitor, visit_pat, pats),
-        PatKind::Tuple(ref tuple_elements, _) => {
+        PatKind::Or(pats) => walk_list!(visitor, visit_pat, pats),
+        PatKind::Tuple(tuple_elements, _) => {
             walk_list!(visitor, visit_pat, tuple_elements);
         }
         PatKind::Box(ref subpattern) | PatKind::Ref(ref subpattern, _) => {
@@ -719,7 +719,7 @@ pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat) {
             visitor.visit_expr(upper_bound)
         }
         PatKind::Wild => (),
-        PatKind::Slice(ref prepatterns, ref slice_pattern, ref postpatterns) => {
+        PatKind::Slice(prepatterns, ref slice_pattern, postpatterns) => {
             walk_list!(visitor, visit_pat, prepatterns);
             walk_list!(visitor, visit_pat, slice_pattern);
             walk_list!(visitor, visit_pat, postpatterns);
@@ -955,13 +955,13 @@ pub fn walk_struct_field<'v, V: Visitor<'v>>(visitor: &mut V, struct_field: &'v
     walk_list!(visitor, visit_attribute, struct_field.attrs);
 }
 
-pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block) {
+pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block<'v>) {
     visitor.visit_id(block.hir_id);
-    walk_list!(visitor, visit_stmt, &block.stmts);
+    walk_list!(visitor, visit_stmt, block.stmts);
     walk_list!(visitor, visit_expr, &block.expr);
 }
 
-pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt) {
+pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt<'v>) {
     visitor.visit_id(statement.hir_id);
     match statement.kind {
         StmtKind::Local(ref local) => visitor.visit_local(local),
@@ -977,19 +977,19 @@ pub fn walk_anon_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v AnonCo
     visitor.visit_nested_body(constant.body);
 }
 
-pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
+pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>) {
     visitor.visit_id(expression.hir_id);
     walk_list!(visitor, visit_attribute, expression.attrs.iter());
     match expression.kind {
         ExprKind::Box(ref subexpression) => visitor.visit_expr(subexpression),
-        ExprKind::Array(ref subexpressions) => {
+        ExprKind::Array(subexpressions) => {
             walk_list!(visitor, visit_expr, subexpressions);
         }
         ExprKind::Repeat(ref element, ref count) => {
             visitor.visit_expr(element);
             visitor.visit_anon_const(count)
         }
-        ExprKind::Struct(ref qpath, ref fields, ref optional_base) => {
+        ExprKind::Struct(ref qpath, fields, ref optional_base) => {
             visitor.visit_qpath(qpath, expression.hir_id, expression.span);
             for field in fields {
                 visitor.visit_id(field.hir_id);
@@ -998,14 +998,14 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
             }
             walk_list!(visitor, visit_expr, optional_base);
         }
-        ExprKind::Tup(ref subexpressions) => {
+        ExprKind::Tup(subexpressions) => {
             walk_list!(visitor, visit_expr, subexpressions);
         }
-        ExprKind::Call(ref callee_expression, ref arguments) => {
+        ExprKind::Call(ref callee_expression, arguments) => {
             visitor.visit_expr(callee_expression);
             walk_list!(visitor, visit_expr, arguments);
         }
-        ExprKind::MethodCall(ref segment, _, ref arguments) => {
+        ExprKind::MethodCall(ref segment, _, arguments) => {
             visitor.visit_path_segment(expression.span, segment);
             walk_list!(visitor, visit_expr, arguments);
         }
@@ -1027,7 +1027,7 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
             walk_list!(visitor, visit_label, opt_label);
             visitor.visit_block(block);
         }
-        ExprKind::Match(ref subexpression, ref arms, _) => {
+        ExprKind::Match(ref subexpression, arms, _) => {
             visitor.visit_expr(subexpression);
             walk_list!(visitor, visit_arm, arms);
         }
@@ -1077,8 +1077,8 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
             walk_list!(visitor, visit_expr, optional_expression);
         }
         ExprKind::InlineAsm(ref asm) => {
-            walk_list!(visitor, visit_expr, &asm.outputs_exprs);
-            walk_list!(visitor, visit_expr, &asm.inputs_exprs);
+            walk_list!(visitor, visit_expr, asm.outputs_exprs);
+            walk_list!(visitor, visit_expr, asm.inputs_exprs);
         }
         ExprKind::Yield(ref subexpression, _) => {
             visitor.visit_expr(subexpression);
@@ -1087,7 +1087,7 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
     }
 }
 
-pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm) {
+pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm<'v>) {
     visitor.visit_id(arm.hir_id);
     visitor.visit_pat(&arm.pat);
     if let Some(ref g) = arm.guard {
@@ -1096,7 +1096,7 @@ pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm) {
         }
     }
     visitor.visit_expr(&arm.body);
-    walk_list!(visitor, visit_attribute, &arm.attrs);
+    walk_list!(visitor, visit_attribute, arm.attrs);
 }
 
 pub fn walk_vis<'v, V: Visitor<'v>>(visitor: &mut V, vis: &'v Visibility) {