Allocate script scopes using a separate constructor

src/ast/scopes.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/ast/scopes.h"
 
 #include <set>
 
 #include "src/accessors.h"
 #include "src/bootstrapper.h"
@@ skipping 59 matching lines @@
       ZoneHashMap::LookupOrInsert(const_cast<AstRawString*>(name), name->hash(),
                                   ZoneAllocationPolicy(zone));
   stmt->set_next(static_cast<SloppyBlockFunctionStatement*>(p->value));
   p->value = stmt;
 }
 
 
 // ----------------------------------------------------------------------------
 // Implementation of Scope
 
+Scope::Scope(Zone* zone)
+    : zone_(zone),
+      outer_scope_(nullptr),
+      variables_(zone),
+      ordered_variables_(4, zone),
+      decls_(4, zone),
+      scope_type_(SCRIPT_SCOPE) {
+  SetDefaults();
+}
+
 Scope::Scope(Zone* zone, Scope* outer_scope, ScopeType scope_type)
     : zone_(zone),
       outer_scope_(outer_scope),
       variables_(zone),
       ordered_variables_(4, zone),
       decls_(4, zone),
       scope_type_(scope_type) {
+  DCHECK_NE(SCRIPT_SCOPE, scope_type);
   SetDefaults();
-  if (outer_scope == nullptr) {
-    // If the outer scope is null, this cannot be a with scope. The outermost
-    // scope must be a script scope.
-    DCHECK_EQ(SCRIPT_SCOPE, scope_type);
-  } else {
-    set_language_mode(outer_scope->language_mode());
-    force_context_allocation_ =
-        !is_function_scope() && outer_scope->has_forced_context_allocation();
-    outer_scope_->AddInnerScope(this);
-  }
+  set_language_mode(outer_scope->language_mode());
+  force_context_allocation_ =
+      !is_function_scope() && outer_scope->has_forced_context_allocation();
+  outer_scope_->AddInnerScope(this);
 }
 
 Scope::Snapshot::Snapshot(Scope* scope)
     : outer_scope_(scope),
       top_inner_scope_(scope->inner_scope_),
       top_unresolved_(scope->unresolved_),
       top_temp_(scope->GetClosureScope()->temps()->length()) {}
 
+DeclarationScope::DeclarationScope(Zone* zone)
+    : Scope(zone),
+      function_kind_(kNormalFunction),
+      temps_(4, zone),
+      params_(4, zone),
+      sloppy_block_function_map_(zone) {
+  SetDefaults();
+}
+
 DeclarationScope::DeclarationScope(Zone* zone, Scope* outer_scope,
                                    ScopeType scope_type,
                                    FunctionKind function_kind)
     : Scope(zone, outer_scope, scope_type),
       function_kind_(function_kind),
       temps_(4, zone),
       params_(4, zone),
       sloppy_block_function_map_(zone) {
   SetDefaults();
-  if (outer_scope != nullptr) asm_function_ = outer_scope_->IsAsmModule();
+  asm_function_ = outer_scope_->IsAsmModule();
 }
 
 ModuleScope::ModuleScope(Zone* zone, DeclarationScope* script_scope,
                          AstValueFactory* ast_value_factory)
     : DeclarationScope(zone, script_scope, MODULE_SCOPE) {
   module_descriptor_ = new (zone) ModuleDescriptor(zone);
   set_language_mode(STRICT);
   DeclareThis(ast_value_factory);
 }
 
@@ skipping 1602 matching lines @@
       function != nullptr && function->IsContextSlot();
   return num_heap_slots() - Context::MIN_CONTEXT_SLOTS - num_global_slots() -
          (is_function_var_in_context ? 1 : 0);
 }
 
 
 int Scope::ContextGlobalCount() const { return num_global_slots(); }
 
 }  // namespace internal
 }  // namespace v8