Fully deserialize the scope chain after parsing, not before

src/parsing/parser.h

 // 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.
 
 #ifndef V8_PARSING_PARSER_H_
 #define V8_PARSING_PARSER_H_
 
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/parsing/parser-base.h"
@@ skipping 166 matching lines @@
     cached_parse_data_ = NULL;
   }
 
   // Parses the source code represented by the compilation info and sets its
   // function literal.  Returns false (and deallocates any allocated AST
   // nodes) if parsing failed.
   static bool ParseStatic(ParseInfo* info);
   bool Parse(ParseInfo* info);
   void ParseOnBackground(ParseInfo* info);
 
-  void DeserializeScopeChain(ParseInfo* info, Handle<Context> context,
-                             Scope::DeserializationMode deserialization_mode);
+  // Deserialize the scope chain prior to parsing in which the script is going
+  // to be executed. If the script is a top-level script, or the scope chain
+  // consists of only a native context, maybe_context should be an empty
+  // handle.
+  //
+  // This only deserializes the scope chain, but doesn't connect the scopes to
+  // their corresponding scope infos. Therefore, looking up variables in the
+  // deserialized scopes is not possible.
+  void DeserializeScopeChain(ParseInfo* info,
+                             MaybeHandle<Context> maybe_context);
 
   // Handle errors detected during parsing, move statistics to Isolate,
   // internalize strings (move them to the heap).
   void Internalize(Isolate* isolate, Handle<Script> script, bool error);
   void HandleSourceURLComments(Isolate* isolate, Handle<Script> script);
 
  private:
   friend class ParserBase<Parser>;
   friend class v8::internal::ExpressionClassifier<ParserTypes<Parser>>;
 
@@ skipping 227 matching lines @@
   // The var declarations are hoisted to the function scope, but originate from
   // a scope where the name has also been let bound or the var declaration is
   // hoisted over such a scope.
   void CheckConflictingVarDeclarations(Scope* scope, bool* ok);
 
   // Insert initializer statements for var-bindings shadowing parameter bindings
   // from a non-simple parameter list.
   void InsertShadowingVarBindingInitializers(Block* block);
 
   // Implement sloppy block-scoped functions, ES2015 Annex B 3.3
-  void InsertSloppyBlockFunctionVarBindings(DeclarationScope* scope,
-                                            bool* ok);
+  void InsertSloppyBlockFunctionVarBindings(DeclarationScope* scope);
 
   VariableProxy* NewUnresolved(const AstRawString* name, int begin_pos,
                                int end_pos = kNoSourcePosition,
                                VariableKind kind = NORMAL_VARIABLE);
   VariableProxy* NewUnresolved(const AstRawString* name);
   Variable* Declare(Declaration* declaration,
                     DeclarationDescriptor::Kind declaration_kind,
                     VariableMode mode, InitializationFlag init, bool* ok,
                     Scope* declaration_scope = nullptr);
   Declaration* DeclareVariable(const AstRawString* name, VariableMode mode,
@@ skipping 625 matching lines @@
 
 #ifdef DEBUG
   void Print(AstNode* node);
 #endif  // DEBUG
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PARSER_H_