Only create ScopeInfos for eagerly parsed scopes.

src/ast/scopes.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_AST_SCOPES_H_
 #define V8_AST_SCOPES_H_
 
 #include "src/base/hashmap.h"
 #include "src/globals.h"
 #include "src/objects.h"
@@ skipping 393 matching lines @@
 
   // Check that all Scopes in the scope tree use the same Zone.
   void CheckZones();
 #endif
 
   // Retrieve `IsSimpleParameterList` of current or outer function.
   bool HasSimpleParameters();
   void set_is_debug_evaluate_scope() { is_debug_evaluate_scope_ = true; }
   bool is_debug_evaluate_scope() const { return is_debug_evaluate_scope_; }
 
+  void set_is_lazily_parsed(bool is_lazily_parsed) {
+    is_lazily_parsed_ = is_lazily_parsed;
+  }
+
  protected:
   explicit Scope(Zone* zone);
 
   void set_language_mode(LanguageMode language_mode) {
     is_strict_ = is_strict(language_mode);
   }
 
  private:
   Variable* Declare(Zone* zone, Scope* scope, const AstRawString* name,
                     VariableMode mode, VariableKind kind,
                     InitializationFlag initialization_flag,
                     MaybeAssignedFlag maybe_assigned_flag = kNotAssigned) {
     bool added;
     Variable* var =
         variables_.Declare(zone, scope, name, mode, kind, initialization_flag,
                            maybe_assigned_flag, &added);
     if (added) locals_.Add(var, zone);
     return var;
   }
 
   // This method should only be invoked on scopes created during parsing (i.e.,
   // not deserialized from a context). Also, since NeedsContext() is only
   // returning a valid result after variables are resolved, NeedsScopeInfo()
   // should also be invoked after resolution.
   bool NeedsScopeInfo() const {
     DCHECK(!already_resolved_);
+    // A lazily parsed scope doesn't contain enough information to create a
+    // ScopeInfo from it.
+    if (is_lazily_parsed_) return false;
     return NeedsContext() || is_script_scope() || is_function_scope() ||
            is_eval_scope() || is_module_scope();
   }
 
   Zone* zone_;
 
   // Scope tree.
   Scope* outer_scope_;  // the immediately enclosing outer scope, or NULL
   Scope* inner_scope_;  // an inner scope of this scope
   Scope* sibling_;  // a sibling inner scope of the outer scope of this scope.
@@ skipping 49 matching lines @@
   bool is_hidden_ : 1;
   // Temporary workaround that allows masking of 'this' in debug-evalute scopes.
   bool is_debug_evaluate_scope_ : 1;
 
   bool inner_scope_calls_eval_ : 1;
   bool force_context_allocation_ : 1;
 
   // True if it holds 'var' declarations.
   bool is_declaration_scope_ : 1;
 
+  bool is_lazily_parsed_ : 1;
+
   // Create a non-local variable with a given name.
   // These variables are looked up dynamically at runtime.
   Variable* NonLocal(const AstRawString* name, VariableMode mode);
 
   // Variable resolution.
   // Lookup a variable reference given by name recursively starting with this
   // scope, and stopping when reaching the outer_scope_end scope. If the code is
   // executed because of a call to 'eval', the context parameter should be set
   // to the calling context of 'eval'.
   // {declare_free} indicates whether nullptr should be returned for free
@@ skipping 344 matching lines @@
   void AllocateModuleVariables();
 
  private:
   ModuleDescriptor* module_descriptor_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_AST_SCOPES_H_