[debugger] Hide scopes that originate from desugaring.

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 "src/accessors.h"
 #include "src/ast/scopeinfo.h"
 #include "src/bootstrapper.h"
 #include "src/messages.h"
@@ skipping 175 matching lines @@
   num_stack_slots_ = 0;
   num_heap_slots_ = 0;
   num_global_slots_ = 0;
   arity_ = 0;
   has_simple_parameters_ = true;
   rest_parameter_ = NULL;
   rest_index_ = -1;
   scope_info_ = scope_info;
   start_position_ = RelocInfo::kNoPosition;
   end_position_ = RelocInfo::kNoPosition;
+  is_hidden_ = false;
   if (!scope_info.is_null()) {
     scope_calls_eval_ = scope_info->CallsEval();
     language_mode_ = scope_info->language_mode();
     is_declaration_scope_ = scope_info->is_declaration_scope();
     function_kind_ = scope_info->function_kind();
   }
 }
 
 
 Scope* Scope::DeserializeScopeChain(Isolate* isolate, Zone* zone,
@@ skipping 74 matching lines @@
                                                     info->script());
       return false;
     }
   }
 
 #ifdef DEBUG
   if (info->script_is_native() ? FLAG_print_builtin_scopes
                                : FLAG_print_scopes) {
     scope->Print();
   }
+  scope->CheckScopePositions();
 #endif
 
   info->set_scope(scope);
   return true;
 }
 
 
 void Scope::Initialize() {
   DCHECK(!already_resolved());
 
@@ skipping 700 matching lines @@
   // Print inner scopes (disable by providing negative n).
   if (n >= 0) {
     for (int i = 0; i < inner_scopes_.length(); i++) {
       PrintF("\n");
       inner_scopes_[i]->Print(n1);
     }
   }
 
   Indent(n0, "}\n");
 }
+
+void Scope::CheckScopePositions() {
+  // A scope is allowed to have invalid positions if it is hidden and has no
+  // inner scopes
+  if (!is_hidden() && inner_scopes_.length() == 0) {
+    CHECK_NE(RelocInfo::kNoPosition, start_position());
+    CHECK_NE(RelocInfo::kNoPosition, end_position());
+  }
+  for (Scope* scope : inner_scopes_) scope->CheckScopePositions();
+}
 #endif  // DEBUG
 
 
 Variable* Scope::NonLocal(const AstRawString* name, VariableMode mode) {
   if (dynamics_ == NULL) dynamics_ = new (zone()) DynamicScopePart(zone());
   VariableMap* map = dynamics_->GetMap(mode);
   Variable* var = map->Lookup(name);
   if (var == NULL) {
     // Declare a new non-local.
     InitializationFlag init_flag = (mode == VAR)
@@ skipping 479 matching lines @@
       function_ != NULL && function_->proxy()->var()->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