[debugger] Hide scopes that originate from desugaring.

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/ast/ast.h"
 #include "src/hashmap.h"
 #include "src/pending-compilation-error-handler.h"
@@ skipping 277 matching lines @@
   //   end position: end position of '}'
   int start_position() const { return start_position_; }
   void set_start_position(int statement_pos) {
     start_position_ = statement_pos;
   }
   int end_position() const { return end_position_; }
   void set_end_position(int statement_pos) {
     end_position_ = statement_pos;
   }
 
+  // Scopes created for desugaring are hidden. I.e. not visible to the debugger.
+  bool is_hidden() const { return is_hidden_; }
+  void set_is_hidden() { is_hidden_ = true; }
+
   // In some cases we want to force context allocation for a whole scope.
   void ForceContextAllocation() {
     DCHECK(!already_resolved());
     force_context_allocation_ = true;
   }
   bool has_forced_context_allocation() const {
     return force_context_allocation_;
   }
 
   // ---------------------------------------------------------------------------
@@ skipping 259 matching lines @@
   // Error handling.
   void ReportMessage(int start_position, int end_position,
                      MessageTemplate::Template message,
                      const AstRawString* arg);
 
   // ---------------------------------------------------------------------------
   // Debugging.
 
 #ifdef DEBUG
   void Print(int n = 0);  // n = indentation; n < 0 => don't print recursively
+
+  // Check that the scope has positions assigned.
+  void CheckScopePositions();
 #endif
 
   // ---------------------------------------------------------------------------
   // Implementation.
  private:
   // Scope tree.
   Scope* outer_scope_;  // the immediately enclosing outer scope, or NULL
   ZoneList<Scope*> inner_scopes_;  // the immediately enclosed inner scopes
 
   // The scope type.
@@ skipping 51 matching lines @@
   bool asm_module_;
   // This scope's outer context is an asm module.
   bool asm_function_;
   // This scope's declarations might not be executed in order (e.g., switch).
   bool scope_nonlinear_;
   // The language mode of this scope.
   LanguageMode language_mode_;
   // Source positions.
   int start_position_;
   int end_position_;
+  bool is_hidden_;
 
   // Computed via PropagateScopeInfo.
   bool outer_scope_calls_sloppy_eval_;
   bool inner_scope_calls_eval_;
   bool force_eager_compilation_;
   bool force_context_allocation_;
 
   // True if it doesn't need scope resolution (e.g., if the scope was
   // constructed based on a serialized scope info or a catch context).
   bool already_resolved_;
@@ skipping 143 matching lines @@
   AstValueFactory* ast_value_factory_;
   Zone* zone_;
 
   PendingCompilationErrorHandler pending_error_handler_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_AST_SCOPES_H_