gn: attach comments to parse tree

tools/gn/parser.h

 // Copyright (c) 2013 The Chromium 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 TOOLS_GN_PARSER_H_
 #define TOOLS_GN_PARSER_H_
 
 #include <map>
 #include <vector>
 
@@ skipping 55 matching lines @@
   // Helper to parse a comma separated list, optionally allowing trailing
   // commas (allowed in [] lists, not in function calls).
   scoped_ptr<ListNode> ParseList(Token::Type stop_before,
                                  bool allow_trailing_comma);
 
   scoped_ptr<ParseNode> ParseFile();
   scoped_ptr<ParseNode> ParseStatement();
   scoped_ptr<BlockNode> ParseBlock();
   scoped_ptr<ParseNode> ParseCondition();
 
+  // Generates a pre- and post-order traversal of the tree.
+  void TraverseOrder(const ParseNode* root,
+                     std::vector<const ParseNode*>* pre,
+                     std::vector<const ParseNode*>* post);
+
+  // Attach comments to nearby syntax.
+  void AssignComments(ParseNode* file);
+
   bool IsAssignment(const ParseNode* node) const;
   bool IsStatementBreak(Token::Type token_type) const;
 
   bool LookAhead(Token::Type type);
   bool Match(Token::Type type);
   Token Consume(Token::Type type, const char* error_message);
   Token Consume(Token::Type* types,
                 size_t num_types,
                 const char* error_message);
   Token Consume();
 
   const Token& cur_token() const { return tokens_[cur_]; }
 
   bool done() const { return at_end() || has_error(); }
   bool at_end() const { return cur_ >= tokens_.size(); }
   bool has_error() const { return err_->has_error(); }
 
-  const std::vector<Token>& tokens_;
+  std::vector<Token> tokens_;
+  std::vector<Token> line_comment_tokens_;
+  std::vector<Token> suffix_comment_tokens_;
 
   static ParserHelper expressions_[Token::NUM_TYPES];
 
   Err* err_;
 
   // Current index into the tokens.
   size_t cur_;
 
   FRIEND_TEST_ALL_PREFIXES(Parser, BinaryOp);
   FRIEND_TEST_ALL_PREFIXES(Parser, Block);
   FRIEND_TEST_ALL_PREFIXES(Parser, Condition);
   FRIEND_TEST_ALL_PREFIXES(Parser, Expression);
   FRIEND_TEST_ALL_PREFIXES(Parser, FunctionCall);
   FRIEND_TEST_ALL_PREFIXES(Parser, List);
   FRIEND_TEST_ALL_PREFIXES(Parser, ParenExpression);
   FRIEND_TEST_ALL_PREFIXES(Parser, UnaryOp);
 
   DISALLOW_COPY_AND_ASSIGN(Parser);
 };
 
 #endif  // TOOLS_GN_PARSER_H_