gprofng/src/QLParser.h

   1 /* Copyright (C) 2021-2024 Free Software Foundation, Inc.
   2    Contributed by Oracle.
   3
   4    This file is part of GNU Binutils.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3, or (at your option)
   9    any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, 51 Franklin Street - Fifth Floor, Boston,
  19    MA 02110-1301, USA.  */
  20
  21 #ifndef _QLPARSER_H
  22 #define _QLPARSER_H
  23
  24 #include <sstream>
  25 #include <istream>
  26 #include <iostream>
  27 #include "Expression.h"
  28
  29 /* This class contains parser inputs (a string, if non-NULL: if NULL, use cin),
  30    and outputs (obtained via operator(), which resets the output
  31    expression).  The destructor deletes the returned expression to allow
  32    exception throws on syntax error to clean up properly.  */
  33
  34 namespace QL
  35 {
  36   struct Result
  37   {
  38     std::stringstream streamify;
  39   public:
  40     std::istream in;
  41     Expression *out;
  42
  43     Result () : in (std::cin.rdbuf ()), out (NULL) { }
  44     Result (const char *instr) : streamify (std::string (instr)),
  45         in (streamify.rdbuf ()), out (NULL) { }
  46
  47     Expression *operator() ()
  48     {
  49       Expression *o = out;
  50       out = NULL;
  51       return o;
  52     }
  53
  54     ~Result ()
  55     {
  56       delete out;
  57     }
  58   };
  59 };
  60
  61 #endif /* _QLPARSER_H */