ceph/src/boost/libs/spirit/example/x3/calc/calc9/vm.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2014 Joel de Guzman
   3
   4     Distributed under the Boost Software License, Version 1.0. (See accompanying
   5     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 =============================================================================*/
   7 #if !defined(BOOST_SPIRIT_X3_CALC9_VM_HPP)
   8 #define BOOST_SPIRIT_X3_CALC9_VM_HPP
   9
  10 #include <vector>
  11
  12 namespace client
  13 {
  14     ///////////////////////////////////////////////////////////////////////////
  15     //  The Virtual Machine
  16     ///////////////////////////////////////////////////////////////////////////
  17     enum byte_code
  18     {
  19         op_neg,         //  negate the top stack entry
  20         op_add,         //  add top two stack entries
  21         op_sub,         //  subtract top two stack entries
  22         op_mul,         //  multiply top two stack entries
  23         op_div,         //  divide top two stack entries
  24
  25         op_not,         //  boolean negate the top stack entry
  26         op_eq,          //  compare the top two stack entries for ==
  27         op_neq,         //  compare the top two stack entries for !=
  28         op_lt,          //  compare the top two stack entries for <
  29         op_lte,         //  compare the top two stack entries for <=
  30         op_gt,          //  compare the top two stack entries for >
  31         op_gte,         //  compare the top two stack entries for >=
  32
  33         op_and,         //  logical and top two stack entries
  34         op_or,          //  logical or top two stack entries
  35
  36         op_load,        //  load a variable
  37         op_store,       //  store a variable
  38
  39         op_int,         //  push constant integer into the stack
  40         op_true,        //  push constant 0 into the stack
  41         op_false,       //  push constant 1 into the stack
  42
  43         op_jump_if,     //  jump to a relative position in the code if top stack
  44                         //  evaluates to false
  45         op_jump,        //  jump to a relative position in the code
  46
  47         op_stk_adj,     // adjust the stack (for args and locals)
  48         op_call,        // function call
  49         op_return       // return from function
  50     };
  51
  52     class vmachine
  53     {
  54     public:
  55
  56         vmachine(unsigned stackSize = 4096)
  57           : stack(stackSize)
  58         {
  59         }
  60
  61         int execute(
  62             std::vector<int> const& code            // the program code
  63           , std::vector<int>::const_iterator pc     // program counter
  64           , std::vector<int>::iterator frame_ptr    // start of arguments and locals
  65         );
  66
  67         int execute(std::vector<int> const& code)
  68         {
  69             return execute(code, code.begin(), stack.begin());
  70         };
  71
  72         std::vector<int> const& get_stack() const { return stack; };
  73
  74     private:
  75
  76         std::vector<int> stack;
  77     };
  78 }
  79
  80 #endif
  81