1 /*============================================================================= 2 Copyright (c) 2001-2011 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_CONJURE_VM_HPP) 8 #define BOOST_SPIRIT_CONJURE_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 vmachine(unsigned stackSize=4096)56 vmachine(unsigned stackSize = 4096) 57 : stack(stackSize) 58 { 59 } 60 execute(std::vector<int> const & code)61 int execute(std::vector<int> const& code) 62 { 63 return execute(code, code.begin(), stack.begin()); 64 } 65 get_stack() const66 std::vector<int> const& get_stack() const { return stack; }; get_stack()67 std::vector<int>& get_stack() { return stack; }; 68 69 private: 70 71 int execute( 72 std::vector<int> const& code // the program code 73 , std::vector<int>::const_iterator pc // program counter 74 , std::vector<int>::iterator frame_ptr // start of arguments and locals 75 ); 76 77 std::vector<int> stack; 78 }; 79 } 80 81 #endif 82 83