| /*============================================================================= |
| Copyright (c) 2001-2010 Joel de Guzman |
| |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| =============================================================================*/ |
| #if !defined(BOOST_SPIRIT_MINI_C) |
| #define BOOST_SPIRIT_MINI_C |
| |
| #include <boost/config/warning_disable.hpp> |
| #include <boost/spirit/include/qi.hpp> |
| #include <boost/spirit/include/phoenix_core.hpp> |
| #include <boost/spirit/include/phoenix_container.hpp> |
| #include <boost/spirit/include/phoenix_statement.hpp> |
| #include <boost/spirit/include/phoenix_operator.hpp> |
| #include <boost/lexical_cast.hpp> |
| |
| #include <iostream> |
| #include <fstream> |
| #include <string> |
| #include <vector> |
| |
| using boost::phoenix::function; |
| using boost::phoenix::ref; |
| using boost::phoenix::size; |
| |
| using namespace boost::spirit; |
| using namespace boost::spirit::qi; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // The Virtual Machine |
| /////////////////////////////////////////////////////////////////////////////// |
| enum byte_code |
| { |
| op_neg, // negate the top stack entry |
| op_add, // add top two stack entries |
| op_sub, // subtract top two stack entries |
| op_mul, // multiply top two stack entries |
| op_div, // divide top two stack entries |
| |
| op_not, // boolean negate the top stack entry |
| op_eq, // compare the top two stack entries for == |
| op_neq, // compare the top two stack entries for != |
| op_lt, // compare the top two stack entries for < |
| op_lte, // compare the top two stack entries for <= |
| op_gt, // compare the top two stack entries for > |
| op_gte, // compare the top two stack entries for >= |
| |
| op_and, // logical and top two stack entries |
| op_or, // logical or top two stack entries |
| |
| op_load, // load a variable |
| op_store, // store a variable |
| |
| op_int, // push constant integer into the stack |
| op_true, // push constant 0 into the stack |
| op_false, // push constant 1 into the stack |
| |
| op_jump_if, // jump to an absolute position in the code if top stack |
| // evaluates to false |
| op_jump, // jump to an absolute position in the code |
| |
| op_stk_adj, // adjust the stack (for args and locals) |
| op_call, // function call |
| op_return // return from function |
| }; |
| |
| class vmachine |
| { |
| public: |
| |
| vmachine(unsigned stackSize = 4096) |
| : stack(stackSize) |
| { |
| } |
| |
| int execute( |
| std::vector<int> const& code // the program code |
| , std::vector<int>::const_iterator pc // program counter |
| , std::vector<int>::iterator frame_ptr // start of arguments and locals |
| ); |
| |
| std::vector<int> stack; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // A generic compiler that compiles 1 to 3 codes |
| /////////////////////////////////////////////////////////////////////////////// |
| struct function_info |
| { |
| int arity; |
| int address; |
| }; |
| |
| struct compile_op |
| { |
| template <typename A, typename B = unused_type, typename C = unused_type> |
| struct result { typedef void type; }; |
| |
| compile_op(std::vector<int>& code) |
| : code(code) |
| { |
| } |
| |
| void operator()(int a) const |
| { |
| code.push_back(a); |
| } |
| |
| void operator()(int a, int b) const |
| { |
| code.push_back(a); |
| code.push_back(b); |
| } |
| |
| void operator()(int a, int b, int c) const |
| { |
| code.push_back(a); |
| code.push_back(b); |
| code.push_back(c); |
| } |
| |
| // special overload for function calls |
| void operator()(function_info const& info, int got_nargs, bool& parse_result) const |
| { |
| if (got_nargs == info.arity) |
| { |
| code.push_back(op_call); |
| code.push_back(info.arity); |
| code.push_back(info.address); |
| } |
| else |
| { |
| parse_result = false; // fail the parse |
| std::cerr << "wrong number of args" << std::endl; |
| } |
| } |
| |
| std::vector<int>& code; |
| }; |
| |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // Our error handler |
| /////////////////////////////////////////////////////////////////////////////// |
| struct error_handler_ |
| { |
| template <typename, typename, typename> |
| struct result { typedef void type; }; |
| |
| template <typename Iterator> |
| void operator()( |
| info const& what |
| , Iterator err_pos, Iterator last) const |
| { |
| std::cout |
| << "Error! Expecting " |
| << what // what failed? |
| << " here: \"" |
| << std::string(err_pos, last) // iterators to error-pos, end |
| << "\"" |
| << std::endl |
| ; |
| } |
| }; |
| |
| function<error_handler_> const error_handler = error_handler_(); |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // A functor that adds variables to our (variables) symbol-table |
| /////////////////////////////////////////////////////////////////////////////// |
| struct var_adder |
| { |
| template <typename> |
| struct result { typedef void type; }; |
| |
| var_adder(symbols<char, int>& vars, int& nvars) |
| : vars(vars), nvars(nvars) |
| { |
| } |
| |
| void operator()(std::string const& var) const |
| { |
| vars.add(var.begin(), var.end(), nvars++); |
| }; |
| |
| symbols<char, int>& vars; |
| int& nvars; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // A functor that adds functions to our (function) symbol-table |
| /////////////////////////////////////////////////////////////////////////////// |
| struct function_adder |
| { |
| template <typename, typename, typename> |
| struct result { typedef void type; }; |
| |
| function_adder(symbols<char, function_info>& functions) |
| : functions(functions) |
| { |
| } |
| |
| void operator()(std::string const& function_id, int arity, int address) const |
| { |
| function_info info = {arity, address}; |
| functions.add(function_id.begin(), function_id.end(), info); |
| }; |
| |
| symbols<char, function_info>& functions; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // A functor that resets the function-related state variables |
| /////////////////////////////////////////////////////////////////////////////// |
| struct function_state_reset |
| { |
| template <typename> |
| struct result { typedef void type; }; |
| |
| function_state_reset( |
| std::vector<int>& code |
| , symbols<char, int>& vars |
| , int& nvars) |
| : code(code) |
| , vars(vars) |
| , nvars(nvars) |
| { |
| } |
| |
| void operator()(int address) const |
| { |
| code[address+1] = nvars; |
| nvars = 0; // reset |
| vars.clear(); // reset |
| }; |
| |
| std::vector<int>& code; |
| symbols<char, int>& vars; |
| int& nvars; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // White-space and comments grammar definition |
| /////////////////////////////////////////////////////////////////////////////// |
| template <typename Iterator> |
| struct white_space : grammar<Iterator> |
| { |
| white_space() : white_space::base_type(start) |
| { |
| using boost::spirit::ascii::char_; |
| |
| start = |
| space // tab/space/cr/lf |
| | "/*" >> *(char_ - "*/") >> "*/" // C-style comments |
| ; |
| } |
| |
| rule<Iterator> start; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // Our expression grammar and compiler |
| /////////////////////////////////////////////////////////////////////////////// |
| template <typename Iterator> |
| struct expression : grammar<Iterator, white_space<Iterator> > |
| { |
| expression( |
| std::vector<int>& code |
| , symbols<char, int>& vars |
| , symbols<char, function_info>& functions); |
| |
| typedef white_space<Iterator> white_space_; |
| |
| rule<Iterator, white_space_> |
| expr, equality_expr, relational_expr |
| , logical_expr, additive_expr, multiplicative_expr |
| , unary_expr, primary_expr, variable |
| ; |
| |
| rule<Iterator, locals<function_info, int>, white_space_> function_call; |
| |
| std::vector<int>& code; |
| symbols<char, int>& vars; |
| symbols<char, function_info>& functions; |
| function<compile_op> op; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // Our statement grammar and compiler |
| /////////////////////////////////////////////////////////////////////////////// |
| template <typename Iterator> |
| struct statement : grammar<Iterator, white_space<Iterator> > |
| { |
| statement(std::vector<int>& code, symbols<char, function_info>& functions); |
| |
| typedef white_space<Iterator> white_space_; |
| |
| std::vector<int>& code; |
| symbols<char, int> vars; |
| symbols<char, function_info>& functions; |
| int nvars; |
| bool has_return; |
| |
| expression<Iterator> expr; |
| rule<Iterator, white_space_> |
| statement_, statement_list, var_decl, compound_statement |
| , return_statement; |
| |
| rule<Iterator, locals<int>, white_space_> if_statement; |
| rule<Iterator, locals<int, int>, white_space_> while_statement; |
| rule<Iterator, std::string(), white_space_> identifier; |
| rule<Iterator, int(), white_space_> var_ref; |
| rule<Iterator, locals<int>, white_space_> assignment; |
| rule<Iterator, void(int), white_space_> assignment_rhs; |
| |
| function<var_adder> add_var; |
| function<compile_op> op; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // Our program grammar and compiler |
| /////////////////////////////////////////////////////////////////////////////// |
| template <typename Iterator> |
| struct program : grammar<Iterator, white_space<Iterator> > |
| { |
| program(std::vector<int>& code); |
| |
| typedef white_space<Iterator> white_space_; |
| |
| std::vector<int>& code; |
| rule<Iterator, std::string(), white_space_> identifier; |
| rule<Iterator, white_space_> start; |
| |
| typedef |
| locals< |
| std::string // function name |
| , int // address |
| > |
| function_locals; |
| |
| symbols<char, function_info> functions; |
| statement<Iterator> statement_; |
| |
| rule<Iterator, function_locals, white_space_> function; |
| boost::phoenix::function<function_adder> add_function; |
| boost::phoenix::function<function_state_reset> state_reset; |
| boost::phoenix::function<compile_op> op; |
| }; |
| |
| #endif |
| |
| |