1// Copyright 2011 Google Inc. 2// All rights reserved. 3// 4// Redistribution and use in source and binary forms, with or without 5// modification, are permitted provided that the following conditions are 6// met: 7// 8// * Redistributions of source code must retain the above copyright 9// notice, this list of conditions and the following disclaimer. 10// * Redistributions in binary form must reproduce the above copyright 11// notice, this list of conditions and the following disclaimer in the 12// documentation and/or other materials provided with the distribution. 13// * Neither the name of Google Inc. nor the names of its contributors 14// may be used to endorse or promote products derived from this software 15// without specific prior written permission. 16// 17// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 20// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 21// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 23// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 29#include <cassert> 30 31#include <lua.hpp> 32 33#include "exceptions.hpp" 34#include "operations.hpp" 35#include "stack_cleaner.hpp" 36#include "state.hpp" 37 38 39/// Creates a module: i.e. a table with a set of methods in it. 40/// 41/// \param s The Lua state. 42/// \param name The name of the module to create. 43/// \param members The list of member functions to add to the module. 44void 45lutok::create_module(state& s, const std::string& name, 46 const std::map< std::string, cxx_function >& members) 47{ 48 stack_cleaner cleaner(s); 49 s.new_table(); 50 for (std::map< std::string, cxx_function >::const_iterator 51 iter = members.begin(); iter != members.end(); iter++) { 52 s.push_string((*iter).first); 53 s.push_cxx_function((*iter).second); 54 s.set_table(-3); 55 } 56 s.set_global(name); 57} 58 59 60/// Loads and processes a Lua file. 61/// 62/// This is a replacement for luaL_dofile but with proper error reporting 63/// and stack control. 64/// 65/// \param s The Lua state. 66/// \param file The file to load. 67/// \param nresults The number of results to expect; -1 for any. 68/// 69/// \return The number of results left on the stack. 70/// 71/// \throw error If there is a problem processing the file. 72unsigned int 73lutok::do_file(state& s, const std::string& file, const int nresults) 74{ 75 assert(nresults >= -1); 76 const int height = s.get_top(); 77 78 stack_cleaner cleaner(s); 79 try { 80 s.load_file(file); 81 s.pcall(0, nresults == -1 ? LUA_MULTRET : nresults, 0); 82 } catch (const lutok::api_error& e) { 83 throw lutok::error("Failed to load Lua file '" + file + "': " + 84 e.what()); 85 } 86 cleaner.forget(); 87 88 const int actual_results = s.get_top() - height; 89 assert(nresults == -1 || actual_results == nresults); 90 assert(actual_results >= 0); 91 return static_cast< unsigned int >(actual_results); 92} 93 94 95/// Processes a Lua script. 96/// 97/// This is a replacement for luaL_dostring but with proper error reporting 98/// and stack control. 99/// 100/// \param s The Lua state. 101/// \param str The string to process. 102/// \param nresults The number of results to expect; -1 for any. 103/// 104/// \return The number of results left on the stack. 105/// 106/// \throw error If there is a problem processing the string. 107unsigned int 108lutok::do_string(state& s, const std::string& str, const int nresults) 109{ 110 assert(nresults >= -1); 111 const int height = s.get_top(); 112 113 stack_cleaner cleaner(s); 114 try { 115 s.load_string(str); 116 s.pcall(0, nresults == -1 ? LUA_MULTRET : nresults, 0); 117 } catch (const lutok::api_error& e) { 118 throw lutok::error("Failed to process Lua string '" + str + "': " + 119 e.what()); 120 } 121 cleaner.forget(); 122 123 const int actual_results = s.get_top() - height; 124 assert(nresults == -1 || actual_results == nresults); 125 assert(actual_results >= 0); 126 return static_cast< unsigned int >(actual_results); 127} 128 129 130/// Convenience function to evaluate a Lua expression. 131/// 132/// \param s The Lua state. 133/// \param expression The textual expression to evaluate. 134/// \param nresults The number of results to leave on the stack. Must be 135/// positive. 136/// 137/// \throw api_error If there is a problem evaluating the expression. 138void 139lutok::eval(state& s, const std::string& expression, const int nresults) 140{ 141 assert(nresults > 0); 142 do_string(s, "return " + expression, nresults); 143} 144