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 nargs The number of arguments on the stack to pass to the file. 68/// \param nresults The number of results to expect; -1 for any. 69/// \param errfunc If not 0, index of a function in the stack to act as an 70/// error handler. 71/// 72/// \return The number of results left on the stack. 73/// 74/// \throw error If there is a problem processing the file. 75unsigned int 76lutok::do_file(state& s, const std::string& file, const int nargs, 77 const int nresults, const int errfunc) 78{ 79 assert(nresults >= -1); 80 const int height = s.get_top() - nargs; 81 82 try { 83 s.load_file(file); 84 if (nargs > 0) 85 s.insert(-nargs - 1); 86 s.pcall(nargs, nresults == -1 ? LUA_MULTRET : nresults, 87 errfunc == 0 ? 0 : errfunc - 1); 88 } catch (const lutok::api_error& e) { 89 throw lutok::error("Failed to load Lua file '" + file + "': " + 90 e.what()); 91 } 92 93 const int actual_results = s.get_top() - height; 94 assert(nresults == -1 || actual_results == nresults); 95 assert(actual_results >= 0); 96 return static_cast< unsigned int >(actual_results); 97} 98 99 100/// Processes a Lua script. 101/// 102/// This is a replacement for luaL_dostring but with proper error reporting 103/// and stack control. 104/// 105/// \param s The Lua state. 106/// \param str The string to process. 107/// \param nargs The number of arguments on the stack to pass to the chunk. 108/// \param nresults The number of results to expect; -1 for any. 109/// \param errfunc If not 0, index of a function in the stack to act as an 110/// error handler. 111/// 112/// \return The number of results left on the stack. 113/// 114/// \throw error If there is a problem processing the string. 115unsigned int 116lutok::do_string(state& s, const std::string& str, const int nargs, 117 const int nresults, const int errfunc) 118{ 119 assert(nresults >= -1); 120 const int height = s.get_top() - nargs; 121 122 try { 123 s.load_string(str); 124 if (nargs > 0) 125 s.insert(-nargs - 1); 126 s.pcall(nargs, nresults == -1 ? LUA_MULTRET : nresults, 127 errfunc == 0 ? 0 : errfunc - 1); 128 } catch (const lutok::api_error& e) { 129 throw lutok::error("Failed to process Lua string '" + str + "': " + 130 e.what()); 131 } 132 133 const int actual_results = s.get_top() - height; 134 assert(nresults == -1 || actual_results == nresults); 135 assert(actual_results >= 0); 136 return static_cast< unsigned int >(actual_results); 137} 138 139 140/// Convenience function to evaluate a Lua expression. 141/// 142/// \param s The Lua state. 143/// \param expression The textual expression to evaluate. 144/// \param nresults The number of results to leave on the stack. Must be 145/// positive. 146/// 147/// \throw api_error If there is a problem evaluating the expression. 148void 149lutok::eval(state& s, const std::string& expression, const int nresults) 150{ 151 assert(nresults > 0); 152 do_string(s, "return " + expression, 0, nresults, 0); 153} 154