src/create_class.cpp

   1 // Copyright (c) 2003 Daniel Wallin and Arvid Norberg
   2
   3 // Permission is hereby granted, free of charge, to any person obtaining a
   4 // copy of this software and associated documentation files (the "Software"),
   5 // to deal in the Software without restriction, including without limitation
   6 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
   7 // and/or sell copies of the Software, and to permit persons to whom the
   8 // Software is furnished to do so, subject to the following conditions:
   9
  10 // The above copyright notice and this permission notice shall be included
  11 // in all copies or substantial portions of the Software.
  12
  13 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
  14 // ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
  15 // TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
  16 // PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
  17 // SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
  18 // ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  19 // ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
  21 // OR OTHER DEALINGS IN THE SOFTWARE.
  22
  23 #include <luabind/lua_include.hpp>
  24
  25 #include <luabind/luabind.hpp>
  26
  27 namespace luabind { namespace detail
  28 {
  29         namespace
  30         {
  31                 // expects two tables on the lua stack:
  32                 // 1: destination
  33                 // 2: source
  34                 void copy_member_table(lua_State* L)
  35                 {
  36                         lua_pushnil(L);
  37
  38                         while (lua_next(L, -2))
  39                         {
  40                                 lua_pushstring(L, "__init");
  41                                 if (lua_equal(L, -1, -3))
  42                                 {
  43                                         lua_pop(L, 2);
  44                                         continue;
  45                                 }
  46                                 else lua_pop(L, 1); // __init string
  47
  48                                 lua_pushstring(L, "__finalize");
  49                                 if (lua_equal(L, -1, -3))
  50                                 {
  51                                         lua_pop(L, 2);
  52                                         continue;
  53                                 }
  54                                 else lua_pop(L, 1); // __finalize string
  55
  56                                 lua_pushvalue(L, -2); // copy key
  57                                 lua_insert(L, -2);
  58                                 lua_settable(L, -5);
  59                         }
  60                 }
  61         }
  62
  63
  64         int create_class::stage2(lua_State* L)
  65         {
  66                 class_rep* crep = static_cast<class_rep*>(lua_touserdata(L, lua_upvalueindex(1)));
  67                 assert((crep != 0) && "internal error, please report");
  68                 assert((is_class_rep(L, lua_upvalueindex(1))) && "internal error, please report");
  69
  70         #ifndef LUABIND_NO_ERROR_CHECKING
  71
  72                 if (!is_class_rep(L, 1))
  73                 {
  74                         lua_pushstring(L, "expected class to derive from or a newline");
  75                         lua_error(L);
  76                 }
  77
  78         #endif
  79
  80                 class_rep* base = static_cast<class_rep*>(lua_touserdata(L, 1));
  81                 class_rep::base_info binfo;
  82
  83                 binfo.pointer_offset = 0;
  84                 binfo.base = base;
  85                 crep->add_base_class(binfo);
  86
  87                 // set holder size and alignment so that we can class_rep::allocate
  88                 // can return the correctly sized buffers
  89                 crep->derived_from(base);
  90
  91                 // copy base class members
  92
  93                 crep->get_table(L);
  94                 base->get_table(L);
  95                 copy_member_table(L);
  96
  97                 crep->get_default_table(L);
  98                 base->get_default_table(L);
  99                 copy_member_table(L);
 100
 101                 crep->set_type(base->type());
 102
 103                 return 0;
 104         }
 105
 106         int create_class::stage1(lua_State* L)
 107         {
 108
 109         #ifndef LUABIND_NO_ERROR_CHECKING
 110
 111                 if (lua_gettop(L) != 1 || lua_type(L, 1) != LUA_TSTRING || lua_isnumber(L, 1))
 112                 {
 113                         lua_pushstring(L, "invalid construct, expected class name");
 114                         lua_error(L);
 115                 }
 116
 117                 if (std::strlen(lua_tostring(L, 1)) != lua_strlen(L, 1))
 118                 {
 119                         lua_pushstring(L, "luabind does not support class names with extra nulls");
 120                         lua_error(L);
 121                 }
 122
 123         #endif
 124
 125                 const char* name = lua_tostring(L, 1);
 126
 127                 void* c = lua_newuserdata(L, sizeof(class_rep));
 128                 new(c) class_rep(L, name);
 129
 130                 // make the class globally available
 131                 lua_pushstring(L, name);
 132                 lua_pushvalue(L, -2);
 133                 lua_settable(L, LUA_GLOBALSINDEX);
 134
 135                 // also add it to the closure as return value
 136                 lua_pushcclosure(L, &stage2, 1);
 137
 138                 return 1;
 139         }
 140
 141 }}
 142