1 /**
2     @file
3     @brief Implementation
4 
5     @date 2012
6 
7     @author
8     Ryan Pavlik
9     <rpavlik@iastate.edu> and <abiryan@ryand.net>
10     http://academic.cleardefinition.com/
11     Iowa State University Virtual Reality Applications Center
12     Human-Computer Interaction Graduate Program
13 */
14 
15 //          Copyright Iowa State University 2012.
16 // Permission is hereby granted, free of charge, to any person obtaining a
17 // copy of this software and associated documentation files (the "Software"),
18 // to deal in the Software without restriction, including without limitation
19 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
20 // and/or sell copies of the Software, and to permit persons to whom the
21 // Software is furnished to do so, subject to the following conditions:
22 
23 // The above copyright notice and this permission notice shall be included
24 // in all copies or substantial portions of the Software.
25 
26 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
27 // ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
28 // TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
29 // PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
30 // SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
31 // ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
32 // ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
33 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
34 // OR OTHER DEALINGS IN THE SOFTWARE.
35 
36 #define LUABIND_BUILDING
37 
38 // Internal Includes
39 #include <luabind/config.hpp>           // for LUABIND_API
40 #include <luabind/object.hpp>
41 #include <luabind/set_package_preload.hpp>
42 
43 // Library/third-party includes
44 #include <luabind/lua_include.hpp>      // for lua_pushstring, lua_rawset, etc
45 
46 // Standard includes
47 // - none
48 
do_set_package_preload(lua_State * L)49 static int do_set_package_preload(lua_State* L)
50 {
51     // Note: Use ordinary set/get instead of the raw variants, because this
52     // function should not be performance sensitive anyway.
53     lua_pushglobaltable(L);
54     lua_getfield(L, -1, "package");
55     lua_remove(L, -2); // Remove global table.
56     lua_getfield(L, -1, "preload");
57     lua_remove(L, -2); // Remove package table.
58     lua_insert(L, -3); // Move package.preload beneath key and value.
59     lua_settable(L, -3); // package.preload[modulename] = loader
60     return 0;
61 }
62 
proxy_loader(lua_State * L)63 static int proxy_loader(lua_State* L)
64 {
65     luaL_checkstring(L, 1); // First argument should be the module name.
66     lua_settop(L, 1); // Ignore any other arguments.
67     lua_pushvalue(L, lua_upvalueindex(1)); // Push the real loader.
68     lua_insert(L, 1); // Move it beneath the argument.
69     lua_call(L, 1, LUA_MULTRET); // Pops everyhing.
70     return lua_gettop(L);
71 }
72 
73 
74 namespace luabind {
set_package_preload(lua_State * L,char const * modulename,object const & loader)75     LUABIND_API void set_package_preload(
76         lua_State * L, char const* modulename, object const& loader)
77     {
78         loader.push(L);
79         lua_pushcclosure(L, &proxy_loader, 1);
80         object const proxy_ldr(from_stack(L, -1));
81         lua_pop(L, 1); // pop do_load.
82         lua_pushcfunction(L, &do_set_package_preload);
83         // Must use object for correct popping in case of errors:
84         object do_set(from_stack(L, -1));
85         lua_pop(L, 1);
86         do_set(modulename, proxy_ldr);
87     }
88 
89 } // namespace luabind
90