1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
|
/* Should be a Lua skang module, roughly the same as test.lua
TODO - see if this still works if it's an app instead of a library.
Seems to be several problems with linking in various OSes, heres some
possibly helpful links -
http://lua.2524044.n2.nabble.com/C-Lua-modules-not-compatible-with-every-Lua-interpreter-td7647522.html
http://lua-users.org/wiki/LuaProxyDllFour
http://stackoverflow.com/questions/11492194/how-do-you-create-a-lua-plugin-that-calls-the-c-lua-api?rq=1
http://lua-users.org/lists/lua-l/2008-01/msg00671.html
*/
#include <lua.h>
#include <lauxlib.h>
//#include <lualib.h>
static const char *ourName = "test_c";
int skang, _M;
static int cfunc (lua_State *L)
{
double arg1 = luaL_checknumber(L, 1);
const char *arg2 = luaL_checkstring(L, 2);
printf("Inside %s.cfunc(%f, %s)\n", ourName, arg1, arg2);
return 0;
}
static void dumpStack(lua_State *L, int i)
{
int type = lua_type(L, i);
switch (type)
{
case LUA_TNONE : printf("Stack %d is empty\n", i); break;
case LUA_TNIL : printf("Stack %d is a nil\n", i); break;
case LUA_TBOOLEAN : printf("Stack %d is a boolean\n", i); break;
case LUA_TNUMBER : printf("Stack %d is a number\n", i); break;
case LUA_TSTRING : printf("Stack %d is a string - %s\n", i, lua_tostring(L, i)); break;
case LUA_TFUNCTION : printf("Stack %d is a function\n", i); break;
case LUA_TTHREAD : printf("Stack %d is a thread\n", i); break;
case LUA_TTABLE : printf("Stack %d is a table\n", i); break;
case LUA_TUSERDATA : printf("Stack %d is a userdata\n", i); break;
case LUA_TLIGHTUSERDATA : printf("Stack %d is a light userdata\n", i); break;
default : printf("Stack %d is unknown\n", i); break;
}
}
/* local test_c = require 'test_c'
Lua's require() function will strip any stuff from the front of the name
separated by a hyphen, so 'GuiLua-test_c' -> 'test_c'. Then it will
search through a path, and eventually find this test_c.so (or test_c.dll
or whatever), then call luaopen_test_c(), which should return a table.
The argument (only thing on the stack) for this function will be
'test_c'.
Normally luaL_register() creates a table of functions, that is the table
returned, but we want to do something different with skang.
*/
int luaopen_test_c(lua_State *L)
{
// In theory, the only thing on the stack now is 'test_c' from the require() call.
// pseudo-indices, special tables that can be accessed like the stack -
// LUA_GLOBALSINDEX - thread environment, where globals are
// LUA_ENVIRONINDEX - C function environment, in this case luaopen_test_c() is the C function
// LUA_REGISTRYINDEX - C registry, global, for unique keys use the module name as a string, or a lightuserdata address to a C object in our module.
// lua_upvalueindex(n) - C function upvalues
// The only locals we care about are skang and _M.
// All modules go into package.loaded[name] as well.
// skang is essentially a global anyway.
// _M we pass back as the result, and our functions get added to it by skang.thing()
// Not entirely true, skang.things is a proxy table, skang.things.ffunc.func would be our function.
// skang.things.ffunc.module is our _M ('environment of our calling function', so that's the 'environment' right here, since we call skang.thing().
// test_c.ffunc() -> test_c.__index(test_c, 'ffunc') -> skang.things[ffunc].value() -> test_c.c->ffunc()
// this is a C function, not a Lua function
// local skang = require 'skang'
lua_getglobal(L, "require");
lua_pushstring(L, "skang");
lua_call(L, 1, 1);
skang = lua_gettop(L);
// dumpStack(L, skang);
// local _M = skang.moduleBegin('test_c', nil, 'Copyright 2014 David Seikel', '0.1', '2014-03-27 03:57:00', nil, true)
lua_getfield(L, skang, "moduleBegin");
lua_pushstring(L, ourName);
lua_pushnil(L); // Author comes from copyright.
lua_pushstring(L, "Copyright 2014 David Seikel");
lua_pushstring(L, "0.1");
lua_pushstring(L, "2014-03-27 03:57:00");
lua_pushnil(L); // No skin.
lua_pushboolean(L, 0); // We are not a Lua module.
lua_call(L, 7, 1); // call 'skang.moduleBegin' with 7 arguments and 1 result.
_M = lua_gettop(L);
// dumpStack(L, _M);
// At this point the stack should be - 'test_c', skang, _M. Let's test that.
/*
int top = 0, i;
top = lua_gettop(L);
printf("MODULE test_c has %d stack items.\n", top);
for (i = 1; i <= top; i++)
dumpStack(L, i);
*/
// Save this module in the C registry.
lua_setfield(L, LUA_REGISTRYINDEX, ourName);
// TODO - This is too verbose. I've had an idea for writing some sort of generic wrapper, though others have done the same.
// http://www.lua.org/pil/25.3.html seems the most reasonable of the examples I've found.
// skang.thing('cfooble,c', 'Help text goes here', 1, 'number', \"'edit', 'The fooble:', 1, 1, 10, 50\", true)
lua_getfield(L, skang, "thing");
lua_pushstring(L, "cfooble,c");
lua_pushstring(L, "Help text");
lua_pushnumber(L, 1);
lua_pushstring(L, "number");
lua_pushstring(L, "'edit', 'The cfooble:', 1, 1, 10, 50");
lua_pushboolean(L, 1); // Is required.
lua_pushnil(L); // Default ACL.
lua_pushnil(L); // No boss.
lua_getfield(L, LUA_REGISTRYINDEX, ourName); // Coz getfenv() can't find C environment.
lua_call(L, 9, 0);
// skang.thing('cbar', 'Help text', 'Default')
lua_getfield(L, skang, "thing");
lua_pushstring(L, "cbar");
lua_pushstring(L, "Help text");
lua_pushstring(L, "Default");
lua_pushnil(L); // No type.
lua_pushnil(L); // No widget.
lua_pushnil(L); // Not required.
lua_pushnil(L); // Default ACL.
lua_pushnil(L); // No boss.
lua_getfield(L, LUA_REGISTRYINDEX, ourName); // Coz getfenv() can't find C environment.
lua_call(L, 9, 0);
// skang.thing('cfoo')
lua_getfield(L, skang, "thing");
lua_pushstring(L, "cfoo");
lua_pushnil(L); // No help.
lua_pushnil(L); // No default.
lua_pushnil(L); // No type.
lua_pushnil(L); // No widget.
lua_pushnil(L); // Not required.
lua_pushnil(L); // Default ACL.
lua_pushnil(L); // No boss.
lua_getfield(L, LUA_REGISTRYINDEX, ourName); // Coz getfenv() can't find C environment.
lua_call(L, 9, 0);
// skang.thing('cfunc', 'Help Text', ffunc, 'number,string')
lua_getfield(L, skang, "thing");
lua_pushstring(L, "cfunc");
lua_pushstring(L, "cfunc does nothing really");
lua_pushcfunction(L, cfunc);
lua_pushstring(L, "number,string");
lua_pushnil(L); // No widget.
lua_pushnil(L); // Not required.
lua_pushnil(L); // Default ACL.
lua_pushnil(L); // No boss.
lua_getfield(L, LUA_REGISTRYINDEX, ourName); // Coz getfenv() can't find C environment.
lua_call(L, 9, 0);
// skang.moduleEnd(_M)
lua_getfield(L, skang, "moduleEnd");
lua_getfield(L, LUA_REGISTRYINDEX, ourName);
lua_call(L, 1, 1);
return 1;
}
|
