1/*
2** $Id: ltm.c,v 2.14.1.1 2013/04/12 18:48:47 roberto Exp $
3** Tag methods
4** See Copyright Notice in lua.h
5*/
6
7
8#include <sys/zfs_context.h>
9
10#define ltm_c
11#define LUA_CORE
12
13#include "lua.h"
14
15#include "lobject.h"
16#include "lstate.h"
17#include "lstring.h"
18#include "ltable.h"
19#include "ltm.h"
20
21
22static const char udatatypename[] = "userdata";
23
24LUAI_DDEF const char *const luaT_typenames_[LUA_TOTALTAGS] = {
25  "no value",
26  "nil", "boolean", udatatypename, "number",
27  "string", "table", "function", udatatypename, "thread",
28  "proto", "upval"  /* these last two cases are used for tests only */
29};
30
31
32void luaT_init (lua_State *L) {
33  static const char *const luaT_eventname[] = {  /* ORDER TM */
34    "__index", "__newindex",
35    "__gc", "__mode", "__len", "__eq",
36    "__add", "__sub", "__mul", "__div", "__mod",
37    "__pow", "__unm", "__lt", "__le",
38    "__concat", "__call"
39  };
40  int i;
41  for (i=0; i<TM_N; i++) {
42    G(L)->tmname[i] = luaS_new(L, luaT_eventname[i]);
43    luaS_fix(G(L)->tmname[i]);  /* never collect these names */
44  }
45}
46
47
48/*
49** function to be used with macro "fasttm": optimized for absence of
50** tag methods
51*/
52const TValue *luaT_gettm (Table *events, TMS event, TString *ename) {
53  const TValue *tm = luaH_getstr(events, ename);
54  lua_assert(event <= TM_EQ);
55  if (ttisnil(tm)) {  /* no tag method? */
56    events->flags |= cast_byte(1u<<event);  /* cache this fact */
57    return NULL;
58  }
59  else return tm;
60}
61
62
63const TValue *luaT_gettmbyobj (lua_State *L, const TValue *o, TMS event) {
64  Table *mt;
65  switch (ttypenv(o)) {
66    case LUA_TTABLE:
67      mt = hvalue(o)->metatable;
68      break;
69    case LUA_TUSERDATA:
70      mt = uvalue(o)->metatable;
71      break;
72    default:
73      mt = G(L)->mt[ttypenv(o)];
74  }
75  return (mt ? luaH_getstr(mt, G(L)->tmname[event]) : luaO_nilobject);
76}
77
78