git.zerfleddert.de Git - proxmark3-svn/blob - liblua/ltm.c

   1 /*
   2 ** $Id: ltm.c,v 2.14 2011/06/02 19:31:40 roberto Exp $
   3 ** Tag methods
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7
   8 #include <string.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
  22 static const char udatatypename[] = "userdata";
  23
  24 LUAI_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
  32 void 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 */
  52 const 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
  63 const 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