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lua/ltm.c
Roberto Ierusalimschy 4b91e9cde6 Tag methods
1997-09-16 16:25:59 -03:00

318 lines
10 KiB
C
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/*
** $Id: $
** Tag methods
** See Copyright Notice in lua.h
*/
#include <stdio.h>
#include <string.h>
#include "lauxlib.h"
#include "ldo.h"
#include "lmem.h"
#include "lobject.h"
#include "ltm.h"
static struct IM init_IM[NUM_TYPES] = {
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}}
};
char *luaT_eventname[] = { /* ORDER IM */
"gettable", "settable", "index", "getglobal", "setglobal", "add",
"sub", "mul", "div", "pow", "unm", "lt", "le", "gt", "ge",
"concat", "gc", "function",
NULL
};
static int luaI_checkevent (char *name, char *list[])
{
int e = luaO_findstring(name, list);
if (e < 0)
luaL_verror("`%.50s' is not a valid event name", name);
return e;
}
struct IM *luaT_IMtable = init_IM;
static int IMtable_size = NUM_TYPES;
static int last_tag = -(NUM_TYPES-1);
/* events in LUA_T_LINE are all allowed, since this is used as a
* 'placeholder' for "default" fallbacks
*/
static char validevents[NUM_TYPES][IM_N] = { /* ORDER LUA_T, ORDER IM */
{1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1}, /* LUA_T_USERDATA */
{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, /* LUA_T_LINE */
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, /* LUA_T_CMARK */
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, /* LUA_T_MARK */
{1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0}, /* LUA_T_CFUNCTION */
{1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0}, /* LUA_T_FUNCTION */
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, /* LUA_T_PROTO */
{0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, /* LUA_T_ARRAY */
{1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}, /* LUA_T_STRING */
{1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1}, /* LUA_T_NUMBER */
{1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1} /* LUA_T_NIL */
};
static int validevent (lua_Type t, int e)
{ /* ORDER LUA_T */
return (t < LUA_T_NIL) ? 1 : validevents[-t][e];
}
static void init_entry (int tag)
{
int i;
for (i=0; i<IM_N; i++)
ttype(luaT_getim(tag, i)) = LUA_T_NIL;
}
int lua_newtag (void)
{
--last_tag;
if ((-last_tag) >= IMtable_size) {
if (luaT_IMtable == init_IM) { /* fist time? */
IMtable_size *= 2;
luaT_IMtable = luaM_newvector(IMtable_size, struct IM);
memcpy(luaT_IMtable, init_IM, sizeof(init_IM));
}
else
IMtable_size = luaM_growvector(&luaT_IMtable, IMtable_size,
struct IM, memEM, MAX_INT);
}
init_entry(last_tag);
return last_tag;
}
static void checktag (int tag)
{ /* ORDER LUA_T */
if (!(last_tag <= tag && tag <= 0))
luaL_verror("%d is not a valid tag", tag);
}
void luaT_realtag (int tag)
{
if (!(last_tag <= tag && tag < LUA_T_NIL))
luaL_verror("tag %d is not result of `newtag'", tag);
}
int luaT_efectivetag (TObject *o)
{
lua_Type t = ttype(o);
if (t == LUA_T_USERDATA) {
int tag = o->value.ts->tag;
return (tag >= 0) ? LUA_T_USERDATA : tag;
}
else if (t == LUA_T_ARRAY)
return o->value.a->htag;
else return t;
}
TObject *luaT_gettagmethod (int t, char *event)
{
int e = luaI_checkevent(event, luaT_eventname);
checktag(t);
if (validevent(t, e))
return luaT_getim(t,e);
else
return luaT_getim(LUA_T_CMARK, IM_GETTABLE); /* always nil */
}
void luaT_settagmethod (int t, char *event, TObject *func)
{
TObject temp = *func;
int e = luaI_checkevent(event, luaT_eventname);
checktag(t);
if (!validevent(t, e))
luaL_verror("settagmethod: cannot change internal method `%s' for tag %d",
luaT_eventname[e], t);
*func = *luaT_getim(t,e);
*luaT_getim(t, e) = temp;
}
char *luaT_travtagmethods (int (*fn)(TObject *))
{
int e;
if (fn(&luaD_errorim))
return "error";
for (e=IM_GETTABLE; e<=IM_FUNCTION; e++) { /* ORDER IM */
int t;
for (t=0; t>=last_tag; t--)
if (fn(luaT_getim(t,e)))
return luaT_eventname[e];
}
return NULL;
}
/*
* ===================================================================
* compatibility with old fallback system
*/
#if LUA_COMPAT2_5
#include "lapi.h"
static void errorFB (void)
{
lua_Object o = lua_getparam(1);
if (lua_isstring(o))
fprintf(stderr, "lua: %s\n", lua_getstring(o));
else
fprintf(stderr, "lua: unknown error\n");
}
static void nilFB (void) { }
static void typeFB (void)
{
lua_error("unexpected type");
}
static void fillvalids (IMS e, TObject *func)
{
int t;
for (t=LUA_T_NIL; t<=LUA_T_USERDATA; t++)
if (validevent(t, e))
*luaT_getim(t, e) = *func;
}
void luaT_setfallback (void)
{
static char *oldnames [] = {"error", "getglobal", "arith", "order", NULL};
TObject oldfunc;
lua_CFunction replace;
char *name = luaL_check_string(1);
lua_Object func = lua_getparam(2);
luaL_arg_check(lua_isfunction(func), 2, "function expected");
switch (luaO_findstring(name, oldnames)) {
case 0: /* old error fallback */
oldfunc = luaD_errorim;
luaD_errorim = *luaA_Address(func);
replace = errorFB;
break;
case 1: /* old getglobal fallback */
oldfunc = *luaT_getim(LUA_T_NIL, IM_GETGLOBAL);
*luaT_getim(LUA_T_NIL, IM_GETGLOBAL) = *luaA_Address(func);
replace = nilFB;
break;
case 2: { /* old arith fallback */
int i;
oldfunc = *luaT_getim(LUA_T_NUMBER, IM_POW);
for (i=IM_ADD; i<=IM_UNM; i++) /* ORDER IM */
fillvalids(i, luaA_Address(func));
replace = typeFB;
break;
}
case 3: { /* old order fallback */
int i;
oldfunc = *luaT_getim(LUA_T_LINE, IM_LT);
for (i=IM_LT; i<=IM_GE; i++) /* ORDER IM */
fillvalids(i, luaA_Address(func));
replace = typeFB;
break;
}
default: {
int e;
if ((e = luaO_findstring(name, luaT_eventname)) >= 0) {
oldfunc = *luaT_getim(LUA_T_LINE, e);
fillvalids(e, luaA_Address(func));
replace = (e == IM_GC || e == IM_INDEX) ? nilFB : typeFB;
}
else {
luaL_verror("`%.50s' is not a valid fallback name", name);
replace = NULL; /* to avoid warnings */
}
}
}
if (oldfunc.ttype != LUA_T_NIL)
luaA_pushobject(&oldfunc);
else
lua_pushcfunction(replace);
}
#endif
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