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`luaV_gettable' returns element position

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This commit is contained in:
Roberto Ierusalimschy
2002-06-24 10:08:45 -03:00
parent 3941af53ad
commit e34f282365
4 changed files with 38 additions and 38 deletions
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62
lvm.c
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@@ -1,5 +1,5 @@
/*
** $Id: lvm.c,v 1.239 2002/06/14 17:21:32 roberto Exp roberto $
** $Id: lvm.c,v 1.240 2002/06/20 20:41:46 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -84,16 +84,14 @@ static void traceexec (lua_State *L) {
static void callTMres (lua_State *L, const TObject *f,
const TObject *p1, const TObject *p2, TObject *result ) {
ptrdiff_t res = savestack(L, result);
const TObject *p1, const TObject *p2) {
setobj(L->top, f); /* push function */
setobj(L->top+1, p1); /* 1st argument */
setobj(L->top+2, p2); /* 2nd argument */
luaD_checkstack(L, 3); /* cannot check before (could invalidate p1, p2) */
L->top += 3;
luaD_call(L, L->top - 3, 1);
result = restorestack(L, res); /* previous call may change stack */
setobj(result, --L->top); /* get result */
L->top--; /* result will be in L->top */
}
@@ -115,32 +113,29 @@ static void callTM (lua_State *L, const TObject *f,
** Receives the table at `t' and the key at `key'.
** leaves the result at `res'.
*/
void luaV_gettable (lua_State *L, const TObject *t, TObject *key, StkId res) {
const TObject *luaV_gettable (lua_State *L, const TObject *t, TObject *key) {
const TObject *tm;
int loop = 0;
do {
if (ttype(t) == LUA_TTABLE) { /* `t' is a table? */
Table *h = hvalue(t);
Table *et = h->metatable;
if ((tm = fasttm(L, et, TM_GETTABLE)) == NULL) { /* no gettable TM? */
const TObject *v = luaH_get(h, key); /* do a primitive get */
if (ttype(v) != LUA_TNIL || /* result is no nil ... */
(tm = fasttm(L, et, TM_INDEX)) == NULL) { /* ... or no index TM? */
setobj(res, v); /* default get */
return;
}
const TObject *v = luaH_get(h, key); /* do a primitive get */
if (ttype(v) != LUA_TNIL || /* result is no nil? */
(tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
return v;
}
/* else will try the tag method */
}
else if (ttype(tm = luaT_gettmbyobj(L, t, TM_GETTABLE)) == LUA_TNIL)
luaG_typeerror(L, t, "index");
if (ttype(tm) == LUA_TFUNCTION) {
callTMres(L, tm, t, key, res);
return;
callTMres(L, tm, t, key);
return L->top;
}
t = tm; /* else repeat access with `tm' */
} while (++loop <= MAXTAGLOOP);
luaG_runerror(L, "loop in gettable");
return NULL; /* to avoid warnings */
}
@@ -153,14 +148,11 @@ void luaV_settable (lua_State *L, const TObject *t, TObject *key, StkId val) {
do {
if (ttype(t) == LUA_TTABLE) { /* `t' is a table? */
Table *h = hvalue(t);
Table *et = h->metatable;
if ((tm = fasttm(L, et, TM_SETTABLE)) == NULL) { /* no settable TM? */
TObject *oldval = luaH_set(L, h, key); /* do a primitive set */
if (ttype(oldval) != LUA_TNIL || /* result is no nil ... */
(tm = fasttm(L, et, TM_NEWINDEX)) == NULL) { /* ... or no TM? */
setobj(oldval, val);
return;
}
TObject *oldval = luaH_set(L, h, key); /* do a primitive set */
if (ttype(oldval) != LUA_TNIL || /* result is no nil? */
(tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
setobj(oldval, val);
return;
}
/* else will try the tag method */
}
@@ -178,11 +170,14 @@ void luaV_settable (lua_State *L, const TObject *t, TObject *key, StkId val) {
static int call_binTM (lua_State *L, const TObject *p1, const TObject *p2,
TObject *res, TMS event) {
ptrdiff_t result = savestack(L, res);
const TObject *tm = luaT_gettmbyobj(L, p1, event); /* try first operand */
if (ttype(tm) == LUA_TNIL)
tm = luaT_gettmbyobj(L, p2, event); /* try second operand */
if (ttype(tm) != LUA_TFUNCTION) return 0;
callTMres(L, tm, p1, p2, res);
callTMres(L, tm, p1, p2);
res = restorestack(L, result); /* previous call may change stack */
setobj(res, L->top);
return 1;
}
@@ -267,7 +262,7 @@ int luaV_equalval (lua_State *L, const TObject *t1, const TObject *t2) {
return 0; /* no TM */
else break; /* will try TM */
}
callTMres(L, tm, t1, t2, L->top); /* call TM */
callTMres(L, tm, t1, t2); /* call TM */
return !l_isfalse(L->top);
}
@@ -308,14 +303,17 @@ void luaV_concat (lua_State *L, int total, int last) {
static void powOp (lua_State *L, StkId ra, StkId rb, StkId rc) {
const TObject *b = rb;
const TObject *c = rc;
ptrdiff_t res = savestack(L, ra);
TObject tempb, tempc;
if (tonumber(b, &tempb) && tonumber(c, &tempc)) {
TObject f, o;
setsvalue(&o, luaS_newliteral(L, "pow"));
luaV_gettable(L, gt(L), &o, &f);
f = *luaV_gettable(L, gt(L), &o);
if (ttype(&f) != LUA_TFUNCTION)
luaG_runerror(L, "`pow' (for `^' operator) is not a function");
callTMres(L, &f, b, c, ra);
callTMres(L, &f, b, c);
ra = restorestack(L, res); /* previous call may change stack */
setobj(ra, L->top);
}
else
call_arith(L, rb, rc, ra, TM_POW);
@@ -402,11 +400,11 @@ StkId luaV_execute (lua_State *L) {
}
case OP_GETGLOBAL: {
lua_assert(ttype(KBx(i)) == LUA_TSTRING && ttype(&cl->g) == LUA_TTABLE);
luaV_gettable(L, &cl->g, KBx(i), ra);
setobj(RA(i), luaV_gettable(L, &cl->g, KBx(i)));
break;
}
case OP_GETTABLE: {
luaV_gettable(L, RB(i), RKC(i), ra);
setobj(RA(i), luaV_gettable(L, RB(i), RKC(i)));
break;
}
case OP_SETGLOBAL: {
@@ -433,7 +431,7 @@ StkId luaV_execute (lua_State *L) {
case OP_SELF: {
StkId rb = RB(i);
setobj(ra+1, rb);
luaV_gettable(L, rb, RKC(i), ra);
setobj(RA(i), luaV_gettable(L, rb, RKC(i)));
break;
}
case OP_ADD: {
@@ -608,7 +606,7 @@ StkId luaV_execute (lua_State *L) {
if (ttype(ra) == LUA_TTABLE) {
setobj(ra+1, ra);
setsvalue(ra, luaS_new(L, "next"));
luaV_gettable(L, gt(L), ra, ra);
setobj(RA(i), luaV_gettable(L, gt(L), ra));
}
dojump(pc, GETARG_sBx(i));
break;