static int call_binTM (lua_State *L, const TValue *p1, const TValue *p2,
StkId res, TMS event) {
const TValue *tm = luaT_gettmbyobj(L, p1, event); /* try first operand */
if (ttisnil(tm))
tm = luaT_gettmbyobj(L, p2, event); /* try second operand */
if (ttisnil(tm)) return 0;
callTMres(L, res, tm, p1, p2);
return 1;
}
static int call_orderTM (lua_State *L, const TValue *p1, const TValue *p2,
TMS event) {
const TValue *tm1 = luaT_gettmbyobj(L, p1, event);
const TValue *tm2;
if (ttisnil(tm1)) return -1; /* no metamethod? */
tm2 = luaT_gettmbyobj(L, p2, event);
if (!luaO_rawequalObj(tm1, tm2)) /* different metamethods? */
return -1;
callTMres(L, L->top, tm1, p1, p2);
return !l_isfalse(L->top);
}
static int call_binTM (lua_State *L, const TObject *p1, const TObject *p2,
StkId res, TMS event) {
ptrdiff_t result = savestack(L, res);
const TObject *tm = luaT_gettmbyobj(L, p1, event); /* try first operand */
if (ttisnil(tm))
tm = luaT_gettmbyobj(L, p2, event); /* try second operand */
if (!ttisfunction(tm)) return 0;
callTMres(L, tm, p1, p2);
res = restorestack(L, result); /* previous call may change stack */
setobjs2s(res, L->top);
return 1;
}
/*
** Finish the table access 'val = t[key]'.
** if 'slot' is NULL, 't' is not a table; otherwise, 'slot' points to
** t[k] entry (which must be nil).
*/
void luaV_finishget (lua_State *L, const TValue *t, TValue *key, StkId val,
const TValue *slot) {
int loop; /* counter to avoid infinite loops */
const TValue *tm; /* metamethod */
for (loop = 0; loop < MAXTAGLOOP; loop++) {
if (slot == NULL) { /* 't' is not a table? */
lua_assert(!ttistable(t));
tm = luaT_gettmbyobj(L, t, TM_INDEX);
if (ttisnil(tm))
luaG_typeerror(L, t, "index"); /* no metamethod */
/* else will try the metamethod */
}
else { /* 't' is a table */
lua_assert(ttisnil(slot));
tm = fasttm(L, hvalue(t)->metatable, TM_INDEX); /* table's metamethod */
if (tm == NULL) { /* no metamethod? */
setnilvalue(val); /* result is nil */
return;
}
/* else will try the metamethod */
}
if (ttisfunction(tm)) { /* is metamethod a function? */
luaT_callTM(L, tm, t, key, val, 1); /* call it */
return;
}
t = tm; /* else try to access 'tm[key]' */
if (luaV_fastget(L,t,key,slot,luaH_get)) { /* fast track? */
setobj2s(L, val, slot); /* done */
return;
}
/* else repeat (tail call 'luaV_finishget') */
}
luaG_runerror(L, "'__index' chain too long; possible loop");
}
/*
* 获取哈希表
* L 虚拟机状态
* t 哈希表的指针
* key 哈希表的键
* val 哈希表的值在栈中的索引
*/
void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
int loop;
/* 遍历 */
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm;
/* 如果t是哈希表类型 */
if (ttistable(t)) { /* `t' is a table? */
Table *h = hvalue(t); /* 获取哈希表值 */
/* 从键中取出值 */
const TValue *res = luaH_get(h, key); /* do a primitive get */
/* 如果不是空值或者其表的元运算为空 */
if (!ttisnil(res) || /* result is not nil? */
(tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
/* 设置哈希值到指定的栈索引位置 */
setobj2s(L, val, res);
return;
}
/* else will try the tag method */
}
/* 如果t不是哈希表则判断其元运算是否为空值 */
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
luaG_typeerror(L, t, "index");
/* 如果元运算是函数则进行调用 */
if (ttisfunction(tm)) {
callTM(L, tm, t, key, val, 1);
return;
}
t = tm; /* else repeat with 'tm' */
}
luaG_runerror(L, "loop in gettable");
}
void luaV_settable (lua_State *L, TValue *t, TValue *key, StkId val) {
int loop;
for (loop = 0; loop < MAXTAGLOOP; loop++) {
TValue *tm;
if (ttistable(t)) { /* `t' is a table? */
Table *h = hvalue(t);
TValue *oldval = luaH_set(L, h, key); /* do a primitive set */
/* oldval is nil=> look for newindex, oldval is not nil => look for usedindex */
if (!((ttisnil(oldval) && ((tm = fasttm(L, h->metatable, TM_NEWINDEX)) != NULL)) ||
((!ttisnil(oldval)) && ((tm = fasttm(L, h->metatable, TM_USEDINDEX)) != NULL)))) {
setobj2t(L, oldval, val);
luaC_barriert(L, h, val);
return;
}
/* else will try the tag method */
}
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
luaG_typeerror(L, t, "index");
if (ttisfunction(tm)) {
callTM(L, tm, t, key, val);
return;
}
t = tm; /* else repeat with `tm' */
}
luaG_runerror(L, "loop in settable");
}
void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val)
{
int loop;
for (loop = 0; loop < MAXTAGLOOP; loop++)
{
const TValue *tm;
if (ttistable(t)) /* `t' is a table? */
{
Table *h = hvalue(t);
const TValue *res = luaH_get(h, key); /* do a primitive get */
if (!ttisnil(res) || /* result is no nil? */
(tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) /* or no TM? */
{
setobj2s(L, val, res);
return;
}
/* else will try the tag method */
}
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
luaG_typeerror(L, t, "index");
if (ttisfunction(tm))
{
callTMres(L, val, tm, t, key);
return;
}
t = tm; /* else repeat with `tm' */
}
luaG_runerror(L, "loop in gettable");
}
void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
int loop;
TValue temp;
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm;
if (ttistable(t) || ttisrotable(t)) { /* `t' is a table? */
void *h = ttistable(t) ? hvalue(t) : rvalue(t);
const TValue *res = ttistable(t) ? luaH_get((Table*)h, key) : luaH_get_ro(h, key); /* do a primitive get */
if (!ttisnil(res) || /* result is no nil? */
(tm = fasttm(L, ttistable(t) ? ((Table*)h)->metatable : (Table*)luaR_getmeta(h), TM_INDEX)) == NULL) { /* or no TM? */
setobj2s(L, val, res);
return;
}
/* else will try the tag method */
}
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
luaG_typeerror(L, t, "index");
if (ttisfunction(tm) || ttislightfunction(tm)) {
callTMres(L, val, tm, t, key);
return;
}
/* else repeat with `tm' */
setobj(L, &temp, tm); /* avoid pointing inside table (may rehash) */
t = &temp;
}
luaG_runerror(L, "loop in gettable");
}
/*
** Main function for table assignment (invoking metamethods if needed).
** Compute 't[key] = val'
*/
void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
int loop; /* counter to avoid infinite loops */
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm;
if (ttistable(t)) { /* 't' is a table? */
Table *h = hvalue(t);
TValue *oldval = cast(TValue *, luaH_get(h, key));
/* if previous value is not nil, there must be a previous entry
in the table; a metamethod has no relevance */
if (!ttisnil(oldval) ||
/* previous value is nil; must check the metamethod */
((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL &&
/* no metamethod; is there a previous entry in the table? */
(oldval != luaO_nilobject ||
/* no previous entry; must create one. (The next test is
always true; we only need the assignment.) */
(oldval = luaH_newkey(L, h, key), 1)))) {
/* no metamethod and (now) there is an entry with given key */
setobj2t(L, oldval, val); /* assign new value to that entry */
invalidateTMcache(h);
luaC_barrierback(L, h, val);
return;
}
/* else will try the metamethod */
}
else /* not a table; check metamethod */
if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
luaG_typeerror(L, t, "index");
/* try the metamethod */
if (ttisfunction(tm)) {
luaT_callTM(L, tm, t, key, val, 0);
return;
}
t = tm; /* else repeat assignment over 'tm' */
}
void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
int loop;
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm;
if (ttistable(t) || ttisrotable(t)) { /* `t' is a table? */
void *h = ttistable(t) ? hvalue(t) : rvalue(t);
TValue *oldval = ttistable(t) ? luaH_set(L, (Table*)h, key) : NULL; /* do a primitive set */
if ((oldval && !ttisnil(oldval)) || /* result is no nil? */
(tm = fasttm(L, ttistable(t) ? ((Table*)h)->metatable : (Table*)luaR_getmeta(h), TM_NEWINDEX)) == NULL) { /* or no TM? */
if(oldval) {
setobj2t(L, oldval, val);
luaC_barriert(L, (Table*)h, val);
}
return;
}
/* else will try the tag method */
}
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
luaG_typeerror(L, t, "index");
if (ttisfunction(tm) || ttislightfunction(tm)) {
callTM(L, tm, t, key, val);
return;
}
t = tm; /* else repeat with `tm' */
}
luaG_runerror(L, "loop in settable");
}
void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
int loop;
TValue temp;
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm;
if (ttistable(t)) { /* `t' is a table? */
Table *h = hvalue(t);
TValue *oldval = luaH_set(L, h, key); /* do a primitive set */
if (!ttisnil(oldval) || /* result is no nil? */
(tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
setobj2t(L, oldval, val);
luaC_barriert(L, h, val);
return;
}
/* else will try the tag method */
}
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
luaG_typeerror(L, t, "index");
if (ttisfunction(tm)) {
callTM(L, tm, t, key, val);
return;
}
/* else repeat with `tm' */
setobj(L, &temp, tm); /* avoid pointing inside table (may rehash) */
t = &temp;
}
luaG_runerror(L, "loop in settable");
}
/*
** Main operation 'ra' = #rb'.
*/
void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) {
const TValue *tm;
switch (ttype(rb)) {
case LUA_TTABLE: {
Table *h = hvalue(rb);
tm = fasttm(L, h->metatable, TM_LEN);
if (tm) break; /* metamethod? break switch to call it */
setivalue(ra, luaH_getn(h)); /* else primitive len */
return;
}
case LUA_TSHRSTR: {
setivalue(ra, tsvalue(rb)->shrlen);
return;
}
case LUA_TLNGSTR: {
setivalue(ra, tsvalue(rb)->u.lnglen);
return;
}
default: { /* try metamethod */
tm = luaT_gettmbyobj(L, rb, TM_LEN);
if (ttisnil(tm)) /* no metamethod? */
luaG_typeerror(L, rb, "get length of");
break;
}
}
luaT_callTM(L, tm, rb, rb, ra, 1);
}
static void GCTM (lua_State *L, int propagateerrors) {
global_State *g = G(L);
const TValue *tm;
TValue v;
setgcovalue(L, &v, udata2finalize(g));
tm = luaT_gettmbyobj(L, &v, TM_GC);
if (tm != NULL && ttisfunction(tm)) { /* is there a finalizer? */
int status;
lu_byte oldah = L->allowhook;
int running = g->gcrunning;
L->allowhook = 0; /* stop debug hooks during GC metamethod */
g->gcrunning = 0; /* avoid GC steps */
setobj2s(L, L->top, tm); /* push finalizer... */
setobj2s(L, L->top + 1, &v); /* ... and its argument */
L->top += 2; /* and (next line) call the finalizer */
status = luaD_pcall(L, dothecall, NULL, savestack(L, L->top - 2), 0);
L->allowhook = oldah; /* restore hooks */
g->gcrunning = running; /* restore state */
if (status != LUA_OK && propagateerrors) { /* error while running __gc? */
if (status == LUA_ERRRUN) { /* is there an error object? */
const char *msg = (ttisstring(L->top - 1))
? svalue(L->top - 1)
: "no message";
luaO_pushfstring(L, "error in __gc metamethod (%s)", msg);
status = LUA_ERRGCMM; /* error in __gc metamethod */
}
luaD_throw(L, status); /* re-throw error */
}
}
}
static const TObject *luaV_getnotable (lua_State *L, const TObject *t,
TObject *key, int loop) {
const TObject *tm = luaT_gettmbyobj(L, t, TM_INDEX);
if (ttisnil(tm))
luaG_typeerror(L, t, "index");
if (ttisfunction(tm)) {
callTMres(L, tm, t, key);
return L->top;
}
else return luaV_gettable(L, tm, key, loop);
}
/*
** finish execution of an opcode interrupted by an yield
*/
void luaV_finishOp (lua_State *L) {
CallInfo *ci = L->ci;
StkId base = ci->u.l.base;
Instruction inst = *(ci->u.l.savedpc - 1); /* interrupted instruction */
OpCode op = GET_OPCODE(inst);
switch (op) { /* finish its execution */
case OP_ADD: case OP_SUB: case OP_MUL: case OP_DIV:
case OP_MOD: case OP_POW: case OP_UNM: case OP_LEN:
case OP_GETTABUP: case OP_GETTABLE: case OP_SELF: {
setobjs2s(L, base + GETARG_A(inst), --L->top);
break;
}
case OP_LE: case OP_LT: case OP_EQ: {
int res = !l_isfalse(L->top - 1);
L->top--;
/* metamethod should not be called when operand is K */
lua_assert(!ISK(GETARG_B(inst)));
if (op == OP_LE && /* "<=" using "<" instead? */
ttisnil(luaT_gettmbyobj(L, base + GETARG_B(inst), TM_LE)))
res = !res; /* invert result */
lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_JMP);
if (res != GETARG_A(inst)) /* condition failed? */
ci->u.l.savedpc++; /* skip jump instruction */
break;
}
case OP_CONCAT: {
StkId top = L->top - 1; /* top when 'call_binTM' was called */
int b = GETARG_B(inst); /* first element to concatenate */
int total = cast_int(top - 1 - (base + b)); /* yet to concatenate */
setobj2s(L, top - 2, top); /* put TM result in proper position */
if (total > 1) { /* are there elements to concat? */
L->top = top - 1; /* top is one after last element (at top-2) */
luaV_concat(L, total); /* concat them (may yield again) */
}
/* move final result to final position */
setobj2s(L, ci->u.l.base + GETARG_A(inst), L->top - 1);
L->top = ci->top; /* restore top */
break;
}
case OP_TFORCALL: {
lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_TFORLOOP);
L->top = ci->top; /* correct top */
break;
}
case OP_CALL: {
if (GETARG_C(inst) - 1 >= 0) /* nresults >= 0? */
L->top = ci->top; /* adjust results */
break;
}
case OP_TAILCALL: case OP_SETTABUP: case OP_SETTABLE:
break;
default: lua_assert(0);
}
}
void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
TValue tmp;
int loop;
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm;
if (ttistable(t)) { /* `t' is a table? */
Table *h = hvalue(t);
TValue *oldval = luaH_set(L, h, key); /* do a primitive set */
if (!ttisnil(oldval) || /* result is no nil? */
(tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
setobj2t(L, oldval, val);
luaC_barriert(L, h, val);
#if LUA_REFCOUNT
if (ttisnil(val)) {
Node* keyNode = luaH_getkey(h, key);
if (keyNode) {
luaH_removekey(L, h, keyNode);
}
}
#endif /* LUA_REFCOUNT */
return;
}
/* else will try the tag method */
}
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
luaG_typeerror(L, t, "index");
if (ttisfunction(tm)) {
callTM(L, tm, t, key, val);
#if LUA_REFCOUNT
{
TValue *newval;
if (ttistable(t)) {
newval = luaH_set(L, hvalue(t), key);
if (ttisnil(newval)) {
Node* keyNode = luaH_getkey(hvalue(t), key);
if (keyNode)
luaH_removekey(L, hvalue(t), keyNode);
}
}
}
#endif /* LUA_REFCOUNT */
return;
}
setobj(L, &tmp, tm);
t = &tmp; /* else repeat with copy of `tm' */
}
luaG_runerror(L, "loop in settable");
}
void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
int loop;
TValue temp;
setnilvalue(L->top);
L->top++;
fixedstack(L);
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm;
if (ttistable(t) || ttisrotable(t)) { /* `t' is a table? */
void *h = ttistable(t) ? hvalue(t) : rvalue(t);
TValue *oldval = ttistable(t) ? luaH_set(L, (Table*)h, key) : NULL; /* do a primitive set */
if ((oldval && !ttisnil(oldval)) || /* result is no nil? */
(tm = fasttm(L, ttistable(t) ? ((Table*)h)->metatable : (Table*)luaR_getmeta(h), TM_NEWINDEX)) == NULL) { /* or no TM? */
if(oldval) {
L->top--;
unfixedstack(L);
setobj2t(L, oldval, val);
((Table *)h)->flags = 0;
luaC_barriert(L, (Table*)h, val);
}
return;
}
/* else will try the tag method */
}
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
luaG_typeerror(L, t, "index");
if (ttisfunction(tm) || ttislightfunction(tm)) {
L->top--;
unfixedstack(L);
callTM(L, tm, t, key, val);
return;
}
/* else repeat with `tm' */
setobj(L, &temp, tm); /* avoid pointing inside table (may rehash) */
t = &temp;
setobj2s(L, L->top-1, t); /* need to protect value from EGC. */
}
luaG_runerror(L, "loop in settable");
}
/*
** Main function for table assignment (invoking metamethods if needed).
** Compute 't[key] = val'
*/
void luaV_finishset (lua_State *L, const TValue *t, TValue *key,
StkId val, const TValue *oldval) {
int loop; /* counter to avoid infinite loops */
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm;
if (oldval != NULL) {
Table *h = hvalue(t); /* save 't' table */
lua_assert(ttisnil(oldval));
/* must check the metamethod */
if ((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL &&
/* no metamethod; is there a previous entry in the table? */
(oldval != luaO_nilobject ||
/* no previous entry; must create one. (The next test is
always true; we only need the assignment.) */
(oldval = luaH_newkey(L, h, key), 1))) {
/* no metamethod and (now) there is an entry with given key */
setobj2t(L, cast(TValue *, oldval), val);
invalidateTMcache(h);
luaC_barrierback(L, h, val);
return;
}
/* else will try the metamethod */
}
else { /* not a table; check metamethod */
if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
luaG_typeerror(L, t, "index");
}
/* try the metamethod */
if (ttisfunction(tm)) {
luaT_callTM(L, tm, t, key, val, 0);
return;
}
t = tm; /* else repeat assignment over 'tm' */
if (luaV_fastset(L, t, key, oldval, luaH_get, val))
return; /* done */
/* else loop */
}
luaG_runerror(L, "settable chain too long; possible loop");
}
/*
** Complete a table access: if 't' is a table, 'tm' has its metamethod;
** otherwise, 'tm' is NULL.
*/
void luaV_finishget (lua_State *L, const TValue *t, TValue *key, StkId val,
const TValue *tm) {
int loop; /* counter to avoid infinite loops */
lua_assert(tm != NULL || !ttistable(t));
for (loop = 0; loop < MAXTAGLOOP; loop++) {
if (tm == NULL) { /* no metamethod (from a table)? */
if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
luaG_typeerror(L, t, "index"); /* no metamethod */
}
if (ttisfunction(tm)) { /* metamethod is a function */
luaT_callTM(L, tm, t, key, val, 1); /* call it */
return;
}
t = tm; /* else repeat access over 'tm' */
if (luaV_fastget(L,t,key,tm,luaH_get)) { /* try fast track */
setobj2s(L, val, tm); /* done */
return;
}
/* else repeat */
}
luaG_runerror(L, "gettable chain too long; possible loop");
}
void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) {
const TValue *tm;
switch (ttype(rb)) {
case LUA_TTABLE: {
Table *h = hvalue(rb);
tm = fasttm(L, h->metatable, TM_LEN);
if (tm) break; /* metamethod? break switch to call it */
setnvalue(ra, cast_num(luaH_getn(h))); /* else primitive len */
return;
}
case LUA_TSTRING: {
setnvalue(ra, cast_num(tsvalue(rb)->len));
return;
}
default: { /* try metamethod */
tm = luaT_gettmbyobj(L, rb, TM_LEN);
if (ttisnil(tm)) /* no metamethod? */
luaG_typeerror(L, rb, "get length of");
break;
}
}
callTMres(L, ra, tm, rb, luaO_nilobject);
}
/*
** Finish a table assignment 't[key] = val'.
** If 'slot' is NULL, 't' is not a table. Otherwise, 'slot' points
** to the entry 't[key]', or to 'luaO_nilobject' if there is no such
** entry. (The value at 'slot' must be nil, otherwise 'luaV_fastset'
** would have done the job.)
*/
void luaV_finishset (lua_State *L, const TValue *t, TValue *key,
StkId val, const TValue *slot) {
int loop; /* counter to avoid infinite loops */
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm; /* '__newindex' metamethod */
if (slot != NULL) { /* is 't' a table? */
Table *h = hvalue(t); /* save 't' table */
lua_assert(ttisnil(slot)); /* old value must be nil */
tm = fasttm(L, h->metatable, TM_NEWINDEX); /* get metamethod */
if (tm == NULL) { /* no metamethod? */
if (slot == luaO_nilobject) /* no previous entry? */
slot = luaH_newkey(L, h, key); /* create one */
/* no metamethod and (now) there is an entry with given key */
setobj2t(L, cast(TValue *, slot), val); /* set its new value */
invalidateTMcache(h);
luaC_barrierback(L, h, val);
return;
}
/* else will try the metamethod */
}
else { /* not a table; check metamethod */
if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
luaG_typeerror(L, t, "index");
}
/* try the metamethod */
if (ttisfunction(tm)) {
luaT_callTM(L, tm, t, key, val, 0);
return;
}
t = tm; /* else repeat assignment over 'tm' */
if (luaV_fastset(L, t, key, slot, luaH_get, val))
return; /* done */
/* else loop */
}
luaG_runerror(L, "'__newindex' chain too long; possible loop");
}
/*
** Receives table at `t', key at `key' and value at `val'.
*/
void luaV_settable (lua_State *L, const TObject *t, TObject *key, StkId val) {
const TObject *tm;
int loop = 0;
do {
if (ttistable(t)) { /* `t' is a table? */
Table *h = hvalue(t);
TObject *oldval = luaH_set(L, h, key); /* do a primitive set */
if (!ttisnil(oldval) || /* result is no nil? */
(tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
setobj2t(oldval, val); /* write barrier */
return;
}
/* else will try the tag method */
}
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
luaG_typeerror(L, t, "index");
if (ttisfunction(tm)) {
callTM(L, tm, t, key, val);
return;
}
t = tm; /* else repeat with `tm' */
} while (++loop <= MAXTAGLOOP);
luaG_runerror(L, "loop in settable");
}
/*
** Main function for table access (invoking metamethods if needed).
** Compute 'val = t[key]'
*/
void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
int loop; /* counter to avoid infinite loops */
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm;
if (ttistable(t)) { /* 't' is a table? */
Table *h = hvalue(t);
const TValue *res = luaH_get(h, key); /* do a primitive get */
if (!ttisnil(res) || /* result is not nil? */
(tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
setobj2s(L, val, res); /* result is the raw get */
return;
}
/* else will try metamethod */
}
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
luaG_typeerror(L, t, "index"); /* no metamethod */
if (ttisfunction(tm)) { /* metamethod is a function */
luaT_callTM(L, tm, t, key, val, 1);
return;
}
t = tm; /* else repeat access over 'tm' */
}
luaG_runerror(L, "gettable chain too long; possible loop");
}
void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
int loop;
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm = 0; /* LUA-VEC -- compiler gives a warning of uninitialized value on this so we set it to 0 */
if (ttistable(t)) { /* `t' is a table? */
Table *h = hvalue(t);
const TValue *res = luaH_get(h, key); /* do a primitive get */
if (!ttisnil(res) || /* result is no nil? */
(tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
setobj2s(L, val, res);
return;
}
/* else will try the tag method */
}
else if (ttisvec(t)) { /* LUA-VEC -- vec[idx] operator */
/* issue: "index" may not be the correct arg for luaG_typeerror in here */
if (ttisnumber(key) && /* acessing vec by a number? */
(nvalue(key) >= 1 && nvalue(key) <= 4)) { /* index is between 1-4? */
TValue res;
setnvalue(&res, vecvalue(t)[(int)nvalue(key)-1]);
setobj2s(L, val, &res);
return;
}
else if (ttisstring(key)) { /* acessing vec by a string? */
if (tsvalue(key)->len == 1) {
/* accessing by a single component, such as vec.x */
TValue res;
switch (*getstr(tsvalue(key))) {
case 'x': setnvalue(&res, vecvalue(t)[0]); break;
case 'y': setnvalue(&res, vecvalue(t)[1]); break;
case 'z': setnvalue(&res, vecvalue(t)[2]); break;
case 'w': setnvalue(&res, vecvalue(t)[3]); break;
default: luaG_typeerror(L, t, "index");
}
setobj2s(L, val, &res);
return;
}
else if (tsvalue(key)->len <= 4) {
/* accessing by swizzling, such as vec.xy, vec.xxyz etc. */
TValue res;
float v[4] = {0.0f,0.0f,0.0f,0.0f};
int i;
for (i = 0; i < (int)tsvalue(key)->len; ++i) {
switch (getstr(tsvalue(key))[i]) {
case 'x': v[i] = vecvalue(t)[0]; break;
case 'y': v[i] = vecvalue(t)[1]; break;
case 'z': v[i] = vecvalue(t)[2]; break;
case 'w': v[i] = vecvalue(t)[3]; break;
default: luaG_typeerror(L, t, "index");
}
}
setvecvalue(&res, v[0], v[1], v[2], v[3]);
setobj2s(L, val, &res);
return;
}
}
luaG_typeerror(L, t, "index");
}
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
luaG_typeerror(L, t, "index");
if (ttisfunction(tm)) {
callTMres(L, val, tm, t, key);
return;
}
t = tm; /* else repeat with `tm' */
}
luaG_runerror(L, "loop in gettable");
}
