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lua/lvm.c

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/*
** $Id: lvm.c,v 2.94 2009/07/01 20:31:25 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define lvm_c
#define LUA_CORE
#include "lua.h"
#include "ldebug.h"
#include "ldo.h"
#include "lfunc.h"
#include "lgc.h"
#include "lobject.h"
#include "lopcodes.h"
#include "lstate.h"
#include "lstring.h"
#include "ltable.h"
#include "ltm.h"
#include "lvm.h"
/* limit for table tag-method chains (to avoid loops) */
#define MAXTAGLOOP 100
const TValue *luaV_tonumber (const TValue *obj, TValue *n) {
lua_Number num;
if (ttisnumber(obj)) return obj;
if (ttisstring(obj) && luaO_str2d(svalue(obj), &num)) {
setnvalue(n, num);
return n;
}
else
return NULL;
}
int luaV_tostring (lua_State *L, StkId obj) {
if (!ttisnumber(obj))
return 0;
else {
char s[LUAI_MAXNUMBER2STR];
lua_Number n = nvalue(obj);
lua_number2str(s, n);
setsvalue2s(L, obj, luaS_new(L, s));
return 1;
}
}
static void traceexec (lua_State *L) {
CallInfo *ci = L->ci;
lu_byte mask = L->hookmask;
if ((mask & LUA_MASKCOUNT) && L->hookcount == 0) {
resethookcount(L);
luaD_callhook(L, LUA_HOOKCOUNT, -1);
}
if (mask & LUA_MASKLINE) {
Proto *p = ci_func(ci)->l.p;
int npc = pcRel(ci->u.l.savedpc, p);
int newline = getfuncline(p, npc);
if (npc == 0 || /* call linehook when enter a new function, */
ci->u.l.savedpc <= L->oldpc || /* when jump back (loop), or when */
newline != getfuncline(p, pcRel(L->oldpc, p))) /* enter a new line */
luaD_callhook(L, LUA_HOOKLINE, newline);
}
L->oldpc = ci->u.l.savedpc;
}
static void callTM (lua_State *L, const TValue *f, const TValue *p1,
const TValue *p2, TValue *p3, int hasres) {
ptrdiff_t result = savestack(L, p3);
setobj2s(L, L->top++, f); /* push function */
setobj2s(L, L->top++, p1); /* 1st argument */
setobj2s(L, L->top++, p2); /* 2nd argument */
if (!hasres) /* no result? 'p3' is third argument */
setobj2s(L, L->top++, p3); /* 3th argument */
luaD_checkstack(L, 0);
/* metamethod may yield only when called from Lua code */
luaD_call(L, L->top - (4 - hasres), hasres, isLua(L->ci));
if (hasres) { /* if has result, move it to its place */
p3 = restorestack(L, result);
setobjs2s(L, p3, --L->top);
}
}
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)) {
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, 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, 0);
return;
}
/* else repeat with 'tm' */
setobj(L, &temp, tm); /* avoid pointing inside table (may rehash) */
t = &temp;
}
luaG_runerror(L, "loop in settable");
}
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;
callTM(L, tm, p1, p2, res, 1);
return 1;
}
static const TValue *get_compTM (lua_State *L, Table *mt1, Table *mt2,
TMS event) {
const TValue *tm1 = fasttm(L, mt1, event);
const TValue *tm2;
if (tm1 == NULL) return NULL; /* no metamethod */
if (mt1 == mt2) return tm1; /* same metatables => same metamethods */
tm2 = fasttm(L, mt2, event);
if (tm2 == NULL) return NULL; /* no metamethod */
if (luaO_rawequalObj(tm1, tm2)) /* same metamethods? */
return tm1;
return NULL;
}
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;
callTM(L, tm1, p1, p2, L->top, 1);
return !l_isfalse(L->top);
}
static int l_strcmp (const TString *ls, const TString *rs) {
const char *l = getstr(ls);
size_t ll = ls->tsv.len;
const char *r = getstr(rs);
size_t lr = rs->tsv.len;
for (;;) {
int temp = strcoll(l, r);
if (temp != 0) return temp;
else { /* strings are equal up to a `\0' */
size_t len = strlen(l); /* index of first `\0' in both strings */
if (len == lr) /* r is finished? */
return (len == ll) ? 0 : 1;
else if (len == ll) /* l is finished? */
return -1; /* l is smaller than r (because r is not finished) */
/* both strings longer than `len'; go on comparing (after the `\0') */
len++;
l += len; ll -= len; r += len; lr -= len;
}
}
}
int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
int res;
if (ttype(l) != ttype(r))
return luaG_ordererror(L, l, r);
else if (ttisnumber(l))
return luai_numlt(L, nvalue(l), nvalue(r));
else if (ttisstring(l))
return l_strcmp(rawtsvalue(l), rawtsvalue(r)) < 0;
else if ((res = call_orderTM(L, l, r, TM_LT)) != -1)
return res;
return luaG_ordererror(L, l, r);
}
int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) {
int res;
if (ttype(l) != ttype(r))
return luaG_ordererror(L, l, r);
else if (ttisnumber(l))
return luai_numle(L, nvalue(l), nvalue(r));
else if (ttisstring(l))
return l_strcmp(rawtsvalue(l), rawtsvalue(r)) <= 0;
else if ((res = call_orderTM(L, l, r, TM_LE)) != -1) /* first try `le' */
return res;
else if ((res = call_orderTM(L, r, l, TM_LT)) != -1) /* else try `lt' */
return !res;
return luaG_ordererror(L, l, r);
}
int luaV_equalval_ (lua_State *L, const TValue *t1, const TValue *t2) {
const TValue *tm;
lua_assert(ttype(t1) == ttype(t2));
switch (ttype(t1)) {
case LUA_TNIL: return 1;
case LUA_TNUMBER: return luai_numeq(nvalue(t1), nvalue(t2));
case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2); /* true must be 1 !! */
case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
case LUA_TUSERDATA: {
if (uvalue(t1) == uvalue(t2)) return 1;
tm = get_compTM(L, uvalue(t1)->metatable, uvalue(t2)->metatable, TM_EQ);
break; /* will try TM */
}
case LUA_TTABLE: {
if (hvalue(t1) == hvalue(t2)) return 1;
tm = get_compTM(L, hvalue(t1)->metatable, hvalue(t2)->metatable, TM_EQ);
break; /* will try TM */
}
default: return gcvalue(t1) == gcvalue(t2);
}
if (tm == NULL) return 0; /* no TM? */
callTM(L, tm, t1, t2, L->top, 1); /* call TM */
return !l_isfalse(L->top);
}
void luaV_concat (lua_State *L, int total) {
lua_assert(total >= 2);
do {
StkId top = L->top;
int n = 2; /* number of elements handled in this pass (at least 2) */
if (!(ttisstring(top-2) || ttisnumber(top-2)) || !tostring(L, top-1)) {
if (!call_binTM(L, top-2, top-1, top-2, TM_CONCAT))
luaG_concaterror(L, top-2, top-1);
}
else if (tsvalue(top-1)->len == 0) /* second operand is empty? */
(void)tostring(L, top - 2); /* result is first operand */
else if (ttisstring(top-2) && tsvalue(top-2)->len == 0) {
setsvalue2s(L, top-2, rawtsvalue(top-1)); /* result is second op. */
}
else {
/* at least two non-empty string values; get as many as possible */
size_t tl = tsvalue(top-1)->len;
char *buffer;
int i;
/* collect total length */
for (n = 1; n < total && tostring(L, top-n-1); n++) {
size_t l = tsvalue(top-n-1)->len;
if (l >= MAX_SIZET - tl) luaG_runerror(L, "string length overflow");
tl += l;
}
buffer = luaZ_openspace(L, &G(L)->buff, tl);
tl = 0;
for (i=n; i>0; i--) { /* concat all strings */
size_t l = tsvalue(top-i)->len;
memcpy(buffer+tl, svalue(top-i), l);
tl += l;
}
setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl));
}
total -= n-1; /* got 'n' strings to create 1 new */
L->top -= n-1; /* poped 'n' strings and pushed one */
} while (total > 1); /* repeat until only 1 result left */
}
static void 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;
}
}
callTM(L, tm, rb, luaO_nilobject, ra, 1);
}
void luaV_arith (lua_State *L, StkId ra, const TValue *rb,
const TValue *rc, TMS op) {
TValue tempb, tempc;
const TValue *b, *c;
if ((b = luaV_tonumber(rb, &tempb)) != NULL &&
(c = luaV_tonumber(rc, &tempc)) != NULL) {
lua_Number res = luaO_arith(op - TM_ADD + LUA_OPADD, nvalue(b), nvalue(c));
setnvalue(ra, res);
}
else if (!call_binTM(L, rb, rc, ra, op))
luaG_aritherror(L, rb, rc);
}
/*
** 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 */
switch (GET_OPCODE(inst)) { /* 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_GETGLOBAL: 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 (GET_OPCODE(inst) == 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 = top - 1 - (base + b); /* elements 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_SETGLOBAL: case OP_SETTABLE:
break;
default: lua_assert(0);
}
}
/*
** some macros for common tasks in `luaV_execute'
*/
#define RA(i) (base+GETARG_A(i))
/* to be used after possible stack reallocation */
#define RB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i))
#define RC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i))
#define RKB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \
ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i))
#define RKC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \
ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i))
#define KBx(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgK, k+GETARG_Bx(i))
#define dojump(i) { ci->u.l.savedpc += (i); luai_threadyield(L);}
#define Protect(x) { {x;}; base = ci->u.l.base; }
#define arith_op(op,tm) { \
TValue *rb = RKB(i); \
TValue *rc = RKC(i); \
if (ttisnumber(rb) && ttisnumber(rc)) { \
lua_Number nb = nvalue(rb), nc = nvalue(rc); \
setnvalue(ra, op(L, nb, nc)); \
} \
else \
Protect(luaV_arith(L, ra, rb, rc, tm)); \
}
void luaV_execute (lua_State *L) {
CallInfo *ci = L->ci;
LClosure *cl = &clvalue(ci->func)->l;
TValue *k = cl->p->k;
StkId base = ci->u.l.base;
lua_assert(isLua(ci));
/* main loop of interpreter */
for (;;) {
Instruction i = *(ci->u.l.savedpc++);
StkId ra;
if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
(--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
traceexec(L);
if (L->status == LUA_YIELD) { /* did hook yield? */
ci->u.l.savedpc--; /* undo increment */
luaD_throw(L, LUA_YIELD);
}
base = ci->u.l.base;
}
/* warning!! several calls may realloc the stack and invalidate `ra' */
ra = RA(i);
lua_assert(base == ci->u.l.base);
lua_assert(base <= L->top && L->top < L->stack + L->stacksize);
switch (GET_OPCODE(i)) {
case OP_MOVE: {
setobjs2s(L, ra, RB(i));
continue;
}
case OP_LOADK: {
setobj2s(L, ra, KBx(i));
continue;
}
case OP_LOADBOOL: {
setbvalue(ra, GETARG_B(i));
if (GETARG_C(i)) ci->u.l.savedpc++; /* skip next instruction (if C) */
continue;
}
case OP_LOADNIL: {
TValue *rb = RB(i);
do {
setnilvalue(rb--);
} while (rb >= ra);
continue;
}
case OP_GETUPVAL: {
int b = GETARG_B(i);
setobj2s(L, ra, cl->upvals[b]->v);
continue;
}
case OP_GETGLOBAL: {
TValue g;
TValue *rb = KBx(i);
sethvalue(L, &g, cl->env);
lua_assert(ttisstring(rb));
Protect(luaV_gettable(L, &g, rb, ra));
continue;
}
case OP_GETTABLE: {
Protect(luaV_gettable(L, RB(i), RKC(i), ra));
continue;
}
case OP_SETGLOBAL: {
TValue g;
sethvalue(L, &g, cl->env);
lua_assert(ttisstring(KBx(i)));
Protect(luaV_settable(L, &g, KBx(i), ra));
continue;
}
case OP_SETUPVAL: {
UpVal *uv = cl->upvals[GETARG_B(i)];
setobj(L, uv->v, ra);
luaC_barrier(L, uv, ra);
continue;
}
case OP_SETTABLE: {
Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
continue;
}
case OP_NEWTABLE: {
int b = GETARG_B(i);
int c = GETARG_C(i);
Table *t = luaH_new(L);
sethvalue(L, ra, t);
if (b != 0 || c != 0)
luaH_resize(L, t, luaO_fb2int(b), luaO_fb2int(c));
Protect(luaC_checkGC(L));
continue;
}
case OP_SELF: {
StkId rb = RB(i);
setobjs2s(L, ra+1, rb);
Protect(luaV_gettable(L, rb, RKC(i), ra));
continue;
}
case OP_ADD: {
arith_op(luai_numadd, TM_ADD);
continue;
}
case OP_SUB: {
arith_op(luai_numsub, TM_SUB);
continue;
}
case OP_MUL: {
arith_op(luai_nummul, TM_MUL);
continue;
}
case OP_DIV: {
arith_op(luai_numdiv, TM_DIV);
continue;
}
case OP_MOD: {
arith_op(luai_nummod, TM_MOD);
continue;
}
case OP_POW: {
arith_op(luai_numpow, TM_POW);
continue;
}
case OP_UNM: {
TValue *rb = RB(i);
if (ttisnumber(rb)) {
lua_Number nb = nvalue(rb);
setnvalue(ra, luai_numunm(L, nb));
}
else {
Protect(luaV_arith(L, ra, rb, rb, TM_UNM));
}
continue;
}
case OP_NOT: {
int res = l_isfalse(RB(i)); /* next assignment may change this value */
setbvalue(ra, res);
continue;
}
case OP_LEN: {
Protect(objlen(L, ra, RB(i)));
continue;
}
case OP_CONCAT: {
int b = GETARG_B(i);
int c = GETARG_C(i);
L->top = base + c + 1; /* mark the end of concat operands */
Protect(luaV_concat(L, c-b+1); luaC_checkGC(L));
L->top = ci->top; /* restore top */
setobjs2s(L, RA(i), base+b);
continue;
}
case OP_JMP: {
dojump(GETARG_sBx(i));
continue;
}
case OP_EQ: {
TValue *rb = RKB(i);
TValue *rc = RKC(i);
Protect(
if (equalobj(L, rb, rc) == GETARG_A(i))
dojump(GETARG_sBx(*ci->u.l.savedpc));
)
ci->u.l.savedpc++;
continue;
}
case OP_LT: {
Protect(
if (luaV_lessthan(L, RKB(i), RKC(i)) == GETARG_A(i))
dojump(GETARG_sBx(*ci->u.l.savedpc));
)
ci->u.l.savedpc++;
continue;
}
case OP_LE: {
Protect(
if (luaV_lessequal(L, RKB(i), RKC(i)) == GETARG_A(i))
dojump(GETARG_sBx(*ci->u.l.savedpc));
)
ci->u.l.savedpc++;
continue;
}
case OP_TEST: {
if (GETARG_C(i) ? !l_isfalse(ra) : l_isfalse(ra))
dojump(GETARG_sBx(*ci->u.l.savedpc));
ci->u.l.savedpc++;
continue;
}
case OP_TESTSET: {
TValue *rb = RB(i);
if (GETARG_C(i) ? !l_isfalse(rb) : l_isfalse(rb)) {
setobjs2s(L, ra, rb);
dojump(GETARG_sBx(*ci->u.l.savedpc));
}
ci->u.l.savedpc++;
continue;
}
case OP_CALL: {
int b = GETARG_B(i);
int nresults = GETARG_C(i) - 1;
if (b != 0) L->top = ra+b; /* else previous instruction set top */
if (luaD_precall(L, ra, nresults)) { /* C function? */
if (nresults >= 0) L->top = ci->top; /* adjust results */
base = ci->u.l.base;
continue;
}
else { /* Lua function */
ci = L->ci;
ci->callstatus |= CIST_REENTRY;
break; /* restart luaV_execute over new Lua function */
}
}
case OP_TAILCALL: {
int b = GETARG_B(i);
if (b != 0) L->top = ra+b; /* else previous instruction set top */
lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
if (luaD_precall(L, ra, LUA_MULTRET)) { /* C function? */
base = ci->u.l.base;
continue;
}
else {
/* tail call: put called frame (n) in place of caller one (o) */
CallInfo *nci = L->ci; /* called frame */
CallInfo *oci = nci->previous; /* caller frame */
StkId nfunc = nci->func; /* called function */
StkId ofunc = oci->func; /* caller function */
/* last stack slot filled by 'precall' */
StkId lim = nci->u.l.base + getproto(nfunc)->numparams;
int aux;
/* close all upvalues from previous call */
if (cl->p->sizep > 0) luaF_close(L, oci->u.l.base);
/* move new frame into old one */
for (aux = 0; nfunc + aux < lim; aux++)
setobjs2s(L, ofunc + aux, nfunc + aux);
oci->u.l.base = ofunc + (nci->u.l.base - nfunc); /* correct base */
oci->top = L->top = ofunc + (L->top - nfunc); /* correct top */
oci->u.l.savedpc = nci->u.l.savedpc;
oci->u.l.tailcalls++; /* one more call lost */
ci = L->ci = oci; /* remove new frame */
lua_assert(L->top == oci->u.l.base + getproto(ofunc)->maxstacksize);
break; /* restart luaV_execute over new Lua function */
}
}
case OP_RETURN: {
int b = GETARG_B(i);
if (b != 0) L->top = ra+b-1;
if (cl->p->sizep > 0) luaF_close(L, base);
b = luaD_poscall(L, ra);
if (!(ci->callstatus & CIST_REENTRY)) /* 'ci' still the called one */
return; /* external invocation: return */
else { /* invocation via reentry: continue execution */
ci = L->ci;
if (b) L->top = ci->top;
lua_assert(isLua(ci));
lua_assert(GET_OPCODE(*((ci)->u.l.savedpc - 1)) == OP_CALL);
break; /* restart luaV_execute over new Lua function */
}
}
case OP_FORLOOP: {
lua_Number step = nvalue(ra+2);
lua_Number idx = luai_numadd(L, nvalue(ra), step); /* increment index */
lua_Number limit = nvalue(ra+1);
if (luai_numlt(L, 0, step) ? luai_numle(L, idx, limit)
: luai_numle(L, limit, idx)) {
dojump(GETARG_sBx(i)); /* jump back */
setnvalue(ra, idx); /* update internal index... */
setnvalue(ra+3, idx); /* ...and external index */
}
continue;
}
case OP_FORPREP: {
const TValue *init = ra;
const TValue *plimit = ra+1;
const TValue *pstep = ra+2;
if (!tonumber(init, ra))
luaG_runerror(L, LUA_QL("for") " initial value must be a number");
else if (!tonumber(plimit, ra+1))
luaG_runerror(L, LUA_QL("for") " limit must be a number");
else if (!tonumber(pstep, ra+2))
luaG_runerror(L, LUA_QL("for") " step must be a number");
setnvalue(ra, luai_numsub(L, nvalue(ra), nvalue(pstep)));
dojump(GETARG_sBx(i));
continue;
}
case OP_TFORCALL: {
StkId cb = ra + 3; /* call base */
setobjs2s(L, cb+2, ra+2);
setobjs2s(L, cb+1, ra+1);
setobjs2s(L, cb, ra);
L->top = cb + 3; /* func. + 2 args (state and index) */
Protect(luaD_call(L, cb, GETARG_C(i), 1));
L->top = ci->top;
i = *(ci->u.l.savedpc++); /* go to next instruction */
ra = RA(i);
lua_assert(GET_OPCODE(i) == OP_TFORLOOP);
/* go through */
}
case OP_TFORLOOP: {
if (!ttisnil(ra + 1)) { /* continue loop? */
setobjs2s(L, ra, ra + 1); /* save control variable */
dojump(GETARG_sBx(i)); /* jump back */
}
continue;
}
case OP_SETLIST: {
int n = GETARG_B(i);
int c = GETARG_C(i);
int last;
Table *h;
if (n == 0) n = cast_int(L->top - ra) - 1;
if (c == 0) {
lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG);
c = GETARG_Ax(*ci->u.l.savedpc++);
}
h = hvalue(ra);
last = ((c-1)*LFIELDS_PER_FLUSH) + n;
if (last > h->sizearray) /* needs more space? */
luaH_resizearray(L, h, last); /* pre-alloc it at once */
for (; n > 0; n--) {
TValue *val = ra+n;
setobj2t(L, luaH_setnum(L, h, last--), val);
luaC_barriert(L, h, val);
}
L->top = ci->top; /* correct top (in case of previous open call) */
continue;
}
case OP_CLOSE: {
luaF_close(L, ra);
continue;
}
case OP_CLOSURE: {
Proto *p;
Closure *ncl;
int nup, j;
p = cl->p->p[GETARG_Bx(i)];
nup = p->nups;
ncl = luaF_newLclosure(L, nup, cl->env);
ncl->l.p = p;
setclvalue(L, ra, ncl);
for (j=0; j<nup; j++) {
Instruction u = *ci->u.l.savedpc++;
if (GET_OPCODE(u) == OP_GETUPVAL)
ncl->l.upvals[j] = cl->upvals[GETARG_B(u)];
else {
lua_assert(GET_OPCODE(u) == OP_MOVE);
ncl->l.upvals[j] = luaF_findupval(L, base + GETARG_B(u));
}
}
Protect(luaC_checkGC(L));
continue;
}
case OP_VARARG: {
int b = GETARG_B(i) - 1;
int j;
int n = cast_int(base - ci->func) - cl->p->numparams - 1;
if (b == LUA_MULTRET) {
Protect(luaD_checkstack(L, n));
ra = RA(i); /* previous call may change the stack */
b = n;
L->top = ra + n;
}
for (j = 0; j < b; j++) {
if (j < n) {
setobjs2s(L, ra + j, base - n + j);
}
else {
setnilvalue(ra + j);
}
}
continue;
}
case OP_EXTRAARG: {
luaG_runerror(L, "bad opcode");
return;
}
}
/* function changed (call/return): update pointers */
lua_assert(ci == L->ci);
cl = &clvalue(ci->func)->l;
k = cl->p->k;
base = ci->u.l.base;
}
}
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