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8927c14317
lua/lvm.c
Roberto Ierusalimschy 3e977f02ac added a few comments
2014-05-15 17:08:32 -03:00

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/*
** $Id: lvm.c,v 2.210 2014/05/14 19:47:11 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
#include <limits.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 2000
/* maximum length of the conversion of a number to a string */
#define MAXNUMBER2STR 50
/*
** Similar to 'tonumber', but does not attempt to convert strings and
** ensure correct precision (no extra bits). Used in comparisons.
*/
static int tofloat (const TValue *obj, lua_Number *n) {
if (ttisfloat(obj)) *n = fltvalue(obj);
else if (ttisinteger(obj)) {
volatile lua_Number x = cast_num(ivalue(obj)); /* avoid extra precision */
*n = x;
}
else {
*n = 0; /* to avoid warnings */
return 0;
}
return 1;
}
/*
** Try to convert a value to a float. Check 'isinteger' first, because
** in general the float case is already handled by the macro 'tonumber'.
*/
int luaV_tonumber_ (const TValue *obj, lua_Number *n) {
TValue v;
again:
if (ttisinteger(obj)) {
*n = cast_num(ivalue(obj));
return 1;
}
else if (ttisfloat(obj)) {
*n = fltvalue(obj);
return 1;
}
else if (ttisstring(obj) && /* string convertible to number? */
luaO_str2num(svalue(obj), &v) == tsvalue(obj)->len + 1) {
obj = &v;
goto again; /* convert result from 'luaO_str2num' to a float */
}
return 0; /* conversion failed */
}
/*
** Check whether a float number is within the range of a lua_Integer.
** (The comparisons are tricky because of rounding, which can or
** not occur depending on the relative sizes of floats and integers.)
** This function should be called only when 'n' has an integral value.
*/
int luaV_numtointeger (lua_Number n, lua_Integer *p) {
if (cast_num(LUA_MININTEGER) <= n && n < (LUA_MAXINTEGER + cast_num(1))) {
*p = cast(lua_Integer, n);
lua_assert(cast_num(*p) == n);
return 1;
}
return 0; /* number is outside integer limits */
}
/*
** try to convert a value to an integer, rounding up if 'up' is true
*/
static int tointeger_aux (const TValue *obj, lua_Integer *p, int up) {
TValue v;
again:
if (ttisfloat(obj)) {
lua_Number n = fltvalue(obj);
n = (up ? -l_floor(-n) : l_floor(n));
return luaV_numtointeger(n, p);
}
else if (ttisinteger(obj)) {
*p = ivalue(obj);
return 1;
}
else if (ttisstring(obj) &&
luaO_str2num(svalue(obj), &v) == tsvalue(obj)->len + 1) {
obj = &v;
goto again; /* convert result from 'luaO_str2num' to an integer */
}
return 0; /* conversion failed */
}
/*
** try to convert a non-integer value to an integer, rounding down
*/
int luaV_tointeger_ (const TValue *obj, lua_Integer *p) {
return tointeger_aux(obj, p, 0);
}
/*
** Convert a number object to a string
*/
int luaV_tostring (lua_State *L, StkId obj) {
if (!ttisnumber(obj))
return 0;
else {
char buff[MAXNUMBER2STR];
size_t len;
if (ttisinteger(obj))
len = lua_integer2str(buff, ivalue(obj));
else {
len = lua_number2str(buff, fltvalue(obj));
#if !defined(LUA_COMPAT_FLOATSTRING)
if (buff[strspn(buff, "-0123456789")] == '\0') { /* looks like an int? */
buff[len++] = '.';
buff[len++] = '0'; /* adds '.0' to result */
}
#endif
}
setsvalue2s(L, obj, luaS_newlstr(L, buff, len));
return 1;
}
}
/*
** Try to convert a 'for' limit to an integer, preserving the
** semantics of the loop.
** (The following explanation assumes a non-negative step; it is valid
** for negative steps, mutatis mutandis.)
** If the limit can be converted to an integer, rounding down, that is
** it.
** Otherwise, check whether the limit can be converted to a number. If
** the number is too large, it is OK to set the limit as LUA_MAXINTEGER,
** which means no limit. If the number is too negative, the loop
** should not run, because any initial integer value is larger than the
** limit. So, it sets the limit to LUA_MININTEGER. 'stopnow' corrects
** the extreme case when the initial value is LUA_MININTEGER, in which
** case the LUA_MININTEGER limit would run the loop once.
*/
static int forlimit (const TValue *obj, lua_Integer *p, lua_Integer step,
int *stopnow) {
*stopnow = 0; /* usually, let loops run */
if (!tointeger_aux(obj, p, (step < 0))) { /* does not fit in integer? */
lua_Number n; /* try to convert to float */
if (!tonumber(obj, &n)) /* cannot convert to float? */
return 0; /* not a number */
if (n > 0) { /* if true, float is larger than max integer */
*p = LUA_MAXINTEGER;
if (step < 0) *stopnow = 1;
}
else { /* float is smaller than min integer */
*p = LUA_MININTEGER;
if (step >= 0) *stopnow = 1;
}
}
return 1;
}
/*
** 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");
}
/*
** 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 assginment over 'tm' */
}
luaG_runerror(L, "settable chain too long; possible loop");
}
/*
** Compare two strings 'ls' x 'rs', returning an integer smaller-equal-
** -larger than zero if 'ls' is smaller-equal-larger than 'rs'.
** The code is a little tricky because it allows '\0' in the strings
** and it uses 'strcoll' (to respect locales) for each segments
** of the strings.
*/
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 (;;) { /* for each segment */
int temp = strcoll(l, r);
if (temp != 0) /* not equal? */
return temp; /* done */
else { /* strings are equal up to a '\0' */
size_t len = strlen(l); /* index of first `\0' in both strings */
if (len == lr) /* 'rs' is finished? */
return (len == ll) ? 0 : 1; /* check 'ls' */
else if (len == ll) /* 'ls' is finished? */
return -1; /* 'ls' is smaller than 'rs' ('rs' is not finished) */
/* both strings longer than `len'; go on comparing after the '\0' */
len++;
l += len; ll -= len; r += len; lr -= len;
}
}
}
/*
** Main operation less than; return 'l < r'.
*/
int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
int res;
lua_Number nl, nr;
if (ttisinteger(l) && ttisinteger(r)) /* both operands are integers? */
return (ivalue(l) < ivalue(r));
else if (tofloat(l, &nl) && tofloat(r, &nr)) /* both are numbers? */
return luai_numlt(nl, nr);
else if (ttisstring(l) && ttisstring(r)) /* both are strings? */
return l_strcmp(rawtsvalue(l), rawtsvalue(r)) < 0;
else if ((res = luaT_callorderTM(L, l, r, TM_LT)) < 0) /* no metamethod? */
luaG_ordererror(L, l, r); /* error */
return res;
}
/*
** Main operation less than or equal to; return 'l <= r'.
*/
int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) {
int res;
lua_Number nl, nr;
if (ttisinteger(l) && ttisinteger(r)) /* both operands are integers? */
return (ivalue(l) <= ivalue(r));
else if (tofloat(l, &nl) && tofloat(r, &nr)) /* both are numbers? */
return luai_numle(nl, nr);
else if (ttisstring(l) && ttisstring(r)) /* both are strings? */
return l_strcmp(rawtsvalue(l), rawtsvalue(r)) <= 0;
else if ((res = luaT_callorderTM(L, l, r, TM_LE)) >= 0) /* first try `le' */
return res;
else if ((res = luaT_callorderTM(L, r, l, TM_LT)) < 0) /* else try `lt' */
luaG_ordererror(L, l, r);
return !res;
}
/*
** Main operation for equality of Lua values; return 't1 == t2'.
** L == NULL means raw equality (no metamethods)
*/
int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) {
const TValue *tm;
if (ttype(t1) != ttype(t2)) { /* not the same variant? */
if (ttnov(t1) != ttnov(t2) || ttnov(t1) != LUA_TNUMBER)
return 0; /* only numbers can be equal with different variants */
else { /* two numbers with different variants */
lua_Number n1, n2; /* compare them as floats */
lua_assert(ttisnumber(t1) && ttisnumber(t2));
cast_void(tofloat(t1, &n1)); cast_void(tofloat(t2, &n2));
return luai_numeq(n1, n2);
}
}
/* values have same type and same variant */
switch (ttype(t1)) {
case LUA_TNIL: return 1;
case LUA_TNUMINT: return (ivalue(t1) == ivalue(t2));
case LUA_TNUMFLT: return luai_numeq(fltvalue(t1), fltvalue(t2));
case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2); /* true must be 1 !! */
case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
case LUA_TLCF: return fvalue(t1) == fvalue(t2);
case LUA_TSHRSTR: return eqshrstr(rawtsvalue(t1), rawtsvalue(t2));
case LUA_TLNGSTR: return luaS_eqlngstr(rawtsvalue(t1), rawtsvalue(t2));
case LUA_TUSERDATA: {
if (uvalue(t1) == uvalue(t2)) return 1;
else if (L == NULL) return 0;
tm = luaT_getequalTM(L, uvalue(t1)->metatable, uvalue(t2)->metatable);
break; /* will try TM */
}
case LUA_TTABLE: {
if (hvalue(t1) == hvalue(t2)) return 1;
else if (L == NULL) return 0;
tm = luaT_getequalTM(L, hvalue(t1)->metatable, hvalue(t2)->metatable);
break; /* will try TM */
}
default:
return gcvalue(t1) == gcvalue(t2);
}
if (tm == NULL) return 0; /* no TM? */
luaT_callTM(L, tm, t1, t2, L->top, 1); /* call TM */
return !l_isfalse(L->top);
}
/* macro used by 'luaV_concat' to ensure that element at 'o' is a string */
#define tostring(L,o) (ttisstring(o) || (luaV_tostring(L, o)))
/*
** Main operation for concatenation: concat 'total' values in the stack,
** from 'L->top - total' up to 'L->top - 1'.
*/
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))
luaT_trybinTM(L, top-2, top-1, top-2, TM_CONCAT);
else if (tsvalue(top-1)->len == 0) /* second operand is empty? */
cast_void(tostring(L, top - 2)); /* result is first operand */
else if (ttisstring(top-2) && tsvalue(top-2)->len == 0) {
setobjs2s(L, top - 2, 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 (i = 1; i < total && tostring(L, top-i-1); i++) {
size_t l = tsvalue(top-i-1)->len;
if (l >= (MAX_SIZE/sizeof(char)) - tl)
luaG_runerror(L, "string length overflow");
tl += l;
}
buffer = luaZ_openspace(L, &G(L)->buff, tl);
tl = 0;
n = i;
do { /* copy all strings to buffer */
size_t l = tsvalue(top-i)->len;
memcpy(buffer+tl, svalue(top-i), l * sizeof(char));
tl += l;
} while (--i > 0);
setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl)); /* create result */
}
total -= n-1; /* got 'n' strings to create 1 new */
L->top -= n-1; /* popped 'n' strings and pushed one */
} while (total > 1); /* repeat until only 1 result left */
}
/*
** Main operation 'ra' = #rb'.
*/
void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) {
const TValue *tm;
switch (ttnov(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_TSTRING: {
setivalue(ra, 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;
}
}
luaT_callTM(L, tm, rb, rb, ra, 1);
}
/*
** Integer division; return 'm // n'.
*/
lua_Integer luaV_div (lua_State *L, lua_Integer m, lua_Integer n) {
if (l_castS2U(n) + 1u <= 1u) { /* special cases: -1 or 0 */
if (n == 0)
luaG_runerror(L, "attempt to divide by zero");
return intop(-, 0, m); /* n==-1; avoid overflow with 0x80000...//-1 */
}
else {
lua_Integer d = m / n; /* perform division */
if ((m ^ n) >= 0 || m % n == 0) /* same signal or no rest? */
return d;
else
return d - 1; /* correct 'div' for negative case */
}
}
/*
** Integer modulus; return 'm % n'.
*/
lua_Integer luaV_mod (lua_State *L, lua_Integer m, lua_Integer n) {
if (l_castS2U(n) + 1u <= 1u) { /* special cases: -1 or 0 */
if (n == 0)
luaG_runerror(L, "attempt to perform 'n%%0'");
return 0; /* m % -1 == 0; avoid overflow with 0x80000...%-1 */
}
else {
lua_Integer r = m % n;
if (r == 0 || (m ^ n) >= 0)
return r;
else
return r + n; /* correct 'mod' for negative case */
}
}
/* number of bits in an integer */
#define NBITS cast_int(sizeof(lua_Integer) * CHAR_BIT)
/*
** Shift left operation. (Shift right just negates 'y'.)
*/
lua_Integer luaV_shiftl (lua_Integer x, lua_Integer y) {
if (y < 0) { /* shift right? */
if (y <= -NBITS) return 0;
else return intop(>>, x, -y);
}
else { /* shift left */
if (y >= NBITS) return 0;
else return intop(<<, x, y);
}
}
/*
** check whether cached closure in prototype 'p' may be reused, that is,
** whether there is a cached closure with the same upvalues needed by
** new closure to be created.
*/
static Closure *getcached (Proto *p, UpVal **encup, StkId base) {
Closure *c = p->cache;
if (c != NULL) { /* is there a cached closure? */
int nup = p->sizeupvalues;
Upvaldesc *uv = p->upvalues;
int i;
for (i = 0; i < nup; i++) { /* check whether it has right upvalues */
TValue *v = uv[i].instack ? base + uv[i].idx : encup[uv[i].idx]->v;
if (c->l.upvals[i]->v != v)
return NULL; /* wrong upvalue; cannot reuse closure */
}
}
return c; /* return cached closure (or NULL if no cached closure) */
}
/*
** create a new Lua closure, push it in the stack, and initialize
** its upvalues. Note that the closure is not cached if prototype is
** already black (which means that 'cache' was already cleared by the
** GC).
*/
static void pushclosure (lua_State *L, Proto *p, UpVal **encup, StkId base,
StkId ra) {
int nup = p->sizeupvalues;
Upvaldesc *uv = p->upvalues;
int i;
Closure *ncl = luaF_newLclosure(L, nup);
ncl->l.p = p;
setclLvalue(L, ra, ncl); /* anchor new closure in stack */
for (i = 0; i < nup; i++) { /* fill in its upvalues */
if (uv[i].instack) /* upvalue refers to local variable? */
ncl->l.upvals[i] = luaF_findupval(L, base + uv[i].idx);
else /* get upvalue from enclosing function */
ncl->l.upvals[i] = encup[uv[i].idx];
ncl->l.upvals[i]->refcount++;
/* new closure is white, so we do not need a barrier here */
}
if (!isblack(obj2gco(p))) /* cache will not break GC invariant? */
p->cache = ncl; /* save it on cache for reuse */
}
/*
** 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_IDIV:
case OP_BAND: case OP_BOR: case OP_BXOR: case OP_SHL: case OP_SHR:
case OP_MOD: case OP_POW:
case OP_UNM: case OP_BNOT: 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 'luaT_trybinTM' 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);
}
}
/*
** {==================================================================
** Function 'luaV_execute': main interpreter loop
** ===================================================================
*/
/*
** some macros for common tasks in `luaV_execute'
*/
#if !defined luai_runtimecheck
#define luai_runtimecheck(L, c) /* void */
#endif
#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) \
(k + (GETARG_Bx(i) != 0 ? GETARG_Bx(i) - 1 : GETARG_Ax(*ci->u.l.savedpc++)))
/* execute a jump instruction */
#define dojump(ci,i,e) \
{ int a = GETARG_A(i); \
if (a > 0) luaF_close(L, ci->u.l.base + a - 1); \
ci->u.l.savedpc += GETARG_sBx(i) + e; }
/* for test instructions, execute the jump instruction that follows it */
#define donextjump(ci) { i = *ci->u.l.savedpc; dojump(ci, i, 1); }
#define Protect(x) { {x;}; base = ci->u.l.base; }
#define checkGC(L,c) \
Protect( luaC_condGC(L,{L->top = (c); /* limit of live values */ \
luaC_step(L); \
L->top = ci->top;}) /* restore top */ \
luai_threadyield(L); )
#define vmdispatch(o) switch(o)
#define vmcase(l,b) case l: {b} break;
#define vmcasenb(l,b) case l: {b} /* nb = no break */
void luaV_execute (lua_State *L) {
CallInfo *ci = L->ci;
LClosure *cl;
TValue *k;
StkId base;
newframe: /* reentry point when frame changes (call/return) */
lua_assert(ci == L->ci);
cl = clLvalue(ci->func);
k = cl->p->k;
base = ci->u.l.base;
/* 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)) {
Protect(luaG_traceexec(L));
}
/* 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);
vmdispatch (GET_OPCODE(i)) {
vmcase(OP_MOVE,
setobjs2s(L, ra, RB(i));
)
vmcase(OP_LOADK,
TValue *rb = k + GETARG_Bx(i);
setobj2s(L, ra, rb);
)
vmcase(OP_LOADKX,
TValue *rb;
lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG);
rb = k + GETARG_Ax(*ci->u.l.savedpc++);
setobj2s(L, ra, rb);
)
vmcase(OP_LOADBOOL,
setbvalue(ra, GETARG_B(i));
if (GETARG_C(i)) ci->u.l.savedpc++; /* skip next instruction (if C) */
)
vmcase(OP_LOADNIL,
int b = GETARG_B(i);
do {
setnilvalue(ra++);
} while (b--);
)
vmcase(OP_GETUPVAL,
int b = GETARG_B(i);
setobj2s(L, ra, cl->upvals[b]->v);
)
vmcase(OP_GETTABUP,
int b = GETARG_B(i);
Protect(luaV_gettable(L, cl->upvals[b]->v, RKC(i), ra));
)
vmcase(OP_GETTABLE,
Protect(luaV_gettable(L, RB(i), RKC(i), ra));
)
vmcase(OP_SETTABUP,
int a = GETARG_A(i);
Protect(luaV_settable(L, cl->upvals[a]->v, RKB(i), RKC(i)));
)
vmcase(OP_SETUPVAL,
UpVal *uv = cl->upvals[GETARG_B(i)];
setobj(L, uv->v, ra);
luaC_upvalbarrier(L, uv);
)
vmcase(OP_SETTABLE,
Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
)
vmcase(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));
checkGC(L, ra + 1);
)
vmcase(OP_SELF,
StkId rb = RB(i);
setobjs2s(L, ra+1, rb);
Protect(luaV_gettable(L, rb, RKC(i), ra));
)
vmcase(OP_ADD,
TValue *rb = RKB(i);
TValue *rc = RKC(i);
lua_Number nb; lua_Number nc;
if (ttisinteger(rb) && ttisinteger(rc)) {
lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc);
setivalue(ra, intop(+, ib, ic));
}
else if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
setfltvalue(ra, luai_numadd(L, nb, nc));
}
else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_ADD)); }
)
vmcase(OP_SUB,
TValue *rb = RKB(i);
TValue *rc = RKC(i);
lua_Number nb; lua_Number nc;
if (ttisinteger(rb) && ttisinteger(rc)) {
lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc);
setivalue(ra, intop(-, ib, ic));
}
else if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
setfltvalue(ra, luai_numsub(L, nb, nc));
}
else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_SUB)); }
)
vmcase(OP_MUL,
TValue *rb = RKB(i);
TValue *rc = RKC(i);
lua_Number nb; lua_Number nc;
if (ttisinteger(rb) && ttisinteger(rc)) {
lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc);
setivalue(ra, intop(*, ib, ic));
}
else if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
setfltvalue(ra, luai_nummul(L, nb, nc));
}
else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_MUL)); }
)
vmcase(OP_DIV, /* float division (always with floats) */
TValue *rb = RKB(i);
TValue *rc = RKC(i);
lua_Number nb; lua_Number nc;
if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
setfltvalue(ra, luai_numdiv(L, nb, nc));
}
else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_DIV)); }
)
vmcase(OP_IDIV, /* integer division */
TValue *rb = RKB(i);
TValue *rc = RKC(i);
lua_Integer ib; lua_Integer ic;
if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
setivalue(ra, luaV_div(L, ib, ic));
}
else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_IDIV)); }
)
vmcase(OP_BAND,
TValue *rb = RKB(i);
TValue *rc = RKC(i);
lua_Integer ib; lua_Integer ic;
if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
setivalue(ra, intop(&, ib, ic));
}
else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_BAND)); }
)
vmcase(OP_BOR,
TValue *rb = RKB(i);
TValue *rc = RKC(i);
lua_Integer ib; lua_Integer ic;
if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
setivalue(ra, intop(|, ib, ic));
}
else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_BOR)); }
)
vmcase(OP_BXOR,
TValue *rb = RKB(i);
TValue *rc = RKC(i);
lua_Integer ib; lua_Integer ic;
if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
setivalue(ra, intop(^, ib, ic));
}
else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_BXOR)); }
)
vmcase(OP_SHL,
TValue *rb = RKB(i);
TValue *rc = RKC(i);
lua_Integer ib; lua_Integer ic;
if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
setivalue(ra, luaV_shiftl(ib, ic));
}
else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_SHL)); }
)
vmcase(OP_SHR,
TValue *rb = RKB(i);
TValue *rc = RKC(i);
lua_Integer ib; lua_Integer ic;
if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
setivalue(ra, luaV_shiftl(ib, -ic));
}
else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_SHR)); }
)
vmcase(OP_MOD,
TValue *rb = RKB(i);
TValue *rc = RKC(i);
lua_Number nb; lua_Number nc;
if (ttisinteger(rb) && ttisinteger(rc)) {
lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc);
setivalue(ra, luaV_mod(L, ib, ic));
}
else if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
lua_Number m;
luai_nummod(L, nb, nc, m);
setfltvalue(ra, m);
}
else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_MOD)); }
)
vmcase(OP_POW,
TValue *rb = RKB(i);
TValue *rc = RKC(i);
lua_Number nb; lua_Number nc;
if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
setfltvalue(ra, luai_numpow(L, nb, nc));
}
else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_POW)); }
)
vmcase(OP_UNM,
TValue *rb = RB(i);
lua_Number nb;
if (ttisinteger(rb)) {
lua_Integer ib = ivalue(rb);
setivalue(ra, intop(-, 0, ib));
}
else if (tonumber(rb, &nb)) {
setfltvalue(ra, luai_numunm(L, nb));
}
else {
Protect(luaT_trybinTM(L, rb, rb, ra, TM_UNM));
}
)
vmcase(OP_BNOT,
TValue *rb = RB(i);
lua_Integer ib;
if (tointeger(rb, &ib)) {
setivalue(ra, intop(^, ~l_castS2U(0), ib));
}
else {
Protect(luaT_trybinTM(L, rb, rb, ra, TM_BNOT));
}
)
vmcase(OP_NOT,
TValue *rb = RB(i);
int res = l_isfalse(rb); /* next assignment may change this value */
setbvalue(ra, res);
)
vmcase(OP_LEN,
Protect(luaV_objlen(L, ra, RB(i)));
)
vmcase(OP_CONCAT,
int b = GETARG_B(i);
int c = GETARG_C(i);
StkId rb;
L->top = base + c + 1; /* mark the end of concat operands */
Protect(luaV_concat(L, c - b + 1));
ra = RA(i); /* 'luav_concat' may invoke TMs and move the stack */
rb = b + base;
setobjs2s(L, ra, rb);
checkGC(L, (ra >= rb ? ra + 1 : rb));
L->top = ci->top; /* restore top */
)
vmcase(OP_JMP,
dojump(ci, i, 0);
)
vmcase(OP_EQ,
TValue *rb = RKB(i);
TValue *rc = RKC(i);
Protect(
if (cast_int(luaV_equalobj(L, rb, rc)) != GETARG_A(i))
ci->u.l.savedpc++;
else
donextjump(ci);
)
)
vmcase(OP_LT,
Protect(
if (luaV_lessthan(L, RKB(i), RKC(i)) != GETARG_A(i))
ci->u.l.savedpc++;
else
donextjump(ci);
)
)
vmcase(OP_LE,
Protect(
if (luaV_lessequal(L, RKB(i), RKC(i)) != GETARG_A(i))
ci->u.l.savedpc++;
else
donextjump(ci);
)
)
vmcase(OP_TEST,
if (GETARG_C(i) ? l_isfalse(ra) : !l_isfalse(ra))
ci->u.l.savedpc++;
else
donextjump(ci);
)
vmcase(OP_TESTSET,
TValue *rb = RB(i);
if (GETARG_C(i) ? l_isfalse(rb) : !l_isfalse(rb))
ci->u.l.savedpc++;
else {
setobjs2s(L, ra, rb);
donextjump(ci);
}
)
vmcase(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;
}
else { /* Lua function */
ci = L->ci;
ci->callstatus |= CIST_REENTRY;
goto newframe; /* restart luaV_execute over new Lua function */
}
)
vmcase(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;
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->callstatus |= CIST_TAIL; /* function was tail called */
ci = L->ci = oci; /* remove new frame */
lua_assert(L->top == oci->u.l.base + getproto(ofunc)->maxstacksize);
goto newframe; /* restart luaV_execute over new Lua function */
}
)
vmcasenb(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);
goto newframe; /* restart luaV_execute over new Lua function */
}
)
vmcase(OP_FORLOOP,
if (ttisinteger(ra)) { /* integer loop? */
lua_Integer step = ivalue(ra + 2);
lua_Integer idx = ivalue(ra) + step; /* increment index */
lua_Integer limit = ivalue(ra + 1);
if ((0 < step) ? (idx <= limit) : (limit <= idx)) {
ci->u.l.savedpc += GETARG_sBx(i); /* jump back */
setivalue(ra, idx); /* update internal index... */
setivalue(ra + 3, idx); /* ...and external index */
}
}
else { /* floating loop */
lua_Number step = fltvalue(ra + 2);
lua_Number idx = luai_numadd(L, fltvalue(ra), step); /* inc. index */
lua_Number limit = fltvalue(ra + 1);
if (luai_numlt(0, step) ? luai_numle(idx, limit)
: luai_numle(limit, idx)) {
ci->u.l.savedpc += GETARG_sBx(i); /* jump back */
setfltvalue(ra, idx); /* update internal index... */
setfltvalue(ra + 3, idx); /* ...and external index */
}
}
)
vmcase(OP_FORPREP,
TValue *init = ra;
TValue *plimit = ra + 1;
TValue *pstep = ra + 2;
lua_Integer ilimit;
int stopnow;
if (ttisinteger(init) && ttisinteger(pstep) &&
forlimit(plimit, &ilimit, ivalue(pstep), &stopnow)) {
/* all values are integer */
lua_Integer initv = (stopnow ? 0 : ivalue(init));
setivalue(plimit, ilimit);
setivalue(init, initv - ivalue(pstep));
}
else { /* try making all values floats */
lua_Number ninit; lua_Number nlimit; lua_Number nstep;
if (!tonumber(plimit, &nlimit))
luaG_runerror(L, LUA_QL("for") " limit must be a number");
setfltvalue(plimit, nlimit);
if (!tonumber(pstep, &nstep))
luaG_runerror(L, LUA_QL("for") " step must be a number");
setfltvalue(pstep, nstep);
if (!tonumber(init, &ninit))
luaG_runerror(L, LUA_QL("for") " initial value must be a number");
setfltvalue(init, luai_numsub(L, ninit, nstep));
}
ci->u.l.savedpc += GETARG_sBx(i);
)
vmcasenb(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);
goto l_tforloop;
)
vmcase(OP_TFORLOOP,
l_tforloop:
if (!ttisnil(ra + 1)) { /* continue loop? */
setobjs2s(L, ra, ra + 1); /* save control variable */
ci->u.l.savedpc += GETARG_sBx(i); /* jump back */
}
)
vmcase(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++);
}
luai_runtimecheck(L, ttistable(ra));
h = hvalue(ra);
last = ((c-1)*LFIELDS_PER_FLUSH) + n;
if (last > h->sizearray) /* needs more space? */
luaH_resizearray(L, h, last); /* pre-allocate it at once */
for (; n > 0; n--) {
TValue *val = ra+n;
luaH_setint(L, h, last--, val);
luaC_barrierback(L, h, val);
}
L->top = ci->top; /* correct top (in case of previous open call) */
)
vmcase(OP_CLOSURE,
Proto *p = cl->p->p[GETARG_Bx(i)];
Closure *ncl = getcached(p, cl->upvals, base); /* cached closure */
if (ncl == NULL) /* no match? */
pushclosure(L, p, cl->upvals, base, ra); /* create a new one */
else
setclLvalue(L, ra, ncl); /* push cashed closure */
checkGC(L, ra + 1);
)
vmcase(OP_VARARG,
int b = GETARG_B(i) - 1;
int j;
int n = cast_int(base - ci->func) - cl->p->numparams - 1;
if (b < 0) { /* B == 0? */
b = n; /* get all var. arguments */
Protect(luaD_checkstack(L, n));
ra = RA(i); /* previous call may change the stack */
L->top = ra + n;
}
for (j = 0; j < b; j++) {
if (j < n) {
setobjs2s(L, ra + j, base - n + j);
}
else {
setnilvalue(ra + j);
}
}
)
vmcase(OP_EXTRAARG,
lua_assert(0);
)
}
}
}
/* }================================================================== */
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