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@roberto-ieru
Latest commit 87a9573 Oct 11, 2021 History
Better explanation about the guaranties of multiple assignment in
the manual.
1 contributor

Users who have contributed to this file

/*
** $Id: lvm.c $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
#define lvm_c
#define LUA_CORE
#include "lprefix.h"
#include <float.h>
#include <limits.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#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"
/*
** By default, use jump tables in the main interpreter loop on gcc
** and compatible compilers.
*/
#if !defined(LUA_USE_JUMPTABLE)
#if defined(__GNUC__)
#define LUA_USE_JUMPTABLE 1
#else
#define LUA_USE_JUMPTABLE 0
#endif
#endif
/* limit for table tag-method chains (to avoid infinite loops) */
#define MAXTAGLOOP 2000
/*
** 'l_intfitsf' checks whether a given integer is in the range that
** can be converted to a float without rounding. Used in comparisons.
*/
/* number of bits in the mantissa of a float */
#define NBM (l_floatatt(MANT_DIG))
/*
** Check whether some integers may not fit in a float, testing whether
** (maxinteger >> NBM) > 0. (That implies (1 << NBM) <= maxinteger.)
** (The shifts are done in parts, to avoid shifting by more than the size
** of an integer. In a worst case, NBM == 113 for long double and
** sizeof(long) == 32.)
*/
#if ((((LUA_MAXINTEGER >> (NBM / 4)) >> (NBM / 4)) >> (NBM / 4)) \
>> (NBM - (3 * (NBM / 4)))) > 0
/* limit for integers that fit in a float */
#define MAXINTFITSF ((lua_Unsigned)1 << NBM)
/* check whether 'i' is in the interval [-MAXINTFITSF, MAXINTFITSF] */
#define l_intfitsf(i) ((MAXINTFITSF + l_castS2U(i)) <= (2 * MAXINTFITSF))
#else /* all integers fit in a float precisely */
#define l_intfitsf(i) 1
#endif
/*
** Try to convert a value from string to a number value.
** If the value is not a string or is a string not representing
** a valid numeral (or if coercions from strings to numbers
** are disabled via macro 'cvt2num'), do not modify 'result'
** and return 0.
*/
static int l_strton (const TValue *obj, TValue *result) {
lua_assert(obj != result);
if (!cvt2num(obj)) /* is object not a string? */
return 0;
else
return (luaO_str2num(svalue(obj), result) == vslen(obj) + 1);
}
/*
** Try to convert a value to a float. The float case is already handled
** by the macro 'tonumber'.
*/
int luaV_tonumber_ (const TValue *obj, lua_Number *n) {
TValue v;
if (ttisinteger(obj)) {
*n = cast_num(ivalue(obj));
return 1;
}
else if (l_strton(obj, &v)) { /* string coercible to number? */
*n = nvalue(&v); /* convert result of 'luaO_str2num' to a float */
return 1;
}
else
return 0; /* conversion failed */
}
/*
** try to convert a float to an integer, rounding according to 'mode'.
*/
int luaV_flttointeger (lua_Number n, lua_Integer *p, F2Imod mode) {
lua_Number f = l_floor(n);
if (n != f) { /* not an integral value? */
if (mode == F2Ieq) return 0; /* fails if mode demands integral value */
else if (mode == F2Iceil) /* needs ceil? */
f += 1; /* convert floor to ceil (remember: n != f) */
}
return lua_numbertointeger(f, p);
}
/*
** try to convert a value to an integer, rounding according to 'mode',
** without string coercion.
** ("Fast track" handled by macro 'tointegerns'.)
*/
int luaV_tointegerns (const TValue *obj, lua_Integer *p, F2Imod mode) {
if (ttisfloat(obj))
return luaV_flttointeger(fltvalue(obj), p, mode);
else if (ttisinteger(obj)) {
*p = ivalue(obj);
return 1;
}
else
return 0;
}
/*
** try to convert a value to an integer.
*/
int luaV_tointeger (const TValue *obj, lua_Integer *p, F2Imod mode) {
TValue v;
if (l_strton(obj, &v)) /* does 'obj' point to a numerical string? */
obj = &v; /* change it to point to its corresponding number */
return luaV_tointegerns(obj, p, mode);
}
/*
** Try to convert a 'for' limit to an integer, preserving the semantics
** of the loop. Return true if the loop must not run; otherwise, '*p'
** gets the integer limit.
** (The following explanation assumes a positive step; it is valid for
** negative steps mutatis mutandis.)
** If the limit is an integer or can be converted to an integer,
** rounding down, that is the limit.
** Otherwise, check whether the limit can be converted to a float. If
** the float is too large, clip it to LUA_MAXINTEGER. If the float
** is too negative, the loop should not run, because any initial
** integer value is greater than such limit; so, the function returns
** true to signal that. (For this latter case, no integer limit would be
** correct; even a limit of LUA_MININTEGER would run the loop once for
** an initial value equal to LUA_MININTEGER.)
*/
static int forlimit (lua_State *L, lua_Integer init, const TValue *lim,
lua_Integer *p, lua_Integer step) {
if (!luaV_tointeger(lim, p, (step < 0 ? F2Iceil : F2Ifloor))) {
/* not coercible to in integer */
lua_Number flim; /* try to convert to float */
if (!tonumber(lim, &flim)) /* cannot convert to float? */
luaG_forerror(L, lim, "limit");
/* else 'flim' is a float out of integer bounds */
if (luai_numlt(0, flim)) { /* if it is positive, it is too large */
if (step < 0) return 1; /* initial value must be less than it */
*p = LUA_MAXINTEGER; /* truncate */
}
else { /* it is less than min integer */
if (step > 0) return 1; /* initial value must be greater than it */
*p = LUA_MININTEGER; /* truncate */
}
}
return (step > 0 ? init > *p : init < *p); /* not to run? */
}
/*
** Prepare a numerical for loop (opcode OP_FORPREP).
** Return true to skip the loop. Otherwise,
** after preparation, stack will be as follows:
** ra : internal index (safe copy of the control variable)
** ra + 1 : loop counter (integer loops) or limit (float loops)
** ra + 2 : step
** ra + 3 : control variable
*/
static int forprep (lua_State *L, StkId ra) {
TValue *pinit = s2v(ra);
TValue *plimit = s2v(ra + 1);
TValue *pstep = s2v(ra + 2);
if (ttisinteger(pinit) && ttisinteger(pstep)) { /* integer loop? */
lua_Integer init = ivalue(pinit);
lua_Integer step = ivalue(pstep);
lua_Integer limit;
if (step == 0)
luaG_runerror(L, "'for' step is zero");
setivalue(s2v(ra + 3), init); /* control variable */
if (forlimit(L, init, plimit, &limit, step))
return 1; /* skip the loop */
else { /* prepare loop counter */
lua_Unsigned count;
if (step > 0) { /* ascending loop? */
count = l_castS2U(limit) - l_castS2U(init);
if (step != 1) /* avoid division in the too common case */
count /= l_castS2U(step);
}
else { /* step < 0; descending loop */
count = l_castS2U(init) - l_castS2U(limit);
/* 'step+1' avoids negating 'mininteger' */
count /= l_castS2U(-(step + 1)) + 1u;
}
/* store the counter in place of the limit (which won't be
needed anymore) */
setivalue(plimit, l_castU2S(count));
}
}
else { /* try making all values floats */
lua_Number init; lua_Number limit; lua_Number step;
if (l_unlikely(!tonumber(plimit, &limit)))
luaG_forerror(L, plimit, "limit");
if (l_unlikely(!tonumber(pstep, &step)))
luaG_forerror(L, pstep, "step");
if (l_unlikely(!tonumber(pinit, &init)))
luaG_forerror(L, pinit, "initial value");
if (step == 0)
luaG_runerror(L, "'for' step is zero");
if (luai_numlt(0, step) ? luai_numlt(limit, init)
: luai_numlt(init, limit))
return 1; /* skip the loop */
else {
/* make sure internal values are all floats */
setfltvalue(plimit, limit);
setfltvalue(pstep, step);
setfltvalue(s2v(ra), init); /* internal index */
setfltvalue(s2v(ra + 3), init); /* control variable */
}
}
return 0;
}
/*
** Execute a step of a float numerical for loop, returning
** true iff the loop must continue. (The integer case is
** written online with opcode OP_FORLOOP, for performance.)
*/
static int floatforloop (StkId ra) {
lua_Number step = fltvalue(s2v(ra + 2));
lua_Number limit = fltvalue(s2v(ra + 1));
lua_Number idx = fltvalue(s2v(ra)); /* internal index */
idx = luai_numadd(L, idx, step); /* increment index */
if (luai_numlt(0, step) ? luai_numle(idx, limit)
: luai_numle(limit, idx)) {
chgfltvalue(s2v(ra), idx); /* update internal index */
setfltvalue(s2v(ra + 3), idx); /* and control variable */
return 1; /* jump back */
}
else
return 0; /* finish the loop */
}
/*
** 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 empty).
*/
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 (l_unlikely(notm(tm)))
luaG_typeerror(L, t, "index"); /* no metamethod */
/* else will try the metamethod */
}
else { /* 't' is a table */
lua_assert(isempty(slot));
tm = fasttm(L, hvalue(t)->metatable, TM_INDEX); /* table's metamethod */
if (tm == NULL) { /* no metamethod? */
setnilvalue(s2v(val)); /* result is nil */
return;
}
/* else will try the metamethod */
}
if (ttisfunction(tm)) { /* is metamethod a function? */
luaT_callTMres(L, tm, t, key, val); /* 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");
}
/*
** 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 a value with an absent key if there
** is no such entry. (The value at 'slot' must be empty, otherwise
** 'luaV_fastget' would have done the job.)
*/
void luaV_finishset (lua_State *L, const TValue *t, TValue *key,
TValue *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(isempty(slot)); /* slot must be empty */
tm = fasttm(L, h->metatable, TM_NEWINDEX); /* get metamethod */
if (tm == NULL) { /* no metamethod? */
luaH_finishset(L, h, key, slot, val); /* set new value */
invalidateTMcache(h);
luaC_barrierback(L, obj2gco(h), val);
return;
}
/* else will try the metamethod */
}
else { /* not a table; check metamethod */
tm = luaT_gettmbyobj(L, t, TM_NEWINDEX);
if (l_unlikely(notm(tm)))
luaG_typeerror(L, t, "index");
}
/* try the metamethod */
if (ttisfunction(tm)) {
luaT_callTM(L, tm, t, key, val);
return;
}
t = tm; /* else repeat assignment over 'tm' */
if (luaV_fastget(L, t, key, slot, luaH_get)) {
luaV_finishfastset(L, t, slot, val);
return; /* done */
}
/* else 'return luaV_finishset(L, t, key, val, slot)' (loop) */
}
luaG_runerror(L, "'__newindex' chain too long; possible loop");
}
/*
** Compare two strings 'ls' x 'rs', returning an integer less-equal-
** -greater than zero if 'ls' is less-equal-greater 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 = tsslen(ls);
const char *r = getstr(rs);
size_t lr = tsslen(rs);
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 less 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;
}
}
}
/*
** Check whether integer 'i' is less than float 'f'. If 'i' has an
** exact representation as a float ('l_intfitsf'), compare numbers as
** floats. Otherwise, use the equivalence 'i < f <=> i < ceil(f)'.
** If 'ceil(f)' is out of integer range, either 'f' is greater than
** all integers or less than all integers.
** (The test with 'l_intfitsf' is only for performance; the else
** case is correct for all values, but it is slow due to the conversion
** from float to int.)
** When 'f' is NaN, comparisons must result in false.
*/
l_sinline int LTintfloat (lua_Integer i, lua_Number f) {
if (l_intfitsf(i))
return luai_numlt(cast_num(i), f); /* compare them as floats */
else { /* i < f <=> i < ceil(f) */
lua_Integer fi;
if (luaV_flttointeger(f, &fi, F2Iceil)) /* fi = ceil(f) */
return i < fi; /* compare them as integers */
else /* 'f' is either greater or less than all integers */
return f > 0; /* greater? */
}
}
/*
** Check whether integer 'i' is less than or equal to float 'f'.
** See comments on previous function.
*/
l_sinline int LEintfloat (lua_Integer i, lua_Number f) {
if (l_intfitsf(i))
return luai_numle(cast_num(i), f); /* compare them as floats */
else { /* i <= f <=> i <= floor(f) */
lua_Integer fi;
if (luaV_flttointeger(f, &fi, F2Ifloor)) /* fi = floor(f) */
return i <= fi; /* compare them as integers */
else /* 'f' is either greater or less than all integers */
return f > 0; /* greater? */
}
}
/*
** Check whether float 'f' is less than integer 'i'.
** See comments on previous function.
*/
l_sinline int LTfloatint (lua_Number f, lua_Integer i) {
if (l_intfitsf(i))
return luai_numlt(f, cast_num(i)); /* compare them as floats */
else { /* f < i <=> floor(f) < i */
lua_Integer fi;
if (luaV_flttointeger(f, &fi, F2Ifloor)) /* fi = floor(f) */
return fi < i; /* compare them as integers */
else /* 'f' is either greater or less than all integers */
return f < 0; /* less? */
}
}
/*
** Check whether float 'f' is less than or equal to integer 'i'.
** See comments on previous function.
*/
l_sinline int LEfloatint (lua_Number f, lua_Integer i) {
if (l_intfitsf(i))
return luai_numle(f, cast_num(i)); /* compare them as floats */
else { /* f <= i <=> ceil(f) <= i */
lua_Integer fi;
if (luaV_flttointeger(f, &fi, F2Iceil)) /* fi = ceil(f) */
return fi <= i; /* compare them as integers */
else /* 'f' is either greater or less than all integers */
return f < 0; /* less? */
}
}
/*
** Return 'l < r', for numbers.
*/
l_sinline int LTnum (const TValue *l, const TValue *r) {
lua_assert(ttisnumber(l) && ttisnumber(r));
if (ttisinteger(l)) {
lua_Integer li = ivalue(l);
if (ttisinteger(r))
return li < ivalue(r); /* both are integers */
else /* 'l' is int and 'r' is float */
return LTintfloat(li, fltvalue(r)); /* l < r ? */
}
else {
lua_Number lf = fltvalue(l); /* 'l' must be float */
if (ttisfloat(r))
return luai_numlt(lf, fltvalue(r)); /* both are float */
else /* 'l' is float and 'r' is int */
return LTfloatint(lf, ivalue(r));
}
}
/*
** Return 'l <= r', for numbers.
*/
l_sinline int LEnum (const TValue *l, const TValue *r) {
lua_assert(ttisnumber(l) && ttisnumber(r));
if (ttisinteger(l)) {
lua_Integer li = ivalue(l);
if (ttisinteger(r))
return li <= ivalue(r); /* both are integers */
else /* 'l' is int and 'r' is float */
return LEintfloat(li, fltvalue(r)); /* l <= r ? */
}
else {
lua_Number lf = fltvalue(l); /* 'l' must be float */
if (ttisfloat(r))
return luai_numle(lf, fltvalue(r)); /* both are float */
else /* 'l' is float and 'r' is int */
return LEfloatint(lf, ivalue(r));
}
}
/*
** return 'l < r' for non-numbers.
*/
static int lessthanothers (lua_State *L, const TValue *l, const TValue *r) {
lua_assert(!ttisnumber(l) || !ttisnumber(r));
if (ttisstring(l) && ttisstring(r)) /* both are strings? */
return l_strcmp(tsvalue(l), tsvalue(r)) < 0;
else
return luaT_callorderTM(L, l, r, TM_LT);
}
/*
** Main operation less than; return 'l < r'.
*/
int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
if (ttisnumber(l) && ttisnumber(r)) /* both operands are numbers? */
return LTnum(l, r);
else return lessthanothers(L, l, r);
}
/*
** return 'l <= r' for non-numbers.
*/
static int lessequalothers (lua_State *L, const TValue *l, const TValue *r) {
lua_assert(!ttisnumber(l) || !ttisnumber(r));
if (ttisstring(l) && ttisstring(r)) /* both are strings? */
return l_strcmp(tsvalue(l), tsvalue(r)) <= 0;
else
return luaT_callorderTM(L, l, r, TM_LE);
}
/*
** Main operation less than or equal to; return 'l <= r'.
*/
int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) {
if (ttisnumber(l) && ttisnumber(r)) /* both operands are numbers? */
return LEnum(l, r);
else return lessequalothers(L, l, r);
}
/*
** 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 (ttypetag(t1) != ttypetag(t2)) { /* not the same variant? */
if (ttype(t1) != ttype(t2) || ttype(t1) != LUA_TNUMBER)
return 0; /* only numbers can be equal with different variants */
else { /* two numbers with different variants */
/* One of them is an integer. If the other does not have an
integer value, they cannot be equal; otherwise, compare their
integer values. */
lua_Integer i1, i2;
return (luaV_tointegerns(t1, &i1, F2Ieq) &&
luaV_tointegerns(t2, &i2, F2Ieq) &&
i1 == i2);
}
}
/* values have same type and same variant */
switch (ttypetag(t1)) {
case LUA_VNIL: case LUA_VFALSE: case LUA_VTRUE: return 1;
case LUA_VNUMINT: return (ivalue(t1) == ivalue(t2));
case LUA_VNUMFLT: return luai_numeq(fltvalue(t1), fltvalue(t2));
case LUA_VLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
case LUA_VLCF: return fvalue(t1) == fvalue(t2);
case LUA_VSHRSTR: return eqshrstr(tsvalue(t1), tsvalue(t2));
case LUA_VLNGSTR: return luaS_eqlngstr(tsvalue(t1), tsvalue(t2));
case LUA_VUSERDATA: {
if (uvalue(t1) == uvalue(t2)) return 1;
else if (L == NULL) return 0;
tm = fasttm(L, uvalue(t1)->metatable, TM_EQ);
if (tm == NULL)
tm = fasttm(L, uvalue(t2)->metatable, TM_EQ);
break; /* will try TM */
}
case LUA_VTABLE: {
if (hvalue(t1) == hvalue(t2)) return 1;
else if (L == NULL) return 0;
tm = fasttm(L, hvalue(t1)->metatable, TM_EQ);
if (tm == NULL)
tm = fasttm(L, hvalue(t2)->metatable, TM_EQ);
break; /* will try TM */
}
default:
return gcvalue(t1) == gcvalue(t2);
}
if (tm == NULL) /* no TM? */
return 0; /* objects are different */
else {
luaT_callTMres(L, tm, t1, t2, L->top); /* call TM */
return !l_isfalse(s2v(L->top));
}
}
/* macro used by 'luaV_concat' to ensure that element at 'o' is a string */
#define tostring(L,o) \
(ttisstring(o) || (cvt2str(o) && (luaO_tostring(L, o), 1)))
#define isemptystr(o) (ttisshrstring(o) && tsvalue(o)->shrlen == 0)
/* copy strings in stack from top - n up to top - 1 to buffer */
static void copy2buff (StkId top, int n, char *buff) {
size_t tl = 0; /* size already copied */
do {
size_t l = vslen(s2v(top - n)); /* length of string being copied */
memcpy(buff + tl, svalue(s2v(top - n)), l * sizeof(char));
tl += l;
} while (--n > 0);
}
/*
** 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) {
if (total == 1)
return; /* "all" values already concatenated */
do {
StkId top = L->top;
int n = 2; /* number of elements handled in this pass (at least 2) */
if (!(ttisstring(s2v(top - 2)) || cvt2str(s2v(top - 2))) ||
!tostring(L, s2v(top - 1)))
luaT_tryconcatTM(L);
else if (isemptystr(s2v(top - 1))) /* second operand is empty? */
cast_void(tostring(L, s2v(top - 2))); /* result is first operand */
else if (isemptystr(s2v(top - 2))) { /* first operand is empty string? */
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 = vslen(s2v(top - 1));
TString *ts;
/* collect total length and number of strings */
for (n = 1; n < total && tostring(L, s2v(top - n - 1)); n++) {
size_t l = vslen(s2v(top - n - 1));
if (l_unlikely(l >= (MAX_SIZE/sizeof(char)) - tl))
luaG_runerror(L, "string length overflow");
tl += l;
}
if (tl <= LUAI_MAXSHORTLEN) { /* is result a short string? */
char buff[LUAI_MAXSHORTLEN];
copy2buff(top, n, buff); /* copy strings to buffer */
ts = luaS_newlstr(L, buff, tl);
}
else { /* long string; copy strings directly to final result */
ts = luaS_createlngstrobj(L, tl);
copy2buff(top, n, getstr(ts));
}
setsvalue2s(L, top - n, ts); /* 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 (ttypetag(rb)) {
case LUA_VTABLE: {
Table *h = hvalue(rb);
tm = fasttm(L, h->metatable, TM_LEN);
if (tm) break; /* metamethod? break switch to call it */
setivalue(s2v(ra), luaH_getn(h)); /* else primitive len */
return;
}
case LUA_VSHRSTR: {
setivalue(s2v(ra), tsvalue(rb)->shrlen);
return;
}
case LUA_VLNGSTR: {
setivalue(s2v(ra), tsvalue(rb)->u.lnglen);
return;
}
default: { /* try metamethod */
tm = luaT_gettmbyobj(L, rb, TM_LEN);
if (l_unlikely(notm(tm))) /* no metamethod? */
luaG_typeerror(L, rb, "get length of");
break;
}
}
luaT_callTMres(L, tm, rb, rb, ra);
}
/*
** Integer division; return 'm // n', that is, floor(m/n).
** C division truncates its result (rounds towards zero).
** 'floor(q) == trunc(q)' when 'q >= 0' or when 'q' is integer,
** otherwise 'floor(q) == trunc(q) - 1'.
*/
lua_Integer luaV_idiv (lua_State *L, lua_Integer m, lua_Integer n) {
if (l_unlikely(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 q = m / n; /* perform C division */
if ((m ^ n) < 0 && m % n != 0) /* 'm/n' would be negative non-integer? */
q -= 1; /* correct result for different rounding */
return q;
}
}
/*
** Integer modulus; return 'm % n'. (Assume that C '%' with
** negative operands follows C99 behavior. See previous comment
** about luaV_idiv.)
*/
lua_Integer luaV_mod (lua_State *L, lua_Integer m, lua_Integer n) {
if (l_unlikely(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 && (r ^ n) < 0) /* 'm/n' would be non-integer negative? */
r += n; /* correct result for different rounding */
return r;
}
}
/*
** Float modulus
*/
lua_Number luaV_modf (lua_State *L, lua_Number m, lua_Number n) {
lua_Number r;
luai_nummod(L, m, n, r);
return r;
}
/* number of bits in an integer */
#define NBITS cast_int(sizeof(lua_Integer) * CHAR_BIT)
/*
** Shift left operation. (Shift right just negates 'y'.)
*/
#define luaV_shiftr(x,y) luaV_shiftl(x,intop(-, 0, 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);
}
}
/*
** create a new Lua closure, push it in the stack, and initialize
** its upvalues.
*/
static void pushclosure (lua_State *L, Proto *p, UpVal **encup, StkId base,
StkId ra) {
int nup = p->sizeupvalues;
Upvaldesc *uv = p->upvalues;
int i;
LClosure *ncl = luaF_newLclosure(L, nup);
ncl->p = p;
setclLvalue2s(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->upvals[i] = luaF_findupval(L, base + uv[i].idx);
else /* get upvalue from enclosing function */
ncl->upvals[i] = encup[uv[i].idx];
luaC_objbarrier(L, ncl, ncl->upvals[i]);
}
}
/*
** finish execution of an opcode interrupted by a yield
*/
void luaV_finishOp (lua_State *L) {
CallInfo *ci = L->ci;
StkId base = ci->func + 1;
Instruction inst = *(ci->u.l.savedpc - 1); /* interrupted instruction */
OpCode op = GET_OPCODE(inst);
switch (op) { /* finish its execution */
case OP_MMBIN: case OP_MMBINI: case OP_MMBINK: {
setobjs2s(L, base + GETARG_A(*(ci->u.l.savedpc - 2)), --L->top);
break;
}
case OP_UNM: case OP_BNOT: case OP_LEN:
case OP_GETTABUP: case OP_GETTABLE: case OP_GETI:
case OP_GETFIELD: case OP_SELF: {
setobjs2s(L, base + GETARG_A(inst), --L->top);
break;
}
case OP_LT: case OP_LE:
case OP_LTI: case OP_LEI:
case OP_GTI: case OP_GEI:
case OP_EQ: { /* note that 'OP_EQI'/'OP_EQK' cannot yield */
int res = !l_isfalse(s2v(L->top - 1));
L->top--;
#if defined(LUA_COMPAT_LT_LE)
if (ci->callstatus & CIST_LEQ) { /* "<=" using "<" instead? */
ci->callstatus ^= CIST_LEQ; /* clear mark */
res = !res; /* negate result */
}
#endif
lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_JMP);
if (res != GETARG_k(inst)) /* condition failed? */
ci->u.l.savedpc++; /* skip jump instruction */
break;
}
case OP_CONCAT: {
StkId top = L->top - 1; /* top when 'luaT_tryconcatTM' was called */
int a = GETARG_A(inst); /* first element to concatenate */
int total = cast_int(top - 1 - (base + a)); /* yet to concatenate */
setobjs2s(L, top - 2, top); /* put TM result in proper position */
L->top = top - 1; /* top is one after last element (at top-2) */
luaV_concat(L, total); /* concat them (may yield again) */
break;
}
case OP_CLOSE: { /* yielded closing variables */
ci->u.l.savedpc--; /* repeat instruction to close other vars. */
break;
}
case OP_RETURN: { /* yielded closing variables */
StkId ra = base + GETARG_A(inst);
/* adjust top to signal correct number of returns, in case the
return is "up to top" ('isIT') */
L->top = ra + ci->u2.nres;
/* repeat instruction to close other vars. and complete the return */
ci->u.l.savedpc--;
break;
}
default: {
/* only these other opcodes can yield */
lua_assert(op == OP_TFORCALL || op == OP_CALL ||
op == OP_TAILCALL || op == OP_SETTABUP || op == OP_SETTABLE ||
op == OP_SETI || op == OP_SETFIELD);
break;
}
}
}
/*
** {==================================================================
** Macros for arithmetic/bitwise/comparison opcodes in 'luaV_execute'
** ===================================================================
*/
#define l_addi(L,a,b) intop(+, a, b)
#define l_subi(L,a,b) intop(-, a, b)
#define l_muli(L,a,b) intop(*, a, b)
#define l_band(a,b) intop(&, a, b)
#define l_bor(a,b) intop(|, a, b)
#define l_bxor(a,b) intop(^, a, b)
#define l_lti(a,b) (a < b)
#define l_lei(a,b) (a <= b)
#define l_gti(a,b) (a > b)
#define l_gei(a,b) (a >= b)
/*
** Arithmetic operations with immediate operands. 'iop' is the integer
** operation, 'fop' is the float operation.
*/
#define op_arithI(L,iop,fop) { \
TValue *v1 = vRB(i); \
int imm = GETARG_sC(i); \
if (ttisinteger(v1)) { \
lua_Integer iv1 = ivalue(v1); \
pc++; setivalue(s2v(ra), iop(L, iv1, imm)); \
} \
else if (ttisfloat(v1)) { \
lua_Number nb = fltvalue(v1); \
lua_Number fimm = cast_num(imm); \
pc++; setfltvalue(s2v(ra), fop(L, nb, fimm)); \
}}
/*
** Auxiliary function for arithmetic operations over floats and others
** with two register operands.
*/
#define op_arithf_aux(L,v1,v2,fop) { \
lua_Number n1; lua_Number n2; \
if (tonumberns(v1, n1) && tonumberns(v2, n2)) { \
pc++; setfltvalue(s2v(ra), fop(L, n1, n2)); \
}}
/*
** Arithmetic operations over floats and others with register operands.
*/
#define op_arithf(L,fop) { \
TValue *v1 = vRB(i); \
TValue *v2 = vRC(i); \
op_arithf_aux(L, v1, v2, fop); }
/*
** Arithmetic operations with K operands for floats.
*/
#define op_arithfK(L,fop) { \
TValue *v1 = vRB(i); \
TValue *v2 = KC(i); lua_assert(ttisnumber(v2)); \
op_arithf_aux(L, v1, v2, fop); }
/*
** Arithmetic operations over integers and floats.
*/
#define op_arith_aux(L,v1,v2,iop,fop) { \
if (ttisinteger(v1) && ttisinteger(v2)) { \
lua_Integer i1 = ivalue(v1); lua_Integer i2 = ivalue(v2); \
pc++; setivalue(s2v(ra), iop(L, i1, i2)); \
} \
else op_arithf_aux(L, v1, v2, fop); }
/*
** Arithmetic operations with register operands.
*/
#define op_arith(L,iop,fop) { \
TValue *v1 = vRB(i); \
TValue *v2 = vRC(i); \
op_arith_aux(L, v1, v2, iop, fop); }
/*
** Arithmetic operations with K operands.
*/
#define op_arithK(L,iop,fop) { \
TValue *v1 = vRB(i); \
TValue *v2 = KC(i); lua_assert(ttisnumber(v2)); \
op_arith_aux(L, v1, v2, iop, fop); }
/*
** Bitwise operations with constant operand.
*/
#define op_bitwiseK(L,op) { \
TValue *v1 = vRB(i); \
TValue *v2 = KC(i); \
lua_Integer i1; \
lua_Integer i2 = ivalue(v2); \
if (tointegerns(v1, &i1)) { \
pc++; setivalue(s2v(ra), op(i1, i2)); \
}}
/*
** Bitwise operations with register operands.
*/
#define op_bitwise(L,op) { \
TValue *v1 = vRB(i); \
TValue *v2 = vRC(i); \
lua_Integer i1; lua_Integer i2; \
if (tointegerns(v1, &i1) && tointegerns(v2, &i2)) { \
pc++; setivalue(s2v(ra), op(i1, i2)); \
}}
/*
** Order operations with register operands. 'opn' actually works
** for all numbers, but the fast track improves performance for
** integers.
*/
#define op_order(L,opi,opn,other) { \
int cond; \
TValue *rb = vRB(i); \
if (ttisinteger(s2v(ra)) && ttisinteger(rb)) { \
lua_Integer ia = ivalue(s2v(ra)); \
lua_Integer ib = ivalue(rb); \
cond = opi(ia, ib); \
} \
else if (ttisnumber(s2v(ra)) && ttisnumber(rb)) \
cond = opn(s2v(ra), rb); \
else \
Protect(cond = other(L, s2v(ra), rb)); \
docondjump(); }
/*
** Order operations with immediate operand. (Immediate operand is
** always small enough to have an exact representation as a float.)
*/
#define op_orderI(L,opi,opf,inv,tm) { \
int cond; \
int im = GETARG_sB(i); \
if (ttisinteger(s2v(ra))) \
cond = opi(ivalue(s2v(ra)), im); \
else if (ttisfloat(s2v(ra))) { \
lua_Number fa = fltvalue(s2v(ra)); \
lua_Number fim = cast_num(im); \
cond = opf(fa, fim); \
} \
else { \
int isf = GETARG_C(i); \
Protect(cond = luaT_callorderiTM(L, s2v(ra), im, inv, isf, tm)); \
} \
docondjump(); }
/* }================================================================== */
/*
** {==================================================================
** Function 'luaV_execute': main interpreter loop
** ===================================================================
*/
/*
** some macros for common tasks in 'luaV_execute'
*/
#define RA(i) (base+GETARG_A(i))
#define RB(i) (base+GETARG_B(i))
#define vRB(i) s2v(RB(i))
#define KB(i) (k+GETARG_B(i))
#define RC(i) (base+GETARG_C(i))
#define vRC(i) s2v(RC(i))
#define KC(i) (k+GETARG_C(i))
#define RKC(i) ((TESTARG_k(i)) ? k + GETARG_C(i) : s2v(base + GETARG_C(i)))
#define updatetrap(ci) (trap = ci->u.l.trap)
#define updatebase(ci) (base = ci->func + 1)
#define updatestack(ci) \
{ if (l_unlikely(trap)) { updatebase(ci); ra = RA(i); } }
/*
** Execute a jump instruction. The 'updatetrap' allows signals to stop
** tight loops. (Without it, the local copy of 'trap' could never change.)
*/
#define dojump(ci,i,e) { pc += GETARG_sJ(i) + e; updatetrap(ci); }
/* for test instructions, execute the jump instruction that follows it */
#define donextjump(ci) { Instruction ni = *pc; dojump(ci, ni, 1); }
/*
** do a conditional jump: skip next instruction if 'cond' is not what
** was expected (parameter 'k'), else do next instruction, which must
** be a jump.
*/
#define docondjump() if (cond != GETARG_k(i)) pc++; else donextjump(ci);
/*
** Correct global 'pc'.
*/
#define savepc(L) (ci->u.l.savedpc = pc)
/*
** Whenever code can raise errors, the global 'pc' and the global
** 'top' must be correct to report occasional errors.
*/
#define savestate(L,ci) (savepc(L), L->top = ci->top)
/*
** Protect code that, in general, can raise errors, reallocate the
** stack, and change the hooks.
*/
#define Protect(exp) (savestate(L,ci), (exp), updatetrap(ci))
/* special version that does not change the top */
#define ProtectNT(exp) (savepc(L), (exp), updatetrap(ci))
/*
** Protect code that can only raise errors. (That is, it cannot change
** the stack or hooks.)
*/
#define halfProtect(exp) (savestate(L,ci), (exp))
/* 'c' is the limit of live values in the stack */
#define checkGC(L,c) \
{ luaC_condGC(L, (savepc(L), L->top = (c)), \
updatetrap(ci)); \
luai_threadyield(L); }
/* fetch an instruction and prepare its execution */
#define vmfetch() { \
if (l_unlikely(trap)) { /* stack reallocation or hooks? */ \
trap = luaG_traceexec(L, pc); /* handle hooks */ \
updatebase(ci); /* correct stack */ \
} \
i = *(pc++); \
ra = RA(i); /* WARNING: any stack reallocation invalidates 'ra' */ \
}
#define vmdispatch(o) switch(o)
#define vmcase(l) case l:
#define vmbreak break
void luaV_execute (lua_State *L, CallInfo *ci) {
LClosure *cl;
TValue *k;
StkId base;
const Instruction *pc;
int trap;
#if LUA_USE_JUMPTABLE
#include "ljumptab.h"
#endif
startfunc:
trap = L->hookmask;
returning: /* trap already set */
cl = clLvalue(s2v(ci->func));
k = cl->p->k;
pc = ci->u.l.savedpc;
if (l_unlikely(trap)) {
if (pc == cl->p->code) { /* first instruction (not resuming)? */
if (cl->p->is_vararg)
trap = 0; /* hooks will start after VARARGPREP instruction */
else /* check 'call' hook */
luaD_hookcall(L, ci);
}
ci->u.l.trap = 1; /* assume trap is on, for now */
}
base = ci->func + 1;
/* main loop of interpreter */
for (;;) {
Instruction i; /* instruction being executed */
StkId ra; /* instruction's A register */
vmfetch();
#if 0
/* low-level line tracing for debugging Lua */
printf("line: %d\n", luaG_getfuncline(cl->p, pcRel(pc, cl->p)));
#endif
lua_assert(base == ci->func + 1);
lua_assert(base <= L->top && L->top < L->stack_last);
/* invalidate top for instructions not expecting it */
lua_assert(isIT(i) || (cast_void(L->top = base), 1));
vmdispatch (GET_OPCODE(i)) {
vmcase(OP_MOVE) {
setobjs2s(L, ra, RB(i));
vmbreak;
}
vmcase(OP_LOADI) {
lua_Integer b = GETARG_sBx(i);
setivalue(s2v(ra), b);
vmbreak;
}
vmcase(OP_LOADF) {
int b = GETARG_sBx(i);
setfltvalue(s2v(ra), cast_num(b));
vmbreak;
}
vmcase(OP_LOADK) {
TValue *rb = k + GETARG_Bx(i);
setobj2s(L, ra, rb);
vmbreak;
}
vmcase(OP_LOADKX) {
TValue *rb;
rb = k + GETARG_Ax(*pc); pc++;
setobj2s(L, ra, rb);
vmbreak;
}
vmcase(OP_LOADFALSE) {
setbfvalue(s2v(ra));
vmbreak;
}
vmcase(OP_LFALSESKIP) {
setbfvalue(s2v(ra));
pc++; /* skip next instruction */
vmbreak;
}
vmcase(OP_LOADTRUE) {
setbtvalue(s2v(ra));
vmbreak;
}
vmcase(OP_LOADNIL) {
int b = GETARG_B(i);
do {
setnilvalue(s2v(ra++));
} while (b--);
vmbreak;
}
vmcase(OP_GETUPVAL) {
int b = GETARG_B(i);
setobj2s(L, ra, cl->upvals[b]->v);
vmbreak;
}
vmcase(OP_SETUPVAL) {
UpVal *uv = cl->upvals[GETARG_B(i)];
setobj(L, uv->v, s2v(ra));
luaC_barrier(L, uv, s2v(ra));
vmbreak;
}
vmcase(OP_GETTABUP) {
const TValue *slot;
TValue *upval = cl->upvals[GETARG_B(i)]->v;
TValue *rc = KC(i);
TString *key = tsvalue(rc); /* key must be a string */
if (luaV_fastget(L, upval, key, slot, luaH_getshortstr)) {
setobj2s(L, ra, slot);
}
else
Protect(luaV_finishget(L, upval, rc, ra, slot));
vmbreak;
}
vmcase(OP_GETTABLE) {
const TValue *slot;
TValue *rb = vRB(i);
TValue *rc = vRC(i);
lua_Unsigned n;
if (ttisinteger(rc) /* fast track for integers? */
? (cast_void(n = ivalue(rc)), luaV_fastgeti(L, rb, n, slot))
: luaV_fastget(L, rb, rc, slot, luaH_get)) {
setobj2s(L, ra, slot);
}
else
Protect(luaV_finishget(L, rb, rc, ra, slot));
vmbreak;
}
vmcase(OP_GETI) {
const TValue *slot;
TValue *rb = vRB(i);
int c = GETARG_C(i);
if (luaV_fastgeti(L, rb, c, slot)) {
setobj2s(L, ra, slot);
}
else {
TValue key;
setivalue(&key, c);
Protect(luaV_finishget(L, rb, &key, ra, slot));
}
vmbreak;
}
vmcase(OP_GETFIELD) {
const TValue *slot;
TValue *rb = vRB(i);
TValue *rc = KC(i);
TString *key = tsvalue(rc); /* key must be a string */
if (luaV_fastget(L, rb, key, slot, luaH_getshortstr)) {
setobj2s(L, ra, slot);
}
else
Protect(luaV_finishget(L, rb, rc, ra, slot));
vmbreak;
}
vmcase(OP_SETTABUP) {
const TValue *slot;
TValue *upval = cl->upvals[GETARG_A(i)]->v;
TValue *rb = KB(i);
TValue *rc = RKC(i);
TString *key = tsvalue(rb); /* key must be a string */
if (luaV_fastget(L, upval, key, slot, luaH_getshortstr)) {
luaV_finishfastset(L, upval, slot, rc);
}
else
Protect(luaV_finishset(L, upval, rb, rc, slot));
vmbreak;
}
vmcase(OP_SETTABLE) {
const TValue *slot;
TValue *rb = vRB(i); /* key (table is in 'ra') */
TValue *rc = RKC(i); /* value */
lua_Unsigned n;
if (ttisinteger(rb) /* fast track for integers? */
? (cast_void(n = ivalue(rb)), luaV_fastgeti(L, s2v(ra), n, slot))
: luaV_fastget(L, s2v(ra), rb, slot, luaH_get)) {
luaV_finishfastset(L, s2v(ra), slot, rc);
}
else
Protect(luaV_finishset(L, s2v(ra), rb, rc, slot));
vmbreak;
}
vmcase(OP_SETI) {
const TValue *slot;
int c = GETARG_B(i);
TValue *rc = RKC(i);
if (luaV_fastgeti(L, s2v(ra), c, slot)) {
luaV_finishfastset(L, s2v(ra), slot, rc);
}
else {
TValue key;
setivalue(&key, c);
Protect(luaV_finishset(L, s2v(ra), &key, rc, slot));
}
vmbreak;
}
vmcase(OP_SETFIELD) {
const TValue *slot;
TValue *rb = KB(i);
TValue *rc = RKC(i);
TString *key = tsvalue(rb); /* key must be a string */
if (luaV_fastget(L, s2v(ra), key, slot, luaH_getshortstr)) {
luaV_finishfastset(L, s2v(ra), slot, rc);
}
else
Protect(luaV_finishset(L, s2v(ra), rb, rc, slot));
vmbreak;
}
vmcase(OP_NEWTABLE) {
int b = GETARG_B(i); /* log2(hash size) + 1 */
int c = GETARG_C(i); /* array size */
Table *t;
if (b > 0)
b = 1 << (b - 1); /* size is 2^(b - 1) */
lua_assert((!TESTARG_k(i)) == (GETARG_Ax(*pc) == 0));
if (TESTARG_k(i)) /* non-zero extra argument? */
c += GETARG_Ax(*pc) * (MAXARG_C + 1); /* add it to size */
pc++; /* skip extra argument */
L->top = ra + 1; /* correct top in case of emergency GC */
t = luaH_new(L); /* memory allocation */
sethvalue2s(L, ra, t);
if (b != 0 || c != 0)
luaH_resize(L, t, c, b); /* idem */
checkGC(L, ra + 1);
vmbreak;
}
vmcase(OP_SELF) {
const TValue *slot;
TValue *rb = vRB(i);
TValue *rc = RKC(i);
TString *key = tsvalue(rc); /* key must be a string */
setobj2s(L, ra + 1, rb);
if (luaV_fastget(L, rb, key, slot, luaH_getstr)) {
setobj2s(L, ra, slot);
}
else
Protect(luaV_finishget(L, rb, rc, ra, slot));
vmbreak;
}
vmcase(OP_ADDI) {
op_arithI(L, l_addi, luai_numadd);
vmbreak;
}
vmcase(OP_ADDK) {
op_arithK(L, l_addi, luai_numadd);
vmbreak;
}
vmcase(OP_SUBK) {
op_arithK(L, l_subi, luai_numsub);
vmbreak;
}
vmcase(OP_MULK) {
op_arithK(L, l_muli, luai_nummul);
vmbreak;
}
vmcase(OP_MODK) {
op_arithK(L, luaV_mod, luaV_modf);
vmbreak;
}
vmcase(OP_POWK) {
op_arithfK(L, luai_numpow);
vmbreak;
}
vmcase(OP_DIVK) {
op_arithfK(L, luai_numdiv);
vmbreak;
}
vmcase(OP_IDIVK) {
op_arithK(L, luaV_idiv, luai_numidiv);
vmbreak;
}
vmcase(OP_BANDK) {
op_bitwiseK(L, l_band);
vmbreak;
}
vmcase(OP_BORK) {
op_bitwiseK(L, l_bor);
vmbreak;
}
vmcase(OP_BXORK) {
op_bitwiseK(L, l_bxor);
vmbreak;
}
vmcase(OP_SHRI) {
TValue *rb = vRB(i);
int ic = GETARG_sC(i);
lua_Integer ib;
if (tointegerns(rb, &ib)) {
pc++; setivalue(s2v(ra), luaV_shiftl(ib, -ic));
}
vmbreak;
}
vmcase(OP_SHLI) {
TValue *rb = vRB(i);
int ic = GETARG_sC(i);
lua_Integer ib;
if (tointegerns(rb, &ib)) {
pc++; setivalue(s2v(ra), luaV_shiftl(ic, ib));
}
vmbreak;
}
vmcase(OP_ADD) {
op_arith(L, l_addi, luai_numadd);
vmbreak;
}
vmcase(OP_SUB) {
op_arith(L, l_subi, luai_numsub);
vmbreak;
}
vmcase(OP_MUL) {
op_arith(L, l_muli, luai_nummul);
vmbreak;
}
vmcase(OP_MOD) {
op_arith(L, luaV_mod, luaV_modf);
vmbreak;
}
vmcase(OP_POW) {
op_arithf(L, luai_numpow);
vmbreak;
}
vmcase(OP_DIV) { /* float division (always with floats) */
op_arithf(L, luai_numdiv);
vmbreak;
}
vmcase(OP_IDIV) { /* floor division */
op_arith(L, luaV_idiv, luai_numidiv);
vmbreak;
}
vmcase(OP_BAND) {
op_bitwise(L, l_band);
vmbreak;
}
vmcase(OP_BOR) {
op_bitwise(L, l_bor);
vmbreak;
}
vmcase(OP_BXOR) {
op_bitwise(L, l_bxor);
vmbreak;
}
vmcase(OP_SHR) {
op_bitwise(L, luaV_shiftr);
vmbreak;
}
vmcase(OP_SHL) {
op_bitwise(L, luaV_shiftl);
vmbreak;
}
vmcase(OP_MMBIN) {
Instruction pi = *(pc - 2); /* original arith. expression */
TValue *rb = vRB(i);
TMS tm = (TMS)GETARG_C(i);
StkId result = RA(pi);
lua_assert(OP_ADD <= GET_OPCODE(pi) && GET_OPCODE(pi) <= OP_SHR);
Protect(luaT_trybinTM(L, s2v(ra), rb, result, tm));
vmbreak;
}
vmcase(OP_MMBINI) {
Instruction pi = *(pc - 2); /* original arith. expression */
int imm = GETARG_sB(i);
TMS tm = (TMS)GETARG_C(i);
int flip = GETARG_k(i);
StkId result = RA(pi);
Protect(luaT_trybiniTM(L, s2v(ra), imm, flip, result, tm));
vmbreak;
}
vmcase(OP_MMBINK) {
Instruction pi = *(pc - 2); /* original arith. expression */
TValue *imm = KB(i);
TMS tm = (TMS)GETARG_C(i);
int flip = GETARG_k(i);
StkId result = RA(pi);
Protect(luaT_trybinassocTM(L, s2v(ra), imm, flip, result, tm));
vmbreak;
}
vmcase(OP_UNM) {
TValue *rb = vRB(i);
lua_Number nb;
if (ttisinteger(rb)) {
lua_Integer ib = ivalue(rb);
setivalue(s2v(ra), intop(-, 0, ib));
}
else if (tonumberns(rb, nb)) {
setfltvalue(s2v(ra), luai_numunm(L, nb));
}
else
Protect(luaT_trybinTM(L, rb, rb, ra, TM_UNM));
vmbreak;
}
vmcase(OP_BNOT) {
TValue *rb = vRB(i);
lua_Integer ib;
if (tointegerns(rb, &ib)) {
setivalue(s2v(ra), intop(^, ~l_castS2U(0), ib));
}
else
Protect(luaT_trybinTM(L, rb, rb, ra, TM_BNOT));
vmbreak;
}
vmcase(OP_NOT) {
TValue *rb = vRB(i);
if (l_isfalse(rb))
setbtvalue(s2v(ra));
else
setbfvalue(s2v(ra));
vmbreak;
}
vmcase(OP_LEN) {
Protect(luaV_objlen(L, ra, vRB(i)));
vmbreak;
}
vmcase(OP_CONCAT) {
int n = GETARG_B(i); /* number of elements to concatenate */
L->top = ra + n; /* mark the end of concat operands */
ProtectNT(luaV_concat(L, n));
checkGC(L, L->top); /* 'luaV_concat' ensures correct top */
vmbreak;
}
vmcase(OP_CLOSE) {
Protect(luaF_close(L, ra, LUA_OK, 1));
vmbreak;
}
vmcase(OP_TBC) {
/* create new to-be-closed upvalue */
halfProtect(luaF_newtbcupval(L, ra));
vmbreak;
}
vmcase(OP_JMP) {
dojump(ci, i, 0);
vmbreak;
}
vmcase(OP_EQ) {
int cond;
TValue *rb = vRB(i);
Protect(cond = luaV_equalobj(L, s2v(ra), rb));
docondjump();
vmbreak;
}
vmcase(OP_LT) {
op_order(L, l_lti, LTnum, lessthanothers);
vmbreak;
}
vmcase(OP_LE) {
op_order(L, l_lei, LEnum, lessequalothers);
vmbreak;
}
vmcase(OP_EQK) {
TValue *rb = KB(i);
/* basic types do not use '__eq'; we can use raw equality */
int cond = luaV_rawequalobj(s2v(ra), rb);
docondjump();
vmbreak;
}
vmcase(OP_EQI) {
int cond;
int im = GETARG_sB(i);
if (ttisinteger(s2v(ra)))
cond = (ivalue(s2v(ra)) == im);
else if (ttisfloat(s2v(ra)))
cond = luai_numeq(fltvalue(s2v(ra)), cast_num(im));
else
cond = 0; /* other types cannot be equal to a number */
docondjump();
vmbreak;
}
vmcase(OP_LTI) {
op_orderI(L, l_lti, luai_numlt, 0, TM_LT);
vmbreak;
}
vmcase(OP_LEI) {
op_orderI(L, l_lei, luai_numle, 0, TM_LE);
vmbreak;
}
vmcase(OP_GTI) {
op_orderI(L, l_gti, luai_numgt, 1, TM_LT);
vmbreak;
}
vmcase(OP_GEI) {
op_orderI(L, l_gei, luai_numge, 1, TM_LE);
vmbreak;
}
vmcase(OP_TEST) {
int cond = !l_isfalse(s2v(ra));
docondjump();
vmbreak;
}
vmcase(OP_TESTSET) {
TValue *rb = vRB(i);
if (l_isfalse(rb) == GETARG_k(i))
pc++;
else {
setobj2s(L, ra, rb);
donextjump(ci);
}
vmbreak;
}
vmcase(OP_CALL) {
CallInfo *newci;
int b = GETARG_B(i);
int nresults = GETARG_C(i) - 1;
if (b != 0) /* fixed number of arguments? */
L->top = ra + b; /* top signals number of arguments */
/* else previous instruction set top */
savepc(L); /* in case of errors */
if ((newci = luaD_precall(L, ra, nresults)) == NULL)
updatetrap(ci); /* C call; nothing else to be done */
else { /* Lua call: run function in this same C frame */
ci = newci;
goto startfunc;
}
vmbreak;
}
vmcase(OP_TAILCALL) {
int b = GETARG_B(i); /* number of arguments + 1 (function) */
int nparams1 = GETARG_C(i);
/* delta is virtual 'func' - real 'func' (vararg functions) */
int delta = (nparams1) ? ci->u.l.nextraargs + nparams1 : 0;
if (b != 0)
L->top = ra + b;
else /* previous instruction set top */
b = cast_int(L->top - ra);
savepc(ci); /* several calls here can raise errors */
if (TESTARG_k(i)) {
luaF_closeupval(L, base); /* close upvalues from current call */
lua_assert(L->tbclist < base); /* no pending tbc variables */
lua_assert(base == ci->func + 1);
}
while (!ttisfunction(s2v(ra))) { /* not a function? */
ra = luaD_tryfuncTM(L, ra); /* try '__call' metamethod */
b++; /* there is now one extra argument */
}
if (!ttisLclosure(s2v(ra))) { /* C function? */
luaD_precall(L, ra, LUA_MULTRET); /* call it */
updatetrap(ci);
updatestack(ci); /* stack may have been relocated */
ci->func -= delta; /* restore 'func' (if vararg) */
luaD_poscall(L, ci, cast_int(L->top - ra)); /* finish caller */
updatetrap(ci); /* 'luaD_poscall' can change hooks */
goto ret; /* caller returns after the tail call */
}
else { /* Lua function */
ci->func -= delta; /* restore 'func' (if vararg) */
luaD_pretailcall(L, ci, ra, b); /* prepare call frame */
goto startfunc; /* execute the callee */
}
}
vmcase(OP_RETURN) {
int n = GETARG_B(i) - 1; /* number of results */
int nparams1 = GETARG_C(i);
if (n < 0) /* not fixed? */
n = cast_int(L->top - ra); /* get what is available */
savepc(ci);
if (TESTARG_k(i)) { /* may there be open upvalues? */
ci->u2.nres = n; /* save number of returns */
if (L->top < ci->top)
L->top = ci->top;
luaF_close(L, base, CLOSEKTOP, 1);
updatetrap(ci);
updatestack(ci);
}
if (nparams1) /* vararg function? */
ci->func -= ci->u.l.nextraargs + nparams1;
L->top = ra + n; /* set call for 'luaD_poscall' */
luaD_poscall(L, ci, n);
updatetrap(ci); /* 'luaD_poscall' can change hooks */
goto ret;
}
vmcase(OP_RETURN0) {
if (l_unlikely(L->hookmask)) {
L->top = ra;
savepc(ci);
luaD_poscall(L, ci, 0); /* no hurry... */
trap = 1;
}
else { /* do the 'poscall' here */
int nres;
L->ci = ci->previous; /* back to caller */
L->top = base - 1;
for (nres = ci->nresults; l_unlikely(nres > 0); nres--)
setnilvalue(s2v(L->top++)); /* all results are nil */
}
goto ret;
}
vmcase(OP_RETURN1) {
if (l_unlikely(L->hookmask)) {
L->top = ra + 1;
savepc(ci);
luaD_poscall(L, ci, 1); /* no hurry... */
trap = 1;
}
else { /* do the 'poscall' here */
int nres = ci->nresults;
L->ci = ci->previous; /* back to caller */
if (nres == 0)
L->top = base - 1; /* asked for no results */
else {
setobjs2s(L, base - 1, ra); /* at least this result */
L->top = base;
for (; l_unlikely(nres > 1); nres--)
setnilvalue(s2v(L->top++)); /* complete missing results */
}
}
ret: /* return from a Lua function */
if (ci->callstatus & CIST_FRESH)
return; /* end this frame */
else {
ci = ci->previous;
goto returning; /* continue running caller in this frame */
}
}
vmcase(OP_FORLOOP) {
if (ttisinteger(s2v(ra + 2))) { /* integer loop? */
lua_Unsigned count = l_castS2U(ivalue(s2v(ra + 1)));
if (count > 0) { /* still more iterations? */
lua_Integer step = ivalue(s2v(ra + 2));
lua_Integer idx = ivalue(s2v(ra)); /* internal index */
chgivalue(s2v(ra + 1), count - 1); /* update counter */
idx = intop(+, idx, step); /* add step to index */
chgivalue(s2v(ra), idx); /* update internal index */
setivalue(s2v(ra + 3), idx); /* and control variable */
pc -= GETARG_Bx(i); /* jump back */
}
}
else if (floatforloop(ra)) /* float loop */
pc -= GETARG_Bx(i); /* jump back */
updatetrap(ci); /* allows a signal to break the loop */
vmbreak;
}
vmcase(OP_FORPREP) {
savestate(L, ci); /* in case of errors */
if (forprep(L, ra))
pc += GETARG_Bx(i) + 1; /* skip the loop */
vmbreak;
}
vmcase(OP_TFORPREP) {
/* create to-be-closed upvalue (if needed) */
halfProtect(luaF_newtbcupval(L, ra + 3));
pc += GETARG_Bx(i);
i = *(pc++); /* go to next instruction */
lua_assert(GET_OPCODE(i) == OP_TFORCALL && ra == RA(i));
goto l_tforcall;
}
vmcase(OP_TFORCALL) {
l_tforcall:
/* 'ra' has the iterator function, 'ra + 1' has the state,
'ra + 2' has the control variable, and 'ra + 3' has the
to-be-closed variable. The call will use the stack after
these values (starting at 'ra + 4')
*/
/* push function, state, and control variable */
memcpy(ra + 4, ra, 3 * sizeof(*ra));
L->top = ra + 4 + 3;
ProtectNT(luaD_call(L, ra + 4, GETARG_C(i))); /* do the call */
updatestack(ci); /* stack may have changed */
i = *(pc++); /* go to next instruction */
lua_assert(GET_OPCODE(i) == OP_TFORLOOP && ra == RA(i));
goto l_tforloop;
}
vmcase(OP_TFORLOOP) {
l_tforloop:
if (!ttisnil(s2v(ra + 4))) { /* continue loop? */
setobjs2s(L, ra + 2, ra + 4); /* save control variable */
pc -= GETARG_Bx(i); /* jump back */
}
vmbreak;
}
vmcase(OP_SETLIST) {
int n = GETARG_B(i);
unsigned int last = GETARG_C(i);
Table *h = hvalue(s2v(ra));
if (n == 0)
n = cast_int(L->top - ra) - 1; /* get up to the top */
else
L->top = ci->top; /* correct top in case of emergency GC */
last += n;
if (TESTARG_k(i)) {
last += GETARG_Ax(*pc) * (MAXARG_C + 1);
pc++;
}
if (last > luaH_realasize(h)) /* needs more space? */
luaH_resizearray(L, h, last); /* preallocate it at once */
for (; n > 0; n--) {
TValue *val = s2v(ra + n);
setobj2t(L, &h->array[last - 1], val);
last--;
luaC_barrierback(L, obj2gco(h), val);
}
vmbreak;
}
vmcase(OP_CLOSURE) {
Proto *p = cl->p->p[GETARG_Bx(i)];
halfProtect(pushclosure(L, p, cl->upvals, base, ra));
checkGC(L, ra + 1);
vmbreak;
}
vmcase(OP_VARARG) {
int n = GETARG_C(i) - 1; /* required results */
Protect(luaT_getvarargs(L, ci, ra, n));
vmbreak;
}
vmcase(OP_VARARGPREP) {
ProtectNT(luaT_adjustvarargs(L, GETARG_A(i), ci, cl->p));
if (l_unlikely(trap)) { /* previous "Protect" updated trap */
luaD_hookcall(L, ci);
L->oldpc = 1; /* next opcode will be seen as a "new" line */
}
updatebase(ci); /* function has new base after adjustment */
vmbreak;
}
vmcase(OP_EXTRAARG) {
lua_assert(0);
vmbreak;
}
}
}
}
/* }================================================================== */