/* ** $Id: lvm.c $ ** Lua virtual machine ** See Copyright Notice in lua.h */ #define lvm_c #define LUA_CORE #include "lprefix.h" #include #include #include #include #include #include #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': ** mode == 0: accepts only integral values ** mode == 1: takes the floor of the number ** mode == 2: takes the ceil of the number */ int luaV_flttointeger (lua_Number n, lua_Integer *p, int mode) { lua_Number f = l_floor(n); if (n != f) { /* not an integral value? */ if (mode == 0) return 0; /* fails if mode demands integral value */ else if (mode == 2) /* 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, int 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, int 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 ? 2 : 1))) { /* 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 (unlikely(!tonumber(plimit, &limit))) luaG_forerror(L, plimit, "limit"); if (unlikely(!tonumber(pstep, &step))) luaG_forerror(L, pstep, "step"); if (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 (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? */ if (isabstkey(slot)) /* no previous entry? */ slot = luaH_newkey(L, h, key); /* create one */ /* no metamethod and (now) there is an entry with given key */ setobj2t(L, cast(TValue *, slot), val); /* set its new value */ invalidateTMcache(h); luaC_barrierback(L, obj2gco(h), val); return; } /* else will try the metamethod */ } else { /* not a table; check metamethod */ tm = luaT_gettmbyobj(L, t, TM_NEWINDEX); if (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. */ static 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, 2)) /* 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. */ static 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, 1)) /* 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. */ static 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, 1)) /* 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. */ static 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, 2)) /* 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. */ static 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. */ static 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. ** If it needs a metamethod and there is no '__le', try '__lt', based ** on l <= r iff !(r < l) (assuming a total order). If the metamethod ** yields during this substitution, the continuation has to know about ** it (to negate the result of rmetatable, TM_EQ); if (tm == NULL) tm = fasttm(L, uvalue(t2)->metatable, TM_EQ); break; /* will try TM */ } case LUA_TTABLE: { 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) { lua_assert(total >= 2); 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 (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_TTABLE: { 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_TSHRSTR: { setivalue(s2v(ra), tsvalue(rb)->shrlen); return; } case LUA_TLNGSTR: { setivalue(s2v(ra), tsvalue(rb)->u.lnglen); return; } default: { /* try metamethod */ tm = luaT_gettmbyobj(L, rb, TM_LEN); if (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 (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 (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,-(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 */ 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) */ } 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) /* ** Auxiliary macro for arithmetic operations over floats and others ** with immediate operand. 'fop' is the float operation; 'tm' is the ** corresponding metamethod. */ #define op_arithfI_aux(L,v1,imm,fop,tm) { \ lua_Number nb; \ if (tonumberns(v1, nb)) { \ lua_Number fimm = cast_num(imm); \ pc++; setfltvalue(s2v(ra), fop(L, nb, fimm)); \ }} /* ** Arithmetic operations over floats and others with immediate operand. */ #define op_arithfI(L,fop,tm) { \ TValue *v1 = vRB(i); \ int imm = GETARG_sC(i); \ op_arithfI_aux(L, v1, imm, fop, tm, 0); } /* ** Arithmetic operations with immediate operands. 'iop' is the integer ** operation. */ #define op_arithI(L,iop,fop,tm) { \ 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 op_arithfI_aux(L, v1, imm, fop, tm); } /* ** 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 register operands. */ #define op_arith(L,iop,fop) { \ TValue *v1 = vRB(i); \ TValue *v2 = vRC(i); \ 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 K operands. */ #define op_arithK(L,iop,fop) { \ TValue *v1 = vRB(i); \ TValue *v2 = KC(i); \ if (ttisinteger(v1) && ttisinteger(v2)) { \ lua_Integer i1 = ivalue(v1); lua_Integer i2 = ivalue(v2); \ pc++; setivalue(s2v(ra), iop(L, i1, i2)); \ } \ else { \ lua_Number n1; lua_Number n2; \ if (tonumberns(v1, n1) && tonumberns(v2, n2)) { \ pc++; setfltvalue(s2v(ra), fop(L, n1, n2)); \ }}} /* ** Arithmetic operations with K operands for floats. */ #define op_arithfK(L,fop) { \ TValue *v1 = vRB(i); \ TValue *v2 = KC(i); \ lua_Number n1; lua_Number n2; \ if (tonumberns(v1, n1) && tonumberns(v2, n2)) { \ pc++; setfltvalue(s2v(ra), fop(L, n1, n2)); \ }} /* ** 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. */ #define op_order(L,opi,opf,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 = opf(s2v(ra), rb); \ else \ Protect(cond = other(L, s2v(ra), rb)); \ docondjump(); } /* ** Order operations with immediate operand. */ #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 (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 will finish the loop (returns) or can only raise ** errors. (That is, it will not return to the interpreter main loop ** after changing the stack or hooks.) */ #define halfProtect(exp) (savestate(L,ci), (exp)) /* idem, but without changing the stack */ #define halfProtectNT(exp) (savepc(L), (exp)) #define checkGC(L,c) \ { luaC_condGC(L, L->top = (c), /* limit of live values */ \ updatetrap(ci)); \ luai_threadyield(L); } /* fetch an instruction and prepare its execution */ #define vmfetch() { \ if (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 tailcall: trap = L->hookmask; cl = clLvalue(s2v(ci->func)); k = cl->p->k; pc = ci->u.l.savedpc; if (trap) { if (cl->p->is_vararg) trap = 0; /* hooks will start after VARARGPREP instruction */ else if (pc == cl->p->code) /* first instruction (not resuming)? */ luaD_hookcall(L, ci); ci->u.l.trap = 1; /* there may be other hooks */ } base = ci->func + 1; /* main loop of interpreter */ for (;;) { Instruction i; /* instruction being executed */ StkId ra; /* instruction's A register */ vmfetch(); lua_assert(base == ci->func + 1); lua_assert(base <= L->top && L->top < L->stack + L->stacksize); /* 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_LOADBOOL) { setbvalue(s2v(ra), GETARG_B(i)); if (GETARG_C(i)) pc++; /* skip next instruction (if C) */ 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) */ if (TESTARG_k(i)) c += GETARG_Ax(*pc) * (MAXARG_C + 1); 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, TM_ADD); 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); int nrb = l_isfalse(rb); /* next assignment may change this value */ setbvalue(s2v(ra), nrb); 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)); 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_equalobj(NULL, 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) { 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 */ ProtectNT(luaD_call(L, ra, nresults)); vmbreak; } vmcase(OP_TAILCALL) { int b = GETARG_B(i); /* number of arguments + 1 (function) */ int nparams1 = GETARG_C(i); /* delat 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); /* some calls here can raise errors */ if (TESTARG_k(i)) { /* close upvalues from current call; the compiler ensures that there are no to-be-closed variables here, so this call cannot change the stack */ luaF_close(L, base, NOCLOSINGMETH); lua_assert(base == ci->func + 1); } while (!ttisfunction(s2v(ra))) { /* not a function? */ luaD_tryfuncTM(L, ra); /* try '__call' metamethod */ b++; /* there is now one extra argument */ checkstackp(L, 1, ra); } if (!ttisLclosure(s2v(ra))) { /* C function? */ luaD_call(L, ra, LUA_MULTRET); /* call it */ updatetrap(ci); updatestack(ci); /* stack may have been relocated */ ci->func -= delta; luaD_poscall(L, ci, cast_int(L->top - ra)); return; } ci->func -= delta; luaD_pretailcall(L, ci, ra, b); /* prepare call frame */ goto tailcall; } 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? */ if (L->top < ci->top) L->top = ci->top; luaF_close(L, base, LUA_OK); 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); return; } vmcase(OP_RETURN0) { if (L->hookmask) { L->top = ra; halfProtectNT(luaD_poscall(L, ci, 0)); /* no hurry... */ } else { /* do the 'poscall' here */ int nres = ci->nresults; L->ci = ci->previous; /* back to caller */ L->top = base - 1; while (nres-- > 0) setnilvalue(s2v(L->top++)); /* all results are nil */ } return; } vmcase(OP_RETURN1) { if (L->hookmask) { L->top = ra + 1; halfProtectNT(luaD_poscall(L, ci, 1)); /* no hurry... */ } 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; while (--nres > 0) /* complete missing results */ setnilvalue(s2v(L->top++)); } } return; } 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) { luaT_adjustvarargs(L, GETARG_A(i), ci, cl->p); updatetrap(ci); if (trap) { luaD_hookcall(L, ci); L->oldpc = pc + 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; } } } } /* }================================================================== */