/* ** $Id: lvm.c,v 2.155.1.1 2013/04/12 18:48:47 roberto Exp $ ** Lua virtual machine ** See Copyright Notice in lua.h */ #include #include #include #define lvm_c #define LUA_CORE #include "lua.h" #include "ldebug.h" #include "ldo.h" #include "lfunc.h" #include "lgc.h" #include "lobject.h" #include "lopcodes.h" #include "lstate.h" #include "lstring.h" #include "ltable.h" #include "ltm.h" #include "lvm.h" /* limit for table tag-method chains (to avoid loops) */ #define MAXTAGLOOP 100 const TValue *luaV_tonumber (const TValue *obj, TValue *n) { lua_Number num; if (ttisnumber(obj)) return obj; if (ttisstring(obj) && luaO_str2d(svalue(obj), tsvalue(obj)->len, &num)) { setnvalue(n, num); return n; } else return NULL; } int luaV_tostring (lua_State *L, StkId obj) { if (!ttisnumber(obj)) return 0; else { char s[LUAI_MAXNUMBER2STR]; lua_Number n = nvalue(obj); int l = lua_number2str(s, n); setsvalue2s(L, obj, luaS_newlstr(L, s, l)); return 1; } } static void traceexec (lua_State *L) { CallInfo *ci = L->ci; lu_byte mask = L->hookmask; int counthook = ((mask & LUA_MASKCOUNT) && L->hookcount == 0); if (counthook) resethookcount(L); /* reset count */ if (ci->callstatus & CIST_HOOKYIELD) { /* called hook last time? */ ci->callstatus &= ~CIST_HOOKYIELD; /* erase mark */ return; /* do not call hook again (VM yielded, so it did not move) */ } if (counthook) luaD_hook(L, LUA_HOOKCOUNT, -1); /* call count hook */ if (mask & LUA_MASKLINE) { Proto *p = ci_func(ci)->p; int npc = pcRel(ci->u.l.savedpc, p); int newline = getfuncline(p, npc); if (npc == 0 || /* call linehook when enter a new function, */ ci->u.l.savedpc <= L->oldpc || /* when jump back (loop), or when */ newline != getfuncline(p, pcRel(L->oldpc, p))) /* enter a new line */ luaD_hook(L, LUA_HOOKLINE, newline); /* call line hook */ } L->oldpc = ci->u.l.savedpc; if (L->status == LUA_YIELD) { /* did hook yield? */ if (counthook) L->hookcount = 1; /* undo decrement to zero */ ci->u.l.savedpc--; /* undo increment (resume will increment it again) */ ci->callstatus |= CIST_HOOKYIELD; /* mark that it yielded */ ci->func = L->top - 1; /* protect stack below results */ luaD_throw(L, LUA_YIELD); } } static void callTM (lua_State *L, const TValue *f, const TValue *p1, const TValue *p2, TValue *p3, int hasres) { ptrdiff_t result = savestack(L, p3); setobj2s(L, L->top++, f); /* push function */ setobj2s(L, L->top++, p1); /* 1st argument */ setobj2s(L, L->top++, p2); /* 2nd argument */ if (!hasres) /* no result? 'p3' is third argument */ setobj2s(L, L->top++, p3); /* 3rd argument */ /* metamethod may yield only when called from Lua code */ luaD_call(L, L->top - (4 - hasres), hasres, isLua(L->ci)); if (hasres) { /* if has result, move it to its place */ p3 = restorestack(L, result); setobjs2s(L, p3, --L->top); } } void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) { int loop; for (loop = 0; loop < MAXTAGLOOP; loop++) { const TValue *tm; if (ttistable(t)) { /* `t' is a table? */ Table *h = hvalue(t); const TValue *res = luaH_get(h, key); /* do a primitive get */ if (!ttisnil(res) || /* result is not nil? */ (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */ setobj2s(L, val, res); return; } /* else will try the tag method */ } else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX))) luaG_typeerror(L, t, "index"); if (ttisfunction(tm)) { callTM(L, tm, t, key, val, 1); return; } t = tm; /* else repeat with 'tm' */ } luaG_runerror(L, "loop in gettable"); } void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) { int loop; for (loop = 0; loop < MAXTAGLOOP; loop++) { const TValue *tm; if (ttistable(t)) { /* `t' is a table? */ Table *h = hvalue(t); TValue *oldval = cast(TValue *, luaH_get(h, key)); /* if previous value is not nil, there must be a previous entry in the table; moreover, a metamethod has no relevance */ if (!ttisnil(oldval) || /* previous value is nil; must check the metamethod */ ((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL && /* no metamethod; is there a previous entry in the table? */ (oldval != luaO_nilobject || /* no previous entry; must create one. (The next test is always true; we only need the assignment.) */ (oldval = luaH_newkey(L, h, key), 1)))) { /* no metamethod and (now) there is an entry with given key */ setobj2t(L, oldval, val); /* assign new value to that entry */ invalidateTMcache(h); luaC_barrierback(L, obj2gco(h), val); return; } /* else will try the metamethod */ } else /* not a table; check metamethod */ if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX))) luaG_typeerror(L, t, "index"); /* there is a metamethod */ if (ttisfunction(tm)) { callTM(L, tm, t, key, val, 0); return; } t = tm; /* else repeat with 'tm' */ } luaG_runerror(L, "loop in settable"); } static int call_binTM (lua_State *L, const TValue *p1, const TValue *p2, StkId res, TMS event) { const TValue *tm = luaT_gettmbyobj(L, p1, event); /* try first operand */ if (ttisnil(tm)) tm = luaT_gettmbyobj(L, p2, event); /* try second operand */ if (ttisnil(tm)) return 0; callTM(L, tm, p1, p2, res, 1); return 1; } static const TValue *get_equalTM (lua_State *L, Table *mt1, Table *mt2, TMS event) { const TValue *tm1 = fasttm(L, mt1, event); const TValue *tm2; if (tm1 == NULL) return NULL; /* no metamethod */ if (mt1 == mt2) return tm1; /* same metatables => same metamethods */ tm2 = fasttm(L, mt2, event); if (tm2 == NULL) return NULL; /* no metamethod */ if (luaV_rawequalobj(tm1, tm2)) /* same metamethods? */ return tm1; return NULL; } static int call_orderTM (lua_State *L, const TValue *p1, const TValue *p2, TMS event) { if (!call_binTM(L, p1, p2, L->top, event)) return -1; /* no metamethod */ else return !l_isfalse(L->top); } static int l_strcmp (const TString *ls, const TString *rs) { const char *l = getstr(ls); size_t ll = ls->tsv.len; const char *r = getstr(rs); size_t lr = rs->tsv.len; for (;;) { int temp = strcoll(l, r); if (temp != 0) return temp; else { /* strings are equal up to a `\0' */ size_t len = strlen(l); /* index of first `\0' in both strings */ if (len == lr) /* r is finished? */ return (len == ll) ? 0 : 1; else if (len == ll) /* l is finished? */ return -1; /* l is smaller than r (because r is not finished) */ /* both strings longer than `len'; go on comparing (after the `\0') */ len++; l += len; ll -= len; r += len; lr -= len; } } } int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) { int res; if (ttisnumber(l) && ttisnumber(r)) return luai_numlt(L, nvalue(l), nvalue(r)); else if (ttisstring(l) && ttisstring(r)) return l_strcmp(rawtsvalue(l), rawtsvalue(r)) < 0; else if ((res = call_orderTM(L, l, r, TM_LT)) < 0) luaG_ordererror(L, l, r); return res; } int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) { int res; if (ttisnumber(l) && ttisnumber(r)) return luai_numle(L, nvalue(l), nvalue(r)); else if (ttisstring(l) && ttisstring(r)) return l_strcmp(rawtsvalue(l), rawtsvalue(r)) <= 0; else if ((res = call_orderTM(L, l, r, TM_LE)) >= 0) /* first try `le' */ return res; else if ((res = call_orderTM(L, r, l, TM_LT)) < 0) /* else try `lt' */ luaG_ordererror(L, l, r); return !res; } /* ** equality of Lua values. L == NULL means raw equality (no metamethods) */ int luaV_equalobj_ (lua_State *L, const TValue *t1, const TValue *t2) { const TValue *tm; lua_assert(ttisequal(t1, t2)); switch (ttype(t1)) { case LUA_TNIL: return 1; case LUA_TNUMBER: return luai_numeq(nvalue(t1), nvalue(t2)); case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2); /* true must be 1 !! */ case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2); case LUA_TLCF: return fvalue(t1) == fvalue(t2); case LUA_TSHRSTR: return eqshrstr(rawtsvalue(t1), rawtsvalue(t2)); case LUA_TLNGSTR: return luaS_eqlngstr(rawtsvalue(t1), rawtsvalue(t2)); case LUA_TUSERDATA: { if (uvalue(t1) == uvalue(t2)) return 1; else if (L == NULL) return 0; tm = get_equalTM(L, uvalue(t1)->metatable, 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 = get_equalTM(L, hvalue(t1)->metatable, hvalue(t2)->metatable, TM_EQ); break; /* will try TM */ } default: lua_assert(iscollectable(t1)); return gcvalue(t1) == gcvalue(t2); } if (tm == NULL) return 0; /* no TM? */ callTM(L, tm, t1, t2, L->top, 1); /* call TM */ return !l_isfalse(L->top); } void luaV_concat (lua_State *L, int total) { lua_assert(total >= 2); do { StkId top = L->top; int n = 2; /* number of elements handled in this pass (at least 2) */ if (!(ttisstring(top-2) || ttisnumber(top-2)) || !tostring(L, top-1)) { if (!call_binTM(L, top-2, top-1, top-2, TM_CONCAT)) luaG_concaterror(L, top-2, top-1); } else if (tsvalue(top-1)->len == 0) /* second operand is empty? */ (void)tostring(L, top - 2); /* result is first operand */ else if (ttisstring(top-2) && tsvalue(top-2)->len == 0) { setobjs2s(L, top - 2, top - 1); /* result is second op. */ } else { /* at least two non-empty string values; get as many as possible */ size_t tl = tsvalue(top-1)->len; char *buffer; int i; /* collect total length */ for (i = 1; i < total && tostring(L, top-i-1); i++) { size_t l = tsvalue(top-i-1)->len; if (l >= (MAX_SIZET/sizeof(char)) - tl) luaG_runerror(L, "string length overflow"); tl += l; } buffer = luaZ_openspace(L, &G(L)->buff, tl); tl = 0; n = i; do { /* concat all strings */ size_t l = tsvalue(top-i)->len; memcpy(buffer+tl, svalue(top-i), l * sizeof(char)); tl += l; } while (--i > 0); setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl)); } 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 */ } void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) { const TValue *tm; switch (ttypenv(rb)) { case LUA_TTABLE: { Table *h = hvalue(rb); tm = fasttm(L, h->metatable, TM_LEN); if (tm) break; /* metamethod? break switch to call it */ setnvalue(ra, cast_num(luaH_getn(h))); /* else primitive len */ return; } case LUA_TSTRING: { setnvalue(ra, cast_num(tsvalue(rb)->len)); return; } default: { /* try metamethod */ tm = luaT_gettmbyobj(L, rb, TM_LEN); if (ttisnil(tm)) /* no metamethod? */ luaG_typeerror(L, rb, "get length of"); break; } } callTM(L, tm, rb, rb, ra, 1); } void luaV_arith (lua_State *L, StkId ra, const TValue *rb, const TValue *rc, TMS op) { TValue tempb, tempc; const TValue *b, *c; if ((b = luaV_tonumber(rb, &tempb)) != NULL && (c = luaV_tonumber(rc, &tempc)) != NULL) { lua_Number res = luaO_arith(op - TM_ADD + LUA_OPADD, nvalue(b), nvalue(c)); setnvalue(ra, res); } else if (!call_binTM(L, rb, rc, ra, op)) luaG_aritherror(L, rb, rc); } /* ** check whether cached closure in prototype 'p' may be reused, that is, ** whether there is a cached closure with the same upvalues needed by ** new closure to be created. */ static Closure *getcached (Proto *p, UpVal **encup, StkId base) { Closure *c = p->cache; if (c != NULL) { /* is there a cached closure? */ int nup = p->sizeupvalues; Upvaldesc *uv = p->upvalues; int i; for (i = 0; i < nup; i++) { /* check whether it has right upvalues */ TValue *v = uv[i].instack ? base + uv[i].idx : encup[uv[i].idx]->v; if (c->l.upvals[i]->v != v) return NULL; /* wrong upvalue; cannot reuse closure */ } } return c; /* return cached closure (or NULL if no cached closure) */ } /* ** create a new Lua closure, push it in the stack, and initialize ** its upvalues. Note that the call to 'luaC_barrierproto' must come ** before the assignment to 'p->cache', as the function needs the ** original value of that field. */ static void pushclosure (lua_State *L, Proto *p, UpVal **encup, StkId base, StkId ra) { int nup = p->sizeupvalues; Upvaldesc *uv = p->upvalues; int i; Closure *ncl = luaF_newLclosure(L, nup); ncl->l.p = p; setclLvalue(L, ra, ncl); /* anchor new closure in stack */ for (i = 0; i < nup; i++) { /* fill in its upvalues */ if (uv[i].instack) /* upvalue refers to local variable? */ ncl->l.upvals[i] = luaF_findupval(L, base + uv[i].idx); else /* get upvalue from enclosing function */ ncl->l.upvals[i] = encup[uv[i].idx]; } luaC_barrierproto(L, p, ncl); p->cache = ncl; /* save it on cache for reuse */ } /* ** finish execution of an opcode interrupted by an yield */ void luaV_finishOp (lua_State *L) { CallInfo *ci = L->ci; StkId base = ci->u.l.base; Instruction inst = *(ci->u.l.savedpc - 1); /* interrupted instruction */ OpCode op = GET_OPCODE(inst); switch (op) { /* finish its execution */ case OP_ADD: case OP_SUB: case OP_MUL: case OP_DIV: case OP_MOD: case OP_POW: case OP_UNM: case OP_LEN: case OP_GETTABUP: case OP_GETTABLE: case OP_SELF: { setobjs2s(L, base + GETARG_A(inst), --L->top); break; } case OP_LE: case OP_LT: case OP_EQ: { int res = !l_isfalse(L->top - 1); L->top--; /* metamethod should not be called when operand is K */ lua_assert(!ISK(GETARG_B(inst))); if (op == OP_LE && /* "<=" using "<" instead? */ ttisnil(luaT_gettmbyobj(L, base + GETARG_B(inst), TM_LE))) res = !res; /* invert result */ lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_JMP); if (res != GETARG_A(inst)) /* condition failed? */ ci->u.l.savedpc++; /* skip jump instruction */ break; } case OP_CONCAT: { StkId top = L->top - 1; /* top when 'call_binTM' was called */ int b = GETARG_B(inst); /* first element to concatenate */ int total = cast_int(top - 1 - (base + b)); /* yet to concatenate */ setobj2s(L, top - 2, top); /* put TM result in proper position */ if (total > 1) { /* are there elements to concat? */ L->top = top - 1; /* top is one after last element (at top-2) */ luaV_concat(L, total); /* concat them (may yield again) */ } /* move final result to final position */ setobj2s(L, ci->u.l.base + GETARG_A(inst), L->top - 1); L->top = ci->top; /* restore top */ break; } case OP_TFORCALL: { lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_TFORLOOP); L->top = ci->top; /* correct top */ break; } case OP_CALL: { if (GETARG_C(inst) - 1 >= 0) /* nresults >= 0? */ L->top = ci->top; /* adjust results */ break; } case OP_TAILCALL: case OP_SETTABUP: case OP_SETTABLE: break; default: lua_assert(0); } } /* ** some macros for common tasks in `luaV_execute' */ #if !defined luai_runtimecheck #define luai_runtimecheck(L, c) /* void */ #endif #define RA(i) (base+GETARG_A(i)) /* to be used after possible stack reallocation */ #define RB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i)) #define RC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i)) #define RKB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \ ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i)) #define RKC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \ ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i)) #define KBx(i) \ (k + (GETARG_Bx(i) != 0 ? GETARG_Bx(i) - 1 : GETARG_Ax(*ci->u.l.savedpc++))) /* execute a jump instruction */ #define dojump(ci,i,e) \ { int a = GETARG_A(i); \ if (a > 0) luaF_close(L, ci->u.l.base + a - 1); \ ci->u.l.savedpc += GETARG_sBx(i) + e; } /* for test instructions, execute the jump instruction that follows it */ #define donextjump(ci) { i = *ci->u.l.savedpc; dojump(ci, i, 1); } #define Protect(x) { {x;}; base = ci->u.l.base; } #define checkGC(L,c) \ Protect( luaC_condGC(L,{L->top = (c); /* limit of live values */ \ luaC_step(L); \ L->top = ci->top;}) /* restore top */ \ luai_threadyield(L); ) #define arith_op(op,tm) { \ TValue *rb = RKB(i); \ TValue *rc = RKC(i); \ if (ttisnumber(rb) && ttisnumber(rc)) { \ lua_Number nb = nvalue(rb), nc = nvalue(rc); \ setnvalue(ra, op(L, nb, nc)); \ } \ else { Protect(luaV_arith(L, ra, rb, rc, tm)); } } #define vmdispatch(o) switch(o) #define vmcase(l,b) case l: {b} break; #define vmcasenb(l,b) case l: {b} /* nb = no break */ void luaV_execute (lua_State *L) { CallInfo *ci = L->ci; LClosure *cl; TValue *k; StkId base; newframe: /* reentry point when frame changes (call/return) */ lua_assert(ci == L->ci); cl = clLvalue(ci->func); k = cl->p->k; base = ci->u.l.base; /* main loop of interpreter */ for (;;) { Instruction i = *(ci->u.l.savedpc++); StkId ra; if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) && (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) { Protect(traceexec(L)); } /* WARNING: several calls may realloc the stack and invalidate `ra' */ ra = RA(i); lua_assert(base == ci->u.l.base); lua_assert(base <= L->top && L->top < L->stack + L->stacksize); vmdispatch (GET_OPCODE(i)) { vmcase(OP_MOVE, setobjs2s(L, ra, RB(i)); ) vmcase(OP_LOADK, TValue *rb = k + GETARG_Bx(i); setobj2s(L, ra, rb); ) vmcase(OP_LOADKX, TValue *rb; lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG); rb = k + GETARG_Ax(*ci->u.l.savedpc++); setobj2s(L, ra, rb); ) vmcase(OP_LOADBOOL, setbvalue(ra, GETARG_B(i)); if (GETARG_C(i)) ci->u.l.savedpc++; /* skip next instruction (if C) */ ) vmcase(OP_LOADNIL, int b = GETARG_B(i); do { setnilvalue(ra++); } while (b--); ) vmcase(OP_GETUPVAL, int b = GETARG_B(i); setobj2s(L, ra, cl->upvals[b]->v); ) vmcase(OP_GETTABUP, int b = GETARG_B(i); Protect(luaV_gettable(L, cl->upvals[b]->v, RKC(i), ra)); ) vmcase(OP_GETTABLE, Protect(luaV_gettable(L, RB(i), RKC(i), ra)); ) vmcase(OP_SETTABUP, int a = GETARG_A(i); Protect(luaV_settable(L, cl->upvals[a]->v, RKB(i), RKC(i))); ) vmcase(OP_SETUPVAL, UpVal *uv = cl->upvals[GETARG_B(i)]; setobj(L, uv->v, ra); luaC_barrier(L, uv, ra); ) vmcase(OP_SETTABLE, Protect(luaV_settable(L, ra, RKB(i), RKC(i))); ) vmcase(OP_NEWTABLE, int b = GETARG_B(i); int c = GETARG_C(i); Table *t = luaH_new(L); sethvalue(L, ra, t); if (b != 0 || c != 0) luaH_resize(L, t, luaO_fb2int(b), luaO_fb2int(c)); checkGC(L, ra + 1); ) vmcase(OP_SELF, StkId rb = RB(i); setobjs2s(L, ra+1, rb); Protect(luaV_gettable(L, rb, RKC(i), ra)); ) vmcase(OP_ADD, arith_op(luai_numadd, TM_ADD); ) vmcase(OP_SUB, arith_op(luai_numsub, TM_SUB); ) vmcase(OP_MUL, arith_op(luai_nummul, TM_MUL); ) vmcase(OP_DIV, arith_op(luai_numdiv, TM_DIV); ) vmcase(OP_MOD, arith_op(luai_nummod, TM_MOD); ) vmcase(OP_POW, arith_op(luai_numpow, TM_POW); ) vmcase(OP_UNM, TValue *rb = RB(i); if (ttisnumber(rb)) { lua_Number nb = nvalue(rb); setnvalue(ra, luai_numunm(L, nb)); } else { Protect(luaV_arith(L, ra, rb, rb, TM_UNM)); } ) vmcase(OP_NOT, TValue *rb = RB(i); int res = l_isfalse(rb); /* next assignment may change this value */ setbvalue(ra, res); ) vmcase(OP_LEN, Protect(luaV_objlen(L, ra, RB(i))); ) vmcase(OP_CONCAT, int b = GETARG_B(i); int c = GETARG_C(i); StkId rb; L->top = base + c + 1; /* mark the end of concat operands */ Protect(luaV_concat(L, c - b + 1)); ra = RA(i); /* 'luav_concat' may invoke TMs and move the stack */ rb = b + base; setobjs2s(L, ra, rb); checkGC(L, (ra >= rb ? ra + 1 : rb)); L->top = ci->top; /* restore top */ ) vmcase(OP_JMP, dojump(ci, i, 0); ) vmcase(OP_EQ, TValue *rb = RKB(i); TValue *rc = RKC(i); Protect( if (cast_int(equalobj(L, rb, rc)) != GETARG_A(i)) ci->u.l.savedpc++; else donextjump(ci); ) ) vmcase(OP_LT, Protect( if (luaV_lessthan(L, RKB(i), RKC(i)) != GETARG_A(i)) ci->u.l.savedpc++; else donextjump(ci); ) ) vmcase(OP_LE, Protect( if (luaV_lessequal(L, RKB(i), RKC(i)) != GETARG_A(i)) ci->u.l.savedpc++; else donextjump(ci); ) ) vmcase(OP_TEST, if (GETARG_C(i) ? l_isfalse(ra) : !l_isfalse(ra)) ci->u.l.savedpc++; else donextjump(ci); ) vmcase(OP_TESTSET, TValue *rb = RB(i); if (GETARG_C(i) ? l_isfalse(rb) : !l_isfalse(rb)) ci->u.l.savedpc++; else { setobjs2s(L, ra, rb); donextjump(ci); } ) vmcase(OP_CALL, int b = GETARG_B(i); int nresults = GETARG_C(i) - 1; if (b != 0) L->top = ra+b; /* else previous instruction set top */ if (luaD_precall(L, ra, nresults)) { /* C function? */ if (nresults >= 0) L->top = ci->top; /* adjust results */ base = ci->u.l.base; } else { /* Lua function */ ci = L->ci; ci->callstatus |= CIST_REENTRY; goto newframe; /* restart luaV_execute over new Lua function */ } ) vmcase(OP_TAILCALL, int b = GETARG_B(i); if (b != 0) L->top = ra+b; /* else previous instruction set top */ lua_assert(GETARG_C(i) - 1 == LUA_MULTRET); if (luaD_precall(L, ra, LUA_MULTRET)) /* C function? */ base = ci->u.l.base; else { /* tail call: put called frame (n) in place of caller one (o) */ CallInfo *nci = L->ci; /* called frame */ CallInfo *oci = nci->previous; /* caller frame */ StkId nfunc = nci->func; /* called function */ StkId ofunc = oci->func; /* caller function */ /* last stack slot filled by 'precall' */ StkId lim = nci->u.l.base + getproto(nfunc)->numparams; int aux; /* close all upvalues from previous call */ if (cl->p->sizep > 0) luaF_close(L, oci->u.l.base); /* move new frame into old one */ for (aux = 0; nfunc + aux < lim; aux++) setobjs2s(L, ofunc + aux, nfunc + aux); oci->u.l.base = ofunc + (nci->u.l.base - nfunc); /* correct base */ oci->top = L->top = ofunc + (L->top - nfunc); /* correct top */ oci->u.l.savedpc = nci->u.l.savedpc; oci->callstatus |= CIST_TAIL; /* function was tail called */ ci = L->ci = oci; /* remove new frame */ lua_assert(L->top == oci->u.l.base + getproto(ofunc)->maxstacksize); goto newframe; /* restart luaV_execute over new Lua function */ } ) vmcasenb(OP_RETURN, int b = GETARG_B(i); if (b != 0) L->top = ra+b-1; if (cl->p->sizep > 0) luaF_close(L, base); b = luaD_poscall(L, ra); if (!(ci->callstatus & CIST_REENTRY)) /* 'ci' still the called one */ return; /* external invocation: return */ else { /* invocation via reentry: continue execution */ ci = L->ci; if (b) L->top = ci->top; lua_assert(isLua(ci)); lua_assert(GET_OPCODE(*((ci)->u.l.savedpc - 1)) == OP_CALL); goto newframe; /* restart luaV_execute over new Lua function */ } ) vmcase(OP_FORLOOP, lua_Number step = nvalue(ra+2); lua_Number idx = luai_numadd(L, nvalue(ra), step); /* increment index */ lua_Number limit = nvalue(ra+1); if (luai_numlt(L, 0, step) ? luai_numle(L, idx, limit) : luai_numle(L, limit, idx)) { ci->u.l.savedpc += GETARG_sBx(i); /* jump back */ setnvalue(ra, idx); /* update internal index... */ setnvalue(ra+3, idx); /* ...and external index */ } ) vmcase(OP_FORPREP, const TValue *init = ra; const TValue *plimit = ra+1; const TValue *pstep = ra+2; if (!tonumber(init, ra)) luaG_runerror(L, LUA_QL("for") " initial value must be a number"); else if (!tonumber(plimit, ra+1)) luaG_runerror(L, LUA_QL("for") " limit must be a number"); else if (!tonumber(pstep, ra+2)) luaG_runerror(L, LUA_QL("for") " step must be a number"); setnvalue(ra, luai_numsub(L, nvalue(ra), nvalue(pstep))); ci->u.l.savedpc += GETARG_sBx(i); ) vmcasenb(OP_TFORCALL, StkId cb = ra + 3; /* call base */ setobjs2s(L, cb+2, ra+2); setobjs2s(L, cb+1, ra+1); setobjs2s(L, cb, ra); L->top = cb + 3; /* func. + 2 args (state and index) */ Protect(luaD_call(L, cb, GETARG_C(i), 1)); L->top = ci->top; i = *(ci->u.l.savedpc++); /* go to next instruction */ ra = RA(i); lua_assert(GET_OPCODE(i) == OP_TFORLOOP); goto l_tforloop; ) vmcase(OP_TFORLOOP, l_tforloop: if (!ttisnil(ra + 1)) { /* continue loop? */ setobjs2s(L, ra, ra + 1); /* save control variable */ ci->u.l.savedpc += GETARG_sBx(i); /* jump back */ } ) vmcase(OP_SETLIST, int n = GETARG_B(i); int c = GETARG_C(i); int last; Table *h; if (n == 0) n = cast_int(L->top - ra) - 1; if (c == 0) { lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG); c = GETARG_Ax(*ci->u.l.savedpc++); } luai_runtimecheck(L, ttistable(ra)); h = hvalue(ra); last = ((c-1)*LFIELDS_PER_FLUSH) + n; if (last > h->sizearray) /* needs more space? */ luaH_resizearray(L, h, last); /* pre-allocate it at once */ for (; n > 0; n--) { TValue *val = ra+n; luaH_setint(L, h, last--, val); luaC_barrierback(L, obj2gco(h), val); } L->top = ci->top; /* correct top (in case of previous open call) */ ) vmcase(OP_CLOSURE, Proto *p = cl->p->p[GETARG_Bx(i)]; Closure *ncl = getcached(p, cl->upvals, base); /* cached closure */ if (ncl == NULL) /* no match? */ pushclosure(L, p, cl->upvals, base, ra); /* create a new one */ else setclLvalue(L, ra, ncl); /* push cashed closure */ checkGC(L, ra + 1); ) vmcase(OP_VARARG, int b = GETARG_B(i) - 1; int j; int n = cast_int(base - ci->func) - cl->p->numparams - 1; if (b < 0) { /* B == 0? */ b = n; /* get all var. arguments */ Protect(luaD_checkstack(L, n)); ra = RA(i); /* previous call may change the stack */ L->top = ra + n; } for (j = 0; j < b; j++) { if (j < n) { setobjs2s(L, ra + j, base - n + j); } else { setnilvalue(ra + j); } } ) vmcase(OP_EXTRAARG, lua_assert(0); ) } } }