/* ** $Id: lvm.c,v 2.63.1.5 2011/08/17 20:43:11 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), &num)) { setnvalue(n, num); return n; } else return NULL; } int luaV_tostring (lua_State *L, StkId obj) { if (!ttisnumber(obj)) return 0; else { char s[LUAI_MAXNUMBER2STR]; lua_Number n = nvalue(obj); lua_number2str(s, n); setsvalue2s(L, obj, luaS_new(L, s)); return 1; } } static void traceexec (lua_State *L, const Instruction *pc) { lu_byte mask = L->hookmask; const Instruction *oldpc = L->savedpc; L->savedpc = pc; if ((mask & LUA_MASKCOUNT) && L->hookcount == 0) { resethookcount(L); luaD_callhook(L, LUA_HOOKCOUNT, -1); } if (mask & LUA_MASKLINE) { Proto *p = ci_func(L->ci)->l.p; int npc = pcRel(pc, p); int newline = getline(p, npc); /* call linehook when enter a new function, when jump back (loop), or when enter a new line */ if (npc == 0 || pc <= oldpc || newline != getline(p, pcRel(oldpc, p))) luaD_callhook(L, LUA_HOOKLINE, newline); } } static void callTMres (lua_State *L, StkId res, const TValue *f, const TValue *p1, const TValue *p2) { ptrdiff_t result = savestack(L, res); setobj2s(L, L->top, f); /* push function */ setobj2s(L, L->top+1, p1); /* 1st argument */ setobj2s(L, L->top+2, p2); /* 2nd argument */ luaD_checkstack(L, 3); L->top += 3; luaD_call(L, L->top - 3, 1); res = restorestack(L, result); L->top--; setobjs2s(L, res, L->top); } static void callTM (lua_State *L, const TValue *f, const TValue *p1, const TValue *p2, const TValue *p3) { setobj2s(L, L->top, f); /* push function */ setobj2s(L, L->top+1, p1); /* 1st argument */ setobj2s(L, L->top+2, p2); /* 2nd argument */ setobj2s(L, L->top+3, p3); /* 3th argument */ luaD_checkstack(L, 4); L->top += 4; luaD_call(L, L->top - 4, 0); } void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) { int loop; for (loop = 0; loop < MAXTAGLOOP; loop++) { const TValue *tm; if (ttistable(t)) { /* `t' is a table? */ Table *h = hvalue(t); const TValue *res = luaH_get(h, key); /* do a primitive get */ if (!ttisnil(res) || /* result is no nil? */ (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */ setobj2s(L, val, res); return; } /* else will try the tag method */ } else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX))) luaG_typeerror(L, t, "index"); if (ttisfunction(tm)) { callTMres(L, val, tm, t, key); return; } t = tm; /* else repeat with `tm' */ } luaG_runerror(L, "loop in gettable"); } void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) { int loop; TValue temp; for (loop = 0; loop < MAXTAGLOOP; loop++) { const TValue *tm; if (ttistable(t)) { /* `t' is a table? */ Table *h = hvalue(t); TValue *oldval = luaH_set(L, h, key); /* do a primitive set */ if (!ttisnil(oldval) || /* result is no nil? */ (tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */ setobj2t(L, oldval, val); h->flags = 0; luaC_barriert(L, h, val); return; } /* else will try the tag method */ } else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX))) luaG_typeerror(L, t, "index"); if (ttisfunction(tm)) { callTM(L, tm, t, key, val); return; } /* else repeat with `tm' */ setobj(L, &temp, tm); /* avoid pointing inside table (may rehash) */ t = &temp; } luaG_runerror(L, "loop in settable"); } static int call_binTM (lua_State *L, const TValue *p1, const TValue *p2, StkId res, TMS event) { const TValue *tm = luaT_gettmbyobj(L, p1, event); /* try first operand */ if (ttisnil(tm)) tm = luaT_gettmbyobj(L, p2, event); /* try second operand */ if (ttisnil(tm)) return 0; callTMres(L, res, tm, p1, p2); return 1; } static const TValue *get_compTM (lua_State *L, Table *mt1, Table *mt2, TMS event) { const TValue *tm1 = fasttm(L, mt1, event); const TValue *tm2; if (tm1 == NULL) return NULL; /* no metamethod */ if (mt1 == mt2) return tm1; /* same metatables => same metamethods */ tm2 = fasttm(L, mt2, event); if (tm2 == NULL) return NULL; /* no metamethod */ if (luaO_rawequalObj(tm1, tm2)) /* same metamethods? */ return tm1; return NULL; } static int call_orderTM (lua_State *L, const TValue *p1, const TValue *p2, TMS event) { const TValue *tm1 = luaT_gettmbyobj(L, p1, event); const TValue *tm2; if (ttisnil(tm1)) return -1; /* no metamethod? */ tm2 = luaT_gettmbyobj(L, p2, event); if (!luaO_rawequalObj(tm1, tm2)) /* different metamethods? */ return -1; callTMres(L, L->top, tm1, p1, p2); return !l_isfalse(L->top); } static int l_strcmp (const TString *ls, const TString *rs) { const char *l = getstr(ls); size_t ll = ls->tsv.len; const char *r = getstr(rs); size_t lr = rs->tsv.len; for (;;) { int temp = strcoll(l, r); if (temp != 0) return temp; else { /* strings are equal up to a `\0' */ size_t len = strlen(l); /* index of first `\0' in both strings */ if (len == lr) /* r is finished? */ return (len == ll) ? 0 : 1; else if (len == ll) /* l is finished? */ return -1; /* l is smaller than r (because r is not finished) */ /* both strings longer than `len'; go on comparing (after the `\0') */ len++; l += len; ll -= len; r += len; lr -= len; } } } int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) { int res; if (ttype(l) != ttype(r)) return luaG_ordererror(L, l, r); else if (ttisnumber(l)) return luai_numlt(nvalue(l), nvalue(r)); else if (ttisstring(l)) return l_strcmp(rawtsvalue(l), rawtsvalue(r)) < 0; else if ((res = call_orderTM(L, l, r, TM_LT)) != -1) return res; return luaG_ordererror(L, l, r); } static int lessequal (lua_State *L, const TValue *l, const TValue *r) { int res; if (ttype(l) != ttype(r)) return luaG_ordererror(L, l, r); else if (ttisnumber(l)) return luai_numle(nvalue(l), nvalue(r)); else if (ttisstring(l)) return l_strcmp(rawtsvalue(l), rawtsvalue(r)) <= 0; else if ((res = call_orderTM(L, l, r, TM_LE)) != -1) /* first try `le' */ return res; else if ((res = call_orderTM(L, r, l, TM_LT)) != -1) /* else try `lt' */ return !res; return luaG_ordererror(L, l, r); } int luaV_equalval (lua_State *L, const TValue *t1, const TValue *t2) { const TValue *tm; lua_assert(ttype(t1) == ttype(t2)); switch (ttype(t1)) { case LUA_TNIL: return 1; case LUA_TNUMBER: return luai_numeq(nvalue(t1), nvalue(t2)); case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2); /* true must be 1 !! */ case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2); case LUA_TUSERDATA: { if (uvalue(t1) == uvalue(t2)) return 1; tm = get_compTM(L, uvalue(t1)->metatable, uvalue(t2)->metatable, TM_EQ); break; /* will try TM */ } case LUA_TTABLE: { if (hvalue(t1) == hvalue(t2)) return 1; tm = get_compTM(L, hvalue(t1)->metatable, hvalue(t2)->metatable, TM_EQ); break; /* will try TM */ } default: return gcvalue(t1) == gcvalue(t2); } if (tm == NULL) return 0; /* no TM? */ callTMres(L, L->top, tm, t1, t2); /* call TM */ return !l_isfalse(L->top); } void luaV_concat (lua_State *L, int total, int last) { do { StkId top = L->base + last + 1; 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 op is empty? */ (void)tostring(L, top - 2); /* result is first op (as string) */ else { /* at least two string values; get as many as possible */ size_t tl = tsvalue(top-1)->len; char *buffer; int i; /* collect total length */ for (n = 1; n < total && tostring(L, top-n-1); n++) { size_t l = tsvalue(top-n-1)->len; if (l >= MAX_SIZET - tl) luaG_runerror(L, "string length overflow"); tl += l; } buffer = luaZ_openspace(L, &G(L)->buff, tl); tl = 0; for (i=n; i>0; i--) { /* concat all strings */ size_t l = tsvalue(top-i)->len; memcpy(buffer+tl, svalue(top-i), l); tl += l; } setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl)); } total -= n-1; /* got `n' strings to create 1 new */ last -= n-1; } while (total > 1); /* repeat until only 1 result left */ } static void 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 nb = nvalue(b), nc = nvalue(c); switch (op) { case TM_ADD: setnvalue(ra, luai_numadd(nb, nc)); break; case TM_SUB: setnvalue(ra, luai_numsub(nb, nc)); break; case TM_MUL: setnvalue(ra, luai_nummul(nb, nc)); break; case TM_DIV: setnvalue(ra, luai_numdiv(nb, nc)); break; case TM_MOD: setnvalue(ra, luai_nummod(nb, nc)); break; case TM_POW: setnvalue(ra, luai_numpow(nb, nc)); break; case TM_UNM: setnvalue(ra, luai_numunm(nb)); break; default: lua_assert(0); break; } } else if (!call_binTM(L, rb, rc, ra, op)) luaG_aritherror(L, rb, rc); } /* ** some macros for common tasks in `luaV_execute' */ #define runtime_check(L, c) { if (!(c)) break; } #define RA(i) (base+GETARG_A(i)) /* to be used after possible stack reallocation */ #define RB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i)) #define RC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i)) #define RKB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \ ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i)) #define RKC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \ ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i)) #define KBx(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgK, k+GETARG_Bx(i)) #define dojump(L,pc,i) {(pc) += (i); luai_threadyield(L);} #define Protect(x) { L->savedpc = pc; {x;}; base = L->base; } #define arith_op(op,tm) { \ TValue *rb = RKB(i); \ TValue *rc = RKC(i); \ if (ttisnumber(rb) && ttisnumber(rc)) { \ lua_Number nb = nvalue(rb), nc = nvalue(rc); \ setnvalue(ra, op(nb, nc)); \ } \ else \ Protect(Arith(L, ra, rb, rc, tm)); \ } void luaV_execute (lua_State *L, int nexeccalls) { LClosure *cl; StkId base; TValue *k; const Instruction *pc; reentry: /* entry point */ lua_assert(isLua(L->ci)); pc = L->savedpc; cl = &clvalue(L->ci->func)->l; base = L->base; k = cl->p->k; /* main loop of interpreter */ for (;;) { const Instruction i = *pc++; StkId ra; if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) && (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) { traceexec(L, pc); if (L->status == LUA_YIELD) { /* did hook yield? */ L->savedpc = pc - 1; return; } base = L->base; } /* warning!! several calls may realloc the stack and invalidate `ra' */ ra = RA(i); lua_assert(base == L->base && L->base == L->ci->base); lua_assert(base <= L->top && L->top <= L->stack + L->stacksize); lua_assert(L->top == L->ci->top || luaG_checkopenop(i)); switch (GET_OPCODE(i)) { case OP_MOVE: { setobjs2s(L, ra, RB(i)); continue; } case OP_LOADK: { setobj2s(L, ra, KBx(i)); continue; } case OP_LOADBOOL: { setbvalue(ra, GETARG_B(i)); if (GETARG_C(i)) pc++; /* skip next instruction (if C) */ continue; } case OP_LOADNIL: { TValue *rb = RB(i); do { setnilvalue(rb--); } while (rb >= ra); continue; } case OP_GETUPVAL: { int b = GETARG_B(i); setobj2s(L, ra, cl->upvals[b]->v); continue; } case OP_GETGLOBAL: { TValue g; TValue *rb = KBx(i); sethvalue(L, &g, cl->env); lua_assert(ttisstring(rb)); Protect(luaV_gettable(L, &g, rb, ra)); continue; } case OP_GETTABLE: { Protect(luaV_gettable(L, RB(i), RKC(i), ra)); continue; } case OP_SETGLOBAL: { TValue g; sethvalue(L, &g, cl->env); lua_assert(ttisstring(KBx(i))); Protect(luaV_settable(L, &g, KBx(i), ra)); continue; } case OP_SETUPVAL: { UpVal *uv = cl->upvals[GETARG_B(i)]; setobj(L, uv->v, ra); luaC_barrier(L, uv, ra); continue; } case OP_SETTABLE: { Protect(luaV_settable(L, ra, RKB(i), RKC(i))); continue; } case OP_NEWTABLE: { int b = GETARG_B(i); int c = GETARG_C(i); sethvalue(L, ra, luaH_new(L, luaO_fb2int(b), luaO_fb2int(c))); Protect(luaC_checkGC(L)); continue; } case OP_SELF: { StkId rb = RB(i); setobjs2s(L, ra+1, rb); Protect(luaV_gettable(L, rb, RKC(i), ra)); continue; } case OP_ADD: { arith_op(luai_numadd, TM_ADD); continue; } case OP_SUB: { arith_op(luai_numsub, TM_SUB); continue; } case OP_MUL: { arith_op(luai_nummul, TM_MUL); continue; } case OP_DIV: { arith_op(luai_numdiv, TM_DIV); continue; } case OP_MOD: { arith_op(luai_nummod, TM_MOD); continue; } case OP_POW: { arith_op(luai_numpow, TM_POW); continue; } case OP_UNM: { TValue *rb = RB(i); if (ttisnumber(rb)) { lua_Number nb = nvalue(rb); setnvalue(ra, luai_numunm(nb)); } else { Protect(Arith(L, ra, rb, rb, TM_UNM)); } continue; } case OP_NOT: { int res = l_isfalse(RB(i)); /* next assignment may change this value */ setbvalue(ra, res); continue; } case OP_LEN: { const TValue *rb = RB(i); switch (ttype(rb)) { case LUA_TTABLE: { setnvalue(ra, cast_num(luaH_getn(hvalue(rb)))); break; } case LUA_TSTRING: { setnvalue(ra, cast_num(tsvalue(rb)->len)); break; } default: { /* try metamethod */ Protect( if (!call_binTM(L, rb, luaO_nilobject, ra, TM_LEN)) luaG_typeerror(L, rb, "get length of"); ) } } continue; } case OP_CONCAT: { int b = GETARG_B(i); int c = GETARG_C(i); Protect(luaV_concat(L, c-b+1, c); luaC_checkGC(L)); setobjs2s(L, RA(i), base+b); continue; } case OP_JMP: { dojump(L, pc, GETARG_sBx(i)); continue; } case OP_EQ: { TValue *rb = RKB(i); TValue *rc = RKC(i); Protect( if (equalobj(L, rb, rc) == GETARG_A(i)) dojump(L, pc, GETARG_sBx(*pc)); ) pc++; continue; } case OP_LT: { Protect( if (luaV_lessthan(L, RKB(i), RKC(i)) == GETARG_A(i)) dojump(L, pc, GETARG_sBx(*pc)); ) pc++; continue; } case OP_LE: { Protect( if (lessequal(L, RKB(i), RKC(i)) == GETARG_A(i)) dojump(L, pc, GETARG_sBx(*pc)); ) pc++; continue; } case OP_TEST: { if (l_isfalse(ra) != GETARG_C(i)) dojump(L, pc, GETARG_sBx(*pc)); pc++; continue; } case OP_TESTSET: { TValue *rb = RB(i); if (l_isfalse(rb) != GETARG_C(i)) { setobjs2s(L, ra, rb); dojump(L, pc, GETARG_sBx(*pc)); } pc++; continue; } case OP_CALL: { int b = GETARG_B(i); int nresults = GETARG_C(i) - 1; if (b != 0) L->top = ra+b; /* else previous instruction set top */ L->savedpc = pc; switch (luaD_precall(L, ra, nresults)) { case PCRLUA: { nexeccalls++; goto reentry; /* restart luaV_execute over new Lua function */ } case PCRC: { /* it was a C function (`precall' called it); adjust results */ if (nresults >= 0) L->top = L->ci->top; base = L->base; continue; } default: { return; /* yield */ } } } case OP_TAILCALL: { int b = GETARG_B(i); if (b != 0) L->top = ra+b; /* else previous instruction set top */ L->savedpc = pc; lua_assert(GETARG_C(i) - 1 == LUA_MULTRET); switch (luaD_precall(L, ra, LUA_MULTRET)) { case PCRLUA: { /* tail call: put new frame in place of previous one */ CallInfo *ci = L->ci - 1; /* previous frame */ int aux; StkId func = ci->func; StkId pfunc = (ci+1)->func; /* previous function index */ if (L->openupval) luaF_close(L, ci->base); L->base = ci->base = ci->func + ((ci+1)->base - pfunc); for (aux = 0; pfunc+aux < L->top; aux++) /* move frame down */ setobjs2s(L, func+aux, pfunc+aux); ci->top = L->top = func+aux; /* correct top */ lua_assert(L->top == L->base + clvalue(func)->l.p->maxstacksize); ci->savedpc = L->savedpc; ci->tailcalls++; /* one more call lost */ L->ci--; /* remove new frame */ goto reentry; } case PCRC: { /* it was a C function (`precall' called it) */ base = L->base; continue; } default: { return; /* yield */ } } } case OP_RETURN: { int b = GETARG_B(i); if (b != 0) L->top = ra+b-1; if (L->openupval) luaF_close(L, base); L->savedpc = pc; b = luaD_poscall(L, ra); if (--nexeccalls == 0) /* was previous function running `here'? */ return; /* no: return */ else { /* yes: continue its execution */ if (b) L->top = L->ci->top; lua_assert(isLua(L->ci)); lua_assert(GET_OPCODE(*((L->ci)->savedpc - 1)) == OP_CALL); goto reentry; } } case OP_FORLOOP: { lua_Number step = nvalue(ra+2); lua_Number idx = luai_numadd(nvalue(ra), step); /* increment index */ lua_Number limit = nvalue(ra+1); if (luai_numlt(0, step) ? luai_numle(idx, limit) : luai_numle(limit, idx)) { dojump(L, pc, GETARG_sBx(i)); /* jump back */ setnvalue(ra, idx); /* update internal index... */ setnvalue(ra+3, idx); /* ...and external index */ } continue; } case OP_FORPREP: { const TValue *init = ra; const TValue *plimit = ra+1; const TValue *pstep = ra+2; L->savedpc = pc; /* next steps may throw errors */ 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(nvalue(ra), nvalue(pstep))); dojump(L, pc, GETARG_sBx(i)); continue; } case OP_TFORLOOP: { 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))); L->top = L->ci->top; cb = RA(i) + 3; /* previous call may change the stack */ if (!ttisnil(cb)) { /* continue loop? */ setobjs2s(L, cb-1, cb); /* save control variable */ dojump(L, pc, GETARG_sBx(*pc)); /* jump back */ } pc++; continue; } case OP_SETLIST: { int n = GETARG_B(i); int c = GETARG_C(i); int last; Table *h; if (n == 0) { n = cast_int(L->top - ra) - 1; L->top = L->ci->top; } if (c == 0) c = cast_int(*pc++); runtime_check(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-alloc it at once */ for (; n > 0; n--) { TValue *val = ra+n; setobj2t(L, luaH_setnum(L, h, last--), val); luaC_barriert(L, h, val); } continue; } case OP_CLOSE: { luaF_close(L, ra); continue; } case OP_CLOSURE: { Proto *p; Closure *ncl; int nup, j; p = cl->p->p[GETARG_Bx(i)]; nup = p->nups; ncl = luaF_newLclosure(L, nup, cl->env); ncl->l.p = p; for (j=0; jl.upvals[j] = cl->upvals[GETARG_B(*pc)]; else { lua_assert(GET_OPCODE(*pc) == OP_MOVE); ncl->l.upvals[j] = luaF_findupval(L, base + GETARG_B(*pc)); } } setclvalue(L, ra, ncl); Protect(luaC_checkGC(L)); continue; } case OP_VARARG: { int b = GETARG_B(i) - 1; int j; CallInfo *ci = L->ci; int n = cast_int(ci->base - ci->func) - cl->p->numparams - 1; if (b == LUA_MULTRET) { Protect(luaD_checkstack(L, n)); ra = RA(i); /* previous call may change the stack */ b = n; L->top = ra + n; } for (j = 0; j < b; j++) { if (j < n) { setobjs2s(L, ra + j, ci->base - n + j); } else { setnilvalue(ra + j); } } continue; } } } }