Lua 5.1.4: lvm.c


L0001    /*
L0002    ** $Id: lvm.c,v 2.63.1.3 2007/12/28 15:32:23 roberto Exp $
L0003    ** Lua virtual machine
L0004    ** See Copyright Notice in lua.h
L0005    */
L0006    
L0007    
L0008    #include <stdio.h>
L0009    #include <stdlib.h>
L0010    #include <string.h>
L0011    
L0012    #define lvm_c
L0013    #define LUA_CORE
L0014    
L0015    #include "lua.h"
L0016    
L0017    #include "ldebug.h"
L0018    #include "ldo.h"
L0019    #include "lfunc.h"
L0020    #include "lgc.h"
L0021    #include "lobject.h"
L0022    #include "lopcodes.h"
L0023    #include "lstate.h"
L0024    #include "lstring.h"
L0025    #include "ltable.h"
L0026    #include "ltm.h"
L0027    #include "lvm.h"
L0028    
L0029    
L0030    
L0031    /* limit for table tag-method chains (to avoid loops) */
L0032    #define MAXTAGLOOP	100
L0033    
L0034    
L0035    const TValue *luaV_tonumber (const TValue *obj, TValue *n) {
L0036      lua_Number num;
L0037      if (ttisnumber(obj)) return obj;
L0038      if (ttisstring(obj) && luaO_str2d(svalue(obj), &num)) {
L0039        setnvalue(n, num);
L0040        return n;
L0041      }
L0042      else
L0043        return NULL;
L0044    }
L0045    
L0046    
L0047    int luaV_tostring (lua_State *L, StkId obj) {
L0048      if (!ttisnumber(obj))
L0049        return 0;
L0050      else {
L0051        char s[LUAI_MAXNUMBER2STR];
L0052        lua_Number n = nvalue(obj);
L0053        lua_number2str(s, n);
L0054        setsvalue2s(L, obj, luaS_new(L, s));
L0055        return 1;
L0056      }
L0057    }
L0058    
L0059    
L0060    static void traceexec (lua_State *L, const Instruction *pc) {
L0061      lu_byte mask = L->hookmask;
L0062      const Instruction *oldpc = L->savedpc;
L0063      L->savedpc = pc;
L0064      if ((mask & LUA_MASKCOUNT) && L->hookcount == 0) {
L0065        resethookcount(L);
L0066        luaD_callhook(L, LUA_HOOKCOUNT, -1);
L0067      }
L0068      if (mask & LUA_MASKLINE) {
L0069        Proto *p = ci_func(L->ci)->l.p;
L0070        int npc = pcRel(pc, p);
L0071        int newline = getline(p, npc);
L0072        /* call linehook when enter a new function, when jump back (loop),
L0073           or when enter a new line */
L0074        if (npc == 0 || pc <= oldpc || newline != getline(p, pcRel(oldpc, p)))
L0075          luaD_callhook(L, LUA_HOOKLINE, newline);
L0076      }
L0077    }
L0078    
L0079    
L0080    static void callTMres (lua_State *L, StkId res, const TValue *f,
L0081                            const TValue *p1, const TValue *p2) {
L0082      ptrdiff_t result = savestack(L, res);
L0083      setobj2s(L, L->top, f);  /* push function */
L0084      setobj2s(L, L->top+1, p1);  /* 1st argument */
L0085      setobj2s(L, L->top+2, p2);  /* 2nd argument */
L0086      luaD_checkstack(L, 3);
L0087      L->top += 3;
L0088      luaD_call(L, L->top - 3, 1);
L0089      res = restorestack(L, result);
L0090      L->top--;
L0091      setobjs2s(L, res, L->top);
L0092    }
L0093    
L0094    
L0095    
L0096    static void callTM (lua_State *L, const TValue *f, const TValue *p1,
L0097                        const TValue *p2, const TValue *p3) {
L0098      setobj2s(L, L->top, f);  /* push function */
L0099      setobj2s(L, L->top+1, p1);  /* 1st argument */
L0100      setobj2s(L, L->top+2, p2);  /* 2nd argument */
L0101      setobj2s(L, L->top+3, p3);  /* 3th argument */
L0102      luaD_checkstack(L, 4);
L0103      L->top += 4;
L0104      luaD_call(L, L->top - 4, 0);
L0105    }
L0106    
L0107    
L0108    void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
L0109      int loop;
L0110      for (loop = 0; loop < MAXTAGLOOP; loop++) {
L0111        const TValue *tm;
L0112        if (ttistable(t)) {  /* `t' is a table? */
L0113          Table *h = hvalue(t);
L0114          const TValue *res = luaH_get(h, key); /* do a primitive get */
L0115          if (!ttisnil(res) ||  /* result is no nil? */
L0116              (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
L0117            setobj2s(L, val, res);
L0118            return;
L0119          }
L0120          /* else will try the tag method */
L0121        }
L0122        else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
L0123          luaG_typeerror(L, t, "index");
L0124        if (ttisfunction(tm)) {
L0125          callTMres(L, val, tm, t, key);
L0126          return;
L0127        }
L0128        t = tm;  /* else repeat with `tm' */ 
L0129      }
L0130      luaG_runerror(L, "loop in gettable");
L0131    }
L0132    
L0133    
L0134    void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
L0135      int loop;
L0136      for (loop = 0; loop < MAXTAGLOOP; loop++) {
L0137        const TValue *tm;
L0138        if (ttistable(t)) {  /* `t' is a table? */
L0139          Table *h = hvalue(t);
L0140          TValue *oldval = luaH_set(L, h, key); /* do a primitive set */
L0141          if (!ttisnil(oldval) ||  /* result is no nil? */
L0142              (tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
L0143            setobj2t(L, oldval, val);
L0144            luaC_barriert(L, h, val);
L0145            return;
L0146          }
L0147          /* else will try the tag method */
L0148        }
L0149        else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
L0150          luaG_typeerror(L, t, "index");
L0151        if (ttisfunction(tm)) {
L0152          callTM(L, tm, t, key, val);
L0153          return;
L0154        }
L0155        t = tm;  /* else repeat with `tm' */ 
L0156      }
L0157      luaG_runerror(L, "loop in settable");
L0158    }
L0159    
L0160    
L0161    static int call_binTM (lua_State *L, const TValue *p1, const TValue *p2,
L0162                           StkId res, TMS event) {
L0163      const TValue *tm = luaT_gettmbyobj(L, p1, event);  /* try first operand */
L0164      if (ttisnil(tm))
L0165        tm = luaT_gettmbyobj(L, p2, event);  /* try second operand */
L0166      if (ttisnil(tm)) return 0;
L0167      callTMres(L, res, tm, p1, p2);
L0168      return 1;
L0169    }
L0170    
L0171    
L0172    static const TValue *get_compTM (lua_State *L, Table *mt1, Table *mt2,
L0173                                      TMS event) {
L0174      const TValue *tm1 = fasttm(L, mt1, event);
L0175      const TValue *tm2;
L0176      if (tm1 == NULL) return NULL;  /* no metamethod */
L0177      if (mt1 == mt2) return tm1;  /* same metatables => same metamethods */
L0178      tm2 = fasttm(L, mt2, event);
L0179      if (tm2 == NULL) return NULL;  /* no metamethod */
L0180      if (luaO_rawequalObj(tm1, tm2))  /* same metamethods? */
L0181        return tm1;
L0182      return NULL;
L0183    }
L0184    
L0185    
L0186    static int call_orderTM (lua_State *L, const TValue *p1, const TValue *p2,
L0187                             TMS event) {
L0188      const TValue *tm1 = luaT_gettmbyobj(L, p1, event);
L0189      const TValue *tm2;
L0190      if (ttisnil(tm1)) return -1;  /* no metamethod? */
L0191      tm2 = luaT_gettmbyobj(L, p2, event);
L0192      if (!luaO_rawequalObj(tm1, tm2))  /* different metamethods? */
L0193        return -1;
L0194      callTMres(L, L->top, tm1, p1, p2);
L0195      return !l_isfalse(L->top);
L0196    }
L0197    
L0198    
L0199    static int l_strcmp (const TString *ls, const TString *rs) {
L0200      const char *l = getstr(ls);
L0201      size_t ll = ls->tsv.len;
L0202      const char *r = getstr(rs);
L0203      size_t lr = rs->tsv.len;
L0204      for (;;) {
L0205        int temp = strcoll(l, r);
L0206        if (temp != 0) return temp;
L0207        else {  /* strings are equal up to a `\0' */
L0208          size_t len = strlen(l);  /* index of first `\0' in both strings */
L0209          if (len == lr)  /* r is finished? */
L0210            return (len == ll) ? 0 : 1;
L0211          else if (len == ll)  /* l is finished? */
L0212            return -1;  /* l is smaller than r (because r is not finished) */
L0213          /* both strings longer than `len'; go on comparing (after the `\0') */
L0214          len++;
L0215          l += len; ll -= len; r += len; lr -= len;
L0216        }
L0217      }
L0218    }
L0219    
L0220    
L0221    int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
L0222      int res;
L0223      if (ttype(l) != ttype(r))
L0224        return luaG_ordererror(L, l, r);
L0225      else if (ttisnumber(l))
L0226        return luai_numlt(nvalue(l), nvalue(r));
L0227      else if (ttisstring(l))
L0228        return l_strcmp(rawtsvalue(l), rawtsvalue(r)) < 0;
L0229      else if ((res = call_orderTM(L, l, r, TM_LT)) != -1)
L0230        return res;
L0231      return luaG_ordererror(L, l, r);
L0232    }
L0233    
L0234    
L0235    static int lessequal (lua_State *L, const TValue *l, const TValue *r) {
L0236      int res;
L0237      if (ttype(l) != ttype(r))
L0238        return luaG_ordererror(L, l, r);
L0239      else if (ttisnumber(l))
L0240        return luai_numle(nvalue(l), nvalue(r));
L0241      else if (ttisstring(l))
L0242        return l_strcmp(rawtsvalue(l), rawtsvalue(r)) <= 0;
L0243      else if ((res = call_orderTM(L, l, r, TM_LE)) != -1)  /* first try `le' */
L0244        return res;
L0245      else if ((res = call_orderTM(L, r, l, TM_LT)) != -1)  /* else try `lt' */
L0246        return !res;
L0247      return luaG_ordererror(L, l, r);
L0248    }
L0249    
L0250    
L0251    int luaV_equalval (lua_State *L, const TValue *t1, const TValue *t2) {
L0252      const TValue *tm;
L0253      lua_assert(ttype(t1) == ttype(t2));
L0254      switch (ttype(t1)) {
L0255        case LUA_TNIL: return 1;
L0256        case LUA_TNUMBER: return luai_numeq(nvalue(t1), nvalue(t2));
L0257        case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2);  /* true must be 1 !! */
L0258        case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
L0259        case LUA_TUSERDATA: {
L0260          if (uvalue(t1) == uvalue(t2)) return 1;
L0261          tm = get_compTM(L, uvalue(t1)->metatable, uvalue(t2)->metatable,
L0262                             TM_EQ);
L0263          break;  /* will try TM */
L0264        }
L0265        case LUA_TTABLE: {
L0266          if (hvalue(t1) == hvalue(t2)) return 1;
L0267          tm = get_compTM(L, hvalue(t1)->metatable, hvalue(t2)->metatable, TM_EQ);
L0268          break;  /* will try TM */
L0269        }
L0270        default: return gcvalue(t1) == gcvalue(t2);
L0271      }
L0272      if (tm == NULL) return 0;  /* no TM? */
L0273      callTMres(L, L->top, tm, t1, t2);  /* call TM */
L0274      return !l_isfalse(L->top);
L0275    }
L0276    
L0277    
L0278    void luaV_concat (lua_State *L, int total, int last) {
L0279      do {
L0280        StkId top = L->base + last + 1;
L0281        int n = 2;  /* number of elements handled in this pass (at least 2) */
L0282        if (!(ttisstring(top-2) || ttisnumber(top-2)) || !tostring(L, top-1)) {
L0283          if (!call_binTM(L, top-2, top-1, top-2, TM_CONCAT))
L0284            luaG_concaterror(L, top-2, top-1);
L0285        } else if (tsvalue(top-1)->len == 0)  /* second op is empty? */
L0286          (void)tostring(L, top - 2);  /* result is first op (as string) */
L0287        else {
L0288          /* at least two string values; get as many as possible */
L0289          size_t tl = tsvalue(top-1)->len;
L0290          char *buffer;
L0291          int i;
L0292          /* collect total length */
L0293          for (n = 1; n < total && tostring(L, top-n-1); n++) {
L0294            size_t l = tsvalue(top-n-1)->len;
L0295            if (l >= MAX_SIZET - tl) luaG_runerror(L, "string length overflow");
L0296            tl += l;
L0297          }
L0298          buffer = luaZ_openspace(L, &G(L)->buff, tl);
L0299          tl = 0;
L0300          for (i=n; i>0; i--) {  /* concat all strings */
L0301            size_t l = tsvalue(top-i)->len;
L0302            memcpy(buffer+tl, svalue(top-i), l);
L0303            tl += l;
L0304          }
L0305          setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl));
L0306        }
L0307        total -= n-1;  /* got `n' strings to create 1 new */
L0308        last -= n-1;
L0309      } while (total > 1);  /* repeat until only 1 result left */
L0310    }
L0311    
L0312    
L0313    static void Arith (lua_State *L, StkId ra, const TValue *rb,
L0314                       const TValue *rc, TMS op) {
L0315      TValue tempb, tempc;
L0316      const TValue *b, *c;
L0317      if ((b = luaV_tonumber(rb, &tempb)) != NULL &&
L0318          (c = luaV_tonumber(rc, &tempc)) != NULL) {
L0319        lua_Number nb = nvalue(b), nc = nvalue(c);
L0320        switch (op) {
L0321          case TM_ADD: setnvalue(ra, luai_numadd(nb, nc)); break;
L0322          case TM_SUB: setnvalue(ra, luai_numsub(nb, nc)); break;
L0323          case TM_MUL: setnvalue(ra, luai_nummul(nb, nc)); break;
L0324          case TM_DIV: setnvalue(ra, luai_numdiv(nb, nc)); break;
L0325          case TM_MOD: setnvalue(ra, luai_nummod(nb, nc)); break;
L0326          case TM_POW: setnvalue(ra, luai_numpow(nb, nc)); break;
L0327          case TM_UNM: setnvalue(ra, luai_numunm(nb)); break;
L0328          default: lua_assert(0); break;
L0329        }
L0330      }
L0331      else if (!call_binTM(L, rb, rc, ra, op))
L0332        luaG_aritherror(L, rb, rc);
L0333    }
L0334    
L0335    
L0336    
L0337    /*
L0338    ** some macros for common tasks in `luaV_execute'
L0339    */
L0340    
L0341    #define runtime_check(L, c)	{ if (!(c)) break; }
L0342    
L0343    #define RA(i)	(base+GETARG_A(i))
L0344    /* to be used after possible stack reallocation */
L0345    #define RB(i)	check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i))
L0346    #define RC(i)	check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i))
L0347    #define RKB(i)	check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \
L0348    	ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i))
L0349    #define RKC(i)	check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \
L0350    	ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i))
L0351    #define KBx(i)	check_exp(getBMode(GET_OPCODE(i)) == OpArgK, k+GETARG_Bx(i))
L0352    
L0353    
L0354    #define dojump(L,pc,i)	{(pc) += (i); luai_threadyield(L);}
L0355    
L0356    
L0357    #define Protect(x)	{ L->savedpc = pc; {x;}; base = L->base; }
L0358    
L0359    
L0360    #define arith_op(op,tm) { \
L0361            TValue *rb = RKB(i); \
L0362            TValue *rc = RKC(i); \
L0363            if (ttisnumber(rb) && ttisnumber(rc)) { \
L0364              lua_Number nb = nvalue(rb), nc = nvalue(rc); \
L0365              setnvalue(ra, op(nb, nc)); \
L0366            } \
L0367            else \
L0368              Protect(Arith(L, ra, rb, rc, tm)); \
L0369          }
L0370    
L0371    
L0372    
L0373    void luaV_execute (lua_State *L, int nexeccalls) {
L0374      LClosure *cl;
L0375      StkId base;
L0376      TValue *k;
L0377      const Instruction *pc;
L0378     reentry:  /* entry point */
L0379      lua_assert(isLua(L->ci));
L0380      pc = L->savedpc;
L0381      cl = &clvalue(L->ci->func)->l;
L0382      base = L->base;
L0383      k = cl->p->k;
L0384      /* main loop of interpreter */
L0385      for (;;) {
L0386        const Instruction i = *pc++;
L0387        StkId ra;
L0388        if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
L0389            (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
L0390          traceexec(L, pc);
L0391          if (L->status == LUA_YIELD) {  /* did hook yield? */
L0392            L->savedpc = pc - 1;
L0393            return;
L0394          }
L0395          base = L->base;
L0396        }
L0397        /* warning!! several calls may realloc the stack and invalidate `ra' */
L0398        ra = RA(i);
L0399        lua_assert(base == L->base && L->base == L->ci->base);
L0400        lua_assert(base <= L->top && L->top <= L->stack + L->stacksize);
L0401        lua_assert(L->top == L->ci->top || luaG_checkopenop(i));
L0402        switch (GET_OPCODE(i)) {
L0403          case OP_MOVE: {
L0404            setobjs2s(L, ra, RB(i));
L0405            continue;
L0406          }
L0407          case OP_LOADK: {
L0408            setobj2s(L, ra, KBx(i));
L0409            continue;
L0410          }
L0411          case OP_LOADBOOL: {
L0412            setbvalue(ra, GETARG_B(i));
L0413            if (GETARG_C(i)) pc++;  /* skip next instruction (if C) */
L0414            continue;
L0415          }
L0416          case OP_LOADNIL: {
L0417            TValue *rb = RB(i);
L0418            do {
L0419              setnilvalue(rb--);
L0420            } while (rb >= ra);
L0421            continue;
L0422          }
L0423          case OP_GETUPVAL: {
L0424            int b = GETARG_B(i);
L0425            setobj2s(L, ra, cl->upvals[b]->v);
L0426            continue;
L0427          }
L0428          case OP_GETGLOBAL: {
L0429            TValue g;
L0430            TValue *rb = KBx(i);
L0431            sethvalue(L, &g, cl->env);
L0432            lua_assert(ttisstring(rb));
L0433            Protect(luaV_gettable(L, &g, rb, ra));
L0434            continue;
L0435          }
L0436          case OP_GETTABLE: {
L0437            Protect(luaV_gettable(L, RB(i), RKC(i), ra));
L0438            continue;
L0439          }
L0440          case OP_SETGLOBAL: {
L0441            TValue g;
L0442            sethvalue(L, &g, cl->env);
L0443            lua_assert(ttisstring(KBx(i)));
L0444            Protect(luaV_settable(L, &g, KBx(i), ra));
L0445            continue;
L0446          }
L0447          case OP_SETUPVAL: {
L0448            UpVal *uv = cl->upvals[GETARG_B(i)];
L0449            setobj(L, uv->v, ra);
L0450            luaC_barrier(L, uv, ra);
L0451            continue;
L0452          }
L0453          case OP_SETTABLE: {
L0454            Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
L0455            continue;
L0456          }
L0457          case OP_NEWTABLE: {
L0458            int b = GETARG_B(i);
L0459            int c = GETARG_C(i);
L0460            sethvalue(L, ra, luaH_new(L, luaO_fb2int(b), luaO_fb2int(c)));
L0461            Protect(luaC_checkGC(L));
L0462            continue;
L0463          }
L0464          case OP_SELF: {
L0465            StkId rb = RB(i);
L0466            setobjs2s(L, ra+1, rb);
L0467            Protect(luaV_gettable(L, rb, RKC(i), ra));
L0468            continue;
L0469          }
L0470          case OP_ADD: {
L0471            arith_op(luai_numadd, TM_ADD);
L0472            continue;
L0473          }
L0474          case OP_SUB: {
L0475            arith_op(luai_numsub, TM_SUB);
L0476            continue;
L0477          }
L0478          case OP_MUL: {
L0479            arith_op(luai_nummul, TM_MUL);
L0480            continue;
L0481          }
L0482          case OP_DIV: {
L0483            arith_op(luai_numdiv, TM_DIV);
L0484            continue;
L0485          }
L0486          case OP_MOD: {
L0487            arith_op(luai_nummod, TM_MOD);
L0488            continue;
L0489          }
L0490          case OP_POW: {
L0491            arith_op(luai_numpow, TM_POW);
L0492            continue;
L0493          }
L0494          case OP_UNM: {
L0495            TValue *rb = RB(i);
L0496            if (ttisnumber(rb)) {
L0497              lua_Number nb = nvalue(rb);
L0498              setnvalue(ra, luai_numunm(nb));
L0499            }
L0500            else {
L0501              Protect(Arith(L, ra, rb, rb, TM_UNM));
L0502            }
L0503            continue;
L0504          }
L0505          case OP_NOT: {
L0506            int res = l_isfalse(RB(i));  /* next assignment may change this value */
L0507            setbvalue(ra, res);
L0508            continue;
L0509          }
L0510          case OP_LEN: {
L0511            const TValue *rb = RB(i);
L0512            switch (ttype(rb)) {
L0513              case LUA_TTABLE: {
L0514                setnvalue(ra, cast_num(luaH_getn(hvalue(rb))));
L0515                break;
L0516              }
L0517              case LUA_TSTRING: {
L0518                setnvalue(ra, cast_num(tsvalue(rb)->len));
L0519                break;
L0520              }
L0521              default: {  /* try metamethod */
L0522                Protect(
L0523                  if (!call_binTM(L, rb, luaO_nilobject, ra, TM_LEN))
L0524                    luaG_typeerror(L, rb, "get length of");
L0525                )
L0526              }
L0527            }
L0528            continue;
L0529          }
L0530          case OP_CONCAT: {
L0531            int b = GETARG_B(i);
L0532            int c = GETARG_C(i);
L0533            Protect(luaV_concat(L, c-b+1, c); luaC_checkGC(L));
L0534            setobjs2s(L, RA(i), base+b);
L0535            continue;
L0536          }
L0537          case OP_JMP: {
L0538            dojump(L, pc, GETARG_sBx(i));
L0539            continue;
L0540          }
L0541          case OP_EQ: {
L0542            TValue *rb = RKB(i);
L0543            TValue *rc = RKC(i);
L0544            Protect(
L0545              if (equalobj(L, rb, rc) == GETARG_A(i))
L0546                dojump(L, pc, GETARG_sBx(*pc));
L0547            )
L0548            pc++;
L0549            continue;
L0550          }
L0551          case OP_LT: {
L0552            Protect(
L0553              if (luaV_lessthan(L, RKB(i), RKC(i)) == GETARG_A(i))
L0554                dojump(L, pc, GETARG_sBx(*pc));
L0555            )
L0556            pc++;
L0557            continue;
L0558          }
L0559          case OP_LE: {
L0560            Protect(
L0561              if (lessequal(L, RKB(i), RKC(i)) == GETARG_A(i))
L0562                dojump(L, pc, GETARG_sBx(*pc));
L0563            )
L0564            pc++;
L0565            continue;
L0566          }
L0567          case OP_TEST: {
L0568            if (l_isfalse(ra) != GETARG_C(i))
L0569              dojump(L, pc, GETARG_sBx(*pc));
L0570            pc++;
L0571            continue;
L0572          }
L0573          case OP_TESTSET: {
L0574            TValue *rb = RB(i);
L0575            if (l_isfalse(rb) != GETARG_C(i)) {
L0576              setobjs2s(L, ra, rb);
L0577              dojump(L, pc, GETARG_sBx(*pc));
L0578            }
L0579            pc++;
L0580            continue;
L0581          }
L0582          case OP_CALL: {
L0583            int b = GETARG_B(i);
L0584            int nresults = GETARG_C(i) - 1;
L0585            if (b != 0) L->top = ra+b;  /* else previous instruction set top */
L0586            L->savedpc = pc;
L0587            switch (luaD_precall(L, ra, nresults)) {
L0588              case PCRLUA: {
L0589                nexeccalls++;
L0590                goto reentry;  /* restart luaV_execute over new Lua function */
L0591              }
L0592              case PCRC: {
L0593                /* it was a C function (`precall' called it); adjust results */
L0594                if (nresults >= 0) L->top = L->ci->top;
L0595                base = L->base;
L0596                continue;
L0597              }
L0598              default: {
L0599                return;  /* yield */
L0600              }
L0601            }
L0602          }
L0603          case OP_TAILCALL: {
L0604            int b = GETARG_B(i);
L0605            if (b != 0) L->top = ra+b;  /* else previous instruction set top */
L0606            L->savedpc = pc;
L0607            lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
L0608            switch (luaD_precall(L, ra, LUA_MULTRET)) {
L0609              case PCRLUA: {
L0610                /* tail call: put new frame in place of previous one */
L0611                CallInfo *ci = L->ci - 1;  /* previous frame */
L0612                int aux;
L0613                StkId func = ci->func;
L0614                StkId pfunc = (ci+1)->func;  /* previous function index */
L0615                if (L->openupval) luaF_close(L, ci->base);
L0616                L->base = ci->base = ci->func + ((ci+1)->base - pfunc);
L0617                for (aux = 0; pfunc+aux < L->top; aux++)  /* move frame down */
L0618                  setobjs2s(L, func+aux, pfunc+aux);
L0619                ci->top = L->top = func+aux;  /* correct top */
L0620                lua_assert(L->top == L->base + clvalue(func)->l.p->maxstacksize);
L0621                ci->savedpc = L->savedpc;
L0622                ci->tailcalls++;  /* one more call lost */
L0623                L->ci--;  /* remove new frame */
L0624                goto reentry;
L0625              }
L0626              case PCRC: {  /* it was a C function (`precall' called it) */
L0627                base = L->base;
L0628                continue;
L0629              }
L0630              default: {
L0631                return;  /* yield */
L0632              }
L0633            }
L0634          }
L0635          case OP_RETURN: {
L0636            int b = GETARG_B(i);
L0637            if (b != 0) L->top = ra+b-1;
L0638            if (L->openupval) luaF_close(L, base);
L0639            L->savedpc = pc;
L0640            b = luaD_poscall(L, ra);
L0641            if (--nexeccalls == 0)  /* was previous function running `here'? */
L0642              return;  /* no: return */
L0643            else {  /* yes: continue its execution */
L0644              if (b) L->top = L->ci->top;
L0645              lua_assert(isLua(L->ci));
L0646              lua_assert(GET_OPCODE(*((L->ci)->savedpc - 1)) == OP_CALL);
L0647              goto reentry;
L0648            }
L0649          }
L0650          case OP_FORLOOP: {
L0651            lua_Number step = nvalue(ra+2);
L0652            lua_Number idx = luai_numadd(nvalue(ra), step); /* increment index */
L0653            lua_Number limit = nvalue(ra+1);
L0654            if (luai_numlt(0, step) ? luai_numle(idx, limit)
L0655                                    : luai_numle(limit, idx)) {
L0656              dojump(L, pc, GETARG_sBx(i));  /* jump back */
L0657              setnvalue(ra, idx);  /* update internal index... */
L0658              setnvalue(ra+3, idx);  /* ...and external index */
L0659            }
L0660            continue;
L0661          }
L0662          case OP_FORPREP: {
L0663            const TValue *init = ra;
L0664            const TValue *plimit = ra+1;
L0665            const TValue *pstep = ra+2;
L0666            L->savedpc = pc;  /* next steps may throw errors */
L0667            if (!tonumber(init, ra))
L0668              luaG_runerror(L, LUA_QL("for") " initial value must be a number");
L0669            else if (!tonumber(plimit, ra+1))
L0670              luaG_runerror(L, LUA_QL("for") " limit must be a number");
L0671            else if (!tonumber(pstep, ra+2))
L0672              luaG_runerror(L, LUA_QL("for") " step must be a number");
L0673            setnvalue(ra, luai_numsub(nvalue(ra), nvalue(pstep)));
L0674            dojump(L, pc, GETARG_sBx(i));
L0675            continue;
L0676          }
L0677          case OP_TFORLOOP: {
L0678            StkId cb = ra + 3;  /* call base */
L0679            setobjs2s(L, cb+2, ra+2);
L0680            setobjs2s(L, cb+1, ra+1);
L0681            setobjs2s(L, cb, ra);
L0682            L->top = cb+3;  /* func. + 2 args (state and index) */
L0683            Protect(luaD_call(L, cb, GETARG_C(i)));
L0684            L->top = L->ci->top;
L0685            cb = RA(i) + 3;  /* previous call may change the stack */
L0686            if (!ttisnil(cb)) {  /* continue loop? */
L0687              setobjs2s(L, cb-1, cb);  /* save control variable */
L0688              dojump(L, pc, GETARG_sBx(*pc));  /* jump back */
L0689            }
L0690            pc++;
L0691            continue;
L0692          }
L0693          case OP_SETLIST: {
L0694            int n = GETARG_B(i);
L0695            int c = GETARG_C(i);
L0696            int last;
L0697            Table *h;
L0698            if (n == 0) {
L0699              n = cast_int(L->top - ra) - 1;
L0700              L->top = L->ci->top;
L0701            }
L0702            if (c == 0) c = cast_int(*pc++);
L0703            runtime_check(L, ttistable(ra));
L0704            h = hvalue(ra);
L0705            last = ((c-1)*LFIELDS_PER_FLUSH) + n;
L0706            if (last > h->sizearray)  /* needs more space? */
L0707              luaH_resizearray(L, h, last);  /* pre-alloc it at once */
L0708            for (; n > 0; n--) {
L0709              TValue *val = ra+n;
L0710              setobj2t(L, luaH_setnum(L, h, last--), val);
L0711              luaC_barriert(L, h, val);
L0712            }
L0713            continue;
L0714          }
L0715          case OP_CLOSE: {
L0716            luaF_close(L, ra);
L0717            continue;
L0718          }
L0719          case OP_CLOSURE: {
L0720            Proto *p;
L0721            Closure *ncl;
L0722            int nup, j;
L0723            p = cl->p->p[GETARG_Bx(i)];
L0724            nup = p->nups;
L0725            ncl = luaF_newLclosure(L, nup, cl->env);
L0726            ncl->l.p = p;
L0727            for (j=0; j<nup; j++, pc++) {
L0728              if (GET_OPCODE(*pc) == OP_GETUPVAL)
L0729                ncl->l.upvals[j] = cl->upvals[GETARG_B(*pc)];
L0730              else {
L0731                lua_assert(GET_OPCODE(*pc) == OP_MOVE);
L0732                ncl->l.upvals[j] = luaF_findupval(L, base + GETARG_B(*pc));
L0733              }
L0734            }
L0735            setclvalue(L, ra, ncl);
L0736            Protect(luaC_checkGC(L));
L0737            continue;
L0738          }
L0739          case OP_VARARG: {
L0740            int b = GETARG_B(i) - 1;
L0741            int j;
L0742            CallInfo *ci = L->ci;
L0743            int n = cast_int(ci->base - ci->func) - cl->p->numparams - 1;
L0744            if (b == LUA_MULTRET) {
L0745              Protect(luaD_checkstack(L, n));
L0746              ra = RA(i);  /* previous call may change the stack */
L0747              b = n;
L0748              L->top = ra + n;
L0749            }
L0750            for (j = 0; j < b; j++) {
L0751              if (j < n) {
L0752                setobjs2s(L, ra + j, ci->base - n + j);
L0753              }
L0754              else {
L0755                setnilvalue(ra + j);
L0756              }
L0757            }
L0758            continue;
L0759          }
L0760        }
L0761      }
L0762    }
L0763    

Generated by pretty.lua