コード例 #1
0
ファイル: lib_ffi.c プロジェクト: JakSprats/Alchemy-Database
/* Handle ctype __index/__newindex metamethods. */
static int ffi_index_meta(lua_State *L, CTState *cts, CType *ct, MMS mm)
{
  CTypeID id = ctype_typeid(cts, ct);
  cTValue *tv = lj_ctype_meta(cts, id, mm);
  TValue *base = L->base;
  if (!tv) {
    const char *s;
  err_index:
    s = strdata(lj_ctype_repr(L, id, NULL));
    if (tvisstr(L->base+1))
      lj_err_callerv(L, LJ_ERR_FFI_BADMEMBER, s, strVdata(L->base+1));
    else
      lj_err_callerv(L, LJ_ERR_FFI_BADIDX, s);
  }
  if (!tvisfunc(tv)) {
    if (mm == MM_index) {
      cTValue *o = lj_meta_tget(L, tv, base+1);
      if (o) {
	if (tvisnil(o)) goto err_index;
	copyTV(L, L->top-1, o);
	return 1;
      }
    } else {
      TValue *o = lj_meta_tset(L, tv, base+1);
      if (o) {
	copyTV(L, o, base+2);
	return 0;
      }
    }
    tv = L->top-1;
  }
  return lj_meta_tailcall(L, tv);
}
コード例 #2
0
ファイル: lib_jit.c プロジェクト: ghisguth/lua-cmake-source
static int setjitmode(lua_State *L, int mode)
{
  int idx = 0;
  if (L->base == L->top || tvisnil(L->base)) {  /* jit.on/off/flush([nil]) */
    mode |= LUAJIT_MODE_ENGINE;
  } else {
    /* jit.on/off/flush(func|proto, nil|true|false) */
    if (tvisfunc(L->base) || tvisproto(L->base))
      idx = 1;
    else if (!tvistrue(L->base))  /* jit.on/off/flush(true, nil|true|false) */
      goto err;
    if (L->base+1 < L->top && tvisbool(L->base+1))
      mode |= boolV(L->base+1) ? LUAJIT_MODE_ALLFUNC : LUAJIT_MODE_ALLSUBFUNC;
    else
      mode |= LUAJIT_MODE_FUNC;
  }
  if (luaJIT_setmode(L, idx, mode) != 1) {
  err:
#if LJ_HASJIT
    lj_err_arg(L, 1, LJ_ERR_NOLFUNC);
#else
    lj_err_caller(L, LJ_ERR_NOJIT);
#endif
  }
  return 0;
}
コード例 #3
0
ファイル: lj_meta.c プロジェクト: 449306923/uLui
TValue * LJ_FASTCALL lj_meta_equal_cd(lua_State *L, BCIns ins)
{
  ASMFunction cont = (bc_op(ins) & 1) ? lj_cont_condf : lj_cont_condt;
  int op = (int)bc_op(ins) & ~1;
  TValue tv;
  cTValue *mo, *o2, *o1 = &L->base[bc_a(ins)];
  cTValue *o1mm = o1;
  if (op == BC_ISEQV) {
    o2 = &L->base[bc_d(ins)];
    if (!tviscdata(o1mm)) o1mm = o2;
  } else if (op == BC_ISEQS) {
    setstrV(L, &tv, gco2str(proto_kgc(curr_proto(L), ~(ptrdiff_t)bc_d(ins))));
    o2 = &tv;
  } else if (op == BC_ISEQN) {
    o2 = &mref(curr_proto(L)->k, cTValue)[bc_d(ins)];
  } else {
    lua_assert(op == BC_ISEQP);
    setpriV(&tv, ~bc_d(ins));
    o2 = &tv;
  }
  mo = lj_meta_lookup(L, o1mm, MM_eq);
  if (LJ_LIKELY(!tvisnil(mo)))
    return mmcall(L, cont, mo, o1, o2);
  else
    return (TValue *)(intptr_t)(bc_op(ins) & 1);
}
コード例 #4
0
ファイル: lj_meta.c プロジェクト: JakSprats/Alchemy-Database
/* Helper for LEN. __len metamethod. */
TValue * LJ_FASTCALL lj_meta_len(lua_State *L, cTValue *o)
{
  cTValue *mo = lj_meta_lookup(L, o, MM_len);
  if (tvisnil(mo)) {
    lj_err_optype(L, o, LJ_ERR_OPLEN);
    return NULL;  /* unreachable */
  }
  return mmcall(L, lj_cont_ra, mo, o, niltv(L));
}
コード例 #5
0
ファイル: lj_meta.c プロジェクト: 449306923/uLui
/* Helper for ordered comparisons. String compare, __lt/__le metamethods. */
TValue *lj_meta_comp(lua_State *L, cTValue *o1, cTValue *o2, int op)
{
  if (LJ_HASFFI && (tviscdata(o1) || tviscdata(o2))) {
    ASMFunction cont = (op & 1) ? lj_cont_condf : lj_cont_condt;
    MMS mm = (op & 2) ? MM_le : MM_lt;
    cTValue *mo = lj_meta_lookup(L, tviscdata(o1) ? o1 : o2, mm);
    if (LJ_UNLIKELY(tvisnil(mo))) goto err;
    return mmcall(L, cont, mo, o1, o2);
  } else if (LJ_52 || itype(o1) == itype(o2)) {
    /* Never called with two numbers. */
    if (tvisstr(o1) && tvisstr(o2)) {
      int32_t res = lj_str_cmp(strV(o1), strV(o2));
      return (TValue *)(intptr_t)(((op&2) ? res <= 0 : res < 0) ^ (op&1));
    } else {
    trymt:
      while (1) {
	ASMFunction cont = (op & 1) ? lj_cont_condf : lj_cont_condt;
	MMS mm = (op & 2) ? MM_le : MM_lt;
	cTValue *mo = lj_meta_lookup(L, o1, mm);
#if LJ_52
	if (tvisnil(mo) && tvisnil((mo = lj_meta_lookup(L, o2, mm))))
#else
	cTValue *mo2 = lj_meta_lookup(L, o2, mm);
	if (tvisnil(mo) || !lj_obj_equal(mo, mo2))
#endif
	{
	  if (op & 2) {  /* MM_le not found: retry with MM_lt. */
	    cTValue *ot = o1; o1 = o2; o2 = ot;  /* Swap operands. */
	    op ^= 3;  /* Use LT and flip condition. */
	    continue;
	  }
	  goto err;
	}
	return mmcall(L, cont, mo, o1, o2);
      }
    }
  } else if (tvisbool(o1) && tvisbool(o2)) {
    goto trymt;
  } else {
  err:
    lj_err_comp(L, o1, o2);
    return NULL;
  }
}
コード例 #6
0
ファイル: lj_meta.c プロジェクト: 449306923/uLui
/* Negative caching of a few fast metamethods. See the lj_meta_fast() macro. */
cTValue *lj_meta_cache(GCtab *mt, MMS mm, GCstr *name)
{
  cTValue *mo = lj_tab_getstr(mt, name);
  lua_assert(mm <= MM_FAST);
  if (!mo || tvisnil(mo)) {  /* No metamethod? */
    mt->nomm |= (uint8_t)(1u<<mm);  /* Set negative cache flag. */
    return NULL;
  }
  return mo;
}
コード例 #7
0
ファイル: lj_lib.c プロジェクト: AaronDP/luajit-2.0_adbshell
GCtab *lj_lib_checktabornil(lua_State *L, int narg)
{
  TValue *o = L->base + narg-1;
  if (o < L->top) {
    if (tvistab(o))
      return tabV(o);
    else if (tvisnil(o))
      return NULL;
  }
  lj_err_arg(L, narg, LJ_ERR_NOTABN);
  return NULL;  /* unreachable */
}
コード例 #8
0
ファイル: lj_meta.c プロジェクト: 449306923/uLui
/* Helper for LEN. __len metamethod. */
TValue * LJ_FASTCALL lj_meta_len(lua_State *L, cTValue *o)
{
  cTValue *mo = lj_meta_lookup(L, o, MM_len);
  if (tvisnil(mo)) {
    if (LJ_52 && tvistab(o))
      tabref(tabV(o)->metatable)->nomm |= (uint8_t)(1u<<MM_len);
    else
      lj_err_optype(L, o, LJ_ERR_OPLEN);
    return NULL;
  }
  return mmcall(L, lj_cont_ra, mo, o, LJ_52 ? o : niltv(L));
}
コード例 #9
0
ファイル: lj_meta.c プロジェクト: 449306923/uLui
/* Helper for TSET*. __newindex chain and metamethod. */
TValue *lj_meta_tset(lua_State *L, cTValue *o, cTValue *k)
{
  TValue tmp;
  int loop;
  for (loop = 0; loop < LJ_MAX_IDXCHAIN; loop++) {
    cTValue *mo;
    if (LJ_LIKELY(tvistab(o))) {
      GCtab *t = tabV(o);
      cTValue *tv = lj_tab_get(L, t, k);
      if (LJ_LIKELY(!tvisnil(tv))) {
	t->nomm = 0;  /* Invalidate negative metamethod cache. */
	lj_gc_anybarriert(L, t);
	return (TValue *)tv;
      } else if (!(mo = lj_meta_fast(L, tabref(t->metatable), MM_newindex))) {
	t->nomm = 0;  /* Invalidate negative metamethod cache. */
	lj_gc_anybarriert(L, t);
	if (tv != niltv(L))
	  return (TValue *)tv;
	if (tvisnil(k)) lj_err_msg(L, LJ_ERR_NILIDX);
	else if (tvisint(k)) { setnumV(&tmp, (lua_Number)intV(k)); k = &tmp; }
	else if (tvisnum(k) && tvisnan(k)) lj_err_msg(L, LJ_ERR_NANIDX);
	return lj_tab_newkey(L, t, k);
      }
    } else if (tvisnil(mo = lj_meta_lookup(L, o, MM_newindex))) {
      lj_err_optype(L, o, LJ_ERR_OPINDEX);
      return NULL;  /* unreachable */
    }
    if (tvisfunc(mo)) {
      L->top = mmcall(L, lj_cont_nop, mo, o, k);
      /* L->top+2 = v filled in by caller. */
      return NULL;  /* Trigger metamethod call. */
    }
    copyTV(L, &tmp, mo);
    o = &tmp;
  }
  lj_err_msg(L, LJ_ERR_SETLOOP);
  return NULL;  /* unreachable */
}
コード例 #10
0
ファイル: lj_clib.c プロジェクト: BillTheBest/ironbee
/* Index a C library by name. */
TValue *lj_clib_index(lua_State *L, CLibrary *cl, GCstr *name)
{
  TValue *tv = lj_tab_setstr(L, cl->cache, name);
  if (LJ_UNLIKELY(tvisnil(tv))) {
    CTState *cts = ctype_cts(L);
    CType *ct;
    CTypeID id = lj_ctype_getname(cts, &ct, name, CLNS_INDEX);
    if (!id)
      lj_err_callerv(L, LJ_ERR_FFI_NODECL, strdata(name));
    if (ctype_isconstval(ct->info)) {
      CType *ctt = ctype_child(cts, ct);
      lua_assert(ctype_isinteger(ctt->info) && ctt->size <= 4);
      if ((ctt->info & CTF_UNSIGNED) && (int32_t)ct->size < 0)
	setnumV(tv, (lua_Number)(uint32_t)ct->size);
      else
	setintV(tv, (int32_t)ct->size);
    } else {
      const char *sym = clib_extsym(cts, ct, name);
#if LJ_TARGET_WINDOWS
      DWORD oldwerr = GetLastError();
#endif
      void *p = clib_getsym(cl, sym);
      GCcdata *cd;
      lua_assert(ctype_isfunc(ct->info) || ctype_isextern(ct->info));
#if LJ_TARGET_X86 && LJ_ABI_WIN
      /* Retry with decorated name for fastcall/stdcall functions. */
      if (!p && ctype_isfunc(ct->info)) {
	CTInfo cconv = ctype_cconv(ct->info);
	if (cconv == CTCC_FASTCALL || cconv == CTCC_STDCALL) {
	  CTSize sz = clib_func_argsize(cts, ct);
	  const char *symd = lj_str_pushf(L,
			       cconv == CTCC_FASTCALL ? "@%s@%d" : "_%s@%d",
			       sym, sz);
	  L->top--;
	  p = clib_getsym(cl, symd);
	}
      }
#endif
      if (!p)
	clib_error(L, "cannot resolve symbol " LUA_QS ": %s", sym);
#if LJ_TARGET_WINDOWS
      SetLastError(oldwerr);
#endif
      cd = lj_cdata_new(cts, id, CTSIZE_PTR);
      *(void **)cdataptr(cd) = p;
      setcdataV(L, tv, cd);
    }
  }
  return tv;
}
コード例 #11
0
ファイル: lj_meta.c プロジェクト: 449306923/uLui
/* Helper for arithmetic instructions. Coercion, metamethod. */
TValue *lj_meta_arith(lua_State *L, TValue *ra, cTValue *rb, cTValue *rc,
		      BCReg op)
{
  MMS mm = bcmode_mm(op);
  TValue tempb, tempc;
  cTValue *b, *c;
  if ((b = str2num(rb, &tempb)) != NULL &&
      (c = str2num(rc, &tempc)) != NULL) {  /* Try coercion first. */
    setnumV(ra, lj_vm_foldarith(numV(b), numV(c), (int)mm-MM_add));
    return NULL;
  } else {
    cTValue *mo = lj_meta_lookup(L, rb, mm);
    if (tvisnil(mo)) {
      mo = lj_meta_lookup(L, rc, mm);
      if (tvisnil(mo)) {
	if (str2num(rb, &tempb) == NULL) rc = rb;
	lj_err_optype(L, rc, LJ_ERR_OPARITH);
	return NULL;  /* unreachable */
      }
    }
    return mmcall(L, lj_cont_ra, mo, rb, rc);
  }
}
コード例 #12
0
ファイル: lj_meta.c プロジェクト: 449306923/uLui
/* Helper for TGET*. __index chain and metamethod. */
cTValue *lj_meta_tget(lua_State *L, cTValue *o, cTValue *k)
{
  int loop;
  for (loop = 0; loop < LJ_MAX_IDXCHAIN; loop++) {
    cTValue *mo;
    if (LJ_LIKELY(tvistab(o))) {
      GCtab *t = tabV(o);
      cTValue *tv = lj_tab_get(L, t, k);
      if (!tvisnil(tv) ||
	  !(mo = lj_meta_fast(L, tabref(t->metatable), MM_index)))
	return tv;
    } else if (tvisnil(mo = lj_meta_lookup(L, o, MM_index))) {
      lj_err_optype(L, o, LJ_ERR_OPINDEX);
      return NULL;  /* unreachable */
    }
    if (tvisfunc(mo)) {
      L->top = mmcall(L, lj_cont_ra, mo, o, k);
      return NULL;  /* Trigger metamethod call. */
    }
    o = mo;
  }
  lj_err_msg(L, LJ_ERR_GETLOOP);
  return NULL;  /* unreachable */
}
コード例 #13
0
ファイル: lj_cdata.c プロジェクト: 03050903/Urho3D
void lj_cdata_setfin(lua_State *L, GCcdata *cd, GCobj *obj, uint32_t it)
{
  GCtab *t = ctype_ctsG(G(L))->finalizer;
  if (gcref(t->metatable)) {
    /* Add cdata to finalizer table, if still enabled. */
    TValue *tv, tmp;
    setcdataV(L, &tmp, cd);
    lj_gc_anybarriert(L, t);
    tv = lj_tab_set(L, t, &tmp);
    setgcV(L, tv, obj, it);
    if (!tvisnil(tv))
      cd->marked |= LJ_GC_CDATA_FIN;
    else
      cd->marked &= ~LJ_GC_CDATA_FIN;
  }
}
コード例 #14
0
ファイル: lj_meta.c プロジェクト: LegalEagle/Arianrhod
/* Helper for LEN. __len metamethod. */
TValue * LJ_FASTCALL lj_meta_len(lua_State *L, cTValue *o)
{
  cTValue *mo = lj_meta_lookup(L, o, MM_len);
  if (tvisnil(mo)) {
#ifdef LUAJIT_ENABLE_LUA52COMPAT
    if (tvistab(o))
      tabref(tabV(o)->metatable)->nomm |= (uint8_t)(1u<<MM_len);
    else
#endif
      lj_err_optype(L, o, LJ_ERR_OPLEN);
    return NULL;
  }
#ifdef LUAJIT_ENABLE_LUA52COMPAT
  return mmcall(L, lj_cont_ra, mo, o, o);
#else
  return mmcall(L, lj_cont_ra, mo, o, niltv(L));
#endif
}
コード例 #15
0
ファイル: lj_dispatch.c プロジェクト: derdewey/luajit
/* Call dispatch. Used by call hooks, hot calls or when recording. */
ASMFunction LJ_FASTCALL lj_dispatch_call(lua_State *L, const BCIns *pc)
{
  GCfunc *fn = curr_func(L);
  BCOp op;
  global_State *g = G(L);
#if LJ_HASJIT
  jit_State *J = G2J(g);
#endif
  int missing = call_init(L, fn);
#if LJ_HASJIT
  J->L = L;
  if ((uintptr_t)pc & 1) {  /* Marker for hot call. */
    pc = (const BCIns *)((uintptr_t)pc & ~(uintptr_t)1);
    lj_trace_hot(J, pc);
    goto out;
  } else if (J->state != LJ_TRACE_IDLE &&
	     !(g->hookmask & (HOOK_GC|HOOK_VMEVENT))) {
    /* Record the FUNC* bytecodes, too. */
    lj_trace_ins(J, pc-1);  /* The interpreter bytecode PC is offset by 1. */
  }
#endif
  if ((g->hookmask & LUA_MASKCALL)) {
    int i;
    for (i = 0; i < missing; i++)  /* Add missing parameters. */
      setnilV(L->top++);
    callhook(L, LUA_HOOKCALL, -1);
    /* Preserve modifications of missing parameters by lua_setlocal(). */
    while (missing-- > 0 && tvisnil(L->top - 1))
      L->top--;
  }
#if LJ_HASJIT
out:
#endif
  op = bc_op(pc[-1]);  /* Get FUNC* op. */
#if LJ_HASJIT
  /* Use the non-hotcounting variants if JIT is off or while recording. */
  if ((!(J->flags & JIT_F_ON) || J->state != LJ_TRACE_IDLE) &&
      (op == BC_FUNCF || op == BC_FUNCV))
    op = (BCOp)((int)op+(int)BC_IFUNCF-(int)BC_FUNCF);
#endif
  return makeasmfunc(lj_bc_ofs[op]);  /* Return static dispatch target. */
}
コード例 #16
0
static int io_file_iter(lua_State *L)
{
  GCfunc *fn = curr_func(L);
  IOFileUD *iof = uddata(udataV(&fn->c.upvalue[0]));
  int n = fn->c.nupvalues - 1;
  if (iof->fp == NULL)
    lj_err_caller(L, LJ_ERR_IOCLFL);
  L->top = L->base;
  if (n) {  /* Copy upvalues with options to stack. */
    if (n > LUAI_MAXCSTACK)
      lj_err_caller(L, LJ_ERR_STKOV);
    lj_state_checkstack(L, (MSize)n);
    memcpy(L->top, &fn->c.upvalue[1], n*sizeof(TValue));
    L->top += n;
  }
  n = io_file_read(L, iof->fp, 0);
  if (ferror(iof->fp))
    lj_err_callermsg(L, strVdata(L->top-2));
  if (tvisnil(L->base) && (iof->type & IOFILE_FLAG_CLOSE)) {
    io_file_close(L, iof);  /* Return values are ignored. */
    return 0;
  }
  return n;
}
コード例 #17
0
ファイル: lj_lib.c プロジェクト: AaronDP/luajit-2.0_adbshell
int32_t lj_lib_optint(lua_State *L, int narg, int32_t def)
{
  TValue *o = L->base + narg-1;
  return (o < L->top && !tvisnil(o)) ? lj_lib_checkint(L, narg) : def;
}
コード例 #18
0
ファイル: lj_lib.c プロジェクト: AaronDP/luajit-2.0_adbshell
GCstr *lj_lib_optstr(lua_State *L, int narg)
{
  TValue *o = L->base + narg-1;
  return (o < L->top && !tvisnil(o)) ? lj_lib_checkstr(L, narg) : NULL;
}
コード例 #19
0
ファイル: lj_meta.c プロジェクト: JakSprats/Alchemy-Database
/* Helper for CAT. Coercion, iterative concat, __concat metamethod. */
TValue *lj_meta_cat(lua_State *L, TValue *top, int left)
{
  do {
    int n = 1;
    if (!(tvisstr(top-1) || tvisnumber(top-1)) || !tostring(L, top)) {
      cTValue *mo = lj_meta_lookup(L, top-1, MM_concat);
      if (tvisnil(mo)) {
	mo = lj_meta_lookup(L, top, MM_concat);
	if (tvisnil(mo)) {
	  if (tvisstr(top-1) || tvisnumber(top-1)) top++;
	  lj_err_optype(L, top-1, LJ_ERR_OPCAT);
	  return NULL;  /* unreachable */
	}
      }
      /* One of the top two elements is not a string, call __cat metamethod:
      **
      ** before:    [...][CAT stack .........................]
      **                                 top-1     top         top+1 top+2
      ** pick two:  [...][CAT stack ...] [o1]      [o2]
      ** setup mm:  [...][CAT stack ...] [cont|?]  [mo|tmtype] [o1]  [o2]
      ** in asm:    [...][CAT stack ...] [cont|PC] [mo|delta]  [o1]  [o2]
      **            ^-- func base                              ^-- mm base
      ** after mm:  [...][CAT stack ...] <--push-- [result]
      ** next step: [...][CAT stack .............]
      */
      copyTV(L, top+2, top);  /* Careful with the order of stack copies! */
      copyTV(L, top+1, top-1);
      copyTV(L, top, mo);
      setcont(top-1, lj_cont_cat);
      return top+1;  /* Trigger metamethod call. */
    } else if (strV(top)->len == 0) {  /* Shortcut. */
      (void)tostring(L, top-1);
    } else {
      /* Pick as many strings as possible from the top and concatenate them:
      **
      ** before:    [...][CAT stack ...........................]
      ** pick str:  [...][CAT stack ...] [...... strings ......]
      ** concat:    [...][CAT stack ...] [result]
      ** next step: [...][CAT stack ............]
      */
      MSize tlen = strV(top)->len;
      char *buffer;
      int i;
      for (n = 1; n <= left && tostring(L, top-n); n++) {
	MSize len = strV(top-n)->len;
	if (len >= LJ_MAX_STR - tlen)
	  lj_err_msg(L, LJ_ERR_STROV);
	tlen += len;
      }
      buffer = lj_str_needbuf(L, &G(L)->tmpbuf, tlen);
      n--;
      tlen = 0;
      for (i = n; i >= 0; i--) {
	MSize len = strV(top-i)->len;
	memcpy(buffer + tlen, strVdata(top-i), len);
	tlen += len;
      }
      setstrV(L, top-n, lj_str_new(L, buffer, tlen));
    }
    left -= n;
    top -= n;
  } while (left >= 1);
  lj_gc_check_fixtop(L);
  return NULL;
}
コード例 #20
0
ファイル: lj_meta.c プロジェクト: 449306923/uLui
/* Helper for CAT. Coercion, iterative concat, __concat metamethod. */
TValue *lj_meta_cat(lua_State *L, TValue *top, int left)
{
  int fromc = 0;
  if (left < 0) { left = -left; fromc = 1; }
  do {
    if (!(tvisstr(top) || tvisnumber(top)) ||
	!(tvisstr(top-1) || tvisnumber(top-1))) {
      cTValue *mo = lj_meta_lookup(L, top-1, MM_concat);
      if (tvisnil(mo)) {
	mo = lj_meta_lookup(L, top, MM_concat);
	if (tvisnil(mo)) {
	  if (tvisstr(top-1) || tvisnumber(top-1)) top++;
	  lj_err_optype(L, top-1, LJ_ERR_OPCAT);
	  return NULL;  /* unreachable */
	}
      }
      /* One of the top two elements is not a string, call __cat metamethod:
      **
      ** before:    [...][CAT stack .........................]
      **                                 top-1     top         top+1 top+2
      ** pick two:  [...][CAT stack ...] [o1]      [o2]
      ** setup mm:  [...][CAT stack ...] [cont|?]  [mo|tmtype] [o1]  [o2]
      ** in asm:    [...][CAT stack ...] [cont|PC] [mo|delta]  [o1]  [o2]
      **            ^-- func base                              ^-- mm base
      ** after mm:  [...][CAT stack ...] <--push-- [result]
      ** next step: [...][CAT stack .............]
      */
      copyTV(L, top+2*LJ_FR2+2, top);  /* Carefully ordered stack copies! */
      copyTV(L, top+2*LJ_FR2+1, top-1);
      copyTV(L, top+LJ_FR2, mo);
      setcont(top-1, lj_cont_cat);
      if (LJ_FR2) { setnilV(top); setnilV(top+2); top += 2; }
      return top+1;  /* Trigger metamethod call. */
    } else {
      /* Pick as many strings as possible from the top and concatenate them:
      **
      ** before:    [...][CAT stack ...........................]
      ** pick str:  [...][CAT stack ...] [...... strings ......]
      ** concat:    [...][CAT stack ...] [result]
      ** next step: [...][CAT stack ............]
      */
      TValue *e, *o = top;
      uint64_t tlen = tvisstr(o) ? strV(o)->len : STRFMT_MAXBUF_NUM;
      char *p, *buf;
      do {
	o--; tlen += tvisstr(o) ? strV(o)->len : STRFMT_MAXBUF_NUM;
      } while (--left > 0 && (tvisstr(o-1) || tvisnumber(o-1)));
      if (tlen >= LJ_MAX_STR) lj_err_msg(L, LJ_ERR_STROV);
      p = buf = lj_buf_tmp(L, (MSize)tlen);
      for (e = top, top = o; o <= e; o++) {
	if (tvisstr(o)) {
	  GCstr *s = strV(o);
	  MSize len = s->len;
	  p = lj_buf_wmem(p, strdata(s), len);
	} else if (tvisint(o)) {
	  p = lj_strfmt_wint(p, intV(o));
	} else {
	  lua_assert(tvisnum(o));
	  p = lj_strfmt_wnum(p, o);
	}
      }
      setstrV(L, top, lj_str_new(L, buf, (size_t)(p-buf)));
    }
  } while (left >= 1);
  if (LJ_UNLIKELY(G(L)->gc.total >= G(L)->gc.threshold)) {
    if (!fromc) L->top = curr_topL(L);
    lj_gc_step(L);
  }
  return NULL;
}