自学教程：C++ strV函数代码示例

/* Helper for FORI. Coercion. */void LJ_FASTCALL lj_meta_for(lua_State *L, TValue *o){  if (!(tvisnumber(o) || (tvisstr(o) && lj_str_tonumber(strV(o), o))))    lj_err_msg(L, LJ_ERR_FORINIT);  if (!(tvisnumber(o+1) || (tvisstr(o+1) && lj_str_tonumber(strV(o+1), o+1))))    lj_err_msg(L, LJ_ERR_FORLIM);  if (!(tvisnumber(o+2) || (tvisstr(o+2) && lj_str_tonumber(strV(o+2), o+2))))    lj_err_msg(L, LJ_ERR_FORSTEP);  if (LJ_DUALNUM) {    /* Ensure all slots are integers or all slots are numbers. */    int32_t k[3];    int nint = 0;    ptrdiff_t i;    for (i = 0; i <= 2; i++) {      if (tvisint(o+i)) {	k[i] = intV(o+i); nint++;      } else {	k[i] = lj_num2int(numV(o+i)); nint += ((lua_Number)k[i] == numV(o+i));      }    }    if (nint == 3) {  /* Narrow to integers. */      setintV(o, k[0]);      setintV(o+1, k[1]);      setintV(o+2, k[2]);    } else if (nint != 0) {  /* Widen to numbers. */      if (tvisint(o)) setnumV(o, (lua_Number)intV(o));      if (tvisint(o+1)) setnumV(o+1, (lua_Number)intV(o+1));      if (tvisint(o+2)) setnumV(o+2, (lua_Number)intV(o+2));    }  }}

static void LJ_FASTCALL recff_tonumber(jit_State *J, RecordFFData *rd){  TRef tr = J->base[0];  TRef base = J->base[1];  if (tr && base) {    base = lj_opt_narrow_toint(J, base);    if (!tref_isk(base) || IR(tref_ref(base))->i != 10)      recff_nyiu(J);  }  if (tref_isnumber_str(tr)) {    if (tref_isstr(tr)) {      TValue tmp;      if (!lj_str_tonum(strV(&rd->argv[0]), &tmp))	recff_nyiu(J);  /* Would need an inverted STRTO for this case. */      tr = emitir(IRTG(IR_STRTO, IRT_NUM), tr, 0);    }#if LJ_HASFFI  } else if (tref_iscdata(tr)) {    lj_crecord_tonumber(J, rd);    return;#endif  } else {    tr = TREF_NIL;  }  J->base[0] = tr;  UNUSED(rd);}

/* Narrowing of power operator or math.pow. */TRef lj_opt_narrow_pow(jit_State *J, TRef rb, TRef rc, TValue *vc){  lua_Number n;  if (tvisstr(vc) && !lj_str_tonum(strV(vc), vc))    lj_trace_err(J, LJ_TRERR_BADTYPE);  n = numV(vc);  /* Limit narrowing for pow to small exponents (or for two constants). */  if ((tref_isk(rc) && tref_isint(rc) && tref_isk(rb)) ||      ((J->flags & JIT_F_OPT_NARROW) &&       (numisint(n) && n >= -65536.0 && n <= 65536.0))) {    TRef tmp;    if (!tref_isinteger(rc)) {      if (tref_isstr(rc))	rc = emitir(IRTG(IR_STRTO, IRT_NUM), rc, 0);      rc = emitir(IRTGI(IR_TOINT), rc, IRTOINT_CHECK); /* Guarded TOINT! */    }    if (!tref_isk(rc)) {  /* Range guard: -65536 <= i <= 65536 */      tmp = emitir(IRTI(IR_ADD), rc, lj_ir_kint(J, 65536-2147483647-1));      emitir(IRTGI(IR_LE), tmp, lj_ir_kint(J, 2*65536-2147483647-1));    }    return emitir(IRTN(IR_POWI), rb, rc);  }  /* FOLD covers most cases, but some are easier to do here. */  if (tref_isk(rb) && tvispone(ir_knum(IR(tref_ref(rb)))))    return rb;  /* 1 ^ x ==> 1 */  rc = lj_ir_tonum(J, rc);  if (tref_isk(rc) && ir_knum(IR(tref_ref(rc)))->n == 0.5)    return emitir(IRTN(IR_FPMATH), rb, IRFPM_SQRT);  /* x ^ 0.5 ==> sqrt(x) */  /* Split up b^c into exp2(c*log2(b)). Assembler may rejoin later. */  rb = emitir(IRTN(IR_FPMATH), rb, IRFPM_LOG2);  rc = emitir(IRTN(IR_MUL), rb, rc);  return emitir(IRTN(IR_FPMATH), rc, IRFPM_EXP2);}

static int io_file_write(lua_State *L, FILE *fp, int start){  cTValue *tv;  int status = 1;  for (tv = L->base+start; tv < L->top; tv++) {    if (tvisstr(tv)) {      MSize len = strV(tv)->len;      status = status && (fwrite(strVdata(tv), 1, len, fp) == len);    } else if (tvisint(tv)) {      char buf[LJ_STR_INTBUF];      char *p = lj_str_bufint(buf, intV(tv));      size_t len = (size_t)(buf+LJ_STR_INTBUF-p);      status = status && (fwrite(p, 1, len, fp) == len);    } else if (tvisnum(tv)) {      status = status && (fprintf(fp, LUA_NUMBER_FMT, numV(tv)) > 0);    } else {      lj_err_argt(L, (int)(tv - L->base) + 1, LUA_TSTRING);    }  }  if (LJ_52 && status) {    L->top = L->base+1;    if (start == 0)      setudataV(L, L->base, IOSTDF_UD(L, GCROOT_IO_OUTPUT));    return 1;  }  return luaL_fileresult(L, status, NULL);}

void QPredefProfileEditDialog::on_BtnDelete_clicked(){    int nIndex = ui->CBProfileList->currentIndex();    if( nIndex < 0 ) return;    ui->CBProfileList->removeItem( nIndex );    QString strFilePath( QApplication::applicationDirPath() );    strFilePath += "/config/gestureprofiles.ini";    if( !QFile::exists( strFilePath ) )        return;    QFile file( strFilePath );    if( !file.open( QFile::WriteOnly ) )        return;    for( int i=0; i<ui->CBProfileList->count(); i++ )    {        QString strV( ui->CBProfileList->itemText(i) );        strV += "=" + ui->CBProfileList->itemData(i).toString() + "/n";        file.write( strV.toUtf8().constData() );    }    file.close();}

/* Check first argument for a C type and returns its ID. */static CTypeID ffi_checkctype(lua_State *L, CTState *cts, TValue *param){  TValue *o = L->base;  if (!(o < L->top)) {  err_argtype:    lj_err_argtype(L, 1, "C type");  }  if (tvisstr(o)) {  /* Parse an abstract C type declaration. */    GCstr *s = strV(o);    CPState cp;    int errcode;    cp.L = L;    cp.cts = cts;    cp.srcname = strdata(s);    cp.p = strdata(s);    cp.param = param;    cp.mode = CPARSE_MODE_ABSTRACT|CPARSE_MODE_NOIMPLICIT;    errcode = lj_cparse(&cp);    if (errcode) lj_err_throw(L, errcode);  /* Propagate errors. */    return cp.val.id;  } else {    GCcdata *cd;    if (!tviscdata(o)) goto err_argtype;    if (param && param < L->top) lj_err_arg(L, 1, LJ_ERR_FFI_NUMPARAM);    cd = cdataV(o);    return cd->ctypeid == CTID_CTYPEID ? *(CTypeID *)cdataptr(cd) : cd->ctypeid;  }}

/* Determine mode of select() call. */int32_t lj_ffrecord_select_mode(jit_State *J, TRef tr, TValue *tv){  if (tref_isstr(tr) && *strVdata(tv) == '#') {  /* select('#', ...) */    if (strV(tv)->len == 1) {      emitir(IRTG(IR_EQ, IRT_STR), tr, lj_ir_kstr(J, strV(tv)));    } else {      TRef trptr = emitir(IRT(IR_STRREF, IRT_P32), tr, lj_ir_kint(J, 0));      TRef trchar = emitir(IRT(IR_XLOAD, IRT_U8), trptr, IRXLOAD_READONLY);      emitir(IRTG(IR_EQ, IRT_INT), trchar, lj_ir_kint(J, '#'));    }    return 0;  } else {  /* select(n, ...) */    int32_t start = argv2int(J, tv);    if (start == 0) lj_trace_err(J, LJ_TRERR_BADTYPE);  /* A bit misleading. */    return start;  }}

/* 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;  }}

static cTValue *str2num(cTValue *o, TValue *n){  if (tvisnum(o))    return o;  else if (tvisint(o))    return (setnumV(n, (lua_Number)intV(o)), n);  else if (tvisstr(o) && lj_strscan_num(strV(o), n))    return n;  else    return NULL;}

/* Hash an arbitrary key and return its anchor position in the hash table. */static Node *hashkey(const GCtab *t, cTValue *key){  if (tvisstr(key))    return hashstr(t, strV(key));  else if (tvisnum(key))    return hashnum(t, key);  else if (tvisbool(key))    return hashmask(t, boolV(key));  else    return hashgcref(t, key->gcr);  /* Only hash 32 bits of lightuserdata on a 64 bit CPU. Good enough? */}

static void LJ_FASTCALL recff_type(jit_State *J, RecordFFData *rd){  /* Arguments already specialized. Result is a constant string. Neat, huh? */  uint32_t t;  if (tvisnumber(&rd->argv[0]))    t = ~LJ_TNUMX;  else if (LJ_64 && tvislightud(&rd->argv[0]))    t = ~LJ_TLIGHTUD;  else    t = ~itype(&rd->argv[0]);  J->base[0] = lj_ir_kstr(J, strV(&J->fn->c.upvalue[t]));  UNUSED(rd);}

lua_Number lj_lib_checknum(lua_State *L, int narg){  TValue *o = L->base + narg-1;  if (!(o < L->top &&	(tvisnumber(o) || (tvisstr(o) && lj_strscan_num(strV(o), o)))))    lj_err_argt(L, narg, LUA_TNUMBER);  if (LJ_UNLIKELY(tvisint(o))) {    lua_Number n = (lua_Number)intV(o);    setnumV(o, n);    return n;  } else {    return numV(o);  }}

GCstr *lj_lib_checkstr(lua_State *L, int narg){  TValue *o = L->base + narg-1;  if (o < L->top) {    if (LJ_LIKELY(tvisstr(o))) {      return strV(o);    } else if (tvisnumber(o)) {      GCstr *s = lj_str_fromnumber(L, o);      setstrV(L, o, s);      return s;    }  }  lj_err_argt(L, narg, LUA_TSTRING);  return NULL;  /* unreachable */}

static int io_file_write(lua_State *L, FILE *fp, int start){  cTValue *tv;  int status = 1;  for (tv = L->base+start; tv < L->top; tv++) {    if (tvisstr(tv)) {      MSize len = strV(tv)->len;      status = status && (fwrite(strVdata(tv), 1, len, fp) == len);    } else if (tvisnum(tv)) {      status = status && (fprintf(fp, LUA_NUMBER_FMT, numV(tv)) > 0);    } else {      lj_err_argt(L, cast_int(tv - L->base) + 1, LUA_TSTRING);    }  }  return io_pushresult(L, status, NULL);}

/* Get runtime value of string argument. */static GCstr *argv2str(jit_State *J, TValue *o){  if (LJ_LIKELY(tvisstr(o))) {    return strV(o);  } else {    GCstr *s;    if (!tvisnumber(o))      lj_trace_err(J, LJ_TRERR_BADTYPE);    if (tvisint(o))      s = lj_str_fromint(J->L, intV(o));    else      s = lj_str_fromnum(J->L, &o->n);    setstrV(J->L, o, s);    return s;  }}

static void LJ_FASTCALL recff_tostring(jit_State *J, RecordFFData *rd){  TRef tr = J->base[0];  if (tref_isstr(tr)) {    /* Ignore __tostring in the string base metatable. */    /* Pass on result in J->base[0]. */  } else if (!recff_metacall(J, rd, MM_tostring)) {    if (tref_isnumber(tr)) {      J->base[0] = emitir(IRT(IR_TOSTR, IRT_STR), tr, 0);    } else if (tref_ispri(tr)) {      J->base[0] = lj_ir_kstr(J, strV(&J->fn->c.upvalue[tref_type(tr)]));    } else {      recff_nyiu(J);    }  }}

static int io_file_readchars(lua_State *L, FILE *fp, size_t n){  size_t rlen;  /* how much to read */  size_t nr;  /* number of chars actually read */  luaL_Buffer b;  luaL_buffinit(L, &b);  rlen = LUAL_BUFFERSIZE;  /* try to read that much each time */  do {    char *p = luaL_prepbuffer(&b);    if (rlen > n) rlen = n;  /* cannot read more than asked */    nr = fread(p, 1, rlen, fp);    luaL_addsize(&b, nr);    n -= nr;  /* still have to read `n' chars */  } while (n > 0 && nr == rlen);  /* until end of count or eof */  luaL_pushresult(&b);  /* close buffer */  return (n == 0 || strV(L->top-1)->len > 0);}

static int io_file_readline(lua_State *L, FILE *fp){  luaL_Buffer b;  luaL_buffinit(L, &b);  for (;;) {    size_t len;    char *p = luaL_prepbuffer(&b);    if (fgets(p, LUAL_BUFFERSIZE, fp) == NULL) {  /* EOF? */      luaL_pushresult(&b);      return (strV(L->top-1)->len > 0);  /* Anything read? */    }    len = strlen(p);    if (len == 0 || p[len-1] != '/n') {  /* Partial line? */      luaL_addsize(&b, len);    } else {      luaL_addsize(&b, len - 1);  /* Don't include EOL. */      luaL_pushresult(&b);      return 1;  /* Got at least an EOL. */    }  }}

static int io_file_write(lua_State *L, FILE *fp, int start){  cTValue *tv;  int status = 1;  for (tv = L->base+start; tv < L->top; tv++) {    if (tvisstr(tv)) {      MSize len = strV(tv)->len;      status = status && (fwrite(strVdata(tv), 1, len, fp) == len);    } else if (tvisint(tv)) {      char buf[LJ_STR_INTBUF];      char *p = lj_str_bufint(buf, intV(tv));      size_t len = (size_t)(buf+LJ_STR_INTBUF-p);      status = status && (fwrite(p, 1, len, fp) == len);    } else if (tvisnum(tv)) {      status = status && (fprintf(fp, LUA_NUMBER_FMT, numV(tv)) > 0);    } else {      lj_err_argt(L, (int)(tv - L->base) + 1, LUA_TSTRING);    }  }  return io_pushresult(L, status, NULL);}

static CTypeID argv2ctype(jit_State *J, TRef tr, cTValue *o){  if (tref_isstr(tr)) {    GCstr *s = strV(o);    CPState cp;    CTypeID oldtop;    /* Specialize to the string containing the C type declaration. */    emitir(IRTG(IR_EQ, IRT_STR), tr, lj_ir_kstr(J, s));    cp.L = J->L;    cp.cts = ctype_ctsG(J2G(J));    oldtop = cp.cts->top;    cp.srcname = strdata(s);    cp.p = strdata(s);    cp.mode = CPARSE_MODE_ABSTRACT|CPARSE_MODE_NOIMPLICIT;    if (lj_cparse(&cp) || cp.cts->top > oldtop)  /* Avoid new struct defs. */      lj_trace_err(J, LJ_TRERR_BADTYPE);    return cp.val.id;  } else {    GCcdata *cd = argv2cdata(J, tr, o);    return cd->typeid == CTID_CTYPEID ? *(CTypeID *)cdataptr(cd) : cd->typeid;  }}

int OTLResultSetMetaData::GetColumnType(int i){  int fieldType = COLUMN_UNKNOWN;  int OTLFieldType = m_desc[i]->dbtype;  wxString strV(ConvertFromUnicodeStream(m_desc[i]->name));  switch (OTLFieldType)  {  case extLong:  case extUInt:  case extNumber:  case extInt:  case extVarNum:  case extRowId: //fixme: check    fieldType = COLUMN_INTEGER;    break;  case extVarChar2:  case extLongVarChar:  case extCChar:  case extVarChar:  case extChar:  case extCharZ:  case extMslabel://fixme : Check    fieldType = COLUMN_STRING;    break;  case extFloat:    fieldType = COLUMN_DOUBLE;    break;    /*     case SQL_BIT:       fieldType = COLUMN_BOOL;       break;    */  case extBLOB:  case extCLOB:  case extVarRaw: //fixme : Check    //case extRaw: //fixme : Check  case extLongRaw://fixme : Check  case extLongVarRaw://fixme : Check    fieldType = COLUMN_BLOB;    break;  case extDate:#if (defined(OTL_ORA8I)||defined(OTL_ORA9I))&&defined(OTL_ORA_TIMESTAMP)  case extTimestamp:  case extTimestamp_TZ:  case extTimestamp_LTZ:#endif    fieldType = COLUMN_DATE;    break;  default:    fieldType = COLUMN_UNKNOWN;    break;  };  return fieldType;}

void QTouchSettingWidget::TPDP_OnRSP(T3K_DEVICE_INFO /*devInfo*/, ResponsePart Part, unsigned short /*ticktime*/, const char */*partid*/, int /*id*/, bool /*bFinal*/, const char *cmd){    if( !isVisible() ) return;    if ( strstr(cmd, cstrTimeA) == cmd )    {        m_RequestSensorData.RemoveItem( cstrTimeA );        int nTime = atoi(cmd + sizeof(cstrTimeA) - 1);        if( nTime < NV_DEF_TIME_A_RANGE_START )            nTime = NV_DEF_TIME_A_RANGE_START;        if( nTime > NV_DEF_TIME_A_RANGE_END )            nTime = NV_DEF_TIME_A_RANGE_END;        QString strV( QString("%1").arg(nTime) );        ui->EditTap->setText( strV );        ui->SldTap->setValue( NV_DEF_TIME_A_RANGE_END/100 - nTime/100 + (NV_DEF_TIME_A_RANGE_START)/100 );    }    else if ( strstr(cmd, cstrTimeL) == cmd )    {        m_RequestSensorData.RemoveItem( cstrTimeL );        int nTime = atoi(cmd + sizeof(cstrTimeL) - 1);        if( nTime < NV_DEF_TIME_L_RANGE_START )            nTime = NV_DEF_TIME_L_RANGE_START;        if( nTime > NV_DEF_TIME_L_RANGE_END )            nTime = NV_DEF_TIME_L_RANGE_END;        QString strV( QString("%1").arg(nTime) );        ui->EditLongTap->setText( strV );        ui->SldLongTap->setValue( NV_DEF_TIME_L_RANGE_END/100 - nTime/100 + (NV_DEF_TIME_L_RANGE_START)/100 );    }    else if ( strstr(cmd, cstrWheelSensitivity) == cmd )    {        m_RequestSensorData.RemoveItem( cstrWheelSensitivity );        int nSens = atoi(cmd + sizeof(cstrWheelSensitivity) - 1);        if( !(nSens >= NV_DEF_WHEEL_SENSITIVITY_RANGE_START && nSens <= NV_DEF_WHEEL_SENSITIVITY_RANGE_END) )        {            nSens = NV_DEF_WHEEL_SENSITIVITY;        }        QString strV( QString("%1").arg(nSens) );        ui->EditWheel->setText( strV );        ui->SldWheel->setValue( nSens );    }    else if ( strstr(cmd, cstrZoomSensitivity) == cmd )    {        m_RequestSensorData.RemoveItem( cstrZoomSensitivity );        int nSens = atoi(cmd + sizeof(cstrZoomSensitivity) - 1);        if( !(nSens >= NV_DEF_ZOOM_SENSITIVITY_RANGE_START && nSens <= NV_DEF_ZOOM_SENSITIVITY_RANGE_END) )        {            nSens = NV_DEF_ZOOM_SENSITIVITY;        }        QString strV( QString("%1").arg(nSens) );        ui->EditZoom->setText( strV );        ui->SldZoom->setValue( nSens );    }    else if( strstr(cmd, cstrDetectionThreshold) == cmd )    {        if( Part != MM )        {            m_RequestSensorData.RemoveItem( cstrDetectionThreshold, Part );            int nSensitivity = strtol(cmd + sizeof(cstrDetectionThreshold) - 1, NULL, 10);            m_mapTouchSensitivity.insert( Part, nSensitivity );            nSensitivity = NV_DEF_CAM_TRIGGER_THRESHOLD_RANGE_END;            foreach( int nV, m_mapTouchSensitivity.values() )            {                if( nSensitivity > nV )                    nSensitivity = nV;            }            ui->EditSensitivity->setText( QString::number(nSensitivity) );        }    }

/* Get runtime value of int argument. */static int32_t argv2int(jit_State *J, TValue *o){  if (!tvisnumber(o) && !(tvisstr(o) && lj_str_tonumber(strV(o), o)))    lj_trace_err(J, LJ_TRERR_BADTYPE);  return tvisint(o) ? intV(o) : lj_num2int(numV(o));}

CString GetWClustVersionString(){	CString strV("2.0.0.102");	return strV;}

/* 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;}

/* 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;}

/* Array and hash load forwarding. */static TRef fwd_ahload(jit_State *J, IRRef xref){  IRIns *xr = IR(xref);  IRRef lim = xref;  /* Search limit. */  IRRef ref;  /* Search for conflicting stores. */  ref = J->chain[fins->o+IRDELTA_L2S];  while (ref > xref) {    IRIns *store = IR(ref);    switch (aa_ahref(J, xr, IR(store->op1))) {    case ALIAS_NO:   break;  /* Continue searching. */    case ALIAS_MAY:  lim = ref; goto cselim;  /* Limit search for load. */    case ALIAS_MUST: return store->op2;  /* Store forwarding. */    }    ref = store->prev;  }  /* No conflicting store (yet): const-fold loads from allocations. */  {    IRIns *ir = (xr->o == IR_HREFK || xr->o == IR_AREF) ? IR(xr->op1) : xr;    IRRef tab = ir->op1;    ir = IR(tab);    if (ir->o == IR_TNEW || (ir->o == IR_TDUP && irref_isk(xr->op2))) {      /* A NEWREF with a number key may end up pointing to the array part.      ** But it's referenced from HSTORE and not found in the ASTORE chain.      ** For now simply consider this a conflict without forwarding anything.      */      if (xr->o == IR_AREF) {	IRRef ref2 = J->chain[IR_NEWREF];	while (ref2 > tab) {	  IRIns *newref = IR(ref2);	  if (irt_isnum(IR(newref->op2)->t))	    goto cselim;	  ref2 = newref->prev;	}      }      /* NEWREF inhibits CSE for HREF, and dependent FLOADs from HREFK/AREF.      ** But the above search for conflicting stores was limited by xref.      ** So continue searching, limited by the TNEW/TDUP. Store forwarding      ** is ok, too. A conflict does NOT limit the search for a matching load.      */      while (ref > tab) {	IRIns *store = IR(ref);	switch (aa_ahref(J, xr, IR(store->op1))) {	case ALIAS_NO:   break;  /* Continue searching. */	case ALIAS_MAY:  goto cselim;  /* Conflicting store. */	case ALIAS_MUST: return store->op2;  /* Store forwarding. */	}	ref = store->prev;      }      lua_assert(ir->o != IR_TNEW || irt_isnil(fins->t));      if (irt_ispri(fins->t)) {	return TREF_PRI(irt_type(fins->t));      } else if (irt_isnum(fins->t) || (LJ_DUALNUM && irt_isint(fins->t)) ||		 irt_isstr(fins->t)) {	TValue keyv;	cTValue *tv;	IRIns *key = IR(xr->op2);	if (key->o == IR_KSLOT) key = IR(key->op1);	lj_ir_kvalue(J->L, &keyv, key);	tv = lj_tab_get(J->L, ir_ktab(IR(ir->op1)), &keyv);	lua_assert(itype2irt(tv) == irt_type(fins->t));	if (irt_isnum(fins->t))	  return lj_ir_knum_u64(J, tv->u64);	else if (LJ_DUALNUM && irt_isint(fins->t))	  return lj_ir_kint(J, intV(tv));	else	  return lj_ir_kstr(J, strV(tv));      }      /* Othwerwise: don't intern as a constant. */    }  }cselim:  /* Try to find a matching load. Below the conflicting store, if any. */  ref = J->chain[fins->o];  while (ref > lim) {    IRIns *load = IR(ref);    if (load->op1 == xref)      return ref;  /* Load forwarding. */    ref = load->prev;  }  return 0;  /* Conflict or no match. */}

void lj_lib_register(lua_State *L, const char *libname,		     const uint8_t *p, const lua_CFunction *cf){  GCtab *env = tabref(L->env);  GCfunc *ofn = NULL;  int ffid = *p++;  BCIns *bcff = &L2GG(L)->bcff[*p++];  GCtab *tab = lib_create_table(L, libname, *p++);  ptrdiff_t tpos = L->top - L->base;  /* Avoid barriers further down. */  lj_gc_anybarriert(L, tab);  tab->nomm = 0;  for (;;) {    uint32_t tag = *p++;    MSize len = tag & LIBINIT_LENMASK;    tag &= LIBINIT_TAGMASK;    if (tag != LIBINIT_STRING) {      const char *name;      MSize nuv = (MSize)(L->top - L->base - tpos);      GCfunc *fn = lj_func_newC(L, nuv, env);      if (nuv) {	L->top = L->base + tpos;	memcpy(fn->c.upvalue, L->top, sizeof(TValue)*nuv);      }      fn->c.ffid = (uint8_t)(ffid++);      name = (const char *)p;      p += len;      if (tag == LIBINIT_CF)	setmref(fn->c.pc, &G(L)->bc_cfunc_int);      else	setmref(fn->c.pc, bcff++);      if (tag == LIBINIT_ASM_)	fn->c.f = ofn->c.f;  /* Copy handler from previous function. */      else	fn->c.f = *cf++;  /* Get cf or handler from C function table. */      if (len) {	/* NOBARRIER: See above for common barrier. */	setfuncV(L, lj_tab_setstr(L, tab, lj_str_new(L, name, len)), fn);      }      ofn = fn;    } else {      switch (tag | len) {      case LIBINIT_SET:	L->top -= 2;	if (tvisstr(L->top+1) && strV(L->top+1)->len == 0)	  env = tabV(L->top);	else  /* NOBARRIER: See above for common barrier. */	  copyTV(L, lj_tab_set(L, tab, L->top+1), L->top);	break;      case LIBINIT_NUMBER:	memcpy(&L->top->n, p, sizeof(double));	L->top++;	p += sizeof(double);	break;      case LIBINIT_COPY:	copyTV(L, L->top, L->top - *p++);	L->top++;	break;      case LIBINIT_LASTCL:	setfuncV(L, L->top++, ofn);	break;      case LIBINIT_FFID:	ffid++;	break;      case LIBINIT_END:	return;      default:	setstrV(L, L->top++, lj_str_new(L, (const char *)p, len));	p += len;	break;      }    }  }}

/* Index C data by a TValue. Return CType and pointer. */CType *lj_cdata_index(CTState *cts, GCcdata *cd, cTValue *key, uint8_t **pp,		      CTInfo *qual){  uint8_t *p = (uint8_t *)cdataptr(cd);  CType *ct = ctype_get(cts, cd->ctypeid);  ptrdiff_t idx;  /* Resolve reference for cdata object. */  if (ctype_isref(ct->info)) {    lua_assert(ct->size == CTSIZE_PTR);    p = *(uint8_t **)p;    ct = ctype_child(cts, ct);  }collect_attrib:  /* Skip attributes and collect qualifiers. */  while (ctype_isattrib(ct->info)) {    if (ctype_attrib(ct->info) == CTA_QUAL) *qual |= ct->size;    ct = ctype_child(cts, ct);  }  lua_assert(!ctype_isref(ct->info));  /* Interning rejects refs to refs. */  if (tvisint(key)) {    idx = (ptrdiff_t)intV(key);    goto integer_key;  } else if (tvisnum(key)) {  /* Numeric key. */#ifdef _MSC_VER    /* Workaround for MSVC bug. */    volatile#endif    lua_Number n = numV(key);    idx = LJ_64 ? (ptrdiff_t)n : (ptrdiff_t)lj_num2int(n);  integer_key:    if (ctype_ispointer(ct->info)) {      CTSize sz = lj_ctype_size(cts, ctype_cid(ct->info));  /* Element size. */      if (sz == CTSIZE_INVALID)	lj_err_caller(cts->L, LJ_ERR_FFI_INVSIZE);      if (ctype_isptr(ct->info)) {	p = (uint8_t *)cdata_getptr(p, ct->size);      } else if ((ct->info & (CTF_VECTOR|CTF_COMPLEX))) {	if ((ct->info & CTF_COMPLEX)) idx &= 1;	*qual |= CTF_CONST;  /* Valarray elements are constant. */      }      *pp = p + idx*(int32_t)sz;      return ct;    }  } else if (tviscdata(key)) {  /* Integer cdata key. */    GCcdata *cdk = cdataV(key);    CType *ctk = ctype_raw(cts, cdk->ctypeid);    if (ctype_isenum(ctk->info)) ctk = ctype_child(cts, ctk);    if (ctype_isinteger(ctk->info)) {      lj_cconv_ct_ct(cts, ctype_get(cts, CTID_INT_PSZ), ctk,		     (uint8_t *)&idx, cdataptr(cdk), 0);      goto integer_key;    }  } else if (tvisstr(key)) {  /* String key. */    GCstr *name = strV(key);    if (ctype_isstruct(ct->info)) {      CTSize ofs;      CType *fct = lj_ctype_getfieldq(cts, ct, name, &ofs, qual);      if (fct) {	*pp = p + ofs;	return fct;      }    } else if (ctype_iscomplex(ct->info)) {      if (name->len == 2) {	*qual |= CTF_CONST;  /* Complex fields are constant. */	if (strdata(name)[0] == 'r' && strdata(name)[1] == 'e') {	  *pp = p;	  return ct;	} else if (strdata(name)[0] == 'i' && strdata(name)[1] == 'm') {	  *pp = p + (ct->size >> 1);	  return ct;	}      }    } else if (cd->ctypeid == CTID_CTYPEID) {