SQLite

  DateTime *p
){
  double r;
  if( parseYyyyMmDd(zDate,p)==0 ){
    return 0;
  }else if( parseHhMmSs(zDate, p)==0 ){
    return 0;
  }else if( sqlite3StrICmp(zDate,"now")==0 ){
    sqlite3VdbePureFuncOnly(context);
    return setDateTimeToCurrent(context, p);
  }else if( sqlite3AtoF(zDate, &r, sqlite3Strlen30(zDate), SQLITE_UTF8) ){
    setRawDateNumber(p, r);
    return 0;
  }
  return 1;
}

    case 'l': {
      /*    localtime
      **
      ** Assuming the current time value is UTC (a.k.a. GMT), shift it to
      ** show local time.
      */
      if( sqlite3_stricmp(z, "localtime")==0 ){
        sqlite3VdbePureFuncOnly(pCtx);
        computeJD(p);
        p->iJD += localtimeOffset(p, pCtx, &rc);
        clearYMD_HMS_TZ(p);
      }
      break;
    }
#endif

          p->validJD = 1;
          p->rawS = 0;
          rc = 0;
        }
      }
#ifndef SQLITE_OMIT_LOCALTIME
      else if( sqlite3_stricmp(z, "utc")==0 ){
        sqlite3VdbePureFuncOnly(pCtx);
        if( p->tzSet==0 ){
          sqlite3_int64 c1;
          computeJD(p);
          c1 = localtimeOffset(p, pCtx, &rc);
          if( rc==SQLITE_OK ){
            p->iJD -= c1;
            clearYMD_HMS_TZ(p);

** This function registered all of the above C functions as SQL
** functions.  This should be the only routine in this file with
** external linkage.
*/
void sqlite3RegisterDateTimeFunctions(void){
  static FuncDef aDateTimeFuncs[] = {
#ifndef SQLITE_OMIT_DATETIME_FUNCS
    PURE_DATE(julianday,        -1, 0, 0, juliandayFunc ),
    PURE_DATE(date,             -1, 0, 0, dateFunc      ),
    PURE_DATE(time,             -1, 0, 0, timeFunc      ),
    PURE_DATE(datetime,         -1, 0, 0, datetimeFunc  ),
    PURE_DATE(strftime,         -1, 0, 0, strftimeFunc  ),
    DFUNCTION(current_time,      0, 0, 0, ctimeFunc     ),
    DFUNCTION(current_timestamp, 0, 0, 0, ctimestampFunc),
    DFUNCTION(current_date,      0, 0, 0, cdateFunc     ),
#else
    STR_FUNCTION(current_time,      0, "%H:%M:%S",          0, currentTimeFunc),
    STR_FUNCTION(current_date,      0, "%Y-%m-%d",          0, currentTimeFunc),
    STR_FUNCTION(current_timestamp, 0, "%Y-%m-%d %H:%M:%S", 0, currentTimeFunc),
#endif
  };
  sqlite3InsertBuiltinFuncs(aDateTimeFuncs, ArraySize(aDateTimeFuncs));
}

  int j;
  int regBase;
  int nCol;

  if( piPartIdxLabel ){
    if( pIdx->pPartIdxWhere ){
      *piPartIdxLabel = sqlite3VdbeMakeLabel(v);
      pParse->iSelfTab = iDataCur + 1;
      sqlite3ExprCachePush(pParse);
      sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel, 
                            SQLITE_JUMPIFNULL);
      pParse->iSelfTab = 0;
    }else{
      *piPartIdxLabel = 0;
    }
  }
  nCol = (prefixOnly && pIdx->uniqNotNull) ? pIdx->nKeyCol : pIdx->nColumn;
  regBase = sqlite3GetTempRange(pParse, nCol);
  if( pPrior && (regBase!=regPrior || pPrior->pPartIdxWhere) ) pPrior = 0;

  int iIdxCol,    /* The column of the index to be loaded */
  int regOut      /* Store the index column value in this register */
){
  i16 iTabCol = pIdx->aiColumn[iIdxCol];
  if( iTabCol==XN_EXPR ){
    assert( pIdx->aColExpr );
    assert( pIdx->aColExpr->nExpr>iIdxCol );
    pParse->iSelfTab = iTabCur + 1;
    sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut);
    pParse->iSelfTab = 0;
  }else{
    sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pIdx->pTable, iTabCur,
                                    iTabCol, regOut);
  }
}

/*

      if( iTab<0 ){
        if( pParse->ckBase>0 ){
          /* Generating CHECK constraints or inserting into partial index */
          return pExpr->iColumn + pParse->ckBase;
        }else{
          /* Coding an expression that is part of an index where column names
          ** in the index refer to the table to which the index belongs */
          iTab = pParse->iSelfTab - 1;
        }
      }
      return sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
                               pExpr->iColumn, iTab, target,
                               pExpr->op2);
    }
    case TK_INTEGER: {

        pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr);
      }
#endif
      if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){
        if( !pColl ) pColl = db->pDfltColl; 
        sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
      }
      sqlite3VdbeAddOp4(v, pParse->iSelfTab ? OP_PureFunc0 : OP_Function0,
                        constMask, r1, target, (char*)pDef, P4_FUNCDEF);
      sqlite3VdbeChangeP5(v, (u8)nFarg);
      if( nFarg && constMask==0 ){
        sqlite3ReleaseTempRange(pParse, r1, nFarg);
      }
      return target;
    }
#ifndef SQLITE_OMIT_SUBQUERY

        if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){
          ExprList *pCheck = sqlite3ExprListDup(db, pTab->pCheck, 0);
          if( db->mallocFailed==0 ){
            int addrCkFault = sqlite3VdbeMakeLabel(v);
            int addrCkOk = sqlite3VdbeMakeLabel(v);
            char *zErr;
            int k;
            pParse->iSelfTab = iDataCur+1;
            sqlite3ExprCachePush(pParse);
            for(k=pCheck->nExpr-1; k>0; k--){
              sqlite3ExprIfFalse(pParse, pCheck->a[k].pExpr, addrCkFault, 0);
            }
            sqlite3ExprIfTrue(pParse, pCheck->a[0].pExpr, addrCkOk, 
                SQLITE_JUMPIFNULL);
            sqlite3VdbeResolveLabel(v, addrCkFault);
            pParse->iSelfTab = 0;
            zErr = sqlite3MPrintf(db, "CHECK constraint failed in %s",
                pTab->zName);
            sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, zErr, P4_DYNAMIC);
            integrityCheckResultRow(v, 3);
            sqlite3VdbeResolveLabel(v, addrCkOk);
            sqlite3ExprCachePop(pParse);
          }

**   VFUNCTION(zName, nArg, iArg, bNC, xFunc)
**     Like FUNCTION except it omits the SQLITE_FUNC_CONSTANT flag.
**
**   DFUNCTION(zName, nArg, iArg, bNC, xFunc)
**     Like FUNCTION except it omits the SQLITE_FUNC_CONSTANT flag and
**     adds the SQLITE_FUNC_SLOCHNG flag.  Used for date & time functions
**     and functions like sqlite_version() that can change, but not during
**     a single query.  The iArg is ignored.  The user-data is always set
**     to a NULL pointer.  The bNC parameter is not used.
**
**   PURE_DATE(zName, nArg, iArg, bNC, xFunc)
**     Used for "pure" date/time functions, this macro is like DFUNCTION
**     except that it does set the SQLITE_FUNC_CONSTANT flags.  iArg is
**     ignored and the user-data for these functions is set to an 
**     arbitrary non-NULL pointer.  The bNC parameter is not used.
**
**   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
**     Used to create an aggregate function definition implemented by
**     the C functions xStep and xFinal. The first four parameters
**     are interpreted in the same way as the first 4 parameters to
**     FUNCTION().
**

#define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
  {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
#define VFUNCTION(zName, nArg, iArg, bNC, xFunc) \
  {nArg, SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
#define DFUNCTION(zName, nArg, iArg, bNC, xFunc) \
  {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8, \
   0, 0, xFunc, 0, #zName, {0} }
#define PURE_DATE(zName, nArg, iArg, bNC, xFunc) \
  {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|SQLITE_FUNC_CONSTANT, \
   (void*)xFunc, 0, xFunc, 0, #zName, {0} }
#define FUNCTION2(zName, nArg, iArg, bNC, xFunc, extraFlags) \
  {nArg,SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL)|extraFlags,\
   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
#define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
  {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
   pArg, 0, xFunc, 0, #zName, }
#define LIKEFUNC(zName, nArg, arg, flags) \

  assert( pOp->p4type==P4_COLLSEQ );
  if( pOp->p1 ){
    sqlite3VdbeMemSetInt64(&aMem[pOp->p1], 0);
  }
  break;
}
















































































































/* Opcode: BitAnd P1 P2 P3 * *
** Synopsis: r[P3]=r[P1]&r[P2]
**
** Take the bit-wise AND of the values in register P1 and P2 and
** store the result in register P3.
** If either input is NULL, the result is NULL.
*/

    newMax = sqlite3BtreeLastPage(pBt);
    if( newMax < (unsigned)pOp->p3 ) newMax = (unsigned)pOp->p3;
  }
  pOut->u.i = sqlite3BtreeMaxPageCount(pBt, newMax);
  break;
}
#endif

/* Opcode: Function0 P1 P2 P3 P4 P5
** Synopsis: r[P3]=func(r[P2@P5])
**
** Invoke a user function (P4 is a pointer to a FuncDef object that
** defines the function) with P5 arguments taken from register P2 and
** successors.  The result of the function is stored in register P3.
** Register P3 must not be one of the function inputs.
**
** P1 is a 32-bit bitmask indicating whether or not each argument to the 
** function was determined to be constant at compile time. If the first
** argument was constant then bit 0 of P1 is set. This is used to determine
** whether meta data associated with a user function argument using the
** sqlite3_set_auxdata() API may be safely retained until the next
** invocation of this opcode.
**
** See also: Function, AggStep, AggFinal
*/
/* Opcode: Function P1 P2 P3 P4 P5
** Synopsis: r[P3]=func(r[P2@P5])
**
** Invoke a user function (P4 is a pointer to an sqlite3_context object that
** contains a pointer to the function to be run) with P5 arguments taken
** from register P2 and successors.  The result of the function is stored
** in register P3.  Register P3 must not be one of the function inputs.
**
** P1 is a 32-bit bitmask indicating whether or not each argument to the 
** function was determined to be constant at compile time. If the first
** argument was constant then bit 0 of P1 is set. This is used to determine
** whether meta data associated with a user function argument using the
** sqlite3_set_auxdata() API may be safely retained until the next
** invocation of this opcode.
**
** SQL functions are initially coded as OP_Function0 with P4 pointing
** to a FuncDef object.  But on first evaluation, the P4 operand is
** automatically converted into an sqlite3_context object and the operation
** changed to this OP_Function opcode.  In this way, the initialization of
** the sqlite3_context object occurs only once, rather than once for each
** evaluation of the function.
**
** See also: Function0, AggStep, AggFinal
*/
case OP_PureFunc0:
case OP_Function0: {
  int n;
  sqlite3_context *pCtx;

  assert( pOp->p4type==P4_FUNCDEF );
  n = pOp->p5;
  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem+1 - p->nCursor)+1) );
  assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+n );
  pCtx = sqlite3DbMallocRawNN(db, sizeof(*pCtx) + (n-1)*sizeof(sqlite3_value*));
  if( pCtx==0 ) goto no_mem;
  pCtx->pOut = 0;
  pCtx->pFunc = pOp->p4.pFunc;
  pCtx->iOp = (int)(pOp - aOp);
  pCtx->pVdbe = p;
  pCtx->argc = n;
  pOp->p4type = P4_FUNCCTX;
  pOp->p4.pCtx = pCtx;
  assert( OP_PureFunc == OP_PureFunc0+2 );
  assert( OP_Function == OP_Function0+2 );
  pOp->opcode += 2;
  /* Fall through into OP_Function */
}
case OP_PureFunc:
case OP_Function: {
  int i;
  sqlite3_context *pCtx;

  assert( pOp->p4type==P4_FUNCCTX );
  pCtx = pOp->p4.pCtx;

  /* If this function is inside of a trigger, the register array in aMem[]
  ** might change from one evaluation to the next.  The next block of code
  ** checks to see if the register array has changed, and if so it
  ** reinitializes the relavant parts of the sqlite3_context object */
  pOut = &aMem[pOp->p3];
  if( pCtx->pOut != pOut ){
    pCtx->pOut = pOut;
    for(i=pCtx->argc-1; i>=0; i--) pCtx->argv[i] = &aMem[pOp->p2+i];
  }

  memAboutToChange(p, pOut);
#ifdef SQLITE_DEBUG
  for(i=0; i<pCtx->argc; i++){
    assert( memIsValid(pCtx->argv[i]) );
    REGISTER_TRACE(pOp->p2+i, pCtx->argv[i]);
  }
#endif
  MemSetTypeFlag(pOut, MEM_Null);
  pCtx->fErrorOrAux = 0;
  (*pCtx->pFunc->xSFunc)(pCtx, pCtx->argc, pCtx->argv);/* IMP: R-24505-23230 */

  /* If the function returned an error, throw an exception */
  if( pCtx->fErrorOrAux ){
    if( pCtx->isError ){
      sqlite3VdbeError(p, "%s", sqlite3_value_text(pOut));
      rc = pCtx->isError;
    }
    sqlite3VdbeDeleteAuxData(db, &p->pAuxData, pCtx->iOp, pOp->p1);
    if( rc ) goto abort_due_to_error;
  }

  /* Copy the result of the function into register P3 */
  if( pOut->flags & (MEM_Str|MEM_Blob) ){
    sqlite3VdbeChangeEncoding(pOut, encoding);
    if( sqlite3VdbeMemTooBig(pOut) ) goto too_big;
  }

  REGISTER_TRACE(pOp->p3, pOut);
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}


/* Opcode: Init P1 P2 * P4 *
** Synopsis: Start at P2
**
** Programs contain a single instance of this opcode as the very first
** opcode.

typedef int (*RecordCompare)(int,const void*,UnpackedRecord*);
RecordCompare sqlite3VdbeFindCompare(UnpackedRecord*);

#ifndef SQLITE_OMIT_TRIGGER
void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *);
#endif

void sqlite3VdbePureFuncOnly(sqlite3_context*);

/* Use SQLITE_ENABLE_COMMENTS to enable generation of extra comments on
** each VDBE opcode.
**
** Use the SQLITE_ENABLE_MODULE_COMMENTS macro to see some extra no-op
** comments in VDBE programs that show key decision points in the code
** generator.

  assert( (v->db->flags & SQLITE_EnableQPSG)==0 );
  if( iVar>=32 ){
    v->expmask |= 0x80000000;
  }else{
    v->expmask |= ((u32)1 << (iVar-1));
  }
}

/*
** Cause a function to throw an error if it was call from OP_PureFunc
** rather than OP_Function.
**
** OP_PureFunc means that the function must be deterministic, and should
** throw an error if it is given inputs that would make it non-deterministic.
** This routine is invoked by date/time functions that use non-deterministic
** features such as 'now'.
*/
void sqlite3VdbePureFuncOnly(sqlite3_context *pCtx){
  if( pCtx->pVdbe->aOp[pCtx->iOp].opcode==OP_PureFunc ){
    sqlite3_result_error(pCtx, 
       "non-deterministic functions prohibited in index expressions", -1);
  }
}

#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Transfer error message text from an sqlite3_vtab.zErrMsg (text stored
** in memory obtained from sqlite3_malloc) into a Vdbe.zErrMsg (text stored
** in memory obtained from sqlite3DbMalloc).
*/

  EXPLAIN QUERY PLAN
  SELECT id, b, c FROM t1
   WHERE substr(a,27,3)=='ord' AND d>=29;
} {/USING INDEX t1a2/}


do_catchsql_test indexexpr1-300 {
  CREATE TABLE t2(a,b,c); INSERT INTO t2 VALUES(1,2,3);
  CREATE INDEX t2x1 ON t2(a,b+random());
} {1 {non-deterministic functions prohibited in index expressions}}
do_catchsql_test indexexpr1-301 {
  CREATE INDEX t2x1 ON t2(julianday('now',a));
} {1 {non-deterministic function}}
do_catchsql_test indexexpr1-310 {
  CREATE INDEX t2x2 ON t2(a,b+(SELECT 15));
} {1 {subqueries prohibited in index expressions}}
do_catchsql_test indexexpr1-320 {
  CREATE TABLE e1(x,y,UNIQUE(y,substr(x,1,5)));
} {1 {expressions prohibited in PRIMARY KEY and UNIQUE constraints}}
do_catchsql_test indexexpr1-330 {

#
do_execsql_test indexexpr1-1300.1 {
  CREATE TABLE t1300(a INTEGER PRIMARY KEY, b);
  INSERT INTO t1300 VALUES(1,'coffee'),(2,'COFFEE'),(3,'stress'),(4,'STRESS');
  CREATE INDEX t1300bexpr ON t1300( substr(b,4) );
  SELECT a FROM t1300 WHERE substr(b,4)='ess' COLLATE nocase ORDER BY +a;
} {3 4}

# Date and time functions can participate in an index as long as they
# do not contain

finish_test