SQLite

  }
  break;
}

/* 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

** 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
*/

  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, pCtx->pOut);
#ifdef SQLITE_DEBUG
  for(i=0; i<pCtx->argc; i++){
    assert( memIsValid(pCtx->argv[i]) );

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

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

  }

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

  pIn1 = &aMem[pOp->p1];
  assert( pIn1->flags&MEM_Int );
  VdbeBranchTaken(pIn1->u.i==0, 2);
  if( (pIn1->u.i++)==0 ) goto jump_to_p2;
  break;
}

/* Opcode: AggStep0 * P2 P3 P4 P5
** Synopsis: accum=r[P3] step(r[P2@P5])
**
** Execute the step function for an aggregate.  The
** function has P5 arguments.   P4 is a pointer to the FuncDef
** structure that specifies the function.  Register P3 is the
** accumulator.
**
** The P5 arguments are taken from register P2 and its
** successors.
*/
/* Opcode: AggStep * P2 P3 P4 P5
** Synopsis: accum=r[P3] step(r[P2@P5])
**
** Execute the step function for an aggregate.  The
** function has P5 arguments.   P4 is a pointer to an sqlite3_context
** object that is used to run the function.  Register P3 is
** as the accumulator.
**
** The P5 arguments are taken from register P2 and its
** successors.
**
** This opcode is initially coded as OP_AggStep0.  On first evaluation,
** the FuncDef stored in P4 is converted into an sqlite3_context and
** the opcode is changed.  In this way, the initialization of the
** sqlite3_context only happens once, instead of on each call to the
** step function.
*/
case OP_AggStep0: {
  int n;
  sqlite3_context *pCtx;

  assert( pOp->p4type==P4_FUNCDEF );
  n = pOp->p5;

      break;
    }
    case P4_FUNCDEF: {
      FuncDef *pDef = pOp->p4.pFunc;
      sqlite3_snprintf(nTemp, zTemp, "%s(%d)", pDef->zName, pDef->nArg);
      break;
    }
#ifdef SQLITE_DEBUG
    case P4_FUNCCTX: {
      FuncDef *pDef = pOp->p4.pCtx->pFunc;
      sqlite3_snprintf(nTemp, zTemp, "%s(%d)", pDef->zName, pDef->nArg);
      break;
    }
#endif
    case P4_INT64: {
      sqlite3_snprintf(nTemp, zTemp, "%lld", *pOp->p4.pI64);
      break;
    }
    case P4_INT32: {
      sqlite3_snprintf(nTemp, zTemp, "%d", pOp->p4.i);
      break;