u8 disableLookaside; /* Number of times lookaside has been disabled */
  u8 disableVtab;      /* Disable all virtual tables for this parse */
  int nRangeReg;       /* Size of the temporary register block */
  int iRangeReg;       /* First register in temporary register block */
  int nErr;            /* Number of errors seen */
  int nTab;            /* Number of previously allocated VDBE cursors */
  int nMem;            /* Number of memory cells used so far */
  int nOpAlloc;        /* Number of slots allocated for Vdbe.aOp[] */
  int szOpAlloc;       /* Bytes of memory space allocated for Vdbe.aOp[] */
  int iSelfTab;        /* Table associated with an index on expr, or negative
                       ** of the base register during check-constraint eval */
  int nLabel;          /* Number of labels used */
  int *aLabel;         /* Space to hold the labels */
  ExprList *pConstExpr;/* Constant expressions */
  Token constraintName;/* Name of the constraint currently being parsed */

  u8 disableLookaside; /* Number of times lookaside has been disabled */
  u8 disableVtab;      /* Disable all virtual tables for this parse */
  int nRangeReg;       /* Size of the temporary register block */
  int iRangeReg;       /* First register in temporary register block */
  int nErr;            /* Number of errors seen */
  int nTab;            /* Number of previously allocated VDBE cursors */
  int nMem;            /* Number of memory cells used so far */

  int szOpAlloc;       /* Bytes of memory space allocated for Vdbe.aOp[] */
  int iSelfTab;        /* Table associated with an index on expr, or negative
                       ** of the base register during check-constraint eval */
  int nLabel;          /* Number of labels used */
  int *aLabel;         /* Space to hold the labels */
  ExprList *pConstExpr;/* Constant expressions */
  Token constraintName;/* Name of the constraint currently being parsed */

  int rc;                 /* Value to return */
  int nChange;            /* Number of db changes made since last reset */
  int iStatement;         /* Statement number (or 0 if has no opened stmt) */
  i64 iCurrentTime;       /* Value of julianday('now') for this statement */
  i64 nFkConstraint;      /* Number of imm. FK constraints this VM */
  i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
  i64 nStmtDefImmCons;    /* Number of def. imm constraints when stmt started */





  /* When allocating a new Vdbe object, all of the fields below should be
  ** initialized to zero or NULL */

  Op *aOp;                /* Space to hold the virtual machine's program */
  Mem *aMem;              /* The memory locations */
  Mem **apArg;            /* Arguments to currently executing user function */
  Mem *aColName;          /* Column names to return */
  Mem *pResultSet;        /* Pointer to an array of results */
  char *zErrMsg;          /* Error message written here */
  VdbeCursor **apCsr;     /* One element of this array for each open cursor */
  Mem *aVar;              /* Values for the OP_Variable opcode. */
  VList *pVList;          /* Name of variables */
#ifndef SQLITE_OMIT_TRACE
  i64 startTime;          /* Time when query started - used for profiling */
#endif
  int nOp;                /* Number of instructions in the program */
#ifdef SQLITE_DEBUG
  int rcApp;              /* errcode set by sqlite3_result_error_code() */
  u32 nWrite;             /* Number of write operations that have occurred */
#endif
  u16 nResColumn;         /* Number of columns in one row of the result set */
  u8 errorAction;         /* Recovery action to do in case of an error */
  u8 minWriteFileFormat;  /* Minimum file format for writable database files */

  int rc;                 /* Value to return */
  int nChange;            /* Number of db changes made since last reset */
  int iStatement;         /* Statement number (or 0 if has no opened stmt) */
  i64 iCurrentTime;       /* Value of julianday('now') for this statement */
  i64 nFkConstraint;      /* Number of imm. FK constraints this VM */
  i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
  i64 nStmtDefImmCons;    /* Number of def. imm constraints when stmt started */
  Mem *aMem;              /* The memory locations */
  Mem **apArg;            /* Arguments to currently executing user function */
  VdbeCursor **apCsr;     /* One element of this array for each open cursor */
  Mem *aVar;              /* Values for the OP_Variable opcode. */

  /* When allocating a new Vdbe object, all of the fields below should be
  ** initialized to zero or NULL */

  Op *aOp;                /* Space to hold the virtual machine's program */
  int nOp;                /* Number of instructions in the program */
  int nOpAlloc;           /* Slots allocated for aOp[] */
  Mem *aColName;          /* Column names to return */
  Mem *pResultSet;        /* Pointer to an array of results */
  char *zErrMsg;          /* Error message written here */


  VList *pVList;          /* Name of variables */
#ifndef SQLITE_OMIT_TRACE
  i64 startTime;          /* Time when query started - used for profiling */
#endif

#ifdef SQLITE_DEBUG
  int rcApp;              /* errcode set by sqlite3_result_error_code() */
  u32 nWrite;             /* Number of write operations that have occurred */
#endif
  u16 nResColumn;         /* Number of columns in one row of the result set */
  u8 errorAction;         /* Recovery action to do in case of an error */
  u8 minWriteFileFormat;  /* Minimum file format for writable database files */

  p->pPrev = 0;
  db->pVdbe = p;
  p->magic = VDBE_MAGIC_INIT;
  p->pParse = pParse;
  pParse->pVdbe = p;
  assert( pParse->aLabel==0 );
  assert( pParse->nLabel==0 );
  assert( pParse->nOpAlloc==0 );
  assert( pParse->szOpAlloc==0 );
  sqlite3VdbeAddOp2(p, OP_Init, 0, 1);
  return p;
}

/*
** Change the error string stored in Vdbe.zErrMsg
................................................................................

/*
** Resize the Vdbe.aOp array so that it is at least nOp elements larger 
** than its current size. nOp is guaranteed to be less than or equal
** to 1024/sizeof(Op).
**
** If an out-of-memory error occurs while resizing the array, return
** SQLITE_NOMEM. In this case Vdbe.aOp and Parse.nOpAlloc remain 
** unchanged (this is so that any opcodes already allocated can be 
** correctly deallocated along with the rest of the Vdbe).
*/
static int growOpArray(Vdbe *v, int nOp){
  VdbeOp *pNew;
  Parse *p = v->pParse;

................................................................................
  ** more frequent reallocs and hence provide more opportunities for 
  ** simulated OOM faults.  SQLITE_TEST_REALLOC_STRESS is generally used
  ** during testing only.  With SQLITE_TEST_REALLOC_STRESS grow the op array
  ** by the minimum* amount required until the size reaches 512.  Normal
  ** operation (without SQLITE_TEST_REALLOC_STRESS) is to double the current
  ** size of the op array or add 1KB of space, whichever is smaller. */
#ifdef SQLITE_TEST_REALLOC_STRESS
  int nNew = (p->nOpAlloc>=512 ? p->nOpAlloc*2 : p->nOpAlloc+nOp);
#else
  int nNew = (p->nOpAlloc ? p->nOpAlloc*2 : (int)(1024/sizeof(Op)));
  UNUSED_PARAMETER(nOp);
#endif

  /* Ensure that the size of a VDBE does not grow too large */
  if( nNew > p->db->aLimit[SQLITE_LIMIT_VDBE_OP] ){
    sqlite3OomFault(p->db);
    return SQLITE_NOMEM;
  }

  assert( nOp<=(1024/sizeof(Op)) );
  assert( nNew>=(p->nOpAlloc+nOp) );
  pNew = sqlite3DbRealloc(p->db, v->aOp, nNew*sizeof(Op));
  if( pNew ){
    p->szOpAlloc = sqlite3DbMallocSize(p->db, pNew);
    p->nOpAlloc = p->szOpAlloc/sizeof(Op);
    v->aOp = pNew;
  }
  return (pNew ? SQLITE_OK : SQLITE_NOMEM_BKPT);
}

#ifdef SQLITE_DEBUG
/* This routine is just a convenient place to set a breakpoint that will
................................................................................
**    p1, p2, p3      Operands
**
** Use the sqlite3VdbeResolveLabel() function to fix an address and
** the sqlite3VdbeChangeP4() function to change the value of the P4
** operand.
*/
static SQLITE_NOINLINE int growOp3(Vdbe *p, int op, int p1, int p2, int p3){
  assert( p->pParse->nOpAlloc<=p->nOp );
  if( growOpArray(p, 1) ) return 1;
  assert( p->pParse->nOpAlloc>p->nOp );
  return sqlite3VdbeAddOp3(p, op, p1, p2, p3);
}
int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){
  int i;
  VdbeOp *pOp;

  i = p->nOp;
  assert( p->magic==VDBE_MAGIC_INIT );
  assert( op>=0 && op<0xff );
  if( p->pParse->nOpAlloc<=i ){
    return growOp3(p, op, p1, p2, p3);
  }
  p->nOp++;
  pOp = &p->aOp[i];
  pOp->opcode = (u8)op;
  pOp->p5 = 0;
  pOp->p1 = p1;
................................................................................
** SQLITE_TEST_REALLOC_STRESS).  This interface is used during testing
** to verify that certain calls to sqlite3VdbeAddOpList() can never
** fail due to a OOM fault and hence that the return value from
** sqlite3VdbeAddOpList() will always be non-NULL.
*/
#if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N){
  assert( p->nOp + N <= p->pParse->nOpAlloc );
}
#endif

/*
** Verify that the VM passed as the only argument does not contain
** an OP_ResultRow opcode. Fail an assert() if it does. This is used
** by code in pragma.c to ensure that the implementation of certain
................................................................................
  VdbeOpList const *aOp,       /* The opcodes to be added */
  int iLineno                  /* Source-file line number of first opcode */
){
  int i;
  VdbeOp *pOut, *pFirst;
  assert( nOp>0 );
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p->nOp + nOp > p->pParse->nOpAlloc && growOpArray(p, nOp) ){
    return 0;
  }
  pFirst = pOut = &p->aOp[p->nOp];
  for(i=0; i<nOp; i++, aOp++, pOut++){
    pOut->opcode = aOp->opcode;
    pOut->p1 = aOp->p1;
    pOut->p2 = aOp->p2;
................................................................................
  ** requirements by reusing the opcode array tail, then the second
  ** pass will fill in the remainder using a fresh memory allocation.  
  **
  ** This two-pass approach that reuses as much memory as possible from
  ** the leftover memory at the end of the opcode array.  This can significantly
  ** reduce the amount of memory held by a prepared statement.
  */
  do {
    x.nNeeded = 0;
    p->aMem = allocSpace(&x, p->aMem, nMem*sizeof(Mem));
    p->aVar = allocSpace(&x, p->aVar, nVar*sizeof(Mem));
    p->apArg = allocSpace(&x, p->apArg, nArg*sizeof(Mem*));
    p->apCsr = allocSpace(&x, p->apCsr, nCursor*sizeof(VdbeCursor*));
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
    p->anExec = allocSpace(&x, p->anExec, p->nOp*sizeof(i64));
#endif
    if( x.nNeeded==0 ) break;
    x.pSpace = p->pFree = sqlite3DbMallocRawNN(db, x.nNeeded);
    x.nFree = x.nNeeded;
  }while( !db->mallocFailed );










  p->pVList = pParse->pVList;
  pParse->pVList =  0;
  p->explain = pParse->explain;
  if( db->mallocFailed ){
    p->nVar = 0;
    p->nCursor = 0;

  p->pPrev = 0;
  db->pVdbe = p;
  p->magic = VDBE_MAGIC_INIT;
  p->pParse = pParse;
  pParse->pVdbe = p;
  assert( pParse->aLabel==0 );
  assert( pParse->nLabel==0 );
  assert( p->nOpAlloc==0 );
  assert( pParse->szOpAlloc==0 );
  sqlite3VdbeAddOp2(p, OP_Init, 0, 1);
  return p;
}

/*
** Change the error string stored in Vdbe.zErrMsg
................................................................................

/*
** Resize the Vdbe.aOp array so that it is at least nOp elements larger 
** than its current size. nOp is guaranteed to be less than or equal
** to 1024/sizeof(Op).
**
** If an out-of-memory error occurs while resizing the array, return
** SQLITE_NOMEM. In this case Vdbe.aOp and Vdbe.nOpAlloc remain 
** unchanged (this is so that any opcodes already allocated can be 
** correctly deallocated along with the rest of the Vdbe).
*/
static int growOpArray(Vdbe *v, int nOp){
  VdbeOp *pNew;
  Parse *p = v->pParse;

................................................................................
  ** more frequent reallocs and hence provide more opportunities for 
  ** simulated OOM faults.  SQLITE_TEST_REALLOC_STRESS is generally used
  ** during testing only.  With SQLITE_TEST_REALLOC_STRESS grow the op array
  ** by the minimum* amount required until the size reaches 512.  Normal
  ** operation (without SQLITE_TEST_REALLOC_STRESS) is to double the current
  ** size of the op array or add 1KB of space, whichever is smaller. */
#ifdef SQLITE_TEST_REALLOC_STRESS
  int nNew = (v->nOpAlloc>=512 ? v->nOpAlloc*2 : v->nOpAlloc+nOp);
#else
  int nNew = (v->nOpAlloc ? v->nOpAlloc*2 : (int)(1024/sizeof(Op)));
  UNUSED_PARAMETER(nOp);
#endif

  /* Ensure that the size of a VDBE does not grow too large */
  if( nNew > p->db->aLimit[SQLITE_LIMIT_VDBE_OP] ){
    sqlite3OomFault(p->db);
    return SQLITE_NOMEM;
  }

  assert( nOp<=(1024/sizeof(Op)) );
  assert( nNew>=(v->nOpAlloc+nOp) );
  pNew = sqlite3DbRealloc(p->db, v->aOp, nNew*sizeof(Op));
  if( pNew ){
    p->szOpAlloc = sqlite3DbMallocSize(p->db, pNew);
    v->nOpAlloc = p->szOpAlloc/sizeof(Op);
    v->aOp = pNew;
  }
  return (pNew ? SQLITE_OK : SQLITE_NOMEM_BKPT);
}

#ifdef SQLITE_DEBUG
/* This routine is just a convenient place to set a breakpoint that will
................................................................................
**    p1, p2, p3      Operands
**
** Use the sqlite3VdbeResolveLabel() function to fix an address and
** the sqlite3VdbeChangeP4() function to change the value of the P4
** operand.
*/
static SQLITE_NOINLINE int growOp3(Vdbe *p, int op, int p1, int p2, int p3){
  assert( p->nOpAlloc<=p->nOp );
  if( growOpArray(p, 1) ) return 1;
  assert( p->nOpAlloc>p->nOp );
  return sqlite3VdbeAddOp3(p, op, p1, p2, p3);
}
int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){
  int i;
  VdbeOp *pOp;

  i = p->nOp;
  assert( p->magic==VDBE_MAGIC_INIT );
  assert( op>=0 && op<0xff );
  if( p->nOpAlloc<=i ){
    return growOp3(p, op, p1, p2, p3);
  }
  p->nOp++;
  pOp = &p->aOp[i];
  pOp->opcode = (u8)op;
  pOp->p5 = 0;
  pOp->p1 = p1;
................................................................................
** SQLITE_TEST_REALLOC_STRESS).  This interface is used during testing
** to verify that certain calls to sqlite3VdbeAddOpList() can never
** fail due to a OOM fault and hence that the return value from
** sqlite3VdbeAddOpList() will always be non-NULL.
*/
#if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N){
  assert( p->nOp + N <= p->nOpAlloc );
}
#endif

/*
** Verify that the VM passed as the only argument does not contain
** an OP_ResultRow opcode. Fail an assert() if it does. This is used
** by code in pragma.c to ensure that the implementation of certain
................................................................................
  VdbeOpList const *aOp,       /* The opcodes to be added */
  int iLineno                  /* Source-file line number of first opcode */
){
  int i;
  VdbeOp *pOut, *pFirst;
  assert( nOp>0 );
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p->nOp + nOp > p->nOpAlloc && growOpArray(p, nOp) ){
    return 0;
  }
  pFirst = pOut = &p->aOp[p->nOp];
  for(i=0; i<nOp; i++, aOp++, pOut++){
    pOut->opcode = aOp->opcode;
    pOut->p1 = aOp->p1;
    pOut->p2 = aOp->p2;
................................................................................
  ** requirements by reusing the opcode array tail, then the second
  ** pass will fill in the remainder using a fresh memory allocation.  
  **
  ** This two-pass approach that reuses as much memory as possible from
  ** the leftover memory at the end of the opcode array.  This can significantly
  ** reduce the amount of memory held by a prepared statement.
  */

  x.nNeeded = 0;
  p->aMem = allocSpace(&x, 0, nMem*sizeof(Mem));
  p->aVar = allocSpace(&x, 0, nVar*sizeof(Mem));
  p->apArg = allocSpace(&x, 0, nArg*sizeof(Mem*));
  p->apCsr = allocSpace(&x, 0, nCursor*sizeof(VdbeCursor*));
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  p->anExec = allocSpace(&x, 0, p->nOp*sizeof(i64));
#endif
  if( x.nNeeded ){
    x.pSpace = p->pFree = sqlite3DbMallocRawNN(db, x.nNeeded);
    x.nFree = x.nNeeded;
    if( !db->mallocFailed ){
      p->aMem = allocSpace(&x, p->aMem, nMem*sizeof(Mem));
      p->aVar = allocSpace(&x, p->aVar, nVar*sizeof(Mem));
      p->apArg = allocSpace(&x, p->apArg, nArg*sizeof(Mem*));
      p->apCsr = allocSpace(&x, p->apCsr, nCursor*sizeof(VdbeCursor*));
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
      p->anExec = allocSpace(&x, p->anExec, p->nOp*sizeof(i64));
#endif
    }
  }

  p->pVList = pParse->pVList;
  pParse->pVList =  0;
  p->explain = pParse->explain;
  if( db->mallocFailed ){
    p->nVar = 0;
    p->nCursor = 0;