SQLite

  return i;
}

/*
** Free all memory allocations in the pParse object
*/
void sqlite3ParserReset(Parse *pParse){
  if( pParse ){
    sqlite3 *db = pParse->db;
    sqlite3DbFree(db, pParse->aLabel);
    sqlite3ExprListDelete(db, pParse->pConstExpr);
  }
}

/*
** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
*/
static int sqlite3Prepare(
  sqlite3 *db,              /* Database handle. */

  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 nSet;            /* Number of sets used so far */
  int nOnce;           /* Number of OP_Once instructions so far */
  int nOpAlloc;        /* Number of slots allocated for Vdbe.aOp[] */
  int nLabel;          /* Number of labels used */
  int *aLabel;         /* Space to hold the labels */
  int ckBase;          /* Base register of data during check constraints */
  int iPartIdxTab;     /* Table corresponding to a partial index */
  int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
  int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
  struct yColCache {
    int iTable;           /* Table cursor number */
    int iColumn;          /* Table column number */

struct Vdbe {
  sqlite3 *db;            /* The database connection that owns this statement */
  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 */

  Parse *pParse;          /* Parsing context used to create this Vdbe */

  int nMem;               /* Number of memory locations currently allocated */
  int nOp;                /* Number of instructions in the program */




  int nCursor;            /* Number of slots in apCsr[] */
  u32 magic;              /* Magic number for sanity checking */
  char *zErrMsg;          /* Error message written here */
  Vdbe *pPrev,*pNext;     /* Linked list of VDBEs with the same Vdbe.db */
  VdbeCursor **apCsr;     /* One element of this array for each open cursor */
  Mem *aVar;              /* Values for the OP_Variable opcode. */
  char **azVar;           /* Name of variables */
  ynVar nVar;             /* Number of entries in aVar[] */
  ynVar nzVar;            /* Number of entries in azVar[] */
  u32 cacheCtr;           /* VdbeCursor row cache generation counter */
  int pc;                 /* The program counter */
  int rc;                 /* Value to return */
  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 */
  bft explain:2;          /* True if EXPLAIN present on SQL command */
  bft inVtabMethod:2;     /* See comments above */
  bft changeCntOn:1;      /* True to update the change-counter */
  bft expired:1;          /* True if the VM needs to be recompiled */
  bft runOnlyOnce:1;      /* Automatically expire on reset */

  if( db->pVdbe ){
    db->pVdbe->pPrev = p;
  }
  p->pNext = db->pVdbe;
  p->pPrev = 0;
  db->pVdbe = p;
  p->magic = VDBE_MAGIC_INIT;

  p->pParse = pParse;
  assert( pParse->aLabel==0 );
  assert( pParse->nLabel==0 );
  assert( pParse->nOpAlloc==0 );
  return p;
}

/*
** Remember the SQL string for a prepared statement.
*/
void sqlite3VdbeSetSql(Vdbe *p, const char *z, int n, int isPrepareV2){

** it was.
**
** 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){
  VdbeOp *pNew;
  Parse *p = v->pParse;
  int nNew = (p->nOpAlloc ? p->nOpAlloc*2 : (int)(1024/sizeof(Op)));
  pNew = sqlite3DbRealloc(p->db, v->aOp, nNew*sizeof(Op));
  if( pNew ){
    p->nOpAlloc = sqlite3DbMallocSize(p->db, pNew)/sizeof(Op);
    v->aOp = pNew;
  }
  return (pNew ? SQLITE_OK : SQLITE_NOMEM);
}

#ifdef SQLITE_DEBUG
/* This routine is just a convenient place to set a breakpoint that will
** fire after each opcode is inserted and displayed using

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 ){
    if( growOpArray(p) ){
      return 1;
    }
  }
  p->nOp++;
  pOp = &p->aOp[i];
  pOp->opcode = (u8)op;

**
** The VDBE knows that a P2 value is a label because labels are
** always negative and P2 values are suppose to be non-negative.
** Hence, a negative P2 value is a label that has yet to be resolved.
**
** Zero is returned if a malloc() fails.
*/
int sqlite3VdbeMakeLabel(Vdbe *v){
  Parse *p = v->pParse;
  int i = p->nLabel++;
  assert( v->magic==VDBE_MAGIC_INIT );
  if( (i & (i-1))==0 ){
    p->aLabel = sqlite3DbReallocOrFree(p->db, p->aLabel, 
                                       (i*2+1)*sizeof(p->aLabel[0]));
  }
  if( p->aLabel ){
    p->aLabel[i] = -1;
  }
  return -1-i;
}

/*
** Resolve label "x" to be the address of the next instruction to
** be inserted.  The parameter "x" must have been obtained from
** a prior call to sqlite3VdbeMakeLabel().
*/
void sqlite3VdbeResolveLabel(Vdbe *v, int x){
  Parse *p = v->pParse;
  int j = -1-x;
  assert( v->magic==VDBE_MAGIC_INIT );
  assert( j<p->nLabel );
  if( j>=0 && p->aLabel ){
    p->aLabel[j] = v->nOp;
  }
}

/*
** Mark the VDBE as one that can only be run one time.
*/
void sqlite3VdbeRunOnlyOnce(Vdbe *p){

**
** The Op.opflags field is set on all opcodes.
*/
static void resolveP2Values(Vdbe *p, int *pMaxFuncArgs){
  int i;
  int nMaxArgs = *pMaxFuncArgs;
  Op *pOp;
  Parse *pParse = p->pParse;
  int *aLabel = pParse->aLabel;
  p->readOnly = 1;
  p->bIsReader = 0;
  for(pOp=p->aOp, i=p->nOp-1; i>=0; i--, pOp++){
    u8 opcode = pOp->opcode;

    /* NOTE: Be sure to update mkopcodeh.awk when adding or removing
    ** cases from this switch! */

        pOp->p4type = P4_ADVANCE;
        break;
      }
    }

    pOp->opflags = sqlite3OpcodeProperty[opcode];
    if( (pOp->opflags & OPFLG_JUMP)!=0 && pOp->p2<0 ){
      assert( -1-pOp->p2<pParse->nLabel );
      pOp->p2 = aLabel[-1-pOp->p2];
    }
  }
  sqlite3DbFree(p->db, pParse->aLabel);
  pParse->aLabel = 0;
  pParse->nLabel = 0;
  *pMaxFuncArgs = nMaxArgs;
  assert( p->bIsReader!=0 || p->btreeMask==0 );
}

/*
** Return the address of the next instruction to be inserted.
*/

/*
** Add a whole list of operations to the operation stack.  Return the
** address of the first operation added.
*/
int sqlite3VdbeAddOpList(Vdbe *p, int nOp, VdbeOpList const *aOp){
  int addr;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p->nOp + nOp > p->pParse->nOpAlloc && growOpArray(p) ){
    return 0;
  }
  addr = p->nOp;
  if( ALWAYS(nOp>0) ){
    int i;
    VdbeOpList const *pIn = aOp;
    for(i=0; i<nOp; i++, pIn++){

  u8 *zEnd;                      /* First byte past allocated memory */
  int nByte;                     /* How much extra memory is needed */

  assert( p!=0 );
  assert( p->nOp>0 );
  assert( pParse!=0 );
  assert( p->magic==VDBE_MAGIC_INIT );
  assert( pParse==p->pParse );
  db = p->db;
  assert( db->mallocFailed==0 );
  nVar = pParse->nVar;
  nMem = pParse->nMem;
  nCursor = pParse->nTab;
  nArg = pParse->nMaxArg;
  nOnce = pParse->nOnce;

  ** See also: allocateCursor().
  */
  nMem += nCursor;

  /* Allocate space for memory registers, SQL variables, VDBE cursors and 
  ** an array to marshal SQL function arguments in.
  */
  zCsr = (u8*)&p->aOp[p->nOp];            /* Memory avaliable for allocation */
  zEnd = (u8*)&p->aOp[pParse->nOpAlloc];  /* First byte past end of zCsr[] */

  resolveP2Values(p, &nArg);
  p->usesStmtJournal = (u8)(pParse->isMultiWrite && pParse->mayAbort);
  if( pParse->explain && nMem<10 ){
    nMem = 10;
  }
  memset(zCsr, 0, zEnd-zCsr);

  for(pSub=p->pProgram; pSub; pSub=pNext){
    pNext = pSub->pNext;
    vdbeFreeOpArray(db, pSub->aOp, pSub->nOp);
    sqlite3DbFree(db, pSub);
  }
  for(i=p->nzVar-1; i>=0; i--) sqlite3DbFree(db, p->azVar[i]);
  vdbeFreeOpArray(db, p->aOp, p->nOp);

  sqlite3DbFree(db, p->aColName);
  sqlite3DbFree(db, p->zSql);
  sqlite3DbFree(db, p->pFree);
#if defined(SQLITE_ENABLE_TREE_EXPLAIN)
  sqlite3DbFree(db, p->zExplain);
  sqlite3DbFree(db, p->pExplain);
#endif