SQLite

**
*************************************************************************
**
** This file contains definitions of global variables and contants.
*/
#include "sqliteInt.h"


/* An array to map all upper-case characters into their corresponding
** lower-case character. 
**
** SQLite only considers US-ASCII (or EBCDIC) characters.  We do not
** handle case conversions for the UTF character set since the tables
** involved are nearly as big or bigger than SQLite itself.
*/

**
** IMPORTANT:  Changing the pending byte to any value other than
** 0x40000000 results in an incompatible database file format!
** Changing the pending byte during operating results in undefined
** and dileterious behavior.
*/
int sqlite3PendingByte = 0x40000000;

char *sqlite3Utf16to8(sqlite3 *, const void*, int);
#ifdef SQLITE_ENABLE_STAT2
char *sqlite3Utf8to16(sqlite3 *, u8, char *, int, int *);
#endif
int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
#ifndef SQLITE_AMALGAMATION

extern const unsigned char sqlite3UpperToLower[];
extern const unsigned char sqlite3CtypeMap[];
extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
extern SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
extern int sqlite3PendingByte;
#endif
void sqlite3RootPageMoved(Db*, int, int);

  else if( flags & MEM_Str ){
    pMem->type = SQLITE_TEXT;
  }else{
    pMem->type = SQLITE_BLOB;
  }
}

/*
** Properties of opcodes.  The OPFLG_INITIALIZER macro is
** created by mkopcodeh.awk during compilation.  Data is obtained
** from the comments following the "case OP_xxxx:" statements in
** this file.  
*/
static const unsigned char opcodeProperty[] = OPFLG_INITIALIZER;

/*
** Return true if an opcode has any of the OPFLG_xxx properties
** specified by mask.
*/
int sqlite3VdbeOpcodeHasProperty(int opcode, int mask){
  assert( opcode>0 && opcode<(int)sizeof(opcodeProperty) );
  return (opcodeProperty[opcode]&mask)!=0;
}

/*
** Allocate VdbeCursor number iCur.  Return a pointer to it.  Return NULL
** if we run out of memory.
*/
static VdbeCursor *allocateCursor(
  Vdbe *p,              /* The virtual machine */
  int iCur,             /* Index of the new VdbeCursor */

){
  int pc;                    /* The program counter */
  Op *aOp = p->aOp;          /* Copy of p->aOp */
  Op *pOp;                   /* Current operation */
  int rc = SQLITE_OK;        /* Value to return */
  sqlite3 *db = p->db;       /* The database */
  u8 encoding = ENC(db);     /* The database encoding */






  Mem *pIn1 = 0;             /* 1st input operand */
  Mem *pIn2 = 0;             /* 2nd input operand */
  Mem *pIn3 = 0;             /* 3rd input operand */
  Mem *pOut = 0;             /* Output operand */
  u8 opProperty;
  int iCompare = 0;          /* Result of last OP_Compare operation */
  int *aPermute = 0;         /* Permutation of columns for OP_Compare */
#ifdef VDBE_PROFILE
  u64 start;                 /* CPU clock count at start of opcode */
  int origPc;                /* Program counter at start of opcode */
#endif
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  int nProgressOps = 0;      /* Opcodes executed since progress callback. */
#endif
  /*** INSERT STACK UNION HERE ***/

  assert( p->magic==VDBE_MAGIC_RUN );  /* sqlite3_step() verifies this */
  assert( db->magic==SQLITE_MAGIC_BUSY );
  sqlite3VdbeMutexArrayEnter(p);
  if( p->rc==SQLITE_NOMEM ){
    /* This happens if a malloc() inside a call to sqlite3_column_text() or
    ** sqlite3_column_text16() failed.  */
    goto no_mem;
  }
  assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY );
  p->rc = SQLITE_OK;
  assert( p->explain==0 );
  p->pResultSet = 0;
  db->busyHandler.nBusy = 0;
  CHECK_FOR_INTERRUPT;
  sqlite3VdbeIOTraceSql(p);



#ifdef SQLITE_DEBUG
  sqlite3BeginBenignMalloc();
  if( p->pc==0 
   && ((p->db->flags & SQLITE_VdbeListing) || fileExists(db, "vdbe_explain"))
  ){
    int i;
    printf("VDBE Program Listing:\n");

#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
    /* Call the progress callback if it is configured and the required number
    ** of VDBE ops have been executed (either since this invocation of
    ** sqlite3VdbeExec() or since last time the progress callback was called).
    ** If the progress callback returns non-zero, exit the virtual machine with
    ** a return code SQLITE_ABORT.
    */
    if( db->xProgress ){
      if( db->nProgressOps==nProgressOps ){
        int prc;
        if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
        prc =db->xProgress(db->pProgressArg);
        if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
        if( prc!=0 ){
          rc = SQLITE_INTERRUPT;
          goto vdbe_error_halt;
        }
        nProgressOps = 0;
      }
      nProgressOps++;
    }
#endif

    /* Do common setup processing for any opcode that is marked
    ** with the "out2-prerelease" tag.  Such opcodes have a single
    ** output which is specified by the P2 parameter.  The P2 register
    ** is initialized to a NULL.
    */
    opProperty = opcodeProperty[pOp->opcode];

    if( opProperty & (OPFLG_OUT2_PRERELEASE | OPFLG_IN1 | OPFLG_IN2
                      | OPFLG_IN3 | OPFLG_OUT2 | OPFLG_OUT3)
    ){
      if( (opProperty & OPFLG_OUT2_PRERELEASE)!=0 ){
        assert( pOp->p2>0 );
        assert( pOp->p2<=p->nMem );
        pOut = &p->aMem[pOp->p2];
        sqlite3VdbeMemReleaseExternal(pOut);
        pOut->flags = MEM_Null;
        pOut->n = 0;
      }else{
        if( (opProperty & OPFLG_IN1)!=0 ){
          assert( pOp->p1>0 );
          assert( pOp->p1<=p->nMem );
          pIn1 = &p->aMem[pOp->p1];
          REGISTER_TRACE(pOp->p1, pIn1);
        }
        if( (opProperty & (OPFLG_IN2|OPFLG_OUT2))!=0 ){
          assert( pOp->p2>0 );
          assert( pOp->p2<=p->nMem );
          assert( (opProperty & OPFLG_OUT2)==0 || (opProperty & OPFLG_IN3)==0 );
          pIn2 = pOut = &p->aMem[pOp->p2];
        }
        if( (opProperty & (OPFLG_IN3|OPFLG_OUT3))!=0 ){
          assert( pOp->p3>0 );
          assert( pOp->p3<=p->nMem );
          pIn3 = pOut = &p->aMem[pOp->p3];
        }
#ifdef SQLITE_DEBUG
        if( opProperty & OPFLG_IN2 ){ REGISTER_TRACE(pOp->p2, pIn2); }
        if( opProperty & OPFLG_IN3 ){ REGISTER_TRACE(pOp->p3, pIn3); }
#endif
      }
    }

      ** currently being halted. If the p2 instruction of this OP_Halt
      ** instruction is set to OE_Ignore, then the sub-program is throwing
      ** an IGNORE exception. In this case jump to the address specified
      ** as the p2 of the calling OP_Program.  */
      pc = p->aOp[pc].p2-1;
    }
    aOp = p->aOp;

    break;
  }

  p->rc = pOp->p1;
  p->errorAction = (u8)pOp->p2;
  p->pc = pc;
  if( pOp->p4.z ){

  assert( pOp->p4.z==0 || pOp->p3==1 || pOp->p3==0 );

  while( n-- > 0 ){
    pVar = &p->aVar[p1++];
    if( sqlite3VdbeMemTooBig(pVar) ){
      goto too_big;
    }
    pOut = &p->aMem[p2++];
    sqlite3VdbeMemReleaseExternal(pOut);
    pOut->flags = MEM_Null;
    sqlite3VdbeMemShallowCopy(pOut, pVar, MEM_Static);
    UPDATE_MAX_BLOBSIZE(pOut);
  }
  break;
}

  n = pOp->p3;
  p1 = pOp->p1;
  p2 = pOp->p2;
  assert( n>0 && p1>0 && p2>0 );
  assert( p1+n<=p2 || p2+n<=p1 );

  pIn1 = &p->aMem[p1];
  pOut = &p->aMem[p2];
  while( n-- ){
    assert( pOut<=&p->aMem[p->nMem] );
    assert( pIn1<=&p->aMem[p->nMem] );
    zMalloc = pOut->zMalloc;
    pOut->zMalloc = 0;
    sqlite3VdbeMemMove(pOut, pIn1);
    pIn1->zMalloc = zMalloc;
    REGISTER_TRACE(p2++, pOut);
    pIn1++;
    pOut++;

  /* Invalidate all ephemeral cursor row caches */
  p->cacheCtr = (p->cacheCtr + 2)|1;

  /* Make sure the results of the current row are \000 terminated
  ** and have an assigned type.  The results are de-ephemeralized as
  ** as side effect.
  */
  pMem = p->pResultSet = &p->aMem[pOp->p1];
  for(i=0; i<pOp->p2; i++){
    sqlite3VdbeMemNulTerminate(&pMem[i]);
    sqlite3VdbeMemStoreType(&pMem[i]);
    REGISTER_TRACE(pOp->p1+i, &pMem[i]);
  }
  if( db->mallocFailed ) goto no_mem;

  n = pOp->p5;
  apVal = p->apArg;
  assert( apVal || n==0 );

  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=p->nMem+1) );
  assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+n );
  pArg = &p->aMem[pOp->p2];
  for(i=0; i<n; i++, pArg++){
    apVal[i] = pArg;
    sqlite3VdbeMemStoreType(pArg);
    REGISTER_TRACE(pOp->p2, pArg);
  }

  assert( pOp->p4type==P4_FUNCDEF || pOp->p4type==P4_VDBEFUNC );
  if( pOp->p4type==P4_FUNCDEF ){
    ctx.pFunc = pOp->p4.pFunc;
    ctx.pVdbeFunc = 0;
  }else{
    ctx.pVdbeFunc = (VdbeFunc*)pOp->p4.pVdbeFunc;
    ctx.pFunc = ctx.pVdbeFunc->pFunc;
  }

  assert( pOp->p3>0 && pOp->p3<=p->nMem );
  pOut = &p->aMem[pOp->p3];
  ctx.s.flags = MEM_Null;
  ctx.s.db = db;
  ctx.s.xDel = 0;
  ctx.s.zMalloc = 0;

  /* The output cell may already have a buffer allocated. Move
  ** the pointer to ctx.s so in case the user-function can use

      res = (pIn1->flags & pIn3->flags & MEM_Null)==0;
    }else{
      /* SQLITE_NULLEQ is clear and at least one operand is NULL,
      ** then the result is always NULL.
      ** The jump is taken if the SQLITE_JUMPIFNULL bit is set.
      */
      if( pOp->p5 & SQLITE_STOREP2 ){
        pOut = &p->aMem[pOp->p2];
        MemSetTypeFlag(pOut, MEM_Null);
        REGISTER_TRACE(pOp->p2, pOut);
      }else if( pOp->p5 & SQLITE_JUMPIFNULL ){
        pc = pOp->p2-1;
      }
      break;
    }

    case OP_Lt:    res = res<0;      break;
    case OP_Le:    res = res<=0;     break;
    case OP_Gt:    res = res>0;      break;
    default:       res = res>=0;     break;
  }

  if( pOp->p5 & SQLITE_STOREP2 ){
    pOut = &p->aMem[pOp->p2];
    MemSetTypeFlag(pOut, MEM_Int);
    pOut->u.i = res;
    REGISTER_TRACE(pOp->p2, pOut);
  }else if( res ){
    pc = pOp->p2-1;
  }
  break;

  }else{
    assert( p1>0 && p1+n<=p->nMem+1 );
    assert( p2>0 && p2+n<=p->nMem+1 );
  }
#endif /* SQLITE_DEBUG */
  for(i=0; i<n; i++){
    idx = aPermute ? aPermute[i] : i;
    REGISTER_TRACE(p1+idx, &p->aMem[p1+idx]);
    REGISTER_TRACE(p2+idx, &p->aMem[p2+idx]);
    assert( i<pKeyInfo->nField );
    pColl = pKeyInfo->aColl[i];
    bRev = pKeyInfo->aSortOrder[i];
    iCompare = sqlite3MemCompare(&p->aMem[p1+idx], &p->aMem[p2+idx], pColl);
    if( iCompare ){
      if( bRev ) iCompare = -iCompare;
      break;
    }
  }
  aPermute = 0;
  break;

  p1 = pOp->p1;
  p2 = pOp->p2;
  pC = 0;
  memset(&sMem, 0, sizeof(sMem));
  assert( p1<p->nCursor );
  assert( pOp->p3>0 && pOp->p3<=p->nMem );
  pDest = &p->aMem[pOp->p3];
  MemSetTypeFlag(pDest, MEM_Null);
  zRec = 0;

  /* This block sets the variable payloadSize to be the total number of
  ** bytes in the record.
  **
  ** zRec is set to be the complete text of the record if it is available.

      payloadSize = (u32)payloadSize64;
    }else{
      assert( sqlite3BtreeCursorIsValid(pCrsr) );
      rc = sqlite3BtreeDataSize(pCrsr, &payloadSize);
      assert( rc==SQLITE_OK );   /* DataSize() cannot fail */
    }
  }else if( pC->pseudoTableReg>0 ){
    pReg = &p->aMem[pC->pseudoTableReg];
    assert( pReg->flags & MEM_Blob );
    payloadSize = pReg->n;
    zRec = pReg->z;
    pC->cacheStatus = (pOp->p5&OPFLAG_CLEARCACHE) ? CACHE_STALE : p->cacheCtr;
    assert( payloadSize==0 || zRec!=0 );
  }else{
    /* Consider the row to be NULL */

case OP_Affinity: {
  char *zAffinity;   /* The affinity to be applied */
  Mem *pData0;       /* First register to which to apply affinity */
  Mem *pLast;        /* Last register to which to apply affinity */
  Mem *pRec;         /* Current register */

  zAffinity = pOp->p4.z;
  pData0 = &p->aMem[pOp->p1];
  pLast = &pData0[pOp->p2-1];
  for(pRec=pData0; pRec<=pLast; pRec++){
    ExpandBlob(pRec);
    applyAffinity(pRec, zAffinity[pRec-pData0], encoding);
  }
  break;
}

  nData = 0;         /* Number of bytes of data space */
  nHdr = 0;          /* Number of bytes of header space */
  nByte = 0;         /* Data space required for this record */
  nZero = 0;         /* Number of zero bytes at the end of the record */
  nField = pOp->p1;
  zAffinity = pOp->p4.z;
  assert( nField>0 && pOp->p2>0 && pOp->p2+nField<=p->nMem+1 );
  pData0 = &p->aMem[nField];
  nField = pOp->p2;
  pLast = &pData0[nField-1];
  file_format = p->minWriteFileFormat;

  /* Loop through the elements that will make up the record to figure
  ** out how much space is required for the new record.
  */

  /* Make sure the output register has a buffer large enough to store 
  ** the new record. The output register (pOp->p3) is not allowed to
  ** be one of the input registers (because the following call to
  ** sqlite3VdbeMemGrow() could clobber the value before it is used).
  */
  assert( pOp->p3<pOp->p1 || pOp->p3>=pOp->p1+pOp->p2 );
  pOut = &p->aMem[pOp->p3];
  if( sqlite3VdbeMemGrow(pOut, (int)nByte, 0) ){
    goto no_mem;
  }
  zNewRecord = (u8 *)pOut->z;

  /* Write the record */
  i = putVarint32(zNewRecord, nHdr);

    }
  }else{
    wrFlag = 0;
  }
  if( pOp->p5 ){
    assert( p2>0 );
    assert( p2<=p->nMem );
    pIn2 = &p->aMem[p2];
    sqlite3VdbeMemIntegerify(pIn2);
    p2 = (int)pIn2->u.i;
    /* The p2 value always comes from a prior OP_CreateTable opcode and
    ** that opcode will always set the p2 value to 2 or more or else fail.
    ** If there were a failure, the prepared statement would have halted
    ** before reaching this instruction. */
    if( NEVER(p2<2) ) {

      */
      r.flags = UNPACKED_INCRKEY * (1 & (oc - OP_SeekLt));
      assert( oc!=OP_SeekGt || r.flags==UNPACKED_INCRKEY );
      assert( oc!=OP_SeekLe || r.flags==UNPACKED_INCRKEY );
      assert( oc!=OP_SeekGe || r.flags==0 );
      assert( oc!=OP_SeekLt || r.flags==0 );

      r.aMem = &p->aMem[pOp->p3];
      rc = sqlite3BtreeMovetoUnpacked(pC->pCursor, &r, 0, 0, &res);
      if( rc!=SQLITE_OK ){
        goto abort_due_to_error;
      }
      pC->rowidIsValid = 0;
    }
    pC->deferredMoveto = 0;

** See also: NotFound, NotExists, Found
*/
case OP_IsUnique: {        /* jump, in3 */
  u16 ii;
  VdbeCursor *pCx;
  BtCursor *pCrsr;
  u16 nField;
  Mem *aMem;
  UnpackedRecord r;                  /* B-Tree index search key */
  i64 R;                             /* Rowid stored in register P3 */

  aMem = &p->aMem[pOp->p4.i];
  /* Assert that the values of parameters P1 and P4 are in range. */
  assert( pOp->p4type==P4_INT32 );
  assert( pOp->p4.i>0 && pOp->p4.i<=p->nMem );
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  /* Find the index cursor. */
  pCx = p->apCsr[pOp->p1];
  assert( pCx->deferredMoveto==0 );
  pCx->seekResult = 0;
  pCx->cacheStatus = CACHE_STALE;
  pCrsr = pCx->pCursor;

  /* If any of the values are NULL, take the jump. */
  nField = pCx->pKeyInfo->nField;
  for(ii=0; ii<nField; ii++){
    if( aMem[ii].flags & MEM_Null ){
      pc = pOp->p2 - 1;
      pCrsr = 0;
      break;
    }
  }
  assert( (aMem[nField].flags & MEM_Null)==0 );

  if( pCrsr!=0 ){
    /* Populate the index search key. */
    r.pKeyInfo = pCx->pKeyInfo;
    r.nField = nField + 1;
    r.flags = UNPACKED_PREFIX_SEARCH;
    r.aMem = aMem;

    /* Extract the value of R from register P3. */
    sqlite3VdbeMemIntegerify(pIn3);
    R = pIn3->u.i;

    /* Search the B-Tree index. If no conflicting record is found, jump
    ** to P2. Otherwise, copy the rowid of the conflicting record to

          for(pFrame=p->pFrame; pFrame->pParent; pFrame=pFrame->pParent);
          /* Assert that P3 is a valid memory cell. */
          assert( pOp->p3<=pFrame->nMem );
          pMem = &pFrame->aMem[pOp->p3];
        }else{
          /* Assert that P3 is a valid memory cell. */
          assert( pOp->p3<=p->nMem );
          pMem = &p->aMem[pOp->p3];
        }

        REGISTER_TRACE(pOp->p3, pMem);
        sqlite3VdbeMemIntegerify(pMem);
        assert( (pMem->flags & MEM_Int)!=0 );  /* mem(P3) holds an integer */
        if( pMem->u.i==MAX_ROWID || pC->useRandomRowid ){
          rc = SQLITE_FULL;

  VdbeCursor *pC;   /* Cursor to table into which insert is written */
  int nZero;        /* Number of zero-bytes to append */
  int seekResult;   /* Result of prior seek or 0 if no USESEEKRESULT flag */
  const char *zDb;  /* database name - used by the update hook */
  const char *zTbl; /* Table name - used by the opdate hook */
  int op;           /* Opcode for update hook: SQLITE_UPDATE or SQLITE_INSERT */

  pData = &p->aMem[pOp->p2];
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->pCursor!=0 );
  assert( pC->pseudoTableReg==0 );
  assert( pC->isTable );
  REGISTER_TRACE(pOp->p2, pData);

  if( pOp->opcode==OP_Insert ){
    pKey = &p->aMem[pOp->p3];
    assert( pKey->flags & MEM_Int );
    REGISTER_TRACE(pOp->p3, pKey);
    iKey = pKey->u.i;
  }else{
    assert( pOp->opcode==OP_InsertInt );
    iKey = pOp->p3;
  }

case OP_RowKey:
case OP_RowData: {
  VdbeCursor *pC;
  BtCursor *pCrsr;
  u32 n;
  i64 n64;

  pOut = &p->aMem[pOp->p2];

  /* Note that RowKey and RowData are really exactly the same instruction */
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC->isTable || pOp->opcode==OP_RowKey );
  assert( pC->isIndex || pOp->opcode==OP_RowData );
  assert( pC!=0 );

  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  pCrsr = pC->pCursor;
  if( ALWAYS(pCrsr!=0) ){
    r.pKeyInfo = pC->pKeyInfo;
    r.nField = (u16)pOp->p3;
    r.flags = 0;
    r.aMem = &p->aMem[pOp->p2];
    rc = sqlite3BtreeMovetoUnpacked(pCrsr, &r, 0, 0, &res);
    if( rc==SQLITE_OK && res==0 ){
      rc = sqlite3BtreeDelete(pCrsr);
    }
    assert( pC->deferredMoveto==0 );
    pC->cacheStatus = CACHE_STALE;
  }

    r.pKeyInfo = pC->pKeyInfo;
    r.nField = (u16)pOp->p4.i;
    if( pOp->p5 ){
      r.flags = UNPACKED_INCRKEY | UNPACKED_IGNORE_ROWID;
    }else{
      r.flags = UNPACKED_IGNORE_ROWID;
    }
    r.aMem = &p->aMem[pOp->p3];
    rc = sqlite3VdbeIdxKeyCompare(pC, &r, &res);
    if( pOp->opcode==OP_IdxLT ){
      res = -res;
    }else{
      assert( pOp->opcode==OP_IdxGE );
      res++;
    }

  assert( (p->btreeMask & (1<<pOp->p2))!=0 );
  rc = sqlite3BtreeClearTable(
      db->aDb[pOp->p2].pBt, pOp->p1, (pOp->p3 ? &nChange : 0)
  );
  if( pOp->p3 ){
    p->nChange += nChange;
    if( pOp->p3>0 ){
      p->aMem[pOp->p3].u.i += nChange;
    }
  }
  break;
}

/* Opcode: CreateTable P1 P2 * * *
**

  Mem *pnErr;     /* Register keeping track of errors remaining */
  
  nRoot = pOp->p2;
  assert( nRoot>0 );
  aRoot = sqlite3DbMallocRaw(db, sizeof(int)*(nRoot+1) );
  if( aRoot==0 ) goto no_mem;
  assert( pOp->p3>0 && pOp->p3<=p->nMem );
  pnErr = &p->aMem[pOp->p3];
  assert( (pnErr->flags & MEM_Int)!=0 );
  assert( (pnErr->flags & (MEM_Str|MEM_Blob))==0 );
  pIn1 = &p->aMem[pOp->p1];
  for(j=0; j<nRoot; j++){
    aRoot[j] = (int)sqlite3VdbeIntValue(&pIn1[j]);
  }
  aRoot[j] = 0;
  assert( pOp->p5<db->nDb );
  assert( (p->btreeMask & (1<<pOp->p5))!=0 );
  z = sqlite3BtreeIntegrityCheck(db->aDb[pOp->p5].pBt, aRoot, nRoot,

  Mem *pMem;              /* Used to iterate through memory cells */
  Mem *pEnd;              /* Last memory cell in new array */
  VdbeFrame *pFrame;      /* New vdbe frame to execute in */
  SubProgram *pProgram;   /* Sub-program to execute */
  void *t;                /* Token identifying trigger */

  pProgram = pOp->p4.pProgram;
  pRt = &p->aMem[pOp->p3];
  assert( pProgram->nOp>0 );
  
  /* If the p5 flag is clear, then recursive invocation of triggers is 
  ** disabled for backwards compatibility (p5 is set if this sub-program
  ** is really a trigger, not a foreign key action, and the flag set
  ** and cleared by the "PRAGMA recursive_triggers" command is clear).
  ** 

  p->nFrame++;
  pFrame->pParent = p->pFrame;
  pFrame->lastRowid = db->lastRowid;
  pFrame->nChange = p->nChange;
  p->nChange = 0;
  p->pFrame = pFrame;
  p->aMem = &VdbeFrameMem(pFrame)[-1];
  p->nMem = pFrame->nChildMem;
  p->nCursor = (u16)pFrame->nChildCsr;
  p->apCsr = (VdbeCursor **)&p->aMem[p->nMem+1];
  p->aOp = aOp = pProgram->aOp;
  p->nOp = pProgram->nOp;
  pc = -1;

  break;
}

case OP_MemMax: {        /* in2 */
  Mem *pIn1;
  VdbeFrame *pFrame;
  if( p->pFrame ){
    for(pFrame=p->pFrame; pFrame->pParent; pFrame=pFrame->pParent);
    pIn1 = &pFrame->aMem[pOp->p1];
  }else{
    pIn1 = &p->aMem[pOp->p1];
  }
  sqlite3VdbeMemIntegerify(pIn1);
  sqlite3VdbeMemIntegerify(pIn2);
  if( pIn1->u.i<pIn2->u.i){
    pIn1->u.i = pIn2->u.i;
  }
  break;

  Mem *pMem;
  Mem *pRec;
  sqlite3_context ctx;
  sqlite3_value **apVal;

  n = pOp->p5;
  assert( n>=0 );
  pRec = &p->aMem[pOp->p2];
  apVal = p->apArg;
  assert( apVal || n==0 );
  for(i=0; i<n; i++, pRec++){
    apVal[i] = pRec;
    sqlite3VdbeMemStoreType(pRec);
  }
  ctx.pFunc = pOp->p4.pFunc;
  assert( pOp->p3>0 && pOp->p3<=p->nMem );
  ctx.pMem = pMem = &p->aMem[pOp->p3];
  pMem->n++;
  ctx.s.flags = MEM_Null;
  ctx.s.z = 0;
  ctx.s.zMalloc = 0;
  ctx.s.xDel = 0;
  ctx.s.db = db;
  ctx.isError = 0;

** functions that can take varying numbers of arguments.  The
** P4 argument is only needed for the degenerate case where
** the step function was not previously called.
*/
case OP_AggFinal: {
  Mem *pMem;
  assert( pOp->p1>0 && pOp->p1<=p->nMem );
  pMem = &p->aMem[pOp->p1];
  assert( (pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
  rc = sqlite3VdbeMemFinalize(pMem, pOp->p4.pFunc);
  if( rc ){
    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(pMem));
  }
  sqlite3VdbeChangeEncoding(pMem, encoding);
  UPDATE_MAX_BLOBSIZE(pMem);

  sqlite3_vtab_cursor *pVtabCursor;
  sqlite3_vtab *pVtab;
  VdbeCursor *pCur;
  int res;
  int i;
  Mem **apArg;

  pQuery = &p->aMem[pOp->p3];
  pArgc = &pQuery[1];
  pCur = p->apCsr[pOp->p1];
  REGISTER_TRACE(pOp->p3, pQuery);
  assert( pCur->pVtabCursor );
  pVtabCursor = pCur->pVtabCursor;
  pVtab = pVtabCursor->pVtab;
  pModule = pVtab->pModule;

  const sqlite3_module *pModule;
  Mem *pDest;
  sqlite3_context sContext;

  VdbeCursor *pCur = p->apCsr[pOp->p1];
  assert( pCur->pVtabCursor );
  assert( pOp->p3>0 && pOp->p3<=p->nMem );
  pDest = &p->aMem[pOp->p3];
  if( pCur->nullRow ){
    sqlite3VdbeMemSetNull(pDest);
    break;
  }
  pVtab = pCur->pVtabCursor->pVtab;
  pModule = pVtab->pModule;
  assert( pModule->xColumn );

** in register P1 is passed as the zName argument to the xRename method.
*/
case OP_VRename: {
  sqlite3_vtab *pVtab;
  Mem *pName;

  pVtab = pOp->p4.pVtab->pVtab;
  pName = &p->aMem[pOp->p1];
  assert( pVtab->pModule->xRename );
  REGISTER_TRACE(pOp->p1, pName);
  assert( pName->flags & MEM_Str );
  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
  rc = pVtab->pModule->xRename(pVtab, pName->z);
  sqlite3DbFree(db, p->zErrMsg);
  p->zErrMsg = pVtab->zErrMsg;

  pVtab = pOp->p4.pVtab->pVtab;
  pModule = (sqlite3_module *)pVtab->pModule;
  nArg = pOp->p2;
  assert( pOp->p4type==P4_VTAB );
  if( ALWAYS(pModule->xUpdate) ){
    apArg = p->apArg;
    pX = &p->aMem[pOp->p3];
    for(i=0; i<nArg; i++){
      sqlite3VdbeMemStoreType(pX);
      apArg[i] = pX;
      pX++;
    }
    if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
    rc = pModule->xUpdate(pVtab, nArg, apArg, &rowid);

** A single instruction of the virtual machine has an opcode
** and as many as three operands.  The instruction is recorded
** as an instance of the following structure:
*/
struct VdbeOp {
  u8 opcode;          /* What operation to perform */
  signed char p4type; /* One of the P4_xxx constants for p4 */
  u8 opflags;         /* Not currently used */
  u8 p5;              /* Fifth parameter is an unsigned character */
  int p1;             /* First operand */
  int p2;             /* Second parameter (often the jump destination) */
  int p3;             /* The third parameter */
  union {             /* fourth parameter */
    int i;                 /* Integer value if p4type==P4_INT32 */
    void *p;               /* Generic pointer */

int sqlite3VdbeMemRealify(Mem*);
int sqlite3VdbeMemNumerify(Mem*);
int sqlite3VdbeMemFromBtree(BtCursor*,int,int,int,Mem*);
void sqlite3VdbeMemRelease(Mem *p);
void sqlite3VdbeMemReleaseExternal(Mem *p);
int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
const char *sqlite3OpcodeName(int);
int sqlite3VdbeOpcodeHasProperty(int, int);
int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);
int sqlite3VdbeCloseStatement(Vdbe *, int);
void sqlite3VdbeFrameDelete(VdbeFrame*);
int sqlite3VdbeFrameRestore(VdbeFrame *);
void sqlite3VdbeMemStoreType(Mem *pMem);

#ifndef SQLITE_OMIT_FOREIGN_KEY

** label by setting the P2 value to its correct non-zero value.
**
** This routine is called once after all opcodes have been inserted.
**
** Variable *pMaxFuncArgs is set to the maximum value of any P2 argument 
** to an OP_Function, OP_AggStep or OP_VFilter opcode. This is used by 
** sqlite3VdbeMakeReady() to size the Vdbe.apArg[] array.


*/
static void resolveP2Values(Vdbe *p, int *pMaxFuncArgs){
  int i;
  int nMaxArgs = *pMaxFuncArgs;
  Op *pOp;
  int *aLabel = p->aLabel;
  p->readOnly = 1;
  for(pOp=p->aOp, i=p->nOp-1; i>=0; i--, pOp++){
    u8 opcode = pOp->opcode;


    if( opcode==OP_Function || opcode==OP_AggStep ){
      if( pOp->p5>nMaxArgs ) nMaxArgs = pOp->p5;


#ifndef SQLITE_OMIT_VIRTUALTABLE
    }else if( opcode==OP_VUpdate ){
      if( pOp->p2>nMaxArgs ) nMaxArgs = pOp->p2;
#endif
    }else if( opcode==OP_Transaction && pOp->p2!=0 ){
      p->readOnly = 0;
#ifndef SQLITE_OMIT_VIRTUALTABLE
    }else if( opcode==OP_VFilter ){
      int n;
      assert( p->nOp - i >= 3 );
      assert( pOp[-1].opcode==OP_Integer );
      n = pOp[-1].p1;
      if( n>nMaxArgs ) nMaxArgs = n;
#endif
    }

    if( sqlite3VdbeOpcodeHasProperty(opcode, OPFLG_JUMP) && pOp->p2<0 ){
      assert( -1-pOp->p2<p->nLabel );
      pOp->p2 = aLabel[-1-pOp->p2];
    }
  }
  sqlite3DbFree(p->db, p->aLabel);
  p->aLabel = 0;

    int i;
    VdbeOpList const *pIn = aOp;
    for(i=0; i<nOp; i++, pIn++){
      int p2 = pIn->p2;
      VdbeOp *pOut = &p->aOp[i+addr];
      pOut->opcode = pIn->opcode;
      pOut->p1 = pIn->p1;
      if( p2<0 && sqlite3VdbeOpcodeHasProperty(pOut->opcode, OPFLG_JUMP) ){
        pOut->p2 = addr + ADDR(p2);
      }else{
        pOut->p2 = p2;
      }
      pOut->p3 = pIn->p3;
      pOut->p4type = P4_NOTUSED;
      pOut->p4.p = 0;