SQLite

void sqlite3TableLock(
  Parse *pParse,     /* Parsing context */
  int iDb,           /* Index of the database containing the table to lock */
  int iTab,          /* Root page number of the table to be locked */
  u8 isWriteLock,    /* True for a write lock */
  const char *zName  /* Name of the table to be locked */
){
  Parse *pToplevel = sqlite3ParseToplevel(pParse);
  int i;
  int nBytes;
  TableLock *p;

  assert( iDb>=0 );




  for(i=0; i<pToplevel->nTableLock; i++){
    p = &pToplevel->aTableLock[i];
    if( p->iDb==iDb && p->iTab==iTab ){
      p->isWriteLock = (p->isWriteLock || isWriteLock);
      return;
    }
  }

  nBytes = sizeof(TableLock) * (pToplevel->nTableLock+1);
  pToplevel->aTableLock =
      sqlite3DbReallocOrFree(pToplevel->db, pToplevel->aTableLock, nBytes);
  if( pToplevel->aTableLock ){
    p = &pToplevel->aTableLock[pToplevel->nTableLock++];
    p->iDb = iDb;
    p->iTab = iTab;
    p->isWriteLock = isWriteLock;
    p->zName = zName;
  }else{
    pToplevel->nTableLock = 0;
    pToplevel->db->mallocFailed = 1;
  }
}

/*
** Code an OP_TableLock instruction for each table locked by the
** statement (configured by calls to sqlite3TableLock()).
*/

  if( v && ALWAYS(pParse->nErr==0) && !db->mallocFailed ){
#ifdef SQLITE_DEBUG
    FILE *trace = (db->flags & SQLITE_VdbeTrace)!=0 ? stdout : 0;
    sqlite3VdbeTrace(v, trace);
#endif
    assert( pParse->iCacheLevel==0 );  /* Disables and re-enables match */
    sqlite3VdbeMakeReady(v, pParse->nVar, pParse->nMem,
                         pParse->nTab, pParse->nMaxArg, pParse->explain);
    pParse->rc = SQLITE_DONE;
    pParse->colNamesSet = 0;
  }else if( pParse->rc==SQLITE_OK ){
    pParse->rc = SQLITE_ERROR;
  }
  pParse->nTab = 0;
  pParse->nMem = 0;

** cookie verification subroutine code happens in sqlite3FinishCoding().
**
** If iDb<0 then code the OP_Goto only - don't set flag to verify the
** schema on any databases.  This can be used to position the OP_Goto
** early in the code, before we know if any database tables will be used.
*/
void sqlite3CodeVerifySchema(Parse *pParse, int iDb){
  Parse *pToplevel = sqlite3ParseToplevel(pParse);




  if( pToplevel->cookieGoto==0 ){
    Vdbe *v = sqlite3GetVdbe(pToplevel);
    if( v==0 ) return;  /* This only happens if there was a prior error */


    pToplevel->cookieGoto = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0)+1;
  }
  if( iDb>=0 ){
    sqlite3 *db = pToplevel->db;
    int mask;

    assert( iDb<db->nDb );
    assert( db->aDb[iDb].pBt!=0 || iDb==1 );
    assert( iDb<SQLITE_MAX_ATTACHED+2 );
    mask = 1<<iDb;
    if( (pToplevel->cookieMask & mask)==0 ){
      pToplevel->cookieMask |= mask;
      pToplevel->cookieValue[iDb] = db->aDb[iDb].pSchema->schema_cookie;
      if( !OMIT_TEMPDB && iDb==1 ){
        sqlite3OpenTempDatabase(pToplevel);
      }
    }
  }
}

/*
** Generate VDBE code that prepares for doing an operation that
** might change the database.
**
** This routine starts a new transaction if we are not already within
** a transaction.  If we are already within a transaction, then a checkpoint
** is set if the setStatement parameter is true.  A checkpoint should
** be set for operations that might fail (due to a constraint) part of
** the way through and which will need to undo some writes without having to
** rollback the whole transaction.  For operations where all constraints
** can be checked before any changes are made to the database, it is never
** necessary to undo a write and the checkpoint should not be set.
*/
void sqlite3BeginWriteOperation(Parse *pParse, int setStatement, int iDb){
  Parse *pToplevel = sqlite3ParseToplevel(pParse);
  sqlite3CodeVerifySchema(pParse, iDb);



  pToplevel->writeMask |= 1<<iDb;
  if( setStatement && pParse->nested==0 && pParse==pToplevel ){
    /* Every place where this routine is called with setStatement!=0 has
    ** already successfully created a VDBE. */
    assert( pParse->pVdbe );
    sqlite3VdbeAddOp1(pParse->pVdbe, OP_Statement, iDb);
  }
}

    ** has already been allocated. So assume sqlite3GetVdbe() is always
    ** successful here.
    */
    assert(v);
    if( iCol<0 ){
      int iMem = ++pParse->nMem;
      int iAddr;


      iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
      sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);

      sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
      eType = IN_INDEX_ROWID;

         && (!mustBeUnique || (pIdx->nColumn==1 && pIdx->onError!=OE_None))
        ){
          int iMem = ++pParse->nMem;
          int iAddr;
          char *pKey;
  
          pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);



          iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
          sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
  
          sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, iDb,
                               pKey,P4_KEYINFO_HANDOFF);
          VdbeComment((v, "%s", pIdx->zName));
          eType = IN_INDEX_INDEX;

    }
    case TK_UPLUS: {
      inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
      break;
    }

    case TK_TRIGGER: {
      /* If the opcode is TK_TRIGGER, then the expression is a reference
      ** to a column in the new.* or old.* pseudo-tables available to
      ** trigger programs. In this case Expr.iTable is set to 1 for the
      ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
      ** is set to the column of the pseudo-table to read, or to -1 to
      ** read the rowid field.
      **
      ** The expression is implemented using an OP_Param opcode. The p1
      ** parameter is set to 0 for an old.rowid reference, or to (i+1)
      ** to reference another column of the old.* pseudo-table, where 
      ** i is the index of the column. For a new.rowid reference, p1 is
      ** set to (n+1), where n is the number of columns in each pseudo-table.
      ** For a reference to any other column in the new.* pseudo-table, p1
      ** is set to (n+2+i), where n and i are as defined previously. For
      ** example, if the table on which triggers are being fired is
      ** declared as:
      **
      **   CREATE TABLE t1(a, b);
      **
      ** Then p1 is interpreted as follows:
      **
      **   p1==0   ->    old.rowid     p1==3   ->    new.rowid
      **   p1==1   ->    old.a         p1==4   ->    new.a
      **   p1==2   ->    old.b         p1==5   ->    new.b       
      */
      Table *pTab = pExpr->pTab;
      int p1 = pExpr->iTable * (pTab->nCol+1) + 1 + pExpr->iColumn;

      assert( pExpr->iTable==0 || pExpr->iTable==1 );
      assert( pExpr->iColumn>=-1 && pExpr->iColumn<pTab->nCol );
      assert( pTab->iPKey<0 || pExpr->iColumn!=pTab->iPKey );
      assert( p1>=0 && p1<(pTab->nCol*2+2) );

      sqlite3VdbeAddOp2(v, OP_Param, p1, target);
      VdbeComment((v, "%s.%s -> $%d",
        (pExpr->iTable ? "new" : "old"),
        (pExpr->iColumn<0 ? "rowid" : pExpr->pTab->aCol[pExpr->iColumn].zName),
        target
      ));

      /* If the column has REAL affinity, it may currently be stored as an
      ** integer. Use OP_RealAffinity to make sure it is really real.  */
      if( pExpr->iColumn>=0 
       && pTab->aCol[pExpr->iColumn].affinity==SQLITE_AFF_REAL
      ){
        sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
      }
      break;
    }

static int autoIncBegin(
  Parse *pParse,      /* Parsing context */
  int iDb,            /* Index of the database holding pTab */
  Table *pTab         /* The table we are writing to */
){
  int memId = 0;      /* Register holding maximum rowid */
  if( pTab->tabFlags & TF_Autoincrement ){
    Parse *pToplevel = sqlite3ParseToplevel(pParse);
    AutoincInfo *pInfo;

    pInfo = pToplevel->pAinc;
    while( pInfo && pInfo->pTab!=pTab ){ pInfo = pInfo->pNext; }
    if( pInfo==0 ){
      pInfo = sqlite3DbMallocRaw(pParse->db, sizeof(*pInfo));
      if( pInfo==0 ) return 0;
      pInfo->pNext = pToplevel->pAinc;
      pToplevel->pAinc = pInfo;
      pInfo->pTab = pTab;
      pInfo->iDb = iDb;
      pToplevel->nMem++;                  /* Register to hold name of table */
      pInfo->regCtr = ++pToplevel->nMem;  /* Max rowid register */
      pToplevel->nMem++;                  /* Rowid in sqlite_sequence */
    }
    memId = pInfo->regCtr;
  }
  return memId;
}

/*

  int endOfLoop;        /* Label for the end of the insertion loop */
  int useTempTable = 0; /* Store SELECT results in intermediate table */
  int srcTab = 0;       /* Data comes from this temporary cursor if >=0 */
  int addrInsTop = 0;   /* Jump to label "D" */
  int addrCont = 0;     /* Top of insert loop. Label "C" in templates 3 and 4 */
  int addrSelect = 0;   /* Address of coroutine that implements the SELECT */
  SelectDest dest;      /* Destination for SELECT on rhs of INSERT */

  int iDb;              /* Index of database holding TABLE */
  Db *pDb;              /* The database containing table being inserted into */
  int appendFlag = 0;   /* True if the insert is likely to be an append */

  /* Register allocations */
  int regFromSelect = 0;/* Base register for data coming from SELECT */
  int regAutoinc = 0;   /* Register holding the AUTOINCREMENT counter */
  int regRowCount = 0;  /* Memory cell used for the row counter */
  int regIns;           /* Block of regs holding rowid+data being inserted */
  int regRowid;         /* registers holding insert rowid */
  int regData;          /* register holding first column to insert */
  int regRecord;        /* Holds the assemblied row record */
  int regEof = 0;       /* Register recording end of SELECT data */
  int *aRegIdx = 0;     /* One register allocated to each index */


#ifndef SQLITE_OMIT_TRIGGER
  int isView;                 /* True if attempting to insert into a view */
  Trigger *pTrigger;          /* List of triggers on pTab, if required */
  int tmask;                  /* Mask of trigger times */
#endif

}

/*
** Generate code to do constraint checks prior to an INSERT or an UPDATE.
**
** The input is a range of consecutive registers as follows:
**




**    1.  The rowid of the row after the update.
**
**    2.  The data in the first column of the entry after the update.
**
**    i.  Data from middle columns...
**
**    N.  The data in the last column of the entry after the update.
**
** The regRowid parameter is the index of the register containing (1).
**
** If isUpdate is true and rowidChng is non-zero, then rowidChng contains
** the address of a register containing the rowid before the update takes
** place. isUpdate is true for UPDATEs and false for INSERTs. If isUpdate
** is false, indicating an INSERT statement, then a non-zero rowidChng 
** indicates that the rowid was explicitly specified as part of the
** INSERT statement. If rowidChng is false, it means that  the rowid is
** computed automatically in an insert or that the rowid value is not 
** modified by an update.
**
** The code generated by this routine store new index entries into
** registers identified by aRegIdx[].  No index entry is created for
** indices where aRegIdx[i]==0.  The order of indices in aRegIdx[] is
** the same as the order of indices on the linked list of indices
** attached to the table.
**

  int onError;        /* Conflict resolution strategy */
  int j1;             /* Addresss of jump instruction */
  int j2 = 0, j3;     /* Addresses of jump instructions */
  int regData;        /* Register containing first data column */
  int iCur;           /* Table cursor number */
  Index *pIdx;         /* Pointer to one of the indices */
  int seenReplace = 0; /* True if REPLACE is used to resolve INT PK conflict */
  int regOldRowid = (rowidChng && isUpdate) ? rowidChng : regRowid;

  v = sqlite3GetVdbe(pParse);
  assert( v!=0 );
  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
  nCol = pTab->nCol;
  regData = regRowid + 1;

      if( onError==OE_Ignore ) onError = OE_Replace;
      else if( onError==OE_Fail ) onError = OE_Abort;
    }
    

    /* Check to see if the new index entry will be unique */
    regR = sqlite3GetTempReg(pParse);
    sqlite3VdbeAddOp2(v, OP_SCopy, regOldRowid, regR);
    j3 = sqlite3VdbeAddOp4(v, OP_IsUnique, baseCur+iCur+1, 0,
                           regR, SQLITE_INT_TO_PTR(regIdx),
                           P4_INT32);
    sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn+1);

    /* Generate code that executes if the new index entry is not unique */
    assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail

  db->flags |= SQLITE_ShortColNames
#if SQLITE_DEFAULT_FILE_FORMAT<4
                 | SQLITE_LegacyFileFmt
#endif
#ifdef SQLITE_ENABLE_LOAD_EXTENSION
                 | SQLITE_LoadExtension
#endif
#if 1 || defined(SQLITE_DISABLE_RECURSIVE_TRIGGERS)
                 | SQLITE_NoRecTriggers
#endif
      ;
  sqlite3HashInit(&db->aCollSeq);
#ifndef SQLITE_OMIT_VIRTUALTABLE
  sqlite3HashInit(&db->aModule);
#endif

  if( zErrMsg ){
    sqlite3Error(db, rc, "%s", zErrMsg);
    sqlite3DbFree(db, zErrMsg);
  }else{
    sqlite3Error(db, rc, 0);
  }

  /* Delete any TriggerPrg structures allocated while parsing this statement. */
  while( pParse->pTriggerPrg ){
    TriggerPrg *pT = pParse->pTriggerPrg;
    pParse->pTriggerPrg = pT->pNext;
    sqlite3VdbeProgramDelete(db, pT->pProgram, 0);
    sqlite3DbFree(db, pT);
  }

    }

#ifndef SQLITE_OMIT_TRIGGER
    /* If we have not already resolved the name, then maybe 
    ** it is a new.* or old.* trigger argument reference
    */
    if( zDb==0 && zTab!=0 && cnt==0 && pParse->pTriggerTab!=0 ){
      int op = pParse->eTriggerOp;
      Table *pTab = 0;
      assert( op==TK_DELETE || op==TK_UPDATE || op==TK_INSERT );
      if( op!=TK_DELETE && sqlite3StrICmp("new",zTab) == 0 ){
        pExpr->iTable = 1;
        pTab = pParse->pTriggerTab;
      }else if( op!=TK_INSERT && sqlite3StrICmp("old",zTab)==0 ){
        pExpr->iTable = 0;
        pTab = pParse->pTriggerTab;
      }

      if( pTab ){ 
        int iCol;
        pSchema = pTab->pSchema;

  ** complete, since there may still exist Expr.pTab entries that
  ** refer to the subquery even after flattening.  Ticket #3346.
  **
  ** pSubitem->pTab is always non-NULL by test restrictions and tests above.
  */
  if( ALWAYS(pSubitem->pTab!=0) ){
    Table *pTabToDel = pSubitem->pTab;

    if( pTabToDel->nRef==1 ){
      Parse *pToplevel = sqlite3ParseToplevel(pParse);
      pTabToDel->pNextZombie = pToplevel->pZombieTab;
      pToplevel->pZombieTab = pTabToDel;
    }else{
      pTabToDel->nRef--;
    }
    pSubitem->pTab = 0;
  }

  /* The following loop runs once for each term in a compound-subquery

** completed.
**
** A Vdbe sub-program that implements the body and WHEN clause of trigger
** TriggerPrg.pTrigger, assuming a default ON CONFLICT clause of
** TriggerPrg.orconf, is stored in the TriggerPrg.pProgram variable.
** The Parse.pTriggerPrg list never contains two entries with the same
** values for both pTrigger and orconf.
**
** The TriggerPrg.oldmask variable is set to a mask of old.* columns
** accessed (or set to 0 for triggers fired as a result of INSERT 
** statements).
*/
struct TriggerPrg {
  Trigger *pTrigger;      /* Trigger this program was coded from */
  int orconf;             /* Default ON CONFLICT policy */
  SubProgram *pProgram;   /* Program implementing pTrigger/orconf */
  u32 oldmask;            /* Mask of old.* columns accessed */
  TriggerPrg *pNext;      /* Next entry in Parse.pTriggerPrg list */

#ifndef SQLITE_OMIT_SHARED_CACHE
  int nTableLock;        /* Number of locks in aTableLock */
  TableLock *aTableLock; /* Required table locks for shared-cache mode */
#endif
  int regRowid;        /* Register holding rowid of CREATE TABLE entry */
  int regRoot;         /* Register holding root page number for new objects */
  AutoincInfo *pAinc;  /* Information about AUTOINCREMENT counters */
  int nMaxArg;         /* Max args passed to user function by sub-program */

  /* Information used while coding trigger programs. */
  Parse *pToplevel;    /* Parse structure for main program (or NULL) */
  Table *pTriggerTab;  /* Table triggers are being coded for */
  u32 oldmask;         /* Mask of old.* columns referenced */

  u8 eTriggerOp;       /* TK_UPDATE, TK_INSERT or TK_DELETE */

  u8 eOrconf;          /* Default ON CONFLICT policy for trigger steps */

  /* Above is constant between recursions.  Below is reset before and after
  ** each recursion */

  int nVar;            /* Number of '?' variables seen in the SQL so far */
  int nVarExpr;        /* Number of used slots in apVarExpr[] */
  int nVarExprAlloc;   /* Number of allocated slots in apVarExpr[] */

  TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
                                        ExprList*,Select*,u8);
  TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, u8);
  TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
  void sqlite3DeleteTrigger(sqlite3*, Trigger*);
  void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
  u32 sqlite3TriggerOldmask(Parse*,Trigger*,int,ExprList*,Table*,int);
# define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))
#else
# define sqlite3TriggersExist(B,C,D,E,F) 0
# define sqlite3DeleteTrigger(A,B)
# define sqlite3DropTriggerPtr(A,B)
# define sqlite3UnlinkAndDeleteTrigger(A,B,C)
# define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I,J)
# define sqlite3TriggerList(X, Y) 0
# define sqlite3ParseToplevel(p) p
#endif

int sqlite3JoinType(Parse*, Token*, Token*, Token*);
void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
void sqlite3DeferForeignKey(Parse*, int);
#ifndef SQLITE_OMIT_AUTHORIZATION
  void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);

      pSrc->a[pSrc->nSrc-1].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zName);
    }
  }
  return pSrc;
}

/*
** Generate VDBE code for the statements inside the body of a single 
** trigger.
*/
static int codeTriggerProgram(
  Parse *pParse,            /* The parser context */
  TriggerStep *pStepList,   /* List of statements inside the trigger body */
  int orconf                /* Conflict algorithm. (OE_Abort, etc) */  
){
  TriggerStep *pStep;
  Vdbe *v = pParse->pVdbe;
  sqlite3 *db = pParse->db;

  assert( pParse->pTriggerTab && pParse->pToplevel );
  assert( pStepList );
  assert( v!=0 );
  for(pStep=pStepList; pStep; pStep=pStep->pNext){
    /* Figure out the ON CONFLICT policy that will be used for this step
    ** of the trigger program. If the statement that caused this trigger
    ** to fire had an explicit ON CONFLICT, then use it. Otherwise, use
    ** the ON CONFLICT policy that was specified as part of the trigger
    ** step statement. Example:
    **
    **   CREATE TRIGGER AFTER INSERT ON t1 BEGIN;
    **     INSERT OR REPLACE INTO t2 VALUES(new.a, new.b);
    **   END;
    **
    **   INSERT INTO t1 ... ;            -- insert into t2 uses REPLACE policy
    **   INSERT OR IGNORE INTO t1 ... ;  -- insert into t2 uses IGNORE policy
    */
    pParse->eOrconf = (orconf==OE_Default)?pStep->orconf:orconf;

    switch( pStep->op ){
      case TK_UPDATE: {
        sqlite3Update(pParse, 
          targetSrcList(pParse, pStep),
          sqlite3ExprListDup(db, pStep->pExprList, 0), 
          sqlite3ExprDup(db, pStep->pWhere, 0), 
          pParse->eOrconf
        );
        break;
      }
      case TK_INSERT: {
        sqlite3Insert(pParse, 
          targetSrcList(pParse, pStep),
          sqlite3ExprListDup(db, pStep->pExprList, 0), 
          sqlite3SelectDup(db, pStep->pSelect, 0), 
          sqlite3IdListDup(db, pStep->pIdList), 
          pParse->eOrconf
        );
        break;
      }
      case TK_DELETE: {
        sqlite3DeleteFrom(pParse, 
          targetSrcList(pParse, pStep),
          sqlite3ExprDup(db, pStep->pWhere, 0)

        sqlite3SelectDelete(db, pSelect);
        break;
      }
    } 
    if( pStep->op!=TK_SELECT ){
      sqlite3VdbeAddOp1(v, OP_ResetCount, 1);
    }

  }

  return 0;
}

#ifdef SQLITE_DEBUG
/*

    pTo->zErrMsg = pFrom->zErrMsg;
    pTo->nErr = pFrom->nErr;
  }else{
    sqlite3DbFree(pFrom->db, pFrom->zErrMsg);
  }
}

/*
** Create and populate a new TriggerPrg object with a sub-program 
** implementing trigger pTrigger with ON CONFLICT policy orconf.
*/
static TriggerPrg *codeRowTrigger(

  Parse *pParse,       /* Current parse context */
  Trigger *pTrigger,   /* Trigger to code */

  Table *pTab,         /* The table pTrigger is attached to */
  int orconf           /* ON CONFLICT policy to code trigger program with */
){
  Parse *pTop = sqlite3ParseToplevel(pParse);
  sqlite3 *db = pParse->db;   /* Database handle */
  TriggerPrg *pPrg;           /* Value to return */
  Expr *pWhen = 0;            /* Duplicate of trigger WHEN expression */
  Vdbe *v;                    /* Temporary VM */
  NameContext sNC;            /* Name context for sub-vdbe */
  SubProgram *pProgram = 0;   /* Sub-vdbe for trigger program */
  Parse *pSubParse;           /* Parse context for sub-vdbe */
  int iEndTrigger = 0;        /* Label to jump to if WHEN is false */

  assert( pTab==tableOfTrigger(pTrigger) );

  /* Allocate the TriggerPrg and SubProgram objects. To ensure that they
  ** are freed if an error occurs, link them into the Parse.pTriggerPrg 
  ** list of the top-level Parse object sooner rather than later.  */
  pPrg = sqlite3DbMallocZero(db, sizeof(TriggerPrg));
  if( !pPrg ) return 0;
  pPrg->pNext = pTop->pTriggerPrg;
  pTop->pTriggerPrg = pPrg;
  pPrg->pProgram = pProgram = sqlite3DbMallocZero(db, sizeof(SubProgram));
  if( !pProgram ) return 0;
  pProgram->nRef = 1;




  pPrg->pTrigger = pTrigger;
  pPrg->orconf = orconf;

  /* Allocate and populate a new Parse context to use for coding the 
  ** trigger sub-program.  */
  pSubParse = sqlite3StackAllocZero(db, sizeof(Parse));
  if( !pSubParse ) return 0;
  memset(&sNC, 0, sizeof(sNC));
  sNC.pParse = pSubParse;
  pSubParse->db = db;
  pSubParse->pTriggerTab = pTab;
  pSubParse->pToplevel = pTop;
  pSubParse->zAuthContext = pTrigger->zName;
  pSubParse->eTriggerOp = pTrigger->op;

  v = sqlite3GetVdbe(pSubParse);
  if( v ){
    VdbeComment((v, "Start: %s.%s (%s %s%s%s ON %s)", 
      pTrigger->zName, onErrorText(orconf),
      (pTrigger->tr_tm==TRIGGER_BEFORE ? "BEFORE" : "AFTER"),
        (pTrigger->op==TK_UPDATE ? "UPDATE" : ""),
        (pTrigger->op==TK_INSERT ? "INSERT" : ""),
        (pTrigger->op==TK_DELETE ? "DELETE" : ""),
      pTab->zName
    ));
#ifndef SQLITE_OMIT_TRACE
    sqlite3VdbeChangeP4(v, -1, 
      sqlite3MPrintf(db, "-- TRIGGER %s", pTrigger->zName), P4_DYNAMIC
    );
#endif


    /* If one was specified, code the WHEN clause. If it evaluates to false
    ** (or NULL) the sub-vdbe is immediately halted by jumping to the 
    ** OP_Halt inserted at the end of the program.  */
    if( pTrigger->pWhen ){
      pWhen = sqlite3ExprDup(db, pTrigger->pWhen, 0);
      if( SQLITE_OK==sqlite3ResolveExprNames(&sNC, pWhen) 
       && db->mallocFailed==0 
      ){
        iEndTrigger = sqlite3VdbeMakeLabel(v);
        sqlite3ExprIfFalse(pSubParse, pWhen, iEndTrigger, SQLITE_JUMPIFNULL);
      }
      sqlite3ExprDelete(db, pWhen);
    }

    /* Code the trigger program into the sub-vdbe. */
    codeTriggerProgram(pSubParse, pTrigger->step_list, orconf);

    /* Insert an OP_Halt at the end of the sub-program. */
    if( iEndTrigger ){
      sqlite3VdbeResolveLabel(v, iEndTrigger);
    }
    sqlite3VdbeAddOp0(v, OP_Halt);
    VdbeComment((v, "End: %s.%s", pTrigger->zName, onErrorText(orconf)));

    transferParseError(pParse, pSubParse);
    if( db->mallocFailed==0 ){
      pProgram->aOp = sqlite3VdbeTakeOpArray(v, &pProgram->nOp, &pTop->nMaxArg);
    }
    pProgram->nMem = pSubParse->nMem;
    pProgram->nCsr = pSubParse->nTab;
    pProgram->token = (void *)pTrigger;
    pPrg->oldmask = pSubParse->oldmask;
    sqlite3VdbeDelete(v);
  }






  assert( !pSubParse->pAinc       && !pSubParse->pZombieTab );
  assert( !pSubParse->pTriggerPrg && !pSubParse->nMaxArg );
  sqlite3StackFree(db, pSubParse);

  return pPrg;
}
    
/*
** Return a pointer to a TriggerPrg object containing the sub-program for
** trigger pTrigger with default ON CONFLICT algorithm orconf. If no such
** TriggerPrg object exists, a new object is allocated and populated before
** being returned.
*/
static TriggerPrg *getRowTrigger(
  Parse *pParse,       /* Current parse context */
  Trigger *pTrigger,   /* Trigger to code */

  Table *pTab,         /* The table trigger pTrigger is attached to */
  int orconf           /* ON CONFLICT algorithm. */
){
  Parse *pRoot = sqlite3ParseToplevel(pParse);
  TriggerPrg *pPrg;

  assert( pTab==tableOfTrigger(pTrigger) );

  /* It may be that this trigger has already been coded (or is in the
  ** process of being coded). If this is the case, then an entry with
  ** a matching TriggerPrg.pTrigger field will be present somewhere
  ** in the Parse.pTriggerPrg list. Search for such an entry.  */



  for(pPrg=pRoot->pTriggerPrg; 
      pPrg && (pPrg->pTrigger!=pTrigger || pPrg->orconf!=orconf); 
      pPrg=pPrg->pNext
  );

  /* If an existing TriggerPrg could not be located, create a new one. */
  if( !pPrg ){
    pPrg = codeRowTrigger(pParse, pTrigger, pTab, orconf);
  }

  return pPrg;
}

/*
** This is called to code FOR EACH ROW triggers.

    /* Determine whether we should code this trigger */
    if( p->op==op 
     && p->tr_tm==tr_tm 
     && checkColumnOverlap(p->pColumns,pChanges)
    ){
      Vdbe *v = sqlite3GetVdbe(pParse); /* Main VM */
      TriggerPrg *pPrg;
      pPrg = getRowTrigger(pParse, p, pTab, orconf);
      assert( pPrg || pParse->nErr || pParse->db->mallocFailed );

      /* Code the OP_Program opcode in the parent VDBE. P4 of the OP_Program 
      ** is a pointer to the sub-vdbe containing the trigger program.  */
      if( pPrg ){
        sqlite3VdbeAddOp3(v, OP_Program, oldIdx, ignoreJump, ++pParse->nMem);
        pPrg->pProgram->nRef++;

  u32 mask = 0;
  Trigger *p;

  assert(op==TK_UPDATE || op==TK_DELETE);
  for(p=pTrigger; p; p=p->pNext){
    if( p->op==op && checkColumnOverlap(p->pColumns,pChanges) ){
      TriggerPrg *pPrg;
      pPrg = getRowTrigger(pParse, p, pTab, orconf);
      if( pPrg ){
        mask |= pPrg->oldmask;
      }
    }
  }

  return mask;
}

#endif /* !defined(SQLITE_OMIT_TRIGGER) */

** exception using the RAISE() function. Register P3 contains the address 
** of a memory cell in this (the parent) VM that is used to allocate the 
** memory required by the sub-vdbe at runtime.
**
** P4 is a pointer to the VM containing the trigger program.
*/
case OP_Program: {        /* jump */
  int nMem;               /* Number of memory registers for sub-program */
  int nByte;              /* Bytes of runtime space required for sub-program */
  Mem *pRt;               /* Register to allocate runtime space */
  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 SQLITE_NoRecTriggers flag it set, then recursive invocation of
  ** triggers is disabled for backwards compatibility (flag set/cleared by
  ** the "PRAGMA disable_recursive_triggers" command). 
  ** 
  ** It is recursive invocation of triggers, at the SQL level, that is 
  ** disabled. In some cases a single trigger may generate more than one 
  ** SubProgram (if the trigger may be executed with more than one different 
  ** ON CONFLICT algorithm). SubProgram structures associated with a
  ** single trigger all have the same value for the SubProgram.token 
  ** variable.
  */
  if( db->flags&SQLITE_NoRecTriggers ){
    t = pProgram->token;
    for(pFrame=p->pFrame; pFrame && pFrame->token!=t; pFrame=pFrame->pParent);
    if( pFrame ) break;
  }

  /* TODO: This constant should be configurable. */
  if( p->nFrame>1000 ){
    rc = SQLITE_ERROR;
    sqlite3SetString(&p->zErrMsg, db, "too many levels of trigger recursion");
    break;
  }

  /* Register pRt is used to store the memory required to save the state
  ** of the current program, and the memory required at runtime to execute
  ** the trigger program. If this trigger has been fired before, then pRt 
  ** is already allocated. Otherwise, it must be initialized.  */
  if( (pRt->flags&MEM_Frame)==0 ){



    /* SubProgram.nMem is set to the number of memory cells used by the 
    ** program stored in SubProgram.aOp. As well as these, one memory
    ** cell is required for each cursor used by the program. Set local
    ** variable nMem (and later, VdbeFrame.nChildMem) to this value.
    */
    nMem = pProgram->nMem + pProgram->nCsr;
    nByte = ROUND8(sizeof(VdbeFrame))
              + nMem * sizeof(Mem)
              + pProgram->nCsr * sizeof(VdbeCursor *);
    pFrame = sqlite3DbMallocZero(db, nByte);
    if( !pFrame ){
      goto no_mem;
    }
    sqlite3VdbeMemRelease(pRt);

** and old.* values.
**
** The address of the cell in the parent frame is determined by adding
** the value of the P1 argument to the value of the P1 argument to the
** calling OP_Program instruction.
*/
case OP_Param: {           /* out2-prerelease */
  VdbeFrame *pFrame;
  Mem *pIn;
  pFrame = p->pFrame;
  pIn = &pFrame->aMem[pOp->p1 + pFrame->aOp[pFrame->pc].p1];   
  sqlite3VdbeMemShallowCopy(pOut, pIn, MEM_Ephem);
  break;
}

#endif /* #ifndef SQLITE_OMIT_TRIGGER */

#ifndef SQLITE_OMIT_AUTOINCREMENT

  int payloadSize;      /* Total number of bytes in the record */
  u32 *aType;           /* Type values for all entries in the record */
  u32 *aOffset;         /* Cached offsets to the start of each columns data */
  u8 *aRow;             /* Data for the current row, if all on one page */
};
typedef struct VdbeCursor VdbeCursor;

/*
** When a sub-program is executed (OP_Program), a structure of this type
** is allocated to store the current value of the program counter, as
** well as the current memory cell array and various other frame specific
** values stored in the Vdbe struct. When the sub-program is finished, 
** these values are copied back to the Vdbe from the VdbeFrame structure,
** restoring the state of the VM to as it was before the sub-program
** began executing.
**
** Frames are stored in a linked list headed at Vdbe.pParent. Vdbe.pParent
** is the parent of the current frame, or zero if the current frame
** is the main Vdbe program.
*/
typedef struct VdbeFrame VdbeFrame;
struct VdbeFrame {
  Vdbe *v;                /* VM this frame belongs to */
  int pc;                 /* Program Counter */
  Op *aOp;                /* Program instructions */
  int nOp;                /* Size of aOp array */
  Mem *aMem;              /* Array of memory cells */
  int nMem;               /* Number of entries in aMem */
  VdbeCursor **apCsr;     /* Element of Vdbe cursors */
  u16 nCursor;            /* Number of entries in apCsr */

  void *token;            /* Copy of SubProgram.token */
  int nChildMem;          /* Number of memory cells for child frame */
  int nChildCsr;          /* Number of cursors for child frame */
  i64 lastRowid;          /* Last insert rowid (sqlite3.lastRowid) */
  int nChange;            /* Statement changes (Vdbe.nChanges)     */
  VdbeFrame *pParent;     /* Parent of this frame */
};

#define VdbeFrameMem(p) ((Mem *)&((u8 *)p)[ROUND8(sizeof(VdbeFrame))])

/*
** A value for VdbeCursor.cacheValid that means the cache is always invalid.
*/

  void *pFree;            /* Free this when deleting the vdbe */
  int iStatement;         /* Statement number (or 0 if has not opened stmt) */
#ifdef SQLITE_DEBUG
  FILE *trace;            /* Write an execution trace here, if not NULL */
#endif
  VdbeFrame *pFrame;      /* Parent frame */
  int nFrame;             /* Number of frames in pFrame list */

};

/*
** The following are allowed values for Vdbe.magic
*/
#define VDBE_MAGIC_INIT     0x26bceaa5    /* Building a VDBE program */
#define VDBE_MAGIC_RUN      0xbdf20da3    /* VDBE is ready to execute */

** Return the address of the next instruction to be inserted.
*/
int sqlite3VdbeCurrentAddr(Vdbe *p){
  assert( p->magic==VDBE_MAGIC_INIT );
  return p->nOp;
}

/*
** This function returns a pointer to the array of opcodes associated with
** the Vdbe passed as the first argument. It is the callers responsibility
** to arrange for the returned array to be eventually freed using the 
** vdbeFreeOpArray() function.
**
** Before returning, *pnOp is set to the number of entries in the returned
** array. Also, *pnMaxArg is set to the larger of its current value and 
** the number of entries in the Vdbe.apArg[] array required to execute the 
** returned program.
*/
VdbeOp *sqlite3VdbeTakeOpArray(Vdbe *p, int *pnOp, int *pnMaxArg){
  VdbeOp *aOp = p->aOp;
  assert( aOp && !p->db->mallocFailed );

  /* Check that sqlite3VdbeUsesBtree() was not called on this VM */
  assert( p->aMutex.nMutex==0 );

  resolveP2Values(p, pnMaxArg);
  *pnOp = p->nOp;
  p->aOp = 0;
  return aOp;
}

/*

        sqlite3VdbeProgramDelete(db, (SubProgram *)p4, 1);
        break;
      }
    }
  }
}

/*
** Free the space allocated for aOp and any p4 values allocated for the
** opcodes contained within. If aOp is not NULL it is assumed to contain 
** nOp entries. 
*/
static void vdbeFreeOpArray(sqlite3 *db, Op *aOp, int nOp){
  if( aOp ){
    Op *pOp;
    for(pOp=aOp; pOp<&aOp[nOp]; pOp++){
      freeP4(db, pOp->p4type, pOp->p4.p);
#ifdef SQLITE_DEBUG
      sqlite3DbFree(db, pOp->zComment);
#endif     
    }
  }
  sqlite3DbFree(db, aOp);
}

/*
** Decrement the ref-count on the SubProgram structure passed as the
** second argument. If the ref-count reaches zero, free the structure.
**
** The array of VDBE opcodes stored as SubProgram.aOp is freed if
** either the ref-count reaches zero or parameter freeop is non-zero.
**
** Since the array of opcodes pointed to by SubProgram.aOp may directly
** or indirectly contain a reference to the SubProgram structure itself.
** By passing a non-zero freeop parameter, the caller may ensure that all
** SubProgram structures and their aOp arrays are freed, even when there
** are such circular references.
*/
void sqlite3VdbeProgramDelete(sqlite3 *db, SubProgram *p, int freeop){
  if( p ){
    assert( p->nRef>0 );
    if( freeop || p->nRef==1 ){
      Op *aOp = p->aOp;
      p->aOp = 0;
      vdbeFreeOpArray(db, aOp, p->nOp);

  assert( zP4!=0 );
  return zP4;
}
#endif

/*
** Declare to the Vdbe that the BTree object at db->aDb[i] is used.

*/
void sqlite3VdbeUsesBtree(Vdbe *p, int i){
  int mask;
  assert( i>=0 && i<p->db->nDb && i<sizeof(u32)*8 );
  assert( i<(int)sizeof(p->btreeMask)*8 );
  mask = ((u32)1)<<i;
  if( (p->btreeMask & mask)==0 ){

      p->flags = MEM_Null;
    }
    db->mallocFailed = malloc_failed;
  }
}

/*
** Delete a VdbeFrame object and its contents. VdbeFrame objects are
** allocated by the OP_Program opcode in sqlite3VdbeExec().
*/
void sqlite3VdbeFrameDelete(VdbeFrame *p){
  int i;
  Mem *aMem = VdbeFrameMem(p);
  VdbeCursor **apCsr = (VdbeCursor **)&aMem[p->nChildMem];
  for(i=0; i<p->nChildCsr; i++){
    sqlite3VdbeFreeCursor(p->v, apCsr[i]);
  }

  }
#endif
  if( !pCx->ephemPseudoTable ){
    sqlite3DbFree(p->db, pCx->pData);
  }
}

/*
** Copy the values stored in the VdbeFrame structure to its Vdbe. This
** is used, for example, when a trigger sub-program is halted to restore
** control to the main program.
*/
int sqlite3VdbeFrameRestore(VdbeFrame *pFrame){
  Vdbe *v = pFrame->v;
  v->aOp = pFrame->aOp;
  v->nOp = pFrame->nOp;
  v->aMem = pFrame->aMem;
  v->nMem = pFrame->nMem;
  v->apCsr = pFrame->apCsr;

/*
** Make sure virtual table pTab is contained in the pParse->apVirtualLock[]
** array so that an OP_VBegin will get generated for it.  Add pTab to the
** array if it is missing.  If pTab is already in the array, this routine
** is a no-op.
*/
void sqlite3VtabMakeWritable(Parse *pParse, Table *pTab){
  Parse *pToplevel = sqlite3ParseToplevel(pParse);
  int i, n;
  Table **apVtabLock;


  assert( IsVirtual(pTab) );
  for(i=0; i<pToplevel->nVtabLock; i++){
    if( pTab==pToplevel->apVtabLock[i] ) return;
  }
  n = (pToplevel->nVtabLock+1)*sizeof(pToplevel->apVtabLock[0]);
  apVtabLock = sqlite3_realloc(pToplevel->apVtabLock, n);
  if( apVtabLock ){
    pToplevel->apVtabLock = apVtabLock;
    pToplevel->apVtabLock[pToplevel->nVtabLock++] = pTab;
  }else{
    pToplevel->db->mallocFailed = 1;
  }
}

#endif /* SQLITE_OMIT_VIRTUALTABLE */

  }
  if {[regexp "^\175" $line]} {
    append afterUnion $line\n
    set vlist {}
  } elseif {[llength $vlist]>0} {
    append line " "
    foreach v $vlist {
      regsub -all "(\[^a-zA-Z0-9>.\])${v}(\\W)" $line "\\1u.$sname.$v\\2" line
      regsub -all "(\[^a-zA-Z0-9>.\])${v}(\\W)" $line "\\1u.$sname.$v\\2" line
    }
    append afterUnion [string trimright $line]\n
  } elseif {$line=="" && [eof stdin]} {
    # no-op
  } else {
    append afterUnion $line\n