SQLite

  Parse *pParse = pWalker->pParse;
  int i;
  if( pParse->nErr ) return WRC_Abort;
  if( NEVER(p->selFlags & SF_View) ) return WRC_Prune;
  if( ALWAYS(p->pEList) ){
    ExprList *pList = p->pEList;
    for(i=0; i<pList->nExpr; i++){
      if( pList->a[i].zEName && pList->a[i].eEName==ENAME_NAME ){
        sqlite3RenameTokenRemap(pParse, 0, (void*)pList->a[i].zEName);
      }
    }
  }
  if( ALWAYS(p->pSrc) ){  /* Every Select as a SrcList, even if it is empty */
    SrcList *pSrc = p->pSrc;
    for(i=0; i<pSrc->nSrc; i++){
      sqlite3RenameTokenRemap(pParse, 0, (void*)pSrc->a[i].zName);

    int i;
    Walker sWalker;
    memset(&sWalker, 0, sizeof(Walker));
    sWalker.pParse = pParse;
    sWalker.xExprCallback = renameUnmapExprCb;
    sqlite3WalkExprList(&sWalker, pEList);
    for(i=0; i<pEList->nExpr; i++){
      if( ALWAYS(pEList->a[i].eEName==ENAME_NAME) ){
        sqlite3RenameTokenRemap(pParse, 0, (void*)pEList->a[i].zEName);
      }
    }
  }
}

/*
** Free the list of RenameToken objects given in the second argument
*/

  RenameCtx *pCtx, 
  ExprList *pEList, 
  const char *zOld
){
  if( pEList ){
    int i;
    for(i=0; i<pEList->nExpr; i++){
      char *zName = pEList->a[i].zEName;
      if( ALWAYS(pEList->a[i].eEName==ENAME_NAME)
       && ALWAYS(zName!=0)
       && 0==sqlite3_stricmp(zName, zOld)
      ){
        renameTokenFind(pParse, pCtx, (void*)zName);
      }
    }
  }
}

/*

    goto fk_end;
  }else{
    nCol = pFromCol->nExpr;
  }
  nByte = sizeof(*pFKey) + (nCol-1)*sizeof(pFKey->aCol[0]) + pTo->n + 1;
  if( pToCol ){
    for(i=0; i<pToCol->nExpr; i++){
      nByte += sqlite3Strlen30(pToCol->a[i].zEName) + 1;
    }
  }
  pFKey = sqlite3DbMallocZero(db, nByte );
  if( pFKey==0 ){
    goto fk_end;
  }
  pFKey->pFrom = p;

  pFKey->nCol = nCol;
  if( pFromCol==0 ){
    pFKey->aCol[0].iFrom = p->nCol-1;
  }else{
    for(i=0; i<nCol; i++){
      int j;
      for(j=0; j<p->nCol; j++){
        if( sqlite3StrICmp(p->aCol[j].zName, pFromCol->a[i].zEName)==0 ){
          pFKey->aCol[i].iFrom = j;
          break;
        }
      }
      if( j>=p->nCol ){
        sqlite3ErrorMsg(pParse, 
          "unknown column \"%s\" in foreign key definition", 
          pFromCol->a[i].zEName);
        goto fk_end;
      }
      if( IN_RENAME_OBJECT ){
        sqlite3RenameTokenRemap(pParse, &pFKey->aCol[i], pFromCol->a[i].zEName);
      }
    }
  }
  if( pToCol ){
    for(i=0; i<nCol; i++){
      int n = sqlite3Strlen30(pToCol->a[i].zEName);
      pFKey->aCol[i].zCol = z;
      if( IN_RENAME_OBJECT ){
        sqlite3RenameTokenRemap(pParse, z, pToCol->a[i].zEName);
      }
      memcpy(z, pToCol->a[i].zEName, n);
      z[n] = 0;
      z += n+1;
    }
  }
  pFKey->isDeferred = 0;
  pFKey->aAction[0] = (u8)(flags & 0xff);            /* ON DELETE action */
  pFKey->aAction[1] = (u8)((flags >> 8 ) & 0xff);    /* ON UPDATE action */

        assert( i>0 );
        assert( pItem[-1].pExpr!=0 );
        assert( pNewExpr->iColumn==pItem[-1].pExpr->iColumn+1 );
        assert( pPriorSelectCol==pItem[-1].pExpr->pLeft );
        pNewExpr->pLeft = pPriorSelectCol;
      }
    }
    pItem->zEName = sqlite3DbStrDup(db, pOldItem->zEName);

    pItem->sortFlags = pOldItem->sortFlags;
    pItem->eEName = pOldItem->eEName;
    pItem->done = 0;
    pItem->bNulls = pOldItem->bNulls;

    pItem->bSorterRef = pOldItem->bSorterRef;
    pItem->u = pOldItem->u;
  }
  return pNew;
}

/*

         sizeof(*pList)+(2*(sqlite3_int64)pList->nExpr-1)*sizeof(pList->a[0]));
    if( pNew==0 ){
      goto no_mem;
    }
    pList = pNew;
  }
  pItem = &pList->a[pList->nExpr++];
  assert( offsetof(struct ExprList_item,zEName)==sizeof(pItem->pExpr) );
  assert( offsetof(struct ExprList_item,pExpr)==0 );
  memset(&pItem->zEName,0,sizeof(*pItem)-offsetof(struct ExprList_item,zEName));
  pItem->pExpr = pExpr;
  return pList;

no_mem:     
  /* Avoid leaking memory if malloc has failed. */
  sqlite3ExprDelete(db, pExpr);
  sqlite3ExprListDelete(db, pList);

    assert( pSubExpr!=0 || db->mallocFailed );
    assert( pSubExpr==0 || pSubExpr->iTable==0 );
    if( pSubExpr==0 ) continue;
    pSubExpr->iTable = pColumns->nId;
    pList = sqlite3ExprListAppend(pParse, pList, pSubExpr);
    if( pList ){
      assert( pList->nExpr==iFirst+i+1 );
      pList->a[pList->nExpr-1].zEName = pColumns->a[i].zName;
      pColumns->a[i].zName = 0;
    }
  }

  if( !db->mallocFailed && pExpr->op==TK_SELECT && ALWAYS(pList!=0) ){
    Expr *pFirst = pList->a[iFirst].pExpr;
    assert( pFirst!=0 );

    if( iSortOrder!=eNulls ){
      pItem->sortFlags |= KEYINFO_ORDER_BIGNULL;
    }
  }
}

/*
** Set the ExprList.a[].zEName element of the most recently added item
** on the expression list.
**
** pList might be NULL following an OOM error.  But pName should never be
** NULL.  If a memory allocation fails, the pParse->db->mallocFailed flag
** is set.
*/
void sqlite3ExprListSetName(
  Parse *pParse,          /* Parsing context */
  ExprList *pList,        /* List to which to add the span. */
  Token *pName,           /* Name to be added */
  int dequote             /* True to cause the name to be dequoted */
){
  assert( pList!=0 || pParse->db->mallocFailed!=0 );
  if( pList ){
    struct ExprList_item *pItem;
    assert( pList->nExpr>0 );
    pItem = &pList->a[pList->nExpr-1];
    assert( pItem->zEName==0 );
    assert( pItem->eEName==ENAME_NAME );
    pItem->zEName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n);
    if( dequote ) sqlite3Dequote(pItem->zEName);
    if( IN_RENAME_OBJECT ){
      sqlite3RenameTokenMap(pParse, (void*)pItem->zEName, pName);
    }
  }
}

/*
** Set the ExprList.a[].zSpan element of the most recently added item
** on the expression list.

  const char *zEnd        /* End of the span */
){
  sqlite3 *db = pParse->db;
  assert( pList!=0 || db->mallocFailed!=0 );
  if( pList ){
    struct ExprList_item *pItem = &pList->a[pList->nExpr-1];
    assert( pList->nExpr>0 );
    if( pItem->zEName==0 ){
      pItem->zEName = sqlite3DbSpanDup(db, zStart, zEnd);
      pItem->eEName = ENAME_SPAN;
    }
  }
}

/*
** If the expression list pEList contains more than iLimit elements,
** leave an error message in pParse.
*/

*/
static SQLITE_NOINLINE void exprListDeleteNN(sqlite3 *db, ExprList *pList){
  int i = pList->nExpr;
  struct ExprList_item *pItem =  pList->a;
  assert( pList->nExpr>0 );
  do{
    sqlite3ExprDelete(db, pItem->pExpr);
    sqlite3DbFree(db, pItem->zEName);

    pItem++;
  }while( --i>0 );
  sqlite3DbFreeNN(db, pList);
}
void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
  if( pList ) exprListDeleteNN(db, pList);
}

/*
** The default lookaside-configuration, the format "SZ,N".  SZ is the
** number of bytes in each lookaside slot (should be a multiple of 8)
** and N is the number of slots.  The lookaside-configuration can be
** changed as start-time using sqlite3_config(SQLITE_CONFIG_LOOKASIDE)
** or at run-time for an individual database connection using
** sqlite3_db_config(db, SQLITE_DBCONFIG_LOOKASIDE);
**
** With the two-size-lookaside enhancement, less lookaside is required.
** The default configuration of 1200,40 actually provides 30 1200-byte slots
** and 93 128-byte slots, which is more lookaside than is available
** using the older 1200,100 configuration without two-size-lookaside.
*/
#ifndef SQLITE_DEFAULT_LOOKASIDE
# ifdef SQLITE_OMIT_TWOSIZE_LOOKASIDE
#   define SQLITE_DEFAULT_LOOKASIDE 1200,100  /* 120KB of memory */
# else
#   define SQLITE_DEFAULT_LOOKASIDE 1200,40   /* 48KB of memory */
# endif
#endif


/* The default maximum size of an in-memory database created using
** sqlite3_deserialize()
*/
#ifndef SQLITE_MEMDB_DEFAULT_MAXSIZE

      }
      allOk = sqlite3VdbeMakeLabel(pParse);
      sqlite3VdbeVerifyAbortable(v, onError);
      sqlite3ExprIfTrue(pParse, pExpr, allOk, SQLITE_JUMPIFNULL);
      if( onError==OE_Ignore ){
        sqlite3VdbeGoto(v, ignoreDest);
      }else{
        char *zName = pCheck->a[i].zEName;
        if( zName==0 ) zName = pTab->zName;
        if( onError==OE_Replace ) onError = OE_Abort; /* IMP: R-26383-51744 */
        sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_CHECK,
                              onError, zName, P4_TRANSIENT,
                              P5_ConstraintCheck);
      }
      sqlite3VdbeResolveLabel(v, allOk);

** space for the lookaside memory is obtained from sqlite3_malloc().
** If pStart is not NULL then it is sz*cnt bytes of memory to use for
** the lookaside memory.
*/
static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
#ifndef SQLITE_OMIT_LOOKASIDE
  void *pStart;
  sqlite3_int64 szAlloc = sz*(sqlite3_int64)cnt;
  int nBig;   /* Number of full-size slots */
  int nSm;    /* Number smaller LOOKASIDE_SMALL-byte slots */
  
  if( sqlite3LookasideUsed(db,0)>0 ){
    return SQLITE_BUSY;
  }
  /* Free any existing lookaside buffer for this handle before
  ** allocating a new one so we don't have to have space for 
  ** both at the same time.

  if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
  if( cnt<0 ) cnt = 0;
  if( sz==0 || cnt==0 ){
    sz = 0;
    pStart = 0;
  }else if( pBuf==0 ){
    sqlite3BeginBenignMalloc();
    pStart = sqlite3Malloc( szAlloc );  /* IMP: R-61949-35727 */
    sqlite3EndBenignMalloc();
    if( pStart ) szAlloc = sqlite3MallocSize(pStart);
  }else{
    pStart = pBuf;
  }
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
  if( sz>=LOOKASIDE_SMALL*3 ){
    nBig = szAlloc/(3*LOOKASIDE_SMALL+sz);
    nSm = (szAlloc - sz*nBig)/LOOKASIDE_SMALL;
  }else if( sz>=LOOKASIDE_SMALL*2 ){
    nBig = szAlloc/(LOOKASIDE_SMALL+sz);
    nSm = (szAlloc - sz*nBig)/LOOKASIDE_SMALL;
  }else
#endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
  if( sz>0 ){
    nBig = szAlloc/sz;
    nSm = 0;
  }else{
    nBig = nSm = 0;
  }
  db->lookaside.pStart = pStart;
  db->lookaside.pInit = 0;
  db->lookaside.pFree = 0;
  db->lookaside.sz = (u16)sz;
  db->lookaside.szTrue = (u16)sz;
  if( pStart ){
    int i;
    LookasideSlot *p;
    assert( sz > (int)sizeof(LookasideSlot*) );

    p = (LookasideSlot*)pStart;
    for(i=0; i<nBig; i++){
      p->pNext = db->lookaside.pInit;
      db->lookaside.pInit = p;
      p = (LookasideSlot*)&((u8*)p)[sz];
    }
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
    db->lookaside.pSmallInit = 0;
    db->lookaside.pSmallFree = 0;
    db->lookaside.pMiddle = p;
    for(i=0; i<nSm; i++){
      p->pNext = db->lookaside.pSmallInit;
      db->lookaside.pSmallInit = p;
      p = (LookasideSlot*)&((u8*)p)[LOOKASIDE_SMALL];
    }
#endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
    assert( ((uptr)p)<=szAlloc + (uptr)pStart );
    db->lookaside.pEnd = p;
    db->lookaside.bDisable = 0;
    db->lookaside.bMalloced = pBuf==0 ?1:0;
    db->lookaside.nSlot = nBig+nSm;
  }else{
    db->lookaside.pStart = db;
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
    db->lookaside.pSmallInit = 0;
    db->lookaside.pSmallFree = 0;
    db->lookaside.pMiddle = db;
#endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
    db->lookaside.pEnd = db;
    db->lookaside.bDisable = 1;
    db->lookaside.sz = 0;
    db->lookaside.bMalloced = 0;
    db->lookaside.nSlot = 0;
  }
  assert( sqlite3LookasideUsed(db,0)==0 );
#endif /* SQLITE_OMIT_LOOKASIDE */
  return SQLITE_OK;
}

/*
** Return the mutex associated with a database connection.
*/

/*
** Return the size of a memory allocation previously obtained from
** sqlite3Malloc() or sqlite3_malloc().
*/
int sqlite3MallocSize(void *p){
  assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
  return sqlite3GlobalConfig.m.xSize(p);
}
static int lookasideMallocSize(sqlite3 *db, void *p){
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE    
  return p<db->lookaside.pMiddle ? db->lookaside.szTrue : LOOKASIDE_SMALL;
#else
  return db->lookaside.szTrue;
#endif  
}
int sqlite3DbMallocSize(sqlite3 *db, void *p){
  assert( p!=0 );

#ifdef SQLITE_DEBUG
  if( db==0 || !isLookaside(db,p) ){
    if( db==0 ){
      assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );
      assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
    }else{
      assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
      assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
    }
  }
#endif
  if( db ){
    if( ((uptr)p)<(uptr)(db->lookaside.pEnd) ){
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
      if( ((uptr)p)>=(uptr)(db->lookaside.pMiddle) ){
        assert( sqlite3_mutex_held(db->mutex) );
        return LOOKASIDE_SMALL;
      }
#endif
      if( ((uptr)p)>=(uptr)(db->lookaside.pStart) ){
        assert( sqlite3_mutex_held(db->mutex) );
        return db->lookaside.szTrue;
      }
    }
  }
  return sqlite3GlobalConfig.m.xSize(p);
}
sqlite3_uint64 sqlite3_msize(void *p){
  assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );
  assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
  return p ? sqlite3GlobalConfig.m.xSize(p) : 0;
}

  assert( db==0 || sqlite3_mutex_held(db->mutex) );
  assert( p!=0 );
  if( db ){
    if( db->pnBytesFreed ){
      measureAllocationSize(db, p);
      return;
    }
    if( ((uptr)p)<(uptr)(db->lookaside.pEnd) ){
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
      if( ((uptr)p)>=(uptr)(db->lookaside.pMiddle) ){
        LookasideSlot *pBuf = (LookasideSlot*)p;
#ifdef SQLITE_DEBUG
        memset(p, 0xaa, LOOKASIDE_SMALL);  /* Trash freed content */
#endif
        pBuf->pNext = db->lookaside.pSmallFree;
        db->lookaside.pSmallFree = pBuf;
        return;
      }
#endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
      if( ((uptr)p)>=(uptr)(db->lookaside.pStart) ){
        LookasideSlot *pBuf = (LookasideSlot*)p;
#ifdef SQLITE_DEBUG
        memset(p, 0xaa, db->lookaside.szTrue);  /* Trash freed content */
#endif
        pBuf->pNext = db->lookaside.pFree;
        db->lookaside.pFree = pBuf;
        return;
      }
    }
  }
  assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
  assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
  assert( db!=0 || sqlite3MemdebugNoType(p, MEMTYPE_LOOKASIDE) );
  sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
  sqlite3_free(p);

void *sqlite3DbMallocRawNN(sqlite3 *db, u64 n){
#ifndef SQLITE_OMIT_LOOKASIDE
  LookasideSlot *pBuf;
  assert( db!=0 );
  assert( sqlite3_mutex_held(db->mutex) );
  assert( db->pnBytesFreed==0 );
  if( n>db->lookaside.sz ){
    if( !db->lookaside.bDisable ){
      db->lookaside.anStat[1]++;      
    }else if( db->mallocFailed ){
      return 0;
    }
    return dbMallocRawFinish(db, n);
  }
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
  if( n<=LOOKASIDE_SMALL ){
    if( (pBuf = db->lookaside.pSmallFree)!=0 ){
      db->lookaside.pSmallFree = pBuf->pNext;
      db->lookaside.anStat[0]++;
      return (void*)pBuf;
    }else if( (pBuf = db->lookaside.pSmallInit)!=0 ){
      db->lookaside.pSmallInit = pBuf->pNext;
      db->lookaside.anStat[0]++;
      return (void*)pBuf;
    }
  }
#endif
  if( (pBuf = db->lookaside.pFree)!=0 ){
    db->lookaside.pFree = pBuf->pNext;
    db->lookaside.anStat[0]++;
    return (void*)pBuf;
  }else if( (pBuf = db->lookaside.pInit)!=0 ){
    db->lookaside.pInit = pBuf->pNext;
    db->lookaside.anStat[0]++;
    return (void*)pBuf;

** Resize the block of memory pointed to by p to n bytes. If the
** resize fails, set the mallocFailed flag in the connection object.
*/
void *sqlite3DbRealloc(sqlite3 *db, void *p, u64 n){
  assert( db!=0 );
  if( p==0 ) return sqlite3DbMallocRawNN(db, n);
  assert( sqlite3_mutex_held(db->mutex) );
  if( ((uptr)p)<(uptr)db->lookaside.pEnd ){
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
    if( ((uptr)p)>=(uptr)db->lookaside.pMiddle ){
      if( n<=LOOKASIDE_SMALL ) return p;
    }else
#endif
    if( ((uptr)p)>=(uptr)db->lookaside.pStart ){
      if( n<=db->lookaside.szTrue ) return p;
    }
  }
  return dbReallocFinish(db, p, n);
}
static SQLITE_NOINLINE void *dbReallocFinish(sqlite3 *db, void *p, u64 n){
  void *pNew = 0;
  assert( db!=0 );
  assert( p!=0 );
  if( db->mallocFailed==0 ){
    if( isLookaside(db, p) ){
      pNew = sqlite3DbMallocRawNN(db, n);
      if( pNew ){
        memcpy(pNew, p, lookasideMallocSize(db, p));
        sqlite3DbFree(db, p);
      }
    }else{
      assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
      assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
      sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
      pNew = sqlite3_realloc64(p, n);

/*
** Subqueries stores the original database, table and column names for their
** result sets in ExprList.a[].zSpan, in the form "DATABASE.TABLE.COLUMN".
** Check to see if the zSpan given to this routine matches the zDb, zTab,
** and zCol.  If any of zDb, zTab, and zCol are NULL then those fields will
** match anything.
*/
int sqlite3MatchEName(
  const struct ExprList_item *pItem,
  const char *zCol,
  const char *zTab,
  const char *zDb
){
  int n;
  const char *zSpan;
  if( NEVER(pItem->eEName!=ENAME_TAB) ) return 0;
  zSpan = pItem->zEName;
  for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){}
  if( zDb && (sqlite3StrNICmp(zSpan, zDb, n)!=0 || zDb[n]!=0) ){
    return 0;
  }
  zSpan += n+1;
  for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){}
  if( zTab && (sqlite3StrNICmp(zSpan, zTab, n)!=0 || zTab[n]!=0) ){

        pTab = pItem->pTab;
        assert( pTab!=0 && pTab->zName!=0 );
        assert( pTab->nCol>0 );
        if( pItem->pSelect && (pItem->pSelect->selFlags & SF_NestedFrom)!=0 ){
          int hit = 0;
          pEList = pItem->pSelect->pEList;
          for(j=0; j<pEList->nExpr; j++){
            if( sqlite3MatchEName(&pEList->a[j], zCol, zTab, zDb) ){
              cnt++;
              cntTab = 2;
              pMatch = pItem;
              pExpr->iColumn = j;
              hit = 1;
            }
          }

    if( (pNC->ncFlags & NC_UEList)!=0
     && cnt==0
     && zTab==0
    ){
      pEList = pNC->uNC.pEList;
      assert( pEList!=0 );
      for(j=0; j<pEList->nExpr; j++){
        char *zAs = pEList->a[j].zEName;
        if( pEList->a[j].eEName==ENAME_NAME
         && ALWAYS(zAs!=0)
         && sqlite3StrICmp(zAs, zCol)==0
        ){
          Expr *pOrig;
          assert( pExpr->pLeft==0 && pExpr->pRight==0 );
          assert( pExpr->x.pList==0 );
          assert( pExpr->x.pSelect==0 );
          pOrig = pEList->a[j].pExpr;
          if( (pNC->ncFlags&NC_AllowAgg)==0 && ExprHasProperty(pOrig, EP_Agg) ){
            sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs);

  int i;             /* Loop counter */

  UNUSED_PARAMETER(pParse);

  if( pE->op==TK_ID ){
    char *zCol = pE->u.zToken;
    for(i=0; i<pEList->nExpr; i++){
      char *zAs = pEList->a[i].zEName;
      if( pEList->a[i].eEName==ENAME_NAME
       && ALWAYS(zAs!=0)
       && sqlite3StrICmp(zAs, zCol)==0
      ){
        return i+1;
      }
    }
  }
  return 0;
}

    pParse->nMem += nResultCol;
  }
  pDest->nSdst = nResultCol;
  regOrig = regResult = pDest->iSdst;
  if( srcTab>=0 ){
    for(i=0; i<nResultCol; i++){
      sqlite3VdbeAddOp3(v, OP_Column, srcTab, i, regResult+i);
      VdbeComment((v, "%s", p->pEList->a[i].zEName));
    }
  }else if( eDest!=SRT_Exists ){
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
    ExprList *pExtra = 0;
#endif
    /* If the destination is an EXISTS(...) expression, the actual
    ** values returned by the SELECT are not required.

      int iRead;
      if( aOutEx[i].u.x.iOrderByCol ){
        iRead = aOutEx[i].u.x.iOrderByCol-1;
      }else{
        iRead = iCol--;
      }
      sqlite3VdbeAddOp3(v, OP_Column, iSortTab, iRead, regRow+i);
      VdbeComment((v, "%s", aOutEx[i].zEName));
    }
  }
  switch( eDest ){
    case SRT_Table:
    case SRT_EphemTab: {
      sqlite3VdbeAddOp3(v, OP_Column, iSortTab, nKey+bSeq, regRow);
      sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, regRowid);

  sqlite3VdbeSetNumCols(v, pEList->nExpr);
  for(i=0; i<pEList->nExpr; i++){
    Expr *p = pEList->a[i].pExpr;

    assert( p!=0 );
    assert( p->op!=TK_AGG_COLUMN );  /* Agg processing has not run yet */
    assert( p->op!=TK_COLUMN || p->y.pTab!=0 ); /* Covering idx not yet coded */
    if( pEList->a[i].zEName && pEList->a[i].eEName==ENAME_NAME ){
      /* An AS clause always takes first priority */
      char *zName = pEList->a[i].zEName;
      sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_TRANSIENT);
    }else if( srcName && p->op==TK_COLUMN ){
      char *zCol;
      int iCol = p->iColumn;
      pTab = p->y.pTab;
      assert( pTab!=0 );
      if( iCol<0 ) iCol = pTab->iPKey;

        char *zName = 0;
        zName = sqlite3MPrintf(db, "%s.%s", pTab->zName, zCol);
        sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_DYNAMIC);
      }else{
        sqlite3VdbeSetColName(v, i, COLNAME_NAME, zCol, SQLITE_TRANSIENT);
      }
    }else{
      const char *z = pEList->a[i].zEName;
      z = z==0 ? sqlite3MPrintf(db, "column%d", i+1) : sqlite3DbStrDup(db, z);
      sqlite3VdbeSetColName(v, i, COLNAME_NAME, z, SQLITE_DYNAMIC);
    }
  }
  generateColumnTypes(pParse, pTabList, pEList);
}

  assert( nCol==(i16)nCol );
  *pnCol = nCol;
  *paCol = aCol;

  for(i=0, pCol=aCol; i<nCol && !db->mallocFailed; i++, pCol++){
    /* Get an appropriate name for the column
    */
    if( (zName = pEList->a[i].zEName)!=0 && pEList->a[i].eEName==ENAME_NAME ){
      /* If the column contains an "AS <name>" phrase, use <name> as the name */
    }else{
      Expr *pColExpr = sqlite3ExprSkipCollateAndLikely(pEList->a[i].pExpr);
      while( pColExpr->op==TK_DOT ){
        pColExpr = pColExpr->pRight;
        assert( pColExpr!=0 );
      }
      if( pColExpr->op==TK_COLUMN ){
        /* For columns use the column name name */
        int iCol = pColExpr->iColumn;
        Table *pTab = pColExpr->y.pTab;
        assert( pTab!=0 );
        if( iCol<0 ) iCol = pTab->iPKey;
        zName = iCol>=0 ? pTab->aCol[iCol].zName : "rowid";
      }else if( pColExpr->op==TK_ID ){
        assert( !ExprHasProperty(pColExpr, EP_IntValue) );
        zName = pColExpr->u.zToken;
      }else{
        /* Use the original text of the column expression as its name */
        zName = pEList->a[i].zEName;
      }
    }
    if( zName ){
      zName = sqlite3DbStrDup(db, zName);
    }else{
      zName = sqlite3MPrintf(db,"column%d",i+1);
    }

      if( pE->op!=TK_ASTERISK
       && (pE->op!=TK_DOT || pRight->op!=TK_ASTERISK)
      ){
        /* This particular expression does not need to be expanded.
        */
        pNew = sqlite3ExprListAppend(pParse, pNew, a[k].pExpr);
        if( pNew ){
          pNew->a[pNew->nExpr-1].zEName = a[k].zEName;
          pNew->a[pNew->nExpr-1].eEName = a[k].eEName;
          a[k].zEName = 0;

        }
        a[k].pExpr = 0;
      }else{
        /* This expression is a "*" or a "TABLE.*" and needs to be
        ** expanded. */
        int tableSeen = 0;      /* Set to 1 when TABLE matches */
        char *zTName = 0;       /* text of name of TABLE */

            char *zName = pTab->aCol[j].zName;
            char *zColname;  /* The computed column name */
            char *zToFree;   /* Malloced string that needs to be freed */
            Token sColname;  /* Computed column name as a token */

            assert( zName );
            if( zTName && pSub
             && sqlite3MatchEName(&pSub->pEList->a[j], 0, zTName, 0)==0
            ){
              continue;
            }

            /* If a column is marked as 'hidden', omit it from the expanded
            ** result-set list unless the SELECT has the SF_IncludeHidden
            ** bit set.

              pExpr = pRight;
            }
            pNew = sqlite3ExprListAppend(pParse, pNew, pExpr);
            sqlite3TokenInit(&sColname, zColname);
            sqlite3ExprListSetName(pParse, pNew, &sColname, 0);
            if( pNew && (p->selFlags & SF_NestedFrom)!=0 ){
              struct ExprList_item *pX = &pNew->a[pNew->nExpr-1];
              sqlite3DbFree(db, pX->zEName);
              if( pSub ){
                pX->zEName = sqlite3DbStrDup(db, pSub->pEList->a[j].zEName);
                testcase( pX->zEName==0 );
              }else{
                pX->zEName = sqlite3MPrintf(db, "%s.%s.%s",
                                           zSchemaName, zTabName, zColname);
                testcase( pX->zEName==0 );
              }
              pX->eEName = ENAME_TAB;
            }
            sqlite3DbFree(db, zToFree);
          }
        }
        if( !tableSeen ){
          if( zTName ){
            sqlite3ErrorMsg(pParse, "no such table: %s", zTName);

** lookaside allocations are not used to construct the schema objects.
**
** New lookaside allocations are only allowed if bDisable==0.  When
** bDisable is greater than zero, sz is set to zero which effectively
** disables lookaside without adding a new test for the bDisable flag
** in a performance-critical path.  sz should be set by to szTrue whenever
** bDisable changes back to zero.
**
** Lookaside buffers are initially held on the pInit list.  As they are
** used and freed, they are added back to the pFree list.  New allocations
** come off of pFree first, then pInit as a fallback.  This dual-list
** allows use to compute a high-water mark - the maximum number of allocations
** outstanding at any point in the past - by subtracting the number of
** allocations on the pInit list from the total number of allocations.
**
** Enhancement on 2019-12-12:  Two-size-lookaside
** The default lookaside configuration is 100 slots of 1200 bytes each.
** The larger slot sizes are important for performance, but they waste
** a lot of space, as most lookaside allocations are less than 128 bytes.
** The two-size-lookaside enhancement breaks up the lookaside allocation
** into two pools:  One of 128-byte slots and the other of the default size
** (1200-byte) slots.   Allocations are filled from the small-pool first,
** failing over to the full-size pool if that does not work.  Thus more
** lookaside slots are available while also using less memory.
** This enhancement can be omitted by compiling with
** SQLITE_OMIT_TWOSIZE_LOOKASIDE.
*/
struct Lookaside {
  u32 bDisable;           /* Only operate the lookaside when zero */
  u16 sz;                 /* Size of each buffer in bytes */
  u16 szTrue;             /* True value of sz, even if disabled */
  u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
  u32 nSlot;              /* Number of lookaside slots allocated */
  u32 anStat[3];          /* 0: hits.  1: size misses.  2: full misses */
  LookasideSlot *pInit;   /* List of buffers not previously used */
  LookasideSlot *pFree;   /* List of available buffers */
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
  LookasideSlot *pSmallInit; /* List of small buffers not prediously used */
  LookasideSlot *pSmallFree; /* List of available small buffers */
  void *pMiddle;          /* First byte past end of full-size buffers and
                          ** the first byte of LOOKASIDE_SMALL buffers */
#endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
  void *pStart;           /* First byte of available memory space */
  void *pEnd;             /* First byte past end of available space */
};
struct LookasideSlot {
  LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
};

#define DisableLookaside  db->lookaside.bDisable++;db->lookaside.sz=0
#define EnableLookaside   db->lookaside.bDisable--;\
   db->lookaside.sz=db->lookaside.bDisable?0:db->lookaside.szTrue

/* Size of the smaller allocations in two-size lookside */
#ifdef SQLITE_OMIT_TWOSIZE_LOOKASIDE
#  define LOOKASIDE_SMALL           0
#else
#  define LOOKASIDE_SMALL         128
#endif

/*
** A hash table for built-in function definitions.  (Application-defined
** functions use a regular table table from hash.h.)
**
** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.
** Collisions are on the FuncDef.u.pHash chain.  Use the SQLITE_FUNC_HASH()

** A list of expressions.  Each expression may optionally have a
** name.  An expr/name combination can be used in several ways, such
** as the list of "expr AS ID" fields following a "SELECT" or in the
** list of "ID = expr" items in an UPDATE.  A list of expressions can
** also be used as the argument to a function, in which case the a.zName
** field is not used.
**
** In order to try to keep memory usage down, the Expr.a.zEName field
** is used for multiple purposes:
**
**     eEName          Usage
**    ----------       -------------------------
**    ENAME_NAME       (1) the AS of result set column
**                     (2) COLUMN= of an UPDATE
**
**    ENAME_TAB        DB.TABLE.NAME used to resolve names
**                     of subqueries
**
**    ENAME_SPAN       Text of the original result set
**                     expression.
*/
struct ExprList {
  int nExpr;             /* Number of expressions on the list */
  struct ExprList_item { /* For each expression in the list */
    Expr *pExpr;            /* The parse tree for this expression */
    char *zEName;           /* Token associated with this expression */

    u8 sortFlags;           /* Mask of KEYINFO_ORDER_* flags */
    unsigned eEName :2;     /* Meaning of zEName */
    unsigned done :1;       /* A flag to indicate when processing is finished */

    unsigned reusable :1;   /* Constant expression is reusable */
    unsigned bSorterRef :1; /* Defer evaluation until after sorting */
    unsigned bNulls: 1;     /* True if explicit "NULLS FIRST/LAST" */
    union {
      struct {
        u16 iOrderByCol;      /* For ORDER BY, column number in result set */
        u16 iAlias;           /* Index into Parse.aAlias[] for zName */
      } x;
      int iConstExprReg;      /* Register in which Expr value is cached */
    } u;
  } a[1];                  /* One slot for each expression in the list */
};

/*
** Allowed values for Expr.a.eEName
*/
#define ENAME_NAME  0       /* The AS clause of a result set */
#define ENAME_SPAN  1       /* Complete text of the result set expression */
#define ENAME_TAB   2       /* "DB.TABLE.NAME" for the result set */

/*
** An instance of this structure can hold a simple list of identifiers,
** such as the list "a,b,c" in the following statements:
**
**      INSERT INTO t(a,b,c) VALUES ...;
**      CREATE INDEX idx ON t(a,b,c);
**      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;

int sqlite3GetToken(const unsigned char *, int *);
void sqlite3NestedParse(Parse*, const char*, ...);
void sqlite3ExpirePreparedStatements(sqlite3*, int);
void sqlite3CodeRhsOfIN(Parse*, Expr*, int);
int sqlite3CodeSubselect(Parse*, Expr*);
void sqlite3SelectPrep(Parse*, Select*, NameContext*);
void sqlite3SelectWrongNumTermsError(Parse *pParse, Select *p);
int sqlite3MatchEName(
  const struct ExprList_item*,
  const char*,
  const char*,
  const char*
);
int sqlite3ResolveExprNames(NameContext*, Expr*);
int sqlite3ResolveExprListNames(NameContext*, ExprList*);
void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
int sqlite3ResolveSelfReference(Parse*,Table*,int,Expr*,ExprList*);
int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
void sqlite3ColumnDefault(Vdbe *, Table *, int, int);
void sqlite3AlterFinishAddColumn(Parse *, Token *);

/*
** Count the number of slots of lookaside memory that are outstanding
*/
int sqlite3LookasideUsed(sqlite3 *db, int *pHighwater){
  u32 nInit = countLookasideSlots(db->lookaside.pInit);
  u32 nFree = countLookasideSlots(db->lookaside.pFree);
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
  nInit += countLookasideSlots(db->lookaside.pSmallInit);
  nFree += countLookasideSlots(db->lookaside.pSmallFree);
#endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
  if( pHighwater ) *pHighwater = db->lookaside.nSlot - nInit;
  return db->lookaside.nSlot - (nInit+nFree);
}

/*
** Query status information for a single database connection
*/

        LookasideSlot *p = db->lookaside.pFree;
        if( p ){
          while( p->pNext ) p = p->pNext;
          p->pNext = db->lookaside.pInit;
          db->lookaside.pInit = db->lookaside.pFree;
          db->lookaside.pFree = 0;
        }
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
        p = db->lookaside.pSmallFree;
        if( p ){
          while( p->pNext ) p = p->pNext;
          p->pNext = db->lookaside.pSmallInit;
          db->lookaside.pSmallInit = db->lookaside.pSmallFree;
          db->lookaside.pSmallFree = 0;
        }
#endif
      }
      break;
    }

    case SQLITE_DBSTATUS_LOOKASIDE_HIT:
    case SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE:
    case SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL: {

      const struct Cte *pCte = &pWith->a[i];
      sqlite3StrAccumInit(&x, 0, zLine, sizeof(zLine), 0);
      sqlite3_str_appendf(&x, "%s", pCte->zName);
      if( pCte->pCols && pCte->pCols->nExpr>0 ){
        char cSep = '(';
        int j;
        for(j=0; j<pCte->pCols->nExpr; j++){
          sqlite3_str_appendf(&x, "%c%s", cSep, pCte->pCols->a[j].zEName);
          cSep = ',';
        }
        sqlite3_str_appendf(&x, ")");
      }
      sqlite3_str_appendf(&x, " AS");
      sqlite3StrAccumFinish(&x);
      sqlite3TreeViewItem(pView, zLine, i<pWith->nCte-1);

  if( pList==0 ){
    sqlite3TreeViewLine(pView, "%s (empty)", zLabel);
  }else{
    int i;
    sqlite3TreeViewLine(pView, "%s", zLabel);
    for(i=0; i<pList->nExpr; i++){
      int j = pList->a[i].u.x.iOrderByCol;
      char *zName = pList->a[i].zEName;
      int moreToFollow = i<pList->nExpr - 1;
      if( j || zName ){
        sqlite3TreeViewPush(pView, moreToFollow);
        moreToFollow = 0;
        sqlite3TreeViewLine(pView, 0);
        if( zName ){
          fprintf(stdout, "AS %s ", zName);

** it matches anything so always return true.  Return false only
** if there is no match.
*/
static int checkColumnOverlap(IdList *pIdList, ExprList *pEList){
  int e;
  if( pIdList==0 || NEVER(pEList==0) ) return 1;
  for(e=0; e<pEList->nExpr; e++){
    if( sqlite3IdListIndex(pIdList, pEList->a[e].zEName)>=0 ) return 1;
  }
  return 0; 
}

/*
** Return a list of all triggers on table pTab if there exists at least
** one trigger that must be fired when an operation of type 'op' is 

  */
  chngRowid = chngPk = 0;
  for(i=0; i<pChanges->nExpr; i++){
    if( sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){
      goto update_cleanup;
    }
    for(j=0; j<pTab->nCol; j++){
      if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zEName)==0 ){
        if( j==pTab->iPKey ){
          chngRowid = 1;
          pRowidExpr = pChanges->a[i].pExpr;
        }else if( pPk && (pTab->aCol[j].colFlags & COLFLAG_PRIMKEY)!=0 ){
          chngPk = 1;
        }
#ifndef SQLITE_OMIT_GENERATED_COLUMNS

        }
#endif
        aXRef[j] = i;
        break;
      }
    }
    if( j>=pTab->nCol ){
      if( pPk==0 && sqlite3IsRowid(pChanges->a[i].zEName) ){
        j = -1;
        chngRowid = 1;
        pRowidExpr = pChanges->a[i].pExpr;
      }else{
        sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zEName);
        pParse->checkSchema = 1;
        goto update_cleanup;
      }
    }
#ifndef SQLITE_OMIT_AUTHORIZATION
    {
      int rc;