SQLite

  pNew->pOrderBy = 0;
  p->pPrior = 0;
  pNew->pLimit = 0;
  pNew->pOffset = 0;
  return WRC_Continue;
}

/* If the table identified by FROM clause element p is really
** a common-table-expression (CTE) then return a pointer to the
** CTE definition for that table.
*/
static struct Cte *searchWith(Parse *pParse, struct SrcList_item *p){
  if( p->zDatabase==0 ){
    char *zName = p->zName;
    With *pWith;

    for(pWith=pParse->pWith; pWith; pWith=pWith->pOuter){
      int i;
      for(i=0; i<pWith->nCte; i++){
        if( sqlite3StrICmp(zName, pWith->a[i].zName)==0 ){
          return &pWith->a[i];
        }
      }
    }
  }
  return 0;
}

/* The code generator maintains a stack of active WITH clauses
** with the inner-most WITH clause being at the top of the stack.
**
** These routines push and pull WITH clauses on the stack.
*/
void sqlite3WithPush(Parse *pParse, With *pWith){
  if( pWith ){
    pWith->pOuter = pParse->pWith;
    pParse->pWith = pWith;
  }
}
static void withPop(Parse *pParse, With *pWith){
  if( pWith ){
    assert( pParse->pWith==pWith );
    pParse->pWith = pWith->pOuter;
  }
}

/* Push or pull a CTE on the stack of all CTEs currently being
** coded.
*/
static int ctePush(Parse *pParse, struct Cte *pCte){
  if( pCte ){
    struct Cte *p;
    for(p=pParse->pCte; p; p=p->pOuterCte){
      if( p==pCte ){
        sqlite3ErrorMsg(
            pParse, "illegal recursive defininition in cte: %s", pCte->zName
        );
        return SQLITE_ERROR;
      }
    }
    
    pCte->pOuterCte = pParse->pCte;
    pParse->pCte = pCte;
  }
  return SQLITE_OK;
}

static void ctePop(Parse *pParse, struct Cte *pCte){
  if( pCte ){
    assert( pParse->pCte==pCte );
    pParse->pCte = pCte->pOuterCte;
  }
}

** callbacks.
*/
#define WRC_Continue    0   /* Continue down into children */
#define WRC_Prune       1   /* Omit children but continue walking siblings */
#define WRC_Abort       2   /* Abandon the tree walk */

/*
** An instance of this structure represents a set of on or more CTEs
** (common table expressions) created by a single WITH clause.
*/
struct With {
  int nCte;                       /* Number of CTEs in the WITH clause */
  With *pOuter;                   /* Containing WITH clause, or NULL */
  struct Cte {                    /* For each CTE in the WITH clause.... */
    char *zName;                    /* Name of this CTE */
    ExprList *pCols;                /* List of explicit column names, or NULL */
    Select *pSelect;                /* The definition of this CTE */
    struct Cte *pOuterCte;          /* Next WITH clause in outer context */
    Table *pTab;                    /* Table object for this CTE */
  } a[1];
};

/*
** Assuming zIn points to the first byte of a UTF-8 character,
** advance zIn to point to the first byte of the next UTF-8 character.
*/