SQLite

      pKey = 0;
    }
  }
  return pKey;
}

#ifndef SQLITE_OMIT_CTE
/*
** Create a new CTE object
*/
Cte *sqlite3CteNew(
  Parse *pParse,          /* Parsing context */
  Token *pName,           /* Name of the common-table */
  ExprList *pArglist,     /* Optional column name list for the table */
  Select *pQuery,         /* Query used to initialize the table */
  int eMaterialized       /* Force or prohibit materialization */
){
  Cte *pNew;
  sqlite3 *db = pParse->db;

  assert( eMaterialized==MAT_NotSpec || eMaterialized==MAT_Yes
            || eMaterialized==MAT_No );
  pNew = sqlite3DbMallocZero(db, sizeof(*pNew));
  assert( pNew!=0 || db->mallocFailed );

  if( db->mallocFailed ){
    sqlite3ExprListDelete(db, pArglist);
    sqlite3SelectDelete(db, pQuery);
  }else{
    pNew->pSelect = pQuery;
    pNew->pCols = pArglist;
    pNew->zName = sqlite3NameFromToken(pParse->db, pName);
    pNew->zCteErr = 0;
    pNew->eMaterialized = (u8)eMaterialized;
  }
  return pNew;
}

/*
** Free the contents of the CTE object passed as the second argument.
*/
void sqlite3CteDelete(sqlite3 *db, Cte *pCte){
  if( pCte ){
    sqlite3ExprListDelete(db, pCte->pCols);
    sqlite3SelectDelete(db, pCte->pSelect);
    sqlite3DbFree(db, pCte->zName);
    sqlite3DbFree(db, pCte);
  }
}

/* 
** This routine is invoked once per CTE by the parser while parsing a 
** WITH clause. 
*/
With *sqlite3WithAdd(
  Parse *pParse,          /* Parsing context */
  With *pWith,            /* Existing WITH clause, or NULL */
  Cte *pCte               /* The CTE to add to the WITH clause */


){
  sqlite3 *db = pParse->db;
  With *pNew;
  char *zName;


  if( pCte==0 ){
    return pWith;
  }

  /* Check that the CTE name is unique within this WITH clause. If
  ** not, store an error in the Parse structure. */
  zName = pCte->zName;
  if( zName && pWith ){
    int i;
    for(i=0; i<pWith->nCte; i++){
      if( sqlite3StrICmp(zName, pWith->a[i].zName)==0 ){
        sqlite3ErrorMsg(pParse, "duplicate WITH table name: %s", zName);
      }
    }
  }

  if( pWith ){
    sqlite3_int64 nByte = sizeof(*pWith) + (sizeof(pWith->a[1]) * pWith->nCte);
    pNew = sqlite3DbRealloc(db, pWith, nByte);
  }else{
    pNew = sqlite3DbMallocZero(db, sizeof(*pWith));
  }


  if( db->mallocFailed ){

    sqlite3CteDelete(db, pCte);

    pNew = pWith;
  }else{


    pNew->a[pNew->nCte] = *pCte;
    sqlite3DbFree(db, pCte);
    pNew->nCte++;
  }

  return pNew;
}

/*
** Free the contents of the With object passed as the second argument.
*/
void sqlite3WithDelete(sqlite3 *db, With *pWith){

%endif SQLITE_OMIT_COMPOUND_SELECT
%ifndef SQLITE_OMIT_WINDOWFUNC
  CURRENT FOLLOWING PARTITION PRECEDING RANGE UNBOUNDED
  EXCLUDE GROUPS OTHERS TIES
%endif SQLITE_OMIT_WINDOWFUNC
%ifndef SQLITE_OMIT_GENERATED_COLUMNS
  GENERATED ALWAYS
%endif
%ifndef SQLITE_OMIT_CTE
  MATERIALIZED
%endif
  REINDEX RENAME CTIME_KW IF
  .
%wildcard ANY.

// Define operator precedence early so that this is the first occurrence
// of the operator tokens in the grammer.  Keeping the operators together

anylist ::= anylist ANY.
%endif  SQLITE_OMIT_VIRTUALTABLE


//////////////////////// COMMON TABLE EXPRESSIONS ////////////////////////////
%type wqlist {With*}
%destructor wqlist {sqlite3WithDelete(pParse->db, $$);}
%type wqitem {Cte*}
%destructor wqitem {sqlite3CteDelete(pParse->db, $$);}
%type wqas {int}

with ::= .
%ifndef SQLITE_OMIT_CTE
with ::= WITH wqlist(W).              { sqlite3WithPush(pParse, W, 1); }
with ::= WITH RECURSIVE wqlist(W).    { sqlite3WithPush(pParse, W, 1); }

wqas(A)   ::= AS.                   {A=MAT_NotSpec;}
wqas(A)   ::= AS MATERIALIZED.      {A=MAT_Yes;}
//wqas(A) ::= AS NOT MATERIALIZED.  {A=MAT_No;}
wqitem(A) ::= nm(X) eidlist_opt(Y) wqas(F) LP select(Z) RP. {
  A = sqlite3CteNew(pParse, &X, Y, Z, F); /*A-overwrites-X*/
}
wqlist(A) ::= wqitem(X). {
  A = sqlite3WithAdd(pParse, 0, X); /*A-overwrites-X*/
}
wqlist(A) ::= wqlist(A) COMMA wqitem(X). {
  A = sqlite3WithAdd(pParse, A, X);
}
%endif  SQLITE_OMIT_CTE

//////////////////////// WINDOW FUNCTION EXPRESSIONS /////////////////////////
// These must be at the end of this file. Specifically, the rules that
// introduce tokens WINDOW, OVER and FILTER must appear last. This causes 
// the integer values assigned to these tokens to be larger than all other 

    pTab->zName = sqlite3DbStrDup(db, pCte->zName);
    pTab->iPKey = -1;
    pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
    pTab->tabFlags |= TF_Ephemeral | TF_NoVisibleRowid;
    pFrom->pSelect = sqlite3SelectDup(db, pCte->pSelect, 0);
    if( db->mallocFailed ) return SQLITE_NOMEM_BKPT;
    assert( pFrom->pSelect );
    if( pCte->eMaterialized==MAT_Yes ){
      pFrom->pSelect->selFlags |= SF_OptBarrier;
    }

    /* Check if this is a recursive CTE. */
    pRecTerm = pSel = pFrom->pSelect;
    bMayRecursive = ( pSel->op==TK_ALL || pSel->op==TK_UNION );
    while( bMayRecursive && pRecTerm->op==pSel->op ){
      int i;
      SrcList *pSrc = pRecTerm->pSrc;

     && (p->selFlags & SF_ComplexResult)!=0
     && (pTabList->nSrc==1
         || (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0)
    ){
      continue;
    }

    /* Do not flatten across an optimization barrier */
    if( pSub->selFlags & SF_OptBarrier ) continue;

    if( flattenSubquery(pParse, p, i, isAgg) ){
      if( pParse->nErr ) goto select_end;
      /* This subquery can be absorbed into its parent. */
      i = -1;
    }
    pTabList = p->pSrc;
    if( db->mallocFailed ) goto select_end;

    */
    pParse->nHeight += sqlite3SelectExprHeight(p);

    /* Make copies of constant WHERE-clause terms in the outer query down
    ** inside the subquery.  This can help the subquery to run more efficiently.
    */
    if( OptimizationEnabled(db, SQLITE_PushDown)
     && (pSub->selFlags & SF_OptBarrier)==0
     && pushDownWhereTerms(pParse, pSub, p->pWhere, pItem->iCursor,
                           (pItem->fg.jointype & JT_OUTER)!=0)
    ){
#if SELECTTRACE_ENABLED
      if( sqlite3SelectTrace & 0x100 ){
        SELECTTRACE(0x100,pParse,p,
            ("After WHERE-clause push-down into subquery %d:\n", pSub->selId));
        sqlite3TreeViewSelect(0, p, 0);
      }
#endif
      assert( pItem->pSelect && (pItem->pSelect->selFlags & SF_PushDown)!=0 );
    }else{
      SELECTTRACE(0x100,pParse,p,("Push-down not possible\n"));
    }

    zSavedAuthContext = pParse->zAuthContext;
    pParse->zAuthContext = pItem->zName;

    /* Generate code to implement the subquery
    **
    ** The subquery is implemented as a co-routine if (1) the subquery is
    ** guaranteed to be the outer loop (so that it does not need to be
    ** computed more than once) and if (2) the subquery is not optimization
    ** barrier.
    **
    ** TODO: Are there other reasons beside (1) and (2) to use a co-routine
    ** implementation?
    **
    ** TODO: We might should allow a subquery that is an optimization barrier
    ** to be implemented as a co-routine as long as we know that it is the
    ** only use of the subquery.
    */
    if( i==0
     && (pTabList->nSrc==1
            || (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0)  /* (1) */
     && (pSub->selFlags & SF_OptBarrier)==0                         /* (2) */
    ){
      /* Implement a co-routine that will return a single row of the result
      ** set on each invocation.
      */
      int addrTop = sqlite3VdbeCurrentAddr(v)+1;
     
      pItem->regReturn = ++pParse->nMem;

*/
typedef struct AggInfo AggInfo;
typedef struct AuthContext AuthContext;
typedef struct AutoincInfo AutoincInfo;
typedef struct Bitvec Bitvec;
typedef struct CollSeq CollSeq;
typedef struct Column Column;
typedef struct Cte Cte;
typedef struct Db Db;
typedef struct DbFixer DbFixer;
typedef struct Schema Schema;
typedef struct Expr Expr;
typedef struct ExprList ExprList;
typedef struct FKey FKey;
typedef struct FuncDestructor FuncDestructor;

#define SF_ComplexResult 0x0040000 /* Result contains subquery or function */
#define SF_WhereBegin    0x0080000 /* Really a WhereBegin() call.  Debug Only */
#define SF_WinRewrite    0x0100000 /* Window function rewrite accomplished */
#define SF_View          0x0200000 /* SELECT statement is a view */
#define SF_NoopOrderBy   0x0400000 /* ORDER BY is ignored for this query */
#define SF_UpdateFrom    0x0800000 /* Statement is an UPDATE...FROM */
#define SF_PushDown      0x1000000 /* SELECT has be modified by push-down opt */
#define SF_OptBarrier    0x2000000 /* SELECT is an optimization barrier */

/*
** The results of a SELECT can be distributed in several ways, as defined
** by one of the following macros.  The "SRT" prefix means "SELECT Result
** Type".
**
**     SRT_Union       Store results as a key in a temporary index

** Return code from the parse-tree walking primitives and their
** 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 */

/*
** Allowed values for Cte.eMAterialized
*/
#define MAT_NotSpec     0   /* Not specified */
#define MAT_Yes         1   /* AS MATERIALIZED ... */
#define MAT_No          2   /* AS NOT MATERIALIZED.  Not currently used */

/*
** An instance of this structure represents a set of one or more CTEs
** (common table expressions) created by a single WITH clause.
*/
struct Cte {



  char *zName;                  /* Name of this CTE */
  ExprList *pCols;              /* List of explicit column names, or NULL */
  Select *pSelect;              /* The definition of this CTE */
  const char *zCteErr;          /* Error message for circular references */
  u8 eMaterialized;             /* One of the MAT_* values */
};
struct With {
  int nCte;                     /* Number of CTEs in the WITH clause */
  With *pOuter;                 /* Containing WITH clause, or NULL */
  Cte a[1];                     /* The CTEs of this WITH clause */
};

#ifdef SQLITE_DEBUG
/*
** An instance of the TreeView object is used for printing the content of
** data structures on sqlite3DebugPrintf() using a tree-like view.
*/

int sqlite3TempInMemory(const sqlite3*);
const char *sqlite3JournalModename(int);
#ifndef SQLITE_OMIT_WAL
  int sqlite3Checkpoint(sqlite3*, int, int, int*, int*);
  int sqlite3WalDefaultHook(void*,sqlite3*,const char*,int);
#endif
#ifndef SQLITE_OMIT_CTE
  Cte *sqlite3CteNew(Parse*,Token*,ExprList*,Select*,int);
  With *sqlite3WithAdd(Parse*,With*,Cte*);
  void sqlite3CteDelete(sqlite3*,Cte*);
  void sqlite3WithDelete(sqlite3*,With*);
  void sqlite3WithPush(Parse*, With*, u8);
#else
#define sqlite3WithPush(x,y,z)
#define sqlite3WithDelete(x,y)
#endif
#ifndef SQLITE_OMIT_UPSERT

  { "FILTER",           "TK_FILTER",       WINDOWFUNC,       4      },
  { "FIRST",            "TK_FIRST",        ALWAYS,           4      },
  { "FOLLOWING",        "TK_FOLLOWING",    WINDOWFUNC,       4      },
  { "FOR",              "TK_FOR",          TRIGGER,          2      },
  { "FOREIGN",          "TK_FOREIGN",      FKEY,             1      },
  { "FROM",             "TK_FROM",         ALWAYS,           10     },
  { "FULL",             "TK_JOIN_KW",      ALWAYS,           3      },
  { "GENERATED",        "TK_GENERATED",    ALWAYS,           1      },
  { "GLOB",             "TK_LIKE_KW",      ALWAYS,           3      },
  { "GROUP",            "TK_GROUP",        ALWAYS,           5      },
  { "GROUPS",           "TK_GROUPS",       WINDOWFUNC,       2      },
  { "HAVING",           "TK_HAVING",       ALWAYS,           5      },
  { "IF",               "TK_IF",           ALWAYS,           2      },
  { "IGNORE",           "TK_IGNORE",       CONFLICT|TRIGGER, 1      },
  { "IMMEDIATE",        "TK_IMMEDIATE",    ALWAYS,           1      },

  { "JOIN",             "TK_JOIN",         ALWAYS,           5      },
  { "KEY",              "TK_KEY",          ALWAYS,           1      },
  { "LAST",             "TK_LAST",         ALWAYS,           4      },
  { "LEFT",             "TK_JOIN_KW",      ALWAYS,           5      },
  { "LIKE",             "TK_LIKE_KW",      ALWAYS,           5      },
  { "LIMIT",            "TK_LIMIT",        ALWAYS,           3      },
  { "MATCH",            "TK_MATCH",        ALWAYS,           2      },
  { "MATERIALIZED",     "TK_MATERIALIZED", CTE,              12     },
  { "NATURAL",          "TK_JOIN_KW",      ALWAYS,           3      },
  { "NO",               "TK_NO",           FKEY|WINDOWFUNC,  2      },
  { "NOT",              "TK_NOT",          ALWAYS,           10     },
  { "NOTHING",          "TK_NOTHING",      UPSERT,           1      },
  { "NOTNULL",          "TK_NOTNULL",      ALWAYS,           3      },
  { "NULL",             "TK_NULL",         ALWAYS,           10     },
  { "NULLS",            "TK_NULLS",        ALWAYS,           3      },