SQLite

Expr *sqlite3PExpr(
  Parse *pParse,          /* Parsing context */
  int op,                 /* Expression opcode */
  Expr *pLeft,            /* Left operand */
  Expr *pRight            /* Right operand */
){
  Expr *p;
  if( op==TK_AND && pParse->nErr==0 && !IN_RENAME_OBJECT ){
    /* Take advantage of short-circuit false optimization for AND */
    p = sqlite3ExprAnd(pParse->db, pLeft, pRight);
  }else{
    p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr));
    if( p ){
      memset(p, 0, sizeof(Expr));
      p->op = op & 0xff;
      p->iAgg = -1;
    }
    sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
  }
  if( p ) {
    sqlite3ExprCheckHeight(pParse, p->nHeight);



  }
  return p;
}

/*
** Add pSelect to the Expr.x.pSelect field.  Or, if pExpr is NULL (due
** do a memory allocation failure) then delete the pSelect object.

** Join two expressions using an AND operator.  If either expression is
** NULL, then just return the other expression.
**
** If one side or the other of the AND is known to be false, then instead
** of returning an AND expression, just return a constant expression with
** a value of false.
*/
Expr *sqlite3ExprAnd(sqlite3 *db, Expr *pLeft, Expr *pRight){

  if( pLeft==0 ){
    return pRight;
  }else if( pRight==0 ){
    return pLeft;


  }else if( exprAlwaysFalse(pLeft) || exprAlwaysFalse(pRight) ){
    sqlite3ExprDelete(db, pLeft);
    sqlite3ExprDelete(db, pRight);
    return sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[0], 0);
  }else{
    Expr *pNew = sqlite3ExprAlloc(db, TK_AND, 0, 0);
    sqlite3ExprAttachSubtrees(db, pNew, pLeft, pRight);
    return pNew;
  }
}

/*
** Construct a new expression node for a function with multiple
** arguments.
*/

    iCol = pIdx ? pIdx->aiColumn[i] : -1;
    pLeft = exprTableRegister(pParse, pTab, regData, iCol);
    iCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
    assert( iCol>=0 );
    zCol = pFKey->pFrom->aCol[iCol].zName;
    pRight = sqlite3Expr(db, TK_ID, zCol);
    pEq = sqlite3PExpr(pParse, TK_EQ, pLeft, pRight);
    pWhere = sqlite3ExprAnd(db, pWhere, pEq);
  }

  /* If the child table is the same as the parent table, then add terms
  ** to the WHERE clause that prevent this entry from being scanned.
  ** The added WHERE clause terms are like this:
  **
  **     $current_rowid!=rowid

      assert( pIdx!=0 );
      for(i=0; i<pIdx->nKeyCol; i++){
        i16 iCol = pIdx->aiColumn[i];
        assert( iCol>=0 );
        pLeft = exprTableRegister(pParse, pTab, regData, iCol);
        pRight = sqlite3Expr(db, TK_ID, pTab->aCol[iCol].zName);
        pEq = sqlite3PExpr(pParse, TK_IS, pLeft, pRight);
        pAll = sqlite3ExprAnd(db, pAll, pEq);
      }
      pNe = sqlite3PExpr(pParse, TK_NOT, pAll, 0);
    }
    pWhere = sqlite3ExprAnd(db, pWhere, pNe);
  }

  /* Resolve the references in the WHERE clause. */
  memset(&sNameContext, 0, sizeof(NameContext));
  sNameContext.pSrcList = pSrc;
  sNameContext.pParse = pParse;
  sqlite3ResolveExprNames(&sNameContext, pWhere);

      ** parent table are used for the comparison. */
      pEq = sqlite3PExpr(pParse, TK_EQ,
          sqlite3PExpr(pParse, TK_DOT, 
            sqlite3ExprAlloc(db, TK_ID, &tOld, 0),
            sqlite3ExprAlloc(db, TK_ID, &tToCol, 0)),
          sqlite3ExprAlloc(db, TK_ID, &tFromCol, 0)
      );
      pWhere = sqlite3ExprAnd(db, pWhere, pEq);

      /* For ON UPDATE, construct the next term of the WHEN clause.
      ** The final WHEN clause will be like this:
      **
      **    WHEN NOT(old.col1 IS new.col1 AND ... AND old.colN IS new.colN)
      */
      if( pChanges ){
        pEq = sqlite3PExpr(pParse, TK_IS,
            sqlite3PExpr(pParse, TK_DOT, 
              sqlite3ExprAlloc(db, TK_ID, &tOld, 0),
              sqlite3ExprAlloc(db, TK_ID, &tToCol, 0)),
            sqlite3PExpr(pParse, TK_DOT, 
              sqlite3ExprAlloc(db, TK_ID, &tNew, 0),
              sqlite3ExprAlloc(db, TK_ID, &tToCol, 0))
            );
        pWhen = sqlite3ExprAnd(db, pWhen, pEq);
      }
  
      if( action!=OE_Restrict && (action!=OE_Cascade || pChanges) ){
        Expr *pNew;
        if( action==OE_Cascade ){
          pNew = sqlite3PExpr(pParse, TK_DOT, 
            sqlite3ExprAlloc(db, TK_ID, &tNew, 0),

  if( A ){
    A->x.pList = pList;
  }else{
    sqlite3ExprListDelete(pParse->db, pList);
  }
}

expr(A) ::= expr(A) AND(OP) expr(Y).    {A=sqlite3PExpr(pParse,@OP,A,Y);}
expr(A) ::= expr(A) OR(OP) expr(Y).     {A=sqlite3PExpr(pParse,@OP,A,Y);}
expr(A) ::= expr(A) LT|GT|GE|LE(OP) expr(Y).
                                        {A=sqlite3PExpr(pParse,@OP,A,Y);}
expr(A) ::= expr(A) EQ|NE(OP) expr(Y).  {A=sqlite3PExpr(pParse,@OP,A,Y);}
expr(A) ::= expr(A) BITAND|BITOR|LSHIFT|RSHIFT(OP) expr(Y).
                                        {A=sqlite3PExpr(pParse,@OP,A,Y);}
expr(A) ::= expr(A) PLUS|MINUS(OP) expr(Y).

  pEq = sqlite3PExpr(pParse, TK_EQ, pE1, pE2);
  if( pEq && isOuterJoin ){
    ExprSetProperty(pEq, EP_FromJoin);
    assert( !ExprHasProperty(pEq, EP_TokenOnly|EP_Reduced) );
    ExprSetVVAProperty(pEq, EP_NoReduce);
    pEq->iRightJoinTable = (i16)pE2->iTable;
  }
  *ppWhere = sqlite3ExprAnd(db, *ppWhere, pEq);
}

/*
** Set the EP_FromJoin property on all terms of the given expression.
** And set the Expr.iRightJoinTable to iTable for every term in the
** expression.
**

    }

    /* Add the ON clause to the end of the WHERE clause, connected by
    ** an AND operator.
    */
    if( pRight->pOn ){
      if( isOuter ) setJoinExpr(pRight->pOn, pRight->iCursor);
      p->pWhere = sqlite3ExprAnd(pParse->db, p->pWhere, pRight->pOn);
      pRight->pOn = 0;
    }

    /* Create extra terms on the WHERE clause for each column named
    ** in the USING clause.  Example: If the two tables to be joined are 
    ** A and B and the USING clause names X, Y, and Z, then add this
    ** to the WHERE clause:    A.X=B.X AND A.Y=B.Y AND A.Z=B.Z

      pSub->pOrderBy = 0;
    }
    pWhere = pSub->pWhere;
    pSub->pWhere = 0;
    if( isLeftJoin>0 ){
      setJoinExpr(pWhere, iNewParent);
    }
    pParent->pWhere = sqlite3ExprAnd(db, pWhere, pParent->pWhere);
    if( db->mallocFailed==0 ){
      SubstContext x;
      x.pParse = pParse;
      x.iTable = iParent;
      x.iNewTable = iNewParent;
      x.isLeftJoin = isLeftJoin;
      x.pEList = pSub->pEList;

      x.pParse = pParse;
      x.iTable = iCursor;
      x.iNewTable = iCursor;
      x.isLeftJoin = 0;
      x.pEList = pSubq->pEList;
      pNew = substExpr(&x, pNew);
      if( pSubq->selFlags & SF_Aggregate ){
        pSubq->pHaving = sqlite3ExprAnd(pParse->db, pSubq->pHaving, pNew);
      }else{
        pSubq->pWhere = sqlite3ExprAnd(pParse->db, pSubq->pWhere, pNew);
      }
      pSubq = pSubq->pPrior;
    }
  }
  return nChng;
}
#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */

    Select *pS = pWalker->u.pSelect;
    if( sqlite3ExprIsConstantOrGroupBy(pWalker->pParse, pExpr, pS->pGroupBy) ){
      sqlite3 *db = pWalker->pParse->db;
      Expr *pNew = sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[1], 0);
      if( pNew ){
        Expr *pWhere = pS->pWhere;
        SWAP(Expr, *pNew, *pExpr);
        pNew = sqlite3ExprAnd(db, pWhere, pNew);
        pS->pWhere = pNew;
        pWalker->eCode = 1;
      }
    }
    return WRC_Prune;
  }
  return WRC_Continue;

int sqlite3NoTempsInRange(Parse*,int,int);
#endif
Expr *sqlite3ExprAlloc(sqlite3*,int,const Token*,int);
Expr *sqlite3Expr(sqlite3*,int,const char*);
void sqlite3ExprAttachSubtrees(sqlite3*,Expr*,Expr*,Expr*);
Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*);
void sqlite3PExprAddSelect(Parse*, Expr*, Select*);
Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*, int);
void sqlite3ExprAssignVarNumber(Parse*, Expr*, u32);
void sqlite3ExprDelete(sqlite3*, Expr*);
ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
ExprList *sqlite3ExprListAppendVector(Parse*,ExprList*,IdList*,Expr*);
void sqlite3ExprListSetSortOrder(ExprList*,int);
void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);

    assert( !ExprHasProperty(pExpr, EP_FromJoin)    /* prereq always non-zero */
         || pExpr->iRightJoinTable!=pSrc->iCursor   /*   for the right-hand   */
         || pLoop->prereq!=0 );                     /*   table of a LEFT JOIN */
    if( pLoop->prereq==0
     && (pTerm->wtFlags & TERM_VIRTUAL)==0
     && !ExprHasProperty(pExpr, EP_FromJoin)
     && sqlite3ExprIsTableConstant(pExpr, pSrc->iCursor) ){
      pPartial = sqlite3ExprAnd(pParse->db, pPartial,
                                sqlite3ExprDup(pParse->db, pExpr, 0));
    }
    if( termCanDriveIndex(pTerm, pSrc, notReady) ){
      int iCol = pTerm->u.leftColumn;
      Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
      testcase( iCol==BMS );
      testcase( iCol==BMS-1 );

      sWalker.eCode = 0;
      sWalker.xExprCallback = codeCursorHintCheckExpr;
      sqlite3WalkExpr(&sWalker, pTerm->pExpr);
      if( sWalker.eCode ) continue;
    }

    /* If we survive all prior tests, that means this term is worth hinting */
    pExpr = sqlite3ExprAnd(db, pExpr, sqlite3ExprDup(db, pTerm->pExpr, 0));
  }
  if( pExpr!=0 ){
    sWalker.xExprCallback = codeCursorHintFixExpr;
    sqlite3WalkExpr(&sWalker, pExpr);
    sqlite3VdbeAddOp4(v, OP_CursorHint, 
                      (sHint.pIdx ? sHint.iIdxCur : sHint.iTabCur), 0, 0,
                      (const char*)pExpr, P4_EXPR);

        if( &pWC->a[iTerm] == pTerm ) continue;
        testcase( pWC->a[iTerm].wtFlags & TERM_VIRTUAL );
        testcase( pWC->a[iTerm].wtFlags & TERM_CODED );
        if( (pWC->a[iTerm].wtFlags & (TERM_VIRTUAL|TERM_CODED))!=0 ) continue;
        if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
        testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );
        pExpr = sqlite3ExprDup(db, pExpr, 0);
        pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr);
      }
      if( pAndExpr ){
        /* The extra 0x10000 bit on the opcode is masked off and does not
        ** become part of the new Expr.op.  However, it does make the
        ** op==TK_AND comparison inside of sqlite3PExpr() false, and this
        ** prevents sqlite3PExpr() from implementing AND short-circuit 
        ** optimization, which we do not want here. */