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/*-------------------------------------------------------------------------
*
* var.c--
* Var node manipulation routines
*
* Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/var.c,v 1.12 1998/06/15 19:28:50 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#include <sys/types.h>
#include "postgres.h"
#include <nodes/relation.h>
#include "nodes/primnodes.h"
#include "nodes/plannodes.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/internal.h"
#include "optimizer/clauses.h"
#include "optimizer/var.h"
#include "parser/parsetree.h"
/*
* find_varnos
*
* Descends down part of a parsetree (qual or tlist),
*
* XXX assumes varno's are always integers, which shouldn't be true...
* (though it currently is, see primnodes.h)
*/
List *
pull_varnos(Node *me)
{
List *i,
*result = NIL;
if (me == NULL)
return (NIL);
switch (nodeTag(me))
{
case T_List:
foreach(i, (List *) me)
result = nconc(result, pull_varnos(lfirst(i)));
break;
case T_ArrayRef:
foreach(i, ((ArrayRef *) me)->refupperindexpr)
result = nconc(result, pull_varnos(lfirst(i)));
foreach(i, ((ArrayRef *) me)->reflowerindexpr)
result = nconc(result, pull_varnos(lfirst(i)));
result = nconc(result, pull_varnos(((ArrayRef *) me)->refassgnexpr));
break;
case T_Var:
result = lconsi(((Var *) me)->varno, NIL);
break;
default:
break;
}
return (result);
}
/*
* contain_var_clause--
* Recursively find var nodes from a clause by pulling vars from the
* left and right operands of the clause.
*
* Returns true if any varnode found.
*/
bool
contain_var_clause(Node *clause)
{
if (clause == NULL)
return FALSE;
else if (IsA(clause, Var))
return TRUE;
else if (IsA(clause, Iter))
return contain_var_clause(((Iter *) clause)->iterexpr);
else if (single_node(clause))
return FALSE;
else if (or_clause(clause) || and_clause(clause) || is_funcclause(clause))
{
List *temp;
foreach(temp, ((Expr *) clause)->args)
{
if (contain_var_clause(lfirst(temp)))
return TRUE;
}
return FALSE;
}
else if (is_subplan(clause))
{
List *temp;
foreach(temp, ((Expr *) clause)->args)
{
if (contain_var_clause(lfirst(temp)))
return TRUE;
}
/* Ok - check left sides of Oper-s */
foreach(temp, ((SubPlan *) ((Expr *) clause)->oper)->sublink->oper)
{
if (contain_var_clause(lfirst(((Expr *) lfirst(temp))->args)))
return TRUE;
}
return FALSE;
}
else if (IsA(clause, ArrayRef))
{
List *temp;
foreach(temp, ((ArrayRef *) clause)->refupperindexpr)
{
if (contain_var_clause(lfirst(temp)))
return TRUE;
}
foreach(temp, ((ArrayRef *) clause)->reflowerindexpr)
{
if (contain_var_clause(lfirst(temp)))
return TRUE;
}
if (contain_var_clause(((ArrayRef *) clause)->refexpr))
return TRUE;
if (contain_var_clause(((ArrayRef *) clause)->refassgnexpr))
return TRUE;
return FALSE;
}
else if (not_clause(clause))
return contain_var_clause((Node *) get_notclausearg((Expr *) clause));
else if (is_opclause(clause))
return (contain_var_clause((Node *) get_leftop((Expr *) clause)) ||
contain_var_clause((Node *) get_rightop((Expr *) clause)));
return FALSE;
}
/*
* pull_var_clause--
* Recursively pulls all var nodes from a clause by pulling vars from the
* left and right operands of the clause.
*
* Returns list of varnodes found.
*/
List *
pull_var_clause(Node *clause)
{
List *retval = NIL;
if (clause == NULL)
return (NIL);
else if (IsA(clause, Var))
retval = lcons(clause, NIL);
else if (IsA(clause, Iter))
retval = pull_var_clause(((Iter *) clause)->iterexpr);
else if (single_node(clause))
retval = NIL;
else if (or_clause(clause) || and_clause(clause) || is_funcclause(clause))
{
List *temp;
foreach(temp, ((Expr *) clause)->args)
retval = nconc(retval, pull_var_clause(lfirst(temp)));
}
else if (is_subplan(clause))
{
List *temp;
foreach(temp, ((Expr *) clause)->args)
retval = nconc(retval, pull_var_clause(lfirst(temp)));
/* Ok - get Var-s from left sides of Oper-s */
foreach(temp, ((SubPlan *) ((Expr *) clause)->oper)->sublink->oper)
retval = nconc(retval,
pull_var_clause(lfirst(((Expr *) lfirst(temp))->args)));
}
else if (IsA(clause, Aggreg))
retval = pull_var_clause(((Aggreg *) clause)->target);
else if (IsA(clause, ArrayRef))
{
List *temp;
foreach(temp, ((ArrayRef *) clause)->refupperindexpr)
retval = nconc(retval, pull_var_clause(lfirst(temp)));
foreach(temp, ((ArrayRef *) clause)->reflowerindexpr)
retval = nconc(retval, pull_var_clause(lfirst(temp)));
retval = nconc(retval,
pull_var_clause(((ArrayRef *) clause)->refexpr));
retval = nconc(retval,
pull_var_clause(((ArrayRef *) clause)->refassgnexpr));
}
else if (not_clause(clause))
retval = pull_var_clause((Node *) get_notclausearg((Expr *) clause));
else if (is_opclause(clause))
retval = nconc(pull_var_clause((Node *) get_leftop((Expr *) clause)),
pull_var_clause((Node *) get_rightop((Expr *) clause)));
else
retval = NIL;
return (retval);
}
/*
* var_equal
*
* Returns t iff two var nodes correspond to the same attribute.
*/
bool
var_equal(Var *var1, Var *var2)
{
if (IsA(var1, Var) &&IsA(var2, Var) &&
(((Var *) var1)->varno == ((Var *) var2)->varno) &&
(((Var *) var1)->vartype == ((Var *) var2)->vartype) &&
(((Var *) var1)->vartypmod == ((Var *) var2)->vartypmod) &&
(((Var *) var1)->varlevelsup == ((Var *) var2)->varlevelsup) &&
(((Var *) var1)->varattno == ((Var *) var2)->varattno))
{
Assert(((Var *) var1)->varlevelsup == 0);
return (true);
}
else
return (false);
}
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