nodeFuncs.h

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/*-------------------------------------------------------------------------
 *
 * nodeFuncs.h
 *      Various general-purpose manipulations of Node trees
 *
 * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/nodes/nodeFuncs.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef NODEFUNCS_H
#define NODEFUNCS_H

#include "nodes/parsenodes.h"


/* flags bits for query_tree_walker and query_tree_mutator */
#define QTW_IGNORE_RT_SUBQUERIES    0x01    /* subqueries in rtable */
#define QTW_IGNORE_CTE_SUBQUERIES   0x02    /* subqueries in cteList */
#define QTW_IGNORE_RC_SUBQUERIES    0x03    /* both of above */
#define QTW_IGNORE_JOINALIASES      0x04    /* JOIN alias var lists */
#define QTW_IGNORE_RANGE_TABLE      0x08    /* skip rangetable entirely */
#define QTW_EXAMINE_RTES_BEFORE     0x10    /* examine RTE nodes before their
                                             * contents */
#define QTW_EXAMINE_RTES_AFTER      0x20    /* examine RTE nodes after their
                                             * contents */
#define QTW_DONT_COPY_QUERY         0x40    /* do not copy top Query */
#define QTW_EXAMINE_SORTGROUP       0x80    /* include SortGroupNode lists */

/* callback function for check_functions_in_node */
typedef bool (*check_function_callback) (Oid func_id, void *context);


extern Oid  exprType(const Node *expr);
extern int32 exprTypmod(const Node *expr);
extern bool exprIsLengthCoercion(const Node *expr, int32 *coercedTypmod);
extern Node *relabel_to_typmod(Node *expr, int32 typmod);
extern Node *strip_implicit_coercions(Node *node);
extern bool expression_returns_set(Node *clause);

extern Oid  exprCollation(const Node *expr);
extern Oid  exprInputCollation(const Node *expr);
extern void exprSetCollation(Node *expr, Oid collation);
extern void exprSetInputCollation(Node *expr, Oid inputcollation);

extern int  exprLocation(const Node *expr);

extern void fix_opfuncids(Node *node);
extern void set_opfuncid(OpExpr *opexpr);
extern void set_sa_opfuncid(ScalarArrayOpExpr *opexpr);

/* Is clause a FuncExpr clause? */
static inline bool
is_funcclause(const void *clause)
{
    return clause != NULL && IsA(clause, FuncExpr);
}

/* Is clause an OpExpr clause? */
static inline bool
is_opclause(const void *clause)
{
    return clause != NULL && IsA(clause, OpExpr);
}

/* Extract left arg of a binary opclause, or only arg of a unary opclause */
static inline Node *
get_leftop(const void *clause)
{
    const OpExpr *expr = (const OpExpr *) clause;

    if (expr->args != NIL)
        return (Node *) linitial(expr->args);
    else
        return NULL;
}

/* Extract right arg of a binary opclause (NULL if it's a unary opclause) */
static inline Node *
get_rightop(const void *clause)
{
    const OpExpr *expr = (const OpExpr *) clause;

    if (list_length(expr->args) >= 2)
        return (Node *) lsecond(expr->args);
    else
        return NULL;
}

/* Is clause an AND clause? */
static inline bool
is_andclause(const void *clause)
{
    return (clause != NULL &&
            IsA(clause, BoolExpr) &&
            ((const BoolExpr *) clause)->boolop == AND_EXPR);
}

/* Is clause an OR clause? */
static inline bool
is_orclause(const void *clause)
{
    return (clause != NULL &&
            IsA(clause, BoolExpr) &&
            ((const BoolExpr *) clause)->boolop == OR_EXPR);
}

/* Is clause a NOT clause? */
static inline bool
is_notclause(const void *clause)
{
    return (clause != NULL &&
            IsA(clause, BoolExpr) &&
            ((const BoolExpr *) clause)->boolop == NOT_EXPR);
}

/* Extract argument from a clause known to be a NOT clause */
static inline Expr *
get_notclausearg(const void *notclause)
{
    return (Expr *) linitial(((const BoolExpr *) notclause)->args);
}

extern bool check_functions_in_node(Node *node, check_function_callback checker,
                                    void *context);

extern bool expression_tree_walker(Node *node, bool (*walker) (),
                                   void *context);
extern Node *expression_tree_mutator(Node *node, Node *(*mutator) (),
                                     void *context);

extern bool query_tree_walker(Query *query, bool (*walker) (),
                              void *context, int flags);
extern Query *query_tree_mutator(Query *query, Node *(*mutator) (),
                                 void *context, int flags);

extern bool range_table_walker(List *rtable, bool (*walker) (),
                               void *context, int flags);
extern List *range_table_mutator(List *rtable, Node *(*mutator) (),
                                 void *context, int flags);

extern bool range_table_entry_walker(RangeTblEntry *rte, bool (*walker) (),
                                     void *context, int flags);

extern bool query_or_expression_tree_walker(Node *node, bool (*walker) (),
                                            void *context, int flags);
extern Node *query_or_expression_tree_mutator(Node *node, Node *(*mutator) (),
                                              void *context, int flags);

extern bool raw_expression_tree_walker(Node *node, bool (*walker) (),
                                       void *context);

struct PlanState;
extern bool planstate_tree_walker(struct PlanState *planstate, bool (*walker) (),
                                  void *context);

#endif                          /* NODEFUNCS_H */