clauses.c File Reference

#include "postgres.h"
#include "access/htup_details.h"
#include "catalog/pg_aggregate.h"
#include "catalog/pg_class.h"
#include "catalog/pg_language.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "executor/executor.h"
#include "executor/functions.h"
#include "funcapi.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "nodes/subscripting.h"
#include "nodes/supportnodes.h"
#include "optimizer/clauses.h"
#include "optimizer/cost.h"
#include "optimizer/optimizer.h"
#include "optimizer/plancat.h"
#include "optimizer/planmain.h"
#include "parser/analyze.h"
#include "parser/parse_agg.h"
#include "parser/parse_coerce.h"
#include "parser/parse_func.h"
#include "rewrite/rewriteManip.h"
#include "tcop/tcopprot.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/datum.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/syscache.h"
#include "utils/typcache.h"

Include dependency graph for clauses.c:

Go to the source code of this file.

Data Structures
struct	eval_const_expressions_context
struct	substitute_actual_parameters_context
struct	substitute_actual_srf_parameters_context
struct	inline_error_callback_arg
struct	max_parallel_hazard_context

Macros
#define	CCDN_CASETESTEXPR_OK   0x0001 /* CaseTestExpr okay here? */
#define	ece_generic_processing(node)
#define	ece_all_arguments_const(node)   (!expression_tree_walker((Node *) (node), contain_non_const_walker, NULL))
#define	ece_evaluate_expr(node)

Functions
static bool	contain_agg_clause_walker (Node *node, void *context)
static bool	find_window_functions_walker (Node *node, WindowFuncLists *lists)
static bool	contain_subplans_walker (Node *node, void *context)
static bool	contain_mutable_functions_walker (Node *node, void *context)
static bool	contain_volatile_functions_walker (Node *node, void *context)
static bool	contain_volatile_functions_not_nextval_walker (Node *node, void *context)
static bool	max_parallel_hazard_walker (Node *node, max_parallel_hazard_context *context)
static bool	contain_nonstrict_functions_walker (Node *node, void *context)
static bool	contain_exec_param_walker (Node *node, List *param_ids)
static bool	contain_context_dependent_node (Node *clause)
static bool	contain_context_dependent_node_walker (Node *node, int *flags)
static bool	contain_leaked_vars_walker (Node *node, void *context)
static Relids	find_nonnullable_rels_walker (Node *node, bool top_level)
static List *	find_nonnullable_vars_walker (Node *node, bool top_level)
static bool	is_strict_saop (ScalarArrayOpExpr *expr, bool falseOK)
static Node *	eval_const_expressions_mutator (Node *node, eval_const_expressions_context *context)
static bool	contain_non_const_walker (Node *node, void *context)
static bool	ece_function_is_safe (Oid funcid, eval_const_expressions_context *context)
static List *	simplify_or_arguments (List *args, eval_const_expressions_context *context, bool *haveNull, bool *forceTrue)
static List *	simplify_and_arguments (List *args, eval_const_expressions_context *context, bool *haveNull, bool *forceFalse)
static Node *	simplify_boolean_equality (Oid opno, List *args)
static Expr *	simplify_function (Oid funcid, Oid result_type, int32 result_typmod, Oid result_collid, Oid input_collid, List **args_p, bool funcvariadic, bool process_args, bool allow_non_const, eval_const_expressions_context *context)
static List *	reorder_function_arguments (List *args, HeapTuple func_tuple)
static List *	add_function_defaults (List *args, HeapTuple func_tuple)
static List *	fetch_function_defaults (HeapTuple func_tuple)
static void	recheck_cast_function_args (List *args, Oid result_type, HeapTuple func_tuple)
static Expr *	evaluate_function (Oid funcid, Oid result_type, int32 result_typmod, Oid result_collid, Oid input_collid, List *args, bool funcvariadic, HeapTuple func_tuple, eval_const_expressions_context *context)
static Expr *	inline_function (Oid funcid, Oid result_type, Oid result_collid, Oid input_collid, List *args, bool funcvariadic, HeapTuple func_tuple, eval_const_expressions_context *context)
static Node *	substitute_actual_parameters (Node *expr, int nargs, List *args, int *usecounts)
static Node *	substitute_actual_parameters_mutator (Node *node, substitute_actual_parameters_context *context)
static void	sql_inline_error_callback (void *arg)
static Query *	substitute_actual_srf_parameters (Query *expr, int nargs, List *args)
static Node *	substitute_actual_srf_parameters_mutator (Node *node, substitute_actual_srf_parameters_context *context)
bool	contain_agg_clause (Node *clause)
bool	contain_window_function (Node *clause)
WindowFuncLists *	find_window_functions (Node *clause, Index maxWinRef)
double	expression_returns_set_rows (PlannerInfo *root, Node *clause)
bool	contain_subplans (Node *clause)
bool	contain_mutable_functions (Node *clause)
static bool	contain_mutable_functions_checker (Oid func_id, void *context)
bool	contain_volatile_functions (Node *clause)
static bool	contain_volatile_functions_checker (Oid func_id, void *context)
bool	contain_volatile_functions_not_nextval (Node *clause)
static bool	contain_volatile_functions_not_nextval_checker (Oid func_id, void *context)
char	max_parallel_hazard (Query *parse)
bool	is_parallel_safe (PlannerInfo *root, Node *node)
static bool	max_parallel_hazard_test (char proparallel, max_parallel_hazard_context *context)
static bool	max_parallel_hazard_checker (Oid func_id, void *context)
bool	contain_nonstrict_functions (Node *clause)
static bool	contain_nonstrict_functions_checker (Oid func_id, void *context)
bool	contain_exec_param (Node *clause, List *param_ids)
bool	contain_leaked_vars (Node *clause)
static bool	contain_leaked_vars_checker (Oid func_id, void *context)
Relids	find_nonnullable_rels (Node *clause)
List *	find_nonnullable_vars (Node *clause)
List *	find_forced_null_vars (Node *node)
Var *	find_forced_null_var (Node *node)
bool	is_pseudo_constant_clause (Node *clause)
bool	is_pseudo_constant_clause_relids (Node *clause, Relids relids)
int	NumRelids (PlannerInfo *root, Node *clause)
void	CommuteOpExpr (OpExpr *clause)
static bool	rowtype_field_matches (Oid rowtypeid, int fieldnum, Oid expectedtype, int32 expectedtypmod, Oid expectedcollation)
Node *	eval_const_expressions (PlannerInfo *root, Node *node)
Node *	estimate_expression_value (PlannerInfo *root, Node *node)
List *	expand_function_arguments (List *args, Oid result_type, HeapTuple func_tuple)
Expr *	evaluate_expr (Expr *expr, Oid result_type, int32 result_typmod, Oid result_collation)
Query *	inline_set_returning_function (PlannerInfo *root, RangeTblEntry *rte)

Macro Definition Documentation

CCDN_CASETESTEXPR_OK

#define CCDN_CASETESTEXPR_OK   0x0001 /* CaseTestExpr okay here? */

Definition at line 1000 of file clauses.c.

Referenced by contain_context_dependent_node_walker().

ece_all_arguments_const

#define ece_all_arguments_const

(

node

)

(!expression_tree_walker((Node *) (node), contain_non_const_walker, NULL))

Definition at line 2086 of file clauses.c.

Referenced by eval_const_expressions_mutator().

ece_evaluate_expr

#define ece_evaluate_expr

(

node

)

Value:

((Node *) evaluate_expr((Expr *) (node), \
                            exprType((Node *) (node)), \
                            exprTypmod((Node *) (node)), \
                            exprCollation((Node *) (node))))

Definition at line 2090 of file clauses.c.

Referenced by eval_const_expressions_mutator().

ece_generic_processing

#define ece_generic_processing

(

node

)

Value:

expression_tree_mutator((Node *) (node), eval_const_expressions_mutator, \
                            (void *) context)

Definition at line 2077 of file clauses.c.

Referenced by eval_const_expressions_mutator().

Function Documentation

add_function_defaults()

static List * add_function_defaults ( List *  args, HeapTuple  func_tuple  )

static

Definition at line 3868 of file clauses.c.

References elog, ERROR, fetch_function_defaults(), GETSTRUCT, list_concat_copy(), list_copy_tail(), and list_length().

Referenced by expand_function_arguments().

{
    Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
    int         nargsprovided = list_length(args);
    List       *defaults;
    int         ndelete;

    /* Get all the default expressions from the pg_proc tuple */
    defaults = fetch_function_defaults(func_tuple);

    /* Delete any unused defaults from the list */
    ndelete = nargsprovided + list_length(defaults) - funcform->pronargs;
    if (ndelete < 0)
        elog(ERROR, "not enough default arguments");
    if (ndelete > 0)
        defaults = list_copy_tail(defaults, ndelete);

    /* And form the combined argument list, not modifying the input list */
    return list_concat_copy(args, defaults);
}

CommuteOpExpr()

void CommuteOpExpr

(

OpExpr *

clause

)

Definition at line 1915 of file clauses.c.

References OpExpr::args, elog, ERROR, get_commutator(), InvalidOid, is_opclause(), linitial, list_length(), lsecond, OidIsValid, OpExpr::opfuncid, and OpExpr::opno.

Referenced by get_switched_clauses().

{
    Oid         opoid;
    Node       *temp;

    /* Sanity checks: caller is at fault if these fail */
    if (!is_opclause(clause) ||
        list_length(clause->args) != 2)
        elog(ERROR, "cannot commute non-binary-operator clause");

    opoid = get_commutator(clause->opno);

    if (!OidIsValid(opoid))
        elog(ERROR, "could not find commutator for operator %u",
             clause->opno);

    /*
     * modify the clause in-place!
     */
    clause->opno = opoid;
    clause->opfuncid = InvalidOid;
    /* opresulttype, opretset, opcollid, inputcollid need not change */

    temp = linitial(clause->args);
    linitial(clause->args) = lsecond(clause->args);
    lsecond(clause->args) = temp;
}

contain_agg_clause()

bool contain_agg_clause

(

Node *

clause

)

Definition at line 170 of file clauses.c.

References contain_agg_clause_walker().

Referenced by get_eclass_for_sort_expr(), and subquery_planner().

{
    return contain_agg_clause_walker(clause, NULL);
}

contain_agg_clause_walker()

static bool contain_agg_clause_walker ( Node *  node, void *  context  )

static

Definition at line 176 of file clauses.c.

References Assert, expression_tree_walker(), and IsA.

Referenced by contain_agg_clause().

{
    if (node == NULL)
        return false;
    if (IsA(node, Aggref))
    {
        Assert(((Aggref *) node)->agglevelsup == 0);
        return true;            /* abort the tree traversal and return true */
    }
    if (IsA(node, GroupingFunc))
    {
        Assert(((GroupingFunc *) node)->agglevelsup == 0);
        return true;            /* abort the tree traversal and return true */
    }
    Assert(!IsA(node, SubLink));
    return expression_tree_walker(node, contain_agg_clause_walker, context);
}

contain_context_dependent_node()

static bool contain_context_dependent_node ( Node *  clause )

static

Definition at line 993 of file clauses.c.

References contain_context_dependent_node_walker().

Referenced by inline_function().

{
    int         flags = 0;

    return contain_context_dependent_node_walker(clause, &flags);
}

contain_context_dependent_node_walker()

static bool contain_context_dependent_node_walker ( Node *  node, int *  flags  )

static

Definition at line 1003 of file clauses.c.

References ArrayCoerceExpr::arg, CaseExpr::arg, CCDN_CASETESTEXPR_OK, ArrayCoerceExpr::elemexpr, expression_tree_walker(), and IsA.

Referenced by contain_context_dependent_node().

{
    if (node == NULL)
        return false;
    if (IsA(node, CaseTestExpr))
        return !(*flags & CCDN_CASETESTEXPR_OK);
    else if (IsA(node, CaseExpr))
    {
        CaseExpr   *caseexpr = (CaseExpr *) node;

        /*
         * If this CASE doesn't have a test expression, then it doesn't create
         * a context in which CaseTestExprs should appear, so just fall
         * through and treat it as a generic expression node.
         */
        if (caseexpr->arg)
        {
            int         save_flags = *flags;
            bool        res;

            /*
             * Note: in principle, we could distinguish the various sub-parts
             * of a CASE construct and set the flag bit only for some of them,
             * since we are only expecting CaseTestExprs to appear in the
             * "expr" subtree of the CaseWhen nodes.  But it doesn't really
             * seem worth any extra code.  If there are any bare CaseTestExprs
             * elsewhere in the CASE, something's wrong already.
             */
            *flags |= CCDN_CASETESTEXPR_OK;
            res = expression_tree_walker(node,
                                         contain_context_dependent_node_walker,
                                         (void *) flags);
            *flags = save_flags;
            return res;
        }
    }
    else if (IsA(node, ArrayCoerceExpr))
    {
        ArrayCoerceExpr *ac = (ArrayCoerceExpr *) node;
        int         save_flags;
        bool        res;

        /* Check the array expression */
        if (contain_context_dependent_node_walker((Node *) ac->arg, flags))
            return true;

        /* Check the elemexpr, which is allowed to contain CaseTestExpr */
        save_flags = *flags;
        *flags |= CCDN_CASETESTEXPR_OK;
        res = contain_context_dependent_node_walker((Node *) ac->elemexpr,
                                                    flags);
        *flags = save_flags;
        return res;
    }
    return expression_tree_walker(node, contain_context_dependent_node_walker,
                                  (void *) flags);
}

contain_exec_param()

bool contain_exec_param	(	Node *	clause,
		List *	param_ids
	)

Definition at line 951 of file clauses.c.

References contain_exec_param_walker().

Referenced by test_opexpr_is_hashable().

{
    return contain_exec_param_walker(clause, param_ids);
}

contain_exec_param_walker()

static bool contain_exec_param_walker ( Node *  node, List *  param_ids  )

static

Definition at line 957 of file clauses.c.

References expression_tree_walker(), IsA, list_member_int(), PARAM_EXEC, Param::paramid, and Param::paramkind.

Referenced by contain_exec_param().

{
    if (node == NULL)
        return false;
    if (IsA(node, Param))
    {
        Param      *p = (Param *) node;

        if (p->paramkind == PARAM_EXEC &&
            list_member_int(param_ids, p->paramid))
            return true;
    }
    return expression_tree_walker(node, contain_exec_param_walker, param_ids);
}

contain_leaked_vars()

bool contain_leaked_vars

(

Node *

clause

)

Definition at line 1077 of file clauses.c.

References contain_leaked_vars_walker().

Referenced by make_restrictinfo_internal(), and qual_is_pushdown_safe().

{
    return contain_leaked_vars_walker(clause, NULL);
}

contain_leaked_vars_checker()

static bool contain_leaked_vars_checker ( Oid  func_id, void *  context  )

static

Definition at line 1083 of file clauses.c.

References get_func_leakproof().

Referenced by contain_leaked_vars_walker().

{
    return !get_func_leakproof(func_id);
}

contain_leaked_vars_walker()

static bool contain_leaked_vars_walker ( Node *  node, void *  context  )

static

Definition at line 1089 of file clauses.c.

References MinMaxExpr::args, check_functions_in_node(), TypeCacheEntry::cmp_proc, contain_leaked_vars_checker(), contain_var_clause(), expression_tree_walker(), SubscriptRoutines::fetch_leakproof, forthree, get_func_leakproof(), get_opcode(), getSubscriptingRoutines(), RowCompareExpr::largs, lfirst, lfirst_oid, lookup_type_cache(), MinMaxExpr::minmaxtype, nodeTag, OidIsValid, RowCompareExpr::opnos, RowCompareExpr::rargs, SubscriptingRef::refassgnexpr, SubscriptingRef::refcontainertype, SubscriptRoutines::store_leakproof, T_ArrayCoerceExpr, T_ArrayExpr, T_BooleanTest, T_BoolExpr, T_CaseExpr, T_CaseTestExpr, T_CoerceViaIO, T_CollateExpr, T_Const, T_CurrentOfExpr, T_DistinctExpr, T_FieldSelect, T_FieldStore, T_FuncExpr, T_List, T_MinMaxExpr, T_NamedArgExpr, T_NextValueExpr, T_NullIfExpr, T_NullTest, T_OpExpr, T_Param, T_RelabelType, T_RowCompareExpr, T_RowExpr, T_ScalarArrayOpExpr, T_SQLValueFunction, T_SubscriptingRef, T_Var, and TYPECACHE_CMP_PROC.

Referenced by contain_leaked_vars().

{
    if (node == NULL)
        return false;

    switch (nodeTag(node))
    {
        case T_Var:
        case T_Const:
        case T_Param:
        case T_ArrayExpr:
        case T_FieldSelect:
        case T_FieldStore:
        case T_NamedArgExpr:
        case T_BoolExpr:
        case T_RelabelType:
        case T_CollateExpr:
        case T_CaseExpr:
        case T_CaseTestExpr:
        case T_RowExpr:
        case T_SQLValueFunction:
        case T_NullTest:
        case T_BooleanTest:
        case T_NextValueExpr:
        case T_List:

            /*
             * We know these node types don't contain function calls; but
             * something further down in the node tree might.
             */
            break;

        case T_FuncExpr:
        case T_OpExpr:
        case T_DistinctExpr:
        case T_NullIfExpr:
        case T_ScalarArrayOpExpr:
        case T_CoerceViaIO:
        case T_ArrayCoerceExpr:

            /*
             * If node contains a leaky function call, and there's any Var
             * underneath it, reject.
             */
            if (check_functions_in_node(node, contain_leaked_vars_checker,
                                        context) &&
                contain_var_clause(node))
                return true;
            break;

        case T_SubscriptingRef:
            {
                SubscriptingRef *sbsref = (SubscriptingRef *) node;
                const SubscriptRoutines *sbsroutines;

                /* Consult the subscripting support method info */
                sbsroutines = getSubscriptingRoutines(sbsref->refcontainertype,
                                                      NULL);
                if (!sbsroutines ||
                    !(sbsref->refassgnexpr != NULL ?
                      sbsroutines->store_leakproof :
                      sbsroutines->fetch_leakproof))
                {
                    /* Node is leaky, so reject if it contains Vars */
                    if (contain_var_clause(node))
                        return true;
                }
            }
            break;

        case T_RowCompareExpr:
            {
                /*
                 * It's worth special-casing this because a leaky comparison
                 * function only compromises one pair of row elements, which
                 * might not contain Vars while others do.
                 */
                RowCompareExpr *rcexpr = (RowCompareExpr *) node;
                ListCell   *opid;
                ListCell   *larg;
                ListCell   *rarg;

                forthree(opid, rcexpr->opnos,
                         larg, rcexpr->largs,
                         rarg, rcexpr->rargs)
                {
                    Oid         funcid = get_opcode(lfirst_oid(opid));

                    if (!get_func_leakproof(funcid) &&
                        (contain_var_clause((Node *) lfirst(larg)) ||
                         contain_var_clause((Node *) lfirst(rarg))))
                        return true;
                }
            }
            break;

        case T_MinMaxExpr:
            {
                /*
                 * MinMaxExpr is leakproof if the comparison function it calls
                 * is leakproof.
                 */
                MinMaxExpr *minmaxexpr = (MinMaxExpr *) node;
                TypeCacheEntry *typentry;
                bool        leakproof;

                /* Look up the btree comparison function for the datatype */
                typentry = lookup_type_cache(minmaxexpr->minmaxtype,
                                             TYPECACHE_CMP_PROC);
                if (OidIsValid(typentry->cmp_proc))
                    leakproof = get_func_leakproof(typentry->cmp_proc);
                else
                {
                    /*
                     * The executor will throw an error, but here we just
                     * treat the missing function as leaky.
                     */
                    leakproof = false;
                }

                if (!leakproof &&
                    contain_var_clause((Node *) minmaxexpr->args))
                    return true;
            }
            break;

        case T_CurrentOfExpr:

            /*
             * WHERE CURRENT OF doesn't contain leaky function calls.
             * Moreover, it is essential that this is considered non-leaky,
             * since the planner must always generate a TID scan when CURRENT
             * OF is present -- cf. cost_tidscan.
             */
            return false;

        default:

            /*
             * If we don't recognize the node tag, assume it might be leaky.
             * This prevents an unexpected security hole if someone adds a new
             * node type that can call a function.
             */
            return true;
    }
    return expression_tree_walker(node, contain_leaked_vars_walker,
                                  context);
}

contain_mutable_functions()

bool contain_mutable_functions

(

Node *

clause

)

Definition at line 358 of file clauses.c.

References contain_mutable_functions_walker().

Referenced by can_minmax_aggs(), check_index_predicates(), CheckMutability(), ComputePartitionAttrs(), cookDefault(), create_bitmap_scan_plan(), create_indexscan_plan(), eval_const_expressions_mutator(), exec_save_simple_expr(), inline_function(), is_foreign_expr(), and relation_excluded_by_constraints().

{
    return contain_mutable_functions_walker(clause, NULL);
}

contain_mutable_functions_checker()

static bool contain_mutable_functions_checker ( Oid  func_id, void *  context  )

static

Definition at line 364 of file clauses.c.

References func_volatile().

Referenced by contain_mutable_functions_walker().

{
    return (func_volatile(func_id) != PROVOLATILE_IMMUTABLE);
}

contain_mutable_functions_walker()

static bool contain_mutable_functions_walker ( Node *  node, void *  context  )

static

Definition at line 370 of file clauses.c.

References check_functions_in_node(), contain_mutable_functions_checker(), expression_tree_walker(), IsA, and query_tree_walker().

Referenced by contain_mutable_functions().

{
    if (node == NULL)
        return false;
    /* Check for mutable functions in node itself */
    if (check_functions_in_node(node, contain_mutable_functions_checker,
                                context))
        return true;

    if (IsA(node, SQLValueFunction))
    {
        /* all variants of SQLValueFunction are stable */
        return true;
    }

    if (IsA(node, NextValueExpr))
    {
        /* NextValueExpr is volatile */
        return true;
    }

    /*
     * It should be safe to treat MinMaxExpr as immutable, because it will
     * depend on a non-cross-type btree comparison function, and those should
     * always be immutable.  Treating XmlExpr as immutable is more dubious,
     * and treating CoerceToDomain as immutable is outright dangerous.  But we
     * have done so historically, and changing this would probably cause more
     * problems than it would fix.  In practice, if you have a non-immutable
     * domain constraint you are in for pain anyhow.
     */

    /* Recurse to check arguments */
    if (IsA(node, Query))
    {
        /* Recurse into subselects */
        return query_tree_walker((Query *) node,
                                 contain_mutable_functions_walker,
                                 context, 0);
    }
    return expression_tree_walker(node, contain_mutable_functions_walker,
                                  context);
}

contain_non_const_walker()

static bool contain_non_const_walker ( Node *  node, void *  context  )

static

Definition at line 3325 of file clauses.c.

References expression_tree_walker(), and IsA.

{
    if (node == NULL)
        return false;
    if (IsA(node, Const))
        return false;
    if (IsA(node, List))
        return expression_tree_walker(node, contain_non_const_walker, context);
    /* Otherwise, abort the tree traversal and return true */
    return true;
}

contain_nonstrict_functions()

bool contain_nonstrict_functions

(

Node *

clause

)

Definition at line 807 of file clauses.c.

References contain_nonstrict_functions_walker().

Referenced by inline_function(), process_equivalence(), and pullup_replace_vars_callback().

{
    return contain_nonstrict_functions_walker(clause, NULL);
}

contain_nonstrict_functions_checker()

static bool contain_nonstrict_functions_checker ( Oid  func_id, void *  context  )

static

Definition at line 813 of file clauses.c.

References func_strict().

Referenced by contain_nonstrict_functions_walker().

{
    return !func_strict(func_id);
}

contain_nonstrict_functions_walker()

static bool contain_nonstrict_functions_walker ( Node *  node, void *  context  )

static

Definition at line 819 of file clauses.c.

References AND_EXPR, arg, BoolExpr::boolop, check_functions_in_node(), contain_nonstrict_functions_checker(), expression_tree_walker(), SubscriptRoutines::fetch_strict, getSubscriptingRoutines(), IsA, OR_EXPR, SubscriptingRef::refassgnexpr, and SubscriptingRef::refcontainertype.

Referenced by contain_nonstrict_functions().

{
    if (node == NULL)
        return false;
    if (IsA(node, Aggref))
    {
        /* an aggregate could return non-null with null input */
        return true;
    }
    if (IsA(node, GroupingFunc))
    {
        /*
         * A GroupingFunc doesn't evaluate its arguments, and therefore must
         * be treated as nonstrict.
         */
        return true;
    }
    if (IsA(node, WindowFunc))
    {
        /* a window function could return non-null with null input */
        return true;
    }
    if (IsA(node, SubscriptingRef))
    {
        SubscriptingRef *sbsref = (SubscriptingRef *) node;
        const SubscriptRoutines *sbsroutines;

        /* Subscripting assignment is always presumed nonstrict */
        if (sbsref->refassgnexpr != NULL)
            return true;
        /* Otherwise we must look up the subscripting support methods */
        sbsroutines = getSubscriptingRoutines(sbsref->refcontainertype, NULL);
        if (!(sbsroutines && sbsroutines->fetch_strict))
            return true;
        /* else fall through to check args */
    }
    if (IsA(node, DistinctExpr))
    {
        /* IS DISTINCT FROM is inherently non-strict */
        return true;
    }
    if (IsA(node, NullIfExpr))
    {
        /* NULLIF is inherently non-strict */
        return true;
    }
    if (IsA(node, BoolExpr))
    {
        BoolExpr   *expr = (BoolExpr *) node;

        switch (expr->boolop)
        {
            case AND_EXPR:
            case OR_EXPR:
                /* AND, OR are inherently non-strict */
                return true;
            default:
                break;
        }
    }
    if (IsA(node, SubLink))
    {
        /* In some cases a sublink might be strict, but in general not */
        return true;
    }
    if (IsA(node, SubPlan))
        return true;
    if (IsA(node, AlternativeSubPlan))
        return true;
    if (IsA(node, FieldStore))
        return true;
    if (IsA(node, CoerceViaIO))
    {
        /*
         * CoerceViaIO is strict regardless of whether the I/O functions are,
         * so just go look at its argument; asking check_functions_in_node is
         * useless expense and could deliver the wrong answer.
         */
        return contain_nonstrict_functions_walker((Node *) ((CoerceViaIO *) node)->arg,
                                                  context);
    }
    if (IsA(node, ArrayCoerceExpr))
    {
        /*
         * ArrayCoerceExpr is strict at the array level, regardless of what
         * the per-element expression is; so we should ignore elemexpr and
         * recurse only into the arg.
         */
        return contain_nonstrict_functions_walker((Node *) ((ArrayCoerceExpr *) node)->arg,
                                                  context);
    }
    if (IsA(node, CaseExpr))
        return true;
    if (IsA(node, ArrayExpr))
        return true;
    if (IsA(node, RowExpr))
        return true;
    if (IsA(node, RowCompareExpr))
        return true;
    if (IsA(node, CoalesceExpr))
        return true;
    if (IsA(node, MinMaxExpr))
        return true;
    if (IsA(node, XmlExpr))
        return true;
    if (IsA(node, NullTest))
        return true;
    if (IsA(node, BooleanTest))
        return true;

    /* Check other function-containing nodes */
    if (check_functions_in_node(node, contain_nonstrict_functions_checker,
                                context))
        return true;

    return expression_tree_walker(node, contain_nonstrict_functions_walker,
                                  context);
}

contain_subplans()

bool contain_subplans

(

Node *

clause

)

Definition at line 323 of file clauses.c.

References contain_subplans_walker().

Referenced by convert_EXISTS_to_ANY(), ExecInitValuesScan(), inline_function(), inline_set_returning_function(), qual_is_pushdown_safe(), and subquery_planner().

{
    return contain_subplans_walker(clause, NULL);
}

contain_subplans_walker()

static bool contain_subplans_walker ( Node *  node, void *  context  )

static

Definition at line 329 of file clauses.c.

References expression_tree_walker(), and IsA.

Referenced by contain_subplans().

{
    if (node == NULL)
        return false;
    if (IsA(node, SubPlan) ||
        IsA(node, AlternativeSubPlan) ||
        IsA(node, SubLink))
        return true;            /* abort the tree traversal and return true */
    return expression_tree_walker(node, contain_subplans_walker, context);
}

contain_volatile_functions()

bool contain_volatile_functions

(

Node *

clause

)

Definition at line 437 of file clauses.c.

References contain_volatile_functions_walker().

Referenced by AddRelationNewConstraints(), apply_child_basequals(), check_hashjoinable(), check_mergejoinable(), check_output_expressions(), compute_semijoin_info(), convert_ANY_sublink_to_join(), convert_EXISTS_sublink_to_join(), convert_EXISTS_to_ANY(), CopyFrom(), distribute_qual_to_rels(), estimate_num_groups(), ExecInitWindowAgg(), expand_indexqual_rowcompare(), find_compatible_agg(), get_eclass_for_sort_expr(), initialize_peragg(), inline_function(), inline_set_returning_function(), is_pseudo_constant_clause(), is_pseudo_constant_clause_relids(), is_pseudo_constant_for_index(), is_safe_restriction_clause_for(), is_simple_subquery(), is_simple_values(), IsBinaryTidClause(), IsTidEqualAnyClause(), make_sort_input_target(), match_clause_to_ordering_op(), match_clause_to_partition_key(), match_opclause_to_indexcol(), match_rowcompare_to_indexcol(), match_saopclause_to_indexcol(), process_implied_equality(), qual_is_pushdown_safe(), remove_unused_subquery_outputs(), SS_process_ctes(), and subquery_planner().

{
    return contain_volatile_functions_walker(clause, NULL);
}

contain_volatile_functions_checker()

static bool contain_volatile_functions_checker ( Oid  func_id, void *  context  )

static

Definition at line 443 of file clauses.c.

References func_volatile().

Referenced by contain_volatile_functions_walker().

{
    return (func_volatile(func_id) == PROVOLATILE_VOLATILE);
}

contain_volatile_functions_not_nextval()

bool contain_volatile_functions_not_nextval

(

Node *

clause

)

Definition at line 487 of file clauses.c.

References contain_volatile_functions_not_nextval_walker().

Referenced by BeginCopyFrom().

{
    return contain_volatile_functions_not_nextval_walker(clause, NULL);
}

contain_volatile_functions_not_nextval_checker()

static bool contain_volatile_functions_not_nextval_checker ( Oid  func_id, void *  context  )

static

Definition at line 493 of file clauses.c.

References func_volatile().

Referenced by contain_volatile_functions_not_nextval_walker().

{
    return (func_id != F_NEXTVAL &&
            func_volatile(func_id) == PROVOLATILE_VOLATILE);
}

contain_volatile_functions_not_nextval_walker()

static bool contain_volatile_functions_not_nextval_walker ( Node *  node, void *  context  )

static

Definition at line 500 of file clauses.c.

References check_functions_in_node(), contain_volatile_functions_not_nextval_checker(), expression_tree_walker(), IsA, and query_tree_walker().

Referenced by contain_volatile_functions_not_nextval().

{
    if (node == NULL)
        return false;
    /* Check for volatile functions in node itself */
    if (check_functions_in_node(node,
                                contain_volatile_functions_not_nextval_checker,
                                context))
        return true;

    /*
     * See notes in contain_mutable_functions_walker about why we treat
     * MinMaxExpr, XmlExpr, and CoerceToDomain as immutable, while
     * SQLValueFunction is stable.  Hence, none of them are of interest here.
     * Also, since we're intentionally ignoring nextval(), presumably we
     * should ignore NextValueExpr.
     */

    /* Recurse to check arguments */
    if (IsA(node, Query))
    {
        /* Recurse into subselects */
        return query_tree_walker((Query *) node,
                                 contain_volatile_functions_not_nextval_walker,
                                 context, 0);
    }
    return expression_tree_walker(node,
                                  contain_volatile_functions_not_nextval_walker,
                                  context);
}

contain_volatile_functions_walker()

static bool contain_volatile_functions_walker ( Node *  node, void *  context  )

static

Definition at line 449 of file clauses.c.

References check_functions_in_node(), contain_volatile_functions_checker(), expression_tree_walker(), IsA, and query_tree_walker().

Referenced by contain_volatile_functions().

{
    if (node == NULL)
        return false;
    /* Check for volatile functions in node itself */
    if (check_functions_in_node(node, contain_volatile_functions_checker,
                                context))
        return true;

    if (IsA(node, NextValueExpr))
    {
        /* NextValueExpr is volatile */
        return true;
    }

    /*
     * See notes in contain_mutable_functions_walker about why we treat
     * MinMaxExpr, XmlExpr, and CoerceToDomain as immutable, while
     * SQLValueFunction is stable.  Hence, none of them are of interest here.
     */

    /* Recurse to check arguments */
    if (IsA(node, Query))
    {
        /* Recurse into subselects */
        return query_tree_walker((Query *) node,
                                 contain_volatile_functions_walker,
                                 context, 0);
    }
    return expression_tree_walker(node, contain_volatile_functions_walker,
                                  context);
}

contain_window_function()

bool contain_window_function

(

Node *

clause

)

Definition at line 207 of file clauses.c.

References contain_windowfuncs().

Referenced by get_eclass_for_sort_expr(), and qual_is_pushdown_safe().

{
    return contain_windowfuncs(clause);
}

ece_function_is_safe()

static bool ece_function_is_safe ( Oid  funcid, eval_const_expressions_context *  context  )

static

Definition at line 3341 of file clauses.c.

References eval_const_expressions_context::estimate, and func_volatile().

Referenced by eval_const_expressions_mutator().

{
    char        provolatile = func_volatile(funcid);

    /*
     * Ordinarily we are only allowed to simplify immutable functions. But for
     * purposes of estimation, we consider it okay to simplify functions that
     * are merely stable; the risk that the result might change from planning
     * time to execution time is worth taking in preference to not being able
     * to estimate the value at all.
     */
    if (provolatile == PROVOLATILE_IMMUTABLE)
        return true;
    if (context->estimate && provolatile == PROVOLATILE_STABLE)
        return true;
    return false;
}

estimate_expression_value()

Node* estimate_expression_value	(	PlannerInfo *	root,
		Node *	node
	)

Definition at line 2055 of file clauses.c.

References eval_const_expressions_context::active_fns, eval_const_expressions_context::boundParams, PlannerGlobal::boundParams, eval_const_expressions_context::case_val, eval_const_expressions_context::estimate, eval_const_expressions_mutator(), PlannerInfo::glob, NIL, and eval_const_expressions_context::root.

Referenced by array_unnest_support(), bernoulli_samplescangetsamplesize(), clause_selectivity_ext(), generate_series_int4_support(), generate_series_int8_support(), get_restriction_variable(), gincost_opexpr(), gincost_scalararrayopexpr(), preprocess_limit(), scalararraysel(), system_rows_samplescangetsamplesize(), system_samplescangetsamplesize(), and system_time_samplescangetsamplesize().

{
    eval_const_expressions_context context;

    context.boundParams = root->glob->boundParams;  /* bound Params */
    /* we do not need to mark the plan as depending on inlined functions */
    context.root = NULL;
    context.active_fns = NIL;   /* nothing being recursively simplified */
    context.case_val = NULL;    /* no CASE being examined */
    context.estimate = true;    /* unsafe transformations OK */
    return eval_const_expressions_mutator(node, &context);
}

eval_const_expressions()

Node* eval_const_expressions	(	PlannerInfo *	root,
		Node *	node
	)

Definition at line 2022 of file clauses.c.

References eval_const_expressions_context::active_fns, eval_const_expressions_context::boundParams, PlannerGlobal::boundParams, eval_const_expressions_context::case_val, eval_const_expressions_context::estimate, eval_const_expressions_mutator(), PlannerInfo::glob, NIL, and eval_const_expressions_context::root.

Referenced by apply_child_basequals(), ATExecAttachPartition(), ConstraintImpliedByRelConstraint(), convert_EXISTS_to_ANY(), DoCopy(), expression_planner(), expression_planner_with_deps(), get_proposed_default_constraint(), get_relation_constraints(), preprocess_expression(), preprocess_function_rtes(), process_implied_equality(), RelationBuildPartitionKey(), RelationGetIndexExpressions(), RelationGetIndexPredicate(), and simplify_EXISTS_query().

{
    eval_const_expressions_context context;

    if (root)
        context.boundParams = root->glob->boundParams;  /* bound Params */
    else
        context.boundParams = NULL;
    context.root = root;        /* for inlined-function dependencies */
    context.active_fns = NIL;   /* nothing being recursively simplified */
    context.case_val = NULL;    /* no CASE being examined */
    context.estimate = false;   /* safe transformations only */
    return eval_const_expressions_mutator(node, &context);
}

eval_const_expressions_mutator()

static Node * eval_const_expressions_mutator ( Node *  node, eval_const_expressions_context *  context  )

static

Definition at line 2100 of file clauses.c.

References WindowFunc::aggfilter, AND_EXPR, applyRelabelType(), arg, FieldSelect::arg, RelabelType::arg, CoerceViaIO::arg, ArrayCoerceExpr::arg, ConvertRowtypeExpr::arg, CollateExpr::arg, CaseExpr::arg, NullTest::arg, BooleanTest::arg, CoerceToDomain::arg, NullTest::argisrow, generate_unaccent_rules::args, WindowFunc::args, FuncExpr::args, OpExpr::args, BoolExpr::args, CaseExpr::args, RowExpr::args, CoalesceExpr::args, Assert, BoolGetDatum, BoolExpr::boolop, BooleanTest::booltesttype, eval_const_expressions_context::boundParams, eval_const_expressions_context::case_val, CaseExpr::casecollid, CaseExpr::casetype, castNode, CoalesceExpr::coalescecollid, CoalesceExpr::coalescetype, COERCE_IMPLICIT_CAST, CoerceViaIO::coerceformat, CoerceToDomain::coercionformat, CollateExpr::collOid, Const::constisnull, Const::consttype, Const::constvalue, contain_mutable_functions(), ConvertRowtypeExpr::convertformat, copyObject, datumCopy(), DatumGetBool, CaseExpr::defresult, DomainHasConstraints(), ece_all_arguments_const, ece_evaluate_expr, ece_function_is_safe(), ece_generic_processing, ArrayCoerceExpr::elemexpr, elog, ERROR, eval_const_expressions_context::estimate, evaluate_expr(), expand_function_arguments(), CaseWhen::expr, exprCollation(), expression_tree_mutator(), exprType(), exprTypmod(), FieldSelect::fieldnum, FuncExpr::funccollid, FuncExpr::funcformat, FuncExpr::funcid, FuncExpr::funcresulttype, FuncExpr::funcretset, FuncExpr::funcvariadic, get_typlenbyval(), getTypeInputInfo(), getTypeOutputInfo(), HeapTupleIsValid, WindowFunc::inputcollid, FuncExpr::inputcollid, OpExpr::inputcollid, Int32GetDatum, InvalidAttrNumber, InvalidOid, IS_FALSE, IS_NOT_FALSE, IS_NOT_NULL, IS_NOT_TRUE, IS_NOT_UNKNOWN, IS_NULL, IS_TRUE, IS_UNKNOWN, IsA, ParamExternData::isnull, lappend(), lfirst, lfirst_node, linitial, list_length(), list_make1, list_make3, list_nth(), WindowFunc::location, FuncExpr::location, OpExpr::location, RelabelType::location, CoerceViaIO::location, ConvertRowtypeExpr::location, CollateExpr::location, CaseExpr::location, CaseWhen::location, CoalesceExpr::location, NullTest::location, BooleanTest::location, CoerceToDomain::location, make_andclause(), make_orclause(), makeBoolConst(), makeConst(), makeNode, makeNullConst(), makeVar(), negate_clause(), NIL, nodeTag, NOT_EXPR, NullTest::nulltesttype, ParamListInfoData::numParams, ObjectIdGetDatum, OidIsValid, OpExpr::opcollid, OpExpr::opfuncid, ScalarArrayOpExpr::opfuncid, OpExpr::opno, OpExpr::opresulttype, OpExpr::opretset, OR_EXPR, PARAM_EXTERN, PARAM_FLAG_CONST, Param::paramcollid, ParamListInfoData::paramFetch, Param::paramid, Param::paramkind, ParamListInfoData::params, Param::paramtype, Param::paramtypmod, ParamExternData::pflags, PlaceHolderVar::phexpr, PROCOID, ParamExternData::ptype, record_plan_type_dependency(), RelabelType::relabelformat, ReleaseSysCache(), CaseWhen::result, FieldSelect::resultcollid, RelabelType::resultcollid, CoerceViaIO::resultcollid, CoerceToDomain::resultcollid, FieldSelect::resulttype, RelabelType::resulttype, CoerceViaIO::resulttype, ConvertRowtypeExpr::resulttype, CoerceToDomain::resulttype, FieldSelect::resulttypmod, RelabelType::resulttypmod, CoerceToDomain::resulttypmod, eval_const_expressions_context::root, RowExpr::row_typeid, rowtype_field_matches(), SearchSysCache1(), set_opfuncid(), set_sa_opfuncid(), simplify_and_arguments(), simplify_boolean_equality(), simplify_function(), simplify_or_arguments(), T_AlternativeSubPlan, T_ArrayCoerceExpr, T_ArrayExpr, T_BooleanTest, T_BoolExpr, T_CaseExpr, T_CaseTestExpr, T_CoalesceExpr, T_CoerceToDomain, T_CoerceViaIO, T_CollateExpr, T_ConvertRowtypeExpr, T_DistinctExpr, T_FieldSelect, T_FuncExpr, T_MinMaxExpr, T_NullTest, T_OpExpr, T_Param, T_PlaceHolderVar, T_RelabelType, T_RowExpr, T_ScalarArrayOpExpr, T_SQLValueFunction, T_SubPlan, T_SubscriptingRef, T_WindowFunc, Expr::type, ParamExternData::value, WindowFunc::winagg, WindowFunc::wincollid, WindowFunc::winfnoid, WindowFunc::winref, WindowFunc::winstar, and WindowFunc::wintype.

Referenced by estimate_expression_value(), eval_const_expressions(), inline_function(), simplify_and_arguments(), simplify_function(), and simplify_or_arguments().

{
    if (node == NULL)
        return NULL;
    switch (nodeTag(node))
    {
        case T_Param:
            {
                Param      *param = (Param *) node;
                ParamListInfo paramLI = context->boundParams;

                /* Look to see if we've been given a value for this Param */
                if (param->paramkind == PARAM_EXTERN &&
                    paramLI != NULL &&
                    param->paramid > 0 &&
                    param->paramid <= paramLI->numParams)
                {
                    ParamExternData *prm;
                    ParamExternData prmdata;

                    /*
                     * Give hook a chance in case parameter is dynamic.  Tell
                     * it that this fetch is speculative, so it should avoid
                     * erroring out if parameter is unavailable.
                     */
                    if (paramLI->paramFetch != NULL)
                        prm = paramLI->paramFetch(paramLI, param->paramid,
                                                  true, &prmdata);
                    else
                        prm = &paramLI->params[param->paramid - 1];

                    /*
                     * We don't just check OidIsValid, but insist that the
                     * fetched type match the Param, just in case the hook did
                     * something unexpected.  No need to throw an error here
                     * though; leave that for runtime.
                     */
                    if (OidIsValid(prm->ptype) &&
                        prm->ptype == param->paramtype)
                    {
                        /* OK to substitute parameter value? */
                        if (context->estimate ||
                            (prm->pflags & PARAM_FLAG_CONST))
                        {
                            /*
                             * Return a Const representing the param value.
                             * Must copy pass-by-ref datatypes, since the
                             * Param might be in a memory context
                             * shorter-lived than our output plan should be.
                             */
                            int16       typLen;
                            bool        typByVal;
                            Datum       pval;

                            get_typlenbyval(param->paramtype,
                                            &typLen, &typByVal);
                            if (prm->isnull || typByVal)
                                pval = prm->value;
                            else
                                pval = datumCopy(prm->value, typByVal, typLen);
                            return (Node *) makeConst(param->paramtype,
                                                      param->paramtypmod,
                                                      param->paramcollid,
                                                      (int) typLen,
                                                      pval,
                                                      prm->isnull,
                                                      typByVal);
                        }
                    }
                }

                /*
                 * Not replaceable, so just copy the Param (no need to
                 * recurse)
                 */
                return (Node *) copyObject(param);
            }
        case T_WindowFunc:
            {
                WindowFunc *expr = (WindowFunc *) node;
                Oid         funcid = expr->winfnoid;
                List       *args;
                Expr       *aggfilter;
                HeapTuple   func_tuple;
                WindowFunc *newexpr;

                /*
                 * We can't really simplify a WindowFunc node, but we mustn't
                 * just fall through to the default processing, because we
                 * have to apply expand_function_arguments to its argument
                 * list.  That takes care of inserting default arguments and
                 * expanding named-argument notation.
                 */
                func_tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
                if (!HeapTupleIsValid(func_tuple))
                    elog(ERROR, "cache lookup failed for function %u", funcid);

                args = expand_function_arguments(expr->args, expr->wintype,
                                                 func_tuple);

                ReleaseSysCache(func_tuple);

                /* Now, recursively simplify the args (which are a List) */
                args = (List *)
                    expression_tree_mutator((Node *) args,
                                            eval_const_expressions_mutator,
                                            (void *) context);
                /* ... and the filter expression, which isn't */
                aggfilter = (Expr *)
                    eval_const_expressions_mutator((Node *) expr->aggfilter,
                                                   context);

                /* And build the replacement WindowFunc node */
                newexpr = makeNode(WindowFunc);
                newexpr->winfnoid = expr->winfnoid;
                newexpr->wintype = expr->wintype;
                newexpr->wincollid = expr->wincollid;
                newexpr->inputcollid = expr->inputcollid;
                newexpr->args = args;
                newexpr->aggfilter = aggfilter;
                newexpr->winref = expr->winref;
                newexpr->winstar = expr->winstar;
                newexpr->winagg = expr->winagg;
                newexpr->location = expr->location;

                return (Node *) newexpr;
            }
        case T_FuncExpr:
            {
                FuncExpr   *expr = (FuncExpr *) node;
                List       *args = expr->args;
                Expr       *simple;
                FuncExpr   *newexpr;

                /*
                 * Code for op/func reduction is pretty bulky, so split it out
                 * as a separate function.  Note: exprTypmod normally returns
                 * -1 for a FuncExpr, but not when the node is recognizably a
                 * length coercion; we want to preserve the typmod in the
                 * eventual Const if so.
                 */
                simple = simplify_function(expr->funcid,
                                           expr->funcresulttype,
                                           exprTypmod(node),
                                           expr->funccollid,
                                           expr->inputcollid,
                                           &args,
                                           expr->funcvariadic,
                                           true,
                                           true,
                                           context);
                if (simple)     /* successfully simplified it */
                    return (Node *) simple;

                /*
                 * The expression cannot be simplified any further, so build
                 * and return a replacement FuncExpr node using the
                 * possibly-simplified arguments.  Note that we have also
                 * converted the argument list to positional notation.
                 */
                newexpr = makeNode(FuncExpr);
                newexpr->funcid = expr->funcid;
                newexpr->funcresulttype = expr->funcresulttype;
                newexpr->funcretset = expr->funcretset;
                newexpr->funcvariadic = expr->funcvariadic;
                newexpr->funcformat = expr->funcformat;
                newexpr->funccollid = expr->funccollid;
                newexpr->inputcollid = expr->inputcollid;
                newexpr->args = args;
                newexpr->location = expr->location;
                return (Node *) newexpr;
            }
        case T_OpExpr:
            {
                OpExpr     *expr = (OpExpr *) node;
                List       *args = expr->args;
                Expr       *simple;
                OpExpr     *newexpr;

                /*
                 * Need to get OID of underlying function.  Okay to scribble
                 * on input to this extent.
                 */
                set_opfuncid(expr);

                /*
                 * Code for op/func reduction is pretty bulky, so split it out
                 * as a separate function.
                 */
                simple = simplify_function(expr->opfuncid,
                                           expr->opresulttype, -1,
                                           expr->opcollid,
                                           expr->inputcollid,
                                           &args,
                                           false,
                                           true,
                                           true,
                                           context);
                if (simple)     /* successfully simplified it */
                    return (Node *) simple;

                /*
                 * If the operator is boolean equality or inequality, we know
                 * how to simplify cases involving one constant and one
                 * non-constant argument.
                 */
                if (expr->opno == BooleanEqualOperator ||
                    expr->opno == BooleanNotEqualOperator)
                {
                    simple = (Expr *) simplify_boolean_equality(expr->opno,
                                                                args);
                    if (simple) /* successfully simplified it */
                        return (Node *) simple;
                }

                /*
                 * The expression cannot be simplified any further, so build
                 * and return a replacement OpExpr node using the
                 * possibly-simplified arguments.
                 */
                newexpr = makeNode(OpExpr);
                newexpr->opno = expr->opno;
                newexpr->opfuncid = expr->opfuncid;
                newexpr->opresulttype = expr->opresulttype;
                newexpr->opretset = expr->opretset;
                newexpr->opcollid = expr->opcollid;
                newexpr->inputcollid = expr->inputcollid;
                newexpr->args = args;
                newexpr->location = expr->location;
                return (Node *) newexpr;
            }
        case T_DistinctExpr:
            {
                DistinctExpr *expr = (DistinctExpr *) node;
                List       *args;
                ListCell   *arg;
                bool        has_null_input = false;
                bool        all_null_input = true;
                bool        has_nonconst_input = false;
                Expr       *simple;
                DistinctExpr *newexpr;

                /*
                 * Reduce constants in the DistinctExpr's arguments.  We know
                 * args is either NIL or a List node, so we can call
                 * expression_tree_mutator directly rather than recursing to
                 * self.
                 */
                args = (List *) expression_tree_mutator((Node *) expr->args,
                                                        eval_const_expressions_mutator,
                                                        (void *) context);

                /*
                 * We must do our own check for NULLs because DistinctExpr has
                 * different results for NULL input than the underlying
                 * operator does.
                 */
                foreach(arg, args)
                {
                    if (IsA(lfirst(arg), Const))
                    {
                        has_null_input |= ((Const *) lfirst(arg))->constisnull;
                        all_null_input &= ((Const *) lfirst(arg))->constisnull;
                    }
                    else
                        has_nonconst_input = true;
                }

                /* all constants? then can optimize this out */
                if (!has_nonconst_input)
                {
                    /* all nulls? then not distinct */
                    if (all_null_input)
                        return makeBoolConst(false, false);

                    /* one null? then distinct */
                    if (has_null_input)
                        return makeBoolConst(true, false);

                    /* otherwise try to evaluate the '=' operator */
                    /* (NOT okay to try to inline it, though!) */

                    /*
                     * Need to get OID of underlying function.  Okay to
                     * scribble on input to this extent.
                     */
                    set_opfuncid((OpExpr *) expr);  /* rely on struct
                                                     * equivalence */

                    /*
                     * Code for op/func reduction is pretty bulky, so split it
                     * out as a separate function.
                     */
                    simple = simplify_function(expr->opfuncid,
                                               expr->opresulttype, -1,
                                               expr->opcollid,
                                               expr->inputcollid,
                                               &args,
                                               false,
                                               false,
                                               false,
                                               context);
                    if (simple) /* successfully simplified it */
                    {
                        /*
                         * Since the underlying operator is "=", must negate
                         * its result
                         */
                        Const      *csimple = castNode(Const, simple);

                        csimple->constvalue =
                            BoolGetDatum(!DatumGetBool(csimple->constvalue));
                        return (Node *) csimple;
                    }
                }

                /*
                 * The expression cannot be simplified any further, so build
                 * and return a replacement DistinctExpr node using the
                 * possibly-simplified arguments.
                 */
                newexpr = makeNode(DistinctExpr);
                newexpr->opno = expr->opno;
                newexpr->opfuncid = expr->opfuncid;
                newexpr->opresulttype = expr->opresulttype;
                newexpr->opretset = expr->opretset;
                newexpr->opcollid = expr->opcollid;
                newexpr->inputcollid = expr->inputcollid;
                newexpr->args = args;
                newexpr->location = expr->location;
                return (Node *) newexpr;
            }
        case T_ScalarArrayOpExpr:
            {
                ScalarArrayOpExpr *saop;

                /* Copy the node and const-simplify its arguments */
                saop = (ScalarArrayOpExpr *) ece_generic_processing(node);

                /* Make sure we know underlying function */
                set_sa_opfuncid(saop);

                /*
                 * If all arguments are Consts, and it's a safe function, we
                 * can fold to a constant
                 */
                if (ece_all_arguments_const(saop) &&
                    ece_function_is_safe(saop->opfuncid, context))
                    return ece_evaluate_expr(saop);
                return (Node *) saop;
            }
        case T_BoolExpr:
            {
                BoolExpr   *expr = (BoolExpr *) node;

                switch (expr->boolop)
                {
                    case OR_EXPR:
                        {
                            List       *newargs;
                            bool        haveNull = false;
                            bool        forceTrue = false;

                            newargs = simplify_or_arguments(expr->args,
                                                            context,
                                                            &haveNull,
                                                            &forceTrue);
                            if (forceTrue)
                                return makeBoolConst(true, false);
                            if (haveNull)
                                newargs = lappend(newargs,
                                                  makeBoolConst(false, true));
                            /* If all the inputs are FALSE, result is FALSE */
                            if (newargs == NIL)
                                return makeBoolConst(false, false);

                            /*
                             * If only one nonconst-or-NULL input, it's the
                             * result
                             */
                            if (list_length(newargs) == 1)
                                return (Node *) linitial(newargs);
                            /* Else we still need an OR node */
                            return (Node *) make_orclause(newargs);
                        }
                    case AND_EXPR:
                        {
                            List       *newargs;
                            bool        haveNull = false;
                            bool        forceFalse = false;

                            newargs = simplify_and_arguments(expr->args,
                                                             context,
                                                             &haveNull,
                                                             &forceFalse);
                            if (forceFalse)
                                return makeBoolConst(false, false);
                            if (haveNull)
                                newargs = lappend(newargs,
                                                  makeBoolConst(false, true));
                            /* If all the inputs are TRUE, result is TRUE */
                            if (newargs == NIL)
                                return makeBoolConst(true, false);

                            /*
                             * If only one nonconst-or-NULL input, it's the
                             * result
                             */
                            if (list_length(newargs) == 1)
                                return (Node *) linitial(newargs);
                            /* Else we still need an AND node */
                            return (Node *) make_andclause(newargs);
                        }
                    case NOT_EXPR:
                        {
                            Node       *arg;

                            Assert(list_length(expr->args) == 1);
                            arg = eval_const_expressions_mutator(linitial(expr->args),
                                                                 context);

                            /*
                             * Use negate_clause() to see if we can simplify
                             * away the NOT.
                             */
                            return negate_clause(arg);
                        }
                    default:
                        elog(ERROR, "unrecognized boolop: %d",
                             (int) expr->boolop);
                        break;
                }
                break;
            }
        case T_SubPlan:
        case T_AlternativeSubPlan:

            /*
             * Return a SubPlan unchanged --- too late to do anything with it.
             *
             * XXX should we ereport() here instead?  Probably this routine
             * should never be invoked after SubPlan creation.
             */
            return node;
        case T_RelabelType:
            {
                RelabelType *relabel = (RelabelType *) node;
                Node       *arg;

                /* Simplify the input ... */
                arg = eval_const_expressions_mutator((Node *) relabel->arg,
                                                     context);
                /* ... and attach a new RelabelType node, if needed */
                return applyRelabelType(arg,
                                        relabel->resulttype,
                                        relabel->resulttypmod,
                                        relabel->resultcollid,
                                        relabel->relabelformat,
                                        relabel->location,
                                        true);
            }
        case T_CoerceViaIO:
            {
                CoerceViaIO *expr = (CoerceViaIO *) node;
                List       *args;
                Oid         outfunc;
                bool        outtypisvarlena;
                Oid         infunc;
                Oid         intypioparam;
                Expr       *simple;
                CoerceViaIO *newexpr;

                /* Make a List so we can use simplify_function */
                args = list_make1(expr->arg);

                /*
                 * CoerceViaIO represents calling the source type's output
                 * function then the result type's input function.  So, try to
                 * simplify it as though it were a stack of two such function
                 * calls.  First we need to know what the functions are.
                 *
                 * Note that the coercion functions are assumed not to care
                 * about input collation, so we just pass InvalidOid for that.
                 */
                getTypeOutputInfo(exprType((Node *) expr->arg),
                                  &outfunc, &outtypisvarlena);
                getTypeInputInfo(expr->resulttype,
                                 &infunc, &intypioparam);

                simple = simplify_function(outfunc,
                                           CSTRINGOID, -1,
                                           InvalidOid,
                                           InvalidOid,
                                           &args,
                                           false,
                                           true,
                                           true,
                                           context);
                if (simple)     /* successfully simplified output fn */
                {
                    /*
                     * Input functions may want 1 to 3 arguments.  We always
                     * supply all three, trusting that nothing downstream will
                     * complain.
                     */
                    args = list_make3(simple,
                                      makeConst(OIDOID,
                                                -1,
                                                InvalidOid,
                                                sizeof(Oid),
                                                ObjectIdGetDatum(intypioparam),
                                                false,
                                                true),
                                      makeConst(INT4OID,
                                                -1,
                                                InvalidOid,
                                                sizeof(int32),
                                                Int32GetDatum(-1),
                                                false,
                                                true));

                    simple = simplify_function(infunc,
                                               expr->resulttype, -1,
                                               expr->resultcollid,
                                               InvalidOid,
                                               &args,
                                               false,
                                               false,
                                               true,
                                               context);
                    if (simple) /* successfully simplified input fn */
                        return (Node *) simple;
                }

                /*
                 * The expression cannot be simplified any further, so build
                 * and return a replacement CoerceViaIO node using the
                 * possibly-simplified argument.
                 */
                newexpr = makeNode(CoerceViaIO);
                newexpr->arg = (Expr *) linitial(args);
                newexpr->resulttype = expr->resulttype;
                newexpr->resultcollid = expr->resultcollid;
                newexpr->coerceformat = expr->coerceformat;
                newexpr->location = expr->location;
                return (Node *) newexpr;
            }
        case T_ArrayCoerceExpr:
            {
                ArrayCoerceExpr *ac = makeNode(ArrayCoerceExpr);
                Node       *save_case_val;

                /*
                 * Copy the node and const-simplify its arguments.  We can't
                 * use ece_generic_processing() here because we need to mess
                 * with case_val only while processing the elemexpr.
                 */
                memcpy(ac, node, sizeof(ArrayCoerceExpr));
                ac->arg = (Expr *)
                    eval_const_expressions_mutator((Node *) ac->arg,
                                                   context);

                /*
                 * Set up for the CaseTestExpr node contained in the elemexpr.
                 * We must prevent it from absorbing any outer CASE value.
                 */
                save_case_val = context->case_val;
                context->case_val = NULL;

                ac->elemexpr = (Expr *)
                    eval_const_expressions_mutator((Node *) ac->elemexpr,
                                                   context);

                context->case_val = save_case_val;

                /*
                 * If constant argument and the per-element expression is
                 * immutable, we can simplify the whole thing to a constant.
                 * Exception: although contain_mutable_functions considers
                 * CoerceToDomain immutable for historical reasons, let's not
                 * do so here; this ensures coercion to an array-over-domain
                 * does not apply the domain's constraints until runtime.
                 */
                if (ac->arg && IsA(ac->arg, Const) &&
                    ac->elemexpr && !IsA(ac->elemexpr, CoerceToDomain) &&
                    !contain_mutable_functions((Node *) ac->elemexpr))
                    return ece_evaluate_expr(ac);

                return (Node *) ac;
            }
        case T_CollateExpr:
            {
                /*
                 * We replace CollateExpr with RelabelType, so as to improve
                 * uniformity of expression representation and thus simplify
                 * comparison of expressions.  Hence this looks very nearly
                 * the same as the RelabelType case, and we can apply the same
                 * optimizations to avoid unnecessary RelabelTypes.
                 */
                CollateExpr *collate = (CollateExpr *) node;
                Node       *arg;

                /* Simplify the input ... */
                arg = eval_const_expressions_mutator((Node *) collate->arg,
                                                     context);
                /* ... and attach a new RelabelType node, if needed */
                return applyRelabelType(arg,
                                        exprType(arg),
                                        exprTypmod(arg),
                                        collate->collOid,
                                        COERCE_IMPLICIT_CAST,
                                        collate->location,
                                        true);
            }
        case T_CaseExpr:
            {
                /*----------
                 * CASE expressions can be simplified if there are constant
                 * condition clauses:
                 *      FALSE (or NULL): drop the alternative
                 *      TRUE: drop all remaining alternatives
                 * If the first non-FALSE alternative is a constant TRUE,
                 * we can simplify the entire CASE to that alternative's
                 * expression.  If there are no non-FALSE alternatives,
                 * we simplify the entire CASE to the default result (ELSE).
                 *
                 * If we have a simple-form CASE with constant test
                 * expression, we substitute the constant value for contained
                 * CaseTestExpr placeholder nodes, so that we have the
                 * opportunity to reduce constant test conditions.  For
                 * example this allows
                 *      CASE 0 WHEN 0 THEN 1 ELSE 1/0 END
                 * to reduce to 1 rather than drawing a divide-by-0 error.
                 * Note that when the test expression is constant, we don't
                 * have to include it in the resulting CASE; for example
                 *      CASE 0 WHEN x THEN y ELSE z END
                 * is transformed by the parser to
                 *      CASE 0 WHEN CaseTestExpr = x THEN y ELSE z END
                 * which we can simplify to
                 *      CASE WHEN 0 = x THEN y ELSE z END
                 * It is not necessary for the executor to evaluate the "arg"
                 * expression when executing the CASE, since any contained
                 * CaseTestExprs that might have referred to it will have been
                 * replaced by the constant.
                 *----------
                 */
                CaseExpr   *caseexpr = (CaseExpr *) node;
                CaseExpr   *newcase;
                Node       *save_case_val;
                Node       *newarg;
                List       *newargs;
                bool        const_true_cond;
                Node       *defresult = NULL;
                ListCell   *arg;

                /* Simplify the test expression, if any */
                newarg = eval_const_expressions_mutator((Node *) caseexpr->arg,
                                                        context);

                /* Set up for contained CaseTestExpr nodes */
                save_case_val = context->case_val;
                if (newarg && IsA(newarg, Const))
                {
                    context->case_val = newarg;
                    newarg = NULL;  /* not needed anymore, see above */
                }
                else
                    context->case_val = NULL;

                /* Simplify the WHEN clauses */
                newargs = NIL;
                const_true_cond = false;
                foreach(arg, caseexpr->args)
                {
                    CaseWhen   *oldcasewhen = lfirst_node(CaseWhen, arg);
                    Node       *casecond;
                    Node       *caseresult;

                    /* Simplify this alternative's test condition */
                    casecond = eval_const_expressions_mutator((Node *) oldcasewhen->expr,
                                                              context);

                    /*
                     * If the test condition is constant FALSE (or NULL), then
                     * drop this WHEN clause completely, without processing
                     * the result.
                     */
                    if (casecond && IsA(casecond, Const))
                    {
                        Const      *const_input = (Const *) casecond;

                        if (const_input->constisnull ||
                            !DatumGetBool(const_input->constvalue))
                            continue;   /* drop alternative with FALSE cond */
                        /* Else it's constant TRUE */
                        const_true_cond = true;
                    }

                    /* Simplify this alternative's result value */
                    caseresult = eval_const_expressions_mutator((Node *) oldcasewhen->result,
                                                                context);

                    /* If non-constant test condition, emit a new WHEN node */
                    if (!const_true_cond)
                    {
                        CaseWhen   *newcasewhen = makeNode(CaseWhen);

                        newcasewhen->expr = (Expr *) casecond;
                        newcasewhen->result = (Expr *) caseresult;
                        newcasewhen->location = oldcasewhen->location;
                        newargs = lappend(newargs, newcasewhen);
                        continue;
                    }

                    /*
                     * Found a TRUE condition, so none of the remaining
                     * alternatives can be reached.  We treat the result as
                     * the default result.
                     */
                    defresult = caseresult;
                    break;
                }

                /* Simplify the default result, unless we replaced it above */
                if (!const_true_cond)
                    defresult = eval_const_expressions_mutator((Node *) caseexpr->defresult,
                                                               context);

                context->case_val = save_case_val;

                /*
                 * If no non-FALSE alternatives, CASE reduces to the default
                 * result
                 */
                if (newargs == NIL)
                    return defresult;
                /* Otherwise we need a new CASE node */
                newcase = makeNode(CaseExpr);
                newcase->casetype = caseexpr->casetype;
                newcase->casecollid = caseexpr->casecollid;
                newcase->arg = (Expr *) newarg;
                newcase->args = newargs;
                newcase->defresult = (Expr *) defresult;
                newcase->location = caseexpr->location;
                return (Node *) newcase;
            }
        case T_CaseTestExpr:
            {
                /*
                 * If we know a constant test value for the current CASE
                 * construct, substitute it for the placeholder.  Else just
                 * return the placeholder as-is.
                 */
                if (context->case_val)
                    return copyObject(context->case_val);
                else
                    return copyObject(node);
            }
        case T_SubscriptingRef:
        case T_ArrayExpr:
        case T_RowExpr:
        case T_MinMaxExpr:
            {
                /*
                 * Generic handling for node types whose own processing is
                 * known to be immutable, and for which we need no smarts
                 * beyond "simplify if all inputs are constants".
                 *
                 * Treating SubscriptingRef this way assumes that subscripting
                 * fetch and assignment are both immutable.  This constrains
                 * type-specific subscripting implementations; maybe we should
                 * relax it someday.
                 *
                 * Treating MinMaxExpr this way amounts to assuming that the
                 * btree comparison function it calls is immutable; see the
                 * reasoning in contain_mutable_functions_walker.
                 */

                /* Copy the node and const-simplify its arguments */
                node = ece_generic_processing(node);
                /* If all arguments are Consts, we can fold to a constant */
                if (ece_all_arguments_const(node))
                    return ece_evaluate_expr(node);
                return node;
            }
        case T_CoalesceExpr:
            {
                CoalesceExpr *coalesceexpr = (CoalesceExpr *) node;
                CoalesceExpr *newcoalesce;
                List       *newargs;
                ListCell   *arg;

                newargs = NIL;
                foreach(arg, coalesceexpr->args)
                {
                    Node       *e;

                    e = eval_const_expressions_mutator((Node *) lfirst(arg),
                                                       context);

                    /*
                     * We can remove null constants from the list. For a
                     * non-null constant, if it has not been preceded by any
                     * other non-null-constant expressions then it is the
                     * result. Otherwise, it's the next argument, but we can
                     * drop following arguments since they will never be
                     * reached.
                     */
                    if (IsA(e, Const))
                    {
                        if (((Const *) e)->constisnull)
                            continue;   /* drop null constant */
                        if (newargs == NIL)
                            return e;   /* first expr */
                        newargs = lappend(newargs, e);
                        break;
                    }
                    newargs = lappend(newargs, e);
                }

                /*
                 * If all the arguments were constant null, the result is just
                 * null
                 */
                if (newargs == NIL)
                    return (Node *) makeNullConst(coalesceexpr->coalescetype,
                                                  -1,
                                                  coalesceexpr->coalescecollid);

                newcoalesce = makeNode(CoalesceExpr);
                newcoalesce->coalescetype = coalesceexpr->coalescetype;
                newcoalesce->coalescecollid = coalesceexpr->coalescecollid;
                newcoalesce->args = newargs;
                newcoalesce->location = coalesceexpr->location;
                return (Node *) newcoalesce;
            }
        case T_SQLValueFunction:
            {
                /*
                 * All variants of SQLValueFunction are stable, so if we are
                 * estimating the expression's value, we should evaluate the
                 * current function value.  Otherwise just copy.
                 */
                SQLValueFunction *svf = (SQLValueFunction *) node;

                if (context->estimate)
                    return (Node *) evaluate_expr((Expr *) svf,
                                                  svf->type,
                                                  svf->typmod,
                                                  InvalidOid);
                else
                    return copyObject((Node *) svf);
            }
        case T_FieldSelect:
            {
                /*
                 * We can optimize field selection from a whole-row Var into a
                 * simple Var.  (This case won't be generated directly by the
                 * parser, because ParseComplexProjection short-circuits it.
                 * But it can arise while simplifying functions.)  Also, we
                 * can optimize field selection from a RowExpr construct, or
                 * of course from a constant.
                 *
                 * However, replacing a whole-row Var in this way has a
                 * pitfall: if we've already built the rel targetlist for the
                 * source relation, then the whole-row Var is scheduled to be
                 * produced by the relation scan, but the simple Var probably
                 * isn't, which will lead to a failure in setrefs.c.  This is
                 * not a problem when handling simple single-level queries, in
                 * which expression simplification always happens first.  It
                 * is a risk for lateral references from subqueries, though.
                 * To avoid such failures, don't optimize uplevel references.
                 *
                 * We must also check that the declared type of the field is
                 * still the same as when the FieldSelect was created --- this
                 * can change if someone did ALTER COLUMN TYPE on the rowtype.
                 * If it isn't, we skip the optimization; the case will
                 * probably fail at runtime, but that's not our problem here.
                 */
                FieldSelect *fselect = (FieldSelect *) node;
                FieldSelect *newfselect;
                Node       *arg;

                arg = eval_const_expressions_mutator((Node *) fselect->arg,
                                                     context);
                if (arg && IsA(arg, Var) &&
                    ((Var *) arg)->varattno == InvalidAttrNumber &&
                    ((Var *) arg)->varlevelsup == 0)
                {
                    if (rowtype_field_matches(((Var *) arg)->vartype,
                                              fselect->fieldnum,
                                              fselect->resulttype,
                                              fselect->resulttypmod,
                                              fselect->resultcollid))
                        return (Node *) makeVar(((Var *) arg)->varno,
                                                fselect->fieldnum,
                                                fselect->resulttype,
                                                fselect->resulttypmod,
                                                fselect->resultcollid,
                                                ((Var *) arg)->varlevelsup);
                }
                if (arg && IsA(arg, RowExpr))
                {
                    RowExpr    *rowexpr = (RowExpr *) arg;

                    if (fselect->fieldnum > 0 &&
                        fselect->fieldnum <= list_length(rowexpr->args))
                    {
                        Node       *fld = (Node *) list_nth(rowexpr->args,
                                                            fselect->fieldnum - 1);

                        if (rowtype_field_matches(rowexpr->row_typeid,
                                                  fselect->fieldnum,
                                                  fselect->resulttype,
                                                  fselect->resulttypmod,
                                                  fselect->resultcollid) &&
                            fselect->resulttype == exprType(fld) &&
                            fselect->resulttypmod == exprTypmod(fld) &&
                            fselect->resultcollid == exprCollation(fld))
                            return fld;
                    }
                }
                newfselect = makeNode(FieldSelect);
                newfselect->arg = (Expr *) arg;
                newfselect->fieldnum = fselect->fieldnum;
                newfselect->resulttype = fselect->resulttype;
                newfselect->resulttypmod = fselect->resulttypmod;
                newfselect->resultcollid = fselect->resultcollid;
                if (arg && IsA(arg, Const))
                {
                    Const      *con = (Const *) arg;

                    if (rowtype_field_matches(con->consttype,
                                              newfselect->fieldnum,
                                              newfselect->resulttype,
                                              newfselect->resulttypmod,
                                              newfselect->resultcollid))
                        return ece_evaluate_expr(newfselect);
                }
                return (Node *) newfselect;
            }
        case T_NullTest:
            {
                NullTest   *ntest = (NullTest *) node;
                NullTest   *newntest;
                Node       *arg;

                arg = eval_const_expressions_mutator((Node *) ntest->arg,
                                                     context);
                if (ntest->argisrow && arg && IsA(arg, RowExpr))
                {
                    /*
                     * We break ROW(...) IS [NOT] NULL into separate tests on
                     * its component fields.  This form is usually more
                     * efficient to evaluate, as well as being more amenable
                     * to optimization.
                     */
                    RowExpr    *rarg = (RowExpr *) arg;
                    List       *newargs = NIL;
                    ListCell   *l;

                    foreach(l, rarg->args)
                    {
                        Node       *relem = (Node *) lfirst(l);

                        /*
                         * A constant field refutes the whole NullTest if it's
                         * of the wrong nullness; else we can discard it.
                         */
                        if (relem && IsA(relem, Const))
                        {
                            Const      *carg = (Const *) relem;

                            if (carg->constisnull ?
                                (ntest->nulltesttype == IS_NOT_NULL) :
                                (ntest->nulltesttype == IS_NULL))
                                return makeBoolConst(false, false);
                            continue;
                        }

                        /*
                         * Else, make a scalar (argisrow == false) NullTest
                         * for this field.  Scalar semantics are required
                         * because IS [NOT] NULL doesn't recurse; see comments
                         * in ExecEvalRowNullInt().
                         */
                        newntest = makeNode(NullTest);
                        newntest->arg = (Expr *) relem;
                        newntest->nulltesttype = ntest->nulltesttype;
                        newntest->argisrow = false;
                        newntest->location = ntest->location;
                        newargs = lappend(newargs, newntest);
                    }
                    /* If all the inputs were constants, result is TRUE */
                    if (newargs == NIL)
                        return makeBoolConst(true, false);
                    /* If only one nonconst input, it's the result */
                    if (list_length(newargs) == 1)
                        return (Node *) linitial(newargs);
                    /* Else we need an AND node */
                    return (Node *) make_andclause(newargs);
                }
                if (!ntest->argisrow && arg && IsA(arg, Const))
                {
                    Const      *carg = (Const *) arg;
                    bool        result;

                    switch (ntest->nulltesttype)
                    {
                        case IS_NULL:
                            result = carg->constisnull;
                            break;
                        case IS_NOT_NULL:
                            result = !carg->constisnull;
                            break;
                        default:
                            elog(ERROR, "unrecognized nulltesttype: %d",
                                 (int) ntest->nulltesttype);
                            result = false; /* keep compiler quiet */
                            break;
                    }

                    return makeBoolConst(result, false);
                }

                newntest = makeNode(NullTest);
                newntest->arg = (Expr *) arg;
                newntest->nulltesttype = ntest->nulltesttype;
                newntest->argisrow = ntest->argisrow;
                newntest->location = ntest->location;
                return (Node *) newntest;
            }
        case T_BooleanTest:
            {
                /*
                 * This case could be folded into the generic handling used
                 * for ArrayExpr etc.  But because the simplification logic is
                 * so trivial, applying evaluate_expr() to perform it would be
                 * a heavy overhead.  BooleanTest is probably common enough to
                 * justify keeping this bespoke implementation.
                 */
                BooleanTest *btest = (BooleanTest *) node;
                BooleanTest *newbtest;
                Node       *arg;

                arg = eval_const_expressions_mutator((Node *) btest->arg,
                                                     context);
                if (arg && IsA(arg, Const))
                {
                    Const      *carg = (Const *) arg;
                    bool        result;

                    switch (btest->booltesttype)
                    {
                        case IS_TRUE:
                            result = (!carg->constisnull &&
                                      DatumGetBool(carg->constvalue));
                            break;
                        case IS_NOT_TRUE:
                            result = (carg->constisnull ||
                                      !DatumGetBool(carg->constvalue));
                            break;
                        case IS_FALSE:
                            result = (!carg->constisnull &&
                                      !DatumGetBool(carg->constvalue));
                            break;
                        case IS_NOT_FALSE:
                            result = (carg->constisnull ||
                                      DatumGetBool(carg->constvalue));
                            break;
                        case IS_UNKNOWN:
                            result = carg->constisnull;
                            break;
                        case IS_NOT_UNKNOWN:
                            result = !carg->constisnull;
                            break;
                        default:
                            elog(ERROR, "unrecognized booltesttype: %d",
                                 (int) btest->booltesttype);
                            result = false; /* keep compiler quiet */
                            break;
                    }

                    return makeBoolConst(result, false);
                }

                newbtest = makeNode(BooleanTest);
                newbtest->arg = (Expr *) arg;
                newbtest->booltesttype = btest->booltesttype;
                newbtest->location = btest->location;
                return (Node *) newbtest;
            }
        case T_CoerceToDomain:
            {
                /*
                 * If the domain currently has no constraints, we replace the
                 * CoerceToDomain node with a simple RelabelType, which is
                 * both far faster to execute and more amenable to later
                 * optimization.  We must then mark the plan as needing to be
                 * rebuilt if the domain's constraints change.
                 *
                 * Also, in estimation mode, always replace CoerceToDomain
                 * nodes, effectively assuming that the coercion will succeed.
                 */
                CoerceToDomain *cdomain = (CoerceToDomain *) node;
                CoerceToDomain *newcdomain;
                Node       *arg;

                arg = eval_const_expressions_mutator((Node *) cdomain->arg,
                                                     context);
                if (context->estimate ||
                    !DomainHasConstraints(cdomain->resulttype))
                {
                    /* Record dependency, if this isn't estimation mode */
                    if (context->root && !context->estimate)
                        record_plan_type_dependency(context->root,
                                                    cdomain->resulttype);

                    /* Generate RelabelType to substitute for CoerceToDomain */
                    return applyRelabelType(arg,
                                            cdomain->resulttype,
                                            cdomain->resulttypmod,
                                            cdomain->resultcollid,
                                            cdomain->coercionformat,
                                            cdomain->location,
                                            true);
                }

                newcdomain = makeNode(CoerceToDomain);
                newcdomain->arg = (Expr *) arg;
                newcdomain->resulttype = cdomain->resulttype;
                newcdomain->resulttypmod = cdomain->resulttypmod;
                newcdomain->resultcollid = cdomain->resultcollid;
                newcdomain->coercionformat = cdomain->coercionformat;
                newcdomain->location = cdomain->location;
                return (Node *) newcdomain;
            }
        case T_PlaceHolderVar:

            /*
             * In estimation mode, just strip the PlaceHolderVar node
             * altogether; this amounts to estimating that the contained value
             * won't be forced to null by an outer join.  In regular mode we
             * just use the default behavior (ie, simplify the expression but
             * leave the PlaceHolderVar node intact).
             */
            if (context->estimate)
            {
                PlaceHolderVar *phv = (PlaceHolderVar *) node;

                return eval_const_expressions_mutator((Node *) phv->phexpr,
                                                      context);
            }
            break;
        case T_ConvertRowtypeExpr:
            {
                ConvertRowtypeExpr *cre = castNode(ConvertRowtypeExpr, node);
                Node       *arg;
                ConvertRowtypeExpr *newcre;

                arg = eval_const_expressions_mutator((Node *) cre->arg,
                                                     context);

                newcre = makeNode(ConvertRowtypeExpr);
                newcre->resulttype = cre->resulttype;
                newcre->convertformat = cre->convertformat;
                newcre->location = cre->location;

                /*
                 * In case of a nested ConvertRowtypeExpr, we can convert the
                 * leaf row directly to the topmost row format without any
                 * intermediate conversions. (This works because
                 * ConvertRowtypeExpr is used only for child->parent
                 * conversion in inheritance trees, which works by exact match
                 * of column name, and a column absent in an intermediate
                 * result can't be present in the final result.)
                 *
                 * No need to check more than one level deep, because the
                 * above recursion will have flattened anything else.
                 */
                if (arg != NULL && IsA(arg, ConvertRowtypeExpr))
                {
                    ConvertRowtypeExpr *argcre = (ConvertRowtypeExpr *) arg;

                    arg = (Node *) argcre->arg;

                    /*
                     * Make sure an outer implicit conversion can't hide an
                     * inner explicit one.
                     */
                    if (newcre->convertformat == COERCE_IMPLICIT_CAST)
                        newcre->convertformat = argcre->convertformat;
                }

                newcre->arg = (Expr *) arg;

                if (arg != NULL && IsA(arg, Const))
                    return ece_evaluate_expr((Node *) newcre);
                return (Node *) newcre;
            }
        default:
            break;
    }

    /*
     * For any node type not handled above, copy the node unchanged but
     * const-simplify its subexpressions.  This is the correct thing for node
     * types whose behavior might change between planning and execution, such
     * as CurrentOfExpr.  It's also a safe default for new node types not
     * known to this routine.
     */
    return ece_generic_processing(node);
}

evaluate_expr()

Expr* evaluate_expr	(	Expr *	expr,
		Oid	result_type,
		int32	result_typmod,
		Oid	result_collation
	)

Definition at line 4497 of file clauses.c.

References CreateExecutorState(), datumCopy(), EState::es_query_cxt, ExecEvalExprSwitchContext(), ExecInitExpr(), fix_opfuncids(), FreeExecutorState(), get_typlenbyval(), GetPerTupleExprContext, makeConst(), MemoryContextSwitchTo(), PG_DETOAST_DATUM_COPY, and PointerGetDatum.

Referenced by eval_const_expressions_mutator(), evaluate_function(), and transformPartitionBoundValue().

{
    EState     *estate;
    ExprState  *exprstate;
    MemoryContext oldcontext;
    Datum       const_val;
    bool        const_is_null;
    int16       resultTypLen;
    bool        resultTypByVal;

    /*
     * To use the executor, we need an EState.
     */
    estate = CreateExecutorState();

    /* We can use the estate's working context to avoid memory leaks. */
    oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);

    /* Make sure any opfuncids are filled in. */
    fix_opfuncids((Node *) expr);

    /*
     * Prepare expr for execution.  (Note: we can't use ExecPrepareExpr
     * because it'd result in recursively invoking eval_const_expressions.)
     */
    exprstate = ExecInitExpr(expr, NULL);

    /*
     * And evaluate it.
     *
     * It is OK to use a default econtext because none of the ExecEvalExpr()
     * code used in this situation will use econtext.  That might seem
     * fortuitous, but it's not so unreasonable --- a constant expression does
     * not depend on context, by definition, n'est ce pas?
     */
    const_val = ExecEvalExprSwitchContext(exprstate,
                                          GetPerTupleExprContext(estate),
                                          &const_is_null);

    /* Get info needed about result datatype */
    get_typlenbyval(result_type, &resultTypLen, &resultTypByVal);

    /* Get back to outer memory context */
    MemoryContextSwitchTo(oldcontext);

    /*
     * Must copy result out of sub-context used by expression eval.
     *
     * Also, if it's varlena, forcibly detoast it.  This protects us against
     * storing TOAST pointers into plans that might outlive the referenced
     * data.  (makeConst would handle detoasting anyway, but it's worth a few
     * extra lines here so that we can do the copy and detoast in one step.)
     */
    if (!const_is_null)
    {
        if (resultTypLen == -1)
            const_val = PointerGetDatum(PG_DETOAST_DATUM_COPY(const_val));
        else
            const_val = datumCopy(const_val, resultTypByVal, resultTypLen);
    }

    /* Release all the junk we just created */
    FreeExecutorState(estate);

    /*
     * Make the constant result node.
     */
    return (Expr *) makeConst(result_type, result_typmod, result_collation,
                              resultTypLen,
                              const_val, const_is_null,
                              resultTypByVal);
}

evaluate_function()

static Expr * evaluate_function ( Oid  funcid, Oid  result_type, int32  result_typmod, Oid  result_collid, Oid  input_collid, List *  args, bool  funcvariadic, HeapTuple  func_tuple, eval_const_expressions_context *  context  )

static

Definition at line 3972 of file clauses.c.

References arg, generate_unaccent_rules::args, FuncExpr::args, COERCE_EXPLICIT_CALL, eval_const_expressions_context::estimate, evaluate_expr(), FuncExpr::funccollid, FuncExpr::funcformat, FuncExpr::funcid, FuncExpr::funcresulttype, FuncExpr::funcretset, FuncExpr::funcvariadic, GETSTRUCT, FuncExpr::inputcollid, IsA, lfirst, FuncExpr::location, makeNode, and makeNullConst().

Referenced by simplify_function().

{
    Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
    bool        has_nonconst_input = false;
    bool        has_null_input = false;
    ListCell   *arg;
    FuncExpr   *newexpr;

    /*
     * Can't simplify if it returns a set.
     */
    if (funcform->proretset)
        return NULL;

    /*
     * Can't simplify if it returns RECORD.  The immediate problem is that it
     * will be needing an expected tupdesc which we can't supply here.
     *
     * In the case where it has OUT parameters, it could get by without an
     * expected tupdesc, but we still have issues: get_expr_result_type()
     * doesn't know how to extract type info from a RECORD constant, and in
     * the case of a NULL function result there doesn't seem to be any clean
     * way to fix that.  In view of the likelihood of there being still other
     * gotchas, seems best to leave the function call unreduced.
     */
    if (funcform->prorettype == RECORDOID)
        return NULL;

    /*
     * Check for constant inputs and especially constant-NULL inputs.
     */
    foreach(arg, args)
    {
        if (IsA(lfirst(arg), Const))
            has_null_input |= ((Const *) lfirst(arg))->constisnull;
        else
            has_nonconst_input = true;
    }

    /*
     * If the function is strict and has a constant-NULL input, it will never
     * be called at all, so we can replace the call by a NULL constant, even
     * if there are other inputs that aren't constant, and even if the
     * function is not otherwise immutable.
     */
    if (funcform->proisstrict && has_null_input)
        return (Expr *) makeNullConst(result_type, result_typmod,
                                      result_collid);

    /*
     * Otherwise, can simplify only if all inputs are constants. (For a
     * non-strict function, constant NULL inputs are treated the same as
     * constant non-NULL inputs.)
     */
    if (has_nonconst_input)
        return NULL;

    /*
     * Ordinarily we are only allowed to simplify immutable functions. But for
     * purposes of estimation, we consider it okay to simplify functions that
     * are merely stable; the risk that the result might change from planning
     * time to execution time is worth taking in preference to not being able
     * to estimate the value at all.
     */
    if (funcform->provolatile == PROVOLATILE_IMMUTABLE)
         /* okay */ ;
    else if (context->estimate && funcform->provolatile == PROVOLATILE_STABLE)
         /* okay */ ;
    else
        return NULL;

    /*
     * OK, looks like we can simplify this operator/function.
     *
     * Build a new FuncExpr node containing the already-simplified arguments.
     */
    newexpr = makeNode(FuncExpr);
    newexpr->funcid = funcid;
    newexpr->funcresulttype = result_type;
    newexpr->funcretset = false;
    newexpr->funcvariadic = funcvariadic;
    newexpr->funcformat = COERCE_EXPLICIT_CALL; /* doesn't matter */
    newexpr->funccollid = result_collid;    /* doesn't matter */
    newexpr->inputcollid = input_collid;
    newexpr->args = args;
    newexpr->location = -1;

    return evaluate_expr((Expr *) newexpr, result_type, result_typmod,
                         result_collid);
}

expand_function_arguments()

List* expand_function_arguments	(	List *	args,
		Oid	result_type,
		HeapTuple	func_tuple
	)

Definition at line 3755 of file clauses.c.

References add_function_defaults(), arg, generate_unaccent_rules::args, GETSTRUCT, IsA, lfirst, list_length(), recheck_cast_function_args(), and reorder_function_arguments().

Referenced by eval_const_expressions_mutator(), ExecuteCallStmt(), make_callstmt_target(), and simplify_function().

{
    Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
    bool        has_named_args = false;
    ListCell   *lc;

    /* Do we have any named arguments? */
    foreach(lc, args)
    {
        Node       *arg = (Node *) lfirst(lc);

        if (IsA(arg, NamedArgExpr))
        {
            has_named_args = true;
            break;
        }
    }

    /* If so, we must apply reorder_function_arguments */
    if (has_named_args)
    {
        args = reorder_function_arguments(args, func_tuple);
        /* Recheck argument types and add casts if needed */
        recheck_cast_function_args(args, result_type, func_tuple);
    }
    else if (list_length(args) < funcform->pronargs)
    {
        /* No named args, but we seem to be short some defaults */
        args = add_function_defaults(args, func_tuple);
        /* Recheck argument types and add casts if needed */
        recheck_cast_function_args(args, result_type, func_tuple);
    }

    return args;
}

expression_returns_set_rows()

double expression_returns_set_rows	(	PlannerInfo *	root,
		Node *	clause
	)

Definition at line 282 of file clauses.c.

References clamp_row_est(), FuncExpr::funcid, FuncExpr::funcretset, get_function_rows(), IsA, OpExpr::opfuncid, OpExpr::opretset, and set_opfuncid().

Referenced by create_set_projection_path(), estimate_num_groups(), and set_function_size_estimates().

{
    if (clause == NULL)
        return 1.0;
    if (IsA(clause, FuncExpr))
    {
        FuncExpr   *expr = (FuncExpr *) clause;

        if (expr->funcretset)
            return clamp_row_est(get_function_rows(root, expr->funcid, clause));
    }
    if (IsA(clause, OpExpr))
    {
        OpExpr     *expr = (OpExpr *) clause;

        if (expr->opretset)
        {
            set_opfuncid(expr);
            return clamp_row_est(get_function_rows(root, expr->opfuncid, clause));
        }
    }
    return 1.0;
}

fetch_function_defaults()

static List * fetch_function_defaults ( HeapTuple  func_tuple )

static

Definition at line 3893 of file clauses.c.

References castNode, elog, ERROR, pfree(), PROCOID, generate_unaccent_rules::str, stringToNode(), SysCacheGetAttr(), and TextDatumGetCString.

Referenced by add_function_defaults(), and reorder_function_arguments().

{
    List       *defaults;
    Datum       proargdefaults;
    bool        isnull;
    char       *str;

    /* The error cases here shouldn't happen, but check anyway */
    proargdefaults = SysCacheGetAttr(PROCOID, func_tuple,
                                     Anum_pg_proc_proargdefaults,
                                     &isnull);
    if (isnull)
        elog(ERROR, "not enough default arguments");
    str = TextDatumGetCString(proargdefaults);
    defaults = castNode(List, stringToNode(str));
    pfree(str);
    return defaults;
}

find_forced_null_var()

Var* find_forced_null_var

(

Node *

node

)

Definition at line 1747 of file clauses.c.

References NullTest::arg, BooleanTest::arg, NullTest::argisrow, BooleanTest::booltesttype, IS_NULL, IS_UNKNOWN, IsA, NullTest::nulltesttype, and Var::varlevelsup.

Referenced by check_redundant_nullability_qual(), and find_forced_null_vars().

{
    if (node == NULL)
        return NULL;
    if (IsA(node, NullTest))
    {
        /* check for var IS NULL */
        NullTest   *expr = (NullTest *) node;

        if (expr->nulltesttype == IS_NULL && !expr->argisrow)
        {
            Var        *var = (Var *) expr->arg;

            if (var && IsA(var, Var) &&
                var->varlevelsup == 0)
                return var;
        }
    }
    else if (IsA(node, BooleanTest))
    {
        /* var IS UNKNOWN is equivalent to var IS NULL */
        BooleanTest *expr = (BooleanTest *) node;

        if (expr->booltesttype == IS_UNKNOWN)
        {
            Var        *var = (Var *) expr->arg;

            if (var && IsA(var, Var) &&
                var->varlevelsup == 0)
                return var;
        }
    }
    return NULL;
}

find_forced_null_vars()

List* find_forced_null_vars

(

Node *

node

)

Definition at line 1688 of file clauses.c.

References AND_EXPR, BoolExpr::args, BoolExpr::boolop, find_forced_null_var(), find_forced_null_vars(), IsA, lfirst, list_concat(), list_make1, and NIL.

Referenced by find_forced_null_vars(), and reduce_outer_joins_pass2().

{
    List       *result = NIL;
    Var        *var;
    ListCell   *l;

    if (node == NULL)
        return NIL;
    /* Check single-clause cases using subroutine */
    var = find_forced_null_var(node);
    if (var)
    {
        result = list_make1(var);
    }
    /* Otherwise, handle AND-conditions */
    else if (IsA(node, List))
    {
        /*
         * At top level, we are examining an implicit-AND list: if any of the
         * arms produces FALSE-or-NULL then the result is FALSE-or-NULL.
         */
        foreach(l, (List *) node)
        {
            result = list_concat(result,
                                 find_forced_null_vars(lfirst(l)));
        }
    }
    else if (IsA(node, BoolExpr))
    {
        BoolExpr   *expr = (BoolExpr *) node;

        /*
         * We don't bother considering the OR case, because it's fairly
         * unlikely anyone would write "v1 IS NULL OR v1 IS NULL". Likewise,
         * the NOT case isn't worth expending code on.
         */
        if (expr->boolop == AND_EXPR)
        {
            /* At top level we can just recurse (to the List case) */
            result = find_forced_null_vars((Node *) expr->args);
        }
    }
    return result;
}

find_nonnullable_rels()

Relids find_nonnullable_rels

(

Node *

clause

)

Definition at line 1270 of file clauses.c.

References find_nonnullable_rels_walker().

Referenced by make_outerjoininfo(), and reduce_outer_joins_pass2().

{
    return find_nonnullable_rels_walker(clause, true);
}

find_nonnullable_rels_walker()

static Relids find_nonnullable_rels_walker ( Node *  node, bool  top_level  )

static

Definition at line 1276 of file clauses.c.

References AND_EXPR, RelabelType::arg, CoerceViaIO::arg, ArrayCoerceExpr::arg, ConvertRowtypeExpr::arg, CollateExpr::arg, NullTest::arg, BooleanTest::arg, NullTest::argisrow, FuncExpr::args, OpExpr::args, ScalarArrayOpExpr::args, BoolExpr::args, bms_add_members(), bms_int_members(), bms_is_empty(), bms_join(), bms_make_singleton(), bms_membership(), BMS_SINGLETON, BoolExpr::boolop, BooleanTest::booltesttype, elog, ERROR, func_strict(), FuncExpr::funcid, IS_FALSE, IS_NOT_NULL, IS_NOT_UNKNOWN, is_strict_saop(), IS_TRUE, IsA, lfirst, NOT_EXPR, NullTest::nulltesttype, OpExpr::opfuncid, OR_EXPR, PlaceHolderVar::phexpr, PlaceHolderVar::phlevelsup, PlaceHolderVar::phrels, set_opfuncid(), Var::varlevelsup, and Var::varno.

Referenced by find_nonnullable_rels().

{
    Relids      result = NULL;
    ListCell   *l;

    if (node == NULL)
        return NULL;
    if (IsA(node, Var))
    {
        Var        *var = (Var *) node;

        if (var->varlevelsup == 0)
            result = bms_make_singleton(var->varno);
    }
    else if (IsA(node, List))
    {
        /*
         * At top level, we are examining an implicit-AND list: if any of the
         * arms produces FALSE-or-NULL then the result is FALSE-or-NULL. If
         * not at top level, we are examining the arguments of a strict
         * function: if any of them produce NULL then the result of the
         * function must be NULL.  So in both cases, the set of nonnullable
         * rels is the union of those found in the arms, and we pass down the
         * top_level flag unmodified.
         */
        foreach(l, (List *) node)
        {
            result = bms_join(result,
                              find_nonnullable_rels_walker(lfirst(l),
                                                           top_level));
        }
    }
    else if (IsA(node, FuncExpr))
    {
        FuncExpr   *expr = (FuncExpr *) node;

        if (func_strict(expr->funcid))
            result = find_nonnullable_rels_walker((Node *) expr->args, false);
    }
    else if (IsA(node, OpExpr))
    {
        OpExpr     *expr = (OpExpr *) node;

        set_opfuncid(expr);
        if (func_strict(expr->opfuncid))
            result = find_nonnullable_rels_walker((Node *) expr->args, false);
    }
    else if (IsA(node, ScalarArrayOpExpr))
    {
        ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node;

        if (is_strict_saop(expr, true))
            result = find_nonnullable_rels_walker((Node *) expr->args, false);
    }
    else if (IsA(node, BoolExpr))
    {
        BoolExpr   *expr = (BoolExpr *) node;

        switch (expr->boolop)
        {
            case AND_EXPR:
                /* At top level we can just recurse (to the List case) */
                if (top_level)
                {
                    result = find_nonnullable_rels_walker((Node *) expr->args,
                                                          top_level);
                    break;
                }

                /*
                 * Below top level, even if one arm produces NULL, the result
                 * could be FALSE (hence not NULL).  However, if *all* the
                 * arms produce NULL then the result is NULL, so we can take
                 * the intersection of the sets of nonnullable rels, just as
                 * for OR.  Fall through to share code.
                 */
                /* FALL THRU */
            case OR_EXPR:

                /*
                 * OR is strict if all of its arms are, so we can take the
                 * intersection of the sets of nonnullable rels for each arm.
                 * This works for both values of top_level.
                 */
                foreach(l, expr->args)
                {
                    Relids      subresult;

                    subresult = find_nonnullable_rels_walker(lfirst(l),
                                                             top_level);
                    if (result == NULL) /* first subresult? */
                        result = subresult;
                    else
                        result = bms_int_members(result, subresult);

                    /*
                     * If the intersection is empty, we can stop looking. This
                     * also justifies the test for first-subresult above.
                     */
                    if (bms_is_empty(result))
                        break;
                }
                break;
            case NOT_EXPR:
                /* NOT will return null if its arg is null */
                result = find_nonnullable_rels_walker((Node *) expr->args,
                                                      false);
                break;
            default:
                elog(ERROR, "unrecognized boolop: %d", (int) expr->boolop);
                break;
        }
    }
    else if (IsA(node, RelabelType))
    {
        RelabelType *expr = (RelabelType *) node;

        result = find_nonnullable_rels_walker((Node *) expr->arg, top_level);
    }
    else if (IsA(node, CoerceViaIO))
    {
        /* not clear this is useful, but it can't hurt */
        CoerceViaIO *expr = (CoerceViaIO *) node;

        result = find_nonnullable_rels_walker((Node *) expr->arg, top_level);
    }
    else if (IsA(node, ArrayCoerceExpr))
    {
        /* ArrayCoerceExpr is strict at the array level; ignore elemexpr */
        ArrayCoerceExpr *expr = (ArrayCoerceExpr *) node;

        result = find_nonnullable_rels_walker((Node *) expr->arg, top_level);
    }
    else if (IsA(node, ConvertRowtypeExpr))
    {
        /* not clear this is useful, but it can't hurt */
        ConvertRowtypeExpr *expr = (ConvertRowtypeExpr *) node;

        result = find_nonnullable_rels_walker((Node *) expr->arg, top_level);
    }
    else if (IsA(node, CollateExpr))
    {
        CollateExpr *expr = (CollateExpr *) node;

        result = find_nonnullable_rels_walker((Node *) expr->arg, top_level);
    }
    else if (IsA(node, NullTest))
    {
        /* IS NOT NULL can be considered strict, but only at top level */
        NullTest   *expr = (NullTest *) node;

        if (top_level && expr->nulltesttype == IS_NOT_NULL && !expr->argisrow)
            result = find_nonnullable_rels_walker((Node *) expr->arg, false);
    }
    else if (IsA(node, BooleanTest))
    {
        /* Boolean tests that reject NULL are strict at top level */
        BooleanTest *expr = (BooleanTest *) node;

        if (top_level &&
            (expr->booltesttype == IS_TRUE ||
             expr->booltesttype == IS_FALSE ||
             expr->booltesttype == IS_NOT_UNKNOWN))
            result = find_nonnullable_rels_walker((Node *) expr->arg, false);
    }
    else if (IsA(node, PlaceHolderVar))
    {
        PlaceHolderVar *phv = (PlaceHolderVar *) node;

        /*
         * If the contained expression forces any rels non-nullable, so does
         * the PHV.
         */
        result = find_nonnullable_rels_walker((Node *) phv->phexpr, top_level);

        /*
         * If the PHV's syntactic scope is exactly one rel, it will be forced
         * to be evaluated at that rel, and so it will behave like a Var of
         * that rel: if the rel's entire output goes to null, so will the PHV.
         * (If the syntactic scope is a join, we know that the PHV will go to
         * null if the whole join does; but that is AND semantics while we
         * need OR semantics for find_nonnullable_rels' result, so we can't do
         * anything with the knowledge.)
         */
        if (phv->phlevelsup == 0 &&
            bms_membership(phv->phrels) == BMS_SINGLETON)
            result = bms_add_members(result, phv->phrels);
    }
    return result;
}

find_nonnullable_vars()

List* find_nonnullable_vars

(

Node *

clause

)

Definition at line 1495 of file clauses.c.

References find_nonnullable_vars_walker().

Referenced by reduce_outer_joins_pass2().

{
    return find_nonnullable_vars_walker(clause, true);
}

find_nonnullable_vars_walker()

static List * find_nonnullable_vars_walker ( Node *  node, bool  top_level  )

static

Definition at line 1501 of file clauses.c.

References AND_EXPR, RelabelType::arg, CoerceViaIO::arg, ArrayCoerceExpr::arg, ConvertRowtypeExpr::arg, CollateExpr::arg, NullTest::arg, BooleanTest::arg, NullTest::argisrow, FuncExpr::args, OpExpr::args, ScalarArrayOpExpr::args, BoolExpr::args, BoolExpr::boolop, BooleanTest::booltesttype, elog, ERROR, func_strict(), FuncExpr::funcid, IS_FALSE, IS_NOT_NULL, IS_NOT_UNKNOWN, is_strict_saop(), IS_TRUE, IsA, lfirst, list_concat(), list_intersection(), list_make1, NIL, NOT_EXPR, NullTest::nulltesttype, OpExpr::opfuncid, OR_EXPR, PlaceHolderVar::phexpr, set_opfuncid(), and Var::varlevelsup.

Referenced by find_nonnullable_vars().

{
    List       *result = NIL;
    ListCell   *l;

    if (node == NULL)
        return NIL;
    if (IsA(node, Var))
    {
        Var        *var = (Var *) node;

        if (var->varlevelsup == 0)
            result = list_make1(var);
    }
    else if (IsA(node, List))
    {
        /*
         * At top level, we are examining an implicit-AND list: if any of the
         * arms produces FALSE-or-NULL then the result is FALSE-or-NULL. If
         * not at top level, we are examining the arguments of a strict
         * function: if any of them produce NULL then the result of the
         * function must be NULL.  So in both cases, the set of nonnullable
         * vars is the union of those found in the arms, and we pass down the
         * top_level flag unmodified.
         */
        foreach(l, (List *) node)
        {
            result = list_concat(result,
                                 find_nonnullable_vars_walker(lfirst(l),
                                                              top_level));
        }
    }
    else if (IsA(node, FuncExpr))
    {
        FuncExpr   *expr = (FuncExpr *) node;

        if (func_strict(expr->funcid))
            result = find_nonnullable_vars_walker((Node *) expr->args, false);
    }
    else if (IsA(node, OpExpr))
    {
        OpExpr     *expr = (OpExpr *) node;

        set_opfuncid(expr);
        if (func_strict(expr->opfuncid))
            result = find_nonnullable_vars_walker((Node *) expr->args, false);
    }
    else if (IsA(node, ScalarArrayOpExpr))
    {
        ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node;

        if (is_strict_saop(expr, true))
            result = find_nonnullable_vars_walker((Node *) expr->args, false);
    }
    else if (IsA(node, BoolExpr))
    {
        BoolExpr   *expr = (BoolExpr *) node;

        switch (expr->boolop)
        {
            case AND_EXPR:
                /* At top level we can just recurse (to the List case) */
                if (top_level)
                {
                    result = find_nonnullable_vars_walker((Node *) expr->args,
                                                          top_level);
                    break;
                }

                /*
                 * Below top level, even if one arm produces NULL, the result
                 * could be FALSE (hence not NULL).  However, if *all* the
                 * arms produce NULL then the result is NULL, so we can take
                 * the intersection of the sets of nonnullable vars, just as
                 * for OR.  Fall through to share code.
                 */
                /* FALL THRU */
            case OR_EXPR:

                /*
                 * OR is strict if all of its arms are, so we can take the
                 * intersection of the sets of nonnullable vars for each arm.
                 * This works for both values of top_level.
                 */
                foreach(l, expr->args)
                {
                    List       *subresult;

                    subresult = find_nonnullable_vars_walker(lfirst(l),
                                                             top_level);
                    if (result == NIL)  /* first subresult? */
                        result = subresult;
                    else
                        result = list_intersection(result, subresult);

                    /*
                     * If the intersection is empty, we can stop looking. This
                     * also justifies the test for first-subresult above.
                     */
                    if (result == NIL)
                        break;
                }
                break;
            case NOT_EXPR:
                /* NOT will return null if its arg is null */
                result = find_nonnullable_vars_walker((Node *) expr->args,
                                                      false);
                break;
            default:
                elog(ERROR, "unrecognized boolop: %d", (int) expr->boolop);
                break;
        }
    }
    else if (IsA(node, RelabelType))
    {
        RelabelType *expr = (RelabelType *) node;

        result = find_nonnullable_vars_walker((Node *) expr->arg, top_level);
    }
    else if (IsA(node, CoerceViaIO))
    {
        /* not clear this is useful, but it can't hurt */
        CoerceViaIO *expr = (CoerceViaIO *) node;

        result = find_nonnullable_vars_walker((Node *) expr->arg, false);
    }
    else if (IsA(node, ArrayCoerceExpr))
    {
        /* ArrayCoerceExpr is strict at the array level; ignore elemexpr */
        ArrayCoerceExpr *expr = (ArrayCoerceExpr *) node;

        result = find_nonnullable_vars_walker((Node *) expr->arg, top_level);
    }
    else if (IsA(node, ConvertRowtypeExpr))
    {
        /* not clear this is useful, but it can't hurt */
        ConvertRowtypeExpr *expr = (ConvertRowtypeExpr *) node;

        result = find_nonnullable_vars_walker((Node *) expr->arg, top_level);
    }
    else if (IsA(node, CollateExpr))
    {
        CollateExpr *expr = (CollateExpr *) node;

        result = find_nonnullable_vars_walker((Node *) expr->arg, top_level);
    }
    else if (IsA(node, NullTest))
    {
        /* IS NOT NULL can be considered strict, but only at top level */
        NullTest   *expr = (NullTest *) node;

        if (top_level && expr->nulltesttype == IS_NOT_NULL && !expr->argisrow)
            result = find_nonnullable_vars_walker((Node *) expr->arg, false);
    }
    else if (IsA(node, BooleanTest))
    {
        /* Boolean tests that reject NULL are strict at top level */
        BooleanTest *expr = (BooleanTest *) node;

        if (top_level &&
            (expr->booltesttype == IS_TRUE ||
             expr->booltesttype == IS_FALSE ||
             expr->booltesttype == IS_NOT_UNKNOWN))
            result = find_nonnullable_vars_walker((Node *) expr->arg, false);
    }
    else if (IsA(node, PlaceHolderVar))
    {
        PlaceHolderVar *phv = (PlaceHolderVar *) node;

        result = find_nonnullable_vars_walker((Node *) phv->phexpr, top_level);
    }
    return result;
}

find_window_functions()

WindowFuncLists* find_window_functions	(	Node *	clause,
		Index	maxWinRef
	)

Definition at line 220 of file clauses.c.

References find_window_functions_walker(), WindowFuncLists::maxWinRef, WindowFuncLists::numWindowFuncs, palloc(), palloc0(), and WindowFuncLists::windowFuncs.

Referenced by grouping_planner().

{
    WindowFuncLists *lists = palloc(sizeof(WindowFuncLists));

    lists->numWindowFuncs = 0;
    lists->maxWinRef = maxWinRef;
    lists->windowFuncs = (List **) palloc0((maxWinRef + 1) * sizeof(List *));
    (void) find_window_functions_walker(clause, lists);
    return lists;
}

find_window_functions_walker()

static bool find_window_functions_walker ( Node *  node, WindowFuncLists *  lists  )

static

Definition at line 232 of file clauses.c.

References Assert, elog, ERROR, expression_tree_walker(), IsA, lappend(), list_member(), WindowFuncLists::maxWinRef, WindowFuncLists::numWindowFuncs, WindowFuncLists::windowFuncs, and WindowFunc::winref.

Referenced by find_window_functions().

{
    if (node == NULL)
        return false;
    if (IsA(node, WindowFunc))
    {
        WindowFunc *wfunc = (WindowFunc *) node;

        /* winref is unsigned, so one-sided test is OK */
        if (wfunc->winref > lists->maxWinRef)
            elog(ERROR, "WindowFunc contains out-of-range winref %u",
                 wfunc->winref);
        /* eliminate duplicates, so that we avoid repeated computation */
        if (!list_member(lists->windowFuncs[wfunc->winref], wfunc))
        {
            lists->windowFuncs[wfunc->winref] =
                lappend(lists->windowFuncs[wfunc->winref], wfunc);
            lists->numWindowFuncs++;
        }

        /*
         * We assume that the parser checked that there are no window
         * functions in the arguments or filter clause.  Hence, we need not
         * recurse into them.  (If either the parser or the planner screws up
         * on this point, the executor will still catch it; see ExecInitExpr.)
         */
        return false;
    }
    Assert(!IsA(node, SubLink));
    return expression_tree_walker(node, find_window_functions_walker,
                                  (void *) lists);
}

inline_function()

static Expr * inline_function ( Oid  funcid, Oid  result_type, Oid  result_collid, Oid  input_collid, List *  args, bool  funcvariadic, HeapTuple  func_tuple, eval_const_expressions_context *  context  )

static

Definition at line 4099 of file clauses.c.

References ACL_EXECUTE, ACLCHECK_OK, eval_const_expressions_context::active_fns, ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, arg, ErrorContextCallback::arg, CollateExpr::arg, generate_unaccent_rules::args, FuncExpr::args, ErrorContextCallback::callback, check_sql_fn_retval(), CMD_SELECT, COERCE_EXPLICIT_CALL, CollateExpr::collOid, Query::commandType, contain_context_dependent_node(), contain_mutable_functions(), contain_nonstrict_functions(), contain_subplans(), contain_volatile_functions(), copyObject, cost_qual_eval(), cpu_operator_cost, Query::cteList, CurrentMemoryContext, Query::distinctClause, elog, ERROR, error_context_stack, eval_const_expressions_mutator(), exprCollation(), exprType(), FmgrHookIsNeeded, free_parsestate(), FromExpr::fromlist, FuncExpr::funccollid, FuncExpr::funcformat, FuncExpr::funcid, FuncExpr::funcresulttype, FuncExpr::funcretset, FuncExpr::funcvariadic, get_expr_result_type(), GETSTRUCT, GetUserId(), Query::groupClause, Query::groupingSets, Query::hasAggs, Query::hasSubLinks, Query::hasTargetSRFs, Query::hasWindowFuncs, Query::havingQual, heap_attisnull(), i, FuncExpr::inputcollid, IsA, Query::jointree, lappend_oid(), lfirst, Query::limitCount, Query::limitOffset, linitial, list_delete_last(), list_length(), list_make1, list_member_oid(), FuncExpr::location, CollateExpr::location, make_parsestate(), makeNode, MemoryContextDelete(), MemoryContextSwitchTo(), NameStr, OidIsValid, ParseState::p_sourcetext, palloc0(), QualCost::per_tuple, pg_parse_query(), pg_proc_aclcheck(), prepare_sql_fn_parse_info(), ErrorContextCallback::previous, PROCOID, inline_error_callback_arg::proname, inline_error_callback_arg::prosrc, FromExpr::quals, querytree(), record_plan_function_dependency(), eval_const_expressions_context::root, Query::rtable, Query::setOperations, Query::sortClause, sql_fn_parser_setup(), sql_inline_error_callback(), QualCost::startup, substitute_actual_parameters(), SysCacheGetAttr(), Query::targetList, TextDatumGetCString, transformTopLevelStmt(), and Query::windowClause.

Referenced by simplify_function().

{
    Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
    char       *src;
    Datum       tmp;
    bool        isNull;
    MemoryContext oldcxt;
    MemoryContext mycxt;
    inline_error_callback_arg callback_arg;
    ErrorContextCallback sqlerrcontext;
    FuncExpr   *fexpr;
    SQLFunctionParseInfoPtr pinfo;
    TupleDesc   rettupdesc;
    ParseState *pstate;
    List       *raw_parsetree_list;
    List       *querytree_list;
    Query      *querytree;
    Node       *newexpr;
    int        *usecounts;
    ListCell   *arg;
    int         i;

    /*
     * Forget it if the function is not SQL-language or has other showstopper
     * properties.  (The prokind and nargs checks are just paranoia.)
     */
    if (funcform->prolang != SQLlanguageId ||
        funcform->prokind != PROKIND_FUNCTION ||
        funcform->prosecdef ||
        funcform->proretset ||
        funcform->prorettype == RECORDOID ||
        !heap_attisnull(func_tuple, Anum_pg_proc_proconfig, NULL) ||
        funcform->pronargs != list_length(args))
        return NULL;

    /* Check for recursive function, and give up trying to expand if so */
    if (list_member_oid(context->active_fns, funcid))
        return NULL;

    /* Check permission to call function (fail later, if not) */
    if (pg_proc_aclcheck(funcid, GetUserId(), ACL_EXECUTE) != ACLCHECK_OK)
        return NULL;

    /* Check whether a plugin wants to hook function entry/exit */
    if (FmgrHookIsNeeded(funcid))
        return NULL;

    /*
     * Make a temporary memory context, so that we don't leak all the stuff
     * that parsing might create.
     */
    mycxt = AllocSetContextCreate(CurrentMemoryContext,
                                  "inline_function",
                                  ALLOCSET_DEFAULT_SIZES);
    oldcxt = MemoryContextSwitchTo(mycxt);

    /* Fetch the function body */
    tmp = SysCacheGetAttr(PROCOID,
                          func_tuple,
                          Anum_pg_proc_prosrc,
                          &isNull);
    if (isNull)
        elog(ERROR, "null prosrc for function %u", funcid);
    src = TextDatumGetCString(tmp);

    /*
     * Setup error traceback support for ereport().  This is so that we can
     * finger the function that bad information came from.
     */
    callback_arg.proname = NameStr(funcform->proname);
    callback_arg.prosrc = src;

    sqlerrcontext.callback = sql_inline_error_callback;
    sqlerrcontext.arg = (void *) &callback_arg;
    sqlerrcontext.previous = error_context_stack;
    error_context_stack = &sqlerrcontext;

    /*
     * Set up to handle parameters while parsing the function body.  We need a
     * dummy FuncExpr node containing the already-simplified arguments to pass
     * to prepare_sql_fn_parse_info.  (In some cases we don't really need
     * that, but for simplicity we always build it.)
     */
    fexpr = makeNode(FuncExpr);
    fexpr->funcid = funcid;
    fexpr->funcresulttype = result_type;
    fexpr->funcretset = false;
    fexpr->funcvariadic = funcvariadic;
    fexpr->funcformat = COERCE_EXPLICIT_CALL;   /* doesn't matter */
    fexpr->funccollid = result_collid;  /* doesn't matter */
    fexpr->inputcollid = input_collid;
    fexpr->args = args;
    fexpr->location = -1;

    pinfo = prepare_sql_fn_parse_info(func_tuple,
                                      (Node *) fexpr,
                                      input_collid);

    /* fexpr also provides a convenient way to resolve a composite result */
    (void) get_expr_result_type((Node *) fexpr,
                                NULL,
                                &rettupdesc);

    /*
     * We just do parsing and parse analysis, not rewriting, because rewriting
     * will not affect table-free-SELECT-only queries, which is all that we
     * care about.  Also, we can punt as soon as we detect more than one
     * command in the function body.
     */
    raw_parsetree_list = pg_parse_query(src);
    if (list_length(raw_parsetree_list) != 1)
        goto fail;

    pstate = make_parsestate(NULL);
    pstate->p_sourcetext = src;
    sql_fn_parser_setup(pstate, pinfo);

    querytree = transformTopLevelStmt(pstate, linitial(raw_parsetree_list));

    free_parsestate(pstate);

    /*
     * The single command must be a simple "SELECT expression".
     *
     * Note: if you change the tests involved in this, see also plpgsql's
     * exec_simple_check_plan().  That generally needs to have the same idea
     * of what's a "simple expression", so that inlining a function that
     * previously wasn't inlined won't change plpgsql's conclusion.
     */
    if (!IsA(querytree, Query) ||
        querytree->commandType != CMD_SELECT ||
        querytree->hasAggs ||
        querytree->hasWindowFuncs ||
        querytree->hasTargetSRFs ||
        querytree->hasSubLinks ||
        querytree->cteList ||
        querytree->rtable ||
        querytree->jointree->fromlist ||
        querytree->jointree->quals ||
        querytree->groupClause ||
        querytree->groupingSets ||
        querytree->havingQual ||
        querytree->windowClause ||
        querytree->distinctClause ||
        querytree->sortClause ||
        querytree->limitOffset ||
        querytree->limitCount ||
        querytree->setOperations ||
        list_length(querytree->targetList) != 1)
        goto fail;

    /*
     * Make sure the function (still) returns what it's declared to.  This
     * will raise an error if wrong, but that's okay since the function would
     * fail at runtime anyway.  Note that check_sql_fn_retval will also insert
     * a coercion if needed to make the tlist expression match the declared
     * type of the function.
     *
     * Note: we do not try this until we have verified that no rewriting was
     * needed; that's probably not important, but let's be careful.
     */
    querytree_list = list_make1(querytree);
    if (check_sql_fn_retval(list_make1(querytree_list),
                            result_type, rettupdesc,
                            false, NULL))
        goto fail;              /* reject whole-tuple-result cases */

    /*
     * Given the tests above, check_sql_fn_retval shouldn't have decided to
     * inject a projection step, but let's just make sure.
     */
    if (querytree != linitial(querytree_list))
        goto fail;

    /* Now we can grab the tlist expression */
    newexpr = (Node *) ((TargetEntry *) linitial(querytree->targetList))->expr;

    /*
     * If the SQL function returns VOID, we can only inline it if it is a
     * SELECT of an expression returning VOID (ie, it's just a redirection to
     * another VOID-returning function).  In all non-VOID-returning cases,
     * check_sql_fn_retval should ensure that newexpr returns the function's
     * declared result type, so this test shouldn't fail otherwise; but we may
     * as well cope gracefully if it does.
     */
    if (exprType(newexpr) != result_type)
        goto fail;

    /*
     * Additional validity checks on the expression.  It mustn't be more
     * volatile than the surrounding function (this is to avoid breaking hacks
     * that involve pretending a function is immutable when it really ain't).
     * If the surrounding function is declared strict, then the expression
     * must contain only strict constructs and must use all of the function
     * parameters (this is overkill, but an exact analysis is hard).
     */
    if (funcform->provolatile == PROVOLATILE_IMMUTABLE &&
        contain_mutable_functions(newexpr))
        goto fail;
    else if (funcform->provolatile == PROVOLATILE_STABLE &&
             contain_volatile_functions(newexpr))
        goto fail;

    if (funcform->proisstrict &&
        contain_nonstrict_functions(newexpr))
        goto fail;

    /*
     * If any parameter expression contains a context-dependent node, we can't
     * inline, for fear of putting such a node into the wrong context.
     */
    if (contain_context_dependent_node((Node *) args))
        goto fail;

    /*
     * We may be able to do it; there are still checks on parameter usage to
     * make, but those are most easily done in combination with the actual
     * substitution of the inputs.  So start building expression with inputs
     * substituted.
     */
    usecounts = (int *) palloc0(funcform->pronargs * sizeof(int));
    newexpr = substitute_actual_parameters(newexpr, funcform->pronargs,
                                           args, usecounts);

    /* Now check for parameter usage */
    i = 0;
    foreach(arg, args)
    {
        Node       *param = lfirst(arg);

        if (usecounts[i] == 0)
        {
            /* Param not used at all: uncool if func is strict */
            if (funcform->proisstrict)
                goto fail;
        }
        else if (usecounts[i] != 1)
        {
            /* Param used multiple times: uncool if expensive or volatile */
            QualCost    eval_cost;

            /*
             * We define "expensive" as "contains any subplan or more than 10
             * operators".  Note that the subplan search has to be done
             * explicitly, since cost_qual_eval() will barf on unplanned
             * subselects.
             */
            if (contain_subplans(param))
                goto fail;
            cost_qual_eval(&eval_cost, list_make1(param), NULL);
            if (eval_cost.startup + eval_cost.per_tuple >
                10 * cpu_operator_cost)
                goto fail;

            /*
             * Check volatility last since this is more expensive than the
             * above tests
             */
            if (contain_volatile_functions(param))
                goto fail;
        }
        i++;
    }

    /*
     * Whew --- we can make the substitution.  Copy the modified expression
     * out of the temporary memory context, and clean up.
     */
    MemoryContextSwitchTo(oldcxt);

    newexpr = copyObject(newexpr);

    MemoryContextDelete(mycxt);

    /*
     * If the result is of a collatable type, force the result to expose the
     * correct collation.  In most cases this does not matter, but it's
     * possible that the function result is used directly as a sort key or in
     * other places where we expect exprCollation() to tell the truth.
     */
    if (OidIsValid(result_collid))
    {
        Oid         exprcoll = exprCollation(newexpr);

        if (OidIsValid(exprcoll) && exprcoll != result_collid)
        {
            CollateExpr *newnode = makeNode(CollateExpr);

            newnode->arg = (Expr *) newexpr;
            newnode->collOid = result_collid;
            newnode->location = -1;

            newexpr = (Node *) newnode;
        }
    }

    /*
     * Since there is now no trace of the function in the plan tree, we must
     * explicitly record the plan's dependency on the function.
     */
    if (context->root)
        record_plan_function_dependency(context->root, funcid);

    /*
     * Recursively try to simplify the modified expression.  Here we must add
     * the current function to the context list of active functions.
     */
    context->active_fns = lappend_oid(context->active_fns, funcid);
    newexpr = eval_const_expressions_mutator(newexpr, context);
    context->active_fns = list_delete_last(context->active_fns);

    error_context_stack = sqlerrcontext.previous;

    return (Expr *) newexpr;

    /* Here if func is not inlinable: release temp memory and return NULL */
fail:
    MemoryContextSwitchTo(oldcxt);
    MemoryContextDelete(mycxt);
    error_context_stack = sqlerrcontext.previous;

    return NULL;
}

inline_set_returning_function()

Query* inline_set_returning_function	(	PlannerInfo *	root,
		RangeTblEntry *	rte
	)

Definition at line 4589 of file clauses.c.

References ACL_EXECUTE, ACLCHECK_OK, ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, ErrorContextCallback::arg, FuncExpr::args, Assert, BuildDescFromLists(), ErrorContextCallback::callback, check_sql_fn_retval(), check_stack_depth(), CMD_SELECT, Query::commandType, contain_subplans(), contain_volatile_functions(), copyObject, CurrentMemoryContext, elog, ERROR, error_context_stack, FmgrHookIsNeeded, RangeTblFunction::funccolcollations, RangeTblFunction::funccolnames, RangeTblFunction::funccoltypes, RangeTblFunction::funccoltypmods, RangeTblFunction::funcexpr, FuncExpr::funcid, RangeTblEntry::funcordinality, FuncExpr::funcretset, RangeTblEntry::functions, get_expr_result_type(), GETSTRUCT, GetUserId(), heap_attisnull(), HeapTupleIsValid, IsA, linitial, linitial_node, list_length(), list_make1, MemoryContextDelete(), MemoryContextSwitchTo(), NameStr, ObjectIdGetDatum, pg_analyze_and_rewrite_params(), pg_parse_query(), pg_proc_aclcheck(), prepare_sql_fn_parse_info(), ErrorContextCallback::previous, PROCOID, inline_error_callback_arg::proname, inline_error_callback_arg::prosrc, querytree(), record_plan_function_dependency(), ReleaseSysCache(), RTE_FUNCTION, RangeTblEntry::rtekind, SearchSysCache1(), sql_fn_parser_setup(), sql_inline_error_callback(), substitute_actual_srf_parameters(), SysCacheGetAttr(), TextDatumGetCString, TYPEFUNC_COMPOSITE, TYPEFUNC_COMPOSITE_DOMAIN, and TYPEFUNC_RECORD.

Referenced by preprocess_function_rtes().

{
    RangeTblFunction *rtfunc;
    FuncExpr   *fexpr;
    Oid         func_oid;
    HeapTuple   func_tuple;
    Form_pg_proc funcform;
    char       *src;
    Datum       tmp;
    bool        isNull;
    MemoryContext oldcxt;
    MemoryContext mycxt;
    inline_error_callback_arg callback_arg;
    ErrorContextCallback sqlerrcontext;
    SQLFunctionParseInfoPtr pinfo;
    TypeFuncClass functypclass;
    TupleDesc   rettupdesc;
    List       *raw_parsetree_list;
    List       *querytree_list;
    Query      *querytree;

    Assert(rte->rtekind == RTE_FUNCTION);

    /*
     * It doesn't make a lot of sense for a SQL SRF to refer to itself in its
     * own FROM clause, since that must cause infinite recursion at runtime.
     * It will cause this code to recurse too, so check for stack overflow.
     * (There's no need to do more.)
     */
    check_stack_depth();

    /* Fail if the RTE has ORDINALITY - we don't implement that here. */
    if (rte->funcordinality)
        return NULL;

    /* Fail if RTE isn't a single, simple FuncExpr */
    if (list_length(rte->functions) != 1)
        return NULL;
    rtfunc = (RangeTblFunction *) linitial(rte->functions);

    if (!IsA(rtfunc->funcexpr, FuncExpr))
        return NULL;
    fexpr = (FuncExpr *) rtfunc->funcexpr;

    func_oid = fexpr->funcid;

    /*
     * The function must be declared to return a set, else inlining would
     * change the results if the contained SELECT didn't return exactly one
     * row.
     */
    if (!fexpr->funcretset)
        return NULL;

    /*
     * Refuse to inline if the arguments contain any volatile functions or
     * sub-selects.  Volatile functions are rejected because inlining may
     * result in the arguments being evaluated multiple times, risking a
     * change in behavior.  Sub-selects are rejected partly for implementation
     * reasons (pushing them down another level might change their behavior)
     * and partly because they're likely to be expensive and so multiple
     * evaluation would be bad.
     */
    if (contain_volatile_functions((Node *) fexpr->args) ||
        contain_subplans((Node *) fexpr->args))
        return NULL;

    /* Check permission to call function (fail later, if not) */
    if (pg_proc_aclcheck(func_oid, GetUserId(), ACL_EXECUTE) != ACLCHECK_OK)
        return NULL;

    /* Check whether a plugin wants to hook function entry/exit */
    if (FmgrHookIsNeeded(func_oid))
        return NULL;

    /*
     * OK, let's take a look at the function's pg_proc entry.
     */
    func_tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(func_oid));
    if (!HeapTupleIsValid(func_tuple))
        elog(ERROR, "cache lookup failed for function %u", func_oid);
    funcform = (Form_pg_proc) GETSTRUCT(func_tuple);

    /*
     * Forget it if the function is not SQL-language or has other showstopper
     * properties.  In particular it mustn't be declared STRICT, since we
     * couldn't enforce that.  It also mustn't be VOLATILE, because that is
     * supposed to cause it to be executed with its own snapshot, rather than
     * sharing the snapshot of the calling query.  We also disallow returning
     * SETOF VOID, because inlining would result in exposing the actual result
     * of the function's last SELECT, which should not happen in that case.
     * (Rechecking prokind, proretset, and pronargs is just paranoia.)
     */
    if (funcform->prolang != SQLlanguageId ||
        funcform->prokind != PROKIND_FUNCTION ||
        funcform->proisstrict ||
        funcform->provolatile == PROVOLATILE_VOLATILE ||
        funcform->prorettype == VOIDOID ||
        funcform->prosecdef ||
        !funcform->proretset ||
        list_length(fexpr->args) != funcform->pronargs ||
        !heap_attisnull(func_tuple, Anum_pg_proc_proconfig, NULL))
    {
        ReleaseSysCache(func_tuple);
        return NULL;
    }

    /*
     * Make a temporary memory context, so that we don't leak all the stuff
     * that parsing might create.
     */
    mycxt = AllocSetContextCreate(CurrentMemoryContext,
                                  "inline_set_returning_function",
                                  ALLOCSET_DEFAULT_SIZES);
    oldcxt = MemoryContextSwitchTo(mycxt);

    /* Fetch the function body */
    tmp = SysCacheGetAttr(PROCOID,
                          func_tuple,
                          Anum_pg_proc_prosrc,
                          &isNull);
    if (isNull)
        elog(ERROR, "null prosrc for function %u", func_oid);
    src = TextDatumGetCString(tmp);

    /*
     * Setup error traceback support for ereport().  This is so that we can
     * finger the function that bad information came from.
     */
    callback_arg.proname = NameStr(funcform->proname);
    callback_arg.prosrc = src;

    sqlerrcontext.callback = sql_inline_error_callback;
    sqlerrcontext.arg = (void *) &callback_arg;
    sqlerrcontext.previous = error_context_stack;
    error_context_stack = &sqlerrcontext;

    /*
     * Set up to handle parameters while parsing the function body.  We can
     * use the FuncExpr just created as the input for
     * prepare_sql_fn_parse_info.
     */
    pinfo = prepare_sql_fn_parse_info(func_tuple,
                                      (Node *) fexpr,
                                      fexpr->inputcollid);

    /*
     * Also resolve the actual function result tupdesc, if composite.  If the
     * function is just declared to return RECORD, dig the info out of the AS
     * clause.
     */
    functypclass = get_expr_result_type((Node *) fexpr, NULL, &rettupdesc);
    if (functypclass == TYPEFUNC_RECORD)
        rettupdesc = BuildDescFromLists(rtfunc->funccolnames,
                                        rtfunc->funccoltypes,
                                        rtfunc->funccoltypmods,
                                        rtfunc->funccolcollations);

    /*
     * Parse, analyze, and rewrite (unlike inline_function(), we can't skip
     * rewriting here).  We can fail as soon as we find more than one query,
     * though.
     */
    raw_parsetree_list = pg_parse_query(src);
    if (list_length(raw_parsetree_list) != 1)
        goto fail;

    querytree_list = pg_analyze_and_rewrite_params(linitial(raw_parsetree_list),
                                                   src,
                                                   (ParserSetupHook) sql_fn_parser_setup,
                                                   pinfo, NULL);
    if (list_length(querytree_list) != 1)
        goto fail;
    querytree = linitial(querytree_list);

    /*
     * The single command must be a plain SELECT.
     */
    if (!IsA(querytree, Query) ||
        querytree->commandType != CMD_SELECT)
        goto fail;

    /*
     * Make sure the function (still) returns what it's declared to.  This
     * will raise an error if wrong, but that's okay since the function would
     * fail at runtime anyway.  Note that check_sql_fn_retval will also insert
     * coercions if needed to make the tlist expression(s) match the declared
     * type of the function.  We also ask it to insert dummy NULL columns for
     * any dropped columns in rettupdesc, so that the elements of the modified
     * tlist match up to the attribute numbers.
     *
     * If the function returns a composite type, don't inline unless the check
     * shows it's returning a whole tuple result; otherwise what it's
     * returning is a single composite column which is not what we need.
     */
    if (!check_sql_fn_retval(list_make1(querytree_list),
                             fexpr->funcresulttype, rettupdesc,
                             true, NULL) &&
        (functypclass == TYPEFUNC_COMPOSITE ||
         functypclass == TYPEFUNC_COMPOSITE_DOMAIN ||
         functypclass == TYPEFUNC_RECORD))
        goto fail;              /* reject not-whole-tuple-result cases */

    /*
     * check_sql_fn_retval might've inserted a projection step, but that's
     * fine; just make sure we use the upper Query.
     */
    querytree = linitial_node(Query, querytree_list);

    /*
     * Looks good --- substitute parameters into the query.
     */
    querytree = substitute_actual_srf_parameters(querytree,
                                                 funcform->pronargs,
                                                 fexpr->args);

    /*
     * Copy the modified query out of the temporary memory context, and clean
     * up.
     */
    MemoryContextSwitchTo(oldcxt);

    querytree = copyObject(querytree);

    MemoryContextDelete(mycxt);
    error_context_stack = sqlerrcontext.previous;
    ReleaseSysCache(func_tuple);

    /*
     * We don't have to fix collations here because the upper query is already
     * parsed, ie, the collations in the RTE are what count.
     */

    /*
     * Since there is now no trace of the function in the plan tree, we must
     * explicitly record the plan's dependency on the function.
     */
    record_plan_function_dependency(root, func_oid);

    return querytree;

    /* Here if func is not inlinable: release temp memory and return NULL */
fail:
    MemoryContextSwitchTo(oldcxt);
    MemoryContextDelete(mycxt);
    error_context_stack = sqlerrcontext.previous;
    ReleaseSysCache(func_tuple);

    return NULL;
}