postgresql/src/backend/nodes/nodeFuncs.c

3988 lines
108 KiB
C

/*-------------------------------------------------------------------------
*
* nodeFuncs.c
* Various general-purpose manipulations of Node trees
*
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/nodes/nodeFuncs.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_type.h"
#include "miscadmin.h"
#include "nodes/execnodes.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "nodes/pathnodes.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
static bool expression_returns_set_walker(Node *node, void *context);
static int leftmostLoc(int loc1, int loc2);
static bool fix_opfuncids_walker(Node *node, void *context);
static bool planstate_walk_subplans(List *plans, bool (*walker) (),
void *context);
static bool planstate_walk_members(PlanState **planstates, int nplans,
bool (*walker) (), void *context);
/*
* exprType -
* returns the Oid of the type of the expression's result.
*/
Oid
exprType(const Node *expr)
{
Oid type;
if (!expr)
return InvalidOid;
switch (nodeTag(expr))
{
case T_Var:
type = ((const Var *) expr)->vartype;
break;
case T_Const:
type = ((const Const *) expr)->consttype;
break;
case T_Param:
type = ((const Param *) expr)->paramtype;
break;
case T_Aggref:
type = ((const Aggref *) expr)->aggtype;
break;
case T_GroupingFunc:
type = INT4OID;
break;
case T_WindowFunc:
type = ((const WindowFunc *) expr)->wintype;
break;
case T_SubscriptingRef:
{
const SubscriptingRef *sbsref = (const SubscriptingRef *) expr;
/* slice and/or store operations yield the container type */
if (sbsref->reflowerindexpr || sbsref->refassgnexpr)
type = sbsref->refcontainertype;
else
type = sbsref->refelemtype;
}
break;
case T_FuncExpr:
type = ((const FuncExpr *) expr)->funcresulttype;
break;
case T_NamedArgExpr:
type = exprType((Node *) ((const NamedArgExpr *) expr)->arg);
break;
case T_OpExpr:
type = ((const OpExpr *) expr)->opresulttype;
break;
case T_DistinctExpr:
type = ((const DistinctExpr *) expr)->opresulttype;
break;
case T_NullIfExpr:
type = ((const NullIfExpr *) expr)->opresulttype;
break;
case T_ScalarArrayOpExpr:
type = BOOLOID;
break;
case T_BoolExpr:
type = BOOLOID;
break;
case T_SubLink:
{
const SubLink *sublink = (const SubLink *) expr;
if (sublink->subLinkType == EXPR_SUBLINK ||
sublink->subLinkType == ARRAY_SUBLINK)
{
/* get the type of the subselect's first target column */
Query *qtree = (Query *) sublink->subselect;
TargetEntry *tent;
if (!qtree || !IsA(qtree, Query))
elog(ERROR, "cannot get type for untransformed sublink");
tent = linitial_node(TargetEntry, qtree->targetList);
Assert(!tent->resjunk);
type = exprType((Node *) tent->expr);
if (sublink->subLinkType == ARRAY_SUBLINK)
{
type = get_promoted_array_type(type);
if (!OidIsValid(type))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("could not find array type for data type %s",
format_type_be(exprType((Node *) tent->expr)))));
}
}
else if (sublink->subLinkType == MULTIEXPR_SUBLINK)
{
/* MULTIEXPR is always considered to return RECORD */
type = RECORDOID;
}
else
{
/* for all other sublink types, result is boolean */
type = BOOLOID;
}
}
break;
case T_SubPlan:
{
const SubPlan *subplan = (const SubPlan *) expr;
if (subplan->subLinkType == EXPR_SUBLINK ||
subplan->subLinkType == ARRAY_SUBLINK)
{
/* get the type of the subselect's first target column */
type = subplan->firstColType;
if (subplan->subLinkType == ARRAY_SUBLINK)
{
type = get_promoted_array_type(type);
if (!OidIsValid(type))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("could not find array type for data type %s",
format_type_be(subplan->firstColType))));
}
}
else if (subplan->subLinkType == MULTIEXPR_SUBLINK)
{
/* MULTIEXPR is always considered to return RECORD */
type = RECORDOID;
}
else
{
/* for all other subplan types, result is boolean */
type = BOOLOID;
}
}
break;
case T_AlternativeSubPlan:
{
const AlternativeSubPlan *asplan = (const AlternativeSubPlan *) expr;
/* subplans should all return the same thing */
type = exprType((Node *) linitial(asplan->subplans));
}
break;
case T_FieldSelect:
type = ((const FieldSelect *) expr)->resulttype;
break;
case T_FieldStore:
type = ((const FieldStore *) expr)->resulttype;
break;
case T_RelabelType:
type = ((const RelabelType *) expr)->resulttype;
break;
case T_CoerceViaIO:
type = ((const CoerceViaIO *) expr)->resulttype;
break;
case T_ArrayCoerceExpr:
type = ((const ArrayCoerceExpr *) expr)->resulttype;
break;
case T_ConvertRowtypeExpr:
type = ((const ConvertRowtypeExpr *) expr)->resulttype;
break;
case T_CollateExpr:
type = exprType((Node *) ((const CollateExpr *) expr)->arg);
break;
case T_CaseExpr:
type = ((const CaseExpr *) expr)->casetype;
break;
case T_CaseTestExpr:
type = ((const CaseTestExpr *) expr)->typeId;
break;
case T_ArrayExpr:
type = ((const ArrayExpr *) expr)->array_typeid;
break;
case T_RowExpr:
type = ((const RowExpr *) expr)->row_typeid;
break;
case T_RowCompareExpr:
type = BOOLOID;
break;
case T_CoalesceExpr:
type = ((const CoalesceExpr *) expr)->coalescetype;
break;
case T_MinMaxExpr:
type = ((const MinMaxExpr *) expr)->minmaxtype;
break;
case T_SQLValueFunction:
type = ((const SQLValueFunction *) expr)->type;
break;
case T_XmlExpr:
if (((const XmlExpr *) expr)->op == IS_DOCUMENT)
type = BOOLOID;
else if (((const XmlExpr *) expr)->op == IS_XMLSERIALIZE)
type = TEXTOID;
else
type = XMLOID;
break;
case T_NullTest:
type = BOOLOID;
break;
case T_BooleanTest:
type = BOOLOID;
break;
case T_CoerceToDomain:
type = ((const CoerceToDomain *) expr)->resulttype;
break;
case T_CoerceToDomainValue:
type = ((const CoerceToDomainValue *) expr)->typeId;
break;
case T_SetToDefault:
type = ((const SetToDefault *) expr)->typeId;
break;
case T_CurrentOfExpr:
type = BOOLOID;
break;
case T_NextValueExpr:
type = ((const NextValueExpr *) expr)->typeId;
break;
case T_InferenceElem:
{
const InferenceElem *n = (const InferenceElem *) expr;
type = exprType((Node *) n->expr);
}
break;
case T_PlaceHolderVar:
type = exprType((Node *) ((const PlaceHolderVar *) expr)->phexpr);
break;
default:
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
type = InvalidOid; /* keep compiler quiet */
break;
}
return type;
}
/*
* exprTypmod -
* returns the type-specific modifier of the expression's result type,
* if it can be determined. In many cases, it can't and we return -1.
*/
int32
exprTypmod(const Node *expr)
{
if (!expr)
return -1;
switch (nodeTag(expr))
{
case T_Var:
return ((const Var *) expr)->vartypmod;
case T_Const:
return ((const Const *) expr)->consttypmod;
case T_Param:
return ((const Param *) expr)->paramtypmod;
case T_SubscriptingRef:
/* typmod is the same for container or element */
return ((const SubscriptingRef *) expr)->reftypmod;
case T_FuncExpr:
{
int32 coercedTypmod;
/* Be smart about length-coercion functions... */
if (exprIsLengthCoercion(expr, &coercedTypmod))
return coercedTypmod;
}
break;
case T_NamedArgExpr:
return exprTypmod((Node *) ((const NamedArgExpr *) expr)->arg);
case T_NullIfExpr:
{
/*
* Result is either first argument or NULL, so we can report
* first argument's typmod if known.
*/
const NullIfExpr *nexpr = (const NullIfExpr *) expr;
return exprTypmod((Node *) linitial(nexpr->args));
}
break;
case T_SubLink:
{
const SubLink *sublink = (const SubLink *) expr;
if (sublink->subLinkType == EXPR_SUBLINK ||
sublink->subLinkType == ARRAY_SUBLINK)
{
/* get the typmod of the subselect's first target column */
Query *qtree = (Query *) sublink->subselect;
TargetEntry *tent;
if (!qtree || !IsA(qtree, Query))
elog(ERROR, "cannot get type for untransformed sublink");
tent = linitial_node(TargetEntry, qtree->targetList);
Assert(!tent->resjunk);
return exprTypmod((Node *) tent->expr);
/* note we don't need to care if it's an array */
}
/* otherwise, result is RECORD or BOOLEAN, typmod is -1 */
}
break;
case T_SubPlan:
{
const SubPlan *subplan = (const SubPlan *) expr;
if (subplan->subLinkType == EXPR_SUBLINK ||
subplan->subLinkType == ARRAY_SUBLINK)
{
/* get the typmod of the subselect's first target column */
/* note we don't need to care if it's an array */
return subplan->firstColTypmod;
}
/* otherwise, result is RECORD or BOOLEAN, typmod is -1 */
}
break;
case T_AlternativeSubPlan:
{
const AlternativeSubPlan *asplan = (const AlternativeSubPlan *) expr;
/* subplans should all return the same thing */
return exprTypmod((Node *) linitial(asplan->subplans));
}
break;
case T_FieldSelect:
return ((const FieldSelect *) expr)->resulttypmod;
case T_RelabelType:
return ((const RelabelType *) expr)->resulttypmod;
case T_ArrayCoerceExpr:
return ((const ArrayCoerceExpr *) expr)->resulttypmod;
case T_CollateExpr:
return exprTypmod((Node *) ((const CollateExpr *) expr)->arg);
case T_CaseExpr:
{
/*
* If all the alternatives agree on type/typmod, return that
* typmod, else use -1
*/
const CaseExpr *cexpr = (const CaseExpr *) expr;
Oid casetype = cexpr->casetype;
int32 typmod;
ListCell *arg;
if (!cexpr->defresult)
return -1;
if (exprType((Node *) cexpr->defresult) != casetype)
return -1;
typmod = exprTypmod((Node *) cexpr->defresult);
if (typmod < 0)
return -1; /* no point in trying harder */
foreach(arg, cexpr->args)
{
CaseWhen *w = lfirst_node(CaseWhen, arg);
if (exprType((Node *) w->result) != casetype)
return -1;
if (exprTypmod((Node *) w->result) != typmod)
return -1;
}
return typmod;
}
break;
case T_CaseTestExpr:
return ((const CaseTestExpr *) expr)->typeMod;
case T_ArrayExpr:
{
/*
* If all the elements agree on type/typmod, return that
* typmod, else use -1
*/
const ArrayExpr *arrayexpr = (const ArrayExpr *) expr;
Oid commontype;
int32 typmod;
ListCell *elem;
if (arrayexpr->elements == NIL)
return -1;
typmod = exprTypmod((Node *) linitial(arrayexpr->elements));
if (typmod < 0)
return -1; /* no point in trying harder */
if (arrayexpr->multidims)
commontype = arrayexpr->array_typeid;
else
commontype = arrayexpr->element_typeid;
foreach(elem, arrayexpr->elements)
{
Node *e = (Node *) lfirst(elem);
if (exprType(e) != commontype)
return -1;
if (exprTypmod(e) != typmod)
return -1;
}
return typmod;
}
break;
case T_CoalesceExpr:
{
/*
* If all the alternatives agree on type/typmod, return that
* typmod, else use -1
*/
const CoalesceExpr *cexpr = (const CoalesceExpr *) expr;
Oid coalescetype = cexpr->coalescetype;
int32 typmod;
ListCell *arg;
if (exprType((Node *) linitial(cexpr->args)) != coalescetype)
return -1;
typmod = exprTypmod((Node *) linitial(cexpr->args));
if (typmod < 0)
return -1; /* no point in trying harder */
for_each_cell(arg, cexpr->args, list_second_cell(cexpr->args))
{
Node *e = (Node *) lfirst(arg);
if (exprType(e) != coalescetype)
return -1;
if (exprTypmod(e) != typmod)
return -1;
}
return typmod;
}
break;
case T_MinMaxExpr:
{
/*
* If all the alternatives agree on type/typmod, return that
* typmod, else use -1
*/
const MinMaxExpr *mexpr = (const MinMaxExpr *) expr;
Oid minmaxtype = mexpr->minmaxtype;
int32 typmod;
ListCell *arg;
if (exprType((Node *) linitial(mexpr->args)) != minmaxtype)
return -1;
typmod = exprTypmod((Node *) linitial(mexpr->args));
if (typmod < 0)
return -1; /* no point in trying harder */
for_each_cell(arg, mexpr->args, list_second_cell(mexpr->args))
{
Node *e = (Node *) lfirst(arg);
if (exprType(e) != minmaxtype)
return -1;
if (exprTypmod(e) != typmod)
return -1;
}
return typmod;
}
break;
case T_SQLValueFunction:
return ((const SQLValueFunction *) expr)->typmod;
case T_CoerceToDomain:
return ((const CoerceToDomain *) expr)->resulttypmod;
case T_CoerceToDomainValue:
return ((const CoerceToDomainValue *) expr)->typeMod;
case T_SetToDefault:
return ((const SetToDefault *) expr)->typeMod;
case T_PlaceHolderVar:
return exprTypmod((Node *) ((const PlaceHolderVar *) expr)->phexpr);
default:
break;
}
return -1;
}
/*
* exprIsLengthCoercion
* Detect whether an expression tree is an application of a datatype's
* typmod-coercion function. Optionally extract the result's typmod.
*
* If coercedTypmod is not NULL, the typmod is stored there if the expression
* is a length-coercion function, else -1 is stored there.
*
* Note that a combined type-and-length coercion will be treated as a
* length coercion by this routine.
*/
bool
exprIsLengthCoercion(const Node *expr, int32 *coercedTypmod)
{
if (coercedTypmod != NULL)
*coercedTypmod = -1; /* default result on failure */
/*
* Scalar-type length coercions are FuncExprs, array-type length coercions
* are ArrayCoerceExprs
*/
if (expr && IsA(expr, FuncExpr))
{
const FuncExpr *func = (const FuncExpr *) expr;
int nargs;
Const *second_arg;
/*
* If it didn't come from a coercion context, reject.
*/
if (func->funcformat != COERCE_EXPLICIT_CAST &&
func->funcformat != COERCE_IMPLICIT_CAST)
return false;
/*
* If it's not a two-argument or three-argument function with the
* second argument being an int4 constant, it can't have been created
* from a length coercion (it must be a type coercion, instead).
*/
nargs = list_length(func->args);
if (nargs < 2 || nargs > 3)
return false;
second_arg = (Const *) lsecond(func->args);
if (!IsA(second_arg, Const) ||
second_arg->consttype != INT4OID ||
second_arg->constisnull)
return false;
/*
* OK, it is indeed a length-coercion function.
*/
if (coercedTypmod != NULL)
*coercedTypmod = DatumGetInt32(second_arg->constvalue);
return true;
}
if (expr && IsA(expr, ArrayCoerceExpr))
{
const ArrayCoerceExpr *acoerce = (const ArrayCoerceExpr *) expr;
/* It's not a length coercion unless there's a nondefault typmod */
if (acoerce->resulttypmod < 0)
return false;
/*
* OK, it is indeed a length-coercion expression.
*/
if (coercedTypmod != NULL)
*coercedTypmod = acoerce->resulttypmod;
return true;
}
return false;
}
/*
* relabel_to_typmod
* Add a RelabelType node that changes just the typmod of the expression.
*
* This is primarily intended to be used during planning. Therefore, it
* strips any existing RelabelType nodes to maintain the planner's invariant
* that there are not adjacent RelabelTypes.
*/
Node *
relabel_to_typmod(Node *expr, int32 typmod)
{
Oid type = exprType(expr);
Oid coll = exprCollation(expr);
/* Strip any existing RelabelType node(s) */
while (expr && IsA(expr, RelabelType))
expr = (Node *) ((RelabelType *) expr)->arg;
/* Apply new typmod, preserving the previous exposed type and collation */
return (Node *) makeRelabelType((Expr *) expr, type, typmod, coll,
COERCE_EXPLICIT_CAST);
}
/*
* strip_implicit_coercions: remove implicit coercions at top level of tree
*
* This doesn't modify or copy the input expression tree, just return a
* pointer to a suitable place within it.
*
* Note: there isn't any useful thing we can do with a RowExpr here, so
* just return it unchanged, even if it's marked as an implicit coercion.
*/
Node *
strip_implicit_coercions(Node *node)
{
if (node == NULL)
return NULL;
if (IsA(node, FuncExpr))
{
FuncExpr *f = (FuncExpr *) node;
if (f->funcformat == COERCE_IMPLICIT_CAST)
return strip_implicit_coercions(linitial(f->args));
}
else if (IsA(node, RelabelType))
{
RelabelType *r = (RelabelType *) node;
if (r->relabelformat == COERCE_IMPLICIT_CAST)
return strip_implicit_coercions((Node *) r->arg);
}
else if (IsA(node, CoerceViaIO))
{
CoerceViaIO *c = (CoerceViaIO *) node;
if (c->coerceformat == COERCE_IMPLICIT_CAST)
return strip_implicit_coercions((Node *) c->arg);
}
else if (IsA(node, ArrayCoerceExpr))
{
ArrayCoerceExpr *c = (ArrayCoerceExpr *) node;
if (c->coerceformat == COERCE_IMPLICIT_CAST)
return strip_implicit_coercions((Node *) c->arg);
}
else if (IsA(node, ConvertRowtypeExpr))
{
ConvertRowtypeExpr *c = (ConvertRowtypeExpr *) node;
if (c->convertformat == COERCE_IMPLICIT_CAST)
return strip_implicit_coercions((Node *) c->arg);
}
else if (IsA(node, CoerceToDomain))
{
CoerceToDomain *c = (CoerceToDomain *) node;
if (c->coercionformat == COERCE_IMPLICIT_CAST)
return strip_implicit_coercions((Node *) c->arg);
}
return node;
}
/*
* expression_returns_set
* Test whether an expression returns a set result.
*
* Because we use expression_tree_walker(), this can also be applied to
* whole targetlists; it'll produce true if any one of the tlist items
* returns a set.
*/
bool
expression_returns_set(Node *clause)
{
return expression_returns_set_walker(clause, NULL);
}
static bool
expression_returns_set_walker(Node *node, void *context)
{
if (node == NULL)
return false;
if (IsA(node, FuncExpr))
{
FuncExpr *expr = (FuncExpr *) node;
if (expr->funcretset)
return true;
/* else fall through to check args */
}
if (IsA(node, OpExpr))
{
OpExpr *expr = (OpExpr *) node;
if (expr->opretset)
return true;
/* else fall through to check args */
}
/* Avoid recursion for some cases that parser checks not to return a set */
if (IsA(node, Aggref))
return false;
if (IsA(node, WindowFunc))
return false;
return expression_tree_walker(node, expression_returns_set_walker,
context);
}
/*
* exprCollation -
* returns the Oid of the collation of the expression's result.
*
* Note: expression nodes that can invoke functions generally have an
* "inputcollid" field, which is what the function should use as collation.
* That is the resolved common collation of the node's inputs. It is often
* but not always the same as the result collation; in particular, if the
* function produces a non-collatable result type from collatable inputs
* or vice versa, the two are different.
*/
Oid
exprCollation(const Node *expr)
{
Oid coll;
if (!expr)
return InvalidOid;
switch (nodeTag(expr))
{
case T_Var:
coll = ((const Var *) expr)->varcollid;
break;
case T_Const:
coll = ((const Const *) expr)->constcollid;
break;
case T_Param:
coll = ((const Param *) expr)->paramcollid;
break;
case T_Aggref:
coll = ((const Aggref *) expr)->aggcollid;
break;
case T_GroupingFunc:
coll = InvalidOid;
break;
case T_WindowFunc:
coll = ((const WindowFunc *) expr)->wincollid;
break;
case T_SubscriptingRef:
coll = ((const SubscriptingRef *) expr)->refcollid;
break;
case T_FuncExpr:
coll = ((const FuncExpr *) expr)->funccollid;
break;
case T_NamedArgExpr:
coll = exprCollation((Node *) ((const NamedArgExpr *) expr)->arg);
break;
case T_OpExpr:
coll = ((const OpExpr *) expr)->opcollid;
break;
case T_DistinctExpr:
coll = ((const DistinctExpr *) expr)->opcollid;
break;
case T_NullIfExpr:
coll = ((const NullIfExpr *) expr)->opcollid;
break;
case T_ScalarArrayOpExpr:
coll = InvalidOid; /* result is always boolean */
break;
case T_BoolExpr:
coll = InvalidOid; /* result is always boolean */
break;
case T_SubLink:
{
const SubLink *sublink = (const SubLink *) expr;
if (sublink->subLinkType == EXPR_SUBLINK ||
sublink->subLinkType == ARRAY_SUBLINK)
{
/* get the collation of subselect's first target column */
Query *qtree = (Query *) sublink->subselect;
TargetEntry *tent;
if (!qtree || !IsA(qtree, Query))
elog(ERROR, "cannot get collation for untransformed sublink");
tent = linitial_node(TargetEntry, qtree->targetList);
Assert(!tent->resjunk);
coll = exprCollation((Node *) tent->expr);
/* collation doesn't change if it's converted to array */
}
else
{
/* otherwise, result is RECORD or BOOLEAN */
coll = InvalidOid;
}
}
break;
case T_SubPlan:
{
const SubPlan *subplan = (const SubPlan *) expr;
if (subplan->subLinkType == EXPR_SUBLINK ||
subplan->subLinkType == ARRAY_SUBLINK)
{
/* get the collation of subselect's first target column */
coll = subplan->firstColCollation;
/* collation doesn't change if it's converted to array */
}
else
{
/* otherwise, result is RECORD or BOOLEAN */
coll = InvalidOid;
}
}
break;
case T_AlternativeSubPlan:
{
const AlternativeSubPlan *asplan = (const AlternativeSubPlan *) expr;
/* subplans should all return the same thing */
coll = exprCollation((Node *) linitial(asplan->subplans));
}
break;
case T_FieldSelect:
coll = ((const FieldSelect *) expr)->resultcollid;
break;
case T_FieldStore:
coll = InvalidOid; /* result is always composite */
break;
case T_RelabelType:
coll = ((const RelabelType *) expr)->resultcollid;
break;
case T_CoerceViaIO:
coll = ((const CoerceViaIO *) expr)->resultcollid;
break;
case T_ArrayCoerceExpr:
coll = ((const ArrayCoerceExpr *) expr)->resultcollid;
break;
case T_ConvertRowtypeExpr:
coll = InvalidOid; /* result is always composite */
break;
case T_CollateExpr:
coll = ((const CollateExpr *) expr)->collOid;
break;
case T_CaseExpr:
coll = ((const CaseExpr *) expr)->casecollid;
break;
case T_CaseTestExpr:
coll = ((const CaseTestExpr *) expr)->collation;
break;
case T_ArrayExpr:
coll = ((const ArrayExpr *) expr)->array_collid;
break;
case T_RowExpr:
coll = InvalidOid; /* result is always composite */
break;
case T_RowCompareExpr:
coll = InvalidOid; /* result is always boolean */
break;
case T_CoalesceExpr:
coll = ((const CoalesceExpr *) expr)->coalescecollid;
break;
case T_MinMaxExpr:
coll = ((const MinMaxExpr *) expr)->minmaxcollid;
break;
case T_SQLValueFunction:
/* Returns either NAME or a non-collatable type */
if (((const SQLValueFunction *) expr)->type == NAMEOID)
coll = C_COLLATION_OID;
else
coll = InvalidOid;
break;
case T_XmlExpr:
/*
* XMLSERIALIZE returns text from non-collatable inputs, so its
* collation is always default. The other cases return boolean or
* XML, which are non-collatable.
*/
if (((const XmlExpr *) expr)->op == IS_XMLSERIALIZE)
coll = DEFAULT_COLLATION_OID;
else
coll = InvalidOid;
break;
case T_NullTest:
coll = InvalidOid; /* result is always boolean */
break;
case T_BooleanTest:
coll = InvalidOid; /* result is always boolean */
break;
case T_CoerceToDomain:
coll = ((const CoerceToDomain *) expr)->resultcollid;
break;
case T_CoerceToDomainValue:
coll = ((const CoerceToDomainValue *) expr)->collation;
break;
case T_SetToDefault:
coll = ((const SetToDefault *) expr)->collation;
break;
case T_CurrentOfExpr:
coll = InvalidOid; /* result is always boolean */
break;
case T_NextValueExpr:
coll = InvalidOid; /* result is always an integer type */
break;
case T_InferenceElem:
coll = exprCollation((Node *) ((const InferenceElem *) expr)->expr);
break;
case T_PlaceHolderVar:
coll = exprCollation((Node *) ((const PlaceHolderVar *) expr)->phexpr);
break;
default:
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
coll = InvalidOid; /* keep compiler quiet */
break;
}
return coll;
}
/*
* exprInputCollation -
* returns the Oid of the collation a function should use, if available.
*
* Result is InvalidOid if the node type doesn't store this information.
*/
Oid
exprInputCollation(const Node *expr)
{
Oid coll;
if (!expr)
return InvalidOid;
switch (nodeTag(expr))
{
case T_Aggref:
coll = ((const Aggref *) expr)->inputcollid;
break;
case T_WindowFunc:
coll = ((const WindowFunc *) expr)->inputcollid;
break;
case T_FuncExpr:
coll = ((const FuncExpr *) expr)->inputcollid;
break;
case T_OpExpr:
coll = ((const OpExpr *) expr)->inputcollid;
break;
case T_DistinctExpr:
coll = ((const DistinctExpr *) expr)->inputcollid;
break;
case T_NullIfExpr:
coll = ((const NullIfExpr *) expr)->inputcollid;
break;
case T_ScalarArrayOpExpr:
coll = ((const ScalarArrayOpExpr *) expr)->inputcollid;
break;
case T_MinMaxExpr:
coll = ((const MinMaxExpr *) expr)->inputcollid;
break;
default:
coll = InvalidOid;
break;
}
return coll;
}
/*
* exprSetCollation -
* Assign collation information to an expression tree node.
*
* Note: since this is only used during parse analysis, we don't need to
* worry about subplans or PlaceHolderVars.
*/
void
exprSetCollation(Node *expr, Oid collation)
{
switch (nodeTag(expr))
{
case T_Var:
((Var *) expr)->varcollid = collation;
break;
case T_Const:
((Const *) expr)->constcollid = collation;
break;
case T_Param:
((Param *) expr)->paramcollid = collation;
break;
case T_Aggref:
((Aggref *) expr)->aggcollid = collation;
break;
case T_GroupingFunc:
Assert(!OidIsValid(collation));
break;
case T_WindowFunc:
((WindowFunc *) expr)->wincollid = collation;
break;
case T_SubscriptingRef:
((SubscriptingRef *) expr)->refcollid = collation;
break;
case T_FuncExpr:
((FuncExpr *) expr)->funccollid = collation;
break;
case T_NamedArgExpr:
Assert(collation == exprCollation((Node *) ((NamedArgExpr *) expr)->arg));
break;
case T_OpExpr:
((OpExpr *) expr)->opcollid = collation;
break;
case T_DistinctExpr:
((DistinctExpr *) expr)->opcollid = collation;
break;
case T_NullIfExpr:
((NullIfExpr *) expr)->opcollid = collation;
break;
case T_ScalarArrayOpExpr:
Assert(!OidIsValid(collation)); /* result is always boolean */
break;
case T_BoolExpr:
Assert(!OidIsValid(collation)); /* result is always boolean */
break;
case T_SubLink:
#ifdef USE_ASSERT_CHECKING
{
SubLink *sublink = (SubLink *) expr;
if (sublink->subLinkType == EXPR_SUBLINK ||
sublink->subLinkType == ARRAY_SUBLINK)
{
/* get the collation of subselect's first target column */
Query *qtree = (Query *) sublink->subselect;
TargetEntry *tent;
if (!qtree || !IsA(qtree, Query))
elog(ERROR, "cannot set collation for untransformed sublink");
tent = linitial_node(TargetEntry, qtree->targetList);
Assert(!tent->resjunk);
Assert(collation == exprCollation((Node *) tent->expr));
}
else
{
/* otherwise, result is RECORD or BOOLEAN */
Assert(!OidIsValid(collation));
}
}
#endif /* USE_ASSERT_CHECKING */
break;
case T_FieldSelect:
((FieldSelect *) expr)->resultcollid = collation;
break;
case T_FieldStore:
Assert(!OidIsValid(collation)); /* result is always composite */
break;
case T_RelabelType:
((RelabelType *) expr)->resultcollid = collation;
break;
case T_CoerceViaIO:
((CoerceViaIO *) expr)->resultcollid = collation;
break;
case T_ArrayCoerceExpr:
((ArrayCoerceExpr *) expr)->resultcollid = collation;
break;
case T_ConvertRowtypeExpr:
Assert(!OidIsValid(collation)); /* result is always composite */
break;
case T_CaseExpr:
((CaseExpr *) expr)->casecollid = collation;
break;
case T_ArrayExpr:
((ArrayExpr *) expr)->array_collid = collation;
break;
case T_RowExpr:
Assert(!OidIsValid(collation)); /* result is always composite */
break;
case T_RowCompareExpr:
Assert(!OidIsValid(collation)); /* result is always boolean */
break;
case T_CoalesceExpr:
((CoalesceExpr *) expr)->coalescecollid = collation;
break;
case T_MinMaxExpr:
((MinMaxExpr *) expr)->minmaxcollid = collation;
break;
case T_SQLValueFunction:
Assert((((SQLValueFunction *) expr)->type == NAMEOID) ?
(collation == C_COLLATION_OID) :
(collation == InvalidOid));
break;
case T_XmlExpr:
Assert((((XmlExpr *) expr)->op == IS_XMLSERIALIZE) ?
(collation == DEFAULT_COLLATION_OID) :
(collation == InvalidOid));
break;
case T_NullTest:
Assert(!OidIsValid(collation)); /* result is always boolean */
break;
case T_BooleanTest:
Assert(!OidIsValid(collation)); /* result is always boolean */
break;
case T_CoerceToDomain:
((CoerceToDomain *) expr)->resultcollid = collation;
break;
case T_CoerceToDomainValue:
((CoerceToDomainValue *) expr)->collation = collation;
break;
case T_SetToDefault:
((SetToDefault *) expr)->collation = collation;
break;
case T_CurrentOfExpr:
Assert(!OidIsValid(collation)); /* result is always boolean */
break;
case T_NextValueExpr:
Assert(!OidIsValid(collation)); /* result is always an integer
* type */
break;
default:
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
break;
}
}
/*
* exprSetInputCollation -
* Assign input-collation information to an expression tree node.
*
* This is a no-op for node types that don't store their input collation.
* Note we omit RowCompareExpr, which needs special treatment since it
* contains multiple input collation OIDs.
*/
void
exprSetInputCollation(Node *expr, Oid inputcollation)
{
switch (nodeTag(expr))
{
case T_Aggref:
((Aggref *) expr)->inputcollid = inputcollation;
break;
case T_WindowFunc:
((WindowFunc *) expr)->inputcollid = inputcollation;
break;
case T_FuncExpr:
((FuncExpr *) expr)->inputcollid = inputcollation;
break;
case T_OpExpr:
((OpExpr *) expr)->inputcollid = inputcollation;
break;
case T_DistinctExpr:
((DistinctExpr *) expr)->inputcollid = inputcollation;
break;
case T_NullIfExpr:
((NullIfExpr *) expr)->inputcollid = inputcollation;
break;
case T_ScalarArrayOpExpr:
((ScalarArrayOpExpr *) expr)->inputcollid = inputcollation;
break;
case T_MinMaxExpr:
((MinMaxExpr *) expr)->inputcollid = inputcollation;
break;
default:
break;
}
}
/*
* exprLocation -
* returns the parse location of an expression tree, for error reports
*
* -1 is returned if the location can't be determined.
*
* For expressions larger than a single token, the intent here is to
* return the location of the expression's leftmost token, not necessarily
* the topmost Node's location field. For example, an OpExpr's location
* field will point at the operator name, but if it is not a prefix operator
* then we should return the location of the left-hand operand instead.
* The reason is that we want to reference the entire expression not just
* that operator, and pointing to its start seems to be the most natural way.
*
* The location is not perfect --- for example, since the grammar doesn't
* explicitly represent parentheses in the parsetree, given something that
* had been written "(a + b) * c" we are going to point at "a" not "(".
* But it should be plenty good enough for error reporting purposes.
*
* You might think that this code is overly general, for instance why check
* the operands of a FuncExpr node, when the function name can be expected
* to be to the left of them? There are a couple of reasons. The grammar
* sometimes builds expressions that aren't quite what the user wrote;
* for instance x IS NOT BETWEEN ... becomes a NOT-expression whose keyword
* pointer is to the right of its leftmost argument. Also, nodes that were
* inserted implicitly by parse analysis (such as FuncExprs for implicit
* coercions) will have location -1, and so we can have odd combinations of
* known and unknown locations in a tree.
*/
int
exprLocation(const Node *expr)
{
int loc;
if (expr == NULL)
return -1;
switch (nodeTag(expr))
{
case T_RangeVar:
loc = ((const RangeVar *) expr)->location;
break;
case T_TableFunc:
loc = ((const TableFunc *) expr)->location;
break;
case T_Var:
loc = ((const Var *) expr)->location;
break;
case T_Const:
loc = ((const Const *) expr)->location;
break;
case T_Param:
loc = ((const Param *) expr)->location;
break;
case T_Aggref:
/* function name should always be the first thing */
loc = ((const Aggref *) expr)->location;
break;
case T_GroupingFunc:
loc = ((const GroupingFunc *) expr)->location;
break;
case T_WindowFunc:
/* function name should always be the first thing */
loc = ((const WindowFunc *) expr)->location;
break;
case T_SubscriptingRef:
/* just use container argument's location */
loc = exprLocation((Node *) ((const SubscriptingRef *) expr)->refexpr);
break;
case T_FuncExpr:
{
const FuncExpr *fexpr = (const FuncExpr *) expr;
/* consider both function name and leftmost arg */
loc = leftmostLoc(fexpr->location,
exprLocation((Node *) fexpr->args));
}
break;
case T_NamedArgExpr:
{
const NamedArgExpr *na = (const NamedArgExpr *) expr;
/* consider both argument name and value */
loc = leftmostLoc(na->location,
exprLocation((Node *) na->arg));
}
break;
case T_OpExpr:
case T_DistinctExpr: /* struct-equivalent to OpExpr */
case T_NullIfExpr: /* struct-equivalent to OpExpr */
{
const OpExpr *opexpr = (const OpExpr *) expr;
/* consider both operator name and leftmost arg */
loc = leftmostLoc(opexpr->location,
exprLocation((Node *) opexpr->args));
}
break;
case T_ScalarArrayOpExpr:
{
const ScalarArrayOpExpr *saopexpr = (const ScalarArrayOpExpr *) expr;
/* consider both operator name and leftmost arg */
loc = leftmostLoc(saopexpr->location,
exprLocation((Node *) saopexpr->args));
}
break;
case T_BoolExpr:
{
const BoolExpr *bexpr = (const BoolExpr *) expr;
/*
* Same as above, to handle either NOT or AND/OR. We can't
* special-case NOT because of the way that it's used for
* things like IS NOT BETWEEN.
*/
loc = leftmostLoc(bexpr->location,
exprLocation((Node *) bexpr->args));
}
break;
case T_SubLink:
{
const SubLink *sublink = (const SubLink *) expr;
/* check the testexpr, if any, and the operator/keyword */
loc = leftmostLoc(exprLocation(sublink->testexpr),
sublink->location);
}
break;
case T_FieldSelect:
/* just use argument's location */
loc = exprLocation((Node *) ((const FieldSelect *) expr)->arg);
break;
case T_FieldStore:
/* just use argument's location */
loc = exprLocation((Node *) ((const FieldStore *) expr)->arg);
break;
case T_RelabelType:
{
const RelabelType *rexpr = (const RelabelType *) expr;
/* Much as above */
loc = leftmostLoc(rexpr->location,
exprLocation((Node *) rexpr->arg));
}
break;
case T_CoerceViaIO:
{
const CoerceViaIO *cexpr = (const CoerceViaIO *) expr;
/* Much as above */
loc = leftmostLoc(cexpr->location,
exprLocation((Node *) cexpr->arg));
}
break;
case T_ArrayCoerceExpr:
{
const ArrayCoerceExpr *cexpr = (const ArrayCoerceExpr *) expr;
/* Much as above */
loc = leftmostLoc(cexpr->location,
exprLocation((Node *) cexpr->arg));
}
break;
case T_ConvertRowtypeExpr:
{
const ConvertRowtypeExpr *cexpr = (const ConvertRowtypeExpr *) expr;
/* Much as above */
loc = leftmostLoc(cexpr->location,
exprLocation((Node *) cexpr->arg));
}
break;
case T_CollateExpr:
/* just use argument's location */
loc = exprLocation((Node *) ((const CollateExpr *) expr)->arg);
break;
case T_CaseExpr:
/* CASE keyword should always be the first thing */
loc = ((const CaseExpr *) expr)->location;
break;
case T_CaseWhen:
/* WHEN keyword should always be the first thing */
loc = ((const CaseWhen *) expr)->location;
break;
case T_ArrayExpr:
/* the location points at ARRAY or [, which must be leftmost */
loc = ((const ArrayExpr *) expr)->location;
break;
case T_RowExpr:
/* the location points at ROW or (, which must be leftmost */
loc = ((const RowExpr *) expr)->location;
break;
case T_RowCompareExpr:
/* just use leftmost argument's location */
loc = exprLocation((Node *) ((const RowCompareExpr *) expr)->largs);
break;
case T_CoalesceExpr:
/* COALESCE keyword should always be the first thing */
loc = ((const CoalesceExpr *) expr)->location;
break;
case T_MinMaxExpr:
/* GREATEST/LEAST keyword should always be the first thing */
loc = ((const MinMaxExpr *) expr)->location;
break;
case T_SQLValueFunction:
/* function keyword should always be the first thing */
loc = ((const SQLValueFunction *) expr)->location;
break;
case T_XmlExpr:
{
const XmlExpr *xexpr = (const XmlExpr *) expr;
/* consider both function name and leftmost arg */
loc = leftmostLoc(xexpr->location,
exprLocation((Node *) xexpr->args));
}
break;
case T_NullTest:
{
const NullTest *nexpr = (const NullTest *) expr;
/* Much as above */
loc = leftmostLoc(nexpr->location,
exprLocation((Node *) nexpr->arg));
}
break;
case T_BooleanTest:
{
const BooleanTest *bexpr = (const BooleanTest *) expr;
/* Much as above */
loc = leftmostLoc(bexpr->location,
exprLocation((Node *) bexpr->arg));
}
break;
case T_CoerceToDomain:
{
const CoerceToDomain *cexpr = (const CoerceToDomain *) expr;
/* Much as above */
loc = leftmostLoc(cexpr->location,
exprLocation((Node *) cexpr->arg));
}
break;
case T_CoerceToDomainValue:
loc = ((const CoerceToDomainValue *) expr)->location;
break;
case T_SetToDefault:
loc = ((const SetToDefault *) expr)->location;
break;
case T_TargetEntry:
/* just use argument's location */
loc = exprLocation((Node *) ((const TargetEntry *) expr)->expr);
break;
case T_IntoClause:
/* use the contained RangeVar's location --- close enough */
loc = exprLocation((Node *) ((const IntoClause *) expr)->rel);
break;
case T_List:
{
/* report location of first list member that has a location */
ListCell *lc;
loc = -1; /* just to suppress compiler warning */
foreach(lc, (const List *) expr)
{
loc = exprLocation((Node *) lfirst(lc));
if (loc >= 0)
break;
}
}
break;
case T_A_Expr:
{
const A_Expr *aexpr = (const A_Expr *) expr;
/* use leftmost of operator or left operand (if any) */
/* we assume right operand can't be to left of operator */
loc = leftmostLoc(aexpr->location,
exprLocation(aexpr->lexpr));
}
break;
case T_ColumnRef:
loc = ((const ColumnRef *) expr)->location;
break;
case T_ParamRef:
loc = ((const ParamRef *) expr)->location;
break;
case T_A_Const:
loc = ((const A_Const *) expr)->location;
break;
case T_FuncCall:
{
const FuncCall *fc = (const FuncCall *) expr;
/* consider both function name and leftmost arg */
/* (we assume any ORDER BY nodes must be to right of name) */
loc = leftmostLoc(fc->location,
exprLocation((Node *) fc->args));
}
break;
case T_A_ArrayExpr:
/* the location points at ARRAY or [, which must be leftmost */
loc = ((const A_ArrayExpr *) expr)->location;
break;
case T_ResTarget:
/* we need not examine the contained expression (if any) */
loc = ((const ResTarget *) expr)->location;
break;
case T_MultiAssignRef:
loc = exprLocation(((const MultiAssignRef *) expr)->source);
break;
case T_TypeCast:
{
const TypeCast *tc = (const TypeCast *) expr;
/*
* This could represent CAST(), ::, or TypeName 'literal', so
* any of the components might be leftmost.
*/
loc = exprLocation(tc->arg);
loc = leftmostLoc(loc, tc->typeName->location);
loc = leftmostLoc(loc, tc->location);
}
break;
case T_CollateClause:
/* just use argument's location */
loc = exprLocation(((const CollateClause *) expr)->arg);
break;
case T_SortBy:
/* just use argument's location (ignore operator, if any) */
loc = exprLocation(((const SortBy *) expr)->node);
break;
case T_WindowDef:
loc = ((const WindowDef *) expr)->location;
break;
case T_RangeTableSample:
loc = ((const RangeTableSample *) expr)->location;
break;
case T_TypeName:
loc = ((const TypeName *) expr)->location;
break;
case T_ColumnDef:
loc = ((const ColumnDef *) expr)->location;
break;
case T_Constraint:
loc = ((const Constraint *) expr)->location;
break;
case T_FunctionParameter:
/* just use typename's location */
loc = exprLocation((Node *) ((const FunctionParameter *) expr)->argType);
break;
case T_XmlSerialize:
/* XMLSERIALIZE keyword should always be the first thing */
loc = ((const XmlSerialize *) expr)->location;
break;
case T_GroupingSet:
loc = ((const GroupingSet *) expr)->location;
break;
case T_WithClause:
loc = ((const WithClause *) expr)->location;
break;
case T_InferClause:
loc = ((const InferClause *) expr)->location;
break;
case T_OnConflictClause:
loc = ((const OnConflictClause *) expr)->location;
break;
case T_CommonTableExpr:
loc = ((const CommonTableExpr *) expr)->location;
break;
case T_PlaceHolderVar:
/* just use argument's location */
loc = exprLocation((Node *) ((const PlaceHolderVar *) expr)->phexpr);
break;
case T_InferenceElem:
/* just use nested expr's location */
loc = exprLocation((Node *) ((const InferenceElem *) expr)->expr);
break;
case T_PartitionElem:
loc = ((const PartitionElem *) expr)->location;
break;
case T_PartitionSpec:
loc = ((const PartitionSpec *) expr)->location;
break;
case T_PartitionBoundSpec:
loc = ((const PartitionBoundSpec *) expr)->location;
break;
case T_PartitionRangeDatum:
loc = ((const PartitionRangeDatum *) expr)->location;
break;
default:
/* for any other node type it's just unknown... */
loc = -1;
break;
}
return loc;
}
/*
* leftmostLoc - support for exprLocation
*
* Take the minimum of two parse location values, but ignore unknowns
*/
static int
leftmostLoc(int loc1, int loc2)
{
if (loc1 < 0)
return loc2;
else if (loc2 < 0)
return loc1;
else
return Min(loc1, loc2);
}
/*
* fix_opfuncids
* Calculate opfuncid field from opno for each OpExpr node in given tree.
* The given tree can be anything expression_tree_walker handles.
*
* The argument is modified in-place. (This is OK since we'd want the
* same change for any node, even if it gets visited more than once due to
* shared structure.)
*/
void
fix_opfuncids(Node *node)
{
/* This tree walk requires no special setup, so away we go... */
fix_opfuncids_walker(node, NULL);
}
static bool
fix_opfuncids_walker(Node *node, void *context)
{
if (node == NULL)
return false;
if (IsA(node, OpExpr))
set_opfuncid((OpExpr *) node);
else if (IsA(node, DistinctExpr))
set_opfuncid((OpExpr *) node); /* rely on struct equivalence */
else if (IsA(node, NullIfExpr))
set_opfuncid((OpExpr *) node); /* rely on struct equivalence */
else if (IsA(node, ScalarArrayOpExpr))
set_sa_opfuncid((ScalarArrayOpExpr *) node);
return expression_tree_walker(node, fix_opfuncids_walker, context);
}
/*
* set_opfuncid
* Set the opfuncid (procedure OID) in an OpExpr node,
* if it hasn't been set already.
*
* Because of struct equivalence, this can also be used for
* DistinctExpr and NullIfExpr nodes.
*/
void
set_opfuncid(OpExpr *opexpr)
{
if (opexpr->opfuncid == InvalidOid)
opexpr->opfuncid = get_opcode(opexpr->opno);
}
/*
* set_sa_opfuncid
* As above, for ScalarArrayOpExpr nodes.
*/
void
set_sa_opfuncid(ScalarArrayOpExpr *opexpr)
{
if (opexpr->opfuncid == InvalidOid)
opexpr->opfuncid = get_opcode(opexpr->opno);
}
/*
* check_functions_in_node -
* apply checker() to each function OID contained in given expression node
*
* Returns true if the checker() function does; for nodes representing more
* than one function call, returns true if the checker() function does so
* for any of those functions. Returns false if node does not invoke any
* SQL-visible function. Caller must not pass node == NULL.
*
* This function examines only the given node; it does not recurse into any
* sub-expressions. Callers typically prefer to keep control of the recursion
* for themselves, in case additional checks should be made, or because they
* have special rules about which parts of the tree need to be visited.
*
* Note: we ignore MinMaxExpr, SQLValueFunction, XmlExpr, CoerceToDomain,
* and NextValueExpr nodes, because they do not contain SQL function OIDs.
* However, they can invoke SQL-visible functions, so callers should take
* thought about how to treat them.
*/
bool
check_functions_in_node(Node *node, check_function_callback checker,
void *context)
{
switch (nodeTag(node))
{
case T_Aggref:
{
Aggref *expr = (Aggref *) node;
if (checker(expr->aggfnoid, context))
return true;
}
break;
case T_WindowFunc:
{
WindowFunc *expr = (WindowFunc *) node;
if (checker(expr->winfnoid, context))
return true;
}
break;
case T_FuncExpr:
{
FuncExpr *expr = (FuncExpr *) node;
if (checker(expr->funcid, context))
return true;
}
break;
case T_OpExpr:
case T_DistinctExpr: /* struct-equivalent to OpExpr */
case T_NullIfExpr: /* struct-equivalent to OpExpr */
{
OpExpr *expr = (OpExpr *) node;
/* Set opfuncid if it wasn't set already */
set_opfuncid(expr);
if (checker(expr->opfuncid, context))
return true;
}
break;
case T_ScalarArrayOpExpr:
{
ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node;
set_sa_opfuncid(expr);
if (checker(expr->opfuncid, context))
return true;
}
break;
case T_CoerceViaIO:
{
CoerceViaIO *expr = (CoerceViaIO *) node;
Oid iofunc;
Oid typioparam;
bool typisvarlena;
/* check the result type's input function */
getTypeInputInfo(expr->resulttype,
&iofunc, &typioparam);
if (checker(iofunc, context))
return true;
/* check the input type's output function */
getTypeOutputInfo(exprType((Node *) expr->arg),
&iofunc, &typisvarlena);
if (checker(iofunc, context))
return true;
}
break;
case T_RowCompareExpr:
{
RowCompareExpr *rcexpr = (RowCompareExpr *) node;
ListCell *opid;
foreach(opid, rcexpr->opnos)
{
Oid opfuncid = get_opcode(lfirst_oid(opid));
if (checker(opfuncid, context))
return true;
}
}
break;
default:
break;
}
return false;
}
/*
* Standard expression-tree walking support
*
* We used to have near-duplicate code in many different routines that
* understood how to recurse through an expression node tree. That was
* a pain to maintain, and we frequently had bugs due to some particular
* routine neglecting to support a particular node type. In most cases,
* these routines only actually care about certain node types, and don't
* care about other types except insofar as they have to recurse through
* non-primitive node types. Therefore, we now provide generic tree-walking
* logic to consolidate the redundant "boilerplate" code. There are
* two versions: expression_tree_walker() and expression_tree_mutator().
*/
/*
* expression_tree_walker() is designed to support routines that traverse
* a tree in a read-only fashion (although it will also work for routines
* that modify nodes in-place but never add/delete/replace nodes).
* A walker routine should look like this:
*
* bool my_walker (Node *node, my_struct *context)
* {
* if (node == NULL)
* return false;
* // check for nodes that special work is required for, eg:
* if (IsA(node, Var))
* {
* ... do special actions for Var nodes
* }
* else if (IsA(node, ...))
* {
* ... do special actions for other node types
* }
* // for any node type not specially processed, do:
* return expression_tree_walker(node, my_walker, (void *) context);
* }
*
* The "context" argument points to a struct that holds whatever context
* information the walker routine needs --- it can be used to return data
* gathered by the walker, too. This argument is not touched by
* expression_tree_walker, but it is passed down to recursive sub-invocations
* of my_walker. The tree walk is started from a setup routine that
* fills in the appropriate context struct, calls my_walker with the top-level
* node of the tree, and then examines the results.
*
* The walker routine should return "false" to continue the tree walk, or
* "true" to abort the walk and immediately return "true" to the top-level
* caller. This can be used to short-circuit the traversal if the walker
* has found what it came for. "false" is returned to the top-level caller
* iff no invocation of the walker returned "true".
*
* The node types handled by expression_tree_walker include all those
* normally found in target lists and qualifier clauses during the planning
* stage. In particular, it handles List nodes since a cnf-ified qual clause
* will have List structure at the top level, and it handles TargetEntry nodes
* so that a scan of a target list can be handled without additional code.
* Also, RangeTblRef, FromExpr, JoinExpr, and SetOperationStmt nodes are
* handled, so that query jointrees and setOperation trees can be processed
* without additional code.
*
* expression_tree_walker will handle SubLink nodes by recursing normally
* into the "testexpr" subtree (which is an expression belonging to the outer
* plan). It will also call the walker on the sub-Query node; however, when
* expression_tree_walker itself is called on a Query node, it does nothing
* and returns "false". The net effect is that unless the walker does
* something special at a Query node, sub-selects will not be visited during
* an expression tree walk. This is exactly the behavior wanted in many cases
* --- and for those walkers that do want to recurse into sub-selects, special
* behavior is typically needed anyway at the entry to a sub-select (such as
* incrementing a depth counter). A walker that wants to examine sub-selects
* should include code along the lines of:
*
* if (IsA(node, Query))
* {
* adjust context for subquery;
* result = query_tree_walker((Query *) node, my_walker, context,
* 0); // adjust flags as needed
* restore context if needed;
* return result;
* }
*
* query_tree_walker is a convenience routine (see below) that calls the
* walker on all the expression subtrees of the given Query node.
*
* expression_tree_walker will handle SubPlan nodes by recursing normally
* into the "testexpr" and the "args" list (which are expressions belonging to
* the outer plan). It will not touch the completed subplan, however. Since
* there is no link to the original Query, it is not possible to recurse into
* subselects of an already-planned expression tree. This is OK for current
* uses, but may need to be revisited in future.
*/
bool
expression_tree_walker(Node *node,
bool (*walker) (),
void *context)
{
ListCell *temp;
/*
* The walker has already visited the current node, and so we need only
* recurse into any sub-nodes it has.
*
* We assume that the walker is not interested in List nodes per se, so
* when we expect a List we just recurse directly to self without
* bothering to call the walker.
*/
if (node == NULL)
return false;
/* Guard against stack overflow due to overly complex expressions */
check_stack_depth();
switch (nodeTag(node))
{
case T_Var:
case T_Const:
case T_Param:
case T_CaseTestExpr:
case T_SQLValueFunction:
case T_CoerceToDomainValue:
case T_SetToDefault:
case T_CurrentOfExpr:
case T_NextValueExpr:
case T_RangeTblRef:
case T_SortGroupClause:
/* primitive node types with no expression subnodes */
break;
case T_WithCheckOption:
return walker(((WithCheckOption *) node)->qual, context);
case T_Aggref:
{
Aggref *expr = (Aggref *) node;
/* recurse directly on List */
if (expression_tree_walker((Node *) expr->aggdirectargs,
walker, context))
return true;
if (expression_tree_walker((Node *) expr->args,
walker, context))
return true;
if (expression_tree_walker((Node *) expr->aggorder,
walker, context))
return true;
if (expression_tree_walker((Node *) expr->aggdistinct,
walker, context))
return true;
if (walker((Node *) expr->aggfilter, context))
return true;
}
break;
case T_GroupingFunc:
{
GroupingFunc *grouping = (GroupingFunc *) node;
if (expression_tree_walker((Node *) grouping->args,
walker, context))
return true;
}
break;
case T_WindowFunc:
{
WindowFunc *expr = (WindowFunc *) node;
/* recurse directly on List */
if (expression_tree_walker((Node *) expr->args,
walker, context))
return true;
if (walker((Node *) expr->aggfilter, context))
return true;
}
break;
case T_SubscriptingRef:
{
SubscriptingRef *sbsref = (SubscriptingRef *) node;
/* recurse directly for upper/lower container index lists */
if (expression_tree_walker((Node *) sbsref->refupperindexpr,
walker, context))
return true;
if (expression_tree_walker((Node *) sbsref->reflowerindexpr,
walker, context))
return true;
/* walker must see the refexpr and refassgnexpr, however */
if (walker(sbsref->refexpr, context))
return true;
if (walker(sbsref->refassgnexpr, context))
return true;
}
break;
case T_FuncExpr:
{
FuncExpr *expr = (FuncExpr *) node;
if (expression_tree_walker((Node *) expr->args,
walker, context))
return true;
}
break;
case T_NamedArgExpr:
return walker(((NamedArgExpr *) node)->arg, context);
case T_OpExpr:
case T_DistinctExpr: /* struct-equivalent to OpExpr */
case T_NullIfExpr: /* struct-equivalent to OpExpr */
{
OpExpr *expr = (OpExpr *) node;
if (expression_tree_walker((Node *) expr->args,
walker, context))
return true;
}
break;
case T_ScalarArrayOpExpr:
{
ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node;
if (expression_tree_walker((Node *) expr->args,
walker, context))
return true;
}
break;
case T_BoolExpr:
{
BoolExpr *expr = (BoolExpr *) node;
if (expression_tree_walker((Node *) expr->args,
walker, context))
return true;
}
break;
case T_SubLink:
{
SubLink *sublink = (SubLink *) node;
if (walker(sublink->testexpr, context))
return true;
/*
* Also invoke the walker on the sublink's Query node, so it
* can recurse into the sub-query if it wants to.
*/
return walker(sublink->subselect, context);
}
break;
case T_SubPlan:
{
SubPlan *subplan = (SubPlan *) node;
/* recurse into the testexpr, but not into the Plan */
if (walker(subplan->testexpr, context))
return true;
/* also examine args list */
if (expression_tree_walker((Node *) subplan->args,
walker, context))
return true;
}
break;
case T_AlternativeSubPlan:
return walker(((AlternativeSubPlan *) node)->subplans, context);
case T_FieldSelect:
return walker(((FieldSelect *) node)->arg, context);
case T_FieldStore:
{
FieldStore *fstore = (FieldStore *) node;
if (walker(fstore->arg, context))
return true;
if (walker(fstore->newvals, context))
return true;
}
break;
case T_RelabelType:
return walker(((RelabelType *) node)->arg, context);
case T_CoerceViaIO:
return walker(((CoerceViaIO *) node)->arg, context);
case T_ArrayCoerceExpr:
{
ArrayCoerceExpr *acoerce = (ArrayCoerceExpr *) node;
if (walker(acoerce->arg, context))
return true;
if (walker(acoerce->elemexpr, context))
return true;
}
break;
case T_ConvertRowtypeExpr:
return walker(((ConvertRowtypeExpr *) node)->arg, context);
case T_CollateExpr:
return walker(((CollateExpr *) node)->arg, context);
case T_CaseExpr:
{
CaseExpr *caseexpr = (CaseExpr *) node;
if (walker(caseexpr->arg, context))
return true;
/* we assume walker doesn't care about CaseWhens, either */
foreach(temp, caseexpr->args)
{
CaseWhen *when = lfirst_node(CaseWhen, temp);
if (walker(when->expr, context))
return true;
if (walker(when->result, context))
return true;
}
if (walker(caseexpr->defresult, context))
return true;
}
break;
case T_ArrayExpr:
return walker(((ArrayExpr *) node)->elements, context);
case T_RowExpr:
/* Assume colnames isn't interesting */
return walker(((RowExpr *) node)->args, context);
case T_RowCompareExpr:
{
RowCompareExpr *rcexpr = (RowCompareExpr *) node;
if (walker(rcexpr->largs, context))
return true;
if (walker(rcexpr->rargs, context))
return true;
}
break;
case T_CoalesceExpr:
return walker(((CoalesceExpr *) node)->args, context);
case T_MinMaxExpr:
return walker(((MinMaxExpr *) node)->args, context);
case T_XmlExpr:
{
XmlExpr *xexpr = (XmlExpr *) node;
if (walker(xexpr->named_args, context))
return true;
/* we assume walker doesn't care about arg_names */
if (walker(xexpr->args, context))
return true;
}
break;
case T_NullTest:
return walker(((NullTest *) node)->arg, context);
case T_BooleanTest:
return walker(((BooleanTest *) node)->arg, context);
case T_CoerceToDomain:
return walker(((CoerceToDomain *) node)->arg, context);
case T_TargetEntry:
return walker(((TargetEntry *) node)->expr, context);
case T_Query:
/* Do nothing with a sub-Query, per discussion above */
break;
case T_WindowClause:
{
WindowClause *wc = (WindowClause *) node;
if (walker(wc->partitionClause, context))
return true;
if (walker(wc->orderClause, context))
return true;
if (walker(wc->startOffset, context))
return true;
if (walker(wc->endOffset, context))
return true;
}
break;
case T_CommonTableExpr:
{
CommonTableExpr *cte = (CommonTableExpr *) node;
/*
* Invoke the walker on the CTE's Query node, so it can
* recurse into the sub-query if it wants to.
*/
return walker(cte->ctequery, context);
}
break;
case T_List:
foreach(temp, (List *) node)
{
if (walker((Node *) lfirst(temp), context))
return true;
}
break;
case T_FromExpr:
{
FromExpr *from = (FromExpr *) node;
if (walker(from->fromlist, context))
return true;
if (walker(from->quals, context))
return true;
}
break;
case T_OnConflictExpr:
{
OnConflictExpr *onconflict = (OnConflictExpr *) node;
if (walker((Node *) onconflict->arbiterElems, context))
return true;
if (walker(onconflict->arbiterWhere, context))
return true;
if (walker(onconflict->onConflictSet, context))
return true;
if (walker(onconflict->onConflictWhere, context))
return true;
if (walker(onconflict->exclRelTlist, context))
return true;
}
break;
case T_PartitionPruneStepOp:
{
PartitionPruneStepOp *opstep = (PartitionPruneStepOp *) node;
if (walker((Node *) opstep->exprs, context))
return true;
}
break;
case T_PartitionPruneStepCombine:
/* no expression subnodes */
break;
case T_JoinExpr:
{
JoinExpr *join = (JoinExpr *) node;
if (walker(join->larg, context))
return true;
if (walker(join->rarg, context))
return true;
if (walker(join->quals, context))
return true;
/*
* alias clause, using list are deemed uninteresting.
*/
}
break;
case T_SetOperationStmt:
{
SetOperationStmt *setop = (SetOperationStmt *) node;
if (walker(setop->larg, context))
return true;
if (walker(setop->rarg, context))
return true;
/* groupClauses are deemed uninteresting */
}
break;
case T_IndexClause:
{
IndexClause *iclause = (IndexClause *) node;
if (walker(iclause->rinfo, context))
return true;
if (expression_tree_walker((Node *) iclause->indexquals,
walker, context))
return true;
}
break;
case T_PlaceHolderVar:
return walker(((PlaceHolderVar *) node)->phexpr, context);
case T_InferenceElem:
return walker(((InferenceElem *) node)->expr, context);
case T_AppendRelInfo:
{
AppendRelInfo *appinfo = (AppendRelInfo *) node;
if (expression_tree_walker((Node *) appinfo->translated_vars,
walker, context))
return true;
}
break;
case T_PlaceHolderInfo:
return walker(((PlaceHolderInfo *) node)->ph_var, context);
case T_RangeTblFunction:
return walker(((RangeTblFunction *) node)->funcexpr, context);
case T_TableSampleClause:
{
TableSampleClause *tsc = (TableSampleClause *) node;
if (expression_tree_walker((Node *) tsc->args,
walker, context))
return true;
if (walker((Node *) tsc->repeatable, context))
return true;
}
break;
case T_TableFunc:
{
TableFunc *tf = (TableFunc *) node;
if (walker(tf->ns_uris, context))
return true;
if (walker(tf->docexpr, context))
return true;
if (walker(tf->rowexpr, context))
return true;
if (walker(tf->colexprs, context))
return true;
if (walker(tf->coldefexprs, context))
return true;
}
break;
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(node));
break;
}
return false;
}
/*
* query_tree_walker --- initiate a walk of a Query's expressions
*
* This routine exists just to reduce the number of places that need to know
* where all the expression subtrees of a Query are. Note it can be used
* for starting a walk at top level of a Query regardless of whether the
* walker intends to descend into subqueries. It is also useful for
* descending into subqueries within a walker.
*
* Some callers want to suppress visitation of certain items in the sub-Query,
* typically because they need to process them specially, or don't actually
* want to recurse into subqueries. This is supported by the flags argument,
* which is the bitwise OR of flag values to add or suppress visitation of
* indicated items. (More flag bits may be added as needed.)
*/
bool
query_tree_walker(Query *query,
bool (*walker) (),
void *context,
int flags)
{
Assert(query != NULL && IsA(query, Query));
/*
* We don't walk any utilityStmt here. However, we can't easily assert
* that it is absent, since there are at least two code paths by which
* action statements from CREATE RULE end up here, and NOTIFY is allowed
* in a rule action.
*/
if (walker((Node *) query->targetList, context))
return true;
if (walker((Node *) query->withCheckOptions, context))
return true;
if (walker((Node *) query->onConflict, context))
return true;
if (walker((Node *) query->returningList, context))
return true;
if (walker((Node *) query->jointree, context))
return true;
if (walker(query->setOperations, context))
return true;
if (walker(query->havingQual, context))
return true;
if (walker(query->limitOffset, context))
return true;
if (walker(query->limitCount, context))
return true;
/*
* Most callers aren't interested in SortGroupClause nodes since those
* don't contain actual expressions. However they do contain OIDs which
* may be needed by dependency walkers etc.
*/
if ((flags & QTW_EXAMINE_SORTGROUP))
{
if (walker((Node *) query->groupClause, context))
return true;
if (walker((Node *) query->windowClause, context))
return true;
if (walker((Node *) query->sortClause, context))
return true;
if (walker((Node *) query->distinctClause, context))
return true;
}
else
{
/*
* But we need to walk the expressions under WindowClause nodes even
* if we're not interested in SortGroupClause nodes.
*/
ListCell *lc;
foreach(lc, query->windowClause)
{
WindowClause *wc = lfirst_node(WindowClause, lc);
if (walker(wc->startOffset, context))
return true;
if (walker(wc->endOffset, context))
return true;
}
}
/*
* groupingSets and rowMarks are not walked:
*
* groupingSets contain only ressortgrouprefs (integers) which are
* meaningless without the corresponding groupClause or tlist.
* Accordingly, any walker that needs to care about them needs to handle
* them itself in its Query processing.
*
* rowMarks is not walked because it contains only rangetable indexes (and
* flags etc.) and therefore should be handled at Query level similarly.
*/
if (!(flags & QTW_IGNORE_CTE_SUBQUERIES))
{
if (walker((Node *) query->cteList, context))
return true;
}
if (!(flags & QTW_IGNORE_RANGE_TABLE))
{
if (range_table_walker(query->rtable, walker, context, flags))
return true;
}
return false;
}
/*
* range_table_walker is just the part of query_tree_walker that scans
* a query's rangetable. This is split out since it can be useful on
* its own.
*/
bool
range_table_walker(List *rtable,
bool (*walker) (),
void *context,
int flags)
{
ListCell *rt;
foreach(rt, rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(rt);
/*
* Walkers might need to examine the RTE node itself either before or
* after visiting its contents (or, conceivably, both). Note that if
* you specify neither flag, the walker won't visit the RTE at all.
*/
if (flags & QTW_EXAMINE_RTES_BEFORE)
if (walker(rte, context))
return true;
switch (rte->rtekind)
{
case RTE_RELATION:
if (walker(rte->tablesample, context))
return true;
break;
case RTE_SUBQUERY:
if (!(flags & QTW_IGNORE_RT_SUBQUERIES))
if (walker(rte->subquery, context))
return true;
break;
case RTE_JOIN:
if (!(flags & QTW_IGNORE_JOINALIASES))
if (walker(rte->joinaliasvars, context))
return true;
break;
case RTE_FUNCTION:
if (walker(rte->functions, context))
return true;
break;
case RTE_TABLEFUNC:
if (walker(rte->tablefunc, context))
return true;
break;
case RTE_VALUES:
if (walker(rte->values_lists, context))
return true;
break;
case RTE_CTE:
case RTE_NAMEDTUPLESTORE:
case RTE_RESULT:
/* nothing to do */
break;
}
if (walker(rte->securityQuals, context))
return true;
if (flags & QTW_EXAMINE_RTES_AFTER)
if (walker(rte, context))
return true;
}
return false;
}
/*
* expression_tree_mutator() is designed to support routines that make a
* modified copy of an expression tree, with some nodes being added,
* removed, or replaced by new subtrees. The original tree is (normally)
* not changed. Each recursion level is responsible for returning a copy of
* (or appropriately modified substitute for) the subtree it is handed.
* A mutator routine should look like this:
*
* Node * my_mutator (Node *node, my_struct *context)
* {
* if (node == NULL)
* return NULL;
* // check for nodes that special work is required for, eg:
* if (IsA(node, Var))
* {
* ... create and return modified copy of Var node
* }
* else if (IsA(node, ...))
* {
* ... do special transformations of other node types
* }
* // for any node type not specially processed, do:
* return expression_tree_mutator(node, my_mutator, (void *) context);
* }
*
* The "context" argument points to a struct that holds whatever context
* information the mutator routine needs --- it can be used to return extra
* data gathered by the mutator, too. This argument is not touched by
* expression_tree_mutator, but it is passed down to recursive sub-invocations
* of my_mutator. The tree walk is started from a setup routine that
* fills in the appropriate context struct, calls my_mutator with the
* top-level node of the tree, and does any required post-processing.
*
* Each level of recursion must return an appropriately modified Node.
* If expression_tree_mutator() is called, it will make an exact copy
* of the given Node, but invoke my_mutator() to copy the sub-node(s)
* of that Node. In this way, my_mutator() has full control over the
* copying process but need not directly deal with expression trees
* that it has no interest in.
*
* Just as for expression_tree_walker, the node types handled by
* expression_tree_mutator include all those normally found in target lists
* and qualifier clauses during the planning stage.
*
* expression_tree_mutator will handle SubLink nodes by recursing normally
* into the "testexpr" subtree (which is an expression belonging to the outer
* plan). It will also call the mutator on the sub-Query node; however, when
* expression_tree_mutator itself is called on a Query node, it does nothing
* and returns the unmodified Query node. The net effect is that unless the
* mutator does something special at a Query node, sub-selects will not be
* visited or modified; the original sub-select will be linked to by the new
* SubLink node. Mutators that want to descend into sub-selects will usually
* do so by recognizing Query nodes and calling query_tree_mutator (below).
*
* expression_tree_mutator will handle a SubPlan node by recursing into the
* "testexpr" and the "args" list (which belong to the outer plan), but it
* will simply copy the link to the inner plan, since that's typically what
* expression tree mutators want. A mutator that wants to modify the subplan
* can force appropriate behavior by recognizing SubPlan expression nodes
* and doing the right thing.
*/
Node *
expression_tree_mutator(Node *node,
Node *(*mutator) (),
void *context)
{
/*
* The mutator has already decided not to modify the current node, but we
* must call the mutator for any sub-nodes.
*/
#define FLATCOPY(newnode, node, nodetype) \
( (newnode) = (nodetype *) palloc(sizeof(nodetype)), \
memcpy((newnode), (node), sizeof(nodetype)) )
#define CHECKFLATCOPY(newnode, node, nodetype) \
( AssertMacro(IsA((node), nodetype)), \
(newnode) = (nodetype *) palloc(sizeof(nodetype)), \
memcpy((newnode), (node), sizeof(nodetype)) )
#define MUTATE(newfield, oldfield, fieldtype) \
( (newfield) = (fieldtype) mutator((Node *) (oldfield), context) )
if (node == NULL)
return NULL;
/* Guard against stack overflow due to overly complex expressions */
check_stack_depth();
switch (nodeTag(node))
{
/*
* Primitive node types with no expression subnodes. Var and
* Const are frequent enough to deserve special cases, the others
* we just use copyObject for.
*/
case T_Var:
{
Var *var = (Var *) node;
Var *newnode;
FLATCOPY(newnode, var, Var);
return (Node *) newnode;
}
break;
case T_Const:
{
Const *oldnode = (Const *) node;
Const *newnode;
FLATCOPY(newnode, oldnode, Const);
/* XXX we don't bother with datumCopy; should we? */
return (Node *) newnode;
}
break;
case T_Param:
case T_CaseTestExpr:
case T_SQLValueFunction:
case T_CoerceToDomainValue:
case T_SetToDefault:
case T_CurrentOfExpr:
case T_NextValueExpr:
case T_RangeTblRef:
case T_SortGroupClause:
return (Node *) copyObject(node);
case T_WithCheckOption:
{
WithCheckOption *wco = (WithCheckOption *) node;
WithCheckOption *newnode;
FLATCOPY(newnode, wco, WithCheckOption);
MUTATE(newnode->qual, wco->qual, Node *);
return (Node *) newnode;
}
case T_Aggref:
{
Aggref *aggref = (Aggref *) node;
Aggref *newnode;
FLATCOPY(newnode, aggref, Aggref);
/* assume mutation doesn't change types of arguments */
newnode->aggargtypes = list_copy(aggref->aggargtypes);
MUTATE(newnode->aggdirectargs, aggref->aggdirectargs, List *);
MUTATE(newnode->args, aggref->args, List *);
MUTATE(newnode->aggorder, aggref->aggorder, List *);
MUTATE(newnode->aggdistinct, aggref->aggdistinct, List *);
MUTATE(newnode->aggfilter, aggref->aggfilter, Expr *);
return (Node *) newnode;
}
break;
case T_GroupingFunc:
{
GroupingFunc *grouping = (GroupingFunc *) node;
GroupingFunc *newnode;
FLATCOPY(newnode, grouping, GroupingFunc);
MUTATE(newnode->args, grouping->args, List *);
/*
* We assume here that mutating the arguments does not change
* the semantics, i.e. that the arguments are not mutated in a
* way that makes them semantically different from their
* previously matching expressions in the GROUP BY clause.
*
* If a mutator somehow wanted to do this, it would have to
* handle the refs and cols lists itself as appropriate.
*/
newnode->refs = list_copy(grouping->refs);
newnode->cols = list_copy(grouping->cols);
return (Node *) newnode;
}
break;
case T_WindowFunc:
{
WindowFunc *wfunc = (WindowFunc *) node;
WindowFunc *newnode;
FLATCOPY(newnode, wfunc, WindowFunc);
MUTATE(newnode->args, wfunc->args, List *);
MUTATE(newnode->aggfilter, wfunc->aggfilter, Expr *);
return (Node *) newnode;
}
break;
case T_SubscriptingRef:
{
SubscriptingRef *sbsref = (SubscriptingRef *) node;
SubscriptingRef *newnode;
FLATCOPY(newnode, sbsref, SubscriptingRef);
MUTATE(newnode->refupperindexpr, sbsref->refupperindexpr,
List *);
MUTATE(newnode->reflowerindexpr, sbsref->reflowerindexpr,
List *);
MUTATE(newnode->refexpr, sbsref->refexpr,
Expr *);
MUTATE(newnode->refassgnexpr, sbsref->refassgnexpr,
Expr *);
return (Node *) newnode;
}
break;
case T_FuncExpr:
{
FuncExpr *expr = (FuncExpr *) node;
FuncExpr *newnode;
FLATCOPY(newnode, expr, FuncExpr);
MUTATE(newnode->args, expr->args, List *);
return (Node *) newnode;
}
break;
case T_NamedArgExpr:
{
NamedArgExpr *nexpr = (NamedArgExpr *) node;
NamedArgExpr *newnode;
FLATCOPY(newnode, nexpr, NamedArgExpr);
MUTATE(newnode->arg, nexpr->arg, Expr *);
return (Node *) newnode;
}
break;
case T_OpExpr:
{
OpExpr *expr = (OpExpr *) node;
OpExpr *newnode;
FLATCOPY(newnode, expr, OpExpr);
MUTATE(newnode->args, expr->args, List *);
return (Node *) newnode;
}
break;
case T_DistinctExpr:
{
DistinctExpr *expr = (DistinctExpr *) node;
DistinctExpr *newnode;
FLATCOPY(newnode, expr, DistinctExpr);
MUTATE(newnode->args, expr->args, List *);
return (Node *) newnode;
}
break;
case T_NullIfExpr:
{
NullIfExpr *expr = (NullIfExpr *) node;
NullIfExpr *newnode;
FLATCOPY(newnode, expr, NullIfExpr);
MUTATE(newnode->args, expr->args, List *);
return (Node *) newnode;
}
break;
case T_ScalarArrayOpExpr:
{
ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node;
ScalarArrayOpExpr *newnode;
FLATCOPY(newnode, expr, ScalarArrayOpExpr);
MUTATE(newnode->args, expr->args, List *);
return (Node *) newnode;
}
break;
case T_BoolExpr:
{
BoolExpr *expr = (BoolExpr *) node;
BoolExpr *newnode;
FLATCOPY(newnode, expr, BoolExpr);
MUTATE(newnode->args, expr->args, List *);
return (Node *) newnode;
}
break;
case T_SubLink:
{
SubLink *sublink = (SubLink *) node;
SubLink *newnode;
FLATCOPY(newnode, sublink, SubLink);
MUTATE(newnode->testexpr, sublink->testexpr, Node *);
/*
* Also invoke the mutator on the sublink's Query node, so it
* can recurse into the sub-query if it wants to.
*/
MUTATE(newnode->subselect, sublink->subselect, Node *);
return (Node *) newnode;
}
break;
case T_SubPlan:
{
SubPlan *subplan = (SubPlan *) node;
SubPlan *newnode;
FLATCOPY(newnode, subplan, SubPlan);
/* transform testexpr */
MUTATE(newnode->testexpr, subplan->testexpr, Node *);
/* transform args list (params to be passed to subplan) */
MUTATE(newnode->args, subplan->args, List *);
/* but not the sub-Plan itself, which is referenced as-is */
return (Node *) newnode;
}
break;
case T_AlternativeSubPlan:
{
AlternativeSubPlan *asplan = (AlternativeSubPlan *) node;
AlternativeSubPlan *newnode;
FLATCOPY(newnode, asplan, AlternativeSubPlan);
MUTATE(newnode->subplans, asplan->subplans, List *);
return (Node *) newnode;
}
break;
case T_FieldSelect:
{
FieldSelect *fselect = (FieldSelect *) node;
FieldSelect *newnode;
FLATCOPY(newnode, fselect, FieldSelect);
MUTATE(newnode->arg, fselect->arg, Expr *);
return (Node *) newnode;
}
break;
case T_FieldStore:
{
FieldStore *fstore = (FieldStore *) node;
FieldStore *newnode;
FLATCOPY(newnode, fstore, FieldStore);
MUTATE(newnode->arg, fstore->arg, Expr *);
MUTATE(newnode->newvals, fstore->newvals, List *);
newnode->fieldnums = list_copy(fstore->fieldnums);
return (Node *) newnode;
}
break;
case T_RelabelType:
{
RelabelType *relabel = (RelabelType *) node;
RelabelType *newnode;
FLATCOPY(newnode, relabel, RelabelType);
MUTATE(newnode->arg, relabel->arg, Expr *);
return (Node *) newnode;
}
break;
case T_CoerceViaIO:
{
CoerceViaIO *iocoerce = (CoerceViaIO *) node;
CoerceViaIO *newnode;
FLATCOPY(newnode, iocoerce, CoerceViaIO);
MUTATE(newnode->arg, iocoerce->arg, Expr *);
return (Node *) newnode;
}
break;
case T_ArrayCoerceExpr:
{
ArrayCoerceExpr *acoerce = (ArrayCoerceExpr *) node;
ArrayCoerceExpr *newnode;
FLATCOPY(newnode, acoerce, ArrayCoerceExpr);
MUTATE(newnode->arg, acoerce->arg, Expr *);
MUTATE(newnode->elemexpr, acoerce->elemexpr, Expr *);
return (Node *) newnode;
}
break;
case T_ConvertRowtypeExpr:
{
ConvertRowtypeExpr *convexpr = (ConvertRowtypeExpr *) node;
ConvertRowtypeExpr *newnode;
FLATCOPY(newnode, convexpr, ConvertRowtypeExpr);
MUTATE(newnode->arg, convexpr->arg, Expr *);
return (Node *) newnode;
}
break;
case T_CollateExpr:
{
CollateExpr *collate = (CollateExpr *) node;
CollateExpr *newnode;
FLATCOPY(newnode, collate, CollateExpr);
MUTATE(newnode->arg, collate->arg, Expr *);
return (Node *) newnode;
}
break;
case T_CaseExpr:
{
CaseExpr *caseexpr = (CaseExpr *) node;
CaseExpr *newnode;
FLATCOPY(newnode, caseexpr, CaseExpr);
MUTATE(newnode->arg, caseexpr->arg, Expr *);
MUTATE(newnode->args, caseexpr->args, List *);
MUTATE(newnode->defresult, caseexpr->defresult, Expr *);
return (Node *) newnode;
}
break;
case T_CaseWhen:
{
CaseWhen *casewhen = (CaseWhen *) node;
CaseWhen *newnode;
FLATCOPY(newnode, casewhen, CaseWhen);
MUTATE(newnode->expr, casewhen->expr, Expr *);
MUTATE(newnode->result, casewhen->result, Expr *);
return (Node *) newnode;
}
break;
case T_ArrayExpr:
{
ArrayExpr *arrayexpr = (ArrayExpr *) node;
ArrayExpr *newnode;
FLATCOPY(newnode, arrayexpr, ArrayExpr);
MUTATE(newnode->elements, arrayexpr->elements, List *);
return (Node *) newnode;
}
break;
case T_RowExpr:
{
RowExpr *rowexpr = (RowExpr *) node;
RowExpr *newnode;
FLATCOPY(newnode, rowexpr, RowExpr);
MUTATE(newnode->args, rowexpr->args, List *);
/* Assume colnames needn't be duplicated */
return (Node *) newnode;
}
break;
case T_RowCompareExpr:
{
RowCompareExpr *rcexpr = (RowCompareExpr *) node;
RowCompareExpr *newnode;
FLATCOPY(newnode, rcexpr, RowCompareExpr);
MUTATE(newnode->largs, rcexpr->largs, List *);
MUTATE(newnode->rargs, rcexpr->rargs, List *);
return (Node *) newnode;
}
break;
case T_CoalesceExpr:
{
CoalesceExpr *coalesceexpr = (CoalesceExpr *) node;
CoalesceExpr *newnode;
FLATCOPY(newnode, coalesceexpr, CoalesceExpr);
MUTATE(newnode->args, coalesceexpr->args, List *);
return (Node *) newnode;
}
break;
case T_MinMaxExpr:
{
MinMaxExpr *minmaxexpr = (MinMaxExpr *) node;
MinMaxExpr *newnode;
FLATCOPY(newnode, minmaxexpr, MinMaxExpr);
MUTATE(newnode->args, minmaxexpr->args, List *);
return (Node *) newnode;
}
break;
case T_XmlExpr:
{
XmlExpr *xexpr = (XmlExpr *) node;
XmlExpr *newnode;
FLATCOPY(newnode, xexpr, XmlExpr);
MUTATE(newnode->named_args, xexpr->named_args, List *);
/* assume mutator does not care about arg_names */
MUTATE(newnode->args, xexpr->args, List *);
return (Node *) newnode;
}
break;
case T_NullTest:
{
NullTest *ntest = (NullTest *) node;
NullTest *newnode;
FLATCOPY(newnode, ntest, NullTest);
MUTATE(newnode->arg, ntest->arg, Expr *);
return (Node *) newnode;
}
break;
case T_BooleanTest:
{
BooleanTest *btest = (BooleanTest *) node;
BooleanTest *newnode;
FLATCOPY(newnode, btest, BooleanTest);
MUTATE(newnode->arg, btest->arg, Expr *);
return (Node *) newnode;
}
break;
case T_CoerceToDomain:
{
CoerceToDomain *ctest = (CoerceToDomain *) node;
CoerceToDomain *newnode;
FLATCOPY(newnode, ctest, CoerceToDomain);
MUTATE(newnode->arg, ctest->arg, Expr *);
return (Node *) newnode;
}
break;
case T_TargetEntry:
{
TargetEntry *targetentry = (TargetEntry *) node;
TargetEntry *newnode;
FLATCOPY(newnode, targetentry, TargetEntry);
MUTATE(newnode->expr, targetentry->expr, Expr *);
return (Node *) newnode;
}
break;
case T_Query:
/* Do nothing with a sub-Query, per discussion above */
return node;
case T_WindowClause:
{
WindowClause *wc = (WindowClause *) node;
WindowClause *newnode;
FLATCOPY(newnode, wc, WindowClause);
MUTATE(newnode->partitionClause, wc->partitionClause, List *);
MUTATE(newnode->orderClause, wc->orderClause, List *);
MUTATE(newnode->startOffset, wc->startOffset, Node *);
MUTATE(newnode->endOffset, wc->endOffset, Node *);
return (Node *) newnode;
}
break;
case T_CommonTableExpr:
{
CommonTableExpr *cte = (CommonTableExpr *) node;
CommonTableExpr *newnode;
FLATCOPY(newnode, cte, CommonTableExpr);
/*
* Also invoke the mutator on the CTE's Query node, so it can
* recurse into the sub-query if it wants to.
*/
MUTATE(newnode->ctequery, cte->ctequery, Node *);
return (Node *) newnode;
}
break;
case T_List:
{
/*
* We assume the mutator isn't interested in the list nodes
* per se, so just invoke it on each list element. NOTE: this
* would fail badly on a list with integer elements!
*/
List *resultlist;
ListCell *temp;
resultlist = NIL;
foreach(temp, (List *) node)
{
resultlist = lappend(resultlist,
mutator((Node *) lfirst(temp),
context));
}
return (Node *) resultlist;
}
break;
case T_FromExpr:
{
FromExpr *from = (FromExpr *) node;
FromExpr *newnode;
FLATCOPY(newnode, from, FromExpr);
MUTATE(newnode->fromlist, from->fromlist, List *);
MUTATE(newnode->quals, from->quals, Node *);
return (Node *) newnode;
}
break;
case T_OnConflictExpr:
{
OnConflictExpr *oc = (OnConflictExpr *) node;
OnConflictExpr *newnode;
FLATCOPY(newnode, oc, OnConflictExpr);
MUTATE(newnode->arbiterElems, oc->arbiterElems, List *);
MUTATE(newnode->arbiterWhere, oc->arbiterWhere, Node *);
MUTATE(newnode->onConflictSet, oc->onConflictSet, List *);
MUTATE(newnode->onConflictWhere, oc->onConflictWhere, Node *);
MUTATE(newnode->exclRelTlist, oc->exclRelTlist, List *);
return (Node *) newnode;
}
break;
case T_PartitionPruneStepOp:
{
PartitionPruneStepOp *opstep = (PartitionPruneStepOp *) node;
PartitionPruneStepOp *newnode;
FLATCOPY(newnode, opstep, PartitionPruneStepOp);
MUTATE(newnode->exprs, opstep->exprs, List *);
return (Node *) newnode;
}
break;
case T_PartitionPruneStepCombine:
/* no expression sub-nodes */
return (Node *) copyObject(node);
case T_JoinExpr:
{
JoinExpr *join = (JoinExpr *) node;
JoinExpr *newnode;
FLATCOPY(newnode, join, JoinExpr);
MUTATE(newnode->larg, join->larg, Node *);
MUTATE(newnode->rarg, join->rarg, Node *);
MUTATE(newnode->quals, join->quals, Node *);
/* We do not mutate alias or using by default */
return (Node *) newnode;
}
break;
case T_SetOperationStmt:
{
SetOperationStmt *setop = (SetOperationStmt *) node;
SetOperationStmt *newnode;
FLATCOPY(newnode, setop, SetOperationStmt);
MUTATE(newnode->larg, setop->larg, Node *);
MUTATE(newnode->rarg, setop->rarg, Node *);
/* We do not mutate groupClauses by default */
return (Node *) newnode;
}
break;
case T_IndexClause:
{
IndexClause *iclause = (IndexClause *) node;
IndexClause *newnode;
FLATCOPY(newnode, iclause, IndexClause);
MUTATE(newnode->rinfo, iclause->rinfo, RestrictInfo *);
MUTATE(newnode->indexquals, iclause->indexquals, List *);
return (Node *) newnode;
}
break;
case T_PlaceHolderVar:
{
PlaceHolderVar *phv = (PlaceHolderVar *) node;
PlaceHolderVar *newnode;
FLATCOPY(newnode, phv, PlaceHolderVar);
MUTATE(newnode->phexpr, phv->phexpr, Expr *);
/* Assume we need not copy the relids bitmapset */
return (Node *) newnode;
}
break;
case T_InferenceElem:
{
InferenceElem *inferenceelemdexpr = (InferenceElem *) node;
InferenceElem *newnode;
FLATCOPY(newnode, inferenceelemdexpr, InferenceElem);
MUTATE(newnode->expr, newnode->expr, Node *);
return (Node *) newnode;
}
break;
case T_AppendRelInfo:
{
AppendRelInfo *appinfo = (AppendRelInfo *) node;
AppendRelInfo *newnode;
FLATCOPY(newnode, appinfo, AppendRelInfo);
MUTATE(newnode->translated_vars, appinfo->translated_vars, List *);
return (Node *) newnode;
}
break;
case T_PlaceHolderInfo:
{
PlaceHolderInfo *phinfo = (PlaceHolderInfo *) node;
PlaceHolderInfo *newnode;
FLATCOPY(newnode, phinfo, PlaceHolderInfo);
MUTATE(newnode->ph_var, phinfo->ph_var, PlaceHolderVar *);
/* Assume we need not copy the relids bitmapsets */
return (Node *) newnode;
}
break;
case T_RangeTblFunction:
{
RangeTblFunction *rtfunc = (RangeTblFunction *) node;
RangeTblFunction *newnode;
FLATCOPY(newnode, rtfunc, RangeTblFunction);
MUTATE(newnode->funcexpr, rtfunc->funcexpr, Node *);
/* Assume we need not copy the coldef info lists */
return (Node *) newnode;
}
break;
case T_TableSampleClause:
{
TableSampleClause *tsc = (TableSampleClause *) node;
TableSampleClause *newnode;
FLATCOPY(newnode, tsc, TableSampleClause);
MUTATE(newnode->args, tsc->args, List *);
MUTATE(newnode->repeatable, tsc->repeatable, Expr *);
return (Node *) newnode;
}
break;
case T_TableFunc:
{
TableFunc *tf = (TableFunc *) node;
TableFunc *newnode;
FLATCOPY(newnode, tf, TableFunc);
MUTATE(newnode->ns_uris, tf->ns_uris, List *);
MUTATE(newnode->docexpr, tf->docexpr, Node *);
MUTATE(newnode->rowexpr, tf->rowexpr, Node *);
MUTATE(newnode->colexprs, tf->colexprs, List *);
MUTATE(newnode->coldefexprs, tf->coldefexprs, List *);
return (Node *) newnode;
}
break;
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(node));
break;
}
/* can't get here, but keep compiler happy */
return NULL;
}
/*
* query_tree_mutator --- initiate modification of a Query's expressions
*
* This routine exists just to reduce the number of places that need to know
* where all the expression subtrees of a Query are. Note it can be used
* for starting a walk at top level of a Query regardless of whether the
* mutator intends to descend into subqueries. It is also useful for
* descending into subqueries within a mutator.
*
* Some callers want to suppress mutating of certain items in the Query,
* typically because they need to process them specially, or don't actually
* want to recurse into subqueries. This is supported by the flags argument,
* which is the bitwise OR of flag values to suppress mutating of
* indicated items. (More flag bits may be added as needed.)
*
* Normally the Query node itself is copied, but some callers want it to be
* modified in-place; they must pass QTW_DONT_COPY_QUERY in flags. All
* modified substructure is safely copied in any case.
*/
Query *
query_tree_mutator(Query *query,
Node *(*mutator) (),
void *context,
int flags)
{
Assert(query != NULL && IsA(query, Query));
if (!(flags & QTW_DONT_COPY_QUERY))
{
Query *newquery;
FLATCOPY(newquery, query, Query);
query = newquery;
}
MUTATE(query->targetList, query->targetList, List *);
MUTATE(query->withCheckOptions, query->withCheckOptions, List *);
MUTATE(query->onConflict, query->onConflict, OnConflictExpr *);
MUTATE(query->returningList, query->returningList, List *);
MUTATE(query->jointree, query->jointree, FromExpr *);
MUTATE(query->setOperations, query->setOperations, Node *);
MUTATE(query->havingQual, query->havingQual, Node *);
MUTATE(query->limitOffset, query->limitOffset, Node *);
MUTATE(query->limitCount, query->limitCount, Node *);
/*
* Most callers aren't interested in SortGroupClause nodes since those
* don't contain actual expressions. However they do contain OIDs, which
* may be of interest to some mutators.
*/
if ((flags & QTW_EXAMINE_SORTGROUP))
{
MUTATE(query->groupClause, query->groupClause, List *);
MUTATE(query->windowClause, query->windowClause, List *);
MUTATE(query->sortClause, query->sortClause, List *);
MUTATE(query->distinctClause, query->distinctClause, List *);
}
else
{
/*
* But we need to mutate the expressions under WindowClause nodes even
* if we're not interested in SortGroupClause nodes.
*/
List *resultlist;
ListCell *temp;
resultlist = NIL;
foreach(temp, query->windowClause)
{
WindowClause *wc = lfirst_node(WindowClause, temp);
WindowClause *newnode;
FLATCOPY(newnode, wc, WindowClause);
MUTATE(newnode->startOffset, wc->startOffset, Node *);
MUTATE(newnode->endOffset, wc->endOffset, Node *);
resultlist = lappend(resultlist, (Node *) newnode);
}
query->windowClause = resultlist;
}
/*
* groupingSets and rowMarks are not mutated:
*
* groupingSets contain only ressortgroup refs (integers) which are
* meaningless without the groupClause or tlist. Accordingly, any mutator
* that needs to care about them needs to handle them itself in its Query
* processing.
*
* rowMarks contains only rangetable indexes (and flags etc.) and
* therefore should be handled at Query level similarly.
*/
if (!(flags & QTW_IGNORE_CTE_SUBQUERIES))
MUTATE(query->cteList, query->cteList, List *);
else /* else copy CTE list as-is */
query->cteList = copyObject(query->cteList);
query->rtable = range_table_mutator(query->rtable,
mutator, context, flags);
return query;
}
/*
* range_table_mutator is just the part of query_tree_mutator that processes
* a query's rangetable. This is split out since it can be useful on
* its own.
*/
List *
range_table_mutator(List *rtable,
Node *(*mutator) (),
void *context,
int flags)
{
List *newrt = NIL;
ListCell *rt;
foreach(rt, rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(rt);
RangeTblEntry *newrte;
FLATCOPY(newrte, rte, RangeTblEntry);
switch (rte->rtekind)
{
case RTE_RELATION:
MUTATE(newrte->tablesample, rte->tablesample,
TableSampleClause *);
/* we don't bother to copy eref, aliases, etc; OK? */
break;
case RTE_SUBQUERY:
if (!(flags & QTW_IGNORE_RT_SUBQUERIES))
{
CHECKFLATCOPY(newrte->subquery, rte->subquery, Query);
MUTATE(newrte->subquery, newrte->subquery, Query *);
}
else
{
/* else, copy RT subqueries as-is */
newrte->subquery = copyObject(rte->subquery);
}
break;
case RTE_JOIN:
if (!(flags & QTW_IGNORE_JOINALIASES))
MUTATE(newrte->joinaliasvars, rte->joinaliasvars, List *);
else
{
/* else, copy join aliases as-is */
newrte->joinaliasvars = copyObject(rte->joinaliasvars);
}
break;
case RTE_FUNCTION:
MUTATE(newrte->functions, rte->functions, List *);
break;
case RTE_TABLEFUNC:
MUTATE(newrte->tablefunc, rte->tablefunc, TableFunc *);
break;
case RTE_VALUES:
MUTATE(newrte->values_lists, rte->values_lists, List *);
break;
case RTE_CTE:
case RTE_NAMEDTUPLESTORE:
case RTE_RESULT:
/* nothing to do */
break;
}
MUTATE(newrte->securityQuals, rte->securityQuals, List *);
newrt = lappend(newrt, newrte);
}
return newrt;
}
/*
* query_or_expression_tree_walker --- hybrid form
*
* This routine will invoke query_tree_walker if called on a Query node,
* else will invoke the walker directly. This is a useful way of starting
* the recursion when the walker's normal change of state is not appropriate
* for the outermost Query node.
*/
bool
query_or_expression_tree_walker(Node *node,
bool (*walker) (),
void *context,
int flags)
{
if (node && IsA(node, Query))
return query_tree_walker((Query *) node,
walker,
context,
flags);
else
return walker(node, context);
}
/*
* query_or_expression_tree_mutator --- hybrid form
*
* This routine will invoke query_tree_mutator if called on a Query node,
* else will invoke the mutator directly. This is a useful way of starting
* the recursion when the mutator's normal change of state is not appropriate
* for the outermost Query node.
*/
Node *
query_or_expression_tree_mutator(Node *node,
Node *(*mutator) (),
void *context,
int flags)
{
if (node && IsA(node, Query))
return (Node *) query_tree_mutator((Query *) node,
mutator,
context,
flags);
else
return mutator(node, context);
}
/*
* raw_expression_tree_walker --- walk raw parse trees
*
* This has exactly the same API as expression_tree_walker, but instead of
* walking post-analysis parse trees, it knows how to walk the node types
* found in raw grammar output. (There is not currently any need for a
* combined walker, so we keep them separate in the name of efficiency.)
* Unlike expression_tree_walker, there is no special rule about query
* boundaries: we descend to everything that's possibly interesting.
*
* Currently, the node type coverage here extends only to DML statements
* (SELECT/INSERT/UPDATE/DELETE) and nodes that can appear in them, because
* this is used mainly during analysis of CTEs, and only DML statements can
* appear in CTEs.
*/
bool
raw_expression_tree_walker(Node *node,
bool (*walker) (),
void *context)
{
ListCell *temp;
/*
* The walker has already visited the current node, and so we need only
* recurse into any sub-nodes it has.
*/
if (node == NULL)
return false;
/* Guard against stack overflow due to overly complex expressions */
check_stack_depth();
switch (nodeTag(node))
{
case T_SetToDefault:
case T_CurrentOfExpr:
case T_SQLValueFunction:
case T_Integer:
case T_Float:
case T_String:
case T_BitString:
case T_Null:
case T_ParamRef:
case T_A_Const:
case T_A_Star:
/* primitive node types with no subnodes */
break;
case T_Alias:
/* we assume the colnames list isn't interesting */
break;
case T_RangeVar:
return walker(((RangeVar *) node)->alias, context);
case T_GroupingFunc:
return walker(((GroupingFunc *) node)->args, context);
case T_SubLink:
{
SubLink *sublink = (SubLink *) node;
if (walker(sublink->testexpr, context))
return true;
/* we assume the operName is not interesting */
if (walker(sublink->subselect, context))
return true;
}
break;
case T_CaseExpr:
{
CaseExpr *caseexpr = (CaseExpr *) node;
if (walker(caseexpr->arg, context))
return true;
/* we assume walker doesn't care about CaseWhens, either */
foreach(temp, caseexpr->args)
{
CaseWhen *when = lfirst_node(CaseWhen, temp);
if (walker(when->expr, context))
return true;
if (walker(when->result, context))
return true;
}
if (walker(caseexpr->defresult, context))
return true;
}
break;
case T_RowExpr:
/* Assume colnames isn't interesting */
return walker(((RowExpr *) node)->args, context);
case T_CoalesceExpr:
return walker(((CoalesceExpr *) node)->args, context);
case T_MinMaxExpr:
return walker(((MinMaxExpr *) node)->args, context);
case T_XmlExpr:
{
XmlExpr *xexpr = (XmlExpr *) node;
if (walker(xexpr->named_args, context))
return true;
/* we assume walker doesn't care about arg_names */
if (walker(xexpr->args, context))
return true;
}
break;
case T_NullTest:
return walker(((NullTest *) node)->arg, context);
case T_BooleanTest:
return walker(((BooleanTest *) node)->arg, context);
case T_JoinExpr:
{
JoinExpr *join = (JoinExpr *) node;
if (walker(join->larg, context))
return true;
if (walker(join->rarg, context))
return true;
if (walker(join->quals, context))
return true;
if (walker(join->alias, context))
return true;
/* using list is deemed uninteresting */
}
break;
case T_IntoClause:
{
IntoClause *into = (IntoClause *) node;
if (walker(into->rel, context))
return true;
/* colNames, options are deemed uninteresting */
/* viewQuery should be null in raw parsetree, but check it */
if (walker(into->viewQuery, context))
return true;
}
break;
case T_List:
foreach(temp, (List *) node)
{
if (walker((Node *) lfirst(temp), context))
return true;
}
break;
case T_InsertStmt:
{
InsertStmt *stmt = (InsertStmt *) node;
if (walker(stmt->relation, context))
return true;
if (walker(stmt->cols, context))
return true;
if (walker(stmt->selectStmt, context))
return true;
if (walker(stmt->onConflictClause, context))
return true;
if (walker(stmt->returningList, context))
return true;
if (walker(stmt->withClause, context))
return true;
}
break;
case T_DeleteStmt:
{
DeleteStmt *stmt = (DeleteStmt *) node;
if (walker(stmt->relation, context))
return true;
if (walker(stmt->usingClause, context))
return true;
if (walker(stmt->whereClause, context))
return true;
if (walker(stmt->returningList, context))
return true;
if (walker(stmt->withClause, context))
return true;
}
break;
case T_UpdateStmt:
{
UpdateStmt *stmt = (UpdateStmt *) node;
if (walker(stmt->relation, context))
return true;
if (walker(stmt->targetList, context))
return true;
if (walker(stmt->whereClause, context))
return true;
if (walker(stmt->fromClause, context))
return true;
if (walker(stmt->returningList, context))
return true;
if (walker(stmt->withClause, context))
return true;
}
break;
case T_SelectStmt:
{
SelectStmt *stmt = (SelectStmt *) node;
if (walker(stmt->distinctClause, context))
return true;
if (walker(stmt->intoClause, context))
return true;
if (walker(stmt->targetList, context))
return true;
if (walker(stmt->fromClause, context))
return true;
if (walker(stmt->whereClause, context))
return true;
if (walker(stmt->groupClause, context))
return true;
if (walker(stmt->havingClause, context))
return true;
if (walker(stmt->windowClause, context))
return true;
if (walker(stmt->valuesLists, context))
return true;
if (walker(stmt->sortClause, context))
return true;
if (walker(stmt->limitOffset, context))
return true;
if (walker(stmt->limitCount, context))
return true;
if (walker(stmt->lockingClause, context))
return true;
if (walker(stmt->withClause, context))
return true;
if (walker(stmt->larg, context))
return true;
if (walker(stmt->rarg, context))
return true;
}
break;
case T_A_Expr:
{
A_Expr *expr = (A_Expr *) node;
if (walker(expr->lexpr, context))
return true;
if (walker(expr->rexpr, context))
return true;
/* operator name is deemed uninteresting */
}
break;
case T_BoolExpr:
{
BoolExpr *expr = (BoolExpr *) node;
if (walker(expr->args, context))
return true;
}
break;
case T_ColumnRef:
/* we assume the fields contain nothing interesting */
break;
case T_FuncCall:
{
FuncCall *fcall = (FuncCall *) node;
if (walker(fcall->args, context))
return true;
if (walker(fcall->agg_order, context))
return true;
if (walker(fcall->agg_filter, context))
return true;
if (walker(fcall->over, context))
return true;
/* function name is deemed uninteresting */
}
break;
case T_NamedArgExpr:
return walker(((NamedArgExpr *) node)->arg, context);
case T_A_Indices:
{
A_Indices *indices = (A_Indices *) node;
if (walker(indices->lidx, context))
return true;
if (walker(indices->uidx, context))
return true;
}
break;
case T_A_Indirection:
{
A_Indirection *indir = (A_Indirection *) node;
if (walker(indir->arg, context))
return true;
if (walker(indir->indirection, context))
return true;
}
break;
case T_A_ArrayExpr:
return walker(((A_ArrayExpr *) node)->elements, context);
case T_ResTarget:
{
ResTarget *rt = (ResTarget *) node;
if (walker(rt->indirection, context))
return true;
if (walker(rt->val, context))
return true;
}
break;
case T_MultiAssignRef:
return walker(((MultiAssignRef *) node)->source, context);
case T_TypeCast:
{
TypeCast *tc = (TypeCast *) node;
if (walker(tc->arg, context))
return true;
if (walker(tc->typeName, context))
return true;
}
break;
case T_CollateClause:
return walker(((CollateClause *) node)->arg, context);
case T_SortBy:
return walker(((SortBy *) node)->node, context);
case T_WindowDef:
{
WindowDef *wd = (WindowDef *) node;
if (walker(wd->partitionClause, context))
return true;
if (walker(wd->orderClause, context))
return true;
if (walker(wd->startOffset, context))
return true;
if (walker(wd->endOffset, context))
return true;
}
break;
case T_RangeSubselect:
{
RangeSubselect *rs = (RangeSubselect *) node;
if (walker(rs->subquery, context))
return true;
if (walker(rs->alias, context))
return true;
}
break;
case T_RangeFunction:
{
RangeFunction *rf = (RangeFunction *) node;
if (walker(rf->functions, context))
return true;
if (walker(rf->alias, context))
return true;
if (walker(rf->coldeflist, context))
return true;
}
break;
case T_RangeTableSample:
{
RangeTableSample *rts = (RangeTableSample *) node;
if (walker(rts->relation, context))
return true;
/* method name is deemed uninteresting */
if (walker(rts->args, context))
return true;
if (walker(rts->repeatable, context))
return true;
}
break;
case T_RangeTableFunc:
{
RangeTableFunc *rtf = (RangeTableFunc *) node;
if (walker(rtf->docexpr, context))
return true;
if (walker(rtf->rowexpr, context))
return true;
if (walker(rtf->namespaces, context))
return true;
if (walker(rtf->columns, context))
return true;
if (walker(rtf->alias, context))
return true;
}
break;
case T_RangeTableFuncCol:
{
RangeTableFuncCol *rtfc = (RangeTableFuncCol *) node;
if (walker(rtfc->colexpr, context))
return true;
if (walker(rtfc->coldefexpr, context))
return true;
}
break;
case T_TypeName:
{
TypeName *tn = (TypeName *) node;
if (walker(tn->typmods, context))
return true;
if (walker(tn->arrayBounds, context))
return true;
/* type name itself is deemed uninteresting */
}
break;
case T_ColumnDef:
{
ColumnDef *coldef = (ColumnDef *) node;
if (walker(coldef->typeName, context))
return true;
if (walker(coldef->raw_default, context))
return true;
if (walker(coldef->collClause, context))
return true;
/* for now, constraints are ignored */
}
break;
case T_IndexElem:
{
IndexElem *indelem = (IndexElem *) node;
if (walker(indelem->expr, context))
return true;
/* collation and opclass names are deemed uninteresting */
}
break;
case T_GroupingSet:
return walker(((GroupingSet *) node)->content, context);
case T_LockingClause:
return walker(((LockingClause *) node)->lockedRels, context);
case T_XmlSerialize:
{
XmlSerialize *xs = (XmlSerialize *) node;
if (walker(xs->expr, context))
return true;
if (walker(xs->typeName, context))
return true;
}
break;
case T_WithClause:
return walker(((WithClause *) node)->ctes, context);
case T_InferClause:
{
InferClause *stmt = (InferClause *) node;
if (walker(stmt->indexElems, context))
return true;
if (walker(stmt->whereClause, context))
return true;
}
break;
case T_OnConflictClause:
{
OnConflictClause *stmt = (OnConflictClause *) node;
if (walker(stmt->infer, context))
return true;
if (walker(stmt->targetList, context))
return true;
if (walker(stmt->whereClause, context))
return true;
}
break;
case T_CommonTableExpr:
return walker(((CommonTableExpr *) node)->ctequery, context);
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(node));
break;
}
return false;
}
/*
* planstate_tree_walker --- walk plan state trees
*
* The walker has already visited the current node, and so we need only
* recurse into any sub-nodes it has.
*/
bool
planstate_tree_walker(PlanState *planstate,
bool (*walker) (),
void *context)
{
Plan *plan = planstate->plan;
ListCell *lc;
/* Guard against stack overflow due to overly complex plan trees */
check_stack_depth();
/* initPlan-s */
if (planstate_walk_subplans(planstate->initPlan, walker, context))
return true;
/* lefttree */
if (outerPlanState(planstate))
{
if (walker(outerPlanState(planstate), context))
return true;
}
/* righttree */
if (innerPlanState(planstate))
{
if (walker(innerPlanState(planstate), context))
return true;
}
/* special child plans */
switch (nodeTag(plan))
{
case T_ModifyTable:
if (planstate_walk_members(((ModifyTableState *) planstate)->mt_plans,
((ModifyTableState *) planstate)->mt_nplans,
walker, context))
return true;
break;
case T_Append:
if (planstate_walk_members(((AppendState *) planstate)->appendplans,
((AppendState *) planstate)->as_nplans,
walker, context))
return true;
break;
case T_MergeAppend:
if (planstate_walk_members(((MergeAppendState *) planstate)->mergeplans,
((MergeAppendState *) planstate)->ms_nplans,
walker, context))
return true;
break;
case T_BitmapAnd:
if (planstate_walk_members(((BitmapAndState *) planstate)->bitmapplans,
((BitmapAndState *) planstate)->nplans,
walker, context))
return true;
break;
case T_BitmapOr:
if (planstate_walk_members(((BitmapOrState *) planstate)->bitmapplans,
((BitmapOrState *) planstate)->nplans,
walker, context))
return true;
break;
case T_SubqueryScan:
if (walker(((SubqueryScanState *) planstate)->subplan, context))
return true;
break;
case T_CustomScan:
foreach(lc, ((CustomScanState *) planstate)->custom_ps)
{
if (walker((PlanState *) lfirst(lc), context))
return true;
}
break;
default:
break;
}
/* subPlan-s */
if (planstate_walk_subplans(planstate->subPlan, walker, context))
return true;
return false;
}
/*
* Walk a list of SubPlans (or initPlans, which also use SubPlan nodes).
*/
static bool
planstate_walk_subplans(List *plans,
bool (*walker) (),
void *context)
{
ListCell *lc;
foreach(lc, plans)
{
SubPlanState *sps = lfirst_node(SubPlanState, lc);
if (walker(sps->planstate, context))
return true;
}
return false;
}
/*
* Walk the constituent plans of a ModifyTable, Append, MergeAppend,
* BitmapAnd, or BitmapOr node.
*/
static bool
planstate_walk_members(PlanState **planstates, int nplans,
bool (*walker) (), void *context)
{
int j;
for (j = 0; j < nplans; j++)
{
if (walker(planstates[j], context))
return true;
}
return false;
}