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postgres/src/backend/nodes/nodeFuncs.c
Tom Lane 389af95155 Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. 
This patch implements data-modifying WITH queries according to the
semantics that the updates all happen with the same command counter value,
and in an unspecified order.  Therefore one WITH clause can't see the
effects of another, nor can the outer query see the effects other than
through the RETURNING values.  And attempts to do conflicting updates will
have unpredictable results.  We'll need to document all that.

This commit just fixes the code; documentation updates are waiting on
author.

Marko Tiikkaja and Hitoshi Harada
2011-02-25 18:58:02 -05:00

2833 lines
76 KiB
C
Raw Blame History

/*-------------------------------------------------------------------------
*
* nodeFuncs.c
* Various general-purpose manipulations of Node trees
*
* Portions Copyright (c) 1996-2011, 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/nodeFuncs.h"
#include "nodes/relation.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);
/*
* exprType -
* returns the Oid of the type of the expression's result.
*/
Oid
exprType(Node *expr)
{
Oid type;
if (!expr)
return InvalidOid;
switch (nodeTag(expr))
{
case T_Var:
type = ((Var *) expr)->vartype;
break;
case T_Const:
type = ((Const *) expr)->consttype;
break;
case T_Param:
type = ((Param *) expr)->paramtype;
break;
case T_Aggref:
type = ((Aggref *) expr)->aggtype;
break;
case T_WindowFunc:
type = ((WindowFunc *) expr)->wintype;
break;
case T_ArrayRef:
{
ArrayRef *arrayref = (ArrayRef *) expr;
/* slice and/or store operations yield the array type */
if (arrayref->reflowerindexpr || arrayref->refassgnexpr)
type = arrayref->refarraytype;
else
type = arrayref->refelemtype;
}
break;
case T_FuncExpr:
type = ((FuncExpr *) expr)->funcresulttype;
break;
case T_NamedArgExpr:
type = exprType((Node *) ((NamedArgExpr *) expr)->arg);
break;
case T_OpExpr:
type = ((OpExpr *) expr)->opresulttype;
break;
case T_DistinctExpr:
type = ((DistinctExpr *) expr)->opresulttype;
break;
case T_ScalarArrayOpExpr:
type = BOOLOID;
break;
case T_BoolExpr:
type = BOOLOID;
break;
case T_SubLink:
{
SubLink *sublink = (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 = (TargetEntry *) linitial(qtree->targetList);
Assert(IsA(tent, TargetEntry));
Assert(!tent->resjunk);
type = exprType((Node *) tent->expr);
if (sublink->subLinkType == ARRAY_SUBLINK)
{
type = get_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
{
/* for all other sublink types, result is boolean */
type = BOOLOID;
}
}
break;
case T_SubPlan:
{
SubPlan *subplan = (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_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
{
/* for all other subplan types, result is boolean */
type = BOOLOID;
}
}
break;
case T_AlternativeSubPlan:
{
AlternativeSubPlan *asplan = (AlternativeSubPlan *) expr;
/* subplans should all return the same thing */
type = exprType((Node *) linitial(asplan->subplans));
}
break;
case T_FieldSelect:
type = ((FieldSelect *) expr)->resulttype;
break;
case T_FieldStore:
type = ((FieldStore *) expr)->resulttype;
break;
case T_RelabelType:
type = ((RelabelType *) expr)->resulttype;
break;
case T_CollateClause:
type = exprType((Node *) ((CollateClause *) expr)->arg);
break;
case T_CoerceViaIO:
type = ((CoerceViaIO *) expr)->resulttype;
break;
case T_ArrayCoerceExpr:
type = ((ArrayCoerceExpr *) expr)->resulttype;
break;
case T_ConvertRowtypeExpr:
type = ((ConvertRowtypeExpr *) expr)->resulttype;
break;
case T_CaseExpr:
type = ((CaseExpr *) expr)->casetype;
break;
case T_CaseTestExpr:
type = ((CaseTestExpr *) expr)->typeId;
break;
case T_ArrayExpr:
type = ((ArrayExpr *) expr)->array_typeid;
break;
case T_RowExpr:
type = ((RowExpr *) expr)->row_typeid;
break;
case T_RowCompareExpr:
type = BOOLOID;
break;
case T_CoalesceExpr:
type = ((CoalesceExpr *) expr)->coalescetype;
break;
case T_MinMaxExpr:
type = ((MinMaxExpr *) expr)->minmaxtype;
break;
case T_XmlExpr:
if (((XmlExpr *) expr)->op == IS_DOCUMENT)
type = BOOLOID;
else if (((XmlExpr *) expr)->op == IS_XMLSERIALIZE)
type = TEXTOID;
else
type = XMLOID;
break;
case T_NullIfExpr:
type = exprType((Node *) linitial(((NullIfExpr *) expr)->args));
break;
case T_NullTest:
type = BOOLOID;
break;
case T_BooleanTest:
type = BOOLOID;
break;
case T_CoerceToDomain:
type = ((CoerceToDomain *) expr)->resulttype;
break;
case T_CoerceToDomainValue:
type = ((CoerceToDomainValue *) expr)->typeId;
break;
case T_SetToDefault:
type = ((SetToDefault *) expr)->typeId;
break;
case T_CurrentOfExpr:
type = BOOLOID;
break;
case T_PlaceHolderVar:
type = exprType((Node *) ((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(Node *expr)
{
if (!expr)
return -1;
switch (nodeTag(expr))
{
case T_Var:
return ((Var *) expr)->vartypmod;
case T_Const:
return ((Const *) expr)->consttypmod;
case T_Param:
return ((Param *) expr)->paramtypmod;
case T_ArrayRef:
/* typmod is the same for array or element */
return ((ArrayRef *) 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 *) ((NamedArgExpr *) expr)->arg);
case T_SubLink:
{
SubLink *sublink = (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 = (TargetEntry *) linitial(qtree->targetList);
Assert(IsA(tent, TargetEntry));
Assert(!tent->resjunk);
return exprTypmod((Node *) tent->expr);
/* note we don't need to care if it's an array */
}
}
break;
case T_SubPlan:
{
SubPlan *subplan = (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;
}
else
{
/* for all other subplan types, result is boolean */
return -1;
}
}
break;
case T_AlternativeSubPlan:
{
AlternativeSubPlan *asplan = (AlternativeSubPlan *) expr;
/* subplans should all return the same thing */
return exprTypmod((Node *) linitial(asplan->subplans));
}
break;
case T_FieldSelect:
return ((FieldSelect *) expr)->resulttypmod;
case T_RelabelType:
return ((RelabelType *) expr)->resulttypmod;
case T_ArrayCoerceExpr:
return ((ArrayCoerceExpr *) expr)->resulttypmod;
case T_CaseExpr:
{
/*
* If all the alternatives agree on type/typmod, return that
* typmod, else use -1
*/
CaseExpr *cexpr = (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 = (CaseWhen *) lfirst(arg);
Assert(IsA(w, CaseWhen));
if (exprType((Node *) w->result) != casetype)
return -1;
if (exprTypmod((Node *) w->result) != typmod)
return -1;
}
return typmod;
}
break;
case T_CaseTestExpr:
return ((CaseTestExpr *) expr)->typeMod;
case T_ArrayExpr:
{
/*
* If all the elements agree on type/typmod, return that
* typmod, else use -1
*/
ArrayExpr *arrayexpr = (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
*/
CoalesceExpr *cexpr = (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, lnext(list_head(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
*/
MinMaxExpr *mexpr = (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, lnext(list_head(mexpr->args)))
{
Node *e = (Node *) lfirst(arg);
if (exprType(e) != minmaxtype)
return -1;
if (exprTypmod(e) != typmod)
return -1;
}
return typmod;
}
break;
case T_NullIfExpr:
{
NullIfExpr *nexpr = (NullIfExpr *) expr;
return exprTypmod((Node *) linitial(nexpr->args));
}
break;
case T_CoerceToDomain:
return ((CoerceToDomain *) expr)->resulttypmod;
case T_CoerceToDomainValue:
return ((CoerceToDomainValue *) expr)->typeMod;
case T_SetToDefault:
return ((SetToDefault *) expr)->typeMod;
case T_PlaceHolderVar:
return exprTypmod((Node *) ((PlaceHolderVar *) expr)->phexpr);
default:
break;
}
return -1;
}
/*
* exprCollation -
* returns the Oid of the collation of the expression's result.
*/
Oid
exprCollation(Node *expr)
{
Oid coll;
if (!expr)
return InvalidOid;
switch (nodeTag(expr))
{
case T_Var:
coll = ((Var *) expr)->varcollid;
break;
case T_Const:
coll = ((Const *) expr)->constcollid;
break;
case T_Param:
coll = ((Param *) expr)->paramcollation;
break;
case T_Aggref:
coll = ((Aggref *) expr)->collid;
break;
case T_WindowFunc:
coll = ((WindowFunc *) expr)->collid;
break;
case T_ArrayRef:
coll = ((ArrayRef *) expr)->refcollid;
break;
case T_FuncExpr:
coll = ((FuncExpr *) expr)->collid;
break;
case T_NamedArgExpr:
coll = exprCollation((Node *) ((NamedArgExpr *) expr)->arg);
break;
case T_OpExpr:
coll = ((OpExpr *) expr)->collid;
break;
case T_DistinctExpr:
coll = ((DistinctExpr *) expr)->collid;
break;
case T_ScalarArrayOpExpr:
coll = ((ScalarArrayOpExpr *) expr)->collid;
break;
case T_BoolExpr:
coll = InvalidOid; /* not applicable */
break;
case T_SubLink:
{
SubLink *sublink = (SubLink *) expr;
if (sublink->subLinkType == EXPR_SUBLINK ||
sublink->subLinkType == ARRAY_SUBLINK)
{
/* get the collation of the 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 = (TargetEntry *) linitial(qtree->targetList);
Assert(IsA(tent, TargetEntry));
Assert(!tent->resjunk);
coll = exprCollation((Node *) tent->expr);
/* note we don't need to care if it's an array */
}
else
coll = InvalidOid;
}
break;
case T_SubPlan:
{
SubPlan *subplan = (SubPlan *) expr;
if (subplan->subLinkType == EXPR_SUBLINK ||
subplan->subLinkType == ARRAY_SUBLINK)
{
/* get the collation of the subselect's first target column */
/* note we don't need to care if it's an array */
coll = subplan->firstColCollation;
}
else
{
/* for all other subplan types, result is boolean */
coll = InvalidOid;
}
}
break;
case T_AlternativeSubPlan:
{
AlternativeSubPlan *asplan = (AlternativeSubPlan *) expr;
/* subplans should all return the same thing */
coll = exprCollation((Node *) linitial(asplan->subplans));
}
break;
case T_FieldSelect:
coll = ((FieldSelect *) expr)->resultcollation;
break;
case T_FieldStore:
coll = InvalidOid; /* not applicable */
break;
case T_RelabelType:
coll = exprCollation((Node *) ((RelabelType *) expr)->arg);
break;
case T_CollateClause:
coll = ((CollateClause *) expr)->collOid;
break;
case T_CoerceViaIO:
{
CoerceViaIO *cvio = (CoerceViaIO *) expr;
coll = coercion_expression_result_collation(cvio->resulttype, (Node *) cvio->arg);
break;
}
case T_ArrayCoerceExpr:
{
ArrayCoerceExpr *ace = (ArrayCoerceExpr *) expr;
coll = coercion_expression_result_collation(ace->resulttype, (Node *) ace->arg);
break;
}
case T_ConvertRowtypeExpr:
{
ConvertRowtypeExpr *cre = (ConvertRowtypeExpr *) expr;
coll = coercion_expression_result_collation(cre->resulttype, (Node *) cre->arg);
break;
}
case T_CaseExpr:
coll = ((CaseExpr *) expr)->casecollation;
break;
case T_CaseTestExpr:
coll = ((CaseTestExpr *) expr)->collation;
break;
case T_ArrayExpr:
coll = get_typcollation(((ArrayExpr *) expr)->array_typeid);
break;
case T_RowExpr:
coll = InvalidOid; /* not applicable */
break;
case T_RowCompareExpr:
coll = InvalidOid; /* not applicable */
break;
case T_CoalesceExpr:
coll = ((CoalesceExpr *) expr)->coalescecollation;
break;
case T_MinMaxExpr:
coll = ((MinMaxExpr *) expr)->collid;
break;
case T_XmlExpr:
if (((XmlExpr *) expr)->op == IS_XMLSERIALIZE)
coll = DEFAULT_COLLATION_OID;
else
coll = InvalidOid;
break;
case T_NullIfExpr:
coll = exprCollation((Node *) linitial(((NullIfExpr *) expr)->args));
break;
case T_NullTest:
coll = InvalidOid; /* not applicable */
break;
case T_BooleanTest:
coll = InvalidOid; /* not applicable */
break;
case T_CoerceToDomain:
coll = get_typcollation(((CoerceToDomain *) expr)->resulttype);
if (coll == DEFAULT_COLLATION_OID)
coll = exprCollation((Node *) ((CoerceToDomain *) expr)->arg);
break;
case T_CoerceToDomainValue:
coll = get_typcollation(((CoerceToDomainValue *) expr)->typeId);
break;
case T_SetToDefault:
coll = ((SetToDefault *) expr)->collid;
break;
case T_CurrentOfExpr:
coll = InvalidOid; /* not applicable */
break;
case T_PlaceHolderVar:
coll = exprCollation((Node *) ((PlaceHolderVar *) expr)->phexpr);
break;
default:
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
coll = InvalidOid; /* keep compiler quiet */
break;
}
return coll;
}
/*
* Compute the result collation of a coercion-like expression that
* converts arg to resulttype.
*/
Oid
coercion_expression_result_collation(Oid resulttype, Node *arg)
{
if (type_is_collatable(resulttype))
{
if (type_is_collatable(exprType(arg)))
return exprCollation(arg);
else
return DEFAULT_COLLATION_OID;
}
else
return InvalidOid;
}
/*
* 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(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))
{
FuncExpr *func = (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))
{
ArrayCoerceExpr *acoerce = (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;
}
/*
* 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 can't return a set */
if (IsA(node, Aggref))
return false;
if (IsA(node, WindowFunc))
return false;
if (IsA(node, DistinctExpr))
return false;
if (IsA(node, ScalarArrayOpExpr))
return false;
if (IsA(node, BoolExpr))
return false;
if (IsA(node, SubLink))
return false;
if (IsA(node, SubPlan))
return false;
if (IsA(node, AlternativeSubPlan))
return false;
if (IsA(node, ArrayExpr))
return false;
if (IsA(node, RowExpr))
return false;
if (IsA(node, RowCompareExpr))
return false;
if (IsA(node, CoalesceExpr))
return false;
if (IsA(node, MinMaxExpr))
return false;
if (IsA(node, XmlExpr))
return false;
if (IsA(node, NullIfExpr))
return false;
return expression_tree_walker(node, expression_returns_set_walker,
context);
}
/*
* 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(Node *expr)
{
int loc;
if (expr == NULL)
return -1;
switch (nodeTag(expr))
{
case T_RangeVar:
loc = ((RangeVar *) expr)->location;
break;
case T_Var:
loc = ((Var *) expr)->location;
break;
case T_Const:
loc = ((Const *) expr)->location;
break;
case T_Param:
loc = ((Param *) expr)->location;
break;
case T_Aggref:
/* function name should always be the first thing */
loc = ((Aggref *) expr)->location;
break;
case T_WindowFunc:
/* function name should always be the first thing */
loc = ((WindowFunc *) expr)->location;
break;
case T_ArrayRef:
/* just use array argument's location */
loc = exprLocation((Node *) ((ArrayRef *) expr)->refexpr);
break;
case T_FuncExpr:
{
FuncExpr *fexpr = (FuncExpr *) expr;
/* consider both function name and leftmost arg */
loc = leftmostLoc(fexpr->location,
exprLocation((Node *) fexpr->args));
}
break;
case T_NamedArgExpr:
{
NamedArgExpr *na = (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 */
{
OpExpr *opexpr = (OpExpr *) expr;
/* consider both operator name and leftmost arg */
loc = leftmostLoc(opexpr->location,
exprLocation((Node *) opexpr->args));
}
break;
case T_ScalarArrayOpExpr:
{
ScalarArrayOpExpr *saopexpr = (ScalarArrayOpExpr *) expr;
/* consider both operator name and leftmost arg */
loc = leftmostLoc(saopexpr->location,
exprLocation((Node *) saopexpr->args));
}
break;
case T_BoolExpr:
{
BoolExpr *bexpr = (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:
{
SubLink *sublink = (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 *) ((FieldSelect *) expr)->arg);
break;
case T_FieldStore:
/* just use argument's location */
loc = exprLocation((Node *) ((FieldStore *) expr)->arg);
break;
case T_RelabelType:
{
RelabelType *rexpr = (RelabelType *) expr;
/* Much as above */
loc = leftmostLoc(rexpr->location,
exprLocation((Node *) rexpr->arg));
}
break;
case T_CoerceViaIO:
{
CoerceViaIO *cexpr = (CoerceViaIO *) expr;
/* Much as above */
loc = leftmostLoc(cexpr->location,
exprLocation((Node *) cexpr->arg));
}
break;
case T_ArrayCoerceExpr:
{
ArrayCoerceExpr *cexpr = (ArrayCoerceExpr *) expr;
/* Much as above */
loc = leftmostLoc(cexpr->location,
exprLocation((Node *) cexpr->arg));
}
break;
case T_ConvertRowtypeExpr:
{
ConvertRowtypeExpr *cexpr = (ConvertRowtypeExpr *) expr;
/* Much as above */
loc = leftmostLoc(cexpr->location,
exprLocation((Node *) cexpr->arg));
}
break;
case T_CaseExpr:
/* CASE keyword should always be the first thing */
loc = ((CaseExpr *) expr)->location;
break;
case T_CaseWhen:
/* WHEN keyword should always be the first thing */
loc = ((CaseWhen *) expr)->location;
break;
case T_ArrayExpr:
/* the location points at ARRAY or [, which must be leftmost */
loc = ((ArrayExpr *) expr)->location;
break;
case T_RowExpr:
/* the location points at ROW or (, which must be leftmost */
loc = ((RowExpr *) expr)->location;
break;
case T_RowCompareExpr:
/* just use leftmost argument's location */
loc = exprLocation((Node *) ((RowCompareExpr *) expr)->largs);
break;
case T_CoalesceExpr:
/* COALESCE keyword should always be the first thing */
loc = ((CoalesceExpr *) expr)->location;
break;
case T_MinMaxExpr:
/* GREATEST/LEAST keyword should always be the first thing */
loc = ((MinMaxExpr *) expr)->location;
break;
case T_XmlExpr:
{
XmlExpr *xexpr = (XmlExpr *) expr;
/* consider both function name and leftmost arg */
loc = leftmostLoc(xexpr->location,
exprLocation((Node *) xexpr->args));
}
break;
case T_NullTest:
/* just use argument's location */
loc = exprLocation((Node *) ((NullTest *) expr)->arg);
break;
case T_BooleanTest:
/* just use argument's location */
loc = exprLocation((Node *) ((BooleanTest *) expr)->arg);
break;
case T_CoerceToDomain:
{
CoerceToDomain *cexpr = (CoerceToDomain *) expr;
/* Much as above */
loc = leftmostLoc(cexpr->location,
exprLocation((Node *) cexpr->arg));
}
break;
case T_CoerceToDomainValue:
loc = ((CoerceToDomainValue *) expr)->location;
break;
case T_SetToDefault:
loc = ((SetToDefault *) expr)->location;
break;
case T_TargetEntry:
/* just use argument's location */
loc = exprLocation((Node *) ((TargetEntry *) expr)->expr);
break;
case T_IntoClause:
/* use the contained RangeVar's location --- close enough */
loc = exprLocation((Node *) ((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, (List *) expr)
{
loc = exprLocation((Node *) lfirst(lc));
if (loc >= 0)
break;
}
}
break;
case T_A_Expr:
{
A_Expr *aexpr = (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 = ((ColumnRef *) expr)->location;
break;
case T_ParamRef:
loc = ((ParamRef *) expr)->location;
break;
case T_A_Const:
loc = ((A_Const *) expr)->location;
break;
case T_FuncCall:
{
FuncCall *fc = (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 = ((A_ArrayExpr *) expr)->location;
break;
case T_ResTarget:
/* we need not examine the contained expression (if any) */
loc = ((ResTarget *) expr)->location;
break;
case T_TypeCast:
{
TypeCast *tc = (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:
loc = ((CollateClause *) expr)->location;
break;
case T_SortBy:
/* just use argument's location (ignore operator, if any) */
loc = exprLocation(((SortBy *) expr)->node);
break;
case T_WindowDef:
loc = ((WindowDef *) expr)->location;
break;
case T_TypeName:
loc = ((TypeName *) expr)->location;
break;
case T_Constraint:
loc = ((Constraint *) expr)->location;
break;
case T_XmlSerialize:
/* XMLSERIALIZE keyword should always be the first thing */
loc = ((XmlSerialize *) expr)->location;
break;
case T_WithClause:
loc = ((WithClause *) expr)->location;
break;
case T_CommonTableExpr:
loc = ((CommonTableExpr *) expr)->location;
break;
case T_PlaceHolderVar:
/* just use argument's location */
loc = exprLocation((Node *) ((PlaceHolderVar *) expr)->phexpr);
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);
}
/*
* 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_CoerceToDomainValue:
case T_CaseTestExpr:
case T_SetToDefault:
case T_CurrentOfExpr:
case T_RangeTblRef:
case T_SortGroupClause:
/* primitive node types with no expression subnodes */
break;
case T_Aggref:
{
Aggref *expr = (Aggref *) node;
/* recurse directly on List */
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;
}
break;
case T_WindowFunc:
{
WindowFunc *expr = (WindowFunc *) node;
/* recurse directly on List */
if (expression_tree_walker((Node *) expr->args,
walker, context))
return true;
}
break;
case T_ArrayRef:
{
ArrayRef *aref = (ArrayRef *) node;
/* recurse directly for upper/lower array index lists */
if (expression_tree_walker((Node *) aref->refupperindexpr,
walker, context))
return true;
if (expression_tree_walker((Node *) aref->reflowerindexpr,
walker, context))
return true;
/* walker must see the refexpr and refassgnexpr, however */
if (walker(aref->refexpr, context))
return true;
if (walker(aref->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:
{
OpExpr *expr = (OpExpr *) node;
if (expression_tree_walker((Node *) expr->args,
walker, context))
return true;
}
break;
case T_DistinctExpr:
{
DistinctExpr *expr = (DistinctExpr *) 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_CollateClause:
return walker(((CollateClause *) node)->arg, context);
case T_CoerceViaIO:
return walker(((CoerceViaIO *) node)->arg, context);
case T_ArrayCoerceExpr:
return walker(((ArrayCoerceExpr *) node)->arg, context);
case T_ConvertRowtypeExpr:
return walker(((ConvertRowtypeExpr *) 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 = (CaseWhen *) lfirst(temp);
Assert(IsA(when, CaseWhen));
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_NullIfExpr:
return walker(((NullIfExpr *) node)->args, context);
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_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_PlaceHolderVar:
return walker(((PlaceHolderVar *) node)->phexpr, 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);
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 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));
if (walker((Node *) query->targetList, 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;
if (!(flags & QTW_IGNORE_CTE_SUBQUERIES))
{
if (walker((Node *) query->cteList, context))
return true;
}
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);
/* For historical reasons, visiting RTEs is not the default */
if (flags & QTW_EXAMINE_RTES)
if (walker(rte, context))
return true;
switch (rte->rtekind)
{
case RTE_RELATION:
case RTE_CTE:
/* nothing to do */
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->funcexpr, context))
return true;
break;
case RTE_VALUES:
if (walker(rte->values_lists, context))
return true;
break;
}
}
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_CoerceToDomainValue:
case T_CaseTestExpr:
case T_SetToDefault:
case T_CurrentOfExpr:
case T_RangeTblRef:
case T_SortGroupClause:
return (Node *) copyObject(node);
case T_Aggref:
{
Aggref *aggref = (Aggref *) node;
Aggref *newnode;
FLATCOPY(newnode, aggref, Aggref);
MUTATE(newnode->args, aggref->args, List *);
MUTATE(newnode->aggorder, aggref->aggorder, List *);
MUTATE(newnode->aggdistinct, aggref->aggdistinct, List *);
return (Node *) newnode;
}
break;
case T_WindowFunc:
{
WindowFunc *wfunc = (WindowFunc *) node;
WindowFunc *newnode;
FLATCOPY(newnode, wfunc, WindowFunc);
MUTATE(newnode->args, wfunc->args, List *);
return (Node *) newnode;
}
break;
case T_ArrayRef:
{
ArrayRef *arrayref = (ArrayRef *) node;
ArrayRef *newnode;
FLATCOPY(newnode, arrayref, ArrayRef);
MUTATE(newnode->refupperindexpr, arrayref->refupperindexpr,
List *);
MUTATE(newnode->reflowerindexpr, arrayref->reflowerindexpr,
List *);
MUTATE(newnode->refexpr, arrayref->refexpr,
Expr *);
MUTATE(newnode->refassgnexpr, arrayref->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_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_CollateClause:
{
CollateClause *collate = (CollateClause *) node;
CollateClause *newnode;
FLATCOPY(newnode, collate, CollateClause);
MUTATE(newnode->arg, collate->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 *);
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_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_NullIfExpr:
{
NullIfExpr *expr = (NullIfExpr *) node;
NullIfExpr *newnode;
FLATCOPY(newnode, expr, NullIfExpr);
MUTATE(newnode->args, expr->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_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_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_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;
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->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 *);
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:
case RTE_CTE:
/* 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->funcexpr, rte->funcexpr, Node *);
break;
case RTE_VALUES:
MUTATE(newrte->values_lists, rte->values_lists, List *);
break;
}
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 extends to SelectStmt and everything
* that could appear under it, but not other statement types.
*/
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_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_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 = (CaseWhen *) lfirst(temp);
Assert(IsA(when, CaseWhen));
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 */
}
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->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->withClause, 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->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_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->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_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->funccallnode, context))
return true;
if (walker(rf->alias, 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;
/* for now, constraints are ignored */
}
break;
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_CommonTableExpr:
return walker(((CommonTableExpr *) node)->ctequery, context);
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(node));
break;
}
return false;
}
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