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nodeFuncs.c
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1 /*-------------------------------------------------------------------------
2  *
3  * nodeFuncs.c
4  * Various general-purpose manipulations of Node trees
5  *
6  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  *
10  * IDENTIFICATION
11  * src/backend/nodes/nodeFuncs.c
12  *
13  *-------------------------------------------------------------------------
14  */
15 #include "postgres.h"
16 
17 #include "catalog/pg_collation.h"
18 #include "catalog/pg_type.h"
19 #include "miscadmin.h"
20 #include "nodes/makefuncs.h"
21 #include "nodes/execnodes.h"
22 #include "nodes/nodeFuncs.h"
23 #include "nodes/relation.h"
24 #include "utils/builtins.h"
25 #include "utils/lsyscache.h"
26 
27 
28 static bool expression_returns_set_walker(Node *node, void *context);
29 static int leftmostLoc(int loc1, int loc2);
30 static bool fix_opfuncids_walker(Node *node, void *context);
31 static bool planstate_walk_subplans(List *plans, bool (*walker) (),
32  void *context);
33 static bool planstate_walk_members(List *plans, PlanState **planstates,
34  bool (*walker) (), void *context);
35 
36 
37 /*
38  * exprType -
39  * returns the Oid of the type of the expression's result.
40  */
41 Oid
42 exprType(const Node *expr)
43 {
44  Oid type;
45 
46  if (!expr)
47  return InvalidOid;
48 
49  switch (nodeTag(expr))
50  {
51  case T_Var:
52  type = ((const Var *) expr)->vartype;
53  break;
54  case T_Const:
55  type = ((const Const *) expr)->consttype;
56  break;
57  case T_Param:
58  type = ((const Param *) expr)->paramtype;
59  break;
60  case T_Aggref:
61  type = ((const Aggref *) expr)->aggtype;
62  break;
63  case T_GroupingFunc:
64  type = INT4OID;
65  break;
66  case T_WindowFunc:
67  type = ((const WindowFunc *) expr)->wintype;
68  break;
69  case T_ArrayRef:
70  {
71  const ArrayRef *arrayref = (const ArrayRef *) expr;
72 
73  /* slice and/or store operations yield the array type */
74  if (arrayref->reflowerindexpr || arrayref->refassgnexpr)
75  type = arrayref->refarraytype;
76  else
77  type = arrayref->refelemtype;
78  }
79  break;
80  case T_FuncExpr:
81  type = ((const FuncExpr *) expr)->funcresulttype;
82  break;
83  case T_NamedArgExpr:
84  type = exprType((Node *) ((const NamedArgExpr *) expr)->arg);
85  break;
86  case T_OpExpr:
87  type = ((const OpExpr *) expr)->opresulttype;
88  break;
89  case T_DistinctExpr:
90  type = ((const DistinctExpr *) expr)->opresulttype;
91  break;
92  case T_NullIfExpr:
93  type = ((const NullIfExpr *) expr)->opresulttype;
94  break;
96  type = BOOLOID;
97  break;
98  case T_BoolExpr:
99  type = BOOLOID;
100  break;
101  case T_SubLink:
102  {
103  const SubLink *sublink = (const SubLink *) expr;
104 
105  if (sublink->subLinkType == EXPR_SUBLINK ||
106  sublink->subLinkType == ARRAY_SUBLINK)
107  {
108  /* get the type of the subselect's first target column */
109  Query *qtree = (Query *) sublink->subselect;
110  TargetEntry *tent;
111 
112  if (!qtree || !IsA(qtree, Query))
113  elog(ERROR, "cannot get type for untransformed sublink");
114  tent = linitial_node(TargetEntry, qtree->targetList);
115  Assert(!tent->resjunk);
116  type = exprType((Node *) tent->expr);
117  if (sublink->subLinkType == ARRAY_SUBLINK)
118  {
119  type = get_promoted_array_type(type);
120  if (!OidIsValid(type))
121  ereport(ERROR,
122  (errcode(ERRCODE_UNDEFINED_OBJECT),
123  errmsg("could not find array type for data type %s",
124  format_type_be(exprType((Node *) tent->expr)))));
125  }
126  }
127  else if (sublink->subLinkType == MULTIEXPR_SUBLINK)
128  {
129  /* MULTIEXPR is always considered to return RECORD */
130  type = RECORDOID;
131  }
132  else
133  {
134  /* for all other sublink types, result is boolean */
135  type = BOOLOID;
136  }
137  }
138  break;
139  case T_SubPlan:
140  {
141  const SubPlan *subplan = (const SubPlan *) expr;
142 
143  if (subplan->subLinkType == EXPR_SUBLINK ||
144  subplan->subLinkType == ARRAY_SUBLINK)
145  {
146  /* get the type of the subselect's first target column */
147  type = subplan->firstColType;
148  if (subplan->subLinkType == ARRAY_SUBLINK)
149  {
150  type = get_promoted_array_type(type);
151  if (!OidIsValid(type))
152  ereport(ERROR,
153  (errcode(ERRCODE_UNDEFINED_OBJECT),
154  errmsg("could not find array type for data type %s",
155  format_type_be(subplan->firstColType))));
156  }
157  }
158  else if (subplan->subLinkType == MULTIEXPR_SUBLINK)
159  {
160  /* MULTIEXPR is always considered to return RECORD */
161  type = RECORDOID;
162  }
163  else
164  {
165  /* for all other subplan types, result is boolean */
166  type = BOOLOID;
167  }
168  }
169  break;
171  {
172  const AlternativeSubPlan *asplan = (const AlternativeSubPlan *) expr;
173 
174  /* subplans should all return the same thing */
175  type = exprType((Node *) linitial(asplan->subplans));
176  }
177  break;
178  case T_FieldSelect:
179  type = ((const FieldSelect *) expr)->resulttype;
180  break;
181  case T_FieldStore:
182  type = ((const FieldStore *) expr)->resulttype;
183  break;
184  case T_RelabelType:
185  type = ((const RelabelType *) expr)->resulttype;
186  break;
187  case T_CoerceViaIO:
188  type = ((const CoerceViaIO *) expr)->resulttype;
189  break;
190  case T_ArrayCoerceExpr:
191  type = ((const ArrayCoerceExpr *) expr)->resulttype;
192  break;
194  type = ((const ConvertRowtypeExpr *) expr)->resulttype;
195  break;
196  case T_CollateExpr:
197  type = exprType((Node *) ((const CollateExpr *) expr)->arg);
198  break;
199  case T_CaseExpr:
200  type = ((const CaseExpr *) expr)->casetype;
201  break;
202  case T_CaseTestExpr:
203  type = ((const CaseTestExpr *) expr)->typeId;
204  break;
205  case T_ArrayExpr:
206  type = ((const ArrayExpr *) expr)->array_typeid;
207  break;
208  case T_RowExpr:
209  type = ((const RowExpr *) expr)->row_typeid;
210  break;
211  case T_RowCompareExpr:
212  type = BOOLOID;
213  break;
214  case T_CoalesceExpr:
215  type = ((const CoalesceExpr *) expr)->coalescetype;
216  break;
217  case T_MinMaxExpr:
218  type = ((const MinMaxExpr *) expr)->minmaxtype;
219  break;
220  case T_SQLValueFunction:
221  type = ((const SQLValueFunction *) expr)->type;
222  break;
223  case T_XmlExpr:
224  if (((const XmlExpr *) expr)->op == IS_DOCUMENT)
225  type = BOOLOID;
226  else if (((const XmlExpr *) expr)->op == IS_XMLSERIALIZE)
227  type = TEXTOID;
228  else
229  type = XMLOID;
230  break;
231  case T_NullTest:
232  type = BOOLOID;
233  break;
234  case T_BooleanTest:
235  type = BOOLOID;
236  break;
237  case T_CoerceToDomain:
238  type = ((const CoerceToDomain *) expr)->resulttype;
239  break;
241  type = ((const CoerceToDomainValue *) expr)->typeId;
242  break;
243  case T_SetToDefault:
244  type = ((const SetToDefault *) expr)->typeId;
245  break;
246  case T_CurrentOfExpr:
247  type = BOOLOID;
248  break;
249  case T_NextValueExpr:
250  type = ((const NextValueExpr *) expr)->typeId;
251  break;
252  case T_InferenceElem:
253  {
254  const InferenceElem *n = (const InferenceElem *) expr;
255 
256  type = exprType((Node *) n->expr);
257  }
258  break;
259  case T_PlaceHolderVar:
260  type = exprType((Node *) ((const PlaceHolderVar *) expr)->phexpr);
261  break;
262  default:
263  elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
264  type = InvalidOid; /* keep compiler quiet */
265  break;
266  }
267  return type;
268 }
269 
270 /*
271  * exprTypmod -
272  * returns the type-specific modifier of the expression's result type,
273  * if it can be determined. In many cases, it can't and we return -1.
274  */
275 int32
276 exprTypmod(const Node *expr)
277 {
278  if (!expr)
279  return -1;
280 
281  switch (nodeTag(expr))
282  {
283  case T_Var:
284  return ((const Var *) expr)->vartypmod;
285  case T_Const:
286  return ((const Const *) expr)->consttypmod;
287  case T_Param:
288  return ((const Param *) expr)->paramtypmod;
289  case T_ArrayRef:
290  /* typmod is the same for array or element */
291  return ((const ArrayRef *) expr)->reftypmod;
292  case T_FuncExpr:
293  {
294  int32 coercedTypmod;
295 
296  /* Be smart about length-coercion functions... */
297  if (exprIsLengthCoercion(expr, &coercedTypmod))
298  return coercedTypmod;
299  }
300  break;
301  case T_NamedArgExpr:
302  return exprTypmod((Node *) ((const NamedArgExpr *) expr)->arg);
303  case T_NullIfExpr:
304  {
305  /*
306  * Result is either first argument or NULL, so we can report
307  * first argument's typmod if known.
308  */
309  const NullIfExpr *nexpr = (const NullIfExpr *) expr;
310 
311  return exprTypmod((Node *) linitial(nexpr->args));
312  }
313  break;
314  case T_SubLink:
315  {
316  const SubLink *sublink = (const SubLink *) expr;
317 
318  if (sublink->subLinkType == EXPR_SUBLINK ||
319  sublink->subLinkType == ARRAY_SUBLINK)
320  {
321  /* get the typmod of the subselect's first target column */
322  Query *qtree = (Query *) sublink->subselect;
323  TargetEntry *tent;
324 
325  if (!qtree || !IsA(qtree, Query))
326  elog(ERROR, "cannot get type for untransformed sublink");
327  tent = linitial_node(TargetEntry, qtree->targetList);
328  Assert(!tent->resjunk);
329  return exprTypmod((Node *) tent->expr);
330  /* note we don't need to care if it's an array */
331  }
332  /* otherwise, result is RECORD or BOOLEAN, typmod is -1 */
333  }
334  break;
335  case T_SubPlan:
336  {
337  const SubPlan *subplan = (const SubPlan *) expr;
338 
339  if (subplan->subLinkType == EXPR_SUBLINK ||
340  subplan->subLinkType == ARRAY_SUBLINK)
341  {
342  /* get the typmod of the subselect's first target column */
343  /* note we don't need to care if it's an array */
344  return subplan->firstColTypmod;
345  }
346  /* otherwise, result is RECORD or BOOLEAN, typmod is -1 */
347  }
348  break;
350  {
351  const AlternativeSubPlan *asplan = (const AlternativeSubPlan *) expr;
352 
353  /* subplans should all return the same thing */
354  return exprTypmod((Node *) linitial(asplan->subplans));
355  }
356  break;
357  case T_FieldSelect:
358  return ((const FieldSelect *) expr)->resulttypmod;
359  case T_RelabelType:
360  return ((const RelabelType *) expr)->resulttypmod;
361  case T_ArrayCoerceExpr:
362  return ((const ArrayCoerceExpr *) expr)->resulttypmod;
363  case T_CollateExpr:
364  return exprTypmod((Node *) ((const CollateExpr *) expr)->arg);
365  case T_CaseExpr:
366  {
367  /*
368  * If all the alternatives agree on type/typmod, return that
369  * typmod, else use -1
370  */
371  const CaseExpr *cexpr = (const CaseExpr *) expr;
372  Oid casetype = cexpr->casetype;
373  int32 typmod;
374  ListCell *arg;
375 
376  if (!cexpr->defresult)
377  return -1;
378  if (exprType((Node *) cexpr->defresult) != casetype)
379  return -1;
380  typmod = exprTypmod((Node *) cexpr->defresult);
381  if (typmod < 0)
382  return -1; /* no point in trying harder */
383  foreach(arg, cexpr->args)
384  {
385  CaseWhen *w = lfirst_node(CaseWhen, arg);
386 
387  if (exprType((Node *) w->result) != casetype)
388  return -1;
389  if (exprTypmod((Node *) w->result) != typmod)
390  return -1;
391  }
392  return typmod;
393  }
394  break;
395  case T_CaseTestExpr:
396  return ((const CaseTestExpr *) expr)->typeMod;
397  case T_ArrayExpr:
398  {
399  /*
400  * If all the elements agree on type/typmod, return that
401  * typmod, else use -1
402  */
403  const ArrayExpr *arrayexpr = (const ArrayExpr *) expr;
404  Oid commontype;
405  int32 typmod;
406  ListCell *elem;
407 
408  if (arrayexpr->elements == NIL)
409  return -1;
410  typmod = exprTypmod((Node *) linitial(arrayexpr->elements));
411  if (typmod < 0)
412  return -1; /* no point in trying harder */
413  if (arrayexpr->multidims)
414  commontype = arrayexpr->array_typeid;
415  else
416  commontype = arrayexpr->element_typeid;
417  foreach(elem, arrayexpr->elements)
418  {
419  Node *e = (Node *) lfirst(elem);
420 
421  if (exprType(e) != commontype)
422  return -1;
423  if (exprTypmod(e) != typmod)
424  return -1;
425  }
426  return typmod;
427  }
428  break;
429  case T_CoalesceExpr:
430  {
431  /*
432  * If all the alternatives agree on type/typmod, return that
433  * typmod, else use -1
434  */
435  const CoalesceExpr *cexpr = (const CoalesceExpr *) expr;
436  Oid coalescetype = cexpr->coalescetype;
437  int32 typmod;
438  ListCell *arg;
439 
440  if (exprType((Node *) linitial(cexpr->args)) != coalescetype)
441  return -1;
442  typmod = exprTypmod((Node *) linitial(cexpr->args));
443  if (typmod < 0)
444  return -1; /* no point in trying harder */
445  for_each_cell(arg, lnext(list_head(cexpr->args)))
446  {
447  Node *e = (Node *) lfirst(arg);
448 
449  if (exprType(e) != coalescetype)
450  return -1;
451  if (exprTypmod(e) != typmod)
452  return -1;
453  }
454  return typmod;
455  }
456  break;
457  case T_MinMaxExpr:
458  {
459  /*
460  * If all the alternatives agree on type/typmod, return that
461  * typmod, else use -1
462  */
463  const MinMaxExpr *mexpr = (const MinMaxExpr *) expr;
464  Oid minmaxtype = mexpr->minmaxtype;
465  int32 typmod;
466  ListCell *arg;
467 
468  if (exprType((Node *) linitial(mexpr->args)) != minmaxtype)
469  return -1;
470  typmod = exprTypmod((Node *) linitial(mexpr->args));
471  if (typmod < 0)
472  return -1; /* no point in trying harder */
473  for_each_cell(arg, lnext(list_head(mexpr->args)))
474  {
475  Node *e = (Node *) lfirst(arg);
476 
477  if (exprType(e) != minmaxtype)
478  return -1;
479  if (exprTypmod(e) != typmod)
480  return -1;
481  }
482  return typmod;
483  }
484  break;
485  case T_SQLValueFunction:
486  return ((const SQLValueFunction *) expr)->typmod;
487  case T_CoerceToDomain:
488  return ((const CoerceToDomain *) expr)->resulttypmod;
490  return ((const CoerceToDomainValue *) expr)->typeMod;
491  case T_SetToDefault:
492  return ((const SetToDefault *) expr)->typeMod;
493  case T_PlaceHolderVar:
494  return exprTypmod((Node *) ((const PlaceHolderVar *) expr)->phexpr);
495  default:
496  break;
497  }
498  return -1;
499 }
500 
501 /*
502  * exprIsLengthCoercion
503  * Detect whether an expression tree is an application of a datatype's
504  * typmod-coercion function. Optionally extract the result's typmod.
505  *
506  * If coercedTypmod is not NULL, the typmod is stored there if the expression
507  * is a length-coercion function, else -1 is stored there.
508  *
509  * Note that a combined type-and-length coercion will be treated as a
510  * length coercion by this routine.
511  */
512 bool
513 exprIsLengthCoercion(const Node *expr, int32 *coercedTypmod)
514 {
515  if (coercedTypmod != NULL)
516  *coercedTypmod = -1; /* default result on failure */
517 
518  /*
519  * Scalar-type length coercions are FuncExprs, array-type length coercions
520  * are ArrayCoerceExprs
521  */
522  if (expr && IsA(expr, FuncExpr))
523  {
524  const FuncExpr *func = (const FuncExpr *) expr;
525  int nargs;
526  Const *second_arg;
527 
528  /*
529  * If it didn't come from a coercion context, reject.
530  */
531  if (func->funcformat != COERCE_EXPLICIT_CAST &&
533  return false;
534 
535  /*
536  * If it's not a two-argument or three-argument function with the
537  * second argument being an int4 constant, it can't have been created
538  * from a length coercion (it must be a type coercion, instead).
539  */
540  nargs = list_length(func->args);
541  if (nargs < 2 || nargs > 3)
542  return false;
543 
544  second_arg = (Const *) lsecond(func->args);
545  if (!IsA(second_arg, Const) ||
546  second_arg->consttype != INT4OID ||
547  second_arg->constisnull)
548  return false;
549 
550  /*
551  * OK, it is indeed a length-coercion function.
552  */
553  if (coercedTypmod != NULL)
554  *coercedTypmod = DatumGetInt32(second_arg->constvalue);
555 
556  return true;
557  }
558 
559  if (expr && IsA(expr, ArrayCoerceExpr))
560  {
561  const ArrayCoerceExpr *acoerce = (const ArrayCoerceExpr *) expr;
562 
563  /* It's not a length coercion unless there's a nondefault typmod */
564  if (acoerce->resulttypmod < 0)
565  return false;
566 
567  /*
568  * OK, it is indeed a length-coercion expression.
569  */
570  if (coercedTypmod != NULL)
571  *coercedTypmod = acoerce->resulttypmod;
572 
573  return true;
574  }
575 
576  return false;
577 }
578 
579 /*
580  * relabel_to_typmod
581  * Add a RelabelType node that changes just the typmod of the expression.
582  *
583  * This is primarily intended to be used during planning. Therefore, it
584  * strips any existing RelabelType nodes to maintain the planner's invariant
585  * that there are not adjacent RelabelTypes.
586  */
587 Node *
589 {
590  Oid type = exprType(expr);
591  Oid coll = exprCollation(expr);
592 
593  /* Strip any existing RelabelType node(s) */
594  while (expr && IsA(expr, RelabelType))
595  expr = (Node *) ((RelabelType *) expr)->arg;
596 
597  /* Apply new typmod, preserving the previous exposed type and collation */
598  return (Node *) makeRelabelType((Expr *) expr, type, typmod, coll,
600 }
601 
602 /*
603  * strip_implicit_coercions: remove implicit coercions at top level of tree
604  *
605  * This doesn't modify or copy the input expression tree, just return a
606  * pointer to a suitable place within it.
607  *
608  * Note: there isn't any useful thing we can do with a RowExpr here, so
609  * just return it unchanged, even if it's marked as an implicit coercion.
610  */
611 Node *
613 {
614  if (node == NULL)
615  return NULL;
616  if (IsA(node, FuncExpr))
617  {
618  FuncExpr *f = (FuncExpr *) node;
619 
622  }
623  else if (IsA(node, RelabelType))
624  {
625  RelabelType *r = (RelabelType *) node;
626 
628  return strip_implicit_coercions((Node *) r->arg);
629  }
630  else if (IsA(node, CoerceViaIO))
631  {
632  CoerceViaIO *c = (CoerceViaIO *) node;
633 
635  return strip_implicit_coercions((Node *) c->arg);
636  }
637  else if (IsA(node, ArrayCoerceExpr))
638  {
639  ArrayCoerceExpr *c = (ArrayCoerceExpr *) node;
640 
642  return strip_implicit_coercions((Node *) c->arg);
643  }
644  else if (IsA(node, ConvertRowtypeExpr))
645  {
647 
649  return strip_implicit_coercions((Node *) c->arg);
650  }
651  else if (IsA(node, CoerceToDomain))
652  {
653  CoerceToDomain *c = (CoerceToDomain *) node;
654 
656  return strip_implicit_coercions((Node *) c->arg);
657  }
658  return node;
659 }
660 
661 /*
662  * expression_returns_set
663  * Test whether an expression returns a set result.
664  *
665  * Because we use expression_tree_walker(), this can also be applied to
666  * whole targetlists; it'll produce TRUE if any one of the tlist items
667  * returns a set.
668  */
669 bool
671 {
672  return expression_returns_set_walker(clause, NULL);
673 }
674 
675 static bool
676 expression_returns_set_walker(Node *node, void *context)
677 {
678  if (node == NULL)
679  return false;
680  if (IsA(node, FuncExpr))
681  {
682  FuncExpr *expr = (FuncExpr *) node;
683 
684  if (expr->funcretset)
685  return true;
686  /* else fall through to check args */
687  }
688  if (IsA(node, OpExpr))
689  {
690  OpExpr *expr = (OpExpr *) node;
691 
692  if (expr->opretset)
693  return true;
694  /* else fall through to check args */
695  }
696 
697  /* Avoid recursion for some cases that parser checks not to return a set */
698  if (IsA(node, Aggref))
699  return false;
700  if (IsA(node, WindowFunc))
701  return false;
702 
704  context);
705 }
706 
707 
708 /*
709  * exprCollation -
710  * returns the Oid of the collation of the expression's result.
711  *
712  * Note: expression nodes that can invoke functions generally have an
713  * "inputcollid" field, which is what the function should use as collation.
714  * That is the resolved common collation of the node's inputs. It is often
715  * but not always the same as the result collation; in particular, if the
716  * function produces a non-collatable result type from collatable inputs
717  * or vice versa, the two are different.
718  */
719 Oid
720 exprCollation(const Node *expr)
721 {
722  Oid coll;
723 
724  if (!expr)
725  return InvalidOid;
726 
727  switch (nodeTag(expr))
728  {
729  case T_Var:
730  coll = ((const Var *) expr)->varcollid;
731  break;
732  case T_Const:
733  coll = ((const Const *) expr)->constcollid;
734  break;
735  case T_Param:
736  coll = ((const Param *) expr)->paramcollid;
737  break;
738  case T_Aggref:
739  coll = ((const Aggref *) expr)->aggcollid;
740  break;
741  case T_GroupingFunc:
742  coll = InvalidOid;
743  break;
744  case T_WindowFunc:
745  coll = ((const WindowFunc *) expr)->wincollid;
746  break;
747  case T_ArrayRef:
748  coll = ((const ArrayRef *) expr)->refcollid;
749  break;
750  case T_FuncExpr:
751  coll = ((const FuncExpr *) expr)->funccollid;
752  break;
753  case T_NamedArgExpr:
754  coll = exprCollation((Node *) ((const NamedArgExpr *) expr)->arg);
755  break;
756  case T_OpExpr:
757  coll = ((const OpExpr *) expr)->opcollid;
758  break;
759  case T_DistinctExpr:
760  coll = ((const DistinctExpr *) expr)->opcollid;
761  break;
762  case T_NullIfExpr:
763  coll = ((const NullIfExpr *) expr)->opcollid;
764  break;
765  case T_ScalarArrayOpExpr:
766  coll = InvalidOid; /* result is always boolean */
767  break;
768  case T_BoolExpr:
769  coll = InvalidOid; /* result is always boolean */
770  break;
771  case T_SubLink:
772  {
773  const SubLink *sublink = (const SubLink *) expr;
774 
775  if (sublink->subLinkType == EXPR_SUBLINK ||
776  sublink->subLinkType == ARRAY_SUBLINK)
777  {
778  /* get the collation of subselect's first target column */
779  Query *qtree = (Query *) sublink->subselect;
780  TargetEntry *tent;
781 
782  if (!qtree || !IsA(qtree, Query))
783  elog(ERROR, "cannot get collation for untransformed sublink");
784  tent = linitial_node(TargetEntry, qtree->targetList);
785  Assert(!tent->resjunk);
786  coll = exprCollation((Node *) tent->expr);
787  /* collation doesn't change if it's converted to array */
788  }
789  else
790  {
791  /* otherwise, result is RECORD or BOOLEAN */
792  coll = InvalidOid;
793  }
794  }
795  break;
796  case T_SubPlan:
797  {
798  const SubPlan *subplan = (const SubPlan *) expr;
799 
800  if (subplan->subLinkType == EXPR_SUBLINK ||
801  subplan->subLinkType == ARRAY_SUBLINK)
802  {
803  /* get the collation of subselect's first target column */
804  coll = subplan->firstColCollation;
805  /* collation doesn't change if it's converted to array */
806  }
807  else
808  {
809  /* otherwise, result is RECORD or BOOLEAN */
810  coll = InvalidOid;
811  }
812  }
813  break;
815  {
816  const AlternativeSubPlan *asplan = (const AlternativeSubPlan *) expr;
817 
818  /* subplans should all return the same thing */
819  coll = exprCollation((Node *) linitial(asplan->subplans));
820  }
821  break;
822  case T_FieldSelect:
823  coll = ((const FieldSelect *) expr)->resultcollid;
824  break;
825  case T_FieldStore:
826  coll = InvalidOid; /* result is always composite */
827  break;
828  case T_RelabelType:
829  coll = ((const RelabelType *) expr)->resultcollid;
830  break;
831  case T_CoerceViaIO:
832  coll = ((const CoerceViaIO *) expr)->resultcollid;
833  break;
834  case T_ArrayCoerceExpr:
835  coll = ((const ArrayCoerceExpr *) expr)->resultcollid;
836  break;
838  coll = InvalidOid; /* result is always composite */
839  break;
840  case T_CollateExpr:
841  coll = ((const CollateExpr *) expr)->collOid;
842  break;
843  case T_CaseExpr:
844  coll = ((const CaseExpr *) expr)->casecollid;
845  break;
846  case T_CaseTestExpr:
847  coll = ((const CaseTestExpr *) expr)->collation;
848  break;
849  case T_ArrayExpr:
850  coll = ((const ArrayExpr *) expr)->array_collid;
851  break;
852  case T_RowExpr:
853  coll = InvalidOid; /* result is always composite */
854  break;
855  case T_RowCompareExpr:
856  coll = InvalidOid; /* result is always boolean */
857  break;
858  case T_CoalesceExpr:
859  coll = ((const CoalesceExpr *) expr)->coalescecollid;
860  break;
861  case T_MinMaxExpr:
862  coll = ((const MinMaxExpr *) expr)->minmaxcollid;
863  break;
864  case T_SQLValueFunction:
865  coll = InvalidOid; /* all cases return non-collatable types */
866  break;
867  case T_XmlExpr:
868 
869  /*
870  * XMLSERIALIZE returns text from non-collatable inputs, so its
871  * collation is always default. The other cases return boolean or
872  * XML, which are non-collatable.
873  */
874  if (((const XmlExpr *) expr)->op == IS_XMLSERIALIZE)
875  coll = DEFAULT_COLLATION_OID;
876  else
877  coll = InvalidOid;
878  break;
879  case T_NullTest:
880  coll = InvalidOid; /* result is always boolean */
881  break;
882  case T_BooleanTest:
883  coll = InvalidOid; /* result is always boolean */
884  break;
885  case T_CoerceToDomain:
886  coll = ((const CoerceToDomain *) expr)->resultcollid;
887  break;
889  coll = ((const CoerceToDomainValue *) expr)->collation;
890  break;
891  case T_SetToDefault:
892  coll = ((const SetToDefault *) expr)->collation;
893  break;
894  case T_CurrentOfExpr:
895  coll = InvalidOid; /* result is always boolean */
896  break;
897  case T_NextValueExpr:
898  coll = InvalidOid; /* result is always an integer type */
899  break;
900  case T_InferenceElem:
901  coll = exprCollation((Node *) ((const InferenceElem *) expr)->expr);
902  break;
903  case T_PlaceHolderVar:
904  coll = exprCollation((Node *) ((const PlaceHolderVar *) expr)->phexpr);
905  break;
906  default:
907  elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
908  coll = InvalidOid; /* keep compiler quiet */
909  break;
910  }
911  return coll;
912 }
913 
914 /*
915  * exprInputCollation -
916  * returns the Oid of the collation a function should use, if available.
917  *
918  * Result is InvalidOid if the node type doesn't store this information.
919  */
920 Oid
922 {
923  Oid coll;
924 
925  if (!expr)
926  return InvalidOid;
927 
928  switch (nodeTag(expr))
929  {
930  case T_Aggref:
931  coll = ((const Aggref *) expr)->inputcollid;
932  break;
933  case T_WindowFunc:
934  coll = ((const WindowFunc *) expr)->inputcollid;
935  break;
936  case T_FuncExpr:
937  coll = ((const FuncExpr *) expr)->inputcollid;
938  break;
939  case T_OpExpr:
940  coll = ((const OpExpr *) expr)->inputcollid;
941  break;
942  case T_DistinctExpr:
943  coll = ((const DistinctExpr *) expr)->inputcollid;
944  break;
945  case T_NullIfExpr:
946  coll = ((const NullIfExpr *) expr)->inputcollid;
947  break;
948  case T_ScalarArrayOpExpr:
949  coll = ((const ScalarArrayOpExpr *) expr)->inputcollid;
950  break;
951  case T_MinMaxExpr:
952  coll = ((const MinMaxExpr *) expr)->inputcollid;
953  break;
954  default:
955  coll = InvalidOid;
956  break;
957  }
958  return coll;
959 }
960 
961 /*
962  * exprSetCollation -
963  * Assign collation information to an expression tree node.
964  *
965  * Note: since this is only used during parse analysis, we don't need to
966  * worry about subplans or PlaceHolderVars.
967  */
968 void
969 exprSetCollation(Node *expr, Oid collation)
970 {
971  switch (nodeTag(expr))
972  {
973  case T_Var:
974  ((Var *) expr)->varcollid = collation;
975  break;
976  case T_Const:
977  ((Const *) expr)->constcollid = collation;
978  break;
979  case T_Param:
980  ((Param *) expr)->paramcollid = collation;
981  break;
982  case T_Aggref:
983  ((Aggref *) expr)->aggcollid = collation;
984  break;
985  case T_GroupingFunc:
986  Assert(!OidIsValid(collation));
987  break;
988  case T_WindowFunc:
989  ((WindowFunc *) expr)->wincollid = collation;
990  break;
991  case T_ArrayRef:
992  ((ArrayRef *) expr)->refcollid = collation;
993  break;
994  case T_FuncExpr:
995  ((FuncExpr *) expr)->funccollid = collation;
996  break;
997  case T_NamedArgExpr:
998  Assert(collation == exprCollation((Node *) ((NamedArgExpr *) expr)->arg));
999  break;
1000  case T_OpExpr:
1001  ((OpExpr *) expr)->opcollid = collation;
1002  break;
1003  case T_DistinctExpr:
1004  ((DistinctExpr *) expr)->opcollid = collation;
1005  break;
1006  case T_NullIfExpr:
1007  ((NullIfExpr *) expr)->opcollid = collation;
1008  break;
1009  case T_ScalarArrayOpExpr:
1010  Assert(!OidIsValid(collation)); /* result is always boolean */
1011  break;
1012  case T_BoolExpr:
1013  Assert(!OidIsValid(collation)); /* result is always boolean */
1014  break;
1015  case T_SubLink:
1016 #ifdef USE_ASSERT_CHECKING
1017  {
1018  SubLink *sublink = (SubLink *) expr;
1019 
1020  if (sublink->subLinkType == EXPR_SUBLINK ||
1021  sublink->subLinkType == ARRAY_SUBLINK)
1022  {
1023  /* get the collation of subselect's first target column */
1024  Query *qtree = (Query *) sublink->subselect;
1025  TargetEntry *tent;
1026 
1027  if (!qtree || !IsA(qtree, Query))
1028  elog(ERROR, "cannot set collation for untransformed sublink");
1029  tent = linitial_node(TargetEntry, qtree->targetList);
1030  Assert(!tent->resjunk);
1031  Assert(collation == exprCollation((Node *) tent->expr));
1032  }
1033  else
1034  {
1035  /* otherwise, result is RECORD or BOOLEAN */
1036  Assert(!OidIsValid(collation));
1037  }
1038  }
1039 #endif /* USE_ASSERT_CHECKING */
1040  break;
1041  case T_FieldSelect:
1042  ((FieldSelect *) expr)->resultcollid = collation;
1043  break;
1044  case T_FieldStore:
1045  Assert(!OidIsValid(collation)); /* result is always composite */
1046  break;
1047  case T_RelabelType:
1048  ((RelabelType *) expr)->resultcollid = collation;
1049  break;
1050  case T_CoerceViaIO:
1051  ((CoerceViaIO *) expr)->resultcollid = collation;
1052  break;
1053  case T_ArrayCoerceExpr:
1054  ((ArrayCoerceExpr *) expr)->resultcollid = collation;
1055  break;
1056  case T_ConvertRowtypeExpr:
1057  Assert(!OidIsValid(collation)); /* result is always composite */
1058  break;
1059  case T_CaseExpr:
1060  ((CaseExpr *) expr)->casecollid = collation;
1061  break;
1062  case T_ArrayExpr:
1063  ((ArrayExpr *) expr)->array_collid = collation;
1064  break;
1065  case T_RowExpr:
1066  Assert(!OidIsValid(collation)); /* result is always composite */
1067  break;
1068  case T_RowCompareExpr:
1069  Assert(!OidIsValid(collation)); /* result is always boolean */
1070  break;
1071  case T_CoalesceExpr:
1072  ((CoalesceExpr *) expr)->coalescecollid = collation;
1073  break;
1074  case T_MinMaxExpr:
1075  ((MinMaxExpr *) expr)->minmaxcollid = collation;
1076  break;
1077  case T_SQLValueFunction:
1078  Assert(!OidIsValid(collation)); /* no collatable results */
1079  break;
1080  case T_XmlExpr:
1081  Assert((((XmlExpr *) expr)->op == IS_XMLSERIALIZE) ?
1082  (collation == DEFAULT_COLLATION_OID) :
1083  (collation == InvalidOid));
1084  break;
1085  case T_NullTest:
1086  Assert(!OidIsValid(collation)); /* result is always boolean */
1087  break;
1088  case T_BooleanTest:
1089  Assert(!OidIsValid(collation)); /* result is always boolean */
1090  break;
1091  case T_CoerceToDomain:
1092  ((CoerceToDomain *) expr)->resultcollid = collation;
1093  break;
1094  case T_CoerceToDomainValue:
1095  ((CoerceToDomainValue *) expr)->collation = collation;
1096  break;
1097  case T_SetToDefault:
1098  ((SetToDefault *) expr)->collation = collation;
1099  break;
1100  case T_CurrentOfExpr:
1101  Assert(!OidIsValid(collation)); /* result is always boolean */
1102  break;
1103  case T_NextValueExpr:
1104  Assert(!OidIsValid(collation)); /* result is always an integer
1105  * type */
1106  break;
1107  default:
1108  elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
1109  break;
1110  }
1111 }
1112 
1113 /*
1114  * exprSetInputCollation -
1115  * Assign input-collation information to an expression tree node.
1116  *
1117  * This is a no-op for node types that don't store their input collation.
1118  * Note we omit RowCompareExpr, which needs special treatment since it
1119  * contains multiple input collation OIDs.
1120  */
1121 void
1122 exprSetInputCollation(Node *expr, Oid inputcollation)
1123 {
1124  switch (nodeTag(expr))
1125  {
1126  case T_Aggref:
1127  ((Aggref *) expr)->inputcollid = inputcollation;
1128  break;
1129  case T_WindowFunc:
1130  ((WindowFunc *) expr)->inputcollid = inputcollation;
1131  break;
1132  case T_FuncExpr:
1133  ((FuncExpr *) expr)->inputcollid = inputcollation;
1134  break;
1135  case T_OpExpr:
1136  ((OpExpr *) expr)->inputcollid = inputcollation;
1137  break;
1138  case T_DistinctExpr:
1139  ((DistinctExpr *) expr)->inputcollid = inputcollation;
1140  break;
1141  case T_NullIfExpr:
1142  ((NullIfExpr *) expr)->inputcollid = inputcollation;
1143  break;
1144  case T_ScalarArrayOpExpr:
1145  ((ScalarArrayOpExpr *) expr)->inputcollid = inputcollation;
1146  break;
1147  case T_MinMaxExpr:
1148  ((MinMaxExpr *) expr)->inputcollid = inputcollation;
1149  break;
1150  default:
1151  break;
1152  }
1153 }
1154 
1155 
1156 /*
1157  * exprLocation -
1158  * returns the parse location of an expression tree, for error reports
1159  *
1160  * -1 is returned if the location can't be determined.
1161  *
1162  * For expressions larger than a single token, the intent here is to
1163  * return the location of the expression's leftmost token, not necessarily
1164  * the topmost Node's location field. For example, an OpExpr's location
1165  * field will point at the operator name, but if it is not a prefix operator
1166  * then we should return the location of the left-hand operand instead.
1167  * The reason is that we want to reference the entire expression not just
1168  * that operator, and pointing to its start seems to be the most natural way.
1169  *
1170  * The location is not perfect --- for example, since the grammar doesn't
1171  * explicitly represent parentheses in the parsetree, given something that
1172  * had been written "(a + b) * c" we are going to point at "a" not "(".
1173  * But it should be plenty good enough for error reporting purposes.
1174  *
1175  * You might think that this code is overly general, for instance why check
1176  * the operands of a FuncExpr node, when the function name can be expected
1177  * to be to the left of them? There are a couple of reasons. The grammar
1178  * sometimes builds expressions that aren't quite what the user wrote;
1179  * for instance x IS NOT BETWEEN ... becomes a NOT-expression whose keyword
1180  * pointer is to the right of its leftmost argument. Also, nodes that were
1181  * inserted implicitly by parse analysis (such as FuncExprs for implicit
1182  * coercions) will have location -1, and so we can have odd combinations of
1183  * known and unknown locations in a tree.
1184  */
1185 int
1186 exprLocation(const Node *expr)
1187 {
1188  int loc;
1189 
1190  if (expr == NULL)
1191  return -1;
1192  switch (nodeTag(expr))
1193  {
1194  case T_RangeVar:
1195  loc = ((const RangeVar *) expr)->location;
1196  break;
1197  case T_TableFunc:
1198  loc = ((const TableFunc *) expr)->location;
1199  break;
1200  case T_Var:
1201  loc = ((const Var *) expr)->location;
1202  break;
1203  case T_Const:
1204  loc = ((const Const *) expr)->location;
1205  break;
1206  case T_Param:
1207  loc = ((const Param *) expr)->location;
1208  break;
1209  case T_Aggref:
1210  /* function name should always be the first thing */
1211  loc = ((const Aggref *) expr)->location;
1212  break;
1213  case T_GroupingFunc:
1214  loc = ((const GroupingFunc *) expr)->location;
1215  break;
1216  case T_WindowFunc:
1217  /* function name should always be the first thing */
1218  loc = ((const WindowFunc *) expr)->location;
1219  break;
1220  case T_ArrayRef:
1221  /* just use array argument's location */
1222  loc = exprLocation((Node *) ((const ArrayRef *) expr)->refexpr);
1223  break;
1224  case T_FuncExpr:
1225  {
1226  const FuncExpr *fexpr = (const FuncExpr *) expr;
1227 
1228  /* consider both function name and leftmost arg */
1229  loc = leftmostLoc(fexpr->location,
1230  exprLocation((Node *) fexpr->args));
1231  }
1232  break;
1233  case T_NamedArgExpr:
1234  {
1235  const NamedArgExpr *na = (const NamedArgExpr *) expr;
1236 
1237  /* consider both argument name and value */
1238  loc = leftmostLoc(na->location,
1239  exprLocation((Node *) na->arg));
1240  }
1241  break;
1242  case T_OpExpr:
1243  case T_DistinctExpr: /* struct-equivalent to OpExpr */
1244  case T_NullIfExpr: /* struct-equivalent to OpExpr */
1245  {
1246  const OpExpr *opexpr = (const OpExpr *) expr;
1247 
1248  /* consider both operator name and leftmost arg */
1249  loc = leftmostLoc(opexpr->location,
1250  exprLocation((Node *) opexpr->args));
1251  }
1252  break;
1253  case T_ScalarArrayOpExpr:
1254  {
1255  const ScalarArrayOpExpr *saopexpr = (const ScalarArrayOpExpr *) expr;
1256 
1257  /* consider both operator name and leftmost arg */
1258  loc = leftmostLoc(saopexpr->location,
1259  exprLocation((Node *) saopexpr->args));
1260  }
1261  break;
1262  case T_BoolExpr:
1263  {
1264  const BoolExpr *bexpr = (const BoolExpr *) expr;
1265 
1266  /*
1267  * Same as above, to handle either NOT or AND/OR. We can't
1268  * special-case NOT because of the way that it's used for
1269  * things like IS NOT BETWEEN.
1270  */
1271  loc = leftmostLoc(bexpr->location,
1272  exprLocation((Node *) bexpr->args));
1273  }
1274  break;
1275  case T_SubLink:
1276  {
1277  const SubLink *sublink = (const SubLink *) expr;
1278 
1279  /* check the testexpr, if any, and the operator/keyword */
1280  loc = leftmostLoc(exprLocation(sublink->testexpr),
1281  sublink->location);
1282  }
1283  break;
1284  case T_FieldSelect:
1285  /* just use argument's location */
1286  loc = exprLocation((Node *) ((const FieldSelect *) expr)->arg);
1287  break;
1288  case T_FieldStore:
1289  /* just use argument's location */
1290  loc = exprLocation((Node *) ((const FieldStore *) expr)->arg);
1291  break;
1292  case T_RelabelType:
1293  {
1294  const RelabelType *rexpr = (const RelabelType *) expr;
1295 
1296  /* Much as above */
1297  loc = leftmostLoc(rexpr->location,
1298  exprLocation((Node *) rexpr->arg));
1299  }
1300  break;
1301  case T_CoerceViaIO:
1302  {
1303  const CoerceViaIO *cexpr = (const CoerceViaIO *) expr;
1304 
1305  /* Much as above */
1306  loc = leftmostLoc(cexpr->location,
1307  exprLocation((Node *) cexpr->arg));
1308  }
1309  break;
1310  case T_ArrayCoerceExpr:
1311  {
1312  const ArrayCoerceExpr *cexpr = (const ArrayCoerceExpr *) expr;
1313 
1314  /* Much as above */
1315  loc = leftmostLoc(cexpr->location,
1316  exprLocation((Node *) cexpr->arg));
1317  }
1318  break;
1319  case T_ConvertRowtypeExpr:
1320  {
1321  const ConvertRowtypeExpr *cexpr = (const ConvertRowtypeExpr *) expr;
1322 
1323  /* Much as above */
1324  loc = leftmostLoc(cexpr->location,
1325  exprLocation((Node *) cexpr->arg));
1326  }
1327  break;
1328  case T_CollateExpr:
1329  /* just use argument's location */
1330  loc = exprLocation((Node *) ((const CollateExpr *) expr)->arg);
1331  break;
1332  case T_CaseExpr:
1333  /* CASE keyword should always be the first thing */
1334  loc = ((const CaseExpr *) expr)->location;
1335  break;
1336  case T_CaseWhen:
1337  /* WHEN keyword should always be the first thing */
1338  loc = ((const CaseWhen *) expr)->location;
1339  break;
1340  case T_ArrayExpr:
1341  /* the location points at ARRAY or [, which must be leftmost */
1342  loc = ((const ArrayExpr *) expr)->location;
1343  break;
1344  case T_RowExpr:
1345  /* the location points at ROW or (, which must be leftmost */
1346  loc = ((const RowExpr *) expr)->location;
1347  break;
1348  case T_RowCompareExpr:
1349  /* just use leftmost argument's location */
1350  loc = exprLocation((Node *) ((const RowCompareExpr *) expr)->largs);
1351  break;
1352  case T_CoalesceExpr:
1353  /* COALESCE keyword should always be the first thing */
1354  loc = ((const CoalesceExpr *) expr)->location;
1355  break;
1356  case T_MinMaxExpr:
1357  /* GREATEST/LEAST keyword should always be the first thing */
1358  loc = ((const MinMaxExpr *) expr)->location;
1359  break;
1360  case T_SQLValueFunction:
1361  /* function keyword should always be the first thing */
1362  loc = ((const SQLValueFunction *) expr)->location;
1363  break;
1364  case T_XmlExpr:
1365  {
1366  const XmlExpr *xexpr = (const XmlExpr *) expr;
1367 
1368  /* consider both function name and leftmost arg */
1369  loc = leftmostLoc(xexpr->location,
1370  exprLocation((Node *) xexpr->args));
1371  }
1372  break;
1373  case T_NullTest:
1374  {
1375  const NullTest *nexpr = (const NullTest *) expr;
1376 
1377  /* Much as above */
1378  loc = leftmostLoc(nexpr->location,
1379  exprLocation((Node *) nexpr->arg));
1380  }
1381  break;
1382  case T_BooleanTest:
1383  {
1384  const BooleanTest *bexpr = (const BooleanTest *) expr;
1385 
1386  /* Much as above */
1387  loc = leftmostLoc(bexpr->location,
1388  exprLocation((Node *) bexpr->arg));
1389  }
1390  break;
1391  case T_CoerceToDomain:
1392  {
1393  const CoerceToDomain *cexpr = (const CoerceToDomain *) expr;
1394 
1395  /* Much as above */
1396  loc = leftmostLoc(cexpr->location,
1397  exprLocation((Node *) cexpr->arg));
1398  }
1399  break;
1400  case T_CoerceToDomainValue:
1401  loc = ((const CoerceToDomainValue *) expr)->location;
1402  break;
1403  case T_SetToDefault:
1404  loc = ((const SetToDefault *) expr)->location;
1405  break;
1406  case T_TargetEntry:
1407  /* just use argument's location */
1408  loc = exprLocation((Node *) ((const TargetEntry *) expr)->expr);
1409  break;
1410  case T_IntoClause:
1411  /* use the contained RangeVar's location --- close enough */
1412  loc = exprLocation((Node *) ((const IntoClause *) expr)->rel);
1413  break;
1414  case T_List:
1415  {
1416  /* report location of first list member that has a location */
1417  ListCell *lc;
1418 
1419  loc = -1; /* just to suppress compiler warning */
1420  foreach(lc, (const List *) expr)
1421  {
1422  loc = exprLocation((Node *) lfirst(lc));
1423  if (loc >= 0)
1424  break;
1425  }
1426  }
1427  break;
1428  case T_A_Expr:
1429  {
1430  const A_Expr *aexpr = (const A_Expr *) expr;
1431 
1432  /* use leftmost of operator or left operand (if any) */
1433  /* we assume right operand can't be to left of operator */
1434  loc = leftmostLoc(aexpr->location,
1435  exprLocation(aexpr->lexpr));
1436  }
1437  break;
1438  case T_ColumnRef:
1439  loc = ((const ColumnRef *) expr)->location;
1440  break;
1441  case T_ParamRef:
1442  loc = ((const ParamRef *) expr)->location;
1443  break;
1444  case T_A_Const:
1445  loc = ((const A_Const *) expr)->location;
1446  break;
1447  case T_FuncCall:
1448  {
1449  const FuncCall *fc = (const FuncCall *) expr;
1450 
1451  /* consider both function name and leftmost arg */
1452  /* (we assume any ORDER BY nodes must be to right of name) */
1453  loc = leftmostLoc(fc->location,
1454  exprLocation((Node *) fc->args));
1455  }
1456  break;
1457  case T_A_ArrayExpr:
1458  /* the location points at ARRAY or [, which must be leftmost */
1459  loc = ((const A_ArrayExpr *) expr)->location;
1460  break;
1461  case T_ResTarget:
1462  /* we need not examine the contained expression (if any) */
1463  loc = ((const ResTarget *) expr)->location;
1464  break;
1465  case T_MultiAssignRef:
1466  loc = exprLocation(((const MultiAssignRef *) expr)->source);
1467  break;
1468  case T_TypeCast:
1469  {
1470  const TypeCast *tc = (const TypeCast *) expr;
1471 
1472  /*
1473  * This could represent CAST(), ::, or TypeName 'literal', so
1474  * any of the components might be leftmost.
1475  */
1476  loc = exprLocation(tc->arg);
1477  loc = leftmostLoc(loc, tc->typeName->location);
1478  loc = leftmostLoc(loc, tc->location);
1479  }
1480  break;
1481  case T_CollateClause:
1482  /* just use argument's location */
1483  loc = exprLocation(((const CollateClause *) expr)->arg);
1484  break;
1485  case T_SortBy:
1486  /* just use argument's location (ignore operator, if any) */
1487  loc = exprLocation(((const SortBy *) expr)->node);
1488  break;
1489  case T_WindowDef:
1490  loc = ((const WindowDef *) expr)->location;
1491  break;
1492  case T_RangeTableSample:
1493  loc = ((const RangeTableSample *) expr)->location;
1494  break;
1495  case T_TypeName:
1496  loc = ((const TypeName *) expr)->location;
1497  break;
1498  case T_ColumnDef:
1499  loc = ((const ColumnDef *) expr)->location;
1500  break;
1501  case T_Constraint:
1502  loc = ((const Constraint *) expr)->location;
1503  break;
1504  case T_FunctionParameter:
1505  /* just use typename's location */
1506  loc = exprLocation((Node *) ((const FunctionParameter *) expr)->argType);
1507  break;
1508  case T_XmlSerialize:
1509  /* XMLSERIALIZE keyword should always be the first thing */
1510  loc = ((const XmlSerialize *) expr)->location;
1511  break;
1512  case T_GroupingSet:
1513  loc = ((const GroupingSet *) expr)->location;
1514  break;
1515  case T_WithClause:
1516  loc = ((const WithClause *) expr)->location;
1517  break;
1518  case T_InferClause:
1519  loc = ((const InferClause *) expr)->location;
1520  break;
1521  case T_OnConflictClause:
1522  loc = ((const OnConflictClause *) expr)->location;
1523  break;
1524  case T_CommonTableExpr:
1525  loc = ((const CommonTableExpr *) expr)->location;
1526  break;
1527  case T_PlaceHolderVar:
1528  /* just use argument's location */
1529  loc = exprLocation((Node *) ((const PlaceHolderVar *) expr)->phexpr);
1530  break;
1531  case T_InferenceElem:
1532  /* just use nested expr's location */
1533  loc = exprLocation((Node *) ((const InferenceElem *) expr)->expr);
1534  break;
1535  case T_PartitionElem:
1536  loc = ((const PartitionElem *) expr)->location;
1537  break;
1538  case T_PartitionSpec:
1539  loc = ((const PartitionSpec *) expr)->location;
1540  break;
1541  case T_PartitionBoundSpec:
1542  loc = ((const PartitionBoundSpec *) expr)->location;
1543  break;
1544  case T_PartitionRangeDatum:
1545  loc = ((const PartitionRangeDatum *) expr)->location;
1546  break;
1547  default:
1548  /* for any other node type it's just unknown... */
1549  loc = -1;
1550  break;
1551  }
1552  return loc;
1553 }
1554 
1555 /*
1556  * leftmostLoc - support for exprLocation
1557  *
1558  * Take the minimum of two parse location values, but ignore unknowns
1559  */
1560 static int
1561 leftmostLoc(int loc1, int loc2)
1562 {
1563  if (loc1 < 0)
1564  return loc2;
1565  else if (loc2 < 0)
1566  return loc1;
1567  else
1568  return Min(loc1, loc2);
1569 }
1570 
1571 
1572 /*
1573  * fix_opfuncids
1574  * Calculate opfuncid field from opno for each OpExpr node in given tree.
1575  * The given tree can be anything expression_tree_walker handles.
1576  *
1577  * The argument is modified in-place. (This is OK since we'd want the
1578  * same change for any node, even if it gets visited more than once due to
1579  * shared structure.)
1580  */
1581 void
1583 {
1584  /* This tree walk requires no special setup, so away we go... */
1585  fix_opfuncids_walker(node, NULL);
1586 }
1587 
1588 static bool
1589 fix_opfuncids_walker(Node *node, void *context)
1590 {
1591  if (node == NULL)
1592  return false;
1593  if (IsA(node, OpExpr))
1594  set_opfuncid((OpExpr *) node);
1595  else if (IsA(node, DistinctExpr))
1596  set_opfuncid((OpExpr *) node); /* rely on struct equivalence */
1597  else if (IsA(node, NullIfExpr))
1598  set_opfuncid((OpExpr *) node); /* rely on struct equivalence */
1599  else if (IsA(node, ScalarArrayOpExpr))
1601  return expression_tree_walker(node, fix_opfuncids_walker, context);
1602 }
1603 
1604 /*
1605  * set_opfuncid
1606  * Set the opfuncid (procedure OID) in an OpExpr node,
1607  * if it hasn't been set already.
1608  *
1609  * Because of struct equivalence, this can also be used for
1610  * DistinctExpr and NullIfExpr nodes.
1611  */
1612 void
1614 {
1615  if (opexpr->opfuncid == InvalidOid)
1616  opexpr->opfuncid = get_opcode(opexpr->opno);
1617 }
1618 
1619 /*
1620  * set_sa_opfuncid
1621  * As above, for ScalarArrayOpExpr nodes.
1622  */
1623 void
1625 {
1626  if (opexpr->opfuncid == InvalidOid)
1627  opexpr->opfuncid = get_opcode(opexpr->opno);
1628 }
1629 
1630 
1631 /*
1632  * check_functions_in_node -
1633  * apply checker() to each function OID contained in given expression node
1634  *
1635  * Returns TRUE if the checker() function does; for nodes representing more
1636  * than one function call, returns TRUE if the checker() function does so
1637  * for any of those functions. Returns FALSE if node does not invoke any
1638  * SQL-visible function. Caller must not pass node == NULL.
1639  *
1640  * This function examines only the given node; it does not recurse into any
1641  * sub-expressions. Callers typically prefer to keep control of the recursion
1642  * for themselves, in case additional checks should be made, or because they
1643  * have special rules about which parts of the tree need to be visited.
1644  *
1645  * Note: we ignore MinMaxExpr, SQLValueFunction, XmlExpr, CoerceToDomain,
1646  * and NextValueExpr nodes, because they do not contain SQL function OIDs.
1647  * However, they can invoke SQL-visible functions, so callers should take
1648  * thought about how to treat them.
1649  */
1650 bool
1652  void *context)
1653 {
1654  switch (nodeTag(node))
1655  {
1656  case T_Aggref:
1657  {
1658  Aggref *expr = (Aggref *) node;
1659 
1660  if (checker(expr->aggfnoid, context))
1661  return true;
1662  }
1663  break;
1664  case T_WindowFunc:
1665  {
1666  WindowFunc *expr = (WindowFunc *) node;
1667 
1668  if (checker(expr->winfnoid, context))
1669  return true;
1670  }
1671  break;
1672  case T_FuncExpr:
1673  {
1674  FuncExpr *expr = (FuncExpr *) node;
1675 
1676  if (checker(expr->funcid, context))
1677  return true;
1678  }
1679  break;
1680  case T_OpExpr:
1681  case T_DistinctExpr: /* struct-equivalent to OpExpr */
1682  case T_NullIfExpr: /* struct-equivalent to OpExpr */
1683  {
1684  OpExpr *expr = (OpExpr *) node;
1685 
1686  /* Set opfuncid if it wasn't set already */
1687  set_opfuncid(expr);
1688  if (checker(expr->opfuncid, context))
1689  return true;
1690  }
1691  break;
1692  case T_ScalarArrayOpExpr:
1693  {
1694  ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node;
1695 
1696  set_sa_opfuncid(expr);
1697  if (checker(expr->opfuncid, context))
1698  return true;
1699  }
1700  break;
1701  case T_CoerceViaIO:
1702  {
1703  CoerceViaIO *expr = (CoerceViaIO *) node;
1704  Oid iofunc;
1705  Oid typioparam;
1706  bool typisvarlena;
1707 
1708  /* check the result type's input function */
1710  &iofunc, &typioparam);
1711  if (checker(iofunc, context))
1712  return true;
1713  /* check the input type's output function */
1714  getTypeOutputInfo(exprType((Node *) expr->arg),
1715  &iofunc, &typisvarlena);
1716  if (checker(iofunc, context))
1717  return true;
1718  }
1719  break;
1720  case T_ArrayCoerceExpr:
1721  {
1722  ArrayCoerceExpr *expr = (ArrayCoerceExpr *) node;
1723 
1724  if (OidIsValid(expr->elemfuncid) &&
1725  checker(expr->elemfuncid, context))
1726  return true;
1727  }
1728  break;
1729  case T_RowCompareExpr:
1730  {
1731  RowCompareExpr *rcexpr = (RowCompareExpr *) node;
1732  ListCell *opid;
1733 
1734  foreach(opid, rcexpr->opnos)
1735  {
1736  Oid opfuncid = get_opcode(lfirst_oid(opid));
1737 
1738  if (checker(opfuncid, context))
1739  return true;
1740  }
1741  }
1742  break;
1743  default:
1744  break;
1745  }
1746  return false;
1747 }
1748 
1749 
1750 /*
1751  * Standard expression-tree walking support
1752  *
1753  * We used to have near-duplicate code in many different routines that
1754  * understood how to recurse through an expression node tree. That was
1755  * a pain to maintain, and we frequently had bugs due to some particular
1756  * routine neglecting to support a particular node type. In most cases,
1757  * these routines only actually care about certain node types, and don't
1758  * care about other types except insofar as they have to recurse through
1759  * non-primitive node types. Therefore, we now provide generic tree-walking
1760  * logic to consolidate the redundant "boilerplate" code. There are
1761  * two versions: expression_tree_walker() and expression_tree_mutator().
1762  */
1763 
1764 /*
1765  * expression_tree_walker() is designed to support routines that traverse
1766  * a tree in a read-only fashion (although it will also work for routines
1767  * that modify nodes in-place but never add/delete/replace nodes).
1768  * A walker routine should look like this:
1769  *
1770  * bool my_walker (Node *node, my_struct *context)
1771  * {
1772  * if (node == NULL)
1773  * return false;
1774  * // check for nodes that special work is required for, eg:
1775  * if (IsA(node, Var))
1776  * {
1777  * ... do special actions for Var nodes
1778  * }
1779  * else if (IsA(node, ...))
1780  * {
1781  * ... do special actions for other node types
1782  * }
1783  * // for any node type not specially processed, do:
1784  * return expression_tree_walker(node, my_walker, (void *) context);
1785  * }
1786  *
1787  * The "context" argument points to a struct that holds whatever context
1788  * information the walker routine needs --- it can be used to return data
1789  * gathered by the walker, too. This argument is not touched by
1790  * expression_tree_walker, but it is passed down to recursive sub-invocations
1791  * of my_walker. The tree walk is started from a setup routine that
1792  * fills in the appropriate context struct, calls my_walker with the top-level
1793  * node of the tree, and then examines the results.
1794  *
1795  * The walker routine should return "false" to continue the tree walk, or
1796  * "true" to abort the walk and immediately return "true" to the top-level
1797  * caller. This can be used to short-circuit the traversal if the walker
1798  * has found what it came for. "false" is returned to the top-level caller
1799  * iff no invocation of the walker returned "true".
1800  *
1801  * The node types handled by expression_tree_walker include all those
1802  * normally found in target lists and qualifier clauses during the planning
1803  * stage. In particular, it handles List nodes since a cnf-ified qual clause
1804  * will have List structure at the top level, and it handles TargetEntry nodes
1805  * so that a scan of a target list can be handled without additional code.
1806  * Also, RangeTblRef, FromExpr, JoinExpr, and SetOperationStmt nodes are
1807  * handled, so that query jointrees and setOperation trees can be processed
1808  * without additional code.
1809  *
1810  * expression_tree_walker will handle SubLink nodes by recursing normally
1811  * into the "testexpr" subtree (which is an expression belonging to the outer
1812  * plan). It will also call the walker on the sub-Query node; however, when
1813  * expression_tree_walker itself is called on a Query node, it does nothing
1814  * and returns "false". The net effect is that unless the walker does
1815  * something special at a Query node, sub-selects will not be visited during
1816  * an expression tree walk. This is exactly the behavior wanted in many cases
1817  * --- and for those walkers that do want to recurse into sub-selects, special
1818  * behavior is typically needed anyway at the entry to a sub-select (such as
1819  * incrementing a depth counter). A walker that wants to examine sub-selects
1820  * should include code along the lines of:
1821  *
1822  * if (IsA(node, Query))
1823  * {
1824  * adjust context for subquery;
1825  * result = query_tree_walker((Query *) node, my_walker, context,
1826  * 0); // adjust flags as needed
1827  * restore context if needed;
1828  * return result;
1829  * }
1830  *
1831  * query_tree_walker is a convenience routine (see below) that calls the
1832  * walker on all the expression subtrees of the given Query node.
1833  *
1834  * expression_tree_walker will handle SubPlan nodes by recursing normally
1835  * into the "testexpr" and the "args" list (which are expressions belonging to
1836  * the outer plan). It will not touch the completed subplan, however. Since
1837  * there is no link to the original Query, it is not possible to recurse into
1838  * subselects of an already-planned expression tree. This is OK for current
1839  * uses, but may need to be revisited in future.
1840  */
1841 
1842 bool
1844  bool (*walker) (),
1845  void *context)
1846 {
1847  ListCell *temp;
1848 
1849  /*
1850  * The walker has already visited the current node, and so we need only
1851  * recurse into any sub-nodes it has.
1852  *
1853  * We assume that the walker is not interested in List nodes per se, so
1854  * when we expect a List we just recurse directly to self without
1855  * bothering to call the walker.
1856  */
1857  if (node == NULL)
1858  return false;
1859 
1860  /* Guard against stack overflow due to overly complex expressions */
1862 
1863  switch (nodeTag(node))
1864  {
1865  case T_Var:
1866  case T_Const:
1867  case T_Param:
1868  case T_CaseTestExpr:
1869  case T_SQLValueFunction:
1870  case T_CoerceToDomainValue:
1871  case T_SetToDefault:
1872  case T_CurrentOfExpr:
1873  case T_NextValueExpr:
1874  case T_RangeTblRef:
1875  case T_SortGroupClause:
1876  /* primitive node types with no expression subnodes */
1877  break;
1878  case T_WithCheckOption:
1879  return walker(((WithCheckOption *) node)->qual, context);
1880  case T_Aggref:
1881  {
1882  Aggref *expr = (Aggref *) node;
1883 
1884  /* recurse directly on List */
1886  walker, context))
1887  return true;
1888  if (expression_tree_walker((Node *) expr->args,
1889  walker, context))
1890  return true;
1891  if (expression_tree_walker((Node *) expr->aggorder,
1892  walker, context))
1893  return true;
1894  if (expression_tree_walker((Node *) expr->aggdistinct,
1895  walker, context))
1896  return true;
1897  if (walker((Node *) expr->aggfilter, context))
1898  return true;
1899  }
1900  break;
1901  case T_GroupingFunc:
1902  {
1903  GroupingFunc *grouping = (GroupingFunc *) node;
1904 
1905  if (expression_tree_walker((Node *) grouping->args,
1906  walker, context))
1907  return true;
1908  }
1909  break;
1910  case T_WindowFunc:
1911  {
1912  WindowFunc *expr = (WindowFunc *) node;
1913 
1914  /* recurse directly on List */
1915  if (expression_tree_walker((Node *) expr->args,
1916  walker, context))
1917  return true;
1918  if (walker((Node *) expr->aggfilter, context))
1919  return true;
1920  }
1921  break;
1922  case T_ArrayRef:
1923  {
1924  ArrayRef *aref = (ArrayRef *) node;
1925 
1926  /* recurse directly for upper/lower array index lists */
1928  walker, context))
1929  return true;
1931  walker, context))
1932  return true;
1933  /* walker must see the refexpr and refassgnexpr, however */
1934  if (walker(aref->refexpr, context))
1935  return true;
1936  if (walker(aref->refassgnexpr, context))
1937  return true;
1938  }
1939  break;
1940  case T_FuncExpr:
1941  {
1942  FuncExpr *expr = (FuncExpr *) node;
1943 
1944  if (expression_tree_walker((Node *) expr->args,
1945  walker, context))
1946  return true;
1947  }
1948  break;
1949  case T_NamedArgExpr:
1950  return walker(((NamedArgExpr *) node)->arg, context);
1951  case T_OpExpr:
1952  case T_DistinctExpr: /* struct-equivalent to OpExpr */
1953  case T_NullIfExpr: /* struct-equivalent to OpExpr */
1954  {
1955  OpExpr *expr = (OpExpr *) node;
1956 
1957  if (expression_tree_walker((Node *) expr->args,
1958  walker, context))
1959  return true;
1960  }
1961  break;
1962  case T_ScalarArrayOpExpr:
1963  {
1964  ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node;
1965 
1966  if (expression_tree_walker((Node *) expr->args,
1967  walker, context))
1968  return true;
1969  }
1970  break;
1971  case T_BoolExpr:
1972  {
1973  BoolExpr *expr = (BoolExpr *) node;
1974 
1975  if (expression_tree_walker((Node *) expr->args,
1976  walker, context))
1977  return true;
1978  }
1979  break;
1980  case T_SubLink:
1981  {
1982  SubLink *sublink = (SubLink *) node;
1983 
1984  if (walker(sublink->testexpr, context))
1985  return true;
1986 
1987  /*
1988  * Also invoke the walker on the sublink's Query node, so it
1989  * can recurse into the sub-query if it wants to.
1990  */
1991  return walker(sublink->subselect, context);
1992  }
1993  break;
1994  case T_SubPlan:
1995  {
1996  SubPlan *subplan = (SubPlan *) node;
1997 
1998  /* recurse into the testexpr, but not into the Plan */
1999  if (walker(subplan->testexpr, context))
2000  return true;
2001  /* also examine args list */
2002  if (expression_tree_walker((Node *) subplan->args,
2003  walker, context))
2004  return true;
2005  }
2006  break;
2007  case T_AlternativeSubPlan:
2008  return walker(((AlternativeSubPlan *) node)->subplans, context);
2009  case T_FieldSelect:
2010  return walker(((FieldSelect *) node)->arg, context);
2011  case T_FieldStore:
2012  {
2013  FieldStore *fstore = (FieldStore *) node;
2014 
2015  if (walker(fstore->arg, context))
2016  return true;
2017  if (walker(fstore->newvals, context))
2018  return true;
2019  }
2020  break;
2021  case T_RelabelType:
2022  return walker(((RelabelType *) node)->arg, context);
2023  case T_CoerceViaIO:
2024  return walker(((CoerceViaIO *) node)->arg, context);
2025  case T_ArrayCoerceExpr:
2026  return walker(((ArrayCoerceExpr *) node)->arg, context);
2027  case T_ConvertRowtypeExpr:
2028  return walker(((ConvertRowtypeExpr *) node)->arg, context);
2029  case T_CollateExpr:
2030  return walker(((CollateExpr *) node)->arg, context);
2031  case T_CaseExpr:
2032  {
2033  CaseExpr *caseexpr = (CaseExpr *) node;
2034 
2035  if (walker(caseexpr->arg, context))
2036  return true;
2037  /* we assume walker doesn't care about CaseWhens, either */
2038  foreach(temp, caseexpr->args)
2039  {
2040  CaseWhen *when = lfirst_node(CaseWhen, temp);
2041 
2042  if (walker(when->expr, context))
2043  return true;
2044  if (walker(when->result, context))
2045  return true;
2046  }
2047  if (walker(caseexpr->defresult, context))
2048  return true;
2049  }
2050  break;
2051  case T_ArrayExpr:
2052  return walker(((ArrayExpr *) node)->elements, context);
2053  case T_RowExpr:
2054  /* Assume colnames isn't interesting */
2055  return walker(((RowExpr *) node)->args, context);
2056  case T_RowCompareExpr:
2057  {
2058  RowCompareExpr *rcexpr = (RowCompareExpr *) node;
2059 
2060  if (walker(rcexpr->largs, context))
2061  return true;
2062  if (walker(rcexpr->rargs, context))
2063  return true;
2064  }
2065  break;
2066  case T_CoalesceExpr:
2067  return walker(((CoalesceExpr *) node)->args, context);
2068  case T_MinMaxExpr:
2069  return walker(((MinMaxExpr *) node)->args, context);
2070  case T_XmlExpr:
2071  {
2072  XmlExpr *xexpr = (XmlExpr *) node;
2073 
2074  if (walker(xexpr->named_args, context))
2075  return true;
2076  /* we assume walker doesn't care about arg_names */
2077  if (walker(xexpr->args, context))
2078  return true;
2079  }
2080  break;
2081  case T_NullTest:
2082  return walker(((NullTest *) node)->arg, context);
2083  case T_BooleanTest:
2084  return walker(((BooleanTest *) node)->arg, context);
2085  case T_CoerceToDomain:
2086  return walker(((CoerceToDomain *) node)->arg, context);
2087  case T_TargetEntry:
2088  return walker(((TargetEntry *) node)->expr, context);
2089  case T_Query:
2090  /* Do nothing with a sub-Query, per discussion above */
2091  break;
2092  case T_WindowClause:
2093  {
2094  WindowClause *wc = (WindowClause *) node;
2095 
2096  if (walker(wc->partitionClause, context))
2097  return true;
2098  if (walker(wc->orderClause, context))
2099  return true;
2100  if (walker(wc->startOffset, context))
2101  return true;
2102  if (walker(wc->endOffset, context))
2103  return true;
2104  }
2105  break;
2106  case T_CommonTableExpr:
2107  {
2108  CommonTableExpr *cte = (CommonTableExpr *) node;
2109 
2110  /*
2111  * Invoke the walker on the CTE's Query node, so it can
2112  * recurse into the sub-query if it wants to.
2113  */
2114  return walker(cte->ctequery, context);
2115  }
2116  break;
2117  case T_List:
2118  foreach(temp, (List *) node)
2119  {
2120  if (walker((Node *) lfirst(temp), context))
2121  return true;
2122  }
2123  break;
2124  case T_FromExpr:
2125  {
2126  FromExpr *from = (FromExpr *) node;
2127 
2128  if (walker(from->fromlist, context))
2129  return true;
2130  if (walker(from->quals, context))
2131  return true;
2132  }
2133  break;
2134  case T_OnConflictExpr:
2135  {
2136  OnConflictExpr *onconflict = (OnConflictExpr *) node;
2137 
2138  if (walker((Node *) onconflict->arbiterElems, context))
2139  return true;
2140  if (walker(onconflict->arbiterWhere, context))
2141  return true;
2142  if (walker(onconflict->onConflictSet, context))
2143  return true;
2144  if (walker(onconflict->onConflictWhere, context))
2145  return true;
2146  if (walker(onconflict->exclRelTlist, context))
2147  return true;
2148  }
2149  break;
2150  case T_JoinExpr:
2151  {
2152  JoinExpr *join = (JoinExpr *) node;
2153 
2154  if (walker(join->larg, context))
2155  return true;
2156  if (walker(join->rarg, context))
2157  return true;
2158  if (walker(join->quals, context))
2159  return true;
2160 
2161  /*
2162  * alias clause, using list are deemed uninteresting.
2163  */
2164  }
2165  break;
2166  case T_SetOperationStmt:
2167  {
2168  SetOperationStmt *setop = (SetOperationStmt *) node;
2169 
2170  if (walker(setop->larg, context))
2171  return true;
2172  if (walker(setop->rarg, context))
2173  return true;
2174 
2175  /* groupClauses are deemed uninteresting */
2176  }
2177  break;
2178  case T_PlaceHolderVar:
2179  return walker(((PlaceHolderVar *) node)->phexpr, context);
2180  case T_InferenceElem:
2181  return walker(((InferenceElem *) node)->expr, context);
2182  case T_AppendRelInfo:
2183  {
2184  AppendRelInfo *appinfo = (AppendRelInfo *) node;
2185 
2186  if (expression_tree_walker((Node *) appinfo->translated_vars,
2187  walker, context))
2188  return true;
2189  }
2190  break;
2191  case T_PlaceHolderInfo:
2192  return walker(((PlaceHolderInfo *) node)->ph_var, context);
2193  case T_RangeTblFunction:
2194  return walker(((RangeTblFunction *) node)->funcexpr, context);
2195  case T_TableSampleClause:
2196  {
2197  TableSampleClause *tsc = (TableSampleClause *) node;
2198 
2199  if (expression_tree_walker((Node *) tsc->args,
2200  walker, context))
2201  return true;
2202  if (walker((Node *) tsc->repeatable, context))
2203  return true;
2204  }
2205  break;
2206  case T_TableFunc:
2207  {
2208  TableFunc *tf = (TableFunc *) node;
2209 
2210  if (walker(tf->ns_uris, context))
2211  return true;
2212  if (walker(tf->docexpr, context))
2213  return true;
2214  if (walker(tf->rowexpr, context))
2215  return true;
2216  if (walker(tf->colexprs, context))
2217  return true;
2218  if (walker(tf->coldefexprs, context))
2219  return true;
2220  }
2221  break;
2222  default:
2223  elog(ERROR, "unrecognized node type: %d",
2224  (int) nodeTag(node));
2225  break;
2226  }
2227  return false;
2228 }
2229 
2230 /*
2231  * query_tree_walker --- initiate a walk of a Query's expressions
2232  *
2233  * This routine exists just to reduce the number of places that need to know
2234  * where all the expression subtrees of a Query are. Note it can be used
2235  * for starting a walk at top level of a Query regardless of whether the
2236  * walker intends to descend into subqueries. It is also useful for
2237  * descending into subqueries within a walker.
2238  *
2239  * Some callers want to suppress visitation of certain items in the sub-Query,
2240  * typically because they need to process them specially, or don't actually
2241  * want to recurse into subqueries. This is supported by the flags argument,
2242  * which is the bitwise OR of flag values to suppress visitation of
2243  * indicated items. (More flag bits may be added as needed.)
2244  */
2245 bool
2247  bool (*walker) (),
2248  void *context,
2249  int flags)
2250 {
2251  Assert(query != NULL && IsA(query, Query));
2252 
2253  if (walker((Node *) query->targetList, context))
2254  return true;
2255  if (walker((Node *) query->withCheckOptions, context))
2256  return true;
2257  if (walker((Node *) query->onConflict, context))
2258  return true;
2259  if (walker((Node *) query->returningList, context))
2260  return true;
2261  if (walker((Node *) query->jointree, context))
2262  return true;
2263  if (walker(query->setOperations, context))
2264  return true;
2265  if (walker(query->havingQual, context))
2266  return true;
2267  if (walker(query->limitOffset, context))
2268  return true;
2269  if (walker(query->limitCount, context))
2270  return true;
2271  if (!(flags & QTW_IGNORE_CTE_SUBQUERIES))
2272  {
2273  if (walker((Node *) query->cteList, context))
2274  return true;
2275  }
2276  if (!(flags & QTW_IGNORE_RANGE_TABLE))
2277  {
2278  if (range_table_walker(query->rtable, walker, context, flags))
2279  return true;
2280  }
2281  return false;
2282 }
2283 
2284 /*
2285  * range_table_walker is just the part of query_tree_walker that scans
2286  * a query's rangetable. This is split out since it can be useful on
2287  * its own.
2288  */
2289 bool
2291  bool (*walker) (),
2292  void *context,
2293  int flags)
2294 {
2295  ListCell *rt;
2296 
2297  foreach(rt, rtable)
2298  {
2299  RangeTblEntry *rte = (RangeTblEntry *) lfirst(rt);
2300 
2301  /* For historical reasons, visiting RTEs is not the default */
2302  if (flags & QTW_EXAMINE_RTES)
2303  if (walker(rte, context))
2304  return true;
2305 
2306  switch (rte->rtekind)
2307  {
2308  case RTE_RELATION:
2309  if (walker(rte->tablesample, context))
2310  return true;
2311  break;
2312  case RTE_CTE:
2313  case RTE_NAMEDTUPLESTORE:
2314  /* nothing to do */
2315  break;
2316  case RTE_SUBQUERY:
2317  if (!(flags & QTW_IGNORE_RT_SUBQUERIES))
2318  if (walker(rte->subquery, context))
2319  return true;
2320  break;
2321  case RTE_JOIN:
2322  if (!(flags & QTW_IGNORE_JOINALIASES))
2323  if (walker(rte->joinaliasvars, context))
2324  return true;
2325  break;
2326  case RTE_FUNCTION:
2327  if (walker(rte->functions, context))
2328  return true;
2329  break;
2330  case RTE_TABLEFUNC:
2331  if (walker(rte->tablefunc, context))
2332  return true;
2333  break;
2334  case RTE_VALUES:
2335  if (walker(rte->values_lists, context))
2336  return true;
2337  break;
2338  }
2339 
2340  if (walker(rte->securityQuals, context))
2341  return true;
2342  }
2343  return false;
2344 }
2345 
2346 
2347 /*
2348  * expression_tree_mutator() is designed to support routines that make a
2349  * modified copy of an expression tree, with some nodes being added,
2350  * removed, or replaced by new subtrees. The original tree is (normally)
2351  * not changed. Each recursion level is responsible for returning a copy of
2352  * (or appropriately modified substitute for) the subtree it is handed.
2353  * A mutator routine should look like this:
2354  *
2355  * Node * my_mutator (Node *node, my_struct *context)
2356  * {
2357  * if (node == NULL)
2358  * return NULL;
2359  * // check for nodes that special work is required for, eg:
2360  * if (IsA(node, Var))
2361  * {
2362  * ... create and return modified copy of Var node
2363  * }
2364  * else if (IsA(node, ...))
2365  * {
2366  * ... do special transformations of other node types
2367  * }
2368  * // for any node type not specially processed, do:
2369  * return expression_tree_mutator(node, my_mutator, (void *) context);
2370  * }
2371  *
2372  * The "context" argument points to a struct that holds whatever context
2373  * information the mutator routine needs --- it can be used to return extra
2374  * data gathered by the mutator, too. This argument is not touched by
2375  * expression_tree_mutator, but it is passed down to recursive sub-invocations
2376  * of my_mutator. The tree walk is started from a setup routine that
2377  * fills in the appropriate context struct, calls my_mutator with the
2378  * top-level node of the tree, and does any required post-processing.
2379  *
2380  * Each level of recursion must return an appropriately modified Node.
2381  * If expression_tree_mutator() is called, it will make an exact copy
2382  * of the given Node, but invoke my_mutator() to copy the sub-node(s)
2383  * of that Node. In this way, my_mutator() has full control over the
2384  * copying process but need not directly deal with expression trees
2385  * that it has no interest in.
2386  *
2387  * Just as for expression_tree_walker, the node types handled by
2388  * expression_tree_mutator include all those normally found in target lists
2389  * and qualifier clauses during the planning stage.
2390  *
2391  * expression_tree_mutator will handle SubLink nodes by recursing normally
2392  * into the "testexpr" subtree (which is an expression belonging to the outer
2393  * plan). It will also call the mutator on the sub-Query node; however, when
2394  * expression_tree_mutator itself is called on a Query node, it does nothing
2395  * and returns the unmodified Query node. The net effect is that unless the
2396  * mutator does something special at a Query node, sub-selects will not be
2397  * visited or modified; the original sub-select will be linked to by the new
2398  * SubLink node. Mutators that want to descend into sub-selects will usually
2399  * do so by recognizing Query nodes and calling query_tree_mutator (below).
2400  *
2401  * expression_tree_mutator will handle a SubPlan node by recursing into the
2402  * "testexpr" and the "args" list (which belong to the outer plan), but it
2403  * will simply copy the link to the inner plan, since that's typically what
2404  * expression tree mutators want. A mutator that wants to modify the subplan
2405  * can force appropriate behavior by recognizing SubPlan expression nodes
2406  * and doing the right thing.
2407  */
2408 
2409 Node *
2411  Node *(*mutator) (),
2412  void *context)
2413 {
2414  /*
2415  * The mutator has already decided not to modify the current node, but we
2416  * must call the mutator for any sub-nodes.
2417  */
2418 
2419 #define FLATCOPY(newnode, node, nodetype) \
2420  ( (newnode) = (nodetype *) palloc(sizeof(nodetype)), \
2421  memcpy((newnode), (node), sizeof(nodetype)) )
2422 
2423 #define CHECKFLATCOPY(newnode, node, nodetype) \
2424  ( AssertMacro(IsA((node), nodetype)), \
2425  (newnode) = (nodetype *) palloc(sizeof(nodetype)), \
2426  memcpy((newnode), (node), sizeof(nodetype)) )
2427 
2428 #define MUTATE(newfield, oldfield, fieldtype) \
2429  ( (newfield) = (fieldtype) mutator((Node *) (oldfield), context) )
2430 
2431  if (node == NULL)
2432  return NULL;
2433 
2434  /* Guard against stack overflow due to overly complex expressions */
2436 
2437  switch (nodeTag(node))
2438  {
2439  /*
2440  * Primitive node types with no expression subnodes. Var and
2441  * Const are frequent enough to deserve special cases, the others
2442  * we just use copyObject for.
2443  */
2444  case T_Var:
2445  {
2446  Var *var = (Var *) node;
2447  Var *newnode;
2448 
2449  FLATCOPY(newnode, var, Var);
2450  return (Node *) newnode;
2451  }
2452  break;
2453  case T_Const:
2454  {
2455  Const *oldnode = (Const *) node;
2456  Const *newnode;
2457 
2458  FLATCOPY(newnode, oldnode, Const);
2459  /* XXX we don't bother with datumCopy; should we? */
2460  return (Node *) newnode;
2461  }
2462  break;
2463  case T_Param:
2464  case T_CaseTestExpr:
2465  case T_SQLValueFunction:
2466  case T_CoerceToDomainValue:
2467  case T_SetToDefault:
2468  case T_CurrentOfExpr:
2469  case T_NextValueExpr:
2470  case T_RangeTblRef:
2471  case T_SortGroupClause:
2472  return (Node *) copyObject(node);
2473  case T_WithCheckOption:
2474  {
2475  WithCheckOption *wco = (WithCheckOption *) node;
2476  WithCheckOption *newnode;
2477 
2478  FLATCOPY(newnode, wco, WithCheckOption);
2479  MUTATE(newnode->qual, wco->qual, Node *);
2480  return (Node *) newnode;
2481  }
2482  case T_Aggref:
2483  {
2484  Aggref *aggref = (Aggref *) node;
2485  Aggref *newnode;
2486 
2487  FLATCOPY(newnode, aggref, Aggref);
2488  /* assume mutation doesn't change types of arguments */
2489  newnode->aggargtypes = list_copy(aggref->aggargtypes);
2490  MUTATE(newnode->aggdirectargs, aggref->aggdirectargs, List *);
2491  MUTATE(newnode->args, aggref->args, List *);
2492  MUTATE(newnode->aggorder, aggref->aggorder, List *);
2493  MUTATE(newnode->aggdistinct, aggref->aggdistinct, List *);
2494  MUTATE(newnode->aggfilter, aggref->aggfilter, Expr *);
2495  return (Node *) newnode;
2496  }
2497  break;
2498  case T_GroupingFunc:
2499  {
2500  GroupingFunc *grouping = (GroupingFunc *) node;
2501  GroupingFunc *newnode;
2502 
2503  FLATCOPY(newnode, grouping, GroupingFunc);
2504  MUTATE(newnode->args, grouping->args, List *);
2505 
2506  /*
2507  * We assume here that mutating the arguments does not change
2508  * the semantics, i.e. that the arguments are not mutated in a
2509  * way that makes them semantically different from their
2510  * previously matching expressions in the GROUP BY clause.
2511  *
2512  * If a mutator somehow wanted to do this, it would have to
2513  * handle the refs and cols lists itself as appropriate.
2514  */
2515  newnode->refs = list_copy(grouping->refs);
2516  newnode->cols = list_copy(grouping->cols);
2517 
2518  return (Node *) newnode;
2519  }
2520  break;
2521  case T_WindowFunc:
2522  {
2523  WindowFunc *wfunc = (WindowFunc *) node;
2524  WindowFunc *newnode;
2525 
2526  FLATCOPY(newnode, wfunc, WindowFunc);
2527  MUTATE(newnode->args, wfunc->args, List *);
2528  MUTATE(newnode->aggfilter, wfunc->aggfilter, Expr *);
2529  return (Node *) newnode;
2530  }
2531  break;
2532  case T_ArrayRef:
2533  {
2534  ArrayRef *arrayref = (ArrayRef *) node;
2535  ArrayRef *newnode;
2536 
2537  FLATCOPY(newnode, arrayref, ArrayRef);
2538  MUTATE(newnode->refupperindexpr, arrayref->refupperindexpr,
2539  List *);
2540  MUTATE(newnode->reflowerindexpr, arrayref->reflowerindexpr,
2541  List *);
2542  MUTATE(newnode->refexpr, arrayref->refexpr,
2543  Expr *);
2544  MUTATE(newnode->refassgnexpr, arrayref->refassgnexpr,
2545  Expr *);
2546  return (Node *) newnode;
2547  }
2548  break;
2549  case T_FuncExpr:
2550  {
2551  FuncExpr *expr = (FuncExpr *) node;
2552  FuncExpr *newnode;
2553 
2554  FLATCOPY(newnode, expr, FuncExpr);
2555  MUTATE(newnode->args, expr->args, List *);
2556  return (Node *) newnode;
2557  }
2558  break;
2559  case T_NamedArgExpr:
2560  {
2561  NamedArgExpr *nexpr = (NamedArgExpr *) node;
2562  NamedArgExpr *newnode;
2563 
2564  FLATCOPY(newnode, nexpr, NamedArgExpr);
2565  MUTATE(newnode->arg, nexpr->arg, Expr *);
2566  return (Node *) newnode;
2567  }
2568  break;
2569  case T_OpExpr:
2570  {
2571  OpExpr *expr = (OpExpr *) node;
2572  OpExpr *newnode;
2573 
2574  FLATCOPY(newnode, expr, OpExpr);
2575  MUTATE(newnode->args, expr->args, List *);
2576  return (Node *) newnode;
2577  }
2578  break;
2579  case T_DistinctExpr:
2580  {
2581  DistinctExpr *expr = (DistinctExpr *) node;
2582  DistinctExpr *newnode;
2583 
2584  FLATCOPY(newnode, expr, DistinctExpr);
2585  MUTATE(newnode->args, expr->args, List *);
2586  return (Node *) newnode;
2587  }
2588  break;
2589  case T_NullIfExpr:
2590  {
2591  NullIfExpr *expr = (NullIfExpr *) node;
2592  NullIfExpr *newnode;
2593 
2594  FLATCOPY(newnode, expr, NullIfExpr);
2595  MUTATE(newnode->args, expr->args, List *);
2596  return (Node *) newnode;
2597  }
2598  break;
2599  case T_ScalarArrayOpExpr:
2600  {
2601  ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node;
2602  ScalarArrayOpExpr *newnode;
2603 
2604  FLATCOPY(newnode, expr, ScalarArrayOpExpr);
2605  MUTATE(newnode->args, expr->args, List *);
2606  return (Node *) newnode;
2607  }
2608  break;
2609  case T_BoolExpr:
2610  {
2611  BoolExpr *expr = (BoolExpr *) node;
2612  BoolExpr *newnode;
2613 
2614  FLATCOPY(newnode, expr, BoolExpr);
2615  MUTATE(newnode->args, expr->args, List *);
2616  return (Node *) newnode;
2617  }
2618  break;
2619  case T_SubLink:
2620  {
2621  SubLink *sublink = (SubLink *) node;
2622  SubLink *newnode;
2623 
2624  FLATCOPY(newnode, sublink, SubLink);
2625  MUTATE(newnode->testexpr, sublink->testexpr, Node *);
2626 
2627  /*
2628  * Also invoke the mutator on the sublink's Query node, so it
2629  * can recurse into the sub-query if it wants to.
2630  */
2631  MUTATE(newnode->subselect, sublink->subselect, Node *);
2632  return (Node *) newnode;
2633  }
2634  break;
2635  case T_SubPlan:
2636  {
2637  SubPlan *subplan = (SubPlan *) node;
2638  SubPlan *newnode;
2639 
2640  FLATCOPY(newnode, subplan, SubPlan);
2641  /* transform testexpr */
2642  MUTATE(newnode->testexpr, subplan->testexpr, Node *);
2643  /* transform args list (params to be passed to subplan) */
2644  MUTATE(newnode->args, subplan->args, List *);
2645  /* but not the sub-Plan itself, which is referenced as-is */
2646  return (Node *) newnode;
2647  }
2648  break;
2649  case T_AlternativeSubPlan:
2650  {
2651  AlternativeSubPlan *asplan = (AlternativeSubPlan *) node;
2652  AlternativeSubPlan *newnode;
2653 
2654  FLATCOPY(newnode, asplan, AlternativeSubPlan);
2655  MUTATE(newnode->subplans, asplan->subplans, List *);
2656  return (Node *) newnode;
2657  }
2658  break;
2659  case T_FieldSelect:
2660  {
2661  FieldSelect *fselect = (FieldSelect *) node;
2662  FieldSelect *newnode;
2663 
2664  FLATCOPY(newnode, fselect, FieldSelect);
2665  MUTATE(newnode->arg, fselect->arg, Expr *);
2666  return (Node *) newnode;
2667  }
2668  break;
2669  case T_FieldStore:
2670  {
2671  FieldStore *fstore = (FieldStore *) node;
2672  FieldStore *newnode;
2673 
2674  FLATCOPY(newnode, fstore, FieldStore);
2675  MUTATE(newnode->arg, fstore->arg, Expr *);
2676  MUTATE(newnode->newvals, fstore->newvals, List *);
2677  newnode->fieldnums = list_copy(fstore->fieldnums);
2678  return (Node *) newnode;
2679  }
2680  break;
2681  case T_RelabelType:
2682  {
2683  RelabelType *relabel = (RelabelType *) node;
2684  RelabelType *newnode;
2685 
2686  FLATCOPY(newnode, relabel, RelabelType);
2687  MUTATE(newnode->arg, relabel->arg, Expr *);
2688  return (Node *) newnode;
2689  }
2690  break;
2691  case T_CoerceViaIO:
2692  {
2693  CoerceViaIO *iocoerce = (CoerceViaIO *) node;
2694  CoerceViaIO *newnode;
2695 
2696  FLATCOPY(newnode, iocoerce, CoerceViaIO);
2697  MUTATE(newnode->arg, iocoerce->arg, Expr *);
2698  return (Node *) newnode;
2699  }
2700  break;
2701  case T_ArrayCoerceExpr:
2702  {
2703  ArrayCoerceExpr *acoerce = (ArrayCoerceExpr *) node;
2704  ArrayCoerceExpr *newnode;
2705 
2706  FLATCOPY(newnode, acoerce, ArrayCoerceExpr);
2707  MUTATE(newnode->arg, acoerce->arg, Expr *);
2708  return (Node *) newnode;
2709  }
2710  break;
2711  case T_ConvertRowtypeExpr:
2712  {
2713  ConvertRowtypeExpr *convexpr = (ConvertRowtypeExpr *) node;
2714  ConvertRowtypeExpr *newnode;
2715 
2716  FLATCOPY(newnode, convexpr, ConvertRowtypeExpr);
2717  MUTATE(newnode->arg, convexpr->arg, Expr *);
2718  return (Node *) newnode;
2719  }
2720  break;
2721  case T_CollateExpr:
2722  {
2723  CollateExpr *collate = (CollateExpr *) node;
2724  CollateExpr *newnode;
2725 
2726  FLATCOPY(newnode, collate, CollateExpr);
2727  MUTATE(newnode->arg, collate->arg, Expr *);
2728  return (Node *) newnode;
2729  }
2730  break;
2731  case T_CaseExpr:
2732  {
2733  CaseExpr *caseexpr = (CaseExpr *) node;
2734  CaseExpr *newnode;
2735 
2736  FLATCOPY(newnode, caseexpr, CaseExpr);
2737  MUTATE(newnode->arg, caseexpr->arg, Expr *);
2738  MUTATE(newnode->args, caseexpr->args, List *);
2739  MUTATE(newnode->defresult, caseexpr->defresult, Expr *);
2740  return (Node *) newnode;
2741  }
2742  break;
2743  case T_CaseWhen:
2744  {
2745  CaseWhen *casewhen = (CaseWhen *) node;
2746  CaseWhen *newnode;
2747 
2748  FLATCOPY(newnode, casewhen, CaseWhen);
2749  MUTATE(newnode->expr, casewhen->expr, Expr *);
2750  MUTATE(newnode->result, casewhen->result, Expr *);
2751  return (Node *) newnode;
2752  }
2753  break;
2754  case T_ArrayExpr:
2755  {
2756  ArrayExpr *arrayexpr = (ArrayExpr *) node;
2757  ArrayExpr *newnode;
2758 
2759  FLATCOPY(newnode, arrayexpr, ArrayExpr);
2760  MUTATE(newnode->elements, arrayexpr->elements, List *);
2761  return (Node *) newnode;
2762  }
2763  break;
2764  case T_RowExpr:
2765  {
2766  RowExpr *rowexpr = (RowExpr *) node;
2767  RowExpr *newnode;
2768 
2769  FLATCOPY(newnode, rowexpr, RowExpr);
2770  MUTATE(newnode->args, rowexpr->args, List *);
2771  /* Assume colnames needn't be duplicated */
2772  return (Node *) newnode;
2773  }
2774  break;
2775  case T_RowCompareExpr:
2776  {
2777  RowCompareExpr *rcexpr = (RowCompareExpr *) node;
2778  RowCompareExpr *newnode;
2779 
2780  FLATCOPY(newnode, rcexpr, RowCompareExpr);
2781  MUTATE(newnode->largs, rcexpr->largs, List *);
2782  MUTATE(newnode->rargs, rcexpr->rargs, List *);
2783  return (Node *) newnode;
2784  }
2785  break;
2786  case T_CoalesceExpr:
2787  {
2788  CoalesceExpr *coalesceexpr = (CoalesceExpr *) node;
2789  CoalesceExpr *newnode;
2790 
2791  FLATCOPY(newnode, coalesceexpr, CoalesceExpr);
2792  MUTATE(newnode->args, coalesceexpr->args, List *);
2793  return (Node *) newnode;
2794  }
2795  break;
2796  case T_MinMaxExpr:
2797  {
2798  MinMaxExpr *minmaxexpr = (MinMaxExpr *) node;
2799  MinMaxExpr *newnode;
2800 
2801  FLATCOPY(newnode, minmaxexpr, MinMaxExpr);
2802  MUTATE(newnode->args, minmaxexpr->args, List *);
2803  return (Node *) newnode;
2804  }
2805  break;
2806  case T_XmlExpr:
2807  {
2808  XmlExpr *xexpr = (XmlExpr *) node;
2809  XmlExpr *newnode;
2810 
2811  FLATCOPY(newnode, xexpr, XmlExpr);
2812  MUTATE(newnode->named_args, xexpr->named_args, List *);
2813  /* assume mutator does not care about arg_names */
2814  MUTATE(newnode->args, xexpr->args, List *);
2815  return (Node *) newnode;
2816  }
2817  break;
2818  case T_NullTest:
2819  {
2820  NullTest *ntest = (NullTest *) node;
2821  NullTest *newnode;
2822 
2823  FLATCOPY(newnode, ntest, NullTest);
2824  MUTATE(newnode->arg, ntest->arg, Expr *);
2825  return (Node *) newnode;
2826  }
2827  break;
2828  case T_BooleanTest:
2829  {
2830  BooleanTest *btest = (BooleanTest *) node;
2831  BooleanTest *newnode;
2832 
2833  FLATCOPY(newnode, btest, BooleanTest);
2834  MUTATE(newnode->arg, btest->arg, Expr *);
2835  return (Node *) newnode;
2836  }
2837  break;
2838  case T_CoerceToDomain:
2839  {
2840  CoerceToDomain *ctest = (CoerceToDomain *) node;
2841  CoerceToDomain *newnode;
2842 
2843  FLATCOPY(newnode, ctest, CoerceToDomain);
2844  MUTATE(newnode->arg, ctest->arg, Expr *);
2845  return (Node *) newnode;
2846  }
2847  break;
2848  case T_TargetEntry:
2849  {
2850  TargetEntry *targetentry = (TargetEntry *) node;
2851  TargetEntry *newnode;
2852 
2853  FLATCOPY(newnode, targetentry, TargetEntry);
2854  MUTATE(newnode->expr, targetentry->expr, Expr *);
2855  return (Node *) newnode;
2856  }
2857  break;
2858  case T_Query:
2859  /* Do nothing with a sub-Query, per discussion above */
2860  return node;
2861  case T_WindowClause:
2862  {
2863  WindowClause *wc = (WindowClause *) node;
2864  WindowClause *newnode;
2865 
2866  FLATCOPY(newnode, wc, WindowClause);
2867  MUTATE(newnode->partitionClause, wc->partitionClause, List *);
2868  MUTATE(newnode->orderClause, wc->orderClause, List *);
2869  MUTATE(newnode->startOffset, wc->startOffset, Node *);
2870  MUTATE(newnode->endOffset, wc->endOffset, Node *);
2871  return (Node *) newnode;
2872  }
2873  break;
2874  case T_CommonTableExpr:
2875  {
2876  CommonTableExpr *cte = (CommonTableExpr *) node;
2877  CommonTableExpr *newnode;
2878 
2879  FLATCOPY(newnode, cte, CommonTableExpr);
2880 
2881  /*
2882  * Also invoke the mutator on the CTE's Query node, so it can
2883  * recurse into the sub-query if it wants to.
2884  */
2885  MUTATE(newnode->ctequery, cte->ctequery, Node *);
2886  return (Node *) newnode;
2887  }
2888  break;
2889  case T_List:
2890  {
2891  /*
2892  * We assume the mutator isn't interested in the list nodes
2893  * per se, so just invoke it on each list element. NOTE: this
2894  * would fail badly on a list with integer elements!
2895  */
2896  List *resultlist;
2897  ListCell *temp;
2898 
2899  resultlist = NIL;
2900  foreach(temp, (List *) node)
2901  {
2902  resultlist = lappend(resultlist,
2903  mutator((Node *) lfirst(temp),
2904  context));
2905  }
2906  return (Node *) resultlist;
2907  }
2908  break;
2909  case T_FromExpr:
2910  {
2911  FromExpr *from = (FromExpr *) node;
2912  FromExpr *newnode;
2913 
2914  FLATCOPY(newnode, from, FromExpr);
2915  MUTATE(newnode->fromlist, from->fromlist, List *);
2916  MUTATE(newnode->quals, from->quals, Node *);
2917  return (Node *) newnode;
2918  }
2919  break;
2920  case T_OnConflictExpr:
2921  {
2922  OnConflictExpr *oc = (OnConflictExpr *) node;
2923  OnConflictExpr *newnode;
2924 
2925  FLATCOPY(newnode, oc, OnConflictExpr);
2926  MUTATE(newnode->arbiterElems, oc->arbiterElems, List *);
2927  MUTATE(newnode->arbiterWhere, oc->arbiterWhere, Node *);
2928  MUTATE(newnode->onConflictSet, oc->onConflictSet, List *);
2929  MUTATE(newnode->onConflictWhere, oc->onConflictWhere, Node *);
2930  MUTATE(newnode->exclRelTlist, oc->exclRelTlist, List *);
2931 
2932  return (Node *) newnode;
2933  }
2934  break;
2935  case T_JoinExpr:
2936  {
2937  JoinExpr *join = (JoinExpr *) node;
2938  JoinExpr *newnode;
2939 
2940  FLATCOPY(newnode, join, JoinExpr);
2941  MUTATE(newnode->larg, join->larg, Node *);
2942  MUTATE(newnode->rarg, join->rarg, Node *);
2943  MUTATE(newnode->quals, join->quals, Node *);
2944  /* We do not mutate alias or using by default */
2945  return (Node *) newnode;
2946  }
2947  break;
2948  case T_SetOperationStmt:
2949  {
2950  SetOperationStmt *setop = (SetOperationStmt *) node;
2951  SetOperationStmt *newnode;
2952 
2953  FLATCOPY(newnode, setop, SetOperationStmt);
2954  MUTATE(newnode->larg, setop->larg, Node *);
2955  MUTATE(newnode->rarg, setop->rarg, Node *);
2956  /* We do not mutate groupClauses by default */
2957  return (Node *) newnode;
2958  }
2959  break;
2960  case T_PlaceHolderVar:
2961  {
2962  PlaceHolderVar *phv = (PlaceHolderVar *) node;
2963  PlaceHolderVar *newnode;
2964 
2965  FLATCOPY(newnode, phv, PlaceHolderVar);
2966  MUTATE(newnode->phexpr, phv->phexpr, Expr *);
2967  /* Assume we need not copy the relids bitmapset */
2968  return (Node *) newnode;
2969  }
2970  break;
2971  case T_InferenceElem:
2972  {
2973  InferenceElem *inferenceelemdexpr = (InferenceElem *) node;
2974  InferenceElem *newnode;
2975 
2976  FLATCOPY(newnode, inferenceelemdexpr, InferenceElem);
2977  MUTATE(newnode->expr, newnode->expr, Node *);
2978  return (Node *) newnode;
2979  }
2980  break;
2981  case T_AppendRelInfo:
2982  {
2983  AppendRelInfo *appinfo = (AppendRelInfo *) node;
2984  AppendRelInfo *newnode;
2985 
2986  FLATCOPY(newnode, appinfo, AppendRelInfo);
2987  MUTATE(newnode->translated_vars, appinfo->translated_vars, List *);
2988  return (Node *) newnode;
2989  }
2990  break;
2991  case T_PlaceHolderInfo:
2992  {
2993  PlaceHolderInfo *phinfo = (PlaceHolderInfo *) node;
2994  PlaceHolderInfo *newnode;
2995 
2996  FLATCOPY(newnode, phinfo, PlaceHolderInfo);
2997  MUTATE(newnode->ph_var, phinfo->ph_var, PlaceHolderVar *);
2998  /* Assume we need not copy the relids bitmapsets */
2999  return (Node *) newnode;
3000  }
3001  break;
3002  case T_RangeTblFunction:
3003  {
3004  RangeTblFunction *rtfunc = (RangeTblFunction *) node;
3005  RangeTblFunction *newnode;
3006 
3007  FLATCOPY(newnode, rtfunc, RangeTblFunction);
3008  MUTATE(newnode->funcexpr, rtfunc->funcexpr, Node *);
3009  /* Assume we need not copy the coldef info lists */
3010  return (Node *) newnode;
3011  }
3012  break;
3013  case T_TableSampleClause:
3014  {
3015  TableSampleClause *tsc = (TableSampleClause *) node;
3016  TableSampleClause *newnode;
3017 
3018  FLATCOPY(newnode, tsc, TableSampleClause);
3019  MUTATE(newnode->args, tsc->args, List *);
3020  MUTATE(newnode->repeatable, tsc->repeatable, Expr *);
3021  return (Node *) newnode;
3022  }
3023  break;
3024  case T_TableFunc:
3025  {
3026  TableFunc *tf = (TableFunc *) node;
3027  TableFunc *newnode;
3028 
3029  FLATCOPY(newnode, tf, TableFunc);
3030  MUTATE(newnode->ns_uris, tf->ns_uris, List *);
3031  MUTATE(newnode->docexpr, tf->docexpr, Node *);
3032  MUTATE(newnode->rowexpr, tf->rowexpr, Node *);
3033  MUTATE(newnode->colexprs, tf->colexprs, List *);
3034  MUTATE(newnode->coldefexprs, tf->coldefexprs, List *);
3035  return (Node *) newnode;
3036  }
3037  break;
3038  default:
3039  elog(ERROR, "unrecognized node type: %d",
3040  (int) nodeTag(node));
3041  break;
3042  }
3043  /* can't get here, but keep compiler happy */
3044  return NULL;
3045 }
3046 
3047 
3048 /*
3049  * query_tree_mutator --- initiate modification of a Query's expressions
3050  *
3051  * This routine exists just to reduce the number of places that need to know
3052  * where all the expression subtrees of a Query are. Note it can be used
3053  * for starting a walk at top level of a Query regardless of whether the
3054  * mutator intends to descend into subqueries. It is also useful for
3055  * descending into subqueries within a mutator.
3056  *
3057  * Some callers want to suppress mutating of certain items in the Query,
3058  * typically because they need to process them specially, or don't actually
3059  * want to recurse into subqueries. This is supported by the flags argument,
3060  * which is the bitwise OR of flag values to suppress mutating of
3061  * indicated items. (More flag bits may be added as needed.)
3062  *
3063  * Normally the Query node itself is copied, but some callers want it to be
3064  * modified in-place; they must pass QTW_DONT_COPY_QUERY in flags. All
3065  * modified substructure is safely copied in any case.
3066  */
3067 Query *
3069  Node *(*mutator) (),
3070  void *context,
3071  int flags)
3072 {
3073  Assert(query != NULL && IsA(query, Query));
3074 
3075  if (!(flags & QTW_DONT_COPY_QUERY))
3076  {
3077  Query *newquery;
3078 
3079  FLATCOPY(newquery, query, Query);
3080  query = newquery;
3081  }
3082 
3083  MUTATE(query->targetList, query->targetList, List *);
3084  MUTATE(query->withCheckOptions, query->withCheckOptions, List *);
3085  MUTATE(query->onConflict, query->onConflict, OnConflictExpr *);
3086  MUTATE(query->returningList, query->returningList, List *);
3087  MUTATE(query->jointree, query->jointree, FromExpr *);
3088  MUTATE(query->setOperations, query->setOperations, Node *);
3089  MUTATE(query->havingQual, query->havingQual, Node *);
3090  MUTATE(query->limitOffset, query->limitOffset, Node *);
3091  MUTATE(query->limitCount, query->limitCount, Node *);
3092  if (!(flags & QTW_IGNORE_CTE_SUBQUERIES))
3093  MUTATE(query->cteList, query->cteList, List *);
3094  else /* else copy CTE list as-is */
3095  query->cteList = copyObject(query->cteList);
3096  query->rtable = range_table_mutator(query->rtable,
3097  mutator, context, flags);
3098  return query;
3099 }
3100 
3101 /*
3102  * range_table_mutator is just the part of query_tree_mutator that processes
3103  * a query's rangetable. This is split out since it can be useful on
3104  * its own.
3105  */
3106 List *
3108  Node *(*mutator) (),
3109  void *context,
3110  int flags)
3111 {
3112  List *newrt = NIL;
3113  ListCell *rt;
3114 
3115  foreach(rt, rtable)
3116  {
3117  RangeTblEntry *rte = (RangeTblEntry *) lfirst(rt);
3118  RangeTblEntry *newrte;
3119 
3120  FLATCOPY(newrte, rte, RangeTblEntry);
3121  switch (rte->rtekind)
3122  {
3123  case RTE_RELATION:
3124  MUTATE(newrte->tablesample, rte->tablesample,
3125  TableSampleClause *);
3126  /* we don't bother to copy eref, aliases, etc; OK? */
3127  break;
3128  case RTE_CTE:
3129  case RTE_NAMEDTUPLESTORE:
3130  /* nothing to do */
3131  break;
3132  case RTE_SUBQUERY:
3133  if (!(flags & QTW_IGNORE_RT_SUBQUERIES))
3134  {
3135  CHECKFLATCOPY(newrte->subquery, rte->subquery, Query);
3136  MUTATE(newrte->subquery, newrte->subquery, Query *);
3137  }
3138  else
3139  {
3140  /* else, copy RT subqueries as-is */
3141  newrte->subquery = copyObject(rte->subquery);
3142  }
3143  break;
3144  case RTE_JOIN:
3145  if (!(flags & QTW_IGNORE_JOINALIASES))
3146  MUTATE(newrte->joinaliasvars, rte->joinaliasvars, List *);
3147  else
3148  {
3149  /* else, copy join aliases as-is */
3150  newrte->joinaliasvars = copyObject(rte->joinaliasvars);
3151  }
3152  break;
3153  case RTE_FUNCTION:
3154  MUTATE(newrte->functions, rte->functions, List *);
3155  break;
3156  case RTE_TABLEFUNC:
3157  MUTATE(newrte->tablefunc, rte->tablefunc, TableFunc *);
3158  break;
3159  case RTE_VALUES:
3160  MUTATE(newrte->values_lists, rte->values_lists, List *);
3161  break;
3162  }
3163  MUTATE(newrte->securityQuals, rte->securityQuals, List *);
3164  newrt = lappend(newrt, newrte);
3165  }
3166  return newrt;
3167 }
3168 
3169 /*
3170  * query_or_expression_tree_walker --- hybrid form
3171  *
3172  * This routine will invoke query_tree_walker if called on a Query node,
3173  * else will invoke the walker directly. This is a useful way of starting
3174  * the recursion when the walker's normal change of state is not appropriate
3175  * for the outermost Query node.
3176  */
3177 bool
3179  bool (*walker) (),
3180  void *context,
3181  int flags)
3182 {
3183  if (node && IsA(node, Query))
3184  return query_tree_walker((Query *) node,
3185  walker,
3186  context,
3187  flags);
3188  else
3189  return walker(node, context);
3190 }
3191 
3192 /*
3193  * query_or_expression_tree_mutator --- hybrid form
3194  *
3195  * This routine will invoke query_tree_mutator if called on a Query node,
3196  * else will invoke the mutator directly. This is a useful way of starting
3197  * the recursion when the mutator's normal change of state is not appropriate
3198  * for the outermost Query node.
3199  */
3200 Node *
3202  Node *(*mutator) (),
3203  void *context,
3204  int flags)
3205 {
3206  if (node && IsA(node, Query))
3207  return (Node *) query_tree_mutator((Query *) node,
3208  mutator,
3209  context,
3210  flags);
3211  else
3212  return mutator(node, context);
3213 }
3214 
3215 
3216 /*
3217  * raw_expression_tree_walker --- walk raw parse trees
3218  *
3219  * This has exactly the same API as expression_tree_walker, but instead of
3220  * walking post-analysis parse trees, it knows how to walk the node types
3221  * found in raw grammar output. (There is not currently any need for a
3222  * combined walker, so we keep them separate in the name of efficiency.)
3223  * Unlike expression_tree_walker, there is no special rule about query
3224  * boundaries: we descend to everything that's possibly interesting.
3225  *
3226  * Currently, the node type coverage here extends only to DML statements
3227  * (SELECT/INSERT/UPDATE/DELETE) and nodes that can appear in them, because
3228  * this is used mainly during analysis of CTEs, and only DML statements can
3229  * appear in CTEs.
3230  */
3231 bool
3233  bool (*walker) (),
3234  void *context)
3235 {
3236  ListCell *temp;
3237 
3238  /*
3239  * The walker has already visited the current node, and so we need only
3240  * recurse into any sub-nodes it has.
3241  */
3242  if (node == NULL)
3243  return false;
3244 
3245  /* Guard against stack overflow due to overly complex expressions */
3247 
3248  switch (nodeTag(node))
3249  {
3250  case T_SetToDefault:
3251  case T_CurrentOfExpr:
3252  case T_SQLValueFunction:
3253  case T_Integer:
3254  case T_Float:
3255  case T_String:
3256  case T_BitString:
3257  case T_Null:
3258  case T_ParamRef:
3259  case T_A_Const:
3260  case T_A_Star:
3261  /* primitive node types with no subnodes */
3262  break;
3263  case T_Alias:
3264  /* we assume the colnames list isn't interesting */
3265  break;
3266  case T_RangeVar:
3267  return walker(((RangeVar *) node)->alias, context);
3268  case T_GroupingFunc:
3269  return walker(((GroupingFunc *) node)->args, context);
3270  case T_SubLink:
3271  {
3272  SubLink *sublink = (SubLink *) node;
3273 
3274  if (walker(sublink->testexpr, context))
3275  return true;
3276  /* we assume the operName is not interesting */
3277  if (walker(sublink->subselect, context))
3278  return true;
3279  }
3280  break;
3281  case T_CaseExpr:
3282  {
3283  CaseExpr *caseexpr = (CaseExpr *) node;
3284 
3285  if (walker(caseexpr->arg, context))
3286  return true;
3287  /* we assume walker doesn't care about CaseWhens, either */
3288  foreach(temp, caseexpr->args)
3289  {
3290  CaseWhen *when = lfirst_node(CaseWhen, temp);
3291 
3292  if (walker(when->expr, context))
3293  return true;
3294  if (walker(when->result, context))
3295  return true;
3296  }
3297  if (walker(caseexpr->defresult, context))
3298  return true;
3299  }
3300  break;
3301  case T_RowExpr:
3302  /* Assume colnames isn't interesting */
3303  return walker(((RowExpr *) node)->args, context);
3304  case T_CoalesceExpr:
3305  return walker(((CoalesceExpr *) node)->args, context);
3306  case T_MinMaxExpr:
3307  return walker(((MinMaxExpr *) node)->args, context);
3308  case T_XmlExpr:
3309  {
3310  XmlExpr *xexpr = (XmlExpr *) node;
3311 
3312  if (walker(xexpr->named_args, context))
3313  return true;
3314  /* we assume walker doesn't care about arg_names */
3315  if (walker(xexpr->args, context))
3316  return true;
3317  }
3318  break;
3319  case T_NullTest:
3320  return walker(((NullTest *) node)->arg, context);
3321  case T_BooleanTest:
3322  return walker(((BooleanTest *) node)->arg, context);
3323  case T_JoinExpr:
3324  {
3325  JoinExpr *join = (JoinExpr *) node;
3326 
3327  if (walker(join->larg, context))
3328  return true;
3329  if (walker(join->rarg, context))
3330  return true;
3331  if (walker(join->quals, context))
3332  return true;
3333  if (walker(join->alias, context))
3334  return true;
3335  /* using list is deemed uninteresting */
3336  }
3337  break;
3338  case T_IntoClause:
3339  {
3340  IntoClause *into = (IntoClause *) node;
3341 
3342  if (walker(into->rel, context))
3343  return true;
3344  /* colNames, options are deemed uninteresting */
3345  /* viewQuery should be null in raw parsetree, but check it */
3346  if (walker(into->viewQuery, context))
3347  return true;
3348  }
3349  break;
3350  case T_List:
3351  foreach(temp, (List *) node)
3352  {
3353  if (walker((Node *) lfirst(temp), context))
3354  return true;
3355  }
3356  break;
3357  case T_InsertStmt:
3358  {
3359  InsertStmt *stmt = (InsertStmt *) node;
3360 
3361  if (walker(stmt->relation, context))
3362  return true;
3363  if (walker(stmt->cols, context))
3364  return true;
3365  if (walker(stmt->selectStmt, context))
3366  return true;
3367  if (walker(stmt->onConflictClause, context))
3368  return true;
3369  if (walker(stmt->returningList, context))
3370  return true;
3371  if (walker(stmt->withClause, context))
3372  return true;
3373  }
3374  break;
3375  case T_DeleteStmt:
3376  {
3377  DeleteStmt *stmt = (DeleteStmt *) node;
3378 
3379  if (walker(stmt->relation, context))
3380  return true;
3381  if (walker(stmt->usingClause, context))
3382  return true;
3383  if (walker(stmt->whereClause, context))
3384  return true;
3385  if (walker(stmt->returningList, context))
3386  return true;
3387  if (walker(stmt->withClause, context))
3388  return true;
3389  }
3390  break;
3391  case T_UpdateStmt:
3392  {
3393  UpdateStmt *stmt = (UpdateStmt *) node;
3394 
3395  if (walker(stmt->relation, context))
3396  return true;
3397  if (walker(stmt->targetList, context))
3398  return true;
3399  if (walker(stmt->whereClause, context))
3400  return true;
3401  if (walker(stmt->fromClause, context))
3402  return true;
3403  if (walker(stmt->returningList, context))
3404  return true;
3405  if (walker(stmt->withClause, context))
3406  return true;
3407  }
3408  break;
3409  case T_SelectStmt:
3410  {
3411  SelectStmt *stmt = (SelectStmt *) node;
3412 
3413  if (walker(stmt->distinctClause, context))
3414  return true;
3415  if (walker(stmt->intoClause, context))
3416  return true;
3417  if (walker(stmt->targetList, context))
3418  return true;
3419  if (walker(stmt->fromClause, context))
3420  return true;
3421  if (walker(stmt->whereClause, context))
3422  return true;
3423  if (walker(stmt->groupClause, context))
3424  return true;
3425  if (walker(stmt->havingClause, context))
3426  return true;
3427  if (walker(stmt->windowClause, context))
3428  return true;
3429  if (walker(stmt->valuesLists, context))
3430  return true;
3431  if (walker(stmt->sortClause, context))
3432  return true;
3433  if (walker(stmt->limitOffset, context))
3434  return true;
3435  if (walker(stmt->limitCount, context))
3436  return true;
3437  if (walker(stmt->lockingClause, context))
3438  return true;
3439  if (walker(stmt->withClause, context))
3440  return true;
3441  if (walker(stmt->larg, context))
3442  return true;
3443  if (walker(stmt->rarg, context))
3444  return true;
3445  }
3446  break;
3447  case T_A_Expr:
3448  {
3449  A_Expr *expr = (A_Expr *) node;
3450 
3451  if (walker(expr->lexpr, context))
3452  return true;
3453  if (walker(expr->rexpr, context))
3454  return true;
3455  /* operator name is deemed uninteresting */
3456  }
3457  break;
3458  case T_BoolExpr:
3459  {
3460  BoolExpr *expr = (BoolExpr *) node;
3461 
3462  if (walker(expr->args, context))
3463  return true;
3464  }
3465  break;
3466  case T_ColumnRef:
3467  /* we assume the fields contain nothing interesting */
3468  break;
3469  case T_FuncCall:
3470  {
3471  FuncCall *fcall = (FuncCall *) node;
3472 
3473  if (walker(fcall->args, context))
3474  return true;
3475  if (walker(fcall->agg_order, context))
3476  return true;
3477  if (walker(fcall->agg_filter, context))
3478  return true;
3479  if (walker(fcall->over, context))
3480  return true;
3481  /* function name is deemed uninteresting */
3482  }
3483  break;
3484  case T_NamedArgExpr:
3485  return walker(((NamedArgExpr *) node)->arg, context);
3486  case T_A_Indices:
3487  {
3488  A_Indices *indices = (A_Indices *) node;
3489 
3490  if (walker(indices->lidx, context))
3491  return true;
3492  if (walker(indices->uidx, context))
3493  return true;
3494  }
3495  break;
3496  case T_A_Indirection:
3497  {
3498  A_Indirection *indir = (A_Indirection *) node;
3499 
3500  if (walker(indir->arg, context))
3501  return true;
3502  if (walker(indir->indirection, context))
3503  return true;
3504  }
3505  break;
3506  case T_A_ArrayExpr:
3507  return walker(((A_ArrayExpr *) node)->elements, context);
3508  case T_ResTarget:
3509  {
3510  ResTarget *rt = (ResTarget *) node;
3511 
3512  if (walker(rt->indirection, context))
3513  return true;
3514  if (walker(rt->val, context))
3515  return true;
3516  }
3517  break;
3518  case T_MultiAssignRef:
3519  return walker(((MultiAssignRef *) node)->source, context);
3520  case T_TypeCast:
3521  {
3522  TypeCast *tc = (TypeCast *) node;
3523 
3524  if (walker(tc->arg, context))
3525  return true;
3526  if (walker(tc->typeName, context))
3527  return true;
3528  }
3529  break;
3530  case T_CollateClause:
3531  return walker(((CollateClause *) node)->arg, context);
3532  case T_SortBy:
3533  return walker(((SortBy *) node)->node, context);
3534  case T_WindowDef:
3535  {
3536  WindowDef *wd = (WindowDef *) node;
3537 
3538  if (walker(wd->partitionClause, context))
3539  return true;
3540  if (walker(wd->orderClause, context))
3541  return true;
3542  if (walker(wd->startOffset, context))
3543  return true;
3544  if (walker(wd->endOffset, context))
3545  return true;
3546  }
3547  break;
3548  case T_RangeSubselect:
3549  {
3550  RangeSubselect *rs = (RangeSubselect *) node;
3551 
3552  if (walker(rs->subquery, context))
3553  return true;
3554  if (walker(rs->alias, context))
3555  return true;
3556  }
3557  break;
3558  case T_RangeFunction:
3559  {
3560  RangeFunction *rf = (RangeFunction *) node;
3561 
3562  if (walker(rf->functions, context))
3563  return true;
3564  if (walker(rf->alias, context))
3565  return true;
3566  if (walker(rf->coldeflist, context))
3567  return true;
3568  }
3569  break;
3570  case T_RangeTableSample:
3571  {
3572  RangeTableSample *rts = (RangeTableSample *) node;
3573 
3574  if (walker(rts->relation, context))
3575  return true;
3576  /* method name is deemed uninteresting */
3577  if (walker(rts->args, context))
3578  return true;
3579  if (walker(rts->repeatable, context))
3580  return true;
3581  }
3582  break;
3583  case T_RangeTableFunc:
3584  {
3585  RangeTableFunc *rtf = (RangeTableFunc *) node;
3586 
3587  if (walker(rtf->docexpr, context))
3588  return true;
3589  if (walker(rtf->rowexpr, context))
3590  return true;
3591  if (walker(rtf->namespaces, context))
3592  return true;
3593  if (walker(rtf->columns, context))
3594  return true;
3595  if (walker(rtf->alias, context))
3596  return true;
3597  }
3598  break;
3599  case T_RangeTableFuncCol:
3600  {
3601  RangeTableFuncCol *rtfc = (RangeTableFuncCol *) node;
3602 
3603  if (walker(rtfc->colexpr, context))
3604  return true;
3605  if (walker(rtfc->coldefexpr, context))
3606  return true;
3607  }
3608  break;
3609  case T_TypeName:
3610  {
3611  TypeName *tn = (TypeName *) node;
3612 
3613  if (walker(tn->typmods, context))
3614  return true;
3615  if (walker(tn->arrayBounds, context))
3616  return true;
3617  /* type name itself is deemed uninteresting */
3618  }
3619  break;
3620  case T_ColumnDef:
3621  {
3622  ColumnDef *coldef = (ColumnDef *) node;
3623 
3624  if (walker(coldef->typeName, context))
3625  return true;
3626  if (walker(coldef->raw_default, context))
3627  return true;
3628  if (walker(coldef->collClause, context))
3629  return true;
3630  /* for now, constraints are ignored */
3631  }
3632  break;
3633  case T_IndexElem:
3634  {
3635  IndexElem *indelem = (IndexElem *) node;
3636 
3637  if (walker(indelem->expr, context))
3638  return true;
3639  /* collation and opclass names are deemed uninteresting */
3640  }
3641  break;
3642  case T_GroupingSet:
3643  return walker(((GroupingSet *) node)->content, context);
3644  case T_LockingClause:
3645  return walker(((LockingClause *) node)->lockedRels, context);
3646  case T_XmlSerialize:
3647  {
3648  XmlSerialize *xs = (XmlSerialize *) node;
3649 
3650  if (walker(xs->expr, context))
3651  return true;
3652  if (walker(xs->typeName, context))
3653  return true;
3654  }
3655  break;
3656  case T_WithClause:
3657  return walker(((WithClause *) node)->ctes, context);
3658  case T_InferClause:
3659  {
3660  InferClause *stmt = (InferClause *) node;
3661 
3662  if (walker(stmt->indexElems, context))
3663  return true;
3664  if (walker(stmt->whereClause, context))
3665  return true;
3666  }
3667  break;
3668  case T_OnConflictClause:
3669  {
3670  OnConflictClause *stmt = (OnConflictClause *) node;
3671 
3672  if (walker(stmt->infer, context))
3673  return true;
3674  if (walker(stmt->targetList, context))
3675  return true;
3676  if (walker(stmt->whereClause, context))
3677  return true;
3678  }
3679  break;
3680  case T_CommonTableExpr:
3681  return walker(((CommonTableExpr *) node)->ctequery, context);
3682  default:
3683  elog(ERROR, "unrecognized node type: %d",
3684  (int) nodeTag(node));
3685  break;
3686  }
3687  return false;
3688 }
3689 
3690 /*
3691  * planstate_tree_walker --- walk plan state trees
3692  *
3693  * The walker has already visited the current node, and so we need only
3694  * recurse into any sub-nodes it has.
3695  */
3696 bool
3698  bool (*walker) (),
3699  void *context)
3700 {
3701  Plan *plan = planstate->plan;
3702  ListCell *lc;
3703 
3704  /* initPlan-s */
3705  if (planstate_walk_subplans(planstate->initPlan, walker, context))
3706  return true;
3707 
3708  /* lefttree */
3709  if (outerPlanState(planstate))
3710  {
3711  if (walker(outerPlanState(planstate), context))
3712  return true;
3713  }
3714 
3715  /* righttree */
3716  if (innerPlanState(planstate))
3717  {
3718  if (walker(innerPlanState(planstate), context))
3719  return true;
3720  }
3721 
3722  /* special child plans */
3723  switch (nodeTag(plan))
3724  {
3725  case T_ModifyTable:
3726  if (planstate_walk_members(((ModifyTable *) plan)->plans,
3727  ((ModifyTableState *) planstate)->mt_plans,
3728  walker, context))
3729  return true;
3730  break;
3731  case T_Append:
3732  if (planstate_walk_members(((Append *) plan)->appendplans,
3733  ((AppendState *) planstate)->appendplans,
3734  walker, context))
3735  return true;
3736  break;
3737  case T_MergeAppend:
3738  if (planstate_walk_members(((MergeAppend *) plan)->mergeplans,
3739  ((MergeAppendState *) planstate)->mergeplans,
3740  walker, context))
3741  return true;
3742  break;
3743  case T_BitmapAnd:
3744  if (planstate_walk_members(((BitmapAnd *) plan)->bitmapplans,
3745  ((BitmapAndState *) planstate)->bitmapplans,
3746  walker, context))
3747  return true;
3748  break;
3749  case T_BitmapOr:
3750  if (planstate_walk_members(((BitmapOr *) plan)->bitmapplans,
3751  ((BitmapOrState *) planstate)->bitmapplans,
3752  walker, context))
3753  return true;
3754  break;
3755  case T_SubqueryScan:
3756  if (walker(((SubqueryScanState *) planstate)->subplan, context))
3757  return true;
3758  break;
3759  case T_CustomScan:
3760  foreach(lc, ((CustomScanState *) planstate)->custom_ps)
3761  {
3762  if (walker((PlanState *) lfirst(lc), context))
3763  return true;
3764  }
3765  break;
3766  default:
3767  break;
3768  }
3769 
3770  /* subPlan-s */
3771  if (planstate_walk_subplans(planstate->subPlan, walker, context))
3772  return true;
3773 
3774  return false;
3775 }
3776 
3777 /*
3778  * Walk a list of SubPlans (or initPlans, which also use SubPlan nodes).
3779  */
3780 static bool
3782  bool (*walker) (),
3783  void *context)
3784 {
3785  ListCell *lc;
3786 
3787  foreach(lc, plans)
3788  {
3790 
3791  if (walker(sps->planstate, context))
3792  return true;
3793  }
3794 
3795  return false;
3796 }
3797 
3798 /*
3799  * Walk the constituent plans of a ModifyTable, Append, MergeAppend,
3800  * BitmapAnd, or BitmapOr node.
3801  *
3802  * Note: we don't actually need to examine the Plan list members, but
3803  * we need the list in order to determine the length of the PlanState array.
3804  */
3805 static bool
3807  bool (*walker) (), void *context)
3808 {
3809  int nplans = list_length(plans);
3810  int j;
3811 
3812  for (j = 0; j < nplans; j++)
3813  {
3814  if (walker(planstates[j], context))
3815  return true;
3816  }
3817 
3818  return false;
3819 }
Datum constvalue
Definition: primnodes.h:196
List * aggdistinct
Definition: primnodes.h:303
List * indirection
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Definition: parsenodes.h:350
List * returningList
Definition: parsenodes.h:1473
bool expression_tree_walker(Node *node, bool(*walker)(), void *context)
Definition: nodeFuncs.c:1843
static int list_length(const List *l)
Definition: pg_list.h:89
Oid exprCollation(const Node *expr)
Definition: nodeFuncs.c:720
Node * lidx
Definition: parsenodes.h:382
Expr * arg
Definition: primnodes.h:876
Expr * aggfilter
Definition: primnodes.h:304
TypeName * typeName
Definition: parsenodes.h:640
#define for_each_cell(cell, initcell)
Definition: pg_list.h:169
Node * whereClause
Definition: parsenodes.h:1332
CollateClause * collClause
Definition: parsenodes.h:650
#define BOOLOID
Definition: pg_type.h:288
List * args
Definition: primnodes.h:563
#define nodeTag(nodeptr)
Definition: nodes.h:514
List * groupClause
Definition: parsenodes.h:1511
Oid element_typeid
Definition: primnodes.h:954
CoercionForm coerceformat
Definition: primnodes.h:815
Oid refarraytype
Definition: primnodes.h:399
RTEKind rtekind
Definition: parsenodes.h:944
Definition: nodes.h:286
Node * arbiterWhere
Definition: primnodes.h:1492
List * orderClause
Definition: parsenodes.h:1278
#define QTW_IGNORE_RT_SUBQUERIES
Definition: nodeFuncs.h:20
Definition: nodes.h:283
List * cteList
Definition: parsenodes.h:133
List * arrayBounds
Definition: parsenodes.h:214
Node * setOperations
Definition: parsenodes.h:163
e
Definition: preproc-init.c:82
void exprSetCollation(Node *expr, Oid collation)
Definition: nodeFuncs.c:969
Query * subquery
Definition: parsenodes.h:967
static bool planstate_walk_members(List *plans, PlanState **planstates, bool(*walker)(), void *context)
Definition: nodeFuncs.c:3806
int errmsg(const char *fmt,...)
Definition: elog.c:797
void set_opfuncid(OpExpr *opexpr)
Definition: nodeFuncs.c:1613
RangeVar * rel
Definition: primnodes.h:109
Node * havingClause
Definition: parsenodes.h:1512
#define QTW_IGNORE_RANGE_TABLE
Definition: nodeFuncs.h:24
List * fieldnums
Definition: primnodes.h:770
Oid coalescetype
Definition: primnodes.h:1045
List * onConflictSet
Definition: primnodes.h:1496
Node * expr
Definition: parsenodes.h:749
void * arg
Node * uidx
Definition: parsenodes.h:383
Oid firstColCollation
Definition: primnodes.h:695
Expr * arg
Definition: primnodes.h:908
int location
Definition: primnodes.h:458
Oid opno
Definition: primnodes.h:496
WithClause * withClause
Definition: parsenodes.h:1533
int32 resulttypmod
Definition: primnodes.h:837
#define elog
Definition: elog.h:219
Expr * result
Definition: primnodes.h:921
List * range_table_mutator(List *rtable, Node *(*mutator)(), void *context, int flags)
Definition: nodeFuncs.c:3107
#define copyObject(obj)
Definition: nodes.h:622
List * args
Definition: primnodes.h:502
#define innerPlanState(node)
Definition: execnodes.h:892
Node * havingQual
Definition: parsenodes.h:150
CoercionForm relabelformat
Definition: primnodes.h:795
Expr * defresult
Definition: primnodes.h:910
Expr * expr
Definition: primnodes.h:920
Node * onConflictWhere
Definition: primnodes.h:1497
Definition: pg_list.h:45
bool planstate_tree_walker(PlanState *planstate, bool(*walker)(), void *context)
Definition: nodeFuncs.c:3697
struct TableSampleClause * tablesample
Definition: parsenodes.h:962
void set_sa_opfuncid(ScalarArrayOpExpr *opexpr)
Definition: nodeFuncs.c:1624
int location
Definition: primnodes.h:796
Node * relabel_to_typmod(Node *expr, int32 typmod)
Definition: nodeFuncs.c:588
#define MUTATE(newfield, oldfield, fieldtype)
bool constisnull
Definition: primnodes.h:197
Query * query_tree_mutator(Query *query, Node *(*mutator)(), void *context, int flags)
Definition: nodeFuncs.c:3068
WithClause * withClause
Definition: parsenodes.h:1474
Node * limitCount
Definition: parsenodes.h:1531
Node * whereClause
Definition: parsenodes.h:1510
#define lfirst_oid(lc)
Definition: pg_list.h:108
Expr * refexpr
Definition: primnodes.h:408
bool opretset
Definition: primnodes.h:499
#define QTW_IGNORE_JOINALIASES
Definition: nodeFuncs.h:23
Node * arg
Definition: parsenodes.h:297
Definition: nodes.h:148
Node * strip_implicit_coercions(Node *node)
Definition: nodeFuncs.c:612
List * args
Definition: primnodes.h:710