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rewriteManip.c
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1 /*-------------------------------------------------------------------------
2  *
3  * rewriteManip.c
4  *
5  * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
6  * Portions Copyright (c) 1994, Regents of the University of California
7  *
8  *
9  * IDENTIFICATION
10  * src/backend/rewrite/rewriteManip.c
11  *
12  *-------------------------------------------------------------------------
13  */
14 #include "postgres.h"
15 
16 #include "catalog/pg_type.h"
17 #include "nodes/makefuncs.h"
18 #include "nodes/nodeFuncs.h"
19 #include "nodes/pathnodes.h"
20 #include "nodes/plannodes.h"
21 #include "parser/parse_coerce.h"
22 #include "parser/parse_relation.h"
23 #include "parser/parsetree.h"
24 #include "rewrite/rewriteManip.h"
25 
26 
27 typedef struct
28 {
31 
32 typedef struct
33 {
37 
38 typedef struct
39 {
42 
43 typedef struct
44 {
49 
50 typedef struct
51 {
56 
57 static bool contain_aggs_of_level_walker(Node *node,
59 static bool locate_agg_of_level_walker(Node *node,
61 static bool contain_windowfuncs_walker(Node *node, void *context);
62 static bool locate_windowfunc_walker(Node *node,
63  locate_windowfunc_context *context);
64 static bool checkExprHasSubLink_walker(Node *node, void *context);
65 static Relids offset_relid_set(Relids relids, int offset);
66 static Relids adjust_relid_set(Relids relids, int oldrelid, int newrelid);
71 
72 
73 /*
74  * contain_aggs_of_level -
75  * Check if an expression contains an aggregate function call of a
76  * specified query level.
77  *
78  * The objective of this routine is to detect whether there are aggregates
79  * belonging to the given query level. Aggregates belonging to subqueries
80  * or outer queries do NOT cause a true result. We must recurse into
81  * subqueries to detect outer-reference aggregates that logically belong to
82  * the specified query level.
83  */
84 bool
85 contain_aggs_of_level(Node *node, int levelsup)
86 {
88 
89  context.sublevels_up = levelsup;
90 
91  /*
92  * Must be prepared to start with a Query or a bare expression tree; if
93  * it's a Query, we don't want to increment sublevels_up.
94  */
97  (void *) &context,
98  0);
99 }
100 
101 static bool
104 {
105  if (node == NULL)
106  return false;
107  if (IsA(node, Aggref))
108  {
109  if (((Aggref *) node)->agglevelsup == context->sublevels_up)
110  return true; /* abort the tree traversal and return true */
111  /* else fall through to examine argument */
112  }
113  if (IsA(node, GroupingFunc))
114  {
115  if (((GroupingFunc *) node)->agglevelsup == context->sublevels_up)
116  return true;
117  /* else fall through to examine argument */
118  }
119  if (IsA(node, Query))
120  {
121  /* Recurse into subselects */
122  bool result;
123 
124  context->sublevels_up++;
125  result = query_tree_walker((Query *) node,
127  (void *) context, 0);
128  context->sublevels_up--;
129  return result;
130  }
132  (void *) context);
133 }
134 
135 /*
136  * locate_agg_of_level -
137  * Find the parse location of any aggregate of the specified query level.
138  *
139  * Returns -1 if no such agg is in the querytree, or if they all have
140  * unknown parse location. (The former case is probably caller error,
141  * but we don't bother to distinguish it from the latter case.)
142  *
143  * Note: it might seem appropriate to merge this functionality into
144  * contain_aggs_of_level, but that would complicate that function's API.
145  * Currently, the only uses of this function are for error reporting,
146  * and so shaving cycles probably isn't very important.
147  */
148 int
149 locate_agg_of_level(Node *node, int levelsup)
150 {
152 
153  context.agg_location = -1; /* in case we find nothing */
154  context.sublevels_up = levelsup;
155 
156  /*
157  * Must be prepared to start with a Query or a bare expression tree; if
158  * it's a Query, we don't want to increment sublevels_up.
159  */
162  (void *) &context,
163  0);
164 
165  return context.agg_location;
166 }
167 
168 static bool
171 {
172  if (node == NULL)
173  return false;
174  if (IsA(node, Aggref))
175  {
176  if (((Aggref *) node)->agglevelsup == context->sublevels_up &&
177  ((Aggref *) node)->location >= 0)
178  {
179  context->agg_location = ((Aggref *) node)->location;
180  return true; /* abort the tree traversal and return true */
181  }
182  /* else fall through to examine argument */
183  }
184  if (IsA(node, GroupingFunc))
185  {
186  if (((GroupingFunc *) node)->agglevelsup == context->sublevels_up &&
187  ((GroupingFunc *) node)->location >= 0)
188  {
189  context->agg_location = ((GroupingFunc *) node)->location;
190  return true; /* abort the tree traversal and return true */
191  }
192  }
193  if (IsA(node, Query))
194  {
195  /* Recurse into subselects */
196  bool result;
197 
198  context->sublevels_up++;
199  result = query_tree_walker((Query *) node,
201  (void *) context, 0);
202  context->sublevels_up--;
203  return result;
204  }
206  (void *) context);
207 }
208 
209 /*
210  * contain_windowfuncs -
211  * Check if an expression contains a window function call of the
212  * current query level.
213  */
214 bool
216 {
217  /*
218  * Must be prepared to start with a Query or a bare expression tree; if
219  * it's a Query, we don't want to increment sublevels_up.
220  */
223  NULL,
224  0);
225 }
226 
227 static bool
228 contain_windowfuncs_walker(Node *node, void *context)
229 {
230  if (node == NULL)
231  return false;
232  if (IsA(node, WindowFunc))
233  return true; /* abort the tree traversal and return true */
234  /* Mustn't recurse into subselects */
236  (void *) context);
237 }
238 
239 /*
240  * locate_windowfunc -
241  * Find the parse location of any windowfunc of the current query level.
242  *
243  * Returns -1 if no such windowfunc is in the querytree, or if they all have
244  * unknown parse location. (The former case is probably caller error,
245  * but we don't bother to distinguish it from the latter case.)
246  *
247  * Note: it might seem appropriate to merge this functionality into
248  * contain_windowfuncs, but that would complicate that function's API.
249  * Currently, the only uses of this function are for error reporting,
250  * and so shaving cycles probably isn't very important.
251  */
252 int
254 {
256 
257  context.win_location = -1; /* in case we find nothing */
258 
259  /*
260  * Must be prepared to start with a Query or a bare expression tree; if
261  * it's a Query, we don't want to increment sublevels_up.
262  */
265  (void *) &context,
266  0);
267 
268  return context.win_location;
269 }
270 
271 static bool
273 {
274  if (node == NULL)
275  return false;
276  if (IsA(node, WindowFunc))
277  {
278  if (((WindowFunc *) node)->location >= 0)
279  {
280  context->win_location = ((WindowFunc *) node)->location;
281  return true; /* abort the tree traversal and return true */
282  }
283  /* else fall through to examine argument */
284  }
285  /* Mustn't recurse into subselects */
287  (void *) context);
288 }
289 
290 /*
291  * checkExprHasSubLink -
292  * Check if an expression contains a SubLink.
293  */
294 bool
296 {
297  /*
298  * If a Query is passed, examine it --- but we should not recurse into
299  * sub-Queries that are in its rangetable or CTE list.
300  */
303  NULL,
305 }
306 
307 static bool
308 checkExprHasSubLink_walker(Node *node, void *context)
309 {
310  if (node == NULL)
311  return false;
312  if (IsA(node, SubLink))
313  return true; /* abort the tree traversal and return true */
314  return expression_tree_walker(node, checkExprHasSubLink_walker, context);
315 }
316 
317 /*
318  * Check for MULTIEXPR Param within expression tree
319  *
320  * We intentionally don't descend into SubLinks: only Params at the current
321  * query level are of interest.
322  */
323 static bool
324 contains_multiexpr_param(Node *node, void *context)
325 {
326  if (node == NULL)
327  return false;
328  if (IsA(node, Param))
329  {
330  if (((Param *) node)->paramkind == PARAM_MULTIEXPR)
331  return true; /* abort the tree traversal and return true */
332  return false;
333  }
334  return expression_tree_walker(node, contains_multiexpr_param, context);
335 }
336 
337 /*
338  * CombineRangeTables
339  * Adds the RTEs of 'src_rtable' into 'dst_rtable'
340  *
341  * This also adds the RTEPermissionInfos of 'src_perminfos' (belonging to the
342  * RTEs in 'src_rtable') into *dst_perminfos and also updates perminfoindex of
343  * the RTEs in 'src_rtable' to now point to the perminfos' indexes in
344  * *dst_perminfos.
345  *
346  * Note that this changes both 'dst_rtable' and 'dst_perminfo' destructively,
347  * so the caller should have better passed safe-to-modify copies.
348  */
349 void
350 CombineRangeTables(List **dst_rtable, List **dst_perminfos,
351  List *src_rtable, List *src_perminfos)
352 {
353  ListCell *l;
354  int offset = list_length(*dst_perminfos);
355 
356  if (offset > 0)
357  {
358  foreach(l, src_rtable)
359  {
361 
362  if (rte->perminfoindex > 0)
363  rte->perminfoindex += offset;
364  }
365  }
366 
367  *dst_perminfos = list_concat(*dst_perminfos, src_perminfos);
368  *dst_rtable = list_concat(*dst_rtable, src_rtable);
369 }
370 
371 /*
372  * OffsetVarNodes - adjust Vars when appending one query's RT to another
373  *
374  * Find all Var nodes in the given tree with varlevelsup == sublevels_up,
375  * and increment their varno fields (rangetable indexes) by 'offset'.
376  * The varnosyn fields are adjusted similarly. Also, adjust other nodes
377  * that contain rangetable indexes, such as RangeTblRef and JoinExpr.
378  *
379  * NOTE: although this has the form of a walker, we cheat and modify the
380  * nodes in-place. The given expression tree should have been copied
381  * earlier to ensure that no unwanted side-effects occur!
382  */
383 
384 typedef struct
385 {
386  int offset;
389 
390 static bool
392 {
393  if (node == NULL)
394  return false;
395  if (IsA(node, Var))
396  {
397  Var *var = (Var *) node;
398 
399  if (var->varlevelsup == context->sublevels_up)
400  {
401  var->varno += context->offset;
402  var->varnullingrels = offset_relid_set(var->varnullingrels,
403  context->offset);
404  if (var->varnosyn > 0)
405  var->varnosyn += context->offset;
406  }
407  return false;
408  }
409  if (IsA(node, CurrentOfExpr))
410  {
411  CurrentOfExpr *cexpr = (CurrentOfExpr *) node;
412 
413  if (context->sublevels_up == 0)
414  cexpr->cvarno += context->offset;
415  return false;
416  }
417  if (IsA(node, RangeTblRef))
418  {
419  RangeTblRef *rtr = (RangeTblRef *) node;
420 
421  if (context->sublevels_up == 0)
422  rtr->rtindex += context->offset;
423  /* the subquery itself is visited separately */
424  return false;
425  }
426  if (IsA(node, JoinExpr))
427  {
428  JoinExpr *j = (JoinExpr *) node;
429 
430  if (j->rtindex && context->sublevels_up == 0)
431  j->rtindex += context->offset;
432  /* fall through to examine children */
433  }
434  if (IsA(node, PlaceHolderVar))
435  {
436  PlaceHolderVar *phv = (PlaceHolderVar *) node;
437 
438  if (phv->phlevelsup == context->sublevels_up)
439  {
440  phv->phrels = offset_relid_set(phv->phrels,
441  context->offset);
443  context->offset);
444  }
445  /* fall through to examine children */
446  }
447  if (IsA(node, AppendRelInfo))
448  {
449  AppendRelInfo *appinfo = (AppendRelInfo *) node;
450 
451  if (context->sublevels_up == 0)
452  {
453  appinfo->parent_relid += context->offset;
454  appinfo->child_relid += context->offset;
455  }
456  /* fall through to examine children */
457  }
458  /* Shouldn't need to handle other planner auxiliary nodes here */
459  Assert(!IsA(node, PlanRowMark));
460  Assert(!IsA(node, SpecialJoinInfo));
461  Assert(!IsA(node, PlaceHolderInfo));
462  Assert(!IsA(node, MinMaxAggInfo));
463 
464  if (IsA(node, Query))
465  {
466  /* Recurse into subselects */
467  bool result;
468 
469  context->sublevels_up++;
470  result = query_tree_walker((Query *) node, OffsetVarNodes_walker,
471  (void *) context, 0);
472  context->sublevels_up--;
473  return result;
474  }
476  (void *) context);
477 }
478 
479 void
480 OffsetVarNodes(Node *node, int offset, int sublevels_up)
481 {
482  OffsetVarNodes_context context;
483 
484  context.offset = offset;
485  context.sublevels_up = sublevels_up;
486 
487  /*
488  * Must be prepared to start with a Query or a bare expression tree; if
489  * it's a Query, go straight to query_tree_walker to make sure that
490  * sublevels_up doesn't get incremented prematurely.
491  */
492  if (node && IsA(node, Query))
493  {
494  Query *qry = (Query *) node;
495 
496  /*
497  * If we are starting at a Query, and sublevels_up is zero, then we
498  * must also fix rangetable indexes in the Query itself --- namely
499  * resultRelation, exclRelIndex and rowMarks entries. sublevels_up
500  * cannot be zero when recursing into a subquery, so there's no need
501  * to have the same logic inside OffsetVarNodes_walker.
502  */
503  if (sublevels_up == 0)
504  {
505  ListCell *l;
506 
507  if (qry->resultRelation)
508  qry->resultRelation += offset;
509 
510  if (qry->onConflict && qry->onConflict->exclRelIndex)
511  qry->onConflict->exclRelIndex += offset;
512 
513  foreach(l, qry->rowMarks)
514  {
515  RowMarkClause *rc = (RowMarkClause *) lfirst(l);
516 
517  rc->rti += offset;
518  }
519  }
521  (void *) &context, 0);
522  }
523  else
524  OffsetVarNodes_walker(node, &context);
525 }
526 
527 static Relids
528 offset_relid_set(Relids relids, int offset)
529 {
530  Relids result = NULL;
531  int rtindex;
532 
533  rtindex = -1;
534  while ((rtindex = bms_next_member(relids, rtindex)) >= 0)
535  result = bms_add_member(result, rtindex + offset);
536  return result;
537 }
538 
539 /*
540  * ChangeVarNodes - adjust Var nodes for a specific change of RT index
541  *
542  * Find all Var nodes in the given tree belonging to a specific relation
543  * (identified by sublevels_up and rt_index), and change their varno fields
544  * to 'new_index'. The varnosyn fields are changed too. Also, adjust other
545  * nodes that contain rangetable indexes, such as RangeTblRef and JoinExpr.
546  *
547  * NOTE: although this has the form of a walker, we cheat and modify the
548  * nodes in-place. The given expression tree should have been copied
549  * earlier to ensure that no unwanted side-effects occur!
550  */
551 
552 typedef struct
553 {
554  int rt_index;
558 
559 static bool
561 {
562  if (node == NULL)
563  return false;
564  if (IsA(node, Var))
565  {
566  Var *var = (Var *) node;
567 
568  if (var->varlevelsup == context->sublevels_up)
569  {
570  if (var->varno == context->rt_index)
571  var->varno = context->new_index;
572  var->varnullingrels = adjust_relid_set(var->varnullingrels,
573  context->rt_index,
574  context->new_index);
575  if (var->varnosyn == context->rt_index)
576  var->varnosyn = context->new_index;
577  }
578  return false;
579  }
580  if (IsA(node, CurrentOfExpr))
581  {
582  CurrentOfExpr *cexpr = (CurrentOfExpr *) node;
583 
584  if (context->sublevels_up == 0 &&
585  cexpr->cvarno == context->rt_index)
586  cexpr->cvarno = context->new_index;
587  return false;
588  }
589  if (IsA(node, RangeTblRef))
590  {
591  RangeTblRef *rtr = (RangeTblRef *) node;
592 
593  if (context->sublevels_up == 0 &&
594  rtr->rtindex == context->rt_index)
595  rtr->rtindex = context->new_index;
596  /* the subquery itself is visited separately */
597  return false;
598  }
599  if (IsA(node, JoinExpr))
600  {
601  JoinExpr *j = (JoinExpr *) node;
602 
603  if (context->sublevels_up == 0 &&
604  j->rtindex == context->rt_index)
605  j->rtindex = context->new_index;
606  /* fall through to examine children */
607  }
608  if (IsA(node, PlaceHolderVar))
609  {
610  PlaceHolderVar *phv = (PlaceHolderVar *) node;
611 
612  if (phv->phlevelsup == context->sublevels_up)
613  {
614  phv->phrels = adjust_relid_set(phv->phrels,
615  context->rt_index,
616  context->new_index);
618  context->rt_index,
619  context->new_index);
620  }
621  /* fall through to examine children */
622  }
623  if (IsA(node, PlanRowMark))
624  {
625  PlanRowMark *rowmark = (PlanRowMark *) node;
626 
627  if (context->sublevels_up == 0)
628  {
629  if (rowmark->rti == context->rt_index)
630  rowmark->rti = context->new_index;
631  if (rowmark->prti == context->rt_index)
632  rowmark->prti = context->new_index;
633  }
634  return false;
635  }
636  if (IsA(node, AppendRelInfo))
637  {
638  AppendRelInfo *appinfo = (AppendRelInfo *) node;
639 
640  if (context->sublevels_up == 0)
641  {
642  if (appinfo->parent_relid == context->rt_index)
643  appinfo->parent_relid = context->new_index;
644  if (appinfo->child_relid == context->rt_index)
645  appinfo->child_relid = context->new_index;
646  }
647  /* fall through to examine children */
648  }
649  /* Shouldn't need to handle other planner auxiliary nodes here */
650  Assert(!IsA(node, SpecialJoinInfo));
651  Assert(!IsA(node, PlaceHolderInfo));
652  Assert(!IsA(node, MinMaxAggInfo));
653 
654  if (IsA(node, Query))
655  {
656  /* Recurse into subselects */
657  bool result;
658 
659  context->sublevels_up++;
660  result = query_tree_walker((Query *) node, ChangeVarNodes_walker,
661  (void *) context, 0);
662  context->sublevels_up--;
663  return result;
664  }
666  (void *) context);
667 }
668 
669 void
670 ChangeVarNodes(Node *node, int rt_index, int new_index, int sublevels_up)
671 {
672  ChangeVarNodes_context context;
673 
674  context.rt_index = rt_index;
675  context.new_index = new_index;
676  context.sublevels_up = sublevels_up;
677 
678  /*
679  * Must be prepared to start with a Query or a bare expression tree; if
680  * it's a Query, go straight to query_tree_walker to make sure that
681  * sublevels_up doesn't get incremented prematurely.
682  */
683  if (node && IsA(node, Query))
684  {
685  Query *qry = (Query *) node;
686 
687  /*
688  * If we are starting at a Query, and sublevels_up is zero, then we
689  * must also fix rangetable indexes in the Query itself --- namely
690  * resultRelation and rowMarks entries. sublevels_up cannot be zero
691  * when recursing into a subquery, so there's no need to have the same
692  * logic inside ChangeVarNodes_walker.
693  */
694  if (sublevels_up == 0)
695  {
696  ListCell *l;
697 
698  if (qry->resultRelation == rt_index)
699  qry->resultRelation = new_index;
700 
701  /* this is unlikely to ever be used, but ... */
702  if (qry->onConflict && qry->onConflict->exclRelIndex == rt_index)
703  qry->onConflict->exclRelIndex = new_index;
704 
705  foreach(l, qry->rowMarks)
706  {
707  RowMarkClause *rc = (RowMarkClause *) lfirst(l);
708 
709  if (rc->rti == rt_index)
710  rc->rti = new_index;
711  }
712  }
714  (void *) &context, 0);
715  }
716  else
717  ChangeVarNodes_walker(node, &context);
718 }
719 
720 /*
721  * Substitute newrelid for oldrelid in a Relid set
722  */
723 static Relids
724 adjust_relid_set(Relids relids, int oldrelid, int newrelid)
725 {
726  if (bms_is_member(oldrelid, relids))
727  {
728  /* Ensure we have a modifiable copy */
729  relids = bms_copy(relids);
730  /* Remove old, add new */
731  relids = bms_del_member(relids, oldrelid);
732  relids = bms_add_member(relids, newrelid);
733  }
734  return relids;
735 }
736 
737 /*
738  * IncrementVarSublevelsUp - adjust Var nodes when pushing them down in tree
739  *
740  * Find all Var nodes in the given tree having varlevelsup >= min_sublevels_up,
741  * and add delta_sublevels_up to their varlevelsup value. This is needed when
742  * an expression that's correct for some nesting level is inserted into a
743  * subquery. Ordinarily the initial call has min_sublevels_up == 0 so that
744  * all Vars are affected. The point of min_sublevels_up is that we can
745  * increment it when we recurse into a sublink, so that local variables in
746  * that sublink are not affected, only outer references to vars that belong
747  * to the expression's original query level or parents thereof.
748  *
749  * Likewise for other nodes containing levelsup fields, such as Aggref.
750  *
751  * NOTE: although this has the form of a walker, we cheat and modify the
752  * Var nodes in-place. The given expression tree should have been copied
753  * earlier to ensure that no unwanted side-effects occur!
754  */
755 
756 typedef struct
757 {
761 
762 static bool
765 {
766  if (node == NULL)
767  return false;
768  if (IsA(node, Var))
769  {
770  Var *var = (Var *) node;
771 
772  if (var->varlevelsup >= context->min_sublevels_up)
773  var->varlevelsup += context->delta_sublevels_up;
774  return false; /* done here */
775  }
776  if (IsA(node, CurrentOfExpr))
777  {
778  /* this should not happen */
779  if (context->min_sublevels_up == 0)
780  elog(ERROR, "cannot push down CurrentOfExpr");
781  return false;
782  }
783  if (IsA(node, Aggref))
784  {
785  Aggref *agg = (Aggref *) node;
786 
787  if (agg->agglevelsup >= context->min_sublevels_up)
788  agg->agglevelsup += context->delta_sublevels_up;
789  /* fall through to recurse into argument */
790  }
791  if (IsA(node, GroupingFunc))
792  {
793  GroupingFunc *grp = (GroupingFunc *) node;
794 
795  if (grp->agglevelsup >= context->min_sublevels_up)
796  grp->agglevelsup += context->delta_sublevels_up;
797  /* fall through to recurse into argument */
798  }
799  if (IsA(node, PlaceHolderVar))
800  {
801  PlaceHolderVar *phv = (PlaceHolderVar *) node;
802 
803  if (phv->phlevelsup >= context->min_sublevels_up)
804  phv->phlevelsup += context->delta_sublevels_up;
805  /* fall through to recurse into argument */
806  }
807  if (IsA(node, RangeTblEntry))
808  {
809  RangeTblEntry *rte = (RangeTblEntry *) node;
810 
811  if (rte->rtekind == RTE_CTE)
812  {
813  if (rte->ctelevelsup >= context->min_sublevels_up)
814  rte->ctelevelsup += context->delta_sublevels_up;
815  }
816  return false; /* allow range_table_walker to continue */
817  }
818  if (IsA(node, Query))
819  {
820  /* Recurse into subselects */
821  bool result;
822 
823  context->min_sublevels_up++;
824  result = query_tree_walker((Query *) node,
826  (void *) context,
828  context->min_sublevels_up--;
829  return result;
830  }
832  (void *) context);
833 }
834 
835 void
836 IncrementVarSublevelsUp(Node *node, int delta_sublevels_up,
837  int min_sublevels_up)
838 {
840 
841  context.delta_sublevels_up = delta_sublevels_up;
842  context.min_sublevels_up = min_sublevels_up;
843 
844  /*
845  * Must be prepared to start with a Query or a bare expression tree; if
846  * it's a Query, we don't want to increment sublevels_up.
847  */
850  (void *) &context,
852 }
853 
854 /*
855  * IncrementVarSublevelsUp_rtable -
856  * Same as IncrementVarSublevelsUp, but to be invoked on a range table.
857  */
858 void
859 IncrementVarSublevelsUp_rtable(List *rtable, int delta_sublevels_up,
860  int min_sublevels_up)
861 {
863 
864  context.delta_sublevels_up = delta_sublevels_up;
865  context.min_sublevels_up = min_sublevels_up;
866 
867  range_table_walker(rtable,
869  (void *) &context,
871 }
872 
873 
874 /*
875  * rangeTableEntry_used - detect whether an RTE is referenced somewhere
876  * in var nodes or join or setOp trees of a query or expression.
877  */
878 
879 typedef struct
880 {
881  int rt_index;
884 
885 static bool
888 {
889  if (node == NULL)
890  return false;
891  if (IsA(node, Var))
892  {
893  Var *var = (Var *) node;
894 
895  if (var->varlevelsup == context->sublevels_up &&
896  (var->varno == context->rt_index ||
897  bms_is_member(context->rt_index, var->varnullingrels)))
898  return true;
899  return false;
900  }
901  if (IsA(node, CurrentOfExpr))
902  {
903  CurrentOfExpr *cexpr = (CurrentOfExpr *) node;
904 
905  if (context->sublevels_up == 0 &&
906  cexpr->cvarno == context->rt_index)
907  return true;
908  return false;
909  }
910  if (IsA(node, RangeTblRef))
911  {
912  RangeTblRef *rtr = (RangeTblRef *) node;
913 
914  if (rtr->rtindex == context->rt_index &&
915  context->sublevels_up == 0)
916  return true;
917  /* the subquery itself is visited separately */
918  return false;
919  }
920  if (IsA(node, JoinExpr))
921  {
922  JoinExpr *j = (JoinExpr *) node;
923 
924  if (j->rtindex == context->rt_index &&
925  context->sublevels_up == 0)
926  return true;
927  /* fall through to examine children */
928  }
929  /* Shouldn't need to handle planner auxiliary nodes here */
930  Assert(!IsA(node, PlaceHolderVar));
931  Assert(!IsA(node, PlanRowMark));
932  Assert(!IsA(node, SpecialJoinInfo));
933  Assert(!IsA(node, AppendRelInfo));
934  Assert(!IsA(node, PlaceHolderInfo));
935  Assert(!IsA(node, MinMaxAggInfo));
936 
937  if (IsA(node, Query))
938  {
939  /* Recurse into subselects */
940  bool result;
941 
942  context->sublevels_up++;
944  (void *) context, 0);
945  context->sublevels_up--;
946  return result;
947  }
949  (void *) context);
950 }
951 
952 bool
953 rangeTableEntry_used(Node *node, int rt_index, int sublevels_up)
954 {
956 
957  context.rt_index = rt_index;
958  context.sublevels_up = sublevels_up;
959 
960  /*
961  * Must be prepared to start with a Query or a bare expression tree; if
962  * it's a Query, we don't want to increment sublevels_up.
963  */
966  (void *) &context,
967  0);
968 }
969 
970 
971 /*
972  * If the given Query is an INSERT ... SELECT construct, extract and
973  * return the sub-Query node that represents the SELECT part. Otherwise
974  * return the given Query.
975  *
976  * If subquery_ptr is not NULL, then *subquery_ptr is set to the location
977  * of the link to the SELECT subquery inside parsetree, or NULL if not an
978  * INSERT ... SELECT.
979  *
980  * This is a hack needed because transformations on INSERT ... SELECTs that
981  * appear in rule actions should be applied to the source SELECT, not to the
982  * INSERT part. Perhaps this can be cleaned up with redesigned querytrees.
983  */
984 Query *
985 getInsertSelectQuery(Query *parsetree, Query ***subquery_ptr)
986 {
987  Query *selectquery;
988  RangeTblEntry *selectrte;
989  RangeTblRef *rtr;
990 
991  if (subquery_ptr)
992  *subquery_ptr = NULL;
993 
994  if (parsetree == NULL)
995  return parsetree;
996  if (parsetree->commandType != CMD_INSERT)
997  return parsetree;
998 
999  /*
1000  * Currently, this is ONLY applied to rule-action queries, and so we
1001  * expect to find the OLD and NEW placeholder entries in the given query.
1002  * If they're not there, it must be an INSERT/SELECT in which they've been
1003  * pushed down to the SELECT.
1004  */
1005  if (list_length(parsetree->rtable) >= 2 &&
1006  strcmp(rt_fetch(PRS2_OLD_VARNO, parsetree->rtable)->eref->aliasname,
1007  "old") == 0 &&
1008  strcmp(rt_fetch(PRS2_NEW_VARNO, parsetree->rtable)->eref->aliasname,
1009  "new") == 0)
1010  return parsetree;
1011  Assert(parsetree->jointree && IsA(parsetree->jointree, FromExpr));
1012  if (list_length(parsetree->jointree->fromlist) != 1)
1013  elog(ERROR, "expected to find SELECT subquery");
1014  rtr = (RangeTblRef *) linitial(parsetree->jointree->fromlist);
1015  if (!IsA(rtr, RangeTblRef))
1016  elog(ERROR, "expected to find SELECT subquery");
1017  selectrte = rt_fetch(rtr->rtindex, parsetree->rtable);
1018  if (!(selectrte->rtekind == RTE_SUBQUERY &&
1019  selectrte->subquery &&
1020  IsA(selectrte->subquery, Query) &&
1021  selectrte->subquery->commandType == CMD_SELECT))
1022  elog(ERROR, "expected to find SELECT subquery");
1023  selectquery = selectrte->subquery;
1024  if (list_length(selectquery->rtable) >= 2 &&
1025  strcmp(rt_fetch(PRS2_OLD_VARNO, selectquery->rtable)->eref->aliasname,
1026  "old") == 0 &&
1027  strcmp(rt_fetch(PRS2_NEW_VARNO, selectquery->rtable)->eref->aliasname,
1028  "new") == 0)
1029  {
1030  if (subquery_ptr)
1031  *subquery_ptr = &(selectrte->subquery);
1032  return selectquery;
1033  }
1034  elog(ERROR, "could not find rule placeholders");
1035  return NULL; /* not reached */
1036 }
1037 
1038 
1039 /*
1040  * Add the given qualifier condition to the query's WHERE clause
1041  */
1042 void
1043 AddQual(Query *parsetree, Node *qual)
1044 {
1045  Node *copy;
1046 
1047  if (qual == NULL)
1048  return;
1049 
1050  if (parsetree->commandType == CMD_UTILITY)
1051  {
1052  /*
1053  * There's noplace to put the qual on a utility statement.
1054  *
1055  * If it's a NOTIFY, silently ignore the qual; this means that the
1056  * NOTIFY will execute, whether or not there are any qualifying rows.
1057  * While clearly wrong, this is much more useful than refusing to
1058  * execute the rule at all, and extra NOTIFY events are harmless for
1059  * typical uses of NOTIFY.
1060  *
1061  * If it isn't a NOTIFY, error out, since unconditional execution of
1062  * other utility stmts is unlikely to be wanted. (This case is not
1063  * currently allowed anyway, but keep the test for safety.)
1064  */
1065  if (parsetree->utilityStmt && IsA(parsetree->utilityStmt, NotifyStmt))
1066  return;
1067  else
1068  ereport(ERROR,
1069  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1070  errmsg("conditional utility statements are not implemented")));
1071  }
1072 
1073  if (parsetree->setOperations != NULL)
1074  {
1075  /*
1076  * There's noplace to put the qual on a setop statement, either. (This
1077  * could be fixed, but right now the planner simply ignores any qual
1078  * condition on a setop query.)
1079  */
1080  ereport(ERROR,
1081  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1082  errmsg("conditional UNION/INTERSECT/EXCEPT statements are not implemented")));
1083  }
1084 
1085  /* INTERSECT wants the original, but we need to copy - Jan */
1086  copy = copyObject(qual);
1087 
1088  parsetree->jointree->quals = make_and_qual(parsetree->jointree->quals,
1089  copy);
1090 
1091  /*
1092  * We had better not have stuck an aggregate into the WHERE clause.
1093  */
1094  Assert(!contain_aggs_of_level(copy, 0));
1095 
1096  /*
1097  * Make sure query is marked correctly if added qual has sublinks. Need
1098  * not search qual when query is already marked.
1099  */
1100  if (!parsetree->hasSubLinks)
1101  parsetree->hasSubLinks = checkExprHasSubLink(copy);
1102 }
1103 
1104 
1105 /*
1106  * Invert the given clause and add it to the WHERE qualifications of the
1107  * given querytree. Inversion means "x IS NOT TRUE", not just "NOT x",
1108  * else we will do the wrong thing when x evaluates to NULL.
1109  */
1110 void
1111 AddInvertedQual(Query *parsetree, Node *qual)
1112 {
1113  BooleanTest *invqual;
1114 
1115  if (qual == NULL)
1116  return;
1117 
1118  /* Need not copy input qual, because AddQual will... */
1119  invqual = makeNode(BooleanTest);
1120  invqual->arg = (Expr *) qual;
1121  invqual->booltesttype = IS_NOT_TRUE;
1122  invqual->location = -1;
1123 
1124  AddQual(parsetree, (Node *) invqual);
1125 }
1126 
1127 
1128 /*
1129  * add_nulling_relids() finds Vars and PlaceHolderVars that belong to any
1130  * of the target_relids, and adds added_relids to their varnullingrels
1131  * and phnullingrels fields.
1132  */
1133 Node *
1135  const Bitmapset *target_relids,
1136  const Bitmapset *added_relids)
1137 {
1139 
1140  context.target_relids = target_relids;
1141  context.added_relids = added_relids;
1142  context.sublevels_up = 0;
1145  &context,
1146  0);
1147 }
1148 
1149 static Node *
1151  add_nulling_relids_context *context)
1152 {
1153  if (node == NULL)
1154  return NULL;
1155  if (IsA(node, Var))
1156  {
1157  Var *var = (Var *) node;
1158 
1159  if (var->varlevelsup == context->sublevels_up &&
1160  bms_is_member(var->varno, context->target_relids))
1161  {
1162  Relids newnullingrels = bms_union(var->varnullingrels,
1163  context->added_relids);
1164 
1165  /* Copy the Var ... */
1166  var = copyObject(var);
1167  /* ... and replace the copy's varnullingrels field */
1168  var->varnullingrels = newnullingrels;
1169  return (Node *) var;
1170  }
1171  /* Otherwise fall through to copy the Var normally */
1172  }
1173  else if (IsA(node, PlaceHolderVar))
1174  {
1175  PlaceHolderVar *phv = (PlaceHolderVar *) node;
1176 
1177  if (phv->phlevelsup == context->sublevels_up &&
1178  bms_overlap(phv->phrels, context->target_relids))
1179  {
1180  Relids newnullingrels = bms_union(phv->phnullingrels,
1181  context->added_relids);
1182 
1183  /*
1184  * We don't modify the contents of the PHV's expression, only add
1185  * to phnullingrels. This corresponds to assuming that the PHV
1186  * will be evaluated at the same level as before, then perhaps be
1187  * nulled as it bubbles up. Hence, just flat-copy the node ...
1188  */
1189  phv = makeNode(PlaceHolderVar);
1190  memcpy(phv, node, sizeof(PlaceHolderVar));
1191  /* ... and replace the copy's phnullingrels field */
1192  phv->phnullingrels = newnullingrels;
1193  return (Node *) phv;
1194  }
1195  /* Otherwise fall through to copy the PlaceHolderVar normally */
1196  }
1197  else if (IsA(node, Query))
1198  {
1199  /* Recurse into RTE or sublink subquery */
1200  Query *newnode;
1201 
1202  context->sublevels_up++;
1203  newnode = query_tree_mutator((Query *) node,
1205  (void *) context,
1206  0);
1207  context->sublevels_up--;
1208  return (Node *) newnode;
1209  }
1211  (void *) context);
1212 }
1213 
1214 /*
1215  * remove_nulling_relids() removes mentions of the specified RT index(es)
1216  * in Var.varnullingrels and PlaceHolderVar.phnullingrels fields within
1217  * the given expression, except in nodes belonging to rels listed in
1218  * except_relids.
1219  */
1220 Node *
1222  const Bitmapset *removable_relids,
1223  const Bitmapset *except_relids)
1224 {
1226 
1227  context.removable_relids = removable_relids;
1228  context.except_relids = except_relids;
1229  context.sublevels_up = 0;
1232  &context,
1233  0);
1234 }
1235 
1236 static Node *
1239 {
1240  if (node == NULL)
1241  return NULL;
1242  if (IsA(node, Var))
1243  {
1244  Var *var = (Var *) node;
1245 
1246  if (var->varlevelsup == context->sublevels_up &&
1247  !bms_is_member(var->varno, context->except_relids) &&
1248  bms_overlap(var->varnullingrels, context->removable_relids))
1249  {
1250  /* Copy the Var ... */
1251  var = copyObject(var);
1252  /* ... and replace the copy's varnullingrels field */
1253  var->varnullingrels = bms_difference(var->varnullingrels,
1254  context->removable_relids);
1255  return (Node *) var;
1256  }
1257  /* Otherwise fall through to copy the Var normally */
1258  }
1259  else if (IsA(node, PlaceHolderVar))
1260  {
1261  PlaceHolderVar *phv = (PlaceHolderVar *) node;
1262 
1263  if (phv->phlevelsup == context->sublevels_up &&
1264  !bms_overlap(phv->phrels, context->except_relids))
1265  {
1266  /*
1267  * Note: it might seem desirable to remove the PHV altogether if
1268  * phnullingrels goes to empty. Currently we dare not do that
1269  * because we use PHVs in some cases to enforce separate identity
1270  * of subexpressions; see wrap_non_vars usages in prepjointree.c.
1271  */
1272  /* Copy the PlaceHolderVar and mutate what's below ... */
1273  phv = (PlaceHolderVar *)
1276  (void *) context);
1277  /* ... and replace the copy's phnullingrels field */
1279  context->removable_relids);
1280  /* We must also update phrels, if it contains a removable RTI */
1281  phv->phrels = bms_difference(phv->phrels,
1282  context->removable_relids);
1283  Assert(!bms_is_empty(phv->phrels));
1284  return (Node *) phv;
1285  }
1286  /* Otherwise fall through to copy the PlaceHolderVar normally */
1287  }
1288  else if (IsA(node, Query))
1289  {
1290  /* Recurse into RTE or sublink subquery */
1291  Query *newnode;
1292 
1293  context->sublevels_up++;
1294  newnode = query_tree_mutator((Query *) node,
1296  (void *) context,
1297  0);
1298  context->sublevels_up--;
1299  return (Node *) newnode;
1300  }
1302  (void *) context);
1303 }
1304 
1305 
1306 /*
1307  * replace_rte_variables() finds all Vars in an expression tree
1308  * that reference a particular RTE, and replaces them with substitute
1309  * expressions obtained from a caller-supplied callback function.
1310  *
1311  * When invoking replace_rte_variables on a portion of a Query, pass the
1312  * address of the containing Query's hasSubLinks field as outer_hasSubLinks.
1313  * Otherwise, pass NULL, but inserting a SubLink into a non-Query expression
1314  * will then cause an error.
1315  *
1316  * Note: the business with inserted_sublink is needed to update hasSubLinks
1317  * in subqueries when the replacement adds a subquery inside a subquery.
1318  * Messy, isn't it? We do not need to do similar pushups for hasAggs,
1319  * because it isn't possible for this transformation to insert a level-zero
1320  * aggregate reference into a subquery --- it could only insert outer aggs.
1321  * Likewise for hasWindowFuncs.
1322  *
1323  * Note: usually, we'd not expose the mutator function or context struct
1324  * for a function like this. We do so because callbacks often find it
1325  * convenient to recurse directly to the mutator on sub-expressions of
1326  * what they will return.
1327  */
1328 Node *
1329 replace_rte_variables(Node *node, int target_varno, int sublevels_up,
1331  void *callback_arg,
1332  bool *outer_hasSubLinks)
1333 {
1334  Node *result;
1336 
1337  context.callback = callback;
1338  context.callback_arg = callback_arg;
1339  context.target_varno = target_varno;
1340  context.sublevels_up = sublevels_up;
1341 
1342  /*
1343  * We try to initialize inserted_sublink to true if there is no need to
1344  * detect new sublinks because the query already has some.
1345  */
1346  if (node && IsA(node, Query))
1347  context.inserted_sublink = ((Query *) node)->hasSubLinks;
1348  else if (outer_hasSubLinks)
1349  context.inserted_sublink = *outer_hasSubLinks;
1350  else
1351  context.inserted_sublink = false;
1352 
1353  /*
1354  * Must be prepared to start with a Query or a bare expression tree; if
1355  * it's a Query, we don't want to increment sublevels_up.
1356  */
1357  result = query_or_expression_tree_mutator(node,
1359  (void *) &context,
1360  0);
1361 
1362  if (context.inserted_sublink)
1363  {
1364  if (result && IsA(result, Query))
1365  ((Query *) result)->hasSubLinks = true;
1366  else if (outer_hasSubLinks)
1367  *outer_hasSubLinks = true;
1368  else
1369  elog(ERROR, "replace_rte_variables inserted a SubLink, but has noplace to record it");
1370  }
1371 
1372  return result;
1373 }
1374 
1375 Node *
1378 {
1379  if (node == NULL)
1380  return NULL;
1381  if (IsA(node, Var))
1382  {
1383  Var *var = (Var *) node;
1384 
1385  if (var->varno == context->target_varno &&
1386  var->varlevelsup == context->sublevels_up)
1387  {
1388  /* Found a matching variable, make the substitution */
1389  Node *newnode;
1390 
1391  newnode = context->callback(var, context);
1392  /* Detect if we are adding a sublink to query */
1393  if (!context->inserted_sublink)
1394  context->inserted_sublink = checkExprHasSubLink(newnode);
1395  return newnode;
1396  }
1397  /* otherwise fall through to copy the var normally */
1398  }
1399  else if (IsA(node, CurrentOfExpr))
1400  {
1401  CurrentOfExpr *cexpr = (CurrentOfExpr *) node;
1402 
1403  if (cexpr->cvarno == context->target_varno &&
1404  context->sublevels_up == 0)
1405  {
1406  /*
1407  * We get here if a WHERE CURRENT OF expression turns out to apply
1408  * to a view. Someday we might be able to translate the
1409  * expression to apply to an underlying table of the view, but
1410  * right now it's not implemented.
1411  */
1412  ereport(ERROR,
1413  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1414  errmsg("WHERE CURRENT OF on a view is not implemented")));
1415  }
1416  /* otherwise fall through to copy the expr normally */
1417  }
1418  else if (IsA(node, Query))
1419  {
1420  /* Recurse into RTE subquery or not-yet-planned sublink subquery */
1421  Query *newnode;
1422  bool save_inserted_sublink;
1423 
1424  context->sublevels_up++;
1425  save_inserted_sublink = context->inserted_sublink;
1426  context->inserted_sublink = ((Query *) node)->hasSubLinks;
1427  newnode = query_tree_mutator((Query *) node,
1429  (void *) context,
1430  0);
1431  newnode->hasSubLinks |= context->inserted_sublink;
1432  context->inserted_sublink = save_inserted_sublink;
1433  context->sublevels_up--;
1434  return (Node *) newnode;
1435  }
1437  (void *) context);
1438 }
1439 
1440 
1441 /*
1442  * map_variable_attnos() finds all user-column Vars in an expression tree
1443  * that reference a particular RTE, and adjusts their varattnos according
1444  * to the given mapping array (varattno n is replaced by attno_map[n-1]).
1445  * Vars for system columns are not modified.
1446  *
1447  * A zero in the mapping array represents a dropped column, which should not
1448  * appear in the expression.
1449  *
1450  * If the expression tree contains a whole-row Var for the target RTE,
1451  * *found_whole_row is set to true. In addition, if to_rowtype is
1452  * not InvalidOid, we replace the Var with a Var of that vartype, inserting
1453  * a ConvertRowtypeExpr to map back to the rowtype expected by the expression.
1454  * (Therefore, to_rowtype had better be a child rowtype of the rowtype of the
1455  * RTE we're changing references to.) Callers that don't provide to_rowtype
1456  * should report an error if *found_whole_row is true; we don't do that here
1457  * because we don't know exactly what wording for the error message would
1458  * be most appropriate. The caller will be aware of the context.
1459  *
1460  * This could be built using replace_rte_variables and a callback function,
1461  * but since we don't ever need to insert sublinks, replace_rte_variables is
1462  * overly complicated.
1463  */
1464 
1465 typedef struct
1466 {
1467  int target_varno; /* RTE index to search for */
1468  int sublevels_up; /* (current) nesting depth */
1469  const AttrMap *attno_map; /* map array for user attnos */
1470  Oid to_rowtype; /* change whole-row Vars to this type */
1471  bool *found_whole_row; /* output flag */
1473 
1474 static Node *
1476  map_variable_attnos_context *context)
1477 {
1478  if (node == NULL)
1479  return NULL;
1480  if (IsA(node, Var))
1481  {
1482  Var *var = (Var *) node;
1483 
1484  if (var->varno == context->target_varno &&
1485  var->varlevelsup == context->sublevels_up)
1486  {
1487  /* Found a matching variable, make the substitution */
1488  Var *newvar = (Var *) palloc(sizeof(Var));
1489  int attno = var->varattno;
1490 
1491  *newvar = *var; /* initially copy all fields of the Var */
1492 
1493  if (attno > 0)
1494  {
1495  /* user-defined column, replace attno */
1496  if (attno > context->attno_map->maplen ||
1497  context->attno_map->attnums[attno - 1] == 0)
1498  elog(ERROR, "unexpected varattno %d in expression to be mapped",
1499  attno);
1500  newvar->varattno = context->attno_map->attnums[attno - 1];
1501  /* If the syntactic referent is same RTE, fix it too */
1502  if (newvar->varnosyn == context->target_varno)
1503  newvar->varattnosyn = newvar->varattno;
1504  }
1505  else if (attno == 0)
1506  {
1507  /* whole-row variable, warn caller */
1508  *(context->found_whole_row) = true;
1509 
1510  /* If the caller expects us to convert the Var, do so. */
1511  if (OidIsValid(context->to_rowtype) &&
1512  context->to_rowtype != var->vartype)
1513  {
1514  ConvertRowtypeExpr *r;
1515 
1516  /* This certainly won't work for a RECORD variable. */
1517  Assert(var->vartype != RECORDOID);
1518 
1519  /* Var itself is changed to the requested type. */
1520  newvar->vartype = context->to_rowtype;
1521 
1522  /*
1523  * Add a conversion node on top to convert back to the
1524  * original type expected by the expression.
1525  */
1527  r->arg = (Expr *) newvar;
1528  r->resulttype = var->vartype;
1529  r->convertformat = COERCE_IMPLICIT_CAST;
1530  r->location = -1;
1531 
1532  return (Node *) r;
1533  }
1534  }
1535  return (Node *) newvar;
1536  }
1537  /* otherwise fall through to copy the var normally */
1538  }
1539  else if (IsA(node, ConvertRowtypeExpr))
1540  {
1541  ConvertRowtypeExpr *r = (ConvertRowtypeExpr *) node;
1542  Var *var = (Var *) r->arg;
1543 
1544  /*
1545  * If this is coercing a whole-row Var that we need to convert, then
1546  * just convert the Var without adding an extra ConvertRowtypeExpr.
1547  * Effectively we're simplifying var::parenttype::grandparenttype into
1548  * just var::grandparenttype. This avoids building stacks of CREs if
1549  * this function is applied repeatedly.
1550  */
1551  if (IsA(var, Var) &&
1552  var->varno == context->target_varno &&
1553  var->varlevelsup == context->sublevels_up &&
1554  var->varattno == 0 &&
1555  OidIsValid(context->to_rowtype) &&
1556  context->to_rowtype != var->vartype)
1557  {
1558  ConvertRowtypeExpr *newnode;
1559  Var *newvar = (Var *) palloc(sizeof(Var));
1560 
1561  /* whole-row variable, warn caller */
1562  *(context->found_whole_row) = true;
1563 
1564  *newvar = *var; /* initially copy all fields of the Var */
1565 
1566  /* This certainly won't work for a RECORD variable. */
1567  Assert(var->vartype != RECORDOID);
1568 
1569  /* Var itself is changed to the requested type. */
1570  newvar->vartype = context->to_rowtype;
1571 
1572  newnode = (ConvertRowtypeExpr *) palloc(sizeof(ConvertRowtypeExpr));
1573  *newnode = *r; /* initially copy all fields of the CRE */
1574  newnode->arg = (Expr *) newvar;
1575 
1576  return (Node *) newnode;
1577  }
1578  /* otherwise fall through to process the expression normally */
1579  }
1580  else if (IsA(node, Query))
1581  {
1582  /* Recurse into RTE subquery or not-yet-planned sublink subquery */
1583  Query *newnode;
1584 
1585  context->sublevels_up++;
1586  newnode = query_tree_mutator((Query *) node,
1588  (void *) context,
1589  0);
1590  context->sublevels_up--;
1591  return (Node *) newnode;
1592  }
1594  (void *) context);
1595 }
1596 
1597 Node *
1599  int target_varno, int sublevels_up,
1600  const AttrMap *attno_map,
1601  Oid to_rowtype, bool *found_whole_row)
1602 {
1604 
1605  context.target_varno = target_varno;
1606  context.sublevels_up = sublevels_up;
1607  context.attno_map = attno_map;
1608  context.to_rowtype = to_rowtype;
1609  context.found_whole_row = found_whole_row;
1610 
1611  *found_whole_row = false;
1612 
1613  /*
1614  * Must be prepared to start with a Query or a bare expression tree; if
1615  * it's a Query, we don't want to increment sublevels_up.
1616  */
1619  (void *) &context,
1620  0);
1621 }
1622 
1623 
1624 /*
1625  * ReplaceVarsFromTargetList - replace Vars with items from a targetlist
1626  *
1627  * Vars matching target_varno and sublevels_up are replaced by the
1628  * entry with matching resno from targetlist, if there is one.
1629  *
1630  * If there is no matching resno for such a Var, the action depends on the
1631  * nomatch_option:
1632  * REPLACEVARS_REPORT_ERROR: throw an error
1633  * REPLACEVARS_CHANGE_VARNO: change Var's varno to nomatch_varno
1634  * REPLACEVARS_SUBSTITUTE_NULL: replace Var with a NULL Const of same type
1635  *
1636  * The caller must also provide target_rte, the RTE describing the target
1637  * relation. This is needed to handle whole-row Vars referencing the target.
1638  * We expand such Vars into RowExpr constructs.
1639  *
1640  * outer_hasSubLinks works the same as for replace_rte_variables().
1641  */
1642 
1643 typedef struct
1644 {
1650 
1651 static Node *
1654 {
1656  TargetEntry *tle;
1657 
1658  if (var->varattno == InvalidAttrNumber)
1659  {
1660  /* Must expand whole-tuple reference into RowExpr */
1661  RowExpr *rowexpr;
1662  List *colnames;
1663  List *fields;
1664 
1665  /*
1666  * If generating an expansion for a var of a named rowtype (ie, this
1667  * is a plain relation RTE), then we must include dummy items for
1668  * dropped columns. If the var is RECORD (ie, this is a JOIN), then
1669  * omit dropped columns. In the latter case, attach column names to
1670  * the RowExpr for use of the executor and ruleutils.c.
1671  */
1672  expandRTE(rcon->target_rte,
1673  var->varno, var->varlevelsup, var->location,
1674  (var->vartype != RECORDOID),
1675  &colnames, &fields);
1676  /* Adjust the generated per-field Vars... */
1677  fields = (List *) replace_rte_variables_mutator((Node *) fields,
1678  context);
1679  rowexpr = makeNode(RowExpr);
1680  rowexpr->args = fields;
1681  rowexpr->row_typeid = var->vartype;
1682  rowexpr->row_format = COERCE_IMPLICIT_CAST;
1683  rowexpr->colnames = (var->vartype == RECORDOID) ? colnames : NIL;
1684  rowexpr->location = var->location;
1685 
1686  return (Node *) rowexpr;
1687  }
1688 
1689  /* Normal case referencing one targetlist element */
1690  tle = get_tle_by_resno(rcon->targetlist, var->varattno);
1691 
1692  if (tle == NULL || tle->resjunk)
1693  {
1694  /* Failed to find column in targetlist */
1695  switch (rcon->nomatch_option)
1696  {
1698  /* fall through, throw error below */
1699  break;
1700 
1702  var = (Var *) copyObject(var);
1703  var->varno = rcon->nomatch_varno;
1704  /* we leave the syntactic referent alone */
1705  return (Node *) var;
1706 
1708 
1709  /*
1710  * If Var is of domain type, we should add a CoerceToDomain
1711  * node, in case there is a NOT NULL domain constraint.
1712  */
1713  return coerce_to_domain((Node *) makeNullConst(var->vartype,
1714  var->vartypmod,
1715  var->varcollid),
1716  InvalidOid, -1,
1717  var->vartype,
1720  -1,
1721  false);
1722  }
1723  elog(ERROR, "could not find replacement targetlist entry for attno %d",
1724  var->varattno);
1725  return NULL; /* keep compiler quiet */
1726  }
1727  else
1728  {
1729  /* Make a copy of the tlist item to return */
1730  Expr *newnode = copyObject(tle->expr);
1731 
1732  /* Must adjust varlevelsup if tlist item is from higher query */
1733  if (var->varlevelsup > 0)
1734  IncrementVarSublevelsUp((Node *) newnode, var->varlevelsup, 0);
1735 
1736  /*
1737  * Check to see if the tlist item contains a PARAM_MULTIEXPR Param,
1738  * and throw error if so. This case could only happen when expanding
1739  * an ON UPDATE rule's NEW variable and the referenced tlist item in
1740  * the original UPDATE command is part of a multiple assignment. There
1741  * seems no practical way to handle such cases without multiple
1742  * evaluation of the multiple assignment's sub-select, which would
1743  * create semantic oddities that users of rules would probably prefer
1744  * not to cope with. So treat it as an unimplemented feature.
1745  */
1746  if (contains_multiexpr_param((Node *) newnode, NULL))
1747  ereport(ERROR,
1748  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1749  errmsg("NEW variables in ON UPDATE rules cannot reference columns that are part of a multiple assignment in the subject UPDATE command")));
1750 
1751  return (Node *) newnode;
1752  }
1753 }
1754 
1755 Node *
1757  int target_varno, int sublevels_up,
1758  RangeTblEntry *target_rte,
1759  List *targetlist,
1760  ReplaceVarsNoMatchOption nomatch_option,
1761  int nomatch_varno,
1762  bool *outer_hasSubLinks)
1763 {
1765 
1766  context.target_rte = target_rte;
1767  context.targetlist = targetlist;
1768  context.nomatch_option = nomatch_option;
1769  context.nomatch_varno = nomatch_varno;
1770 
1771  return replace_rte_variables(node, target_varno, sublevels_up,
1773  (void *) &context,
1774  outer_hasSubLinks);
1775 }
#define InvalidAttrNumber
Definition: attnum.h:23
int bms_next_member(const Bitmapset *a, int prevbit)
Definition: bitmapset.c:1039
bool bms_is_member(int x, const Bitmapset *a)
Definition: bitmapset.c:444
Bitmapset * bms_add_member(Bitmapset *a, int x)
Definition: bitmapset.c:755
Bitmapset * bms_union(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:226
Bitmapset * bms_difference(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:298
Bitmapset * bms_del_member(Bitmapset *a, int x)
Definition: bitmapset.c:792
bool bms_overlap(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:511
Bitmapset * bms_copy(const Bitmapset *a)
Definition: bitmapset.c:74
#define bms_is_empty(a)
Definition: bitmapset.h:105
#define OidIsValid(objectId)
Definition: c.h:759
int errcode(int sqlerrcode)
Definition: elog.c:858
int errmsg(const char *fmt,...)
Definition: elog.c:1069
#define ERROR
Definition: elog.h:39
#define ereport(elevel,...)
Definition: elog.h:149
int j
Definition: isn.c:74
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:77
Assert(fmt[strlen(fmt) - 1] !='\n')
List * list_concat(List *list1, const List *list2)
Definition: list.c:560
Const * makeNullConst(Oid consttype, int32 consttypmod, Oid constcollid)
Definition: makefuncs.c:340
Node * make_and_qual(Node *qual1, Node *qual2)
Definition: makefuncs.c:692
void * palloc(Size size)
Definition: mcxt.c:1210
#define expression_tree_mutator(n, m, c)
Definition: nodeFuncs.h:153
#define query_or_expression_tree_mutator(n, m, c, f)
Definition: nodeFuncs.h:171
#define range_table_walker(rt, w, c, f)
Definition: nodeFuncs.h:161
#define query_tree_walker(q, w, c, f)
Definition: nodeFuncs.h:156
#define query_or_expression_tree_walker(n, w, c, f)
Definition: nodeFuncs.h:169
#define expression_tree_walker(n, w, c)
Definition: nodeFuncs.h:151
#define query_tree_mutator(q, m, c, f)
Definition: nodeFuncs.h:158
#define QTW_IGNORE_RC_SUBQUERIES
Definition: nodeFuncs.h:24
#define QTW_EXAMINE_RTES_BEFORE
Definition: nodeFuncs.h:27
#define IsA(nodeptr, _type_)
Definition: nodes.h:179
#define copyObject(obj)
Definition: nodes.h:244
@ CMD_UTILITY
Definition: nodes.h:281
@ CMD_INSERT
Definition: nodes.h:278
@ CMD_SELECT
Definition: nodes.h:276
#define makeNode(_type_)
Definition: nodes.h:176
Node * coerce_to_domain(Node *arg, Oid baseTypeId, int32 baseTypeMod, Oid typeId, CoercionContext ccontext, CoercionForm cformat, int location, bool hideInputCoercion)
Definition: parse_coerce.c:676
TargetEntry * get_tle_by_resno(List *tlist, AttrNumber resno)
void expandRTE(RangeTblEntry *rte, int rtindex, int sublevels_up, int location, bool include_dropped, List **colnames, List **colvars)
@ RTE_CTE
Definition: parsenodes.h:1020
@ RTE_SUBQUERY
Definition: parsenodes.h:1015
#define rt_fetch(rangetable_index, rangetable)
Definition: parsetree.h:31
#define lfirst(lc)
Definition: pg_list.h:172
#define lfirst_node(type, lc)
Definition: pg_list.h:176
static int list_length(const List *l)
Definition: pg_list.h:152
#define NIL
Definition: pg_list.h:68
#define linitial(l)
Definition: pg_list.h:178
#define InvalidOid
Definition: postgres_ext.h:36
unsigned int Oid
Definition: postgres_ext.h:31
@ IS_NOT_TRUE
Definition: primnodes.h:1631
#define PRS2_OLD_VARNO
Definition: primnodes.h:222
@ PARAM_MULTIEXPR
Definition: primnodes.h:348
#define PRS2_NEW_VARNO
Definition: primnodes.h:223
@ COERCE_IMPLICIT_CAST
Definition: primnodes.h:663
@ COERCION_IMPLICIT
Definition: primnodes.h:641
bool contain_windowfuncs(Node *node)
Definition: rewriteManip.c:215
static Node * remove_nulling_relids_mutator(Node *node, remove_nulling_relids_context *context)
Node * ReplaceVarsFromTargetList(Node *node, int target_varno, int sublevels_up, RangeTblEntry *target_rte, List *targetlist, ReplaceVarsNoMatchOption nomatch_option, int nomatch_varno, bool *outer_hasSubLinks)
void IncrementVarSublevelsUp_rtable(List *rtable, int delta_sublevels_up, int min_sublevels_up)
Definition: rewriteManip.c:859
void ChangeVarNodes(Node *node, int rt_index, int new_index, int sublevels_up)
Definition: rewriteManip.c:670
static bool contain_windowfuncs_walker(Node *node, void *context)
Definition: rewriteManip.c:228
static Relids adjust_relid_set(Relids relids, int oldrelid, int newrelid)
Definition: rewriteManip.c:724
Node * replace_rte_variables_mutator(Node *node, replace_rte_variables_context *context)
static bool contains_multiexpr_param(Node *node, void *context)
Definition: rewriteManip.c:324
void OffsetVarNodes(Node *node, int offset, int sublevels_up)
Definition: rewriteManip.c:480
bool checkExprHasSubLink(Node *node)
Definition: rewriteManip.c:295
Node * map_variable_attnos(Node *node, int target_varno, int sublevels_up, const AttrMap *attno_map, Oid to_rowtype, bool *found_whole_row)
static bool locate_windowfunc_walker(Node *node, locate_windowfunc_context *context)
Definition: rewriteManip.c:272
Query * getInsertSelectQuery(Query *parsetree, Query ***subquery_ptr)
Definition: rewriteManip.c:985
void CombineRangeTables(List **dst_rtable, List **dst_perminfos, List *src_rtable, List *src_perminfos)
Definition: rewriteManip.c:350
static bool rangeTableEntry_used_walker(Node *node, rangeTableEntry_used_context *context)
Definition: rewriteManip.c:886
void AddQual(Query *parsetree, Node *qual)
Node * remove_nulling_relids(Node *node, const Bitmapset *removable_relids, const Bitmapset *except_relids)
Node * replace_rte_variables(Node *node, int target_varno, int sublevels_up, replace_rte_variables_callback callback, void *callback_arg, bool *outer_hasSubLinks)
int locate_agg_of_level(Node *node, int levelsup)
Definition: rewriteManip.c:149
static bool checkExprHasSubLink_walker(Node *node, void *context)
Definition: rewriteManip.c:308
static bool IncrementVarSublevelsUp_walker(Node *node, IncrementVarSublevelsUp_context *context)
Definition: rewriteManip.c:763
static bool ChangeVarNodes_walker(Node *node, ChangeVarNodes_context *context)
Definition: rewriteManip.c:560
static bool locate_agg_of_level_walker(Node *node, locate_agg_of_level_context *context)
Definition: rewriteManip.c:169
bool rangeTableEntry_used(Node *node, int rt_index, int sublevels_up)
Definition: rewriteManip.c:953
static bool contain_aggs_of_level_walker(Node *node, contain_aggs_of_level_context *context)
Definition: rewriteManip.c:102
bool contain_aggs_of_level(Node *node, int levelsup)
Definition: rewriteManip.c:85
int locate_windowfunc(Node *node)
Definition: rewriteManip.c:253
void AddInvertedQual(Query *parsetree, Node *qual)
static bool OffsetVarNodes_walker(Node *node, OffsetVarNodes_context *context)
Definition: rewriteManip.c:391
Node * add_nulling_relids(Node *node, const Bitmapset *target_relids, const Bitmapset *added_relids)
static Node * ReplaceVarsFromTargetList_callback(Var *var, replace_rte_variables_context *context)
static Node * map_variable_attnos_mutator(Node *node, map_variable_attnos_context *context)
static Node * add_nulling_relids_mutator(Node *node, add_nulling_relids_context *context)
void IncrementVarSublevelsUp(Node *node, int delta_sublevels_up, int min_sublevels_up)
Definition: rewriteManip.c:836
static Relids offset_relid_set(Relids relids, int offset)
Definition: rewriteManip.c:528
Node *(* replace_rte_variables_callback)(Var *var, replace_rte_variables_context *context)
Definition: rewriteManip.h:24
ReplaceVarsNoMatchOption
Definition: rewriteManip.h:37
@ REPLACEVARS_SUBSTITUTE_NULL
Definition: rewriteManip.h:40
@ REPLACEVARS_CHANGE_VARNO
Definition: rewriteManip.h:39
@ REPLACEVARS_REPORT_ERROR
Definition: rewriteManip.h:38
Index child_relid
Definition: pathnodes.h:2904
Index parent_relid
Definition: pathnodes.h:2903
Definition: attmap.h:35
int maplen
Definition: attmap.h:37
AttrNumber * attnums
Definition: attmap.h:36
BoolTestType booltesttype
Definition: primnodes.h:1638
Expr * arg
Definition: primnodes.h:1637
Node * quals
Definition: primnodes.h:1935
List * fromlist
Definition: primnodes.h:1934
Index agglevelsup
Definition: primnodes.h:529
Definition: pg_list.h:54
Definition: nodes.h:129
Relids phnullingrels
Definition: pathnodes.h:2734
Index phlevelsup
Definition: pathnodes.h:2740
Index prti
Definition: plannodes.h:1384
List * rowMarks
Definition: parsenodes.h:215
FromExpr * jointree
Definition: parsenodes.h:182
Node * setOperations
Definition: parsenodes.h:217
OnConflictExpr * onConflict
Definition: parsenodes.h:194
List * rtable
Definition: parsenodes.h:175
CmdType commandType
Definition: parsenodes.h:128
Node * utilityStmt
Definition: parsenodes.h:143
Index ctelevelsup
Definition: parsenodes.h:1165
Query * subquery
Definition: parsenodes.h:1081
Index perminfoindex
Definition: parsenodes.h:1076
RTEKind rtekind
Definition: parsenodes.h:1033
ReplaceVarsNoMatchOption nomatch_option
int location
Definition: primnodes.h:1360
List * args
Definition: primnodes.h:1336
Definition: primnodes.h:226
AttrNumber varattno
Definition: primnodes.h:238
int varno
Definition: primnodes.h:233
Index varlevelsup
Definition: primnodes.h:258
int location
Definition: primnodes.h:271
const Bitmapset * target_relids
Definition: rewriteManip.c:45
const Bitmapset * added_relids
Definition: rewriteManip.c:46
const Bitmapset * removable_relids
Definition: rewriteManip.c:52
const Bitmapset * except_relids
Definition: rewriteManip.c:53
replace_rte_variables_callback callback
Definition: rewriteManip.h:29
static void callback(struct sockaddr *addr, struct sockaddr *mask, void *unused)
Definition: test_ifaddrs.c:46