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parse_expr.c
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1 /*-------------------------------------------------------------------------
2  *
3  * parse_expr.c
4  * handle expressions in parser
5  *
6  * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  *
10  * IDENTIFICATION
11  * src/backend/parser/parse_expr.c
12  *
13  *-------------------------------------------------------------------------
14  */
15 
16 #include "postgres.h"
17 
18 #include "catalog/pg_type.h"
19 #include "commands/dbcommands.h"
20 #include "miscadmin.h"
21 #include "nodes/makefuncs.h"
22 #include "nodes/nodeFuncs.h"
23 #include "optimizer/optimizer.h"
24 #include "parser/analyze.h"
25 #include "parser/parse_agg.h"
26 #include "parser/parse_clause.h"
27 #include "parser/parse_coerce.h"
28 #include "parser/parse_collate.h"
29 #include "parser/parse_expr.h"
30 #include "parser/parse_func.h"
31 #include "parser/parse_oper.h"
32 #include "parser/parse_relation.h"
33 #include "parser/parse_target.h"
34 #include "parser/parse_type.h"
35 #include "utils/builtins.h"
36 #include "utils/date.h"
37 #include "utils/lsyscache.h"
38 #include "utils/timestamp.h"
39 #include "utils/xml.h"
40 
41 /* GUC parameters */
42 bool Transform_null_equals = false;
43 
44 
45 static Node *transformExprRecurse(ParseState *pstate, Node *expr);
46 static Node *transformParamRef(ParseState *pstate, ParamRef *pref);
47 static Node *transformAExprOp(ParseState *pstate, A_Expr *a);
48 static Node *transformAExprOpAny(ParseState *pstate, A_Expr *a);
49 static Node *transformAExprOpAll(ParseState *pstate, A_Expr *a);
50 static Node *transformAExprDistinct(ParseState *pstate, A_Expr *a);
51 static Node *transformAExprNullIf(ParseState *pstate, A_Expr *a);
52 static Node *transformAExprIn(ParseState *pstate, A_Expr *a);
53 static Node *transformAExprBetween(ParseState *pstate, A_Expr *a);
54 static Node *transformBoolExpr(ParseState *pstate, BoolExpr *a);
55 static Node *transformFuncCall(ParseState *pstate, FuncCall *fn);
56 static Node *transformMultiAssignRef(ParseState *pstate, MultiAssignRef *maref);
57 static Node *transformCaseExpr(ParseState *pstate, CaseExpr *c);
58 static Node *transformSubLink(ParseState *pstate, SubLink *sublink);
59 static Node *transformArrayExpr(ParseState *pstate, A_ArrayExpr *a,
60  Oid array_type, Oid element_type, int32 typmod);
61 static Node *transformRowExpr(ParseState *pstate, RowExpr *r, bool allowDefault);
63 static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
65  SQLValueFunction *svf);
66 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
68 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
69 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
70 static Node *transformColumnRef(ParseState *pstate, ColumnRef *cref);
71 static Node *transformWholeRowRef(ParseState *pstate,
72  ParseNamespaceItem *nsitem,
73  int sublevels_up, int location);
75 static Node *transformTypeCast(ParseState *pstate, TypeCast *tc);
77 static Node *make_row_comparison_op(ParseState *pstate, List *opname,
78  List *largs, List *rargs, int location);
79 static Node *make_row_distinct_op(ParseState *pstate, List *opname,
80  RowExpr *lrow, RowExpr *rrow, int location);
81 static Expr *make_distinct_op(ParseState *pstate, List *opname,
82  Node *ltree, Node *rtree, int location);
84  A_Expr *distincta, Node *arg);
85 
86 
87 /*
88  * transformExpr -
89  * Analyze and transform expressions. Type checking and type casting is
90  * done here. This processing converts the raw grammar output into
91  * expression trees with fully determined semantics.
92  */
93 Node *
94 transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind)
95 {
96  Node *result;
97  ParseExprKind sv_expr_kind;
98 
99  /* Save and restore identity of expression type we're parsing */
100  Assert(exprKind != EXPR_KIND_NONE);
101  sv_expr_kind = pstate->p_expr_kind;
102  pstate->p_expr_kind = exprKind;
103 
104  result = transformExprRecurse(pstate, expr);
105 
106  pstate->p_expr_kind = sv_expr_kind;
107 
108  return result;
109 }
110 
111 static Node *
113 {
114  Node *result;
115 
116  if (expr == NULL)
117  return NULL;
118 
119  /* Guard against stack overflow due to overly complex expressions */
121 
122  switch (nodeTag(expr))
123  {
124  case T_ColumnRef:
125  result = transformColumnRef(pstate, (ColumnRef *) expr);
126  break;
127 
128  case T_ParamRef:
129  result = transformParamRef(pstate, (ParamRef *) expr);
130  break;
131 
132  case T_A_Const:
133  {
134  A_Const *con = (A_Const *) expr;
135  Value *val = &con->val;
136 
137  result = (Node *) make_const(pstate, val, con->location);
138  break;
139  }
140 
141  case T_A_Indirection:
142  result = transformIndirection(pstate, (A_Indirection *) expr);
143  break;
144 
145  case T_A_ArrayExpr:
146  result = transformArrayExpr(pstate, (A_ArrayExpr *) expr,
147  InvalidOid, InvalidOid, -1);
148  break;
149 
150  case T_TypeCast:
151  result = transformTypeCast(pstate, (TypeCast *) expr);
152  break;
153 
154  case T_CollateClause:
155  result = transformCollateClause(pstate, (CollateClause *) expr);
156  break;
157 
158  case T_A_Expr:
159  {
160  A_Expr *a = (A_Expr *) expr;
161 
162  switch (a->kind)
163  {
164  case AEXPR_OP:
165  result = transformAExprOp(pstate, a);
166  break;
167  case AEXPR_OP_ANY:
168  result = transformAExprOpAny(pstate, a);
169  break;
170  case AEXPR_OP_ALL:
171  result = transformAExprOpAll(pstate, a);
172  break;
173  case AEXPR_DISTINCT:
174  case AEXPR_NOT_DISTINCT:
175  result = transformAExprDistinct(pstate, a);
176  break;
177  case AEXPR_NULLIF:
178  result = transformAExprNullIf(pstate, a);
179  break;
180  case AEXPR_IN:
181  result = transformAExprIn(pstate, a);
182  break;
183  case AEXPR_LIKE:
184  case AEXPR_ILIKE:
185  case AEXPR_SIMILAR:
186  /* we can transform these just like AEXPR_OP */
187  result = transformAExprOp(pstate, a);
188  break;
189  case AEXPR_BETWEEN:
190  case AEXPR_NOT_BETWEEN:
191  case AEXPR_BETWEEN_SYM:
193  result = transformAExprBetween(pstate, a);
194  break;
195  default:
196  elog(ERROR, "unrecognized A_Expr kind: %d", a->kind);
197  result = NULL; /* keep compiler quiet */
198  break;
199  }
200  break;
201  }
202 
203  case T_BoolExpr:
204  result = transformBoolExpr(pstate, (BoolExpr *) expr);
205  break;
206 
207  case T_FuncCall:
208  result = transformFuncCall(pstate, (FuncCall *) expr);
209  break;
210 
211  case T_MultiAssignRef:
212  result = transformMultiAssignRef(pstate, (MultiAssignRef *) expr);
213  break;
214 
215  case T_GroupingFunc:
216  result = transformGroupingFunc(pstate, (GroupingFunc *) expr);
217  break;
218 
219  case T_NamedArgExpr:
220  {
221  NamedArgExpr *na = (NamedArgExpr *) expr;
222 
223  na->arg = (Expr *) transformExprRecurse(pstate, (Node *) na->arg);
224  result = expr;
225  break;
226  }
227 
228  case T_SubLink:
229  result = transformSubLink(pstate, (SubLink *) expr);
230  break;
231 
232  case T_CaseExpr:
233  result = transformCaseExpr(pstate, (CaseExpr *) expr);
234  break;
235 
236  case T_RowExpr:
237  result = transformRowExpr(pstate, (RowExpr *) expr, false);
238  break;
239 
240  case T_CoalesceExpr:
241  result = transformCoalesceExpr(pstate, (CoalesceExpr *) expr);
242  break;
243 
244  case T_MinMaxExpr:
245  result = transformMinMaxExpr(pstate, (MinMaxExpr *) expr);
246  break;
247 
248  case T_SQLValueFunction:
249  result = transformSQLValueFunction(pstate,
250  (SQLValueFunction *) expr);
251  break;
252 
253  case T_XmlExpr:
254  result = transformXmlExpr(pstate, (XmlExpr *) expr);
255  break;
256 
257  case T_XmlSerialize:
258  result = transformXmlSerialize(pstate, (XmlSerialize *) expr);
259  break;
260 
261  case T_NullTest:
262  {
263  NullTest *n = (NullTest *) expr;
264 
265  n->arg = (Expr *) transformExprRecurse(pstate, (Node *) n->arg);
266  /* the argument can be any type, so don't coerce it */
267  n->argisrow = type_is_rowtype(exprType((Node *) n->arg));
268  result = expr;
269  break;
270  }
271 
272  case T_BooleanTest:
273  result = transformBooleanTest(pstate, (BooleanTest *) expr);
274  break;
275 
276  case T_CurrentOfExpr:
277  result = transformCurrentOfExpr(pstate, (CurrentOfExpr *) expr);
278  break;
279 
280  /*
281  * In all places where DEFAULT is legal, the caller should have
282  * processed it rather than passing it to transformExpr().
283  */
284  case T_SetToDefault:
285  ereport(ERROR,
286  (errcode(ERRCODE_SYNTAX_ERROR),
287  errmsg("DEFAULT is not allowed in this context"),
288  parser_errposition(pstate,
289  ((SetToDefault *) expr)->location)));
290  break;
291 
292  /*
293  * CaseTestExpr doesn't require any processing; it is only
294  * injected into parse trees in a fully-formed state.
295  *
296  * Ordinarily we should not see a Var here, but it is convenient
297  * for transformJoinUsingClause() to create untransformed operator
298  * trees containing already-transformed Vars. The best
299  * alternative would be to deconstruct and reconstruct column
300  * references, which seems expensively pointless. So allow it.
301  */
302  case T_CaseTestExpr:
303  case T_Var:
304  {
305  result = (Node *) expr;
306  break;
307  }
308 
309  default:
310  /* should not reach here */
311  elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
312  result = NULL; /* keep compiler quiet */
313  break;
314  }
315 
316  return result;
317 }
318 
319 /*
320  * helper routine for delivering "column does not exist" error message
321  *
322  * (Usually we don't have to work this hard, but the general case of field
323  * selection from an arbitrary node needs it.)
324  */
325 static void
326 unknown_attribute(ParseState *pstate, Node *relref, const char *attname,
327  int location)
328 {
329  RangeTblEntry *rte;
330 
331  if (IsA(relref, Var) &&
332  ((Var *) relref)->varattno == InvalidAttrNumber)
333  {
334  /* Reference the RTE by alias not by actual table name */
335  rte = GetRTEByRangeTablePosn(pstate,
336  ((Var *) relref)->varno,
337  ((Var *) relref)->varlevelsup);
338  ereport(ERROR,
339  (errcode(ERRCODE_UNDEFINED_COLUMN),
340  errmsg("column %s.%s does not exist",
341  rte->eref->aliasname, attname),
342  parser_errposition(pstate, location)));
343  }
344  else
345  {
346  /* Have to do it by reference to the type of the expression */
347  Oid relTypeId = exprType(relref);
348 
349  if (ISCOMPLEX(relTypeId))
350  ereport(ERROR,
351  (errcode(ERRCODE_UNDEFINED_COLUMN),
352  errmsg("column \"%s\" not found in data type %s",
353  attname, format_type_be(relTypeId)),
354  parser_errposition(pstate, location)));
355  else if (relTypeId == RECORDOID)
356  ereport(ERROR,
357  (errcode(ERRCODE_UNDEFINED_COLUMN),
358  errmsg("could not identify column \"%s\" in record data type",
359  attname),
360  parser_errposition(pstate, location)));
361  else
362  ereport(ERROR,
363  (errcode(ERRCODE_WRONG_OBJECT_TYPE),
364  errmsg("column notation .%s applied to type %s, "
365  "which is not a composite type",
366  attname, format_type_be(relTypeId)),
367  parser_errposition(pstate, location)));
368  }
369 }
370 
371 static Node *
373 {
374  Node *last_srf = pstate->p_last_srf;
375  Node *result = transformExprRecurse(pstate, ind->arg);
376  List *subscripts = NIL;
377  int location = exprLocation(result);
378  ListCell *i;
379 
380  /*
381  * We have to split any field-selection operations apart from
382  * subscripting. Adjacent A_Indices nodes have to be treated as a single
383  * multidimensional subscript operation.
384  */
385  foreach(i, ind->indirection)
386  {
387  Node *n = lfirst(i);
388 
389  if (IsA(n, A_Indices))
390  subscripts = lappend(subscripts, n);
391  else if (IsA(n, A_Star))
392  {
393  ereport(ERROR,
394  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
395  errmsg("row expansion via \"*\" is not supported here"),
396  parser_errposition(pstate, location)));
397  }
398  else
399  {
400  Node *newresult;
401 
402  Assert(IsA(n, String));
403 
404  /* process subscripts before this field selection */
405  if (subscripts)
406  result = (Node *) transformContainerSubscripts(pstate,
407  result,
408  exprType(result),
409  exprTypmod(result),
410  subscripts,
411  false);
412  subscripts = NIL;
413 
414  newresult = ParseFuncOrColumn(pstate,
415  list_make1(n),
416  list_make1(result),
417  last_srf,
418  NULL,
419  false,
420  location);
421  if (newresult == NULL)
422  unknown_attribute(pstate, result, strVal(n), location);
423  result = newresult;
424  }
425  }
426  /* process trailing subscripts, if any */
427  if (subscripts)
428  result = (Node *) transformContainerSubscripts(pstate,
429  result,
430  exprType(result),
431  exprTypmod(result),
432  subscripts,
433  false);
434 
435  return result;
436 }
437 
438 /*
439  * Transform a ColumnRef.
440  *
441  * If you find yourself changing this code, see also ExpandColumnRefStar.
442  */
443 static Node *
445 {
446  Node *node = NULL;
447  char *nspname = NULL;
448  char *relname = NULL;
449  char *colname = NULL;
450  ParseNamespaceItem *nsitem;
451  int levels_up;
452  enum
453  {
454  CRERR_NO_COLUMN,
455  CRERR_NO_RTE,
456  CRERR_WRONG_DB,
457  CRERR_TOO_MANY
458  } crerr = CRERR_NO_COLUMN;
459  const char *err;
460 
461  /*
462  * Check to see if the column reference is in an invalid place within the
463  * query. We allow column references in most places, except in default
464  * expressions and partition bound expressions.
465  */
466  err = NULL;
467  switch (pstate->p_expr_kind)
468  {
469  case EXPR_KIND_NONE:
470  Assert(false); /* can't happen */
471  break;
472  case EXPR_KIND_OTHER:
473  case EXPR_KIND_JOIN_ON:
477  case EXPR_KIND_WHERE:
478  case EXPR_KIND_POLICY:
479  case EXPR_KIND_HAVING:
480  case EXPR_KIND_FILTER:
490  case EXPR_KIND_GROUP_BY:
491  case EXPR_KIND_ORDER_BY:
493  case EXPR_KIND_LIMIT:
494  case EXPR_KIND_OFFSET:
495  case EXPR_KIND_RETURNING:
496  case EXPR_KIND_VALUES:
512  /* okay */
513  break;
514 
516  err = _("cannot use column reference in DEFAULT expression");
517  break;
519  err = _("cannot use column reference in partition bound expression");
520  break;
521 
522  /*
523  * There is intentionally no default: case here, so that the
524  * compiler will warn if we add a new ParseExprKind without
525  * extending this switch. If we do see an unrecognized value at
526  * runtime, the behavior will be the same as for EXPR_KIND_OTHER,
527  * which is sane anyway.
528  */
529  }
530  if (err)
531  ereport(ERROR,
532  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
533  errmsg_internal("%s", err),
534  parser_errposition(pstate, cref->location)));
535 
536  /*
537  * Give the PreParseColumnRefHook, if any, first shot. If it returns
538  * non-null then that's all, folks.
539  */
540  if (pstate->p_pre_columnref_hook != NULL)
541  {
542  node = pstate->p_pre_columnref_hook(pstate, cref);
543  if (node != NULL)
544  return node;
545  }
546 
547  /*----------
548  * The allowed syntaxes are:
549  *
550  * A First try to resolve as unqualified column name;
551  * if no luck, try to resolve as unqualified table name (A.*).
552  * A.B A is an unqualified table name; B is either a
553  * column or function name (trying column name first).
554  * A.B.C schema A, table B, col or func name C.
555  * A.B.C.D catalog A, schema B, table C, col or func D.
556  * A.* A is an unqualified table name; means whole-row value.
557  * A.B.* whole-row value of table B in schema A.
558  * A.B.C.* whole-row value of table C in schema B in catalog A.
559  *
560  * We do not need to cope with bare "*"; that will only be accepted by
561  * the grammar at the top level of a SELECT list, and transformTargetList
562  * will take care of it before it ever gets here. Also, "A.*" etc will
563  * be expanded by transformTargetList if they appear at SELECT top level,
564  * so here we are only going to see them as function or operator inputs.
565  *
566  * Currently, if a catalog name is given then it must equal the current
567  * database name; we check it here and then discard it.
568  *----------
569  */
570  switch (list_length(cref->fields))
571  {
572  case 1:
573  {
574  Node *field1 = (Node *) linitial(cref->fields);
575 
576  Assert(IsA(field1, String));
577  colname = strVal(field1);
578 
579  /* Try to identify as an unqualified column */
580  node = colNameToVar(pstate, colname, false, cref->location);
581 
582  if (node == NULL)
583  {
584  /*
585  * Not known as a column of any range-table entry.
586  *
587  * Try to find the name as a relation. Note that only
588  * relations already entered into the rangetable will be
589  * recognized.
590  *
591  * This is a hack for backwards compatibility with
592  * PostQUEL-inspired syntax. The preferred form now is
593  * "rel.*".
594  */
595  nsitem = refnameNamespaceItem(pstate, NULL, colname,
596  cref->location,
597  &levels_up);
598  if (nsitem)
599  node = transformWholeRowRef(pstate, nsitem, levels_up,
600  cref->location);
601  }
602  break;
603  }
604  case 2:
605  {
606  Node *field1 = (Node *) linitial(cref->fields);
607  Node *field2 = (Node *) lsecond(cref->fields);
608 
609  Assert(IsA(field1, String));
610  relname = strVal(field1);
611 
612  /* Locate the referenced nsitem */
613  nsitem = refnameNamespaceItem(pstate, nspname, relname,
614  cref->location,
615  &levels_up);
616  if (nsitem == NULL)
617  {
618  crerr = CRERR_NO_RTE;
619  break;
620  }
621 
622  /* Whole-row reference? */
623  if (IsA(field2, A_Star))
624  {
625  node = transformWholeRowRef(pstate, nsitem, levels_up,
626  cref->location);
627  break;
628  }
629 
630  Assert(IsA(field2, String));
631  colname = strVal(field2);
632 
633  /* Try to identify as a column of the nsitem */
634  node = scanNSItemForColumn(pstate, nsitem, levels_up, colname,
635  cref->location);
636  if (node == NULL)
637  {
638  /* Try it as a function call on the whole row */
639  node = transformWholeRowRef(pstate, nsitem, levels_up,
640  cref->location);
641  node = ParseFuncOrColumn(pstate,
642  list_make1(makeString(colname)),
643  list_make1(node),
644  pstate->p_last_srf,
645  NULL,
646  false,
647  cref->location);
648  }
649  break;
650  }
651  case 3:
652  {
653  Node *field1 = (Node *) linitial(cref->fields);
654  Node *field2 = (Node *) lsecond(cref->fields);
655  Node *field3 = (Node *) lthird(cref->fields);
656 
657  Assert(IsA(field1, String));
658  nspname = strVal(field1);
659  Assert(IsA(field2, String));
660  relname = strVal(field2);
661 
662  /* Locate the referenced nsitem */
663  nsitem = refnameNamespaceItem(pstate, nspname, relname,
664  cref->location,
665  &levels_up);
666  if (nsitem == NULL)
667  {
668  crerr = CRERR_NO_RTE;
669  break;
670  }
671 
672  /* Whole-row reference? */
673  if (IsA(field3, A_Star))
674  {
675  node = transformWholeRowRef(pstate, nsitem, levels_up,
676  cref->location);
677  break;
678  }
679 
680  Assert(IsA(field3, String));
681  colname = strVal(field3);
682 
683  /* Try to identify as a column of the nsitem */
684  node = scanNSItemForColumn(pstate, nsitem, levels_up, colname,
685  cref->location);
686  if (node == NULL)
687  {
688  /* Try it as a function call on the whole row */
689  node = transformWholeRowRef(pstate, nsitem, levels_up,
690  cref->location);
691  node = ParseFuncOrColumn(pstate,
692  list_make1(makeString(colname)),
693  list_make1(node),
694  pstate->p_last_srf,
695  NULL,
696  false,
697  cref->location);
698  }
699  break;
700  }
701  case 4:
702  {
703  Node *field1 = (Node *) linitial(cref->fields);
704  Node *field2 = (Node *) lsecond(cref->fields);
705  Node *field3 = (Node *) lthird(cref->fields);
706  Node *field4 = (Node *) lfourth(cref->fields);
707  char *catname;
708 
709  Assert(IsA(field1, String));
710  catname = strVal(field1);
711  Assert(IsA(field2, String));
712  nspname = strVal(field2);
713  Assert(IsA(field3, String));
714  relname = strVal(field3);
715 
716  /*
717  * We check the catalog name and then ignore it.
718  */
719  if (strcmp(catname, get_database_name(MyDatabaseId)) != 0)
720  {
721  crerr = CRERR_WRONG_DB;
722  break;
723  }
724 
725  /* Locate the referenced nsitem */
726  nsitem = refnameNamespaceItem(pstate, nspname, relname,
727  cref->location,
728  &levels_up);
729  if (nsitem == NULL)
730  {
731  crerr = CRERR_NO_RTE;
732  break;
733  }
734 
735  /* Whole-row reference? */
736  if (IsA(field4, A_Star))
737  {
738  node = transformWholeRowRef(pstate, nsitem, levels_up,
739  cref->location);
740  break;
741  }
742 
743  Assert(IsA(field4, String));
744  colname = strVal(field4);
745 
746  /* Try to identify as a column of the nsitem */
747  node = scanNSItemForColumn(pstate, nsitem, levels_up, colname,
748  cref->location);
749  if (node == NULL)
750  {
751  /* Try it as a function call on the whole row */
752  node = transformWholeRowRef(pstate, nsitem, levels_up,
753  cref->location);
754  node = ParseFuncOrColumn(pstate,
755  list_make1(makeString(colname)),
756  list_make1(node),
757  pstate->p_last_srf,
758  NULL,
759  false,
760  cref->location);
761  }
762  break;
763  }
764  default:
765  crerr = CRERR_TOO_MANY; /* too many dotted names */
766  break;
767  }
768 
769  /*
770  * Now give the PostParseColumnRefHook, if any, a chance. We pass the
771  * translation-so-far so that it can throw an error if it wishes in the
772  * case that it has a conflicting interpretation of the ColumnRef. (If it
773  * just translates anyway, we'll throw an error, because we can't undo
774  * whatever effects the preceding steps may have had on the pstate.) If it
775  * returns NULL, use the standard translation, or throw a suitable error
776  * if there is none.
777  */
778  if (pstate->p_post_columnref_hook != NULL)
779  {
780  Node *hookresult;
781 
782  hookresult = pstate->p_post_columnref_hook(pstate, cref, node);
783  if (node == NULL)
784  node = hookresult;
785  else if (hookresult != NULL)
786  ereport(ERROR,
787  (errcode(ERRCODE_AMBIGUOUS_COLUMN),
788  errmsg("column reference \"%s\" is ambiguous",
789  NameListToString(cref->fields)),
790  parser_errposition(pstate, cref->location)));
791  }
792 
793  /*
794  * Throw error if no translation found.
795  */
796  if (node == NULL)
797  {
798  switch (crerr)
799  {
800  case CRERR_NO_COLUMN:
801  errorMissingColumn(pstate, relname, colname, cref->location);
802  break;
803  case CRERR_NO_RTE:
804  errorMissingRTE(pstate, makeRangeVar(nspname, relname,
805  cref->location));
806  break;
807  case CRERR_WRONG_DB:
808  ereport(ERROR,
809  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
810  errmsg("cross-database references are not implemented: %s",
811  NameListToString(cref->fields)),
812  parser_errposition(pstate, cref->location)));
813  break;
814  case CRERR_TOO_MANY:
815  ereport(ERROR,
816  (errcode(ERRCODE_SYNTAX_ERROR),
817  errmsg("improper qualified name (too many dotted names): %s",
818  NameListToString(cref->fields)),
819  parser_errposition(pstate, cref->location)));
820  break;
821  }
822  }
823 
824  return node;
825 }
826 
827 static Node *
829 {
830  Node *result;
831 
832  /*
833  * The core parser knows nothing about Params. If a hook is supplied,
834  * call it. If not, or if the hook returns NULL, throw a generic error.
835  */
836  if (pstate->p_paramref_hook != NULL)
837  result = pstate->p_paramref_hook(pstate, pref);
838  else
839  result = NULL;
840 
841  if (result == NULL)
842  ereport(ERROR,
843  (errcode(ERRCODE_UNDEFINED_PARAMETER),
844  errmsg("there is no parameter $%d", pref->number),
845  parser_errposition(pstate, pref->location)));
846 
847  return result;
848 }
849 
850 /* Test whether an a_expr is a plain NULL constant or not */
851 static bool
853 {
854  if (arg && IsA(arg, A_Const))
855  {
856  A_Const *con = (A_Const *) arg;
857 
858  if (con->val.type == T_Null)
859  return true;
860  }
861  return false;
862 }
863 
864 static Node *
866 {
867  Node *lexpr = a->lexpr;
868  Node *rexpr = a->rexpr;
869  Node *result;
870 
871  /*
872  * Special-case "foo = NULL" and "NULL = foo" for compatibility with
873  * standards-broken products (like Microsoft's). Turn these into IS NULL
874  * exprs. (If either side is a CaseTestExpr, then the expression was
875  * generated internally from a CASE-WHEN expression, and
876  * transform_null_equals does not apply.)
877  */
878  if (Transform_null_equals &&
879  list_length(a->name) == 1 &&
880  strcmp(strVal(linitial(a->name)), "=") == 0 &&
881  (exprIsNullConstant(lexpr) || exprIsNullConstant(rexpr)) &&
882  (!IsA(lexpr, CaseTestExpr) && !IsA(rexpr, CaseTestExpr)))
883  {
884  NullTest *n = makeNode(NullTest);
885 
886  n->nulltesttype = IS_NULL;
887  n->location = a->location;
888 
889  if (exprIsNullConstant(lexpr))
890  n->arg = (Expr *) rexpr;
891  else
892  n->arg = (Expr *) lexpr;
893 
894  result = transformExprRecurse(pstate, (Node *) n);
895  }
896  else if (lexpr && IsA(lexpr, RowExpr) &&
897  rexpr && IsA(rexpr, SubLink) &&
898  ((SubLink *) rexpr)->subLinkType == EXPR_SUBLINK)
899  {
900  /*
901  * Convert "row op subselect" into a ROWCOMPARE sublink. Formerly the
902  * grammar did this, but now that a row construct is allowed anywhere
903  * in expressions, it's easier to do it here.
904  */
905  SubLink *s = (SubLink *) rexpr;
906 
908  s->testexpr = lexpr;
909  s->operName = a->name;
910  s->location = a->location;
911  result = transformExprRecurse(pstate, (Node *) s);
912  }
913  else if (lexpr && IsA(lexpr, RowExpr) &&
914  rexpr && IsA(rexpr, RowExpr))
915  {
916  /* ROW() op ROW() is handled specially */
917  lexpr = transformExprRecurse(pstate, lexpr);
918  rexpr = transformExprRecurse(pstate, rexpr);
919 
920  result = make_row_comparison_op(pstate,
921  a->name,
922  castNode(RowExpr, lexpr)->args,
923  castNode(RowExpr, rexpr)->args,
924  a->location);
925  }
926  else
927  {
928  /* Ordinary scalar operator */
929  Node *last_srf = pstate->p_last_srf;
930 
931  lexpr = transformExprRecurse(pstate, lexpr);
932  rexpr = transformExprRecurse(pstate, rexpr);
933 
934  result = (Node *) make_op(pstate,
935  a->name,
936  lexpr,
937  rexpr,
938  last_srf,
939  a->location);
940  }
941 
942  return result;
943 }
944 
945 static Node *
947 {
948  Node *lexpr = transformExprRecurse(pstate, a->lexpr);
949  Node *rexpr = transformExprRecurse(pstate, a->rexpr);
950 
951  return (Node *) make_scalar_array_op(pstate,
952  a->name,
953  true,
954  lexpr,
955  rexpr,
956  a->location);
957 }
958 
959 static Node *
961 {
962  Node *lexpr = transformExprRecurse(pstate, a->lexpr);
963  Node *rexpr = transformExprRecurse(pstate, a->rexpr);
964 
965  return (Node *) make_scalar_array_op(pstate,
966  a->name,
967  false,
968  lexpr,
969  rexpr,
970  a->location);
971 }
972 
973 static Node *
975 {
976  Node *lexpr = a->lexpr;
977  Node *rexpr = a->rexpr;
978  Node *result;
979 
980  /*
981  * If either input is an undecorated NULL literal, transform to a NullTest
982  * on the other input. That's simpler to process than a full DistinctExpr,
983  * and it avoids needing to require that the datatype have an = operator.
984  */
985  if (exprIsNullConstant(rexpr))
986  return make_nulltest_from_distinct(pstate, a, lexpr);
987  if (exprIsNullConstant(lexpr))
988  return make_nulltest_from_distinct(pstate, a, rexpr);
989 
990  lexpr = transformExprRecurse(pstate, lexpr);
991  rexpr = transformExprRecurse(pstate, rexpr);
992 
993  if (lexpr && IsA(lexpr, RowExpr) &&
994  rexpr && IsA(rexpr, RowExpr))
995  {
996  /* ROW() op ROW() is handled specially */
997  result = make_row_distinct_op(pstate, a->name,
998  (RowExpr *) lexpr,
999  (RowExpr *) rexpr,
1000  a->location);
1001  }
1002  else
1003  {
1004  /* Ordinary scalar operator */
1005  result = (Node *) make_distinct_op(pstate,
1006  a->name,
1007  lexpr,
1008  rexpr,
1009  a->location);
1010  }
1011 
1012  /*
1013  * If it's NOT DISTINCT, we first build a DistinctExpr and then stick a
1014  * NOT on top.
1015  */
1016  if (a->kind == AEXPR_NOT_DISTINCT)
1017  result = (Node *) makeBoolExpr(NOT_EXPR,
1018  list_make1(result),
1019  a->location);
1020 
1021  return result;
1022 }
1023 
1024 static Node *
1026 {
1027  Node *lexpr = transformExprRecurse(pstate, a->lexpr);
1028  Node *rexpr = transformExprRecurse(pstate, a->rexpr);
1029  OpExpr *result;
1030 
1031  result = (OpExpr *) make_op(pstate,
1032  a->name,
1033  lexpr,
1034  rexpr,
1035  pstate->p_last_srf,
1036  a->location);
1037 
1038  /*
1039  * The comparison operator itself should yield boolean ...
1040  */
1041  if (result->opresulttype != BOOLOID)
1042  ereport(ERROR,
1043  (errcode(ERRCODE_DATATYPE_MISMATCH),
1044  errmsg("NULLIF requires = operator to yield boolean"),
1045  parser_errposition(pstate, a->location)));
1046  if (result->opretset)
1047  ereport(ERROR,
1048  (errcode(ERRCODE_DATATYPE_MISMATCH),
1049  /* translator: %s is name of a SQL construct, eg NULLIF */
1050  errmsg("%s must not return a set", "NULLIF"),
1051  parser_errposition(pstate, a->location)));
1052 
1053  /*
1054  * ... but the NullIfExpr will yield the first operand's type.
1055  */
1056  result->opresulttype = exprType((Node *) linitial(result->args));
1057 
1058  /*
1059  * We rely on NullIfExpr and OpExpr being the same struct
1060  */
1061  NodeSetTag(result, T_NullIfExpr);
1062 
1063  return (Node *) result;
1064 }
1065 
1066 static Node *
1068 {
1069  Node *result = NULL;
1070  Node *lexpr;
1071  List *rexprs;
1072  List *rvars;
1073  List *rnonvars;
1074  bool useOr;
1075  ListCell *l;
1076 
1077  /*
1078  * If the operator is <>, combine with AND not OR.
1079  */
1080  if (strcmp(strVal(linitial(a->name)), "<>") == 0)
1081  useOr = false;
1082  else
1083  useOr = true;
1084 
1085  /*
1086  * We try to generate a ScalarArrayOpExpr from IN/NOT IN, but this is only
1087  * possible if there is a suitable array type available. If not, we fall
1088  * back to a boolean condition tree with multiple copies of the lefthand
1089  * expression. Also, any IN-list items that contain Vars are handled as
1090  * separate boolean conditions, because that gives the planner more scope
1091  * for optimization on such clauses.
1092  *
1093  * First step: transform all the inputs, and detect whether any contain
1094  * Vars.
1095  */
1096  lexpr = transformExprRecurse(pstate, a->lexpr);
1097  rexprs = rvars = rnonvars = NIL;
1098  foreach(l, (List *) a->rexpr)
1099  {
1100  Node *rexpr = transformExprRecurse(pstate, lfirst(l));
1101 
1102  rexprs = lappend(rexprs, rexpr);
1103  if (contain_vars_of_level(rexpr, 0))
1104  rvars = lappend(rvars, rexpr);
1105  else
1106  rnonvars = lappend(rnonvars, rexpr);
1107  }
1108 
1109  /*
1110  * ScalarArrayOpExpr is only going to be useful if there's more than one
1111  * non-Var righthand item.
1112  */
1113  if (list_length(rnonvars) > 1)
1114  {
1115  List *allexprs;
1116  Oid scalar_type;
1117  Oid array_type;
1118 
1119  /*
1120  * Try to select a common type for the array elements. Note that
1121  * since the LHS' type is first in the list, it will be preferred when
1122  * there is doubt (eg, when all the RHS items are unknown literals).
1123  *
1124  * Note: use list_concat here not lcons, to avoid damaging rnonvars.
1125  */
1126  allexprs = list_concat(list_make1(lexpr), rnonvars);
1127  scalar_type = select_common_type(pstate, allexprs, NULL, NULL);
1128 
1129  /*
1130  * Do we have an array type to use? Aside from the case where there
1131  * isn't one, we don't risk using ScalarArrayOpExpr when the common
1132  * type is RECORD, because the RowExpr comparison logic below can cope
1133  * with some cases of non-identical row types.
1134  */
1135  if (OidIsValid(scalar_type) && scalar_type != RECORDOID)
1136  array_type = get_array_type(scalar_type);
1137  else
1138  array_type = InvalidOid;
1139  if (array_type != InvalidOid)
1140  {
1141  /*
1142  * OK: coerce all the right-hand non-Var inputs to the common type
1143  * and build an ArrayExpr for them.
1144  */
1145  List *aexprs;
1146  ArrayExpr *newa;
1147 
1148  aexprs = NIL;
1149  foreach(l, rnonvars)
1150  {
1151  Node *rexpr = (Node *) lfirst(l);
1152 
1153  rexpr = coerce_to_common_type(pstate, rexpr,
1154  scalar_type,
1155  "IN");
1156  aexprs = lappend(aexprs, rexpr);
1157  }
1158  newa = makeNode(ArrayExpr);
1159  newa->array_typeid = array_type;
1160  /* array_collid will be set by parse_collate.c */
1161  newa->element_typeid = scalar_type;
1162  newa->elements = aexprs;
1163  newa->multidims = false;
1164  newa->location = -1;
1165 
1166  result = (Node *) make_scalar_array_op(pstate,
1167  a->name,
1168  useOr,
1169  lexpr,
1170  (Node *) newa,
1171  a->location);
1172 
1173  /* Consider only the Vars (if any) in the loop below */
1174  rexprs = rvars;
1175  }
1176  }
1177 
1178  /*
1179  * Must do it the hard way, ie, with a boolean expression tree.
1180  */
1181  foreach(l, rexprs)
1182  {
1183  Node *rexpr = (Node *) lfirst(l);
1184  Node *cmp;
1185 
1186  if (IsA(lexpr, RowExpr) &&
1187  IsA(rexpr, RowExpr))
1188  {
1189  /* ROW() op ROW() is handled specially */
1190  cmp = make_row_comparison_op(pstate,
1191  a->name,
1192  copyObject(((RowExpr *) lexpr)->args),
1193  ((RowExpr *) rexpr)->args,
1194  a->location);
1195  }
1196  else
1197  {
1198  /* Ordinary scalar operator */
1199  cmp = (Node *) make_op(pstate,
1200  a->name,
1201  copyObject(lexpr),
1202  rexpr,
1203  pstate->p_last_srf,
1204  a->location);
1205  }
1206 
1207  cmp = coerce_to_boolean(pstate, cmp, "IN");
1208  if (result == NULL)
1209  result = cmp;
1210  else
1211  result = (Node *) makeBoolExpr(useOr ? OR_EXPR : AND_EXPR,
1212  list_make2(result, cmp),
1213  a->location);
1214  }
1215 
1216  return result;
1217 }
1218 
1219 static Node *
1221 {
1222  Node *aexpr;
1223  Node *bexpr;
1224  Node *cexpr;
1225  Node *result;
1226  Node *sub1;
1227  Node *sub2;
1228  List *args;
1229 
1230  /* Deconstruct A_Expr into three subexprs */
1231  aexpr = a->lexpr;
1232  args = castNode(List, a->rexpr);
1233  Assert(list_length(args) == 2);
1234  bexpr = (Node *) linitial(args);
1235  cexpr = (Node *) lsecond(args);
1236 
1237  /*
1238  * Build the equivalent comparison expression. Make copies of
1239  * multiply-referenced subexpressions for safety. (XXX this is really
1240  * wrong since it results in multiple runtime evaluations of what may be
1241  * volatile expressions ...)
1242  *
1243  * Ideally we would not use hard-wired operators here but instead use
1244  * opclasses. However, mixed data types and other issues make this
1245  * difficult:
1246  * http://archives.postgresql.org/pgsql-hackers/2008-08/msg01142.php
1247  */
1248  switch (a->kind)
1249  {
1250  case AEXPR_BETWEEN:
1251  args = list_make2(makeSimpleA_Expr(AEXPR_OP, ">=",
1252  aexpr, bexpr,
1253  a->location),
1254  makeSimpleA_Expr(AEXPR_OP, "<=",
1255  copyObject(aexpr), cexpr,
1256  a->location));
1257  result = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
1258  break;
1259  case AEXPR_NOT_BETWEEN:
1260  args = list_make2(makeSimpleA_Expr(AEXPR_OP, "<",
1261  aexpr, bexpr,
1262  a->location),
1264  copyObject(aexpr), cexpr,
1265  a->location));
1266  result = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
1267  break;
1268  case AEXPR_BETWEEN_SYM:
1269  args = list_make2(makeSimpleA_Expr(AEXPR_OP, ">=",
1270  aexpr, bexpr,
1271  a->location),
1272  makeSimpleA_Expr(AEXPR_OP, "<=",
1273  copyObject(aexpr), cexpr,
1274  a->location));
1275  sub1 = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
1276  args = list_make2(makeSimpleA_Expr(AEXPR_OP, ">=",
1277  copyObject(aexpr), copyObject(cexpr),
1278  a->location),
1279  makeSimpleA_Expr(AEXPR_OP, "<=",
1280  copyObject(aexpr), copyObject(bexpr),
1281  a->location));
1282  sub2 = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
1283  args = list_make2(sub1, sub2);
1284  result = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
1285  break;
1286  case AEXPR_NOT_BETWEEN_SYM:
1287  args = list_make2(makeSimpleA_Expr(AEXPR_OP, "<",
1288  aexpr, bexpr,
1289  a->location),
1291  copyObject(aexpr), cexpr,
1292  a->location));
1293  sub1 = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
1294  args = list_make2(makeSimpleA_Expr(AEXPR_OP, "<",
1295  copyObject(aexpr), copyObject(cexpr),
1296  a->location),
1298  copyObject(aexpr), copyObject(bexpr),
1299  a->location));
1300  sub2 = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
1301  args = list_make2(sub1, sub2);
1302  result = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
1303  break;
1304  default:
1305  elog(ERROR, "unrecognized A_Expr kind: %d", a->kind);
1306  result = NULL; /* keep compiler quiet */
1307  break;
1308  }
1309 
1310  return transformExprRecurse(pstate, result);
1311 }
1312 
1313 static Node *
1315 {
1316  List *args = NIL;
1317  const char *opname;
1318  ListCell *lc;
1319 
1320  switch (a->boolop)
1321  {
1322  case AND_EXPR:
1323  opname = "AND";
1324  break;
1325  case OR_EXPR:
1326  opname = "OR";
1327  break;
1328  case NOT_EXPR:
1329  opname = "NOT";
1330  break;
1331  default:
1332  elog(ERROR, "unrecognized boolop: %d", (int) a->boolop);
1333  opname = NULL; /* keep compiler quiet */
1334  break;
1335  }
1336 
1337  foreach(lc, a->args)
1338  {
1339  Node *arg = (Node *) lfirst(lc);
1340 
1341  arg = transformExprRecurse(pstate, arg);
1342  arg = coerce_to_boolean(pstate, arg, opname);
1343  args = lappend(args, arg);
1344  }
1345 
1346  return (Node *) makeBoolExpr(a->boolop, args, a->location);
1347 }
1348 
1349 static Node *
1351 {
1352  Node *last_srf = pstate->p_last_srf;
1353  List *targs;
1354  ListCell *args;
1355 
1356  /* Transform the list of arguments ... */
1357  targs = NIL;
1358  foreach(args, fn->args)
1359  {
1360  targs = lappend(targs, transformExprRecurse(pstate,
1361  (Node *) lfirst(args)));
1362  }
1363 
1364  /*
1365  * When WITHIN GROUP is used, we treat its ORDER BY expressions as
1366  * additional arguments to the function, for purposes of function lookup
1367  * and argument type coercion. So, transform each such expression and add
1368  * them to the targs list. We don't explicitly mark where each argument
1369  * came from, but ParseFuncOrColumn can tell what's what by reference to
1370  * list_length(fn->agg_order).
1371  */
1372  if (fn->agg_within_group)
1373  {
1374  Assert(fn->agg_order != NIL);
1375  foreach(args, fn->agg_order)
1376  {
1377  SortBy *arg = (SortBy *) lfirst(args);
1378 
1379  targs = lappend(targs, transformExpr(pstate, arg->node,
1381  }
1382  }
1383 
1384  /* ... and hand off to ParseFuncOrColumn */
1385  return ParseFuncOrColumn(pstate,
1386  fn->funcname,
1387  targs,
1388  last_srf,
1389  fn,
1390  false,
1391  fn->location);
1392 }
1393 
1394 static Node *
1396 {
1397  SubLink *sublink;
1398  RowExpr *rexpr;
1399  Query *qtree;
1400  TargetEntry *tle;
1401 
1402  /* We should only see this in first-stage processing of UPDATE tlists */
1404 
1405  /* We only need to transform the source if this is the first column */
1406  if (maref->colno == 1)
1407  {
1408  /*
1409  * For now, we only allow EXPR SubLinks and RowExprs as the source of
1410  * an UPDATE multiassignment. This is sufficient to cover interesting
1411  * cases; at worst, someone would have to write (SELECT * FROM expr)
1412  * to expand a composite-returning expression of another form.
1413  */
1414  if (IsA(maref->source, SubLink) &&
1415  ((SubLink *) maref->source)->subLinkType == EXPR_SUBLINK)
1416  {
1417  /* Relabel it as a MULTIEXPR_SUBLINK */
1418  sublink = (SubLink *) maref->source;
1419  sublink->subLinkType = MULTIEXPR_SUBLINK;
1420  /* And transform it */
1421  sublink = (SubLink *) transformExprRecurse(pstate,
1422  (Node *) sublink);
1423 
1424  qtree = castNode(Query, sublink->subselect);
1425 
1426  /* Check subquery returns required number of columns */
1427  if (count_nonjunk_tlist_entries(qtree->targetList) != maref->ncolumns)
1428  ereport(ERROR,
1429  (errcode(ERRCODE_SYNTAX_ERROR),
1430  errmsg("number of columns does not match number of values"),
1431  parser_errposition(pstate, sublink->location)));
1432 
1433  /*
1434  * Build a resjunk tlist item containing the MULTIEXPR SubLink,
1435  * and add it to pstate->p_multiassign_exprs, whence it will later
1436  * get appended to the completed targetlist. We needn't worry
1437  * about selecting a resno for it; transformUpdateStmt will do
1438  * that.
1439  */
1440  tle = makeTargetEntry((Expr *) sublink, 0, NULL, true);
1442  tle);
1443 
1444  /*
1445  * Assign a unique-within-this-targetlist ID to the MULTIEXPR
1446  * SubLink. We can just use its position in the
1447  * p_multiassign_exprs list.
1448  */
1449  sublink->subLinkId = list_length(pstate->p_multiassign_exprs);
1450  }
1451  else if (IsA(maref->source, RowExpr))
1452  {
1453  /* Transform the RowExpr, allowing SetToDefault items */
1454  rexpr = (RowExpr *) transformRowExpr(pstate,
1455  (RowExpr *) maref->source,
1456  true);
1457 
1458  /* Check it returns required number of columns */
1459  if (list_length(rexpr->args) != maref->ncolumns)
1460  ereport(ERROR,
1461  (errcode(ERRCODE_SYNTAX_ERROR),
1462  errmsg("number of columns does not match number of values"),
1463  parser_errposition(pstate, rexpr->location)));
1464 
1465  /*
1466  * Temporarily append it to p_multiassign_exprs, so we can get it
1467  * back when we come back here for additional columns.
1468  */
1469  tle = makeTargetEntry((Expr *) rexpr, 0, NULL, true);
1471  tle);
1472  }
1473  else
1474  ereport(ERROR,
1475  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1476  errmsg("source for a multiple-column UPDATE item must be a sub-SELECT or ROW() expression"),
1477  parser_errposition(pstate, exprLocation(maref->source))));
1478  }
1479  else
1480  {
1481  /*
1482  * Second or later column in a multiassignment. Re-fetch the
1483  * transformed SubLink or RowExpr, which we assume is still the last
1484  * entry in p_multiassign_exprs.
1485  */
1486  Assert(pstate->p_multiassign_exprs != NIL);
1487  tle = (TargetEntry *) llast(pstate->p_multiassign_exprs);
1488  }
1489 
1490  /*
1491  * Emit the appropriate output expression for the current column
1492  */
1493  if (IsA(tle->expr, SubLink))
1494  {
1495  Param *param;
1496 
1497  sublink = (SubLink *) tle->expr;
1498  Assert(sublink->subLinkType == MULTIEXPR_SUBLINK);
1499  qtree = castNode(Query, sublink->subselect);
1500 
1501  /* Build a Param representing the current subquery output column */
1502  tle = (TargetEntry *) list_nth(qtree->targetList, maref->colno - 1);
1503  Assert(!tle->resjunk);
1504 
1505  param = makeNode(Param);
1506  param->paramkind = PARAM_MULTIEXPR;
1507  param->paramid = (sublink->subLinkId << 16) | maref->colno;
1508  param->paramtype = exprType((Node *) tle->expr);
1509  param->paramtypmod = exprTypmod((Node *) tle->expr);
1510  param->paramcollid = exprCollation((Node *) tle->expr);
1511  param->location = exprLocation((Node *) tle->expr);
1512 
1513  return (Node *) param;
1514  }
1515 
1516  if (IsA(tle->expr, RowExpr))
1517  {
1518  Node *result;
1519 
1520  rexpr = (RowExpr *) tle->expr;
1521 
1522  /* Just extract and return the next element of the RowExpr */
1523  result = (Node *) list_nth(rexpr->args, maref->colno - 1);
1524 
1525  /*
1526  * If we're at the last column, delete the RowExpr from
1527  * p_multiassign_exprs; we don't need it anymore, and don't want it in
1528  * the finished UPDATE tlist. We assume this is still the last entry
1529  * in p_multiassign_exprs.
1530  */
1531  if (maref->colno == maref->ncolumns)
1532  pstate->p_multiassign_exprs =
1534 
1535  return result;
1536  }
1537 
1538  elog(ERROR, "unexpected expr type in multiassign list");
1539  return NULL; /* keep compiler quiet */
1540 }
1541 
1542 static Node *
1544 {
1545  CaseExpr *newc = makeNode(CaseExpr);
1546  Node *last_srf = pstate->p_last_srf;
1547  Node *arg;
1548  CaseTestExpr *placeholder;
1549  List *newargs;
1550  List *resultexprs;
1551  ListCell *l;
1552  Node *defresult;
1553  Oid ptype;
1554 
1555  /* transform the test expression, if any */
1556  arg = transformExprRecurse(pstate, (Node *) c->arg);
1557 
1558  /* generate placeholder for test expression */
1559  if (arg)
1560  {
1561  /*
1562  * If test expression is an untyped literal, force it to text. We have
1563  * to do something now because we won't be able to do this coercion on
1564  * the placeholder. This is not as flexible as what was done in 7.4
1565  * and before, but it's good enough to handle the sort of silly coding
1566  * commonly seen.
1567  */
1568  if (exprType(arg) == UNKNOWNOID)
1569  arg = coerce_to_common_type(pstate, arg, TEXTOID, "CASE");
1570 
1571  /*
1572  * Run collation assignment on the test expression so that we know
1573  * what collation to mark the placeholder with. In principle we could
1574  * leave it to parse_collate.c to do that later, but propagating the
1575  * result to the CaseTestExpr would be unnecessarily complicated.
1576  */
1577  assign_expr_collations(pstate, arg);
1578 
1579  placeholder = makeNode(CaseTestExpr);
1580  placeholder->typeId = exprType(arg);
1581  placeholder->typeMod = exprTypmod(arg);
1582  placeholder->collation = exprCollation(arg);
1583  }
1584  else
1585  placeholder = NULL;
1586 
1587  newc->arg = (Expr *) arg;
1588 
1589  /* transform the list of arguments */
1590  newargs = NIL;
1591  resultexprs = NIL;
1592  foreach(l, c->args)
1593  {
1594  CaseWhen *w = lfirst_node(CaseWhen, l);
1595  CaseWhen *neww = makeNode(CaseWhen);
1596  Node *warg;
1597 
1598  warg = (Node *) w->expr;
1599  if (placeholder)
1600  {
1601  /* shorthand form was specified, so expand... */
1602  warg = (Node *) makeSimpleA_Expr(AEXPR_OP, "=",
1603  (Node *) placeholder,
1604  warg,
1605  w->location);
1606  }
1607  neww->expr = (Expr *) transformExprRecurse(pstate, warg);
1608 
1609  neww->expr = (Expr *) coerce_to_boolean(pstate,
1610  (Node *) neww->expr,
1611  "CASE/WHEN");
1612 
1613  warg = (Node *) w->result;
1614  neww->result = (Expr *) transformExprRecurse(pstate, warg);
1615  neww->location = w->location;
1616 
1617  newargs = lappend(newargs, neww);
1618  resultexprs = lappend(resultexprs, neww->result);
1619  }
1620 
1621  newc->args = newargs;
1622 
1623  /* transform the default clause */
1624  defresult = (Node *) c->defresult;
1625  if (defresult == NULL)
1626  {
1627  A_Const *n = makeNode(A_Const);
1628 
1629  n->val.type = T_Null;
1630  n->location = -1;
1631  defresult = (Node *) n;
1632  }
1633  newc->defresult = (Expr *) transformExprRecurse(pstate, defresult);
1634 
1635  /*
1636  * Note: default result is considered the most significant type in
1637  * determining preferred type. This is how the code worked before, but it
1638  * seems a little bogus to me --- tgl
1639  */
1640  resultexprs = lcons(newc->defresult, resultexprs);
1641 
1642  ptype = select_common_type(pstate, resultexprs, "CASE", NULL);
1643  Assert(OidIsValid(ptype));
1644  newc->casetype = ptype;
1645  /* casecollid will be set by parse_collate.c */
1646 
1647  /* Convert default result clause, if necessary */
1648  newc->defresult = (Expr *)
1649  coerce_to_common_type(pstate,
1650  (Node *) newc->defresult,
1651  ptype,
1652  "CASE/ELSE");
1653 
1654  /* Convert when-clause results, if necessary */
1655  foreach(l, newc->args)
1656  {
1657  CaseWhen *w = (CaseWhen *) lfirst(l);
1658 
1659  w->result = (Expr *)
1660  coerce_to_common_type(pstate,
1661  (Node *) w->result,
1662  ptype,
1663  "CASE/WHEN");
1664  }
1665 
1666  /* if any subexpression contained a SRF, complain */
1667  if (pstate->p_last_srf != last_srf)
1668  ereport(ERROR,
1669  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1670  /* translator: %s is name of a SQL construct, eg GROUP BY */
1671  errmsg("set-returning functions are not allowed in %s",
1672  "CASE"),
1673  errhint("You might be able to move the set-returning function into a LATERAL FROM item."),
1674  parser_errposition(pstate,
1675  exprLocation(pstate->p_last_srf))));
1676 
1677  newc->location = c->location;
1678 
1679  return (Node *) newc;
1680 }
1681 
1682 static Node *
1684 {
1685  Node *result = (Node *) sublink;
1686  Query *qtree;
1687  const char *err;
1688 
1689  /*
1690  * Check to see if the sublink is in an invalid place within the query. We
1691  * allow sublinks everywhere in SELECT/INSERT/UPDATE/DELETE, but generally
1692  * not in utility statements.
1693  */
1694  err = NULL;
1695  switch (pstate->p_expr_kind)
1696  {
1697  case EXPR_KIND_NONE:
1698  Assert(false); /* can't happen */
1699  break;
1700  case EXPR_KIND_OTHER:
1701  /* Accept sublink here; caller must throw error if wanted */
1702  break;
1703  case EXPR_KIND_JOIN_ON:
1704  case EXPR_KIND_JOIN_USING:
1707  case EXPR_KIND_WHERE:
1708  case EXPR_KIND_POLICY:
1709  case EXPR_KIND_HAVING:
1710  case EXPR_KIND_FILTER:
1720  case EXPR_KIND_GROUP_BY:
1721  case EXPR_KIND_ORDER_BY:
1722  case EXPR_KIND_DISTINCT_ON:
1723  case EXPR_KIND_LIMIT:
1724  case EXPR_KIND_OFFSET:
1725  case EXPR_KIND_RETURNING:
1726  case EXPR_KIND_VALUES:
1728  case EXPR_KIND_CYCLE_MARK:
1729  /* okay */
1730  break;
1733  err = _("cannot use subquery in check constraint");
1734  break;
1737  err = _("cannot use subquery in DEFAULT expression");
1738  break;
1740  err = _("cannot use subquery in index expression");
1741  break;
1743  err = _("cannot use subquery in index predicate");
1744  break;
1746  err = _("cannot use subquery in statistics expression");
1747  break;
1749  err = _("cannot use subquery in transform expression");
1750  break;
1752  err = _("cannot use subquery in EXECUTE parameter");
1753  break;
1755  err = _("cannot use subquery in trigger WHEN condition");
1756  break;
1758  err = _("cannot use subquery in partition bound");
1759  break;
1761  err = _("cannot use subquery in partition key expression");
1762  break;
1764  err = _("cannot use subquery in CALL argument");
1765  break;
1766  case EXPR_KIND_COPY_WHERE:
1767  err = _("cannot use subquery in COPY FROM WHERE condition");
1768  break;
1770  err = _("cannot use subquery in column generation expression");
1771  break;
1772 
1773  /*
1774  * There is intentionally no default: case here, so that the
1775  * compiler will warn if we add a new ParseExprKind without
1776  * extending this switch. If we do see an unrecognized value at
1777  * runtime, the behavior will be the same as for EXPR_KIND_OTHER,
1778  * which is sane anyway.
1779  */
1780  }
1781  if (err)
1782  ereport(ERROR,
1783  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1784  errmsg_internal("%s", err),
1785  parser_errposition(pstate, sublink->location)));
1786 
1787  pstate->p_hasSubLinks = true;
1788 
1789  /*
1790  * OK, let's transform the sub-SELECT.
1791  */
1792  qtree = parse_sub_analyze(sublink->subselect, pstate, NULL, false, true);
1793 
1794  /*
1795  * Check that we got a SELECT. Anything else should be impossible given
1796  * restrictions of the grammar, but check anyway.
1797  */
1798  if (!IsA(qtree, Query) ||
1799  qtree->commandType != CMD_SELECT)
1800  elog(ERROR, "unexpected non-SELECT command in SubLink");
1801 
1802  sublink->subselect = (Node *) qtree;
1803 
1804  if (sublink->subLinkType == EXISTS_SUBLINK)
1805  {
1806  /*
1807  * EXISTS needs no test expression or combining operator. These fields
1808  * should be null already, but make sure.
1809  */
1810  sublink->testexpr = NULL;
1811  sublink->operName = NIL;
1812  }
1813  else if (sublink->subLinkType == EXPR_SUBLINK ||
1814  sublink->subLinkType == ARRAY_SUBLINK)
1815  {
1816  /*
1817  * Make sure the subselect delivers a single column (ignoring resjunk
1818  * targets).
1819  */
1820  if (count_nonjunk_tlist_entries(qtree->targetList) != 1)
1821  ereport(ERROR,
1822  (errcode(ERRCODE_SYNTAX_ERROR),
1823  errmsg("subquery must return only one column"),
1824  parser_errposition(pstate, sublink->location)));
1825 
1826  /*
1827  * EXPR and ARRAY need no test expression or combining operator. These
1828  * fields should be null already, but make sure.
1829  */
1830  sublink->testexpr = NULL;
1831  sublink->operName = NIL;
1832  }
1833  else if (sublink->subLinkType == MULTIEXPR_SUBLINK)
1834  {
1835  /* Same as EXPR case, except no restriction on number of columns */
1836  sublink->testexpr = NULL;
1837  sublink->operName = NIL;
1838  }
1839  else
1840  {
1841  /* ALL, ANY, or ROWCOMPARE: generate row-comparing expression */
1842  Node *lefthand;
1843  List *left_list;
1844  List *right_list;
1845  ListCell *l;
1846 
1847  /*
1848  * If the source was "x IN (select)", convert to "x = ANY (select)".
1849  */
1850  if (sublink->operName == NIL)
1851  sublink->operName = list_make1(makeString("="));
1852 
1853  /*
1854  * Transform lefthand expression, and convert to a list
1855  */
1856  lefthand = transformExprRecurse(pstate, sublink->testexpr);
1857  if (lefthand && IsA(lefthand, RowExpr))
1858  left_list = ((RowExpr *) lefthand)->args;
1859  else
1860  left_list = list_make1(lefthand);
1861 
1862  /*
1863  * Build a list of PARAM_SUBLINK nodes representing the output columns
1864  * of the subquery.
1865  */
1866  right_list = NIL;
1867  foreach(l, qtree->targetList)
1868  {
1869  TargetEntry *tent = (TargetEntry *) lfirst(l);
1870  Param *param;
1871 
1872  if (tent->resjunk)
1873  continue;
1874 
1875  param = makeNode(Param);
1876  param->paramkind = PARAM_SUBLINK;
1877  param->paramid = tent->resno;
1878  param->paramtype = exprType((Node *) tent->expr);
1879  param->paramtypmod = exprTypmod((Node *) tent->expr);
1880  param->paramcollid = exprCollation((Node *) tent->expr);
1881  param->location = -1;
1882 
1883  right_list = lappend(right_list, param);
1884  }
1885 
1886  /*
1887  * We could rely on make_row_comparison_op to complain if the list
1888  * lengths differ, but we prefer to generate a more specific error
1889  * message.
1890  */
1891  if (list_length(left_list) < list_length(right_list))
1892  ereport(ERROR,
1893  (errcode(ERRCODE_SYNTAX_ERROR),
1894  errmsg("subquery has too many columns"),
1895  parser_errposition(pstate, sublink->location)));
1896  if (list_length(left_list) > list_length(right_list))
1897  ereport(ERROR,
1898  (errcode(ERRCODE_SYNTAX_ERROR),
1899  errmsg("subquery has too few columns"),
1900  parser_errposition(pstate, sublink->location)));
1901 
1902  /*
1903  * Identify the combining operator(s) and generate a suitable
1904  * row-comparison expression.
1905  */
1906  sublink->testexpr = make_row_comparison_op(pstate,
1907  sublink->operName,
1908  left_list,
1909  right_list,
1910  sublink->location);
1911  }
1912 
1913  return result;
1914 }
1915 
1916 /*
1917  * transformArrayExpr
1918  *
1919  * If the caller specifies the target type, the resulting array will
1920  * be of exactly that type. Otherwise we try to infer a common type
1921  * for the elements using select_common_type().
1922  */
1923 static Node *
1925  Oid array_type, Oid element_type, int32 typmod)
1926 {
1927  ArrayExpr *newa = makeNode(ArrayExpr);
1928  List *newelems = NIL;
1929  List *newcoercedelems = NIL;
1930  ListCell *element;
1931  Oid coerce_type;
1932  bool coerce_hard;
1933 
1934  /*
1935  * Transform the element expressions
1936  *
1937  * Assume that the array is one-dimensional unless we find an array-type
1938  * element expression.
1939  */
1940  newa->multidims = false;
1941  foreach(element, a->elements)
1942  {
1943  Node *e = (Node *) lfirst(element);
1944  Node *newe;
1945 
1946  /*
1947  * If an element is itself an A_ArrayExpr, recurse directly so that we
1948  * can pass down any target type we were given.
1949  */
1950  if (IsA(e, A_ArrayExpr))
1951  {
1952  newe = transformArrayExpr(pstate,
1953  (A_ArrayExpr *) e,
1954  array_type,
1955  element_type,
1956  typmod);
1957  /* we certainly have an array here */
1958  Assert(array_type == InvalidOid || array_type == exprType(newe));
1959  newa->multidims = true;
1960  }
1961  else
1962  {
1963  newe = transformExprRecurse(pstate, e);
1964 
1965  /*
1966  * Check for sub-array expressions, if we haven't already found
1967  * one.
1968  */
1969  if (!newa->multidims && type_is_array(exprType(newe)))
1970  newa->multidims = true;
1971  }
1972 
1973  newelems = lappend(newelems, newe);
1974  }
1975 
1976  /*
1977  * Select a target type for the elements.
1978  *
1979  * If we haven't been given a target array type, we must try to deduce a
1980  * common type based on the types of the individual elements present.
1981  */
1982  if (OidIsValid(array_type))
1983  {
1984  /* Caller must ensure array_type matches element_type */
1985  Assert(OidIsValid(element_type));
1986  coerce_type = (newa->multidims ? array_type : element_type);
1987  coerce_hard = true;
1988  }
1989  else
1990  {
1991  /* Can't handle an empty array without a target type */
1992  if (newelems == NIL)
1993  ereport(ERROR,
1994  (errcode(ERRCODE_INDETERMINATE_DATATYPE),
1995  errmsg("cannot determine type of empty array"),
1996  errhint("Explicitly cast to the desired type, "
1997  "for example ARRAY[]::integer[]."),
1998  parser_errposition(pstate, a->location)));
1999 
2000  /* Select a common type for the elements */
2001  coerce_type = select_common_type(pstate, newelems, "ARRAY", NULL);
2002 
2003  if (newa->multidims)
2004  {
2005  array_type = coerce_type;
2006  element_type = get_element_type(array_type);
2007  if (!OidIsValid(element_type))
2008  ereport(ERROR,
2009  (errcode(ERRCODE_UNDEFINED_OBJECT),
2010  errmsg("could not find element type for data type %s",
2011  format_type_be(array_type)),
2012  parser_errposition(pstate, a->location)));
2013  }
2014  else
2015  {
2016  element_type = coerce_type;
2017  array_type = get_array_type(element_type);
2018  if (!OidIsValid(array_type))
2019  ereport(ERROR,
2020  (errcode(ERRCODE_UNDEFINED_OBJECT),
2021  errmsg("could not find array type for data type %s",
2022  format_type_be(element_type)),
2023  parser_errposition(pstate, a->location)));
2024  }
2025  coerce_hard = false;
2026  }
2027 
2028  /*
2029  * Coerce elements to target type
2030  *
2031  * If the array has been explicitly cast, then the elements are in turn
2032  * explicitly coerced.
2033  *
2034  * If the array's type was merely derived from the common type of its
2035  * elements, then the elements are implicitly coerced to the common type.
2036  * This is consistent with other uses of select_common_type().
2037  */
2038  foreach(element, newelems)
2039  {
2040  Node *e = (Node *) lfirst(element);
2041  Node *newe;
2042 
2043  if (coerce_hard)
2044  {
2045  newe = coerce_to_target_type(pstate, e,
2046  exprType(e),
2047  coerce_type,
2048  typmod,
2051  -1);
2052  if (newe == NULL)
2053  ereport(ERROR,
2054  (errcode(ERRCODE_CANNOT_COERCE),
2055  errmsg("cannot cast type %s to %s",
2057  format_type_be(coerce_type)),
2058  parser_errposition(pstate, exprLocation(e))));
2059  }
2060  else
2061  newe = coerce_to_common_type(pstate, e,
2062  coerce_type,
2063  "ARRAY");
2064  newcoercedelems = lappend(newcoercedelems, newe);
2065  }
2066 
2067  newa->array_typeid = array_type;
2068  /* array_collid will be set by parse_collate.c */
2069  newa->element_typeid = element_type;
2070  newa->elements = newcoercedelems;
2071  newa->location = a->location;
2072 
2073  return (Node *) newa;
2074 }
2075 
2076 static Node *
2077 transformRowExpr(ParseState *pstate, RowExpr *r, bool allowDefault)
2078 {
2079  RowExpr *newr;
2080  char fname[16];
2081  int fnum;
2082 
2083  newr = makeNode(RowExpr);
2084 
2085  /* Transform the field expressions */
2086  newr->args = transformExpressionList(pstate, r->args,
2087  pstate->p_expr_kind, allowDefault);
2088 
2089  /* Barring later casting, we consider the type RECORD */
2090  newr->row_typeid = RECORDOID;
2092 
2093  /* ROW() has anonymous columns, so invent some field names */
2094  newr->colnames = NIL;
2095  for (fnum = 1; fnum <= list_length(newr->args); fnum++)
2096  {
2097  snprintf(fname, sizeof(fname), "f%d", fnum);
2098  newr->colnames = lappend(newr->colnames, makeString(pstrdup(fname)));
2099  }
2100 
2101  newr->location = r->location;
2102 
2103  return (Node *) newr;
2104 }
2105 
2106 static Node *
2108 {
2110  Node *last_srf = pstate->p_last_srf;
2111  List *newargs = NIL;
2112  List *newcoercedargs = NIL;
2113  ListCell *args;
2114 
2115  foreach(args, c->args)
2116  {
2117  Node *e = (Node *) lfirst(args);
2118  Node *newe;
2119 
2120  newe = transformExprRecurse(pstate, e);
2121  newargs = lappend(newargs, newe);
2122  }
2123 
2124  newc->coalescetype = select_common_type(pstate, newargs, "COALESCE", NULL);
2125  /* coalescecollid will be set by parse_collate.c */
2126 
2127  /* Convert arguments if necessary */
2128  foreach(args, newargs)
2129  {
2130  Node *e = (Node *) lfirst(args);
2131  Node *newe;
2132 
2133  newe = coerce_to_common_type(pstate, e,
2134  newc->coalescetype,
2135  "COALESCE");
2136  newcoercedargs = lappend(newcoercedargs, newe);
2137  }
2138 
2139  /* if any subexpression contained a SRF, complain */
2140  if (pstate->p_last_srf != last_srf)
2141  ereport(ERROR,
2142  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2143  /* translator: %s is name of a SQL construct, eg GROUP BY */
2144  errmsg("set-returning functions are not allowed in %s",
2145  "COALESCE"),
2146  errhint("You might be able to move the set-returning function into a LATERAL FROM item."),
2147  parser_errposition(pstate,
2148  exprLocation(pstate->p_last_srf))));
2149 
2150  newc->args = newcoercedargs;
2151  newc->location = c->location;
2152  return (Node *) newc;
2153 }
2154 
2155 static Node *
2157 {
2158  MinMaxExpr *newm = makeNode(MinMaxExpr);
2159  List *newargs = NIL;
2160  List *newcoercedargs = NIL;
2161  const char *funcname = (m->op == IS_GREATEST) ? "GREATEST" : "LEAST";
2162  ListCell *args;
2163 
2164  newm->op = m->op;
2165  foreach(args, m->args)
2166  {
2167  Node *e = (Node *) lfirst(args);
2168  Node *newe;
2169 
2170  newe = transformExprRecurse(pstate, e);
2171  newargs = lappend(newargs, newe);
2172  }
2173 
2174  newm->minmaxtype = select_common_type(pstate, newargs, funcname, NULL);
2175  /* minmaxcollid and inputcollid will be set by parse_collate.c */
2176 
2177  /* Convert arguments if necessary */
2178  foreach(args, newargs)
2179  {
2180  Node *e = (Node *) lfirst(args);
2181  Node *newe;
2182 
2183  newe = coerce_to_common_type(pstate, e,
2184  newm->minmaxtype,
2185  funcname);
2186  newcoercedargs = lappend(newcoercedargs, newe);
2187  }
2188 
2189  newm->args = newcoercedargs;
2190  newm->location = m->location;
2191  return (Node *) newm;
2192 }
2193 
2194 static Node *
2196 {
2197  /*
2198  * All we need to do is insert the correct result type and (where needed)
2199  * validate the typmod, so we just modify the node in-place.
2200  */
2201  switch (svf->op)
2202  {
2203  case SVFOP_CURRENT_DATE:
2204  svf->type = DATEOID;
2205  break;
2206  case SVFOP_CURRENT_TIME:
2207  svf->type = TIMETZOID;
2208  break;
2209  case SVFOP_CURRENT_TIME_N:
2210  svf->type = TIMETZOID;
2211  svf->typmod = anytime_typmod_check(true, svf->typmod);
2212  break;
2214  svf->type = TIMESTAMPTZOID;
2215  break;
2217  svf->type = TIMESTAMPTZOID;
2218  svf->typmod = anytimestamp_typmod_check(true, svf->typmod);
2219  break;
2220  case SVFOP_LOCALTIME:
2221  svf->type = TIMEOID;
2222  break;
2223  case SVFOP_LOCALTIME_N:
2224  svf->type = TIMEOID;
2225  svf->typmod = anytime_typmod_check(false, svf->typmod);
2226  break;
2227  case SVFOP_LOCALTIMESTAMP:
2228  svf->type = TIMESTAMPOID;
2229  break;
2231  svf->type = TIMESTAMPOID;
2232  svf->typmod = anytimestamp_typmod_check(false, svf->typmod);
2233  break;
2234  case SVFOP_CURRENT_ROLE:
2235  case SVFOP_CURRENT_USER:
2236  case SVFOP_USER:
2237  case SVFOP_SESSION_USER:
2238  case SVFOP_CURRENT_CATALOG:
2239  case SVFOP_CURRENT_SCHEMA:
2240  svf->type = NAMEOID;
2241  break;
2242  }
2243 
2244  return (Node *) svf;
2245 }
2246 
2247 static Node *
2249 {
2250  XmlExpr *newx;
2251  ListCell *lc;
2252  int i;
2253 
2254  newx = makeNode(XmlExpr);
2255  newx->op = x->op;
2256  if (x->name)
2257  newx->name = map_sql_identifier_to_xml_name(x->name, false, false);
2258  else
2259  newx->name = NULL;
2260  newx->xmloption = x->xmloption;
2261  newx->type = XMLOID; /* this just marks the node as transformed */
2262  newx->typmod = -1;
2263  newx->location = x->location;
2264 
2265  /*
2266  * gram.y built the named args as a list of ResTarget. Transform each,
2267  * and break the names out as a separate list.
2268  */
2269  newx->named_args = NIL;
2270  newx->arg_names = NIL;
2271 
2272  foreach(lc, x->named_args)
2273  {
2274  ResTarget *r = lfirst_node(ResTarget, lc);
2275  Node *expr;
2276  char *argname;
2277 
2278  expr = transformExprRecurse(pstate, r->val);
2279 
2280  if (r->name)
2281  argname = map_sql_identifier_to_xml_name(r->name, false, false);
2282  else if (IsA(r->val, ColumnRef))
2284  true, false);
2285  else
2286  {
2287  ereport(ERROR,
2288  (errcode(ERRCODE_SYNTAX_ERROR),
2289  x->op == IS_XMLELEMENT
2290  ? errmsg("unnamed XML attribute value must be a column reference")
2291  : errmsg("unnamed XML element value must be a column reference"),
2292  parser_errposition(pstate, r->location)));
2293  argname = NULL; /* keep compiler quiet */
2294  }
2295 
2296  /* reject duplicate argnames in XMLELEMENT only */
2297  if (x->op == IS_XMLELEMENT)
2298  {
2299  ListCell *lc2;
2300 
2301  foreach(lc2, newx->arg_names)
2302  {
2303  if (strcmp(argname, strVal(lfirst(lc2))) == 0)
2304  ereport(ERROR,
2305  (errcode(ERRCODE_SYNTAX_ERROR),
2306  errmsg("XML attribute name \"%s\" appears more than once",
2307  argname),
2308  parser_errposition(pstate, r->location)));
2309  }
2310  }
2311 
2312  newx->named_args = lappend(newx->named_args, expr);
2313  newx->arg_names = lappend(newx->arg_names, makeString(argname));
2314  }
2315 
2316  /* The other arguments are of varying types depending on the function */
2317  newx->args = NIL;
2318  i = 0;
2319  foreach(lc, x->args)
2320  {
2321  Node *e = (Node *) lfirst(lc);
2322  Node *newe;
2323 
2324  newe = transformExprRecurse(pstate, e);
2325  switch (x->op)
2326  {
2327  case IS_XMLCONCAT:
2328  newe = coerce_to_specific_type(pstate, newe, XMLOID,
2329  "XMLCONCAT");
2330  break;
2331  case IS_XMLELEMENT:
2332  /* no coercion necessary */
2333  break;
2334  case IS_XMLFOREST:
2335  newe = coerce_to_specific_type(pstate, newe, XMLOID,
2336  "XMLFOREST");
2337  break;
2338  case IS_XMLPARSE:
2339  if (i == 0)
2340  newe = coerce_to_specific_type(pstate, newe, TEXTOID,
2341  "XMLPARSE");
2342  else
2343  newe = coerce_to_boolean(pstate, newe, "XMLPARSE");
2344  break;
2345  case IS_XMLPI:
2346  newe = coerce_to_specific_type(pstate, newe, TEXTOID,
2347  "XMLPI");
2348  break;
2349  case IS_XMLROOT:
2350  if (i == 0)
2351  newe = coerce_to_specific_type(pstate, newe, XMLOID,
2352  "XMLROOT");
2353  else if (i == 1)
2354  newe = coerce_to_specific_type(pstate, newe, TEXTOID,
2355  "XMLROOT");
2356  else
2357  newe = coerce_to_specific_type(pstate, newe, INT4OID,
2358  "XMLROOT");
2359  break;
2360  case IS_XMLSERIALIZE:
2361  /* not handled here */
2362  Assert(false);
2363  break;
2364  case IS_DOCUMENT:
2365  newe = coerce_to_specific_type(pstate, newe, XMLOID,
2366  "IS DOCUMENT");
2367  break;
2368  }
2369  newx->args = lappend(newx->args, newe);
2370  i++;
2371  }
2372 
2373  return (Node *) newx;
2374 }
2375 
2376 static Node *
2378 {
2379  Node *result;
2380  XmlExpr *xexpr;
2381  Oid targetType;
2382  int32 targetTypmod;
2383 
2384  xexpr = makeNode(XmlExpr);
2385  xexpr->op = IS_XMLSERIALIZE;
2386  xexpr->args = list_make1(coerce_to_specific_type(pstate,
2387  transformExprRecurse(pstate, xs->expr),
2388  XMLOID,
2389  "XMLSERIALIZE"));
2390 
2391  typenameTypeIdAndMod(pstate, xs->typeName, &targetType, &targetTypmod);
2392 
2393  xexpr->xmloption = xs->xmloption;
2394  xexpr->location = xs->location;
2395  /* We actually only need these to be able to parse back the expression. */
2396  xexpr->type = targetType;
2397  xexpr->typmod = targetTypmod;
2398 
2399  /*
2400  * The actual target type is determined this way. SQL allows char and
2401  * varchar as target types. We allow anything that can be cast implicitly
2402  * from text. This way, user-defined text-like data types automatically
2403  * fit in.
2404  */
2405  result = coerce_to_target_type(pstate, (Node *) xexpr,
2406  TEXTOID, targetType, targetTypmod,
2409  -1);
2410  if (result == NULL)
2411  ereport(ERROR,
2412  (errcode(ERRCODE_CANNOT_COERCE),
2413  errmsg("cannot cast XMLSERIALIZE result to %s",
2414  format_type_be(targetType)),
2415  parser_errposition(pstate, xexpr->location)));
2416  return result;
2417 }
2418 
2419 static Node *
2421 {
2422  const char *clausename;
2423 
2424  switch (b->booltesttype)
2425  {
2426  case IS_TRUE:
2427  clausename = "IS TRUE";
2428  break;
2429  case IS_NOT_TRUE:
2430  clausename = "IS NOT TRUE";
2431  break;
2432  case IS_FALSE:
2433  clausename = "IS FALSE";
2434  break;
2435  case IS_NOT_FALSE:
2436  clausename = "IS NOT FALSE";
2437  break;
2438  case IS_UNKNOWN:
2439  clausename = "IS UNKNOWN";
2440  break;
2441  case IS_NOT_UNKNOWN:
2442  clausename = "IS NOT UNKNOWN";
2443  break;
2444  default:
2445  elog(ERROR, "unrecognized booltesttype: %d",
2446  (int) b->booltesttype);
2447  clausename = NULL; /* keep compiler quiet */
2448  }
2449 
2450  b->arg = (Expr *) transformExprRecurse(pstate, (Node *) b->arg);
2451 
2452  b->arg = (Expr *) coerce_to_boolean(pstate,
2453  (Node *) b->arg,
2454  clausename);
2455 
2456  return (Node *) b;
2457 }
2458 
2459 static Node *
2461 {
2462  /* CURRENT OF can only appear at top level of UPDATE/DELETE */
2463  Assert(pstate->p_target_nsitem != NULL);
2464  cexpr->cvarno = pstate->p_target_nsitem->p_rtindex;
2465 
2466  /*
2467  * Check to see if the cursor name matches a parameter of type REFCURSOR.
2468  * If so, replace the raw name reference with a parameter reference. (This
2469  * is a hack for the convenience of plpgsql.)
2470  */
2471  if (cexpr->cursor_name != NULL) /* in case already transformed */
2472  {
2473  ColumnRef *cref = makeNode(ColumnRef);
2474  Node *node = NULL;
2475 
2476  /* Build an unqualified ColumnRef with the given name */
2477  cref->fields = list_make1(makeString(cexpr->cursor_name));
2478  cref->location = -1;
2479 
2480  /* See if there is a translation available from a parser hook */
2481  if (pstate->p_pre_columnref_hook != NULL)
2482  node = pstate->p_pre_columnref_hook(pstate, cref);
2483  if (node == NULL && pstate->p_post_columnref_hook != NULL)
2484  node = pstate->p_post_columnref_hook(pstate, cref, NULL);
2485 
2486  /*
2487  * XXX Should we throw an error if we get a translation that isn't a
2488  * refcursor Param? For now it seems best to silently ignore false
2489  * matches.
2490  */
2491  if (node != NULL && IsA(node, Param))
2492  {
2493  Param *p = (Param *) node;
2494 
2495  if (p->paramkind == PARAM_EXTERN &&
2496  p->paramtype == REFCURSOROID)
2497  {
2498  /* Matches, so convert CURRENT OF to a param reference */
2499  cexpr->cursor_name = NULL;
2500  cexpr->cursor_param = p->paramid;
2501  }
2502  }
2503  }
2504 
2505  return (Node *) cexpr;
2506 }
2507 
2508 /*
2509  * Construct a whole-row reference to represent the notation "relation.*".
2510  */
2511 static Node *
2513  int sublevels_up, int location)
2514 {
2515  /*
2516  * Build the appropriate referencing node. Normally this can be a
2517  * whole-row Var, but if the nsitem is a JOIN USING alias then it contains
2518  * only a subset of the columns of the underlying join RTE, so that will
2519  * not work. Instead we immediately expand the reference into a RowExpr.
2520  * Since the JOIN USING's common columns are fully determined at this
2521  * point, there seems no harm in expanding it now rather than during
2522  * planning.
2523  *
2524  * Note that if the RTE is a function returning scalar, we create just a
2525  * plain reference to the function value, not a composite containing a
2526  * single column. This is pretty inconsistent at first sight, but it's
2527  * what we've done historically. One argument for it is that "rel" and
2528  * "rel.*" mean the same thing for composite relations, so why not for
2529  * scalar functions...
2530  */
2531  if (nsitem->p_names == nsitem->p_rte->eref)
2532  {
2533  Var *result;
2534 
2535  result = makeWholeRowVar(nsitem->p_rte, nsitem->p_rtindex,
2536  sublevels_up, true);
2537 
2538  /* location is not filled in by makeWholeRowVar */
2539  result->location = location;
2540 
2541  /* mark relation as requiring whole-row SELECT access */
2542  markVarForSelectPriv(pstate, result);
2543 
2544  return (Node *) result;
2545  }
2546  else
2547  {
2548  RowExpr *rowexpr;
2549  List *fields;
2550 
2551  /*
2552  * We want only as many columns as are listed in p_names->colnames,
2553  * and we should use those names not whatever possibly-aliased names
2554  * are in the RTE. We needn't worry about marking the RTE for SELECT
2555  * access, as the common columns are surely so marked already.
2556  */
2557  expandRTE(nsitem->p_rte, nsitem->p_rtindex,
2558  sublevels_up, location, false,
2559  NULL, &fields);
2560  rowexpr = makeNode(RowExpr);
2561  rowexpr->args = list_truncate(fields,
2562  list_length(nsitem->p_names->colnames));
2563  rowexpr->row_typeid = RECORDOID;
2564  rowexpr->row_format = COERCE_IMPLICIT_CAST;
2565  rowexpr->colnames = copyObject(nsitem->p_names->colnames);
2566  rowexpr->location = location;
2567 
2568  return (Node *) rowexpr;
2569  }
2570 }
2571 
2572 /*
2573  * Handle an explicit CAST construct.
2574  *
2575  * Transform the argument, look up the type name, and apply any necessary
2576  * coercion function(s).
2577  */
2578 static Node *
2580 {
2581  Node *result;
2582  Node *arg = tc->arg;
2583  Node *expr;
2584  Oid inputType;
2585  Oid targetType;
2586  int32 targetTypmod;
2587  int location;
2588 
2589  /* Look up the type name first */
2590  typenameTypeIdAndMod(pstate, tc->typeName, &targetType, &targetTypmod);
2591 
2592  /*
2593  * If the subject of the typecast is an ARRAY[] construct and the target
2594  * type is an array type, we invoke transformArrayExpr() directly so that
2595  * we can pass down the type information. This avoids some cases where
2596  * transformArrayExpr() might not infer the correct type. Otherwise, just
2597  * transform the argument normally.
2598  */
2599  if (IsA(arg, A_ArrayExpr))
2600  {
2601  Oid targetBaseType;
2602  int32 targetBaseTypmod;
2603  Oid elementType;
2604 
2605  /*
2606  * If target is a domain over array, work with the base array type
2607  * here. Below, we'll cast the array type to the domain. In the
2608  * usual case that the target is not a domain, the remaining steps
2609  * will be a no-op.
2610  */
2611  targetBaseTypmod = targetTypmod;
2612  targetBaseType = getBaseTypeAndTypmod(targetType, &targetBaseTypmod);
2613  elementType = get_element_type(targetBaseType);
2614  if (OidIsValid(elementType))
2615  {
2616  expr = transformArrayExpr(pstate,
2617  (A_ArrayExpr *) arg,
2618  targetBaseType,
2619  elementType,
2620  targetBaseTypmod);
2621  }
2622  else
2623  expr = transformExprRecurse(pstate, arg);
2624  }
2625  else
2626  expr = transformExprRecurse(pstate, arg);
2627 
2628  inputType = exprType(expr);
2629  if (inputType == InvalidOid)
2630  return expr; /* do nothing if NULL input */
2631 
2632  /*
2633  * Location of the coercion is preferentially the location of the :: or
2634  * CAST symbol, but if there is none then use the location of the type
2635  * name (this can happen in TypeName 'string' syntax, for instance).
2636  */
2637  location = tc->location;
2638  if (location < 0)
2639  location = tc->typeName->location;
2640 
2641  result = coerce_to_target_type(pstate, expr, inputType,
2642  targetType, targetTypmod,
2645  location);
2646  if (result == NULL)
2647  ereport(ERROR,
2648  (errcode(ERRCODE_CANNOT_COERCE),
2649  errmsg("cannot cast type %s to %s",
2650  format_type_be(inputType),
2651  format_type_be(targetType)),
2652  parser_coercion_errposition(pstate, location, expr)));
2653 
2654  return result;
2655 }
2656 
2657 /*
2658  * Handle an explicit COLLATE clause.
2659  *
2660  * Transform the argument, and look up the collation name.
2661  */
2662 static Node *
2664 {
2665  CollateExpr *newc;
2666  Oid argtype;
2667 
2668  newc = makeNode(CollateExpr);
2669  newc->arg = (Expr *) transformExprRecurse(pstate, c->arg);
2670 
2671  argtype = exprType((Node *) newc->arg);
2672 
2673  /*
2674  * The unknown type is not collatable, but coerce_type() takes care of it
2675  * separately, so we'll let it go here.
2676  */
2677  if (!type_is_collatable(argtype) && argtype != UNKNOWNOID)
2678  ereport(ERROR,
2679  (errcode(ERRCODE_DATATYPE_MISMATCH),
2680  errmsg("collations are not supported by type %s",
2681  format_type_be(argtype)),
2682  parser_errposition(pstate, c->location)));
2683 
2684  newc->collOid = LookupCollation(pstate, c->collname, c->location);
2685  newc->location = c->location;
2686 
2687  return (Node *) newc;
2688 }
2689 
2690 /*
2691  * Transform a "row compare-op row" construct
2692  *
2693  * The inputs are lists of already-transformed expressions.
2694  * As with coerce_type, pstate may be NULL if no special unknown-Param
2695  * processing is wanted.
2696  *
2697  * The output may be a single OpExpr, an AND or OR combination of OpExprs,
2698  * or a RowCompareExpr. In all cases it is guaranteed to return boolean.
2699  * The AND, OR, and RowCompareExpr cases further imply things about the
2700  * behavior of the operators (ie, they behave as =, <>, or < <= > >=).
2701  */
2702 static Node *
2704  List *largs, List *rargs, int location)
2705 {
2706  RowCompareExpr *rcexpr;
2707  RowCompareType rctype;
2708  List *opexprs;
2709  List *opnos;
2710  List *opfamilies;
2711  ListCell *l,
2712  *r;
2713  List **opinfo_lists;
2714  Bitmapset *strats;
2715  int nopers;
2716  int i;
2717 
2718  nopers = list_length(largs);
2719  if (nopers != list_length(rargs))
2720  ereport(ERROR,
2721  (errcode(ERRCODE_SYNTAX_ERROR),
2722  errmsg("unequal number of entries in row expressions"),
2723  parser_errposition(pstate, location)));
2724 
2725  /*
2726  * We can't compare zero-length rows because there is no principled basis
2727  * for figuring out what the operator is.
2728  */
2729  if (nopers == 0)
2730  ereport(ERROR,
2731  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2732  errmsg("cannot compare rows of zero length"),
2733  parser_errposition(pstate, location)));
2734 
2735  /*
2736  * Identify all the pairwise operators, using make_op so that behavior is
2737  * the same as in the simple scalar case.
2738  */
2739  opexprs = NIL;
2740  forboth(l, largs, r, rargs)
2741  {
2742  Node *larg = (Node *) lfirst(l);
2743  Node *rarg = (Node *) lfirst(r);
2744  OpExpr *cmp;
2745 
2746  cmp = castNode(OpExpr, make_op(pstate, opname, larg, rarg,
2747  pstate->p_last_srf, location));
2748 
2749  /*
2750  * We don't use coerce_to_boolean here because we insist on the
2751  * operator yielding boolean directly, not via coercion. If it
2752  * doesn't yield bool it won't be in any index opfamilies...
2753  */
2754  if (cmp->opresulttype != BOOLOID)
2755  ereport(ERROR,
2756  (errcode(ERRCODE_DATATYPE_MISMATCH),
2757  errmsg("row comparison operator must yield type boolean, "
2758  "not type %s",
2760  parser_errposition(pstate, location)));
2761  if (expression_returns_set((Node *) cmp))
2762  ereport(ERROR,
2763  (errcode(ERRCODE_DATATYPE_MISMATCH),
2764  errmsg("row comparison operator must not return a set"),
2765  parser_errposition(pstate, location)));
2766  opexprs = lappend(opexprs, cmp);
2767  }
2768 
2769  /*
2770  * If rows are length 1, just return the single operator. In this case we
2771  * don't insist on identifying btree semantics for the operator (but we
2772  * still require it to return boolean).
2773  */
2774  if (nopers == 1)
2775  return (Node *) linitial(opexprs);
2776 
2777  /*
2778  * Now we must determine which row comparison semantics (= <> < <= > >=)
2779  * apply to this set of operators. We look for btree opfamilies
2780  * containing the operators, and see which interpretations (strategy
2781  * numbers) exist for each operator.
2782  */
2783  opinfo_lists = (List **) palloc(nopers * sizeof(List *));
2784  strats = NULL;
2785  i = 0;
2786  foreach(l, opexprs)
2787  {
2788  Oid opno = ((OpExpr *) lfirst(l))->opno;
2789  Bitmapset *this_strats;
2790  ListCell *j;
2791 
2792  opinfo_lists[i] = get_op_btree_interpretation(opno);
2793 
2794  /*
2795  * convert strategy numbers into a Bitmapset to make the intersection
2796  * calculation easy.
2797  */
2798  this_strats = NULL;
2799  foreach(j, opinfo_lists[i])
2800  {
2801  OpBtreeInterpretation *opinfo = lfirst(j);
2802 
2803  this_strats = bms_add_member(this_strats, opinfo->strategy);
2804  }
2805  if (i == 0)
2806  strats = this_strats;
2807  else
2808  strats = bms_int_members(strats, this_strats);
2809  i++;
2810  }
2811 
2812  /*
2813  * If there are multiple common interpretations, we may use any one of
2814  * them ... this coding arbitrarily picks the lowest btree strategy
2815  * number.
2816  */
2817  i = bms_first_member(strats);
2818  if (i < 0)
2819  {
2820  /* No common interpretation, so fail */
2821  ereport(ERROR,
2822  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2823  errmsg("could not determine interpretation of row comparison operator %s",
2824  strVal(llast(opname))),
2825  errhint("Row comparison operators must be associated with btree operator families."),
2826  parser_errposition(pstate, location)));
2827  }
2828  rctype = (RowCompareType) i;
2829 
2830  /*
2831  * For = and <> cases, we just combine the pairwise operators with AND or
2832  * OR respectively.
2833  */
2834  if (rctype == ROWCOMPARE_EQ)
2835  return (Node *) makeBoolExpr(AND_EXPR, opexprs, location);
2836  if (rctype == ROWCOMPARE_NE)
2837  return (Node *) makeBoolExpr(OR_EXPR, opexprs, location);
2838 
2839  /*
2840  * Otherwise we need to choose exactly which opfamily to associate with
2841  * each operator.
2842  */
2843  opfamilies = NIL;
2844  for (i = 0; i < nopers; i++)
2845  {
2846  Oid opfamily = InvalidOid;
2847  ListCell *j;
2848 
2849  foreach(j, opinfo_lists[i])
2850  {
2851  OpBtreeInterpretation *opinfo = lfirst(j);
2852 
2853  if (opinfo->strategy == rctype)
2854  {
2855  opfamily = opinfo->opfamily_id;
2856  break;
2857  }
2858  }
2859  if (OidIsValid(opfamily))
2860  opfamilies = lappend_oid(opfamilies, opfamily);
2861  else /* should not happen */
2862  ereport(ERROR,
2863  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2864  errmsg("could not determine interpretation of row comparison operator %s",
2865  strVal(llast(opname))),
2866  errdetail("There are multiple equally-plausible candidates."),
2867  parser_errposition(pstate, location)));
2868  }
2869 
2870  /*
2871  * Now deconstruct the OpExprs and create a RowCompareExpr.
2872  *
2873  * Note: can't just reuse the passed largs/rargs lists, because of
2874  * possibility that make_op inserted coercion operations.
2875  */
2876  opnos = NIL;
2877  largs = NIL;
2878  rargs = NIL;
2879  foreach(l, opexprs)
2880  {
2881  OpExpr *cmp = (OpExpr *) lfirst(l);
2882 
2883  opnos = lappend_oid(opnos, cmp->opno);
2884  largs = lappend(largs, linitial(cmp->args));
2885  rargs = lappend(rargs, lsecond(cmp->args));
2886  }
2887 
2888  rcexpr = makeNode(RowCompareExpr);
2889  rcexpr->rctype = rctype;
2890  rcexpr->opnos = opnos;
2891  rcexpr->opfamilies = opfamilies;
2892  rcexpr->inputcollids = NIL; /* assign_expr_collations will fix this */
2893  rcexpr->largs = largs;
2894  rcexpr->rargs = rargs;
2895 
2896  return (Node *) rcexpr;
2897 }
2898 
2899 /*
2900  * Transform a "row IS DISTINCT FROM row" construct
2901  *
2902  * The input RowExprs are already transformed
2903  */
2904 static Node *
2906  RowExpr *lrow, RowExpr *rrow,
2907  int location)
2908 {
2909  Node *result = NULL;
2910  List *largs = lrow->args;
2911  List *rargs = rrow->args;
2912  ListCell *l,
2913  *r;
2914 
2915  if (list_length(largs) != list_length(rargs))
2916  ereport(ERROR,
2917  (errcode(ERRCODE_SYNTAX_ERROR),
2918  errmsg("unequal number of entries in row expressions"),
2919  parser_errposition(pstate, location)));
2920 
2921  forboth(l, largs, r, rargs)
2922  {
2923  Node *larg = (Node *) lfirst(l);
2924  Node *rarg = (Node *) lfirst(r);
2925  Node *cmp;
2926 
2927  cmp = (Node *) make_distinct_op(pstate, opname, larg, rarg, location);
2928  if (result == NULL)
2929  result = cmp;
2930  else
2931  result = (Node *) makeBoolExpr(OR_EXPR,
2932  list_make2(result, cmp),
2933  location);
2934  }
2935 
2936  if (result == NULL)
2937  {
2938  /* zero-length rows? Generate constant FALSE */
2939  result = makeBoolConst(false, false);
2940  }
2941 
2942  return result;
2943 }
2944 
2945 /*
2946  * make the node for an IS DISTINCT FROM operator
2947  */
2948 static Expr *
2949 make_distinct_op(ParseState *pstate, List *opname, Node *ltree, Node *rtree,
2950  int location)
2951 {
2952  Expr *result;
2953 
2954  result = make_op(pstate, opname, ltree, rtree,
2955  pstate->p_last_srf, location);
2956  if (((OpExpr *) result)->opresulttype != BOOLOID)
2957  ereport(ERROR,
2958  (errcode(ERRCODE_DATATYPE_MISMATCH),
2959  errmsg("IS DISTINCT FROM requires = operator to yield boolean"),
2960  parser_errposition(pstate, location)));
2961  if (((OpExpr *) result)->opretset)
2962  ereport(ERROR,
2963  (errcode(ERRCODE_DATATYPE_MISMATCH),
2964  /* translator: %s is name of a SQL construct, eg NULLIF */
2965  errmsg("%s must not return a set", "IS DISTINCT FROM"),
2966  parser_errposition(pstate, location)));
2967 
2968  /*
2969  * We rely on DistinctExpr and OpExpr being same struct
2970  */
2971  NodeSetTag(result, T_DistinctExpr);
2972 
2973  return result;
2974 }
2975 
2976 /*
2977  * Produce a NullTest node from an IS [NOT] DISTINCT FROM NULL construct
2978  *
2979  * "arg" is the untransformed other argument
2980  */
2981 static Node *
2983 {
2984  NullTest *nt = makeNode(NullTest);
2985 
2986  nt->arg = (Expr *) transformExprRecurse(pstate, arg);
2987  /* the argument can be any type, so don't coerce it */
2988  if (distincta->kind == AEXPR_NOT_DISTINCT)
2989  nt->nulltesttype = IS_NULL;
2990  else
2991  nt->nulltesttype = IS_NOT_NULL;
2992  /* argisrow = false is correct whether or not arg is composite */
2993  nt->argisrow = false;
2994  nt->location = distincta->location;
2995  return (Node *) nt;
2996 }
2997 
2998 /*
2999  * Produce a string identifying an expression by kind.
3000  *
3001  * Note: when practical, use a simple SQL keyword for the result. If that
3002  * doesn't work well, check call sites to see whether custom error message
3003  * strings are required.
3004  */
3005 const char *
3007 {
3008  switch (exprKind)
3009  {
3010  case EXPR_KIND_NONE:
3011  return "invalid expression context";
3012  case EXPR_KIND_OTHER:
3013  return "extension expression";
3014  case EXPR_KIND_JOIN_ON:
3015  return "JOIN/ON";
3016  case EXPR_KIND_JOIN_USING:
3017  return "JOIN/USING";
3019  return "sub-SELECT in FROM";
3021  return "function in FROM";
3022  case EXPR_KIND_WHERE:
3023  return "WHERE";
3024  case EXPR_KIND_POLICY:
3025  return "POLICY";
3026  case EXPR_KIND_HAVING:
3027  return "HAVING";
3028  case EXPR_KIND_FILTER:
3029  return "FILTER";
3031  return "window PARTITION BY";
3033  return "window ORDER BY";
3035  return "window RANGE";
3037  return "window ROWS";
3039  return "window GROUPS";
3041  return "SELECT";
3043  return "INSERT";
3046  return "UPDATE";
3047  case EXPR_KIND_GROUP_BY:
3048  return "GROUP BY";
3049  case EXPR_KIND_ORDER_BY:
3050  return "ORDER BY";
3051  case EXPR_KIND_DISTINCT_ON:
3052  return "DISTINCT ON";
3053  case EXPR_KIND_LIMIT:
3054  return "LIMIT";
3055  case EXPR_KIND_OFFSET:
3056  return "OFFSET";
3057  case EXPR_KIND_RETURNING:
3058  return "RETURNING";
3059  case EXPR_KIND_VALUES:
3061  return "VALUES";
3064  return "CHECK";
3067  return "DEFAULT";
3069  return "index expression";
3071  return "index predicate";
3073  return "statistics expression";
3075  return "USING";
3077  return "EXECUTE";
3079  return "WHEN";
3081  return "partition bound";
3083  return "PARTITION BY";
3085  return "CALL";
3086  case EXPR_KIND_COPY_WHERE:
3087  return "WHERE";
3089  return "GENERATED AS";
3090  case EXPR_KIND_CYCLE_MARK:
3091  return "CYCLE";
3092 
3093  /*
3094  * There is intentionally no default: case here, so that the
3095  * compiler will warn if we add a new ParseExprKind without
3096  * extending this switch. If we do see an unrecognized value at
3097  * runtime, we'll fall through to the "unrecognized" return.
3098  */
3099  }
3100  return "unrecognized expression kind";
3101 }
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Definition: parsenodes.h:286
static Node * transformCaseExpr(ParseState *pstate, CaseExpr *c)
Definition: parse_expr.c:1543
#define InvalidAttrNumber
Definition: attnum.h:23
#define nodeTag(nodeptr)
Definition: nodes.h:544
Oid element_typeid
Definition: primnodes.h:1026
Definition: nodes.h:300
static Node * transformTypeCast(ParseState *pstate, TypeCast *tc)
Definition: parse_expr.c:2579
List * collname
Definition: parsenodes.h:320
e
Definition: preproc-init.c:82
static Node * transformColumnRef(ParseState *pstate, ColumnRef *cref)
Definition: parse_expr.c:444
void * palloc(Size size)
Definition: mcxt.c:1062
int errmsg(const char *fmt,...)
Definition: elog.c:909
static Node * transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
Definition: parse_expr.c:2377
int parser_coercion_errposition(ParseState *pstate, int coerce_location, Node *input_expr)
#define elog(elevel,...)
Definition: elog.h:232
int i
Oid coalescetype
Definition: primnodes.h:1120
int count_nonjunk_tlist_entries(List *tlist)
Definition: tlist.c:175
static Node * transformSQLValueFunction(ParseState *pstate, SQLValueFunction *svf)
Definition: parse_expr.c:2195
Node * coerce_to_specific_type(ParseState *pstate, Node *node, Oid targetTypeId, const char *constructName)
Node * expr
Definition: parsenodes.h:776
void * arg
Oid select_common_type(ParseState *pstate, List *exprs, const char *context, Node **which_expr)
#define lthird(l)
Definition: pg_list.h:184
bool argisrow
Definition: primnodes.h:1257
MinMaxOp op
Definition: primnodes.h:1141
Expr * arg
Definition: primnodes.h:968
Oid opno
Definition: primnodes.h:542
PreParseColumnRefHook p_pre_columnref_hook
Definition: parse_node.h:220
List * funcname
Definition: parsenodes.h:361
Alias * eref
Definition: parsenodes.h:1141
Expr * result
Definition: primnodes.h:981
Node * node
Definition: parsenodes.h:481
bool agg_within_group
Definition: parsenodes.h:366
#define copyObject(obj)
Definition: nodes.h:655
List * args
Definition: primnodes.h:548
Bitmapset * bms_int_members(Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:902
List * inputcollids
Definition: primnodes.h:1109
Expr * defresult
Definition: primnodes.h:970
Expr * expr
Definition: primnodes.h:980
int location
Definition: primnodes.h:938
CoercionForm row_format
Definition: primnodes.h:1073
bool type_is_collatable(Oid typid)
Definition: lsyscache.c:3028
Value val
Definition: parsenodes.h:298
Definition: pg_list.h:50
#define snprintf
Definition: port.h:216
#define _(x)
Definition: elog.c:89
long val
Definition: informix.c:664
Oid paramtype
Definition: primnodes.h:269
RangeVar * makeRangeVar(char *schemaname, char *relname, int location)
Definition: makefuncs.c:422
static Node * transformAExprBetween(ParseState *pstate, A_Expr *a)
Definition: parse_expr.c:1220
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Definition: parsenodes.h:247
NodeTag type
Definition: value.h:44
Node * colNameToVar(ParseState *pstate, const char *colname, bool localonly, int location)
bool opretset
Definition: primnodes.h:545
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Definition: regc_locale.c:747
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Definition: parsenodes.h:308
static Node * transformAExprIn(ParseState *pstate, A_Expr *a)
Definition: parse_expr.c:1067
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