1 /*-------------------------------------------------------------------------
2 *
3 * parse_expr.c
4 * handle expressions in parser
5 *
6 * Portions Copyright (c) 1996-2018, 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/tlist.h"
24 #include "optimizer/var.h"
25 #include "parser/analyze.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 "parser/parse_agg.h"
36 #include "utils/builtins.h"
37 #include "utils/date.h"
38 #include "utils/lsyscache.h"
39 #include "utils/timestamp.h"
40 #include "utils/xml.h"
41
42
43 /* GUC parameters */
44 bool operator_precedence_warning = false;
45 bool Transform_null_equals = false;
46
47 /*
48 * Node-type groups for operator precedence warnings
49 * We use zero for everything not otherwise classified
50 */
51 #define PREC_GROUP_POSTFIX_IS 1 /* postfix IS tests (NullTest, etc) */
52 #define PREC_GROUP_INFIX_IS 2 /* infix IS (IS DISTINCT FROM, etc) */
53 #define PREC_GROUP_LESS 3 /* < > */
54 #define PREC_GROUP_EQUAL 4 /* = */
55 #define PREC_GROUP_LESS_EQUAL 5 /* <= >= <> */
56 #define PREC_GROUP_LIKE 6 /* LIKE ILIKE SIMILAR */
57 #define PREC_GROUP_BETWEEN 7 /* BETWEEN */
58 #define PREC_GROUP_IN 8 /* IN */
59 #define PREC_GROUP_NOT_LIKE 9 /* NOT LIKE/ILIKE/SIMILAR */
60 #define PREC_GROUP_NOT_BETWEEN 10 /* NOT BETWEEN */
61 #define PREC_GROUP_NOT_IN 11 /* NOT IN */
62 #define PREC_GROUP_POSTFIX_OP 12 /* generic postfix operators */
63 #define PREC_GROUP_INFIX_OP 13 /* generic infix operators */
64 #define PREC_GROUP_PREFIX_OP 14 /* generic prefix operators */
65
66 /*
67 * Map precedence groupings to old precedence ordering
68 *
69 * Old precedence order:
70 * 1. NOT
71 * 2. =
72 * 3. < >
73 * 4. LIKE ILIKE SIMILAR
74 * 5. BETWEEN
75 * 6. IN
76 * 7. generic postfix Op
77 * 8. generic Op, including <= => <>
78 * 9. generic prefix Op
79 * 10. IS tests (NullTest, BooleanTest, etc)
80 *
81 * NOT BETWEEN etc map to BETWEEN etc when considered as being on the left,
82 * but to NOT when considered as being on the right, because of the buggy
83 * precedence handling of those productions in the old grammar.
84 */
85 static const int oldprecedence_l[] = {
86 0, 10, 10, 3, 2, 8, 4, 5, 6, 4, 5, 6, 7, 8, 9
87 };
88 static const int oldprecedence_r[] = {
89 0, 10, 10, 3, 2, 8, 4, 5, 6, 1, 1, 1, 7, 8, 9
90 };
91
92 static Node *transformExprRecurse(ParseState *pstate, Node *expr);
93 static Node *transformParamRef(ParseState *pstate, ParamRef *pref);
94 static Node *transformAExprOp(ParseState *pstate, A_Expr *a);
95 static Node *transformAExprOpAny(ParseState *pstate, A_Expr *a);
96 static Node *transformAExprOpAll(ParseState *pstate, A_Expr *a);
97 static Node *transformAExprDistinct(ParseState *pstate, A_Expr *a);
98 static Node *transformAExprNullIf(ParseState *pstate, A_Expr *a);
99 static Node *transformAExprOf(ParseState *pstate, A_Expr *a);
100 static Node *transformAExprIn(ParseState *pstate, A_Expr *a);
101 static Node *transformAExprBetween(ParseState *pstate, A_Expr *a);
102 static Node *transformBoolExpr(ParseState *pstate, BoolExpr *a);
103 static Node *transformFuncCall(ParseState *pstate, FuncCall *fn);
104 static Node *transformMultiAssignRef(ParseState *pstate, MultiAssignRef *maref);
105 static Node *transformCaseExpr(ParseState *pstate, CaseExpr *c);
106 static Node *transformSubLink(ParseState *pstate, SubLink *sublink);
107 static Node *transformArrayExpr(ParseState *pstate, A_ArrayExpr *a,
108 Oid array_type, Oid element_type, int32 typmod);
109 static Node *transformRowExpr(ParseState *pstate, RowExpr *r, bool allowDefault);
110 static Node *transformCoalesceExpr(ParseState *pstate, CoalesceExpr *c);
111 static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
112 static Node *transformSQLValueFunction(ParseState *pstate,
113 SQLValueFunction *svf);
114 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
115 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
116 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
117 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
118 static Node *transformColumnRef(ParseState *pstate, ColumnRef *cref);
119 static Node *transformWholeRowRef(ParseState *pstate, RangeTblEntry *rte,
120 int location);
121 static Node *transformIndirection(ParseState *pstate, A_Indirection *ind);
122 static Node *transformTypeCast(ParseState *pstate, TypeCast *tc);
123 static Node *transformCollateClause(ParseState *pstate, CollateClause *c);
124 static Node *make_row_comparison_op(ParseState *pstate, List *opname,
125 List *largs, List *rargs, int location);
126 static Node *make_row_distinct_op(ParseState *pstate, List *opname,
127 RowExpr *lrow, RowExpr *rrow, int location);
128 static Expr *make_distinct_op(ParseState *pstate, List *opname,
129 Node *ltree, Node *rtree, int location);
130 static Node *make_nulltest_from_distinct(ParseState *pstate,
131 A_Expr *distincta, Node *arg);
132 static int operator_precedence_group(Node *node, const char **nodename);
133 static void emit_precedence_warnings(ParseState *pstate,
134 int opgroup, const char *opname,
135 Node *lchild, Node *rchild,
136 int location);
137
138
139 /*
140 * transformExpr -
141 * Analyze and transform expressions. Type checking and type casting is
142 * done here. This processing converts the raw grammar output into
143 * expression trees with fully determined semantics.
144 */
145 Node *
transformExpr(ParseState * pstate,Node * expr,ParseExprKind exprKind)146 transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind)
147 {
148 Node *result;
149 ParseExprKind sv_expr_kind;
150
151 /* Save and restore identity of expression type we're parsing */
152 Assert(exprKind != EXPR_KIND_NONE);
153 sv_expr_kind = pstate->p_expr_kind;
154 pstate->p_expr_kind = exprKind;
155
156 result = transformExprRecurse(pstate, expr);
157
158 pstate->p_expr_kind = sv_expr_kind;
159
160 return result;
161 }
162
163 static Node *
transformExprRecurse(ParseState * pstate,Node * expr)164 transformExprRecurse(ParseState *pstate, Node *expr)
165 {
166 Node *result;
167
168 if (expr == NULL)
169 return NULL;
170
171 /* Guard against stack overflow due to overly complex expressions */
172 check_stack_depth();
173
174 switch (nodeTag(expr))
175 {
176 case T_ColumnRef:
177 result = transformColumnRef(pstate, (ColumnRef *) expr);
178 break;
179
180 case T_ParamRef:
181 result = transformParamRef(pstate, (ParamRef *) expr);
182 break;
183
184 case T_A_Const:
185 {
186 A_Const *con = (A_Const *) expr;
187 Value *val = &con->val;
188
189 result = (Node *) make_const(pstate, val, con->location);
190 break;
191 }
192
193 case T_A_Indirection:
194 result = transformIndirection(pstate, (A_Indirection *) expr);
195 break;
196
197 case T_A_ArrayExpr:
198 result = transformArrayExpr(pstate, (A_ArrayExpr *) expr,
199 InvalidOid, InvalidOid, -1);
200 break;
201
202 case T_TypeCast:
203 result = transformTypeCast(pstate, (TypeCast *) expr);
204 break;
205
206 case T_CollateClause:
207 result = transformCollateClause(pstate, (CollateClause *) expr);
208 break;
209
210 case T_A_Expr:
211 {
212 A_Expr *a = (A_Expr *) expr;
213
214 switch (a->kind)
215 {
216 case AEXPR_OP:
217 result = transformAExprOp(pstate, a);
218 break;
219 case AEXPR_OP_ANY:
220 result = transformAExprOpAny(pstate, a);
221 break;
222 case AEXPR_OP_ALL:
223 result = transformAExprOpAll(pstate, a);
224 break;
225 case AEXPR_DISTINCT:
226 case AEXPR_NOT_DISTINCT:
227 result = transformAExprDistinct(pstate, a);
228 break;
229 case AEXPR_NULLIF:
230 result = transformAExprNullIf(pstate, a);
231 break;
232 case AEXPR_OF:
233 result = transformAExprOf(pstate, a);
234 break;
235 case AEXPR_IN:
236 result = transformAExprIn(pstate, a);
237 break;
238 case AEXPR_LIKE:
239 case AEXPR_ILIKE:
240 case AEXPR_SIMILAR:
241 /* we can transform these just like AEXPR_OP */
242 result = transformAExprOp(pstate, a);
243 break;
244 case AEXPR_BETWEEN:
245 case AEXPR_NOT_BETWEEN:
246 case AEXPR_BETWEEN_SYM:
247 case AEXPR_NOT_BETWEEN_SYM:
248 result = transformAExprBetween(pstate, a);
249 break;
250 case AEXPR_PAREN:
251 result = transformExprRecurse(pstate, a->lexpr);
252 break;
253 default:
254 elog(ERROR, "unrecognized A_Expr kind: %d", a->kind);
255 result = NULL; /* keep compiler quiet */
256 break;
257 }
258 break;
259 }
260
261 case T_BoolExpr:
262 result = transformBoolExpr(pstate, (BoolExpr *) expr);
263 break;
264
265 case T_FuncCall:
266 result = transformFuncCall(pstate, (FuncCall *) expr);
267 break;
268
269 case T_MultiAssignRef:
270 result = transformMultiAssignRef(pstate, (MultiAssignRef *) expr);
271 break;
272
273 case T_GroupingFunc:
274 result = transformGroupingFunc(pstate, (GroupingFunc *) expr);
275 break;
276
277 case T_NamedArgExpr:
278 {
279 NamedArgExpr *na = (NamedArgExpr *) expr;
280
281 na->arg = (Expr *) transformExprRecurse(pstate, (Node *) na->arg);
282 result = expr;
283 break;
284 }
285
286 case T_SubLink:
287 result = transformSubLink(pstate, (SubLink *) expr);
288 break;
289
290 case T_CaseExpr:
291 result = transformCaseExpr(pstate, (CaseExpr *) expr);
292 break;
293
294 case T_RowExpr:
295 result = transformRowExpr(pstate, (RowExpr *) expr, false);
296 break;
297
298 case T_CoalesceExpr:
299 result = transformCoalesceExpr(pstate, (CoalesceExpr *) expr);
300 break;
301
302 case T_MinMaxExpr:
303 result = transformMinMaxExpr(pstate, (MinMaxExpr *) expr);
304 break;
305
306 case T_SQLValueFunction:
307 result = transformSQLValueFunction(pstate,
308 (SQLValueFunction *) expr);
309 break;
310
311 case T_XmlExpr:
312 result = transformXmlExpr(pstate, (XmlExpr *) expr);
313 break;
314
315 case T_XmlSerialize:
316 result = transformXmlSerialize(pstate, (XmlSerialize *) expr);
317 break;
318
319 case T_NullTest:
320 {
321 NullTest *n = (NullTest *) expr;
322
323 if (operator_precedence_warning)
324 emit_precedence_warnings(pstate, PREC_GROUP_POSTFIX_IS, "IS",
325 (Node *) n->arg, NULL,
326 n->location);
327
328 n->arg = (Expr *) transformExprRecurse(pstate, (Node *) n->arg);
329 /* the argument can be any type, so don't coerce it */
330 n->argisrow = type_is_rowtype(exprType((Node *) n->arg));
331 result = expr;
332 break;
333 }
334
335 case T_BooleanTest:
336 result = transformBooleanTest(pstate, (BooleanTest *) expr);
337 break;
338
339 case T_CurrentOfExpr:
340 result = transformCurrentOfExpr(pstate, (CurrentOfExpr *) expr);
341 break;
342
343 /*
344 * In all places where DEFAULT is legal, the caller should have
345 * processed it rather than passing it to transformExpr().
346 */
347 case T_SetToDefault:
348 ereport(ERROR,
349 (errcode(ERRCODE_SYNTAX_ERROR),
350 errmsg("DEFAULT is not allowed in this context"),
351 parser_errposition(pstate,
352 ((SetToDefault *) expr)->location)));
353 break;
354
355 /*
356 * CaseTestExpr doesn't require any processing; it is only
357 * injected into parse trees in a fully-formed state.
358 *
359 * Ordinarily we should not see a Var here, but it is convenient
360 * for transformJoinUsingClause() to create untransformed operator
361 * trees containing already-transformed Vars. The best
362 * alternative would be to deconstruct and reconstruct column
363 * references, which seems expensively pointless. So allow it.
364 */
365 case T_CaseTestExpr:
366 case T_Var:
367 {
368 result = (Node *) expr;
369 break;
370 }
371
372 default:
373 /* should not reach here */
374 elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
375 result = NULL; /* keep compiler quiet */
376 break;
377 }
378
379 return result;
380 }
381
382 /*
383 * helper routine for delivering "column does not exist" error message
384 *
385 * (Usually we don't have to work this hard, but the general case of field
386 * selection from an arbitrary node needs it.)
387 */
388 static void
unknown_attribute(ParseState * pstate,Node * relref,const char * attname,int location)389 unknown_attribute(ParseState *pstate, Node *relref, const char *attname,
390 int location)
391 {
392 RangeTblEntry *rte;
393
394 if (IsA(relref, Var) &&
395 ((Var *) relref)->varattno == InvalidAttrNumber)
396 {
397 /* Reference the RTE by alias not by actual table name */
398 rte = GetRTEByRangeTablePosn(pstate,
399 ((Var *) relref)->varno,
400 ((Var *) relref)->varlevelsup);
401 ereport(ERROR,
402 (errcode(ERRCODE_UNDEFINED_COLUMN),
403 errmsg("column %s.%s does not exist",
404 rte->eref->aliasname, attname),
405 parser_errposition(pstate, location)));
406 }
407 else
408 {
409 /* Have to do it by reference to the type of the expression */
410 Oid relTypeId = exprType(relref);
411
412 if (ISCOMPLEX(relTypeId))
413 ereport(ERROR,
414 (errcode(ERRCODE_UNDEFINED_COLUMN),
415 errmsg("column \"%s\" not found in data type %s",
416 attname, format_type_be(relTypeId)),
417 parser_errposition(pstate, location)));
418 else if (relTypeId == RECORDOID)
419 ereport(ERROR,
420 (errcode(ERRCODE_UNDEFINED_COLUMN),
421 errmsg("could not identify column \"%s\" in record data type",
422 attname),
423 parser_errposition(pstate, location)));
424 else
425 ereport(ERROR,
426 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
427 errmsg("column notation .%s applied to type %s, "
428 "which is not a composite type",
429 attname, format_type_be(relTypeId)),
430 parser_errposition(pstate, location)));
431 }
432 }
433
434 static Node *
transformIndirection(ParseState * pstate,A_Indirection * ind)435 transformIndirection(ParseState *pstate, A_Indirection *ind)
436 {
437 Node *last_srf = pstate->p_last_srf;
438 Node *result = transformExprRecurse(pstate, ind->arg);
439 List *subscripts = NIL;
440 int location = exprLocation(result);
441 ListCell *i;
442
443 /*
444 * We have to split any field-selection operations apart from
445 * subscripting. Adjacent A_Indices nodes have to be treated as a single
446 * multidimensional subscript operation.
447 */
448 foreach(i, ind->indirection)
449 {
450 Node *n = lfirst(i);
451
452 if (IsA(n, A_Indices))
453 subscripts = lappend(subscripts, n);
454 else if (IsA(n, A_Star))
455 {
456 ereport(ERROR,
457 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
458 errmsg("row expansion via \"*\" is not supported here"),
459 parser_errposition(pstate, location)));
460 }
461 else
462 {
463 Node *newresult;
464
465 Assert(IsA(n, String));
466
467 /* process subscripts before this field selection */
468 if (subscripts)
469 result = (Node *) transformArraySubscripts(pstate,
470 result,
471 exprType(result),
472 InvalidOid,
473 exprTypmod(result),
474 subscripts,
475 NULL);
476 subscripts = NIL;
477
478 newresult = ParseFuncOrColumn(pstate,
479 list_make1(n),
480 list_make1(result),
481 last_srf,
482 NULL,
483 false,
484 location);
485 if (newresult == NULL)
486 unknown_attribute(pstate, result, strVal(n), location);
487 result = newresult;
488 }
489 }
490 /* process trailing subscripts, if any */
491 if (subscripts)
492 result = (Node *) transformArraySubscripts(pstate,
493 result,
494 exprType(result),
495 InvalidOid,
496 exprTypmod(result),
497 subscripts,
498 NULL);
499
500 return result;
501 }
502
503 /*
504 * Transform a ColumnRef.
505 *
506 * If you find yourself changing this code, see also ExpandColumnRefStar.
507 */
508 static Node *
transformColumnRef(ParseState * pstate,ColumnRef * cref)509 transformColumnRef(ParseState *pstate, ColumnRef *cref)
510 {
511 Node *node = NULL;
512 char *nspname = NULL;
513 char *relname = NULL;
514 char *colname = NULL;
515 RangeTblEntry *rte;
516 int levels_up;
517 enum
518 {
519 CRERR_NO_COLUMN,
520 CRERR_NO_RTE,
521 CRERR_WRONG_DB,
522 CRERR_TOO_MANY
523 } crerr = CRERR_NO_COLUMN;
524
525 /*
526 * Give the PreParseColumnRefHook, if any, first shot. If it returns
527 * non-null then that's all, folks.
528 */
529 if (pstate->p_pre_columnref_hook != NULL)
530 {
531 node = pstate->p_pre_columnref_hook(pstate, cref);
532 if (node != NULL)
533 return node;
534 }
535
536 /*----------
537 * The allowed syntaxes are:
538 *
539 * A First try to resolve as unqualified column name;
540 * if no luck, try to resolve as unqualified table name (A.*).
541 * A.B A is an unqualified table name; B is either a
542 * column or function name (trying column name first).
543 * A.B.C schema A, table B, col or func name C.
544 * A.B.C.D catalog A, schema B, table C, col or func D.
545 * A.* A is an unqualified table name; means whole-row value.
546 * A.B.* whole-row value of table B in schema A.
547 * A.B.C.* whole-row value of table C in schema B in catalog A.
548 *
549 * We do not need to cope with bare "*"; that will only be accepted by
550 * the grammar at the top level of a SELECT list, and transformTargetList
551 * will take care of it before it ever gets here. Also, "A.*" etc will
552 * be expanded by transformTargetList if they appear at SELECT top level,
553 * so here we are only going to see them as function or operator inputs.
554 *
555 * Currently, if a catalog name is given then it must equal the current
556 * database name; we check it here and then discard it.
557 *----------
558 */
559 switch (list_length(cref->fields))
560 {
561 case 1:
562 {
563 Node *field1 = (Node *) linitial(cref->fields);
564
565 Assert(IsA(field1, String));
566 colname = strVal(field1);
567
568 /* Try to identify as an unqualified column */
569 node = colNameToVar(pstate, colname, false, cref->location);
570
571 if (node == NULL)
572 {
573 /*
574 * Not known as a column of any range-table entry.
575 *
576 * Try to find the name as a relation. Note that only
577 * relations already entered into the rangetable will be
578 * recognized.
579 *
580 * This is a hack for backwards compatibility with
581 * PostQUEL-inspired syntax. The preferred form now is
582 * "rel.*".
583 */
584 rte = refnameRangeTblEntry(pstate, NULL, colname,
585 cref->location,
586 &levels_up);
587 if (rte)
588 node = transformWholeRowRef(pstate, rte,
589 cref->location);
590 }
591 break;
592 }
593 case 2:
594 {
595 Node *field1 = (Node *) linitial(cref->fields);
596 Node *field2 = (Node *) lsecond(cref->fields);
597
598 Assert(IsA(field1, String));
599 relname = strVal(field1);
600
601 /* Locate the referenced RTE */
602 rte = refnameRangeTblEntry(pstate, nspname, relname,
603 cref->location,
604 &levels_up);
605 if (rte == NULL)
606 {
607 crerr = CRERR_NO_RTE;
608 break;
609 }
610
611 /* Whole-row reference? */
612 if (IsA(field2, A_Star))
613 {
614 node = transformWholeRowRef(pstate, rte, cref->location);
615 break;
616 }
617
618 Assert(IsA(field2, String));
619 colname = strVal(field2);
620
621 /* Try to identify as a column of the RTE */
622 node = scanRTEForColumn(pstate, rte, colname, cref->location,
623 0, NULL);
624 if (node == NULL)
625 {
626 /* Try it as a function call on the whole row */
627 node = transformWholeRowRef(pstate, rte, cref->location);
628 node = ParseFuncOrColumn(pstate,
629 list_make1(makeString(colname)),
630 list_make1(node),
631 pstate->p_last_srf,
632 NULL,
633 false,
634 cref->location);
635 }
636 break;
637 }
638 case 3:
639 {
640 Node *field1 = (Node *) linitial(cref->fields);
641 Node *field2 = (Node *) lsecond(cref->fields);
642 Node *field3 = (Node *) lthird(cref->fields);
643
644 Assert(IsA(field1, String));
645 nspname = strVal(field1);
646 Assert(IsA(field2, String));
647 relname = strVal(field2);
648
649 /* Locate the referenced RTE */
650 rte = refnameRangeTblEntry(pstate, nspname, relname,
651 cref->location,
652 &levels_up);
653 if (rte == NULL)
654 {
655 crerr = CRERR_NO_RTE;
656 break;
657 }
658
659 /* Whole-row reference? */
660 if (IsA(field3, A_Star))
661 {
662 node = transformWholeRowRef(pstate, rte, cref->location);
663 break;
664 }
665
666 Assert(IsA(field3, String));
667 colname = strVal(field3);
668
669 /* Try to identify as a column of the RTE */
670 node = scanRTEForColumn(pstate, rte, colname, cref->location,
671 0, NULL);
672 if (node == NULL)
673 {
674 /* Try it as a function call on the whole row */
675 node = transformWholeRowRef(pstate, rte, cref->location);
676 node = ParseFuncOrColumn(pstate,
677 list_make1(makeString(colname)),
678 list_make1(node),
679 pstate->p_last_srf,
680 NULL,
681 false,
682 cref->location);
683 }
684 break;
685 }
686 case 4:
687 {
688 Node *field1 = (Node *) linitial(cref->fields);
689 Node *field2 = (Node *) lsecond(cref->fields);
690 Node *field3 = (Node *) lthird(cref->fields);
691 Node *field4 = (Node *) lfourth(cref->fields);
692 char *catname;
693
694 Assert(IsA(field1, String));
695 catname = strVal(field1);
696 Assert(IsA(field2, String));
697 nspname = strVal(field2);
698 Assert(IsA(field3, String));
699 relname = strVal(field3);
700
701 /*
702 * We check the catalog name and then ignore it.
703 */
704 if (strcmp(catname, get_database_name(MyDatabaseId)) != 0)
705 {
706 crerr = CRERR_WRONG_DB;
707 break;
708 }
709
710 /* Locate the referenced RTE */
711 rte = refnameRangeTblEntry(pstate, nspname, relname,
712 cref->location,
713 &levels_up);
714 if (rte == NULL)
715 {
716 crerr = CRERR_NO_RTE;
717 break;
718 }
719
720 /* Whole-row reference? */
721 if (IsA(field4, A_Star))
722 {
723 node = transformWholeRowRef(pstate, rte, cref->location);
724 break;
725 }
726
727 Assert(IsA(field4, String));
728 colname = strVal(field4);
729
730 /* Try to identify as a column of the RTE */
731 node = scanRTEForColumn(pstate, rte, colname, cref->location,
732 0, NULL);
733 if (node == NULL)
734 {
735 /* Try it as a function call on the whole row */
736 node = transformWholeRowRef(pstate, rte, cref->location);
737 node = ParseFuncOrColumn(pstate,
738 list_make1(makeString(colname)),
739 list_make1(node),
740 pstate->p_last_srf,
741 NULL,
742 false,
743 cref->location);
744 }
745 break;
746 }
747 default:
748 crerr = CRERR_TOO_MANY; /* too many dotted names */
749 break;
750 }
751
752 /*
753 * Now give the PostParseColumnRefHook, if any, a chance. We pass the
754 * translation-so-far so that it can throw an error if it wishes in the
755 * case that it has a conflicting interpretation of the ColumnRef. (If it
756 * just translates anyway, we'll throw an error, because we can't undo
757 * whatever effects the preceding steps may have had on the pstate.) If it
758 * returns NULL, use the standard translation, or throw a suitable error
759 * if there is none.
760 */
761 if (pstate->p_post_columnref_hook != NULL)
762 {
763 Node *hookresult;
764
765 hookresult = pstate->p_post_columnref_hook(pstate, cref, node);
766 if (node == NULL)
767 node = hookresult;
768 else if (hookresult != NULL)
769 ereport(ERROR,
770 (errcode(ERRCODE_AMBIGUOUS_COLUMN),
771 errmsg("column reference \"%s\" is ambiguous",
772 NameListToString(cref->fields)),
773 parser_errposition(pstate, cref->location)));
774 }
775
776 /*
777 * Throw error if no translation found.
778 */
779 if (node == NULL)
780 {
781 switch (crerr)
782 {
783 case CRERR_NO_COLUMN:
784 errorMissingColumn(pstate, relname, colname, cref->location);
785 break;
786 case CRERR_NO_RTE:
787 errorMissingRTE(pstate, makeRangeVar(nspname, relname,
788 cref->location));
789 break;
790 case CRERR_WRONG_DB:
791 ereport(ERROR,
792 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
793 errmsg("cross-database references are not implemented: %s",
794 NameListToString(cref->fields)),
795 parser_errposition(pstate, cref->location)));
796 break;
797 case CRERR_TOO_MANY:
798 ereport(ERROR,
799 (errcode(ERRCODE_SYNTAX_ERROR),
800 errmsg("improper qualified name (too many dotted names): %s",
801 NameListToString(cref->fields)),
802 parser_errposition(pstate, cref->location)));
803 break;
804 }
805 }
806
807 return node;
808 }
809
810 static Node *
transformParamRef(ParseState * pstate,ParamRef * pref)811 transformParamRef(ParseState *pstate, ParamRef *pref)
812 {
813 Node *result;
814
815 /*
816 * The core parser knows nothing about Params. If a hook is supplied,
817 * call it. If not, or if the hook returns NULL, throw a generic error.
818 */
819 if (pstate->p_paramref_hook != NULL)
820 result = pstate->p_paramref_hook(pstate, pref);
821 else
822 result = NULL;
823
824 if (result == NULL)
825 ereport(ERROR,
826 (errcode(ERRCODE_UNDEFINED_PARAMETER),
827 errmsg("there is no parameter $%d", pref->number),
828 parser_errposition(pstate, pref->location)));
829
830 return result;
831 }
832
833 /* Test whether an a_expr is a plain NULL constant or not */
834 static bool
exprIsNullConstant(Node * arg)835 exprIsNullConstant(Node *arg)
836 {
837 if (arg && IsA(arg, A_Const))
838 {
839 A_Const *con = (A_Const *) arg;
840
841 if (con->val.type == T_Null)
842 return true;
843 }
844 return false;
845 }
846
847 static Node *
transformAExprOp(ParseState * pstate,A_Expr * a)848 transformAExprOp(ParseState *pstate, A_Expr *a)
849 {
850 Node *lexpr = a->lexpr;
851 Node *rexpr = a->rexpr;
852 Node *result;
853
854 if (operator_precedence_warning)
855 {
856 int opgroup;
857 const char *opname;
858
859 opgroup = operator_precedence_group((Node *) a, &opname);
860 if (opgroup > 0)
861 emit_precedence_warnings(pstate, opgroup, opname,
862 lexpr, rexpr,
863 a->location);
864
865 /* Look through AEXPR_PAREN nodes so they don't affect tests below */
866 while (lexpr && IsA(lexpr, A_Expr) &&
867 ((A_Expr *) lexpr)->kind == AEXPR_PAREN)
868 lexpr = ((A_Expr *) lexpr)->lexpr;
869 while (rexpr && IsA(rexpr, A_Expr) &&
870 ((A_Expr *) rexpr)->kind == AEXPR_PAREN)
871 rexpr = ((A_Expr *) rexpr)->lexpr;
872 }
873
874 /*
875 * Special-case "foo = NULL" and "NULL = foo" for compatibility with
876 * standards-broken products (like Microsoft's). Turn these into IS NULL
877 * exprs. (If either side is a CaseTestExpr, then the expression was
878 * generated internally from a CASE-WHEN expression, and
879 * transform_null_equals does not apply.)
880 */
881 if (Transform_null_equals &&
882 list_length(a->name) == 1 &&
883 strcmp(strVal(linitial(a->name)), "=") == 0 &&
884 (exprIsNullConstant(lexpr) || exprIsNullConstant(rexpr)) &&
885 (!IsA(lexpr, CaseTestExpr) &&!IsA(rexpr, CaseTestExpr)))
886 {
887 NullTest *n = makeNode(NullTest);
888
889 n->nulltesttype = IS_NULL;
890 n->location = a->location;
891
892 if (exprIsNullConstant(lexpr))
893 n->arg = (Expr *) rexpr;
894 else
895 n->arg = (Expr *) lexpr;
896
897 result = transformExprRecurse(pstate, (Node *) n);
898 }
899 else if (lexpr && IsA(lexpr, RowExpr) &&
900 rexpr && IsA(rexpr, SubLink) &&
901 ((SubLink *) rexpr)->subLinkType == EXPR_SUBLINK)
902 {
903 /*
904 * Convert "row op subselect" into a ROWCOMPARE sublink. Formerly the
905 * grammar did this, but now that a row construct is allowed anywhere
906 * in expressions, it's easier to do it here.
907 */
908 SubLink *s = (SubLink *) rexpr;
909
910 s->subLinkType = ROWCOMPARE_SUBLINK;
911 s->testexpr = lexpr;
912 s->operName = a->name;
913 s->location = a->location;
914 result = transformExprRecurse(pstate, (Node *) s);
915 }
916 else if (lexpr && IsA(lexpr, RowExpr) &&
917 rexpr && IsA(rexpr, RowExpr))
918 {
919 /* ROW() op ROW() is handled specially */
920 lexpr = transformExprRecurse(pstate, lexpr);
921 rexpr = transformExprRecurse(pstate, rexpr);
922
923 result = make_row_comparison_op(pstate,
924 a->name,
925 castNode(RowExpr, lexpr)->args,
926 castNode(RowExpr, rexpr)->args,
927 a->location);
928 }
929 else
930 {
931 /* Ordinary scalar operator */
932 Node *last_srf = pstate->p_last_srf;
933
934 lexpr = transformExprRecurse(pstate, lexpr);
935 rexpr = transformExprRecurse(pstate, rexpr);
936
937 result = (Node *) make_op(pstate,
938 a->name,
939 lexpr,
940 rexpr,
941 last_srf,
942 a->location);
943 }
944
945 return result;
946 }
947
948 static Node *
transformAExprOpAny(ParseState * pstate,A_Expr * a)949 transformAExprOpAny(ParseState *pstate, A_Expr *a)
950 {
951 Node *lexpr = a->lexpr;
952 Node *rexpr = a->rexpr;
953
954 if (operator_precedence_warning)
955 emit_precedence_warnings(pstate, PREC_GROUP_POSTFIX_OP,
956 strVal(llast(a->name)),
957 lexpr, NULL,
958 a->location);
959
960 lexpr = transformExprRecurse(pstate, lexpr);
961 rexpr = transformExprRecurse(pstate, rexpr);
962
963 return (Node *) make_scalar_array_op(pstate,
964 a->name,
965 true,
966 lexpr,
967 rexpr,
968 a->location);
969 }
970
971 static Node *
transformAExprOpAll(ParseState * pstate,A_Expr * a)972 transformAExprOpAll(ParseState *pstate, A_Expr *a)
973 {
974 Node *lexpr = a->lexpr;
975 Node *rexpr = a->rexpr;
976
977 if (operator_precedence_warning)
978 emit_precedence_warnings(pstate, PREC_GROUP_POSTFIX_OP,
979 strVal(llast(a->name)),
980 lexpr, NULL,
981 a->location);
982
983 lexpr = transformExprRecurse(pstate, lexpr);
984 rexpr = transformExprRecurse(pstate, rexpr);
985
986 return (Node *) make_scalar_array_op(pstate,
987 a->name,
988 false,
989 lexpr,
990 rexpr,
991 a->location);
992 }
993
994 static Node *
transformAExprDistinct(ParseState * pstate,A_Expr * a)995 transformAExprDistinct(ParseState *pstate, A_Expr *a)
996 {
997 Node *lexpr = a->lexpr;
998 Node *rexpr = a->rexpr;
999 Node *result;
1000
1001 if (operator_precedence_warning)
1002 emit_precedence_warnings(pstate, PREC_GROUP_INFIX_IS, "IS",
1003 lexpr, rexpr,
1004 a->location);
1005
1006 /*
1007 * If either input is an undecorated NULL literal, transform to a NullTest
1008 * on the other input. That's simpler to process than a full DistinctExpr,
1009 * and it avoids needing to require that the datatype have an = operator.
1010 */
1011 if (exprIsNullConstant(rexpr))
1012 return make_nulltest_from_distinct(pstate, a, lexpr);
1013 if (exprIsNullConstant(lexpr))
1014 return make_nulltest_from_distinct(pstate, a, rexpr);
1015
1016 lexpr = transformExprRecurse(pstate, lexpr);
1017 rexpr = transformExprRecurse(pstate, rexpr);
1018
1019 if (lexpr && IsA(lexpr, RowExpr) &&
1020 rexpr && IsA(rexpr, RowExpr))
1021 {
1022 /* ROW() op ROW() is handled specially */
1023 result = make_row_distinct_op(pstate, a->name,
1024 (RowExpr *) lexpr,
1025 (RowExpr *) rexpr,
1026 a->location);
1027 }
1028 else
1029 {
1030 /* Ordinary scalar operator */
1031 result = (Node *) make_distinct_op(pstate,
1032 a->name,
1033 lexpr,
1034 rexpr,
1035 a->location);
1036 }
1037
1038 /*
1039 * If it's NOT DISTINCT, we first build a DistinctExpr and then stick a
1040 * NOT on top.
1041 */
1042 if (a->kind == AEXPR_NOT_DISTINCT)
1043 result = (Node *) makeBoolExpr(NOT_EXPR,
1044 list_make1(result),
1045 a->location);
1046
1047 return result;
1048 }
1049
1050 static Node *
transformAExprNullIf(ParseState * pstate,A_Expr * a)1051 transformAExprNullIf(ParseState *pstate, A_Expr *a)
1052 {
1053 Node *lexpr = transformExprRecurse(pstate, a->lexpr);
1054 Node *rexpr = transformExprRecurse(pstate, a->rexpr);
1055 OpExpr *result;
1056
1057 result = (OpExpr *) make_op(pstate,
1058 a->name,
1059 lexpr,
1060 rexpr,
1061 pstate->p_last_srf,
1062 a->location);
1063
1064 /*
1065 * The comparison operator itself should yield boolean ...
1066 */
1067 if (result->opresulttype != BOOLOID)
1068 ereport(ERROR,
1069 (errcode(ERRCODE_DATATYPE_MISMATCH),
1070 errmsg("NULLIF requires = operator to yield boolean"),
1071 parser_errposition(pstate, a->location)));
1072 if (result->opretset)
1073 ereport(ERROR,
1074 (errcode(ERRCODE_DATATYPE_MISMATCH),
1075 /* translator: %s is name of a SQL construct, eg NULLIF */
1076 errmsg("%s must not return a set", "NULLIF"),
1077 parser_errposition(pstate, a->location)));
1078
1079 /*
1080 * ... but the NullIfExpr will yield the first operand's type.
1081 */
1082 result->opresulttype = exprType((Node *) linitial(result->args));
1083
1084 /*
1085 * We rely on NullIfExpr and OpExpr being the same struct
1086 */
1087 NodeSetTag(result, T_NullIfExpr);
1088
1089 return (Node *) result;
1090 }
1091
1092 /*
1093 * Checking an expression for match to a list of type names. Will result
1094 * in a boolean constant node.
1095 */
1096 static Node *
transformAExprOf(ParseState * pstate,A_Expr * a)1097 transformAExprOf(ParseState *pstate, A_Expr *a)
1098 {
1099 Node *lexpr = a->lexpr;
1100 Const *result;
1101 ListCell *telem;
1102 Oid ltype,
1103 rtype;
1104 bool matched = false;
1105
1106 if (operator_precedence_warning)
1107 emit_precedence_warnings(pstate, PREC_GROUP_POSTFIX_IS, "IS",
1108 lexpr, NULL,
1109 a->location);
1110
1111 lexpr = transformExprRecurse(pstate, lexpr);
1112
1113 ltype = exprType(lexpr);
1114 foreach(telem, (List *) a->rexpr)
1115 {
1116 rtype = typenameTypeId(pstate, lfirst(telem));
1117 matched = (rtype == ltype);
1118 if (matched)
1119 break;
1120 }
1121
1122 /*
1123 * We have two forms: equals or not equals. Flip the sense of the result
1124 * for not equals.
1125 */
1126 if (strcmp(strVal(linitial(a->name)), "<>") == 0)
1127 matched = (!matched);
1128
1129 result = (Const *) makeBoolConst(matched, false);
1130
1131 /* Make the result have the original input's parse location */
1132 result->location = exprLocation((Node *) a);
1133
1134 return (Node *) result;
1135 }
1136
1137 static Node *
transformAExprIn(ParseState * pstate,A_Expr * a)1138 transformAExprIn(ParseState *pstate, A_Expr *a)
1139 {
1140 Node *result = NULL;
1141 Node *lexpr;
1142 List *rexprs;
1143 List *rvars;
1144 List *rnonvars;
1145 bool useOr;
1146 ListCell *l;
1147
1148 /*
1149 * If the operator is <>, combine with AND not OR.
1150 */
1151 if (strcmp(strVal(linitial(a->name)), "<>") == 0)
1152 useOr = false;
1153 else
1154 useOr = true;
1155
1156 if (operator_precedence_warning)
1157 emit_precedence_warnings(pstate,
1158 useOr ? PREC_GROUP_IN : PREC_GROUP_NOT_IN,
1159 "IN",
1160 a->lexpr, NULL,
1161 a->location);
1162
1163 /*
1164 * We try to generate a ScalarArrayOpExpr from IN/NOT IN, but this is only
1165 * possible if there is a suitable array type available. If not, we fall
1166 * back to a boolean condition tree with multiple copies of the lefthand
1167 * expression. Also, any IN-list items that contain Vars are handled as
1168 * separate boolean conditions, because that gives the planner more scope
1169 * for optimization on such clauses.
1170 *
1171 * First step: transform all the inputs, and detect whether any contain
1172 * Vars.
1173 */
1174 lexpr = transformExprRecurse(pstate, a->lexpr);
1175 rexprs = rvars = rnonvars = NIL;
1176 foreach(l, (List *) a->rexpr)
1177 {
1178 Node *rexpr = transformExprRecurse(pstate, lfirst(l));
1179
1180 rexprs = lappend(rexprs, rexpr);
1181 if (contain_vars_of_level(rexpr, 0))
1182 rvars = lappend(rvars, rexpr);
1183 else
1184 rnonvars = lappend(rnonvars, rexpr);
1185 }
1186
1187 /*
1188 * ScalarArrayOpExpr is only going to be useful if there's more than one
1189 * non-Var righthand item.
1190 */
1191 if (list_length(rnonvars) > 1)
1192 {
1193 List *allexprs;
1194 Oid scalar_type;
1195 Oid array_type;
1196
1197 /*
1198 * Try to select a common type for the array elements. Note that
1199 * since the LHS' type is first in the list, it will be preferred when
1200 * there is doubt (eg, when all the RHS items are unknown literals).
1201 *
1202 * Note: use list_concat here not lcons, to avoid damaging rnonvars.
1203 */
1204 allexprs = list_concat(list_make1(lexpr), rnonvars);
1205 scalar_type = select_common_type(pstate, allexprs, NULL, NULL);
1206
1207 /*
1208 * Do we have an array type to use? Aside from the case where there
1209 * isn't one, we don't risk using ScalarArrayOpExpr when the common
1210 * type is RECORD, because the RowExpr comparison logic below can cope
1211 * with some cases of non-identical row types.
1212 */
1213 if (OidIsValid(scalar_type) && scalar_type != RECORDOID)
1214 array_type = get_array_type(scalar_type);
1215 else
1216 array_type = InvalidOid;
1217 if (array_type != InvalidOid)
1218 {
1219 /*
1220 * OK: coerce all the right-hand non-Var inputs to the common type
1221 * and build an ArrayExpr for them.
1222 */
1223 List *aexprs;
1224 ArrayExpr *newa;
1225
1226 aexprs = NIL;
1227 foreach(l, rnonvars)
1228 {
1229 Node *rexpr = (Node *) lfirst(l);
1230
1231 rexpr = coerce_to_common_type(pstate, rexpr,
1232 scalar_type,
1233 "IN");
1234 aexprs = lappend(aexprs, rexpr);
1235 }
1236 newa = makeNode(ArrayExpr);
1237 newa->array_typeid = array_type;
1238 /* array_collid will be set by parse_collate.c */
1239 newa->element_typeid = scalar_type;
1240 newa->elements = aexprs;
1241 newa->multidims = false;
1242 newa->location = -1;
1243
1244 result = (Node *) make_scalar_array_op(pstate,
1245 a->name,
1246 useOr,
1247 lexpr,
1248 (Node *) newa,
1249 a->location);
1250
1251 /* Consider only the Vars (if any) in the loop below */
1252 rexprs = rvars;
1253 }
1254 }
1255
1256 /*
1257 * Must do it the hard way, ie, with a boolean expression tree.
1258 */
1259 foreach(l, rexprs)
1260 {
1261 Node *rexpr = (Node *) lfirst(l);
1262 Node *cmp;
1263
1264 if (IsA(lexpr, RowExpr) &&
1265 IsA(rexpr, RowExpr))
1266 {
1267 /* ROW() op ROW() is handled specially */
1268 cmp = make_row_comparison_op(pstate,
1269 a->name,
1270 copyObject(((RowExpr *) lexpr)->args),
1271 ((RowExpr *) rexpr)->args,
1272 a->location);
1273 }
1274 else
1275 {
1276 /* Ordinary scalar operator */
1277 cmp = (Node *) make_op(pstate,
1278 a->name,
1279 copyObject(lexpr),
1280 rexpr,
1281 pstate->p_last_srf,
1282 a->location);
1283 }
1284
1285 cmp = coerce_to_boolean(pstate, cmp, "IN");
1286 if (result == NULL)
1287 result = cmp;
1288 else
1289 result = (Node *) makeBoolExpr(useOr ? OR_EXPR : AND_EXPR,
1290 list_make2(result, cmp),
1291 a->location);
1292 }
1293
1294 return result;
1295 }
1296
1297 static Node *
transformAExprBetween(ParseState * pstate,A_Expr * a)1298 transformAExprBetween(ParseState *pstate, A_Expr *a)
1299 {
1300 Node *aexpr;
1301 Node *bexpr;
1302 Node *cexpr;
1303 Node *result;
1304 Node *sub1;
1305 Node *sub2;
1306 List *args;
1307
1308 /* Deconstruct A_Expr into three subexprs */
1309 aexpr = a->lexpr;
1310 args = castNode(List, a->rexpr);
1311 Assert(list_length(args) == 2);
1312 bexpr = (Node *) linitial(args);
1313 cexpr = (Node *) lsecond(args);
1314
1315 if (operator_precedence_warning)
1316 {
1317 int opgroup;
1318 const char *opname;
1319
1320 opgroup = operator_precedence_group((Node *) a, &opname);
1321 emit_precedence_warnings(pstate, opgroup, opname,
1322 aexpr, cexpr,
1323 a->location);
1324 /* We can ignore bexpr thanks to syntactic restrictions */
1325 /* Wrap subexpressions to prevent extra warnings */
1326 aexpr = (Node *) makeA_Expr(AEXPR_PAREN, NIL, aexpr, NULL, -1);
1327 bexpr = (Node *) makeA_Expr(AEXPR_PAREN, NIL, bexpr, NULL, -1);
1328 cexpr = (Node *) makeA_Expr(AEXPR_PAREN, NIL, cexpr, NULL, -1);
1329 }
1330
1331 /*
1332 * Build the equivalent comparison expression. Make copies of
1333 * multiply-referenced subexpressions for safety. (XXX this is really
1334 * wrong since it results in multiple runtime evaluations of what may be
1335 * volatile expressions ...)
1336 *
1337 * Ideally we would not use hard-wired operators here but instead use
1338 * opclasses. However, mixed data types and other issues make this
1339 * difficult:
1340 * http://archives.postgresql.org/pgsql-hackers/2008-08/msg01142.php
1341 */
1342 switch (a->kind)
1343 {
1344 case AEXPR_BETWEEN:
1345 args = list_make2(makeSimpleA_Expr(AEXPR_OP, ">=",
1346 aexpr, bexpr,
1347 a->location),
1348 makeSimpleA_Expr(AEXPR_OP, "<=",
1349 copyObject(aexpr), cexpr,
1350 a->location));
1351 result = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
1352 break;
1353 case AEXPR_NOT_BETWEEN:
1354 args = list_make2(makeSimpleA_Expr(AEXPR_OP, "<",
1355 aexpr, bexpr,
1356 a->location),
1357 makeSimpleA_Expr(AEXPR_OP, ">",
1358 copyObject(aexpr), cexpr,
1359 a->location));
1360 result = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
1361 break;
1362 case AEXPR_BETWEEN_SYM:
1363 args = list_make2(makeSimpleA_Expr(AEXPR_OP, ">=",
1364 aexpr, bexpr,
1365 a->location),
1366 makeSimpleA_Expr(AEXPR_OP, "<=",
1367 copyObject(aexpr), cexpr,
1368 a->location));
1369 sub1 = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
1370 args = list_make2(makeSimpleA_Expr(AEXPR_OP, ">=",
1371 copyObject(aexpr), copyObject(cexpr),
1372 a->location),
1373 makeSimpleA_Expr(AEXPR_OP, "<=",
1374 copyObject(aexpr), copyObject(bexpr),
1375 a->location));
1376 sub2 = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
1377 args = list_make2(sub1, sub2);
1378 result = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
1379 break;
1380 case AEXPR_NOT_BETWEEN_SYM:
1381 args = list_make2(makeSimpleA_Expr(AEXPR_OP, "<",
1382 aexpr, bexpr,
1383 a->location),
1384 makeSimpleA_Expr(AEXPR_OP, ">",
1385 copyObject(aexpr), cexpr,
1386 a->location));
1387 sub1 = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
1388 args = list_make2(makeSimpleA_Expr(AEXPR_OP, "<",
1389 copyObject(aexpr), copyObject(cexpr),
1390 a->location),
1391 makeSimpleA_Expr(AEXPR_OP, ">",
1392 copyObject(aexpr), copyObject(bexpr),
1393 a->location));
1394 sub2 = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
1395 args = list_make2(sub1, sub2);
1396 result = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
1397 break;
1398 default:
1399 elog(ERROR, "unrecognized A_Expr kind: %d", a->kind);
1400 result = NULL; /* keep compiler quiet */
1401 break;
1402 }
1403
1404 return transformExprRecurse(pstate, result);
1405 }
1406
1407 static Node *
transformBoolExpr(ParseState * pstate,BoolExpr * a)1408 transformBoolExpr(ParseState *pstate, BoolExpr *a)
1409 {
1410 List *args = NIL;
1411 const char *opname;
1412 ListCell *lc;
1413
1414 switch (a->boolop)
1415 {
1416 case AND_EXPR:
1417 opname = "AND";
1418 break;
1419 case OR_EXPR:
1420 opname = "OR";
1421 break;
1422 case NOT_EXPR:
1423 opname = "NOT";
1424 break;
1425 default:
1426 elog(ERROR, "unrecognized boolop: %d", (int) a->boolop);
1427 opname = NULL; /* keep compiler quiet */
1428 break;
1429 }
1430
1431 foreach(lc, a->args)
1432 {
1433 Node *arg = (Node *) lfirst(lc);
1434
1435 arg = transformExprRecurse(pstate, arg);
1436 arg = coerce_to_boolean(pstate, arg, opname);
1437 args = lappend(args, arg);
1438 }
1439
1440 return (Node *) makeBoolExpr(a->boolop, args, a->location);
1441 }
1442
1443 static Node *
transformFuncCall(ParseState * pstate,FuncCall * fn)1444 transformFuncCall(ParseState *pstate, FuncCall *fn)
1445 {
1446 Node *last_srf = pstate->p_last_srf;
1447 List *targs;
1448 ListCell *args;
1449
1450 /* Transform the list of arguments ... */
1451 targs = NIL;
1452 foreach(args, fn->args)
1453 {
1454 targs = lappend(targs, transformExprRecurse(pstate,
1455 (Node *) lfirst(args)));
1456 }
1457
1458 /*
1459 * When WITHIN GROUP is used, we treat its ORDER BY expressions as
1460 * additional arguments to the function, for purposes of function lookup
1461 * and argument type coercion. So, transform each such expression and add
1462 * them to the targs list. We don't explicitly mark where each argument
1463 * came from, but ParseFuncOrColumn can tell what's what by reference to
1464 * list_length(fn->agg_order).
1465 */
1466 if (fn->agg_within_group)
1467 {
1468 Assert(fn->agg_order != NIL);
1469 foreach(args, fn->agg_order)
1470 {
1471 SortBy *arg = (SortBy *) lfirst(args);
1472
1473 targs = lappend(targs, transformExpr(pstate, arg->node,
1474 EXPR_KIND_ORDER_BY));
1475 }
1476 }
1477
1478 /* ... and hand off to ParseFuncOrColumn */
1479 return ParseFuncOrColumn(pstate,
1480 fn->funcname,
1481 targs,
1482 last_srf,
1483 fn,
1484 false,
1485 fn->location);
1486 }
1487
1488 static Node *
transformMultiAssignRef(ParseState * pstate,MultiAssignRef * maref)1489 transformMultiAssignRef(ParseState *pstate, MultiAssignRef *maref)
1490 {
1491 SubLink *sublink;
1492 RowExpr *rexpr;
1493 Query *qtree;
1494 TargetEntry *tle;
1495
1496 /* We should only see this in first-stage processing of UPDATE tlists */
1497 Assert(pstate->p_expr_kind == EXPR_KIND_UPDATE_SOURCE);
1498
1499 /* We only need to transform the source if this is the first column */
1500 if (maref->colno == 1)
1501 {
1502 /*
1503 * For now, we only allow EXPR SubLinks and RowExprs as the source of
1504 * an UPDATE multiassignment. This is sufficient to cover interesting
1505 * cases; at worst, someone would have to write (SELECT * FROM expr)
1506 * to expand a composite-returning expression of another form.
1507 */
1508 if (IsA(maref->source, SubLink) &&
1509 ((SubLink *) maref->source)->subLinkType == EXPR_SUBLINK)
1510 {
1511 /* Relabel it as a MULTIEXPR_SUBLINK */
1512 sublink = (SubLink *) maref->source;
1513 sublink->subLinkType = MULTIEXPR_SUBLINK;
1514 /* And transform it */
1515 sublink = (SubLink *) transformExprRecurse(pstate,
1516 (Node *) sublink);
1517
1518 qtree = castNode(Query, sublink->subselect);
1519
1520 /* Check subquery returns required number of columns */
1521 if (count_nonjunk_tlist_entries(qtree->targetList) != maref->ncolumns)
1522 ereport(ERROR,
1523 (errcode(ERRCODE_SYNTAX_ERROR),
1524 errmsg("number of columns does not match number of values"),
1525 parser_errposition(pstate, sublink->location)));
1526
1527 /*
1528 * Build a resjunk tlist item containing the MULTIEXPR SubLink,
1529 * and add it to pstate->p_multiassign_exprs, whence it will later
1530 * get appended to the completed targetlist. We needn't worry
1531 * about selecting a resno for it; transformUpdateStmt will do
1532 * that.
1533 */
1534 tle = makeTargetEntry((Expr *) sublink, 0, NULL, true);
1535 pstate->p_multiassign_exprs = lappend(pstate->p_multiassign_exprs,
1536 tle);
1537
1538 /*
1539 * Assign a unique-within-this-targetlist ID to the MULTIEXPR
1540 * SubLink. We can just use its position in the
1541 * p_multiassign_exprs list.
1542 */
1543 sublink->subLinkId = list_length(pstate->p_multiassign_exprs);
1544 }
1545 else if (IsA(maref->source, RowExpr))
1546 {
1547 /* Transform the RowExpr, allowing SetToDefault items */
1548 rexpr = (RowExpr *) transformRowExpr(pstate,
1549 (RowExpr *) maref->source,
1550 true);
1551
1552 /* Check it returns required number of columns */
1553 if (list_length(rexpr->args) != maref->ncolumns)
1554 ereport(ERROR,
1555 (errcode(ERRCODE_SYNTAX_ERROR),
1556 errmsg("number of columns does not match number of values"),
1557 parser_errposition(pstate, rexpr->location)));
1558
1559 /*
1560 * Temporarily append it to p_multiassign_exprs, so we can get it
1561 * back when we come back here for additional columns.
1562 */
1563 tle = makeTargetEntry((Expr *) rexpr, 0, NULL, true);
1564 pstate->p_multiassign_exprs = lappend(pstate->p_multiassign_exprs,
1565 tle);
1566 }
1567 else
1568 ereport(ERROR,
1569 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1570 errmsg("source for a multiple-column UPDATE item must be a sub-SELECT or ROW() expression"),
1571 parser_errposition(pstate, exprLocation(maref->source))));
1572 }
1573 else
1574 {
1575 /*
1576 * Second or later column in a multiassignment. Re-fetch the
1577 * transformed SubLink or RowExpr, which we assume is still the last
1578 * entry in p_multiassign_exprs.
1579 */
1580 Assert(pstate->p_multiassign_exprs != NIL);
1581 tle = (TargetEntry *) llast(pstate->p_multiassign_exprs);
1582 }
1583
1584 /*
1585 * Emit the appropriate output expression for the current column
1586 */
1587 if (IsA(tle->expr, SubLink))
1588 {
1589 Param *param;
1590
1591 sublink = (SubLink *) tle->expr;
1592 Assert(sublink->subLinkType == MULTIEXPR_SUBLINK);
1593 qtree = castNode(Query, sublink->subselect);
1594
1595 /* Build a Param representing the current subquery output column */
1596 tle = (TargetEntry *) list_nth(qtree->targetList, maref->colno - 1);
1597 Assert(!tle->resjunk);
1598
1599 param = makeNode(Param);
1600 param->paramkind = PARAM_MULTIEXPR;
1601 param->paramid = (sublink->subLinkId << 16) | maref->colno;
1602 param->paramtype = exprType((Node *) tle->expr);
1603 param->paramtypmod = exprTypmod((Node *) tle->expr);
1604 param->paramcollid = exprCollation((Node *) tle->expr);
1605 param->location = exprLocation((Node *) tle->expr);
1606
1607 return (Node *) param;
1608 }
1609
1610 if (IsA(tle->expr, RowExpr))
1611 {
1612 Node *result;
1613
1614 rexpr = (RowExpr *) tle->expr;
1615
1616 /* Just extract and return the next element of the RowExpr */
1617 result = (Node *) list_nth(rexpr->args, maref->colno - 1);
1618
1619 /*
1620 * If we're at the last column, delete the RowExpr from
1621 * p_multiassign_exprs; we don't need it anymore, and don't want it in
1622 * the finished UPDATE tlist.
1623 */
1624 if (maref->colno == maref->ncolumns)
1625 pstate->p_multiassign_exprs =
1626 list_delete_ptr(pstate->p_multiassign_exprs, tle);
1627
1628 return result;
1629 }
1630
1631 elog(ERROR, "unexpected expr type in multiassign list");
1632 return NULL; /* keep compiler quiet */
1633 }
1634
1635 static Node *
transformCaseExpr(ParseState * pstate,CaseExpr * c)1636 transformCaseExpr(ParseState *pstate, CaseExpr *c)
1637 {
1638 CaseExpr *newc = makeNode(CaseExpr);
1639 Node *last_srf = pstate->p_last_srf;
1640 Node *arg;
1641 CaseTestExpr *placeholder;
1642 List *newargs;
1643 List *resultexprs;
1644 ListCell *l;
1645 Node *defresult;
1646 Oid ptype;
1647
1648 /* transform the test expression, if any */
1649 arg = transformExprRecurse(pstate, (Node *) c->arg);
1650
1651 /* generate placeholder for test expression */
1652 if (arg)
1653 {
1654 /*
1655 * If test expression is an untyped literal, force it to text. We have
1656 * to do something now because we won't be able to do this coercion on
1657 * the placeholder. This is not as flexible as what was done in 7.4
1658 * and before, but it's good enough to handle the sort of silly coding
1659 * commonly seen.
1660 */
1661 if (exprType(arg) == UNKNOWNOID)
1662 arg = coerce_to_common_type(pstate, arg, TEXTOID, "CASE");
1663
1664 /*
1665 * Run collation assignment on the test expression so that we know
1666 * what collation to mark the placeholder with. In principle we could
1667 * leave it to parse_collate.c to do that later, but propagating the
1668 * result to the CaseTestExpr would be unnecessarily complicated.
1669 */
1670 assign_expr_collations(pstate, arg);
1671
1672 placeholder = makeNode(CaseTestExpr);
1673 placeholder->typeId = exprType(arg);
1674 placeholder->typeMod = exprTypmod(arg);
1675 placeholder->collation = exprCollation(arg);
1676 }
1677 else
1678 placeholder = NULL;
1679
1680 newc->arg = (Expr *) arg;
1681
1682 /* transform the list of arguments */
1683 newargs = NIL;
1684 resultexprs = NIL;
1685 foreach(l, c->args)
1686 {
1687 CaseWhen *w = lfirst_node(CaseWhen, l);
1688 CaseWhen *neww = makeNode(CaseWhen);
1689 Node *warg;
1690
1691 warg = (Node *) w->expr;
1692 if (placeholder)
1693 {
1694 /* shorthand form was specified, so expand... */
1695 warg = (Node *) makeSimpleA_Expr(AEXPR_OP, "=",
1696 (Node *) placeholder,
1697 warg,
1698 w->location);
1699 }
1700 neww->expr = (Expr *) transformExprRecurse(pstate, warg);
1701
1702 neww->expr = (Expr *) coerce_to_boolean(pstate,
1703 (Node *) neww->expr,
1704 "CASE/WHEN");
1705
1706 warg = (Node *) w->result;
1707 neww->result = (Expr *) transformExprRecurse(pstate, warg);
1708 neww->location = w->location;
1709
1710 newargs = lappend(newargs, neww);
1711 resultexprs = lappend(resultexprs, neww->result);
1712 }
1713
1714 newc->args = newargs;
1715
1716 /* transform the default clause */
1717 defresult = (Node *) c->defresult;
1718 if (defresult == NULL)
1719 {
1720 A_Const *n = makeNode(A_Const);
1721
1722 n->val.type = T_Null;
1723 n->location = -1;
1724 defresult = (Node *) n;
1725 }
1726 newc->defresult = (Expr *) transformExprRecurse(pstate, defresult);
1727
1728 /*
1729 * Note: default result is considered the most significant type in
1730 * determining preferred type. This is how the code worked before, but it
1731 * seems a little bogus to me --- tgl
1732 */
1733 resultexprs = lcons(newc->defresult, resultexprs);
1734
1735 ptype = select_common_type(pstate, resultexprs, "CASE", NULL);
1736 Assert(OidIsValid(ptype));
1737 newc->casetype = ptype;
1738 /* casecollid will be set by parse_collate.c */
1739
1740 /* Convert default result clause, if necessary */
1741 newc->defresult = (Expr *)
1742 coerce_to_common_type(pstate,
1743 (Node *) newc->defresult,
1744 ptype,
1745 "CASE/ELSE");
1746
1747 /* Convert when-clause results, if necessary */
1748 foreach(l, newc->args)
1749 {
1750 CaseWhen *w = (CaseWhen *) lfirst(l);
1751
1752 w->result = (Expr *)
1753 coerce_to_common_type(pstate,
1754 (Node *) w->result,
1755 ptype,
1756 "CASE/WHEN");
1757 }
1758
1759 /* if any subexpression contained a SRF, complain */
1760 if (pstate->p_last_srf != last_srf)
1761 ereport(ERROR,
1762 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1763 /* translator: %s is name of a SQL construct, eg GROUP BY */
1764 errmsg("set-returning functions are not allowed in %s",
1765 "CASE"),
1766 errhint("You might be able to move the set-returning function into a LATERAL FROM item."),
1767 parser_errposition(pstate,
1768 exprLocation(pstate->p_last_srf))));
1769
1770 newc->location = c->location;
1771
1772 return (Node *) newc;
1773 }
1774
1775 static Node *
transformSubLink(ParseState * pstate,SubLink * sublink)1776 transformSubLink(ParseState *pstate, SubLink *sublink)
1777 {
1778 Node *result = (Node *) sublink;
1779 Query *qtree;
1780 const char *err;
1781
1782 /*
1783 * Check to see if the sublink is in an invalid place within the query. We
1784 * allow sublinks everywhere in SELECT/INSERT/UPDATE/DELETE, but generally
1785 * not in utility statements.
1786 */
1787 err = NULL;
1788 switch (pstate->p_expr_kind)
1789 {
1790 case EXPR_KIND_NONE:
1791 Assert(false); /* can't happen */
1792 break;
1793 case EXPR_KIND_OTHER:
1794 /* Accept sublink here; caller must throw error if wanted */
1795 break;
1796 case EXPR_KIND_JOIN_ON:
1797 case EXPR_KIND_JOIN_USING:
1798 case EXPR_KIND_FROM_SUBSELECT:
1799 case EXPR_KIND_FROM_FUNCTION:
1800 case EXPR_KIND_WHERE:
1801 case EXPR_KIND_POLICY:
1802 case EXPR_KIND_HAVING:
1803 case EXPR_KIND_FILTER:
1804 case EXPR_KIND_WINDOW_PARTITION:
1805 case EXPR_KIND_WINDOW_ORDER:
1806 case EXPR_KIND_WINDOW_FRAME_RANGE:
1807 case EXPR_KIND_WINDOW_FRAME_ROWS:
1808 case EXPR_KIND_WINDOW_FRAME_GROUPS:
1809 case EXPR_KIND_SELECT_TARGET:
1810 case EXPR_KIND_INSERT_TARGET:
1811 case EXPR_KIND_UPDATE_SOURCE:
1812 case EXPR_KIND_UPDATE_TARGET:
1813 case EXPR_KIND_GROUP_BY:
1814 case EXPR_KIND_ORDER_BY:
1815 case EXPR_KIND_DISTINCT_ON:
1816 case EXPR_KIND_LIMIT:
1817 case EXPR_KIND_OFFSET:
1818 case EXPR_KIND_RETURNING:
1819 case EXPR_KIND_VALUES:
1820 case EXPR_KIND_VALUES_SINGLE:
1821 /* okay */
1822 break;
1823 case EXPR_KIND_CHECK_CONSTRAINT:
1824 case EXPR_KIND_DOMAIN_CHECK:
1825 err = _("cannot use subquery in check constraint");
1826 break;
1827 case EXPR_KIND_COLUMN_DEFAULT:
1828 case EXPR_KIND_FUNCTION_DEFAULT:
1829 err = _("cannot use subquery in DEFAULT expression");
1830 break;
1831 case EXPR_KIND_INDEX_EXPRESSION:
1832 err = _("cannot use subquery in index expression");
1833 break;
1834 case EXPR_KIND_INDEX_PREDICATE:
1835 err = _("cannot use subquery in index predicate");
1836 break;
1837 case EXPR_KIND_ALTER_COL_TRANSFORM:
1838 err = _("cannot use subquery in transform expression");
1839 break;
1840 case EXPR_KIND_EXECUTE_PARAMETER:
1841 err = _("cannot use subquery in EXECUTE parameter");
1842 break;
1843 case EXPR_KIND_TRIGGER_WHEN:
1844 err = _("cannot use subquery in trigger WHEN condition");
1845 break;
1846 case EXPR_KIND_PARTITION_EXPRESSION:
1847 err = _("cannot use subquery in partition key expression");
1848 break;
1849 case EXPR_KIND_CALL_ARGUMENT:
1850 err = _("cannot use subquery in CALL argument");
1851 break;
1852
1853 /*
1854 * There is intentionally no default: case here, so that the
1855 * compiler will warn if we add a new ParseExprKind without
1856 * extending this switch. If we do see an unrecognized value at
1857 * runtime, the behavior will be the same as for EXPR_KIND_OTHER,
1858 * which is sane anyway.
1859 */
1860 }
1861 if (err)
1862 ereport(ERROR,
1863 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1864 errmsg_internal("%s", err),
1865 parser_errposition(pstate, sublink->location)));
1866
1867 pstate->p_hasSubLinks = true;
1868
1869 /*
1870 * OK, let's transform the sub-SELECT.
1871 */
1872 qtree = parse_sub_analyze(sublink->subselect, pstate, NULL, false, true);
1873
1874 /*
1875 * Check that we got a SELECT. Anything else should be impossible given
1876 * restrictions of the grammar, but check anyway.
1877 */
1878 if (!IsA(qtree, Query) ||
1879 qtree->commandType != CMD_SELECT)
1880 elog(ERROR, "unexpected non-SELECT command in SubLink");
1881
1882 sublink->subselect = (Node *) qtree;
1883
1884 if (sublink->subLinkType == EXISTS_SUBLINK)
1885 {
1886 /*
1887 * EXISTS needs no test expression or combining operator. These fields
1888 * should be null already, but make sure.
1889 */
1890 sublink->testexpr = NULL;
1891 sublink->operName = NIL;
1892 }
1893 else if (sublink->subLinkType == EXPR_SUBLINK ||
1894 sublink->subLinkType == ARRAY_SUBLINK)
1895 {
1896 /*
1897 * Make sure the subselect delivers a single column (ignoring resjunk
1898 * targets).
1899 */
1900 if (count_nonjunk_tlist_entries(qtree->targetList) != 1)
1901 ereport(ERROR,
1902 (errcode(ERRCODE_SYNTAX_ERROR),
1903 errmsg("subquery must return only one column"),
1904 parser_errposition(pstate, sublink->location)));
1905
1906 /*
1907 * EXPR and ARRAY need no test expression or combining operator. These
1908 * fields should be null already, but make sure.
1909 */
1910 sublink->testexpr = NULL;
1911 sublink->operName = NIL;
1912 }
1913 else if (sublink->subLinkType == MULTIEXPR_SUBLINK)
1914 {
1915 /* Same as EXPR case, except no restriction on number of columns */
1916 sublink->testexpr = NULL;
1917 sublink->operName = NIL;
1918 }
1919 else
1920 {
1921 /* ALL, ANY, or ROWCOMPARE: generate row-comparing expression */
1922 Node *lefthand;
1923 List *left_list;
1924 List *right_list;
1925 ListCell *l;
1926
1927 if (operator_precedence_warning)
1928 {
1929 if (sublink->operName == NIL)
1930 emit_precedence_warnings(pstate, PREC_GROUP_IN, "IN",
1931 sublink->testexpr, NULL,
1932 sublink->location);
1933 else
1934 emit_precedence_warnings(pstate, PREC_GROUP_POSTFIX_OP,
1935 strVal(llast(sublink->operName)),
1936 sublink->testexpr, NULL,
1937 sublink->location);
1938 }
1939
1940 /*
1941 * If the source was "x IN (select)", convert to "x = ANY (select)".
1942 */
1943 if (sublink->operName == NIL)
1944 sublink->operName = list_make1(makeString("="));
1945
1946 /*
1947 * Transform lefthand expression, and convert to a list
1948 */
1949 lefthand = transformExprRecurse(pstate, sublink->testexpr);
1950 if (lefthand && IsA(lefthand, RowExpr))
1951 left_list = ((RowExpr *) lefthand)->args;
1952 else
1953 left_list = list_make1(lefthand);
1954
1955 /*
1956 * Build a list of PARAM_SUBLINK nodes representing the output columns
1957 * of the subquery.
1958 */
1959 right_list = NIL;
1960 foreach(l, qtree->targetList)
1961 {
1962 TargetEntry *tent = (TargetEntry *) lfirst(l);
1963 Param *param;
1964
1965 if (tent->resjunk)
1966 continue;
1967
1968 param = makeNode(Param);
1969 param->paramkind = PARAM_SUBLINK;
1970 param->paramid = tent->resno;
1971 param->paramtype = exprType((Node *) tent->expr);
1972 param->paramtypmod = exprTypmod((Node *) tent->expr);
1973 param->paramcollid = exprCollation((Node *) tent->expr);
1974 param->location = -1;
1975
1976 right_list = lappend(right_list, param);
1977 }
1978
1979 /*
1980 * We could rely on make_row_comparison_op to complain if the list
1981 * lengths differ, but we prefer to generate a more specific error
1982 * message.
1983 */
1984 if (list_length(left_list) < list_length(right_list))
1985 ereport(ERROR,
1986 (errcode(ERRCODE_SYNTAX_ERROR),
1987 errmsg("subquery has too many columns"),
1988 parser_errposition(pstate, sublink->location)));
1989 if (list_length(left_list) > list_length(right_list))
1990 ereport(ERROR,
1991 (errcode(ERRCODE_SYNTAX_ERROR),
1992 errmsg("subquery has too few columns"),
1993 parser_errposition(pstate, sublink->location)));
1994
1995 /*
1996 * Identify the combining operator(s) and generate a suitable
1997 * row-comparison expression.
1998 */
1999 sublink->testexpr = make_row_comparison_op(pstate,
2000 sublink->operName,
2001 left_list,
2002 right_list,
2003 sublink->location);
2004 }
2005
2006 return result;
2007 }
2008
2009 /*
2010 * transformArrayExpr
2011 *
2012 * If the caller specifies the target type, the resulting array will
2013 * be of exactly that type. Otherwise we try to infer a common type
2014 * for the elements using select_common_type().
2015 */
2016 static Node *
transformArrayExpr(ParseState * pstate,A_ArrayExpr * a,Oid array_type,Oid element_type,int32 typmod)2017 transformArrayExpr(ParseState *pstate, A_ArrayExpr *a,
2018 Oid array_type, Oid element_type, int32 typmod)
2019 {
2020 ArrayExpr *newa = makeNode(ArrayExpr);
2021 List *newelems = NIL;
2022 List *newcoercedelems = NIL;
2023 ListCell *element;
2024 Oid coerce_type;
2025 bool coerce_hard;
2026
2027 /*
2028 * Transform the element expressions
2029 *
2030 * Assume that the array is one-dimensional unless we find an array-type
2031 * element expression.
2032 */
2033 newa->multidims = false;
2034 foreach(element, a->elements)
2035 {
2036 Node *e = (Node *) lfirst(element);
2037 Node *newe;
2038
2039 /* Look through AEXPR_PAREN nodes so they don't affect test below */
2040 while (e && IsA(e, A_Expr) &&
2041 ((A_Expr *) e)->kind == AEXPR_PAREN)
2042 e = ((A_Expr *) e)->lexpr;
2043
2044 /*
2045 * If an element is itself an A_ArrayExpr, recurse directly so that we
2046 * can pass down any target type we were given.
2047 */
2048 if (IsA(e, A_ArrayExpr))
2049 {
2050 newe = transformArrayExpr(pstate,
2051 (A_ArrayExpr *) e,
2052 array_type,
2053 element_type,
2054 typmod);
2055 /* we certainly have an array here */
2056 Assert(array_type == InvalidOid || array_type == exprType(newe));
2057 newa->multidims = true;
2058 }
2059 else
2060 {
2061 newe = transformExprRecurse(pstate, e);
2062
2063 /*
2064 * Check for sub-array expressions, if we haven't already found
2065 * one.
2066 */
2067 if (!newa->multidims && type_is_array(exprType(newe)))
2068 newa->multidims = true;
2069 }
2070
2071 newelems = lappend(newelems, newe);
2072 }
2073
2074 /*
2075 * Select a target type for the elements.
2076 *
2077 * If we haven't been given a target array type, we must try to deduce a
2078 * common type based on the types of the individual elements present.
2079 */
2080 if (OidIsValid(array_type))
2081 {
2082 /* Caller must ensure array_type matches element_type */
2083 Assert(OidIsValid(element_type));
2084 coerce_type = (newa->multidims ? array_type : element_type);
2085 coerce_hard = true;
2086 }
2087 else
2088 {
2089 /* Can't handle an empty array without a target type */
2090 if (newelems == NIL)
2091 ereport(ERROR,
2092 (errcode(ERRCODE_INDETERMINATE_DATATYPE),
2093 errmsg("cannot determine type of empty array"),
2094 errhint("Explicitly cast to the desired type, "
2095 "for example ARRAY[]::integer[]."),
2096 parser_errposition(pstate, a->location)));
2097
2098 /* Select a common type for the elements */
2099 coerce_type = select_common_type(pstate, newelems, "ARRAY", NULL);
2100
2101 if (newa->multidims)
2102 {
2103 array_type = coerce_type;
2104 element_type = get_element_type(array_type);
2105 if (!OidIsValid(element_type))
2106 ereport(ERROR,
2107 (errcode(ERRCODE_UNDEFINED_OBJECT),
2108 errmsg("could not find element type for data type %s",
2109 format_type_be(array_type)),
2110 parser_errposition(pstate, a->location)));
2111 }
2112 else
2113 {
2114 element_type = coerce_type;
2115 array_type = get_array_type(element_type);
2116 if (!OidIsValid(array_type))
2117 ereport(ERROR,
2118 (errcode(ERRCODE_UNDEFINED_OBJECT),
2119 errmsg("could not find array type for data type %s",
2120 format_type_be(element_type)),
2121 parser_errposition(pstate, a->location)));
2122 }
2123 coerce_hard = false;
2124 }
2125
2126 /*
2127 * Coerce elements to target type
2128 *
2129 * If the array has been explicitly cast, then the elements are in turn
2130 * explicitly coerced.
2131 *
2132 * If the array's type was merely derived from the common type of its
2133 * elements, then the elements are implicitly coerced to the common type.
2134 * This is consistent with other uses of select_common_type().
2135 */
2136 foreach(element, newelems)
2137 {
2138 Node *e = (Node *) lfirst(element);
2139 Node *newe;
2140
2141 if (coerce_hard)
2142 {
2143 newe = coerce_to_target_type(pstate, e,
2144 exprType(e),
2145 coerce_type,
2146 typmod,
2147 COERCION_EXPLICIT,
2148 COERCE_EXPLICIT_CAST,
2149 -1);
2150 if (newe == NULL)
2151 ereport(ERROR,
2152 (errcode(ERRCODE_CANNOT_COERCE),
2153 errmsg("cannot cast type %s to %s",
2154 format_type_be(exprType(e)),
2155 format_type_be(coerce_type)),
2156 parser_errposition(pstate, exprLocation(e))));
2157 }
2158 else
2159 newe = coerce_to_common_type(pstate, e,
2160 coerce_type,
2161 "ARRAY");
2162 newcoercedelems = lappend(newcoercedelems, newe);
2163 }
2164
2165 newa->array_typeid = array_type;
2166 /* array_collid will be set by parse_collate.c */
2167 newa->element_typeid = element_type;
2168 newa->elements = newcoercedelems;
2169 newa->location = a->location;
2170
2171 return (Node *) newa;
2172 }
2173
2174 static Node *
transformRowExpr(ParseState * pstate,RowExpr * r,bool allowDefault)2175 transformRowExpr(ParseState *pstate, RowExpr *r, bool allowDefault)
2176 {
2177 RowExpr *newr;
2178 char fname[16];
2179 int fnum;
2180 ListCell *lc;
2181
2182 newr = makeNode(RowExpr);
2183
2184 /* Transform the field expressions */
2185 newr->args = transformExpressionList(pstate, r->args,
2186 pstate->p_expr_kind, allowDefault);
2187
2188 /* Barring later casting, we consider the type RECORD */
2189 newr->row_typeid = RECORDOID;
2190 newr->row_format = COERCE_IMPLICIT_CAST;
2191
2192 /* ROW() has anonymous columns, so invent some field names */
2193 newr->colnames = NIL;
2194 fnum = 1;
2195 foreach(lc, newr->args)
2196 {
2197 snprintf(fname, sizeof(fname), "f%d", fnum++);
2198 newr->colnames = lappend(newr->colnames, makeString(pstrdup(fname)));
2199 }
2200
2201 newr->location = r->location;
2202
2203 return (Node *) newr;
2204 }
2205
2206 static Node *
transformCoalesceExpr(ParseState * pstate,CoalesceExpr * c)2207 transformCoalesceExpr(ParseState *pstate, CoalesceExpr *c)
2208 {
2209 CoalesceExpr *newc = makeNode(CoalesceExpr);
2210 Node *last_srf = pstate->p_last_srf;
2211 List *newargs = NIL;
2212 List *newcoercedargs = NIL;
2213 ListCell *args;
2214
2215 foreach(args, c->args)
2216 {
2217 Node *e = (Node *) lfirst(args);
2218 Node *newe;
2219
2220 newe = transformExprRecurse(pstate, e);
2221 newargs = lappend(newargs, newe);
2222 }
2223
2224 newc->coalescetype = select_common_type(pstate, newargs, "COALESCE", NULL);
2225 /* coalescecollid will be set by parse_collate.c */
2226
2227 /* Convert arguments if necessary */
2228 foreach(args, newargs)
2229 {
2230 Node *e = (Node *) lfirst(args);
2231 Node *newe;
2232
2233 newe = coerce_to_common_type(pstate, e,
2234 newc->coalescetype,
2235 "COALESCE");
2236 newcoercedargs = lappend(newcoercedargs, newe);
2237 }
2238
2239 /* if any subexpression contained a SRF, complain */
2240 if (pstate->p_last_srf != last_srf)
2241 ereport(ERROR,
2242 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2243 /* translator: %s is name of a SQL construct, eg GROUP BY */
2244 errmsg("set-returning functions are not allowed in %s",
2245 "COALESCE"),
2246 errhint("You might be able to move the set-returning function into a LATERAL FROM item."),
2247 parser_errposition(pstate,
2248 exprLocation(pstate->p_last_srf))));
2249
2250 newc->args = newcoercedargs;
2251 newc->location = c->location;
2252 return (Node *) newc;
2253 }
2254
2255 static Node *
transformMinMaxExpr(ParseState * pstate,MinMaxExpr * m)2256 transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m)
2257 {
2258 MinMaxExpr *newm = makeNode(MinMaxExpr);
2259 List *newargs = NIL;
2260 List *newcoercedargs = NIL;
2261 const char *funcname = (m->op == IS_GREATEST) ? "GREATEST" : "LEAST";
2262 ListCell *args;
2263
2264 newm->op = m->op;
2265 foreach(args, m->args)
2266 {
2267 Node *e = (Node *) lfirst(args);
2268 Node *newe;
2269
2270 newe = transformExprRecurse(pstate, e);
2271 newargs = lappend(newargs, newe);
2272 }
2273
2274 newm->minmaxtype = select_common_type(pstate, newargs, funcname, NULL);
2275 /* minmaxcollid and inputcollid will be set by parse_collate.c */
2276
2277 /* Convert arguments if necessary */
2278 foreach(args, newargs)
2279 {
2280 Node *e = (Node *) lfirst(args);
2281 Node *newe;
2282
2283 newe = coerce_to_common_type(pstate, e,
2284 newm->minmaxtype,
2285 funcname);
2286 newcoercedargs = lappend(newcoercedargs, newe);
2287 }
2288
2289 newm->args = newcoercedargs;
2290 newm->location = m->location;
2291 return (Node *) newm;
2292 }
2293
2294 static Node *
transformSQLValueFunction(ParseState * pstate,SQLValueFunction * svf)2295 transformSQLValueFunction(ParseState *pstate, SQLValueFunction *svf)
2296 {
2297 /*
2298 * All we need to do is insert the correct result type and (where needed)
2299 * validate the typmod, so we just modify the node in-place.
2300 */
2301 switch (svf->op)
2302 {
2303 case SVFOP_CURRENT_DATE:
2304 svf->type = DATEOID;
2305 break;
2306 case SVFOP_CURRENT_TIME:
2307 svf->type = TIMETZOID;
2308 break;
2309 case SVFOP_CURRENT_TIME_N:
2310 svf->type = TIMETZOID;
2311 svf->typmod = anytime_typmod_check(true, svf->typmod);
2312 break;
2313 case SVFOP_CURRENT_TIMESTAMP:
2314 svf->type = TIMESTAMPTZOID;
2315 break;
2316 case SVFOP_CURRENT_TIMESTAMP_N:
2317 svf->type = TIMESTAMPTZOID;
2318 svf->typmod = anytimestamp_typmod_check(true, svf->typmod);
2319 break;
2320 case SVFOP_LOCALTIME:
2321 svf->type = TIMEOID;
2322 break;
2323 case SVFOP_LOCALTIME_N:
2324 svf->type = TIMEOID;
2325 svf->typmod = anytime_typmod_check(false, svf->typmod);
2326 break;
2327 case SVFOP_LOCALTIMESTAMP:
2328 svf->type = TIMESTAMPOID;
2329 break;
2330 case SVFOP_LOCALTIMESTAMP_N:
2331 svf->type = TIMESTAMPOID;
2332 svf->typmod = anytimestamp_typmod_check(false, svf->typmod);
2333 break;
2334 case SVFOP_CURRENT_ROLE:
2335 case SVFOP_CURRENT_USER:
2336 case SVFOP_USER:
2337 case SVFOP_SESSION_USER:
2338 case SVFOP_CURRENT_CATALOG:
2339 case SVFOP_CURRENT_SCHEMA:
2340 svf->type = NAMEOID;
2341 break;
2342 }
2343
2344 return (Node *) svf;
2345 }
2346
2347 static Node *
transformXmlExpr(ParseState * pstate,XmlExpr * x)2348 transformXmlExpr(ParseState *pstate, XmlExpr *x)
2349 {
2350 XmlExpr *newx;
2351 ListCell *lc;
2352 int i;
2353
2354 if (operator_precedence_warning && x->op == IS_DOCUMENT)
2355 emit_precedence_warnings(pstate, PREC_GROUP_POSTFIX_IS, "IS",
2356 (Node *) linitial(x->args), NULL,
2357 x->location);
2358
2359 newx = makeNode(XmlExpr);
2360 newx->op = x->op;
2361 if (x->name)
2362 newx->name = map_sql_identifier_to_xml_name(x->name, false, false);
2363 else
2364 newx->name = NULL;
2365 newx->xmloption = x->xmloption;
2366 newx->type = XMLOID; /* this just marks the node as transformed */
2367 newx->typmod = -1;
2368 newx->location = x->location;
2369
2370 /*
2371 * gram.y built the named args as a list of ResTarget. Transform each,
2372 * and break the names out as a separate list.
2373 */
2374 newx->named_args = NIL;
2375 newx->arg_names = NIL;
2376
2377 foreach(lc, x->named_args)
2378 {
2379 ResTarget *r = lfirst_node(ResTarget, lc);
2380 Node *expr;
2381 char *argname;
2382
2383 expr = transformExprRecurse(pstate, r->val);
2384
2385 if (r->name)
2386 argname = map_sql_identifier_to_xml_name(r->name, false, false);
2387 else if (IsA(r->val, ColumnRef))
2388 argname = map_sql_identifier_to_xml_name(FigureColname(r->val),
2389 true, false);
2390 else
2391 {
2392 ereport(ERROR,
2393 (errcode(ERRCODE_SYNTAX_ERROR),
2394 x->op == IS_XMLELEMENT
2395 ? errmsg("unnamed XML attribute value must be a column reference")
2396 : errmsg("unnamed XML element value must be a column reference"),
2397 parser_errposition(pstate, r->location)));
2398 argname = NULL; /* keep compiler quiet */
2399 }
2400
2401 /* reject duplicate argnames in XMLELEMENT only */
2402 if (x->op == IS_XMLELEMENT)
2403 {
2404 ListCell *lc2;
2405
2406 foreach(lc2, newx->arg_names)
2407 {
2408 if (strcmp(argname, strVal(lfirst(lc2))) == 0)
2409 ereport(ERROR,
2410 (errcode(ERRCODE_SYNTAX_ERROR),
2411 errmsg("XML attribute name \"%s\" appears more than once",
2412 argname),
2413 parser_errposition(pstate, r->location)));
2414 }
2415 }
2416
2417 newx->named_args = lappend(newx->named_args, expr);
2418 newx->arg_names = lappend(newx->arg_names, makeString(argname));
2419 }
2420
2421 /* The other arguments are of varying types depending on the function */
2422 newx->args = NIL;
2423 i = 0;
2424 foreach(lc, x->args)
2425 {
2426 Node *e = (Node *) lfirst(lc);
2427 Node *newe;
2428
2429 newe = transformExprRecurse(pstate, e);
2430 switch (x->op)
2431 {
2432 case IS_XMLCONCAT:
2433 newe = coerce_to_specific_type(pstate, newe, XMLOID,
2434 "XMLCONCAT");
2435 break;
2436 case IS_XMLELEMENT:
2437 /* no coercion necessary */
2438 break;
2439 case IS_XMLFOREST:
2440 newe = coerce_to_specific_type(pstate, newe, XMLOID,
2441 "XMLFOREST");
2442 break;
2443 case IS_XMLPARSE:
2444 if (i == 0)
2445 newe = coerce_to_specific_type(pstate, newe, TEXTOID,
2446 "XMLPARSE");
2447 else
2448 newe = coerce_to_boolean(pstate, newe, "XMLPARSE");
2449 break;
2450 case IS_XMLPI:
2451 newe = coerce_to_specific_type(pstate, newe, TEXTOID,
2452 "XMLPI");
2453 break;
2454 case IS_XMLROOT:
2455 if (i == 0)
2456 newe = coerce_to_specific_type(pstate, newe, XMLOID,
2457 "XMLROOT");
2458 else if (i == 1)
2459 newe = coerce_to_specific_type(pstate, newe, TEXTOID,
2460 "XMLROOT");
2461 else
2462 newe = coerce_to_specific_type(pstate, newe, INT4OID,
2463 "XMLROOT");
2464 break;
2465 case IS_XMLSERIALIZE:
2466 /* not handled here */
2467 Assert(false);
2468 break;
2469 case IS_DOCUMENT:
2470 newe = coerce_to_specific_type(pstate, newe, XMLOID,
2471 "IS DOCUMENT");
2472 break;
2473 }
2474 newx->args = lappend(newx->args, newe);
2475 i++;
2476 }
2477
2478 return (Node *) newx;
2479 }
2480
2481 static Node *
transformXmlSerialize(ParseState * pstate,XmlSerialize * xs)2482 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
2483 {
2484 Node *result;
2485 XmlExpr *xexpr;
2486 Oid targetType;
2487 int32 targetTypmod;
2488
2489 xexpr = makeNode(XmlExpr);
2490 xexpr->op = IS_XMLSERIALIZE;
2491 xexpr->args = list_make1(coerce_to_specific_type(pstate,
2492 transformExprRecurse(pstate, xs->expr),
2493 XMLOID,
2494 "XMLSERIALIZE"));
2495
2496 typenameTypeIdAndMod(pstate, xs->typeName, &targetType, &targetTypmod);
2497
2498 xexpr->xmloption = xs->xmloption;
2499 xexpr->location = xs->location;
2500 /* We actually only need these to be able to parse back the expression. */
2501 xexpr->type = targetType;
2502 xexpr->typmod = targetTypmod;
2503
2504 /*
2505 * The actual target type is determined this way. SQL allows char and
2506 * varchar as target types. We allow anything that can be cast implicitly
2507 * from text. This way, user-defined text-like data types automatically
2508 * fit in.
2509 */
2510 result = coerce_to_target_type(pstate, (Node *) xexpr,
2511 TEXTOID, targetType, targetTypmod,
2512 COERCION_IMPLICIT,
2513 COERCE_IMPLICIT_CAST,
2514 -1);
2515 if (result == NULL)
2516 ereport(ERROR,
2517 (errcode(ERRCODE_CANNOT_COERCE),
2518 errmsg("cannot cast XMLSERIALIZE result to %s",
2519 format_type_be(targetType)),
2520 parser_errposition(pstate, xexpr->location)));
2521 return result;
2522 }
2523
2524 static Node *
transformBooleanTest(ParseState * pstate,BooleanTest * b)2525 transformBooleanTest(ParseState *pstate, BooleanTest *b)
2526 {
2527 const char *clausename;
2528
2529 if (operator_precedence_warning)
2530 emit_precedence_warnings(pstate, PREC_GROUP_POSTFIX_IS, "IS",
2531 (Node *) b->arg, NULL,
2532 b->location);
2533
2534 switch (b->booltesttype)
2535 {
2536 case IS_TRUE:
2537 clausename = "IS TRUE";
2538 break;
2539 case IS_NOT_TRUE:
2540 clausename = "IS NOT TRUE";
2541 break;
2542 case IS_FALSE:
2543 clausename = "IS FALSE";
2544 break;
2545 case IS_NOT_FALSE:
2546 clausename = "IS NOT FALSE";
2547 break;
2548 case IS_UNKNOWN:
2549 clausename = "IS UNKNOWN";
2550 break;
2551 case IS_NOT_UNKNOWN:
2552 clausename = "IS NOT UNKNOWN";
2553 break;
2554 default:
2555 elog(ERROR, "unrecognized booltesttype: %d",
2556 (int) b->booltesttype);
2557 clausename = NULL; /* keep compiler quiet */
2558 }
2559
2560 b->arg = (Expr *) transformExprRecurse(pstate, (Node *) b->arg);
2561
2562 b->arg = (Expr *) coerce_to_boolean(pstate,
2563 (Node *) b->arg,
2564 clausename);
2565
2566 return (Node *) b;
2567 }
2568
2569 static Node *
transformCurrentOfExpr(ParseState * pstate,CurrentOfExpr * cexpr)2570 transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr)
2571 {
2572 int sublevels_up;
2573
2574 /* CURRENT OF can only appear at top level of UPDATE/DELETE */
2575 Assert(pstate->p_target_rangetblentry != NULL);
2576 cexpr->cvarno = RTERangeTablePosn(pstate,
2577 pstate->p_target_rangetblentry,
2578 &sublevels_up);
2579 Assert(sublevels_up == 0);
2580
2581 /*
2582 * Check to see if the cursor name matches a parameter of type REFCURSOR.
2583 * If so, replace the raw name reference with a parameter reference. (This
2584 * is a hack for the convenience of plpgsql.)
2585 */
2586 if (cexpr->cursor_name != NULL) /* in case already transformed */
2587 {
2588 ColumnRef *cref = makeNode(ColumnRef);
2589 Node *node = NULL;
2590
2591 /* Build an unqualified ColumnRef with the given name */
2592 cref->fields = list_make1(makeString(cexpr->cursor_name));
2593 cref->location = -1;
2594
2595 /* See if there is a translation available from a parser hook */
2596 if (pstate->p_pre_columnref_hook != NULL)
2597 node = pstate->p_pre_columnref_hook(pstate, cref);
2598 if (node == NULL && pstate->p_post_columnref_hook != NULL)
2599 node = pstate->p_post_columnref_hook(pstate, cref, NULL);
2600
2601 /*
2602 * XXX Should we throw an error if we get a translation that isn't a
2603 * refcursor Param? For now it seems best to silently ignore false
2604 * matches.
2605 */
2606 if (node != NULL && IsA(node, Param))
2607 {
2608 Param *p = (Param *) node;
2609
2610 if (p->paramkind == PARAM_EXTERN &&
2611 p->paramtype == REFCURSOROID)
2612 {
2613 /* Matches, so convert CURRENT OF to a param reference */
2614 cexpr->cursor_name = NULL;
2615 cexpr->cursor_param = p->paramid;
2616 }
2617 }
2618 }
2619
2620 return (Node *) cexpr;
2621 }
2622
2623 /*
2624 * Construct a whole-row reference to represent the notation "relation.*".
2625 */
2626 static Node *
transformWholeRowRef(ParseState * pstate,RangeTblEntry * rte,int location)2627 transformWholeRowRef(ParseState *pstate, RangeTblEntry *rte, int location)
2628 {
2629 Var *result;
2630 int vnum;
2631 int sublevels_up;
2632
2633 /* Find the RTE's rangetable location */
2634 vnum = RTERangeTablePosn(pstate, rte, &sublevels_up);
2635
2636 /*
2637 * Build the appropriate referencing node. Note that if the RTE is a
2638 * function returning scalar, we create just a plain reference to the
2639 * function value, not a composite containing a single column. This is
2640 * pretty inconsistent at first sight, but it's what we've done
2641 * historically. One argument for it is that "rel" and "rel.*" mean the
2642 * same thing for composite relations, so why not for scalar functions...
2643 */
2644 result = makeWholeRowVar(rte, vnum, sublevels_up, true);
2645
2646 /* location is not filled in by makeWholeRowVar */
2647 result->location = location;
2648
2649 /* mark relation as requiring whole-row SELECT access */
2650 markVarForSelectPriv(pstate, result, rte);
2651
2652 return (Node *) result;
2653 }
2654
2655 /*
2656 * Handle an explicit CAST construct.
2657 *
2658 * Transform the argument, look up the type name, and apply any necessary
2659 * coercion function(s).
2660 */
2661 static Node *
transformTypeCast(ParseState * pstate,TypeCast * tc)2662 transformTypeCast(ParseState *pstate, TypeCast *tc)
2663 {
2664 Node *result;
2665 Node *arg = tc->arg;
2666 Node *expr;
2667 Oid inputType;
2668 Oid targetType;
2669 int32 targetTypmod;
2670 int location;
2671
2672 /* Look up the type name first */
2673 typenameTypeIdAndMod(pstate, tc->typeName, &targetType, &targetTypmod);
2674
2675 /*
2676 * Look through any AEXPR_PAREN nodes that may have been inserted thanks
2677 * to operator_precedence_warning. Otherwise, ARRAY[]::foo[] behaves
2678 * differently from (ARRAY[])::foo[].
2679 */
2680 while (arg && IsA(arg, A_Expr) &&
2681 ((A_Expr *) arg)->kind == AEXPR_PAREN)
2682 arg = ((A_Expr *) arg)->lexpr;
2683
2684 /*
2685 * If the subject of the typecast is an ARRAY[] construct and the target
2686 * type is an array type, we invoke transformArrayExpr() directly so that
2687 * we can pass down the type information. This avoids some cases where
2688 * transformArrayExpr() might not infer the correct type. Otherwise, just
2689 * transform the argument normally.
2690 */
2691 if (IsA(arg, A_ArrayExpr))
2692 {
2693 Oid targetBaseType;
2694 int32 targetBaseTypmod;
2695 Oid elementType;
2696
2697 /*
2698 * If target is a domain over array, work with the base array type
2699 * here. Below, we'll cast the array type to the domain. In the
2700 * usual case that the target is not a domain, the remaining steps
2701 * will be a no-op.
2702 */
2703 targetBaseTypmod = targetTypmod;
2704 targetBaseType = getBaseTypeAndTypmod(targetType, &targetBaseTypmod);
2705 elementType = get_element_type(targetBaseType);
2706 if (OidIsValid(elementType))
2707 {
2708 expr = transformArrayExpr(pstate,
2709 (A_ArrayExpr *) arg,
2710 targetBaseType,
2711 elementType,
2712 targetBaseTypmod);
2713 }
2714 else
2715 expr = transformExprRecurse(pstate, arg);
2716 }
2717 else
2718 expr = transformExprRecurse(pstate, arg);
2719
2720 inputType = exprType(expr);
2721 if (inputType == InvalidOid)
2722 return expr; /* do nothing if NULL input */
2723
2724 /*
2725 * Location of the coercion is preferentially the location of the :: or
2726 * CAST symbol, but if there is none then use the location of the type
2727 * name (this can happen in TypeName 'string' syntax, for instance).
2728 */
2729 location = tc->location;
2730 if (location < 0)
2731 location = tc->typeName->location;
2732
2733 result = coerce_to_target_type(pstate, expr, inputType,
2734 targetType, targetTypmod,
2735 COERCION_EXPLICIT,
2736 COERCE_EXPLICIT_CAST,
2737 location);
2738 if (result == NULL)
2739 ereport(ERROR,
2740 (errcode(ERRCODE_CANNOT_COERCE),
2741 errmsg("cannot cast type %s to %s",
2742 format_type_be(inputType),
2743 format_type_be(targetType)),
2744 parser_coercion_errposition(pstate, location, expr)));
2745
2746 return result;
2747 }
2748
2749 /*
2750 * Handle an explicit COLLATE clause.
2751 *
2752 * Transform the argument, and look up the collation name.
2753 */
2754 static Node *
transformCollateClause(ParseState * pstate,CollateClause * c)2755 transformCollateClause(ParseState *pstate, CollateClause *c)
2756 {
2757 CollateExpr *newc;
2758 Oid argtype;
2759
2760 newc = makeNode(CollateExpr);
2761 newc->arg = (Expr *) transformExprRecurse(pstate, c->arg);
2762
2763 argtype = exprType((Node *) newc->arg);
2764
2765 /*
2766 * The unknown type is not collatable, but coerce_type() takes care of it
2767 * separately, so we'll let it go here.
2768 */
2769 if (!type_is_collatable(argtype) && argtype != UNKNOWNOID)
2770 ereport(ERROR,
2771 (errcode(ERRCODE_DATATYPE_MISMATCH),
2772 errmsg("collations are not supported by type %s",
2773 format_type_be(argtype)),
2774 parser_errposition(pstate, c->location)));
2775
2776 newc->collOid = LookupCollation(pstate, c->collname, c->location);
2777 newc->location = c->location;
2778
2779 return (Node *) newc;
2780 }
2781
2782 /*
2783 * Transform a "row compare-op row" construct
2784 *
2785 * The inputs are lists of already-transformed expressions.
2786 * As with coerce_type, pstate may be NULL if no special unknown-Param
2787 * processing is wanted.
2788 *
2789 * The output may be a single OpExpr, an AND or OR combination of OpExprs,
2790 * or a RowCompareExpr. In all cases it is guaranteed to return boolean.
2791 * The AND, OR, and RowCompareExpr cases further imply things about the
2792 * behavior of the operators (ie, they behave as =, <>, or < <= > >=).
2793 */
2794 static Node *
make_row_comparison_op(ParseState * pstate,List * opname,List * largs,List * rargs,int location)2795 make_row_comparison_op(ParseState *pstate, List *opname,
2796 List *largs, List *rargs, int location)
2797 {
2798 RowCompareExpr *rcexpr;
2799 RowCompareType rctype;
2800 List *opexprs;
2801 List *opnos;
2802 List *opfamilies;
2803 ListCell *l,
2804 *r;
2805 List **opinfo_lists;
2806 Bitmapset *strats;
2807 int nopers;
2808 int i;
2809
2810 nopers = list_length(largs);
2811 if (nopers != list_length(rargs))
2812 ereport(ERROR,
2813 (errcode(ERRCODE_SYNTAX_ERROR),
2814 errmsg("unequal number of entries in row expressions"),
2815 parser_errposition(pstate, location)));
2816
2817 /*
2818 * We can't compare zero-length rows because there is no principled basis
2819 * for figuring out what the operator is.
2820 */
2821 if (nopers == 0)
2822 ereport(ERROR,
2823 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2824 errmsg("cannot compare rows of zero length"),
2825 parser_errposition(pstate, location)));
2826
2827 /*
2828 * Identify all the pairwise operators, using make_op so that behavior is
2829 * the same as in the simple scalar case.
2830 */
2831 opexprs = NIL;
2832 forboth(l, largs, r, rargs)
2833 {
2834 Node *larg = (Node *) lfirst(l);
2835 Node *rarg = (Node *) lfirst(r);
2836 OpExpr *cmp;
2837
2838 cmp = castNode(OpExpr, make_op(pstate, opname, larg, rarg,
2839 pstate->p_last_srf, location));
2840
2841 /*
2842 * We don't use coerce_to_boolean here because we insist on the
2843 * operator yielding boolean directly, not via coercion. If it
2844 * doesn't yield bool it won't be in any index opfamilies...
2845 */
2846 if (cmp->opresulttype != BOOLOID)
2847 ereport(ERROR,
2848 (errcode(ERRCODE_DATATYPE_MISMATCH),
2849 errmsg("row comparison operator must yield type boolean, "
2850 "not type %s",
2851 format_type_be(cmp->opresulttype)),
2852 parser_errposition(pstate, location)));
2853 if (expression_returns_set((Node *) cmp))
2854 ereport(ERROR,
2855 (errcode(ERRCODE_DATATYPE_MISMATCH),
2856 errmsg("row comparison operator must not return a set"),
2857 parser_errposition(pstate, location)));
2858 opexprs = lappend(opexprs, cmp);
2859 }
2860
2861 /*
2862 * If rows are length 1, just return the single operator. In this case we
2863 * don't insist on identifying btree semantics for the operator (but we
2864 * still require it to return boolean).
2865 */
2866 if (nopers == 1)
2867 return (Node *) linitial(opexprs);
2868
2869 /*
2870 * Now we must determine which row comparison semantics (= <> < <= > >=)
2871 * apply to this set of operators. We look for btree opfamilies
2872 * containing the operators, and see which interpretations (strategy
2873 * numbers) exist for each operator.
2874 */
2875 opinfo_lists = (List **) palloc(nopers * sizeof(List *));
2876 strats = NULL;
2877 i = 0;
2878 foreach(l, opexprs)
2879 {
2880 Oid opno = ((OpExpr *) lfirst(l))->opno;
2881 Bitmapset *this_strats;
2882 ListCell *j;
2883
2884 opinfo_lists[i] = get_op_btree_interpretation(opno);
2885
2886 /*
2887 * convert strategy numbers into a Bitmapset to make the intersection
2888 * calculation easy.
2889 */
2890 this_strats = NULL;
2891 foreach(j, opinfo_lists[i])
2892 {
2893 OpBtreeInterpretation *opinfo = lfirst(j);
2894
2895 this_strats = bms_add_member(this_strats, opinfo->strategy);
2896 }
2897 if (i == 0)
2898 strats = this_strats;
2899 else
2900 strats = bms_int_members(strats, this_strats);
2901 i++;
2902 }
2903
2904 /*
2905 * If there are multiple common interpretations, we may use any one of
2906 * them ... this coding arbitrarily picks the lowest btree strategy
2907 * number.
2908 */
2909 i = bms_first_member(strats);
2910 if (i < 0)
2911 {
2912 /* No common interpretation, so fail */
2913 ereport(ERROR,
2914 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2915 errmsg("could not determine interpretation of row comparison operator %s",
2916 strVal(llast(opname))),
2917 errhint("Row comparison operators must be associated with btree operator families."),
2918 parser_errposition(pstate, location)));
2919 }
2920 rctype = (RowCompareType) i;
2921
2922 /*
2923 * For = and <> cases, we just combine the pairwise operators with AND or
2924 * OR respectively.
2925 */
2926 if (rctype == ROWCOMPARE_EQ)
2927 return (Node *) makeBoolExpr(AND_EXPR, opexprs, location);
2928 if (rctype == ROWCOMPARE_NE)
2929 return (Node *) makeBoolExpr(OR_EXPR, opexprs, location);
2930
2931 /*
2932 * Otherwise we need to choose exactly which opfamily to associate with
2933 * each operator.
2934 */
2935 opfamilies = NIL;
2936 for (i = 0; i < nopers; i++)
2937 {
2938 Oid opfamily = InvalidOid;
2939 ListCell *j;
2940
2941 foreach(j, opinfo_lists[i])
2942 {
2943 OpBtreeInterpretation *opinfo = lfirst(j);
2944
2945 if (opinfo->strategy == rctype)
2946 {
2947 opfamily = opinfo->opfamily_id;
2948 break;
2949 }
2950 }
2951 if (OidIsValid(opfamily))
2952 opfamilies = lappend_oid(opfamilies, opfamily);
2953 else /* should not happen */
2954 ereport(ERROR,
2955 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2956 errmsg("could not determine interpretation of row comparison operator %s",
2957 strVal(llast(opname))),
2958 errdetail("There are multiple equally-plausible candidates."),
2959 parser_errposition(pstate, location)));
2960 }
2961
2962 /*
2963 * Now deconstruct the OpExprs and create a RowCompareExpr.
2964 *
2965 * Note: can't just reuse the passed largs/rargs lists, because of
2966 * possibility that make_op inserted coercion operations.
2967 */
2968 opnos = NIL;
2969 largs = NIL;
2970 rargs = NIL;
2971 foreach(l, opexprs)
2972 {
2973 OpExpr *cmp = (OpExpr *) lfirst(l);
2974
2975 opnos = lappend_oid(opnos, cmp->opno);
2976 largs = lappend(largs, linitial(cmp->args));
2977 rargs = lappend(rargs, lsecond(cmp->args));
2978 }
2979
2980 rcexpr = makeNode(RowCompareExpr);
2981 rcexpr->rctype = rctype;
2982 rcexpr->opnos = opnos;
2983 rcexpr->opfamilies = opfamilies;
2984 rcexpr->inputcollids = NIL; /* assign_expr_collations will fix this */
2985 rcexpr->largs = largs;
2986 rcexpr->rargs = rargs;
2987
2988 return (Node *) rcexpr;
2989 }
2990
2991 /*
2992 * Transform a "row IS DISTINCT FROM row" construct
2993 *
2994 * The input RowExprs are already transformed
2995 */
2996 static Node *
make_row_distinct_op(ParseState * pstate,List * opname,RowExpr * lrow,RowExpr * rrow,int location)2997 make_row_distinct_op(ParseState *pstate, List *opname,
2998 RowExpr *lrow, RowExpr *rrow,
2999 int location)
3000 {
3001 Node *result = NULL;
3002 List *largs = lrow->args;
3003 List *rargs = rrow->args;
3004 ListCell *l,
3005 *r;
3006
3007 if (list_length(largs) != list_length(rargs))
3008 ereport(ERROR,
3009 (errcode(ERRCODE_SYNTAX_ERROR),
3010 errmsg("unequal number of entries in row expressions"),
3011 parser_errposition(pstate, location)));
3012
3013 forboth(l, largs, r, rargs)
3014 {
3015 Node *larg = (Node *) lfirst(l);
3016 Node *rarg = (Node *) lfirst(r);
3017 Node *cmp;
3018
3019 cmp = (Node *) make_distinct_op(pstate, opname, larg, rarg, location);
3020 if (result == NULL)
3021 result = cmp;
3022 else
3023 result = (Node *) makeBoolExpr(OR_EXPR,
3024 list_make2(result, cmp),
3025 location);
3026 }
3027
3028 if (result == NULL)
3029 {
3030 /* zero-length rows? Generate constant FALSE */
3031 result = makeBoolConst(false, false);
3032 }
3033
3034 return result;
3035 }
3036
3037 /*
3038 * make the node for an IS DISTINCT FROM operator
3039 */
3040 static Expr *
make_distinct_op(ParseState * pstate,List * opname,Node * ltree,Node * rtree,int location)3041 make_distinct_op(ParseState *pstate, List *opname, Node *ltree, Node *rtree,
3042 int location)
3043 {
3044 Expr *result;
3045
3046 result = make_op(pstate, opname, ltree, rtree,
3047 pstate->p_last_srf, location);
3048 if (((OpExpr *) result)->opresulttype != BOOLOID)
3049 ereport(ERROR,
3050 (errcode(ERRCODE_DATATYPE_MISMATCH),
3051 errmsg("IS DISTINCT FROM requires = operator to yield boolean"),
3052 parser_errposition(pstate, location)));
3053 if (((OpExpr *) result)->opretset)
3054 ereport(ERROR,
3055 (errcode(ERRCODE_DATATYPE_MISMATCH),
3056 /* translator: %s is name of a SQL construct, eg NULLIF */
3057 errmsg("%s must not return a set", "IS DISTINCT FROM"),
3058 parser_errposition(pstate, location)));
3059
3060 /*
3061 * We rely on DistinctExpr and OpExpr being same struct
3062 */
3063 NodeSetTag(result, T_DistinctExpr);
3064
3065 return result;
3066 }
3067
3068 /*
3069 * Produce a NullTest node from an IS [NOT] DISTINCT FROM NULL construct
3070 *
3071 * "arg" is the untransformed other argument
3072 */
3073 static Node *
make_nulltest_from_distinct(ParseState * pstate,A_Expr * distincta,Node * arg)3074 make_nulltest_from_distinct(ParseState *pstate, A_Expr *distincta, Node *arg)
3075 {
3076 NullTest *nt = makeNode(NullTest);
3077
3078 nt->arg = (Expr *) transformExprRecurse(pstate, arg);
3079 /* the argument can be any type, so don't coerce it */
3080 if (distincta->kind == AEXPR_NOT_DISTINCT)
3081 nt->nulltesttype = IS_NULL;
3082 else
3083 nt->nulltesttype = IS_NOT_NULL;
3084 /* argisrow = false is correct whether or not arg is composite */
3085 nt->argisrow = false;
3086 nt->location = distincta->location;
3087 return (Node *) nt;
3088 }
3089
3090 /*
3091 * Identify node's group for operator precedence warnings
3092 *
3093 * For items in nonzero groups, also return a suitable node name into *nodename
3094 *
3095 * Note: group zero is used for nodes that are higher or lower precedence
3096 * than everything that changed precedence; we need never issue warnings
3097 * related to such nodes.
3098 */
3099 static int
operator_precedence_group(Node * node,const char ** nodename)3100 operator_precedence_group(Node *node, const char **nodename)
3101 {
3102 int group = 0;
3103
3104 *nodename = NULL;
3105 if (node == NULL)
3106 return 0;
3107
3108 if (IsA(node, A_Expr))
3109 {
3110 A_Expr *aexpr = (A_Expr *) node;
3111
3112 if (aexpr->kind == AEXPR_OP &&
3113 aexpr->lexpr != NULL &&
3114 aexpr->rexpr != NULL)
3115 {
3116 /* binary operator */
3117 if (list_length(aexpr->name) == 1)
3118 {
3119 *nodename = strVal(linitial(aexpr->name));
3120 /* Ignore if op was always higher priority than IS-tests */
3121 if (strcmp(*nodename, "+") == 0 ||
3122 strcmp(*nodename, "-") == 0 ||
3123 strcmp(*nodename, "*") == 0 ||
3124 strcmp(*nodename, "/") == 0 ||
3125 strcmp(*nodename, "%") == 0 ||
3126 strcmp(*nodename, "^") == 0)
3127 group = 0;
3128 else if (strcmp(*nodename, "<") == 0 ||
3129 strcmp(*nodename, ">") == 0)
3130 group = PREC_GROUP_LESS;
3131 else if (strcmp(*nodename, "=") == 0)
3132 group = PREC_GROUP_EQUAL;
3133 else if (strcmp(*nodename, "<=") == 0 ||
3134 strcmp(*nodename, ">=") == 0 ||
3135 strcmp(*nodename, "<>") == 0)
3136 group = PREC_GROUP_LESS_EQUAL;
3137 else
3138 group = PREC_GROUP_INFIX_OP;
3139 }
3140 else
3141 {
3142 /* schema-qualified operator syntax */
3143 *nodename = "OPERATOR()";
3144 group = PREC_GROUP_INFIX_OP;
3145 }
3146 }
3147 else if (aexpr->kind == AEXPR_OP &&
3148 aexpr->lexpr == NULL &&
3149 aexpr->rexpr != NULL)
3150 {
3151 /* prefix operator */
3152 if (list_length(aexpr->name) == 1)
3153 {
3154 *nodename = strVal(linitial(aexpr->name));
3155 /* Ignore if op was always higher priority than IS-tests */
3156 if (strcmp(*nodename, "+") == 0 ||
3157 strcmp(*nodename, "-") == 0)
3158 group = 0;
3159 else
3160 group = PREC_GROUP_PREFIX_OP;
3161 }
3162 else
3163 {
3164 /* schema-qualified operator syntax */
3165 *nodename = "OPERATOR()";
3166 group = PREC_GROUP_PREFIX_OP;
3167 }
3168 }
3169 else if (aexpr->kind == AEXPR_OP &&
3170 aexpr->lexpr != NULL &&
3171 aexpr->rexpr == NULL)
3172 {
3173 /* postfix operator */
3174 if (list_length(aexpr->name) == 1)
3175 {
3176 *nodename = strVal(linitial(aexpr->name));
3177 group = PREC_GROUP_POSTFIX_OP;
3178 }
3179 else
3180 {
3181 /* schema-qualified operator syntax */
3182 *nodename = "OPERATOR()";
3183 group = PREC_GROUP_POSTFIX_OP;
3184 }
3185 }
3186 else if (aexpr->kind == AEXPR_OP_ANY ||
3187 aexpr->kind == AEXPR_OP_ALL)
3188 {
3189 *nodename = strVal(llast(aexpr->name));
3190 group = PREC_GROUP_POSTFIX_OP;
3191 }
3192 else if (aexpr->kind == AEXPR_DISTINCT ||
3193 aexpr->kind == AEXPR_NOT_DISTINCT)
3194 {
3195 *nodename = "IS";
3196 group = PREC_GROUP_INFIX_IS;
3197 }
3198 else if (aexpr->kind == AEXPR_OF)
3199 {
3200 *nodename = "IS";
3201 group = PREC_GROUP_POSTFIX_IS;
3202 }
3203 else if (aexpr->kind == AEXPR_IN)
3204 {
3205 *nodename = "IN";
3206 if (strcmp(strVal(linitial(aexpr->name)), "=") == 0)
3207 group = PREC_GROUP_IN;
3208 else
3209 group = PREC_GROUP_NOT_IN;
3210 }
3211 else if (aexpr->kind == AEXPR_LIKE)
3212 {
3213 *nodename = "LIKE";
3214 if (strcmp(strVal(linitial(aexpr->name)), "~~") == 0)
3215 group = PREC_GROUP_LIKE;
3216 else
3217 group = PREC_GROUP_NOT_LIKE;
3218 }
3219 else if (aexpr->kind == AEXPR_ILIKE)
3220 {
3221 *nodename = "ILIKE";
3222 if (strcmp(strVal(linitial(aexpr->name)), "~~*") == 0)
3223 group = PREC_GROUP_LIKE;
3224 else
3225 group = PREC_GROUP_NOT_LIKE;
3226 }
3227 else if (aexpr->kind == AEXPR_SIMILAR)
3228 {
3229 *nodename = "SIMILAR";
3230 if (strcmp(strVal(linitial(aexpr->name)), "~") == 0)
3231 group = PREC_GROUP_LIKE;
3232 else
3233 group = PREC_GROUP_NOT_LIKE;
3234 }
3235 else if (aexpr->kind == AEXPR_BETWEEN ||
3236 aexpr->kind == AEXPR_BETWEEN_SYM)
3237 {
3238 Assert(list_length(aexpr->name) == 1);
3239 *nodename = strVal(linitial(aexpr->name));
3240 group = PREC_GROUP_BETWEEN;
3241 }
3242 else if (aexpr->kind == AEXPR_NOT_BETWEEN ||
3243 aexpr->kind == AEXPR_NOT_BETWEEN_SYM)
3244 {
3245 Assert(list_length(aexpr->name) == 1);
3246 *nodename = strVal(linitial(aexpr->name));
3247 group = PREC_GROUP_NOT_BETWEEN;
3248 }
3249 }
3250 else if (IsA(node, NullTest) ||
3251 IsA(node, BooleanTest))
3252 {
3253 *nodename = "IS";
3254 group = PREC_GROUP_POSTFIX_IS;
3255 }
3256 else if (IsA(node, XmlExpr))
3257 {
3258 XmlExpr *x = (XmlExpr *) node;
3259
3260 if (x->op == IS_DOCUMENT)
3261 {
3262 *nodename = "IS";
3263 group = PREC_GROUP_POSTFIX_IS;
3264 }
3265 }
3266 else if (IsA(node, SubLink))
3267 {
3268 SubLink *s = (SubLink *) node;
3269
3270 if (s->subLinkType == ANY_SUBLINK ||
3271 s->subLinkType == ALL_SUBLINK)
3272 {
3273 if (s->operName == NIL)
3274 {
3275 *nodename = "IN";
3276 group = PREC_GROUP_IN;
3277 }
3278 else
3279 {
3280 *nodename = strVal(llast(s->operName));
3281 group = PREC_GROUP_POSTFIX_OP;
3282 }
3283 }
3284 }
3285 else if (IsA(node, BoolExpr))
3286 {
3287 /*
3288 * Must dig into NOTs to see if it's IS NOT DOCUMENT or NOT IN. This
3289 * opens us to possibly misrecognizing, eg, NOT (x IS DOCUMENT) as a
3290 * problematic construct. We can tell the difference by checking
3291 * whether the parse locations of the two nodes are identical.
3292 *
3293 * Note that when we are comparing the child node to its own children,
3294 * we will not know that it was a NOT. Fortunately, that doesn't
3295 * matter for these cases.
3296 */
3297 BoolExpr *b = (BoolExpr *) node;
3298
3299 if (b->boolop == NOT_EXPR)
3300 {
3301 Node *child = (Node *) linitial(b->args);
3302
3303 if (IsA(child, XmlExpr))
3304 {
3305 XmlExpr *x = (XmlExpr *) child;
3306
3307 if (x->op == IS_DOCUMENT &&
3308 x->location == b->location)
3309 {
3310 *nodename = "IS";
3311 group = PREC_GROUP_POSTFIX_IS;
3312 }
3313 }
3314 else if (IsA(child, SubLink))
3315 {
3316 SubLink *s = (SubLink *) child;
3317
3318 if (s->subLinkType == ANY_SUBLINK && s->operName == NIL &&
3319 s->location == b->location)
3320 {
3321 *nodename = "IN";
3322 group = PREC_GROUP_NOT_IN;
3323 }
3324 }
3325 }
3326 }
3327 return group;
3328 }
3329
3330 /*
3331 * helper routine for delivering 9.4-to-9.5 operator precedence warnings
3332 *
3333 * opgroup/opname/location represent some parent node
3334 * lchild, rchild are its left and right children (either could be NULL)
3335 *
3336 * This should be called before transforming the child nodes, since if a
3337 * precedence-driven parsing change has occurred in a query that used to work,
3338 * it's quite possible that we'll get a semantic failure while analyzing the
3339 * child expression. We want to produce the warning before that happens.
3340 * In any case, operator_precedence_group() expects untransformed input.
3341 */
3342 static void
emit_precedence_warnings(ParseState * pstate,int opgroup,const char * opname,Node * lchild,Node * rchild,int location)3343 emit_precedence_warnings(ParseState *pstate,
3344 int opgroup, const char *opname,
3345 Node *lchild, Node *rchild,
3346 int location)
3347 {
3348 int cgroup;
3349 const char *copname;
3350
3351 Assert(opgroup > 0);
3352
3353 /*
3354 * Complain if left child, which should be same or higher precedence
3355 * according to current rules, used to be lower precedence.
3356 *
3357 * Exception to precedence rules: if left child is IN or NOT IN or a
3358 * postfix operator, the grouping is syntactically forced regardless of
3359 * precedence.
3360 */
3361 cgroup = operator_precedence_group(lchild, &copname);
3362 if (cgroup > 0)
3363 {
3364 if (oldprecedence_l[cgroup] < oldprecedence_r[opgroup] &&
3365 cgroup != PREC_GROUP_IN &&
3366 cgroup != PREC_GROUP_NOT_IN &&
3367 cgroup != PREC_GROUP_POSTFIX_OP &&
3368 cgroup != PREC_GROUP_POSTFIX_IS)
3369 ereport(WARNING,
3370 (errmsg("operator precedence change: %s is now lower precedence than %s",
3371 opname, copname),
3372 parser_errposition(pstate, location)));
3373 }
3374
3375 /*
3376 * Complain if right child, which should be higher precedence according to
3377 * current rules, used to be same or lower precedence.
3378 *
3379 * Exception to precedence rules: if right child is a prefix operator, the
3380 * grouping is syntactically forced regardless of precedence.
3381 */
3382 cgroup = operator_precedence_group(rchild, &copname);
3383 if (cgroup > 0)
3384 {
3385 if (oldprecedence_r[cgroup] <= oldprecedence_l[opgroup] &&
3386 cgroup != PREC_GROUP_PREFIX_OP)
3387 ereport(WARNING,
3388 (errmsg("operator precedence change: %s is now lower precedence than %s",
3389 opname, copname),
3390 parser_errposition(pstate, location)));
3391 }
3392 }
3393
3394 /*
3395 * Produce a string identifying an expression by kind.
3396 *
3397 * Note: when practical, use a simple SQL keyword for the result. If that
3398 * doesn't work well, check call sites to see whether custom error message
3399 * strings are required.
3400 */
3401 const char *
ParseExprKindName(ParseExprKind exprKind)3402 ParseExprKindName(ParseExprKind exprKind)
3403 {
3404 switch (exprKind)
3405 {
3406 case EXPR_KIND_NONE:
3407 return "invalid expression context";
3408 case EXPR_KIND_OTHER:
3409 return "extension expression";
3410 case EXPR_KIND_JOIN_ON:
3411 return "JOIN/ON";
3412 case EXPR_KIND_JOIN_USING:
3413 return "JOIN/USING";
3414 case EXPR_KIND_FROM_SUBSELECT:
3415 return "sub-SELECT in FROM";
3416 case EXPR_KIND_FROM_FUNCTION:
3417 return "function in FROM";
3418 case EXPR_KIND_WHERE:
3419 return "WHERE";
3420 case EXPR_KIND_POLICY:
3421 return "POLICY";
3422 case EXPR_KIND_HAVING:
3423 return "HAVING";
3424 case EXPR_KIND_FILTER:
3425 return "FILTER";
3426 case EXPR_KIND_WINDOW_PARTITION:
3427 return "window PARTITION BY";
3428 case EXPR_KIND_WINDOW_ORDER:
3429 return "window ORDER BY";
3430 case EXPR_KIND_WINDOW_FRAME_RANGE:
3431 return "window RANGE";
3432 case EXPR_KIND_WINDOW_FRAME_ROWS:
3433 return "window ROWS";
3434 case EXPR_KIND_WINDOW_FRAME_GROUPS:
3435 return "window GROUPS";
3436 case EXPR_KIND_SELECT_TARGET:
3437 return "SELECT";
3438 case EXPR_KIND_INSERT_TARGET:
3439 return "INSERT";
3440 case EXPR_KIND_UPDATE_SOURCE:
3441 case EXPR_KIND_UPDATE_TARGET:
3442 return "UPDATE";
3443 case EXPR_KIND_GROUP_BY:
3444 return "GROUP BY";
3445 case EXPR_KIND_ORDER_BY:
3446 return "ORDER BY";
3447 case EXPR_KIND_DISTINCT_ON:
3448 return "DISTINCT ON";
3449 case EXPR_KIND_LIMIT:
3450 return "LIMIT";
3451 case EXPR_KIND_OFFSET:
3452 return "OFFSET";
3453 case EXPR_KIND_RETURNING:
3454 return "RETURNING";
3455 case EXPR_KIND_VALUES:
3456 case EXPR_KIND_VALUES_SINGLE:
3457 return "VALUES";
3458 case EXPR_KIND_CHECK_CONSTRAINT:
3459 case EXPR_KIND_DOMAIN_CHECK:
3460 return "CHECK";
3461 case EXPR_KIND_COLUMN_DEFAULT:
3462 case EXPR_KIND_FUNCTION_DEFAULT:
3463 return "DEFAULT";
3464 case EXPR_KIND_INDEX_EXPRESSION:
3465 return "index expression";
3466 case EXPR_KIND_INDEX_PREDICATE:
3467 return "index predicate";
3468 case EXPR_KIND_ALTER_COL_TRANSFORM:
3469 return "USING";
3470 case EXPR_KIND_EXECUTE_PARAMETER:
3471 return "EXECUTE";
3472 case EXPR_KIND_TRIGGER_WHEN:
3473 return "WHEN";
3474 case EXPR_KIND_PARTITION_EXPRESSION:
3475 return "PARTITION BY";
3476 case EXPR_KIND_CALL_ARGUMENT:
3477 return "CALL";
3478
3479 /*
3480 * There is intentionally no default: case here, so that the
3481 * compiler will warn if we add a new ParseExprKind without
3482 * extending this switch. If we do see an unrecognized value at
3483 * runtime, we'll fall through to the "unrecognized" return.
3484 */
3485 }
3486 return "unrecognized expression kind";
3487 }
3488