PostgreSQL Source Code: src/backend/parser/parse_coerce.c Source File

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parse_coerce.c
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1/*-------------------------------------------------------------------------
2 *
3 * parse_coerce.c
4 * handle type coercions/conversions for parser
5 *
6 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
8 *
9 *
10 * IDENTIFICATION
11 * src/backend/parser/parse_coerce.c
12 *
13 *-------------------------------------------------------------------------
14 */
15#include "postgres.h"
16
17#include "access/htup_details.h"
18#include "catalog/pg_cast.h"
19#include "catalog/pg_class.h"
20#include "catalog/pg_inherits.h"
21#include "catalog/pg_proc.h"
22#include "catalog/pg_type.h"
23#include "nodes/makefuncs.h"
24#include "nodes/nodeFuncs.h"
25#include "parser/parse_coerce.h"
26#include "parser/parse_relation.h"
27#include "parser/parse_type.h"
28#include "utils/builtins.h"
29#include "utils/datum.h" /* needed for datumIsEqual() */
30#include "utils/fmgroids.h"
31#include "utils/lsyscache.h"
32#include "utils/syscache.h"
33#include "utils/typcache.h"
34
35
36static Node *coerce_type_typmod(Node *node,
37 Oid targetTypeId, int32 targetTypMod,
38 CoercionContext ccontext, CoercionForm cformat,
39 int location,
40 bool hideInputCoercion);
41static void hide_coercion_node(Node *node);
42static Node *build_coercion_expression(Node *node,
43 CoercionPathType pathtype,
44 Oid funcId,
45 Oid targetTypeId, int32 targetTypMod,
46 CoercionContext ccontext, CoercionForm cformat,
47 int location);
48static Node *coerce_record_to_complex(ParseState *pstate, Node *node,
49 Oid targetTypeId,
50 CoercionContext ccontext,
51 CoercionForm cformat,
52 int location);
53static bool is_complex_array(Oid typid);
54static bool typeIsOfTypedTable(Oid reltypeId, Oid reloftypeId);
55
56
57/*
58 * coerce_to_target_type()
59 * Convert an expression to a target type and typmod.
60 *
61 * This is the general-purpose entry point for arbitrary type coercion
62 * operations. Direct use of the component operations can_coerce_type,
63 * coerce_type, and coerce_type_typmod should be restricted to special
64 * cases (eg, when the conversion is expected to succeed).
65 *
66 * Returns the possibly-transformed expression tree, or NULL if the type
67 * conversion is not possible. (We do this, rather than ereport'ing directly,
68 * so that callers can generate custom error messages indicating context.)
69 *
70 * pstate - parse state (can be NULL, see coerce_type)
71 * expr - input expression tree (already transformed by transformExpr)
72 * exprtype - result type of expr
73 * targettype - desired result type
74 * targettypmod - desired result typmod
75 * ccontext, cformat - context indicators to control coercions
76 * location - parse location of the coercion request, or -1 if unknown/implicit
77 */
78Node *
79 coerce_to_target_type(ParseState *pstate, Node *expr, Oid exprtype,
80 Oid targettype, int32 targettypmod,
81 CoercionContext ccontext,
82 CoercionForm cformat,
83 int location)
84{
85 Node *result;
86 Node *origexpr;
87
88 if (!can_coerce_type(1, &exprtype, &targettype, ccontext))
89 return NULL;
90
91 /*
92 * If the input has a CollateExpr at the top, strip it off, perform the
93 * coercion, and put a new one back on. This is annoying since it
94 * duplicates logic in coerce_type, but if we don't do this then it's too
95 * hard to tell whether coerce_type actually changed anything, and we
96 * *must* know that to avoid possibly calling hide_coercion_node on
97 * something that wasn't generated by coerce_type. Note that if there are
98 * multiple stacked CollateExprs, we just discard all but the topmost.
99 * Also, if the target type isn't collatable, we discard the CollateExpr.
100 */
101 origexpr = expr;
102 while (expr && IsA(expr, CollateExpr))
103 expr = (Node *) ((CollateExpr *) expr)->arg;
104
105 result = coerce_type(pstate, expr, exprtype,
106 targettype, targettypmod,
107 ccontext, cformat, location);
108
109 /*
110 * If the target is a fixed-length type, it may need a length coercion as
111 * well as a type coercion. If we find ourselves adding both, force the
112 * inner coercion node to implicit display form.
113 */
114 result = coerce_type_typmod(result,
115 targettype, targettypmod,
116 ccontext, cformat, location,
117 (result != expr && !IsA(result, Const)));
118
119 if (expr != origexpr && type_is_collatable(targettype))
120 {
121 /* Reinstall top CollateExpr */
122 CollateExpr *coll = (CollateExpr *) origexpr;
123 CollateExpr *newcoll = makeNode(CollateExpr);
124
125 newcoll->arg = (Expr *) result;
126 newcoll->collOid = coll->collOid;
127 newcoll->location = coll->location;
128 result = (Node *) newcoll;
129 }
130
131 return result;
132}
133
134
135/*
136 * coerce_type()
137 * Convert an expression to a different type.
138 *
139 * The caller should already have determined that the coercion is possible;
140 * see can_coerce_type.
141 *
142 * Normally, no coercion to a typmod (length) is performed here. The caller
143 * must call coerce_type_typmod as well, if a typmod constraint is wanted.
144 * (But if the target type is a domain, it may internally contain a
145 * typmod constraint, which will be applied inside coerce_to_domain.)
146 * In some cases pg_cast specifies a type coercion function that also
147 * applies length conversion, and in those cases only, the result will
148 * already be properly coerced to the specified typmod.
149 *
150 * pstate is only used in the case that we are able to resolve the type of
151 * a previously UNKNOWN Param. It is okay to pass pstate = NULL if the
152 * caller does not want type information updated for Params.
153 *
154 * Note: this function must not modify the given expression tree, only add
155 * decoration on top of it. See transformSetOperationTree, for example.
156 */
157Node *
158 coerce_type(ParseState *pstate, Node *node,
159 Oid inputTypeId, Oid targetTypeId, int32 targetTypeMod,
160 CoercionContext ccontext, CoercionForm cformat, int location)
161{
162 Node *result;
163 CoercionPathType pathtype;
164 Oid funcId;
165
166 if (targetTypeId == inputTypeId ||
167 node == NULL)
168 {
169 /* no conversion needed */
170 return node;
171 }
172 if (targetTypeId == ANYOID ||
173 targetTypeId == ANYELEMENTOID ||
174 targetTypeId == ANYNONARRAYOID ||
175 targetTypeId == ANYCOMPATIBLEOID ||
176 targetTypeId == ANYCOMPATIBLENONARRAYOID)
177 {
178 /*
179 * Assume can_coerce_type verified that implicit coercion is okay.
180 *
181 * Note: by returning the unmodified node here, we are saying that
182 * it's OK to treat an UNKNOWN constant as a valid input for a
183 * function accepting one of these pseudotypes. This should be all
184 * right, since an UNKNOWN value is still a perfectly valid Datum.
185 *
186 * NB: we do NOT want a RelabelType here: the exposed type of the
187 * function argument must be its actual type, not the polymorphic
188 * pseudotype.
189 */
190 return node;
191 }
192 if (targetTypeId == ANYARRAYOID ||
193 targetTypeId == ANYENUMOID ||
194 targetTypeId == ANYRANGEOID ||
195 targetTypeId == ANYMULTIRANGEOID ||
196 targetTypeId == ANYCOMPATIBLEARRAYOID ||
197 targetTypeId == ANYCOMPATIBLERANGEOID ||
198 targetTypeId == ANYCOMPATIBLEMULTIRANGEOID)
199 {
200 /*
201 * Assume can_coerce_type verified that implicit coercion is okay.
202 *
203 * These cases are unlike the ones above because the exposed type of
204 * the argument must be an actual array, enum, range, or multirange
205 * type. In particular the argument must *not* be an UNKNOWN
206 * constant. If it is, we just fall through; below, we'll call the
207 * pseudotype's input function, which will produce an error. Also, if
208 * what we have is a domain over array, enum, range, or multirange, we
209 * have to relabel it to its base type.
210 *
211 * Note: currently, we can't actually see a domain-over-enum here,
212 * since the other functions in this file will not match such a
213 * parameter to ANYENUM. But that should get changed eventually.
214 */
215 if (inputTypeId != UNKNOWNOID)
216 {
217 Oid baseTypeId = getBaseType(inputTypeId);
218
219 if (baseTypeId != inputTypeId)
220 {
221 RelabelType *r = makeRelabelType((Expr *) node,
222 baseTypeId, -1,
223 InvalidOid,
224 cformat);
225
226 r->location = location;
227 return (Node *) r;
228 }
229 /* Not a domain type, so return it as-is */
230 return node;
231 }
232 }
233 if (inputTypeId == UNKNOWNOID && IsA(node, Const))
234 {
235 /*
236 * Input is a string constant with previously undetermined type. Apply
237 * the target type's typinput function to it to produce a constant of
238 * the target type.
239 *
240 * NOTE: this case cannot be folded together with the other
241 * constant-input case, since the typinput function does not
242 * necessarily behave the same as a type conversion function. For
243 * example, int4's typinput function will reject "1.2", whereas
244 * float-to-int type conversion will round to integer.
245 *
246 * XXX if the typinput function is not immutable, we really ought to
247 * postpone evaluation of the function call until runtime. But there
248 * is no way to represent a typinput function call as an expression
249 * tree, because C-string values are not Datums. (XXX This *is*
250 * possible as of 7.3, do we want to do it?)
251 */
252 Const *con = (Const *) node;
253 Const *newcon = makeNode(Const);
254 Oid baseTypeId;
255 int32 baseTypeMod;
256 int32 inputTypeMod;
257 Type baseType;
258 ParseCallbackState pcbstate;
259
260 /*
261 * If the target type is a domain, we want to call its base type's
262 * input routine, not domain_in(). This is to avoid premature failure
263 * when the domain applies a typmod: existing input routines follow
264 * implicit-coercion semantics for length checks, which is not always
265 * what we want here. The needed check will be applied properly
266 * inside coerce_to_domain().
267 */
268 baseTypeMod = targetTypeMod;
269 baseTypeId = getBaseTypeAndTypmod(targetTypeId, &baseTypeMod);
270
271 /*
272 * For most types we pass typmod -1 to the input routine, because
273 * existing input routines follow implicit-coercion semantics for
274 * length checks, which is not always what we want here. Any length
275 * constraint will be applied later by our caller. An exception
276 * however is the INTERVAL type, for which we *must* pass the typmod
277 * or it won't be able to obey the bizarre SQL-spec input rules. (Ugly
278 * as sin, but so is this part of the spec...)
279 */
280 if (baseTypeId == INTERVALOID)
281 inputTypeMod = baseTypeMod;
282 else
283 inputTypeMod = -1;
284
285 baseType = typeidType(baseTypeId);
286
287 newcon->consttype = baseTypeId;
288 newcon->consttypmod = inputTypeMod;
289 newcon->constcollid = typeTypeCollation(baseType);
290 newcon->constlen = typeLen(baseType);
291 newcon->constbyval = typeByVal(baseType);
292 newcon->constisnull = con->constisnull;
293
294 /*
295 * We use the original literal's location regardless of the position
296 * of the coercion. This is a change from pre-9.2 behavior, meant to
297 * simplify life for pg_stat_statements.
298 */
299 newcon->location = con->location;
300
301 /*
302 * Set up to point at the constant's text if the input routine throws
303 * an error.
304 */
305 setup_parser_errposition_callback(&pcbstate, pstate, con->location);
306
307 /*
308 * We assume here that UNKNOWN's internal representation is the same
309 * as CSTRING.
310 */
311 if (!con->constisnull)
312 newcon->constvalue = stringTypeDatum(baseType,
313 DatumGetCString(con->constvalue),
314 inputTypeMod);
315 else
316 newcon->constvalue = stringTypeDatum(baseType,
317 NULL,
318 inputTypeMod);
319
320 /*
321 * If it's a varlena value, force it to be in non-expanded
322 * (non-toasted) format; this avoids any possible dependency on
323 * external values and improves consistency of representation.
324 */
325 if (!con->constisnull && newcon->constlen == -1)
326 newcon->constvalue =
327 PointerGetDatum(PG_DETOAST_DATUM(newcon->constvalue));
328
329#ifdef RANDOMIZE_ALLOCATED_MEMORY
330
331 /*
332 * For pass-by-reference data types, repeat the conversion to see if
333 * the input function leaves any uninitialized bytes in the result. We
334 * can only detect that reliably if RANDOMIZE_ALLOCATED_MEMORY is
335 * enabled, so we don't bother testing otherwise. The reason we don't
336 * want any instability in the input function is that comparison of
337 * Const nodes relies on bytewise comparison of the datums, so if the
338 * input function leaves garbage then subexpressions that should be
339 * identical may not get recognized as such. See pgsql-hackers
340 * discussion of 2008年04月04日.
341 */
342 if (!con->constisnull && !newcon->constbyval)
343 {
344 Datum val2;
345
346 val2 = stringTypeDatum(baseType,
347 DatumGetCString(con->constvalue),
348 inputTypeMod);
349 if (newcon->constlen == -1)
350 val2 = PointerGetDatum(PG_DETOAST_DATUM(val2));
351 if (!datumIsEqual(newcon->constvalue, val2, false, newcon->constlen))
352 elog(WARNING, "type %s has unstable input conversion for \"%s\"",
353 typeTypeName(baseType), DatumGetCString(con->constvalue));
354 }
355#endif
356
357 cancel_parser_errposition_callback(&pcbstate);
358
359 result = (Node *) newcon;
360
361 /* If target is a domain, apply constraints. */
362 if (baseTypeId != targetTypeId)
363 result = coerce_to_domain(result,
364 baseTypeId, baseTypeMod,
365 targetTypeId,
366 ccontext, cformat, location,
367 false);
368
369 ReleaseSysCache(baseType);
370
371 return result;
372 }
373 if (IsA(node, Param) &&
374 pstate != NULL && pstate->p_coerce_param_hook != NULL)
375 {
376 /*
377 * Allow the CoerceParamHook to decide what happens. It can return a
378 * transformed node (very possibly the same Param node), or return
379 * NULL to indicate we should proceed with normal coercion.
380 */
381 result = pstate->p_coerce_param_hook(pstate,
382 (Param *) node,
383 targetTypeId,
384 targetTypeMod,
385 location);
386 if (result)
387 return result;
388 }
389 if (IsA(node, CollateExpr))
390 {
391 /*
392 * If we have a COLLATE clause, we have to push the coercion
393 * underneath the COLLATE; or discard the COLLATE if the target type
394 * isn't collatable. This is really ugly, but there is little choice
395 * because the above hacks on Consts and Params wouldn't happen
396 * otherwise. This kluge has consequences in coerce_to_target_type.
397 */
398 CollateExpr *coll = (CollateExpr *) node;
399
400 result = coerce_type(pstate, (Node *) coll->arg,
401 inputTypeId, targetTypeId, targetTypeMod,
402 ccontext, cformat, location);
403 if (type_is_collatable(targetTypeId))
404 {
405 CollateExpr *newcoll = makeNode(CollateExpr);
406
407 newcoll->arg = (Expr *) result;
408 newcoll->collOid = coll->collOid;
409 newcoll->location = coll->location;
410 result = (Node *) newcoll;
411 }
412 return result;
413 }
414 pathtype = find_coercion_pathway(targetTypeId, inputTypeId, ccontext,
415 &funcId);
416 if (pathtype != COERCION_PATH_NONE)
417 {
418 Oid baseTypeId;
419 int32 baseTypeMod;
420
421 baseTypeMod = targetTypeMod;
422 baseTypeId = getBaseTypeAndTypmod(targetTypeId, &baseTypeMod);
423
424 if (pathtype != COERCION_PATH_RELABELTYPE)
425 {
426 /*
427 * Generate an expression tree representing run-time application
428 * of the conversion function. If we are dealing with a domain
429 * target type, the conversion function will yield the base type,
430 * and we need to extract the correct typmod to use from the
431 * domain's typtypmod.
432 */
433 result = build_coercion_expression(node, pathtype, funcId,
434 baseTypeId, baseTypeMod,
435 ccontext, cformat, location);
436
437 /*
438 * If domain, coerce to the domain type and relabel with domain
439 * type ID, hiding the previous coercion node.
440 */
441 if (targetTypeId != baseTypeId)
442 result = coerce_to_domain(result, baseTypeId, baseTypeMod,
443 targetTypeId,
444 ccontext, cformat, location,
445 true);
446 }
447 else
448 {
449 /*
450 * We don't need to do a physical conversion, but we do need to
451 * attach a RelabelType node so that the expression will be seen
452 * to have the intended type when inspected by higher-level code.
453 *
454 * Also, domains may have value restrictions beyond the base type
455 * that must be accounted for. If the destination is a domain
456 * then we won't need a RelabelType node.
457 */
458 result = coerce_to_domain(node, baseTypeId, baseTypeMod,
459 targetTypeId,
460 ccontext, cformat, location,
461 false);
462 if (result == node)
463 {
464 /*
465 * XXX could we label result with exprTypmod(node) instead of
466 * default -1 typmod, to save a possible length-coercion
467 * later? Would work if both types have same interpretation of
468 * typmod, which is likely but not certain.
469 */
470 RelabelType *r = makeRelabelType((Expr *) result,
471 targetTypeId, -1,
472 InvalidOid,
473 cformat);
474
475 r->location = location;
476 result = (Node *) r;
477 }
478 }
479 return result;
480 }
481 if (inputTypeId == RECORDOID &&
482 ISCOMPLEX(targetTypeId))
483 {
484 /* Coerce a RECORD to a specific complex type */
485 return coerce_record_to_complex(pstate, node, targetTypeId,
486 ccontext, cformat, location);
487 }
488 if (targetTypeId == RECORDOID &&
489 ISCOMPLEX(inputTypeId))
490 {
491 /* Coerce a specific complex type to RECORD */
492 /* NB: we do NOT want a RelabelType here */
493 return node;
494 }
495#ifdef NOT_USED
496 if (inputTypeId == RECORDARRAYOID &&
497 is_complex_array(targetTypeId))
498 {
499 /* Coerce record[] to a specific complex array type */
500 /* not implemented yet ... */
501 }
502#endif
503 if (targetTypeId == RECORDARRAYOID &&
504 is_complex_array(inputTypeId))
505 {
506 /* Coerce a specific complex array type to record[] */
507 /* NB: we do NOT want a RelabelType here */
508 return node;
509 }
510 if (typeInheritsFrom(inputTypeId, targetTypeId)
511 || typeIsOfTypedTable(inputTypeId, targetTypeId))
512 {
513 /*
514 * Input class type is a subclass of target, so generate an
515 * appropriate runtime conversion (removing unneeded columns and
516 * possibly rearranging the ones that are wanted).
517 *
518 * We will also get here when the input is a domain over a subclass of
519 * the target type. To keep life simple for the executor, we define
520 * ConvertRowtypeExpr as only working between regular composite types;
521 * therefore, in such cases insert a RelabelType to smash the input
522 * expression down to its base type.
523 */
524 Oid baseTypeId = getBaseType(inputTypeId);
525 ConvertRowtypeExpr *r = makeNode(ConvertRowtypeExpr);
526
527 if (baseTypeId != inputTypeId)
528 {
529 RelabelType *rt = makeRelabelType((Expr *) node,
530 baseTypeId, -1,
531 InvalidOid,
532 COERCE_IMPLICIT_CAST);
533
534 rt->location = location;
535 node = (Node *) rt;
536 }
537 r->arg = (Expr *) node;
538 r->resulttype = targetTypeId;
539 r->convertformat = cformat;
540 r->location = location;
541 return (Node *) r;
542 }
543 /* If we get here, caller blew it */
544 elog(ERROR, "failed to find conversion function from %s to %s",
545 format_type_be(inputTypeId), format_type_be(targetTypeId));
546 return NULL; /* keep compiler quiet */
547}
548
549
550/*
551 * can_coerce_type()
552 * Can input_typeids be coerced to target_typeids?
553 *
554 * We must be told the context (CAST construct, assignment, implicit coercion)
555 * as this determines the set of available casts.
556 */
557bool
558 can_coerce_type(int nargs, const Oid *input_typeids, const Oid *target_typeids,
559 CoercionContext ccontext)
560{
561 bool have_generics = false;
562 int i;
563
564 /* run through argument list... */
565 for (i = 0; i < nargs; i++)
566 {
567 Oid inputTypeId = input_typeids[i];
568 Oid targetTypeId = target_typeids[i];
569 CoercionPathType pathtype;
570 Oid funcId;
571
572 /* no problem if same type */
573 if (inputTypeId == targetTypeId)
574 continue;
575
576 /* accept if target is ANY */
577 if (targetTypeId == ANYOID)
578 continue;
579
580 /* accept if target is polymorphic, for now */
581 if (IsPolymorphicType(targetTypeId))
582 {
583 have_generics = true; /* do more checking later */
584 continue;
585 }
586
587 /*
588 * If input is an untyped string constant, assume we can convert it to
589 * anything.
590 */
591 if (inputTypeId == UNKNOWNOID)
592 continue;
593
594 /*
595 * If pg_cast shows that we can coerce, accept. This test now covers
596 * both binary-compatible and coercion-function cases.
597 */
598 pathtype = find_coercion_pathway(targetTypeId, inputTypeId, ccontext,
599 &funcId);
600 if (pathtype != COERCION_PATH_NONE)
601 continue;
602
603 /*
604 * If input is RECORD and target is a composite type, assume we can
605 * coerce (may need tighter checking here)
606 */
607 if (inputTypeId == RECORDOID &&
608 ISCOMPLEX(targetTypeId))
609 continue;
610
611 /*
612 * If input is a composite type and target is RECORD, accept
613 */
614 if (targetTypeId == RECORDOID &&
615 ISCOMPLEX(inputTypeId))
616 continue;
617
618#ifdef NOT_USED /* not implemented yet */
619
620 /*
621 * If input is record[] and target is a composite array type, assume
622 * we can coerce (may need tighter checking here)
623 */
624 if (inputTypeId == RECORDARRAYOID &&
625 is_complex_array(targetTypeId))
626 continue;
627#endif
628
629 /*
630 * If input is a composite array type and target is record[], accept
631 */
632 if (targetTypeId == RECORDARRAYOID &&
633 is_complex_array(inputTypeId))
634 continue;
635
636 /*
637 * If input is a class type that inherits from target, accept
638 */
639 if (typeInheritsFrom(inputTypeId, targetTypeId)
640 || typeIsOfTypedTable(inputTypeId, targetTypeId))
641 continue;
642
643 /*
644 * Else, cannot coerce at this argument position
645 */
646 return false;
647 }
648
649 /* If we found any generic argument types, cross-check them */
650 if (have_generics)
651 {
652 if (!check_generic_type_consistency(input_typeids, target_typeids,
653 nargs))
654 return false;
655 }
656
657 return true;
658}
659
660
661/*
662 * Create an expression tree to represent coercion to a domain type.
663 *
664 * 'arg': input expression
665 * 'baseTypeId': base type of domain
666 * 'baseTypeMod': base type typmod of domain
667 * 'typeId': target type to coerce to
668 * 'ccontext': context indicator to control coercions
669 * 'cformat': coercion display format
670 * 'location': coercion request location
671 * 'hideInputCoercion': if true, hide the input coercion under this one.
672 *
673 * If the target type isn't a domain, the given 'arg' is returned as-is.
674 */
675Node *
676 coerce_to_domain(Node *arg, Oid baseTypeId, int32 baseTypeMod, Oid typeId,
677 CoercionContext ccontext, CoercionForm cformat, int location,
678 bool hideInputCoercion)
679{
680 CoerceToDomain *result;
681
682 /* We now require the caller to supply correct baseTypeId/baseTypeMod */
683 Assert(OidIsValid(baseTypeId));
684
685 /* If it isn't a domain, return the node as it was passed in */
686 if (baseTypeId == typeId)
687 return arg;
688
689 /* Suppress display of nested coercion steps */
690 if (hideInputCoercion)
691 hide_coercion_node(arg);
692
693 /*
694 * If the domain applies a typmod to its base type, build the appropriate
695 * coercion step. Mark it implicit for display purposes, because we don't
696 * want it shown separately by ruleutils.c; but the isExplicit flag passed
697 * to the conversion function depends on the manner in which the domain
698 * coercion is invoked, so that the semantics of implicit and explicit
699 * coercion differ. (Is that really the behavior we want?)
700 *
701 * NOTE: because we apply this as part of the fixed expression structure,
702 * ALTER DOMAIN cannot alter the typtypmod. But it's unclear that that
703 * would be safe to do anyway, without lots of knowledge about what the
704 * base type thinks the typmod means.
705 */
706 arg = coerce_type_typmod(arg, baseTypeId, baseTypeMod,
707 ccontext, COERCE_IMPLICIT_CAST, location,
708 false);
709
710 /*
711 * Now build the domain coercion node. This represents run-time checking
712 * of any constraints currently attached to the domain. This also ensures
713 * that the expression is properly labeled as to result type.
714 */
715 result = makeNode(CoerceToDomain);
716 result->arg = (Expr *) arg;
717 result->resulttype = typeId;
718 result->resulttypmod = -1; /* currently, always -1 for domains */
719 /* resultcollid will be set by parse_collate.c */
720 result->coercionformat = cformat;
721 result->location = location;
722
723 return (Node *) result;
724}
725
726
727/*
728 * coerce_type_typmod()
729 * Force a value to a particular typmod, if meaningful and possible.
730 *
731 * This is applied to values that are going to be stored in a relation
732 * (where we have an atttypmod for the column) as well as values being
733 * explicitly CASTed (where the typmod comes from the target type spec).
734 *
735 * The caller must have already ensured that the value is of the correct
736 * type, typically by applying coerce_type.
737 *
738 * ccontext may affect semantics, depending on whether the length coercion
739 * function pays attention to the isExplicit flag it's passed.
740 *
741 * cformat determines the display properties of the generated node (if any).
742 *
743 * If hideInputCoercion is true *and* we generate a node, the input node is
744 * forced to IMPLICIT display form, so that only the typmod coercion node will
745 * be visible when displaying the expression.
746 *
747 * NOTE: this does not need to work on domain types, because any typmod
748 * coercion for a domain is considered to be part of the type coercion
749 * needed to produce the domain value in the first place. So, no getBaseType.
750 */
751static Node *
752 coerce_type_typmod(Node *node, Oid targetTypeId, int32 targetTypMod,
753 CoercionContext ccontext, CoercionForm cformat,
754 int location,
755 bool hideInputCoercion)
756{
757 CoercionPathType pathtype;
758 Oid funcId;
759
760 /* Skip coercion if already done */
761 if (targetTypMod == exprTypmod(node))
762 return node;
763
764 /* Suppress display of nested coercion steps */
765 if (hideInputCoercion)
766 hide_coercion_node(node);
767
768 /*
769 * A negative typmod means that no actual coercion is needed, but we still
770 * want a RelabelType to ensure that the expression exposes the intended
771 * typmod.
772 */
773 if (targetTypMod < 0)
774 pathtype = COERCION_PATH_NONE;
775 else
776 pathtype = find_typmod_coercion_function(targetTypeId, &funcId);
777
778 if (pathtype != COERCION_PATH_NONE)
779 {
780 node = build_coercion_expression(node, pathtype, funcId,
781 targetTypeId, targetTypMod,
782 ccontext, cformat, location);
783 }
784 else
785 {
786 /*
787 * We don't need to perform any actual coercion step, but we should
788 * apply a RelabelType to ensure that the expression exposes the
789 * intended typmod.
790 */
791 node = applyRelabelType(node, targetTypeId, targetTypMod,
792 exprCollation(node),
793 cformat, location, false);
794 }
795
796 return node;
797}
798
799/*
800 * Mark a coercion node as IMPLICIT so it will never be displayed by
801 * ruleutils.c. We use this when we generate a nest of coercion nodes
802 * to implement what is logically one conversion; the inner nodes are
803 * forced to IMPLICIT_CAST format. This does not change their semantics,
804 * only display behavior.
805 *
806 * It is caller error to call this on something that doesn't have a
807 * CoercionForm field.
808 */
809static void
810 hide_coercion_node(Node *node)
811{
812 if (IsA(node, FuncExpr))
813 ((FuncExpr *) node)->funcformat = COERCE_IMPLICIT_CAST;
814 else if (IsA(node, RelabelType))
815 ((RelabelType *) node)->relabelformat = COERCE_IMPLICIT_CAST;
816 else if (IsA(node, CoerceViaIO))
817 ((CoerceViaIO *) node)->coerceformat = COERCE_IMPLICIT_CAST;
818 else if (IsA(node, ArrayCoerceExpr))
819 ((ArrayCoerceExpr *) node)->coerceformat = COERCE_IMPLICIT_CAST;
820 else if (IsA(node, ConvertRowtypeExpr))
821 ((ConvertRowtypeExpr *) node)->convertformat = COERCE_IMPLICIT_CAST;
822 else if (IsA(node, RowExpr))
823 ((RowExpr *) node)->row_format = COERCE_IMPLICIT_CAST;
824 else if (IsA(node, CoerceToDomain))
825 ((CoerceToDomain *) node)->coercionformat = COERCE_IMPLICIT_CAST;
826 else
827 elog(ERROR, "unsupported node type: %d", (int) nodeTag(node));
828}
829
830/*
831 * build_coercion_expression()
832 * Construct an expression tree for applying a pg_cast entry.
833 *
834 * This is used for both type-coercion and length-coercion operations,
835 * since there is no difference in terms of the calling convention.
836 */
837static Node *
838 build_coercion_expression(Node *node,
839 CoercionPathType pathtype,
840 Oid funcId,
841 Oid targetTypeId, int32 targetTypMod,
842 CoercionContext ccontext, CoercionForm cformat,
843 int location)
844{
845 int nargs = 0;
846
847 if (OidIsValid(funcId))
848 {
849 HeapTuple tp;
850 Form_pg_proc procstruct;
851
852 tp = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcId));
853 if (!HeapTupleIsValid(tp))
854 elog(ERROR, "cache lookup failed for function %u", funcId);
855 procstruct = (Form_pg_proc) GETSTRUCT(tp);
856
857 /*
858 * These Asserts essentially check that function is a legal coercion
859 * function. We can't make the seemingly obvious tests on prorettype
860 * and proargtypes[0], even in the COERCION_PATH_FUNC case, because of
861 * various binary-compatibility cases.
862 */
863 /* Assert(targetTypeId == procstruct->prorettype); */
864 Assert(!procstruct->proretset);
865 Assert(procstruct->prokind == PROKIND_FUNCTION);
866 nargs = procstruct->pronargs;
867 Assert(nargs >= 1 && nargs <= 3);
868 /* Assert(procstruct->proargtypes.values[0] == exprType(node)); */
869 Assert(nargs < 2 || procstruct->proargtypes.values[1] == INT4OID);
870 Assert(nargs < 3 || procstruct->proargtypes.values[2] == BOOLOID);
871
872 ReleaseSysCache(tp);
873 }
874
875 if (pathtype == COERCION_PATH_FUNC)
876 {
877 /* We build an ordinary FuncExpr with special arguments */
878 FuncExpr *fexpr;
879 List *args;
880 Const *cons;
881
882 Assert(OidIsValid(funcId));
883
884 args = list_make1(node);
885
886 if (nargs >= 2)
887 {
888 /* Pass target typmod as an int4 constant */
889 cons = makeConst(INT4OID,
890 -1,
891 InvalidOid,
892 sizeof(int32),
893 Int32GetDatum(targetTypMod),
894 false,
895 true);
896
897 args = lappend(args, cons);
898 }
899
900 if (nargs == 3)
901 {
902 /* Pass it a boolean isExplicit parameter, too */
903 cons = makeConst(BOOLOID,
904 -1,
905 InvalidOid,
906 sizeof(bool),
907 BoolGetDatum(ccontext == COERCION_EXPLICIT),
908 false,
909 true);
910
911 args = lappend(args, cons);
912 }
913
914 fexpr = makeFuncExpr(funcId, targetTypeId, args,
915 InvalidOid, InvalidOid, cformat);
916 fexpr->location = location;
917 return (Node *) fexpr;
918 }
919 else if (pathtype == COERCION_PATH_ARRAYCOERCE)
920 {
921 /* We need to build an ArrayCoerceExpr */
922 ArrayCoerceExpr *acoerce = makeNode(ArrayCoerceExpr);
923 CaseTestExpr *ctest = makeNode(CaseTestExpr);
924 Oid sourceBaseTypeId;
925 int32 sourceBaseTypeMod;
926 Oid targetElementType;
927 Node *elemexpr;
928
929 /*
930 * Look through any domain over the source array type. Note we don't
931 * expect that the target type is a domain; it must be a plain array.
932 * (To get to a domain target type, we'll do coerce_to_domain later.)
933 */
934 sourceBaseTypeMod = exprTypmod(node);
935 sourceBaseTypeId = getBaseTypeAndTypmod(exprType(node),
936 &sourceBaseTypeMod);
937
938 /*
939 * Set up a CaseTestExpr representing one element of the source array.
940 * This is an abuse of CaseTestExpr, but it's OK as long as there
941 * can't be any CaseExpr or ArrayCoerceExpr within the completed
942 * elemexpr.
943 */
944 ctest->typeId = get_element_type(sourceBaseTypeId);
945 Assert(OidIsValid(ctest->typeId));
946 ctest->typeMod = sourceBaseTypeMod;
947 ctest->collation = InvalidOid; /* Assume coercions don't care */
948
949 /* And coerce it to the target element type */
950 targetElementType = get_element_type(targetTypeId);
951 Assert(OidIsValid(targetElementType));
952
953 elemexpr = coerce_to_target_type(NULL,
954 (Node *) ctest,
955 ctest->typeId,
956 targetElementType,
957 targetTypMod,
958 ccontext,
959 cformat,
960 location);
961 if (elemexpr == NULL) /* shouldn't happen */
962 elog(ERROR, "failed to coerce array element type as expected");
963
964 acoerce->arg = (Expr *) node;
965 acoerce->elemexpr = (Expr *) elemexpr;
966 acoerce->resulttype = targetTypeId;
967
968 /*
969 * Label the output as having a particular element typmod only if we
970 * ended up with a per-element expression that is labeled that way.
971 */
972 acoerce->resulttypmod = exprTypmod(elemexpr);
973 /* resultcollid will be set by parse_collate.c */
974 acoerce->coerceformat = cformat;
975 acoerce->location = location;
976
977 return (Node *) acoerce;
978 }
979 else if (pathtype == COERCION_PATH_COERCEVIAIO)
980 {
981 /* We need to build a CoerceViaIO node */
982 CoerceViaIO *iocoerce = makeNode(CoerceViaIO);
983
984 Assert(!OidIsValid(funcId));
985
986 iocoerce->arg = (Expr *) node;
987 iocoerce->resulttype = targetTypeId;
988 /* resultcollid will be set by parse_collate.c */
989 iocoerce->coerceformat = cformat;
990 iocoerce->location = location;
991
992 return (Node *) iocoerce;
993 }
994 else
995 {
996 elog(ERROR, "unsupported pathtype %d in build_coercion_expression",
997 (int) pathtype);
998 return NULL; /* keep compiler quiet */
999 }
1000}
1001
1002
1003/*
1004 * coerce_record_to_complex
1005 * Coerce a RECORD to a specific composite type.
1006 *
1007 * Currently we only support this for inputs that are RowExprs or whole-row
1008 * Vars.
1009 */
1010static Node *
1011 coerce_record_to_complex(ParseState *pstate, Node *node,
1012 Oid targetTypeId,
1013 CoercionContext ccontext,
1014 CoercionForm cformat,
1015 int location)
1016{
1017 RowExpr *rowexpr;
1018 Oid baseTypeId;
1019 int32 baseTypeMod = -1;
1020 TupleDesc tupdesc;
1021 List *args = NIL;
1022 List *newargs;
1023 int i;
1024 int ucolno;
1025 ListCell *arg;
1026
1027 if (node && IsA(node, RowExpr))
1028 {
1029 /*
1030 * Since the RowExpr must be of type RECORD, we needn't worry about it
1031 * containing any dropped columns.
1032 */
1033 args = ((RowExpr *) node)->args;
1034 }
1035 else if (node && IsA(node, Var) &&
1036 ((Var *) node)->varattno == InvalidAttrNumber)
1037 {
1038 int rtindex = ((Var *) node)->varno;
1039 int sublevels_up = ((Var *) node)->varlevelsup;
1040 int vlocation = ((Var *) node)->location;
1041 ParseNamespaceItem *nsitem;
1042
1043 nsitem = GetNSItemByRangeTablePosn(pstate, rtindex, sublevels_up);
1044 args = expandNSItemVars(pstate, nsitem, sublevels_up, vlocation, NULL);
1045 }
1046 else
1047 ereport(ERROR,
1048 (errcode(ERRCODE_CANNOT_COERCE),
1049 errmsg("cannot cast type %s to %s",
1050 format_type_be(RECORDOID),
1051 format_type_be(targetTypeId)),
1052 parser_coercion_errposition(pstate, location, node)));
1053
1054 /*
1055 * Look up the composite type, accounting for possibility that what we are
1056 * given is a domain over composite.
1057 */
1058 baseTypeId = getBaseTypeAndTypmod(targetTypeId, &baseTypeMod);
1059 tupdesc = lookup_rowtype_tupdesc(baseTypeId, baseTypeMod);
1060
1061 /* Process the fields */
1062 newargs = NIL;
1063 ucolno = 1;
1064 arg = list_head(args);
1065 for (i = 0; i < tupdesc->natts; i++)
1066 {
1067 Node *expr;
1068 Node *cexpr;
1069 Oid exprtype;
1070 Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
1071
1072 /* Fill in NULLs for dropped columns in rowtype */
1073 if (attr->attisdropped)
1074 {
1075 /*
1076 * can't use atttypid here, but it doesn't really matter what type
1077 * the Const claims to be.
1078 */
1079 newargs = lappend(newargs,
1080 makeNullConst(INT4OID, -1, InvalidOid));
1081 continue;
1082 }
1083
1084 if (arg == NULL)
1085 ereport(ERROR,
1086 (errcode(ERRCODE_CANNOT_COERCE),
1087 errmsg("cannot cast type %s to %s",
1088 format_type_be(RECORDOID),
1089 format_type_be(targetTypeId)),
1090 errdetail("Input has too few columns."),
1091 parser_coercion_errposition(pstate, location, node)));
1092 expr = (Node *) lfirst(arg);
1093 exprtype = exprType(expr);
1094
1095 cexpr = coerce_to_target_type(pstate,
1096 expr, exprtype,
1097 attr->atttypid,
1098 attr->atttypmod,
1099 ccontext,
1100 COERCE_IMPLICIT_CAST,
1101 -1);
1102 if (cexpr == NULL)
1103 ereport(ERROR,
1104 (errcode(ERRCODE_CANNOT_COERCE),
1105 errmsg("cannot cast type %s to %s",
1106 format_type_be(RECORDOID),
1107 format_type_be(targetTypeId)),
1108 errdetail("Cannot cast type %s to %s in column %d.",
1109 format_type_be(exprtype),
1110 format_type_be(attr->atttypid),
1111 ucolno),
1112 parser_coercion_errposition(pstate, location, expr)));
1113 newargs = lappend(newargs, cexpr);
1114 ucolno++;
1115 arg = lnext(args, arg);
1116 }
1117 if (arg != NULL)
1118 ereport(ERROR,
1119 (errcode(ERRCODE_CANNOT_COERCE),
1120 errmsg("cannot cast type %s to %s",
1121 format_type_be(RECORDOID),
1122 format_type_be(targetTypeId)),
1123 errdetail("Input has too many columns."),
1124 parser_coercion_errposition(pstate, location, node)));
1125
1126 ReleaseTupleDesc(tupdesc);
1127
1128 rowexpr = makeNode(RowExpr);
1129 rowexpr->args = newargs;
1130 rowexpr->row_typeid = baseTypeId;
1131 rowexpr->row_format = cformat;
1132 rowexpr->colnames = NIL; /* not needed for named target type */
1133 rowexpr->location = location;
1134
1135 /* If target is a domain, apply constraints */
1136 if (baseTypeId != targetTypeId)
1137 {
1138 rowexpr->row_format = COERCE_IMPLICIT_CAST;
1139 return coerce_to_domain((Node *) rowexpr,
1140 baseTypeId, baseTypeMod,
1141 targetTypeId,
1142 ccontext, cformat, location,
1143 false);
1144 }
1145
1146 return (Node *) rowexpr;
1147}
1148
1149/*
1150 * coerce_to_boolean()
1151 * Coerce an argument of a construct that requires boolean input
1152 * (AND, OR, NOT, etc). Also check that input is not a set.
1153 *
1154 * Returns the possibly-transformed node tree.
1155 *
1156 * As with coerce_type, pstate may be NULL if no special unknown-Param
1157 * processing is wanted.
1158 */
1159Node *
1160 coerce_to_boolean(ParseState *pstate, Node *node,
1161 const char *constructName)
1162{
1163 Oid inputTypeId = exprType(node);
1164
1165 if (inputTypeId != BOOLOID)
1166 {
1167 Node *newnode;
1168
1169 newnode = coerce_to_target_type(pstate, node, inputTypeId,
1170 BOOLOID, -1,
1171 COERCION_ASSIGNMENT,
1172 COERCE_IMPLICIT_CAST,
1173 -1);
1174 if (newnode == NULL)
1175 ereport(ERROR,
1176 (errcode(ERRCODE_DATATYPE_MISMATCH),
1177 /* translator: first %s is name of a SQL construct, eg WHERE */
1178 errmsg("argument of %s must be type %s, not type %s",
1179 constructName, "boolean",
1180 format_type_be(inputTypeId)),
1181 parser_errposition(pstate, exprLocation(node))));
1182 node = newnode;
1183 }
1184
1185 if (expression_returns_set(node))
1186 ereport(ERROR,
1187 (errcode(ERRCODE_DATATYPE_MISMATCH),
1188 /* translator: %s is name of a SQL construct, eg WHERE */
1189 errmsg("argument of %s must not return a set",
1190 constructName),
1191 parser_errposition(pstate, exprLocation(node))));
1192
1193 return node;
1194}
1195
1196/*
1197 * coerce_to_specific_type_typmod()
1198 * Coerce an argument of a construct that requires a specific data type,
1199 * with a specific typmod. Also check that input is not a set.
1200 *
1201 * Returns the possibly-transformed node tree.
1202 *
1203 * As with coerce_type, pstate may be NULL if no special unknown-Param
1204 * processing is wanted.
1205 */
1206Node *
1207 coerce_to_specific_type_typmod(ParseState *pstate, Node *node,
1208 Oid targetTypeId, int32 targetTypmod,
1209 const char *constructName)
1210{
1211 Oid inputTypeId = exprType(node);
1212
1213 if (inputTypeId != targetTypeId)
1214 {
1215 Node *newnode;
1216
1217 newnode = coerce_to_target_type(pstate, node, inputTypeId,
1218 targetTypeId, targetTypmod,
1219 COERCION_ASSIGNMENT,
1220 COERCE_IMPLICIT_CAST,
1221 -1);
1222 if (newnode == NULL)
1223 ereport(ERROR,
1224 (errcode(ERRCODE_DATATYPE_MISMATCH),
1225 /* translator: first %s is name of a SQL construct, eg LIMIT */
1226 errmsg("argument of %s must be type %s, not type %s",
1227 constructName,
1228 format_type_be(targetTypeId),
1229 format_type_be(inputTypeId)),
1230 parser_errposition(pstate, exprLocation(node))));
1231 node = newnode;
1232 }
1233
1234 if (expression_returns_set(node))
1235 ereport(ERROR,
1236 (errcode(ERRCODE_DATATYPE_MISMATCH),
1237 /* translator: %s is name of a SQL construct, eg LIMIT */
1238 errmsg("argument of %s must not return a set",
1239 constructName),
1240 parser_errposition(pstate, exprLocation(node))));
1241
1242 return node;
1243}
1244
1245/*
1246 * coerce_to_specific_type()
1247 * Coerce an argument of a construct that requires a specific data type.
1248 * Also check that input is not a set.
1249 *
1250 * Returns the possibly-transformed node tree.
1251 *
1252 * As with coerce_type, pstate may be NULL if no special unknown-Param
1253 * processing is wanted.
1254 */
1255Node *
1256 coerce_to_specific_type(ParseState *pstate, Node *node,
1257 Oid targetTypeId,
1258 const char *constructName)
1259{
1260 return coerce_to_specific_type_typmod(pstate, node,
1261 targetTypeId, -1,
1262 constructName);
1263}
1264
1265/*
1266 * coerce_null_to_domain()
1267 * Build a NULL constant, then wrap it in CoerceToDomain
1268 * if the desired type is a domain type. This allows any
1269 * NOT NULL domain constraint to be enforced at runtime.
1270 */
1271Node *
1272 coerce_null_to_domain(Oid typid, int32 typmod, Oid collation,
1273 int typlen, bool typbyval)
1274{
1275 Node *result;
1276 Oid baseTypeId;
1277 int32 baseTypeMod = typmod;
1278
1279 /*
1280 * The constant must appear to have the domain's base type/typmod, else
1281 * coerce_to_domain() will apply a length coercion which is useless.
1282 */
1283 baseTypeId = getBaseTypeAndTypmod(typid, &baseTypeMod);
1284 result = (Node *) makeConst(baseTypeId,
1285 baseTypeMod,
1286 collation,
1287 typlen,
1288 (Datum) 0,
1289 true, /* isnull */
1290 typbyval);
1291 if (typid != baseTypeId)
1292 result = coerce_to_domain(result,
1293 baseTypeId, baseTypeMod,
1294 typid,
1295 COERCION_IMPLICIT,
1296 COERCE_IMPLICIT_CAST,
1297 -1,
1298 false);
1299 return result;
1300}
1301
1302/*
1303 * parser_coercion_errposition - report coercion error location, if possible
1304 *
1305 * We prefer to point at the coercion request (CAST, ::, etc) if possible;
1306 * but there may be no such location in the case of an implicit coercion.
1307 * In that case point at the input expression.
1308 *
1309 * XXX possibly this is more generally useful than coercion errors;
1310 * if so, should rename and place with parser_errposition.
1311 */
1312int
1313 parser_coercion_errposition(ParseState *pstate,
1314 int coerce_location,
1315 Node *input_expr)
1316{
1317 if (coerce_location >= 0)
1318 return parser_errposition(pstate, coerce_location);
1319 else
1320 return parser_errposition(pstate, exprLocation(input_expr));
1321}
1322
1323
1324/*
1325 * select_common_type()
1326 * Determine the common supertype of a list of input expressions.
1327 * This is used for determining the output type of CASE, UNION,
1328 * and similar constructs.
1329 *
1330 * 'exprs' is a *nonempty* list of expressions. Note that earlier items
1331 * in the list will be preferred if there is doubt.
1332 * 'context' is a phrase to use in the error message if we fail to select
1333 * a usable type. Pass NULL to have the routine return InvalidOid
1334 * rather than throwing an error on failure.
1335 * 'which_expr': if not NULL, receives a pointer to the particular input
1336 * expression from which the result type was taken.
1337 *
1338 * Caution: "failure" just means that there were inputs of different type
1339 * categories. It is not guaranteed that all the inputs are coercible to the
1340 * selected type; caller must check that (see verify_common_type).
1341 */
1342Oid
1343 select_common_type(ParseState *pstate, List *exprs, const char *context,
1344 Node **which_expr)
1345{
1346 Node *pexpr;
1347 Oid ptype;
1348 TYPCATEGORY pcategory;
1349 bool pispreferred;
1350 ListCell *lc;
1351
1352 Assert(exprs != NIL);
1353 pexpr = (Node *) linitial(exprs);
1354 lc = list_second_cell(exprs);
1355 ptype = exprType(pexpr);
1356
1357 /*
1358 * If all input types are valid and exactly the same, just pick that type.
1359 * This is the only way that we will resolve the result as being a domain
1360 * type; otherwise domains are smashed to their base types for comparison.
1361 */
1362 if (ptype != UNKNOWNOID)
1363 {
1364 for_each_cell(lc, exprs, lc)
1365 {
1366 Node *nexpr = (Node *) lfirst(lc);
1367 Oid ntype = exprType(nexpr);
1368
1369 if (ntype != ptype)
1370 break;
1371 }
1372 if (lc == NULL) /* got to the end of the list? */
1373 {
1374 if (which_expr)
1375 *which_expr = pexpr;
1376 return ptype;
1377 }
1378 }
1379
1380 /*
1381 * Nope, so set up for the full algorithm. Note that at this point, lc
1382 * points to the first list item with type different from pexpr's; we need
1383 * not re-examine any items the previous loop advanced over.
1384 */
1385 ptype = getBaseType(ptype);
1386 get_type_category_preferred(ptype, &pcategory, &pispreferred);
1387
1388 for_each_cell(lc, exprs, lc)
1389 {
1390 Node *nexpr = (Node *) lfirst(lc);
1391 Oid ntype = getBaseType(exprType(nexpr));
1392
1393 /* move on to next one if no new information... */
1394 if (ntype != UNKNOWNOID && ntype != ptype)
1395 {
1396 TYPCATEGORY ncategory;
1397 bool nispreferred;
1398
1399 get_type_category_preferred(ntype, &ncategory, &nispreferred);
1400 if (ptype == UNKNOWNOID)
1401 {
1402 /* so far, only unknowns so take anything... */
1403 pexpr = nexpr;
1404 ptype = ntype;
1405 pcategory = ncategory;
1406 pispreferred = nispreferred;
1407 }
1408 else if (ncategory != pcategory)
1409 {
1410 /*
1411 * both types in different categories? then not much hope...
1412 */
1413 if (context == NULL)
1414 return InvalidOid;
1415 ereport(ERROR,
1416 (errcode(ERRCODE_DATATYPE_MISMATCH),
1417 /*------
1418 translator: first %s is name of a SQL construct, eg CASE */
1419 errmsg("%s types %s and %s cannot be matched",
1420 context,
1421 format_type_be(ptype),
1422 format_type_be(ntype)),
1423 parser_errposition(pstate, exprLocation(nexpr))));
1424 }
1425 else if (!pispreferred &&
1426 can_coerce_type(1, &ptype, &ntype, COERCION_IMPLICIT) &&
1427 !can_coerce_type(1, &ntype, &ptype, COERCION_IMPLICIT))
1428 {
1429 /*
1430 * take new type if can coerce to it implicitly but not the
1431 * other way; but if we have a preferred type, stay on it.
1432 */
1433 pexpr = nexpr;
1434 ptype = ntype;
1435 pcategory = ncategory;
1436 pispreferred = nispreferred;
1437 }
1438 }
1439 }
1440
1441 /*
1442 * If all the inputs were UNKNOWN type --- ie, unknown-type literals ---
1443 * then resolve as type TEXT. This situation comes up with constructs
1444 * like SELECT (CASE WHEN foo THEN 'bar' ELSE 'baz' END); SELECT 'foo'
1445 * UNION SELECT 'bar'; It might seem desirable to leave the construct's
1446 * output type as UNKNOWN, but that really doesn't work, because we'd
1447 * probably end up needing a runtime coercion from UNKNOWN to something
1448 * else, and we usually won't have it. We need to coerce the unknown
1449 * literals while they are still literals, so a decision has to be made
1450 * now.
1451 */
1452 if (ptype == UNKNOWNOID)
1453 ptype = TEXTOID;
1454
1455 if (which_expr)
1456 *which_expr = pexpr;
1457 return ptype;
1458}
1459
1460/*
1461 * select_common_type_from_oids()
1462 * Determine the common supertype of an array of type OIDs.
1463 *
1464 * This is the same logic as select_common_type(), but working from
1465 * an array of type OIDs not a list of expressions. As in that function,
1466 * earlier entries in the array have some preference over later ones.
1467 * On failure, return InvalidOid if noerror is true, else throw an error.
1468 *
1469 * Caution: "failure" just means that there were inputs of different type
1470 * categories. It is not guaranteed that all the inputs are coercible to the
1471 * selected type; caller must check that (see verify_common_type_from_oids).
1472 *
1473 * Note: neither caller will pass any UNKNOWNOID entries, so the tests
1474 * for that in this function are dead code. However, they don't cost much,
1475 * and it seems better to keep this logic as close to select_common_type()
1476 * as possible.
1477 */
1478static Oid
1479 select_common_type_from_oids(int nargs, const Oid *typeids, bool noerror)
1480{
1481 Oid ptype;
1482 TYPCATEGORY pcategory;
1483 bool pispreferred;
1484 int i = 1;
1485
1486 Assert(nargs > 0);
1487 ptype = typeids[0];
1488
1489 /* If all input types are valid and exactly the same, pick that type. */
1490 if (ptype != UNKNOWNOID)
1491 {
1492 for (; i < nargs; i++)
1493 {
1494 if (typeids[i] != ptype)
1495 break;
1496 }
1497 if (i == nargs)
1498 return ptype;
1499 }
1500
1501 /*
1502 * Nope, so set up for the full algorithm. Note that at this point, we
1503 * can skip array entries before "i"; they are all equal to ptype.
1504 */
1505 ptype = getBaseType(ptype);
1506 get_type_category_preferred(ptype, &pcategory, &pispreferred);
1507
1508 for (; i < nargs; i++)
1509 {
1510 Oid ntype = getBaseType(typeids[i]);
1511
1512 /* move on to next one if no new information... */
1513 if (ntype != UNKNOWNOID && ntype != ptype)
1514 {
1515 TYPCATEGORY ncategory;
1516 bool nispreferred;
1517
1518 get_type_category_preferred(ntype, &ncategory, &nispreferred);
1519 if (ptype == UNKNOWNOID)
1520 {
1521 /* so far, only unknowns so take anything... */
1522 ptype = ntype;
1523 pcategory = ncategory;
1524 pispreferred = nispreferred;
1525 }
1526 else if (ncategory != pcategory)
1527 {
1528 /*
1529 * both types in different categories? then not much hope...
1530 */
1531 if (noerror)
1532 return InvalidOid;
1533 ereport(ERROR,
1534 (errcode(ERRCODE_DATATYPE_MISMATCH),
1535 errmsg("argument types %s and %s cannot be matched",
1536 format_type_be(ptype),
1537 format_type_be(ntype))));
1538 }
1539 else if (!pispreferred &&
1540 can_coerce_type(1, &ptype, &ntype, COERCION_IMPLICIT) &&
1541 !can_coerce_type(1, &ntype, &ptype, COERCION_IMPLICIT))
1542 {
1543 /*
1544 * take new type if can coerce to it implicitly but not the
1545 * other way; but if we have a preferred type, stay on it.
1546 */
1547 ptype = ntype;
1548 pcategory = ncategory;
1549 pispreferred = nispreferred;
1550 }
1551 }
1552 }
1553
1554 /* Like select_common_type(), choose TEXT if all inputs were UNKNOWN */
1555 if (ptype == UNKNOWNOID)
1556 ptype = TEXTOID;
1557
1558 return ptype;
1559}
1560
1561/*
1562 * coerce_to_common_type()
1563 * Coerce an expression to the given type.
1564 *
1565 * This is used following select_common_type() to coerce the individual
1566 * expressions to the desired type. 'context' is a phrase to use in the
1567 * error message if we fail to coerce.
1568 *
1569 * As with coerce_type, pstate may be NULL if no special unknown-Param
1570 * processing is wanted.
1571 */
1572Node *
1573 coerce_to_common_type(ParseState *pstate, Node *node,
1574 Oid targetTypeId, const char *context)
1575{
1576 Oid inputTypeId = exprType(node);
1577
1578 if (inputTypeId == targetTypeId)
1579 return node; /* no work */
1580 if (can_coerce_type(1, &inputTypeId, &targetTypeId, COERCION_IMPLICIT))
1581 node = coerce_type(pstate, node, inputTypeId, targetTypeId, -1,
1582 COERCION_IMPLICIT, COERCE_IMPLICIT_CAST, -1);
1583 else
1584 ereport(ERROR,
1585 (errcode(ERRCODE_CANNOT_COERCE),
1586 /* translator: first %s is name of a SQL construct, eg CASE */
1587 errmsg("%s could not convert type %s to %s",
1588 context,
1589 format_type_be(inputTypeId),
1590 format_type_be(targetTypeId)),
1591 parser_errposition(pstate, exprLocation(node))));
1592 return node;
1593}
1594
1595/*
1596 * verify_common_type()
1597 * Verify that all input types can be coerced to a proposed common type.
1598 * Return true if so, false if not all coercions are possible.
1599 *
1600 * Most callers of select_common_type() don't need to do this explicitly
1601 * because the checks will happen while trying to convert input expressions
1602 * to the right type, e.g. in coerce_to_common_type(). However, if a separate
1603 * check step is needed to validate the applicability of the common type, call
1604 * this.
1605 */
1606bool
1607 verify_common_type(Oid common_type, List *exprs)
1608{
1609 ListCell *lc;
1610
1611 foreach(lc, exprs)
1612 {
1613 Node *nexpr = (Node *) lfirst(lc);
1614 Oid ntype = exprType(nexpr);
1615
1616 if (!can_coerce_type(1, &ntype, &common_type, COERCION_IMPLICIT))
1617 return false;
1618 }
1619 return true;
1620}
1621
1622/*
1623 * verify_common_type_from_oids()
1624 * As above, but work from an array of type OIDs.
1625 */
1626static bool
1627 verify_common_type_from_oids(Oid common_type, int nargs, const Oid *typeids)
1628{
1629 for (int i = 0; i < nargs; i++)
1630 {
1631 if (!can_coerce_type(1, &typeids[i], &common_type, COERCION_IMPLICIT))
1632 return false;
1633 }
1634 return true;
1635}
1636
1637/*
1638 * select_common_typmod()
1639 * Determine the common typmod of a list of input expressions.
1640 *
1641 * common_type is the selected common type of the expressions, typically
1642 * computed using select_common_type().
1643 */
1644int32
1645 select_common_typmod(ParseState *pstate, List *exprs, Oid common_type)
1646{
1647 ListCell *lc;
1648 bool first = true;
1649 int32 result = -1;
1650
1651 foreach(lc, exprs)
1652 {
1653 Node *expr = (Node *) lfirst(lc);
1654
1655 /* Types must match */
1656 if (exprType(expr) != common_type)
1657 return -1;
1658 else if (first)
1659 {
1660 result = exprTypmod(expr);
1661 first = false;
1662 }
1663 else
1664 {
1665 /* As soon as we see a non-matching typmod, fall back to -1 */
1666 if (result != exprTypmod(expr))
1667 return -1;
1668 }
1669 }
1670
1671 return result;
1672}
1673
1674/*
1675 * check_generic_type_consistency()
1676 * Are the actual arguments potentially compatible with a
1677 * polymorphic function?
1678 *
1679 * The argument consistency rules are:
1680 *
1681 * 1) All arguments declared ANYELEMENT must have the same datatype.
1682 * 2) All arguments declared ANYARRAY must have the same datatype,
1683 * which must be a varlena array type.
1684 * 3) All arguments declared ANYRANGE must be the same range type.
1685 * Similarly, all arguments declared ANYMULTIRANGE must be the same
1686 * multirange type; and if both of these appear, the ANYRANGE type
1687 * must be the element type of the ANYMULTIRANGE type.
1688 * 4) If there are arguments of more than one of these polymorphic types,
1689 * the array element type and/or range subtype must be the same as each
1690 * other and the same as the ANYELEMENT type.
1691 * 5) ANYENUM is treated the same as ANYELEMENT except that if it is used
1692 * (alone or in combination with plain ANYELEMENT), we add the extra
1693 * condition that the ANYELEMENT type must be an enum.
1694 * 6) ANYNONARRAY is treated the same as ANYELEMENT except that if it is used,
1695 * we add the extra condition that the ANYELEMENT type must not be an array.
1696 * (This is a no-op if used in combination with ANYARRAY or ANYENUM, but
1697 * is an extra restriction if not.)
1698 * 7) All arguments declared ANYCOMPATIBLE must be implicitly castable
1699 * to a common supertype (chosen as per select_common_type's rules).
1700 * ANYCOMPATIBLENONARRAY works like ANYCOMPATIBLE but also requires the
1701 * common supertype to not be an array. If there are ANYCOMPATIBLEARRAY
1702 * or ANYCOMPATIBLERANGE or ANYCOMPATIBLEMULTIRANGE arguments, their element
1703 * types or subtypes are included while making the choice of common supertype.
1704 * 8) The resolved type of ANYCOMPATIBLEARRAY arguments will be the array
1705 * type over the common supertype (which might not be the same array type
1706 * as any of the original arrays).
1707 * 9) All ANYCOMPATIBLERANGE arguments must be the exact same range type
1708 * (after domain flattening), since we have no preference rule that would
1709 * let us choose one over another. Furthermore, that range's subtype
1710 * must exactly match the common supertype chosen by rule 7.
1711 * 10) All ANYCOMPATIBLEMULTIRANGE arguments must be the exact same multirange
1712 * type (after domain flattening), since we have no preference rule that
1713 * would let us choose one over another. Furthermore, if ANYCOMPATIBLERANGE
1714 * also appears, that range type must be the multirange's element type;
1715 * otherwise, the multirange's range's subtype must exactly match the
1716 * common supertype chosen by rule 7.
1717 *
1718 * Domains over arrays match ANYARRAY, and are immediately flattened to their
1719 * base type. (Thus, for example, we will consider it a match if one ANYARRAY
1720 * argument is a domain over int4[] while another one is just int4[].) Also
1721 * notice that such a domain does *not* match ANYNONARRAY. The same goes
1722 * for ANYCOMPATIBLEARRAY and ANYCOMPATIBLENONARRAY.
1723 *
1724 * Similarly, domains over ranges match ANYRANGE or ANYCOMPATIBLERANGE,
1725 * and are immediately flattened to their base type. Likewise, domains
1726 * over multiranges match ANYMULTIRANGE or ANYCOMPATIBLEMULTIRANGE and are
1727 * immediately flattened to their base type.
1728 *
1729 * Note that domains aren't currently considered to match ANYENUM,
1730 * even if their base type would match.
1731 *
1732 * If we have UNKNOWN input (ie, an untyped literal) for any polymorphic
1733 * argument, assume it is okay.
1734 *
1735 * We do not ereport here, but just return false if a rule is violated.
1736 */
1737bool
1738 check_generic_type_consistency(const Oid *actual_arg_types,
1739 const Oid *declared_arg_types,
1740 int nargs)
1741{
1742 Oid elem_typeid = InvalidOid;
1743 Oid array_typeid = InvalidOid;
1744 Oid range_typeid = InvalidOid;
1745 Oid multirange_typeid = InvalidOid;
1746 Oid anycompatible_range_typeid = InvalidOid;
1747 Oid anycompatible_range_typelem = InvalidOid;
1748 Oid anycompatible_multirange_typeid = InvalidOid;
1749 Oid anycompatible_multirange_typelem = InvalidOid;
1750 Oid range_typelem = InvalidOid;
1751 bool have_anynonarray = false;
1752 bool have_anyenum = false;
1753 bool have_anycompatible_nonarray = false;
1754 int n_anycompatible_args = 0;
1755 Oid anycompatible_actual_types[FUNC_MAX_ARGS];
1756
1757 /*
1758 * Loop through the arguments to see if we have any that are polymorphic.
1759 * If so, require the actual types to be consistent.
1760 */
1761 Assert(nargs <= FUNC_MAX_ARGS);
1762 for (int j = 0; j < nargs; j++)
1763 {
1764 Oid decl_type = declared_arg_types[j];
1765 Oid actual_type = actual_arg_types[j];
1766
1767 if (decl_type == ANYELEMENTOID ||
1768 decl_type == ANYNONARRAYOID ||
1769 decl_type == ANYENUMOID)
1770 {
1771 if (decl_type == ANYNONARRAYOID)
1772 have_anynonarray = true;
1773 else if (decl_type == ANYENUMOID)
1774 have_anyenum = true;
1775 if (actual_type == UNKNOWNOID)
1776 continue;
1777 if (OidIsValid(elem_typeid) && actual_type != elem_typeid)
1778 return false;
1779 elem_typeid = actual_type;
1780 }
1781 else if (decl_type == ANYARRAYOID)
1782 {
1783 if (actual_type == UNKNOWNOID)
1784 continue;
1785 actual_type = getBaseType(actual_type); /* flatten domains */
1786 if (OidIsValid(array_typeid) && actual_type != array_typeid)
1787 return false;
1788 array_typeid = actual_type;
1789 }
1790 else if (decl_type == ANYRANGEOID)
1791 {
1792 if (actual_type == UNKNOWNOID)
1793 continue;
1794 actual_type = getBaseType(actual_type); /* flatten domains */
1795 if (OidIsValid(range_typeid) && actual_type != range_typeid)
1796 return false;
1797 range_typeid = actual_type;
1798 }
1799 else if (decl_type == ANYMULTIRANGEOID)
1800 {
1801 if (actual_type == UNKNOWNOID)
1802 continue;
1803 actual_type = getBaseType(actual_type); /* flatten domains */
1804 if (OidIsValid(multirange_typeid) && actual_type != multirange_typeid)
1805 return false;
1806 multirange_typeid = actual_type;
1807 }
1808 else if (decl_type == ANYCOMPATIBLEOID ||
1809 decl_type == ANYCOMPATIBLENONARRAYOID)
1810 {
1811 if (decl_type == ANYCOMPATIBLENONARRAYOID)
1812 have_anycompatible_nonarray = true;
1813 if (actual_type == UNKNOWNOID)
1814 continue;
1815 /* collect the actual types of non-unknown COMPATIBLE args */
1816 anycompatible_actual_types[n_anycompatible_args++] = actual_type;
1817 }
1818 else if (decl_type == ANYCOMPATIBLEARRAYOID)
1819 {
1820 Oid elem_type;
1821
1822 if (actual_type == UNKNOWNOID)
1823 continue;
1824 actual_type = getBaseType(actual_type); /* flatten domains */
1825 elem_type = get_element_type(actual_type);
1826 if (!OidIsValid(elem_type))
1827 return false; /* not an array */
1828 /* collect the element type for common-supertype choice */
1829 anycompatible_actual_types[n_anycompatible_args++] = elem_type;
1830 }
1831 else if (decl_type == ANYCOMPATIBLERANGEOID)
1832 {
1833 if (actual_type == UNKNOWNOID)
1834 continue;
1835 actual_type = getBaseType(actual_type); /* flatten domains */
1836 if (OidIsValid(anycompatible_range_typeid))
1837 {
1838 /* All ANYCOMPATIBLERANGE arguments must be the same type */
1839 if (anycompatible_range_typeid != actual_type)
1840 return false;
1841 }
1842 else
1843 {
1844 anycompatible_range_typeid = actual_type;
1845 anycompatible_range_typelem = get_range_subtype(actual_type);
1846 if (!OidIsValid(anycompatible_range_typelem))
1847 return false; /* not a range type */
1848 /* collect the subtype for common-supertype choice */
1849 anycompatible_actual_types[n_anycompatible_args++] = anycompatible_range_typelem;
1850 }
1851 }
1852 else if (decl_type == ANYCOMPATIBLEMULTIRANGEOID)
1853 {
1854 if (actual_type == UNKNOWNOID)
1855 continue;
1856 actual_type = getBaseType(actual_type); /* flatten domains */
1857 if (OidIsValid(anycompatible_multirange_typeid))
1858 {
1859 /* All ANYCOMPATIBLEMULTIRANGE arguments must be the same type */
1860 if (anycompatible_multirange_typeid != actual_type)
1861 return false;
1862 }
1863 else
1864 {
1865 anycompatible_multirange_typeid = actual_type;
1866 anycompatible_multirange_typelem = get_multirange_range(actual_type);
1867 if (!OidIsValid(anycompatible_multirange_typelem))
1868 return false; /* not a multirange type */
1869 /* we'll consider the subtype below */
1870 }
1871 }
1872 }
1873
1874 /* Get the element type based on the array type, if we have one */
1875 if (OidIsValid(array_typeid))
1876 {
1877 if (array_typeid == ANYARRAYOID)
1878 {
1879 /*
1880 * Special case for matching ANYARRAY input to an ANYARRAY
1881 * argument: allow it for now. enforce_generic_type_consistency()
1882 * might complain later, depending on the presence of other
1883 * polymorphic arguments or results, but it will deliver a less
1884 * surprising error message than "function does not exist".
1885 *
1886 * (If you think to change this, note that can_coerce_type will
1887 * consider such a situation as a match, so that we might not even
1888 * get here.)
1889 */
1890 }
1891 else
1892 {
1893 Oid array_typelem;
1894
1895 array_typelem = get_element_type(array_typeid);
1896 if (!OidIsValid(array_typelem))
1897 return false; /* should be an array, but isn't */
1898
1899 if (!OidIsValid(elem_typeid))
1900 {
1901 /*
1902 * if we don't have an element type yet, use the one we just
1903 * got
1904 */
1905 elem_typeid = array_typelem;
1906 }
1907 else if (array_typelem != elem_typeid)
1908 {
1909 /* otherwise, they better match */
1910 return false;
1911 }
1912 }
1913 }
1914
1915 /* Deduce range type from multirange type, or check that they agree */
1916 if (OidIsValid(multirange_typeid))
1917 {
1918 Oid multirange_typelem;
1919
1920 multirange_typelem = get_multirange_range(multirange_typeid);
1921 if (!OidIsValid(multirange_typelem))
1922 return false; /* should be a multirange, but isn't */
1923
1924 if (!OidIsValid(range_typeid))
1925 {
1926 /* If we don't have a range type yet, use the one we just got */
1927 range_typeid = multirange_typelem;
1928 range_typelem = get_range_subtype(multirange_typelem);
1929 if (!OidIsValid(range_typelem))
1930 return false; /* should be a range, but isn't */
1931 }
1932 else if (multirange_typelem != range_typeid)
1933 {
1934 /* otherwise, they better match */
1935 return false;
1936 }
1937 }
1938
1939 /* Get the element type based on the range type, if we have one */
1940 if (OidIsValid(range_typeid))
1941 {
1942 range_typelem = get_range_subtype(range_typeid);
1943 if (!OidIsValid(range_typelem))
1944 return false; /* should be a range, but isn't */
1945
1946 if (!OidIsValid(elem_typeid))
1947 {
1948 /*
1949 * If we don't have an element type yet, use the one we just got
1950 */
1951 elem_typeid = range_typelem;
1952 }
1953 else if (range_typelem != elem_typeid)
1954 {
1955 /* otherwise, they better match */
1956 return false;
1957 }
1958 }
1959
1960 if (have_anynonarray)
1961 {
1962 /* require the element type to not be an array or domain over array */
1963 if (type_is_array_domain(elem_typeid))
1964 return false;
1965 }
1966
1967 if (have_anyenum)
1968 {
1969 /* require the element type to be an enum */
1970 if (!type_is_enum(elem_typeid))
1971 return false;
1972 }
1973
1974 /* Deduce range type from multirange type, or check that they agree */
1975 if (OidIsValid(anycompatible_multirange_typeid))
1976 {
1977 if (OidIsValid(anycompatible_range_typeid))
1978 {
1979 if (anycompatible_multirange_typelem !=
1980 anycompatible_range_typeid)
1981 return false;
1982 }
1983 else
1984 {
1985 anycompatible_range_typeid = anycompatible_multirange_typelem;
1986 anycompatible_range_typelem = get_range_subtype(anycompatible_range_typeid);
1987 if (!OidIsValid(anycompatible_range_typelem))
1988 return false; /* not a range type */
1989 /* collect the subtype for common-supertype choice */
1990 anycompatible_actual_types[n_anycompatible_args++] =
1991 anycompatible_range_typelem;
1992 }
1993 }
1994
1995 /* Check matching of ANYCOMPATIBLE-family arguments, if any */
1996 if (n_anycompatible_args > 0)
1997 {
1998 Oid anycompatible_typeid;
1999
2000 anycompatible_typeid =
2001 select_common_type_from_oids(n_anycompatible_args,
2002 anycompatible_actual_types,
2003 true);
2004
2005 if (!OidIsValid(anycompatible_typeid))
2006 return false; /* there's definitely no common supertype */
2007
2008 /* We have to verify that the selected type actually works */
2009 if (!verify_common_type_from_oids(anycompatible_typeid,
2010 n_anycompatible_args,
2011 anycompatible_actual_types))
2012 return false;
2013
2014 if (have_anycompatible_nonarray)
2015 {
2016 /*
2017 * require the anycompatible type to not be an array or domain
2018 * over array
2019 */
2020 if (type_is_array_domain(anycompatible_typeid))
2021 return false;
2022 }
2023
2024 /*
2025 * The anycompatible type must exactly match the range element type,
2026 * if we were able to identify one. This checks compatibility for
2027 * anycompatiblemultirange too since that also sets
2028 * anycompatible_range_typelem above.
2029 */
2030 if (OidIsValid(anycompatible_range_typelem) &&
2031 anycompatible_range_typelem != anycompatible_typeid)
2032 return false;
2033 }
2034
2035 /* Looks valid */
2036 return true;
2037}
2038
2039/*
2040 * enforce_generic_type_consistency()
2041 * Make sure a polymorphic function is legally callable, and
2042 * deduce actual argument and result types.
2043 *
2044 * If any polymorphic pseudotype is used in a function's arguments or
2045 * return type, we make sure the actual data types are consistent with
2046 * each other. The argument consistency rules are shown above for
2047 * check_generic_type_consistency().
2048 *
2049 * If we have UNKNOWN input (ie, an untyped literal) for any polymorphic
2050 * argument, we attempt to deduce the actual type it should have. If
2051 * successful, we alter that position of declared_arg_types[] so that
2052 * make_fn_arguments will coerce the literal to the right thing.
2053 *
2054 * If we have polymorphic arguments of the ANYCOMPATIBLE family,
2055 * we similarly alter declared_arg_types[] entries to show the resolved
2056 * common supertype, so that make_fn_arguments will coerce the actual
2057 * arguments to the proper type.
2058 *
2059 * Rules are applied to the function's return type (possibly altering it)
2060 * if it is declared as a polymorphic type and there is at least one
2061 * polymorphic argument type:
2062 *
2063 * 1) If return type is ANYELEMENT, and any argument is ANYELEMENT, use the
2064 * argument's actual type as the function's return type.
2065 * 2) If return type is ANYARRAY, and any argument is ANYARRAY, use the
2066 * argument's actual type as the function's return type.
2067 * 3) Similarly, if return type is ANYRANGE or ANYMULTIRANGE, and any
2068 * argument is ANYRANGE or ANYMULTIRANGE, use that argument's actual type
2069 * (or the corresponding range or multirange type) as the function's return
2070 * type.
2071 * 4) Otherwise, if return type is ANYELEMENT or ANYARRAY, and there is
2072 * at least one ANYELEMENT, ANYARRAY, ANYRANGE, or ANYMULTIRANGE input,
2073 * deduce the return type from those inputs, or throw error if we can't.
2074 * 5) Otherwise, if return type is ANYRANGE or ANYMULTIRANGE, throw error.
2075 * (We have no way to select a specific range type if the arguments don't
2076 * include ANYRANGE or ANYMULTIRANGE.)
2077 * 6) ANYENUM is treated the same as ANYELEMENT except that if it is used
2078 * (alone or in combination with plain ANYELEMENT), we add the extra
2079 * condition that the ANYELEMENT type must be an enum.
2080 * 7) ANYNONARRAY is treated the same as ANYELEMENT except that if it is used,
2081 * we add the extra condition that the ANYELEMENT type must not be an array.
2082 * (This is a no-op if used in combination with ANYARRAY or ANYENUM, but
2083 * is an extra restriction if not.)
2084 * 8) ANYCOMPATIBLE, ANYCOMPATIBLEARRAY, and ANYCOMPATIBLENONARRAY are handled
2085 * by resolving the common supertype of those arguments (or their element
2086 * types, for array inputs), and then coercing all those arguments to the
2087 * common supertype, or the array type over the common supertype for
2088 * ANYCOMPATIBLEARRAY.
2089 * 9) For ANYCOMPATIBLERANGE and ANYCOMPATIBLEMULTIRANGE, there must be at
2090 * least one non-UNKNOWN input matching those arguments, and all such
2091 * inputs must be the same range type (or its multirange type, as
2092 * appropriate), since we cannot deduce a range type from non-range types.
2093 * Furthermore, the range type's subtype is included while choosing the
2094 * common supertype for ANYCOMPATIBLE et al, and it must exactly match
2095 * that common supertype.
2096 *
2097 * Domains over arrays or ranges match ANYARRAY or ANYRANGE arguments,
2098 * respectively, and are immediately flattened to their base type. (In
2099 * particular, if the return type is also ANYARRAY or ANYRANGE, we'll set
2100 * it to the base type not the domain type.) The same is true for
2101 * ANYMULTIRANGE, ANYCOMPATIBLEARRAY, ANYCOMPATIBLERANGE, and
2102 * ANYCOMPATIBLEMULTIRANGE.
2103 *
2104 * When allow_poly is false, we are not expecting any of the actual_arg_types
2105 * to be polymorphic, and we should not return a polymorphic result type
2106 * either. When allow_poly is true, it is okay to have polymorphic "actual"
2107 * arg types, and we can return a matching polymorphic type as the result.
2108 * (This case is currently used only to check compatibility of an aggregate's
2109 * declaration with the underlying transfn.)
2110 *
2111 * A special case is that we could see ANYARRAY as an actual_arg_type even
2112 * when allow_poly is false (this is possible only because pg_statistic has
2113 * columns shown as anyarray in the catalogs). We allow this to match a
2114 * declared ANYARRAY argument, but only if there is no other polymorphic
2115 * argument that we would need to match it with, and no need to determine
2116 * the element type to infer the result type. Note this means that functions
2117 * taking ANYARRAY had better behave sanely if applied to the pg_statistic
2118 * columns; they can't just assume that successive inputs are of the same
2119 * actual element type. There is no similar logic for ANYCOMPATIBLEARRAY;
2120 * there isn't a need for it since there are no catalog columns of that type,
2121 * so we won't see it as input. We could consider matching an actual ANYARRAY
2122 * input to an ANYCOMPATIBLEARRAY argument, but at present that seems useless
2123 * as well, since there's no value in using ANYCOMPATIBLEARRAY unless there's
2124 * at least one other ANYCOMPATIBLE-family argument or result.
2125 *
2126 * Also, if there are no arguments declared to be of polymorphic types,
2127 * we'll return the rettype unmodified even if it's polymorphic. This should
2128 * never occur for user-declared functions, because CREATE FUNCTION prevents
2129 * it. But it does happen for some built-in functions, such as array_in().
2130 */
2131Oid
2132 enforce_generic_type_consistency(const Oid *actual_arg_types,
2133 Oid *declared_arg_types,
2134 int nargs,
2135 Oid rettype,
2136 bool allow_poly)
2137{
2138 bool have_poly_anycompatible = false;
2139 bool have_poly_unknowns = false;
2140 Oid elem_typeid = InvalidOid;
2141 Oid array_typeid = InvalidOid;
2142 Oid range_typeid = InvalidOid;
2143 Oid multirange_typeid = InvalidOid;
2144 Oid anycompatible_typeid = InvalidOid;
2145 Oid anycompatible_array_typeid = InvalidOid;
2146 Oid anycompatible_range_typeid = InvalidOid;
2147 Oid anycompatible_range_typelem = InvalidOid;
2148 Oid anycompatible_multirange_typeid = InvalidOid;
2149 Oid anycompatible_multirange_typelem = InvalidOid;
2150 bool have_anynonarray = (rettype == ANYNONARRAYOID);
2151 bool have_anyenum = (rettype == ANYENUMOID);
2152 bool have_anymultirange = (rettype == ANYMULTIRANGEOID);
2153 bool have_anycompatible_nonarray = (rettype == ANYCOMPATIBLENONARRAYOID);
2154 bool have_anycompatible_array = (rettype == ANYCOMPATIBLEARRAYOID);
2155 bool have_anycompatible_range = (rettype == ANYCOMPATIBLERANGEOID);
2156 bool have_anycompatible_multirange = (rettype == ANYCOMPATIBLEMULTIRANGEOID);
2157 int n_poly_args = 0; /* this counts all family-1 arguments */
2158 int n_anycompatible_args = 0; /* this counts only non-unknowns */
2159 Oid anycompatible_actual_types[FUNC_MAX_ARGS];
2160
2161 /*
2162 * Loop through the arguments to see if we have any that are polymorphic.
2163 * If so, require the actual types to be consistent.
2164 */
2165 Assert(nargs <= FUNC_MAX_ARGS);
2166 for (int j = 0; j < nargs; j++)
2167 {
2168 Oid decl_type = declared_arg_types[j];
2169 Oid actual_type = actual_arg_types[j];
2170
2171 if (decl_type == ANYELEMENTOID ||
2172 decl_type == ANYNONARRAYOID ||
2173 decl_type == ANYENUMOID)
2174 {
2175 n_poly_args++;
2176 if (decl_type == ANYNONARRAYOID)
2177 have_anynonarray = true;
2178 else if (decl_type == ANYENUMOID)
2179 have_anyenum = true;
2180 if (actual_type == UNKNOWNOID)
2181 {
2182 have_poly_unknowns = true;
2183 continue;
2184 }
2185 if (allow_poly && decl_type == actual_type)
2186 continue; /* no new information here */
2187 if (OidIsValid(elem_typeid) && actual_type != elem_typeid)
2188 ereport(ERROR,
2189 (errcode(ERRCODE_DATATYPE_MISMATCH),
2190 errmsg("arguments declared \"%s\" are not all alike", "anyelement"),
2191 errdetail("%s versus %s",
2192 format_type_be(elem_typeid),
2193 format_type_be(actual_type))));
2194 elem_typeid = actual_type;
2195 }
2196 else if (decl_type == ANYARRAYOID)
2197 {
2198 n_poly_args++;
2199 if (actual_type == UNKNOWNOID)
2200 {
2201 have_poly_unknowns = true;
2202 continue;
2203 }
2204 if (allow_poly && decl_type == actual_type)
2205 continue; /* no new information here */
2206 actual_type = getBaseType(actual_type); /* flatten domains */
2207 if (OidIsValid(array_typeid) && actual_type != array_typeid)
2208 ereport(ERROR,
2209 (errcode(ERRCODE_DATATYPE_MISMATCH),
2210 errmsg("arguments declared \"%s\" are not all alike", "anyarray"),
2211 errdetail("%s versus %s",
2212 format_type_be(array_typeid),
2213 format_type_be(actual_type))));
2214 array_typeid = actual_type;
2215 }
2216 else if (decl_type == ANYRANGEOID)
2217 {
2218 n_poly_args++;
2219 if (actual_type == UNKNOWNOID)
2220 {
2221 have_poly_unknowns = true;
2222 continue;
2223 }
2224 if (allow_poly && decl_type == actual_type)
2225 continue; /* no new information here */
2226 actual_type = getBaseType(actual_type); /* flatten domains */
2227 if (OidIsValid(range_typeid) && actual_type != range_typeid)
2228 ereport(ERROR,
2229 (errcode(ERRCODE_DATATYPE_MISMATCH),
2230 errmsg("arguments declared \"%s\" are not all alike", "anyrange"),
2231 errdetail("%s versus %s",
2232 format_type_be(range_typeid),
2233 format_type_be(actual_type))));
2234 range_typeid = actual_type;
2235 }
2236 else if (decl_type == ANYMULTIRANGEOID)
2237 {
2238 n_poly_args++;
2239 have_anymultirange = true;
2240 if (actual_type == UNKNOWNOID)
2241 {
2242 have_poly_unknowns = true;
2243 continue;
2244 }
2245 if (allow_poly && decl_type == actual_type)
2246 continue; /* no new information here */
2247 actual_type = getBaseType(actual_type); /* flatten domains */
2248 if (OidIsValid(multirange_typeid) && actual_type != multirange_typeid)
2249 ereport(ERROR,
2250 (errcode(ERRCODE_DATATYPE_MISMATCH),
2251 errmsg("arguments declared \"%s\" are not all alike", "anymultirange"),
2252 errdetail("%s versus %s",
2253 format_type_be(multirange_typeid),
2254 format_type_be(actual_type))));
2255 multirange_typeid = actual_type;
2256 }
2257 else if (decl_type == ANYCOMPATIBLEOID ||
2258 decl_type == ANYCOMPATIBLENONARRAYOID)
2259 {
2260 have_poly_anycompatible = true;
2261 if (decl_type == ANYCOMPATIBLENONARRAYOID)
2262 have_anycompatible_nonarray = true;
2263 if (actual_type == UNKNOWNOID)
2264 continue;
2265 if (allow_poly && decl_type == actual_type)
2266 continue; /* no new information here */
2267 /* collect the actual types of non-unknown COMPATIBLE args */
2268 anycompatible_actual_types[n_anycompatible_args++] = actual_type;
2269 }
2270 else if (decl_type == ANYCOMPATIBLEARRAYOID)
2271 {
2272 Oid anycompatible_elem_type;
2273
2274 have_poly_anycompatible = true;
2275 have_anycompatible_array = true;
2276 if (actual_type == UNKNOWNOID)
2277 continue;
2278 if (allow_poly && decl_type == actual_type)
2279 continue; /* no new information here */
2280 actual_type = getBaseType(actual_type); /* flatten domains */
2281 anycompatible_elem_type = get_element_type(actual_type);
2282 if (!OidIsValid(anycompatible_elem_type))
2283 ereport(ERROR,
2284 (errcode(ERRCODE_DATATYPE_MISMATCH),
2285 errmsg("argument declared %s is not an array but type %s",
2286 "anycompatiblearray",
2287 format_type_be(actual_type))));
2288 /* collect the element type for common-supertype choice */
2289 anycompatible_actual_types[n_anycompatible_args++] = anycompatible_elem_type;
2290 }
2291 else if (decl_type == ANYCOMPATIBLERANGEOID)
2292 {
2293 have_poly_anycompatible = true;
2294 have_anycompatible_range = true;
2295 if (actual_type == UNKNOWNOID)
2296 continue;
2297 if (allow_poly && decl_type == actual_type)
2298 continue; /* no new information here */
2299 actual_type = getBaseType(actual_type); /* flatten domains */
2300 if (OidIsValid(anycompatible_range_typeid))
2301 {
2302 /* All ANYCOMPATIBLERANGE arguments must be the same type */
2303 if (anycompatible_range_typeid != actual_type)
2304 ereport(ERROR,
2305 (errcode(ERRCODE_DATATYPE_MISMATCH),
2306 errmsg("arguments declared \"%s\" are not all alike", "anycompatiblerange"),
2307 errdetail("%s versus %s",
2308 format_type_be(anycompatible_range_typeid),
2309 format_type_be(actual_type))));
2310 }
2311 else
2312 {
2313 anycompatible_range_typeid = actual_type;
2314 anycompatible_range_typelem = get_range_subtype(actual_type);
2315 if (!OidIsValid(anycompatible_range_typelem))
2316 ereport(ERROR,
2317 (errcode(ERRCODE_DATATYPE_MISMATCH),
2318 errmsg("argument declared %s is not a range type but type %s",
2319 "anycompatiblerange",
2320 format_type_be(actual_type))));
2321 /* collect the subtype for common-supertype choice */
2322 anycompatible_actual_types[n_anycompatible_args++] = anycompatible_range_typelem;
2323 }
2324 }
2325 else if (decl_type == ANYCOMPATIBLEMULTIRANGEOID)
2326 {
2327 have_poly_anycompatible = true;
2328 have_anycompatible_multirange = true;
2329 if (actual_type == UNKNOWNOID)
2330 continue;
2331 if (allow_poly && decl_type == actual_type)
2332 continue; /* no new information here */
2333 actual_type = getBaseType(actual_type); /* flatten domains */
2334 if (OidIsValid(anycompatible_multirange_typeid))
2335 {
2336 /* All ANYCOMPATIBLEMULTIRANGE arguments must be the same type */
2337 if (anycompatible_multirange_typeid != actual_type)
2338 ereport(ERROR,
2339 (errcode(ERRCODE_DATATYPE_MISMATCH),
2340 errmsg("arguments declared \"%s\" are not all alike", "anycompatiblemultirange"),
2341 errdetail("%s versus %s",
2342 format_type_be(anycompatible_multirange_typeid),
2343 format_type_be(actual_type))));
2344 }
2345 else
2346 {
2347 anycompatible_multirange_typeid = actual_type;
2348 anycompatible_multirange_typelem = get_multirange_range(actual_type);
2349 if (!OidIsValid(anycompatible_multirange_typelem))
2350 ereport(ERROR,
2351 (errcode(ERRCODE_DATATYPE_MISMATCH),
2352 errmsg("argument declared %s is not a multirange type but type %s",
2353 "anycompatiblemultirange",
2354 format_type_be(actual_type))));
2355 /* we'll consider the subtype below */
2356 }
2357 }
2358 }
2359
2360 /*
2361 * Fast Track: if none of the arguments are polymorphic, return the
2362 * unmodified rettype. Not our job to resolve it if it's polymorphic.
2363 */
2364 if (n_poly_args == 0 && !have_poly_anycompatible)
2365 return rettype;
2366
2367 /* Check matching of family-1 polymorphic arguments, if any */
2368 if (n_poly_args)
2369 {
2370 /* Get the element type based on the array type, if we have one */
2371 if (OidIsValid(array_typeid))
2372 {
2373 Oid array_typelem;
2374
2375 if (array_typeid == ANYARRAYOID)
2376 {
2377 /*
2378 * Special case for matching ANYARRAY input to an ANYARRAY
2379 * argument: allow it iff no other arguments are family-1
2380 * polymorphics (otherwise we couldn't be sure whether the
2381 * array element type matches up) and the result type doesn't
2382 * require us to infer a specific element type.
2383 */
2384 if (n_poly_args != 1 ||
2385 (rettype != ANYARRAYOID &&
2386 IsPolymorphicTypeFamily1(rettype)))
2387 ereport(ERROR,
2388 (errcode(ERRCODE_DATATYPE_MISMATCH),
2389 errmsg("cannot determine element type of \"anyarray\" argument")));
2390 array_typelem = ANYELEMENTOID;
2391 }
2392 else
2393 {
2394 array_typelem = get_element_type(array_typeid);
2395 if (!OidIsValid(array_typelem))
2396 ereport(ERROR,
2397 (errcode(ERRCODE_DATATYPE_MISMATCH),
2398 errmsg("argument declared %s is not an array but type %s",
2399 "anyarray", format_type_be(array_typeid))));
2400 }
2401
2402 if (!OidIsValid(elem_typeid))
2403 {
2404 /*
2405 * if we don't have an element type yet, use the one we just
2406 * got
2407 */
2408 elem_typeid = array_typelem;
2409 }
2410 else if (array_typelem != elem_typeid)
2411 {
2412 /* otherwise, they better match */
2413 ereport(ERROR,
2414 (errcode(ERRCODE_DATATYPE_MISMATCH),
2415 errmsg("argument declared %s is not consistent with argument declared %s",
2416 "anyarray", "anyelement"),
2417 errdetail("%s versus %s",
2418 format_type_be(array_typeid),
2419 format_type_be(elem_typeid))));
2420 }
2421 }
2422
2423 /* Deduce range type from multirange type, or vice versa */
2424 if (OidIsValid(multirange_typeid))
2425 {
2426 Oid multirange_typelem;
2427
2428 multirange_typelem = get_multirange_range(multirange_typeid);
2429 if (!OidIsValid(multirange_typelem))
2430 ereport(ERROR,
2431 (errcode(ERRCODE_DATATYPE_MISMATCH),
2432 errmsg("argument declared %s is not a multirange type but type %s",
2433 "anymultirange",
2434 format_type_be(multirange_typeid))));
2435
2436 if (!OidIsValid(range_typeid))
2437 {
2438 /* if we don't have a range type yet, use the one we just got */
2439 range_typeid = multirange_typelem;
2440 }
2441 else if (multirange_typelem != range_typeid)
2442 {
2443 /* otherwise, they better match */
2444 ereport(ERROR,
2445 (errcode(ERRCODE_DATATYPE_MISMATCH),
2446 errmsg("argument declared %s is not consistent with argument declared %s",
2447 "anymultirange", "anyrange"),
2448 errdetail("%s versus %s",
2449 format_type_be(multirange_typeid),
2450 format_type_be(range_typeid))));
2451 }
2452 }
2453 else if (have_anymultirange && OidIsValid(range_typeid))
2454 {
2455 multirange_typeid = get_range_multirange(range_typeid);
2456 /* We'll complain below if that didn't work */
2457 }
2458
2459 /* Get the element type based on the range type, if we have one */
2460 if (OidIsValid(range_typeid))
2461 {
2462 Oid range_typelem;
2463
2464 range_typelem = get_range_subtype(range_typeid);
2465 if (!OidIsValid(range_typelem))
2466 ereport(ERROR,
2467 (errcode(ERRCODE_DATATYPE_MISMATCH),
2468 errmsg("argument declared %s is not a range type but type %s",
2469 "anyrange",
2470 format_type_be(range_typeid))));
2471
2472 if (!OidIsValid(elem_typeid))
2473 {
2474 /*
2475 * if we don't have an element type yet, use the one we just
2476 * got
2477 */
2478 elem_typeid = range_typelem;
2479 }
2480 else if (range_typelem != elem_typeid)
2481 {
2482 /* otherwise, they better match */
2483 ereport(ERROR,
2484 (errcode(ERRCODE_DATATYPE_MISMATCH),
2485 errmsg("argument declared %s is not consistent with argument declared %s",
2486 "anyrange", "anyelement"),
2487 errdetail("%s versus %s",
2488 format_type_be(range_typeid),
2489 format_type_be(elem_typeid))));
2490 }
2491 }
2492
2493 if (!OidIsValid(elem_typeid))
2494 {
2495 if (allow_poly)
2496 {
2497 elem_typeid = ANYELEMENTOID;
2498 array_typeid = ANYARRAYOID;
2499 range_typeid = ANYRANGEOID;
2500 multirange_typeid = ANYMULTIRANGEOID;
2501 }
2502 else
2503 {
2504 /*
2505 * Only way to get here is if all the family-1 polymorphic
2506 * arguments have UNKNOWN inputs.
2507 */
2508 ereport(ERROR,
2509 (errcode(ERRCODE_DATATYPE_MISMATCH),
2510 errmsg("could not determine polymorphic type because input has type %s",
2511 "unknown")));
2512 }
2513 }
2514
2515 if (have_anynonarray && elem_typeid != ANYELEMENTOID)
2516 {
2517 /*
2518 * require the element type to not be an array or domain over
2519 * array
2520 */
2521 if (type_is_array_domain(elem_typeid))
2522 ereport(ERROR,
2523 (errcode(ERRCODE_DATATYPE_MISMATCH),
2524 errmsg("type matched to anynonarray is an array type: %s",
2525 format_type_be(elem_typeid))));
2526 }
2527
2528 if (have_anyenum && elem_typeid != ANYELEMENTOID)
2529 {
2530 /* require the element type to be an enum */
2531 if (!type_is_enum(elem_typeid))
2532 ereport(ERROR,
2533 (errcode(ERRCODE_DATATYPE_MISMATCH),
2534 errmsg("type matched to anyenum is not an enum type: %s",
2535 format_type_be(elem_typeid))));
2536 }
2537 }
2538
2539 /* Check matching of family-2 polymorphic arguments, if any */
2540 if (have_poly_anycompatible)
2541 {
2542 /* Deduce range type from multirange type, or vice versa */
2543 if (OidIsValid(anycompatible_multirange_typeid))
2544 {
2545 if (OidIsValid(anycompatible_range_typeid))
2546 {
2547 if (anycompatible_multirange_typelem !=
2548 anycompatible_range_typeid)
2549 ereport(ERROR,
2550 (errcode(ERRCODE_DATATYPE_MISMATCH),
2551 errmsg("argument declared %s is not consistent with argument declared %s",
2552 "anycompatiblemultirange",
2553 "anycompatiblerange"),
2554 errdetail("%s versus %s",
2555 format_type_be(anycompatible_multirange_typeid),
2556 format_type_be(anycompatible_range_typeid))));
2557 }
2558 else
2559 {
2560 anycompatible_range_typeid = anycompatible_multirange_typelem;
2561 anycompatible_range_typelem = get_range_subtype(anycompatible_range_typeid);
2562 if (!OidIsValid(anycompatible_range_typelem))
2563 ereport(ERROR,
2564 (errcode(ERRCODE_DATATYPE_MISMATCH),
2565 errmsg("argument declared %s is not a multirange type but type %s",
2566 "anycompatiblemultirange",
2567 format_type_be(anycompatible_multirange_typeid))));
2568 /* this enables element type matching check below */
2569 have_anycompatible_range = true;
2570 /* collect the subtype for common-supertype choice */
2571 anycompatible_actual_types[n_anycompatible_args++] =
2572 anycompatible_range_typelem;
2573 }
2574 }
2575 else if (have_anycompatible_multirange &&
2576 OidIsValid(anycompatible_range_typeid))
2577 {
2578 anycompatible_multirange_typeid = get_range_multirange(anycompatible_range_typeid);
2579 /* We'll complain below if that didn't work */
2580 }
2581
2582 if (n_anycompatible_args > 0)
2583 {
2584 anycompatible_typeid =
2585 select_common_type_from_oids(n_anycompatible_args,
2586 anycompatible_actual_types,
2587 false);
2588
2589 /* We have to verify that the selected type actually works */
2590 if (!verify_common_type_from_oids(anycompatible_typeid,
2591 n_anycompatible_args,
2592 anycompatible_actual_types))
2593 ereport(ERROR,
2594 (errcode(ERRCODE_DATATYPE_MISMATCH),
2595 errmsg("arguments of anycompatible family cannot be cast to a common type")));
2596
2597 if (have_anycompatible_array)
2598 {
2599 anycompatible_array_typeid = get_array_type(anycompatible_typeid);
2600 if (!OidIsValid(anycompatible_array_typeid))
2601 ereport(ERROR,
2602 (errcode(ERRCODE_UNDEFINED_OBJECT),
2603 errmsg("could not find array type for data type %s",
2604 format_type_be(anycompatible_typeid))));
2605 }
2606
2607 if (have_anycompatible_range)
2608 {
2609 /* we can't infer a range type from the others */
2610 if (!OidIsValid(anycompatible_range_typeid))
2611 ereport(ERROR,
2612 (errcode(ERRCODE_DATATYPE_MISMATCH),
2613 errmsg("could not determine polymorphic type %s because input has type %s",
2614 "anycompatiblerange", "unknown")));
2615
2616 /*
2617 * the anycompatible type must exactly match the range element
2618 * type
2619 */
2620 if (anycompatible_range_typelem != anycompatible_typeid)
2621 ereport(ERROR,
2622 (errcode(ERRCODE_DATATYPE_MISMATCH),
2623 errmsg("anycompatiblerange type %s does not match anycompatible type %s",
2624 format_type_be(anycompatible_range_typeid),
2625 format_type_be(anycompatible_typeid))));
2626 }
2627
2628 if (have_anycompatible_multirange)
2629 {
2630 /* we can't infer a multirange type from the others */
2631 if (!OidIsValid(anycompatible_multirange_typeid))
2632 ereport(ERROR,
2633 (errcode(ERRCODE_DATATYPE_MISMATCH),
2634 errmsg("could not determine polymorphic type %s because input has type %s",
2635 "anycompatiblemultirange", "unknown")));
2636
2637 /*
2638 * the anycompatible type must exactly match the multirange
2639 * element type
2640 */
2641 if (anycompatible_range_typelem != anycompatible_typeid)
2642 ereport(ERROR,
2643 (errcode(ERRCODE_DATATYPE_MISMATCH),
2644 errmsg("anycompatiblemultirange type %s does not match anycompatible type %s",
2645 format_type_be(anycompatible_multirange_typeid),
2646 format_type_be(anycompatible_typeid))));
2647 }
2648
2649 if (have_anycompatible_nonarray)
2650 {
2651 /*
2652 * require the element type to not be an array or domain over
2653 * array
2654 */
2655 if (type_is_array_domain(anycompatible_typeid))
2656 ereport(ERROR,
2657 (errcode(ERRCODE_DATATYPE_MISMATCH),
2658 errmsg("type matched to anycompatiblenonarray is an array type: %s",
2659 format_type_be(anycompatible_typeid))));
2660 }
2661 }
2662 else
2663 {
2664 if (allow_poly)
2665 {
2666 anycompatible_typeid = ANYCOMPATIBLEOID;
2667 anycompatible_array_typeid = ANYCOMPATIBLEARRAYOID;
2668 anycompatible_range_typeid = ANYCOMPATIBLERANGEOID;
2669 anycompatible_multirange_typeid = ANYCOMPATIBLEMULTIRANGEOID;
2670 }
2671 else
2672 {
2673 /*
2674 * Only way to get here is if all the family-2 polymorphic
2675 * arguments have UNKNOWN inputs. Resolve to TEXT as
2676 * select_common_type() would do. That doesn't license us to
2677 * use TEXTRANGE or TEXTMULTIRANGE, though.
2678 */
2679 anycompatible_typeid = TEXTOID;
2680 anycompatible_array_typeid = TEXTARRAYOID;
2681 if (have_anycompatible_range)
2682 ereport(ERROR,
2683 (errcode(ERRCODE_DATATYPE_MISMATCH),
2684 errmsg("could not determine polymorphic type %s because input has type %s",
2685 "anycompatiblerange", "unknown")));
2686 if (have_anycompatible_multirange)
2687 ereport(ERROR,
2688 (errcode(ERRCODE_DATATYPE_MISMATCH),
2689 errmsg("could not determine polymorphic type %s because input has type %s",
2690 "anycompatiblemultirange", "unknown")));
2691 }
2692 }
2693
2694 /* replace family-2 polymorphic types by selected types */
2695 for (int j = 0; j < nargs; j++)
2696 {
2697 Oid decl_type = declared_arg_types[j];
2698
2699 if (decl_type == ANYCOMPATIBLEOID ||
2700 decl_type == ANYCOMPATIBLENONARRAYOID)
2701 declared_arg_types[j] = anycompatible_typeid;
2702 else if (decl_type == ANYCOMPATIBLEARRAYOID)
2703 declared_arg_types[j] = anycompatible_array_typeid;
2704 else if (decl_type == ANYCOMPATIBLERANGEOID)
2705 declared_arg_types[j] = anycompatible_range_typeid;
2706 else if (decl_type == ANYCOMPATIBLEMULTIRANGEOID)
2707 declared_arg_types[j] = anycompatible_multirange_typeid;
2708 }
2709 }
2710
2711 /*
2712 * If we had any UNKNOWN inputs for family-1 polymorphic arguments,
2713 * re-scan to assign correct types to them.
2714 *
2715 * Note: we don't have to consider unknown inputs that were matched to
2716 * family-2 polymorphic arguments, because we forcibly updated their
2717 * declared_arg_types[] positions just above.
2718 */
2719 if (have_poly_unknowns)
2720 {
2721 for (int j = 0; j < nargs; j++)
2722 {
2723 Oid decl_type = declared_arg_types[j];
2724 Oid actual_type = actual_arg_types[j];
2725
2726 if (actual_type != UNKNOWNOID)
2727 continue;
2728
2729 if (decl_type == ANYELEMENTOID ||
2730 decl_type == ANYNONARRAYOID ||
2731 decl_type == ANYENUMOID)
2732 declared_arg_types[j] = elem_typeid;
2733 else if (decl_type == ANYARRAYOID)
2734 {
2735 if (!OidIsValid(array_typeid))
2736 {
2737 array_typeid = get_array_type(elem_typeid);
2738 if (!OidIsValid(array_typeid))
2739 ereport(ERROR,
2740 (errcode(ERRCODE_UNDEFINED_OBJECT),
2741 errmsg("could not find array type for data type %s",
2742 format_type_be(elem_typeid))));
2743 }
2744 declared_arg_types[j] = array_typeid;
2745 }
2746 else if (decl_type == ANYRANGEOID)
2747 {
2748 if (!OidIsValid(range_typeid))
2749 {
2750 /* we can't infer a range type from the others */
2751 ereport(ERROR,
2752 (errcode(ERRCODE_DATATYPE_MISMATCH),
2753 errmsg("could not determine polymorphic type %s because input has type %s",
2754 "anyrange", "unknown")));
2755 }
2756 declared_arg_types[j] = range_typeid;
2757 }
2758 else if (decl_type == ANYMULTIRANGEOID)
2759 {
2760 if (!OidIsValid(multirange_typeid))
2761 {
2762 /* we can't infer a multirange type from the others */
2763 ereport(ERROR,
2764 (errcode(ERRCODE_DATATYPE_MISMATCH),
2765 errmsg("could not determine polymorphic type %s because input has type %s",
2766 "anymultirange", "unknown")));
2767 }
2768 declared_arg_types[j] = multirange_typeid;
2769 }
2770 }
2771 }
2772
2773 /* if we return ANYELEMENT use the appropriate argument type */
2774 if (rettype == ANYELEMENTOID ||
2775 rettype == ANYNONARRAYOID ||
2776 rettype == ANYENUMOID)
2777 return elem_typeid;
2778
2779 /* if we return ANYARRAY use the appropriate argument type */
2780 if (rettype == ANYARRAYOID)
2781 {
2782 if (!OidIsValid(array_typeid))
2783 {
2784 array_typeid = get_array_type(elem_typeid);
2785 if (!OidIsValid(array_typeid))
2786 ereport(ERROR,
2787 (errcode(ERRCODE_UNDEFINED_OBJECT),
2788 errmsg("could not find array type for data type %s",
2789 format_type_be(elem_typeid))));
2790 }
2791 return array_typeid;
2792 }
2793
2794 /* if we return ANYRANGE use the appropriate argument type */
2795 if (rettype == ANYRANGEOID)
2796 {
2797 /* this error is unreachable if the function signature is valid: */
2798 if (!OidIsValid(range_typeid))
2799 ereport(ERROR,
2800 (errcode(ERRCODE_DATATYPE_MISMATCH),
2801 errmsg_internal("could not determine polymorphic type %s because input has type %s",
2802 "anyrange", "unknown")));
2803 return range_typeid;
2804 }
2805
2806 /* if we return ANYMULTIRANGE use the appropriate argument type */
2807 if (rettype == ANYMULTIRANGEOID)
2808 {
2809 /* this error is unreachable if the function signature is valid: */
2810 if (!OidIsValid(multirange_typeid))
2811 ereport(ERROR,
2812 (errcode(ERRCODE_DATATYPE_MISMATCH),
2813 errmsg_internal("could not determine polymorphic type %s because input has type %s",
2814 "anymultirange", "unknown")));
2815 return multirange_typeid;
2816 }
2817
2818 /* if we return ANYCOMPATIBLE use the appropriate type */
2819 if (rettype == ANYCOMPATIBLEOID ||
2820 rettype == ANYCOMPATIBLENONARRAYOID)
2821 {
2822 /* this error is unreachable if the function signature is valid: */
2823 if (!OidIsValid(anycompatible_typeid))
2824 ereport(ERROR,
2825 (errcode(ERRCODE_DATATYPE_MISMATCH),
2826 errmsg_internal("could not identify anycompatible type")));
2827 return anycompatible_typeid;
2828 }
2829
2830 /* if we return ANYCOMPATIBLEARRAY use the appropriate type */
2831 if (rettype == ANYCOMPATIBLEARRAYOID)
2832 {
2833 /* this error is unreachable if the function signature is valid: */
2834 if (!OidIsValid(anycompatible_array_typeid))
2835 ereport(ERROR,
2836 (errcode(ERRCODE_DATATYPE_MISMATCH),
2837 errmsg_internal("could not identify anycompatiblearray type")));
2838 return anycompatible_array_typeid;
2839 }
2840
2841 /* if we return ANYCOMPATIBLERANGE use the appropriate argument type */
2842 if (rettype == ANYCOMPATIBLERANGEOID)
2843 {
2844 /* this error is unreachable if the function signature is valid: */
2845 if (!OidIsValid(anycompatible_range_typeid))
2846 ereport(ERROR,
2847 (errcode(ERRCODE_DATATYPE_MISMATCH),
2848 errmsg_internal("could not identify anycompatiblerange type")));
2849 return anycompatible_range_typeid;
2850 }
2851
2852 /* if we return ANYCOMPATIBLEMULTIRANGE use the appropriate argument type */
2853 if (rettype == ANYCOMPATIBLEMULTIRANGEOID)
2854 {
2855 /* this error is unreachable if the function signature is valid: */
2856 if (!OidIsValid(anycompatible_multirange_typeid))
2857 ereport(ERROR,
2858 (errcode(ERRCODE_DATATYPE_MISMATCH),
2859 errmsg_internal("could not identify anycompatiblemultirange type")));
2860 return anycompatible_multirange_typeid;
2861 }
2862
2863 /* we don't return a generic type; send back the original return type */
2864 return rettype;
2865}
2866
2867/*
2868 * check_valid_polymorphic_signature()
2869 * Is a proposed function signature valid per polymorphism rules?
2870 *
2871 * Returns NULL if the signature is valid (either ret_type is not polymorphic,
2872 * or it can be deduced from the given declared argument types). Otherwise,
2873 * returns a palloc'd, already translated errdetail string saying why not.
2874 */
2875char *
2876 check_valid_polymorphic_signature(Oid ret_type,
2877 const Oid *declared_arg_types,
2878 int nargs)
2879{
2880 if (ret_type == ANYRANGEOID || ret_type == ANYMULTIRANGEOID)
2881 {
2882 /*
2883 * ANYRANGE and ANYMULTIRANGE require an ANYRANGE or ANYMULTIRANGE
2884 * input, else we can't tell which of several range types with the
2885 * same element type to use.
2886 */
2887 for (int i = 0; i < nargs; i++)
2888 {
2889 if (declared_arg_types[i] == ANYRANGEOID ||
2890 declared_arg_types[i] == ANYMULTIRANGEOID)
2891 return NULL; /* OK */
2892 }
2893 return psprintf(_("A result of type %s requires at least one input of type anyrange or anymultirange."),
2894 format_type_be(ret_type));
2895 }
2896 else if (ret_type == ANYCOMPATIBLERANGEOID || ret_type == ANYCOMPATIBLEMULTIRANGEOID)
2897 {
2898 /*
2899 * ANYCOMPATIBLERANGE and ANYCOMPATIBLEMULTIRANGE require an
2900 * ANYCOMPATIBLERANGE or ANYCOMPATIBLEMULTIRANGE input, else we can't
2901 * tell which of several range types with the same element type to
2902 * use.
2903 */
2904 for (int i = 0; i < nargs; i++)
2905 {
2906 if (declared_arg_types[i] == ANYCOMPATIBLERANGEOID ||
2907 declared_arg_types[i] == ANYCOMPATIBLEMULTIRANGEOID)
2908 return NULL; /* OK */
2909 }
2910 return psprintf(_("A result of type %s requires at least one input of type anycompatiblerange or anycompatiblemultirange."),
2911 format_type_be(ret_type));
2912 }
2913 else if (IsPolymorphicTypeFamily1(ret_type))
2914 {
2915 /* Otherwise, any family-1 type can be deduced from any other */
2916 for (int i = 0; i < nargs; i++)
2917 {
2918 if (IsPolymorphicTypeFamily1(declared_arg_types[i]))
2919 return NULL; /* OK */
2920 }
2921 /* Keep this list in sync with IsPolymorphicTypeFamily1! */
2922 return psprintf(_("A result of type %s requires at least one input of type anyelement, anyarray, anynonarray, anyenum, anyrange, or anymultirange."),
2923 format_type_be(ret_type));
2924 }
2925 else if (IsPolymorphicTypeFamily2(ret_type))
2926 {
2927 /* Otherwise, any family-2 type can be deduced from any other */
2928 for (int i = 0; i < nargs; i++)
2929 {
2930 if (IsPolymorphicTypeFamily2(declared_arg_types[i]))
2931 return NULL; /* OK */
2932 }
2933 /* Keep this list in sync with IsPolymorphicTypeFamily2! */
2934 return psprintf(_("A result of type %s requires at least one input of type anycompatible, anycompatiblearray, anycompatiblenonarray, anycompatiblerange, or anycompatiblemultirange."),
2935 format_type_be(ret_type));
2936 }
2937 else
2938 return NULL; /* OK, ret_type is not polymorphic */
2939}
2940
2941/*
2942 * check_valid_internal_signature()
2943 * Is a proposed function signature valid per INTERNAL safety rules?
2944 *
2945 * Returns NULL if OK, or a suitable error message if ret_type is INTERNAL but
2946 * none of the declared arg types are. (It's unsafe to create such a function
2947 * since it would allow invocation of INTERNAL-consuming functions directly
2948 * from SQL.) It's overkill to return the error detail message, since there
2949 * is only one possibility, but we do it like this to keep the API similar to
2950 * check_valid_polymorphic_signature().
2951 */
2952char *
2953 check_valid_internal_signature(Oid ret_type,
2954 const Oid *declared_arg_types,
2955 int nargs)
2956{
2957 if (ret_type == INTERNALOID)
2958 {
2959 for (int i = 0; i < nargs; i++)
2960 {
2961 if (declared_arg_types[i] == ret_type)
2962 return NULL; /* OK */
2963 }
2964 return pstrdup(_("A result of type internal requires at least one input of type internal."));
2965 }
2966 else
2967 return NULL; /* OK, ret_type is not INTERNAL */
2968}
2969
2970
2971/* TypeCategory()
2972 * Assign a category to the specified type OID.
2973 *
2974 * NB: this must not return TYPCATEGORY_INVALID.
2975 */
2976TYPCATEGORY
2977 TypeCategory(Oid type)
2978{
2979 char typcategory;
2980 bool typispreferred;
2981
2982 get_type_category_preferred(type, &typcategory, &typispreferred);
2983 Assert(typcategory != TYPCATEGORY_INVALID);
2984 return (TYPCATEGORY) typcategory;
2985}
2986
2987
2988/* IsPreferredType()
2989 * Check if this type is a preferred type for the given category.
2990 *
2991 * If category is TYPCATEGORY_INVALID, then we'll return true for preferred
2992 * types of any category; otherwise, only for preferred types of that
2993 * category.
2994 */
2995bool
2996 IsPreferredType(TYPCATEGORY category, Oid type)
2997{
2998 char typcategory;
2999 bool typispreferred;
3000
3001 get_type_category_preferred(type, &typcategory, &typispreferred);
3002 if (category == typcategory || category == TYPCATEGORY_INVALID)
3003 return typispreferred;
3004 else
3005 return false;
3006}
3007
3008
3009/* IsBinaryCoercible()
3010 * Check if srctype is binary-coercible to targettype.
3011 *
3012 * This notion allows us to cheat and directly exchange values without
3013 * going through the trouble of calling a conversion function. Note that
3014 * in general, this should only be an implementation shortcut. Before 7.4,
3015 * this was also used as a heuristic for resolving overloaded functions and
3016 * operators, but that's basically a bad idea.
3017 *
3018 * As of 7.3, binary coercibility isn't hardwired into the code anymore.
3019 * We consider two types binary-coercible if there is an implicitly
3020 * invokable, no-function-needed pg_cast entry. Also, a domain is always
3021 * binary-coercible to its base type, though *not* vice versa (in the other
3022 * direction, one must apply domain constraint checks before accepting the
3023 * value as legitimate). We also need to special-case various polymorphic
3024 * types.
3025 *
3026 * This function replaces IsBinaryCompatible(), which was an inherently
3027 * symmetric test. Since the pg_cast entries aren't necessarily symmetric,
3028 * the order of the operands is now significant.
3029 */
3030bool
3031 IsBinaryCoercible(Oid srctype, Oid targettype)
3032{
3033 Oid castoid;
3034
3035 return IsBinaryCoercibleWithCast(srctype, targettype, &castoid);
3036}
3037
3038/* IsBinaryCoercibleWithCast()
3039 * Check if srctype is binary-coercible to targettype.
3040 *
3041 * This variant also returns the OID of the pg_cast entry if one is involved.
3042 * *castoid is set to InvalidOid if no binary-coercible cast exists, or if
3043 * there is a hard-wired rule for it rather than a pg_cast entry.
3044 */
3045bool
3046 IsBinaryCoercibleWithCast(Oid srctype, Oid targettype,
3047 Oid *castoid)
3048{
3049 HeapTuple tuple;
3050 Form_pg_cast castForm;
3051 bool result;
3052
3053 *castoid = InvalidOid;
3054
3055 /* Fast path if same type */
3056 if (srctype == targettype)
3057 return true;
3058
3059 /* Anything is coercible to ANY or ANYELEMENT or ANYCOMPATIBLE */
3060 if (targettype == ANYOID || targettype == ANYELEMENTOID ||
3061 targettype == ANYCOMPATIBLEOID)
3062 return true;
3063
3064 /* If srctype is a domain, reduce to its base type */
3065 if (OidIsValid(srctype))
3066 srctype = getBaseType(srctype);
3067
3068 /* Somewhat-fast path for domain -> base type case */
3069 if (srctype == targettype)
3070 return true;
3071
3072 /* Also accept any array type as coercible to ANY[COMPATIBLE]ARRAY */
3073 if (targettype == ANYARRAYOID || targettype == ANYCOMPATIBLEARRAYOID)
3074 if (type_is_array(srctype))
3075 return true;
3076
3077 /* Also accept any non-array type as coercible to ANY[COMPATIBLE]NONARRAY */
3078 if (targettype == ANYNONARRAYOID || targettype == ANYCOMPATIBLENONARRAYOID)
3079 if (!type_is_array(srctype))
3080 return true;
3081
3082 /* Also accept any enum type as coercible to ANYENUM */
3083 if (targettype == ANYENUMOID)
3084 if (type_is_enum(srctype))
3085 return true;
3086
3087 /* Also accept any range type as coercible to ANY[COMPATIBLE]RANGE */
3088 if (targettype == ANYRANGEOID || targettype == ANYCOMPATIBLERANGEOID)
3089 if (type_is_range(srctype))
3090 return true;
3091
3092 /* Also, any multirange type is coercible to ANY[COMPATIBLE]MULTIRANGE */
3093 if (targettype == ANYMULTIRANGEOID || targettype == ANYCOMPATIBLEMULTIRANGEOID)
3094 if (type_is_multirange(srctype))
3095 return true;
3096
3097 /* Also accept any composite type as coercible to RECORD */
3098 if (targettype == RECORDOID)
3099 if (ISCOMPLEX(srctype))
3100 return true;
3101
3102 /* Also accept any composite array type as coercible to RECORD[] */
3103 if (targettype == RECORDARRAYOID)
3104 if (is_complex_array(srctype))
3105 return true;
3106
3107 /* Else look in pg_cast */
3108 tuple = SearchSysCache2(CASTSOURCETARGET,
3109 ObjectIdGetDatum(srctype),
3110 ObjectIdGetDatum(targettype));
3111 if (!HeapTupleIsValid(tuple))
3112 return false; /* no cast */
3113 castForm = (Form_pg_cast) GETSTRUCT(tuple);
3114
3115 result = (castForm->castmethod == COERCION_METHOD_BINARY &&
3116 castForm->castcontext == COERCION_CODE_IMPLICIT);
3117
3118 if (result)
3119 *castoid = castForm->oid;
3120
3121 ReleaseSysCache(tuple);
3122
3123 return result;
3124}
3125
3126
3127/*
3128 * find_coercion_pathway
3129 * Look for a coercion pathway between two types.
3130 *
3131 * Currently, this deals only with scalar-type cases; it does not consider
3132 * polymorphic types nor casts between composite types. (Perhaps fold
3133 * those in someday?)
3134 *
3135 * ccontext determines the set of available casts.
3136 *
3137 * The possible result codes are:
3138 * COERCION_PATH_NONE: failed to find any coercion pathway
3139 * *funcid is set to InvalidOid
3140 * COERCION_PATH_FUNC: apply the coercion function returned in *funcid
3141 * COERCION_PATH_RELABELTYPE: binary-compatible cast, no function needed
3142 * *funcid is set to InvalidOid
3143 * COERCION_PATH_ARRAYCOERCE: need an ArrayCoerceExpr node
3144 * *funcid is set to InvalidOid
3145 * COERCION_PATH_COERCEVIAIO: need a CoerceViaIO node
3146 * *funcid is set to InvalidOid
3147 *
3148 * Note: COERCION_PATH_RELABELTYPE does not necessarily mean that no work is
3149 * needed to do the coercion; if the target is a domain then we may need to
3150 * apply domain constraint checking. If you want to check for a zero-effort
3151 * conversion then use IsBinaryCoercible().
3152 */
3153CoercionPathType
3154 find_coercion_pathway(Oid targetTypeId, Oid sourceTypeId,
3155 CoercionContext ccontext,
3156 Oid *funcid)
3157{
3158 CoercionPathType result = COERCION_PATH_NONE;
3159 HeapTuple tuple;
3160
3161 *funcid = InvalidOid;
3162
3163 /* Perhaps the types are domains; if so, look at their base types */
3164 if (OidIsValid(sourceTypeId))
3165 sourceTypeId = getBaseType(sourceTypeId);
3166 if (OidIsValid(targetTypeId))
3167 targetTypeId = getBaseType(targetTypeId);
3168
3169 /* Domains are always coercible to and from their base type */
3170 if (sourceTypeId == targetTypeId)
3171 return COERCION_PATH_RELABELTYPE;
3172
3173 /* Look in pg_cast */
3174 tuple = SearchSysCache2(CASTSOURCETARGET,
3175 ObjectIdGetDatum(sourceTypeId),
3176 ObjectIdGetDatum(targetTypeId));
3177
3178 if (HeapTupleIsValid(tuple))
3179 {
3180 Form_pg_cast castForm = (Form_pg_cast) GETSTRUCT(tuple);
3181 CoercionContext castcontext;
3182
3183 /* convert char value for castcontext to CoercionContext enum */
3184 switch (castForm->castcontext)
3185 {
3186 case COERCION_CODE_IMPLICIT:
3187 castcontext = COERCION_IMPLICIT;
3188 break;
3189 case COERCION_CODE_ASSIGNMENT:
3190 castcontext = COERCION_ASSIGNMENT;
3191 break;
3192 case COERCION_CODE_EXPLICIT:
3193 castcontext = COERCION_EXPLICIT;
3194 break;
3195 default:
3196 elog(ERROR, "unrecognized castcontext: %d",
3197 (int) castForm->castcontext);
3198 castcontext = 0; /* keep compiler quiet */
3199 break;
3200 }
3201
3202 /* Rely on ordering of enum for correct behavior here */
3203 if (ccontext >= castcontext)
3204 {
3205 switch (castForm->castmethod)
3206 {
3207 case COERCION_METHOD_FUNCTION:
3208 result = COERCION_PATH_FUNC;
3209 *funcid = castForm->castfunc;
3210 break;
3211 case COERCION_METHOD_INOUT:
3212 result = COERCION_PATH_COERCEVIAIO;
3213 break;
3214 case COERCION_METHOD_BINARY:
3215 result = COERCION_PATH_RELABELTYPE;
3216 break;
3217 default:
3218 elog(ERROR, "unrecognized castmethod: %d",
3219 (int) castForm->castmethod);
3220 break;
3221 }
3222 }
3223
3224 ReleaseSysCache(tuple);
3225 }
3226 else
3227 {
3228 /*
3229 * If there's no pg_cast entry, perhaps we are dealing with a pair of
3230 * array types. If so, and if their element types have a conversion
3231 * pathway, report that we can coerce with an ArrayCoerceExpr.
3232 *
3233 * Hack: disallow coercions to oidvector and int2vector, which
3234 * otherwise tend to capture coercions that should go to "real" array
3235 * types. We want those types to be considered "real" arrays for many
3236 * purposes, but not this one. (Also, ArrayCoerceExpr isn't
3237 * guaranteed to produce an output that meets the restrictions of
3238 * these datatypes, such as being 1-dimensional.)
3239 */
3240 if (targetTypeId != OIDVECTOROID && targetTypeId != INT2VECTOROID)
3241 {
3242 Oid targetElem;
3243 Oid sourceElem;
3244
3245 if ((targetElem = get_element_type(targetTypeId)) != InvalidOid &&
3246 (sourceElem = get_element_type(sourceTypeId)) != InvalidOid)
3247 {
3248 CoercionPathType elempathtype;
3249 Oid elemfuncid;
3250
3251 elempathtype = find_coercion_pathway(targetElem,
3252 sourceElem,
3253 ccontext,
3254 &elemfuncid);
3255 if (elempathtype != COERCION_PATH_NONE)
3256 {
3257 result = COERCION_PATH_ARRAYCOERCE;
3258 }
3259 }
3260 }
3261
3262 /*
3263 * If we still haven't found a possibility, consider automatic casting
3264 * using I/O functions. We allow assignment casts to string types and
3265 * explicit casts from string types to be handled this way. (The
3266 * CoerceViaIO mechanism is a lot more general than that, but this is
3267 * all we want to allow in the absence of a pg_cast entry.) It would
3268 * probably be better to insist on explicit casts in both directions,
3269 * but this is a compromise to preserve something of the pre-8.3
3270 * behavior that many types had implicit (yipes!) casts to text.
3271 */
3272 if (result == COERCION_PATH_NONE)
3273 {
3274 if (ccontext >= COERCION_ASSIGNMENT &&
3275 TypeCategory(targetTypeId) == TYPCATEGORY_STRING)
3276 result = COERCION_PATH_COERCEVIAIO;
3277 else if (ccontext >= COERCION_EXPLICIT &&
3278 TypeCategory(sourceTypeId) == TYPCATEGORY_STRING)
3279 result = COERCION_PATH_COERCEVIAIO;
3280 }
3281 }
3282
3283 /*
3284 * When parsing PL/pgSQL assignments, allow an I/O cast to be used
3285 * whenever no normal coercion is available.
3286 */
3287 if (result == COERCION_PATH_NONE &&
3288 ccontext == COERCION_PLPGSQL)
3289 result = COERCION_PATH_COERCEVIAIO;
3290
3291 return result;
3292}
3293
3294
3295/*
3296 * find_typmod_coercion_function -- does the given type need length coercion?
3297 *
3298 * If the target type possesses a pg_cast function from itself to itself,
3299 * it must need length coercion.
3300 *
3301 * "bpchar" (ie, char(N)) and "numeric" are examples of such types.
3302 *
3303 * If the given type is a varlena array type, we do not look for a coercion
3304 * function associated directly with the array type, but instead look for
3305 * one associated with the element type. An ArrayCoerceExpr node must be
3306 * used to apply such a function. (Note: currently, it's pointless to
3307 * return the funcid in this case, because it'll just get looked up again
3308 * in the recursive construction of the ArrayCoerceExpr's elemexpr.)
3309 *
3310 * We use the same result enum as find_coercion_pathway, but the only possible
3311 * result codes are:
3312 * COERCION_PATH_NONE: no length coercion needed
3313 * COERCION_PATH_FUNC: apply the function returned in *funcid
3314 * COERCION_PATH_ARRAYCOERCE: apply the function using ArrayCoerceExpr
3315 */
3316CoercionPathType
3317 find_typmod_coercion_function(Oid typeId,
3318 Oid *funcid)
3319{
3320 CoercionPathType result;
3321 Type targetType;
3322 Form_pg_type typeForm;
3323 HeapTuple tuple;
3324
3325 *funcid = InvalidOid;
3326 result = COERCION_PATH_FUNC;
3327
3328 targetType = typeidType(typeId);
3329 typeForm = (Form_pg_type) GETSTRUCT(targetType);
3330
3331 /* Check for a "true" array type */
3332 if (IsTrueArrayType(typeForm))
3333 {
3334 /* Yes, switch our attention to the element type */
3335 typeId = typeForm->typelem;
3336 result = COERCION_PATH_ARRAYCOERCE;
3337 }
3338 ReleaseSysCache(targetType);
3339
3340 /* Look in pg_cast */
3341 tuple = SearchSysCache2(CASTSOURCETARGET,
3342 ObjectIdGetDatum(typeId),
3343 ObjectIdGetDatum(typeId));
3344
3345 if (HeapTupleIsValid(tuple))
3346 {
3347 Form_pg_cast castForm = (Form_pg_cast) GETSTRUCT(tuple);
3348
3349 *funcid = castForm->castfunc;
3350 ReleaseSysCache(tuple);
3351 }
3352
3353 if (!OidIsValid(*funcid))
3354 result = COERCION_PATH_NONE;
3355
3356 return result;
3357}
3358
3359/*
3360 * is_complex_array
3361 * Is this type an array of composite?
3362 *
3363 * Note: this will not return true for record[]; check for RECORDARRAYOID
3364 * separately if needed.
3365 */
3366static bool
3367 is_complex_array(Oid typid)
3368{
3369 Oid elemtype = get_element_type(typid);
3370
3371 return (OidIsValid(elemtype) && ISCOMPLEX(elemtype));
3372}
3373
3374
3375/*
3376 * Check whether reltypeId is the row type of a typed table of type
3377 * reloftypeId, or is a domain over such a row type. (This is conceptually
3378 * similar to the subtype relationship checked by typeInheritsFrom().)
3379 */
3380static bool
3381 typeIsOfTypedTable(Oid reltypeId, Oid reloftypeId)
3382{
3383 Oid relid = typeOrDomainTypeRelid(reltypeId);
3384 bool result = false;
3385
3386 if (relid)
3387 {
3388 HeapTuple tp;
3389 Form_pg_class reltup;
3390
3391 tp = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
3392 if (!HeapTupleIsValid(tp))
3393 elog(ERROR, "cache lookup failed for relation %u", relid);
3394
3395 reltup = (Form_pg_class) GETSTRUCT(tp);
3396 if (reltup->reloftype == reloftypeId)
3397 result = true;
3398
3399 ReleaseSysCache(tp);
3400 }
3401
3402 return result;
3403}
#define InvalidAttrNumber
Definition: attnum.h:23
int32_t int32
Definition: c.h:534
#define OidIsValid(objectId)
Definition: c.h:774
bool datumIsEqual(Datum value1, Datum value2, bool typByVal, int typLen)
Definition: datum.c:223
int errmsg_internal(const char *fmt,...)
Definition: elog.c:1161
int errdetail(const char *fmt,...)
Definition: elog.c:1207
int errcode(int sqlerrcode)
Definition: elog.c:854
int errmsg(const char *fmt,...)
Definition: elog.c:1071
_
#define _(x)
Definition: elog.c:91
#define WARNING
Definition: elog.h:36
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:226
#define ereport(elevel,...)
Definition: elog.h:150
#define PG_DETOAST_DATUM(datum)
Definition: fmgr.h:240
char * format_type_be(Oid type_oid)
Definition: format_type.c:343
Assert(PointerIsAligned(start, uint64))
#define HeapTupleIsValid(tuple)
Definition: htup.h:78
static void * GETSTRUCT(const HeapTupleData *tuple)
Definition: htup_details.h:728
j
int j
Definition: isn.c:78
i
int i
Definition: isn.c:77
List * lappend(List *list, void *datum)
Definition: list.c:339
Oid get_range_subtype(Oid rangeOid)
Definition: lsyscache.c:3574
Oid get_element_type(Oid typid)
Definition: lsyscache.c:2926
bool type_is_range(Oid typid)
Definition: lsyscache.c:2855
bool type_is_enum(Oid typid)
Definition: lsyscache.c:2845
Oid get_multirange_range(Oid multirangeOid)
Definition: lsyscache.c:3650
Oid get_range_multirange(Oid rangeOid)
Definition: lsyscache.c:3625
bool type_is_collatable(Oid typid)
Definition: lsyscache.c:3248
Oid getBaseTypeAndTypmod(Oid typid, int32 *typmod)
Definition: lsyscache.c:2705
Oid getBaseType(Oid typid)
Definition: lsyscache.c:2688
Oid get_array_type(Oid typid)
Definition: lsyscache.c:2954
void get_type_category_preferred(Oid typid, char *typcategory, bool *typispreferred)
Definition: lsyscache.c:2877
bool type_is_multirange(Oid typid)
Definition: lsyscache.c:2865
#define type_is_array(typid)
Definition: lsyscache.h:214
#define type_is_array_domain(typid)
Definition: lsyscache.h:216
Const * makeNullConst(Oid consttype, int32 consttypmod, Oid constcollid)
Definition: makefuncs.c:388
RelabelType * makeRelabelType(Expr *arg, Oid rtype, int32 rtypmod, Oid rcollid, CoercionForm rformat)
Definition: makefuncs.c:453
FuncExpr * makeFuncExpr(Oid funcid, Oid rettype, List *args, Oid funccollid, Oid inputcollid, CoercionForm fformat)
Definition: makefuncs.c:594
Const * makeConst(Oid consttype, int32 consttypmod, Oid constcollid, int constlen, Datum constvalue, bool constisnull, bool constbyval)
Definition: makefuncs.c:350
char * pstrdup(const char *in)
Definition: mcxt.c:1759
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:42
int32 exprTypmod(const Node *expr)
Definition: nodeFuncs.c:301
Oid exprCollation(const Node *expr)
Definition: nodeFuncs.c:821
Node * applyRelabelType(Node *arg, Oid rtype, int32 rtypmod, Oid rcollid, CoercionForm rformat, int rlocation, bool overwrite_ok)
Definition: nodeFuncs.c:636
int exprLocation(const Node *expr)
Definition: nodeFuncs.c:1388
bool expression_returns_set(Node *clause)
Definition: nodeFuncs.c:763
#define IsA(nodeptr, _type_)
Definition: nodes.h:164
#define nodeTag(nodeptr)
Definition: nodes.h:139
#define makeNode(_type_)
Definition: nodes.h:161
TYPCATEGORY TypeCategory(Oid type)
Definition: parse_coerce.c:2977
static bool verify_common_type_from_oids(Oid common_type, int nargs, const Oid *typeids)
Definition: parse_coerce.c:1627
Oid enforce_generic_type_consistency(const Oid *actual_arg_types, Oid *declared_arg_types, int nargs, Oid rettype, bool allow_poly)
Definition: parse_coerce.c:2132
Node * coerce_to_common_type(ParseState *pstate, Node *node, Oid targetTypeId, const char *context)
Definition: parse_coerce.c:1573
static bool typeIsOfTypedTable(Oid reltypeId, Oid reloftypeId)
Definition: parse_coerce.c:3381
static Node * coerce_record_to_complex(ParseState *pstate, Node *node, Oid targetTypeId, CoercionContext ccontext, CoercionForm cformat, int location)
Definition: parse_coerce.c:1011
CoercionPathType find_typmod_coercion_function(Oid typeId, Oid *funcid)
Definition: parse_coerce.c:3317
static Node * coerce_type_typmod(Node *node, Oid targetTypeId, int32 targetTypMod, CoercionContext ccontext, CoercionForm cformat, int location, bool hideInputCoercion)
Definition: parse_coerce.c:752
bool check_generic_type_consistency(const Oid *actual_arg_types, const Oid *declared_arg_types, int nargs)
Definition: parse_coerce.c:1738
bool verify_common_type(Oid common_type, List *exprs)
Definition: parse_coerce.c:1607
char * check_valid_internal_signature(Oid ret_type, const Oid *declared_arg_types, int nargs)
Definition: parse_coerce.c:2953
Node * coerce_to_domain(Node *arg, Oid baseTypeId, int32 baseTypeMod, Oid typeId, CoercionContext ccontext, CoercionForm cformat, int location, bool hideInputCoercion)
Definition: parse_coerce.c:676
char * check_valid_polymorphic_signature(Oid ret_type, const Oid *declared_arg_types, int nargs)
Definition: parse_coerce.c:2876
Node * coerce_to_specific_type_typmod(ParseState *pstate, Node *node, Oid targetTypeId, int32 targetTypmod, const char *constructName)
Definition: parse_coerce.c:1207
CoercionPathType find_coercion_pathway(Oid targetTypeId, Oid sourceTypeId, CoercionContext ccontext, Oid *funcid)
Definition: parse_coerce.c:3154
int parser_coercion_errposition(ParseState *pstate, int coerce_location, Node *input_expr)
Definition: parse_coerce.c:1313
Node * coerce_null_to_domain(Oid typid, int32 typmod, Oid collation, int typlen, bool typbyval)
Definition: parse_coerce.c:1272
int32 select_common_typmod(ParseState *pstate, List *exprs, Oid common_type)
Definition: parse_coerce.c:1645
static Node * build_coercion_expression(Node *node, CoercionPathType pathtype, Oid funcId, Oid targetTypeId, int32 targetTypMod, CoercionContext ccontext, CoercionForm cformat, int location)
Definition: parse_coerce.c:838
Node * coerce_to_specific_type(ParseState *pstate, Node *node, Oid targetTypeId, const char *constructName)
Definition: parse_coerce.c:1256
Node * coerce_type(ParseState *pstate, Node *node, Oid inputTypeId, Oid targetTypeId, int32 targetTypeMod, CoercionContext ccontext, CoercionForm cformat, int location)
Definition: parse_coerce.c:158
static bool is_complex_array(Oid typid)
Definition: parse_coerce.c:3367
bool IsBinaryCoercible(Oid srctype, Oid targettype)
Definition: parse_coerce.c:3031
bool IsPreferredType(TYPCATEGORY category, Oid type)
Definition: parse_coerce.c:2996
static void hide_coercion_node(Node *node)
Definition: parse_coerce.c:810
Node * coerce_to_boolean(ParseState *pstate, Node *node, const char *constructName)
Definition: parse_coerce.c:1160
Oid select_common_type(ParseState *pstate, List *exprs, const char *context, Node **which_expr)
Definition: parse_coerce.c:1343
bool can_coerce_type(int nargs, const Oid *input_typeids, const Oid *target_typeids, CoercionContext ccontext)
Definition: parse_coerce.c:558
Node * coerce_to_target_type(ParseState *pstate, Node *expr, Oid exprtype, Oid targettype, int32 targettypmod, CoercionContext ccontext, CoercionForm cformat, int location)
Definition: parse_coerce.c:79
static Oid select_common_type_from_oids(int nargs, const Oid *typeids, bool noerror)
Definition: parse_coerce.c:1479
bool IsBinaryCoercibleWithCast(Oid srctype, Oid targettype, Oid *castoid)
Definition: parse_coerce.c:3046
char TYPCATEGORY
Definition: parse_coerce.h:21
CoercionPathType
Definition: parse_coerce.h:25
@ COERCION_PATH_NONE
Definition: parse_coerce.h:26
@ COERCION_PATH_COERCEVIAIO
Definition: parse_coerce.h:30
@ COERCION_PATH_ARRAYCOERCE
Definition: parse_coerce.h:29
@ COERCION_PATH_FUNC
Definition: parse_coerce.h:27
@ COERCION_PATH_RELABELTYPE
Definition: parse_coerce.h:28
void cancel_parser_errposition_callback(ParseCallbackState *pcbstate)
Definition: parse_node.c:156
int parser_errposition(ParseState *pstate, int location)
Definition: parse_node.c:106
void setup_parser_errposition_callback(ParseCallbackState *pcbstate, ParseState *pstate, int location)
Definition: parse_node.c:140
List * expandNSItemVars(ParseState *pstate, ParseNamespaceItem *nsitem, int sublevels_up, int location, List **colnames)
ParseNamespaceItem * GetNSItemByRangeTablePosn(ParseState *pstate, int varno, int sublevels_up)
Oid typeOrDomainTypeRelid(Oid type_id)
Definition: parse_type.c:689
Type typeidType(Oid id)
Definition: parse_type.c:578
Oid typeTypeCollation(Type typ)
Definition: parse_type.c:640
char * typeTypeName(Type t)
Definition: parse_type.c:619
Datum stringTypeDatum(Type tp, char *string, int32 atttypmod)
Definition: parse_type.c:654
bool typeByVal(Type t)
Definition: parse_type.c:609
int16 typeLen(Type t)
Definition: parse_type.c:599
#define ISCOMPLEX(typeid)
Definition: parse_type.h:59
FormData_pg_attribute * Form_pg_attribute
Definition: pg_attribute.h:202
void * arg
FormData_pg_cast * Form_pg_cast
Definition: pg_cast.h:57
FormData_pg_class * Form_pg_class
Definition: pg_class.h:156
#define FUNC_MAX_ARGS
bool typeInheritsFrom(Oid subclassTypeId, Oid superclassTypeId)
Definition: pg_inherits.c:406
#define lfirst(lc)
Definition: pg_list.h:172
#define NIL
Definition: pg_list.h:68
#define list_make1(x1)
Definition: pg_list.h:212
#define for_each_cell(cell, lst, initcell)
Definition: pg_list.h:438
#define linitial(l)
Definition: pg_list.h:178
static ListCell * list_head(const List *l)
Definition: pg_list.h:128
static ListCell * list_second_cell(const List *l)
Definition: pg_list.h:142
static ListCell * lnext(const List *l, const ListCell *c)
Definition: pg_list.h:343
FormData_pg_proc * Form_pg_proc
Definition: pg_proc.h:136
FormData_pg_type * Form_pg_type
Definition: pg_type.h:261
static Datum PointerGetDatum(const void *X)
Definition: postgres.h:332
static Datum BoolGetDatum(bool X)
Definition: postgres.h:112
static Datum ObjectIdGetDatum(Oid X)
Definition: postgres.h:262
static char * DatumGetCString(Datum X)
Definition: postgres.h:345
uint64_t Datum
Definition: postgres.h:70
static Datum Int32GetDatum(int32 X)
Definition: postgres.h:222
#define InvalidOid
Definition: postgres_ext.h:37
unsigned int Oid
Definition: postgres_ext.h:32
CoercionForm
Definition: primnodes.h:765
@ COERCE_IMPLICIT_CAST
Definition: primnodes.h:768
CoercionContext
Definition: primnodes.h:745
@ COERCION_PLPGSQL
Definition: primnodes.h:748
@ COERCION_ASSIGNMENT
Definition: primnodes.h:747
@ COERCION_EXPLICIT
Definition: primnodes.h:749
@ COERCION_IMPLICIT
Definition: primnodes.h:746
char * psprintf(const char *fmt,...)
Definition: psprintf.c:43
Expr * elemexpr
Definition: primnodes.h:1266
ParseLoc location
Definition: primnodes.h:1274
Expr * arg
Definition: primnodes.h:1265
Oid typeId
Definition: primnodes.h:1387
Oid resulttype
Definition: primnodes.h:2053
ParseLoc location
Definition: primnodes.h:2060
Expr * arg
Definition: primnodes.h:2052
Expr * arg
Definition: primnodes.h:1239
ParseLoc location
Definition: primnodes.h:1246
Oid resulttype
Definition: primnodes.h:1240
Expr * arg
Definition: primnodes.h:1311
Oid collOid
Definition: primnodes.h:1312
ParseLoc location
Definition: primnodes.h:1313
Definition: primnodes.h:324
Oid consttype
Definition: primnodes.h:329
ParseLoc location
Definition: primnodes.h:1298
Definition: primnodes.h:189
ParseLoc location
Definition: primnodes.h:802
Definition: pg_list.h:54
Definition: nodes.h:135
Definition: primnodes.h:391
CoerceParamHook p_coerce_param_hook
Definition: parse_node.h:241
ParseLoc location
Definition: primnodes.h:1224
List * args
Definition: primnodes.h:1447
ParseLoc location
Definition: primnodes.h:1471
int natts
Definition: tupdesc.h:137
Definition: primnodes.h:262
void ReleaseSysCache(HeapTuple tuple)
Definition: syscache.c:264
HeapTuple SearchSysCache1(int cacheId, Datum key1)
Definition: syscache.c:220
HeapTuple SearchSysCache2(int cacheId, Datum key1, Datum key2)
Definition: syscache.c:230
#define ReleaseTupleDesc(tupdesc)
Definition: tupdesc.h:219
static FormData_pg_attribute * TupleDescAttr(TupleDesc tupdesc, int i)
Definition: tupdesc.h:160
TupleDesc lookup_rowtype_tupdesc(Oid type_id, int32 typmod)
Definition: typcache.c:1921
Definition: pg_list.h:46
const char * type

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