1/*-------------------------------------------------------------------------
2 *
3 * funcapi.c
4 * Utility and convenience functions for fmgr functions that return
5 * sets and/or composite types, or deal with VARIADIC inputs.
6 *
7 * Copyright (c) 2002-2019, PostgreSQL Global Development Group
8 *
9 * IDENTIFICATION
10 * src/backend/utils/fmgr/funcapi.c
11 *
12 *-------------------------------------------------------------------------
13 */
14#include "postgres.h"
15
16#include "access/htup_details.h"
17#include "access/relation.h"
18#include "catalog/namespace.h"
19#include "catalog/pg_proc.h"
20#include "catalog/pg_type.h"
21#include "funcapi.h"
22#include "nodes/nodeFuncs.h"
23#include "parser/parse_coerce.h"
24#include "utils/array.h"
25#include "utils/builtins.h"
26#include "utils/lsyscache.h"
27#include "utils/memutils.h"
28#include "utils/regproc.h"
29#include "utils/rel.h"
30#include "utils/syscache.h"
31#include "utils/typcache.h"
32
33
34static void shutdown_MultiFuncCall(Datum arg);
35static TypeFuncClass internal_get_result_type(Oid funcid,
36 Node *call_expr,
37 ReturnSetInfo *rsinfo,
38 Oid *resultTypeId,
39 TupleDesc *resultTupleDesc);
40static bool resolve_polymorphic_tupdesc(TupleDesc tupdesc,
41 oidvector *declared_args,
42 Node *call_expr);
43static TypeFuncClass get_type_func_class(Oid typid, Oid *base_typeid);
44
45
46/*
47 * init_MultiFuncCall
48 * Create an empty FuncCallContext data structure
49 * and do some other basic Multi-function call setup
50 * and error checking
51 */
52FuncCallContext *
53init_MultiFuncCall(PG_FUNCTION_ARGS)
54{
55 FuncCallContext *retval;
56
57 /*
58 * Bail if we're called in the wrong context
59 */
60 if (fcinfo->resultinfo == NULL || !IsA(fcinfo->resultinfo, ReturnSetInfo))
61 ereport(ERROR,
62 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
63 errmsg("set-valued function called in context that cannot accept a set")));
64
65 if (fcinfo->flinfo->fn_extra == NULL)
66 {
67 /*
68 * First call
69 */
70 ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
71 MemoryContext multi_call_ctx;
72
73 /*
74 * Create a suitably long-lived context to hold cross-call data
75 */
76 multi_call_ctx = AllocSetContextCreate(fcinfo->flinfo->fn_mcxt,
77 "SRF multi-call context",
78 ALLOCSET_SMALL_SIZES);
79
80 /*
81 * Allocate suitably long-lived space and zero it
82 */
83 retval = (FuncCallContext *)
84 MemoryContextAllocZero(multi_call_ctx,
85 sizeof(FuncCallContext));
86
87 /*
88 * initialize the elements
89 */
90 retval->call_cntr = 0;
91 retval->max_calls = 0;
92 retval->user_fctx = NULL;
93 retval->attinmeta = NULL;
94 retval->tuple_desc = NULL;
95 retval->multi_call_memory_ctx = multi_call_ctx;
96
97 /*
98 * save the pointer for cross-call use
99 */
100 fcinfo->flinfo->fn_extra = retval;
101
102 /*
103 * Ensure we will get shut down cleanly if the exprcontext is not run
104 * to completion.
105 */
106 RegisterExprContextCallback(rsi->econtext,
107 shutdown_MultiFuncCall,
108 PointerGetDatum(fcinfo->flinfo));
109 }
110 else
111 {
112 /* second and subsequent calls */
113 elog(ERROR, "init_MultiFuncCall cannot be called more than once");
114
115 /* never reached, but keep compiler happy */
116 retval = NULL;
117 }
118
119 return retval;
120}
121
122/*
123 * per_MultiFuncCall
124 *
125 * Do Multi-function per-call setup
126 */
127FuncCallContext *
128per_MultiFuncCall(PG_FUNCTION_ARGS)
129{
130 FuncCallContext *retval = (FuncCallContext *) fcinfo->flinfo->fn_extra;
131
132 return retval;
133}
134
135/*
136 * end_MultiFuncCall
137 * Clean up after init_MultiFuncCall
138 */
139void
140end_MultiFuncCall(PG_FUNCTION_ARGS, FuncCallContext *funcctx)
141{
142 ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
143
144 /* Deregister the shutdown callback */
145 UnregisterExprContextCallback(rsi->econtext,
146 shutdown_MultiFuncCall,
147 PointerGetDatum(fcinfo->flinfo));
148
149 /* But use it to do the real work */
150 shutdown_MultiFuncCall(PointerGetDatum(fcinfo->flinfo));
151}
152
153/*
154 * shutdown_MultiFuncCall
155 * Shutdown function to clean up after init_MultiFuncCall
156 */
157static void
158shutdown_MultiFuncCall(Datum arg)
159{
160 FmgrInfo *flinfo = (FmgrInfo *) DatumGetPointer(arg);
161 FuncCallContext *funcctx = (FuncCallContext *) flinfo->fn_extra;
162
163 /* unbind from flinfo */
164 flinfo->fn_extra = NULL;
165
166 /*
167 * Delete context that holds all multi-call data, including the
168 * FuncCallContext itself
169 */
170 MemoryContextDelete(funcctx->multi_call_memory_ctx);
171}
172
173
174/*
175 * get_call_result_type
176 * Given a function's call info record, determine the kind of datatype
177 * it is supposed to return. If resultTypeId isn't NULL, *resultTypeId
178 * receives the actual datatype OID (this is mainly useful for scalar
179 * result types). If resultTupleDesc isn't NULL, *resultTupleDesc
180 * receives a pointer to a TupleDesc when the result is of a composite
181 * type, or NULL when it's a scalar result.
182 *
183 * One hard case that this handles is resolution of actual rowtypes for
184 * functions returning RECORD (from either the function's OUT parameter
185 * list, or a ReturnSetInfo context node). TYPEFUNC_RECORD is returned
186 * only when we couldn't resolve the actual rowtype for lack of information.
187 *
188 * The other hard case that this handles is resolution of polymorphism.
189 * We will never return polymorphic pseudotypes (ANYELEMENT etc), either
190 * as a scalar result type or as a component of a rowtype.
191 *
192 * This function is relatively expensive --- in a function returning set,
193 * try to call it only the first time through.
194 */
195TypeFuncClass
196get_call_result_type(FunctionCallInfo fcinfo,
197 Oid *resultTypeId,
198 TupleDesc *resultTupleDesc)
199{
200 return internal_get_result_type(fcinfo->flinfo->fn_oid,
201 fcinfo->flinfo->fn_expr,
202 (ReturnSetInfo *) fcinfo->resultinfo,
203 resultTypeId,
204 resultTupleDesc);
205}
206
207/*
208 * get_expr_result_type
209 * As above, but work from a calling expression node tree
210 */
211TypeFuncClass
212get_expr_result_type(Node *expr,
213 Oid *resultTypeId,
214 TupleDesc *resultTupleDesc)
215{
216 TypeFuncClass result;
217
218 if (expr && IsA(expr, FuncExpr))
219 result = internal_get_result_type(((FuncExpr *) expr)->funcid,
220 expr,
221 NULL,
222 resultTypeId,
223 resultTupleDesc);
224 else if (expr && IsA(expr, OpExpr))
225 result = internal_get_result_type(get_opcode(((OpExpr *) expr)->opno),
226 expr,
227 NULL,
228 resultTypeId,
229 resultTupleDesc);
230 else
231 {
232 /* handle as a generic expression; no chance to resolve RECORD */
233 Oid typid = exprType(expr);
234 Oid base_typid;
235
236 if (resultTypeId)
237 *resultTypeId = typid;
238 if (resultTupleDesc)
239 *resultTupleDesc = NULL;
240 result = get_type_func_class(typid, &base_typid);
241 if ((result == TYPEFUNC_COMPOSITE ||
242 result == TYPEFUNC_COMPOSITE_DOMAIN) &&
243 resultTupleDesc)
244 *resultTupleDesc = lookup_rowtype_tupdesc_copy(base_typid, -1);
245 }
246
247 return result;
248}
249
250/*
251 * get_func_result_type
252 * As above, but work from a function's OID only
253 *
254 * This will not be able to resolve pure-RECORD results nor polymorphism.
255 */
256TypeFuncClass
257get_func_result_type(Oid functionId,
258 Oid *resultTypeId,
259 TupleDesc *resultTupleDesc)
260{
261 return internal_get_result_type(functionId,
262 NULL,
263 NULL,
264 resultTypeId,
265 resultTupleDesc);
266}
267
268/*
269 * internal_get_result_type -- workhorse code implementing all the above
270 *
271 * funcid must always be supplied. call_expr and rsinfo can be NULL if not
272 * available. We will return TYPEFUNC_RECORD, and store NULL into
273 * *resultTupleDesc, if we cannot deduce the complete result rowtype from
274 * the available information.
275 */
276static TypeFuncClass
277internal_get_result_type(Oid funcid,
278 Node *call_expr,
279 ReturnSetInfo *rsinfo,
280 Oid *resultTypeId,
281 TupleDesc *resultTupleDesc)
282{
283 TypeFuncClass result;
284 HeapTuple tp;
285 Form_pg_proc procform;
286 Oid rettype;
287 Oid base_rettype;
288 TupleDesc tupdesc;
289
290 /* First fetch the function's pg_proc row to inspect its rettype */
291 tp = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
292 if (!HeapTupleIsValid(tp))
293 elog(ERROR, "cache lookup failed for function %u", funcid);
294 procform = (Form_pg_proc) GETSTRUCT(tp);
295
296 rettype = procform->prorettype;
297
298 /* Check for OUT parameters defining a RECORD result */
299 tupdesc = build_function_result_tupdesc_t(tp);
300 if (tupdesc)
301 {
302 /*
303 * It has OUT parameters, so it's basically like a regular composite
304 * type, except we have to be able to resolve any polymorphic OUT
305 * parameters.
306 */
307 if (resultTypeId)
308 *resultTypeId = rettype;
309
310 if (resolve_polymorphic_tupdesc(tupdesc,
311 &procform->proargtypes,
312 call_expr))
313 {
314 if (tupdesc->tdtypeid == RECORDOID &&
315 tupdesc->tdtypmod < 0)
316 assign_record_type_typmod(tupdesc);
317 if (resultTupleDesc)
318 *resultTupleDesc = tupdesc;
319 result = TYPEFUNC_COMPOSITE;
320 }
321 else
322 {
323 if (resultTupleDesc)
324 *resultTupleDesc = NULL;
325 result = TYPEFUNC_RECORD;
326 }
327
328 ReleaseSysCache(tp);
329
330 return result;
331 }
332
333 /*
334 * If scalar polymorphic result, try to resolve it.
335 */
336 if (IsPolymorphicType(rettype))
337 {
338 Oid newrettype = exprType(call_expr);
339
340 if (newrettype == InvalidOid) /* this probably should not happen */
341 ereport(ERROR,
342 (errcode(ERRCODE_DATATYPE_MISMATCH),
343 errmsg("could not determine actual result type for function \"%s\" declared to return type %s",
344 NameStr(procform->proname),
345 format_type_be(rettype))));
346 rettype = newrettype;
347 }
348
349 if (resultTypeId)
350 *resultTypeId = rettype;
351 if (resultTupleDesc)
352 *resultTupleDesc = NULL; /* default result */
353
354 /* Classify the result type */
355 result = get_type_func_class(rettype, &base_rettype);
356 switch (result)
357 {
358 case TYPEFUNC_COMPOSITE:
359 case TYPEFUNC_COMPOSITE_DOMAIN:
360 if (resultTupleDesc)
361 *resultTupleDesc = lookup_rowtype_tupdesc_copy(base_rettype, -1);
362 /* Named composite types can't have any polymorphic columns */
363 break;
364 case TYPEFUNC_SCALAR:
365 break;
366 case TYPEFUNC_RECORD:
367 /* We must get the tupledesc from call context */
368 if (rsinfo && IsA(rsinfo, ReturnSetInfo) &&
369 rsinfo->expectedDesc != NULL)
370 {
371 result = TYPEFUNC_COMPOSITE;
372 if (resultTupleDesc)
373 *resultTupleDesc = rsinfo->expectedDesc;
374 /* Assume no polymorphic columns here, either */
375 }
376 break;
377 default:
378 break;
379 }
380
381 ReleaseSysCache(tp);
382
383 return result;
384}
385
386/*
387 * get_expr_result_tupdesc
388 * Get a tupdesc describing the result of a composite-valued expression
389 *
390 * If expression is not composite or rowtype can't be determined, returns NULL
391 * if noError is true, else throws error.
392 *
393 * This is a simpler version of get_expr_result_type() for use when the caller
394 * is only interested in determinate rowtype results.
395 */
396TupleDesc
397get_expr_result_tupdesc(Node *expr, bool noError)
398{
399 TupleDesc tupleDesc;
400 TypeFuncClass functypclass;
401
402 functypclass = get_expr_result_type(expr, NULL, &tupleDesc);
403
404 if (functypclass == TYPEFUNC_COMPOSITE ||
405 functypclass == TYPEFUNC_COMPOSITE_DOMAIN)
406 return tupleDesc;
407
408 if (!noError)
409 {
410 Oid exprTypeId = exprType(expr);
411
412 if (exprTypeId != RECORDOID)
413 ereport(ERROR,
414 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
415 errmsg("type %s is not composite",
416 format_type_be(exprTypeId))));
417 else
418 ereport(ERROR,
419 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
420 errmsg("record type has not been registered")));
421 }
422
423 return NULL;
424}
425
426/*
427 * Given the result tuple descriptor for a function with OUT parameters,
428 * replace any polymorphic columns (ANYELEMENT etc) with correct data types
429 * deduced from the input arguments. Returns true if able to deduce all types,
430 * false if not.
431 */
432static bool
433resolve_polymorphic_tupdesc(TupleDesc tupdesc, oidvector *declared_args,
434 Node *call_expr)
435{
436 int natts = tupdesc->natts;
437 int nargs = declared_args->dim1;
438 bool have_anyelement_result = false;
439 bool have_anyarray_result = false;
440 bool have_anyrange_result = false;
441 bool have_anynonarray = false;
442 bool have_anyenum = false;
443 Oid anyelement_type = InvalidOid;
444 Oid anyarray_type = InvalidOid;
445 Oid anyrange_type = InvalidOid;
446 Oid anycollation = InvalidOid;
447 int i;
448
449 /* See if there are any polymorphic outputs; quick out if not */
450 for (i = 0; i < natts; i++)
451 {
452 switch (TupleDescAttr(tupdesc, i)->atttypid)
453 {
454 case ANYELEMENTOID:
455 have_anyelement_result = true;
456 break;
457 case ANYARRAYOID:
458 have_anyarray_result = true;
459 break;
460 case ANYNONARRAYOID:
461 have_anyelement_result = true;
462 have_anynonarray = true;
463 break;
464 case ANYENUMOID:
465 have_anyelement_result = true;
466 have_anyenum = true;
467 break;
468 case ANYRANGEOID:
469 have_anyrange_result = true;
470 break;
471 default:
472 break;
473 }
474 }
475 if (!have_anyelement_result && !have_anyarray_result &&
476 !have_anyrange_result)
477 return true;
478
479 /*
480 * Otherwise, extract actual datatype(s) from input arguments. (We assume
481 * the parser already validated consistency of the arguments.)
482 */
483 if (!call_expr)
484 return false; /* no hope */
485
486 for (i = 0; i < nargs; i++)
487 {
488 switch (declared_args->values[i])
489 {
490 case ANYELEMENTOID:
491 case ANYNONARRAYOID:
492 case ANYENUMOID:
493 if (!OidIsValid(anyelement_type))
494 anyelement_type = get_call_expr_argtype(call_expr, i);
495 break;
496 case ANYARRAYOID:
497 if (!OidIsValid(anyarray_type))
498 anyarray_type = get_call_expr_argtype(call_expr, i);
499 break;
500 case ANYRANGEOID:
501 if (!OidIsValid(anyrange_type))
502 anyrange_type = get_call_expr_argtype(call_expr, i);
503 break;
504 default:
505 break;
506 }
507 }
508
509 /* If nothing found, parser messed up */
510 if (!OidIsValid(anyelement_type) && !OidIsValid(anyarray_type) &&
511 !OidIsValid(anyrange_type))
512 return false;
513
514 /* If needed, deduce one polymorphic type from others */
515 if (have_anyelement_result && !OidIsValid(anyelement_type))
516 {
517 if (OidIsValid(anyarray_type))
518 anyelement_type = resolve_generic_type(ANYELEMENTOID,
519 anyarray_type,
520 ANYARRAYOID);
521 if (OidIsValid(anyrange_type))
522 {
523 Oid subtype = resolve_generic_type(ANYELEMENTOID,
524 anyrange_type,
525 ANYRANGEOID);
526
527 /* check for inconsistent array and range results */
528 if (OidIsValid(anyelement_type) && anyelement_type != subtype)
529 return false;
530 anyelement_type = subtype;
531 }
532 }
533
534 if (have_anyarray_result && !OidIsValid(anyarray_type))
535 anyarray_type = resolve_generic_type(ANYARRAYOID,
536 anyelement_type,
537 ANYELEMENTOID);
538
539 /*
540 * We can't deduce a range type from other polymorphic inputs, because
541 * there may be multiple range types for the same subtype.
542 */
543 if (have_anyrange_result && !OidIsValid(anyrange_type))
544 return false;
545
546 /* Enforce ANYNONARRAY if needed */
547 if (have_anynonarray && type_is_array(anyelement_type))
548 return false;
549
550 /* Enforce ANYENUM if needed */
551 if (have_anyenum && !type_is_enum(anyelement_type))
552 return false;
553
554 /*
555 * Identify the collation to use for polymorphic OUT parameters. (It'll
556 * necessarily be the same for both anyelement and anyarray.) Note that
557 * range types are not collatable, so any possible internal collation of a
558 * range type is not considered here.
559 */
560 if (OidIsValid(anyelement_type))
561 anycollation = get_typcollation(anyelement_type);
562 else if (OidIsValid(anyarray_type))
563 anycollation = get_typcollation(anyarray_type);
564
565 if (OidIsValid(anycollation))
566 {
567 /*
568 * The types are collatable, so consider whether to use a nondefault
569 * collation. We do so if we can identify the input collation used
570 * for the function.
571 */
572 Oid inputcollation = exprInputCollation(call_expr);
573
574 if (OidIsValid(inputcollation))
575 anycollation = inputcollation;
576 }
577
578 /* And finally replace the tuple column types as needed */
579 for (i = 0; i < natts; i++)
580 {
581 Form_pg_attribute att = TupleDescAttr(tupdesc, i);
582
583 switch (att->atttypid)
584 {
585 case ANYELEMENTOID:
586 case ANYNONARRAYOID:
587 case ANYENUMOID:
588 TupleDescInitEntry(tupdesc, i + 1,
589 NameStr(att->attname),
590 anyelement_type,
591 -1,
592 0);
593 TupleDescInitEntryCollation(tupdesc, i + 1, anycollation);
594 break;
595 case ANYARRAYOID:
596 TupleDescInitEntry(tupdesc, i + 1,
597 NameStr(att->attname),
598 anyarray_type,
599 -1,
600 0);
601 TupleDescInitEntryCollation(tupdesc, i + 1, anycollation);
602 break;
603 case ANYRANGEOID:
604 TupleDescInitEntry(tupdesc, i + 1,
605 NameStr(att->attname),
606 anyrange_type,
607 -1,
608 0);
609 /* no collation should be attached to a range type */
610 break;
611 default:
612 break;
613 }
614 }
615
616 return true;
617}
618
619/*
620 * Given the declared argument types and modes for a function, replace any
621 * polymorphic types (ANYELEMENT etc) with correct data types deduced from the
622 * input arguments. Returns true if able to deduce all types, false if not.
623 * This is the same logic as resolve_polymorphic_tupdesc, but with a different
624 * argument representation.
625 *
626 * argmodes may be NULL, in which case all arguments are assumed to be IN mode.
627 */
628bool
629resolve_polymorphic_argtypes(int numargs, Oid *argtypes, char *argmodes,
630 Node *call_expr)
631{
632 bool have_anyelement_result = false;
633 bool have_anyarray_result = false;
634 bool have_anyrange_result = false;
635 Oid anyelement_type = InvalidOid;
636 Oid anyarray_type = InvalidOid;
637 Oid anyrange_type = InvalidOid;
638 int inargno;
639 int i;
640
641 /* First pass: resolve polymorphic inputs, check for outputs */
642 inargno = 0;
643 for (i = 0; i < numargs; i++)
644 {
645 char argmode = argmodes ? argmodes[i] : PROARGMODE_IN;
646
647 switch (argtypes[i])
648 {
649 case ANYELEMENTOID:
650 case ANYNONARRAYOID:
651 case ANYENUMOID:
652 if (argmode == PROARGMODE_OUT || argmode == PROARGMODE_TABLE)
653 have_anyelement_result = true;
654 else
655 {
656 if (!OidIsValid(anyelement_type))
657 {
658 anyelement_type = get_call_expr_argtype(call_expr,
659 inargno);
660 if (!OidIsValid(anyelement_type))
661 return false;
662 }
663 argtypes[i] = anyelement_type;
664 }
665 break;
666 case ANYARRAYOID:
667 if (argmode == PROARGMODE_OUT || argmode == PROARGMODE_TABLE)
668 have_anyarray_result = true;
669 else
670 {
671 if (!OidIsValid(anyarray_type))
672 {
673 anyarray_type = get_call_expr_argtype(call_expr,
674 inargno);
675 if (!OidIsValid(anyarray_type))
676 return false;
677 }
678 argtypes[i] = anyarray_type;
679 }
680 break;
681 case ANYRANGEOID:
682 if (argmode == PROARGMODE_OUT || argmode == PROARGMODE_TABLE)
683 have_anyrange_result = true;
684 else
685 {
686 if (!OidIsValid(anyrange_type))
687 {
688 anyrange_type = get_call_expr_argtype(call_expr,
689 inargno);
690 if (!OidIsValid(anyrange_type))
691 return false;
692 }
693 argtypes[i] = anyrange_type;
694 }
695 break;
696 default:
697 break;
698 }
699 if (argmode != PROARGMODE_OUT && argmode != PROARGMODE_TABLE)
700 inargno++;
701 }
702
703 /* Done? */
704 if (!have_anyelement_result && !have_anyarray_result &&
705 !have_anyrange_result)
706 return true;
707
708 /* If no input polymorphics, parser messed up */
709 if (!OidIsValid(anyelement_type) && !OidIsValid(anyarray_type) &&
710 !OidIsValid(anyrange_type))
711 return false;
712
713 /* If needed, deduce one polymorphic type from others */
714 if (have_anyelement_result && !OidIsValid(anyelement_type))
715 {
716 if (OidIsValid(anyarray_type))
717 anyelement_type = resolve_generic_type(ANYELEMENTOID,
718 anyarray_type,
719 ANYARRAYOID);
720 if (OidIsValid(anyrange_type))
721 {
722 Oid subtype = resolve_generic_type(ANYELEMENTOID,
723 anyrange_type,
724 ANYRANGEOID);
725
726 /* check for inconsistent array and range results */
727 if (OidIsValid(anyelement_type) && anyelement_type != subtype)
728 return false;
729 anyelement_type = subtype;
730 }
731 }
732
733 if (have_anyarray_result && !OidIsValid(anyarray_type))
734 anyarray_type = resolve_generic_type(ANYARRAYOID,
735 anyelement_type,
736 ANYELEMENTOID);
737
738 /*
739 * We can't deduce a range type from other polymorphic inputs, because
740 * there may be multiple range types for the same subtype.
741 */
742 if (have_anyrange_result && !OidIsValid(anyrange_type))
743 return false;
744
745 /* XXX do we need to enforce ANYNONARRAY or ANYENUM here? I think not */
746
747 /* And finally replace the output column types as needed */
748 for (i = 0; i < numargs; i++)
749 {
750 switch (argtypes[i])
751 {
752 case ANYELEMENTOID:
753 case ANYNONARRAYOID:
754 case ANYENUMOID:
755 argtypes[i] = anyelement_type;
756 break;
757 case ANYARRAYOID:
758 argtypes[i] = anyarray_type;
759 break;
760 case ANYRANGEOID:
761 argtypes[i] = anyrange_type;
762 break;
763 default:
764 break;
765 }
766 }
767
768 return true;
769}
770
771/*
772 * get_type_func_class
773 * Given the type OID, obtain its TYPEFUNC classification.
774 * Also, if it's a domain, return the base type OID.
775 *
776 * This is intended to centralize a bunch of formerly ad-hoc code for
777 * classifying types. The categories used here are useful for deciding
778 * how to handle functions returning the datatype.
779 */
780static TypeFuncClass
781get_type_func_class(Oid typid, Oid *base_typeid)
782{
783 *base_typeid = typid;
784
785 switch (get_typtype(typid))
786 {
787 case TYPTYPE_COMPOSITE:
788 return TYPEFUNC_COMPOSITE;
789 case TYPTYPE_BASE:
790 case TYPTYPE_ENUM:
791 case TYPTYPE_RANGE:
792 return TYPEFUNC_SCALAR;
793 case TYPTYPE_DOMAIN:
794 *base_typeid = typid = getBaseType(typid);
795 if (get_typtype(typid) == TYPTYPE_COMPOSITE)
796 return TYPEFUNC_COMPOSITE_DOMAIN;
797 else /* domain base type can't be a pseudotype */
798 return TYPEFUNC_SCALAR;
799 case TYPTYPE_PSEUDO:
800 if (typid == RECORDOID)
801 return TYPEFUNC_RECORD;
802
803 /*
804 * We treat VOID and CSTRING as legitimate scalar datatypes,
805 * mostly for the convenience of the JDBC driver (which wants to
806 * be able to do "SELECT * FROM foo()" for all legitimately
807 * user-callable functions).
808 */
809 if (typid == VOIDOID || typid == CSTRINGOID)
810 return TYPEFUNC_SCALAR;
811 return TYPEFUNC_OTHER;
812 }
813 /* shouldn't get here, probably */
814 return TYPEFUNC_OTHER;
815}
816
817
818/*
819 * get_func_arg_info
820 *
821 * Fetch info about the argument types, names, and IN/OUT modes from the
822 * pg_proc tuple. Return value is the total number of arguments.
823 * Other results are palloc'd. *p_argtypes is always filled in, but
824 * *p_argnames and *p_argmodes will be set NULL in the default cases
825 * (no names, and all IN arguments, respectively).
826 *
827 * Note that this function simply fetches what is in the pg_proc tuple;
828 * it doesn't do any interpretation of polymorphic types.
829 */
830int
831get_func_arg_info(HeapTuple procTup,
832 Oid **p_argtypes, char ***p_argnames, char **p_argmodes)
833{
834 Form_pg_proc procStruct = (Form_pg_proc) GETSTRUCT(procTup);
835 Datum proallargtypes;
836 Datum proargmodes;
837 Datum proargnames;
838 bool isNull;
839 ArrayType *arr;
840 int numargs;
841 Datum *elems;
842 int nelems;
843 int i;
844
845 /* First discover the total number of parameters and get their types */
846 proallargtypes = SysCacheGetAttr(PROCOID, procTup,
847 Anum_pg_proc_proallargtypes,
848 &isNull);
849 if (!isNull)
850 {
851 /*
852 * We expect the arrays to be 1-D arrays of the right types; verify
853 * that. For the OID and char arrays, we don't need to use
854 * deconstruct_array() since the array data is just going to look like
855 * a C array of values.
856 */
857 arr = DatumGetArrayTypeP(proallargtypes); /* ensure not toasted */
858 numargs = ARR_DIMS(arr)[0];
859 if (ARR_NDIM(arr) != 1 ||
860 numargs < 0 ||
861 ARR_HASNULL(arr) ||
862 ARR_ELEMTYPE(arr) != OIDOID)
863 elog(ERROR, "proallargtypes is not a 1-D Oid array");
864 Assert(numargs >= procStruct->pronargs);
865 *p_argtypes = (Oid *) palloc(numargs * sizeof(Oid));
866 memcpy(*p_argtypes, ARR_DATA_PTR(arr),
867 numargs * sizeof(Oid));
868 }
869 else
870 {
871 /* If no proallargtypes, use proargtypes */
872 numargs = procStruct->proargtypes.dim1;
873 Assert(numargs == procStruct->pronargs);
874 *p_argtypes = (Oid *) palloc(numargs * sizeof(Oid));
875 memcpy(*p_argtypes, procStruct->proargtypes.values,
876 numargs * sizeof(Oid));
877 }
878
879 /* Get argument names, if available */
880 proargnames = SysCacheGetAttr(PROCOID, procTup,
881 Anum_pg_proc_proargnames,
882 &isNull);
883 if (isNull)
884 *p_argnames = NULL;
885 else
886 {
887 deconstruct_array(DatumGetArrayTypeP(proargnames),
888 TEXTOID, -1, false, 'i',
889 &elems, NULL, &nelems);
890 if (nelems != numargs) /* should not happen */
891 elog(ERROR, "proargnames must have the same number of elements as the function has arguments");
892 *p_argnames = (char **) palloc(sizeof(char *) * numargs);
893 for (i = 0; i < numargs; i++)
894 (*p_argnames)[i] = TextDatumGetCString(elems[i]);
895 }
896
897 /* Get argument modes, if available */
898 proargmodes = SysCacheGetAttr(PROCOID, procTup,
899 Anum_pg_proc_proargmodes,
900 &isNull);
901 if (isNull)
902 *p_argmodes = NULL;
903 else
904 {
905 arr = DatumGetArrayTypeP(proargmodes); /* ensure not toasted */
906 if (ARR_NDIM(arr) != 1 ||
907 ARR_DIMS(arr)[0] != numargs ||
908 ARR_HASNULL(arr) ||
909 ARR_ELEMTYPE(arr) != CHAROID)
910 elog(ERROR, "proargmodes is not a 1-D char array");
911 *p_argmodes = (char *) palloc(numargs * sizeof(char));
912 memcpy(*p_argmodes, ARR_DATA_PTR(arr),
913 numargs * sizeof(char));
914 }
915
916 return numargs;
917}
918
919/*
920 * get_func_trftypes
921 *
922 * Returns the number of transformed types used by function.
923 */
924int
925get_func_trftypes(HeapTuple procTup,
926 Oid **p_trftypes)
927{
928 Datum protrftypes;
929 ArrayType *arr;
930 int nelems;
931 bool isNull;
932
933 protrftypes = SysCacheGetAttr(PROCOID, procTup,
934 Anum_pg_proc_protrftypes,
935 &isNull);
936 if (!isNull)
937 {
938 /*
939 * We expect the arrays to be 1-D arrays of the right types; verify
940 * that. For the OID and char arrays, we don't need to use
941 * deconstruct_array() since the array data is just going to look like
942 * a C array of values.
943 */
944 arr = DatumGetArrayTypeP(protrftypes); /* ensure not toasted */
945 nelems = ARR_DIMS(arr)[0];
946 if (ARR_NDIM(arr) != 1 ||
947 nelems < 0 ||
948 ARR_HASNULL(arr) ||
949 ARR_ELEMTYPE(arr) != OIDOID)
950 elog(ERROR, "protrftypes is not a 1-D Oid array");
951 Assert(nelems >= ((Form_pg_proc) GETSTRUCT(procTup))->pronargs);
952 *p_trftypes = (Oid *) palloc(nelems * sizeof(Oid));
953 memcpy(*p_trftypes, ARR_DATA_PTR(arr),
954 nelems * sizeof(Oid));
955
956 return nelems;
957 }
958 else
959 return 0;
960}
961
962/*
963 * get_func_input_arg_names
964 *
965 * Extract the names of input arguments only, given a function's
966 * proargnames and proargmodes entries in Datum form.
967 *
968 * Returns the number of input arguments, which is the length of the
969 * palloc'd array returned to *arg_names. Entries for unnamed args
970 * are set to NULL. You don't get anything if proargnames is NULL.
971 */
972int
973get_func_input_arg_names(Datum proargnames, Datum proargmodes,
974 char ***arg_names)
975{
976 ArrayType *arr;
977 int numargs;
978 Datum *argnames;
979 char *argmodes;
980 char **inargnames;
981 int numinargs;
982 int i;
983
984 /* Do nothing if null proargnames */
985 if (proargnames == PointerGetDatum(NULL))
986 {
987 *arg_names = NULL;
988 return 0;
989 }
990
991 /*
992 * We expect the arrays to be 1-D arrays of the right types; verify that.
993 * For proargmodes, we don't need to use deconstruct_array() since the
994 * array data is just going to look like a C array of values.
995 */
996 arr = DatumGetArrayTypeP(proargnames); /* ensure not toasted */
997 if (ARR_NDIM(arr) != 1 ||
998 ARR_HASNULL(arr) ||
999 ARR_ELEMTYPE(arr) != TEXTOID)
1000 elog(ERROR, "proargnames is not a 1-D text array");
1001 deconstruct_array(arr, TEXTOID, -1, false, 'i',
1002 &argnames, NULL, &numargs);
1003 if (proargmodes != PointerGetDatum(NULL))
1004 {
1005 arr = DatumGetArrayTypeP(proargmodes); /* ensure not toasted */
1006 if (ARR_NDIM(arr) != 1 ||
1007 ARR_DIMS(arr)[0] != numargs ||
1008 ARR_HASNULL(arr) ||
1009 ARR_ELEMTYPE(arr) != CHAROID)
1010 elog(ERROR, "proargmodes is not a 1-D char array");
1011 argmodes = (char *) ARR_DATA_PTR(arr);
1012 }
1013 else
1014 argmodes = NULL;
1015
1016 /* zero elements probably shouldn't happen, but handle it gracefully */
1017 if (numargs <= 0)
1018 {
1019 *arg_names = NULL;
1020 return 0;
1021 }
1022
1023 /* extract input-argument names */
1024 inargnames = (char **) palloc(numargs * sizeof(char *));
1025 numinargs = 0;
1026 for (i = 0; i < numargs; i++)
1027 {
1028 if (argmodes == NULL ||
1029 argmodes[i] == PROARGMODE_IN ||
1030 argmodes[i] == PROARGMODE_INOUT ||
1031 argmodes[i] == PROARGMODE_VARIADIC)
1032 {
1033 char *pname = TextDatumGetCString(argnames[i]);
1034
1035 if (pname[0] != '\0')
1036 inargnames[numinargs] = pname;
1037 else
1038 inargnames[numinargs] = NULL;
1039 numinargs++;
1040 }
1041 }
1042
1043 *arg_names = inargnames;
1044 return numinargs;
1045}
1046
1047
1048/*
1049 * get_func_result_name
1050 *
1051 * If the function has exactly one output parameter, and that parameter
1052 * is named, return the name (as a palloc'd string). Else return NULL.
1053 *
1054 * This is used to determine the default output column name for functions
1055 * returning scalar types.
1056 */
1057char *
1058get_func_result_name(Oid functionId)
1059{
1060 char *result;
1061 HeapTuple procTuple;
1062 Datum proargmodes;
1063 Datum proargnames;
1064 bool isnull;
1065 ArrayType *arr;
1066 int numargs;
1067 char *argmodes;
1068 Datum *argnames;
1069 int numoutargs;
1070 int nargnames;
1071 int i;
1072
1073 /* First fetch the function's pg_proc row */
1074 procTuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(functionId));
1075 if (!HeapTupleIsValid(procTuple))
1076 elog(ERROR, "cache lookup failed for function %u", functionId);
1077
1078 /* If there are no named OUT parameters, return NULL */
1079 if (heap_attisnull(procTuple, Anum_pg_proc_proargmodes, NULL) ||
1080 heap_attisnull(procTuple, Anum_pg_proc_proargnames, NULL))
1081 result = NULL;
1082 else
1083 {
1084 /* Get the data out of the tuple */
1085 proargmodes = SysCacheGetAttr(PROCOID, procTuple,
1086 Anum_pg_proc_proargmodes,
1087 &isnull);
1088 Assert(!isnull);
1089 proargnames = SysCacheGetAttr(PROCOID, procTuple,
1090 Anum_pg_proc_proargnames,
1091 &isnull);
1092 Assert(!isnull);
1093
1094 /*
1095 * We expect the arrays to be 1-D arrays of the right types; verify
1096 * that. For the char array, we don't need to use deconstruct_array()
1097 * since the array data is just going to look like a C array of
1098 * values.
1099 */
1100 arr = DatumGetArrayTypeP(proargmodes); /* ensure not toasted */
1101 numargs = ARR_DIMS(arr)[0];
1102 if (ARR_NDIM(arr) != 1 ||
1103 numargs < 0 ||
1104 ARR_HASNULL(arr) ||
1105 ARR_ELEMTYPE(arr) != CHAROID)
1106 elog(ERROR, "proargmodes is not a 1-D char array");
1107 argmodes = (char *) ARR_DATA_PTR(arr);
1108 arr = DatumGetArrayTypeP(proargnames); /* ensure not toasted */
1109 if (ARR_NDIM(arr) != 1 ||
1110 ARR_DIMS(arr)[0] != numargs ||
1111 ARR_HASNULL(arr) ||
1112 ARR_ELEMTYPE(arr) != TEXTOID)
1113 elog(ERROR, "proargnames is not a 1-D text array");
1114 deconstruct_array(arr, TEXTOID, -1, false, 'i',
1115 &argnames, NULL, &nargnames);
1116 Assert(nargnames == numargs);
1117
1118 /* scan for output argument(s) */
1119 result = NULL;
1120 numoutargs = 0;
1121 for (i = 0; i < numargs; i++)
1122 {
1123 if (argmodes[i] == PROARGMODE_IN ||
1124 argmodes[i] == PROARGMODE_VARIADIC)
1125 continue;
1126 Assert(argmodes[i] == PROARGMODE_OUT ||
1127 argmodes[i] == PROARGMODE_INOUT ||
1128 argmodes[i] == PROARGMODE_TABLE);
1129 if (++numoutargs > 1)
1130 {
1131 /* multiple out args, so forget it */
1132 result = NULL;
1133 break;
1134 }
1135 result = TextDatumGetCString(argnames[i]);
1136 if (result == NULL || result[0] == '\0')
1137 {
1138 /* Parameter is not named, so forget it */
1139 result = NULL;
1140 break;
1141 }
1142 }
1143 }
1144
1145 ReleaseSysCache(procTuple);
1146
1147 return result;
1148}
1149
1150
1151/*
1152 * build_function_result_tupdesc_t
1153 *
1154 * Given a pg_proc row for a function, return a tuple descriptor for the
1155 * result rowtype, or NULL if the function does not have OUT parameters.
1156 *
1157 * Note that this does not handle resolution of polymorphic types;
1158 * that is deliberate.
1159 */
1160TupleDesc
1161build_function_result_tupdesc_t(HeapTuple procTuple)
1162{
1163 Form_pg_proc procform = (Form_pg_proc) GETSTRUCT(procTuple);
1164 Datum proallargtypes;
1165 Datum proargmodes;
1166 Datum proargnames;
1167 bool isnull;
1168
1169 /* Return NULL if the function isn't declared to return RECORD */
1170 if (procform->prorettype != RECORDOID)
1171 return NULL;
1172
1173 /* If there are no OUT parameters, return NULL */
1174 if (heap_attisnull(procTuple, Anum_pg_proc_proallargtypes, NULL) ||
1175 heap_attisnull(procTuple, Anum_pg_proc_proargmodes, NULL))
1176 return NULL;
1177
1178 /* Get the data out of the tuple */
1179 proallargtypes = SysCacheGetAttr(PROCOID, procTuple,
1180 Anum_pg_proc_proallargtypes,
1181 &isnull);
1182 Assert(!isnull);
1183 proargmodes = SysCacheGetAttr(PROCOID, procTuple,
1184 Anum_pg_proc_proargmodes,
1185 &isnull);
1186 Assert(!isnull);
1187 proargnames = SysCacheGetAttr(PROCOID, procTuple,
1188 Anum_pg_proc_proargnames,
1189 &isnull);
1190 if (isnull)
1191 proargnames = PointerGetDatum(NULL); /* just to be sure */
1192
1193 return build_function_result_tupdesc_d(procform->prokind,
1194 proallargtypes,
1195 proargmodes,
1196 proargnames);
1197}
1198
1199/*
1200 * build_function_result_tupdesc_d
1201 *
1202 * Build a RECORD function's tupledesc from the pg_proc proallargtypes,
1203 * proargmodes, and proargnames arrays. This is split out for the
1204 * convenience of ProcedureCreate, which needs to be able to compute the
1205 * tupledesc before actually creating the function.
1206 *
1207 * For functions (but not for procedures), returns NULL if there are not at
1208 * least two OUT or INOUT arguments.
1209 */
1210TupleDesc
1211build_function_result_tupdesc_d(char prokind,
1212 Datum proallargtypes,
1213 Datum proargmodes,
1214 Datum proargnames)
1215{
1216 TupleDesc desc;
1217 ArrayType *arr;
1218 int numargs;
1219 Oid *argtypes;
1220 char *argmodes;
1221 Datum *argnames = NULL;
1222 Oid *outargtypes;
1223 char **outargnames;
1224 int numoutargs;
1225 int nargnames;
1226 int i;
1227
1228 /* Can't have output args if columns are null */
1229 if (proallargtypes == PointerGetDatum(NULL) ||
1230 proargmodes == PointerGetDatum(NULL))
1231 return NULL;
1232
1233 /*
1234 * We expect the arrays to be 1-D arrays of the right types; verify that.
1235 * For the OID and char arrays, we don't need to use deconstruct_array()
1236 * since the array data is just going to look like a C array of values.
1237 */
1238 arr = DatumGetArrayTypeP(proallargtypes); /* ensure not toasted */
1239 numargs = ARR_DIMS(arr)[0];
1240 if (ARR_NDIM(arr) != 1 ||
1241 numargs < 0 ||
1242 ARR_HASNULL(arr) ||
1243 ARR_ELEMTYPE(arr) != OIDOID)
1244 elog(ERROR, "proallargtypes is not a 1-D Oid array");
1245 argtypes = (Oid *) ARR_DATA_PTR(arr);
1246 arr = DatumGetArrayTypeP(proargmodes); /* ensure not toasted */
1247 if (ARR_NDIM(arr) != 1 ||
1248 ARR_DIMS(arr)[0] != numargs ||
1249 ARR_HASNULL(arr) ||
1250 ARR_ELEMTYPE(arr) != CHAROID)
1251 elog(ERROR, "proargmodes is not a 1-D char array");
1252 argmodes = (char *) ARR_DATA_PTR(arr);
1253 if (proargnames != PointerGetDatum(NULL))
1254 {
1255 arr = DatumGetArrayTypeP(proargnames); /* ensure not toasted */
1256 if (ARR_NDIM(arr) != 1 ||
1257 ARR_DIMS(arr)[0] != numargs ||
1258 ARR_HASNULL(arr) ||
1259 ARR_ELEMTYPE(arr) != TEXTOID)
1260 elog(ERROR, "proargnames is not a 1-D text array");
1261 deconstruct_array(arr, TEXTOID, -1, false, 'i',
1262 &argnames, NULL, &nargnames);
1263 Assert(nargnames == numargs);
1264 }
1265
1266 /* zero elements probably shouldn't happen, but handle it gracefully */
1267 if (numargs <= 0)
1268 return NULL;
1269
1270 /* extract output-argument types and names */
1271 outargtypes = (Oid *) palloc(numargs * sizeof(Oid));
1272 outargnames = (char **) palloc(numargs * sizeof(char *));
1273 numoutargs = 0;
1274 for (i = 0; i < numargs; i++)
1275 {
1276 char *pname;
1277
1278 if (argmodes[i] == PROARGMODE_IN ||
1279 argmodes[i] == PROARGMODE_VARIADIC)
1280 continue;
1281 Assert(argmodes[i] == PROARGMODE_OUT ||
1282 argmodes[i] == PROARGMODE_INOUT ||
1283 argmodes[i] == PROARGMODE_TABLE);
1284 outargtypes[numoutargs] = argtypes[i];
1285 if (argnames)
1286 pname = TextDatumGetCString(argnames[i]);
1287 else
1288 pname = NULL;
1289 if (pname == NULL || pname[0] == '\0')
1290 {
1291 /* Parameter is not named, so gin up a column name */
1292 pname = psprintf("column%d", numoutargs + 1);
1293 }
1294 outargnames[numoutargs] = pname;
1295 numoutargs++;
1296 }
1297
1298 /*
1299 * If there is no output argument, or only one, the function does not
1300 * return tuples.
1301 */
1302 if (numoutargs < 2 && prokind != PROKIND_PROCEDURE)
1303 return NULL;
1304
1305 desc = CreateTemplateTupleDesc(numoutargs);
1306 for (i = 0; i < numoutargs; i++)
1307 {
1308 TupleDescInitEntry(desc, i + 1,
1309 outargnames[i],
1310 outargtypes[i],
1311 -1,
1312 0);
1313 }
1314
1315 return desc;
1316}
1317
1318
1319/*
1320 * RelationNameGetTupleDesc
1321 *
1322 * Given a (possibly qualified) relation name, build a TupleDesc.
1323 *
1324 * Note: while this works as advertised, it's seldom the best way to
1325 * build a tupdesc for a function's result type. It's kept around
1326 * only for backwards compatibility with existing user-written code.
1327 */
1328TupleDesc
1329RelationNameGetTupleDesc(const char *relname)
1330{
1331 RangeVar *relvar;
1332 Relation rel;
1333 TupleDesc tupdesc;
1334 List *relname_list;
1335
1336 /* Open relation and copy the tuple description */
1337 relname_list = stringToQualifiedNameList(relname);
1338 relvar = makeRangeVarFromNameList(relname_list);
1339 rel = relation_openrv(relvar, AccessShareLock);
1340 tupdesc = CreateTupleDescCopy(RelationGetDescr(rel));
1341 relation_close(rel, AccessShareLock);
1342
1343 return tupdesc;
1344}
1345
1346/*
1347 * TypeGetTupleDesc
1348 *
1349 * Given a type Oid, build a TupleDesc. (In most cases you should be
1350 * using get_call_result_type or one of its siblings instead of this
1351 * routine, so that you can handle OUT parameters, RECORD result type,
1352 * and polymorphic results.)
1353 *
1354 * If the type is composite, *and* a colaliases List is provided, *and*
1355 * the List is of natts length, use the aliases instead of the relation
1356 * attnames. (NB: this usage is deprecated since it may result in
1357 * creation of unnecessary transient record types.)
1358 *
1359 * If the type is a base type, a single item alias List is required.
1360 */
1361TupleDesc
1362TypeGetTupleDesc(Oid typeoid, List *colaliases)
1363{
1364 Oid base_typeoid;
1365 TypeFuncClass functypclass = get_type_func_class(typeoid, &base_typeoid);
1366 TupleDesc tupdesc = NULL;
1367
1368 /*
1369 * Build a suitable tupledesc representing the output rows. We
1370 * intentionally do not support TYPEFUNC_COMPOSITE_DOMAIN here, as it's
1371 * unlikely that legacy callers of this obsolete function would be
1372 * prepared to apply domain constraints.
1373 */
1374 if (functypclass == TYPEFUNC_COMPOSITE)
1375 {
1376 /* Composite data type, e.g. a table's row type */
1377 tupdesc = lookup_rowtype_tupdesc_copy(base_typeoid, -1);
1378
1379 if (colaliases != NIL)
1380 {
1381 int natts = tupdesc->natts;
1382 int varattno;
1383
1384 /* does the list length match the number of attributes? */
1385 if (list_length(colaliases) != natts)
1386 ereport(ERROR,
1387 (errcode(ERRCODE_DATATYPE_MISMATCH),
1388 errmsg("number of aliases does not match number of columns")));
1389
1390 /* OK, use the aliases instead */
1391 for (varattno = 0; varattno < natts; varattno++)
1392 {
1393 char *label = strVal(list_nth(colaliases, varattno));
1394 Form_pg_attribute attr = TupleDescAttr(tupdesc, varattno);
1395
1396 if (label != NULL)
1397 namestrcpy(&(attr->attname), label);
1398 }
1399
1400 /* The tuple type is now an anonymous record type */
1401 tupdesc->tdtypeid = RECORDOID;
1402 tupdesc->tdtypmod = -1;
1403 }
1404 }
1405 else if (functypclass == TYPEFUNC_SCALAR)
1406 {
1407 /* Base data type, i.e. scalar */
1408 char *attname;
1409
1410 /* the alias list is required for base types */
1411 if (colaliases == NIL)
1412 ereport(ERROR,
1413 (errcode(ERRCODE_DATATYPE_MISMATCH),
1414 errmsg("no column alias was provided")));
1415
1416 /* the alias list length must be 1 */
1417 if (list_length(colaliases) != 1)
1418 ereport(ERROR,
1419 (errcode(ERRCODE_DATATYPE_MISMATCH),
1420 errmsg("number of aliases does not match number of columns")));
1421
1422 /* OK, get the column alias */
1423 attname = strVal(linitial(colaliases));
1424
1425 tupdesc = CreateTemplateTupleDesc(1);
1426 TupleDescInitEntry(tupdesc,
1427 (AttrNumber) 1,
1428 attname,
1429 typeoid,
1430 -1,
1431 0);
1432 }
1433 else if (functypclass == TYPEFUNC_RECORD)
1434 {
1435 /* XXX can't support this because typmod wasn't passed in ... */
1436 ereport(ERROR,
1437 (errcode(ERRCODE_DATATYPE_MISMATCH),
1438 errmsg("could not determine row description for function returning record")));
1439 }
1440 else
1441 {
1442 /* crummy error message, but parser should have caught this */
1443 elog(ERROR, "function in FROM has unsupported return type");
1444 }
1445
1446 return tupdesc;
1447}
1448
1449/*
1450 * extract_variadic_args
1451 *
1452 * Extract a set of argument values, types and NULL markers for a given
1453 * input function which makes use of a VARIADIC input whose argument list
1454 * depends on the caller context. When doing a VARIADIC call, the caller
1455 * has provided one argument made of an array of values, so deconstruct the
1456 * array data before using it for the next processing. If no VARIADIC call
1457 * is used, just fill in the status data based on all the arguments given
1458 * by the caller.
1459 *
1460 * This function returns the number of arguments generated, or -1 in the
1461 * case of "VARIADIC NULL".
1462 */
1463int
1464extract_variadic_args(FunctionCallInfo fcinfo, int variadic_start,
1465 bool convert_unknown, Datum **args, Oid **types,
1466 bool **nulls)
1467{
1468 bool variadic = get_fn_expr_variadic(fcinfo->flinfo);
1469 Datum *args_res;
1470 bool *nulls_res;
1471 Oid *types_res;
1472 int nargs,
1473 i;
1474
1475 *args = NULL;
1476 *types = NULL;
1477 *nulls = NULL;
1478
1479 if (variadic)
1480 {
1481 ArrayType *array_in;
1482 Oid element_type;
1483 bool typbyval;
1484 char typalign;
1485 int16 typlen;
1486
1487 Assert(PG_NARGS() == variadic_start + 1);
1488
1489 if (PG_ARGISNULL(variadic_start))
1490 return -1;
1491
1492 array_in = PG_GETARG_ARRAYTYPE_P(variadic_start);
1493 element_type = ARR_ELEMTYPE(array_in);
1494
1495 get_typlenbyvalalign(element_type,
1496 &typlen, &typbyval, &typalign);
1497 deconstruct_array(array_in, element_type, typlen, typbyval,
1498 typalign, &args_res, &nulls_res,
1499 &nargs);
1500
1501 /* All the elements of the array have the same type */
1502 types_res = (Oid *) palloc0(nargs * sizeof(Oid));
1503 for (i = 0; i < nargs; i++)
1504 types_res[i] = element_type;
1505 }
1506 else
1507 {
1508 nargs = PG_NARGS() - variadic_start;
1509 Assert(nargs > 0);
1510 nulls_res = (bool *) palloc0(nargs * sizeof(bool));
1511 args_res = (Datum *) palloc0(nargs * sizeof(Datum));
1512 types_res = (Oid *) palloc0(nargs * sizeof(Oid));
1513
1514 for (i = 0; i < nargs; i++)
1515 {
1516 nulls_res[i] = PG_ARGISNULL(i + variadic_start);
1517 types_res[i] = get_fn_expr_argtype(fcinfo->flinfo,
1518 i + variadic_start);
1519
1520 /*
1521 * Turn a constant (more or less literal) value that's of unknown
1522 * type into text if required. Unknowns come in as a cstring
1523 * pointer. Note: for functions declared as taking type "any", the
1524 * parser will not do any type conversion on unknown-type literals
1525 * (that is, undecorated strings or NULLs).
1526 */
1527 if (convert_unknown &&
1528 types_res[i] == UNKNOWNOID &&
1529 get_fn_expr_arg_stable(fcinfo->flinfo, i + variadic_start))
1530 {
1531 types_res[i] = TEXTOID;
1532
1533 if (PG_ARGISNULL(i + variadic_start))
1534 args_res[i] = (Datum) 0;
1535 else
1536 args_res[i] =
1537 CStringGetTextDatum(PG_GETARG_POINTER(i + variadic_start));
1538 }
1539 else
1540 {
1541 /* no conversion needed, just take the datum as given */
1542 args_res[i] = PG_GETARG_DATUM(i + variadic_start);
1543 }
1544
1545 if (!OidIsValid(types_res[i]) ||
1546 (convert_unknown && types_res[i] == UNKNOWNOID))
1547 ereport(ERROR,
1548 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1549 errmsg("could not determine data type for argument %d",
1550 i + 1)));
1551 }
1552 }
1553
1554 /* Fill in results */
1555 *args = args_res;
1556 *nulls = nulls_res;
1557 *types = types_res;
1558
1559 return nargs;
1560}
1561