granicus.if.org Git - postgresql/blob - src/backend/utils/fmgr/funcapi.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * funcapi.c
   4  *        Utility and convenience functions for fmgr functions that return
   5  *        sets and/or composite types.
   6  *
   7  * Copyright (c) 2002-2014, 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 "catalog/namespace.h"
  18 #include "catalog/pg_proc.h"
  19 #include "catalog/pg_type.h"
  20 #include "funcapi.h"
  21 #include "nodes/nodeFuncs.h"
  22 #include "parser/parse_coerce.h"
  23 #include "utils/array.h"
  24 #include "utils/builtins.h"
  25 #include "utils/lsyscache.h"
  26 #include "utils/memutils.h"
  27 #include "utils/rel.h"
  28 #include "utils/syscache.h"
  29 #include "utils/typcache.h"
  30
  31
  32 static void shutdown_MultiFuncCall(Datum arg);
  33 static TypeFuncClass internal_get_result_type(Oid funcid,
  34                                                  Node *call_expr,
  35                                                  ReturnSetInfo *rsinfo,
  36                                                  Oid *resultTypeId,
  37                                                  TupleDesc *resultTupleDesc);
  38 static bool resolve_polymorphic_tupdesc(TupleDesc tupdesc,
  39                                                         oidvector *declared_args,
  40                                                         Node *call_expr);
  41 static TypeFuncClass get_type_func_class(Oid typid);
  42
  43
  44 /*
  45  * init_MultiFuncCall
  46  * Create an empty FuncCallContext data structure
  47  * and do some other basic Multi-function call setup
  48  * and error checking
  49  */
  50 FuncCallContext *
  51 init_MultiFuncCall(PG_FUNCTION_ARGS)
  52 {
  53         FuncCallContext *retval;
  54
  55         /*
  56          * Bail if we're called in the wrong context
  57          */
  58         if (fcinfo->resultinfo == NULL || !IsA(fcinfo->resultinfo, ReturnSetInfo))
  59                 ereport(ERROR,
  60                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
  61                                  errmsg("set-valued function called in context that cannot accept a set")));
  62
  63         if (fcinfo->flinfo->fn_extra == NULL)
  64         {
  65                 /*
  66                  * First call
  67                  */
  68                 ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
  69                 MemoryContext multi_call_ctx;
  70
  71                 /*
  72                  * Create a suitably long-lived context to hold cross-call data
  73                  */
  74                 multi_call_ctx = AllocSetContextCreate(fcinfo->flinfo->fn_mcxt,
  75                                                                                            "SRF multi-call context",
  76                                                                                            ALLOCSET_SMALL_MINSIZE,
  77                                                                                            ALLOCSET_SMALL_INITSIZE,
  78                                                                                            ALLOCSET_SMALL_MAXSIZE);
  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->slot = NULL;
  93                 retval->user_fctx = NULL;
  94                 retval->attinmeta = NULL;
  95                 retval->tuple_desc = NULL;
  96                 retval->multi_call_memory_ctx = multi_call_ctx;
  97
  98                 /*
  99                  * save the pointer for cross-call use
 100                  */
 101                 fcinfo->flinfo->fn_extra = retval;
 102
 103                 /*
 104                  * Ensure we will get shut down cleanly if the exprcontext is not run
 105                  * to completion.
 106                  */
 107                 RegisterExprContextCallback(rsi->econtext,
 108                                                                         shutdown_MultiFuncCall,
 109                                                                         PointerGetDatum(fcinfo->flinfo));
 110         }
 111         else
 112         {
 113                 /* second and subsequent calls */
 114                 elog(ERROR, "init_MultiFuncCall cannot be called more than once");
 115
 116                 /* never reached, but keep compiler happy */
 117                 retval = NULL;
 118         }
 119
 120         return retval;
 121 }
 122
 123 /*
 124  * per_MultiFuncCall
 125  *
 126  * Do Multi-function per-call setup
 127  */
 128 FuncCallContext *
 129 per_MultiFuncCall(PG_FUNCTION_ARGS)
 130 {
 131         FuncCallContext *retval = (FuncCallContext *) fcinfo->flinfo->fn_extra;
 132
 133         /*
 134          * Clear the TupleTableSlot, if present.  This is for safety's sake: the
 135          * Slot will be in a long-lived context (it better be, if the
 136          * FuncCallContext is pointing to it), but in most usage patterns the
 137          * tuples stored in it will be in the function's per-tuple context. So at
 138          * the beginning of each call, the Slot will hold a dangling pointer to an
 139          * already-recycled tuple.      We clear it out here.
 140          *
 141          * Note: use of retval->slot is obsolete as of 8.0, and we expect that it
 142          * will always be NULL.  This is just here for backwards compatibility in
 143          * case someone creates a slot anyway.
 144          */
 145         if (retval->slot != NULL)
 146                 ExecClearTuple(retval->slot);
 147
 148         return retval;
 149 }
 150
 151 /*
 152  * end_MultiFuncCall
 153  * Clean up after init_MultiFuncCall
 154  */
 155 void
 156 end_MultiFuncCall(PG_FUNCTION_ARGS, FuncCallContext *funcctx)
 157 {
 158         ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
 159
 160         /* Deregister the shutdown callback */
 161         UnregisterExprContextCallback(rsi->econtext,
 162                                                                   shutdown_MultiFuncCall,
 163                                                                   PointerGetDatum(fcinfo->flinfo));
 164
 165         /* But use it to do the real work */
 166         shutdown_MultiFuncCall(PointerGetDatum(fcinfo->flinfo));
 167 }
 168
 169 /*
 170  * shutdown_MultiFuncCall
 171  * Shutdown function to clean up after init_MultiFuncCall
 172  */
 173 static void
 174 shutdown_MultiFuncCall(Datum arg)
 175 {
 176         FmgrInfo   *flinfo = (FmgrInfo *) DatumGetPointer(arg);
 177         FuncCallContext *funcctx = (FuncCallContext *) flinfo->fn_extra;
 178
 179         /* unbind from flinfo */
 180         flinfo->fn_extra = NULL;
 181
 182         /*
 183          * Delete context that holds all multi-call data, including the
 184          * FuncCallContext itself
 185          */
 186         MemoryContextDelete(funcctx->multi_call_memory_ctx);
 187 }
 188
 189
 190 /*
 191  * get_call_result_type
 192  *              Given a function's call info record, determine the kind of datatype
 193  *              it is supposed to return.  If resultTypeId isn't NULL, *resultTypeId
 194  *              receives the actual datatype OID (this is mainly useful for scalar
 195  *              result types).  If resultTupleDesc isn't NULL, *resultTupleDesc
 196  *              receives a pointer to a TupleDesc when the result is of a composite
 197  *              type, or NULL when it's a scalar result.
 198  *
 199  * One hard case that this handles is resolution of actual rowtypes for
 200  * functions returning RECORD (from either the function's OUT parameter
 201  * list, or a ReturnSetInfo context node).      TYPEFUNC_RECORD is returned
 202  * only when we couldn't resolve the actual rowtype for lack of information.
 203  *
 204  * The other hard case that this handles is resolution of polymorphism.
 205  * We will never return polymorphic pseudotypes (ANYELEMENT etc), either
 206  * as a scalar result type or as a component of a rowtype.
 207  *
 208  * This function is relatively expensive --- in a function returning set,
 209  * try to call it only the first time through.
 210  */
 211 TypeFuncClass
 212 get_call_result_type(FunctionCallInfo fcinfo,
 213                                          Oid *resultTypeId,
 214                                          TupleDesc *resultTupleDesc)
 215 {
 216         return internal_get_result_type(fcinfo->flinfo->fn_oid,
 217                                                                         fcinfo->flinfo->fn_expr,
 218                                                                         (ReturnSetInfo *) fcinfo->resultinfo,
 219                                                                         resultTypeId,
 220                                                                         resultTupleDesc);
 221 }
 222
 223 /*
 224  * get_expr_result_type
 225  *              As above, but work from a calling expression node tree
 226  */
 227 TypeFuncClass
 228 get_expr_result_type(Node *expr,
 229                                          Oid *resultTypeId,
 230                                          TupleDesc *resultTupleDesc)
 231 {
 232         TypeFuncClass result;
 233
 234         if (expr && IsA(expr, FuncExpr))
 235                 result = internal_get_result_type(((FuncExpr *) expr)->funcid,
 236                                                                                   expr,
 237                                                                                   NULL,
 238                                                                                   resultTypeId,
 239                                                                                   resultTupleDesc);
 240         else if (expr && IsA(expr, OpExpr))
 241                 result = internal_get_result_type(get_opcode(((OpExpr *) expr)->opno),
 242                                                                                   expr,
 243                                                                                   NULL,
 244                                                                                   resultTypeId,
 245                                                                                   resultTupleDesc);
 246         else
 247         {
 248                 /* handle as a generic expression; no chance to resolve RECORD */
 249                 Oid                     typid = exprType(expr);
 250
 251                 if (resultTypeId)
 252                         *resultTypeId = typid;
 253                 if (resultTupleDesc)
 254                         *resultTupleDesc = NULL;
 255                 result = get_type_func_class(typid);
 256                 if (result == TYPEFUNC_COMPOSITE && resultTupleDesc)
 257                         *resultTupleDesc = lookup_rowtype_tupdesc_copy(typid, -1);
 258         }
 259
 260         return result;
 261 }
 262
 263 /*
 264  * get_func_result_type
 265  *              As above, but work from a function's OID only
 266  *
 267  * This will not be able to resolve pure-RECORD results nor polymorphism.
 268  */
 269 TypeFuncClass
 270 get_func_result_type(Oid functionId,
 271                                          Oid *resultTypeId,
 272                                          TupleDesc *resultTupleDesc)
 273 {
 274         return internal_get_result_type(functionId,
 275                                                                         NULL,
 276                                                                         NULL,
 277                                                                         resultTypeId,
 278                                                                         resultTupleDesc);
 279 }
 280
 281 /*
 282  * internal_get_result_type -- workhorse code implementing all the above
 283  *
 284  * funcid must always be supplied.      call_expr and rsinfo can be NULL if not
 285  * available.  We will return TYPEFUNC_RECORD, and store NULL into
 286  * *resultTupleDesc, if we cannot deduce the complete result rowtype from
 287  * the available information.
 288  */
 289 static TypeFuncClass
 290 internal_get_result_type(Oid funcid,
 291                                                  Node *call_expr,
 292                                                  ReturnSetInfo *rsinfo,
 293                                                  Oid *resultTypeId,
 294                                                  TupleDesc *resultTupleDesc)
 295 {
 296         TypeFuncClass result;
 297         HeapTuple       tp;
 298         Form_pg_proc procform;
 299         Oid                     rettype;
 300         TupleDesc       tupdesc;
 301
 302         /* First fetch the function's pg_proc row to inspect its rettype */
 303         tp = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
 304         if (!HeapTupleIsValid(tp))
 305                 elog(ERROR, "cache lookup failed for function %u", funcid);
 306         procform = (Form_pg_proc) GETSTRUCT(tp);
 307
 308         rettype = procform->prorettype;
 309
 310         /* Check for OUT parameters defining a RECORD result */
 311         tupdesc = build_function_result_tupdesc_t(tp);
 312         if (tupdesc)
 313         {
 314                 /*
 315                  * It has OUT parameters, so it's basically like a regular composite
 316                  * type, except we have to be able to resolve any polymorphic OUT
 317                  * parameters.
 318                  */
 319                 if (resultTypeId)
 320                         *resultTypeId = rettype;
 321
 322                 if (resolve_polymorphic_tupdesc(tupdesc,
 323                                                                                 &procform->proargtypes,
 324                                                                                 call_expr))
 325                 {
 326                         if (tupdesc->tdtypeid == RECORDOID &&
 327                                 tupdesc->tdtypmod < 0)
 328                                 assign_record_type_typmod(tupdesc);
 329                         if (resultTupleDesc)
 330                                 *resultTupleDesc = tupdesc;
 331                         result = TYPEFUNC_COMPOSITE;
 332                 }
 333                 else
 334                 {
 335                         if (resultTupleDesc)
 336                                 *resultTupleDesc = NULL;
 337                         result = TYPEFUNC_RECORD;
 338                 }
 339
 340                 ReleaseSysCache(tp);
 341
 342                 return result;
 343         }
 344
 345         /*
 346          * If scalar polymorphic result, try to resolve it.
 347          */
 348         if (IsPolymorphicType(rettype))
 349         {
 350                 Oid                     newrettype = exprType(call_expr);
 351
 352                 if (newrettype == InvalidOid)   /* this probably should not happen */
 353                         ereport(ERROR,
 354                                         (errcode(ERRCODE_DATATYPE_MISMATCH),
 355                                          errmsg("could not determine actual result type for function \"%s\" declared to return type %s",
 356                                                         NameStr(procform->proname),
 357                                                         format_type_be(rettype))));
 358                 rettype = newrettype;
 359         }
 360
 361         if (resultTypeId)
 362                 *resultTypeId = rettype;
 363         if (resultTupleDesc)
 364                 *resultTupleDesc = NULL;        /* default result */
 365
 366         /* Classify the result type */
 367         result = get_type_func_class(rettype);
 368         switch (result)
 369         {
 370                 case TYPEFUNC_COMPOSITE:
 371                         if (resultTupleDesc)
 372                                 *resultTupleDesc = lookup_rowtype_tupdesc_copy(rettype, -1);
 373                         /* Named composite types can't have any polymorphic columns */
 374                         break;
 375                 case TYPEFUNC_SCALAR:
 376                         break;
 377                 case TYPEFUNC_RECORD:
 378                         /* We must get the tupledesc from call context */
 379                         if (rsinfo && IsA(rsinfo, ReturnSetInfo) &&
 380                                 rsinfo->expectedDesc != NULL)
 381                         {
 382                                 result = TYPEFUNC_COMPOSITE;
 383                                 if (resultTupleDesc)
 384                                         *resultTupleDesc = rsinfo->expectedDesc;
 385                                 /* Assume no polymorphic columns here, either */
 386                         }
 387                         break;
 388                 default:
 389                         break;
 390         }
 391
 392         ReleaseSysCache(tp);
 393
 394         return result;
 395 }
 396
 397 /*
 398  * Given the result tuple descriptor for a function with OUT parameters,
 399  * replace any polymorphic columns (ANYELEMENT etc) with correct data types
 400  * deduced from the input arguments. Returns TRUE if able to deduce all types,
 401  * FALSE if not.
 402  */
 403 static bool
 404 resolve_polymorphic_tupdesc(TupleDesc tupdesc, oidvector *declared_args,
 405                                                         Node *call_expr)
 406 {
 407         int                     natts = tupdesc->natts;
 408         int                     nargs = declared_args->dim1;
 409         bool            have_anyelement_result = false;
 410         bool            have_anyarray_result = false;
 411         bool            have_anyrange_result = false;
 412         bool            have_anynonarray = false;
 413         bool            have_anyenum = false;
 414         Oid                     anyelement_type = InvalidOid;
 415         Oid                     anyarray_type = InvalidOid;
 416         Oid                     anyrange_type = InvalidOid;
 417         Oid                     anycollation = InvalidOid;
 418         int                     i;
 419
 420         /* See if there are any polymorphic outputs; quick out if not */
 421         for (i = 0; i < natts; i++)
 422         {
 423                 switch (tupdesc->attrs[i]->atttypid)
 424                 {
 425                         case ANYELEMENTOID:
 426                                 have_anyelement_result = true;
 427                                 break;
 428                         case ANYARRAYOID:
 429                                 have_anyarray_result = true;
 430                                 break;
 431                         case ANYNONARRAYOID:
 432                                 have_anyelement_result = true;
 433                                 have_anynonarray = true;
 434                                 break;
 435                         case ANYENUMOID:
 436                                 have_anyelement_result = true;
 437                                 have_anyenum = true;
 438                                 break;
 439                         case ANYRANGEOID:
 440                                 have_anyrange_result = true;
 441                                 break;
 442                         default:
 443                                 break;
 444                 }
 445         }
 446         if (!have_anyelement_result && !have_anyarray_result &&
 447                 !have_anyrange_result)
 448                 return true;
 449
 450         /*
 451          * Otherwise, extract actual datatype(s) from input arguments.  (We assume
 452          * the parser already validated consistency of the arguments.)
 453          */
 454         if (!call_expr)
 455                 return false;                   /* no hope */
 456
 457         for (i = 0; i < nargs; i++)
 458         {
 459                 switch (declared_args->values[i])
 460                 {
 461                         case ANYELEMENTOID:
 462                         case ANYNONARRAYOID:
 463                         case ANYENUMOID:
 464                                 if (!OidIsValid(anyelement_type))
 465                                         anyelement_type = get_call_expr_argtype(call_expr, i);
 466                                 break;
 467                         case ANYARRAYOID:
 468                                 if (!OidIsValid(anyarray_type))
 469                                         anyarray_type = get_call_expr_argtype(call_expr, i);
 470                                 break;
 471                         case ANYRANGEOID:
 472                                 if (!OidIsValid(anyrange_type))
 473                                         anyrange_type = get_call_expr_argtype(call_expr, i);
 474                                 break;
 475                         default:
 476                                 break;
 477                 }
 478         }
 479
 480         /* If nothing found, parser messed up */
 481         if (!OidIsValid(anyelement_type) && !OidIsValid(anyarray_type) &&
 482                 !OidIsValid(anyrange_type))
 483                 return false;
 484
 485         /* If needed, deduce one polymorphic type from others */
 486         if (have_anyelement_result && !OidIsValid(anyelement_type))
 487         {
 488                 if (OidIsValid(anyarray_type))
 489                         anyelement_type = resolve_generic_type(ANYELEMENTOID,
 490                                                                                                    anyarray_type,
 491                                                                                                    ANYARRAYOID);
 492                 if (OidIsValid(anyrange_type))
 493                 {
 494                         Oid                     subtype = resolve_generic_type(ANYELEMENTOID,
 495                                                                                                            anyrange_type,
 496                                                                                                            ANYRANGEOID);
 497
 498                         /* check for inconsistent array and range results */
 499                         if (OidIsValid(anyelement_type) && anyelement_type != subtype)
 500                                 return false;
 501                         anyelement_type = subtype;
 502                 }
 503         }
 504
 505         if (have_anyarray_result && !OidIsValid(anyarray_type))
 506                 anyarray_type = resolve_generic_type(ANYARRAYOID,
 507                                                                                          anyelement_type,
 508                                                                                          ANYELEMENTOID);
 509
 510         /*
 511          * We can't deduce a range type from other polymorphic inputs, because
 512          * there may be multiple range types for the same subtype.
 513          */
 514         if (have_anyrange_result && !OidIsValid(anyrange_type))
 515                 return false;
 516
 517         /* Enforce ANYNONARRAY if needed */
 518         if (have_anynonarray && type_is_array(anyelement_type))
 519                 return false;
 520
 521         /* Enforce ANYENUM if needed */
 522         if (have_anyenum && !type_is_enum(anyelement_type))
 523                 return false;
 524
 525         /*
 526          * Identify the collation to use for polymorphic OUT parameters. (It'll
 527          * necessarily be the same for both anyelement and anyarray.)  Note that
 528          * range types are not collatable, so any possible internal collation of a
 529          * range type is not considered here.
 530          */
 531         if (OidIsValid(anyelement_type))
 532                 anycollation = get_typcollation(anyelement_type);
 533         else if (OidIsValid(anyarray_type))
 534                 anycollation = get_typcollation(anyarray_type);
 535
 536         if (OidIsValid(anycollation))
 537         {
 538                 /*
 539                  * The types are collatable, so consider whether to use a nondefault
 540                  * collation.  We do so if we can identify the input collation used
 541                  * for the function.
 542                  */
 543                 Oid                     inputcollation = exprInputCollation(call_expr);
 544
 545                 if (OidIsValid(inputcollation))
 546                         anycollation = inputcollation;
 547         }
 548
 549         /* And finally replace the tuple column types as needed */
 550         for (i = 0; i < natts; i++)
 551         {
 552                 switch (tupdesc->attrs[i]->atttypid)
 553                 {
 554                         case ANYELEMENTOID:
 555                         case ANYNONARRAYOID:
 556                         case ANYENUMOID:
 557                                 TupleDescInitEntry(tupdesc, i + 1,
 558                                                                    NameStr(tupdesc->attrs[i]->attname),
 559                                                                    anyelement_type,
 560                                                                    -1,
 561                                                                    0);
 562                                 TupleDescInitEntryCollation(tupdesc, i + 1, anycollation);
 563                                 break;
 564                         case ANYARRAYOID:
 565                                 TupleDescInitEntry(tupdesc, i + 1,
 566                                                                    NameStr(tupdesc->attrs[i]->attname),
 567                                                                    anyarray_type,
 568                                                                    -1,
 569                                                                    0);
 570                                 TupleDescInitEntryCollation(tupdesc, i + 1, anycollation);
 571                                 break;
 572                         case ANYRANGEOID:
 573                                 TupleDescInitEntry(tupdesc, i + 1,
 574                                                                    NameStr(tupdesc->attrs[i]->attname),
 575                                                                    anyrange_type,
 576                                                                    -1,
 577                                                                    0);
 578                                 /* no collation should be attached to a range type */
 579                                 break;
 580                         default:
 581                                 break;
 582                 }
 583         }
 584
 585         return true;
 586 }
 587
 588 /*
 589  * Given the declared argument types and modes for a function, replace any
 590  * polymorphic types (ANYELEMENT etc) with correct data types deduced from the
 591  * input arguments.  Returns TRUE if able to deduce all types, FALSE if not.
 592  * This is the same logic as resolve_polymorphic_tupdesc, but with a different
 593  * argument representation.
 594  *
 595  * argmodes may be NULL, in which case all arguments are assumed to be IN mode.
 596  */
 597 bool
 598 resolve_polymorphic_argtypes(int numargs, Oid *argtypes, char *argmodes,
 599                                                          Node *call_expr)
 600 {
 601         bool            have_anyelement_result = false;
 602         bool            have_anyarray_result = false;
 603         bool            have_anyrange_result = false;
 604         Oid                     anyelement_type = InvalidOid;
 605         Oid                     anyarray_type = InvalidOid;
 606         Oid                     anyrange_type = InvalidOid;
 607         int                     inargno;
 608         int                     i;
 609
 610         /* First pass: resolve polymorphic inputs, check for outputs */
 611         inargno = 0;
 612         for (i = 0; i < numargs; i++)
 613         {
 614                 char            argmode = argmodes ? argmodes[i] : PROARGMODE_IN;
 615
 616                 switch (argtypes[i])
 617                 {
 618                         case ANYELEMENTOID:
 619                         case ANYNONARRAYOID:
 620                         case ANYENUMOID:
 621                                 if (argmode == PROARGMODE_OUT || argmode == PROARGMODE_TABLE)
 622                                         have_anyelement_result = true;
 623                                 else
 624                                 {
 625                                         if (!OidIsValid(anyelement_type))
 626                                         {
 627                                                 anyelement_type = get_call_expr_argtype(call_expr,
 628                                                                                                                                 inargno);
 629                                                 if (!OidIsValid(anyelement_type))
 630                                                         return false;
 631                                         }
 632                                         argtypes[i] = anyelement_type;
 633                                 }
 634                                 break;
 635                         case ANYARRAYOID:
 636                                 if (argmode == PROARGMODE_OUT || argmode == PROARGMODE_TABLE)
 637                                         have_anyarray_result = true;
 638                                 else
 639                                 {
 640                                         if (!OidIsValid(anyarray_type))
 641                                         {
 642                                                 anyarray_type = get_call_expr_argtype(call_expr,
 643                                                                                                                           inargno);
 644                                                 if (!OidIsValid(anyarray_type))
 645                                                         return false;
 646                                         }
 647                                         argtypes[i] = anyarray_type;
 648                                 }
 649                                 break;
 650                         case ANYRANGEOID:
 651                                 if (argmode == PROARGMODE_OUT || argmode == PROARGMODE_TABLE)
 652                                         have_anyrange_result = true;
 653                                 else
 654                                 {
 655                                         if (!OidIsValid(anyrange_type))
 656                                         {
 657                                                 anyrange_type = get_call_expr_argtype(call_expr,
 658                                                                                                                           inargno);
 659                                                 if (!OidIsValid(anyrange_type))
 660                                                         return false;
 661                                         }
 662                                         argtypes[i] = anyrange_type;
 663                                 }
 664                                 break;
 665                         default:
 666                                 break;
 667                 }
 668                 if (argmode != PROARGMODE_OUT && argmode != PROARGMODE_TABLE)
 669                         inargno++;
 670         }
 671
 672         /* Done? */
 673         if (!have_anyelement_result && !have_anyarray_result &&
 674                 !have_anyrange_result)
 675                 return true;
 676
 677         /* If no input polymorphics, parser messed up */
 678         if (!OidIsValid(anyelement_type) && !OidIsValid(anyarray_type) &&
 679                 !OidIsValid(anyrange_type))
 680                 return false;
 681
 682         /* If needed, deduce one polymorphic type from others */
 683         if (have_anyelement_result && !OidIsValid(anyelement_type))
 684         {
 685                 if (OidIsValid(anyarray_type))
 686                         anyelement_type = resolve_generic_type(ANYELEMENTOID,
 687                                                                                                    anyarray_type,
 688                                                                                                    ANYARRAYOID);
 689                 if (OidIsValid(anyrange_type))
 690                 {
 691                         Oid                     subtype = resolve_generic_type(ANYELEMENTOID,
 692                                                                                                            anyrange_type,
 693                                                                                                            ANYRANGEOID);
 694
 695                         /* check for inconsistent array and range results */
 696                         if (OidIsValid(anyelement_type) && anyelement_type != subtype)
 697                                 return false;
 698                         anyelement_type = subtype;
 699                 }
 700         }
 701
 702         if (have_anyarray_result && !OidIsValid(anyarray_type))
 703                 anyarray_type = resolve_generic_type(ANYARRAYOID,
 704                                                                                          anyelement_type,
 705                                                                                          ANYELEMENTOID);
 706
 707         /*
 708          * We can't deduce a range type from other polymorphic inputs, because
 709          * there may be multiple range types for the same subtype.
 710          */
 711         if (have_anyrange_result && !OidIsValid(anyrange_type))
 712                 return false;
 713
 714         /* XXX do we need to enforce ANYNONARRAY or ANYENUM here?  I think not */
 715
 716         /* And finally replace the output column types as needed */
 717         for (i = 0; i < numargs; i++)
 718         {
 719                 switch (argtypes[i])
 720                 {
 721                         case ANYELEMENTOID:
 722                         case ANYNONARRAYOID:
 723                         case ANYENUMOID:
 724                                 argtypes[i] = anyelement_type;
 725                                 break;
 726                         case ANYARRAYOID:
 727                                 argtypes[i] = anyarray_type;
 728                                 break;
 729                         case ANYRANGEOID:
 730                                 argtypes[i] = anyrange_type;
 731                                 break;
 732                         default:
 733                                 break;
 734                 }
 735         }
 736
 737         return true;
 738 }
 739
 740 /*
 741  * get_type_func_class
 742  *              Given the type OID, obtain its TYPEFUNC classification.
 743  *
 744  * This is intended to centralize a bunch of formerly ad-hoc code for
 745  * classifying types.  The categories used here are useful for deciding
 746  * how to handle functions returning the datatype.
 747  */
 748 static TypeFuncClass
 749 get_type_func_class(Oid typid)
 750 {
 751         switch (get_typtype(typid))
 752         {
 753                 case TYPTYPE_COMPOSITE:
 754                         return TYPEFUNC_COMPOSITE;
 755                 case TYPTYPE_BASE:
 756                 case TYPTYPE_DOMAIN:
 757                 case TYPTYPE_ENUM:
 758                 case TYPTYPE_RANGE:
 759                         return TYPEFUNC_SCALAR;
 760                 case TYPTYPE_PSEUDO:
 761                         if (typid == RECORDOID)
 762                                 return TYPEFUNC_RECORD;
 763
 764                         /*
 765                          * We treat VOID and CSTRING as legitimate scalar datatypes,
 766                          * mostly for the convenience of the JDBC driver (which wants to
 767                          * be able to do "SELECT * FROM foo()" for all legitimately
 768                          * user-callable functions).
 769                          */
 770                         if (typid == VOIDOID || typid == CSTRINGOID)
 771                                 return TYPEFUNC_SCALAR;
 772                         return TYPEFUNC_OTHER;
 773         }
 774         /* shouldn't get here, probably */
 775         return TYPEFUNC_OTHER;
 776 }
 777
 778
 779 /*
 780  * get_func_arg_info
 781  *
 782  * Fetch info about the argument types, names, and IN/OUT modes from the
 783  * pg_proc tuple.  Return value is the total number of arguments.
 784  * Other results are palloc'd.  *p_argtypes is always filled in, but
 785  * *p_argnames and *p_argmodes will be set NULL in the default cases
 786  * (no names, and all IN arguments, respectively).
 787  *
 788  * Note that this function simply fetches what is in the pg_proc tuple;
 789  * it doesn't do any interpretation of polymorphic types.
 790  */
 791 int
 792 get_func_arg_info(HeapTuple procTup,
 793                                   Oid **p_argtypes, char ***p_argnames, char **p_argmodes)
 794 {
 795         Form_pg_proc procStruct = (Form_pg_proc) GETSTRUCT(procTup);
 796         Datum           proallargtypes;
 797         Datum           proargmodes;
 798         Datum           proargnames;
 799         bool            isNull;
 800         ArrayType  *arr;
 801         int                     numargs;
 802         Datum      *elems;
 803         int                     nelems;
 804         int                     i;
 805
 806         /* First discover the total number of parameters and get their types */
 807         proallargtypes = SysCacheGetAttr(PROCOID, procTup,
 808                                                                          Anum_pg_proc_proallargtypes,
 809                                                                          &isNull);
 810         if (!isNull)
 811         {
 812                 /*
 813                  * We expect the arrays to be 1-D arrays of the right types; verify
 814                  * that.  For the OID and char arrays, we don't need to use
 815                  * deconstruct_array() since the array data is just going to look like
 816                  * a C array of values.
 817                  */
 818                 arr = DatumGetArrayTypeP(proallargtypes);               /* ensure not toasted */
 819                 numargs = ARR_DIMS(arr)[0];
 820                 if (ARR_NDIM(arr) != 1 ||
 821                         numargs < 0 ||
 822                         ARR_HASNULL(arr) ||
 823                         ARR_ELEMTYPE(arr) != OIDOID)
 824                         elog(ERROR, "proallargtypes is not a 1-D Oid array");
 825                 Assert(numargs >= procStruct->pronargs);
 826                 *p_argtypes = (Oid *) palloc(numargs * sizeof(Oid));
 827                 memcpy(*p_argtypes, ARR_DATA_PTR(arr),
 828                            numargs * sizeof(Oid));
 829         }
 830         else
 831         {
 832                 /* If no proallargtypes, use proargtypes */
 833                 numargs = procStruct->proargtypes.dim1;
 834                 Assert(numargs == procStruct->pronargs);
 835                 *p_argtypes = (Oid *) palloc(numargs * sizeof(Oid));
 836                 memcpy(*p_argtypes, procStruct->proargtypes.values,
 837                            numargs * sizeof(Oid));
 838         }
 839
 840         /* Get argument names, if available */
 841         proargnames = SysCacheGetAttr(PROCOID, procTup,
 842                                                                   Anum_pg_proc_proargnames,
 843                                                                   &isNull);
 844         if (isNull)
 845                 *p_argnames = NULL;
 846         else
 847         {
 848                 deconstruct_array(DatumGetArrayTypeP(proargnames),
 849                                                   TEXTOID, -1, false, 'i',
 850                                                   &elems, NULL, &nelems);
 851                 if (nelems != numargs)  /* should not happen */
 852                         elog(ERROR, "proargnames must have the same number of elements as the function has arguments");
 853                 *p_argnames = (char **) palloc(sizeof(char *) * numargs);
 854                 for (i = 0; i < numargs; i++)
 855                         (*p_argnames)[i] = TextDatumGetCString(elems[i]);
 856         }
 857
 858         /* Get argument modes, if available */
 859         proargmodes = SysCacheGetAttr(PROCOID, procTup,
 860                                                                   Anum_pg_proc_proargmodes,
 861                                                                   &isNull);
 862         if (isNull)
 863                 *p_argmodes = NULL;
 864         else
 865         {
 866                 arr = DatumGetArrayTypeP(proargmodes);  /* ensure not toasted */
 867                 if (ARR_NDIM(arr) != 1 ||
 868                         ARR_DIMS(arr)[0] != numargs ||
 869                         ARR_HASNULL(arr) ||
 870                         ARR_ELEMTYPE(arr) != CHAROID)
 871                         elog(ERROR, "proargmodes is not a 1-D char array");
 872                 *p_argmodes = (char *) palloc(numargs * sizeof(char));
 873                 memcpy(*p_argmodes, ARR_DATA_PTR(arr),
 874                            numargs * sizeof(char));
 875         }
 876
 877         return numargs;
 878 }
 879
 880
 881 /*
 882  * get_func_input_arg_names
 883  *
 884  * Extract the names of input arguments only, given a function's
 885  * proargnames and proargmodes entries in Datum form.
 886  *
 887  * Returns the number of input arguments, which is the length of the
 888  * palloc'd array returned to *arg_names.  Entries for unnamed args
 889  * are set to NULL.  You don't get anything if proargnames is NULL.
 890  */
 891 int
 892 get_func_input_arg_names(Datum proargnames, Datum proargmodes,
 893                                                  char ***arg_names)
 894 {
 895         ArrayType  *arr;
 896         int                     numargs;
 897         Datum      *argnames;
 898         char       *argmodes;
 899         char      **inargnames;
 900         int                     numinargs;
 901         int                     i;
 902
 903         /* Do nothing if null proargnames */
 904         if (proargnames == PointerGetDatum(NULL))
 905         {
 906                 *arg_names = NULL;
 907                 return 0;
 908         }
 909
 910         /*
 911          * We expect the arrays to be 1-D arrays of the right types; verify that.
 912          * For proargmodes, we don't need to use deconstruct_array() since the
 913          * array data is just going to look like a C array of values.
 914          */
 915         arr = DatumGetArrayTypeP(proargnames);          /* ensure not toasted */
 916         if (ARR_NDIM(arr) != 1 ||
 917                 ARR_HASNULL(arr) ||
 918                 ARR_ELEMTYPE(arr) != TEXTOID)
 919                 elog(ERROR, "proargnames is not a 1-D text array");
 920         deconstruct_array(arr, TEXTOID, -1, false, 'i',
 921                                           &argnames, NULL, &numargs);
 922         if (proargmodes != PointerGetDatum(NULL))
 923         {
 924                 arr = DatumGetArrayTypeP(proargmodes);  /* ensure not toasted */
 925                 if (ARR_NDIM(arr) != 1 ||
 926                         ARR_DIMS(arr)[0] != numargs ||
 927                         ARR_HASNULL(arr) ||
 928                         ARR_ELEMTYPE(arr) != CHAROID)
 929                         elog(ERROR, "proargmodes is not a 1-D char array");
 930                 argmodes = (char *) ARR_DATA_PTR(arr);
 931         }
 932         else
 933                 argmodes = NULL;
 934
 935         /* zero elements probably shouldn't happen, but handle it gracefully */
 936         if (numargs <= 0)
 937         {
 938                 *arg_names = NULL;
 939                 return 0;
 940         }
 941
 942         /* extract input-argument names */
 943         inargnames = (char **) palloc(numargs * sizeof(char *));
 944         numinargs = 0;
 945         for (i = 0; i < numargs; i++)
 946         {
 947                 if (argmodes == NULL ||
 948                         argmodes[i] == PROARGMODE_IN ||
 949                         argmodes[i] == PROARGMODE_INOUT ||
 950                         argmodes[i] == PROARGMODE_VARIADIC)
 951                 {
 952                         char       *pname = TextDatumGetCString(argnames[i]);
 953
 954                         if (pname[0] != '\0')
 955                                 inargnames[numinargs] = pname;
 956                         else
 957                                 inargnames[numinargs] = NULL;
 958                         numinargs++;
 959                 }
 960         }
 961
 962         *arg_names = inargnames;
 963         return numinargs;
 964 }
 965
 966
 967 /*
 968  * get_func_result_name
 969  *
 970  * If the function has exactly one output parameter, and that parameter
 971  * is named, return the name (as a palloc'd string).  Else return NULL.
 972  *
 973  * This is used to determine the default output column name for functions
 974  * returning scalar types.
 975  */
 976 char *
 977 get_func_result_name(Oid functionId)
 978 {
 979         char       *result;
 980         HeapTuple       procTuple;
 981         Datum           proargmodes;
 982         Datum           proargnames;
 983         bool            isnull;
 984         ArrayType  *arr;
 985         int                     numargs;
 986         char       *argmodes;
 987         Datum      *argnames;
 988         int                     numoutargs;
 989         int                     nargnames;
 990         int                     i;
 991
 992         /* First fetch the function's pg_proc row */
 993         procTuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(functionId));
 994         if (!HeapTupleIsValid(procTuple))
 995                 elog(ERROR, "cache lookup failed for function %u", functionId);
 996
 997         /* If there are no named OUT parameters, return NULL */
 998         if (heap_attisnull(procTuple, Anum_pg_proc_proargmodes) ||
 999                 heap_attisnull(procTuple, Anum_pg_proc_proargnames))
1000                 result = NULL;
1001         else
1002         {
1003                 /* Get the data out of the tuple */
1004                 proargmodes = SysCacheGetAttr(PROCOID, procTuple,
1005                                                                           Anum_pg_proc_proargmodes,
1006                                                                           &isnull);
1007                 Assert(!isnull);
1008                 proargnames = SysCacheGetAttr(PROCOID, procTuple,
1009                                                                           Anum_pg_proc_proargnames,
1010                                                                           &isnull);
1011                 Assert(!isnull);
1012
1013                 /*
1014                  * We expect the arrays to be 1-D arrays of the right types; verify
1015                  * that.  For the char array, we don't need to use deconstruct_array()
1016                  * since the array data is just going to look like a C array of
1017                  * values.
1018                  */
1019                 arr = DatumGetArrayTypeP(proargmodes);  /* ensure not toasted */
1020                 numargs = ARR_DIMS(arr)[0];
1021                 if (ARR_NDIM(arr) != 1 ||
1022                         numargs < 0 ||
1023                         ARR_HASNULL(arr) ||
1024                         ARR_ELEMTYPE(arr) != CHAROID)
1025                         elog(ERROR, "proargmodes is not a 1-D char array");
1026                 argmodes = (char *) ARR_DATA_PTR(arr);
1027                 arr = DatumGetArrayTypeP(proargnames);  /* ensure not toasted */
1028                 if (ARR_NDIM(arr) != 1 ||
1029                         ARR_DIMS(arr)[0] != numargs ||
1030                         ARR_HASNULL(arr) ||
1031                         ARR_ELEMTYPE(arr) != TEXTOID)
1032                         elog(ERROR, "proargnames is not a 1-D text array");
1033                 deconstruct_array(arr, TEXTOID, -1, false, 'i',
1034                                                   &argnames, NULL, &nargnames);
1035                 Assert(nargnames == numargs);
1036
1037                 /* scan for output argument(s) */
1038                 result = NULL;
1039                 numoutargs = 0;
1040                 for (i = 0; i < numargs; i++)
1041                 {
1042                         if (argmodes[i] == PROARGMODE_IN ||
1043                                 argmodes[i] == PROARGMODE_VARIADIC)
1044                                 continue;
1045                         Assert(argmodes[i] == PROARGMODE_OUT ||
1046                                    argmodes[i] == PROARGMODE_INOUT ||
1047                                    argmodes[i] == PROARGMODE_TABLE);
1048                         if (++numoutargs > 1)
1049                         {
1050                                 /* multiple out args, so forget it */
1051                                 result = NULL;
1052                                 break;
1053                         }
1054                         result = TextDatumGetCString(argnames[i]);
1055                         if (result == NULL || result[0] == '\0')
1056                         {
1057                                 /* Parameter is not named, so forget it */
1058                                 result = NULL;
1059                                 break;
1060                         }
1061                 }
1062         }
1063
1064         ReleaseSysCache(procTuple);
1065
1066         return result;
1067 }
1068
1069
1070 /*
1071  * build_function_result_tupdesc_t
1072  *
1073  * Given a pg_proc row for a function, return a tuple descriptor for the
1074  * result rowtype, or NULL if the function does not have OUT parameters.
1075  *
1076  * Note that this does not handle resolution of polymorphic types;
1077  * that is deliberate.
1078  */
1079 TupleDesc
1080 build_function_result_tupdesc_t(HeapTuple procTuple)
1081 {
1082         Form_pg_proc procform = (Form_pg_proc) GETSTRUCT(procTuple);
1083         Datum           proallargtypes;
1084         Datum           proargmodes;
1085         Datum           proargnames;
1086         bool            isnull;
1087
1088         /* Return NULL if the function isn't declared to return RECORD */
1089         if (procform->prorettype != RECORDOID)
1090                 return NULL;
1091
1092         /* If there are no OUT parameters, return NULL */
1093         if (heap_attisnull(procTuple, Anum_pg_proc_proallargtypes) ||
1094                 heap_attisnull(procTuple, Anum_pg_proc_proargmodes))
1095                 return NULL;
1096
1097         /* Get the data out of the tuple */
1098         proallargtypes = SysCacheGetAttr(PROCOID, procTuple,
1099                                                                          Anum_pg_proc_proallargtypes,
1100                                                                          &isnull);
1101         Assert(!isnull);
1102         proargmodes = SysCacheGetAttr(PROCOID, procTuple,
1103                                                                   Anum_pg_proc_proargmodes,
1104                                                                   &isnull);
1105         Assert(!isnull);
1106         proargnames = SysCacheGetAttr(PROCOID, procTuple,
1107                                                                   Anum_pg_proc_proargnames,
1108                                                                   &isnull);
1109         if (isnull)
1110                 proargnames = PointerGetDatum(NULL);    /* just to be sure */
1111
1112         return build_function_result_tupdesc_d(proallargtypes,
1113                                                                                    proargmodes,
1114                                                                                    proargnames);
1115 }
1116
1117 /*
1118  * build_function_result_tupdesc_d
1119  *
1120  * Build a RECORD function's tupledesc from the pg_proc proallargtypes,
1121  * proargmodes, and proargnames arrays.  This is split out for the
1122  * convenience of ProcedureCreate, which needs to be able to compute the
1123  * tupledesc before actually creating the function.
1124  *
1125  * Returns NULL if there are not at least two OUT or INOUT arguments.
1126  */
1127 TupleDesc
1128 build_function_result_tupdesc_d(Datum proallargtypes,
1129                                                                 Datum proargmodes,
1130                                                                 Datum proargnames)
1131 {
1132         TupleDesc       desc;
1133         ArrayType  *arr;
1134         int                     numargs;
1135         Oid                *argtypes;
1136         char       *argmodes;
1137         Datum      *argnames = NULL;
1138         Oid                *outargtypes;
1139         char      **outargnames;
1140         int                     numoutargs;
1141         int                     nargnames;
1142         int                     i;
1143
1144         /* Can't have output args if columns are null */
1145         if (proallargtypes == PointerGetDatum(NULL) ||
1146                 proargmodes == PointerGetDatum(NULL))
1147                 return NULL;
1148
1149         /*
1150          * We expect the arrays to be 1-D arrays of the right types; verify that.
1151          * For the OID and char arrays, we don't need to use deconstruct_array()
1152          * since the array data is just going to look like a C array of values.
1153          */
1154         arr = DatumGetArrayTypeP(proallargtypes);       /* ensure not toasted */
1155         numargs = ARR_DIMS(arr)[0];
1156         if (ARR_NDIM(arr) != 1 ||
1157                 numargs < 0 ||
1158                 ARR_HASNULL(arr) ||
1159                 ARR_ELEMTYPE(arr) != OIDOID)
1160                 elog(ERROR, "proallargtypes is not a 1-D Oid array");
1161         argtypes = (Oid *) ARR_DATA_PTR(arr);
1162         arr = DatumGetArrayTypeP(proargmodes);          /* ensure not toasted */
1163         if (ARR_NDIM(arr) != 1 ||
1164                 ARR_DIMS(arr)[0] != numargs ||
1165                 ARR_HASNULL(arr) ||
1166                 ARR_ELEMTYPE(arr) != CHAROID)
1167                 elog(ERROR, "proargmodes is not a 1-D char array");
1168         argmodes = (char *) ARR_DATA_PTR(arr);
1169         if (proargnames != PointerGetDatum(NULL))
1170         {
1171                 arr = DatumGetArrayTypeP(proargnames);  /* ensure not toasted */
1172                 if (ARR_NDIM(arr) != 1 ||
1173                         ARR_DIMS(arr)[0] != numargs ||
1174                         ARR_HASNULL(arr) ||
1175                         ARR_ELEMTYPE(arr) != TEXTOID)
1176                         elog(ERROR, "proargnames is not a 1-D text array");
1177                 deconstruct_array(arr, TEXTOID, -1, false, 'i',
1178                                                   &argnames, NULL, &nargnames);
1179                 Assert(nargnames == numargs);
1180         }
1181
1182         /* zero elements probably shouldn't happen, but handle it gracefully */
1183         if (numargs <= 0)
1184                 return NULL;
1185
1186         /* extract output-argument types and names */
1187         outargtypes = (Oid *) palloc(numargs * sizeof(Oid));
1188         outargnames = (char **) palloc(numargs * sizeof(char *));
1189         numoutargs = 0;
1190         for (i = 0; i < numargs; i++)
1191         {
1192                 char       *pname;
1193
1194                 if (argmodes[i] == PROARGMODE_IN ||
1195                         argmodes[i] == PROARGMODE_VARIADIC)
1196                         continue;
1197                 Assert(argmodes[i] == PROARGMODE_OUT ||
1198                            argmodes[i] == PROARGMODE_INOUT ||
1199                            argmodes[i] == PROARGMODE_TABLE);
1200                 outargtypes[numoutargs] = argtypes[i];
1201                 if (argnames)
1202                         pname = TextDatumGetCString(argnames[i]);
1203                 else
1204                         pname = NULL;
1205                 if (pname == NULL || pname[0] == '\0')
1206                 {
1207                         /* Parameter is not named, so gin up a column name */
1208                         pname = psprintf("column%d", numoutargs + 1);
1209                 }
1210                 outargnames[numoutargs] = pname;
1211                 numoutargs++;
1212         }
1213
1214         /*
1215          * If there is no output argument, or only one, the function does not
1216          * return tuples.
1217          */
1218         if (numoutargs < 2)
1219                 return NULL;
1220
1221         desc = CreateTemplateTupleDesc(numoutargs, false);
1222         for (i = 0; i < numoutargs; i++)
1223         {
1224                 TupleDescInitEntry(desc, i + 1,
1225                                                    outargnames[i],
1226                                                    outargtypes[i],
1227                                                    -1,
1228                                                    0);
1229         }
1230
1231         return desc;
1232 }
1233
1234
1235 /*
1236  * RelationNameGetTupleDesc
1237  *
1238  * Given a (possibly qualified) relation name, build a TupleDesc.
1239  *
1240  * Note: while this works as advertised, it's seldom the best way to
1241  * build a tupdesc for a function's result type.  It's kept around
1242  * only for backwards compatibility with existing user-written code.
1243  */
1244 TupleDesc
1245 RelationNameGetTupleDesc(const char *relname)
1246 {
1247         RangeVar   *relvar;
1248         Relation        rel;
1249         TupleDesc       tupdesc;
1250         List       *relname_list;
1251
1252         /* Open relation and copy the tuple description */
1253         relname_list = stringToQualifiedNameList(relname);
1254         relvar = makeRangeVarFromNameList(relname_list);
1255         rel = relation_openrv(relvar, AccessShareLock);
1256         tupdesc = CreateTupleDescCopy(RelationGetDescr(rel));
1257         relation_close(rel, AccessShareLock);
1258
1259         return tupdesc;
1260 }
1261
1262 /*
1263  * TypeGetTupleDesc
1264  *
1265  * Given a type Oid, build a TupleDesc.  (In most cases you should be
1266  * using get_call_result_type or one of its siblings instead of this
1267  * routine, so that you can handle OUT parameters, RECORD result type,
1268  * and polymorphic results.)
1269  *
1270  * If the type is composite, *and* a colaliases List is provided, *and*
1271  * the List is of natts length, use the aliases instead of the relation
1272  * attnames.  (NB: this usage is deprecated since it may result in
1273  * creation of unnecessary transient record types.)
1274  *
1275  * If the type is a base type, a single item alias List is required.
1276  */
1277 TupleDesc
1278 TypeGetTupleDesc(Oid typeoid, List *colaliases)
1279 {
1280         TypeFuncClass functypclass = get_type_func_class(typeoid);
1281         TupleDesc       tupdesc = NULL;
1282
1283         /*
1284          * Build a suitable tupledesc representing the output rows
1285          */
1286         if (functypclass == TYPEFUNC_COMPOSITE)
1287         {
1288                 /* Composite data type, e.g. a table's row type */
1289                 tupdesc = lookup_rowtype_tupdesc_copy(typeoid, -1);
1290
1291                 if (colaliases != NIL)
1292                 {
1293                         int                     natts = tupdesc->natts;
1294                         int                     varattno;
1295
1296                         /* does the list length match the number of attributes? */
1297                         if (list_length(colaliases) != natts)
1298                                 ereport(ERROR,
1299                                                 (errcode(ERRCODE_DATATYPE_MISMATCH),
1300                                                  errmsg("number of aliases does not match number of columns")));
1301
1302                         /* OK, use the aliases instead */
1303                         for (varattno = 0; varattno < natts; varattno++)
1304                         {
1305                                 char       *label = strVal(list_nth(colaliases, varattno));
1306
1307                                 if (label != NULL)
1308                                         namestrcpy(&(tupdesc->attrs[varattno]->attname), label);
1309                         }
1310
1311                         /* The tuple type is now an anonymous record type */
1312                         tupdesc->tdtypeid = RECORDOID;
1313                         tupdesc->tdtypmod = -1;
1314                 }
1315         }
1316         else if (functypclass == TYPEFUNC_SCALAR)
1317         {
1318                 /* Base data type, i.e. scalar */
1319                 char       *attname;
1320
1321                 /* the alias list is required for base types */
1322                 if (colaliases == NIL)
1323                         ereport(ERROR,
1324                                         (errcode(ERRCODE_DATATYPE_MISMATCH),
1325                                          errmsg("no column alias was provided")));
1326
1327                 /* the alias list length must be 1 */
1328                 if (list_length(colaliases) != 1)
1329                         ereport(ERROR,
1330                                         (errcode(ERRCODE_DATATYPE_MISMATCH),
1331                           errmsg("number of aliases does not match number of columns")));
1332
1333                 /* OK, get the column alias */
1334                 attname = strVal(linitial(colaliases));
1335
1336                 tupdesc = CreateTemplateTupleDesc(1, false);
1337                 TupleDescInitEntry(tupdesc,
1338                                                    (AttrNumber) 1,
1339                                                    attname,
1340                                                    typeoid,
1341                                                    -1,
1342                                                    0);
1343         }
1344         else if (functypclass == TYPEFUNC_RECORD)
1345         {
1346                 /* XXX can't support this because typmod wasn't passed in ... */
1347                 ereport(ERROR,
1348                                 (errcode(ERRCODE_DATATYPE_MISMATCH),
1349                                  errmsg("could not determine row description for function returning record")));
1350         }
1351         else
1352         {
1353                 /* crummy error message, but parser should have caught this */
1354                 elog(ERROR, "function in FROM has unsupported return type");
1355         }
1356
1357         return tupdesc;
1358 }