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) 2002-2017, 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/regproc.h"
  28 #include "utils/rel.h"
  29 #include "utils/syscache.h"
  30 #include "utils/typcache.h"
  31
  32
  33 static void shutdown_MultiFuncCall(Datum arg);
  34 static TypeFuncClass internal_get_result_type(Oid funcid,
  35                                                  Node *call_expr,
  36                                                  ReturnSetInfo *rsinfo,
  37                                                  Oid *resultTypeId,
  38                                                  TupleDesc *resultTupleDesc);
  39 static bool resolve_polymorphic_tupdesc(TupleDesc tupdesc,
  40                                                         oidvector *declared_args,
  41                                                         Node *call_expr);
  42 static TypeFuncClass get_type_func_class(Oid typid);
  43
  44
  45 /*
  46  * init_MultiFuncCall
  47  * Create an empty FuncCallContext data structure
  48  * and do some other basic Multi-function call setup
  49  * and error checking
  50  */
  51 FuncCallContext *
  52 init_MultiFuncCall(PG_FUNCTION_ARGS)
  53 {
  54         FuncCallContext *retval;
  55
  56         /*
  57          * Bail if we're called in the wrong context
  58          */
  59         if (fcinfo->resultinfo == NULL || !IsA(fcinfo->resultinfo, ReturnSetInfo))
  60                 ereport(ERROR,
  61                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
  62                                  errmsg("set-valued function called in context that cannot accept a set")));
  63
  64         if (fcinfo->flinfo->fn_extra == NULL)
  65         {
  66                 /*
  67                  * First call
  68                  */
  69                 ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
  70                 MemoryContext multi_call_ctx;
  71
  72                 /*
  73                  * Create a suitably long-lived context to hold cross-call data
  74                  */
  75                 multi_call_ctx = AllocSetContextCreate(fcinfo->flinfo->fn_mcxt,
  76                                                                                            "SRF multi-call context",
  77                                                                                            ALLOCSET_SMALL_SIZES);
  78
  79                 /*
  80                  * Allocate suitably long-lived space and zero it
  81                  */
  82                 retval = (FuncCallContext *)
  83                         MemoryContextAllocZero(multi_call_ctx,
  84                                                                    sizeof(FuncCallContext));
  85
  86                 /*
  87                  * initialize the elements
  88                  */
  89                 retval->call_cntr = 0;
  90                 retval->max_calls = 0;
  91                 retval->slot = NULL;
  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  */
 127 FuncCallContext *
 128 per_MultiFuncCall(PG_FUNCTION_ARGS)
 129 {
 130         FuncCallContext *retval = (FuncCallContext *) fcinfo->flinfo->fn_extra;
 131
 132         /*
 133          * Clear the TupleTableSlot, if present.  This is for safety's sake: the
 134          * Slot will be in a long-lived context (it better be, if the
 135          * FuncCallContext is pointing to it), but in most usage patterns the
 136          * tuples stored in it will be in the function's per-tuple context. So at
 137          * the beginning of each call, the Slot will hold a dangling pointer to an
 138          * already-recycled tuple.  We clear it out here.
 139          *
 140          * Note: use of retval->slot is obsolete as of 8.0, and we expect that it
 141          * will always be NULL.  This is just here for backwards compatibility in
 142          * case someone creates a slot anyway.
 143          */
 144         if (retval->slot != NULL)
 145                 ExecClearTuple(retval->slot);
 146
 147         return retval;
 148 }
 149
 150 /*
 151  * end_MultiFuncCall
 152  * Clean up after init_MultiFuncCall
 153  */
 154 void
 155 end_MultiFuncCall(PG_FUNCTION_ARGS, FuncCallContext *funcctx)
 156 {
 157         ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
 158
 159         /* Deregister the shutdown callback */
 160         UnregisterExprContextCallback(rsi->econtext,
 161                                                                   shutdown_MultiFuncCall,
 162                                                                   PointerGetDatum(fcinfo->flinfo));
 163
 164         /* But use it to do the real work */
 165         shutdown_MultiFuncCall(PointerGetDatum(fcinfo->flinfo));
 166 }
 167
 168 /*
 169  * shutdown_MultiFuncCall
 170  * Shutdown function to clean up after init_MultiFuncCall
 171  */
 172 static void
 173 shutdown_MultiFuncCall(Datum arg)
 174 {
 175         FmgrInfo   *flinfo = (FmgrInfo *) DatumGetPointer(arg);
 176         FuncCallContext *funcctx = (FuncCallContext *) flinfo->fn_extra;
 177
 178         /* unbind from flinfo */
 179         flinfo->fn_extra = NULL;
 180
 181         /*
 182          * Delete context that holds all multi-call data, including the
 183          * FuncCallContext itself
 184          */
 185         MemoryContextDelete(funcctx->multi_call_memory_ctx);
 186 }
 187
 188
 189 /*
 190  * get_call_result_type
 191  *              Given a function's call info record, determine the kind of datatype
 192  *              it is supposed to return.  If resultTypeId isn't NULL, *resultTypeId
 193  *              receives the actual datatype OID (this is mainly useful for scalar
 194  *              result types).  If resultTupleDesc isn't NULL, *resultTupleDesc
 195  *              receives a pointer to a TupleDesc when the result is of a composite
 196  *              type, or NULL when it's a scalar result.
 197  *
 198  * One hard case that this handles is resolution of actual rowtypes for
 199  * functions returning RECORD (from either the function's OUT parameter
 200  * list, or a ReturnSetInfo context node).  TYPEFUNC_RECORD is returned
 201  * only when we couldn't resolve the actual rowtype for lack of information.
 202  *
 203  * The other hard case that this handles is resolution of polymorphism.
 204  * We will never return polymorphic pseudotypes (ANYELEMENT etc), either
 205  * as a scalar result type or as a component of a rowtype.
 206  *
 207  * This function is relatively expensive --- in a function returning set,
 208  * try to call it only the first time through.
 209  */
 210 TypeFuncClass
 211 get_call_result_type(FunctionCallInfo fcinfo,
 212                                          Oid *resultTypeId,
 213                                          TupleDesc *resultTupleDesc)
 214 {
 215         return internal_get_result_type(fcinfo->flinfo->fn_oid,
 216                                                                         fcinfo->flinfo->fn_expr,
 217                                                                         (ReturnSetInfo *) fcinfo->resultinfo,
 218                                                                         resultTypeId,
 219                                                                         resultTupleDesc);
 220 }
 221
 222 /*
 223  * get_expr_result_type
 224  *              As above, but work from a calling expression node tree
 225  */
 226 TypeFuncClass
 227 get_expr_result_type(Node *expr,
 228                                          Oid *resultTypeId,
 229                                          TupleDesc *resultTupleDesc)
 230 {
 231         TypeFuncClass result;
 232
 233         if (expr && IsA(expr, FuncExpr))
 234                 result = internal_get_result_type(((FuncExpr *) expr)->funcid,
 235                                                                                   expr,
 236                                                                                   NULL,
 237                                                                                   resultTypeId,
 238                                                                                   resultTupleDesc);
 239         else if (expr && IsA(expr, OpExpr))
 240                 result = internal_get_result_type(get_opcode(((OpExpr *) expr)->opno),
 241                                                                                   expr,
 242                                                                                   NULL,
 243                                                                                   resultTypeId,
 244                                                                                   resultTupleDesc);
 245         else
 246         {
 247                 /* handle as a generic expression; no chance to resolve RECORD */
 248                 Oid                     typid = exprType(expr);
 249
 250                 if (resultTypeId)
 251                         *resultTypeId = typid;
 252                 if (resultTupleDesc)
 253                         *resultTupleDesc = NULL;
 254                 result = get_type_func_class(typid);
 255                 if (result == TYPEFUNC_COMPOSITE && resultTupleDesc)
 256                         *resultTupleDesc = lookup_rowtype_tupdesc_copy(typid, -1);
 257         }
 258
 259         return result;
 260 }
 261
 262 /*
 263  * get_func_result_type
 264  *              As above, but work from a function's OID only
 265  *
 266  * This will not be able to resolve pure-RECORD results nor polymorphism.
 267  */
 268 TypeFuncClass
 269 get_func_result_type(Oid functionId,
 270                                          Oid *resultTypeId,
 271                                          TupleDesc *resultTupleDesc)
 272 {
 273         return internal_get_result_type(functionId,
 274                                                                         NULL,
 275                                                                         NULL,
 276                                                                         resultTypeId,
 277                                                                         resultTupleDesc);
 278 }
 279
 280 /*
 281  * internal_get_result_type -- workhorse code implementing all the above
 282  *
 283  * funcid must always be supplied.  call_expr and rsinfo can be NULL if not
 284  * available.  We will return TYPEFUNC_RECORD, and store NULL into
 285  * *resultTupleDesc, if we cannot deduce the complete result rowtype from
 286  * the available information.
 287  */
 288 static TypeFuncClass
 289 internal_get_result_type(Oid funcid,
 290                                                  Node *call_expr,
 291                                                  ReturnSetInfo *rsinfo,
 292                                                  Oid *resultTypeId,
 293                                                  TupleDesc *resultTupleDesc)
 294 {
 295         TypeFuncClass result;
 296         HeapTuple       tp;
 297         Form_pg_proc procform;
 298         Oid                     rettype;
 299         TupleDesc       tupdesc;
 300
 301         /* First fetch the function's pg_proc row to inspect its rettype */
 302         tp = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
 303         if (!HeapTupleIsValid(tp))
 304                 elog(ERROR, "cache lookup failed for function %u", funcid);
 305         procform = (Form_pg_proc) GETSTRUCT(tp);
 306
 307         rettype = procform->prorettype;
 308
 309         /* Check for OUT parameters defining a RECORD result */
 310         tupdesc = build_function_result_tupdesc_t(tp);
 311         if (tupdesc)
 312         {
 313                 /*
 314                  * It has OUT parameters, so it's basically like a regular composite
 315                  * type, except we have to be able to resolve any polymorphic OUT
 316                  * parameters.
 317                  */
 318                 if (resultTypeId)
 319                         *resultTypeId = rettype;
 320
 321                 if (resolve_polymorphic_tupdesc(tupdesc,
 322                                                                                 &procform->proargtypes,
 323                                                                                 call_expr))
 324                 {
 325                         if (tupdesc->tdtypeid == RECORDOID &&
 326                                 tupdesc->tdtypmod < 0)
 327                                 assign_record_type_typmod(tupdesc);
 328                         if (resultTupleDesc)
 329                                 *resultTupleDesc = tupdesc;
 330                         result = TYPEFUNC_COMPOSITE;
 331                 }
 332                 else
 333                 {
 334                         if (resultTupleDesc)
 335                                 *resultTupleDesc = NULL;
 336                         result = TYPEFUNC_RECORD;
 337                 }
 338
 339                 ReleaseSysCache(tp);
 340
 341                 return result;
 342         }
 343
 344         /*
 345          * If scalar polymorphic result, try to resolve it.
 346          */
 347         if (IsPolymorphicType(rettype))
 348         {
 349                 Oid                     newrettype = exprType(call_expr);
 350
 351                 if (newrettype == InvalidOid)   /* this probably should not happen */
 352                         ereport(ERROR,
 353                                         (errcode(ERRCODE_DATATYPE_MISMATCH),
 354                                          errmsg("could not determine actual result type for function \"%s\" declared to return type %s",
 355                                                         NameStr(procform->proname),
 356                                                         format_type_be(rettype))));
 357                 rettype = newrettype;
 358         }
 359
 360         if (resultTypeId)
 361                 *resultTypeId = rettype;
 362         if (resultTupleDesc)
 363                 *resultTupleDesc = NULL;        /* default result */
 364
 365         /* Classify the result type */
 366         result = get_type_func_class(rettype);
 367         switch (result)
 368         {
 369                 case TYPEFUNC_COMPOSITE:
 370                         if (resultTupleDesc)
 371                                 *resultTupleDesc = lookup_rowtype_tupdesc_copy(rettype, -1);
 372                         /* Named composite types can't have any polymorphic columns */
 373                         break;
 374                 case TYPEFUNC_SCALAR:
 375                         break;
 376                 case TYPEFUNC_RECORD:
 377                         /* We must get the tupledesc from call context */
 378                         if (rsinfo && IsA(rsinfo, ReturnSetInfo) &&
 379                                 rsinfo->expectedDesc != NULL)
 380                         {
 381                                 result = TYPEFUNC_COMPOSITE;
 382                                 if (resultTupleDesc)
 383                                         *resultTupleDesc = rsinfo->expectedDesc;
 384                                 /* Assume no polymorphic columns here, either */
 385                         }
 386                         break;
 387                 default:
 388                         break;
 389         }
 390
 391         ReleaseSysCache(tp);
 392
 393         return result;
 394 }
 395
 396 /*
 397  * Given the result tuple descriptor for a function with OUT parameters,
 398  * replace any polymorphic columns (ANYELEMENT etc) with correct data types
 399  * deduced from the input arguments. Returns TRUE if able to deduce all types,
 400  * FALSE if not.
 401  */
 402 static bool
 403 resolve_polymorphic_tupdesc(TupleDesc tupdesc, oidvector *declared_args,
 404                                                         Node *call_expr)
 405 {
 406         int                     natts = tupdesc->natts;
 407         int                     nargs = declared_args->dim1;
 408         bool            have_anyelement_result = false;
 409         bool            have_anyarray_result = false;
 410         bool            have_anyrange_result = false;
 411         bool            have_anynonarray = false;
 412         bool            have_anyenum = false;
 413         Oid                     anyelement_type = InvalidOid;
 414         Oid                     anyarray_type = InvalidOid;
 415         Oid                     anyrange_type = InvalidOid;
 416         Oid                     anycollation = InvalidOid;
 417         int                     i;
 418
 419         /* See if there are any polymorphic outputs; quick out if not */
 420         for (i = 0; i < natts; i++)
 421         {
 422                 switch (tupdesc->attrs[i]->atttypid)
 423                 {
 424                         case ANYELEMENTOID:
 425                                 have_anyelement_result = true;
 426                                 break;
 427                         case ANYARRAYOID:
 428                                 have_anyarray_result = true;
 429                                 break;
 430                         case ANYNONARRAYOID:
 431                                 have_anyelement_result = true;
 432                                 have_anynonarray = true;
 433                                 break;
 434                         case ANYENUMOID:
 435                                 have_anyelement_result = true;
 436                                 have_anyenum = true;
 437                                 break;
 438                         case ANYRANGEOID:
 439                                 have_anyrange_result = true;
 440                                 break;
 441                         default:
 442                                 break;
 443                 }
 444         }
 445         if (!have_anyelement_result && !have_anyarray_result &&
 446                 !have_anyrange_result)
 447                 return true;
 448
 449         /*
 450          * Otherwise, extract actual datatype(s) from input arguments.  (We assume
 451          * the parser already validated consistency of the arguments.)
 452          */
 453         if (!call_expr)
 454                 return false;                   /* no hope */
 455
 456         for (i = 0; i < nargs; i++)
 457         {
 458                 switch (declared_args->values[i])
 459                 {
 460                         case ANYELEMENTOID:
 461                         case ANYNONARRAYOID:
 462                         case ANYENUMOID:
 463                                 if (!OidIsValid(anyelement_type))
 464                                         anyelement_type = get_call_expr_argtype(call_expr, i);
 465                                 break;
 466                         case ANYARRAYOID:
 467                                 if (!OidIsValid(anyarray_type))
 468                                         anyarray_type = get_call_expr_argtype(call_expr, i);
 469                                 break;
 470                         case ANYRANGEOID:
 471                                 if (!OidIsValid(anyrange_type))
 472                                         anyrange_type = get_call_expr_argtype(call_expr, i);
 473                                 break;
 474                         default:
 475                                 break;
 476                 }
 477         }
 478
 479         /* If nothing found, parser messed up */
 480         if (!OidIsValid(anyelement_type) && !OidIsValid(anyarray_type) &&
 481                 !OidIsValid(anyrange_type))
 482                 return false;
 483
 484         /* If needed, deduce one polymorphic type from others */
 485         if (have_anyelement_result && !OidIsValid(anyelement_type))
 486         {
 487                 if (OidIsValid(anyarray_type))
 488                         anyelement_type = resolve_generic_type(ANYELEMENTOID,
 489                                                                                                    anyarray_type,
 490                                                                                                    ANYARRAYOID);
 491                 if (OidIsValid(anyrange_type))
 492                 {
 493                         Oid                     subtype = resolve_generic_type(ANYELEMENTOID,
 494                                                                                                            anyrange_type,
 495                                                                                                            ANYRANGEOID);
 496
 497                         /* check for inconsistent array and range results */
 498                         if (OidIsValid(anyelement_type) && anyelement_type != subtype)
 499                                 return false;
 500                         anyelement_type = subtype;
 501                 }
 502         }
 503
 504         if (have_anyarray_result && !OidIsValid(anyarray_type))
 505                 anyarray_type = resolve_generic_type(ANYARRAYOID,
 506                                                                                          anyelement_type,
 507                                                                                          ANYELEMENTOID);
 508
 509         /*
 510          * We can't deduce a range type from other polymorphic inputs, because
 511          * there may be multiple range types for the same subtype.
 512          */
 513         if (have_anyrange_result && !OidIsValid(anyrange_type))
 514                 return false;
 515
 516         /* Enforce ANYNONARRAY if needed */
 517         if (have_anynonarray && type_is_array(anyelement_type))
 518                 return false;
 519
 520         /* Enforce ANYENUM if needed */
 521         if (have_anyenum && !type_is_enum(anyelement_type))
 522                 return false;
 523
 524         /*
 525          * Identify the collation to use for polymorphic OUT parameters. (It'll
 526          * necessarily be the same for both anyelement and anyarray.)  Note that
 527          * range types are not collatable, so any possible internal collation of a
 528          * range type is not considered here.
 529          */
 530         if (OidIsValid(anyelement_type))
 531                 anycollation = get_typcollation(anyelement_type);
 532         else if (OidIsValid(anyarray_type))
 533                 anycollation = get_typcollation(anyarray_type);
 534
 535         if (OidIsValid(anycollation))
 536         {
 537                 /*
 538                  * The types are collatable, so consider whether to use a nondefault
 539                  * collation.  We do so if we can identify the input collation used
 540                  * for the function.
 541                  */
 542                 Oid                     inputcollation = exprInputCollation(call_expr);
 543
 544                 if (OidIsValid(inputcollation))
 545                         anycollation = inputcollation;
 546         }
 547
 548         /* And finally replace the tuple column types as needed */
 549         for (i = 0; i < natts; i++)
 550         {
 551                 switch (tupdesc->attrs[i]->atttypid)
 552                 {
 553                         case ANYELEMENTOID:
 554                         case ANYNONARRAYOID:
 555                         case ANYENUMOID:
 556                                 TupleDescInitEntry(tupdesc, i + 1,
 557                                                                    NameStr(tupdesc->attrs[i]->attname),
 558                                                                    anyelement_type,
 559                                                                    -1,
 560                                                                    0);
 561                                 TupleDescInitEntryCollation(tupdesc, i + 1, anycollation);
 562                                 break;
 563                         case ANYARRAYOID:
 564                                 TupleDescInitEntry(tupdesc, i + 1,
 565                                                                    NameStr(tupdesc->attrs[i]->attname),
 566                                                                    anyarray_type,
 567                                                                    -1,
 568                                                                    0);
 569                                 TupleDescInitEntryCollation(tupdesc, i + 1, anycollation);
 570                                 break;
 571                         case ANYRANGEOID:
 572                                 TupleDescInitEntry(tupdesc, i + 1,
 573                                                                    NameStr(tupdesc->attrs[i]->attname),
 574                                                                    anyrange_type,
 575                                                                    -1,
 576                                                                    0);
 577                                 /* no collation should be attached to a range type */
 578                                 break;
 579                         default:
 580                                 break;
 581                 }
 582         }
 583
 584         return true;
 585 }
 586
 587 /*
 588  * Given the declared argument types and modes for a function, replace any
 589  * polymorphic types (ANYELEMENT etc) with correct data types deduced from the
 590  * input arguments.  Returns TRUE if able to deduce all types, FALSE if not.
 591  * This is the same logic as resolve_polymorphic_tupdesc, but with a different
 592  * argument representation.
 593  *
 594  * argmodes may be NULL, in which case all arguments are assumed to be IN mode.
 595  */
 596 bool
 597 resolve_polymorphic_argtypes(int numargs, Oid *argtypes, char *argmodes,
 598                                                          Node *call_expr)
 599 {
 600         bool            have_anyelement_result = false;
 601         bool            have_anyarray_result = false;
 602         bool            have_anyrange_result = false;
 603         Oid                     anyelement_type = InvalidOid;
 604         Oid                     anyarray_type = InvalidOid;
 605         Oid                     anyrange_type = InvalidOid;
 606         int                     inargno;
 607         int                     i;
 608
 609         /* First pass: resolve polymorphic inputs, check for outputs */
 610         inargno = 0;
 611         for (i = 0; i < numargs; i++)
 612         {
 613                 char            argmode = argmodes ? argmodes[i] : PROARGMODE_IN;
 614
 615                 switch (argtypes[i])
 616                 {
 617                         case ANYELEMENTOID:
 618                         case ANYNONARRAYOID:
 619                         case ANYENUMOID:
 620                                 if (argmode == PROARGMODE_OUT || argmode == PROARGMODE_TABLE)
 621                                         have_anyelement_result = true;
 622                                 else
 623                                 {
 624                                         if (!OidIsValid(anyelement_type))
 625                                         {
 626                                                 anyelement_type = get_call_expr_argtype(call_expr,
 627                                                                                                                                 inargno);
 628                                                 if (!OidIsValid(anyelement_type))
 629                                                         return false;
 630                                         }
 631                                         argtypes[i] = anyelement_type;
 632                                 }
 633                                 break;
 634                         case ANYARRAYOID:
 635                                 if (argmode == PROARGMODE_OUT || argmode == PROARGMODE_TABLE)
 636                                         have_anyarray_result = true;
 637                                 else
 638                                 {
 639                                         if (!OidIsValid(anyarray_type))
 640                                         {
 641                                                 anyarray_type = get_call_expr_argtype(call_expr,
 642                                                                                                                           inargno);
 643                                                 if (!OidIsValid(anyarray_type))
 644                                                         return false;
 645                                         }
 646                                         argtypes[i] = anyarray_type;
 647                                 }
 648                                 break;
 649                         case ANYRANGEOID:
 650                                 if (argmode == PROARGMODE_OUT || argmode == PROARGMODE_TABLE)
 651                                         have_anyrange_result = true;
 652                                 else
 653                                 {
 654                                         if (!OidIsValid(anyrange_type))
 655                                         {
 656                                                 anyrange_type = get_call_expr_argtype(call_expr,
 657                                                                                                                           inargno);
 658                                                 if (!OidIsValid(anyrange_type))
 659                                                         return false;
 660                                         }
 661                                         argtypes[i] = anyrange_type;
 662                                 }
 663                                 break;
 664                         default:
 665                                 break;
 666                 }
 667                 if (argmode != PROARGMODE_OUT && argmode != PROARGMODE_TABLE)
 668                         inargno++;
 669         }
 670
 671         /* Done? */
 672         if (!have_anyelement_result && !have_anyarray_result &&
 673                 !have_anyrange_result)
 674                 return true;
 675
 676         /* If no input polymorphics, parser messed up */
 677         if (!OidIsValid(anyelement_type) && !OidIsValid(anyarray_type) &&
 678                 !OidIsValid(anyrange_type))
 679                 return false;
 680
 681         /* If needed, deduce one polymorphic type from others */
 682         if (have_anyelement_result && !OidIsValid(anyelement_type))
 683         {
 684                 if (OidIsValid(anyarray_type))
 685                         anyelement_type = resolve_generic_type(ANYELEMENTOID,
 686                                                                                                    anyarray_type,
 687                                                                                                    ANYARRAYOID);
 688                 if (OidIsValid(anyrange_type))
 689                 {
 690                         Oid                     subtype = resolve_generic_type(ANYELEMENTOID,
 691                                                                                                            anyrange_type,
 692                                                                                                            ANYRANGEOID);
 693
 694                         /* check for inconsistent array and range results */
 695                         if (OidIsValid(anyelement_type) && anyelement_type != subtype)
 696                                 return false;
 697                         anyelement_type = subtype;
 698                 }
 699         }
 700
 701         if (have_anyarray_result && !OidIsValid(anyarray_type))
 702                 anyarray_type = resolve_generic_type(ANYARRAYOID,
 703                                                                                          anyelement_type,
 704                                                                                          ANYELEMENTOID);
 705
 706         /*
 707          * We can't deduce a range type from other polymorphic inputs, because
 708          * there may be multiple range types for the same subtype.
 709          */
 710         if (have_anyrange_result && !OidIsValid(anyrange_type))
 711                 return false;
 712
 713         /* XXX do we need to enforce ANYNONARRAY or ANYENUM here?  I think not */
 714
 715         /* And finally replace the output column types as needed */
 716         for (i = 0; i < numargs; i++)
 717         {
 718                 switch (argtypes[i])
 719                 {
 720                         case ANYELEMENTOID:
 721                         case ANYNONARRAYOID:
 722                         case ANYENUMOID:
 723                                 argtypes[i] = anyelement_type;
 724                                 break;
 725                         case ANYARRAYOID:
 726                                 argtypes[i] = anyarray_type;
 727                                 break;
 728                         case ANYRANGEOID:
 729                                 argtypes[i] = anyrange_type;
 730                                 break;
 731                         default:
 732                                 break;
 733                 }
 734         }
 735
 736         return true;
 737 }
 738
 739 /*
 740  * get_type_func_class
 741  *              Given the type OID, obtain its TYPEFUNC classification.
 742  *
 743  * This is intended to centralize a bunch of formerly ad-hoc code for
 744  * classifying types.  The categories used here are useful for deciding
 745  * how to handle functions returning the datatype.
 746  */
 747 static TypeFuncClass
 748 get_type_func_class(Oid typid)
 749 {
 750         switch (get_typtype(typid))
 751         {
 752                 case TYPTYPE_COMPOSITE:
 753                         return TYPEFUNC_COMPOSITE;
 754                 case TYPTYPE_BASE:
 755                 case TYPTYPE_DOMAIN:
 756                 case TYPTYPE_ENUM:
 757                 case TYPTYPE_RANGE:
 758                         return TYPEFUNC_SCALAR;
 759                 case TYPTYPE_PSEUDO:
 760                         if (typid == RECORDOID)
 761                                 return TYPEFUNC_RECORD;
 762
 763                         /*
 764                          * We treat VOID and CSTRING as legitimate scalar datatypes,
 765                          * mostly for the convenience of the JDBC driver (which wants to
 766                          * be able to do "SELECT * FROM foo()" for all legitimately
 767                          * user-callable functions).
 768                          */
 769                         if (typid == VOIDOID || typid == CSTRINGOID)
 770                                 return TYPEFUNC_SCALAR;
 771                         return TYPEFUNC_OTHER;
 772         }
 773         /* shouldn't get here, probably */
 774         return TYPEFUNC_OTHER;
 775 }
 776
 777
 778 /*
 779  * get_func_arg_info
 780  *
 781  * Fetch info about the argument types, names, and IN/OUT modes from the
 782  * pg_proc tuple.  Return value is the total number of arguments.
 783  * Other results are palloc'd.  *p_argtypes is always filled in, but
 784  * *p_argnames and *p_argmodes will be set NULL in the default cases
 785  * (no names, and all IN arguments, respectively).
 786  *
 787  * Note that this function simply fetches what is in the pg_proc tuple;
 788  * it doesn't do any interpretation of polymorphic types.
 789  */
 790 int
 791 get_func_arg_info(HeapTuple procTup,
 792                                   Oid **p_argtypes, char ***p_argnames, char **p_argmodes)
 793 {
 794         Form_pg_proc procStruct = (Form_pg_proc) GETSTRUCT(procTup);
 795         Datum           proallargtypes;
 796         Datum           proargmodes;
 797         Datum           proargnames;
 798         bool            isNull;
 799         ArrayType  *arr;
 800         int                     numargs;
 801         Datum      *elems;
 802         int                     nelems;
 803         int                     i;
 804
 805         /* First discover the total number of parameters and get their types */
 806         proallargtypes = SysCacheGetAttr(PROCOID, procTup,
 807                                                                          Anum_pg_proc_proallargtypes,
 808                                                                          &isNull);
 809         if (!isNull)
 810         {
 811                 /*
 812                  * We expect the arrays to be 1-D arrays of the right types; verify
 813                  * that.  For the OID and char arrays, we don't need to use
 814                  * deconstruct_array() since the array data is just going to look like
 815                  * a C array of values.
 816                  */
 817                 arr = DatumGetArrayTypeP(proallargtypes);       /* ensure not toasted */
 818                 numargs = ARR_DIMS(arr)[0];
 819                 if (ARR_NDIM(arr) != 1 ||
 820                         numargs < 0 ||
 821                         ARR_HASNULL(arr) ||
 822                         ARR_ELEMTYPE(arr) != OIDOID)
 823                         elog(ERROR, "proallargtypes is not a 1-D Oid array");
 824                 Assert(numargs >= procStruct->pronargs);
 825                 *p_argtypes = (Oid *) palloc(numargs * sizeof(Oid));
 826                 memcpy(*p_argtypes, ARR_DATA_PTR(arr),
 827                            numargs * sizeof(Oid));
 828         }
 829         else
 830         {
 831                 /* If no proallargtypes, use proargtypes */
 832                 numargs = procStruct->proargtypes.dim1;
 833                 Assert(numargs == procStruct->pronargs);
 834                 *p_argtypes = (Oid *) palloc(numargs * sizeof(Oid));
 835                 memcpy(*p_argtypes, procStruct->proargtypes.values,
 836                            numargs * sizeof(Oid));
 837         }
 838
 839         /* Get argument names, if available */
 840         proargnames = SysCacheGetAttr(PROCOID, procTup,
 841                                                                   Anum_pg_proc_proargnames,
 842                                                                   &isNull);
 843         if (isNull)
 844                 *p_argnames = NULL;
 845         else
 846         {
 847                 deconstruct_array(DatumGetArrayTypeP(proargnames),
 848                                                   TEXTOID, -1, false, 'i',
 849                                                   &elems, NULL, &nelems);
 850                 if (nelems != numargs)  /* should not happen */
 851                         elog(ERROR, "proargnames must have the same number of elements as the function has arguments");
 852                 *p_argnames = (char **) palloc(sizeof(char *) * numargs);
 853                 for (i = 0; i < numargs; i++)
 854                         (*p_argnames)[i] = TextDatumGetCString(elems[i]);
 855         }
 856
 857         /* Get argument modes, if available */
 858         proargmodes = SysCacheGetAttr(PROCOID, procTup,
 859                                                                   Anum_pg_proc_proargmodes,
 860                                                                   &isNull);
 861         if (isNull)
 862                 *p_argmodes = NULL;
 863         else
 864         {
 865                 arr = DatumGetArrayTypeP(proargmodes);  /* ensure not toasted */
 866                 if (ARR_NDIM(arr) != 1 ||
 867                         ARR_DIMS(arr)[0] != numargs ||
 868                         ARR_HASNULL(arr) ||
 869                         ARR_ELEMTYPE(arr) != CHAROID)
 870                         elog(ERROR, "proargmodes is not a 1-D char array");
 871                 *p_argmodes = (char *) palloc(numargs * sizeof(char));
 872                 memcpy(*p_argmodes, ARR_DATA_PTR(arr),
 873                            numargs * sizeof(char));
 874         }
 875
 876         return numargs;
 877 }
 878
 879 /*
 880  * get_func_trftypes
 881  *
 882  * Returns the number of transformed types used by function.
 883  */
 884 int
 885 get_func_trftypes(HeapTuple procTup,
 886                                   Oid **p_trftypes)
 887 {
 888         Datum           protrftypes;
 889         ArrayType  *arr;
 890         int                     nelems;
 891         bool            isNull;
 892
 893         protrftypes = SysCacheGetAttr(PROCOID, procTup,
 894                                                                   Anum_pg_proc_protrftypes,
 895                                                                   &isNull);
 896         if (!isNull)
 897         {
 898                 /*
 899                  * We expect the arrays to be 1-D arrays of the right types; verify
 900                  * that.  For the OID and char arrays, we don't need to use
 901                  * deconstruct_array() since the array data is just going to look like
 902                  * a C array of values.
 903                  */
 904                 arr = DatumGetArrayTypeP(protrftypes);  /* ensure not toasted */
 905                 nelems = ARR_DIMS(arr)[0];
 906                 if (ARR_NDIM(arr) != 1 ||
 907                         nelems < 0 ||
 908                         ARR_HASNULL(arr) ||
 909                         ARR_ELEMTYPE(arr) != OIDOID)
 910                         elog(ERROR, "protrftypes is not a 1-D Oid array");
 911                 Assert(nelems >= ((Form_pg_proc) GETSTRUCT(procTup))->pronargs);
 912                 *p_trftypes = (Oid *) palloc(nelems * sizeof(Oid));
 913                 memcpy(*p_trftypes, ARR_DATA_PTR(arr),
 914                            nelems * sizeof(Oid));
 915
 916                 return nelems;
 917         }
 918         else
 919                 return 0;
 920 }
 921
 922 /*
 923  * get_func_input_arg_names
 924  *
 925  * Extract the names of input arguments only, given a function's
 926  * proargnames and proargmodes entries in Datum form.
 927  *
 928  * Returns the number of input arguments, which is the length of the
 929  * palloc'd array returned to *arg_names.  Entries for unnamed args
 930  * are set to NULL.  You don't get anything if proargnames is NULL.
 931  */
 932 int
 933 get_func_input_arg_names(Datum proargnames, Datum proargmodes,
 934                                                  char ***arg_names)
 935 {
 936         ArrayType  *arr;
 937         int                     numargs;
 938         Datum      *argnames;
 939         char       *argmodes;
 940         char      **inargnames;
 941         int                     numinargs;
 942         int                     i;
 943
 944         /* Do nothing if null proargnames */
 945         if (proargnames == PointerGetDatum(NULL))
 946         {
 947                 *arg_names = NULL;
 948                 return 0;
 949         }
 950
 951         /*
 952          * We expect the arrays to be 1-D arrays of the right types; verify that.
 953          * For proargmodes, we don't need to use deconstruct_array() since the
 954          * array data is just going to look like a C array of values.
 955          */
 956         arr = DatumGetArrayTypeP(proargnames);  /* ensure not toasted */
 957         if (ARR_NDIM(arr) != 1 ||
 958                 ARR_HASNULL(arr) ||
 959                 ARR_ELEMTYPE(arr) != TEXTOID)
 960                 elog(ERROR, "proargnames is not a 1-D text array");
 961         deconstruct_array(arr, TEXTOID, -1, false, 'i',
 962                                           &argnames, NULL, &numargs);
 963         if (proargmodes != PointerGetDatum(NULL))
 964         {
 965                 arr = DatumGetArrayTypeP(proargmodes);  /* ensure not toasted */
 966                 if (ARR_NDIM(arr) != 1 ||
 967                         ARR_DIMS(arr)[0] != numargs ||
 968                         ARR_HASNULL(arr) ||
 969                         ARR_ELEMTYPE(arr) != CHAROID)
 970                         elog(ERROR, "proargmodes is not a 1-D char array");
 971                 argmodes = (char *) ARR_DATA_PTR(arr);
 972         }
 973         else
 974                 argmodes = NULL;
 975
 976         /* zero elements probably shouldn't happen, but handle it gracefully */
 977         if (numargs <= 0)
 978         {
 979                 *arg_names = NULL;
 980                 return 0;
 981         }
 982
 983         /* extract input-argument names */
 984         inargnames = (char **) palloc(numargs * sizeof(char *));
 985         numinargs = 0;
 986         for (i = 0; i < numargs; i++)
 987         {
 988                 if (argmodes == NULL ||
 989                         argmodes[i] == PROARGMODE_IN ||
 990                         argmodes[i] == PROARGMODE_INOUT ||
 991                         argmodes[i] == PROARGMODE_VARIADIC)
 992                 {
 993                         char       *pname = TextDatumGetCString(argnames[i]);
 994
 995                         if (pname[0] != '\0')
 996                                 inargnames[numinargs] = pname;
 997                         else
 998                                 inargnames[numinargs] = NULL;
 999                         numinargs++;
1000                 }
1001         }
1002
1003         *arg_names = inargnames;
1004         return numinargs;
1005 }
1006
1007
1008 /*
1009  * get_func_result_name
1010  *
1011  * If the function has exactly one output parameter, and that parameter
1012  * is named, return the name (as a palloc'd string).  Else return NULL.
1013  *
1014  * This is used to determine the default output column name for functions
1015  * returning scalar types.
1016  */
1017 char *
1018 get_func_result_name(Oid functionId)
1019 {
1020         char       *result;
1021         HeapTuple       procTuple;
1022         Datum           proargmodes;
1023         Datum           proargnames;
1024         bool            isnull;
1025         ArrayType  *arr;
1026         int                     numargs;
1027         char       *argmodes;
1028         Datum      *argnames;
1029         int                     numoutargs;
1030         int                     nargnames;
1031         int                     i;
1032
1033         /* First fetch the function's pg_proc row */
1034         procTuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(functionId));
1035         if (!HeapTupleIsValid(procTuple))
1036                 elog(ERROR, "cache lookup failed for function %u", functionId);
1037
1038         /* If there are no named OUT parameters, return NULL */
1039         if (heap_attisnull(procTuple, Anum_pg_proc_proargmodes) ||
1040                 heap_attisnull(procTuple, Anum_pg_proc_proargnames))
1041                 result = NULL;
1042         else
1043         {
1044                 /* Get the data out of the tuple */
1045                 proargmodes = SysCacheGetAttr(PROCOID, procTuple,
1046                                                                           Anum_pg_proc_proargmodes,
1047                                                                           &isnull);
1048                 Assert(!isnull);
1049                 proargnames = SysCacheGetAttr(PROCOID, procTuple,
1050                                                                           Anum_pg_proc_proargnames,
1051                                                                           &isnull);
1052                 Assert(!isnull);
1053
1054                 /*
1055                  * We expect the arrays to be 1-D arrays of the right types; verify
1056                  * that.  For the char array, we don't need to use deconstruct_array()
1057                  * since the array data is just going to look like a C array of
1058                  * values.
1059                  */
1060                 arr = DatumGetArrayTypeP(proargmodes);  /* ensure not toasted */
1061                 numargs = ARR_DIMS(arr)[0];
1062                 if (ARR_NDIM(arr) != 1 ||
1063                         numargs < 0 ||
1064                         ARR_HASNULL(arr) ||
1065                         ARR_ELEMTYPE(arr) != CHAROID)
1066                         elog(ERROR, "proargmodes is not a 1-D char array");
1067                 argmodes = (char *) ARR_DATA_PTR(arr);
1068                 arr = DatumGetArrayTypeP(proargnames);  /* ensure not toasted */
1069                 if (ARR_NDIM(arr) != 1 ||
1070                         ARR_DIMS(arr)[0] != numargs ||
1071                         ARR_HASNULL(arr) ||
1072                         ARR_ELEMTYPE(arr) != TEXTOID)
1073                         elog(ERROR, "proargnames is not a 1-D text array");
1074                 deconstruct_array(arr, TEXTOID, -1, false, 'i',
1075                                                   &argnames, NULL, &nargnames);
1076                 Assert(nargnames == numargs);
1077
1078                 /* scan for output argument(s) */
1079                 result = NULL;
1080                 numoutargs = 0;
1081                 for (i = 0; i < numargs; i++)
1082                 {
1083                         if (argmodes[i] == PROARGMODE_IN ||
1084                                 argmodes[i] == PROARGMODE_VARIADIC)
1085                                 continue;
1086                         Assert(argmodes[i] == PROARGMODE_OUT ||
1087                                    argmodes[i] == PROARGMODE_INOUT ||
1088                                    argmodes[i] == PROARGMODE_TABLE);
1089                         if (++numoutargs > 1)
1090                         {
1091                                 /* multiple out args, so forget it */
1092                                 result = NULL;
1093                                 break;
1094                         }
1095                         result = TextDatumGetCString(argnames[i]);
1096                         if (result == NULL || result[0] == '\0')
1097                         {
1098                                 /* Parameter is not named, so forget it */
1099                                 result = NULL;
1100                                 break;
1101                         }
1102                 }
1103         }
1104
1105         ReleaseSysCache(procTuple);
1106
1107         return result;
1108 }
1109
1110
1111 /*
1112  * build_function_result_tupdesc_t
1113  *
1114  * Given a pg_proc row for a function, return a tuple descriptor for the
1115  * result rowtype, or NULL if the function does not have OUT parameters.
1116  *
1117  * Note that this does not handle resolution of polymorphic types;
1118  * that is deliberate.
1119  */
1120 TupleDesc
1121 build_function_result_tupdesc_t(HeapTuple procTuple)
1122 {
1123         Form_pg_proc procform = (Form_pg_proc) GETSTRUCT(procTuple);
1124         Datum           proallargtypes;
1125         Datum           proargmodes;
1126         Datum           proargnames;
1127         bool            isnull;
1128
1129         /* Return NULL if the function isn't declared to return RECORD */
1130         if (procform->prorettype != RECORDOID)
1131                 return NULL;
1132
1133         /* If there are no OUT parameters, return NULL */
1134         if (heap_attisnull(procTuple, Anum_pg_proc_proallargtypes) ||
1135                 heap_attisnull(procTuple, Anum_pg_proc_proargmodes))
1136                 return NULL;
1137
1138         /* Get the data out of the tuple */
1139         proallargtypes = SysCacheGetAttr(PROCOID, procTuple,
1140                                                                          Anum_pg_proc_proallargtypes,
1141                                                                          &isnull);
1142         Assert(!isnull);
1143         proargmodes = SysCacheGetAttr(PROCOID, procTuple,
1144                                                                   Anum_pg_proc_proargmodes,
1145                                                                   &isnull);
1146         Assert(!isnull);
1147         proargnames = SysCacheGetAttr(PROCOID, procTuple,
1148                                                                   Anum_pg_proc_proargnames,
1149                                                                   &isnull);
1150         if (isnull)
1151                 proargnames = PointerGetDatum(NULL);    /* just to be sure */
1152
1153         return build_function_result_tupdesc_d(proallargtypes,
1154                                                                                    proargmodes,
1155                                                                                    proargnames);
1156 }
1157
1158 /*
1159  * build_function_result_tupdesc_d
1160  *
1161  * Build a RECORD function's tupledesc from the pg_proc proallargtypes,
1162  * proargmodes, and proargnames arrays.  This is split out for the
1163  * convenience of ProcedureCreate, which needs to be able to compute the
1164  * tupledesc before actually creating the function.
1165  *
1166  * Returns NULL if there are not at least two OUT or INOUT arguments.
1167  */
1168 TupleDesc
1169 build_function_result_tupdesc_d(Datum proallargtypes,
1170                                                                 Datum proargmodes,
1171                                                                 Datum proargnames)
1172 {
1173         TupleDesc       desc;
1174         ArrayType  *arr;
1175         int                     numargs;
1176         Oid                *argtypes;
1177         char       *argmodes;
1178         Datum      *argnames = NULL;
1179         Oid                *outargtypes;
1180         char      **outargnames;
1181         int                     numoutargs;
1182         int                     nargnames;
1183         int                     i;
1184
1185         /* Can't have output args if columns are null */
1186         if (proallargtypes == PointerGetDatum(NULL) ||
1187                 proargmodes == PointerGetDatum(NULL))
1188                 return NULL;
1189
1190         /*
1191          * We expect the arrays to be 1-D arrays of the right types; verify that.
1192          * For the OID and char arrays, we don't need to use deconstruct_array()
1193          * since the array data is just going to look like a C array of values.
1194          */
1195         arr = DatumGetArrayTypeP(proallargtypes);       /* ensure not toasted */
1196         numargs = ARR_DIMS(arr)[0];
1197         if (ARR_NDIM(arr) != 1 ||
1198                 numargs < 0 ||
1199                 ARR_HASNULL(arr) ||
1200                 ARR_ELEMTYPE(arr) != OIDOID)
1201                 elog(ERROR, "proallargtypes is not a 1-D Oid array");
1202         argtypes = (Oid *) ARR_DATA_PTR(arr);
1203         arr = DatumGetArrayTypeP(proargmodes);  /* ensure not toasted */
1204         if (ARR_NDIM(arr) != 1 ||
1205                 ARR_DIMS(arr)[0] != numargs ||
1206                 ARR_HASNULL(arr) ||
1207                 ARR_ELEMTYPE(arr) != CHAROID)
1208                 elog(ERROR, "proargmodes is not a 1-D char array");
1209         argmodes = (char *) ARR_DATA_PTR(arr);
1210         if (proargnames != PointerGetDatum(NULL))
1211         {
1212                 arr = DatumGetArrayTypeP(proargnames);  /* ensure not toasted */
1213                 if (ARR_NDIM(arr) != 1 ||
1214                         ARR_DIMS(arr)[0] != numargs ||
1215                         ARR_HASNULL(arr) ||
1216                         ARR_ELEMTYPE(arr) != TEXTOID)
1217                         elog(ERROR, "proargnames is not a 1-D text array");
1218                 deconstruct_array(arr, TEXTOID, -1, false, 'i',
1219                                                   &argnames, NULL, &nargnames);
1220                 Assert(nargnames == numargs);
1221         }
1222
1223         /* zero elements probably shouldn't happen, but handle it gracefully */
1224         if (numargs <= 0)
1225                 return NULL;
1226
1227         /* extract output-argument types and names */
1228         outargtypes = (Oid *) palloc(numargs * sizeof(Oid));
1229         outargnames = (char **) palloc(numargs * sizeof(char *));
1230         numoutargs = 0;
1231         for (i = 0; i < numargs; i++)
1232         {
1233                 char       *pname;
1234
1235                 if (argmodes[i] == PROARGMODE_IN ||
1236                         argmodes[i] == PROARGMODE_VARIADIC)
1237                         continue;
1238                 Assert(argmodes[i] == PROARGMODE_OUT ||
1239                            argmodes[i] == PROARGMODE_INOUT ||
1240                            argmodes[i] == PROARGMODE_TABLE);
1241                 outargtypes[numoutargs] = argtypes[i];
1242                 if (argnames)
1243                         pname = TextDatumGetCString(argnames[i]);
1244                 else
1245                         pname = NULL;
1246                 if (pname == NULL || pname[0] == '\0')
1247                 {
1248                         /* Parameter is not named, so gin up a column name */
1249                         pname = psprintf("column%d", numoutargs + 1);
1250                 }
1251                 outargnames[numoutargs] = pname;
1252                 numoutargs++;
1253         }
1254
1255         /*
1256          * If there is no output argument, or only one, the function does not
1257          * return tuples.
1258          */
1259         if (numoutargs < 2)
1260                 return NULL;
1261
1262         desc = CreateTemplateTupleDesc(numoutargs, false);
1263         for (i = 0; i < numoutargs; i++)
1264         {
1265                 TupleDescInitEntry(desc, i + 1,
1266                                                    outargnames[i],
1267                                                    outargtypes[i],
1268                                                    -1,
1269                                                    0);
1270         }
1271
1272         return desc;
1273 }
1274
1275
1276 /*
1277  * RelationNameGetTupleDesc
1278  *
1279  * Given a (possibly qualified) relation name, build a TupleDesc.
1280  *
1281  * Note: while this works as advertised, it's seldom the best way to
1282  * build a tupdesc for a function's result type.  It's kept around
1283  * only for backwards compatibility with existing user-written code.
1284  */
1285 TupleDesc
1286 RelationNameGetTupleDesc(const char *relname)
1287 {
1288         RangeVar   *relvar;
1289         Relation        rel;
1290         TupleDesc       tupdesc;
1291         List       *relname_list;
1292
1293         /* Open relation and copy the tuple description */
1294         relname_list = stringToQualifiedNameList(relname);
1295         relvar = makeRangeVarFromNameList(relname_list);
1296         rel = relation_openrv(relvar, AccessShareLock);
1297         tupdesc = CreateTupleDescCopy(RelationGetDescr(rel));
1298         relation_close(rel, AccessShareLock);
1299
1300         return tupdesc;
1301 }
1302
1303 /*
1304  * TypeGetTupleDesc
1305  *
1306  * Given a type Oid, build a TupleDesc.  (In most cases you should be
1307  * using get_call_result_type or one of its siblings instead of this
1308  * routine, so that you can handle OUT parameters, RECORD result type,
1309  * and polymorphic results.)
1310  *
1311  * If the type is composite, *and* a colaliases List is provided, *and*
1312  * the List is of natts length, use the aliases instead of the relation
1313  * attnames.  (NB: this usage is deprecated since it may result in
1314  * creation of unnecessary transient record types.)
1315  *
1316  * If the type is a base type, a single item alias List is required.
1317  */
1318 TupleDesc
1319 TypeGetTupleDesc(Oid typeoid, List *colaliases)
1320 {
1321         TypeFuncClass functypclass = get_type_func_class(typeoid);
1322         TupleDesc       tupdesc = NULL;
1323
1324         /*
1325          * Build a suitable tupledesc representing the output rows
1326          */
1327         if (functypclass == TYPEFUNC_COMPOSITE)
1328         {
1329                 /* Composite data type, e.g. a table's row type */
1330                 tupdesc = lookup_rowtype_tupdesc_copy(typeoid, -1);
1331
1332                 if (colaliases != NIL)
1333                 {
1334                         int                     natts = tupdesc->natts;
1335                         int                     varattno;
1336
1337                         /* does the list length match the number of attributes? */
1338                         if (list_length(colaliases) != natts)
1339                                 ereport(ERROR,
1340                                                 (errcode(ERRCODE_DATATYPE_MISMATCH),
1341                                                  errmsg("number of aliases does not match number of columns")));
1342
1343                         /* OK, use the aliases instead */
1344                         for (varattno = 0; varattno < natts; varattno++)
1345                         {
1346                                 char       *label = strVal(list_nth(colaliases, varattno));
1347
1348                                 if (label != NULL)
1349                                         namestrcpy(&(tupdesc->attrs[varattno]->attname), label);
1350                         }
1351
1352                         /* The tuple type is now an anonymous record type */
1353                         tupdesc->tdtypeid = RECORDOID;
1354                         tupdesc->tdtypmod = -1;
1355                 }
1356         }
1357         else if (functypclass == TYPEFUNC_SCALAR)
1358         {
1359                 /* Base data type, i.e. scalar */
1360                 char       *attname;
1361
1362                 /* the alias list is required for base types */
1363                 if (colaliases == NIL)
1364                         ereport(ERROR,
1365                                         (errcode(ERRCODE_DATATYPE_MISMATCH),
1366                                          errmsg("no column alias was provided")));
1367
1368                 /* the alias list length must be 1 */
1369                 if (list_length(colaliases) != 1)
1370                         ereport(ERROR,
1371                                         (errcode(ERRCODE_DATATYPE_MISMATCH),
1372                                          errmsg("number of aliases does not match number of columns")));
1373
1374                 /* OK, get the column alias */
1375                 attname = strVal(linitial(colaliases));
1376
1377                 tupdesc = CreateTemplateTupleDesc(1, false);
1378                 TupleDescInitEntry(tupdesc,
1379                                                    (AttrNumber) 1,
1380                                                    attname,
1381                                                    typeoid,
1382                                                    -1,
1383                                                    0);
1384         }
1385         else if (functypclass == TYPEFUNC_RECORD)
1386         {
1387                 /* XXX can't support this because typmod wasn't passed in ... */
1388                 ereport(ERROR,
1389                                 (errcode(ERRCODE_DATATYPE_MISMATCH),
1390                                  errmsg("could not determine row description for function returning record")));
1391         }
1392         else
1393         {
1394                 /* crummy error message, but parser should have caught this */
1395                 elog(ERROR, "function in FROM has unsupported return type");
1396         }
1397
1398         return tupdesc;
1399 }