granicus.if.org Git - postgresql/blob - src/backend/catalog/pg_proc.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * pg_proc.c
   4  *        routines to support manipulation of the pg_proc relation
   5  *
   6  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  *
  10  * IDENTIFICATION
  11  *        $PostgreSQL: pgsql/src/backend/catalog/pg_proc.c,v 1.152 2008/07/16 16:55:23 tgl Exp $
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15 #include "postgres.h"
  16
  17 #include "access/heapam.h"
  18 #include "access/xact.h"
  19 #include "catalog/dependency.h"
  20 #include "catalog/indexing.h"
  21 #include "catalog/pg_language.h"
  22 #include "catalog/pg_namespace.h"
  23 #include "catalog/pg_proc.h"
  24 #include "catalog/pg_proc_fn.h"
  25 #include "catalog/pg_type.h"
  26 #include "executor/functions.h"
  27 #include "funcapi.h"
  28 #include "mb/pg_wchar.h"
  29 #include "miscadmin.h"
  30 #include "parser/parse_type.h"
  31 #include "tcop/pquery.h"
  32 #include "tcop/tcopprot.h"
  33 #include "utils/acl.h"
  34 #include "utils/builtins.h"
  35 #include "utils/lsyscache.h"
  36 #include "utils/syscache.h"
  37
  38
  39 Datum           fmgr_internal_validator(PG_FUNCTION_ARGS);
  40 Datum           fmgr_c_validator(PG_FUNCTION_ARGS);
  41 Datum           fmgr_sql_validator(PG_FUNCTION_ARGS);
  42
  43 static void sql_function_parse_error_callback(void *arg);
  44 static int match_prosrc_to_query(const char *prosrc, const char *queryText,
  45                                           int cursorpos);
  46 static bool match_prosrc_to_literal(const char *prosrc, const char *literal,
  47                                                 int cursorpos, int *newcursorpos);
  48
  49
  50 /* ----------------------------------------------------------------
  51  *              ProcedureCreate
  52  *
  53  * Note: allParameterTypes, parameterModes, parameterNames, and proconfig
  54  * are either arrays of the proper types or NULL.  We declare them Datum,
  55  * not "ArrayType *", to avoid importing array.h into pg_proc.h.
  56  * ----------------------------------------------------------------
  57  */
  58 Oid
  59 ProcedureCreate(const char *procedureName,
  60                                 Oid procNamespace,
  61                                 bool replace,
  62                                 bool returnsSet,
  63                                 Oid returnType,
  64                                 Oid languageObjectId,
  65                                 Oid languageValidator,
  66                                 const char *prosrc,
  67                                 const char *probin,
  68                                 bool isAgg,
  69                                 bool security_definer,
  70                                 bool isStrict,
  71                                 char volatility,
  72                                 oidvector *parameterTypes,
  73                                 Datum allParameterTypes,
  74                                 Datum parameterModes,
  75                                 Datum parameterNames,
  76                                 Datum proconfig,
  77                                 float4 procost,
  78                                 float4 prorows)
  79 {
  80         Oid                     retval;
  81         int                     parameterCount;
  82         int                     allParamCount;
  83         Oid                *allParams;
  84         bool            genericInParam = false;
  85         bool            genericOutParam = false;
  86         bool            internalInParam = false;
  87         bool            internalOutParam = false;
  88         Oid                     variadicType = InvalidOid;
  89         Relation        rel;
  90         HeapTuple       tup;
  91         HeapTuple       oldtup;
  92         char            nulls[Natts_pg_proc];
  93         Datum           values[Natts_pg_proc];
  94         char            replaces[Natts_pg_proc];
  95         Oid                     relid;
  96         NameData        procname;
  97         TupleDesc       tupDesc;
  98         bool            is_update;
  99         ObjectAddress myself,
 100                                 referenced;
 101         int                     i;
 102
 103         /*
 104          * sanity checks
 105          */
 106         Assert(PointerIsValid(prosrc));
 107
 108         parameterCount = parameterTypes->dim1;
 109         if (parameterCount < 0 || parameterCount > FUNC_MAX_ARGS)
 110                 ereport(ERROR,
 111                                 (errcode(ERRCODE_TOO_MANY_ARGUMENTS),
 112                                  errmsg("functions cannot have more than %d arguments",
 113                                                 FUNC_MAX_ARGS)));
 114         /* note: the above is correct, we do NOT count output arguments */
 115
 116         if (allParameterTypes != PointerGetDatum(NULL))
 117         {
 118                 /*
 119                  * We expect the array to be a 1-D OID array; verify that. We don't
 120                  * need to use deconstruct_array() since the array data is just going
 121                  * to look like a C array of OID values.
 122                  */
 123                 ArrayType  *allParamArray = (ArrayType *) DatumGetPointer(allParameterTypes);
 124
 125                 allParamCount = ARR_DIMS(allParamArray)[0];
 126                 if (ARR_NDIM(allParamArray) != 1 ||
 127                         allParamCount <= 0 ||
 128                         ARR_HASNULL(allParamArray) ||
 129                         ARR_ELEMTYPE(allParamArray) != OIDOID)
 130                         elog(ERROR, "allParameterTypes is not a 1-D Oid array");
 131                 allParams = (Oid *) ARR_DATA_PTR(allParamArray);
 132                 Assert(allParamCount >= parameterCount);
 133                 /* we assume caller got the contents right */
 134         }
 135         else
 136         {
 137                 allParamCount = parameterCount;
 138                 allParams = parameterTypes->values;
 139         }
 140
 141         /*
 142          * Do not allow polymorphic return type unless at least one input argument
 143          * is polymorphic.      Also, do not allow return type INTERNAL unless at
 144          * least one input argument is INTERNAL.
 145          */
 146         for (i = 0; i < parameterCount; i++)
 147         {
 148                 switch (parameterTypes->values[i])
 149                 {
 150                         case ANYARRAYOID:
 151                         case ANYELEMENTOID:
 152                         case ANYNONARRAYOID:
 153                         case ANYENUMOID:
 154                                 genericInParam = true;
 155                                 break;
 156                         case INTERNALOID:
 157                                 internalInParam = true;
 158                                 break;
 159                 }
 160         }
 161
 162         if (allParameterTypes != PointerGetDatum(NULL))
 163         {
 164                 for (i = 0; i < allParamCount; i++)
 165                 {
 166                         /*
 167                          * We don't bother to distinguish input and output params here, so
 168                          * if there is, say, just an input INTERNAL param then we will
 169                          * still set internalOutParam.  This is OK since we don't really
 170                          * care.
 171                          */
 172                         switch (allParams[i])
 173                         {
 174                                 case ANYARRAYOID:
 175                                 case ANYELEMENTOID:
 176                                 case ANYNONARRAYOID:
 177                                 case ANYENUMOID:
 178                                         genericOutParam = true;
 179                                         break;
 180                                 case INTERNALOID:
 181                                         internalOutParam = true;
 182                                         break;
 183                         }
 184                 }
 185         }
 186
 187         if ((IsPolymorphicType(returnType) || genericOutParam)
 188                 && !genericInParam)
 189                 ereport(ERROR,
 190                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 191                                  errmsg("cannot determine result data type"),
 192                                  errdetail("A function returning a polymorphic type must have at least one polymorphic argument.")));
 193
 194         if ((returnType == INTERNALOID || internalOutParam) && !internalInParam)
 195                 ereport(ERROR,
 196                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 197                                  errmsg("unsafe use of pseudo-type \"internal\""),
 198                                  errdetail("A function returning \"internal\" must have at least one \"internal\" argument.")));
 199
 200         /*
 201          * don't allow functions of complex types that have the same name as
 202          * existing attributes of the type
 203          */
 204         if (parameterCount == 1 &&
 205                 OidIsValid(parameterTypes->values[0]) &&
 206                 (relid = typeidTypeRelid(parameterTypes->values[0])) != InvalidOid &&
 207                 get_attnum(relid, procedureName) != InvalidAttrNumber)
 208                 ereport(ERROR,
 209                                 (errcode(ERRCODE_DUPLICATE_COLUMN),
 210                                  errmsg("\"%s\" is already an attribute of type %s",
 211                                                 procedureName,
 212                                                 format_type_be(parameterTypes->values[0]))));
 213
 214         if (parameterModes != PointerGetDatum(NULL))
 215         {
 216                 /*
 217                  * We expect the array to be a 1-D CHAR array; verify that. We don't
 218                  * need to use deconstruct_array() since the array data is just going
 219                  * to look like a C array of char values.
 220                  */
 221                 ArrayType  *modesArray = (ArrayType *) DatumGetPointer(parameterModes);
 222                 char       *modes;
 223
 224                 if (ARR_NDIM(modesArray) != 1 ||
 225                         ARR_DIMS(modesArray)[0] != allParamCount ||
 226                         ARR_HASNULL(modesArray) ||
 227                         ARR_ELEMTYPE(modesArray) != CHAROID)
 228                         elog(ERROR, "parameterModes is not a 1-D char array");
 229                 modes = (char *) ARR_DATA_PTR(modesArray);
 230                 /*
 231                  * Only the last input parameter can be variadic; if it is, save
 232                  * its element type.  Errors here are just elog since caller should
 233                  * have checked this already.
 234                  */
 235                 for (i = 0; i < allParamCount; i++)
 236                 {
 237                         switch (modes[i])
 238                         {
 239                                 case PROARGMODE_IN:
 240                                 case PROARGMODE_INOUT:
 241                                         if (OidIsValid(variadicType))
 242                                                 elog(ERROR, "variadic parameter must be last");
 243                                         break;
 244                                 case PROARGMODE_OUT:
 245                                         /* okay */
 246                                         break;
 247                                 case PROARGMODE_VARIADIC:
 248                                         if (OidIsValid(variadicType))
 249                                                 elog(ERROR, "variadic parameter must be last");
 250                                         switch (allParams[i])
 251                                         {
 252                                                 case ANYOID:
 253                                                         variadicType = ANYOID;
 254                                                         break;
 255                                                 case ANYARRAYOID:
 256                                                         variadicType = ANYELEMENTOID;
 257                                                         break;
 258                                                 default:
 259                                                         variadicType = get_element_type(allParams[i]);
 260                                                         if (!OidIsValid(variadicType))
 261                                                                 elog(ERROR, "variadic parameter is not an array");
 262                                                         break;
 263                                         }
 264                                         break;
 265                                 default:
 266                                         elog(ERROR, "invalid parameter mode '%c'", modes[i]);
 267                                         break;
 268                         }
 269                 }
 270         }
 271
 272         /*
 273          * All seems OK; prepare the data to be inserted into pg_proc.
 274          */
 275
 276         for (i = 0; i < Natts_pg_proc; ++i)
 277         {
 278                 nulls[i] = ' ';
 279                 values[i] = (Datum) 0;
 280                 replaces[i] = 'r';
 281         }
 282
 283         namestrcpy(&procname, procedureName);
 284         values[Anum_pg_proc_proname - 1] = NameGetDatum(&procname);
 285         values[Anum_pg_proc_pronamespace - 1] = ObjectIdGetDatum(procNamespace);
 286         values[Anum_pg_proc_proowner - 1] = ObjectIdGetDatum(GetUserId());
 287         values[Anum_pg_proc_prolang - 1] = ObjectIdGetDatum(languageObjectId);
 288         values[Anum_pg_proc_procost - 1] = Float4GetDatum(procost);
 289         values[Anum_pg_proc_prorows - 1] = Float4GetDatum(prorows);
 290         values[Anum_pg_proc_provariadic - 1] = ObjectIdGetDatum(variadicType);
 291         values[Anum_pg_proc_proisagg - 1] = BoolGetDatum(isAgg);
 292         values[Anum_pg_proc_prosecdef - 1] = BoolGetDatum(security_definer);
 293         values[Anum_pg_proc_proisstrict - 1] = BoolGetDatum(isStrict);
 294         values[Anum_pg_proc_proretset - 1] = BoolGetDatum(returnsSet);
 295         values[Anum_pg_proc_provolatile - 1] = CharGetDatum(volatility);
 296         values[Anum_pg_proc_pronargs - 1] = UInt16GetDatum(parameterCount);
 297         values[Anum_pg_proc_prorettype - 1] = ObjectIdGetDatum(returnType);
 298         values[Anum_pg_proc_proargtypes - 1] = PointerGetDatum(parameterTypes);
 299         if (allParameterTypes != PointerGetDatum(NULL))
 300                 values[Anum_pg_proc_proallargtypes - 1] = allParameterTypes;
 301         else
 302                 nulls[Anum_pg_proc_proallargtypes - 1] = 'n';
 303         if (parameterModes != PointerGetDatum(NULL))
 304                 values[Anum_pg_proc_proargmodes - 1] = parameterModes;
 305         else
 306                 nulls[Anum_pg_proc_proargmodes - 1] = 'n';
 307         if (parameterNames != PointerGetDatum(NULL))
 308                 values[Anum_pg_proc_proargnames - 1] = parameterNames;
 309         else
 310                 nulls[Anum_pg_proc_proargnames - 1] = 'n';
 311         values[Anum_pg_proc_prosrc - 1] = CStringGetTextDatum(prosrc);
 312         if (probin)
 313                 values[Anum_pg_proc_probin - 1] = CStringGetTextDatum(probin);
 314         else
 315                 nulls[Anum_pg_proc_probin - 1] = 'n';
 316         if (proconfig != PointerGetDatum(NULL))
 317                 values[Anum_pg_proc_proconfig - 1] = proconfig;
 318         else
 319                 nulls[Anum_pg_proc_proconfig - 1] = 'n';
 320         /* start out with empty permissions */
 321         nulls[Anum_pg_proc_proacl - 1] = 'n';
 322
 323         rel = heap_open(ProcedureRelationId, RowExclusiveLock);
 324         tupDesc = RelationGetDescr(rel);
 325
 326         /* Check for pre-existing definition */
 327         oldtup = SearchSysCache(PROCNAMEARGSNSP,
 328                                                         PointerGetDatum(procedureName),
 329                                                         PointerGetDatum(parameterTypes),
 330                                                         ObjectIdGetDatum(procNamespace),
 331                                                         0);
 332
 333         if (HeapTupleIsValid(oldtup))
 334         {
 335                 /* There is one; okay to replace it? */
 336                 Form_pg_proc oldproc = (Form_pg_proc) GETSTRUCT(oldtup);
 337
 338                 if (!replace)
 339                         ereport(ERROR,
 340                                         (errcode(ERRCODE_DUPLICATE_FUNCTION),
 341                         errmsg("function \"%s\" already exists with same argument types",
 342                                    procedureName)));
 343                 if (!pg_proc_ownercheck(HeapTupleGetOid(oldtup), GetUserId()))
 344                         aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
 345                                                    procedureName);
 346
 347                 /*
 348                  * Not okay to change the return type of the existing proc, since
 349                  * existing rules, views, etc may depend on the return type.
 350                  */
 351                 if (returnType != oldproc->prorettype ||
 352                         returnsSet != oldproc->proretset)
 353                         ereport(ERROR,
 354                                         (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 355                                          errmsg("cannot change return type of existing function"),
 356                                          errhint("Use DROP FUNCTION first.")));
 357
 358                 /*
 359                  * If it returns RECORD, check for possible change of record type
 360                  * implied by OUT parameters
 361                  */
 362                 if (returnType == RECORDOID)
 363                 {
 364                         TupleDesc       olddesc;
 365                         TupleDesc       newdesc;
 366
 367                         olddesc = build_function_result_tupdesc_t(oldtup);
 368                         newdesc = build_function_result_tupdesc_d(allParameterTypes,
 369                                                                                                           parameterModes,
 370                                                                                                           parameterNames);
 371                         if (olddesc == NULL && newdesc == NULL)
 372                                  /* ok, both are runtime-defined RECORDs */ ;
 373                         else if (olddesc == NULL || newdesc == NULL ||
 374                                          !equalTupleDescs(olddesc, newdesc))
 375                                 ereport(ERROR,
 376                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 377                                         errmsg("cannot change return type of existing function"),
 378                                 errdetail("Row type defined by OUT parameters is different."),
 379                                                  errhint("Use DROP FUNCTION first.")));
 380                 }
 381
 382                 /* Can't change aggregate status, either */
 383                 if (oldproc->proisagg != isAgg)
 384                 {
 385                         if (oldproc->proisagg)
 386                                 ereport(ERROR,
 387                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 388                                                  errmsg("function \"%s\" is an aggregate",
 389                                                                 procedureName)));
 390                         else
 391                                 ereport(ERROR,
 392                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 393                                                  errmsg("function \"%s\" is not an aggregate",
 394                                                                 procedureName)));
 395                 }
 396
 397                 /* do not change existing ownership or permissions, either */
 398                 replaces[Anum_pg_proc_proowner - 1] = ' ';
 399                 replaces[Anum_pg_proc_proacl - 1] = ' ';
 400
 401                 /* Okay, do it... */
 402                 tup = heap_modifytuple(oldtup, tupDesc, values, nulls, replaces);
 403                 simple_heap_update(rel, &tup->t_self, tup);
 404
 405                 ReleaseSysCache(oldtup);
 406                 is_update = true;
 407         }
 408         else
 409         {
 410                 /* Creating a new procedure */
 411                 tup = heap_formtuple(tupDesc, values, nulls);
 412                 simple_heap_insert(rel, tup);
 413                 is_update = false;
 414         }
 415
 416         /* Need to update indexes for either the insert or update case */
 417         CatalogUpdateIndexes(rel, tup);
 418
 419         retval = HeapTupleGetOid(tup);
 420
 421         /*
 422          * Create dependencies for the new function.  If we are updating an
 423          * existing function, first delete any existing pg_depend entries.
 424          */
 425         if (is_update)
 426         {
 427                 deleteDependencyRecordsFor(ProcedureRelationId, retval);
 428                 deleteSharedDependencyRecordsFor(ProcedureRelationId, retval);
 429         }
 430
 431         myself.classId = ProcedureRelationId;
 432         myself.objectId = retval;
 433         myself.objectSubId = 0;
 434
 435         /* dependency on namespace */
 436         referenced.classId = NamespaceRelationId;
 437         referenced.objectId = procNamespace;
 438         referenced.objectSubId = 0;
 439         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 440
 441         /* dependency on implementation language */
 442         referenced.classId = LanguageRelationId;
 443         referenced.objectId = languageObjectId;
 444         referenced.objectSubId = 0;
 445         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 446
 447         /* dependency on return type */
 448         referenced.classId = TypeRelationId;
 449         referenced.objectId = returnType;
 450         referenced.objectSubId = 0;
 451         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 452
 453         /* dependency on parameter types */
 454         for (i = 0; i < allParamCount; i++)
 455         {
 456                 referenced.classId = TypeRelationId;
 457                 referenced.objectId = allParams[i];
 458                 referenced.objectSubId = 0;
 459                 recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 460         }
 461
 462         /* dependency on owner */
 463         recordDependencyOnOwner(ProcedureRelationId, retval, GetUserId());
 464
 465         heap_freetuple(tup);
 466
 467         heap_close(rel, RowExclusiveLock);
 468
 469         /* Verify function body */
 470         if (OidIsValid(languageValidator))
 471         {
 472                 /* Advance command counter so new tuple can be seen by validator */
 473                 CommandCounterIncrement();
 474                 OidFunctionCall1(languageValidator, ObjectIdGetDatum(retval));
 475         }
 476
 477         return retval;
 478 }
 479
 480
 481
 482 /*
 483  * Validator for internal functions
 484  *
 485  * Check that the given internal function name (the "prosrc" value) is
 486  * a known builtin function.
 487  */
 488 Datum
 489 fmgr_internal_validator(PG_FUNCTION_ARGS)
 490 {
 491         Oid                     funcoid = PG_GETARG_OID(0);
 492         HeapTuple       tuple;
 493         Form_pg_proc proc;
 494         bool            isnull;
 495         Datum           tmp;
 496         char       *prosrc;
 497
 498         /*
 499          * We do not honor check_function_bodies since it's unlikely the function
 500          * name will be found later if it isn't there now.
 501          */
 502
 503         tuple = SearchSysCache(PROCOID,
 504                                                    ObjectIdGetDatum(funcoid),
 505                                                    0, 0, 0);
 506         if (!HeapTupleIsValid(tuple))
 507                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 508         proc = (Form_pg_proc) GETSTRUCT(tuple);
 509
 510         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 511         if (isnull)
 512                 elog(ERROR, "null prosrc");
 513         prosrc = TextDatumGetCString(tmp);
 514
 515         if (fmgr_internal_function(prosrc) == InvalidOid)
 516                 ereport(ERROR,
 517                                 (errcode(ERRCODE_UNDEFINED_FUNCTION),
 518                                  errmsg("there is no built-in function named \"%s\"",
 519                                                 prosrc)));
 520
 521         ReleaseSysCache(tuple);
 522
 523         PG_RETURN_VOID();
 524 }
 525
 526
 527
 528 /*
 529  * Validator for C language functions
 530  *
 531  * Make sure that the library file exists, is loadable, and contains
 532  * the specified link symbol. Also check for a valid function
 533  * information record.
 534  */
 535 Datum
 536 fmgr_c_validator(PG_FUNCTION_ARGS)
 537 {
 538         Oid                     funcoid = PG_GETARG_OID(0);
 539         void       *libraryhandle;
 540         HeapTuple       tuple;
 541         Form_pg_proc proc;
 542         bool            isnull;
 543         Datum           tmp;
 544         char       *prosrc;
 545         char       *probin;
 546
 547         /*
 548          * It'd be most consistent to skip the check if !check_function_bodies,
 549          * but the purpose of that switch is to be helpful for pg_dump loading,
 550          * and for pg_dump loading it's much better if we *do* check.
 551          */
 552
 553         tuple = SearchSysCache(PROCOID,
 554                                                    ObjectIdGetDatum(funcoid),
 555                                                    0, 0, 0);
 556         if (!HeapTupleIsValid(tuple))
 557                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 558         proc = (Form_pg_proc) GETSTRUCT(tuple);
 559
 560         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 561         if (isnull)
 562                 elog(ERROR, "null prosrc for C function %u", funcoid);
 563         prosrc = TextDatumGetCString(tmp);
 564
 565         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_probin, &isnull);
 566         if (isnull)
 567                 elog(ERROR, "null probin for C function %u", funcoid);
 568         probin = TextDatumGetCString(tmp);
 569
 570         (void) load_external_function(probin, prosrc, true, &libraryhandle);
 571         (void) fetch_finfo_record(libraryhandle, prosrc);
 572
 573         ReleaseSysCache(tuple);
 574
 575         PG_RETURN_VOID();
 576 }
 577
 578
 579 /*
 580  * Validator for SQL language functions
 581  *
 582  * Parse it here in order to be sure that it contains no syntax errors.
 583  */
 584 Datum
 585 fmgr_sql_validator(PG_FUNCTION_ARGS)
 586 {
 587         Oid                     funcoid = PG_GETARG_OID(0);
 588         HeapTuple       tuple;
 589         Form_pg_proc proc;
 590         List       *querytree_list;
 591         bool            isnull;
 592         Datum           tmp;
 593         char       *prosrc;
 594         ErrorContextCallback sqlerrcontext;
 595         bool            haspolyarg;
 596         int                     i;
 597
 598         tuple = SearchSysCache(PROCOID,
 599                                                    ObjectIdGetDatum(funcoid),
 600                                                    0, 0, 0);
 601         if (!HeapTupleIsValid(tuple))
 602                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 603         proc = (Form_pg_proc) GETSTRUCT(tuple);
 604
 605         /* Disallow pseudotype result */
 606         /* except for RECORD, VOID, or polymorphic */
 607         if (get_typtype(proc->prorettype) == TYPTYPE_PSEUDO &&
 608                 proc->prorettype != RECORDOID &&
 609                 proc->prorettype != VOIDOID &&
 610                 !IsPolymorphicType(proc->prorettype))
 611                 ereport(ERROR,
 612                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 613                                  errmsg("SQL functions cannot return type %s",
 614                                                 format_type_be(proc->prorettype))));
 615
 616         /* Disallow pseudotypes in arguments */
 617         /* except for polymorphic */
 618         haspolyarg = false;
 619         for (i = 0; i < proc->pronargs; i++)
 620         {
 621                 if (get_typtype(proc->proargtypes.values[i]) == TYPTYPE_PSEUDO)
 622                 {
 623                         if (IsPolymorphicType(proc->proargtypes.values[i]))
 624                                 haspolyarg = true;
 625                         else
 626                                 ereport(ERROR,
 627                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 628                                          errmsg("SQL functions cannot have arguments of type %s",
 629                                                         format_type_be(proc->proargtypes.values[i]))));
 630                 }
 631         }
 632
 633         /* Postpone body checks if !check_function_bodies */
 634         if (check_function_bodies)
 635         {
 636                 tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 637                 if (isnull)
 638                         elog(ERROR, "null prosrc");
 639
 640                 prosrc = TextDatumGetCString(tmp);
 641
 642                 /*
 643                  * Setup error traceback support for ereport().
 644                  */
 645                 sqlerrcontext.callback = sql_function_parse_error_callback;
 646                 sqlerrcontext.arg = tuple;
 647                 sqlerrcontext.previous = error_context_stack;
 648                 error_context_stack = &sqlerrcontext;
 649
 650                 /*
 651                  * We can't do full prechecking of the function definition if there
 652                  * are any polymorphic input types, because actual datatypes of
 653                  * expression results will be unresolvable.  The check will be done at
 654                  * runtime instead.
 655                  *
 656                  * We can run the text through the raw parser though; this will at
 657                  * least catch silly syntactic errors.
 658                  */
 659                 if (!haspolyarg)
 660                 {
 661                         querytree_list = pg_parse_and_rewrite(prosrc,
 662                                                                                                   proc->proargtypes.values,
 663                                                                                                   proc->pronargs);
 664                         (void) check_sql_fn_retval(funcoid, proc->prorettype,
 665                                                                            querytree_list,
 666                                                                            false, NULL);
 667                 }
 668                 else
 669                         querytree_list = pg_parse_query(prosrc);
 670
 671                 error_context_stack = sqlerrcontext.previous;
 672         }
 673
 674         ReleaseSysCache(tuple);
 675
 676         PG_RETURN_VOID();
 677 }
 678
 679 /*
 680  * Error context callback for handling errors in SQL function definitions
 681  */
 682 static void
 683 sql_function_parse_error_callback(void *arg)
 684 {
 685         HeapTuple       tuple = (HeapTuple) arg;
 686         Form_pg_proc proc = (Form_pg_proc) GETSTRUCT(tuple);
 687         bool            isnull;
 688         Datum           tmp;
 689         char       *prosrc;
 690
 691         /* See if it's a syntax error; if so, transpose to CREATE FUNCTION */
 692         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 693         if (isnull)
 694                 elog(ERROR, "null prosrc");
 695         prosrc = TextDatumGetCString(tmp);
 696
 697         if (!function_parse_error_transpose(prosrc))
 698         {
 699                 /* If it's not a syntax error, push info onto context stack */
 700                 errcontext("SQL function \"%s\"", NameStr(proc->proname));
 701         }
 702
 703         pfree(prosrc);
 704 }
 705
 706 /*
 707  * Adjust a syntax error occurring inside the function body of a CREATE
 708  * FUNCTION command.  This can be used by any function validator, not only
 709  * for SQL-language functions.  It is assumed that the syntax error position
 710  * is initially relative to the function body string (as passed in).  If
 711  * possible, we adjust the position to reference the original CREATE command;
 712  * if we can't manage that, we set up an "internal query" syntax error instead.
 713  *
 714  * Returns true if a syntax error was processed, false if not.
 715  */
 716 bool
 717 function_parse_error_transpose(const char *prosrc)
 718 {
 719         int                     origerrposition;
 720         int                     newerrposition;
 721         const char *queryText;
 722
 723         /*
 724          * Nothing to do unless we are dealing with a syntax error that has a
 725          * cursor position.
 726          *
 727          * Some PLs may prefer to report the error position as an internal error
 728          * to begin with, so check that too.
 729          */
 730         origerrposition = geterrposition();
 731         if (origerrposition <= 0)
 732         {
 733                 origerrposition = getinternalerrposition();
 734                 if (origerrposition <= 0)
 735                         return false;
 736         }
 737
 738         /* We can get the original query text from the active portal (hack...) */
 739         Assert(ActivePortal && ActivePortal->status == PORTAL_ACTIVE);
 740         queryText = ActivePortal->sourceText;
 741
 742         /* Try to locate the prosrc in the original text */
 743         newerrposition = match_prosrc_to_query(prosrc, queryText, origerrposition);
 744
 745         if (newerrposition > 0)
 746         {
 747                 /* Successful, so fix error position to reference original query */
 748                 errposition(newerrposition);
 749                 /* Get rid of any report of the error as an "internal query" */
 750                 internalerrposition(0);
 751                 internalerrquery(NULL);
 752         }
 753         else
 754         {
 755                 /*
 756                  * If unsuccessful, convert the position to an internal position
 757                  * marker and give the function text as the internal query.
 758                  */
 759                 errposition(0);
 760                 internalerrposition(origerrposition);
 761                 internalerrquery(prosrc);
 762         }
 763
 764         return true;
 765 }
 766
 767 /*
 768  * Try to locate the string literal containing the function body in the
 769  * given text of the CREATE FUNCTION command.  If successful, return the
 770  * character (not byte) index within the command corresponding to the
 771  * given character index within the literal.  If not successful, return 0.
 772  */
 773 static int
 774 match_prosrc_to_query(const char *prosrc, const char *queryText,
 775                                           int cursorpos)
 776 {
 777         /*
 778          * Rather than fully parsing the CREATE FUNCTION command, we just scan the
 779          * command looking for $prosrc$ or 'prosrc'.  This could be fooled (though
 780          * not in any very probable scenarios), so fail if we find more than one
 781          * match.
 782          */
 783         int                     prosrclen = strlen(prosrc);
 784         int                     querylen = strlen(queryText);
 785         int                     matchpos = 0;
 786         int                     curpos;
 787         int                     newcursorpos;
 788
 789         for (curpos = 0; curpos < querylen - prosrclen; curpos++)
 790         {
 791                 if (queryText[curpos] == '$' &&
 792                         strncmp(prosrc, &queryText[curpos + 1], prosrclen) == 0 &&
 793                         queryText[curpos + 1 + prosrclen] == '$')
 794                 {
 795                         /*
 796                          * Found a $foo$ match.  Since there are no embedded quoting
 797                          * characters in a dollar-quoted literal, we don't have to do any
 798                          * fancy arithmetic; just offset by the starting position.
 799                          */
 800                         if (matchpos)
 801                                 return 0;               /* multiple matches, fail */
 802                         matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
 803                                 + cursorpos;
 804                 }
 805                 else if (queryText[curpos] == '\'' &&
 806                                  match_prosrc_to_literal(prosrc, &queryText[curpos + 1],
 807                                                                                  cursorpos, &newcursorpos))
 808                 {
 809                         /*
 810                          * Found a 'foo' match.  match_prosrc_to_literal() has adjusted
 811                          * for any quotes or backslashes embedded in the literal.
 812                          */
 813                         if (matchpos)
 814                                 return 0;               /* multiple matches, fail */
 815                         matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
 816                                 + newcursorpos;
 817                 }
 818         }
 819
 820         return matchpos;
 821 }
 822
 823 /*
 824  * Try to match the given source text to a single-quoted literal.
 825  * If successful, adjust newcursorpos to correspond to the character
 826  * (not byte) index corresponding to cursorpos in the source text.
 827  *
 828  * At entry, literal points just past a ' character.  We must check for the
 829  * trailing quote.
 830  */
 831 static bool
 832 match_prosrc_to_literal(const char *prosrc, const char *literal,
 833                                                 int cursorpos, int *newcursorpos)
 834 {
 835         int                     newcp = cursorpos;
 836         int                     chlen;
 837
 838         /*
 839          * This implementation handles backslashes and doubled quotes in the
 840          * string literal.      It does not handle the SQL syntax for literals
 841          * continued across line boundaries.
 842          *
 843          * We do the comparison a character at a time, not a byte at a time, so
 844          * that we can do the correct cursorpos math.
 845          */
 846         while (*prosrc)
 847         {
 848                 cursorpos--;                    /* characters left before cursor */
 849
 850                 /*
 851                  * Check for backslashes and doubled quotes in the literal; adjust
 852                  * newcp when one is found before the cursor.
 853                  */
 854                 if (*literal == '\\')
 855                 {
 856                         literal++;
 857                         if (cursorpos > 0)
 858                                 newcp++;
 859                 }
 860                 else if (*literal == '\'')
 861                 {
 862                         if (literal[1] != '\'')
 863                                 goto fail;
 864                         literal++;
 865                         if (cursorpos > 0)
 866                                 newcp++;
 867                 }
 868                 chlen = pg_mblen(prosrc);
 869                 if (strncmp(prosrc, literal, chlen) != 0)
 870                         goto fail;
 871                 prosrc += chlen;
 872                 literal += chlen;
 873         }
 874
 875         if (*literal == '\'' && literal[1] != '\'')
 876         {
 877                 /* success */
 878                 *newcursorpos = newcp;
 879                 return true;
 880         }
 881
 882 fail:
 883         /* Must set *newcursorpos to suppress compiler warning */
 884         *newcursorpos = newcp;
 885         return false;
 886 }