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  *        $PostgreSQL$
  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         bool            nulls[Natts_pg_proc];
  93         Datum           values[Natts_pg_proc];
  94         bool            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                                 case PROARGMODE_TABLE:
 246                                         /* okay */
 247                                         break;
 248                                 case PROARGMODE_VARIADIC:
 249                                         if (OidIsValid(variadicType))
 250                                                 elog(ERROR, "variadic parameter must be last");
 251                                         switch (allParams[i])
 252                                         {
 253                                                 case ANYOID:
 254                                                         variadicType = ANYOID;
 255                                                         break;
 256                                                 case ANYARRAYOID:
 257                                                         variadicType = ANYELEMENTOID;
 258                                                         break;
 259                                                 default:
 260                                                         variadicType = get_element_type(allParams[i]);
 261                                                         if (!OidIsValid(variadicType))
 262                                                                 elog(ERROR, "variadic parameter is not an array");
 263                                                         break;
 264                                         }
 265                                         break;
 266                                 default:
 267                                         elog(ERROR, "invalid parameter mode '%c'", modes[i]);
 268                                         break;
 269                         }
 270                 }
 271         }
 272
 273         /*
 274          * All seems OK; prepare the data to be inserted into pg_proc.
 275          */
 276
 277         for (i = 0; i < Natts_pg_proc; ++i)
 278         {
 279                 nulls[i] = false;
 280                 values[i] = (Datum) 0;
 281                 replaces[i] = true;
 282         }
 283
 284         namestrcpy(&procname, procedureName);
 285         values[Anum_pg_proc_proname - 1] = NameGetDatum(&procname);
 286         values[Anum_pg_proc_pronamespace - 1] = ObjectIdGetDatum(procNamespace);
 287         values[Anum_pg_proc_proowner - 1] = ObjectIdGetDatum(GetUserId());
 288         values[Anum_pg_proc_prolang - 1] = ObjectIdGetDatum(languageObjectId);
 289         values[Anum_pg_proc_procost - 1] = Float4GetDatum(procost);
 290         values[Anum_pg_proc_prorows - 1] = Float4GetDatum(prorows);
 291         values[Anum_pg_proc_provariadic - 1] = ObjectIdGetDatum(variadicType);
 292         values[Anum_pg_proc_proisagg - 1] = BoolGetDatum(isAgg);
 293         values[Anum_pg_proc_prosecdef - 1] = BoolGetDatum(security_definer);
 294         values[Anum_pg_proc_proisstrict - 1] = BoolGetDatum(isStrict);
 295         values[Anum_pg_proc_proretset - 1] = BoolGetDatum(returnsSet);
 296         values[Anum_pg_proc_provolatile - 1] = CharGetDatum(volatility);
 297         values[Anum_pg_proc_pronargs - 1] = UInt16GetDatum(parameterCount);
 298         values[Anum_pg_proc_prorettype - 1] = ObjectIdGetDatum(returnType);
 299         values[Anum_pg_proc_proargtypes - 1] = PointerGetDatum(parameterTypes);
 300         if (allParameterTypes != PointerGetDatum(NULL))
 301                 values[Anum_pg_proc_proallargtypes - 1] = allParameterTypes;
 302         else
 303                 nulls[Anum_pg_proc_proallargtypes - 1] = true;
 304         if (parameterModes != PointerGetDatum(NULL))
 305                 values[Anum_pg_proc_proargmodes - 1] = parameterModes;
 306         else
 307                 nulls[Anum_pg_proc_proargmodes - 1] = true;
 308         if (parameterNames != PointerGetDatum(NULL))
 309                 values[Anum_pg_proc_proargnames - 1] = parameterNames;
 310         else
 311                 nulls[Anum_pg_proc_proargnames - 1] = true;
 312         values[Anum_pg_proc_prosrc - 1] = CStringGetTextDatum(prosrc);
 313         if (probin)
 314                 values[Anum_pg_proc_probin - 1] = CStringGetTextDatum(probin);
 315         else
 316                 nulls[Anum_pg_proc_probin - 1] = true;
 317         if (proconfig != PointerGetDatum(NULL))
 318                 values[Anum_pg_proc_proconfig - 1] = proconfig;
 319         else
 320                 nulls[Anum_pg_proc_proconfig - 1] = true;
 321         /* start out with empty permissions */
 322         nulls[Anum_pg_proc_proacl - 1] = true;
 323
 324         rel = heap_open(ProcedureRelationId, RowExclusiveLock);
 325         tupDesc = RelationGetDescr(rel);
 326
 327         /* Check for pre-existing definition */
 328         oldtup = SearchSysCache(PROCNAMEARGSNSP,
 329                                                         PointerGetDatum(procedureName),
 330                                                         PointerGetDatum(parameterTypes),
 331                                                         ObjectIdGetDatum(procNamespace),
 332                                                         0);
 333
 334         if (HeapTupleIsValid(oldtup))
 335         {
 336                 /* There is one; okay to replace it? */
 337                 Form_pg_proc oldproc = (Form_pg_proc) GETSTRUCT(oldtup);
 338
 339                 if (!replace)
 340                         ereport(ERROR,
 341                                         (errcode(ERRCODE_DUPLICATE_FUNCTION),
 342                         errmsg("function \"%s\" already exists with same argument types",
 343                                    procedureName)));
 344                 if (!pg_proc_ownercheck(HeapTupleGetOid(oldtup), GetUserId()))
 345                         aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
 346                                                    procedureName);
 347
 348                 /*
 349                  * Not okay to change the return type of the existing proc, since
 350                  * existing rules, views, etc may depend on the return type.
 351                  */
 352                 if (returnType != oldproc->prorettype ||
 353                         returnsSet != oldproc->proretset)
 354                         ereport(ERROR,
 355                                         (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 356                                          errmsg("cannot change return type of existing function"),
 357                                          errhint("Use DROP FUNCTION first.")));
 358
 359                 /*
 360                  * If it returns RECORD, check for possible change of record type
 361                  * implied by OUT parameters
 362                  */
 363                 if (returnType == RECORDOID)
 364                 {
 365                         TupleDesc       olddesc;
 366                         TupleDesc       newdesc;
 367
 368                         olddesc = build_function_result_tupdesc_t(oldtup);
 369                         newdesc = build_function_result_tupdesc_d(allParameterTypes,
 370                                                                                                           parameterModes,
 371                                                                                                           parameterNames);
 372                         if (olddesc == NULL && newdesc == NULL)
 373                                  /* ok, both are runtime-defined RECORDs */ ;
 374                         else if (olddesc == NULL || newdesc == NULL ||
 375                                          !equalTupleDescs(olddesc, newdesc))
 376                                 ereport(ERROR,
 377                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 378                                         errmsg("cannot change return type of existing function"),
 379                                 errdetail("Row type defined by OUT parameters is different."),
 380                                                  errhint("Use DROP FUNCTION first.")));
 381                 }
 382
 383                 /* Can't change aggregate status, either */
 384                 if (oldproc->proisagg != isAgg)
 385                 {
 386                         if (oldproc->proisagg)
 387                                 ereport(ERROR,
 388                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 389                                                  errmsg("function \"%s\" is an aggregate",
 390                                                                 procedureName)));
 391                         else
 392                                 ereport(ERROR,
 393                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 394                                                  errmsg("function \"%s\" is not an aggregate",
 395                                                                 procedureName)));
 396                 }
 397
 398                 /* do not change existing ownership or permissions, either */
 399                 replaces[Anum_pg_proc_proowner - 1] = false;
 400                 replaces[Anum_pg_proc_proacl - 1] = false;
 401
 402                 /* Okay, do it... */
 403                 tup = heap_modify_tuple(oldtup, tupDesc, values, nulls, replaces);
 404                 simple_heap_update(rel, &tup->t_self, tup);
 405
 406                 ReleaseSysCache(oldtup);
 407                 is_update = true;
 408         }
 409         else
 410         {
 411                 /* Creating a new procedure */
 412                 tup = heap_form_tuple(tupDesc, values, nulls);
 413                 simple_heap_insert(rel, tup);
 414                 is_update = false;
 415         }
 416
 417         /* Need to update indexes for either the insert or update case */
 418         CatalogUpdateIndexes(rel, tup);
 419
 420         retval = HeapTupleGetOid(tup);
 421
 422         /*
 423          * Create dependencies for the new function.  If we are updating an
 424          * existing function, first delete any existing pg_depend entries.
 425          */
 426         if (is_update)
 427         {
 428                 deleteDependencyRecordsFor(ProcedureRelationId, retval);
 429                 deleteSharedDependencyRecordsFor(ProcedureRelationId, retval);
 430         }
 431
 432         myself.classId = ProcedureRelationId;
 433         myself.objectId = retval;
 434         myself.objectSubId = 0;
 435
 436         /* dependency on namespace */
 437         referenced.classId = NamespaceRelationId;
 438         referenced.objectId = procNamespace;
 439         referenced.objectSubId = 0;
 440         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 441
 442         /* dependency on implementation language */
 443         referenced.classId = LanguageRelationId;
 444         referenced.objectId = languageObjectId;
 445         referenced.objectSubId = 0;
 446         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 447
 448         /* dependency on return type */
 449         referenced.classId = TypeRelationId;
 450         referenced.objectId = returnType;
 451         referenced.objectSubId = 0;
 452         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 453
 454         /* dependency on parameter types */
 455         for (i = 0; i < allParamCount; i++)
 456         {
 457                 referenced.classId = TypeRelationId;
 458                 referenced.objectId = allParams[i];
 459                 referenced.objectSubId = 0;
 460                 recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 461         }
 462
 463         /* dependency on owner */
 464         recordDependencyOnOwner(ProcedureRelationId, retval, GetUserId());
 465
 466         heap_freetuple(tup);
 467
 468         heap_close(rel, RowExclusiveLock);
 469
 470         /* Verify function body */
 471         if (OidIsValid(languageValidator))
 472         {
 473                 /* Advance command counter so new tuple can be seen by validator */
 474                 CommandCounterIncrement();
 475                 OidFunctionCall1(languageValidator, ObjectIdGetDatum(retval));
 476         }
 477
 478         return retval;
 479 }
 480
 481
 482
 483 /*
 484  * Validator for internal functions
 485  *
 486  * Check that the given internal function name (the "prosrc" value) is
 487  * a known builtin function.
 488  */
 489 Datum
 490 fmgr_internal_validator(PG_FUNCTION_ARGS)
 491 {
 492         Oid                     funcoid = PG_GETARG_OID(0);
 493         HeapTuple       tuple;
 494         Form_pg_proc proc;
 495         bool            isnull;
 496         Datum           tmp;
 497         char       *prosrc;
 498
 499         /*
 500          * We do not honor check_function_bodies since it's unlikely the function
 501          * name will be found later if it isn't there now.
 502          */
 503
 504         tuple = SearchSysCache(PROCOID,
 505                                                    ObjectIdGetDatum(funcoid),
 506                                                    0, 0, 0);
 507         if (!HeapTupleIsValid(tuple))
 508                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 509         proc = (Form_pg_proc) GETSTRUCT(tuple);
 510
 511         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 512         if (isnull)
 513                 elog(ERROR, "null prosrc");
 514         prosrc = TextDatumGetCString(tmp);
 515
 516         if (fmgr_internal_function(prosrc) == InvalidOid)
 517                 ereport(ERROR,
 518                                 (errcode(ERRCODE_UNDEFINED_FUNCTION),
 519                                  errmsg("there is no built-in function named \"%s\"",
 520                                                 prosrc)));
 521
 522         ReleaseSysCache(tuple);
 523
 524         PG_RETURN_VOID();
 525 }
 526
 527
 528
 529 /*
 530  * Validator for C language functions
 531  *
 532  * Make sure that the library file exists, is loadable, and contains
 533  * the specified link symbol. Also check for a valid function
 534  * information record.
 535  */
 536 Datum
 537 fmgr_c_validator(PG_FUNCTION_ARGS)
 538 {
 539         Oid                     funcoid = PG_GETARG_OID(0);
 540         void       *libraryhandle;
 541         HeapTuple       tuple;
 542         Form_pg_proc proc;
 543         bool            isnull;
 544         Datum           tmp;
 545         char       *prosrc;
 546         char       *probin;
 547
 548         /*
 549          * It'd be most consistent to skip the check if !check_function_bodies,
 550          * but the purpose of that switch is to be helpful for pg_dump loading,
 551          * and for pg_dump loading it's much better if we *do* check.
 552          */
 553
 554         tuple = SearchSysCache(PROCOID,
 555                                                    ObjectIdGetDatum(funcoid),
 556                                                    0, 0, 0);
 557         if (!HeapTupleIsValid(tuple))
 558                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 559         proc = (Form_pg_proc) GETSTRUCT(tuple);
 560
 561         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 562         if (isnull)
 563                 elog(ERROR, "null prosrc for C function %u", funcoid);
 564         prosrc = TextDatumGetCString(tmp);
 565
 566         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_probin, &isnull);
 567         if (isnull)
 568                 elog(ERROR, "null probin for C function %u", funcoid);
 569         probin = TextDatumGetCString(tmp);
 570
 571         (void) load_external_function(probin, prosrc, true, &libraryhandle);
 572         (void) fetch_finfo_record(libraryhandle, prosrc);
 573
 574         ReleaseSysCache(tuple);
 575
 576         PG_RETURN_VOID();
 577 }
 578
 579
 580 /*
 581  * Validator for SQL language functions
 582  *
 583  * Parse it here in order to be sure that it contains no syntax errors.
 584  */
 585 Datum
 586 fmgr_sql_validator(PG_FUNCTION_ARGS)
 587 {
 588         Oid                     funcoid = PG_GETARG_OID(0);
 589         HeapTuple       tuple;
 590         Form_pg_proc proc;
 591         List       *querytree_list;
 592         bool            isnull;
 593         Datum           tmp;
 594         char       *prosrc;
 595         ErrorContextCallback sqlerrcontext;
 596         bool            haspolyarg;
 597         int                     i;
 598
 599         tuple = SearchSysCache(PROCOID,
 600                                                    ObjectIdGetDatum(funcoid),
 601                                                    0, 0, 0);
 602         if (!HeapTupleIsValid(tuple))
 603                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 604         proc = (Form_pg_proc) GETSTRUCT(tuple);
 605
 606         /* Disallow pseudotype result */
 607         /* except for RECORD, VOID, or polymorphic */
 608         if (get_typtype(proc->prorettype) == TYPTYPE_PSEUDO &&
 609                 proc->prorettype != RECORDOID &&
 610                 proc->prorettype != VOIDOID &&
 611                 !IsPolymorphicType(proc->prorettype))
 612                 ereport(ERROR,
 613                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 614                                  errmsg("SQL functions cannot return type %s",
 615                                                 format_type_be(proc->prorettype))));
 616
 617         /* Disallow pseudotypes in arguments */
 618         /* except for polymorphic */
 619         haspolyarg = false;
 620         for (i = 0; i < proc->pronargs; i++)
 621         {
 622                 if (get_typtype(proc->proargtypes.values[i]) == TYPTYPE_PSEUDO)
 623                 {
 624                         if (IsPolymorphicType(proc->proargtypes.values[i]))
 625                                 haspolyarg = true;
 626                         else
 627                                 ereport(ERROR,
 628                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 629                                          errmsg("SQL functions cannot have arguments of type %s",
 630                                                         format_type_be(proc->proargtypes.values[i]))));
 631                 }
 632         }
 633
 634         /* Postpone body checks if !check_function_bodies */
 635         if (check_function_bodies)
 636         {
 637                 tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 638                 if (isnull)
 639                         elog(ERROR, "null prosrc");
 640
 641                 prosrc = TextDatumGetCString(tmp);
 642
 643                 /*
 644                  * Setup error traceback support for ereport().
 645                  */
 646                 sqlerrcontext.callback = sql_function_parse_error_callback;
 647                 sqlerrcontext.arg = tuple;
 648                 sqlerrcontext.previous = error_context_stack;
 649                 error_context_stack = &sqlerrcontext;
 650
 651                 /*
 652                  * We can't do full prechecking of the function definition if there
 653                  * are any polymorphic input types, because actual datatypes of
 654                  * expression results will be unresolvable.  The check will be done at
 655                  * runtime instead.
 656                  *
 657                  * We can run the text through the raw parser though; this will at
 658                  * least catch silly syntactic errors.
 659                  */
 660                 if (!haspolyarg)
 661                 {
 662                         querytree_list = pg_parse_and_rewrite(prosrc,
 663                                                                                                   proc->proargtypes.values,
 664                                                                                                   proc->pronargs);
 665                         (void) check_sql_fn_retval(funcoid, proc->prorettype,
 666                                                                            querytree_list,
 667                                                                            false, NULL);
 668                 }
 669                 else
 670                         querytree_list = pg_parse_query(prosrc);
 671
 672                 error_context_stack = sqlerrcontext.previous;
 673         }
 674
 675         ReleaseSysCache(tuple);
 676
 677         PG_RETURN_VOID();
 678 }
 679
 680 /*
 681  * Error context callback for handling errors in SQL function definitions
 682  */
 683 static void
 684 sql_function_parse_error_callback(void *arg)
 685 {
 686         HeapTuple       tuple = (HeapTuple) arg;
 687         Form_pg_proc proc = (Form_pg_proc) GETSTRUCT(tuple);
 688         bool            isnull;
 689         Datum           tmp;
 690         char       *prosrc;
 691
 692         /* See if it's a syntax error; if so, transpose to CREATE FUNCTION */
 693         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 694         if (isnull)
 695                 elog(ERROR, "null prosrc");
 696         prosrc = TextDatumGetCString(tmp);
 697
 698         if (!function_parse_error_transpose(prosrc))
 699         {
 700                 /* If it's not a syntax error, push info onto context stack */
 701                 errcontext("SQL function \"%s\"", NameStr(proc->proname));
 702         }
 703
 704         pfree(prosrc);
 705 }
 706
 707 /*
 708  * Adjust a syntax error occurring inside the function body of a CREATE
 709  * FUNCTION command.  This can be used by any function validator, not only
 710  * for SQL-language functions.  It is assumed that the syntax error position
 711  * is initially relative to the function body string (as passed in).  If
 712  * possible, we adjust the position to reference the original CREATE command;
 713  * if we can't manage that, we set up an "internal query" syntax error instead.
 714  *
 715  * Returns true if a syntax error was processed, false if not.
 716  */
 717 bool
 718 function_parse_error_transpose(const char *prosrc)
 719 {
 720         int                     origerrposition;
 721         int                     newerrposition;
 722         const char *queryText;
 723
 724         /*
 725          * Nothing to do unless we are dealing with a syntax error that has a
 726          * cursor position.
 727          *
 728          * Some PLs may prefer to report the error position as an internal error
 729          * to begin with, so check that too.
 730          */
 731         origerrposition = geterrposition();
 732         if (origerrposition <= 0)
 733         {
 734                 origerrposition = getinternalerrposition();
 735                 if (origerrposition <= 0)
 736                         return false;
 737         }
 738
 739         /* We can get the original query text from the active portal (hack...) */
 740         Assert(ActivePortal && ActivePortal->status == PORTAL_ACTIVE);
 741         queryText = ActivePortal->sourceText;
 742
 743         /* Try to locate the prosrc in the original text */
 744         newerrposition = match_prosrc_to_query(prosrc, queryText, origerrposition);
 745
 746         if (newerrposition > 0)
 747         {
 748                 /* Successful, so fix error position to reference original query */
 749                 errposition(newerrposition);
 750                 /* Get rid of any report of the error as an "internal query" */
 751                 internalerrposition(0);
 752                 internalerrquery(NULL);
 753         }
 754         else
 755         {
 756                 /*
 757                  * If unsuccessful, convert the position to an internal position
 758                  * marker and give the function text as the internal query.
 759                  */
 760                 errposition(0);
 761                 internalerrposition(origerrposition);
 762                 internalerrquery(prosrc);
 763         }
 764
 765         return true;
 766 }
 767
 768 /*
 769  * Try to locate the string literal containing the function body in the
 770  * given text of the CREATE FUNCTION command.  If successful, return the
 771  * character (not byte) index within the command corresponding to the
 772  * given character index within the literal.  If not successful, return 0.
 773  */
 774 static int
 775 match_prosrc_to_query(const char *prosrc, const char *queryText,
 776                                           int cursorpos)
 777 {
 778         /*
 779          * Rather than fully parsing the CREATE FUNCTION command, we just scan the
 780          * command looking for $prosrc$ or 'prosrc'.  This could be fooled (though
 781          * not in any very probable scenarios), so fail if we find more than one
 782          * match.
 783          */
 784         int                     prosrclen = strlen(prosrc);
 785         int                     querylen = strlen(queryText);
 786         int                     matchpos = 0;
 787         int                     curpos;
 788         int                     newcursorpos;
 789
 790         for (curpos = 0; curpos < querylen - prosrclen; curpos++)
 791         {
 792                 if (queryText[curpos] == '$' &&
 793                         strncmp(prosrc, &queryText[curpos + 1], prosrclen) == 0 &&
 794                         queryText[curpos + 1 + prosrclen] == '$')
 795                 {
 796                         /*
 797                          * Found a $foo$ match.  Since there are no embedded quoting
 798                          * characters in a dollar-quoted literal, we don't have to do any
 799                          * fancy arithmetic; just offset by the starting position.
 800                          */
 801                         if (matchpos)
 802                                 return 0;               /* multiple matches, fail */
 803                         matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
 804                                 + cursorpos;
 805                 }
 806                 else if (queryText[curpos] == '\'' &&
 807                                  match_prosrc_to_literal(prosrc, &queryText[curpos + 1],
 808                                                                                  cursorpos, &newcursorpos))
 809                 {
 810                         /*
 811                          * Found a 'foo' match.  match_prosrc_to_literal() has adjusted
 812                          * for any quotes or backslashes embedded in the literal.
 813                          */
 814                         if (matchpos)
 815                                 return 0;               /* multiple matches, fail */
 816                         matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
 817                                 + newcursorpos;
 818                 }
 819         }
 820
 821         return matchpos;
 822 }
 823
 824 /*
 825  * Try to match the given source text to a single-quoted literal.
 826  * If successful, adjust newcursorpos to correspond to the character
 827  * (not byte) index corresponding to cursorpos in the source text.
 828  *
 829  * At entry, literal points just past a ' character.  We must check for the
 830  * trailing quote.
 831  */
 832 static bool
 833 match_prosrc_to_literal(const char *prosrc, const char *literal,
 834                                                 int cursorpos, int *newcursorpos)
 835 {
 836         int                     newcp = cursorpos;
 837         int                     chlen;
 838
 839         /*
 840          * This implementation handles backslashes and doubled quotes in the
 841          * string literal.      It does not handle the SQL syntax for literals
 842          * continued across line boundaries.
 843          *
 844          * We do the comparison a character at a time, not a byte at a time, so
 845          * that we can do the correct cursorpos math.
 846          */
 847         while (*prosrc)
 848         {
 849                 cursorpos--;                    /* characters left before cursor */
 850
 851                 /*
 852                  * Check for backslashes and doubled quotes in the literal; adjust
 853                  * newcp when one is found before the cursor.
 854                  */
 855                 if (*literal == '\\')
 856                 {
 857                         literal++;
 858                         if (cursorpos > 0)
 859                                 newcp++;
 860                 }
 861                 else if (*literal == '\'')
 862                 {
 863                         if (literal[1] != '\'')
 864                                 goto fail;
 865                         literal++;
 866                         if (cursorpos > 0)
 867                                 newcp++;
 868                 }
 869                 chlen = pg_mblen(prosrc);
 870                 if (strncmp(prosrc, literal, chlen) != 0)
 871                         goto fail;
 872                 prosrc += chlen;
 873                 literal += chlen;
 874         }
 875
 876         if (*literal == '\'' && literal[1] != '\'')
 877         {
 878                 /* success */
 879                 *newcursorpos = newcp;
 880                 return true;
 881         }
 882
 883 fail:
 884         /* Must set *newcursorpos to suppress compiler warning */
 885         *newcursorpos = newcp;
 886         return false;
 887 }