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 1.149 2008/03/18 22:04:14 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_type.h"
  25 #include "executor/functions.h"
  26 #include "funcapi.h"
  27 #include "mb/pg_wchar.h"
  28 #include "miscadmin.h"
  29 #include "parser/parse_type.h"
  30 #include "tcop/pquery.h"
  31 #include "tcop/tcopprot.h"
  32 #include "utils/acl.h"
  33 #include "utils/builtins.h"
  34 #include "utils/lsyscache.h"
  35 #include "utils/syscache.h"
  36
  37
  38 Datum           fmgr_internal_validator(PG_FUNCTION_ARGS);
  39 Datum           fmgr_c_validator(PG_FUNCTION_ARGS);
  40 Datum           fmgr_sql_validator(PG_FUNCTION_ARGS);
  41
  42 static void sql_function_parse_error_callback(void *arg);
  43 static int match_prosrc_to_query(const char *prosrc, const char *queryText,
  44                                           int cursorpos);
  45 static bool match_prosrc_to_literal(const char *prosrc, const char *literal,
  46                                                 int cursorpos, int *newcursorpos);
  47
  48
  49 /* ----------------------------------------------------------------
  50  *              ProcedureCreate
  51  *
  52  * Note: allParameterTypes, parameterModes, parameterNames, and proconfig
  53  * are either arrays of the proper types or NULL.  We declare them Datum,
  54  * not "ArrayType *", to avoid importing array.h into pg_proc.h.
  55  * ----------------------------------------------------------------
  56  */
  57 Oid
  58 ProcedureCreate(const char *procedureName,
  59                                 Oid procNamespace,
  60                                 bool replace,
  61                                 bool returnsSet,
  62                                 Oid returnType,
  63                                 Oid languageObjectId,
  64                                 Oid languageValidator,
  65                                 const char *prosrc,
  66                                 const char *probin,
  67                                 bool isAgg,
  68                                 bool security_definer,
  69                                 bool isStrict,
  70                                 char volatility,
  71                                 oidvector *parameterTypes,
  72                                 Datum allParameterTypes,
  73                                 Datum parameterModes,
  74                                 Datum parameterNames,
  75                                 Datum proconfig,
  76                                 float4 procost,
  77                                 float4 prorows)
  78 {
  79         Oid                     retval;
  80         int                     parameterCount;
  81         int                     allParamCount;
  82         Oid                *allParams;
  83         bool            genericInParam = false;
  84         bool            genericOutParam = false;
  85         bool            internalInParam = false;
  86         bool            internalOutParam = false;
  87         Relation        rel;
  88         HeapTuple       tup;
  89         HeapTuple       oldtup;
  90         char            nulls[Natts_pg_proc];
  91         Datum           values[Natts_pg_proc];
  92         char            replaces[Natts_pg_proc];
  93         Oid                     relid;
  94         NameData        procname;
  95         TupleDesc       tupDesc;
  96         bool            is_update;
  97         ObjectAddress myself,
  98                                 referenced;
  99         int                     i;
 100
 101         /*
 102          * sanity checks
 103          */
 104         Assert(PointerIsValid(prosrc));
 105         Assert(PointerIsValid(probin));
 106
 107         parameterCount = parameterTypes->dim1;
 108         if (parameterCount < 0 || parameterCount > FUNC_MAX_ARGS)
 109                 ereport(ERROR,
 110                                 (errcode(ERRCODE_TOO_MANY_ARGUMENTS),
 111                                  errmsg("functions cannot have more than %d arguments",
 112                                                 FUNC_MAX_ARGS)));
 113         /* note: the above is correct, we do NOT count output arguments */
 114
 115         if (allParameterTypes != PointerGetDatum(NULL))
 116         {
 117                 /*
 118                  * We expect the array to be a 1-D OID array; verify that. We don't
 119                  * need to use deconstruct_array() since the array data is just going
 120                  * to look like a C array of OID values.
 121                  */
 122                 ArrayType  *allParamArray = (ArrayType *) DatumGetPointer(allParameterTypes);
 123
 124                 allParamCount = ARR_DIMS(allParamArray)[0];
 125                 if (ARR_NDIM(allParamArray) != 1 ||
 126                         allParamCount <= 0 ||
 127                         ARR_HASNULL(allParamArray) ||
 128                         ARR_ELEMTYPE(allParamArray) != OIDOID)
 129                         elog(ERROR, "allParameterTypes is not a 1-D Oid array");
 130                 allParams = (Oid *) ARR_DATA_PTR(allParamArray);
 131                 Assert(allParamCount >= parameterCount);
 132                 /* we assume caller got the contents right */
 133         }
 134         else
 135         {
 136                 allParamCount = parameterCount;
 137                 allParams = parameterTypes->values;
 138         }
 139
 140         /*
 141          * Do not allow polymorphic return type unless at least one input argument
 142          * is polymorphic.      Also, do not allow return type INTERNAL unless at
 143          * least one input argument is INTERNAL.
 144          */
 145         for (i = 0; i < parameterCount; i++)
 146         {
 147                 switch (parameterTypes->values[i])
 148                 {
 149                         case ANYARRAYOID:
 150                         case ANYELEMENTOID:
 151                         case ANYNONARRAYOID:
 152                         case ANYENUMOID:
 153                                 genericInParam = true;
 154                                 break;
 155                         case INTERNALOID:
 156                                 internalInParam = true;
 157                                 break;
 158                 }
 159         }
 160
 161         if (allParameterTypes != PointerGetDatum(NULL))
 162         {
 163                 for (i = 0; i < allParamCount; i++)
 164                 {
 165                         /*
 166                          * We don't bother to distinguish input and output params here, so
 167                          * if there is, say, just an input INTERNAL param then we will
 168                          * still set internalOutParam.  This is OK since we don't really
 169                          * care.
 170                          */
 171                         switch (allParams[i])
 172                         {
 173                                 case ANYARRAYOID:
 174                                 case ANYELEMENTOID:
 175                                 case ANYNONARRAYOID:
 176                                 case ANYENUMOID:
 177                                         genericOutParam = true;
 178                                         break;
 179                                 case INTERNALOID:
 180                                         internalOutParam = true;
 181                                         break;
 182                         }
 183                 }
 184         }
 185
 186         if ((IsPolymorphicType(returnType) || genericOutParam)
 187                 && !genericInParam)
 188                 ereport(ERROR,
 189                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 190                                  errmsg("cannot determine result data type"),
 191                                  errdetail("A function returning a polymorphic type must have at least one polymorphic argument.")));
 192
 193         if ((returnType == INTERNALOID || internalOutParam) && !internalInParam)
 194                 ereport(ERROR,
 195                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 196                                  errmsg("unsafe use of pseudo-type \"internal\""),
 197                                  errdetail("A function returning \"internal\" must have at least one \"internal\" argument.")));
 198
 199         /*
 200          * don't allow functions of complex types that have the same name as
 201          * existing attributes of the type
 202          */
 203         if (parameterCount == 1 &&
 204                 OidIsValid(parameterTypes->values[0]) &&
 205                 (relid = typeidTypeRelid(parameterTypes->values[0])) != InvalidOid &&
 206                 get_attnum(relid, procedureName) != InvalidAttrNumber)
 207                 ereport(ERROR,
 208                                 (errcode(ERRCODE_DUPLICATE_COLUMN),
 209                                  errmsg("\"%s\" is already an attribute of type %s",
 210                                                 procedureName,
 211                                                 format_type_be(parameterTypes->values[0]))));
 212
 213         /*
 214          * All seems OK; prepare the data to be inserted into pg_proc.
 215          */
 216
 217         for (i = 0; i < Natts_pg_proc; ++i)
 218         {
 219                 nulls[i] = ' ';
 220                 values[i] = (Datum) 0;
 221                 replaces[i] = 'r';
 222         }
 223
 224         namestrcpy(&procname, procedureName);
 225         values[Anum_pg_proc_proname - 1] = NameGetDatum(&procname);
 226         values[Anum_pg_proc_pronamespace - 1] = ObjectIdGetDatum(procNamespace);
 227         values[Anum_pg_proc_proowner - 1] = ObjectIdGetDatum(GetUserId());
 228         values[Anum_pg_proc_prolang - 1] = ObjectIdGetDatum(languageObjectId);
 229         values[Anum_pg_proc_procost - 1] = Float4GetDatum(procost);
 230         values[Anum_pg_proc_prorows - 1] = Float4GetDatum(prorows);
 231         values[Anum_pg_proc_proisagg - 1] = BoolGetDatum(isAgg);
 232         values[Anum_pg_proc_prosecdef - 1] = BoolGetDatum(security_definer);
 233         values[Anum_pg_proc_proisstrict - 1] = BoolGetDatum(isStrict);
 234         values[Anum_pg_proc_proretset - 1] = BoolGetDatum(returnsSet);
 235         values[Anum_pg_proc_provolatile - 1] = CharGetDatum(volatility);
 236         values[Anum_pg_proc_pronargs - 1] = UInt16GetDatum(parameterCount);
 237         values[Anum_pg_proc_prorettype - 1] = ObjectIdGetDatum(returnType);
 238         values[Anum_pg_proc_proargtypes - 1] = PointerGetDatum(parameterTypes);
 239         if (allParameterTypes != PointerGetDatum(NULL))
 240                 values[Anum_pg_proc_proallargtypes - 1] = allParameterTypes;
 241         else
 242                 nulls[Anum_pg_proc_proallargtypes - 1] = 'n';
 243         if (parameterModes != PointerGetDatum(NULL))
 244                 values[Anum_pg_proc_proargmodes - 1] = parameterModes;
 245         else
 246                 nulls[Anum_pg_proc_proargmodes - 1] = 'n';
 247         if (parameterNames != PointerGetDatum(NULL))
 248                 values[Anum_pg_proc_proargnames - 1] = parameterNames;
 249         else
 250                 nulls[Anum_pg_proc_proargnames - 1] = 'n';
 251         values[Anum_pg_proc_prosrc - 1] = DirectFunctionCall1(textin,
 252                                                                                                         CStringGetDatum(prosrc));
 253         values[Anum_pg_proc_probin - 1] = DirectFunctionCall1(textin,
 254                                                                                                         CStringGetDatum(probin));
 255         if (proconfig != PointerGetDatum(NULL))
 256                 values[Anum_pg_proc_proconfig - 1] = proconfig;
 257         else
 258                 nulls[Anum_pg_proc_proconfig - 1] = 'n';
 259         /* start out with empty permissions */
 260         nulls[Anum_pg_proc_proacl - 1] = 'n';
 261
 262         rel = heap_open(ProcedureRelationId, RowExclusiveLock);
 263         tupDesc = RelationGetDescr(rel);
 264
 265         /* Check for pre-existing definition */
 266         oldtup = SearchSysCache(PROCNAMEARGSNSP,
 267                                                         PointerGetDatum(procedureName),
 268                                                         PointerGetDatum(parameterTypes),
 269                                                         ObjectIdGetDatum(procNamespace),
 270                                                         0);
 271
 272         if (HeapTupleIsValid(oldtup))
 273         {
 274                 /* There is one; okay to replace it? */
 275                 Form_pg_proc oldproc = (Form_pg_proc) GETSTRUCT(oldtup);
 276
 277                 if (!replace)
 278                         ereport(ERROR,
 279                                         (errcode(ERRCODE_DUPLICATE_FUNCTION),
 280                         errmsg("function \"%s\" already exists with same argument types",
 281                                    procedureName)));
 282                 if (!pg_proc_ownercheck(HeapTupleGetOid(oldtup), GetUserId()))
 283                         aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
 284                                                    procedureName);
 285
 286                 /*
 287                  * Not okay to change the return type of the existing proc, since
 288                  * existing rules, views, etc may depend on the return type.
 289                  */
 290                 if (returnType != oldproc->prorettype ||
 291                         returnsSet != oldproc->proretset)
 292                         ereport(ERROR,
 293                                         (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 294                                          errmsg("cannot change return type of existing function"),
 295                                          errhint("Use DROP FUNCTION first.")));
 296
 297                 /*
 298                  * If it returns RECORD, check for possible change of record type
 299                  * implied by OUT parameters
 300                  */
 301                 if (returnType == RECORDOID)
 302                 {
 303                         TupleDesc       olddesc;
 304                         TupleDesc       newdesc;
 305
 306                         olddesc = build_function_result_tupdesc_t(oldtup);
 307                         newdesc = build_function_result_tupdesc_d(allParameterTypes,
 308                                                                                                           parameterModes,
 309                                                                                                           parameterNames);
 310                         if (olddesc == NULL && newdesc == NULL)
 311                                  /* ok, both are runtime-defined RECORDs */ ;
 312                         else if (olddesc == NULL || newdesc == NULL ||
 313                                          !equalTupleDescs(olddesc, newdesc))
 314                                 ereport(ERROR,
 315                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 316                                         errmsg("cannot change return type of existing function"),
 317                                 errdetail("Row type defined by OUT parameters is different."),
 318                                                  errhint("Use DROP FUNCTION first.")));
 319                 }
 320
 321                 /* Can't change aggregate status, either */
 322                 if (oldproc->proisagg != isAgg)
 323                 {
 324                         if (oldproc->proisagg)
 325                                 ereport(ERROR,
 326                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 327                                                  errmsg("function \"%s\" is an aggregate",
 328                                                                 procedureName)));
 329                         else
 330                                 ereport(ERROR,
 331                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 332                                                  errmsg("function \"%s\" is not an aggregate",
 333                                                                 procedureName)));
 334                 }
 335
 336                 /* do not change existing ownership or permissions, either */
 337                 replaces[Anum_pg_proc_proowner - 1] = ' ';
 338                 replaces[Anum_pg_proc_proacl - 1] = ' ';
 339
 340                 /* Okay, do it... */
 341                 tup = heap_modifytuple(oldtup, tupDesc, values, nulls, replaces);
 342                 simple_heap_update(rel, &tup->t_self, tup);
 343
 344                 ReleaseSysCache(oldtup);
 345                 is_update = true;
 346         }
 347         else
 348         {
 349                 /* Creating a new procedure */
 350                 tup = heap_formtuple(tupDesc, values, nulls);
 351                 simple_heap_insert(rel, tup);
 352                 is_update = false;
 353         }
 354
 355         /* Need to update indexes for either the insert or update case */
 356         CatalogUpdateIndexes(rel, tup);
 357
 358         retval = HeapTupleGetOid(tup);
 359
 360         /*
 361          * Create dependencies for the new function.  If we are updating an
 362          * existing function, first delete any existing pg_depend entries.
 363          */
 364         if (is_update)
 365         {
 366                 deleteDependencyRecordsFor(ProcedureRelationId, retval);
 367                 deleteSharedDependencyRecordsFor(ProcedureRelationId, retval);
 368         }
 369
 370         myself.classId = ProcedureRelationId;
 371         myself.objectId = retval;
 372         myself.objectSubId = 0;
 373
 374         /* dependency on namespace */
 375         referenced.classId = NamespaceRelationId;
 376         referenced.objectId = procNamespace;
 377         referenced.objectSubId = 0;
 378         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 379
 380         /* dependency on implementation language */
 381         referenced.classId = LanguageRelationId;
 382         referenced.objectId = languageObjectId;
 383         referenced.objectSubId = 0;
 384         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 385
 386         /* dependency on return type */
 387         referenced.classId = TypeRelationId;
 388         referenced.objectId = returnType;
 389         referenced.objectSubId = 0;
 390         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 391
 392         /* dependency on parameter types */
 393         for (i = 0; i < allParamCount; i++)
 394         {
 395                 referenced.classId = TypeRelationId;
 396                 referenced.objectId = allParams[i];
 397                 referenced.objectSubId = 0;
 398                 recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 399         }
 400
 401         /* dependency on owner */
 402         recordDependencyOnOwner(ProcedureRelationId, retval, GetUserId());
 403
 404         heap_freetuple(tup);
 405
 406         heap_close(rel, RowExclusiveLock);
 407
 408         /* Verify function body */
 409         if (OidIsValid(languageValidator))
 410         {
 411                 /* Advance command counter so new tuple can be seen by validator */
 412                 CommandCounterIncrement();
 413                 OidFunctionCall1(languageValidator, ObjectIdGetDatum(retval));
 414         }
 415
 416         return retval;
 417 }
 418
 419
 420
 421 /*
 422  * Validator for internal functions
 423  *
 424  * Check that the given internal function name (the "prosrc" value) is
 425  * a known builtin function.
 426  */
 427 Datum
 428 fmgr_internal_validator(PG_FUNCTION_ARGS)
 429 {
 430         Oid                     funcoid = PG_GETARG_OID(0);
 431         HeapTuple       tuple;
 432         Form_pg_proc proc;
 433         bool            isnull;
 434         Datum           tmp;
 435         char       *prosrc;
 436
 437         /*
 438          * We do not honor check_function_bodies since it's unlikely the function
 439          * name will be found later if it isn't there now.
 440          */
 441
 442         tuple = SearchSysCache(PROCOID,
 443                                                    ObjectIdGetDatum(funcoid),
 444                                                    0, 0, 0);
 445         if (!HeapTupleIsValid(tuple))
 446                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 447         proc = (Form_pg_proc) GETSTRUCT(tuple);
 448
 449         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 450         if (isnull)
 451                 elog(ERROR, "null prosrc");
 452         prosrc = DatumGetCString(DirectFunctionCall1(textout, tmp));
 453
 454         if (fmgr_internal_function(prosrc) == InvalidOid)
 455                 ereport(ERROR,
 456                                 (errcode(ERRCODE_UNDEFINED_FUNCTION),
 457                                  errmsg("there is no built-in function named \"%s\"",
 458                                                 prosrc)));
 459
 460         ReleaseSysCache(tuple);
 461
 462         PG_RETURN_VOID();
 463 }
 464
 465
 466
 467 /*
 468  * Validator for C language functions
 469  *
 470  * Make sure that the library file exists, is loadable, and contains
 471  * the specified link symbol. Also check for a valid function
 472  * information record.
 473  */
 474 Datum
 475 fmgr_c_validator(PG_FUNCTION_ARGS)
 476 {
 477         Oid                     funcoid = PG_GETARG_OID(0);
 478         void       *libraryhandle;
 479         HeapTuple       tuple;
 480         Form_pg_proc proc;
 481         bool            isnull;
 482         Datum           tmp;
 483         char       *prosrc;
 484         char       *probin;
 485
 486         /*
 487          * It'd be most consistent to skip the check if !check_function_bodies,
 488          * but the purpose of that switch is to be helpful for pg_dump loading,
 489          * and for pg_dump loading it's much better if we *do* check.
 490          */
 491
 492         tuple = SearchSysCache(PROCOID,
 493                                                    ObjectIdGetDatum(funcoid),
 494                                                    0, 0, 0);
 495         if (!HeapTupleIsValid(tuple))
 496                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 497         proc = (Form_pg_proc) GETSTRUCT(tuple);
 498
 499         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 500         if (isnull)
 501                 elog(ERROR, "null prosrc");
 502         prosrc = DatumGetCString(DirectFunctionCall1(textout, tmp));
 503
 504         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_probin, &isnull);
 505         if (isnull)
 506                 elog(ERROR, "null probin");
 507         probin = DatumGetCString(DirectFunctionCall1(textout, tmp));
 508
 509         (void) load_external_function(probin, prosrc, true, &libraryhandle);
 510         (void) fetch_finfo_record(libraryhandle, prosrc);
 511
 512         ReleaseSysCache(tuple);
 513
 514         PG_RETURN_VOID();
 515 }
 516
 517
 518 /*
 519  * Validator for SQL language functions
 520  *
 521  * Parse it here in order to be sure that it contains no syntax errors.
 522  */
 523 Datum
 524 fmgr_sql_validator(PG_FUNCTION_ARGS)
 525 {
 526         Oid                     funcoid = PG_GETARG_OID(0);
 527         HeapTuple       tuple;
 528         Form_pg_proc proc;
 529         List       *querytree_list;
 530         bool            isnull;
 531         Datum           tmp;
 532         char       *prosrc;
 533         ErrorContextCallback sqlerrcontext;
 534         bool            haspolyarg;
 535         int                     i;
 536
 537         tuple = SearchSysCache(PROCOID,
 538                                                    ObjectIdGetDatum(funcoid),
 539                                                    0, 0, 0);
 540         if (!HeapTupleIsValid(tuple))
 541                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 542         proc = (Form_pg_proc) GETSTRUCT(tuple);
 543
 544         /* Disallow pseudotype result */
 545         /* except for RECORD, VOID, or polymorphic */
 546         if (get_typtype(proc->prorettype) == TYPTYPE_PSEUDO &&
 547                 proc->prorettype != RECORDOID &&
 548                 proc->prorettype != VOIDOID &&
 549                 !IsPolymorphicType(proc->prorettype))
 550                 ereport(ERROR,
 551                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 552                                  errmsg("SQL functions cannot return type %s",
 553                                                 format_type_be(proc->prorettype))));
 554
 555         /* Disallow pseudotypes in arguments */
 556         /* except for polymorphic */
 557         haspolyarg = false;
 558         for (i = 0; i < proc->pronargs; i++)
 559         {
 560                 if (get_typtype(proc->proargtypes.values[i]) == TYPTYPE_PSEUDO)
 561                 {
 562                         if (IsPolymorphicType(proc->proargtypes.values[i]))
 563                                 haspolyarg = true;
 564                         else
 565                                 ereport(ERROR,
 566                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 567                                          errmsg("SQL functions cannot have arguments of type %s",
 568                                                         format_type_be(proc->proargtypes.values[i]))));
 569                 }
 570         }
 571
 572         /* Postpone body checks if !check_function_bodies */
 573         if (check_function_bodies)
 574         {
 575                 tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 576                 if (isnull)
 577                         elog(ERROR, "null prosrc");
 578
 579                 prosrc = DatumGetCString(DirectFunctionCall1(textout, tmp));
 580
 581                 /*
 582                  * Setup error traceback support for ereport().
 583                  */
 584                 sqlerrcontext.callback = sql_function_parse_error_callback;
 585                 sqlerrcontext.arg = tuple;
 586                 sqlerrcontext.previous = error_context_stack;
 587                 error_context_stack = &sqlerrcontext;
 588
 589                 /*
 590                  * We can't do full prechecking of the function definition if there
 591                  * are any polymorphic input types, because actual datatypes of
 592                  * expression results will be unresolvable.  The check will be done at
 593                  * runtime instead.
 594                  *
 595                  * We can run the text through the raw parser though; this will at
 596                  * least catch silly syntactic errors.
 597                  */
 598                 if (!haspolyarg)
 599                 {
 600                         querytree_list = pg_parse_and_rewrite(prosrc,
 601                                                                                                   proc->proargtypes.values,
 602                                                                                                   proc->pronargs);
 603                         (void) check_sql_fn_retval(funcoid, proc->prorettype,
 604                                                                            querytree_list,
 605                                                                            false, NULL);
 606                 }
 607                 else
 608                         querytree_list = pg_parse_query(prosrc);
 609
 610                 error_context_stack = sqlerrcontext.previous;
 611         }
 612
 613         ReleaseSysCache(tuple);
 614
 615         PG_RETURN_VOID();
 616 }
 617
 618 /*
 619  * Error context callback for handling errors in SQL function definitions
 620  */
 621 static void
 622 sql_function_parse_error_callback(void *arg)
 623 {
 624         HeapTuple       tuple = (HeapTuple) arg;
 625         Form_pg_proc proc = (Form_pg_proc) GETSTRUCT(tuple);
 626         bool            isnull;
 627         Datum           tmp;
 628         char       *prosrc;
 629
 630         /* See if it's a syntax error; if so, transpose to CREATE FUNCTION */
 631         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 632         if (isnull)
 633                 elog(ERROR, "null prosrc");
 634         prosrc = DatumGetCString(DirectFunctionCall1(textout, tmp));
 635
 636         if (!function_parse_error_transpose(prosrc))
 637         {
 638                 /* If it's not a syntax error, push info onto context stack */
 639                 errcontext("SQL function \"%s\"", NameStr(proc->proname));
 640         }
 641
 642         pfree(prosrc);
 643 }
 644
 645 /*
 646  * Adjust a syntax error occurring inside the function body of a CREATE
 647  * FUNCTION command.  This can be used by any function validator, not only
 648  * for SQL-language functions.  It is assumed that the syntax error position
 649  * is initially relative to the function body string (as passed in).  If
 650  * possible, we adjust the position to reference the original CREATE command;
 651  * if we can't manage that, we set up an "internal query" syntax error instead.
 652  *
 653  * Returns true if a syntax error was processed, false if not.
 654  */
 655 bool
 656 function_parse_error_transpose(const char *prosrc)
 657 {
 658         int                     origerrposition;
 659         int                     newerrposition;
 660         const char *queryText;
 661
 662         /*
 663          * Nothing to do unless we are dealing with a syntax error that has a
 664          * cursor position.
 665          *
 666          * Some PLs may prefer to report the error position as an internal error
 667          * to begin with, so check that too.
 668          */
 669         origerrposition = geterrposition();
 670         if (origerrposition <= 0)
 671         {
 672                 origerrposition = getinternalerrposition();
 673                 if (origerrposition <= 0)
 674                         return false;
 675         }
 676
 677         /* We can get the original query text from the active portal (hack...) */
 678         Assert(ActivePortal && ActivePortal->status == PORTAL_ACTIVE);
 679         queryText = ActivePortal->sourceText;
 680
 681         /* Try to locate the prosrc in the original text */
 682         newerrposition = match_prosrc_to_query(prosrc, queryText, origerrposition);
 683
 684         if (newerrposition > 0)
 685         {
 686                 /* Successful, so fix error position to reference original query */
 687                 errposition(newerrposition);
 688                 /* Get rid of any report of the error as an "internal query" */
 689                 internalerrposition(0);
 690                 internalerrquery(NULL);
 691         }
 692         else
 693         {
 694                 /*
 695                  * If unsuccessful, convert the position to an internal position
 696                  * marker and give the function text as the internal query.
 697                  */
 698                 errposition(0);
 699                 internalerrposition(origerrposition);
 700                 internalerrquery(prosrc);
 701         }
 702
 703         return true;
 704 }
 705
 706 /*
 707  * Try to locate the string literal containing the function body in the
 708  * given text of the CREATE FUNCTION command.  If successful, return the
 709  * character (not byte) index within the command corresponding to the
 710  * given character index within the literal.  If not successful, return 0.
 711  */
 712 static int
 713 match_prosrc_to_query(const char *prosrc, const char *queryText,
 714                                           int cursorpos)
 715 {
 716         /*
 717          * Rather than fully parsing the CREATE FUNCTION command, we just scan the
 718          * command looking for $prosrc$ or 'prosrc'.  This could be fooled (though
 719          * not in any very probable scenarios), so fail if we find more than one
 720          * match.
 721          */
 722         int                     prosrclen = strlen(prosrc);
 723         int                     querylen = strlen(queryText);
 724         int                     matchpos = 0;
 725         int                     curpos;
 726         int                     newcursorpos;
 727
 728         for (curpos = 0; curpos < querylen - prosrclen; curpos++)
 729         {
 730                 if (queryText[curpos] == '$' &&
 731                         strncmp(prosrc, &queryText[curpos + 1], prosrclen) == 0 &&
 732                         queryText[curpos + 1 + prosrclen] == '$')
 733                 {
 734                         /*
 735                          * Found a $foo$ match.  Since there are no embedded quoting
 736                          * characters in a dollar-quoted literal, we don't have to do any
 737                          * fancy arithmetic; just offset by the starting position.
 738                          */
 739                         if (matchpos)
 740                                 return 0;               /* multiple matches, fail */
 741                         matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
 742                                 + cursorpos;
 743                 }
 744                 else if (queryText[curpos] == '\'' &&
 745                                  match_prosrc_to_literal(prosrc, &queryText[curpos + 1],
 746                                                                                  cursorpos, &newcursorpos))
 747                 {
 748                         /*
 749                          * Found a 'foo' match.  match_prosrc_to_literal() has adjusted
 750                          * for any quotes or backslashes embedded in the literal.
 751                          */
 752                         if (matchpos)
 753                                 return 0;               /* multiple matches, fail */
 754                         matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
 755                                 + newcursorpos;
 756                 }
 757         }
 758
 759         return matchpos;
 760 }
 761
 762 /*
 763  * Try to match the given source text to a single-quoted literal.
 764  * If successful, adjust newcursorpos to correspond to the character
 765  * (not byte) index corresponding to cursorpos in the source text.
 766  *
 767  * At entry, literal points just past a ' character.  We must check for the
 768  * trailing quote.
 769  */
 770 static bool
 771 match_prosrc_to_literal(const char *prosrc, const char *literal,
 772                                                 int cursorpos, int *newcursorpos)
 773 {
 774         int                     newcp = cursorpos;
 775         int                     chlen;
 776
 777         /*
 778          * This implementation handles backslashes and doubled quotes in the
 779          * string literal.      It does not handle the SQL syntax for literals
 780          * continued across line boundaries.
 781          *
 782          * We do the comparison a character at a time, not a byte at a time, so
 783          * that we can do the correct cursorpos math.
 784          */
 785         while (*prosrc)
 786         {
 787                 cursorpos--;                    /* characters left before cursor */
 788
 789                 /*
 790                  * Check for backslashes and doubled quotes in the literal; adjust
 791                  * newcp when one is found before the cursor.
 792                  */
 793                 if (*literal == '\\')
 794                 {
 795                         literal++;
 796                         if (cursorpos > 0)
 797                                 newcp++;
 798                 }
 799                 else if (*literal == '\'')
 800                 {
 801                         if (literal[1] != '\'')
 802                                 goto fail;
 803                         literal++;
 804                         if (cursorpos > 0)
 805                                 newcp++;
 806                 }
 807                 chlen = pg_mblen(prosrc);
 808                 if (strncmp(prosrc, literal, chlen) != 0)
 809                         goto fail;
 810                 prosrc += chlen;
 811                 literal += chlen;
 812         }
 813
 814         if (*literal == '\'' && literal[1] != '\'')
 815         {
 816                 /* success */
 817                 *newcursorpos = newcp;
 818                 return true;
 819         }
 820
 821 fail:
 822         /* Must set *newcursorpos to suppress compiler warning */
 823         *newcursorpos = newcp;
 824         return false;
 825 }