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 1.151 2008/03/27 03:57:33 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         Relation        rel;
  89         HeapTuple       tup;
  90         HeapTuple       oldtup;
  91         char            nulls[Natts_pg_proc];
  92         Datum           values[Natts_pg_proc];
  93         char            replaces[Natts_pg_proc];
  94         Oid                     relid;
  95         NameData        procname;
  96         TupleDesc       tupDesc;
  97         bool            is_update;
  98         ObjectAddress myself,
  99                                 referenced;
 100         int                     i;
 101
 102         /*
 103          * sanity checks
 104          */
 105         Assert(PointerIsValid(prosrc));
 106         Assert(PointerIsValid(probin));
 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         /*
 215          * All seems OK; prepare the data to be inserted into pg_proc.
 216          */
 217
 218         for (i = 0; i < Natts_pg_proc; ++i)
 219         {
 220                 nulls[i] = ' ';
 221                 values[i] = (Datum) 0;
 222                 replaces[i] = 'r';
 223         }
 224
 225         namestrcpy(&procname, procedureName);
 226         values[Anum_pg_proc_proname - 1] = NameGetDatum(&procname);
 227         values[Anum_pg_proc_pronamespace - 1] = ObjectIdGetDatum(procNamespace);
 228         values[Anum_pg_proc_proowner - 1] = ObjectIdGetDatum(GetUserId());
 229         values[Anum_pg_proc_prolang - 1] = ObjectIdGetDatum(languageObjectId);
 230         values[Anum_pg_proc_procost - 1] = Float4GetDatum(procost);
 231         values[Anum_pg_proc_prorows - 1] = Float4GetDatum(prorows);
 232         values[Anum_pg_proc_proisagg - 1] = BoolGetDatum(isAgg);
 233         values[Anum_pg_proc_prosecdef - 1] = BoolGetDatum(security_definer);
 234         values[Anum_pg_proc_proisstrict - 1] = BoolGetDatum(isStrict);
 235         values[Anum_pg_proc_proretset - 1] = BoolGetDatum(returnsSet);
 236         values[Anum_pg_proc_provolatile - 1] = CharGetDatum(volatility);
 237         values[Anum_pg_proc_pronargs - 1] = UInt16GetDatum(parameterCount);
 238         values[Anum_pg_proc_prorettype - 1] = ObjectIdGetDatum(returnType);
 239         values[Anum_pg_proc_proargtypes - 1] = PointerGetDatum(parameterTypes);
 240         if (allParameterTypes != PointerGetDatum(NULL))
 241                 values[Anum_pg_proc_proallargtypes - 1] = allParameterTypes;
 242         else
 243                 nulls[Anum_pg_proc_proallargtypes - 1] = 'n';
 244         if (parameterModes != PointerGetDatum(NULL))
 245                 values[Anum_pg_proc_proargmodes - 1] = parameterModes;
 246         else
 247                 nulls[Anum_pg_proc_proargmodes - 1] = 'n';
 248         if (parameterNames != PointerGetDatum(NULL))
 249                 values[Anum_pg_proc_proargnames - 1] = parameterNames;
 250         else
 251                 nulls[Anum_pg_proc_proargnames - 1] = 'n';
 252         values[Anum_pg_proc_prosrc - 1] = CStringGetTextDatum(prosrc);
 253         values[Anum_pg_proc_probin - 1] = CStringGetTextDatum(probin);
 254         if (proconfig != PointerGetDatum(NULL))
 255                 values[Anum_pg_proc_proconfig - 1] = proconfig;
 256         else
 257                 nulls[Anum_pg_proc_proconfig - 1] = 'n';
 258         /* start out with empty permissions */
 259         nulls[Anum_pg_proc_proacl - 1] = 'n';
 260
 261         rel = heap_open(ProcedureRelationId, RowExclusiveLock);
 262         tupDesc = RelationGetDescr(rel);
 263
 264         /* Check for pre-existing definition */
 265         oldtup = SearchSysCache(PROCNAMEARGSNSP,
 266                                                         PointerGetDatum(procedureName),
 267                                                         PointerGetDatum(parameterTypes),
 268                                                         ObjectIdGetDatum(procNamespace),
 269                                                         0);
 270
 271         if (HeapTupleIsValid(oldtup))
 272         {
 273                 /* There is one; okay to replace it? */
 274                 Form_pg_proc oldproc = (Form_pg_proc) GETSTRUCT(oldtup);
 275
 276                 if (!replace)
 277                         ereport(ERROR,
 278                                         (errcode(ERRCODE_DUPLICATE_FUNCTION),
 279                         errmsg("function \"%s\" already exists with same argument types",
 280                                    procedureName)));
 281                 if (!pg_proc_ownercheck(HeapTupleGetOid(oldtup), GetUserId()))
 282                         aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
 283                                                    procedureName);
 284
 285                 /*
 286                  * Not okay to change the return type of the existing proc, since
 287                  * existing rules, views, etc may depend on the return type.
 288                  */
 289                 if (returnType != oldproc->prorettype ||
 290                         returnsSet != oldproc->proretset)
 291                         ereport(ERROR,
 292                                         (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 293                                          errmsg("cannot change return type of existing function"),
 294                                          errhint("Use DROP FUNCTION first.")));
 295
 296                 /*
 297                  * If it returns RECORD, check for possible change of record type
 298                  * implied by OUT parameters
 299                  */
 300                 if (returnType == RECORDOID)
 301                 {
 302                         TupleDesc       olddesc;
 303                         TupleDesc       newdesc;
 304
 305                         olddesc = build_function_result_tupdesc_t(oldtup);
 306                         newdesc = build_function_result_tupdesc_d(allParameterTypes,
 307                                                                                                           parameterModes,
 308                                                                                                           parameterNames);
 309                         if (olddesc == NULL && newdesc == NULL)
 310                                  /* ok, both are runtime-defined RECORDs */ ;
 311                         else if (olddesc == NULL || newdesc == NULL ||
 312                                          !equalTupleDescs(olddesc, newdesc))
 313                                 ereport(ERROR,
 314                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 315                                         errmsg("cannot change return type of existing function"),
 316                                 errdetail("Row type defined by OUT parameters is different."),
 317                                                  errhint("Use DROP FUNCTION first.")));
 318                 }
 319
 320                 /* Can't change aggregate status, either */
 321                 if (oldproc->proisagg != isAgg)
 322                 {
 323                         if (oldproc->proisagg)
 324                                 ereport(ERROR,
 325                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 326                                                  errmsg("function \"%s\" is an aggregate",
 327                                                                 procedureName)));
 328                         else
 329                                 ereport(ERROR,
 330                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 331                                                  errmsg("function \"%s\" is not an aggregate",
 332                                                                 procedureName)));
 333                 }
 334
 335                 /* do not change existing ownership or permissions, either */
 336                 replaces[Anum_pg_proc_proowner - 1] = ' ';
 337                 replaces[Anum_pg_proc_proacl - 1] = ' ';
 338
 339                 /* Okay, do it... */
 340                 tup = heap_modifytuple(oldtup, tupDesc, values, nulls, replaces);
 341                 simple_heap_update(rel, &tup->t_self, tup);
 342
 343                 ReleaseSysCache(oldtup);
 344                 is_update = true;
 345         }
 346         else
 347         {
 348                 /* Creating a new procedure */
 349                 tup = heap_formtuple(tupDesc, values, nulls);
 350                 simple_heap_insert(rel, tup);
 351                 is_update = false;
 352         }
 353
 354         /* Need to update indexes for either the insert or update case */
 355         CatalogUpdateIndexes(rel, tup);
 356
 357         retval = HeapTupleGetOid(tup);
 358
 359         /*
 360          * Create dependencies for the new function.  If we are updating an
 361          * existing function, first delete any existing pg_depend entries.
 362          */
 363         if (is_update)
 364         {
 365                 deleteDependencyRecordsFor(ProcedureRelationId, retval);
 366                 deleteSharedDependencyRecordsFor(ProcedureRelationId, retval);
 367         }
 368
 369         myself.classId = ProcedureRelationId;
 370         myself.objectId = retval;
 371         myself.objectSubId = 0;
 372
 373         /* dependency on namespace */
 374         referenced.classId = NamespaceRelationId;
 375         referenced.objectId = procNamespace;
 376         referenced.objectSubId = 0;
 377         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 378
 379         /* dependency on implementation language */
 380         referenced.classId = LanguageRelationId;
 381         referenced.objectId = languageObjectId;
 382         referenced.objectSubId = 0;
 383         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 384
 385         /* dependency on return type */
 386         referenced.classId = TypeRelationId;
 387         referenced.objectId = returnType;
 388         referenced.objectSubId = 0;
 389         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 390
 391         /* dependency on parameter types */
 392         for (i = 0; i < allParamCount; i++)
 393         {
 394                 referenced.classId = TypeRelationId;
 395                 referenced.objectId = allParams[i];
 396                 referenced.objectSubId = 0;
 397                 recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 398         }
 399
 400         /* dependency on owner */
 401         recordDependencyOnOwner(ProcedureRelationId, retval, GetUserId());
 402
 403         heap_freetuple(tup);
 404
 405         heap_close(rel, RowExclusiveLock);
 406
 407         /* Verify function body */
 408         if (OidIsValid(languageValidator))
 409         {
 410                 /* Advance command counter so new tuple can be seen by validator */
 411                 CommandCounterIncrement();
 412                 OidFunctionCall1(languageValidator, ObjectIdGetDatum(retval));
 413         }
 414
 415         return retval;
 416 }
 417
 418
 419
 420 /*
 421  * Validator for internal functions
 422  *
 423  * Check that the given internal function name (the "prosrc" value) is
 424  * a known builtin function.
 425  */
 426 Datum
 427 fmgr_internal_validator(PG_FUNCTION_ARGS)
 428 {
 429         Oid                     funcoid = PG_GETARG_OID(0);
 430         HeapTuple       tuple;
 431         Form_pg_proc proc;
 432         bool            isnull;
 433         Datum           tmp;
 434         char       *prosrc;
 435
 436         /*
 437          * We do not honor check_function_bodies since it's unlikely the function
 438          * name will be found later if it isn't there now.
 439          */
 440
 441         tuple = SearchSysCache(PROCOID,
 442                                                    ObjectIdGetDatum(funcoid),
 443                                                    0, 0, 0);
 444         if (!HeapTupleIsValid(tuple))
 445                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 446         proc = (Form_pg_proc) GETSTRUCT(tuple);
 447
 448         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 449         if (isnull)
 450                 elog(ERROR, "null prosrc");
 451         prosrc = TextDatumGetCString(tmp);
 452
 453         if (fmgr_internal_function(prosrc) == InvalidOid)
 454                 ereport(ERROR,
 455                                 (errcode(ERRCODE_UNDEFINED_FUNCTION),
 456                                  errmsg("there is no built-in function named \"%s\"",
 457                                                 prosrc)));
 458
 459         ReleaseSysCache(tuple);
 460
 461         PG_RETURN_VOID();
 462 }
 463
 464
 465
 466 /*
 467  * Validator for C language functions
 468  *
 469  * Make sure that the library file exists, is loadable, and contains
 470  * the specified link symbol. Also check for a valid function
 471  * information record.
 472  */
 473 Datum
 474 fmgr_c_validator(PG_FUNCTION_ARGS)
 475 {
 476         Oid                     funcoid = PG_GETARG_OID(0);
 477         void       *libraryhandle;
 478         HeapTuple       tuple;
 479         Form_pg_proc proc;
 480         bool            isnull;
 481         Datum           tmp;
 482         char       *prosrc;
 483         char       *probin;
 484
 485         /*
 486          * It'd be most consistent to skip the check if !check_function_bodies,
 487          * but the purpose of that switch is to be helpful for pg_dump loading,
 488          * and for pg_dump loading it's much better if we *do* check.
 489          */
 490
 491         tuple = SearchSysCache(PROCOID,
 492                                                    ObjectIdGetDatum(funcoid),
 493                                                    0, 0, 0);
 494         if (!HeapTupleIsValid(tuple))
 495                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 496         proc = (Form_pg_proc) GETSTRUCT(tuple);
 497
 498         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 499         if (isnull)
 500                 elog(ERROR, "null prosrc");
 501         prosrc = TextDatumGetCString(tmp);
 502
 503         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_probin, &isnull);
 504         if (isnull)
 505                 elog(ERROR, "null probin");
 506         probin = TextDatumGetCString(tmp);
 507
 508         (void) load_external_function(probin, prosrc, true, &libraryhandle);
 509         (void) fetch_finfo_record(libraryhandle, prosrc);
 510
 511         ReleaseSysCache(tuple);
 512
 513         PG_RETURN_VOID();
 514 }
 515
 516
 517 /*
 518  * Validator for SQL language functions
 519  *
 520  * Parse it here in order to be sure that it contains no syntax errors.
 521  */
 522 Datum
 523 fmgr_sql_validator(PG_FUNCTION_ARGS)
 524 {
 525         Oid                     funcoid = PG_GETARG_OID(0);
 526         HeapTuple       tuple;
 527         Form_pg_proc proc;
 528         List       *querytree_list;
 529         bool            isnull;
 530         Datum           tmp;
 531         char       *prosrc;
 532         ErrorContextCallback sqlerrcontext;
 533         bool            haspolyarg;
 534         int                     i;
 535
 536         tuple = SearchSysCache(PROCOID,
 537                                                    ObjectIdGetDatum(funcoid),
 538                                                    0, 0, 0);
 539         if (!HeapTupleIsValid(tuple))
 540                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 541         proc = (Form_pg_proc) GETSTRUCT(tuple);
 542
 543         /* Disallow pseudotype result */
 544         /* except for RECORD, VOID, or polymorphic */
 545         if (get_typtype(proc->prorettype) == TYPTYPE_PSEUDO &&
 546                 proc->prorettype != RECORDOID &&
 547                 proc->prorettype != VOIDOID &&
 548                 !IsPolymorphicType(proc->prorettype))
 549                 ereport(ERROR,
 550                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 551                                  errmsg("SQL functions cannot return type %s",
 552                                                 format_type_be(proc->prorettype))));
 553
 554         /* Disallow pseudotypes in arguments */
 555         /* except for polymorphic */
 556         haspolyarg = false;
 557         for (i = 0; i < proc->pronargs; i++)
 558         {
 559                 if (get_typtype(proc->proargtypes.values[i]) == TYPTYPE_PSEUDO)
 560                 {
 561                         if (IsPolymorphicType(proc->proargtypes.values[i]))
 562                                 haspolyarg = true;
 563                         else
 564                                 ereport(ERROR,
 565                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 566                                          errmsg("SQL functions cannot have arguments of type %s",
 567                                                         format_type_be(proc->proargtypes.values[i]))));
 568                 }
 569         }
 570
 571         /* Postpone body checks if !check_function_bodies */
 572         if (check_function_bodies)
 573         {
 574                 tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 575                 if (isnull)
 576                         elog(ERROR, "null prosrc");
 577
 578                 prosrc = TextDatumGetCString(tmp);
 579
 580                 /*
 581                  * Setup error traceback support for ereport().
 582                  */
 583                 sqlerrcontext.callback = sql_function_parse_error_callback;
 584                 sqlerrcontext.arg = tuple;
 585                 sqlerrcontext.previous = error_context_stack;
 586                 error_context_stack = &sqlerrcontext;
 587
 588                 /*
 589                  * We can't do full prechecking of the function definition if there
 590                  * are any polymorphic input types, because actual datatypes of
 591                  * expression results will be unresolvable.  The check will be done at
 592                  * runtime instead.
 593                  *
 594                  * We can run the text through the raw parser though; this will at
 595                  * least catch silly syntactic errors.
 596                  */
 597                 if (!haspolyarg)
 598                 {
 599                         querytree_list = pg_parse_and_rewrite(prosrc,
 600                                                                                                   proc->proargtypes.values,
 601                                                                                                   proc->pronargs);
 602                         (void) check_sql_fn_retval(funcoid, proc->prorettype,
 603                                                                            querytree_list,
 604                                                                            false, NULL);
 605                 }
 606                 else
 607                         querytree_list = pg_parse_query(prosrc);
 608
 609                 error_context_stack = sqlerrcontext.previous;
 610         }
 611
 612         ReleaseSysCache(tuple);
 613
 614         PG_RETURN_VOID();
 615 }
 616
 617 /*
 618  * Error context callback for handling errors in SQL function definitions
 619  */
 620 static void
 621 sql_function_parse_error_callback(void *arg)
 622 {
 623         HeapTuple       tuple = (HeapTuple) arg;
 624         Form_pg_proc proc = (Form_pg_proc) GETSTRUCT(tuple);
 625         bool            isnull;
 626         Datum           tmp;
 627         char       *prosrc;
 628
 629         /* See if it's a syntax error; if so, transpose to CREATE FUNCTION */
 630         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 631         if (isnull)
 632                 elog(ERROR, "null prosrc");
 633         prosrc = TextDatumGetCString(tmp);
 634
 635         if (!function_parse_error_transpose(prosrc))
 636         {
 637                 /* If it's not a syntax error, push info onto context stack */
 638                 errcontext("SQL function \"%s\"", NameStr(proc->proname));
 639         }
 640
 641         pfree(prosrc);
 642 }
 643
 644 /*
 645  * Adjust a syntax error occurring inside the function body of a CREATE
 646  * FUNCTION command.  This can be used by any function validator, not only
 647  * for SQL-language functions.  It is assumed that the syntax error position
 648  * is initially relative to the function body string (as passed in).  If
 649  * possible, we adjust the position to reference the original CREATE command;
 650  * if we can't manage that, we set up an "internal query" syntax error instead.
 651  *
 652  * Returns true if a syntax error was processed, false if not.
 653  */
 654 bool
 655 function_parse_error_transpose(const char *prosrc)
 656 {
 657         int                     origerrposition;
 658         int                     newerrposition;
 659         const char *queryText;
 660
 661         /*
 662          * Nothing to do unless we are dealing with a syntax error that has a
 663          * cursor position.
 664          *
 665          * Some PLs may prefer to report the error position as an internal error
 666          * to begin with, so check that too.
 667          */
 668         origerrposition = geterrposition();
 669         if (origerrposition <= 0)
 670         {
 671                 origerrposition = getinternalerrposition();
 672                 if (origerrposition <= 0)
 673                         return false;
 674         }
 675
 676         /* We can get the original query text from the active portal (hack...) */
 677         Assert(ActivePortal && ActivePortal->status == PORTAL_ACTIVE);
 678         queryText = ActivePortal->sourceText;
 679
 680         /* Try to locate the prosrc in the original text */
 681         newerrposition = match_prosrc_to_query(prosrc, queryText, origerrposition);
 682
 683         if (newerrposition > 0)
 684         {
 685                 /* Successful, so fix error position to reference original query */
 686                 errposition(newerrposition);
 687                 /* Get rid of any report of the error as an "internal query" */
 688                 internalerrposition(0);
 689                 internalerrquery(NULL);
 690         }
 691         else
 692         {
 693                 /*
 694                  * If unsuccessful, convert the position to an internal position
 695                  * marker and give the function text as the internal query.
 696                  */
 697                 errposition(0);
 698                 internalerrposition(origerrposition);
 699                 internalerrquery(prosrc);
 700         }
 701
 702         return true;
 703 }
 704
 705 /*
 706  * Try to locate the string literal containing the function body in the
 707  * given text of the CREATE FUNCTION command.  If successful, return the
 708  * character (not byte) index within the command corresponding to the
 709  * given character index within the literal.  If not successful, return 0.
 710  */
 711 static int
 712 match_prosrc_to_query(const char *prosrc, const char *queryText,
 713                                           int cursorpos)
 714 {
 715         /*
 716          * Rather than fully parsing the CREATE FUNCTION command, we just scan the
 717          * command looking for $prosrc$ or 'prosrc'.  This could be fooled (though
 718          * not in any very probable scenarios), so fail if we find more than one
 719          * match.
 720          */
 721         int                     prosrclen = strlen(prosrc);
 722         int                     querylen = strlen(queryText);
 723         int                     matchpos = 0;
 724         int                     curpos;
 725         int                     newcursorpos;
 726
 727         for (curpos = 0; curpos < querylen - prosrclen; curpos++)
 728         {
 729                 if (queryText[curpos] == '$' &&
 730                         strncmp(prosrc, &queryText[curpos + 1], prosrclen) == 0 &&
 731                         queryText[curpos + 1 + prosrclen] == '$')
 732                 {
 733                         /*
 734                          * Found a $foo$ match.  Since there are no embedded quoting
 735                          * characters in a dollar-quoted literal, we don't have to do any
 736                          * fancy arithmetic; just offset by the starting position.
 737                          */
 738                         if (matchpos)
 739                                 return 0;               /* multiple matches, fail */
 740                         matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
 741                                 + cursorpos;
 742                 }
 743                 else if (queryText[curpos] == '\'' &&
 744                                  match_prosrc_to_literal(prosrc, &queryText[curpos + 1],
 745                                                                                  cursorpos, &newcursorpos))
 746                 {
 747                         /*
 748                          * Found a 'foo' match.  match_prosrc_to_literal() has adjusted
 749                          * for any quotes or backslashes embedded in the literal.
 750                          */
 751                         if (matchpos)
 752                                 return 0;               /* multiple matches, fail */
 753                         matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
 754                                 + newcursorpos;
 755                 }
 756         }
 757
 758         return matchpos;
 759 }
 760
 761 /*
 762  * Try to match the given source text to a single-quoted literal.
 763  * If successful, adjust newcursorpos to correspond to the character
 764  * (not byte) index corresponding to cursorpos in the source text.
 765  *
 766  * At entry, literal points just past a ' character.  We must check for the
 767  * trailing quote.
 768  */
 769 static bool
 770 match_prosrc_to_literal(const char *prosrc, const char *literal,
 771                                                 int cursorpos, int *newcursorpos)
 772 {
 773         int                     newcp = cursorpos;
 774         int                     chlen;
 775
 776         /*
 777          * This implementation handles backslashes and doubled quotes in the
 778          * string literal.      It does not handle the SQL syntax for literals
 779          * continued across line boundaries.
 780          *
 781          * We do the comparison a character at a time, not a byte at a time, so
 782          * that we can do the correct cursorpos math.
 783          */
 784         while (*prosrc)
 785         {
 786                 cursorpos--;                    /* characters left before cursor */
 787
 788                 /*
 789                  * Check for backslashes and doubled quotes in the literal; adjust
 790                  * newcp when one is found before the cursor.
 791                  */
 792                 if (*literal == '\\')
 793                 {
 794                         literal++;
 795                         if (cursorpos > 0)
 796                                 newcp++;
 797                 }
 798                 else if (*literal == '\'')
 799                 {
 800                         if (literal[1] != '\'')
 801                                 goto fail;
 802                         literal++;
 803                         if (cursorpos > 0)
 804                                 newcp++;
 805                 }
 806                 chlen = pg_mblen(prosrc);
 807                 if (strncmp(prosrc, literal, chlen) != 0)
 808                         goto fail;
 809                 prosrc += chlen;
 810                 literal += chlen;
 811         }
 812
 813         if (*literal == '\'' && literal[1] != '\'')
 814         {
 815                 /* success */
 816                 *newcursorpos = newcp;
 817                 return true;
 818         }
 819
 820 fail:
 821         /* Must set *newcursorpos to suppress compiler warning */
 822         *newcursorpos = newcp;
 823         return false;
 824 }