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) 1996-2007, 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 1.143 2007/01/22 01:35:20 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 are either arrays
  53  * of the proper types or NULL.  We declare them Datum, not "ArrayType *",
  54  * 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                                 float4 procost,
  76                                 float4 prorows)
  77 {
  78         Oid                     retval;
  79         int                     parameterCount;
  80         int                     allParamCount;
  81         Oid                *allParams;
  82         bool            genericInParam = false;
  83         bool            genericOutParam = false;
  84         bool            internalInParam = false;
  85         bool            internalOutParam = false;
  86         Relation        rel;
  87         HeapTuple       tup;
  88         HeapTuple       oldtup;
  89         char            nulls[Natts_pg_proc];
  90         Datum           values[Natts_pg_proc];
  91         char            replaces[Natts_pg_proc];
  92         Oid                     relid;
  93         NameData        procname;
  94         TupleDesc       tupDesc;
  95         bool            is_update;
  96         ObjectAddress myself,
  97                                 referenced;
  98         int                     i;
  99
 100         /*
 101          * sanity checks
 102          */
 103         Assert(PointerIsValid(prosrc));
 104         Assert(PointerIsValid(probin));
 105
 106         parameterCount = parameterTypes->dim1;
 107         if (parameterCount < 0 || parameterCount > FUNC_MAX_ARGS)
 108                 ereport(ERROR,
 109                                 (errcode(ERRCODE_TOO_MANY_ARGUMENTS),
 110                                  errmsg("functions cannot have more than %d arguments",
 111                                                 FUNC_MAX_ARGS)));
 112         /* note: the above is correct, we do NOT count output arguments */
 113
 114         if (allParameterTypes != PointerGetDatum(NULL))
 115         {
 116                 /*
 117                  * We expect the array to be a 1-D OID array; verify that. We don't
 118                  * need to use deconstruct_array() since the array data is just going
 119                  * to look like a C array of OID values.
 120                  */
 121                 ArrayType  *allParamArray = (ArrayType *) DatumGetPointer(allParameterTypes);
 122
 123                 allParamCount = ARR_DIMS(allParamArray)[0];
 124                 if (ARR_NDIM(allParamArray) != 1 ||
 125                         allParamCount <= 0 ||
 126                         ARR_HASNULL(allParamArray) ||
 127                         ARR_ELEMTYPE(allParamArray) != OIDOID)
 128                         elog(ERROR, "allParameterTypes is not a 1-D Oid array");
 129                 allParams = (Oid *) ARR_DATA_PTR(allParamArray);
 130                 Assert(allParamCount >= parameterCount);
 131                 /* we assume caller got the contents right */
 132         }
 133         else
 134         {
 135                 allParamCount = parameterCount;
 136                 allParams = parameterTypes->values;
 137         }
 138
 139         /*
 140          * Do not allow return type ANYARRAY or ANYELEMENT unless at least one
 141          * input argument is ANYARRAY or ANYELEMENT.  Also, do not allow return
 142          * type INTERNAL unless at least one input argument is INTERNAL.
 143          */
 144         for (i = 0; i < parameterCount; i++)
 145         {
 146                 switch (parameterTypes->values[i])
 147                 {
 148                         case ANYARRAYOID:
 149                         case ANYELEMENTOID:
 150                                 genericInParam = true;
 151                                 break;
 152                         case INTERNALOID:
 153                                 internalInParam = true;
 154                                 break;
 155                 }
 156         }
 157
 158         if (allParameterTypes != PointerGetDatum(NULL))
 159         {
 160                 for (i = 0; i < allParamCount; i++)
 161                 {
 162                         /*
 163                          * We don't bother to distinguish input and output params here, so
 164                          * if there is, say, just an input INTERNAL param then we will
 165                          * still set internalOutParam.  This is OK since we don't really
 166                          * care.
 167                          */
 168                         switch (allParams[i])
 169                         {
 170                                 case ANYARRAYOID:
 171                                 case ANYELEMENTOID:
 172                                         genericOutParam = true;
 173                                         break;
 174                                 case INTERNALOID:
 175                                         internalOutParam = true;
 176                                         break;
 177                         }
 178                 }
 179         }
 180
 181         if ((returnType == ANYARRAYOID || returnType == ANYELEMENTOID ||
 182                  genericOutParam) && !genericInParam)
 183                 ereport(ERROR,
 184                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 185                                  errmsg("cannot determine result data type"),
 186                                  errdetail("A function returning \"anyarray\" or \"anyelement\" must have at least one argument of either type.")));
 187
 188         if ((returnType == INTERNALOID || internalOutParam) && !internalInParam)
 189                 ereport(ERROR,
 190                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 191                                  errmsg("unsafe use of pseudo-type \"internal\""),
 192                                  errdetail("A function returning \"internal\" must have at least one \"internal\" argument.")));
 193
 194         /*
 195          * don't allow functions of complex types that have the same name as
 196          * existing attributes of the type
 197          */
 198         if (parameterCount == 1 &&
 199                 OidIsValid(parameterTypes->values[0]) &&
 200                 (relid = typeidTypeRelid(parameterTypes->values[0])) != InvalidOid &&
 201                 get_attnum(relid, procedureName) != InvalidAttrNumber)
 202                 ereport(ERROR,
 203                                 (errcode(ERRCODE_DUPLICATE_COLUMN),
 204                                  errmsg("\"%s\" is already an attribute of type %s",
 205                                                 procedureName,
 206                                                 format_type_be(parameterTypes->values[0]))));
 207
 208         /*
 209          * All seems OK; prepare the data to be inserted into pg_proc.
 210          */
 211
 212         for (i = 0; i < Natts_pg_proc; ++i)
 213         {
 214                 nulls[i] = ' ';
 215                 values[i] = (Datum) 0;
 216                 replaces[i] = 'r';
 217         }
 218
 219         namestrcpy(&procname, procedureName);
 220         values[Anum_pg_proc_proname - 1] = NameGetDatum(&procname);
 221         values[Anum_pg_proc_pronamespace - 1] = ObjectIdGetDatum(procNamespace);
 222         values[Anum_pg_proc_proowner - 1] = ObjectIdGetDatum(GetUserId());
 223         values[Anum_pg_proc_prolang - 1] = ObjectIdGetDatum(languageObjectId);
 224         values[Anum_pg_proc_procost - 1] = Float4GetDatum(procost);
 225         values[Anum_pg_proc_prorows - 1] = Float4GetDatum(prorows);
 226         values[Anum_pg_proc_proisagg - 1] = BoolGetDatum(isAgg);
 227         values[Anum_pg_proc_prosecdef - 1] = BoolGetDatum(security_definer);
 228         values[Anum_pg_proc_proisstrict - 1] = BoolGetDatum(isStrict);
 229         values[Anum_pg_proc_proretset - 1] = BoolGetDatum(returnsSet);
 230         values[Anum_pg_proc_provolatile - 1] = CharGetDatum(volatility);
 231         values[Anum_pg_proc_pronargs - 1] = UInt16GetDatum(parameterCount);
 232         values[Anum_pg_proc_prorettype - 1] = ObjectIdGetDatum(returnType);
 233         values[Anum_pg_proc_proargtypes - 1] = PointerGetDatum(parameterTypes);
 234         if (allParameterTypes != PointerGetDatum(NULL))
 235                 values[Anum_pg_proc_proallargtypes - 1] = allParameterTypes;
 236         else
 237                 nulls[Anum_pg_proc_proallargtypes - 1] = 'n';
 238         if (parameterModes != PointerGetDatum(NULL))
 239                 values[Anum_pg_proc_proargmodes - 1] = parameterModes;
 240         else
 241                 nulls[Anum_pg_proc_proargmodes - 1] = 'n';
 242         if (parameterNames != PointerGetDatum(NULL))
 243                 values[Anum_pg_proc_proargnames - 1] = parameterNames;
 244         else
 245                 nulls[Anum_pg_proc_proargnames - 1] = 'n';
 246         values[Anum_pg_proc_prosrc - 1] = DirectFunctionCall1(textin,
 247                                                                                                         CStringGetDatum(prosrc));
 248         values[Anum_pg_proc_probin - 1] = DirectFunctionCall1(textin,
 249                                                                                                         CStringGetDatum(probin));
 250         /* start out with empty permissions */
 251         nulls[Anum_pg_proc_proacl - 1] = 'n';
 252
 253         rel = heap_open(ProcedureRelationId, RowExclusiveLock);
 254         tupDesc = RelationGetDescr(rel);
 255
 256         /* Check for pre-existing definition */
 257         oldtup = SearchSysCache(PROCNAMEARGSNSP,
 258                                                         PointerGetDatum(procedureName),
 259                                                         PointerGetDatum(parameterTypes),
 260                                                         ObjectIdGetDatum(procNamespace),
 261                                                         0);
 262
 263         if (HeapTupleIsValid(oldtup))
 264         {
 265                 /* There is one; okay to replace it? */
 266                 Form_pg_proc oldproc = (Form_pg_proc) GETSTRUCT(oldtup);
 267
 268                 if (!replace)
 269                         ereport(ERROR,
 270                                         (errcode(ERRCODE_DUPLICATE_FUNCTION),
 271                         errmsg("function \"%s\" already exists with same argument types",
 272                                    procedureName)));
 273                 if (!pg_proc_ownercheck(HeapTupleGetOid(oldtup), GetUserId()))
 274                         aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
 275                                                    procedureName);
 276
 277                 /*
 278                  * Not okay to change the return type of the existing proc, since
 279                  * existing rules, views, etc may depend on the return type.
 280                  */
 281                 if (returnType != oldproc->prorettype ||
 282                         returnsSet != oldproc->proretset)
 283                         ereport(ERROR,
 284                                         (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 285                                          errmsg("cannot change return type of existing function"),
 286                                          errhint("Use DROP FUNCTION first.")));
 287
 288                 /*
 289                  * If it returns RECORD, check for possible change of record type
 290                  * implied by OUT parameters
 291                  */
 292                 if (returnType == RECORDOID)
 293                 {
 294                         TupleDesc       olddesc;
 295                         TupleDesc       newdesc;
 296
 297                         olddesc = build_function_result_tupdesc_t(oldtup);
 298                         newdesc = build_function_result_tupdesc_d(allParameterTypes,
 299                                                                                                           parameterModes,
 300                                                                                                           parameterNames);
 301                         if (olddesc == NULL && newdesc == NULL)
 302                                  /* ok, both are runtime-defined RECORDs */ ;
 303                         else if (olddesc == NULL || newdesc == NULL ||
 304                                          !equalTupleDescs(olddesc, newdesc))
 305                                 ereport(ERROR,
 306                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 307                                         errmsg("cannot change return type of existing function"),
 308                                 errdetail("Row type defined by OUT parameters is different."),
 309                                                  errhint("Use DROP FUNCTION first.")));
 310                 }
 311
 312                 /* Can't change aggregate status, either */
 313                 if (oldproc->proisagg != isAgg)
 314                 {
 315                         if (oldproc->proisagg)
 316                                 ereport(ERROR,
 317                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 318                                                  errmsg("function \"%s\" is an aggregate",
 319                                                                 procedureName)));
 320                         else
 321                                 ereport(ERROR,
 322                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 323                                                  errmsg("function \"%s\" is not an aggregate",
 324                                                                 procedureName)));
 325                 }
 326
 327                 /* do not change existing ownership or permissions, either */
 328                 replaces[Anum_pg_proc_proowner - 1] = ' ';
 329                 replaces[Anum_pg_proc_proacl - 1] = ' ';
 330
 331                 /* Okay, do it... */
 332                 tup = heap_modifytuple(oldtup, tupDesc, values, nulls, replaces);
 333                 simple_heap_update(rel, &tup->t_self, tup);
 334
 335                 ReleaseSysCache(oldtup);
 336                 is_update = true;
 337         }
 338         else
 339         {
 340                 /* Creating a new procedure */
 341                 tup = heap_formtuple(tupDesc, values, nulls);
 342                 simple_heap_insert(rel, tup);
 343                 is_update = false;
 344         }
 345
 346         /* Need to update indexes for either the insert or update case */
 347         CatalogUpdateIndexes(rel, tup);
 348
 349         retval = HeapTupleGetOid(tup);
 350
 351         /*
 352          * Create dependencies for the new function.  If we are updating an
 353          * existing function, first delete any existing pg_depend entries.
 354          */
 355         if (is_update)
 356         {
 357                 deleteDependencyRecordsFor(ProcedureRelationId, retval);
 358                 deleteSharedDependencyRecordsFor(ProcedureRelationId, retval);
 359         }
 360
 361         myself.classId = ProcedureRelationId;
 362         myself.objectId = retval;
 363         myself.objectSubId = 0;
 364
 365         /* dependency on namespace */
 366         referenced.classId = NamespaceRelationId;
 367         referenced.objectId = procNamespace;
 368         referenced.objectSubId = 0;
 369         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 370
 371         /* dependency on implementation language */
 372         referenced.classId = LanguageRelationId;
 373         referenced.objectId = languageObjectId;
 374         referenced.objectSubId = 0;
 375         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 376
 377         /* dependency on return type */
 378         referenced.classId = TypeRelationId;
 379         referenced.objectId = returnType;
 380         referenced.objectSubId = 0;
 381         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 382
 383         /* dependency on parameter types */
 384         for (i = 0; i < allParamCount; i++)
 385         {
 386                 referenced.classId = TypeRelationId;
 387                 referenced.objectId = allParams[i];
 388                 referenced.objectSubId = 0;
 389                 recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 390         }
 391
 392         /* dependency on owner */
 393         recordDependencyOnOwner(ProcedureRelationId, retval, GetUserId());
 394
 395         heap_freetuple(tup);
 396
 397         heap_close(rel, RowExclusiveLock);
 398
 399         /* Verify function body */
 400         if (OidIsValid(languageValidator))
 401         {
 402                 /* Advance command counter so new tuple can be seen by validator */
 403                 CommandCounterIncrement();
 404                 OidFunctionCall1(languageValidator, ObjectIdGetDatum(retval));
 405         }
 406
 407         return retval;
 408 }
 409
 410
 411
 412 /*
 413  * Validator for internal functions
 414  *
 415  * Check that the given internal function name (the "prosrc" value) is
 416  * a known builtin function.
 417  */
 418 Datum
 419 fmgr_internal_validator(PG_FUNCTION_ARGS)
 420 {
 421         Oid                     funcoid = PG_GETARG_OID(0);
 422         HeapTuple       tuple;
 423         Form_pg_proc proc;
 424         bool            isnull;
 425         Datum           tmp;
 426         char       *prosrc;
 427
 428         /*
 429          * We do not honor check_function_bodies since it's unlikely the function
 430          * name will be found later if it isn't there now.
 431          */
 432
 433         tuple = SearchSysCache(PROCOID,
 434                                                    ObjectIdGetDatum(funcoid),
 435                                                    0, 0, 0);
 436         if (!HeapTupleIsValid(tuple))
 437                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 438         proc = (Form_pg_proc) GETSTRUCT(tuple);
 439
 440         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 441         if (isnull)
 442                 elog(ERROR, "null prosrc");
 443         prosrc = DatumGetCString(DirectFunctionCall1(textout, tmp));
 444
 445         if (fmgr_internal_function(prosrc) == InvalidOid)
 446                 ereport(ERROR,
 447                                 (errcode(ERRCODE_UNDEFINED_FUNCTION),
 448                                  errmsg("there is no built-in function named \"%s\"",
 449                                                 prosrc)));
 450
 451         ReleaseSysCache(tuple);
 452
 453         PG_RETURN_VOID();
 454 }
 455
 456
 457
 458 /*
 459  * Validator for C language functions
 460  *
 461  * Make sure that the library file exists, is loadable, and contains
 462  * the specified link symbol. Also check for a valid function
 463  * information record.
 464  */
 465 Datum
 466 fmgr_c_validator(PG_FUNCTION_ARGS)
 467 {
 468         Oid                     funcoid = PG_GETARG_OID(0);
 469         void       *libraryhandle;
 470         HeapTuple       tuple;
 471         Form_pg_proc proc;
 472         bool            isnull;
 473         Datum           tmp;
 474         char       *prosrc;
 475         char       *probin;
 476
 477         /*
 478          * It'd be most consistent to skip the check if !check_function_bodies,
 479          * but the purpose of that switch is to be helpful for pg_dump loading,
 480          * and for pg_dump loading it's much better if we *do* check.
 481          */
 482
 483         tuple = SearchSysCache(PROCOID,
 484                                                    ObjectIdGetDatum(funcoid),
 485                                                    0, 0, 0);
 486         if (!HeapTupleIsValid(tuple))
 487                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 488         proc = (Form_pg_proc) GETSTRUCT(tuple);
 489
 490         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 491         if (isnull)
 492                 elog(ERROR, "null prosrc");
 493         prosrc = DatumGetCString(DirectFunctionCall1(textout, tmp));
 494
 495         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_probin, &isnull);
 496         if (isnull)
 497                 elog(ERROR, "null probin");
 498         probin = DatumGetCString(DirectFunctionCall1(textout, tmp));
 499
 500         (void) load_external_function(probin, prosrc, true, &libraryhandle);
 501         (void) fetch_finfo_record(libraryhandle, prosrc);
 502
 503         ReleaseSysCache(tuple);
 504
 505         PG_RETURN_VOID();
 506 }
 507
 508
 509 /*
 510  * Validator for SQL language functions
 511  *
 512  * Parse it here in order to be sure that it contains no syntax errors.
 513  */
 514 Datum
 515 fmgr_sql_validator(PG_FUNCTION_ARGS)
 516 {
 517         Oid                     funcoid = PG_GETARG_OID(0);
 518         HeapTuple       tuple;
 519         Form_pg_proc proc;
 520         List       *querytree_list;
 521         bool            isnull;
 522         Datum           tmp;
 523         char       *prosrc;
 524         ErrorContextCallback sqlerrcontext;
 525         bool            haspolyarg;
 526         int                     i;
 527
 528         tuple = SearchSysCache(PROCOID,
 529                                                    ObjectIdGetDatum(funcoid),
 530                                                    0, 0, 0);
 531         if (!HeapTupleIsValid(tuple))
 532                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 533         proc = (Form_pg_proc) GETSTRUCT(tuple);
 534
 535         /* Disallow pseudotype result */
 536         /* except for RECORD, VOID, ANYARRAY, or ANYELEMENT */
 537         if (get_typtype(proc->prorettype) == 'p' &&
 538                 proc->prorettype != RECORDOID &&
 539                 proc->prorettype != VOIDOID &&
 540                 proc->prorettype != ANYARRAYOID &&
 541                 proc->prorettype != ANYELEMENTOID)
 542                 ereport(ERROR,
 543                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 544                                  errmsg("SQL functions cannot return type %s",
 545                                                 format_type_be(proc->prorettype))));
 546
 547         /* Disallow pseudotypes in arguments */
 548         /* except for ANYARRAY or ANYELEMENT */
 549         haspolyarg = false;
 550         for (i = 0; i < proc->pronargs; i++)
 551         {
 552                 if (get_typtype(proc->proargtypes.values[i]) == 'p')
 553                 {
 554                         if (proc->proargtypes.values[i] == ANYARRAYOID ||
 555                                 proc->proargtypes.values[i] == ANYELEMENTOID)
 556                                 haspolyarg = true;
 557                         else
 558                                 ereport(ERROR,
 559                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 560                                          errmsg("SQL functions cannot have arguments of type %s",
 561                                                         format_type_be(proc->proargtypes.values[i]))));
 562                 }
 563         }
 564
 565         /* Postpone body checks if !check_function_bodies */
 566         if (check_function_bodies)
 567         {
 568                 tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 569                 if (isnull)
 570                         elog(ERROR, "null prosrc");
 571
 572                 prosrc = DatumGetCString(DirectFunctionCall1(textout, tmp));
 573
 574                 /*
 575                  * Setup error traceback support for ereport().
 576                  */
 577                 sqlerrcontext.callback = sql_function_parse_error_callback;
 578                 sqlerrcontext.arg = tuple;
 579                 sqlerrcontext.previous = error_context_stack;
 580                 error_context_stack = &sqlerrcontext;
 581
 582                 /*
 583                  * We can't do full prechecking of the function definition if there
 584                  * are any polymorphic input types, because actual datatypes of
 585                  * expression results will be unresolvable.  The check will be done at
 586                  * runtime instead.
 587                  *
 588                  * We can run the text through the raw parser though; this will at
 589                  * least catch silly syntactic errors.
 590                  */
 591                 if (!haspolyarg)
 592                 {
 593                         querytree_list = pg_parse_and_rewrite(prosrc,
 594                                                                                                   proc->proargtypes.values,
 595                                                                                                   proc->pronargs);
 596                         (void) check_sql_fn_retval(funcoid, proc->prorettype,
 597                                                                            querytree_list, NULL);
 598                 }
 599                 else
 600                         querytree_list = pg_parse_query(prosrc);
 601
 602                 error_context_stack = sqlerrcontext.previous;
 603         }
 604
 605         ReleaseSysCache(tuple);
 606
 607         PG_RETURN_VOID();
 608 }
 609
 610 /*
 611  * Error context callback for handling errors in SQL function definitions
 612  */
 613 static void
 614 sql_function_parse_error_callback(void *arg)
 615 {
 616         HeapTuple       tuple = (HeapTuple) arg;
 617         Form_pg_proc proc = (Form_pg_proc) GETSTRUCT(tuple);
 618         bool            isnull;
 619         Datum           tmp;
 620         char       *prosrc;
 621
 622         /* See if it's a syntax error; if so, transpose to CREATE FUNCTION */
 623         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 624         if (isnull)
 625                 elog(ERROR, "null prosrc");
 626         prosrc = DatumGetCString(DirectFunctionCall1(textout, tmp));
 627
 628         if (!function_parse_error_transpose(prosrc))
 629         {
 630                 /* If it's not a syntax error, push info onto context stack */
 631                 errcontext("SQL function \"%s\"", NameStr(proc->proname));
 632         }
 633
 634         pfree(prosrc);
 635 }
 636
 637 /*
 638  * Adjust a syntax error occurring inside the function body of a CREATE
 639  * FUNCTION command.  This can be used by any function validator, not only
 640  * for SQL-language functions.  It is assumed that the syntax error position
 641  * is initially relative to the function body string (as passed in).  If
 642  * possible, we adjust the position to reference the original CREATE command;
 643  * if we can't manage that, we set up an "internal query" syntax error instead.
 644  *
 645  * Returns true if a syntax error was processed, false if not.
 646  */
 647 bool
 648 function_parse_error_transpose(const char *prosrc)
 649 {
 650         int                     origerrposition;
 651         int                     newerrposition;
 652         const char *queryText;
 653
 654         /*
 655          * Nothing to do unless we are dealing with a syntax error that has a
 656          * cursor position.
 657          *
 658          * Some PLs may prefer to report the error position as an internal error
 659          * to begin with, so check that too.
 660          */
 661         origerrposition = geterrposition();
 662         if (origerrposition <= 0)
 663         {
 664                 origerrposition = getinternalerrposition();
 665                 if (origerrposition <= 0)
 666                         return false;
 667         }
 668
 669         /* We can get the original query text from the active portal (hack...) */
 670         Assert(ActivePortal && ActivePortal->status == PORTAL_ACTIVE);
 671         queryText = ActivePortal->sourceText;
 672
 673         /* Try to locate the prosrc in the original text */
 674         newerrposition = match_prosrc_to_query(prosrc, queryText, origerrposition);
 675
 676         if (newerrposition > 0)
 677         {
 678                 /* Successful, so fix error position to reference original query */
 679                 errposition(newerrposition);
 680                 /* Get rid of any report of the error as an "internal query" */
 681                 internalerrposition(0);
 682                 internalerrquery(NULL);
 683         }
 684         else
 685         {
 686                 /*
 687                  * If unsuccessful, convert the position to an internal position
 688                  * marker and give the function text as the internal query.
 689                  */
 690                 errposition(0);
 691                 internalerrposition(origerrposition);
 692                 internalerrquery(prosrc);
 693         }
 694
 695         return true;
 696 }
 697
 698 /*
 699  * Try to locate the string literal containing the function body in the
 700  * given text of the CREATE FUNCTION command.  If successful, return the
 701  * character (not byte) index within the command corresponding to the
 702  * given character index within the literal.  If not successful, return 0.
 703  */
 704 static int
 705 match_prosrc_to_query(const char *prosrc, const char *queryText,
 706                                           int cursorpos)
 707 {
 708         /*
 709          * Rather than fully parsing the CREATE FUNCTION command, we just scan the
 710          * command looking for $prosrc$ or 'prosrc'.  This could be fooled (though
 711          * not in any very probable scenarios), so fail if we find more than one
 712          * match.
 713          */
 714         int                     prosrclen = strlen(prosrc);
 715         int                     querylen = strlen(queryText);
 716         int                     matchpos = 0;
 717         int                     curpos;
 718         int                     newcursorpos;
 719
 720         for (curpos = 0; curpos < querylen - prosrclen; curpos++)
 721         {
 722                 if (queryText[curpos] == '$' &&
 723                         strncmp(prosrc, &queryText[curpos + 1], prosrclen) == 0 &&
 724                         queryText[curpos + 1 + prosrclen] == '$')
 725                 {
 726                         /*
 727                          * Found a $foo$ match.  Since there are no embedded quoting
 728                          * characters in a dollar-quoted literal, we don't have to do any
 729                          * fancy arithmetic; just offset by the starting position.
 730                          */
 731                         if (matchpos)
 732                                 return 0;               /* multiple matches, fail */
 733                         matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
 734                                 + cursorpos;
 735                 }
 736                 else if (queryText[curpos] == '\'' &&
 737                                  match_prosrc_to_literal(prosrc, &queryText[curpos + 1],
 738                                                                                  cursorpos, &newcursorpos))
 739                 {
 740                         /*
 741                          * Found a 'foo' match.  match_prosrc_to_literal() has adjusted
 742                          * for any quotes or backslashes embedded in the literal.
 743                          */
 744                         if (matchpos)
 745                                 return 0;               /* multiple matches, fail */
 746                         matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
 747                                 + newcursorpos;
 748                 }
 749         }
 750
 751         return matchpos;
 752 }
 753
 754 /*
 755  * Try to match the given source text to a single-quoted literal.
 756  * If successful, adjust newcursorpos to correspond to the character
 757  * (not byte) index corresponding to cursorpos in the source text.
 758  *
 759  * At entry, literal points just past a ' character.  We must check for the
 760  * trailing quote.
 761  */
 762 static bool
 763 match_prosrc_to_literal(const char *prosrc, const char *literal,
 764                                                 int cursorpos, int *newcursorpos)
 765 {
 766         int                     newcp = cursorpos;
 767         int                     chlen;
 768
 769         /*
 770          * This implementation handles backslashes and doubled quotes in the
 771          * string literal.      It does not handle the SQL syntax for literals
 772          * continued across line boundaries.
 773          *
 774          * We do the comparison a character at a time, not a byte at a time, so
 775          * that we can do the correct cursorpos math.
 776          */
 777         while (*prosrc)
 778         {
 779                 cursorpos--;                    /* characters left before cursor */
 780
 781                 /*
 782                  * Check for backslashes and doubled quotes in the literal; adjust
 783                  * newcp when one is found before the cursor.
 784                  */
 785                 if (*literal == '\\')
 786                 {
 787                         literal++;
 788                         if (cursorpos > 0)
 789                                 newcp++;
 790                 }
 791                 else if (*literal == '\'')
 792                 {
 793                         if (literal[1] != '\'')
 794                                 goto fail;
 795                         literal++;
 796                         if (cursorpos > 0)
 797                                 newcp++;
 798                 }
 799                 chlen = pg_mblen(prosrc);
 800                 if (strncmp(prosrc, literal, chlen) != 0)
 801                         goto fail;
 802                 prosrc += chlen;
 803                 literal += chlen;
 804         }
 805
 806         if (*literal == '\'' && literal[1] != '\'')
 807         {
 808                 /* success */
 809                 *newcursorpos = newcp;
 810                 return true;
 811         }
 812
 813 fail:
 814         /* Must set *newcursorpos to suppress compiler warning */
 815         *newcursorpos = newcp;
 816         return false;
 817 }