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) 1996-2009, 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 1.165 2009/09/22 23:43:37 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 "nodes/nodeFuncs.h"
  31 #include "parser/parse_type.h"
  32 #include "tcop/pquery.h"
  33 #include "tcop/tcopprot.h"
  34 #include "utils/acl.h"
  35 #include "utils/builtins.h"
  36 #include "utils/lsyscache.h"
  37 #include "utils/syscache.h"
  38
  39
  40 Datum           fmgr_internal_validator(PG_FUNCTION_ARGS);
  41 Datum           fmgr_c_validator(PG_FUNCTION_ARGS);
  42 Datum           fmgr_sql_validator(PG_FUNCTION_ARGS);
  43
  44 static void sql_function_parse_error_callback(void *arg);
  45 static int match_prosrc_to_query(const char *prosrc, const char *queryText,
  46                                           int cursorpos);
  47 static bool match_prosrc_to_literal(const char *prosrc, const char *literal,
  48                                                 int cursorpos, int *newcursorpos);
  49
  50
  51 /* ----------------------------------------------------------------
  52  *              ProcedureCreate
  53  *
  54  * Note: allParameterTypes, parameterModes, parameterNames, and proconfig
  55  * are either arrays of the proper types or NULL.  We declare them Datum,
  56  * not "ArrayType *", to avoid importing array.h into pg_proc_fn.h.
  57  * ----------------------------------------------------------------
  58  */
  59 Oid
  60 ProcedureCreate(const char *procedureName,
  61                                 Oid procNamespace,
  62                                 bool replace,
  63                                 bool returnsSet,
  64                                 Oid returnType,
  65                                 Oid languageObjectId,
  66                                 Oid languageValidator,
  67                                 const char *prosrc,
  68                                 const char *probin,
  69                                 bool isAgg,
  70                                 bool isWindowFunc,
  71                                 bool security_definer,
  72                                 bool isStrict,
  73                                 char volatility,
  74                                 oidvector *parameterTypes,
  75                                 Datum allParameterTypes,
  76                                 Datum parameterModes,
  77                                 Datum parameterNames,
  78                                 List *parameterDefaults,
  79                                 Datum proconfig,
  80                                 float4 procost,
  81                                 float4 prorows)
  82 {
  83         Oid                     retval;
  84         int                     parameterCount;
  85         int                     allParamCount;
  86         Oid                *allParams;
  87         bool            genericInParam = false;
  88         bool            genericOutParam = false;
  89         bool            internalInParam = false;
  90         bool            internalOutParam = false;
  91         Oid                     variadicType = InvalidOid;
  92         Relation        rel;
  93         HeapTuple       tup;
  94         HeapTuple       oldtup;
  95         bool            nulls[Natts_pg_proc];
  96         Datum           values[Natts_pg_proc];
  97         bool            replaces[Natts_pg_proc];
  98         Oid                     relid;
  99         NameData        procname;
 100         TupleDesc       tupDesc;
 101         bool            is_update;
 102         ObjectAddress myself,
 103                                 referenced;
 104         int                     i;
 105
 106         /*
 107          * sanity checks
 108          */
 109         Assert(PointerIsValid(prosrc));
 110
 111         parameterCount = parameterTypes->dim1;
 112         if (parameterCount < 0 || parameterCount > FUNC_MAX_ARGS)
 113                 ereport(ERROR,
 114                                 (errcode(ERRCODE_TOO_MANY_ARGUMENTS),
 115                                  errmsg_plural("functions cannot have more than %d argument",
 116                                                            "functions cannot have more than %d arguments",
 117                                                            FUNC_MAX_ARGS,
 118                                                            FUNC_MAX_ARGS)));
 119         /* note: the above is correct, we do NOT count output arguments */
 120
 121         if (allParameterTypes != PointerGetDatum(NULL))
 122         {
 123                 /*
 124                  * We expect the array to be a 1-D OID array; verify that. We don't
 125                  * need to use deconstruct_array() since the array data is just going
 126                  * to look like a C array of OID values.
 127                  */
 128                 ArrayType  *allParamArray = (ArrayType *) DatumGetPointer(allParameterTypes);
 129
 130                 allParamCount = ARR_DIMS(allParamArray)[0];
 131                 if (ARR_NDIM(allParamArray) != 1 ||
 132                         allParamCount <= 0 ||
 133                         ARR_HASNULL(allParamArray) ||
 134                         ARR_ELEMTYPE(allParamArray) != OIDOID)
 135                         elog(ERROR, "allParameterTypes is not a 1-D Oid array");
 136                 allParams = (Oid *) ARR_DATA_PTR(allParamArray);
 137                 Assert(allParamCount >= parameterCount);
 138                 /* we assume caller got the contents right */
 139         }
 140         else
 141         {
 142                 allParamCount = parameterCount;
 143                 allParams = parameterTypes->values;
 144         }
 145
 146         /*
 147          * Do not allow polymorphic return type unless at least one input argument
 148          * is polymorphic.      Also, do not allow return type INTERNAL unless at
 149          * least one input argument is INTERNAL.
 150          */
 151         for (i = 0; i < parameterCount; i++)
 152         {
 153                 switch (parameterTypes->values[i])
 154                 {
 155                         case ANYARRAYOID:
 156                         case ANYELEMENTOID:
 157                         case ANYNONARRAYOID:
 158                         case ANYENUMOID:
 159                                 genericInParam = true;
 160                                 break;
 161                         case INTERNALOID:
 162                                 internalInParam = true;
 163                                 break;
 164                 }
 165         }
 166
 167         if (allParameterTypes != PointerGetDatum(NULL))
 168         {
 169                 for (i = 0; i < allParamCount; i++)
 170                 {
 171                         /*
 172                          * We don't bother to distinguish input and output params here, so
 173                          * if there is, say, just an input INTERNAL param then we will
 174                          * still set internalOutParam.  This is OK since we don't really
 175                          * care.
 176                          */
 177                         switch (allParams[i])
 178                         {
 179                                 case ANYARRAYOID:
 180                                 case ANYELEMENTOID:
 181                                 case ANYNONARRAYOID:
 182                                 case ANYENUMOID:
 183                                         genericOutParam = true;
 184                                         break;
 185                                 case INTERNALOID:
 186                                         internalOutParam = true;
 187                                         break;
 188                         }
 189                 }
 190         }
 191
 192         if ((IsPolymorphicType(returnType) || genericOutParam)
 193                 && !genericInParam)
 194                 ereport(ERROR,
 195                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 196                                  errmsg("cannot determine result data type"),
 197                                  errdetail("A function returning a polymorphic type must have at least one polymorphic argument.")));
 198
 199         if ((returnType == INTERNALOID || internalOutParam) && !internalInParam)
 200                 ereport(ERROR,
 201                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 202                                  errmsg("unsafe use of pseudo-type \"internal\""),
 203                                  errdetail("A function returning \"internal\" must have at least one \"internal\" argument.")));
 204
 205         /*
 206          * don't allow functions of complex types that have the same name as
 207          * existing attributes of the type
 208          */
 209         if (parameterCount == 1 &&
 210                 OidIsValid(parameterTypes->values[0]) &&
 211                 (relid = typeidTypeRelid(parameterTypes->values[0])) != InvalidOid &&
 212                 get_attnum(relid, procedureName) != InvalidAttrNumber)
 213                 ereport(ERROR,
 214                                 (errcode(ERRCODE_DUPLICATE_COLUMN),
 215                                  errmsg("\"%s\" is already an attribute of type %s",
 216                                                 procedureName,
 217                                                 format_type_be(parameterTypes->values[0]))));
 218
 219         if (parameterModes != PointerGetDatum(NULL))
 220         {
 221                 /*
 222                  * We expect the array to be a 1-D CHAR array; verify that. We don't
 223                  * need to use deconstruct_array() since the array data is just going
 224                  * to look like a C array of char values.
 225                  */
 226                 ArrayType  *modesArray = (ArrayType *) DatumGetPointer(parameterModes);
 227                 char       *modes;
 228
 229                 if (ARR_NDIM(modesArray) != 1 ||
 230                         ARR_DIMS(modesArray)[0] != allParamCount ||
 231                         ARR_HASNULL(modesArray) ||
 232                         ARR_ELEMTYPE(modesArray) != CHAROID)
 233                         elog(ERROR, "parameterModes is not a 1-D char array");
 234                 modes = (char *) ARR_DATA_PTR(modesArray);
 235
 236                 /*
 237                  * Only the last input parameter can be variadic; if it is, save its
 238                  * element type.  Errors here are just elog since caller should have
 239                  * checked this already.
 240                  */
 241                 for (i = 0; i < allParamCount; i++)
 242                 {
 243                         switch (modes[i])
 244                         {
 245                                 case PROARGMODE_IN:
 246                                 case PROARGMODE_INOUT:
 247                                         if (OidIsValid(variadicType))
 248                                                 elog(ERROR, "variadic parameter must be last");
 249                                         break;
 250                                 case PROARGMODE_OUT:
 251                                 case PROARGMODE_TABLE:
 252                                         /* okay */
 253                                         break;
 254                                 case PROARGMODE_VARIADIC:
 255                                         if (OidIsValid(variadicType))
 256                                                 elog(ERROR, "variadic parameter must be last");
 257                                         switch (allParams[i])
 258                                         {
 259                                                 case ANYOID:
 260                                                         variadicType = ANYOID;
 261                                                         break;
 262                                                 case ANYARRAYOID:
 263                                                         variadicType = ANYELEMENTOID;
 264                                                         break;
 265                                                 default:
 266                                                         variadicType = get_element_type(allParams[i]);
 267                                                         if (!OidIsValid(variadicType))
 268                                                                 elog(ERROR, "variadic parameter is not an array");
 269                                                         break;
 270                                         }
 271                                         break;
 272                                 default:
 273                                         elog(ERROR, "invalid parameter mode '%c'", modes[i]);
 274                                         break;
 275                         }
 276                 }
 277         }
 278
 279         /*
 280          * All seems OK; prepare the data to be inserted into pg_proc.
 281          */
 282
 283         for (i = 0; i < Natts_pg_proc; ++i)
 284         {
 285                 nulls[i] = false;
 286                 values[i] = (Datum) 0;
 287                 replaces[i] = true;
 288         }
 289
 290         namestrcpy(&procname, procedureName);
 291         values[Anum_pg_proc_proname - 1] = NameGetDatum(&procname);
 292         values[Anum_pg_proc_pronamespace - 1] = ObjectIdGetDatum(procNamespace);
 293         values[Anum_pg_proc_proowner - 1] = ObjectIdGetDatum(GetUserId());
 294         values[Anum_pg_proc_prolang - 1] = ObjectIdGetDatum(languageObjectId);
 295         values[Anum_pg_proc_procost - 1] = Float4GetDatum(procost);
 296         values[Anum_pg_proc_prorows - 1] = Float4GetDatum(prorows);
 297         values[Anum_pg_proc_provariadic - 1] = ObjectIdGetDatum(variadicType);
 298         values[Anum_pg_proc_proisagg - 1] = BoolGetDatum(isAgg);
 299         values[Anum_pg_proc_proiswindow - 1] = BoolGetDatum(isWindowFunc);
 300         values[Anum_pg_proc_prosecdef - 1] = BoolGetDatum(security_definer);
 301         values[Anum_pg_proc_proisstrict - 1] = BoolGetDatum(isStrict);
 302         values[Anum_pg_proc_proretset - 1] = BoolGetDatum(returnsSet);
 303         values[Anum_pg_proc_provolatile - 1] = CharGetDatum(volatility);
 304         values[Anum_pg_proc_pronargs - 1] = UInt16GetDatum(parameterCount);
 305         values[Anum_pg_proc_pronargdefaults - 1] = UInt16GetDatum(list_length(parameterDefaults));
 306         values[Anum_pg_proc_prorettype - 1] = ObjectIdGetDatum(returnType);
 307         values[Anum_pg_proc_proargtypes - 1] = PointerGetDatum(parameterTypes);
 308         if (allParameterTypes != PointerGetDatum(NULL))
 309                 values[Anum_pg_proc_proallargtypes - 1] = allParameterTypes;
 310         else
 311                 nulls[Anum_pg_proc_proallargtypes - 1] = true;
 312         if (parameterModes != PointerGetDatum(NULL))
 313                 values[Anum_pg_proc_proargmodes - 1] = parameterModes;
 314         else
 315                 nulls[Anum_pg_proc_proargmodes - 1] = true;
 316         if (parameterNames != PointerGetDatum(NULL))
 317                 values[Anum_pg_proc_proargnames - 1] = parameterNames;
 318         else
 319                 nulls[Anum_pg_proc_proargnames - 1] = true;
 320         if (parameterDefaults != NIL)
 321                 values[Anum_pg_proc_proargdefaults - 1] = CStringGetTextDatum(nodeToString(parameterDefaults));
 322         else
 323                 nulls[Anum_pg_proc_proargdefaults - 1] = true;
 324         values[Anum_pg_proc_prosrc - 1] = CStringGetTextDatum(prosrc);
 325         if (probin)
 326                 values[Anum_pg_proc_probin - 1] = CStringGetTextDatum(probin);
 327         else
 328                 nulls[Anum_pg_proc_probin - 1] = true;
 329         if (proconfig != PointerGetDatum(NULL))
 330                 values[Anum_pg_proc_proconfig - 1] = proconfig;
 331         else
 332                 nulls[Anum_pg_proc_proconfig - 1] = true;
 333         /* start out with empty permissions */
 334         nulls[Anum_pg_proc_proacl - 1] = true;
 335
 336         rel = heap_open(ProcedureRelationId, RowExclusiveLock);
 337         tupDesc = RelationGetDescr(rel);
 338
 339         /* Check for pre-existing definition */
 340         oldtup = SearchSysCache(PROCNAMEARGSNSP,
 341                                                         PointerGetDatum(procedureName),
 342                                                         PointerGetDatum(parameterTypes),
 343                                                         ObjectIdGetDatum(procNamespace),
 344                                                         0);
 345
 346         if (HeapTupleIsValid(oldtup))
 347         {
 348                 /* There is one; okay to replace it? */
 349                 Form_pg_proc oldproc = (Form_pg_proc) GETSTRUCT(oldtup);
 350
 351                 if (!replace)
 352                         ereport(ERROR,
 353                                         (errcode(ERRCODE_DUPLICATE_FUNCTION),
 354                         errmsg("function \"%s\" already exists with same argument types",
 355                                    procedureName)));
 356                 if (!pg_proc_ownercheck(HeapTupleGetOid(oldtup), GetUserId()))
 357                         aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
 358                                                    procedureName);
 359
 360                 /*
 361                  * Not okay to change the return type of the existing proc, since
 362                  * existing rules, views, etc may depend on the return type.
 363                  */
 364                 if (returnType != oldproc->prorettype ||
 365                         returnsSet != oldproc->proretset)
 366                         ereport(ERROR,
 367                                         (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 368                                          errmsg("cannot change return type of existing function"),
 369                                          errhint("Use DROP FUNCTION first.")));
 370
 371                 /*
 372                  * If it returns RECORD, check for possible change of record type
 373                  * implied by OUT parameters
 374                  */
 375                 if (returnType == RECORDOID)
 376                 {
 377                         TupleDesc       olddesc;
 378                         TupleDesc       newdesc;
 379
 380                         olddesc = build_function_result_tupdesc_t(oldtup);
 381                         newdesc = build_function_result_tupdesc_d(allParameterTypes,
 382                                                                                                           parameterModes,
 383                                                                                                           parameterNames);
 384                         if (olddesc == NULL && newdesc == NULL)
 385                                  /* ok, both are runtime-defined RECORDs */ ;
 386                         else if (olddesc == NULL || newdesc == NULL ||
 387                                          !equalTupleDescs(olddesc, newdesc))
 388                                 ereport(ERROR,
 389                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 390                                         errmsg("cannot change return type of existing function"),
 391                                 errdetail("Row type defined by OUT parameters is different."),
 392                                                  errhint("Use DROP FUNCTION first.")));
 393                 }
 394
 395                 /*
 396                  * If there are existing defaults, check compatibility: redefinition
 397                  * must not remove any defaults nor change their types.  (Removing a
 398                  * default might cause a function to fail to satisfy an existing call.
 399                  * Changing type would only be possible if the associated parameter is
 400                  * polymorphic, and in such cases a change of default type might alter
 401                  * the resolved output type of existing calls.)
 402                  */
 403                 if (oldproc->pronargdefaults != 0)
 404                 {
 405                         Datum           proargdefaults;
 406                         bool            isnull;
 407                         List       *oldDefaults;
 408                         ListCell   *oldlc;
 409                         ListCell   *newlc;
 410
 411                         if (list_length(parameterDefaults) < oldproc->pronargdefaults)
 412                                 ereport(ERROR,
 413                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 414                                                  errmsg("cannot remove parameter defaults from existing function"),
 415                                                  errhint("Use DROP FUNCTION first.")));
 416
 417                         proargdefaults = SysCacheGetAttr(PROCNAMEARGSNSP, oldtup,
 418                                                                                          Anum_pg_proc_proargdefaults,
 419                                                                                          &isnull);
 420                         Assert(!isnull);
 421                         oldDefaults = (List *) stringToNode(TextDatumGetCString(proargdefaults));
 422                         Assert(IsA(oldDefaults, List));
 423                         Assert(list_length(oldDefaults) == oldproc->pronargdefaults);
 424
 425                         /* new list can have more defaults than old, advance over 'em */
 426                         newlc = list_head(parameterDefaults);
 427                         for (i = list_length(parameterDefaults) - oldproc->pronargdefaults;
 428                                  i > 0;
 429                                  i--)
 430                                 newlc = lnext(newlc);
 431
 432                         foreach(oldlc, oldDefaults)
 433                         {
 434                                 Node       *oldDef = (Node *) lfirst(oldlc);
 435                                 Node       *newDef = (Node *) lfirst(newlc);
 436
 437                                 if (exprType(oldDef) != exprType(newDef))
 438                                         ereport(ERROR,
 439                                                         (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 440                                                          errmsg("cannot change data type of existing parameter default value"),
 441                                                          errhint("Use DROP FUNCTION first.")));
 442                                 newlc = lnext(newlc);
 443                         }
 444                 }
 445
 446                 /* Can't change aggregate or window-function status, either */
 447                 if (oldproc->proisagg != isAgg)
 448                 {
 449                         if (oldproc->proisagg)
 450                                 ereport(ERROR,
 451                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 452                                                  errmsg("function \"%s\" is an aggregate function",
 453                                                                 procedureName)));
 454                         else
 455                                 ereport(ERROR,
 456                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 457                                            errmsg("function \"%s\" is not an aggregate function",
 458                                                           procedureName)));
 459                 }
 460                 if (oldproc->proiswindow != isWindowFunc)
 461                 {
 462                         if (oldproc->proiswindow)
 463                                 ereport(ERROR,
 464                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 465                                                  errmsg("function \"%s\" is a window function",
 466                                                                 procedureName)));
 467                         else
 468                                 ereport(ERROR,
 469                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 470                                                  errmsg("function \"%s\" is not a window function",
 471                                                                 procedureName)));
 472                 }
 473
 474                 /* do not change existing ownership or permissions, either */
 475                 replaces[Anum_pg_proc_proowner - 1] = false;
 476                 replaces[Anum_pg_proc_proacl - 1] = false;
 477
 478                 /* Okay, do it... */
 479                 tup = heap_modify_tuple(oldtup, tupDesc, values, nulls, replaces);
 480                 simple_heap_update(rel, &tup->t_self, tup);
 481
 482                 ReleaseSysCache(oldtup);
 483                 is_update = true;
 484         }
 485         else
 486         {
 487                 /* Creating a new procedure */
 488                 tup = heap_form_tuple(tupDesc, values, nulls);
 489                 simple_heap_insert(rel, tup);
 490                 is_update = false;
 491         }
 492
 493         /* Need to update indexes for either the insert or update case */
 494         CatalogUpdateIndexes(rel, tup);
 495
 496         retval = HeapTupleGetOid(tup);
 497
 498         /*
 499          * Create dependencies for the new function.  If we are updating an
 500          * existing function, first delete any existing pg_depend entries.
 501          */
 502         if (is_update)
 503         {
 504                 deleteDependencyRecordsFor(ProcedureRelationId, retval);
 505                 deleteSharedDependencyRecordsFor(ProcedureRelationId, retval, 0);
 506         }
 507
 508         myself.classId = ProcedureRelationId;
 509         myself.objectId = retval;
 510         myself.objectSubId = 0;
 511
 512         /* dependency on namespace */
 513         referenced.classId = NamespaceRelationId;
 514         referenced.objectId = procNamespace;
 515         referenced.objectSubId = 0;
 516         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 517
 518         /* dependency on implementation language */
 519         referenced.classId = LanguageRelationId;
 520         referenced.objectId = languageObjectId;
 521         referenced.objectSubId = 0;
 522         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 523
 524         /* dependency on return type */
 525         referenced.classId = TypeRelationId;
 526         referenced.objectId = returnType;
 527         referenced.objectSubId = 0;
 528         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 529
 530         /* dependency on parameter types */
 531         for (i = 0; i < allParamCount; i++)
 532         {
 533                 referenced.classId = TypeRelationId;
 534                 referenced.objectId = allParams[i];
 535                 referenced.objectSubId = 0;
 536                 recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 537         }
 538
 539         /* dependency on owner */
 540         recordDependencyOnOwner(ProcedureRelationId, retval, GetUserId());
 541
 542         heap_freetuple(tup);
 543
 544         heap_close(rel, RowExclusiveLock);
 545
 546         /* Verify function body */
 547         if (OidIsValid(languageValidator))
 548         {
 549                 /* Advance command counter so new tuple can be seen by validator */
 550                 CommandCounterIncrement();
 551                 OidFunctionCall1(languageValidator, ObjectIdGetDatum(retval));
 552         }
 553
 554         return retval;
 555 }
 556
 557
 558
 559 /*
 560  * Validator for internal functions
 561  *
 562  * Check that the given internal function name (the "prosrc" value) is
 563  * a known builtin function.
 564  */
 565 Datum
 566 fmgr_internal_validator(PG_FUNCTION_ARGS)
 567 {
 568         Oid                     funcoid = PG_GETARG_OID(0);
 569         HeapTuple       tuple;
 570         Form_pg_proc proc;
 571         bool            isnull;
 572         Datum           tmp;
 573         char       *prosrc;
 574
 575         /*
 576          * We do not honor check_function_bodies since it's unlikely the function
 577          * name will be found later if it isn't there now.
 578          */
 579
 580         tuple = SearchSysCache(PROCOID,
 581                                                    ObjectIdGetDatum(funcoid),
 582                                                    0, 0, 0);
 583         if (!HeapTupleIsValid(tuple))
 584                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 585         proc = (Form_pg_proc) GETSTRUCT(tuple);
 586
 587         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 588         if (isnull)
 589                 elog(ERROR, "null prosrc");
 590         prosrc = TextDatumGetCString(tmp);
 591
 592         if (fmgr_internal_function(prosrc) == InvalidOid)
 593                 ereport(ERROR,
 594                                 (errcode(ERRCODE_UNDEFINED_FUNCTION),
 595                                  errmsg("there is no built-in function named \"%s\"",
 596                                                 prosrc)));
 597
 598         ReleaseSysCache(tuple);
 599
 600         PG_RETURN_VOID();
 601 }
 602
 603
 604
 605 /*
 606  * Validator for C language functions
 607  *
 608  * Make sure that the library file exists, is loadable, and contains
 609  * the specified link symbol. Also check for a valid function
 610  * information record.
 611  */
 612 Datum
 613 fmgr_c_validator(PG_FUNCTION_ARGS)
 614 {
 615         Oid                     funcoid = PG_GETARG_OID(0);
 616         void       *libraryhandle;
 617         HeapTuple       tuple;
 618         Form_pg_proc proc;
 619         bool            isnull;
 620         Datum           tmp;
 621         char       *prosrc;
 622         char       *probin;
 623
 624         /*
 625          * It'd be most consistent to skip the check if !check_function_bodies,
 626          * but the purpose of that switch is to be helpful for pg_dump loading,
 627          * and for pg_dump loading it's much better if we *do* check.
 628          */
 629
 630         tuple = SearchSysCache(PROCOID,
 631                                                    ObjectIdGetDatum(funcoid),
 632                                                    0, 0, 0);
 633         if (!HeapTupleIsValid(tuple))
 634                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 635         proc = (Form_pg_proc) GETSTRUCT(tuple);
 636
 637         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 638         if (isnull)
 639                 elog(ERROR, "null prosrc for C function %u", funcoid);
 640         prosrc = TextDatumGetCString(tmp);
 641
 642         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_probin, &isnull);
 643         if (isnull)
 644                 elog(ERROR, "null probin for C function %u", funcoid);
 645         probin = TextDatumGetCString(tmp);
 646
 647         (void) load_external_function(probin, prosrc, true, &libraryhandle);
 648         (void) fetch_finfo_record(libraryhandle, prosrc);
 649
 650         ReleaseSysCache(tuple);
 651
 652         PG_RETURN_VOID();
 653 }
 654
 655
 656 /*
 657  * Validator for SQL language functions
 658  *
 659  * Parse it here in order to be sure that it contains no syntax errors.
 660  */
 661 Datum
 662 fmgr_sql_validator(PG_FUNCTION_ARGS)
 663 {
 664         Oid                     funcoid = PG_GETARG_OID(0);
 665         HeapTuple       tuple;
 666         Form_pg_proc proc;
 667         List       *querytree_list;
 668         bool            isnull;
 669         Datum           tmp;
 670         char       *prosrc;
 671         ErrorContextCallback sqlerrcontext;
 672         bool            haspolyarg;
 673         int                     i;
 674
 675         tuple = SearchSysCache(PROCOID,
 676                                                    ObjectIdGetDatum(funcoid),
 677                                                    0, 0, 0);
 678         if (!HeapTupleIsValid(tuple))
 679                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 680         proc = (Form_pg_proc) GETSTRUCT(tuple);
 681
 682         /* Disallow pseudotype result */
 683         /* except for RECORD, VOID, or polymorphic */
 684         if (get_typtype(proc->prorettype) == TYPTYPE_PSEUDO &&
 685                 proc->prorettype != RECORDOID &&
 686                 proc->prorettype != VOIDOID &&
 687                 !IsPolymorphicType(proc->prorettype))
 688                 ereport(ERROR,
 689                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 690                                  errmsg("SQL functions cannot return type %s",
 691                                                 format_type_be(proc->prorettype))));
 692
 693         /* Disallow pseudotypes in arguments */
 694         /* except for polymorphic */
 695         haspolyarg = false;
 696         for (i = 0; i < proc->pronargs; i++)
 697         {
 698                 if (get_typtype(proc->proargtypes.values[i]) == TYPTYPE_PSEUDO)
 699                 {
 700                         if (IsPolymorphicType(proc->proargtypes.values[i]))
 701                                 haspolyarg = true;
 702                         else
 703                                 ereport(ERROR,
 704                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 705                                          errmsg("SQL functions cannot have arguments of type %s",
 706                                                         format_type_be(proc->proargtypes.values[i]))));
 707                 }
 708         }
 709
 710         /* Postpone body checks if !check_function_bodies */
 711         if (check_function_bodies)
 712         {
 713                 tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 714                 if (isnull)
 715                         elog(ERROR, "null prosrc");
 716
 717                 prosrc = TextDatumGetCString(tmp);
 718
 719                 /*
 720                  * Setup error traceback support for ereport().
 721                  */
 722                 sqlerrcontext.callback = sql_function_parse_error_callback;
 723                 sqlerrcontext.arg = tuple;
 724                 sqlerrcontext.previous = error_context_stack;
 725                 error_context_stack = &sqlerrcontext;
 726
 727                 /*
 728                  * We can't do full prechecking of the function definition if there
 729                  * are any polymorphic input types, because actual datatypes of
 730                  * expression results will be unresolvable.  The check will be done at
 731                  * runtime instead.
 732                  *
 733                  * We can run the text through the raw parser though; this will at
 734                  * least catch silly syntactic errors.
 735                  */
 736                 if (!haspolyarg)
 737                 {
 738                         querytree_list = pg_parse_and_rewrite(prosrc,
 739                                                                                                   proc->proargtypes.values,
 740                                                                                                   proc->pronargs);
 741                         (void) check_sql_fn_retval(funcoid, proc->prorettype,
 742                                                                            querytree_list,
 743                                                                            false, NULL);
 744                 }
 745                 else
 746                         querytree_list = pg_parse_query(prosrc);
 747
 748                 error_context_stack = sqlerrcontext.previous;
 749         }
 750
 751         ReleaseSysCache(tuple);
 752
 753         PG_RETURN_VOID();
 754 }
 755
 756 /*
 757  * Error context callback for handling errors in SQL function definitions
 758  */
 759 static void
 760 sql_function_parse_error_callback(void *arg)
 761 {
 762         HeapTuple       tuple = (HeapTuple) arg;
 763         Form_pg_proc proc = (Form_pg_proc) GETSTRUCT(tuple);
 764         bool            isnull;
 765         Datum           tmp;
 766         char       *prosrc;
 767
 768         /* See if it's a syntax error; if so, transpose to CREATE FUNCTION */
 769         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 770         if (isnull)
 771                 elog(ERROR, "null prosrc");
 772         prosrc = TextDatumGetCString(tmp);
 773
 774         if (!function_parse_error_transpose(prosrc))
 775         {
 776                 /* If it's not a syntax error, push info onto context stack */
 777                 errcontext("SQL function \"%s\"", NameStr(proc->proname));
 778         }
 779
 780         pfree(prosrc);
 781 }
 782
 783 /*
 784  * Adjust a syntax error occurring inside the function body of a CREATE
 785  * FUNCTION or DO command.  This can be used by any function validator or
 786  * anonymous-block handler, not only for SQL-language functions.
 787  * It is assumed that the syntax error position is initially relative to the
 788  * function body string (as passed in).  If possible, we adjust the position
 789  * to reference the original command text; if we can't manage that, we set
 790  * up an "internal query" syntax error instead.
 791  *
 792  * Returns true if a syntax error was processed, false if not.
 793  */
 794 bool
 795 function_parse_error_transpose(const char *prosrc)
 796 {
 797         int                     origerrposition;
 798         int                     newerrposition;
 799         const char *queryText;
 800
 801         /*
 802          * Nothing to do unless we are dealing with a syntax error that has a
 803          * cursor position.
 804          *
 805          * Some PLs may prefer to report the error position as an internal error
 806          * to begin with, so check that too.
 807          */
 808         origerrposition = geterrposition();
 809         if (origerrposition <= 0)
 810         {
 811                 origerrposition = getinternalerrposition();
 812                 if (origerrposition <= 0)
 813                         return false;
 814         }
 815
 816         /* We can get the original query text from the active portal (hack...) */
 817         Assert(ActivePortal && ActivePortal->status == PORTAL_ACTIVE);
 818         queryText = ActivePortal->sourceText;
 819
 820         /* Try to locate the prosrc in the original text */
 821         newerrposition = match_prosrc_to_query(prosrc, queryText, origerrposition);
 822
 823         if (newerrposition > 0)
 824         {
 825                 /* Successful, so fix error position to reference original query */
 826                 errposition(newerrposition);
 827                 /* Get rid of any report of the error as an "internal query" */
 828                 internalerrposition(0);
 829                 internalerrquery(NULL);
 830         }
 831         else
 832         {
 833                 /*
 834                  * If unsuccessful, convert the position to an internal position
 835                  * marker and give the function text as the internal query.
 836                  */
 837                 errposition(0);
 838                 internalerrposition(origerrposition);
 839                 internalerrquery(prosrc);
 840         }
 841
 842         return true;
 843 }
 844
 845 /*
 846  * Try to locate the string literal containing the function body in the
 847  * given text of the CREATE FUNCTION or DO command.  If successful, return
 848  * the character (not byte) index within the command corresponding to the
 849  * given character index within the literal.  If not successful, return 0.
 850  */
 851 static int
 852 match_prosrc_to_query(const char *prosrc, const char *queryText,
 853                                           int cursorpos)
 854 {
 855         /*
 856          * Rather than fully parsing the original command, we just scan the
 857          * command looking for $prosrc$ or 'prosrc'.  This could be fooled (though
 858          * not in any very probable scenarios), so fail if we find more than one
 859          * match.
 860          */
 861         int                     prosrclen = strlen(prosrc);
 862         int                     querylen = strlen(queryText);
 863         int                     matchpos = 0;
 864         int                     curpos;
 865         int                     newcursorpos;
 866
 867         for (curpos = 0; curpos < querylen - prosrclen; curpos++)
 868         {
 869                 if (queryText[curpos] == '$' &&
 870                         strncmp(prosrc, &queryText[curpos + 1], prosrclen) == 0 &&
 871                         queryText[curpos + 1 + prosrclen] == '$')
 872                 {
 873                         /*
 874                          * Found a $foo$ match.  Since there are no embedded quoting
 875                          * characters in a dollar-quoted literal, we don't have to do any
 876                          * fancy arithmetic; just offset by the starting position.
 877                          */
 878                         if (matchpos)
 879                                 return 0;               /* multiple matches, fail */
 880                         matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
 881                                 + cursorpos;
 882                 }
 883                 else if (queryText[curpos] == '\'' &&
 884                                  match_prosrc_to_literal(prosrc, &queryText[curpos + 1],
 885                                                                                  cursorpos, &newcursorpos))
 886                 {
 887                         /*
 888                          * Found a 'foo' match.  match_prosrc_to_literal() has adjusted
 889                          * for any quotes or backslashes embedded in the literal.
 890                          */
 891                         if (matchpos)
 892                                 return 0;               /* multiple matches, fail */
 893                         matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
 894                                 + newcursorpos;
 895                 }
 896         }
 897
 898         return matchpos;
 899 }
 900
 901 /*
 902  * Try to match the given source text to a single-quoted literal.
 903  * If successful, adjust newcursorpos to correspond to the character
 904  * (not byte) index corresponding to cursorpos in the source text.
 905  *
 906  * At entry, literal points just past a ' character.  We must check for the
 907  * trailing quote.
 908  */
 909 static bool
 910 match_prosrc_to_literal(const char *prosrc, const char *literal,
 911                                                 int cursorpos, int *newcursorpos)
 912 {
 913         int                     newcp = cursorpos;
 914         int                     chlen;
 915
 916         /*
 917          * This implementation handles backslashes and doubled quotes in the
 918          * string literal.      It does not handle the SQL syntax for literals
 919          * continued across line boundaries.
 920          *
 921          * We do the comparison a character at a time, not a byte at a time, so
 922          * that we can do the correct cursorpos math.
 923          */
 924         while (*prosrc)
 925         {
 926                 cursorpos--;                    /* characters left before cursor */
 927
 928                 /*
 929                  * Check for backslashes and doubled quotes in the literal; adjust
 930                  * newcp when one is found before the cursor.
 931                  */
 932                 if (*literal == '\\')
 933                 {
 934                         literal++;
 935                         if (cursorpos > 0)
 936                                 newcp++;
 937                 }
 938                 else if (*literal == '\'')
 939                 {
 940                         if (literal[1] != '\'')
 941                                 goto fail;
 942                         literal++;
 943                         if (cursorpos > 0)
 944                                 newcp++;
 945                 }
 946                 chlen = pg_mblen(prosrc);
 947                 if (strncmp(prosrc, literal, chlen) != 0)
 948                         goto fail;
 949                 prosrc += chlen;
 950                 literal += chlen;
 951         }
 952
 953         if (*literal == '\'' && literal[1] != '\'')
 954         {
 955                 /* success */
 956                 *newcursorpos = newcp;
 957                 return true;
 958         }
 959
 960 fail:
 961         /* Must set *newcursorpos to suppress compiler warning */
 962         *newcursorpos = newcp;
 963         return false;
 964 }