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 1.166 2009/10/02 18:13:04 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         Oid                     proowner = GetUserId();
  93         Relation        rel;
  94         HeapTuple       tup;
  95         HeapTuple       oldtup;
  96         bool            nulls[Natts_pg_proc];
  97         Datum           values[Natts_pg_proc];
  98         bool            replaces[Natts_pg_proc];
  99         Oid                     relid;
 100         NameData        procname;
 101         TupleDesc       tupDesc;
 102         bool            is_update;
 103         ObjectAddress myself,
 104                                 referenced;
 105         int                     i;
 106
 107         /*
 108          * sanity checks
 109          */
 110         Assert(PointerIsValid(prosrc));
 111
 112         parameterCount = parameterTypes->dim1;
 113         if (parameterCount < 0 || parameterCount > FUNC_MAX_ARGS)
 114                 ereport(ERROR,
 115                                 (errcode(ERRCODE_TOO_MANY_ARGUMENTS),
 116                                  errmsg_plural("functions cannot have more than %d argument",
 117                                                            "functions cannot have more than %d arguments",
 118                                                            FUNC_MAX_ARGS,
 119                                                            FUNC_MAX_ARGS)));
 120         /* note: the above is correct, we do NOT count output arguments */
 121
 122         if (allParameterTypes != PointerGetDatum(NULL))
 123         {
 124                 /*
 125                  * We expect the array to be a 1-D OID array; verify that. We don't
 126                  * need to use deconstruct_array() since the array data is just going
 127                  * to look like a C array of OID values.
 128                  */
 129                 ArrayType  *allParamArray = (ArrayType *) DatumGetPointer(allParameterTypes);
 130
 131                 allParamCount = ARR_DIMS(allParamArray)[0];
 132                 if (ARR_NDIM(allParamArray) != 1 ||
 133                         allParamCount <= 0 ||
 134                         ARR_HASNULL(allParamArray) ||
 135                         ARR_ELEMTYPE(allParamArray) != OIDOID)
 136                         elog(ERROR, "allParameterTypes is not a 1-D Oid array");
 137                 allParams = (Oid *) ARR_DATA_PTR(allParamArray);
 138                 Assert(allParamCount >= parameterCount);
 139                 /* we assume caller got the contents right */
 140         }
 141         else
 142         {
 143                 allParamCount = parameterCount;
 144                 allParams = parameterTypes->values;
 145         }
 146
 147         /*
 148          * Do not allow polymorphic return type unless at least one input argument
 149          * is polymorphic.      Also, do not allow return type INTERNAL unless at
 150          * least one input argument is INTERNAL.
 151          */
 152         for (i = 0; i < parameterCount; i++)
 153         {
 154                 switch (parameterTypes->values[i])
 155                 {
 156                         case ANYARRAYOID:
 157                         case ANYELEMENTOID:
 158                         case ANYNONARRAYOID:
 159                         case ANYENUMOID:
 160                                 genericInParam = true;
 161                                 break;
 162                         case INTERNALOID:
 163                                 internalInParam = true;
 164                                 break;
 165                 }
 166         }
 167
 168         if (allParameterTypes != PointerGetDatum(NULL))
 169         {
 170                 for (i = 0; i < allParamCount; i++)
 171                 {
 172                         /*
 173                          * We don't bother to distinguish input and output params here, so
 174                          * if there is, say, just an input INTERNAL param then we will
 175                          * still set internalOutParam.  This is OK since we don't really
 176                          * care.
 177                          */
 178                         switch (allParams[i])
 179                         {
 180                                 case ANYARRAYOID:
 181                                 case ANYELEMENTOID:
 182                                 case ANYNONARRAYOID:
 183                                 case ANYENUMOID:
 184                                         genericOutParam = true;
 185                                         break;
 186                                 case INTERNALOID:
 187                                         internalOutParam = true;
 188                                         break;
 189                         }
 190                 }
 191         }
 192
 193         if ((IsPolymorphicType(returnType) || genericOutParam)
 194                 && !genericInParam)
 195                 ereport(ERROR,
 196                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 197                                  errmsg("cannot determine result data type"),
 198                                  errdetail("A function returning a polymorphic type must have at least one polymorphic argument.")));
 199
 200         if ((returnType == INTERNALOID || internalOutParam) && !internalInParam)
 201                 ereport(ERROR,
 202                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 203                                  errmsg("unsafe use of pseudo-type \"internal\""),
 204                                  errdetail("A function returning \"internal\" must have at least one \"internal\" argument.")));
 205
 206         /*
 207          * don't allow functions of complex types that have the same name as
 208          * existing attributes of the type
 209          */
 210         if (parameterCount == 1 &&
 211                 OidIsValid(parameterTypes->values[0]) &&
 212                 (relid = typeidTypeRelid(parameterTypes->values[0])) != InvalidOid &&
 213                 get_attnum(relid, procedureName) != InvalidAttrNumber)
 214                 ereport(ERROR,
 215                                 (errcode(ERRCODE_DUPLICATE_COLUMN),
 216                                  errmsg("\"%s\" is already an attribute of type %s",
 217                                                 procedureName,
 218                                                 format_type_be(parameterTypes->values[0]))));
 219
 220         if (parameterModes != PointerGetDatum(NULL))
 221         {
 222                 /*
 223                  * We expect the array to be a 1-D CHAR array; verify that. We don't
 224                  * need to use deconstruct_array() since the array data is just going
 225                  * to look like a C array of char values.
 226                  */
 227                 ArrayType  *modesArray = (ArrayType *) DatumGetPointer(parameterModes);
 228                 char       *modes;
 229
 230                 if (ARR_NDIM(modesArray) != 1 ||
 231                         ARR_DIMS(modesArray)[0] != allParamCount ||
 232                         ARR_HASNULL(modesArray) ||
 233                         ARR_ELEMTYPE(modesArray) != CHAROID)
 234                         elog(ERROR, "parameterModes is not a 1-D char array");
 235                 modes = (char *) ARR_DATA_PTR(modesArray);
 236
 237                 /*
 238                  * Only the last input parameter can be variadic; if it is, save its
 239                  * element type.  Errors here are just elog since caller should have
 240                  * checked this already.
 241                  */
 242                 for (i = 0; i < allParamCount; i++)
 243                 {
 244                         switch (modes[i])
 245                         {
 246                                 case PROARGMODE_IN:
 247                                 case PROARGMODE_INOUT:
 248                                         if (OidIsValid(variadicType))
 249                                                 elog(ERROR, "variadic parameter must be last");
 250                                         break;
 251                                 case PROARGMODE_OUT:
 252                                 case PROARGMODE_TABLE:
 253                                         /* okay */
 254                                         break;
 255                                 case PROARGMODE_VARIADIC:
 256                                         if (OidIsValid(variadicType))
 257                                                 elog(ERROR, "variadic parameter must be last");
 258                                         switch (allParams[i])
 259                                         {
 260                                                 case ANYOID:
 261                                                         variadicType = ANYOID;
 262                                                         break;
 263                                                 case ANYARRAYOID:
 264                                                         variadicType = ANYELEMENTOID;
 265                                                         break;
 266                                                 default:
 267                                                         variadicType = get_element_type(allParams[i]);
 268                                                         if (!OidIsValid(variadicType))
 269                                                                 elog(ERROR, "variadic parameter is not an array");
 270                                                         break;
 271                                         }
 272                                         break;
 273                                 default:
 274                                         elog(ERROR, "invalid parameter mode '%c'", modes[i]);
 275                                         break;
 276                         }
 277                 }
 278         }
 279
 280         /*
 281          * All seems OK; prepare the data to be inserted into pg_proc.
 282          */
 283
 284         for (i = 0; i < Natts_pg_proc; ++i)
 285         {
 286                 nulls[i] = false;
 287                 values[i] = (Datum) 0;
 288                 replaces[i] = true;
 289         }
 290
 291         namestrcpy(&procname, procedureName);
 292         values[Anum_pg_proc_proname - 1] = NameGetDatum(&procname);
 293         values[Anum_pg_proc_pronamespace - 1] = ObjectIdGetDatum(procNamespace);
 294         values[Anum_pg_proc_proowner - 1] = ObjectIdGetDatum(proowner);
 295         values[Anum_pg_proc_prolang - 1] = ObjectIdGetDatum(languageObjectId);
 296         values[Anum_pg_proc_procost - 1] = Float4GetDatum(procost);
 297         values[Anum_pg_proc_prorows - 1] = Float4GetDatum(prorows);
 298         values[Anum_pg_proc_provariadic - 1] = ObjectIdGetDatum(variadicType);
 299         values[Anum_pg_proc_proisagg - 1] = BoolGetDatum(isAgg);
 300         values[Anum_pg_proc_proiswindow - 1] = BoolGetDatum(isWindowFunc);
 301         values[Anum_pg_proc_prosecdef - 1] = BoolGetDatum(security_definer);
 302         values[Anum_pg_proc_proisstrict - 1] = BoolGetDatum(isStrict);
 303         values[Anum_pg_proc_proretset - 1] = BoolGetDatum(returnsSet);
 304         values[Anum_pg_proc_provolatile - 1] = CharGetDatum(volatility);
 305         values[Anum_pg_proc_pronargs - 1] = UInt16GetDatum(parameterCount);
 306         values[Anum_pg_proc_pronargdefaults - 1] = UInt16GetDatum(list_length(parameterDefaults));
 307         values[Anum_pg_proc_prorettype - 1] = ObjectIdGetDatum(returnType);
 308         values[Anum_pg_proc_proargtypes - 1] = PointerGetDatum(parameterTypes);
 309         if (allParameterTypes != PointerGetDatum(NULL))
 310                 values[Anum_pg_proc_proallargtypes - 1] = allParameterTypes;
 311         else
 312                 nulls[Anum_pg_proc_proallargtypes - 1] = true;
 313         if (parameterModes != PointerGetDatum(NULL))
 314                 values[Anum_pg_proc_proargmodes - 1] = parameterModes;
 315         else
 316                 nulls[Anum_pg_proc_proargmodes - 1] = true;
 317         if (parameterNames != PointerGetDatum(NULL))
 318                 values[Anum_pg_proc_proargnames - 1] = parameterNames;
 319         else
 320                 nulls[Anum_pg_proc_proargnames - 1] = true;
 321         if (parameterDefaults != NIL)
 322                 values[Anum_pg_proc_proargdefaults - 1] = CStringGetTextDatum(nodeToString(parameterDefaults));
 323         else
 324                 nulls[Anum_pg_proc_proargdefaults - 1] = true;
 325         values[Anum_pg_proc_prosrc - 1] = CStringGetTextDatum(prosrc);
 326         if (probin)
 327                 values[Anum_pg_proc_probin - 1] = CStringGetTextDatum(probin);
 328         else
 329                 nulls[Anum_pg_proc_probin - 1] = true;
 330         if (proconfig != PointerGetDatum(NULL))
 331                 values[Anum_pg_proc_proconfig - 1] = proconfig;
 332         else
 333                 nulls[Anum_pg_proc_proconfig - 1] = true;
 334         /* start out with empty permissions */
 335         nulls[Anum_pg_proc_proacl - 1] = true;
 336
 337         rel = heap_open(ProcedureRelationId, RowExclusiveLock);
 338         tupDesc = RelationGetDescr(rel);
 339
 340         /* Check for pre-existing definition */
 341         oldtup = SearchSysCache(PROCNAMEARGSNSP,
 342                                                         PointerGetDatum(procedureName),
 343                                                         PointerGetDatum(parameterTypes),
 344                                                         ObjectIdGetDatum(procNamespace),
 345                                                         0);
 346
 347         if (HeapTupleIsValid(oldtup))
 348         {
 349                 /* There is one; okay to replace it? */
 350                 Form_pg_proc oldproc = (Form_pg_proc) GETSTRUCT(oldtup);
 351
 352                 if (!replace)
 353                         ereport(ERROR,
 354                                         (errcode(ERRCODE_DUPLICATE_FUNCTION),
 355                         errmsg("function \"%s\" already exists with same argument types",
 356                                    procedureName)));
 357                 if (!pg_proc_ownercheck(HeapTupleGetOid(oldtup), proowner))
 358                         aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
 359                                                    procedureName);
 360
 361                 /*
 362                  * Not okay to change the return type of the existing proc, since
 363                  * existing rules, views, etc may depend on the return type.
 364                  */
 365                 if (returnType != oldproc->prorettype ||
 366                         returnsSet != oldproc->proretset)
 367                         ereport(ERROR,
 368                                         (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 369                                          errmsg("cannot change return type of existing function"),
 370                                          errhint("Use DROP FUNCTION first.")));
 371
 372                 /*
 373                  * If it returns RECORD, check for possible change of record type
 374                  * implied by OUT parameters
 375                  */
 376                 if (returnType == RECORDOID)
 377                 {
 378                         TupleDesc       olddesc;
 379                         TupleDesc       newdesc;
 380
 381                         olddesc = build_function_result_tupdesc_t(oldtup);
 382                         newdesc = build_function_result_tupdesc_d(allParameterTypes,
 383                                                                                                           parameterModes,
 384                                                                                                           parameterNames);
 385                         if (olddesc == NULL && newdesc == NULL)
 386                                  /* ok, both are runtime-defined RECORDs */ ;
 387                         else if (olddesc == NULL || newdesc == NULL ||
 388                                          !equalTupleDescs(olddesc, newdesc))
 389                                 ereport(ERROR,
 390                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 391                                         errmsg("cannot change return type of existing function"),
 392                                 errdetail("Row type defined by OUT parameters is different."),
 393                                                  errhint("Use DROP FUNCTION first.")));
 394                 }
 395
 396                 /*
 397                  * If there are existing defaults, check compatibility: redefinition
 398                  * must not remove any defaults nor change their types.  (Removing a
 399                  * default might cause a function to fail to satisfy an existing call.
 400                  * Changing type would only be possible if the associated parameter is
 401                  * polymorphic, and in such cases a change of default type might alter
 402                  * the resolved output type of existing calls.)
 403                  */
 404                 if (oldproc->pronargdefaults != 0)
 405                 {
 406                         Datum           proargdefaults;
 407                         bool            isnull;
 408                         List       *oldDefaults;
 409                         ListCell   *oldlc;
 410                         ListCell   *newlc;
 411
 412                         if (list_length(parameterDefaults) < oldproc->pronargdefaults)
 413                                 ereport(ERROR,
 414                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 415                                                  errmsg("cannot remove parameter defaults from existing function"),
 416                                                  errhint("Use DROP FUNCTION first.")));
 417
 418                         proargdefaults = SysCacheGetAttr(PROCNAMEARGSNSP, oldtup,
 419                                                                                          Anum_pg_proc_proargdefaults,
 420                                                                                          &isnull);
 421                         Assert(!isnull);
 422                         oldDefaults = (List *) stringToNode(TextDatumGetCString(proargdefaults));
 423                         Assert(IsA(oldDefaults, List));
 424                         Assert(list_length(oldDefaults) == oldproc->pronargdefaults);
 425
 426                         /* new list can have more defaults than old, advance over 'em */
 427                         newlc = list_head(parameterDefaults);
 428                         for (i = list_length(parameterDefaults) - oldproc->pronargdefaults;
 429                                  i > 0;
 430                                  i--)
 431                                 newlc = lnext(newlc);
 432
 433                         foreach(oldlc, oldDefaults)
 434                         {
 435                                 Node       *oldDef = (Node *) lfirst(oldlc);
 436                                 Node       *newDef = (Node *) lfirst(newlc);
 437
 438                                 if (exprType(oldDef) != exprType(newDef))
 439                                         ereport(ERROR,
 440                                                         (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 441                                                          errmsg("cannot change data type of existing parameter default value"),
 442                                                          errhint("Use DROP FUNCTION first.")));
 443                                 newlc = lnext(newlc);
 444                         }
 445                 }
 446
 447                 /* Can't change aggregate or window-function status, either */
 448                 if (oldproc->proisagg != isAgg)
 449                 {
 450                         if (oldproc->proisagg)
 451                                 ereport(ERROR,
 452                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 453                                                  errmsg("function \"%s\" is an aggregate function",
 454                                                                 procedureName)));
 455                         else
 456                                 ereport(ERROR,
 457                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 458                                            errmsg("function \"%s\" is not an aggregate function",
 459                                                           procedureName)));
 460                 }
 461                 if (oldproc->proiswindow != isWindowFunc)
 462                 {
 463                         if (oldproc->proiswindow)
 464                                 ereport(ERROR,
 465                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 466                                                  errmsg("function \"%s\" is a window function",
 467                                                                 procedureName)));
 468                         else
 469                                 ereport(ERROR,
 470                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 471                                                  errmsg("function \"%s\" is not a window function",
 472                                                                 procedureName)));
 473                 }
 474
 475                 /*
 476                  * Do not change existing ownership or permissions, either.  Note
 477                  * dependency-update code below has to agree with this decision.
 478                  */
 479                 replaces[Anum_pg_proc_proowner - 1] = false;
 480                 replaces[Anum_pg_proc_proacl - 1] = false;
 481
 482                 /* Okay, do it... */
 483                 tup = heap_modify_tuple(oldtup, tupDesc, values, nulls, replaces);
 484                 simple_heap_update(rel, &tup->t_self, tup);
 485
 486                 ReleaseSysCache(oldtup);
 487                 is_update = true;
 488         }
 489         else
 490         {
 491                 /* Creating a new procedure */
 492                 tup = heap_form_tuple(tupDesc, values, nulls);
 493                 simple_heap_insert(rel, tup);
 494                 is_update = false;
 495         }
 496
 497         /* Need to update indexes for either the insert or update case */
 498         CatalogUpdateIndexes(rel, tup);
 499
 500         retval = HeapTupleGetOid(tup);
 501
 502         /*
 503          * Create dependencies for the new function.  If we are updating an
 504          * existing function, first delete any existing pg_depend entries.
 505          * (However, since we are not changing ownership or permissions, the
 506          * shared dependencies do *not* need to change, and we leave them alone.)
 507          */
 508         if (is_update)
 509                 deleteDependencyRecordsFor(ProcedureRelationId, retval);
 510
 511         myself.classId = ProcedureRelationId;
 512         myself.objectId = retval;
 513         myself.objectSubId = 0;
 514
 515         /* dependency on namespace */
 516         referenced.classId = NamespaceRelationId;
 517         referenced.objectId = procNamespace;
 518         referenced.objectSubId = 0;
 519         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 520
 521         /* dependency on implementation language */
 522         referenced.classId = LanguageRelationId;
 523         referenced.objectId = languageObjectId;
 524         referenced.objectSubId = 0;
 525         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 526
 527         /* dependency on return type */
 528         referenced.classId = TypeRelationId;
 529         referenced.objectId = returnType;
 530         referenced.objectSubId = 0;
 531         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 532
 533         /* dependency on parameter types */
 534         for (i = 0; i < allParamCount; i++)
 535         {
 536                 referenced.classId = TypeRelationId;
 537                 referenced.objectId = allParams[i];
 538                 referenced.objectSubId = 0;
 539                 recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 540         }
 541
 542         /* dependency on owner */
 543         if (!is_update)
 544                 recordDependencyOnOwner(ProcedureRelationId, retval, proowner);
 545
 546         heap_freetuple(tup);
 547
 548         heap_close(rel, RowExclusiveLock);
 549
 550         /* Verify function body */
 551         if (OidIsValid(languageValidator))
 552         {
 553                 /* Advance command counter so new tuple can be seen by validator */
 554                 CommandCounterIncrement();
 555                 OidFunctionCall1(languageValidator, ObjectIdGetDatum(retval));
 556         }
 557
 558         return retval;
 559 }
 560
 561
 562
 563 /*
 564  * Validator for internal functions
 565  *
 566  * Check that the given internal function name (the "prosrc" value) is
 567  * a known builtin function.
 568  */
 569 Datum
 570 fmgr_internal_validator(PG_FUNCTION_ARGS)
 571 {
 572         Oid                     funcoid = PG_GETARG_OID(0);
 573         HeapTuple       tuple;
 574         Form_pg_proc proc;
 575         bool            isnull;
 576         Datum           tmp;
 577         char       *prosrc;
 578
 579         /*
 580          * We do not honor check_function_bodies since it's unlikely the function
 581          * name will be found later if it isn't there now.
 582          */
 583
 584         tuple = SearchSysCache(PROCOID,
 585                                                    ObjectIdGetDatum(funcoid),
 586                                                    0, 0, 0);
 587         if (!HeapTupleIsValid(tuple))
 588                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 589         proc = (Form_pg_proc) GETSTRUCT(tuple);
 590
 591         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 592         if (isnull)
 593                 elog(ERROR, "null prosrc");
 594         prosrc = TextDatumGetCString(tmp);
 595
 596         if (fmgr_internal_function(prosrc) == InvalidOid)
 597                 ereport(ERROR,
 598                                 (errcode(ERRCODE_UNDEFINED_FUNCTION),
 599                                  errmsg("there is no built-in function named \"%s\"",
 600                                                 prosrc)));
 601
 602         ReleaseSysCache(tuple);
 603
 604         PG_RETURN_VOID();
 605 }
 606
 607
 608
 609 /*
 610  * Validator for C language functions
 611  *
 612  * Make sure that the library file exists, is loadable, and contains
 613  * the specified link symbol. Also check for a valid function
 614  * information record.
 615  */
 616 Datum
 617 fmgr_c_validator(PG_FUNCTION_ARGS)
 618 {
 619         Oid                     funcoid = PG_GETARG_OID(0);
 620         void       *libraryhandle;
 621         HeapTuple       tuple;
 622         Form_pg_proc proc;
 623         bool            isnull;
 624         Datum           tmp;
 625         char       *prosrc;
 626         char       *probin;
 627
 628         /*
 629          * It'd be most consistent to skip the check if !check_function_bodies,
 630          * but the purpose of that switch is to be helpful for pg_dump loading,
 631          * and for pg_dump loading it's much better if we *do* check.
 632          */
 633
 634         tuple = SearchSysCache(PROCOID,
 635                                                    ObjectIdGetDatum(funcoid),
 636                                                    0, 0, 0);
 637         if (!HeapTupleIsValid(tuple))
 638                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 639         proc = (Form_pg_proc) GETSTRUCT(tuple);
 640
 641         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 642         if (isnull)
 643                 elog(ERROR, "null prosrc for C function %u", funcoid);
 644         prosrc = TextDatumGetCString(tmp);
 645
 646         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_probin, &isnull);
 647         if (isnull)
 648                 elog(ERROR, "null probin for C function %u", funcoid);
 649         probin = TextDatumGetCString(tmp);
 650
 651         (void) load_external_function(probin, prosrc, true, &libraryhandle);
 652         (void) fetch_finfo_record(libraryhandle, prosrc);
 653
 654         ReleaseSysCache(tuple);
 655
 656         PG_RETURN_VOID();
 657 }
 658
 659
 660 /*
 661  * Validator for SQL language functions
 662  *
 663  * Parse it here in order to be sure that it contains no syntax errors.
 664  */
 665 Datum
 666 fmgr_sql_validator(PG_FUNCTION_ARGS)
 667 {
 668         Oid                     funcoid = PG_GETARG_OID(0);
 669         HeapTuple       tuple;
 670         Form_pg_proc proc;
 671         List       *querytree_list;
 672         bool            isnull;
 673         Datum           tmp;
 674         char       *prosrc;
 675         ErrorContextCallback sqlerrcontext;
 676         bool            haspolyarg;
 677         int                     i;
 678
 679         tuple = SearchSysCache(PROCOID,
 680                                                    ObjectIdGetDatum(funcoid),
 681                                                    0, 0, 0);
 682         if (!HeapTupleIsValid(tuple))
 683                 elog(ERROR, "cache lookup failed for function %u", funcoid);
 684         proc = (Form_pg_proc) GETSTRUCT(tuple);
 685
 686         /* Disallow pseudotype result */
 687         /* except for RECORD, VOID, or polymorphic */
 688         if (get_typtype(proc->prorettype) == TYPTYPE_PSEUDO &&
 689                 proc->prorettype != RECORDOID &&
 690                 proc->prorettype != VOIDOID &&
 691                 !IsPolymorphicType(proc->prorettype))
 692                 ereport(ERROR,
 693                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 694                                  errmsg("SQL functions cannot return type %s",
 695                                                 format_type_be(proc->prorettype))));
 696
 697         /* Disallow pseudotypes in arguments */
 698         /* except for polymorphic */
 699         haspolyarg = false;
 700         for (i = 0; i < proc->pronargs; i++)
 701         {
 702                 if (get_typtype(proc->proargtypes.values[i]) == TYPTYPE_PSEUDO)
 703                 {
 704                         if (IsPolymorphicType(proc->proargtypes.values[i]))
 705                                 haspolyarg = true;
 706                         else
 707                                 ereport(ERROR,
 708                                                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 709                                          errmsg("SQL functions cannot have arguments of type %s",
 710                                                         format_type_be(proc->proargtypes.values[i]))));
 711                 }
 712         }
 713
 714         /* Postpone body checks if !check_function_bodies */
 715         if (check_function_bodies)
 716         {
 717                 tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 718                 if (isnull)
 719                         elog(ERROR, "null prosrc");
 720
 721                 prosrc = TextDatumGetCString(tmp);
 722
 723                 /*
 724                  * Setup error traceback support for ereport().
 725                  */
 726                 sqlerrcontext.callback = sql_function_parse_error_callback;
 727                 sqlerrcontext.arg = tuple;
 728                 sqlerrcontext.previous = error_context_stack;
 729                 error_context_stack = &sqlerrcontext;
 730
 731                 /*
 732                  * We can't do full prechecking of the function definition if there
 733                  * are any polymorphic input types, because actual datatypes of
 734                  * expression results will be unresolvable.  The check will be done at
 735                  * runtime instead.
 736                  *
 737                  * We can run the text through the raw parser though; this will at
 738                  * least catch silly syntactic errors.
 739                  */
 740                 if (!haspolyarg)
 741                 {
 742                         querytree_list = pg_parse_and_rewrite(prosrc,
 743                                                                                                   proc->proargtypes.values,
 744                                                                                                   proc->pronargs);
 745                         (void) check_sql_fn_retval(funcoid, proc->prorettype,
 746                                                                            querytree_list,
 747                                                                            false, NULL);
 748                 }
 749                 else
 750                         querytree_list = pg_parse_query(prosrc);
 751
 752                 error_context_stack = sqlerrcontext.previous;
 753         }
 754
 755         ReleaseSysCache(tuple);
 756
 757         PG_RETURN_VOID();
 758 }
 759
 760 /*
 761  * Error context callback for handling errors in SQL function definitions
 762  */
 763 static void
 764 sql_function_parse_error_callback(void *arg)
 765 {
 766         HeapTuple       tuple = (HeapTuple) arg;
 767         Form_pg_proc proc = (Form_pg_proc) GETSTRUCT(tuple);
 768         bool            isnull;
 769         Datum           tmp;
 770         char       *prosrc;
 771
 772         /* See if it's a syntax error; if so, transpose to CREATE FUNCTION */
 773         tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
 774         if (isnull)
 775                 elog(ERROR, "null prosrc");
 776         prosrc = TextDatumGetCString(tmp);
 777
 778         if (!function_parse_error_transpose(prosrc))
 779         {
 780                 /* If it's not a syntax error, push info onto context stack */
 781                 errcontext("SQL function \"%s\"", NameStr(proc->proname));
 782         }
 783
 784         pfree(prosrc);
 785 }
 786
 787 /*
 788  * Adjust a syntax error occurring inside the function body of a CREATE
 789  * FUNCTION or DO command.  This can be used by any function validator or
 790  * anonymous-block handler, not only for SQL-language functions.
 791  * It is assumed that the syntax error position is initially relative to the
 792  * function body string (as passed in).  If possible, we adjust the position
 793  * to reference the original command text; if we can't manage that, we set
 794  * up an "internal query" syntax error instead.
 795  *
 796  * Returns true if a syntax error was processed, false if not.
 797  */
 798 bool
 799 function_parse_error_transpose(const char *prosrc)
 800 {
 801         int                     origerrposition;
 802         int                     newerrposition;
 803         const char *queryText;
 804
 805         /*
 806          * Nothing to do unless we are dealing with a syntax error that has a
 807          * cursor position.
 808          *
 809          * Some PLs may prefer to report the error position as an internal error
 810          * to begin with, so check that too.
 811          */
 812         origerrposition = geterrposition();
 813         if (origerrposition <= 0)
 814         {
 815                 origerrposition = getinternalerrposition();
 816                 if (origerrposition <= 0)
 817                         return false;
 818         }
 819
 820         /* We can get the original query text from the active portal (hack...) */
 821         Assert(ActivePortal && ActivePortal->status == PORTAL_ACTIVE);
 822         queryText = ActivePortal->sourceText;
 823
 824         /* Try to locate the prosrc in the original text */
 825         newerrposition = match_prosrc_to_query(prosrc, queryText, origerrposition);
 826
 827         if (newerrposition > 0)
 828         {
 829                 /* Successful, so fix error position to reference original query */
 830                 errposition(newerrposition);
 831                 /* Get rid of any report of the error as an "internal query" */
 832                 internalerrposition(0);
 833                 internalerrquery(NULL);
 834         }
 835         else
 836         {
 837                 /*
 838                  * If unsuccessful, convert the position to an internal position
 839                  * marker and give the function text as the internal query.
 840                  */
 841                 errposition(0);
 842                 internalerrposition(origerrposition);
 843                 internalerrquery(prosrc);
 844         }
 845
 846         return true;
 847 }
 848
 849 /*
 850  * Try to locate the string literal containing the function body in the
 851  * given text of the CREATE FUNCTION or DO command.  If successful, return
 852  * the character (not byte) index within the command corresponding to the
 853  * given character index within the literal.  If not successful, return 0.
 854  */
 855 static int
 856 match_prosrc_to_query(const char *prosrc, const char *queryText,
 857                                           int cursorpos)
 858 {
 859         /*
 860          * Rather than fully parsing the original command, we just scan the
 861          * command looking for $prosrc$ or 'prosrc'.  This could be fooled (though
 862          * not in any very probable scenarios), so fail if we find more than one
 863          * match.
 864          */
 865         int                     prosrclen = strlen(prosrc);
 866         int                     querylen = strlen(queryText);
 867         int                     matchpos = 0;
 868         int                     curpos;
 869         int                     newcursorpos;
 870
 871         for (curpos = 0; curpos < querylen - prosrclen; curpos++)
 872         {
 873                 if (queryText[curpos] == '$' &&
 874                         strncmp(prosrc, &queryText[curpos + 1], prosrclen) == 0 &&
 875                         queryText[curpos + 1 + prosrclen] == '$')
 876                 {
 877                         /*
 878                          * Found a $foo$ match.  Since there are no embedded quoting
 879                          * characters in a dollar-quoted literal, we don't have to do any
 880                          * fancy arithmetic; just offset by the starting position.
 881                          */
 882                         if (matchpos)
 883                                 return 0;               /* multiple matches, fail */
 884                         matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
 885                                 + cursorpos;
 886                 }
 887                 else if (queryText[curpos] == '\'' &&
 888                                  match_prosrc_to_literal(prosrc, &queryText[curpos + 1],
 889                                                                                  cursorpos, &newcursorpos))
 890                 {
 891                         /*
 892                          * Found a 'foo' match.  match_prosrc_to_literal() has adjusted
 893                          * for any quotes or backslashes embedded in the literal.
 894                          */
 895                         if (matchpos)
 896                                 return 0;               /* multiple matches, fail */
 897                         matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
 898                                 + newcursorpos;
 899                 }
 900         }
 901
 902         return matchpos;
 903 }
 904
 905 /*
 906  * Try to match the given source text to a single-quoted literal.
 907  * If successful, adjust newcursorpos to correspond to the character
 908  * (not byte) index corresponding to cursorpos in the source text.
 909  *
 910  * At entry, literal points just past a ' character.  We must check for the
 911  * trailing quote.
 912  */
 913 static bool
 914 match_prosrc_to_literal(const char *prosrc, const char *literal,
 915                                                 int cursorpos, int *newcursorpos)
 916 {
 917         int                     newcp = cursorpos;
 918         int                     chlen;
 919
 920         /*
 921          * This implementation handles backslashes and doubled quotes in the
 922          * string literal.      It does not handle the SQL syntax for literals
 923          * continued across line boundaries.
 924          *
 925          * We do the comparison a character at a time, not a byte at a time, so
 926          * that we can do the correct cursorpos math.
 927          */
 928         while (*prosrc)
 929         {
 930                 cursorpos--;                    /* characters left before cursor */
 931
 932                 /*
 933                  * Check for backslashes and doubled quotes in the literal; adjust
 934                  * newcp when one is found before the cursor.
 935                  */
 936                 if (*literal == '\\')
 937                 {
 938                         literal++;
 939                         if (cursorpos > 0)
 940                                 newcp++;
 941                 }
 942                 else if (*literal == '\'')
 943                 {
 944                         if (literal[1] != '\'')
 945                                 goto fail;
 946                         literal++;
 947                         if (cursorpos > 0)
 948                                 newcp++;
 949                 }
 950                 chlen = pg_mblen(prosrc);
 951                 if (strncmp(prosrc, literal, chlen) != 0)
 952                         goto fail;
 953                 prosrc += chlen;
 954                 literal += chlen;
 955         }
 956
 957         if (*literal == '\'' && literal[1] != '\'')
 958         {
 959                 /* success */
 960                 *newcursorpos = newcp;
 961                 return true;
 962         }
 963
 964 fail:
 965         /* Must set *newcursorpos to suppress compiler warning */
 966         *newcursorpos = newcp;
 967         return false;
 968 }