1 /*-------------------------------------------------------------------------
4 * routines to support manipulation of the pg_proc relation
6 * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
11 * $PostgreSQL: pgsql/src/backend/catalog/pg_proc.c,v 1.153 2008/07/18 03:32:52 tgl Exp $
13 *-------------------------------------------------------------------------
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"
28 #include "mb/pg_wchar.h"
29 #include "miscadmin.h"
30 #include "parser/parse_type.h"
31 #include "tcop/pquery.h"
32 #include "tcop/tcopprot.h"
33 #include "utils/acl.h"
34 #include "utils/builtins.h"
35 #include "utils/lsyscache.h"
36 #include "utils/syscache.h"
39 Datum fmgr_internal_validator(PG_FUNCTION_ARGS);
40 Datum fmgr_c_validator(PG_FUNCTION_ARGS);
41 Datum fmgr_sql_validator(PG_FUNCTION_ARGS);
43 static void sql_function_parse_error_callback(void *arg);
44 static int match_prosrc_to_query(const char *prosrc, const char *queryText,
46 static bool match_prosrc_to_literal(const char *prosrc, const char *literal,
47 int cursorpos, int *newcursorpos);
50 /* ----------------------------------------------------------------
53 * Note: allParameterTypes, parameterModes, parameterNames, and proconfig
54 * are either arrays of the proper types or NULL. We declare them Datum,
55 * not "ArrayType *", to avoid importing array.h into pg_proc.h.
56 * ----------------------------------------------------------------
59 ProcedureCreate(const char *procedureName,
65 Oid languageValidator,
69 bool security_definer,
72 oidvector *parameterTypes,
73 Datum allParameterTypes,
84 bool genericInParam = false;
85 bool genericOutParam = false;
86 bool internalInParam = false;
87 bool internalOutParam = false;
88 Oid variadicType = InvalidOid;
92 char nulls[Natts_pg_proc];
93 Datum values[Natts_pg_proc];
94 char replaces[Natts_pg_proc];
106 Assert(PointerIsValid(prosrc));
108 parameterCount = parameterTypes->dim1;
109 if (parameterCount < 0 || parameterCount > FUNC_MAX_ARGS)
111 (errcode(ERRCODE_TOO_MANY_ARGUMENTS),
112 errmsg("functions cannot have more than %d arguments",
114 /* note: the above is correct, we do NOT count output arguments */
116 if (allParameterTypes != PointerGetDatum(NULL))
119 * We expect the array to be a 1-D OID array; verify that. We don't
120 * need to use deconstruct_array() since the array data is just going
121 * to look like a C array of OID values.
123 ArrayType *allParamArray = (ArrayType *) DatumGetPointer(allParameterTypes);
125 allParamCount = ARR_DIMS(allParamArray)[0];
126 if (ARR_NDIM(allParamArray) != 1 ||
127 allParamCount <= 0 ||
128 ARR_HASNULL(allParamArray) ||
129 ARR_ELEMTYPE(allParamArray) != OIDOID)
130 elog(ERROR, "allParameterTypes is not a 1-D Oid array");
131 allParams = (Oid *) ARR_DATA_PTR(allParamArray);
132 Assert(allParamCount >= parameterCount);
133 /* we assume caller got the contents right */
137 allParamCount = parameterCount;
138 allParams = parameterTypes->values;
142 * Do not allow polymorphic return type unless at least one input argument
143 * is polymorphic. Also, do not allow return type INTERNAL unless at
144 * least one input argument is INTERNAL.
146 for (i = 0; i < parameterCount; i++)
148 switch (parameterTypes->values[i])
154 genericInParam = true;
157 internalInParam = true;
162 if (allParameterTypes != PointerGetDatum(NULL))
164 for (i = 0; i < allParamCount; i++)
167 * We don't bother to distinguish input and output params here, so
168 * if there is, say, just an input INTERNAL param then we will
169 * still set internalOutParam. This is OK since we don't really
172 switch (allParams[i])
178 genericOutParam = true;
181 internalOutParam = true;
187 if ((IsPolymorphicType(returnType) || genericOutParam)
190 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
191 errmsg("cannot determine result data type"),
192 errdetail("A function returning a polymorphic type must have at least one polymorphic argument.")));
194 if ((returnType == INTERNALOID || internalOutParam) && !internalInParam)
196 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
197 errmsg("unsafe use of pseudo-type \"internal\""),
198 errdetail("A function returning \"internal\" must have at least one \"internal\" argument.")));
201 * don't allow functions of complex types that have the same name as
202 * existing attributes of the type
204 if (parameterCount == 1 &&
205 OidIsValid(parameterTypes->values[0]) &&
206 (relid = typeidTypeRelid(parameterTypes->values[0])) != InvalidOid &&
207 get_attnum(relid, procedureName) != InvalidAttrNumber)
209 (errcode(ERRCODE_DUPLICATE_COLUMN),
210 errmsg("\"%s\" is already an attribute of type %s",
212 format_type_be(parameterTypes->values[0]))));
214 if (parameterModes != PointerGetDatum(NULL))
217 * We expect the array to be a 1-D CHAR array; verify that. We don't
218 * need to use deconstruct_array() since the array data is just going
219 * to look like a C array of char values.
221 ArrayType *modesArray = (ArrayType *) DatumGetPointer(parameterModes);
224 if (ARR_NDIM(modesArray) != 1 ||
225 ARR_DIMS(modesArray)[0] != allParamCount ||
226 ARR_HASNULL(modesArray) ||
227 ARR_ELEMTYPE(modesArray) != CHAROID)
228 elog(ERROR, "parameterModes is not a 1-D char array");
229 modes = (char *) ARR_DATA_PTR(modesArray);
231 * Only the last input parameter can be variadic; if it is, save
232 * its element type. Errors here are just elog since caller should
233 * have checked this already.
235 for (i = 0; i < allParamCount; i++)
240 case PROARGMODE_INOUT:
241 if (OidIsValid(variadicType))
242 elog(ERROR, "variadic parameter must be last");
245 case PROARGMODE_TABLE:
248 case PROARGMODE_VARIADIC:
249 if (OidIsValid(variadicType))
250 elog(ERROR, "variadic parameter must be last");
251 switch (allParams[i])
254 variadicType = ANYOID;
257 variadicType = ANYELEMENTOID;
260 variadicType = get_element_type(allParams[i]);
261 if (!OidIsValid(variadicType))
262 elog(ERROR, "variadic parameter is not an array");
267 elog(ERROR, "invalid parameter mode '%c'", modes[i]);
274 * All seems OK; prepare the data to be inserted into pg_proc.
277 for (i = 0; i < Natts_pg_proc; ++i)
280 values[i] = (Datum) 0;
284 namestrcpy(&procname, procedureName);
285 values[Anum_pg_proc_proname - 1] = NameGetDatum(&procname);
286 values[Anum_pg_proc_pronamespace - 1] = ObjectIdGetDatum(procNamespace);
287 values[Anum_pg_proc_proowner - 1] = ObjectIdGetDatum(GetUserId());
288 values[Anum_pg_proc_prolang - 1] = ObjectIdGetDatum(languageObjectId);
289 values[Anum_pg_proc_procost - 1] = Float4GetDatum(procost);
290 values[Anum_pg_proc_prorows - 1] = Float4GetDatum(prorows);
291 values[Anum_pg_proc_provariadic - 1] = ObjectIdGetDatum(variadicType);
292 values[Anum_pg_proc_proisagg - 1] = BoolGetDatum(isAgg);
293 values[Anum_pg_proc_prosecdef - 1] = BoolGetDatum(security_definer);
294 values[Anum_pg_proc_proisstrict - 1] = BoolGetDatum(isStrict);
295 values[Anum_pg_proc_proretset - 1] = BoolGetDatum(returnsSet);
296 values[Anum_pg_proc_provolatile - 1] = CharGetDatum(volatility);
297 values[Anum_pg_proc_pronargs - 1] = UInt16GetDatum(parameterCount);
298 values[Anum_pg_proc_prorettype - 1] = ObjectIdGetDatum(returnType);
299 values[Anum_pg_proc_proargtypes - 1] = PointerGetDatum(parameterTypes);
300 if (allParameterTypes != PointerGetDatum(NULL))
301 values[Anum_pg_proc_proallargtypes - 1] = allParameterTypes;
303 nulls[Anum_pg_proc_proallargtypes - 1] = 'n';
304 if (parameterModes != PointerGetDatum(NULL))
305 values[Anum_pg_proc_proargmodes - 1] = parameterModes;
307 nulls[Anum_pg_proc_proargmodes - 1] = 'n';
308 if (parameterNames != PointerGetDatum(NULL))
309 values[Anum_pg_proc_proargnames - 1] = parameterNames;
311 nulls[Anum_pg_proc_proargnames - 1] = 'n';
312 values[Anum_pg_proc_prosrc - 1] = CStringGetTextDatum(prosrc);
314 values[Anum_pg_proc_probin - 1] = CStringGetTextDatum(probin);
316 nulls[Anum_pg_proc_probin - 1] = 'n';
317 if (proconfig != PointerGetDatum(NULL))
318 values[Anum_pg_proc_proconfig - 1] = proconfig;
320 nulls[Anum_pg_proc_proconfig - 1] = 'n';
321 /* start out with empty permissions */
322 nulls[Anum_pg_proc_proacl - 1] = 'n';
324 rel = heap_open(ProcedureRelationId, RowExclusiveLock);
325 tupDesc = RelationGetDescr(rel);
327 /* Check for pre-existing definition */
328 oldtup = SearchSysCache(PROCNAMEARGSNSP,
329 PointerGetDatum(procedureName),
330 PointerGetDatum(parameterTypes),
331 ObjectIdGetDatum(procNamespace),
334 if (HeapTupleIsValid(oldtup))
336 /* There is one; okay to replace it? */
337 Form_pg_proc oldproc = (Form_pg_proc) GETSTRUCT(oldtup);
341 (errcode(ERRCODE_DUPLICATE_FUNCTION),
342 errmsg("function \"%s\" already exists with same argument types",
344 if (!pg_proc_ownercheck(HeapTupleGetOid(oldtup), GetUserId()))
345 aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
349 * Not okay to change the return type of the existing proc, since
350 * existing rules, views, etc may depend on the return type.
352 if (returnType != oldproc->prorettype ||
353 returnsSet != oldproc->proretset)
355 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
356 errmsg("cannot change return type of existing function"),
357 errhint("Use DROP FUNCTION first.")));
360 * If it returns RECORD, check for possible change of record type
361 * implied by OUT parameters
363 if (returnType == RECORDOID)
368 olddesc = build_function_result_tupdesc_t(oldtup);
369 newdesc = build_function_result_tupdesc_d(allParameterTypes,
372 if (olddesc == NULL && newdesc == NULL)
373 /* ok, both are runtime-defined RECORDs */ ;
374 else if (olddesc == NULL || newdesc == NULL ||
375 !equalTupleDescs(olddesc, newdesc))
377 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
378 errmsg("cannot change return type of existing function"),
379 errdetail("Row type defined by OUT parameters is different."),
380 errhint("Use DROP FUNCTION first.")));
383 /* Can't change aggregate status, either */
384 if (oldproc->proisagg != isAgg)
386 if (oldproc->proisagg)
388 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
389 errmsg("function \"%s\" is an aggregate",
393 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
394 errmsg("function \"%s\" is not an aggregate",
398 /* do not change existing ownership or permissions, either */
399 replaces[Anum_pg_proc_proowner - 1] = ' ';
400 replaces[Anum_pg_proc_proacl - 1] = ' ';
403 tup = heap_modifytuple(oldtup, tupDesc, values, nulls, replaces);
404 simple_heap_update(rel, &tup->t_self, tup);
406 ReleaseSysCache(oldtup);
411 /* Creating a new procedure */
412 tup = heap_formtuple(tupDesc, values, nulls);
413 simple_heap_insert(rel, tup);
417 /* Need to update indexes for either the insert or update case */
418 CatalogUpdateIndexes(rel, tup);
420 retval = HeapTupleGetOid(tup);
423 * Create dependencies for the new function. If we are updating an
424 * existing function, first delete any existing pg_depend entries.
428 deleteDependencyRecordsFor(ProcedureRelationId, retval);
429 deleteSharedDependencyRecordsFor(ProcedureRelationId, retval);
432 myself.classId = ProcedureRelationId;
433 myself.objectId = retval;
434 myself.objectSubId = 0;
436 /* dependency on namespace */
437 referenced.classId = NamespaceRelationId;
438 referenced.objectId = procNamespace;
439 referenced.objectSubId = 0;
440 recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
442 /* dependency on implementation language */
443 referenced.classId = LanguageRelationId;
444 referenced.objectId = languageObjectId;
445 referenced.objectSubId = 0;
446 recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
448 /* dependency on return type */
449 referenced.classId = TypeRelationId;
450 referenced.objectId = returnType;
451 referenced.objectSubId = 0;
452 recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
454 /* dependency on parameter types */
455 for (i = 0; i < allParamCount; i++)
457 referenced.classId = TypeRelationId;
458 referenced.objectId = allParams[i];
459 referenced.objectSubId = 0;
460 recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
463 /* dependency on owner */
464 recordDependencyOnOwner(ProcedureRelationId, retval, GetUserId());
468 heap_close(rel, RowExclusiveLock);
470 /* Verify function body */
471 if (OidIsValid(languageValidator))
473 /* Advance command counter so new tuple can be seen by validator */
474 CommandCounterIncrement();
475 OidFunctionCall1(languageValidator, ObjectIdGetDatum(retval));
484 * Validator for internal functions
486 * Check that the given internal function name (the "prosrc" value) is
487 * a known builtin function.
490 fmgr_internal_validator(PG_FUNCTION_ARGS)
492 Oid funcoid = PG_GETARG_OID(0);
500 * We do not honor check_function_bodies since it's unlikely the function
501 * name will be found later if it isn't there now.
504 tuple = SearchSysCache(PROCOID,
505 ObjectIdGetDatum(funcoid),
507 if (!HeapTupleIsValid(tuple))
508 elog(ERROR, "cache lookup failed for function %u", funcoid);
509 proc = (Form_pg_proc) GETSTRUCT(tuple);
511 tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
513 elog(ERROR, "null prosrc");
514 prosrc = TextDatumGetCString(tmp);
516 if (fmgr_internal_function(prosrc) == InvalidOid)
518 (errcode(ERRCODE_UNDEFINED_FUNCTION),
519 errmsg("there is no built-in function named \"%s\"",
522 ReleaseSysCache(tuple);
530 * Validator for C language functions
532 * Make sure that the library file exists, is loadable, and contains
533 * the specified link symbol. Also check for a valid function
534 * information record.
537 fmgr_c_validator(PG_FUNCTION_ARGS)
539 Oid funcoid = PG_GETARG_OID(0);
549 * It'd be most consistent to skip the check if !check_function_bodies,
550 * but the purpose of that switch is to be helpful for pg_dump loading,
551 * and for pg_dump loading it's much better if we *do* check.
554 tuple = SearchSysCache(PROCOID,
555 ObjectIdGetDatum(funcoid),
557 if (!HeapTupleIsValid(tuple))
558 elog(ERROR, "cache lookup failed for function %u", funcoid);
559 proc = (Form_pg_proc) GETSTRUCT(tuple);
561 tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
563 elog(ERROR, "null prosrc for C function %u", funcoid);
564 prosrc = TextDatumGetCString(tmp);
566 tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_probin, &isnull);
568 elog(ERROR, "null probin for C function %u", funcoid);
569 probin = TextDatumGetCString(tmp);
571 (void) load_external_function(probin, prosrc, true, &libraryhandle);
572 (void) fetch_finfo_record(libraryhandle, prosrc);
574 ReleaseSysCache(tuple);
581 * Validator for SQL language functions
583 * Parse it here in order to be sure that it contains no syntax errors.
586 fmgr_sql_validator(PG_FUNCTION_ARGS)
588 Oid funcoid = PG_GETARG_OID(0);
591 List *querytree_list;
595 ErrorContextCallback sqlerrcontext;
599 tuple = SearchSysCache(PROCOID,
600 ObjectIdGetDatum(funcoid),
602 if (!HeapTupleIsValid(tuple))
603 elog(ERROR, "cache lookup failed for function %u", funcoid);
604 proc = (Form_pg_proc) GETSTRUCT(tuple);
606 /* Disallow pseudotype result */
607 /* except for RECORD, VOID, or polymorphic */
608 if (get_typtype(proc->prorettype) == TYPTYPE_PSEUDO &&
609 proc->prorettype != RECORDOID &&
610 proc->prorettype != VOIDOID &&
611 !IsPolymorphicType(proc->prorettype))
613 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
614 errmsg("SQL functions cannot return type %s",
615 format_type_be(proc->prorettype))));
617 /* Disallow pseudotypes in arguments */
618 /* except for polymorphic */
620 for (i = 0; i < proc->pronargs; i++)
622 if (get_typtype(proc->proargtypes.values[i]) == TYPTYPE_PSEUDO)
624 if (IsPolymorphicType(proc->proargtypes.values[i]))
628 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
629 errmsg("SQL functions cannot have arguments of type %s",
630 format_type_be(proc->proargtypes.values[i]))));
634 /* Postpone body checks if !check_function_bodies */
635 if (check_function_bodies)
637 tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
639 elog(ERROR, "null prosrc");
641 prosrc = TextDatumGetCString(tmp);
644 * Setup error traceback support for ereport().
646 sqlerrcontext.callback = sql_function_parse_error_callback;
647 sqlerrcontext.arg = tuple;
648 sqlerrcontext.previous = error_context_stack;
649 error_context_stack = &sqlerrcontext;
652 * We can't do full prechecking of the function definition if there
653 * are any polymorphic input types, because actual datatypes of
654 * expression results will be unresolvable. The check will be done at
657 * We can run the text through the raw parser though; this will at
658 * least catch silly syntactic errors.
662 querytree_list = pg_parse_and_rewrite(prosrc,
663 proc->proargtypes.values,
665 (void) check_sql_fn_retval(funcoid, proc->prorettype,
670 querytree_list = pg_parse_query(prosrc);
672 error_context_stack = sqlerrcontext.previous;
675 ReleaseSysCache(tuple);
681 * Error context callback for handling errors in SQL function definitions
684 sql_function_parse_error_callback(void *arg)
686 HeapTuple tuple = (HeapTuple) arg;
687 Form_pg_proc proc = (Form_pg_proc) GETSTRUCT(tuple);
692 /* See if it's a syntax error; if so, transpose to CREATE FUNCTION */
693 tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
695 elog(ERROR, "null prosrc");
696 prosrc = TextDatumGetCString(tmp);
698 if (!function_parse_error_transpose(prosrc))
700 /* If it's not a syntax error, push info onto context stack */
701 errcontext("SQL function \"%s\"", NameStr(proc->proname));
708 * Adjust a syntax error occurring inside the function body of a CREATE
709 * FUNCTION command. This can be used by any function validator, not only
710 * for SQL-language functions. It is assumed that the syntax error position
711 * is initially relative to the function body string (as passed in). If
712 * possible, we adjust the position to reference the original CREATE command;
713 * if we can't manage that, we set up an "internal query" syntax error instead.
715 * Returns true if a syntax error was processed, false if not.
718 function_parse_error_transpose(const char *prosrc)
722 const char *queryText;
725 * Nothing to do unless we are dealing with a syntax error that has a
728 * Some PLs may prefer to report the error position as an internal error
729 * to begin with, so check that too.
731 origerrposition = geterrposition();
732 if (origerrposition <= 0)
734 origerrposition = getinternalerrposition();
735 if (origerrposition <= 0)
739 /* We can get the original query text from the active portal (hack...) */
740 Assert(ActivePortal && ActivePortal->status == PORTAL_ACTIVE);
741 queryText = ActivePortal->sourceText;
743 /* Try to locate the prosrc in the original text */
744 newerrposition = match_prosrc_to_query(prosrc, queryText, origerrposition);
746 if (newerrposition > 0)
748 /* Successful, so fix error position to reference original query */
749 errposition(newerrposition);
750 /* Get rid of any report of the error as an "internal query" */
751 internalerrposition(0);
752 internalerrquery(NULL);
757 * If unsuccessful, convert the position to an internal position
758 * marker and give the function text as the internal query.
761 internalerrposition(origerrposition);
762 internalerrquery(prosrc);
769 * Try to locate the string literal containing the function body in the
770 * given text of the CREATE FUNCTION command. If successful, return the
771 * character (not byte) index within the command corresponding to the
772 * given character index within the literal. If not successful, return 0.
775 match_prosrc_to_query(const char *prosrc, const char *queryText,
779 * Rather than fully parsing the CREATE FUNCTION command, we just scan the
780 * command looking for $prosrc$ or 'prosrc'. This could be fooled (though
781 * not in any very probable scenarios), so fail if we find more than one
784 int prosrclen = strlen(prosrc);
785 int querylen = strlen(queryText);
790 for (curpos = 0; curpos < querylen - prosrclen; curpos++)
792 if (queryText[curpos] == '$' &&
793 strncmp(prosrc, &queryText[curpos + 1], prosrclen) == 0 &&
794 queryText[curpos + 1 + prosrclen] == '$')
797 * Found a $foo$ match. Since there are no embedded quoting
798 * characters in a dollar-quoted literal, we don't have to do any
799 * fancy arithmetic; just offset by the starting position.
802 return 0; /* multiple matches, fail */
803 matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
806 else if (queryText[curpos] == '\'' &&
807 match_prosrc_to_literal(prosrc, &queryText[curpos + 1],
808 cursorpos, &newcursorpos))
811 * Found a 'foo' match. match_prosrc_to_literal() has adjusted
812 * for any quotes or backslashes embedded in the literal.
815 return 0; /* multiple matches, fail */
816 matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
825 * Try to match the given source text to a single-quoted literal.
826 * If successful, adjust newcursorpos to correspond to the character
827 * (not byte) index corresponding to cursorpos in the source text.
829 * At entry, literal points just past a ' character. We must check for the
833 match_prosrc_to_literal(const char *prosrc, const char *literal,
834 int cursorpos, int *newcursorpos)
836 int newcp = cursorpos;
840 * This implementation handles backslashes and doubled quotes in the
841 * string literal. It does not handle the SQL syntax for literals
842 * continued across line boundaries.
844 * We do the comparison a character at a time, not a byte at a time, so
845 * that we can do the correct cursorpos math.
849 cursorpos--; /* characters left before cursor */
852 * Check for backslashes and doubled quotes in the literal; adjust
853 * newcp when one is found before the cursor.
855 if (*literal == '\\')
861 else if (*literal == '\'')
863 if (literal[1] != '\'')
869 chlen = pg_mblen(prosrc);
870 if (strncmp(prosrc, literal, chlen) != 0)
876 if (*literal == '\'' && literal[1] != '\'')
879 *newcursorpos = newcp;
884 /* Must set *newcursorpos to suppress compiler warning */
885 *newcursorpos = newcp;