/*
* moveArrayTypeName
* - try to reassign an array type name that the user wants to use.
*
* The given type name has been discovered to already exist (with the given
* OID). If it is an autogenerated array type, change the array type's name
* to not conflict. This allows the user to create type "foo" followed by
* type "_foo" without problems. (Of course, there are race conditions if
* two backends try to create similarly-named types concurrently, but the
* worst that can happen is an unnecessary failure --- anything we do here
* will be rolled back if the type creation fails due to conflicting names.)
*
* Note that this must be called *before* calling makeArrayTypeName to
* determine the new type's own array type name; else the latter will
* certainly pick the same name.
*
* Returns TRUE if successfully moved the type, FALSE if not.
*
* We also return TRUE if the given type is a shell type. In this case
* the type has not been renamed out of the way, but nonetheless it can
* be expected that TypeCreate will succeed. This behavior is convenient
* for most callers --- those that need to distinguish the shell-type case
* must do their own typisdefined test.
*/
bool
moveArrayTypeName(Oid typeOid, const char *typeName, Oid typeNamespace)
{
Oid elemOid;
char *newname;
/* We need do nothing if it's a shell type. */
if (!get_typisdefined(typeOid))
return true;
/* Can't change it if it's not an autogenerated array type. */
elemOid = get_element_type(typeOid);
if (!OidIsValid(elemOid) ||
get_array_type(elemOid) != typeOid)
return false;
/*
* OK, use makeArrayTypeName to pick an unused modification of the name.
* Note that since makeArrayTypeName is an iterative process, this will
* produce a name that it might have produced the first time, had the
* conflicting type we are about to create already existed.
*/
newname = makeArrayTypeName(typeName, typeNamespace);
/* Apply the rename */
RenameTypeInternal(typeOid, newname, typeNamespace);
/*
* We must bump the command counter so that any subsequent use of
* makeArrayTypeName sees what we just did and doesn't pick the same name.
*/
CommandCounterIncrement();
pfree(newname);
return true;
}
/*
* RenameTypeInternal
* This renames a type, as well as any associated array type.
*
* Caller must have already checked privileges.
*
* Currently this is used for renaming table rowtypes and for
* ALTER TYPE RENAME TO command.
*/
void
RenameTypeInternal(Oid typeOid, const char *newTypeName, Oid typeNamespace)
{
Relation pg_type_desc;
HeapTuple tuple;
Form_pg_type typ;
Oid arrayOid;
Oid oldTypeOid;
pg_type_desc = table_open(TypeRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopy1(TYPEOID, ObjectIdGetDatum(typeOid));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for type %u", typeOid);
typ = (Form_pg_type) GETSTRUCT(tuple);
/* We are not supposed to be changing schemas here */
Assert(typeNamespace == typ->typnamespace);
arrayOid = typ->typarray;
/* Check for a conflicting type name. */
oldTypeOid = GetSysCacheOid2(TYPENAMENSP, Anum_pg_type_oid,
CStringGetDatum(newTypeName),
ObjectIdGetDatum(typeNamespace));
/*
* If there is one, see if it's an autogenerated array type, and if so
* rename it out of the way. (But we must skip that for a shell type
* because moveArrayTypeName will do the wrong thing in that case.)
* Otherwise, we can at least give a more friendly error than unique-index
* violation.
*/
if (OidIsValid(oldTypeOid))
{
if (get_typisdefined(oldTypeOid) &&
moveArrayTypeName(oldTypeOid, newTypeName, typeNamespace))
/* successfully dodged the problem */ ;
else
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
errmsg("type \"%s\" already exists", newTypeName)));
}
/* OK, do the rename --- tuple is a copy, so OK to scribble on it */
namestrcpy(&(typ->typname), newTypeName);
CatalogTupleUpdate(pg_type_desc, &tuple->t_self, tuple);
InvokeObjectPostAlterHook(TypeRelationId, typeOid, 0);
heap_freetuple(tuple);
table_close(pg_type_desc, RowExclusiveLock);
/*
* If the type has an array type, recurse to handle that. But we don't
* need to do anything more if we already renamed that array type above
* (which would happen when, eg, renaming "foo" to "_foo").
*/
if (OidIsValid(arrayOid) && arrayOid != oldTypeOid)
{
char *arrname = makeArrayTypeName(newTypeName, typeNamespace);
RenameTypeInternal(arrayOid, arrname, typeNamespace);
pfree(arrname);
}
}
/*
* Examine the RETURNS clause of the CREATE FUNCTION statement
* and return information about it as *prorettype_p and *returnsSet.
*
* This is more complex than the average typename lookup because we want to
* allow a shell type to be used, or even created if the specified return type
* doesn't exist yet. (Without this, there's no way to define the I/O procs
* for a new type.) But SQL function creation won't cope, so error out if
* the target language is SQL. (We do this here, not in the SQL-function
* validator, so as not to produce a NOTICE and then an ERROR for the same
* condition.)
*/
static void
compute_return_type(TypeName *returnType, Oid languageOid,
Oid *prorettype_p, bool *returnsSet_p)
{
Oid rettype;
rettype = LookupTypeName(NULL, returnType);
if (OidIsValid(rettype))
{
if (!get_typisdefined(rettype))
{
if (languageOid == SQLlanguageId)
ereport(ERROR,
(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
errmsg("SQL function cannot return shell type %s",
TypeNameToString(returnType))));
else
ereport(NOTICE,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("return type %s is only a shell",
TypeNameToString(returnType))));
}
}
else
{
char *typnam = TypeNameToString(returnType);
Oid namespaceId;
AclResult aclresult;
char *typname;
/*
* Only C-coded functions can be I/O functions. We enforce this
* restriction here mainly to prevent littering the catalogs with
* shell types due to simple typos in user-defined function
* definitions.
*/
if (languageOid != INTERNALlanguageId &&
languageOid != ClanguageId)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("type \"%s\" does not exist", typnam)));
/* Otherwise, go ahead and make a shell type */
ereport(NOTICE,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("type \"%s\" is not yet defined", typnam),
errdetail("Creating a shell type definition.")));
namespaceId = QualifiedNameGetCreationNamespace(returnType->names,
&typname);
aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(),
ACL_CREATE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
get_namespace_name(namespaceId));
rettype = TypeShellMake(typname, namespaceId);
Assert(OidIsValid(rettype));
}
*prorettype_p = rettype;
*returnsSet_p = returnType->setof;
}
/*
* Interpret the parameter list of the CREATE FUNCTION statement.
*
* Results are stored into output parameters. parameterTypes must always
* be created, but the other arrays are set to NULL if not needed.
* requiredResultType is set to InvalidOid if there are no OUT parameters,
* else it is set to the OID of the implied result type.
*/
static void
examine_parameter_list(List *parameters, Oid languageOid,
oidvector **parameterTypes,
ArrayType **allParameterTypes,
ArrayType **parameterModes,
ArrayType **parameterNames,
Oid *requiredResultType)
{
int parameterCount = list_length(parameters);
Oid *inTypes;
int inCount = 0;
Datum *allTypes;
Datum *paramModes;
Datum *paramNames;
int outCount = 0;
bool have_names = false;
ListCell *x;
int i;
*requiredResultType = InvalidOid; /* default result */
inTypes = (Oid *) palloc(parameterCount * sizeof(Oid));
allTypes = (Datum *) palloc(parameterCount * sizeof(Datum));
paramModes = (Datum *) palloc(parameterCount * sizeof(Datum));
paramNames = (Datum *) palloc0(parameterCount * sizeof(Datum));
/* Scan the list and extract data into work arrays */
i = 0;
foreach(x, parameters)
{
FunctionParameter *fp = (FunctionParameter *) lfirst(x);
TypeName *t = fp->argType;
Oid toid;
toid = LookupTypeName(NULL, t);
if (OidIsValid(toid))
{
if (!get_typisdefined(toid))
{
/* As above, hard error if language is SQL */
if (languageOid == SQLlanguageId)
ereport(ERROR,
(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
errmsg("SQL function cannot accept shell type %s",
TypeNameToString(t))));
else
ereport(NOTICE,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("argument type %s is only a shell",
TypeNameToString(t))));
}
}
else
{
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("type %s does not exist",
TypeNameToString(t))));
}
if (t->setof)
ereport(ERROR,
(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
errmsg("functions cannot accept set arguments")));
if (fp->mode != FUNC_PARAM_OUT)
inTypes[inCount++] = toid;
if (fp->mode != FUNC_PARAM_IN)
{
if (outCount == 0) /* save first OUT param's type */
*requiredResultType = toid;
outCount++;
}
allTypes[i] = ObjectIdGetDatum(toid);
paramModes[i] = CharGetDatum(fp->mode);
if (fp->name && fp->name[0])
{
paramNames[i] = DirectFunctionCall1(textin,
CStringGetDatum(fp->name));
have_names = true;
}
i++;
}
